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Sample records for cu aln cu

  1. Cu-doped AlN: A possible spinaligner at room-temperature grown by molecular beam epitaxy?

    Science.gov (United States)

    Ganz, P. R.; Schaadt, D. M.

    2011-12-01

    Cu-doped AlN was prepared by plasma assisted molecular beam epitaxy on C-plane sapphire substrates. The growth conditions were investigated for different Cu to Al flux ratios from 1.0% to 4.0%. The formation of Cu-Al alloys on the surface was observed for all doping level. In contrast to Cu-doped GaN, all samples showed diamagnetic behavior determined by SQUID measurements.

  2. NiTiCu/AlN/NiTiCu shape memory thin film heterostructures for vibration damping in MEMS

    Energy Technology Data Exchange (ETDEWEB)

    Kaur, Navjot; Kaur, Davinder, E-mail: dkaurfph@iitr.ernet.in

    2014-03-25

    Highlights: • Fabrication of NiTiCu/AlN/NiTiCu heterostructure using dc/rf magnetron sputtering. • Exhibits highest hardness (38 GPa) and elastic modulus (187 GPa). • Enhanced dissipation of mechanical energy (E{sub d} = 5.7 N J). • High damping capacity (0.052) and figure of merit (∼0.62). • Can be applied for vibration damping in MEMS. -- Abstract: Shape memory alloy (NiTiCu) thin films coupled with piezoelectric AlN layer produce an intelligent material for vibration damping. In the present study pure NiTiCu, NiTiCu/AlN and NiTiCu/AlN/NiTiCu heterostructures have been deposited on Si substrate using magnetron sputtering technique. By the use of the interfaces and shape memory effect provided by NiTiCu layers, the damping capacity can be increased along with increase in stiffness and mechanical hardness. The heterostructures were characterized in terms of structural, electrical, morphological and mechanical properties by X-ray diffraction (XRD), four probe resistivity method, atomic force microscopy, field emission scanning electron microscopy, and nanoindentation. The NiTiCu/AlN/NiTiCu heterostructure exhibit enhanced mechanical and damping properties as compared to NiTiCu/AlN and pure NiTiCu. This enhancement in hardness and damping of the heterostructure could be attributed to the shape memory effect of NiTiCu, intrinsic piezoelectricity of AlN and increased number of interfaces in heterostructure that help in dissipation of mechanical vibrations. The findings of this work provide additional impetus for the application of these heterostructures in emerging fields of nanotechnology and microelectro mechanical (MEMS) devices.

  3. NiTiCu/AlN/NiTiCu shape memory thin film heterostructures for vibration damping in MEMS

    International Nuclear Information System (INIS)

    Kaur, Navjot; Kaur, Davinder

    2014-01-01

    Highlights: • Fabrication of NiTiCu/AlN/NiTiCu heterostructure using dc/rf magnetron sputtering. • Exhibits highest hardness (38 GPa) and elastic modulus (187 GPa). • Enhanced dissipation of mechanical energy (E d = 5.7 N J). • High damping capacity (0.052) and figure of merit (∼0.62). • Can be applied for vibration damping in MEMS. -- Abstract: Shape memory alloy (NiTiCu) thin films coupled with piezoelectric AlN layer produce an intelligent material for vibration damping. In the present study pure NiTiCu, NiTiCu/AlN and NiTiCu/AlN/NiTiCu heterostructures have been deposited on Si substrate using magnetron sputtering technique. By the use of the interfaces and shape memory effect provided by NiTiCu layers, the damping capacity can be increased along with increase in stiffness and mechanical hardness. The heterostructures were characterized in terms of structural, electrical, morphological and mechanical properties by X-ray diffraction (XRD), four probe resistivity method, atomic force microscopy, field emission scanning electron microscopy, and nanoindentation. The NiTiCu/AlN/NiTiCu heterostructure exhibit enhanced mechanical and damping properties as compared to NiTiCu/AlN and pure NiTiCu. This enhancement in hardness and damping of the heterostructure could be attributed to the shape memory effect of NiTiCu, intrinsic piezoelectricity of AlN and increased number of interfaces in heterostructure that help in dissipation of mechanical vibrations. The findings of this work provide additional impetus for the application of these heterostructures in emerging fields of nanotechnology and microelectro mechanical (MEMS) devices

  4. Barrier effect of AlN film in flexible Cu(In,Ga)Se{sub 2} solar cells on stainless steel foil and solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Li, Boyan; Li, Jianjun [Institute of Photo-electronic Thin Film Devices and Technology, Key Laboratory of Photo-electronic Thin Film Devices and Technology of Tianjin, Nankai University, Tianjin 300071 (China); Wu, Li [The MOE Key Laboratory of Weak-Light Nonlinear Photonics, School of Physics, Nankai University, Tianjin 300071 (China); Liu, Wei; Sun, Yun [Institute of Photo-electronic Thin Film Devices and Technology, Key Laboratory of Photo-electronic Thin Film Devices and Technology of Tianjin, Nankai University, Tianjin 300071 (China); Zhang, Yi, E-mail: yizhang@nankai.edu.cn [Institute of Photo-electronic Thin Film Devices and Technology, Key Laboratory of Photo-electronic Thin Film Devices and Technology of Tianjin, Nankai University, Tianjin 300071 (China)

    2015-04-05

    Highlights: • The adhension between AlN film and Mo are verygood. • AlN film can be effectively used as the barrier of flexible CIGS solar cell on SS substrate. • AlN film is suitable as the insulation barrier of flexible CIGS solar cell on SS substrate. - Abstract: The AlN film deposited by DC magnetron sputtering on stainless steel (SS) foils was used as the barrier in flexible Cu(In,Ga)Se{sub 2} (CIGS) solar cells on stainless steel foil and characterized comprehensively by X-ray diffraction (XRD), scanning electron microscopy (SEM), I–V, and QE measurements study. The study of AlN as insulation barrier in the flexible CIGS solar cell showed that the adhesion strength between the SS foil and the deposited AlN film was very strong even after annealing at high temperature at 530 °C. More importantly, a high resistance of over 10 MΩ was remained with the film with thickness of around 200 nm after annealing. This indicates that the AlN film is suitable as an effective insulation barrier in flexible CIGS solar cells based on SS foil. In addition, the XRD and SEM results showed that the AlN film did not influence the crystal structure of the Mo film which was deposited upon the AlN layer and used as the electrical contact in CIGS solar cells. It was found that the AlN film contributed to an improved crystallinity of the Mo contact layer compared to the bare SS foil. The combined results of secondary ion mass spectrometry, I–V and EQE measurements of the corresponding flexible CIGS solar cells confirmed that 1 μm-thick AlN film could be used as an efficient barrier layer in CIGS solar cells on SS foil.

  5. Phase constitution and interface structure of nano-sized Ag-Cu/AlN multilayers: Experiment and ab initio modeling

    Energy Technology Data Exchange (ETDEWEB)

    Pigozzi, Giancarlo; Janczak-Rusch, Jolanta; Passerone, Daniele; Antonio Pignedoli, Carlo; Patscheider, Joerg; Jeurgens, Lars P. H. [Empa, Swiss Federal Laboratories for Materials Science and Technology, Ueberlandstrasse 129, CH-8600 Duebendorf (Switzerland); Antusek, Andrej [Empa, Swiss Federal Laboratories for Materials Science and Technology, Ueberlandstrasse 129, CH-8600 Duebendorf (Switzerland); Faculty of Materials Science and Technology, Slovak University of Technology in Bratislava, Paulinska 16, 917 24 Trnava (Slovakia); Parlinska-Wojtan, Magdalena [Empa, Swiss Federal Laboratories for Materials Science and Technology, Ueberlandstrasse 129, CH-8600 Duebendorf (Switzerland); University of Rzeszow, Institute of Physics, ul. Rejtana 16a, 35-959 Rzeszow (Poland); Bissig, Vinzenz [Kirsten Soldering AG, Hinterbergstrasse 32, CH-6330 Cham (Switzerland)

    2012-10-29

    Nano-sized Ag-Cu{sub 8nm}/AlN{sub 10nm} multilayers were deposited by reactive DC sputtering on {alpha}-Al{sub 2}O{sub 3}(0001) substrates. Investigation of the phase constitution and interface structure of the multilayers evidences a phase separation of the alloy sublayers into nanosized grains of Ag and Cu. The interfaces between the Ag grains and the quasi-single-crystalline AlN sublayers are semi-coherent, whereas the corresponding Cu/AlN interfaces are incoherent. The orientation relationship between Ag and AlN is constant throughout the entire multilayer stack. These observations are consistent with atomistic models of the interfaces as obtained by ab initio calculations.

  6. Deuterium transport in Cu, CuCrZr, and Cu/Be

    Science.gov (United States)

    Anderl, R. A.; Hankins, M. R.; Longhurst, G. R.; Pawelko, R. J.

    This paper presents the results of deuterium implantation/permeation experiments and TMAP4 simulations for a CuCrZr alloy, for OFHC-Cu and for a Cu/Be bi-layered structure at temperatures from 700 to 800 K. Experiments used a mass-analyzed, 3-keV D 3+ ion beam with particle flux densities of 5 × 10 19 to 7 × 10 19 D/m 2 s. Effective diffusivities and surface molecular recombination coefficients were derived giving Arrhenius pre-exponentials and activation energies for each material: CuCrZr alloy, (2.0 × 10 -2 m 2/s, 1.2 eV) for diffusivity and (2.9 × x10 -14 m 4/s, 1.92 eV) for surface molecular recombination coefficients; OFHC Cu, (2.1 × 10 -6 m 2/s, 0.52 eV) for diffusivity and (9.1 × 10 -18 m 4/s, 0.99 eV) for surface molecular recombination coefficients. TMAP4 simulation of permeation data measured for a Cu/Be bi-layer sample was achieved using a four-layer structure (Cu/BeO interface/Be/BeO back surface) and recommended values for diffusivity and solubility in Be, BeO and Cu.

  7. Thermochemical properties of oxides in Y-Ba-Cu-O, Sr-Bi-O, Cu-Nb-O, Sr-Cu-O, Ca-Cu-O, Cu-O and Hg-Ba-Ca-Cu-O systems

    International Nuclear Information System (INIS)

    Moiseev, G.K.; Vatolin, N.A.; Il'inykh, N.I.

    2000-01-01

    Thermochemical properties (ΔH 0 298 , S 0 298 , H 0 298 -H 0 0 , C p (T), C p at T>T melt ) of complex oxides in Y-Ba-Cu-O, Sr-Bi-O, Cu-Nb-O, Sr-Cu-O, Ca-Cu-O, Cu-O and Hg-Ba-Ca-Cu-O systems obtained with application of calculation methods are presented. Nonexperimental methods of estimation, revision and correction of standard formation enthalpies of inorganic compounds are described [ru

  8. Growth of intermetallics between Sn/Ni/Cu, Sn/Ag/Cu and Sn/Cu layered structures

    International Nuclear Information System (INIS)

    Horváth, Barbara; Illés, Balázs; Shinohara, Tadashi

    2014-01-01

    Intermetallic growth mechanisms and rates are investigated in Sn/Ni/Cu, Sn/Ag/Cu and Sn/Cu layer systems. An 8–10 μm thick Sn surface finish layer was electroplated onto a Cu substrate with a 1.5–2 μm thick Ni or Ag barrier layer. In order to induce intermetallic layer growth, the samples were aged in elevated temperatures: 50 °C and 125 °C. Intermetallic layer growth was checked by focused ion beam–scanning ion microscope. The microstructures and chemical compositions of the intermetallic layers were observed with a transmission electron microscope. It has been found that Ni barrier layers can effectively block the development of Cu 6 Sn 5 intermetallics. The intermetallic growth characteristics in the Sn/Cu and Sn/Ni/Cu systems are very similar. The intermetallic layer grows towards the Sn layer and forms a discrete layer. Differences were observed only in the growth gradients and surface roughness of the intermetallic layer which may explain the different tin whiskering properties. It was observed that the intermetallic layer growth mechanisms are completely different in the Ag barrier layers compared to the Ni layers. In the case of Sn/Ag/Cu systems, the Sn and Cu diffused through the Ag layer, formed Cu 6 Sn 5 intermetallics mainly at the Sn/Ag interface and consumed the Ag barrier layer. - Highlights: • Intermetallic growth was characterised in Sn/Ni/Cu, Sn/Ag/Cu and Sn/Cu layer systems. • Intermetallic growth rates and roughness are similar in the Sn/Cu and Sn/Ni/Cu systems. • Sn/Ni/Cu system contains the following intermetallic layer structure Sn–Ni3Sn4–Ni3Sn2–Ni3Sn–Ni. • In the case of Sn/Ag/Cu systems the Sn and Cu diffusion consumes the Ag barrier layer. • When Cu reaches the Sn/Ag interface a large amount of Cu 6 Sn 5 forms above the Ag layer

  9. CuO reduction induced formation of CuO/Cu2O hybrid oxides

    Science.gov (United States)

    Yuan, Lu; Yin, Qiyue; Wang, Yiqian; Zhou, Guangwen

    2013-12-01

    Reduction of CuO nanowires results in the formation of a unique hierarchical hybrid nanostructure, in which the parent oxide phase (CuO) works as the skeleton while the lower oxide (Cu2O) resulting from the reduction reaction forms as partially embedded nanoparticles that decorate the skeleton of the parent oxide. Using in situ transmission electron microscopy observations of the reduction process of CuO nanowires, we demonstrate that the formation of such a hierarchical hybrid oxide structure is induced by topotactic nucleation and growth of Cu2O islands on the parent CuO nanowires.

  10. Morphology and chemical composition of Cu/Sn/Cu and Cu(5 at-%Ni)/Sn/Cu(5 at-%Ni) interconnections

    NARCIS (Netherlands)

    Wierzbicka-Miernik, A.; Wojewoda-Budka, J.; Litynska-Dobrzynska, L.; Kodentsov, A.; Zieba, P.

    2012-01-01

    In the present paper, scanning and transmission electron microscopies as well as energy dispersive X-ray spectroscopy investigations were performed to describe the morphology and chemical composition of the intermetallic phases growing in Cu/Sn/Cu and Cu(Ni)/Sn/Cu(Ni) interconnections during the

  11. IR and TPD studies of the interaction of alkenes with Cu + sites in CuNaY and CuNaX zeolites of various Cu content. The heterogeneity of Cu + sites

    Science.gov (United States)

    Datka, J.; Kukulska-Zajaç, E.; Kozyra, P.

    2006-08-01

    Cu + ions in zeolites activate organic molecules containing π electrons by π back donation, which results in a distinct weakening of multiple bonds. In this study, we followed the activation of alkenes (ethene and propene) by Cu + ions in CuY and CuX zeolites of various Cu content. We also studied the strength of bonding of alkenes to Cu + ions. IR studies have shown that there are two kinds of Cu + sites of various electron donor properties. We suppose that they could be attributed to the presence of Cu + ions of various number of oxygen atoms surrounding the cation. IR studies have shown that Cu ions introduced into Y and X zeolites in the first-order (at low Cu content) form Cu + ions of stronger electron donor properties (i.e. activate alkenes to larger extend) than Cu ions introduced in the next order (at higher Cu content). IR and TPD studies of alkenes desorption evidenced that Cu + ions of stronger electron donor properties bond alkenes stronger than less electron donor ones. It suggests that π back donation has more important contribution to the strength of bonding alkenes to cation than π donation.

  12. Porous HKUST-1 derived CuO/Cu2O shell wrapped Cu(OH)2 derived CuO/Cu2O core nanowire arrays for electrochemical nonenzymatic glucose sensors with ultrahigh sensitivity

    Science.gov (United States)

    Yu, Cuiping; Cui, Jiewu; Wang, Yan; Zheng, Hongmei; Zhang, Jianfang; Shu, Xia; Liu, Jiaqin; Zhang, Yong; Wu, Yucheng

    2018-05-01

    Self-supported CuO/Cu2O@CuO/Cu2O core-shell nanowire arrays (NWAs) are successfully fabricated by a simple and efficient method in this paper. Anodized Cu(OH)2 NWAs could in-situ convert to HKUST-1 at room temperature easily. Cu(OH)2 NWAs cores and HKUST-1 shells transform into CuO/Cu2O simultaneously after calcinations and form CuO/Cu2O@CuO/Cu2O core-shell NWAs. This smart configuration of the core-shell structure not only avoids the agglomeration of the traditional MOF-derived materials in particle-shape, but also facilitates the ion diffusion and increases the active sites. This novel structure is employed as substrate to construct nonenzymatic glucose sensors. The results indicate that glucose sensor based on CuO/Cu2O@CuO/Cu2O core-shell NWAs presents ultrahigh sensitivity (10,090 μA mM-1 cm-2), low detection limit (0.48 μM) and wide linear range (0.99-1,330 μM). In addition, it also shows excellent anti-interference ability toward uric acid, ascorbic acid and L-Cysteine co-existing with glucose, good reproducibility and superior ability of real sample analysis.

  13. Comparative study of Cu-Zr and Cu-Ru alloy films for barrier-free Cu metallization

    International Nuclear Information System (INIS)

    Wang Ying; Cao Fei; Zhang Milin; Liu Yuntao

    2011-01-01

    The properties of Cu-Zr and Cu-Ru alloy films were comparatively studied to evaluate their potential use as alloying elements. Cu alloy films were deposited on SiO 2 /Si substrates by magnetron sputtering. Samples were subsequently annealed and analyzed by four-point probe measurement, X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy and Auger electron spectroscopy. X-ray diffraction data suggest that Cu film has preferential (111) crystal orientation and no extra peak corresponding to any compound of Cu, Zr, Ru, and Si. According to transmission electron microscopy results, Cu grains grow in size for both systems but the grain sizes of the Cu alloy films are smaller than that of pure Cu films. These results indicate that Cu-Zr film is suitable for advanced barrier-free metallization in terms of interfacial stability and lower resistivity.

  14. Cu/Cu{sub 2}O/CuO nanoparticles: Novel synthesis by exploding wire technique and extensive characterization

    Energy Technology Data Exchange (ETDEWEB)

    Sahai, Anshuman [Department of Physics and Materials Science and Engineering, Jaypee Institute of Information Technology, A-10, Sector-62, Noida 201307 (India); Goswami, Navendu, E-mail: navendugoswami@gmail.com [Department of Physics and Materials Science and Engineering, Jaypee Institute of Information Technology, A-10, Sector-62, Noida 201307 (India); Kaushik, S.D. [UGC-DAE-Consortium for Scientific Research Mumbai Centre, R5 Shed, BARC, Mumbai 400085 (India); Tripathi, Shilpa [UGC-DAE Consortium for Scientific Research, Indore, M.P. (India)

    2016-12-30

    Highlights: The salient features of this research article are following: • Mixed phase synthesis of Cu/Cu{sub 2}O/CuO nanoparticles prepared by Exploding Wire Technique (EWT). • Predominant Cu/Cu{sub 2}O phases along with minor CuO phase revealed through XRD, TEM, Raman, FTIR, UV–Visible and PL analyses. • XPS analysis provided direct evidences of Cu{sup 2+} and Cu{sup +} along with O deficiency for prepared nanoparticles. • Room temperature weak ferromagnetic behaviour was demonstrated for Cu/Cu{sub 2}O/CuO nanoparticles. - Abstract: In this article, we explore potential of Exploding Wire Technique (EWT) to synthesize the copper nanoparticles using the copper metal in a plate and wire geometry. Rietveld refinement of X-ray diffraction (XRD) pattern of prepared material indicates presence of mixed phases of copper (Cu) and copper oxide (Cu{sub 2}O). Agglomerates of copper and copper oxide comprised of ∼20 nm average size nanoparticles observed through high resolution transmission electron microscope (HRTEM) and energy dispersive x-ray (EDX) spectroscopy. Micro-Raman (μR) and Fourier transform infrared (FTIR) spectroscopies of prepared nanoparticles reveal existence of additional minority CuO phase, not determined earlier through XRD and TEM analysis. μR investigations vividly reveal cubic Cu{sub 2}O and monoclinic CuO phases based on the difference of space group symmetries. In good agreement with μRaman analysis, FTIR stretching modes corresponding to Cu{sub 2}-O and Cu-O were also distinguished. Investigations of μR and FTIR vibrational modes are in accordance and affirm concurrence of CuO phases besides predominant Cu and Cu{sub 2}O phase. Quantum confinement effects along with increase of band gaps for direct and indirect optical transitions of Cu/Cu{sub 2}O/CuO nanoparticles are reflected through UV–vis (UV–vis) spectroscopy. Photoluminescence (PL) spectroscopy spots the electronic levels of each phase and optical transitions processes

  15. CH{sub 4} dehydrogenation on Cu(1 1 1), Cu@Cu(1 1 1), Rh@Cu(1 1 1) and RhCu(1 1 1) surfaces: A comparison studies of catalytic activity

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Riguang; Duan, Tian [Key Laboratory of Coal Science and Technology of Ministry of Education and Shanxi Province, Taiyuan University of Technology, Taiyuan 030024, Shanxi (China); Ling, Lixia [Key Laboratory of Coal Science and Technology of Ministry of Education and Shanxi Province, Taiyuan University of Technology, Taiyuan 030024, Shanxi (China); Research Institute of Special Chemicals, Taiyuan University of Technology, Taiyuan 030024, Shanxi (China); Wang, Baojun, E-mail: wangbaojun@tyut.edu.cn [Key Laboratory of Coal Science and Technology of Ministry of Education and Shanxi Province, Taiyuan University of Technology, Taiyuan 030024, Shanxi (China)

    2015-06-30

    Highlights: • Adsorbed Rh atom on Cu catalyst exhibits better catalytic activity for CH{sub 4} dehydrogenation. • The adsorbed Rh atom is the reaction active center for CH{sub 4} dehydrogenation. • The morphology of Cu substrate has negligible effect on CH{sub 4} dehydrogenation. - Abstract: In the CVD growth of graphene, the reaction barriers of the dehydrogenation for hydrocarbon molecules directly decide the graphene CVD growth temperature. In this study, density functional theory method has been employed to comparatively probe into CH{sub 4} dehydrogenation on four types of Cu(1 1 1) surface, including the flat Cu(1 1 1) surface (labeled as Cu(1 1 1)) and the Cu(1 1 1) surface with one surface Cu atom substituted by one Rh atom (labeled as RhCu(1 1 1)), as well as the Cu(1 1 1) surface with one Cu or Rh adatom (labeled as Cu@Cu(1 1 1) and Rh@Cu(1 1 1), respectively). Our results show that the highest barrier of the whole CH{sub 4} dehydrogenation process is remarkably reduced from 448.7 and 418.4 kJ mol{sup −1} on the flat Cu(1 1 1) and Cu@Cu(1 1 1) surfaces to 258.9 kJ mol{sup −1} on RhCu(1 1 1) surface, and to 180.0 kJ mol{sup −1} on Rh@Cu(1 1 1) surface, indicating that the adsorbed or substituted Rh atom on Cu catalyst can exhibit better catalytic activity for CH{sub 4} complete dehydrogenation; meanwhile, since the differences for the highest barrier between Cu@Cu(1 1 1) and Cu(1 1 1) surfaces are smaller, the catalytic behaviors of Cu@Cu(1 1 1) surface are very close to the flat Cu(1 1 1) surface, suggesting that the morphology of Cu substrate does not obviously affect the dehydrogenation of CH{sub 4}, which accords with the reported experimental observations. As a result, the adsorbed or substituted Rh atom on Cu catalyst exhibit a better catalytic activity for CH{sub 4} dehydrogenation compared to the pure Cu catalyst, especially on Rh-adsorbed Cu catalyst, we can conclude that the potential of synthesizing high-quality graphene with the

  16. Cu/Cu2O/CuO nanoparticles: Novel synthesis by exploding wire technique and extensive characterization

    Science.gov (United States)

    Sahai, Anshuman; Goswami, Navendu; Kaushik, S. D.; Tripathi, Shilpa

    2016-12-01

    In this article, we explore potential of Exploding Wire Technique (EWT) to synthesize the copper nanoparticles using the copper metal in a plate and wire geometry. Rietveld refinement of X-ray diffraction (XRD) pattern of prepared material indicates presence of mixed phases of copper (Cu) and copper oxide (Cu2O). Agglomerates of copper and copper oxide comprised of ∼20 nm average size nanoparticles observed through high resolution transmission electron microscope (HRTEM) and energy dispersive x-ray (EDX) spectroscopy. Micro-Raman (μR) and Fourier transform infrared (FTIR) spectroscopies of prepared nanoparticles reveal existence of additional minority CuO phase, not determined earlier through XRD and TEM analysis. μR investigations vividly reveal cubic Cu2O and monoclinic CuO phases based on the difference of space group symmetries. In good agreement with μRaman analysis, FTIR stretching modes corresponding to Cu2-O and Cu-O were also distinguished. Investigations of μR and FTIR vibrational modes are in accordance and affirm concurrence of CuO phases besides predominant Cu and Cu2O phase. Quantum confinement effects along with increase of band gaps for direct and indirect optical transitions of Cu/Cu2O/CuO nanoparticles are reflected through UV-vis (UV-vis) spectroscopy. Photoluminescence (PL) spectroscopy spots the electronic levels of each phase and optical transitions processes occurring therein. Iterative X-ray photoelectron spectroscopy (XPS) fitting of core level spectra of Cu (2p3/2) and O (1s), divulges presence of Cu2+ and Cu+ in the lattice with an interesting evidence of O deficiency in the lattice structure and surface adsorption. Magnetic analysis illustrates that the prepared nanomaterial demonstrates ferromagnetic behaviour at room temperature.

  17. Tailoring Graphene Morphology and Orientation on Cu(100), Cu(110), and Cu(111)

    Science.gov (United States)

    Jacobberger, Robert; Arnold, Michael

    2013-03-01

    Graphene CVD on Cu is phenomenologically complex, yielding diverse crystal morphologies, such as lobes, dendrites, stars, and hexagons, of various orientations. We present a comprehensive study of the evolution of these morphologies as a function of Cu surface orientation, pressure, H2:CH4, and nucleation density. Growth was studied on ultra-smooth, epitaxial Cu films inside Cu enclosures to minimize factors that normally complicate growth. With low H2:CH4, Mullins-Sekerka instabilities propagate to form dendrites, indicating transport limited growth. In LPCVD, the dendrites extend hundreds of microns in the 100, 111, and 110 directions on Cu(100), (110), and (111) and are perturbed by twin boundaries. In APCVD, multiple preferred dendrite orientations exist. With increasing H2:CH4, the dendritic nature of growth is suppressed. In LPCVD, square, rectangle, and hexagon crystals form on Cu(100), (110) and (111), reflecting the Cu crystallography. In APCVD, the morphology becomes hexagonal on each surface. If given ample time, every growth regime yields high-quality monolayers with D:G Raman ratio rationally tailor the graphene crystal morphology and orientation.

  18. Cu-62, Cu-64 and Cu-66 production with 4.2 MeV deuterons

    International Nuclear Information System (INIS)

    Avila, Mario; Morales, J.R.; Riquelme, H.O.

    1996-01-01

    Full text: The natural copper irradiation with deuterons produces the Cu-62, Cu-64 and Cu-66 radionuclides. Of two radioisotopes, those with deficiencies in neutrons, are applied in nuclear medicine diagnostic processes, mainly for the nuclear characteristic of the decay modes. The positron emitters, of short life mean Cu-62 (9.1 min, β + ) and Cu(12.7 h), are radionuclides applied in radio pharmacological preparation for brain, core, blood flux studies. The radiochemical process consists in the de solution of the irradiated metallic copper target, in acid medium. The result solution, can be neutralized with a base or a buffer at wished pH. Using a deuteron beam of 4,2 ± 0,1 MeV energy has been obtained total yields of 1,103 ± 0,011 μCl/μAh medium for 62 Cu and of 0,148 ± 0,015 μCl/μAh for 64 Cu

  19. Cu-ZSM-5, Cu-ZSM-11, and Cu-ZSM-12 Catalysts for Direct NO Decomposition

    DEFF Research Database (Denmark)

    Kustova, Marina; Kustov, Arkadii; Christiansen, Sofie E.

    2006-01-01

    Cu-ZSM-5 has for many years been recognized as a unique catalyst for direct NO decomposition. Here, it is discovered that both Cu-ZSM-11 and Cu-ZSM-12 are about twice as active as Cu-ZSM-5. This difference is attributed to the active sites located almost exclusively in the straight zeolite pores...

  20. Electromigration in Cu(Al) and Cu(Mn) damascene lines

    Science.gov (United States)

    Hu, C.-K.; Ohm, J.; Gignac, L. M.; Breslin, C. M.; Mittal, S.; Bonilla, G.; Edelstein, D.; Rosenberg, R.; Choi, S.; An, J. J.; Simon, A. H.; Angyal, M. S.; Clevenger, L.; Maniscalco, J.; Nogami, T.; Penny, C.; Kim, B. Y.

    2012-05-01

    The effects of impurities, Mn or Al, on interface and grain boundary electromigration (EM) in Cu damascene lines were investigated. The addition of Mn or Al solute caused a reduction in diffusivity at the Cu/dielectric cap interface and the EM activation energies for both Cu-alloys were found to increase by about 0.2 eV as compared to pure Cu. Mn mitigated and Al enhanced Cu grain boundary diffusion; however, no significant mitigation in Cu grain boundary diffusion was observed in low Mn concentration samples. The activation energies for Cu grain boundary diffusion were found to be 0.74 ± 0.05 eV and 0.77 ± 0.05 eV for 1.5 μm wide polycrystalline lines with pure Cu and Cu (0.5 at. % Mn) seeds, respectively. The effective charge number in Cu grain boundaries Z*GB was estimated from drift velocity and was found to be about -0.4. A significant enhancement in EM lifetimes for Cu(Al) or low Mn concentration bamboo-polycrystalline and near-bamboo grain structures was observed but not for polycrystalline-only alloy lines. These results indicated that the existence of bamboo grains in bamboo-polycrystalline lines played a critical role in slowing down the EM-induced void growth rate. The bamboo grains act as Cu diffusion blocking boundaries for grain boundary mass flow, thus generating a mechanical stress-induced back flow counterbalancing the EM force, which is the equality known as the "Blech short length effect."

  1. Physical mechanisms of Cu-Cu wafer bonding

    International Nuclear Information System (INIS)

    Rebhan, B.

    2014-01-01

    Modern manufacturing processes of complex integrated semiconductor devices are based on wafer-level manufacturing of components which are subsequently interconnected. When compared with classical monolithic bi-dimensional integrated circuits (2D ICs), the new approach of three-dimensional integrated circuits (3D ICs) exhibits significant benefits in terms of signal propagation delay and power consumption due to the reduced metal interconnection length and allows high integration levels with reduced form factor. Metal thermo-compression bonding is a process suitable for 3D interconnects applications at wafer level, which facilitates the electrical and mechanical connection of two wafers even processed in different technologies, such as complementary metal oxide semiconductor (CMOS) and microelectromechanical systems (MEMS). Due to its high electrical conductivity, copper is a very attractive material for electrical interconnects. For Cu-Cu wafer bonding the process requires typically bonding for around 1 h at 400°C and high contact pressure applied during bonding. Temperature reduction below such values is required in order to solve issues regarding (i) throughput in the wafer bonder, (ii) wafer-to-wafer misalignment after bonding and (iii) to minimise thermo-mechanical stresses or device degradation. The aim of this work was to study the physical mechanisms of Cu-Cu bonding and based on this study to further optimise the bonding process for low temperatures. The critical sample parameters (roughness, oxide, crystallinity) were identified using selected analytical techniques and correlated with the characteristics of the bonded Cu-Cu interfaces. Based on the results of this study the impact of several materials and process specifications on the bonding result were theoretically defined and experimentally proven. These fundamental findings subsequently facilitated low temperature (LT) metal thermo-compression Cu-Cu wafer bonding and even room temperature direct

  2. Carbon Supported Oxide-Rich Pd-Cu Bimetallic Electrocatalysts for Ethanol Electrooxidation in Alkaline Media Enhanced by Cu/CuOx

    Directory of Open Access Journals (Sweden)

    Zengfeng Guo

    2016-04-01

    Full Text Available Different proportions of oxide-rich PdCu/C nanoparticle catalysts were prepared by the NaBH4 reduction method, and their compositions were tuned by the molar ratios of the metal precursors. Among them, oxide-rich Pd0.9Cu0.1/C (Pd:Cu = 9:1, metal atomic ratio exhibits the highest electrocatalytic activity for ethanol oxidation reaction (EOR in alkaline media. X-ray photoelectron spectroscopy (XPS and high resolution transmission electron microscopy (HRTEM confirmed the existence of both Cu and CuOx in the as-prepared Pd0.9Cu0.1/C. About 74% of the Cu atoms are in their oxide form (CuO or Cu2O. Besides the synergistic effect of Cu, CuOx existed in the Pd-Cu bimetallic nanoparticles works as a promoter for the EOR. The decreased Pd 3d electron density disclosed by XPS is ascribed to the formation of CuOx and the spill-over of oxygen-containing species from CuOx to Pd. The low Pd 3d electron density will decrease the adsorption of CH3COads intermediates. As a result, the electrocatalytic activity is enhanced. The onset potential of oxide-rich Pd0.9Cu0.1/C is negative shifted 150 mV compared to Pd/C. The oxide-rich Pd0.9Cu0.1/C also exhibited high stability, which indicated that it is a candidate for the anode of direct ethanol fuel cells (DEFCs.

  3. Highly charged swelling mica reduces Cu bioavailability in Cu-contaminated soils

    Energy Technology Data Exchange (ETDEWEB)

    Stuckey, Jason W. [Department of Crop and Soil Sciences, Pennsylvania State University, 116 ASI Building, University Park, PA 16802 (United States); Neaman, Alexander [Facultad de Agronomia, P. Universidad Catolica de Valparaiso, Centro Regional de Estudios en Alimentos Saludables (Chile); Ravella, Ramesh; Komarneni, Sridhar [Department of Crop and Soil Sciences, Pennsylvania State University, 116 ASI Building, University Park, PA 16802 (United States); Martinez, Carmen Enid [Department of Crop and Soil Sciences, Pennsylvania State University, 116 ASI Building, University Park, PA 16802 (United States)], E-mail: cem17@psu.edu

    2009-01-15

    This is the first test of a highly charged swelling mica's (Na-2-mica) ability to reduce the plant-absorbed Cu in Cu-contaminated soils from Chile. Perennial ryegrass (Lolium perenne L.) was grown in two acid soils (Sector 2: pH 4.2, total Cu = 172 mg Cu kg{sup -1} and Sector 3: pH 4.2, total Cu = 112 mg Cu kg{sup -1}) amended with 0.5% and 1% (w/w) mica, and 1% (w/w) montmorillonite. At 10 weeks of growth, both mica treatments decreased the shoot Cu of ryegrass grown in Sector 2 producing shoot Cu concentrations above 21-22 mg Cu kg{sup -1} (the phytotoxicity threshold for that species), yet the mica treatments did not reduce shoot Cu concentrations when grown in Sector 3, which were at a typical level. The mica treatments improved shoot growth in Sector 3 by reducing free and extractable Cu to low enough levels where other nutrients could compete for plant absorption and translocation. In addition, the mica treatments improved root growth in both soils, and the 1% mica treatment reduced root Cu in both soils. This swelling mica warrants further testing of its ability to assist re-vegetation and reduce Cu bioavailability in Cu-contaminated surface soils. - In situ remediation of Cu-contaminated soils with a synthetic mica (Na-2-mica) will aid in re-vegetative efforts.

  4. Punicalagin Green Functionalized Cu/Cu2O/ZnO/CuO Nanocomposite for Potential Electrochemical Transducer and Catalyst

    Science.gov (United States)

    Fuku, X.; Kaviyarasu, K.; Matinise, N.; Maaza, M.

    2016-09-01

    A novel ternary Punica granatum L-Cu/Cu2O/CuO/ZnO nanocomposite was successfully synthesised via green route. In this work, we demonstrate that the green synthesis of metal oxides is more viable and facile compare to other methods, i.e., physical and chemical routes while presenting a potential electrode for energy applications. The prepared nanocomposite was characterised by both microscopic and spectroscopic techniques. High-resolution scanning electron microscopy (HRSEM) and X-ray diffraction (XRD) techniques revealed different transitional phases with an average nanocrystallite size of 29-20 mm. It was observed that the nanocomposites changed from amorphous-slightly crystalline Cu/Cu2O to polycrystalline Cu/Cu2O/CuO/ZnO at different calcination temperatures (room temperature-RT- 600 °C). The Cu/Cu2O/ZnO/CuO metal oxides proved to be highly crystalline and showed irregularly distributed particles with different sizes. Meanwhile, Fourier transform infrared (FTIR) spectroscopy confirmed the purity while together with ultraviolet-visible (UV-Vis) spectroscopy proved the proposed mechanism of the synthesised nanocomposite. UV-Vis showed improved catalytic activity of the prepared metal oxides, evident by narrow band gap energy. The redox and electrochemical properties of the prepared nanocomposite were achieved by cyclic voltammetry (CV), electrochemical impedance (EIS) and galvanostatic charge-discharge (GCD). The maximum specific capacitance ( C s) was calculated to be 241 F g-1 at 50 mV s-1 for Cu/Cu2O/CuO/ZnO nanoplatelets structured electrode. Moreover, all the CuO nanostructures reveal better power performance, excellent rate as well as long term cycling stability. Such a study will encourages a new design for a wide spectrum of materials for smart electronic device applications.

  5. Cu-62, Cu-64 and Cu-66 production with 4.2 MeV deuterons; Produccion de {sup 62} Cu y {sup 64} Cu con deuterones de 4,2 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Avila, Mario; Morales, J R; Riquelme, H O [Chile Univ., Santiago (Chile). Facultad de Ciencias. Dept. de Fisica

    1997-12-31

    Full text: The natural copper irradiation with deuterons produces the Cu-62, Cu-64 and Cu-66 radionuclides. Of two radioisotopes, those with deficiencies in neutrons, are applied in nuclear medicine diagnostic processes, mainly for the nuclear characteristic of the decay modes. The positron emitters, of short life mean Cu-62 (9.1 min, {beta}{sup +}) and Cu(12.7 h), are radionuclides applied in radio pharmacological preparation for brain, core, blood flux studies. The radiochemical process consists in the de solution of the irradiated metallic copper target, in acid medium. The result solution, can be neutralized with a base or a buffer at wished pH. Using a deuteron beam of 4,2 {+-} 0,1 MeV energy has been obtained total yields of 1,103 {+-} 0,011 {mu}Cl/{mu}Ah medium for 62 Cu and of 0,148 {+-} 0,015 {mu}Cl/{mu}Ah for 64 Cu.

  6. Preparation of conductive Cu patterns by directly writing using nano-Cu ink

    Energy Technology Data Exchange (ETDEWEB)

    Li, Wei [School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China); Li, Wenjiang; Wei, Jun [School of Materials Science and Engineering, Tianjin University of Technology, Tianjin 300384 (China); Tan, Junjun [School of Chemical and Materials and Engineering, Hubei University of Technology, Hubei 435003 (China); Chen, Minfang, E-mail: mfchentj@126.com [School of Materials Science and Engineering, Tianjin University of Technology, Tianjin 300384 (China)

    2014-07-01

    Conductive and air-stable Cu patterns were directly made on ordinary photo paper using a roller pen filled with nano-Cu ink, which was mainly composed of metallic Cu nanoparticles (NPs) capped with poly(N-vinylpyrrolidone) (PVP). The nano-Cu NPs were obtained via the reduction of Cu{sup 2+} ions by using an excess of hydrazine and PVP. The low sintering temperature (160 °C) in Ar atmosphere played an important role for the preparation of air-stable Cu patterns. The conductivity of a radio-frequency identification antenna made from nano-Cu ink was tested by a lamp, and its resistivity achieved 13.4 ± 0.4 μΩ cm. The Cu NPs were confirmed by means of X-ray powder diffraction and X-ray photoelectron spectra, and the Cu patterns were characterized by scanning electron microscopy and energy dispersive X-ray spectrometry. A mechanism for the high conductivity of the Cu pattern made from Cu NPs is proposed. - Highlights: • The synthesis of pure Cu is related to the reducing agent and capping agent. • The sintering under Ar atmosphere prevents Cu pattern's rapid oxidation. • The formation of the bulk Cu decreases the resistivity of the Cu pattern.

  7. Cu/Cu{sub 2}O/CuO loaded on the carbon layer derived from novel precursors with amazing catalytic performance

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Xiaoli, E-mail: zhaoxiaoli_zxl@126.com [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Tan, Yixin [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Wu, Fengchang, E-mail: wu_fengchang@126.com [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Niu, Hongyun [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Tang, Zhi [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Cai, Yaqi [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Giesy, John P. [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Department of Veterinary Biomedical Sciences and Toxicology Centre, University of Saskatchewan, Saskatoon, Saskatchewan (Canada)

    2016-11-15

    A simple, novel method for synthesis of Cu/Cu{sub 2}O/CuO on surfaces of carbon (Cu/Cu{sub 2}O/CuO@C) as a non-noble-metal catalyst for reduction of organic compounds is presented. Compared with noble metals, Cu/Cu{sub 2}O/CuO@C particles are more efficient and less expensive. Characterization of the Cu/Cu{sub 2}O/CuO@C composites by high-resolution transmission electron microscope (HRTEM), x-ray diffraction (XRD), infrared spectroscopy and Raman analysis, revealed that it was composed of graphitized carbon with numerous nanoparticles (100 nm in diameter) of Cu/CuO/Cu{sub 2}O that were uniformly distributed on internal and external surfaces of the carbon support. Gallic acid (GA) has been used as both organic ligand and carbon precursor with metal organic frameworks (MOFs) as the sacrificial template and metal oxide precursor in this green synthesis. The material combined the advantages of MOFs and Cu-containing materials, the porous structure provided a large contact area and channels for the pollutions, which results in more rapid catalytic degradation of pollutants and leads to greater efficiency of catalysis. The material gave excellent catalytic performance for organic dyes and phenols. In this study, Cu/Cu{sub 2}O/CuO@C was used as catalytic to reduce 4-NP, which has been usually adopted as a model reaction to check the catalytic ability. Catalytic experiment results show that 4-NP was degraded approximately 3 min by use of 0.04 mg of catalyst and the conversion of pollutants can reach more than 99%. The catalyst exhibited little change in efficacy after being utilized five times. Rates of degradation of dyes, such as Methylene blue (MB) and Rhodamine B (RhB) and phenolic compounds such as O-Nitrophenol (O-NP) and 2-Nitroaniline (2-NA) were all similar. - Highlights: • We present an effective catalyst for reductive degradation of organic dyes and phenols in water. • Compared with noble metals, Cu/Cu{sub 2}O/CuO@C particles are more efficient and less

  8. Stability of Cu-Precipitates in Al-Cu Alloys

    Directory of Open Access Journals (Sweden)

    Torsten E. M. Staab

    2018-06-01

    Full Text Available We present first principle calculations on formation and binding energies for Cu and Zn as solute atoms forming small clusters up to nine atoms in Al-Cu and Al-Zn alloys. We employ a density-functional approach implemented using projector-augmented waves and plane wave expansions. We find that some structures, in which Cu atoms are closely packed on {100}-planes, turn out to be extraordinary stable. We compare the results with existing numerical or experimental data when possible. We find that Cu atoms precipitating in the form of two-dimensional platelets on {100}-planes in the fcc aluminum are more stable than three-dimensional structures consisting of the same number of Cu-atoms. The preference turns out to be opposite for Zn in Al. Both observations are in agreement with experimental observations.

  9. Influence of Cu content on the cell biocompatibility of Ti–Cu sintered alloys

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Erlin, E-mail: zhangel@atm.neu.edu.cn [Key Lab. for Anisotropy and Texture of Materials, Education Ministry of China, Northeastern University, Shenyang 110819 (China); Jiamusi University, Jiamusi 154007 (China); Zheng, Lanlan [Jiamusi University, Jiamusi 154007 (China); Liu, Jie [Key Lab. for Anisotropy and Texture of Materials, Education Ministry of China, Northeastern University, Shenyang 110819 (China); Dept. of Prosthodontics, The Affiliated Hospital of Medical College, Qingdao University, Qingdao 266003 (China); Bai, Bing [Dept. of Prosthodontics, School of Stomatology, China Medical University, Liaoning Institute of Dental Research, Shenyang 110001 (China); Liu, Cong [Jiamusi University, Jiamusi 154007 (China)

    2015-01-01

    The cell toxicity and the cell function of Ti–Cu sintered alloys with different Cu contents (2, 5, 10 and 25 wt.%, respectively) have been investigated in comparison with commercial pure titanium in order to assess the influence of Cu content on the cell biocompatibility of the Ti–Cu alloys. The cytotoxicity was studied by examining the MG63 cell response by CCK8 assessment. The cell morphology was evaluated by acridine orange/ethidium bromide (AO/EB) fluorescence and observed under scanning electronic microscopy (SEM). The cell function was monitored by measuring the AKP activity. It has been shown by the AO/EB morphology results that the cell death on both cp-Ti sample and Ti–Cu samples is due to apoptosis rather than necrosis. Although more apoptotic cells were found on the Ti–2Cu and Ti–5Cu samples, no evidence of Cu content dependent manner of apoptosis has been found. SEM observation indicated very good cell adhesion and spread on the cp-Ti sample and the Ti–Cu samples with different Cu contents. CCK8 results displayed that increase in the Cu content in Ti–Cu alloys does not bring about any difference in the cell viability. In addition, AKP test results indicated that no difference in the differentiation of MG63 was found between the cp-Ti and the Ti–Cu samples and among the Ti–Cu samples. All results indicated that Ti–Cu alloys exhibit very good cell biocompatibility and the Cu content up to 25 wt.% in the Ti–Cu alloys has no influence on the cell proliferation and differentiation. - Highlights: • The effect of Cu content on the cell biocompatibility has been investigated. • Cu content shows no influence on the cell proliferation. • Cu content shows no effect on the cell differentiation.

  10. Influence of Cu content on the cell biocompatibility of Ti–Cu sintered alloys

    International Nuclear Information System (INIS)

    Zhang, Erlin; Zheng, Lanlan; Liu, Jie; Bai, Bing; Liu, Cong

    2015-01-01

    The cell toxicity and the cell function of Ti–Cu sintered alloys with different Cu contents (2, 5, 10 and 25 wt.%, respectively) have been investigated in comparison with commercial pure titanium in order to assess the influence of Cu content on the cell biocompatibility of the Ti–Cu alloys. The cytotoxicity was studied by examining the MG63 cell response by CCK8 assessment. The cell morphology was evaluated by acridine orange/ethidium bromide (AO/EB) fluorescence and observed under scanning electronic microscopy (SEM). The cell function was monitored by measuring the AKP activity. It has been shown by the AO/EB morphology results that the cell death on both cp-Ti sample and Ti–Cu samples is due to apoptosis rather than necrosis. Although more apoptotic cells were found on the Ti–2Cu and Ti–5Cu samples, no evidence of Cu content dependent manner of apoptosis has been found. SEM observation indicated very good cell adhesion and spread on the cp-Ti sample and the Ti–Cu samples with different Cu contents. CCK8 results displayed that increase in the Cu content in Ti–Cu alloys does not bring about any difference in the cell viability. In addition, AKP test results indicated that no difference in the differentiation of MG63 was found between the cp-Ti and the Ti–Cu samples and among the Ti–Cu samples. All results indicated that Ti–Cu alloys exhibit very good cell biocompatibility and the Cu content up to 25 wt.% in the Ti–Cu alloys has no influence on the cell proliferation and differentiation. - Highlights: • The effect of Cu content on the cell biocompatibility has been investigated. • Cu content shows no influence on the cell proliferation. • Cu content shows no effect on the cell differentiation

  11. Renal Cu and Na excretion and hepatic Cu metabolism in both Cu acclimated and non acclimated rainbow trout (Oncorhynchus mykiss)

    DEFF Research Database (Denmark)

    Grosell, M.; Hogstrand, C.; Wood, C.M.

    1998-01-01

    protein depending on whether the Cu is derived from recent branchial uptake or is already present in the plasma prior to Cu-64 exposure. The plasma Cu pool derived from recent branchial uptake and the Cu pool present in the plasma prior to Cu-64 exposure is accessible to renal excretion to different...... Na+ efflux decreased by 40%, which was largely due to increased tubular Na+ reabsorption. Renal compensation for the impaired branchial Na+ uptake, seen during Cu exposure, thus seems to be involved in Cu acclimation in rainbow trout. (C) 1998 Elsevier Science B.V....

  12. Cu-Zr-Ag bulk metallic glasses based on Cu8Zr5 icosahedron

    International Nuclear Information System (INIS)

    Xia Junhai; Qiang Jianbing; Wang Yingmin; Wang Qing; Dong Chuang

    2007-01-01

    Based on the cluster line criterion, the Ag addition into the Cu 8 Zr 5 cluster composition is investigated for the search of ternary Cu-Zr-Ag bulk metallic glasses with high glass forming abilities. Two initial binary compositions Cu 0.618 Zr 0.382 and Cu 0.64 Zr 0.36 are selected. The former one corresponds to a deep eutectic point; it is also the composition of the Cu 8 Zr 5 icosahedron, which is derived from the Cu 8 Zr 3 structure. The latter one, which can be regarded as the Cu 8 Zr 5 cluster plus a glue atom Cu, is the best glass-forming composition in the Cu-Zr binary system. Two composition lines (Cu 0.618 Zr 0.382 ) 1-x Ag x and (Cu 0.64 Zr 0.36 ) 1-x Ag x are thus constructed in the Cu-Zr-Ag system by linking these two compositions with the third constitute Ag. A series of Cu-Zr-Ag bulk metallic glasses are found with 2-8 at.% Ag contents in both composition lines. The optimum composition (Cu 0.618 Zr 0.382 ) 0.92 Ag 0.08 within the searched region with the highest T g /T l = 0.633, is located along the cluster line (Cu 0.618 Zr 0.382 ) 1-x Ag x , where the deep eutectic Cu 0.618 Zr 0.382 exactly corresponds to the dense packing cluster Cu 8 Zr 5 . The alloying mechanism is discussed in the light of atomic size and electron concentration factors

  13. Stability enhancement of Cu2S against Cu vacancy formation by Ag alloying

    Science.gov (United States)

    Barman, Sajib K.; Huda, Muhammad N.

    2018-04-01

    As a potential solar absorber material, Cu2S has proved its importance in the field of renewable energy. However, almost all the known minerals of Cu2S suffer from spontaneous Cu vacancy formation in the structure. The Cu vacancy formation causes the structure to possess very high p-type doping that leads the material to behave as a degenerate semiconductor. This vacancy formation tendency is a major obstacle for this material in this regard. A relatively new predicted phase of Cu2S which has an acanthite-like structure was found to be preferable than the well-known low chalcocite Cu2S. However, the Cu-vacancy formation tendency in this phase remained similar. We have found that alloying silver with this structure can help to reduce Cu vacancy formation tendency without altering its electronic property. The band gap of silver alloyed structure is higher than pristine acanthite Cu2S. In addition, Cu diffusion in the structure can be reduced with Ag doped in Cu sites. In this study, a systematic approach is presented within the density functional theory framework to study Cu vacancy formation tendency and diffusion in silver alloyed acanthite Cu2S, and proposed a possible route to stabilize Cu2S against Cu vacancy formations by alloying it with Ag.

  14. Characterization of p-CuI prepared by the SILAR technique on Cu-tape/n-CuInS2 for solar cells

    International Nuclear Information System (INIS)

    Sankapal, B.R.; Ennaoui, A.; Guminskaya, T.; Dittrich, Th.; Bohne, W.; Roehrich, J.; Strub, E.; Lux-Steiner, M.Ch.

    2005-01-01

    CuI has been synthesized at room temperature on Cu-tape/n-CuInS 2 by using the SILAR technique (successive ionic layer adsorption and reaction). The influence of wet chemical iodine treatment on the CuI has been investigated in more detail. The films were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), elastic recoil detection analysis (ERDA) and surface photovoltage (SPV) techniques. The CuI films contain the no. gammano. -phase of the Zinkblende structure. The crystallites are preferentially oriented in the (111) direction. After wet chemical iodine treatment, the fibrous surface morphology changed to a more dense CuI film with larger crystallites. Oxides could not be detected on the CuI surface. The density of surface states of CIS decreased after the CuI deposition. The importance of the wet chemical iodine treatment for the performance of Cu-tape/n-CuInS 2 /p-CuI solar cells has been demonstrated

  15. Cu diffusion as an alternative method for nanopatterned CuTCNQ film growth

    International Nuclear Information System (INIS)

    Capitán, M J; Álvarez, J; Miranda, R; Navío, C

    2016-01-01

    In this paper we show by means of ‘in situ’ x-ray diffraction studies that CuTCNQ formation from Cu(solid)–TCNQ(solid tetracyanoquinodimethane) goes through Cu diffusion at room temperature. The film quality depends on the TCNQ evaporation rate. At low evaporation rate we get a single phase-I CuTCNQ film very well crystallized and well oriented. The film has a CuTCNQ(0 2 0) orientation. The film is formed by CuTCNQ nanorods of a very homogeneous size. The film homogeneity has also been seen by atomic force microscopy (AFM). The electronic properties of the film have been measured by x-ray photoelectron spectroscopy (XPS) and ultra-violet photoelectron spectroscopy (UPS). Thus, the Cu-diffusion method has arisen as a very simple, clean and efficient method to grow localized CuTCNQ nanorods on Cu, opening up new insights for technological applications. (paper)

  16. Controllable synthesis and enhanced photocatalytic properties of Cu2O/Cu31S16 composites

    International Nuclear Information System (INIS)

    Liu, Xueqin; Li, Zhen; Zhang, Qiang; Li, Fei

    2012-01-01

    Highlights: ► Facile sonochemical route. ► The content of Cu 31 S 16 in the Cu 2 O/Cu 31 S 16 can be easily controlled. ► Structure and optical properties of Cu 2 O/Cu 31 S 16 were discussed. ► Enhanced photocatalytic property of Cu 2 O/Cu 31 S 16 . ► Cu 2 O/Cu 31 S 16 core/shell structures were more stable than single Cu 2 O particles. -- Abstract: The controlled synthesis of Cu 2 O/Cu 31 S 16 microcomposites with hierarchical structures had been prepared via a convenient sonochemical route. Ultrasonic irradiation of a mixture of Cu 2 O and (NH 2 ) 2 CS in an aqueous medium yielded Cu 2 O/Cu 31 S 16 composites. The content of Cu 31 S 16 in the Cu 2 O/Cu 31 S 16 can be easily controlled by adjusting the synthesis time. The Cu 31 S 16 layer not only protected and stabilized Cu 2 O particles, but also prohibited the recombination of photogenerated electrons–holes pair between Cu 31 S 16 and Cu 2 O. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR) spectra, ultraviolet–visible (UV–Vis) spectroscopy and photoluminescence (PL) spectroscopy were used to characterize the products. Photocatalytic performance of the Cu 2 O/Cu 31 S 16 hierarchical structures was evaluated by measuring the decomposition rate of methyl orange solution under natural light. To the best of our knowledge, this is the first report on the preparation and photocatalytic activity of Cu 2 O/Cu 31 S 16 microcomposite. Additionally, the Cu 2 O/Cu 31 S 16 core/shell structures were more stable than single Cu 2 O particles during photocatalytic process since the photocatalytic activity of the second reused architecture sample was much higher than that of pure Cu 2 O. The Cu 2 O/Cu 31 S 16 microcomposites may be a good promising candidate for wastewater treatment.

  17. Growth and characterisation of potentiostatically electrodeposited Cu2O and Cu thin films

    International Nuclear Information System (INIS)

    Wijesundera, R.P.; Hidaka, M.; Koga, K.; Sakai, M.; Siripala, W.

    2006-01-01

    Cuprous oxide and copper thin films were potentiostatically electrodeposited in an acetate bath. Voltammetric curves were used to investigate the growth parameters; deposition potential, pH and temperature of the bath. Deposition potential dependency on the structural, morphological, optical and electronic properties of the films were investigated by the X-ray diffraction measurements, scanning electron micrographs, absorption measurements and dark and light current-voltage characterisations. It was observed that single phase polycrystalline Cu 2 O can be deposited from 0 to - 300 mV Vs saturated calomel electrode (SCE) and co-deposition of Cu and Cu 2 O starts at - 400 mV Vs SCE. Further increase in deposition potential from - 700 mV Vs SCE produces single phase Cu thin films. Single phase polycrystalline Cu 2 O thin films with cubic grains of 1-2 μm can be possible within the very narrow potential domain around - 200 mV Vs SCE. Enhanced photoresponse in a photoelectrochemical cell is produced by the Cu 2 O thin film prepared at - 400 mV Vs SCE, where Cu is co-deposited with Cu 2 O with random distribution of Cu spheres on the Cu 2 O surface. This study reveals that a single deposition bath can be used to deposit both Cu and Cu 2 O separately and an admixture of Cu-Cu 2 O by controlling the deposition parameters

  18. Synthesis of Cu/Cu2O nanoparticles by laser ablation in deionized water and their annealing transformation into CuO nanoparticles

    KAUST Repository

    Gondal, M. A.; Qahtan, Talal F.; Dastageer, Mohamed Abdulkader; Maganda, Yasin W.; Anjum, Dalaver H.

    2013-01-01

    Nano-structured Cupric Oxide (CuO) has been synthesized using pulsed laser ablation of pure copper in water using Q-switched pulsed laser beam of 532 nm wavelength and, 5 nanosecond pulse duration and laser pulse energy of 100 mJ/pulse. In the initial unannealed colloidal suspension, the nanoparticles of Copper (Cu) and Cuprious oxide (Cu2O) were identified. Further the suspension was dried and annealed at different temperatures and we noticed the product (Cu/Cu2O) was converted predominantly into CuO at annealing temperature of 300 'C for 3 hours. As the annealing temperature was raised from 300 to 900 'C, the grain sizes of CuO reduced to the range of 9 to 26 nm. The structure and the morphology of the prepared samples were investigated using X-ray diffraction and Transmission Electron Microscope. Photoluminescence and UV absorption spectrometrystudies revealed that the band gap and other optical properties of nano-structured CuO were changed due to post annealing. Fourier transform spectrometry also confirmed the transformation of Cu/Cu2O into CuO. Copyright © 2013 American Scientific Publishers All rights reserved.

  19. Synthesis of Cu/Cu2O nanoparticles by laser ablation in deionized water and their annealing transformation into CuO nanoparticles

    KAUST Repository

    Gondal, M. A.

    2013-08-01

    Nano-structured Cupric Oxide (CuO) has been synthesized using pulsed laser ablation of pure copper in water using Q-switched pulsed laser beam of 532 nm wavelength and, 5 nanosecond pulse duration and laser pulse energy of 100 mJ/pulse. In the initial unannealed colloidal suspension, the nanoparticles of Copper (Cu) and Cuprious oxide (Cu2O) were identified. Further the suspension was dried and annealed at different temperatures and we noticed the product (Cu/Cu2O) was converted predominantly into CuO at annealing temperature of 300 \\'C for 3 hours. As the annealing temperature was raised from 300 to 900 \\'C, the grain sizes of CuO reduced to the range of 9 to 26 nm. The structure and the morphology of the prepared samples were investigated using X-ray diffraction and Transmission Electron Microscope. Photoluminescence and UV absorption spectrometrystudies revealed that the band gap and other optical properties of nano-structured CuO were changed due to post annealing. Fourier transform spectrometry also confirmed the transformation of Cu/Cu2O into CuO. Copyright © 2013 American Scientific Publishers All rights reserved.

  20. Effect of AlN layer on the bipolar resistive switching behavior in TiN thin film based ReRAM device for non-volatile memory application

    Science.gov (United States)

    Prakash, Ravi; Kaur, Davinder

    2018-05-01

    The effect of an additional AlN layer in the Cu/TiN/AlN/Pt stack configuration deposited using sputtering has been investigated. The Cu/TiN/AlN/Pt device shows a tristate resistive switching. Multilevel switching is facilitated by ionic and metallic filament formation, and the nature of the filaments formed is confirmed by performing a resistance vs. temperature measurement. Ohmic behaviour and trap controlled space charge limited current (SCLC) conduction mechanisms are confirmed as dominant conduction mechanism at low resistance state (LRS) and high resistance state (HRS). High resistance ratio (102) corresponding to HRS and LRS, good write/erase endurance (105) and non-volatile long retention (105s) are also observed. Higher thermal conductivity of the AlN layer is the main reasons for the enhancement of resistive switching performance in Cu/TiN/AlN/Pt cell. The above result suggests the feasibility of Cu/TiN/AlN/Pt devices for multilevel nonvolatile ReRAM application.

  1. TPD IR studies of CO desorption from zeolites CuY and CuX

    Science.gov (United States)

    Datka, Jerzy; Kozyra, Paweł

    2005-06-01

    The desorption of CO from zeolites CuY and CuX was followed by TPD-IR method. This is a combination of temperature programmed desorption and IR spectroscopy. In this method, the status of activated zeolite (before adsorption), the process of adsorption, and the status of adsorbed molecules can be followed by IR spectroscopy, and the process of desorption (with linear temperature increase) can be followed both by IR spectroscopy and by mass spectrometry. IR spectra have shown two kinds of Cu + sites in both CuY and CuX. Low frequency (l.f.) band (2140 cm -1 in CuY and 2130 cm -1 in CuX) of adsorbed CO represents Cu + sites for which π back donation is stronger and σ donation is weaker whereas high frequency h.f. band (2160 cm -1 in CuY and 2155 cm -1 in CuX) represent Cu + sites for which π back donation is weaker and σ donation is stronger. The TPD-IR experiments evidenced that the Cu + sites represented by l.f. band bond CO more weakly than those represented by h.f. one, indicating that σ donation has more important impact to the strength of Cu +-CO bonding. On the contrary, π back donation has bigger contribution to the activation of adsorbed molecules.

  2. Electromigration in 3D-IC scale Cu/Sn/Cu solder joints

    Energy Technology Data Exchange (ETDEWEB)

    Ho, Cheng-En, E-mail: ceho1975@hotmail.com; Lee, Pei-Tzu; Chen, Chih-Nan; Yang, Cheng-Hsien

    2016-08-15

    The electromigration effect on the three-dimensional integrated circuits (3D-IC) scale solder joints with a Cu/Sn(25–50 μm)/Cu configuration was investigated using a field-emission scanning electron microscope (FE–SEM) combined with electron backscatter diffraction (EBSD) analysis system. Electron current stressing for a few days caused the pronounced accumulation of Cu{sub 6}Sn{sub 5} in specific Sn grain boundaries (GBs). The EBSD analysis indicated that both the β-Sn crystallographic orientation and GB orientation play dominant roles in this accumulation. The dependencies of the Cu{sub 6}Sn{sub 5} accumulation on the two above factors (i.e., Sn grain orientation and GB orientation) can be well rationalized via a proposed mathematic model based on the Huntington and Grone's electromigration theory with the Cu anisotropic diffusion data in a β-Sn lattice. - Highlights: • Anisotropic Cu electromigration in the 3D-IC scale microelectronic solder joints. • Pronounced accumulation of Cu{sub 6}Sn{sub 5} intermetallic in specific Sn grain boundaries. • A linear dependence of Cu{sub 6}Sn{sub 5} accumulation over the current stressing time. • β-Sn and grain boundary orientations are the dominant factors in Cu{sub 6}Sn{sub 5} accumulation.

  3. Effect of 67Cu and 99Mo labeled tetrathiomolybdate on the distribution of 67Cu, Cu, and 99Mo in bile fractions in sheep

    International Nuclear Information System (INIS)

    Gooneratne, R.; Laarveld, B.; Christensen, D.

    1989-01-01

    The effect of intravenous administration of 67 Cu and 99 Mo labeled tetrathiomolybdate (TTM) on the appearance of 67 Cu, stable Cu, and 99 Mo in gel chromatographic fractions of bile was examined in sheep fed either 5 or 35 mg Cu kg-1 DM. Peak excretory periods of biliary 67 Cu, stable Cu, and 99 Mo were observed at 30 min-1.25 hr, 2-3 hr, and 11-13 hr after 67 Cu and after 99 Mo labeled TTM. Sephadex G-75 gel filtration of bile samples collected at 1, 3, and 12 hr after 67 Cu administration revealed two major protein peaks of molecular weights of greater than 80,000 (peak I) and 7,000 (peak II) containing both 67 Cu and Cu. But the ratio of 67 Cu in the two peaks varied with time of bile collection. The ratio of areas of peak I:II 1 hr after 67 Cu administration was approximately 0.48; at 3 hr, 0.62, and at 12 hr 1.35. Tetrathiomolybdate administration increased both 67 Cu and stable Cu in bile by severalfold and induced a major shift of Cu into the higher molecular weight protein fraction. The experiments confirm the effectiveness of TTM as a ''decoppering'' agent. Furthermore, TTM not only promoted bile Cu excretion, but it also increased the incorporation of Cu into the macromolecular fraction. This may limit enterohepatic circulation of biliary Cu and thereby cause an overall Cu depletion and a negative Cu balance

  4. Characterization of Cu-exchanged SSZ-13: a comparative FTIR, UV-Vis, and EPR study with Cu-ZSM-5 and Cu-β with similar Si/Al and Cu/Al ratios

    DEFF Research Database (Denmark)

    Giordanino, Filippo; Vennestrøm, Peter N. R.; Lundegaard, Lars Fahl

    2013-01-01

    concentration of reduced copper centres, i.e. isolated Cu+ ions located in different environments, able to form Cu+(N2), Cu+(CO)n (n = 1, 2, 3), and Cu+(NO)n (n = 1, 2) upon interaction with N2, CO and NO probe molecules, respectively. Low temperature FTIR, DRUV-Vis and EPR analysis on O2 activated samples...... an intense and finely structured d–d quadruplet, unique to Cu-SSZ-13, which is persistent under SCR conditions. This differs from the 22 700 cm−1 band of the mono(μ-oxo)dicopper species of the O2 activated Cu-ZSM-5, which disappears under SCR conditions. The EPR signal intensity sets Cu-β apart from...

  5. Characterization of p-CuI prepared by the SILAR technique on Cu-tape/n-CuInS{sub 2} for solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Sankapal, B.R. [Hahn-Meitner-Institut, Glienicker Strasse 100, D-14109, Berlin (Germany)]. E-mail: brsankapal@rediffmail.com; Ennaoui, A. [Hahn-Meitner-Institut, Glienicker Strasse 100, D-14109, Berlin (Germany); Guminskaya, T. [Hahn-Meitner-Institut, Glienicker Strasse 100, D-14109, Berlin (Germany); Dittrich, Th. [Hahn-Meitner-Institut, Glienicker Strasse 100, D-14109, Berlin (Germany); Bohne, W. [Hahn-Meitner-Institut, Glienicker Strasse 100, D-14109, Berlin (Germany); Roehrich, J. [Hahn-Meitner-Institut, Glienicker Strasse 100, D-14109, Berlin (Germany); Strub, E. [Hahn-Meitner-Institut, Glienicker Strasse 100, D-14109, Berlin (Germany); Lux-Steiner, M.Ch. [Hahn-Meitner-Institut, Glienicker Strasse 100, D-14109, Berlin (Germany)

    2005-06-01

    CuI has been synthesized at room temperature on Cu-tape/n-CuInS{sub 2} by using the SILAR technique (successive ionic layer adsorption and reaction). The influence of wet chemical iodine treatment on the CuI has been investigated in more detail. The films were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), elastic recoil detection analysis (ERDA) and surface photovoltage (SPV) techniques. The CuI films contain the no. gammano. -phase of the Zinkblende structure. The crystallites are preferentially oriented in the (111) direction. After wet chemical iodine treatment, the fibrous surface morphology changed to a more dense CuI film with larger crystallites. Oxides could not be detected on the CuI surface. The density of surface states of CIS decreased after the CuI deposition. The importance of the wet chemical iodine treatment for the performance of Cu-tape/n-CuInS{sub 2}/p-CuI solar cells has been demonstrated.

  6. Direct Observation of Reduction of Cu(II) to Cu(I) by Terminal Alkynes

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Guanghui; Yi, Hong; Zhang, Guoting; Deng, Yi; Bai, Ruopeng; Zhang, Heng; Miller, Jeffrey T.; Kropf, Arthur J.; Bunel, Emilio E.; Lei, Aiwen

    2014-01-06

    ABSTRACT: X-ray absorption spectroscopy and in situ electron paramagnetic resonance evidence were provided for the reduction of Cu(II) to Cu(I) species by alkynes in the presence of tetramethylethylenediamine (TMEDA), in which TMEDA plays dual roles as both ligand and base. The structures of the starting Cu(II) species and the obtained Cu(I) species were determined as (TMEDA)- CuCl2 and [(TMEDA)CuCl]2 dimer, respectively.

  7. New Production Routes for Medical Isotopes 64Cu and 67Cu Using Accelerator Neutrons

    Science.gov (United States)

    Kin, Tadahiro; Nagai, Yasuki; Iwamoto, Nobuyuki; Minato, Futoshi; Iwamoto, Osamu; Hatsukawa, Yuichi; Segawa, Mariko; Harada, Hideo; Konno, Chikara; Ochiai, Kentaro; Takakura, Kosuke

    2013-03-01

    We have measured the activation cross sections producing 64Cu and 67Cu, promising medical radioisotopes for molecular imaging and radioimmunotherapy, by bombarding a natural zinc sample with 14 MeV neutrons. We estimated the production yields of 64Cu and 67Cu by fast neutrons from \\text{natC(d,n) with 40 MeV 5 mA deuterons. We used the present result together with the evaluated cross section of Zn isotopes. The calculated 64Cu yield is 1.8 TBq (175 g 64Zn) for 12 h of irradiation; the yields of 67Cu by 67Zn(n,p)67Cu and 68Zn(n,x)67Cu were 249 GBq (184 g 67Zn) and 287 GBq (186 g 68Zn) at the end of 2 days of irradiation, respectively. From the results, we proposed a new route to produce 67Cu with very little radionuclide impurity via the 68Zn(n,x)67Cu reaction, and showed the 64Zn(n,p)64Cu reaction to be a promising route to produce 64Cu. Both 67Cu and 64Cu are noted to be produced using fast neutrons.

  8. The influence of dietary Cu and diabetes on tissue 67Cu retention kinetics in rats

    International Nuclear Information System (INIS)

    Uriu-Hare, J.Y.; Rucker, R.B.; Keen, C.L.

    1991-01-01

    Compared to controls, diabetes results in higher plasma, liver and kidney Cu concentrations. Since alterations in Cu metabolism may be associated with diabetic pathology, the authors investigated how Cu metabolism is affected by diabetes and dietary Cu intake. Nondiabetic and STZ diabetic rats were fed Cu suppl. or Cu def. diets for 5 wks. Rats were intubated with 28 μCi 67 Cu and killed after 8, 16, 24, 32, 64, or 128 h. There were marked effects of both diet and diabetes on 67 Cu metabolism. Independent of diabetes, deficient rats had a higher % of retained 67 Cu, in liver, plasma, RBC, muscle, spleen, brain, lung, uterus, and intestine than adequate Cu rats. Independent of dietary Cu, diabetic rats had a lower % of retained 67 Cu in liver, plasma, RBC, muscle, spleen, lung, bone, pancreas, skin, uterus and heart than controls. Differential effects were noted for kidney; adequate Cu diabetic rats had a higher % of retained 67 Cu than all other groups. Marked effects of both diet and diabetes were evident when tissue Cu turnover was examined. Compared to Cu suppl. rats, Cu def. rats had a slower turnover of 67 Cu, in liver, plasma, intestine, pancreas, eye, brain, muscle, spleen, lung and heart. Diabetic rats had a slower turnover of 67 Cu than nondiabetic rats in liver, plasma, intestine, pancreas, eye, kidney, RBC and uterus. The data imply that a focus on Cu metabolism with regard to cellular Cu trafficking and pathology may be warranted

  9. Copper interactions in TlCu7S4 and TlCu7Se4

    International Nuclear Information System (INIS)

    Noren, L.; Delaplane, R.G.; Berger, R.

    1999-01-01

    Complete text of publication follows. The copper chalcogenides ACu 7 S 4 (A=NH 4 + , Tl + , Rb + ) are quasi-one-dimensional metals at ambient and higher temperatures which is due to the high mobility of copper in these structures. TlCu 7 S 4 and TlCu 7 Se 4 are isostructural compounds, space group I4/m, which can be described on the basis of a TlX 8 cube with two different Cu sites, Cu(1) and Cu(2). Cu(2)-Cu(2) zigzag chains run along the c axis with only 3/4 occupation of the Cu(2) sites. However, these two compounds differ in behaviour on cooling. The sulphide shows a polymorphic first-order transition to the CsAg 7 S 4 type (P4/n) owing to ordering of the vacancies in the Cu(2)-Cu(2) chains. In order to study the nature of the Cu(2) order/disorder in the two title compounds, a series of neutron diffraction measurements (both Bragg and diffuse scattering) were made at several temperatures from 40 to 713 K on the instrument SLAD at Studsvik. The structure at each temperature was modelled using RMC techniques. The resulting configuration show that as the temperature increases, there is a marked increase in the mobility of the Cu atoms in the Cu(2)-Cu(2) chains for TlCu 7 S 4 but not for TlCu 7 Se 4 . This is due to the initial difference in the Cu(2)-Cu(2) distances, only 2.2A for the thiocuprate, but 2.7A in the selenocuprate which explains the relative ease for Cu(2) ordering in the latter case. (author)

  10. Behavior of CuP and OFHC Cu anodes under electrodeposition conditions

    Energy Technology Data Exchange (ETDEWEB)

    Frankel, G.S.; Schrott, A.G.; Horkans, J.; Andricacos, P.C. (International Business Machines Corp., Yorktown Heights, NY (United States). Thomas J. Watson Research Center); Isaacs, H.S. (Brookhaven National Lab., Upton, NY (United States))

    1992-01-01

    Films formed on CuP (with 0.05 wt % P) and OFHC Cu anodes in electroplating solutions were studied by X-ray Photoelectron Spectroscopy, X-ray Absorption Spectroscopy, electrochemical methods, and a newly developed gravimetric technique. The black film formed on CuP in Cl-containing solutions was found to resemble a porous sponge composed of CuCl but laden/with concentrated CuSO{sub 4} solution. The difference between the buoyancy-corrected measured mass change and the charge-equivalent mass change was found to have two components: a reversible part that comes and goes as the current is turned on and off, and an irreversible part that remains on the surface and increase in mass with time. The irreversible part results from the anodic film, which increases linearly with charge density but independent of current density. The reversible part of the mass change arises from the weight of the diffusion layer. In contrast to CuP, OFHC Cu releases much more Cu{sup +1} during anodic polarization and forms a poorly-adherent anodic film that is considerably heavier than the black film for a given charge density.

  11. Behavior of CuP and OFHC Cu anodes under electrodeposition conditions

    Energy Technology Data Exchange (ETDEWEB)

    Frankel, G.S.; Schrott, A.G.; Horkans, J.; Andricacos, P.C. [International Business Machines Corp., Yorktown Heights, NY (United States). Thomas J. Watson Research Center; Isaacs, H.S. [Brookhaven National Lab., Upton, NY (United States)

    1992-08-01

    Films formed on CuP (with 0.05 wt % P) and OFHC Cu anodes in electroplating solutions were studied by X-ray Photoelectron Spectroscopy, X-ray Absorption Spectroscopy, electrochemical methods, and a newly developed gravimetric technique. The black film formed on CuP in Cl-containing solutions was found to resemble a porous sponge composed of CuCl but laden/with concentrated CuSO{sub 4} solution. The difference between the buoyancy-corrected measured mass change and the charge-equivalent mass change was found to have two components: a reversible part that comes and goes as the current is turned on and off, and an irreversible part that remains on the surface and increase in mass with time. The irreversible part results from the anodic film, which increases linearly with charge density but independent of current density. The reversible part of the mass change arises from the weight of the diffusion layer. In contrast to CuP, OFHC Cu releases much more Cu{sup +1} during anodic polarization and forms a poorly-adherent anodic film that is considerably heavier than the black film for a given charge density.

  12. In Situ Study of Reduction Process of CuO Paste and Its Effect on Bondability of Cu-to-Cu Joints

    Science.gov (United States)

    Yao, Takafumi; Matsuda, Tomoki; Sano, Tomokazu; Morikawa, Chiaki; Ohbuchi, Atsushi; Yashiro, Hisashi; Hirose, Akio

    2018-04-01

    A bonding method utilizing redox reactions of metallic oxide microparticles achieves metal-to-metal bonding in air, which can be alternative to lead-rich high-melting point solder. However, it is known that the degree of the reduction of metallic oxide microparticles have an influence on the joint strength using this bonding method. In this paper, the reduction behavior of CuO paste and its effect on Cu-to-Cu joints were investigated through simultaneous microstructure-related x-ray diffraction and differential scanning calorimetry measurements. The CuO microparticles in the paste were gradually reduced to submicron Cu2O particles at 210-250°C. Subsequently, Cu nanoparticles were generated instantaneously at 300-315°C. There was a marked difference in the strengths of the joints formed at 300°C and 350°C. Thus, the Cu nanoparticles play a critical role in sintering-based bonding using CuO paste. Furthermore, once the Cu nanoparticles have formed, the joint strength increases with higher bonding temperature (from 350°C to 500°C) and pressure (5-15 MPa), which can exceed the strength of Pb-5Sn solder at higher temperature and pressure.

  13. CuGaTe2-CuAlTe2 system

    International Nuclear Information System (INIS)

    Bodnar', I.V.

    2003-01-01

    The results of studies on the chemical interaction in the CuGaTe 2 -CuAlTe 2 as well as on the thermal and optical properties of the formed solid solutions are presented. It is shown, that continuous number of solid solutions are formed in the CuGaTe 2 -CuAlTe 2 system, which crystallize in the chalcopyrite structure. The diagram of state of this system is plotted. The thermal expansion of these materials is studied through the dilatometric method. The linear dependence of the thermal expansion coefficient on the composition is established. The concentration dependences of the forbidden zone width diverge from the linearity [ru

  14. The effect of inducing uniform Cu growth on formation of electroless Cu seed layer

    International Nuclear Information System (INIS)

    Lim, Taeho; Kim, Myung Jun; Park, Kyung Ju; Kim, Kwang Hwan; Choe, Seunghoe; Lee, Young-Soo; Kim, Jae Jeong

    2014-01-01

    The uniformity of Cu growth on Pd nanocatalysts was controlled by using organic additives in the formation of electroless Cu seed layers. Polyethylene glycol (PEG, Mw. 8000) not only reduced the deposition rate but also improved the uniformity of Cu growth on each Pd nanocatalyst during the seed layer formation. The stronger suppression effect of PEG on Cu than on Pd reduced the difference in the deposition rate between the two surfaces, resulting in the uniform deposition. Meanwhile, bis(3-sulfopropyl) disulfide degraded the uniformity by strong and nonselective suppression. The sheet resistance measurement and atomic force microscopy imaging revealed that the uniform Cu growth by PEG was more advantageous for the formation of a thin and smooth Cu seed layer than the non-uniform growth. The uniform Cu growth also had a positive influence on the subsequent Cu electrodeposition: the 60-nm-thick electrodeposited Cu film on the Cu seed layer showed low resistivity (2.70 μΩ·cm), low surface roughness (6.98 nm), and good adhesion strength. - Highlights: • Uniform Cu growth on Pd was achieved in formation of electroless Cu seed layer. • PEG addition to electroless bath improved the uniformity of Cu growth on Pd. • A thin, smooth and continuous Cu seed layer was obtained with PEG. • Adhesion strength of the Cu seed layer was also improved with PEG. • The uniformity improvement positively affected subsequent Cu electrodeposition

  15. Colloidal synthesis of Cu-ZnO and Cu@CuNi-ZnO hybrid nanocrystals with controlled morphologies and multifunctional properties

    Science.gov (United States)

    Zeng, Deqian; Gong, Pingyun; Chen, Yuanzhi; Zhang, Qinfu; Xie, Qingshui; Peng, Dong-Liang

    2016-06-01

    Metal-semiconductor hybrid nanocrystals have received extensive attention owing to their multiple functionalities which can find wide technological applications. The utilization of low-cost non-noble metals to construct novel metal-semiconductor hybrid nanocrystals is important and meaningful for their large-scale applications. In this study, a facile solution approach is developed for the synthesis of Cu-ZnO hybrid nanocrystals with well-controlled morphologies, including nanomultipods, core-shell nanoparticles, nanopyramids and core-shell nanowires. In the synthetic strategy, Cu nanocrystals formed in situ serve as seeds for the heterogeneous nucleation and growth of ZnO, and it eventually forms various Cu-ZnO hetero-nanostructures under different reaction conditions. These hybrid nanocrystals possess well-defined and stable heterostructure junctions. The ultraviolet-visible-near infrared spectra reveal morphology-dependent surface plasmon resonance absorption of Cu and the band gap absorption of ZnO. Furthermore, we construct a novel Cu@CuNi-ZnO ternary hetero-nanostructure by incorporating the magnetic metal Ni into the pre-synthesized colloidal Cu nanocrystals. Such hybrid nanocrystals possess a magnetic Cu-Ni intermediate layer between the ZnO shell and the Cu core, and exhibit ferromagnetic/superparamagnetic properties which expand their functionalities. Finally, enhanced photocatalytic activities are observed in the as-prepared non-noble metal-ZnO hybrid nanocrystals. This study not only provides an economical way to prepare high-quality morphology-controlled Cu-ZnO hybrid nanocrystals for potential applications in the fields of photocatalysis and photovoltaic devices, but also opens up new opportunities in designing ternary non-noble metal-semiconductor hybrid nanocrystals with multifunctionalities.Metal-semiconductor hybrid nanocrystals have received extensive attention owing to their multiple functionalities which can find wide technological applications

  16. Phase relationships in Cu-rich corner of the Cu-Cr-Zr phase diagram

    International Nuclear Information System (INIS)

    Zeng, K.J.; Haemaelaeinen, M.; Lilius, K.

    1995-01-01

    In the available experimental information on the Cu-Cr-Zr ternary system, there exist different opinions concerning the phase relationships in the Cu-rich corner of Cu-Cr-Zr phase diagram. Glazov et al. and Zakharov et al. investigated the Cu-rich corner of the Cu-Cr-Zr phase diagram within the composition range up to 3.5 Cr and 3.5 Zr (wt. %). A quasi-eutectic reaction L → (Cu) + αCr 2 Zr was observed to occur at 1,020 C and several isothermal sections were constructed within the temperature range from 600 to 1,000 C to show the (Cu)-αCr 2 Zr two phase equilibrium. Therefore, a pseudobinary Cu-Cr 2 Zr system was supposed. Afterwards, Dawakatsu et al, Fedorov et al, and Kuznetsov et al studied the cu-rich corner of the phase diagram in a wider composition range up to 5 Cr and 20 Zr (at.%). Contrary to Glazov et al. and Zakharov et al., they found no Cr 2 Zr phase in their samples. Hence, the pseudobinary Cu-Cr 2 Zr system does not exist. In this study an experimental investigation is presented on the phase relationships in Cu-rich corner of the Cu-Cr-Zr phase diagram at 940 C in order to clear up the confusion

  17. Hydrodynamic evolution and jet energy loss in Cu + Cu collisions

    International Nuclear Information System (INIS)

    Schenke, Bjoern; Jeon, Sangyong; Gale, Charles

    2011-01-01

    We present results from a hybrid description of Cu + Cu collisions using (3 + 1)-dimensional hydrodynamics (music) for the bulk evolution and a Monte Carlo simulation (martini) for the evolution of high-momentum partons in the hydrodynamical background. We explore the limits of this description by going to small system sizes and determine the dependence on different fractions of wounded nucleon and binary collisions scaling of the initial energy density. We find that Cu + Cu collisions are well described by the hybrid description at least up to 20% central collisions.

  18. Massive spalling of Cu-Zn and Cu-Al intermetallic compounds at the interface between solders and Cu substrate during liquid state reaction

    Science.gov (United States)

    Kotadia, H. R.; Panneerselvam, A.; Mokhtari, O.; Green, M. A.; Mannan, S. H.

    2012-04-01

    The interfacial intermetallic compound (IMC) formation between Cu substrate and Sn-3.8Ag-0.7Cu-X (wt.%) solder alloys has been studied, where X consists of 0-5% Zn or 0-2% Al. The study has focused on the effect of solder volume as well as the Zn or Al concentration. With low solder volume, when the Zn and Al concentrations in the solder are also low, the initial Cu-Zn and Al-Cu IMC layers, which form at the solder/substrate interface, are not stable and spall off, displaced by a Cu6Sn5 IMC layer. As the total Zn or Al content in the system increases by increasing solder volume, stable CuZn or Al2Cu IMCs form on the substrate and are not displaced. Increasing concentration of Zn has a similar effect of stabilizing the Cu-Zn IMC layer and also of forming a stable Cu5Zn8 layer, but increasing Al concentration alone does not prevent spalling of Al2Cu. These results are explained using a combination of thermodynamic- and kinetics-based arguments.

  19. Cu and Cu-Based Nanoparticles: Synthesis and Applications in Catalysis.

    Science.gov (United States)

    Gawande, Manoj B; Goswami, Anandarup; Felpin, François-Xavier; Asefa, Tewodros; Huang, Xiaoxi; Silva, Rafael; Zou, Xiaoxin; Zboril, Radek; Varma, Rajender S

    2016-03-23

    The applications of copper (Cu) and Cu-based nanoparticles, which are based on the earth-abundant and inexpensive copper metal, have generated a great deal of interest in recent years, especially in the field of catalysis. The possible modification of the chemical and physical properties of these nanoparticles using different synthetic strategies and conditions and/or via postsynthetic chemical treatments has been largely responsible for the rapid growth of interest in these nanomaterials and their applications in catalysis. In addition, the design and development of novel support and/or multimetallic systems (e.g., alloys, etc.) has also made significant contributions to the field. In this comprehensive review, we report different synthetic approaches to Cu and Cu-based nanoparticles (metallic copper, copper oxides, and hybrid copper nanostructures) and copper nanoparticles immobilized into or supported on various support materials (SiO2, magnetic support materials, etc.), along with their applications in catalysis. The synthesis part discusses numerous preparative protocols for Cu and Cu-based nanoparticles, whereas the application sections describe their utility as catalysts, including electrocatalysis, photocatalysis, and gas-phase catalysis. We believe this critical appraisal will provide necessary background information to further advance the applications of Cu-based nanostructured materials in catalysis.

  20. Cu uptake and turnover in both Cu-acclimated and non-acclimated rainbow trout (Oncorhynchus mykiss)

    DEFF Research Database (Denmark)

    Grosell, M.; Hogstrand, C.; Wood, C.M.

    1997-01-01

    -acclimation clearly involves changes in copper accumulation kinetics in the plasma. The acclimated fish showed a 65% reduced Cu-64 accumulation after 65 h and an increased turnover of Cu in the plasma compared to the non-acclimated fish. Total Cu in the plasma increased by 59% after 3 h of exposure in the non...... aortic catheter. By measuring both Cu-64 accumulation and total Cu concentrations, we were able to analyse the ongoing uptake and turnover of ambient Cu, independent of any Cu already present in the fish. Plasma accounted for at least 90% of the Cu-64 labelled Cu present in the blood and Cu...... h of exposure. Acclimation did not have an unambiguous effect on branchial Cu uptake and differences in branchial uptake could not explain the reduced accumulation in the plasma. The rapidly exchangeable Cu pools were 54% in the gills and 33% in the liver, suggesting a considerable hepatic Cu...

  1. Bimetallic AgCu/Cu2O hybrid for the synergetic adsorption of iodide from solution.

    Science.gov (United States)

    Mao, Ping; Liu, Ying; Liu, Xiaodong; Wang, Yuechan; Liang, Jie; Zhou, Qihang; Dai, Yuexuan; Jiao, Yan; Chen, Shouwen; Yang, Yi

    2017-08-01

    To further improve the capacity of Cu 2 O to absorb I - anions from solution, and to understand the difference between the adsorption mechanisms of Ag/Cu 2 O and Cu/Cu 2 O adsorbents, bimetallic AgCu was doped into Cu 2 O through a facile solvothermal route. Samples were characterized and employed to adsorb I - anions under different experimental conditions. The results show that the Cu content can be tuned by adding different volumes of Ag sols. After doping bimetallic AgCu, the adsorption capacity of the samples can be increased from 0.02 mmol g -1 to 0.52 mmol g -1 . Moreover, the optimal adsorption is reached within only 240 min. Meanwhile, the difference between the adsorption mechanisms of Ag/Cu 2 O and Cu/Cu 2 O adsorbents was verified, and the cooperative adsorption mechanism of the AgCu/Cu 2 O hybrid was proposed and verified. In addition, the AgCu/Cu 2 O hybrid showed excellent selectivity, e.g., its adsorption efficiencies are 85.1%, 81.9%, 85.9% and 85.7% in the presence of the Cl - , CO 3 2- , SO 4 2- and NO 3 - competitive anions, respectively. Furthermore, the AgCu/Cu 2 O hybrid can worked well in other harsh environments (e.g., acidic, alkaline and seawater environments). Therefore, this study is expected to promote the development of Cu 2 O into a highly efficient adsorbent for the removal of iodide from solution. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Crystallization and electrical resistivity of Cu2O and CuO obtained by thermal oxidation of Cu thin films on SiO2/Si substrates

    International Nuclear Information System (INIS)

    De Los Santos Valladares, L.; Salinas, D. Hurtado; Dominguez, A. Bustamante; Najarro, D. Acosta; Khondaker, S.I.; Mitrelias, T.; Barnes, C.H.W.; Aguiar, J. Albino; Majima, Y.

    2012-01-01

    In this work, we study the crystallization and electrical resistivity of the formed oxides in a Cu/SiO 2 /Si thin film after thermal oxidation by ex-situ annealing at different temperatures up to 1000 °C. Upon increasing the annealing temperature, from the X ray diffractogram the phase evolution CuCu + Cu 2 O → Cu 2 O → Cu 2 O + CuO → CuO was detected. Pure Cu 2 O films are obtained at 200 °C, whereas uniform CuO films without structural surface defects such as terraces, kinks, porosity or cracks are obtained in the temperature range 300–550 °C. In both oxides, crystallization improves with annealing temperature. A resistivity phase diagram, which is obtained from the current–voltage response, is presented here. The resistivity was expected to increase linearly as a function of the annealing temperature due to evolution of oxides. However, anomalous decreases are observed at different temperatures ranges, this may be related to the improvement of the crystallization and crystallite size when the temperature increases. - Highlights: ► The crystallization and electrical resistivity of oxides in a Cu films are studied. ► In annealing Cu films, the phase evolution Cu + Cu 2 O → Cu 2 O → Cu 2 O + CuO → CuO occurs. ► A resistivity phase diagram, obtained from the current–voltage response, is presented. ► Some decreases in the resistivity may be related to the crystallization.

  3. Effects of plasma cleaning of the Cu seed layer surface on Cu electroplating

    International Nuclear Information System (INIS)

    O, Jun Hwan; Lee, Seong Wook; Kim, Jae Bum; Lee, Chong Mu

    2001-01-01

    Effects of plasma pretreatment to Cu seed/tantalum nitride (TaN)/ borophosphosilicate glass (BPSG) samples on copper (Cu) electroplating were investigated. Copper seed layers were deposited by magnetron sputtering onto tantalum nitride barrier layers before electroplating copper in the forward pulsed mode. The Cu seed layer was cleaned by plasma H 2 and N 2 prior to electroplating a copper film. Cu films electroplated on the copper seed layer with plasma pretreatment showed better electrical and physical properties such as electrical resistivities, surface morphologies, levels of impurities, adhesion and surface roughness than those without plasma pretreatment. It is shown that carbon and metal oxide contaminants at the sputtered Cu seed/TaN surface could be effectively removed by plasma H 2 cleaning. The degree of the (111) prefered orientation of the Cu film with plasma H 2 pretreatment is as high as pulse plated Cu film without plasma pretreatment. Also, plasma H 2 precleaning is more effective in enhancing the Cu electroplating properties onto the Cu seed layer than plasma N 2 precleaning

  4. Approaching the limit of Cu(II)/Cu(I) mixed valency in a Cu(I)Br2-N-methylquinoxalinium hybrid compound.

    Science.gov (United States)

    Leblanc, Nicolas; Sproules, Stephen; Pasquier, Claude; Auban-Senzier, Pascale; Raffy, Helene; Powell, Annie K

    2015-08-18

    A novel 1D hybrid salt (MQ)[CuBr2]∞ (MQ = N-methylquinoxalinium) is reported. Structural, spectroscopic and magnetic investigations reveal a minimal Cu(II) doping of less than 0.1%. However it is not possible to distinguish Cu(I) and Cu(II). The unusually close packing of the organic moieties and the dark brown colour of the crystals suggest a defect electronic structure.

  5. Nucleation and Growth of Cu-Al Intermetallics in Al-Modified Sn-Cu and Sn-Ag-Cu Lead-Free Solder Alloys

    Science.gov (United States)

    Reeve, Kathlene N.; Anderson, Iver E.; Handwerker, Carol A.

    2015-03-01

    Lead-free solder alloys Sn-Cu (SC) and Sn-Ag-Cu (SAC) are widely used by the microelectronics industry, but enhanced control of the microstructure is needed to improve solder performance. For such control, nucleation and stability of Cu-Al intermetallic compound (IMC) solidification catalysts were investigated by variation of the Cu (0.7-3.0 wt.%) and Al (0.0-0.4 wt.%) content of SC + Al and SAC + Al alloys, and of SAC + Al ball-grid array (BGA) solder joints. All of the Al-modified alloys produced Cu-Al IMC particles with different morphologies and phases (occasionally non-equilibrium phases). A trend of increasing Cu-Al IMC volume fraction with increasing Al content was established. Because of solidification of non-equilibrium phases in wire alloy structures, differential scanning calorimetry (DSC) experiments revealed delayed, non-equilibrium melting at high temperatures related to quenched-in Cu-Al phases; a final liquidus of 960-1200°C was recorded. During cooling from 1200°C, the DSC samples had the solidification behavior expected from thermodynamic equilibrium calculations. Solidification of the ternary alloys commenced with formation of ternary β and Cu-Al δ phases at 450-550°C; this was followed by β-Sn, and, finally, Cu6Sn5 and Cu-Al γ1. Because of the presence of the retained, high-temperature phases in the alloys, particle size and volume fraction of the room temperature Cu-Al IMC phases were observed to increase when the alloy casting temperature was reduced from 1200°C to 800°C, even though both temperatures are above the calculated liquidus temperature of the alloys. Preliminary electron backscatter diffraction results seemed to show Sn grain refinement in the SAC + Al BGA alloy.

  6. High-temperature stability of Au/Pd/Cu and Au/Pd(P)/Cu surface finishes

    Science.gov (United States)

    Ho, C. E.; Hsieh, W. Z.; Lee, P. T.; Huang, Y. H.; Kuo, T. T.

    2018-03-01

    Thermal reliability of Au/Pd/Cu and Au/Pd(4-6 wt.% P)/Cu trilayers in the isothermal annealing at 180 °C were investigated by X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (TOF-SIMS), and transmission electron microscopy (TEM). The pure Pd film possessed a nanocrystalline structure with numerous grain boundaries, thereby facilitating the interdiffusion between Au and Cu. Out-diffusion of Cu through Pd and Au grain boundaries yielded a significant amount of Cu oxides (CuO and Cu2O) over the Au surface and gave rise to void formation in the Cu film. By contrast, the Pd(P) film was amorphous and served as a good diffusion barrier against Cu diffusion. The results of this study indicated that amorphous Pd(P) possessed better oxidation resistance and thermal reliability than crystalline Pd.

  7. Computer simulation of the structure of liquid metal halides RbBr, CuCl, CuBr, CuI, and AgBr

    International Nuclear Information System (INIS)

    Belashchenko, D.K.; Ostrovskij, O.I.

    2003-01-01

    The computerized models of the RbBr, AgBr, CuCl, CuBr and CuI liquid ion systems of 498 ions dimension are simulated at the temperatures of 753-960 K on the basis of the known diffraction data through the BELION algorithm. Good agreement of diffraction and model partial pair correlation functions (PPCF), excluding the PPCF first peaks heights, is obtained in all the cases. The simulation is carried out by the varied ion charges (the atomization energy values, close to the real ones, are obtained by ion charges ±1.00 for the RbBr, ±1.15 for AgBr, ±1.20 for CuCl, ±1.48 for CuBr and ±1.367 for CuI). The noncoulomb contributions in the interparticle potentials are calculated [ru

  8. Species dependence of [64Cu]Cu-Bis(thiosemicarbazone) radiopharmaceutical binding to serum albumins

    International Nuclear Information System (INIS)

    Basken, Nathan E.; Mathias, Carla J.; Lipka, Alexander E.; Green, Mark A.

    2008-01-01

    Introduction: Interactions of three copper(II) bis(thiosemicarbazone) positron emission tomography radiopharmaceuticals with human serum albumin, and the serum albumins of four additional mammalian species, were evaluated. Methods: 64 Cu-labeled diacetyl bis(N 4 -methylthiosemicarbazonato)copper(II) (Cu-ATSM), pyruvaldehyde bis(N 4 -methylthiosemicarbazonato)copper(II) (Cu-PTSM) and ethylglyoxal bis(thiosemicarbazonato)copper(II) (Cu-ETS) were synthesized and their binding to human, canine, rat, baboon and porcine serum albumins quantified by ultrafiltration. Protein binding was also measured for each tracer in human, porcine, rat and mouse serum. Results: The interaction of these neutral, lipophilic copper chelates with serum albumin is highly compound- and species-dependent. Cu-PTSM and Cu-ATSM exhibit particularly high affinity for human serum albumin (HSA), while the albumin binding of Cu-ETS is relatively insensitive to species. At HSA concentrations of 40 mg/ml, '% free' (non-albumin-bound) levels of radiopharmaceutical were 4.0±0.1%, 5.3±0.2% and 38.6±0.8% for Cu-PTSM, Cu-ATSM and Cu-ETS, respectively. Conclusions: Species-dependent variations in radiopharmaceutical binding to serum albumin may need to be considered when using animal models to predict the distribution and kinetics of these compounds in humans

  9. Cu and Cu2O films with semi-spherical particles grown by electrochemical deposition

    International Nuclear Information System (INIS)

    Zheng, Jin You; Jadhav, Abhijit P.; Song, Guang; Kim, Chang Woo; Kang, Young Soo

    2012-01-01

    Cu and Cu 2 O films can be prepared on indium-doped tin oxide glass substrates by simple electrodeposition in a solution containing 0.1 M Cu(NO 3 ) 2 and 3 M lactic acid at different pH values. At low pH (pH = 1.2), the uniform Cu films were obtained; when pH ≥ 7, the pure Cu 2 O films can be deposited. Especially, at pH = 11, the deposited Cu 2 O films exhibited cubic surface morphology exposing mainly {100} plane; in contrast, the films consisting of semi-spherical particles were obtained when the solution was being stirred for 2 weeks prior to use. The possible growth process and mechanism were comparatively discussed. - Highlights: ► Cu and Cu 2 O films were prepared by facile electrodeposition. ► Electrodeposition was preformed in electrolyte at different pH values. ► Dendritic Cu films were obtained at 1.2 pH with relatively high deposition potential. ► Semi-spherical Cu 2 O films were obtained with solution at 11 pH and stirred for 2 weeks. ► The possible growth mechanism of semi-spherical Cu 2 O films was discussed.

  10. The activation energy for loop growth in Cu and Cu-Ni alloys

    International Nuclear Information System (INIS)

    Barlow, P.; Leffers, T.; Singh, B.N.

    1978-08-01

    The apparent activation energy for the growth of interstitial dislocation loops in copper, Cu-1%Ni, Cu-2%Ni, and Cu-5%Ni during high voltage electron microscope irradiation was determined. The apparent activation energy for loop growth in all these materials can be taken to be 0.34eV+-0.02eV. This value together with the corresponding value of 0.44eV+-0.02eV determined earlier for Cu-10%Ni is discussed with reference to the void growth rates observed in these materials. The apparent activation energy for loop growth in copper (and in Cu-1%Ni that has a void growth rate similar to that in pure copper) is interpreted as twice the vacancy migration energy (indicating that divacancies do not play any significant role). For the materials with higher Ni content (in which the void growth rate is much lower than that in Cu and Cu-1%Ni) the measured apparent activation energy is interpreted to be characteristic of loops positioned fairly close to the foil surface and not of loops in ''bulk material''. From the present results in combination with the earlier results for Cu-10%Ni it is concluded that interstitial trapping is the most likely explanation of the reduced void growth rate in Cu-Ni alloys. (author)

  11. Giant Cu 2p Resonances in CuO Valence-Band Photoemission

    NARCIS (Netherlands)

    Tjeng, L.H.; Chen, C.T.; Ghijsen, J.; Rudolf, P.; Sette, F.

    1991-01-01

    We report the observation of a giant resonance in the Cu 2p resonant-photoemission spectra of CuO. The study allows the unambiguous identification of the local Cu 3d8 configuration in the valence-band photoemission spectrum, providing conclusive evidence for the charge-transfer nature of the

  12. Diffusion of Cu+ in β-phase CuI

    International Nuclear Information System (INIS)

    Johansson, J.X.M.Z.; Skoeld, K.; Joergensen, J.E.

    1992-01-01

    Measurements of ionic diffusion of Cu + in solid CuI in the β-phase is carried out with a non-destructive radioactive tracer technique, utilizing coincidence counting of the annihilation gammas from the positron decay of 64 Cu. The diffusion coefficient and the activation energy for the diffusion are evaluated. The experimental results show distinct diffusion character in the β-phase which differs from those in the γ- and α-phases. The β-phase diffusion properties together with the previous results for γ-and α-phases will provide valuable guidance for MD calculations, in which the diffusion coefficients and activation energies have been overestimated and the γ-β phase transition does not appear. The ionic conductivity of CuI estimated from tracer diffusion results and the Nernst-Einstein relation are compared with values from electro-chemical methods. In all three phases the conductivities obtained from electro-chemical methods are much lower than those calculated from the measured tracer diffusion coefficients. (author). 7 refs.; 4 figs.; 2 tabs

  13. Soil solution dynamics of Cu and Zn in a Cu- and Zn-polluted soil as influenced by gamma-irradiation and Cu-Zn interaction.

    Science.gov (United States)

    Luo, Y M; Yan, W D; Christie, P

    2001-01-01

    A pot experiment was conducted to study soil solution dynamics of Cu and Zn in a Cu/Zn-polluted soil as influenced by gamma-irradiation and Cu-Zn interaction. A slightly acid sandy loam was amended with Cu and Zn (as nitrates) either singly or in combination (100 mg Cu and 150 mg Zn kg(-1) soil) and was then gamma-irradiated (10 kGy). Unamended and unirradiated controls were included, and spring barley (Hordeum vulgare L. cv. Forrester) was grown for 50 days. Soil solution samples obtained using soil moisture samplers immediately before transplantation and every ten days thereafter were used directly for determination of Cu, Zn, pH and absorbance at 360 nm (A360). Cu and Zn concentrations in the solution of metal-polluted soil changed with time and were affected by gamma-irradiation and metal interaction. gamma-Irradiation raised soil solution Cu substantially but generally decreased soil solution Zn. These trends were consistent with increased dissolved organic matter (A360) and solution pH after gamma-irradiation. Combined addition of Cu and Zn usually gave higher soil solution concentrations of Cu or Zn compared with single addition of Cu or Zn in gamma-irradiated and non-irradiated soils, indicating an interaction between Cu and Zn. Cu would have been organically complexed and consequently maintained a relatively high concentration in the soil solution under higher pH conditions. Zn tends to occur mainly as free ion forms in the soil solution and is therefore sensitive to changes in pH. The extent to which gamma-irradiation and metal interaction affected solubility and bioavailability of Cu and Zn was a function of time during plant growth. Studies on soil solution metal dynamics provide very useful information for understanding metal mobility and bioavailability.

  14. Spin dynamics in CuO and Cu[sub 1[minus][ital x

    Energy Technology Data Exchange (ETDEWEB)

    Carretta, P.; Corti, M.; Rigamonti, A. (Department of Physics Alessandro Volta,' ' University of Pavia, Via Bassi 6, 27100 Pavia (Italy))

    1993-08-01

    [sup 63]Cu nuclear quadrupole resonance (NQR), nuclear antiferromagnetic resonance (AFNMR), and spin-lattice relaxation, as well as [sup 7]Li NMR and relaxation measurements in CuO and in Cu[sub 1[minus][ital x

  15. Novel CuCr_2O_4 embedded CuO nanocomposites for efficient photodegradation of organic dyes

    International Nuclear Information System (INIS)

    Mageshwari, K.; Sathyamoorthy, R.; Lee, Jeong Yong; Park, Jinsub

    2015-01-01

    Graphical abstract: - Highlights: • Novel CuO–CuCr_2O_4 nanocomposites synthesized by reflux condensation method. • Methyl orange and methylene blue dye degradation studied under UV light irradiation. • Nanocomposites characterized by XRD, FESEM, TEM, EDX, UV–vis DRS and PL. • CuCr_2O_4 loading effectively enhanced the catalytic activity of CuO. - Abstract: Novel photocatalyst based on CuO–CuCr_2O_4 nanocomposites was synthesized for different Cr"3"+ concentration by reflux condensation method, and their photocatalytic activity was evaluated by monitoring the photodegradation of methyl orange (MO) and methylene blue dyes (MB) under UV light irradiation. Phase evolution by X-ray diffraction showed monoclinic CuO and tetragonal CuCr_2O_4 as the components of the prepared nanocomposites. Morphological analysis by scanning electron microscope and transmission electron microscope revealed that the incorporation of Cr"3"+ in CuO lattice alters the morphology of CuO from microsphere to cluster shape. Photoluminescence spectra of CuO–CuCr_2O_4 nanocomposites exhibited reduced PL emissions compared to pure CuO, indicating the low recombination rate of photogenerated electrons and holes. As expected, the CuCr_2O_4 loaded CuO showed enhanced photocatalytic activity for MO and MB dyes, and the kinetic studies suggest that the degradation follows pseudo-first-order kinetics. The enhanced photocatalytic activity of CuO–CuCr_2O_4 nanocomposites can be attributed to the presence of CuCr_2O_4 as an electron acceptor, which improves the effective charge separation in CuO.

  16. Fabrication of Cu-riched W–Cu composites by combustion synthesis and melt-infiltration in ultrahigh-gravity field

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Pei [Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100039 (China); Guo, Shibin; Liu, Guanghua; Chen, Yixiang [Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Li, Jiangtao, E-mail: ljt0012@vip.sina.com [Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190 (China)

    2013-10-15

    Unadulterated Cu-riched W–Cu composites of W27–Cu73, W34–Cu66, W40–Cu60, W49–Cu51 and W56–Cu44 have been prepared by a novel method called combustion synthesis and melt-infiltration in ultrahigh-gravity field, of which W27–Cu73 and W34–Cu66 showed good ductility and W40–Cu60, W49–Cu51 and W56–Cu44 were brittle. In this technique, Cu melt accompanied with a great amount of heat was produced by thermit reaction and infiltrated into W–Cu powder bed. When the powder bed was Cu-riched powder bed such as W50–Cu50 or W60–Cu40, Cu melt would go through the powder bed, reach the bottom of the graphite crucible and then form a heat dissipation channel. Thus the cooling rate was so fast that the product was mixed up with impurity. The problem can be solved by putting some W powders under W50–Cu50 or W60–Cu40 powder bed to prevent the formation of heat dissipation channel.

  17. Properties of the CuGaSe2 and CuInSe2 (001) surface

    International Nuclear Information System (INIS)

    Deniozou, T.

    2005-01-01

    The main task of this work was to investigate the (001) CuGaSe 2 and CuInSe 2 surface in dependence of preparation and stoichiometry. The knowledge of the atomic structure as well as other surface properties is important in respect to optimization of novel thin film solar cells. For the characterization of the layers mainly Auger electron Spectroscopy, low-energy electron diffraction and photoelectron spectroscopy were implemented. The development of an appropriate procedure with Ar + sputtering and annealing combined with decapping enabled the preparation of clean and well-ordered surfaces. Different surface structures were observed in dependence of the layer preparation and composition. A (4 x 1) reconstruction was observed for the first time on CuGaSe 2 layers grown with a moderate Cu-excess after preparation by sputtering and annealing. Similarly a (4 x 2) reconstruction was detected on CuInSe2 surfaces of Cu-poor layers. A reconstruction could be also observed on Cu-poorer layers, however the facets/steps could not be completely removed. Cu-richer layers were facet-free, however the observed reconstruction was also weaker. Thus it was shown that in contrary to recent expectations, according to which only the (112) surface is stable, also the (001) can be stable under particular conditions. The appearance of facets or steps is correlated with the presence of CuIn 3 Se 5 or CuGa 3 Se 5 phases. This information is furthermore important for the understanding of grain boundaries in polycrystalline CuGaSe 2 and CuInSe 2 . Binding energy shifts were observed for the first time on all Se3d, In4d, Ga3d, Cu3d core levels of the reconstructed surfaces. By comparison with results from the literature from the similar ZnSe (100) surface a modell for the (4 x 2) reconstruction was proposed. The surface components in the Se3d, In4d and Cu3d emission were attributed to Se dimers or In and Cu adatoms respectively. The x 1 periodicity of the (4 x 1) reconstruction of CuGaSe 2 is

  18. Facile synthesis of dendritic Cu by electroless reaction of Cu-Al alloys in multiphase solution

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Ying; Liang, Shuhua, E-mail: liangxaut@gmail.com; Yang, Qing; Wang, Xianhui

    2016-11-30

    Highlights: • Nano- or micro-scale fractal dendritic copper (FDC) was synthesized by electroless immersing of Cu-Al alloys in CuCl{sub 2} + HCl. • FDC size increases with the increase of Al content in Cu-Al alloys immersed in CuCl{sub 2} + HCl solution. • Nanoscale Cu{sub 2}O was found at the edge of FDC. Nanoporous copper (NPC) can also be obtained by using Cu{sub 17}Al{sub 83} alloy. • The potential difference between CuAl{sub 2} and α-Al phase and the replacement reaction in multiphase solution are key factors. - Abstract: Two-dimensional nano- or micro-scale fractal dendritic coppers (FDCs) were synthesized by electroless immersing of Cu-Al alloys in hydrochloric acid solution containing copper chloride without any assistance of template or surfactant. The FDC size increases with the increase of Al content in Cu-Al alloys immersed in CuCl{sub 2} + HCl solution. Compared to Cu{sub 40}Al{sub 60} and Cu{sub 45}Al{sub 55} alloys, the FDC shows hierarchical distribution and homogeneous structures using Cu{sub 17}Al{sub 83} alloy as the starting alloy. The growth direction of the FDC is <110>, and all angles between the trunks and branches are 60°. Nanoscale Cu{sub 2}O was found at the edge of FDC. Interestingly, nanoporous copper (NPC) can also be obtained through Cu{sub 17}Al{sub 83} alloy. Studies showed that the formation of FDC depended on two key factors: the potential difference between CuAl{sub 2} intermetallic and α-Al phase of dual-phase Cu-Al alloys; a replacement reaction that usually occurs in multiphase solution. The electrochemical experiment further proved that the multi-branch dendritic structure is very beneficial to the proton transfer in the process of catalyzing methanol.

  19. Separations on a cellulose exchanger with salicylic acid as functional group. [Fe/sup 3//sup+//Cu/sup 2//sup+/, Cu/sup 2//sup+//Ni/sup 2//sup+//, and Cu/sup 2//sup+//Cu complex separations

    Energy Technology Data Exchange (ETDEWEB)

    Burba, P; Lieser, K H [Technische Hochschule Darmstadt (F.R. Germany). Fachbereich Anorganische Chemie und Kernchemie

    1976-07-01

    The use of a cellulose compound containing salicylic acid as functional group (capacity 0.6 mequ./g) for different problems is described. The seperations Fe/sup 3 +//Cu/sup 2 +/ and Cu/sup 2 +//Ni/sup 2 +/ in aqueous solutions are achieved smoothly at pH 2 and 2.5 resp. In organic solvents (pyridine) copper ions are separated from copper complexes as shown by the examples Cu/sup 2 +//(Cu(mnt)/sub 2/)/sup 2 -/ (mnt = maleonitril-1,2-dithiolate) and Cu/sup 2 +//dibenzo(b.i.)(5.9.14.18)tetraazacyclotetradecene-copper (Cu(chel)). The complex (Cu(mnt)/sub 2/)/sup 2 -/ can be labelled with Cu-64 on a separation column, whereas (Cu-(chel)) is substition inert.

  20. Laser Photolytic Approach to Cu/polymer Sols and Cu/polymer Nanocomposites with Amorphous Cu Phase.

    Czech Academy of Sciences Publication Activity Database

    Pola, Josef; Ouchi, A.; Bakardjieva, Snejana; Urbanová, Markéta; Boháček, Jaroslav; Šubrt, Jan

    2007-01-01

    Roč. 192, 2-3 (2007) , s. 84-92 ISSN 1010-6030 Institutional research plan: CEZ:AV0Z40720504; CEZ:AV0Z40320502 Keywords : Cu-polymer nanocomposite * laser solution photolysis * amorphous Cu phase Subject RIV: CH - Nuclear ; Quantum Chemistry Impact factor: 1.911, year: 2007

  1. Synthesis, Characterization and Catalytic Activity of Cu/Cu2O Nanoparticles Prepared in Aqueous Medium

    Directory of Open Access Journals (Sweden)

    Sayed M. Badawy

    2015-07-01

    Full Text Available Copper/Copper oxide (Cu/Cu2O nanoparticles were synthesized by modified chemical reduction method in an aqueous medium using hydrazine as reducing agent and copper sulfate pentahydrate as precursor. The Cu/Cu2O nanoparticles were characterized by X-ray Diffraction (XRD, Energy Dispersive X-ray Fluorescence (EDXRF, Scanning Electron Microscope (SEM, and Transmission Electron Microscope (TEM. The analysis revealed the pattern of face-centered cubic (fcc crystal structure of copper Cu metal and cubic cuprites structure for Cu2O. The SEM result showed monodispersed and agglomerated particles with two micron sizes of about 180 nm and 800 nm, respectively. The TEM result showed few single crystal particles of face-centered cubic structures with average particle size about 11-14 nm. The catalytic activity of Cu/Cu2O nanoparticles for the decomposition of hydrogen peroxide was investigated and compared with manganese oxide MnO2. The results showed that the second-order equation provides the best correlation for the catalytic decomposition of H2O2 on Cu/Cu2O. The catalytic activity of hydrogen peroxide by Cu/Cu2O is less than the catalytic activity of MnO2 due to the presence of copper metal Cu with cuprous oxide Cu2O. © 2015 BCREC UNDIP. All rights reservedReceived: 6th January 2015; Revised: 14th March 2015; Accepted: 15th March 2015How to Cite: Badawy, S.M., El-Khashab, R.A., Nayl, A.A. (2015. Synthesis, Characterization and Catalytic Activity of Cu/Cu2O Nanoparticles Prepared in Aqueous Medium. Bulletin of Chemical Reaction Engineering & Catalysis, 10 (2: 169-174. (doi:10.9767/bcrec.10.2.7984.169-174 Permalink/DOI: http://dx.doi.org/10.9767/bcrec.10.2.7984.169-174  

  2. Synthesis of Cu2O from CuO thin films: Optical and electrical properties

    Directory of Open Access Journals (Sweden)

    Dhanya S. Murali

    2015-04-01

    Full Text Available Hole conducting, optically transparent Cu2O thin films on glass substrates have been synthesized by vacuum annealing (5×10−6 mbar at 700 K for 1 hour of magnetron sputtered (at 300 K CuO thin films. The Cu2O thin films are p-type and show enhanced properties: grain size (54.7 nm, optical transmission 72% (at 600 nm and Hall mobility 51 cm2/Vs. The bulk and surface Valence band spectra of Cu2O and CuO thin films are studied by temperature dependent Hall effect and Ultra violet photo electron Spectroscopy (UPS. CuO thin films show a significant band bending downwards (due to higher hole concentration than Cu2O thin films.

  3. Direct synthesis of RGO/Cu{sub 2}O composite films on Cu foil for supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Xiangmao; Wang, Kun [Key Laboratory for Ultrafine Materials of the Ministry of Education, Shanghai Key Laboratory of Advanced Polymeric Materials, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China); Zhao, Chongjun, E-mail: chongjunzhao@ecust.edu.cn [Key Laboratory for Ultrafine Materials of the Ministry of Education, Shanghai Key Laboratory of Advanced Polymeric Materials, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China); Institute for Superconducting and Electronic Materials, University of Wollongong, Wollongong 2500 (Australia); Qian, Xiuzhen [Key Laboratory for Ultrafine Materials of the Ministry of Education, Shanghai Key Laboratory of Advanced Polymeric Materials, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China); Chen, Shi [School of Information Engineering, Wuhan University of Technology, Wuhan 430070 (China); Li, Zhen, E-mail: zhenl@uow.edu.au [Institute for Superconducting and Electronic Materials, University of Wollongong, Wollongong 2500 (Australia); Liu, Huakun; Dou, Shixue [Institute for Superconducting and Electronic Materials, University of Wollongong, Wollongong 2500 (Australia)

    2014-02-15

    Graphical abstract: RGO/Cu{sub 2}O/Cu composites were synthesized by simple hydrothermal treatment of copper foils with graphene oxide, in which the reduction of graphene oxide and the formation of Cu{sub 2}O nanoparticles simultaneously happened in one-pot reaction. These composites can be directly used as electrodes of supercapacitors with the highest specific capacitance of 98.5 F/g at 1 A g{sup −1}, which is much better than that of CuO or Cu{sub 2}O electrodes. -- Highlights: • The RGO/Cu{sub 2}O/Cu composites were obtained by a friendly method in one step. • Improved capacitance performance is realized by the hydrothermal treatment of graphene oxides with Cu foils. • RGO/Cu{sub 2}O/Cu-200 composites exhibit the largest specific capacitance of 98.5 F g{sup −1} at 1 A g{sup −1}. -- Abstract: Reduced graphene oxide/cuprous oxide (RGO/Cu{sub 2}O) composite films were directly synthesized on the surface of copper foil substrates through a straight redox reaction between GO and Cu foil via a hydrothermal approach. Characterization of the resultant composites with X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, and field emission scanning electron microscope (FESEM) confirms the formation of Cu{sub 2}O and reduction of GO, in which Cu{sub 2}O nanoparticles were well covered by RGO. The resultant composites (referred to as RGO/Cu{sub 2}O/Cu) were directly used as electrodes for supercapacitors, and their electrochemical performance was assessed by cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectrometry (EIS) in 1 M KOH aqueous solution. A specific capacitance of 98.5 F g{sup −1} at 1 A g{sup −1} was obtained, which is much higher than that of pure Cu{sub 2}O prepared under the same conditions, due to the presence of RGO.

  4. Species dependence of [{sup 64}Cu]Cu-Bis(thiosemicarbazone) radiopharmaceutical binding to serum albumins

    Energy Technology Data Exchange (ETDEWEB)

    Basken, Nathan E. [Division of Nuclear Pharmacy, Department of Industrial and Physical Pharmacy, Purdue University, West Lafayette, IN 47907 (United States)], E-mail: nbasken@purdue.edu; Mathias, Carla J. [Division of Nuclear Pharmacy, Department of Industrial and Physical Pharmacy, Purdue University, West Lafayette, IN 47907 (United States); Lipka, Alexander E. [Department of Statistics, Purdue University, West Lafayette, IN 47907 (United States); Green, Mark A. [Division of Nuclear Pharmacy, Department of Industrial and Physical Pharmacy, Purdue University, West Lafayette, IN 47907 (United States)], E-mail: magreen@purdue.edu

    2008-04-15

    Introduction: Interactions of three copper(II) bis(thiosemicarbazone) positron emission tomography radiopharmaceuticals with human serum albumin, and the serum albumins of four additional mammalian species, were evaluated. Methods: {sup 64}Cu-labeled diacetyl bis(N{sup 4}-methylthiosemicarbazonato)copper(II) (Cu-ATSM), pyruvaldehyde bis(N{sup 4}-methylthiosemicarbazonato)copper(II) (Cu-PTSM) and ethylglyoxal bis(thiosemicarbazonato)copper(II) (Cu-ETS) were synthesized and their binding to human, canine, rat, baboon and porcine serum albumins quantified by ultrafiltration. Protein binding was also measured for each tracer in human, porcine, rat and mouse serum. Results: The interaction of these neutral, lipophilic copper chelates with serum albumin is highly compound- and species-dependent. Cu-PTSM and Cu-ATSM exhibit particularly high affinity for human serum albumin (HSA), while the albumin binding of Cu-ETS is relatively insensitive to species. At HSA concentrations of 40 mg/ml, '% free' (non-albumin-bound) levels of radiopharmaceutical were 4.0{+-}0.1%, 5.3{+-}0.2% and 38.6{+-}0.8% for Cu-PTSM, Cu-ATSM and Cu-ETS, respectively. Conclusions: Species-dependent variations in radiopharmaceutical binding to serum albumin may need to be considered when using animal models to predict the distribution and kinetics of these compounds in humans.

  5. Operations and Performance of RHIC as a Cu-Cu Collider

    CERN Document Server

    Pilat, Fulvia Caterina; Bai, Mei; Barton, Donald; Beebe-Wang, Joanne; Blaskiewicz, Michael; Brennan, Joseph M; Bruno, Donald; Cameron, Peter; Connolly, Roger; De Long, Joseph; Drees, Angelika; Fischer, Wolfram; Ganetis, George; Gardner, Chris J; Glenn, Joseph; Harvey, Margaret; Hayes, Thomas; Hseuh Hsiao Chaun; Huang, Haixin; Ingrassia, Peter; Iriso, Ubaldo; Lee, Roger C; Litvinenko, Vladimir N; Luo, Yun; MacKay, William W; Marr, Gregory J; Marusic, Al; Michnoff, Robert; Montag, Christoph; Morris, John; Nicoletti, Tony; Oerter, Brian; Ptitsyn, Vadim; Roser, Thomas; Russo, Thomas; Sandberg, Jon; Satogata, Todd; Schultheiss, Carl; Tepikian, Steven; Tomas, Rogelio; Trbojevic, Dejan; Tsoupas, Nicholaos; Tuozzolo, Joseph; Vetter, Kurt; Zaltsman, Alex; Zeno, Keith; Zhang, S Y; Zhang, Wu

    2005-01-01

    The 5th year of RHIC operations, started in November 2004 and expected to last till June 2005, consists of a physics run with Cu-Cu collisions at 100 GeV/u followed by one with polarized protons at 100 GeV. We will address here overall performance of the RHIC complex used for the first time as a Cu-Cu collider, and compare it with previous operational experience with Au, PP and asymmetric d-Au collisions. We will also discuss operational improvements, such as a ?* squeeze to 85cm in the high luminosity interaction regions from the design value of 1m, system improvements and machine performance limitations, such as vacuum pressure rise, intra-beam scattering, and beam beam interaction.

  6. Effect of Cu Salt Molarity on the Nanostructure of CuO Prolate Spheroid

    Science.gov (United States)

    Sabeeh, Sabah H.; Hussein, Hashim Abed; Judran, Hadia Kadhim

    Copper sulfate pentahydrate was used as a source of Cu ion with five different molarities (0.02, 0.05, 0.1, 0.15, 2 and 0.25M). XRD, FE-SEM and TEM techniques all showed that CuO samples have polycrystalline monoclinic structure. CuO prolate spheroid is assembled from nanoparticles as building units. It was demonstrated that the purity, morphology, size range of prolate spheroid and density of nano building units are significantly influenced by Cu precursor’s molarity. The pure phase of CuO prolate spheroid was produced via molarity of 0.2M with crystallite size of 15.1565nm while the particle size of building units ranges from 16nm to 21nm. The stability of CuO nanosuspension or nanofluid was evaluated by zeta potential analysis. The obtained properties of specific structure with large surface area of CuO prolate spheroid make it a promising candidate for wide range of potential applications as in nanofluids for cooling purposes.

  7. Synthesis of Cu Nanoparticles Using Copper Carbonate as Cu Source Toward Versatile Applications.

    Science.gov (United States)

    Yano, Kazuhisa; Ishizaki, Toshitaka; Sugiyama, Hidehiko

    2018-07-01

    Cu nanoparticles (NPs) coated with polyvinylpyrrolidone (PVP) were fabricated by polyol method using copper carbonate as a raw material. To increase the reaction temperature, glycol multimers such as diethylene glycol, triethylene glycol, or tetraethylene glycol were examined as a solvent. With increasing degree of multimerization, average diameter of Cu NPs decreased. The synthesis of Cu NPs was further investigated by changing reaction temperature, the amount and molecular weight of PVP in triethylene glycol as a solvent. Average diameter and standard deviation of Cu NPs were found to be highly dependent on those factors. As a result, fine Cu NPs ranging from 28 to 67 nm in average size with narrow size distribution (standard deviation: 16-28%) were obtained. The obtained Cu NPs were applied to a nanofluid, which showed higher thermal conductivity than the theoretical value. The antibacterial activity of Cu NPs was also demonstrated, and found to have strong antibacterial activity.

  8. Elastocaloric effect in CuAlZn and CuAlMn shape memory alloys under compression

    OpenAIRE

    Qian, Suxin; Geng, Yunlong; Wang, Yi; Pillsbury, Thomas E.; Hada, Yoshiharu; Yamaguchi, Yuki; Fujimoto, Kenjiro; Hwang, Yunho; Radermacher, Reinhard; Cui, Jun; Yuki, Yoji; Toyotake, Koutaro; Takeuchi, Ichiro

    2016-01-01

    This paper reports the elastocaloric effect of two Cu-based shape memory alloys: Cu68Al16Zn16 (CuAlZn) and Cu73Al15Mn12 (CuAlMn), under compression at ambient temperature. The compression tests were conducted at two different rates to approach isothermal and adiabatic conditions. Upon unloading at a strain rate of 0.1 s−1 (adiabatic condition) from 4% strain, the highest adiabatic temperature changes (ΔTad) of 4.0 K for CuAlZn and 3.9 K for CuAlMn were obtained. The maximum stress and hystere...

  9. Synthesis and photocatalytic activity of carbon spheres loaded Cu2O/Cu composites

    International Nuclear Information System (INIS)

    Li, Yinhui; Zhao, Mengyao; Zhang, Na; Li, Ruijuan; Chen, Jianxin

    2015-01-01

    Highlights: • Carbon spheres loaded Cu 2 O/Cu composites are obtained by hydrothermal process. • Cu 2 O/Cu nanocrystals grow on the surface of carbon spheres. • The composites with core–shell structure show highly photo-catalytic activity. • The composites can degrade methyl orange under simulated solar light irradiation. • The composites can be used to treat dye wastewater or organic pollutants. - Abstract: In this work, using amylose as carbon source and cupric acetate as copper source, carbon spheres loaded Cu 2 O/Cu composites were obtained by hydrothermal synthesis. The effects of the molar ratios between glucose and Cu(II), and hydrothermal time on the morphology and sizes of the composites were investigated. The result of photocatalytic experiments demonstrated that the composites could degrade methyl orange in aqueous solution under simulated solar light irradiation. The highest degradation rate was achieved to 93.83% when the composites were prepared by hydrothermal synthesis at 180 °C for 16 h and the molar ratio between glucose and Cu(II) was 10/1. The composites, as new and promising materials, can be used to treat dye wastewater or other organic pollutants

  10. Low-Temperature Cu-Cu Bonding Using Silver Nanoparticles Fabricated by Physical Vapor Deposition

    Science.gov (United States)

    Wu, Zijian; Cai, Jian; Wang, Junqiang; Geng, Zhiting; Wang, Qian

    2018-02-01

    Silver nanoparticles (Ag NPs) fabricated by physical vapor deposition (PVD) were introduced in Cu-Cu bonding as surface modification layer. The bonding structure consisted of a Ti adhesive/barrier layer and a Cu substrate layer was fabricated on the silicon wafer. Ag NPs were deposited on the Cu surface by magnetron sputtering in a high-pressure environment and a loose structure with NPs was obtained. Shear tests were performed after bonding, and the influences of PVD pressure, bonding pressure, bonding temperature and annealing time on shear strength were assessed. Cu-Cu bonding with Ag NPs was accomplished at 200°C for 3 min under the pressure of 30 MPa without a post-annealing process, and the average bonding strength of 13.99 MPa was reached. According to cross-sectional observations, a void-free bonding interface with an Ag film thickness of around 20 nm was achieved. These results demonstrated that a reliable low-temperature short-time Cu-Cu bonding was realized by the sintering process of Ag NPs between the bonding pairs, which indicated that this bonding method could be a potential candidate for future ultra-fine pitch 3D integration.

  11. Investigation of Cu-poor and Cu-rich Cu(In,Ga)Se{sub 2}/CdS interfaces using hard X-ray photoelectron spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Ümsür, B., E-mail: buenyamin.uemsuer@helmholtz-berlin.de [Helmholtz-Zentrum-Berlin, Hahn-Meitner-Platz 1, D-14109 Berlin (Germany); Calvet, W.; Höpfner, B.; Steigert, A.; Lauermann, I.; Gorgoi, M.; Prietzel, K.; Navirian, H.A.; Kaufmann, C.A.; Unold, T. [Helmholtz-Zentrum-Berlin, Hahn-Meitner-Platz 1, D-14109 Berlin (Germany); Lux-Steiner, M. Ch. [Helmholtz-Zentrum-Berlin, Hahn-Meitner-Platz 1, D-14109 Berlin (Germany); Freie Universität Berlin, Department of Physics, Arnimallee 14, D-14195 Berlin (Germany)

    2015-05-01

    Cu-poor and Cu-rich Cu(In,Ga)Se{sub 2} (CIGSe) absorbers were used as substrates for the chemical bath deposition of ultrathin CdS buffer layers in the thickness range of a few nanometers in order to make the CIGSe/CdS interface accessible by hard X-ray photo-emission spectroscopy. The composition of both, the absorber and the buffer layer as well as the energetics of the interface was investigated at room temperature and after heating the samples to elevated temperatures (200 °C, 300 °C and 400 °C). It was found that the amount of Cd after the heating treatment depends on the near surface composition of the CIGSe absorber. No Cd was detected on the Cu-poor surface after the 400 °C treatment due to its diffusion into the CIGSe layer. In contrast, Cd was still present on the Cu-rich surface after the same treatment at 400 °C. - Highlights: • Cd diffusion into Cu(In,Ga)Se{sub 2} (CIGSe) absorber is investigated. • Cu-poor and Cu-rich CIGSe samples are compared. • Cd diffusion into CIGSe is found to be dependent on the surface composition of CIGSe.

  12. Cu-Doping Effects in CdI(2) Nanocrystals: The Role of Cu-Agglomerates.

    Science.gov (United States)

    Miah, M Idrish

    2008-11-22

    Cu-doping effects in CdI(2) nanocrystals are studied experimentally. We use the photostimulated second harmonic generation (PSSHG) as a tool to investigate the effects. It is found that the PSSHG increases with increasing Cu content up to 0.6% and then decreases due to the formation of the Cu-agglomerates. The PSSHG for the crystal with Cu content higher than 1% reduces to that for the undoped CdI(2) crystal. The results suggest that a crucial role of the Cu-metallic agglomerates is involved in the processes as responsible for the observed effects.

  13. Cu-Doping Effects in CdI2Nanocrystals: The Role of Cu-Agglomerates

    Directory of Open Access Journals (Sweden)

    Miah M

    2008-01-01

    Full Text Available Abstract Cu-doping effects in CdI2nanocrystals are studied experimentally. We use the photostimulated second harmonic generation (PSSHG as a tool to investigate the effects. It is found that the PSSHG increases with increasing Cu content up to 0.6% and then decreases due to the formation of the Cu-agglomerates. The PSSHG for the crystal with Cu content higher than 1% reduces to that for the undoped CdI2crystal. The results suggest that a crucial role of the Cu-metallic agglomerates is involved in the processes as responsible for the observed effects.

  14. Crystallization and electrical resistivity of Cu{sub 2}O and CuO obtained by thermal oxidation of Cu thin films on SiO{sub 2}/Si substrates

    Energy Technology Data Exchange (ETDEWEB)

    De Los Santos Valladares, L., E-mail: ld301@cam.ac.uk [Cavendish Laboratory, University of Cambridge, J.J Thomson Av., Cambridge CB3 0HE (United Kingdom); Materials and Structures Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8503 (Japan); Departamento de Fisica, Universidade Federal de Pernambuco, 50670-901, Recife-Pe (Brazil); Salinas, D. Hurtado [Materials and Structures Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8503 (Japan); Laboratorio de Ceramicos y Nanomateriales, Facultad de Ciencias Fisicas, Universidad Nacional Mayor de San Marcos, Ap. Postal 14-0149, Lima (Peru); Dominguez, A. Bustamante [Laboratorio de Ceramicos y Nanomateriales, Facultad de Ciencias Fisicas, Universidad Nacional Mayor de San Marcos, Ap. Postal 14-0149, Lima (Peru); Najarro, D. Acosta [Instituto de Fisica, Departamento de Materia Condensada, Universidad Nacional Autonoma de Mexico, Ap. Postal 20-364, CP 01000 (Mexico); Khondaker, S.I. [NanoScience Technology Centre and Department of Physics, University of Central Florida, Orlando, FL 32826 (United States); Mitrelias, T.; Barnes, C.H.W. [Cavendish Laboratory, University of Cambridge, J.J Thomson Av., Cambridge CB3 0HE (United Kingdom); Aguiar, J. Albino [Departamento de Fisica, Universidade Federal de Pernambuco, 50670-901, Recife-Pe (Brazil); Majima, Y. [Materials and Structures Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8503 (Japan); CREST, Japan Science and Technology Agency (JST), 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8503 (Japan)

    2012-08-01

    In this work, we study the crystallization and electrical resistivity of the formed oxides in a Cu/SiO{sub 2}/Si thin film after thermal oxidation by ex-situ annealing at different temperatures up to 1000 Degree-Sign C. Upon increasing the annealing temperature, from the X ray diffractogram the phase evolution Cu {yields} Cu + Cu{sub 2}O {yields} Cu{sub 2}O {yields} Cu{sub 2}O + CuO {yields} CuO was detected. Pure Cu{sub 2}O films are obtained at 200 Degree-Sign C, whereas uniform CuO films without structural surface defects such as terraces, kinks, porosity or cracks are obtained in the temperature range 300-550 Degree-Sign C. In both oxides, crystallization improves with annealing temperature. A resistivity phase diagram, which is obtained from the current-voltage response, is presented here. The resistivity was expected to increase linearly as a function of the annealing temperature due to evolution of oxides. However, anomalous decreases are observed at different temperatures ranges, this may be related to the improvement of the crystallization and crystallite size when the temperature increases. - Highlights: Black-Right-Pointing-Pointer The crystallization and electrical resistivity of oxides in a Cu films are studied. Black-Right-Pointing-Pointer In annealing Cu films, the phase evolution Cu + Cu{sub 2}O {yields} Cu{sub 2}O {yields} Cu{sub 2}O + CuO {yields} CuO occurs. Black-Right-Pointing-Pointer A resistivity phase diagram, obtained from the current-voltage response, is presented. Black-Right-Pointing-Pointer Some decreases in the resistivity may be related to the crystallization.

  15. Room temperature Cu-Cu direct bonding using surface activated bonding method

    International Nuclear Information System (INIS)

    Kim, T.H.; Howlader, M.M.R.; Itoh, T.; Suga, T.

    2003-01-01

    Thin copper (Cu) films of 80 nm thickness deposited on a diffusion barrier layered 8 in. silicon wafers were directly bonded at room temperature using the surface activated bonding method. A low energy Ar ion beam of 40-100 eV was used to activate the Cu surface prior to bonding. Contacting two surface-activated wafers enables successful Cu-Cu direct bonding. The bonding process was carried out under an ultrahigh vacuum condition. No thermal annealing was required to increase the bonding strength since the bonded interface was strong enough at room temperature. The chemical constitution of the Cu surface was examined by Auger electron spectroscope. It was observed that carbon-based contaminations and native oxides on copper surface were effectively removed by Ar ion beam irradiation for 60 s without any wet cleaning processes. An atomic force microscope study shows that the Ar ion beam process causes no surface roughness degradation. Tensile test results show that high bonding strength equivalent to bulk material is achieved at room temperature. The cross-sectional transmission electron microscope observations reveal the presence of void-free bonding interface without intermediate layer at the bonded Cu surfaces

  16. Facile synthesis of Cu2O/CuO/RGO nanocomposite and its superior cyclability in supercapacitor

    International Nuclear Information System (INIS)

    Wang, Kun; Dong, Xiangmao; Zhao, Chongjun; Qian, Xiuzhen; Xu, Yunlong

    2015-01-01

    A reduced graphene oxide (RGO)-based nanocomposite of redox counterpart of the oxides of Cu(I)-Cu(II) pair for Faradaic reaction, Cu 2 O/CuO/RGO, was controllably synthesized through a facile, eco-friendly one-step hydrothermal-assisted redox reaction of elemental Cu and graphene oxide (GO) without the addition of any other reagents. The resultant Cu 2 O/CuO/RGO nanocomposites were characterized by X-ray diffraction (XRD), Raman spectroscopy, Thermogravimetric analysis (TG), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM). It is found that, when dealloyed nanoporous Cu was used as a Cu source, the uniform spherical Cu 2 O/CuO nanoparticles with double size scales (∼25 nm and ∼5 nm) were anchored on RGO sheets. This Cu 2 O/CuO/RGO nanocomposite redox counterpart exhibits improved rate capability and excellent cycling stability, i.e., only ca. 21.4% of the capacity was lost when the discharge current density increases from 1 A g −1 (173.4 F g −1 ) to 10 A g −1 (136.3 F g −1 ). Especially, the capacity remains almost unchanged (98.2%) after 100,000 cycles at 10 A g −1 . The good electrochemical performance and simple accessibility prove that this Cu 2 O/CuO/RGO composite consisting of a pair of redox counterparts is a promising material for supercapacitor applications

  17. Based on Cu as framework constructed nanoporous CuO/Cu composites by a dealloy method for sodium-ion battery anode

    Science.gov (United States)

    Zheng, Tian; Li, Guangda; Li, Deming; Meng, Xiangeng

    2018-05-01

    Nanoporous CuO/Cu composites with a continuous channel structure were fabricated through a corroding Cu-Al alloy process. The width of the continuous channels was about 20 50 nm. Nanoporous structure could effectively sustain the volume expansion during the Na+ insertion/extraction process and shorten the Na+ diffusion length as well, which thus helps improve the Na+ storage performance. Moreover, the nanoporous structure can improve the contact area between the electrolyte and the electrode, leading to an increment in the number of Na+ insertion/extraction sites. When used as the anode for sodium-ion batteries, the CuO/Cu exhibited an initial capacity of 580 mAh g-1, and the capacity is maintained at 200 mAh g-1 after 200 cycles at a current density of 500 mA g-1.

  18. Atomistic models of Cu diffusion in CuInSe2 under variations in composition

    Science.gov (United States)

    Sommer, David E.; Dunham, Scott T.

    2018-03-01

    We construct an analytic model for the composition dependence of the vacancy-mediated Cu diffusion coefficient in undoped CuInSe2 using parameters from density functional theory. The applicability of this model is supported numerically with kinetic lattice Monte Carlo and Onsager transport tensors. We discuss how this model relates to experimental measurements of Cu diffusion, arguing that our results can account for significant contributions to the bulk diffusion of Cu tracers in non-stoichiometric CuInSe2.

  19. Interfacial Reaction of Sn-Ag-Cu Lead-Free Solder Alloy on Cu: A Review

    Directory of Open Access Journals (Sweden)

    Liu Mei Lee

    2013-01-01

    Full Text Available This paper reviews the function and importance of Sn-Ag-Cu solder alloys in electronics industry and the interfacial reaction of Sn-Ag-Cu/Cu solder joint at various solder forms and solder reflow conditions. The Sn-Ag-Cu solder alloys are examined in bulk and in thin film. It then examines the effect of soldering conditions to the formation of intermetallic compounds such as Cu substrate selection, structural phases, morphology evolution, the growth kinetics, temperature and time is also discussed. Sn-Ag-Cu lead-free solder alloys are the most promising candidate for the replacement of Sn-Pb solders in modern microelectronic technology. Sn-Ag-Cu solders could possibly be considered and adapted in miniaturization technologies. Therefore, this paper should be of great interest to a large selection of electronics interconnect materials, reliability, processes, and assembly community.

  20. Magnetron sputtered Cu{sub 3}N/NiTiCu shape memory thin film heterostructures for MEMS applications

    Energy Technology Data Exchange (ETDEWEB)

    Kaur, Navjot; Choudhary, Nitin [Indian Institute of Technology Roorkee, Roorkee, Functional Nanomaterials Research Lab, Department of Physics and Centre of Nanotechnology (India); Goyal, Rajendra N. [Indian Institute of Technology, Roorkee, Department of Chemistry (India); Viladkar, S. [Indian Institute of Technology Roorkee, Roorkee, Functional Nanomaterials Research Lab, Department of Physics and Centre of Nanotechnology (India); Matai, I.; Gopinath, P. [Indian Institute of Technology, Roorkee, Centre for Nanotechnology (India); Chockalingam, S. [Indian Institute of Technology, Guwahati, Department of Biotechnology (India); Kaur, Davinder, E-mail: dkaurfph@iitr.ernet.in [Indian Institute of Technology Roorkee, Roorkee, Functional Nanomaterials Research Lab, Department of Physics and Centre of Nanotechnology (India)

    2013-03-15

    In the present study, for the first time, Cu{sub 3}N/NiTiCu/Si heterostructures were successfully grown using magnetron sputtering technique. Nanocrystalline copper nitride (Cu{sub 3}N with thickness {approx}200 nm) thin films and copper nanodots were subsequently deposited on the surface of 2-{mu}m-thick NiTiCu shape memory thin films in order to improve the surface corrosion and nickel release properties of NiTiCu thin films. Interestingly, the phase transformation from martensite phase to austenite phase has been observed in Cu{sub 3}N/NiTiCu heterostructures with corresponding change in texture and surface morphology of top Cu{sub 3}N films. Field emission scanning electron microscopy and atomic force microscope images of the heterostructures reveals the formation of 20-nm-sized copper nanodots on NiTiCu surface at higher deposition temperature (450 Degree-Sign C) of Cu{sub 3}N. Cu{sub 3}N passivated NiTiCu films possess low corrosion current density with higher corrosion potential and, therefore, better corrosion resistance as compared to pure NiTiCu films. The concentration of Ni released from the Cu{sub 3}N/NiTiCu samples was observed to be much less than that of pure NiTiCu film. It can be reduced to the factor of about one-ninth after the surface passivation resulting in smooth, homogeneous and highly corrosion resistant surface. The antibacterial and cytotoxicity of pure and Cu{sub 3}N coated NiTiCu thin films were investigated through green fluorescent protein expressing E. coli bacteria and human embryonic kidney cells. The results show the strong antibacterial property and non cytotoxicity of Cu{sub 3}N/NiTiCu heterostructure. This work is of immense technological importance due to variety of BioMEMS applications.

  1. The structure of molten CuCl, CuI and their mixtures as investigated by using neutron diffraction

    International Nuclear Information System (INIS)

    Drewitt, James W E; Salmon, Philip S; Takeda, Shin'ichi; Kawakita, Yukinobu

    2009-01-01

    The structure of molten CuCl, CuI and their mixtures (CuCl) x (CuI) 1-x with x = 0.294, 0.576, 0.801 was studied by using neutron diffraction. The results are discussed by reference to the information that is available on the structure of CuCl and CuI from experiment, theory and computer simulation. The comparison points to a need for more realistic models for the CuCl-CuI system which should take into account the presence of chemical bonds that have been found in CuI by the application of ab initio molecular dynamics methods.

  2. Facile synthesis of dendritic Cu by electroless reaction of Cu-Al alloys in multiphase solution

    Science.gov (United States)

    Wang, Ying; Liang, Shuhua; Yang, Qing; Wang, Xianhui

    2016-11-01

    Two-dimensional nano- or micro-scale fractal dendritic coppers (FDCs) were synthesized by electroless immersing of Cu-Al alloys in hydrochloric acid solution containing copper chloride without any assistance of template or surfactant. The FDC size increases with the increase of Al content in Cu-Al alloys immersed in CuCl2 + HCl solution. Compared to Cu40Al60 and Cu45Al55 alloys, the FDC shows hierarchical distribution and homogeneous structures using Cu17Al83 alloy as the starting alloy. The growth direction of the FDC is , and all angles between the trunks and branches are 60°. Nanoscale Cu2O was found at the edge of FDC. Interestingly, nanoporous copper (NPC) can also be obtained through Cu17Al83 alloy. Studies showed that the formation of FDC depended on two key factors: the potential difference between CuAl2 intermetallic and α-Al phase of dual-phase Cu-Al alloys; a replacement reaction that usually occurs in multiphase solution. The electrochemical experiment further proved that the multi-branch dendritic structure is very beneficial to the proton transfer in the process of catalyzing methanol.

  3. Recycled tetrahedron-like CuCl from waste Cu scraps for lithium ion battery anode.

    Science.gov (United States)

    Hou, Hongying; Yao, Yuan; Liu, Song; Duan, Jixiang; Liao, Qishu; Yu, Chengyi; Li, Dongdong; Dai, Zhipeng

    2017-07-01

    The wide applications of metal Cu inevitably resulted in a large quantity of waste Cu materials. In order to recover the useful Cu under the mild conditions and reduce the environmental emission, waste Cu scraps were recycled in the form of CuCl powders with high economic value added (EVA) via the facile hydrothermal route. The recycled CuCl powders were characterized in terms of scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD). The results suggested that the recycled CuCl powders consisted of many regular tetrahedron-like micro-particles. Furthermore, in order to reduce the cost of lithium ion battery (LIB) anode and build the connection of waste Cu scraps and LIB, the recycled CuCl powders were evaluated as the anode active material of LIB. As expected, the reversible discharge capacity was about 171.8mAh/g at 2.0C even after 50 cycles, implying the satisfactory cycle stability. Clearly, the satisfactory results may open a new avenue to develop the circular economy and the sustainable energy industry, which would be very important in terms of both the resource recovery and the environmental protection. Copyright © 2017. Published by Elsevier Ltd.

  4. Effect of Cu content on wear resistance and mechanical behavior of Ti-Cu binary alloys

    Science.gov (United States)

    Yu, Feifei; Wang, Hefeng; Yuan, Guozheng; Shu, Xuefeng

    2017-04-01

    Arc melting with nonconsumable tungsten electrode and water-cooled copper crucible was used to fabricate Ti-Cu binary alloys with different Cu contents in an argon atmosphere. The compositions and phase structures of the fabricated alloys were investigated by glow discharge optical emission spectroscopy (GDOES) and X-ray diffraction (XRD). Nanoindentation tests through continuous stiffness measurement were then performed at room temperature to analyze the mechanical behaviors of the alloys. Results indicated that the composition of each Ti-Cu binary alloy was Ti(100- x) Cu x ( x = 43, 60, 69, and 74 at.%). The XRD analysis results showed that the alloys were composed of different phases, indicating that different Cu contents led to the variations in alloy hardness. The wear tests results revealed that elemental Cu positively affects the wear resistance properties of the Ti-Cu alloys. Nanoindentation testing results showed that the moduli of the Ti-Cu alloys were minimally changed at increasing Cu content, whereas their hardness evidently increased according to the wear test results.

  5. CuAlO2 and CuAl2O4 thin films obtained by stacking Cu and Al films using physical vapor deposition

    Science.gov (United States)

    Castillo-Hernández, G.; Mayén-Hernández, S.; Castaño-Tostado, E.; DeMoure-Flores, F.; Campos-González, E.; Martínez-Alonso, C.; Santos-Cruz, J.

    2018-06-01

    CuAlO2 and CuAl2O4 thin films were synthesized by the deposition of the precursor metals using the physical vapor deposition technique and subsequent annealing. Annealing was carried out for 4-6 h in open and nitrogen atmospheres respectively at temperatures of 900-1000 °C with control of heating and cooling ramps. The band gap measurements ranged from 3.3 to 4.5 eV. Electrical properties were measured using the van der Pauw technique. The preferred orientations of CuAlO2 and CuAl2O4 were found to be along the (1 1 2) and (3 1 1) planes, respectively. The phase percentages were quantified using a Rietveld refinement simulation and the energy dispersive X-ray spectroscopy indicated that the composition is very close to the stoichiometry of CuAlO2 samples and with excess of aluminum and deficiency of copper for CuAl2O4 respectively. High resolution transmission electron microscopy identified the principal planes in CuAlO2 and in CuAl2O4. Higher purities were achieved in nitrogen atmosphere with the control of the cooling ramps.

  6. Thermal gravimetric analysis of the CsCuCl3, Cs2CuCl4 and Cs2CuCl4x2H2O crystals

    International Nuclear Information System (INIS)

    Soboleva, L.V.; Vasil'eva, M.G.

    1977-01-01

    The thermal characteristics of crystals of Cs 2 CuCl 4 , Cs 2 CuCl 4 x2H 2 O, and CsCuCl 3 were investigated thermogravimetrically. The derivatogram of the Cs 2 CuCl 4 crystal is characterized by the presence of a single endothermal effect at 505 deg C. The derivatogram of the Cs 2 CuCl 4 x2H 2 O crystal contains three endothermal effects: at 40, 135, and 480 deg C. The derivatogram of the CsCuCl 3 crystal shows the presence of two endothermal effects at 142 and 455 deg C. The thermogravimetric data on Cs 2 CuCl 4 and CsCuCl 3 crystals reveal crystal decomposition on melting; hence, these crystals cannot be grown from melts

  7. Stark broadening in the laser-induced Cu I and Cu II spectra

    International Nuclear Information System (INIS)

    Skočić, M; Burger, M; Nikolić, Z; Bukvić, S; Djeniže, S

    2013-01-01

    In this work we present the Stark widths (W) of 22 neutral (Cu I) and 100 singly ionized (Cu II) copper spectral lines that have been measured at 18 400 K and 19 300 K electron temperatures and 6.3 × 10  22 m −3 and 2.1 × 10  23 m −3 electron densities, respectively. The experiment is conducted in the laser-induced plasma—the Nd:YAG laser, operating at 532 nm, was used to produce plasma from the copper sample in the residual air atmosphere at a pressure of 8 Pa. The electron temperature and density were estimated by the Boltzmann-plot method and from the Saha equation. The investigated Cu I lines belong to the 4s–4p′, 4s  2 –4p″ and 4p′–4d′ transitions while Cu II spectral lines belong to the 4s–4p, 4p–5s, 4p–4d, 4p–4s  2 , 4d–4f and 4d–v transitions. Comparison with existing experimental data was possible only in the case of 17 Cu II lines due to a lack of experimental and theoretical values. The rest of the data, Stark widths of 22 Cu I and 83 Cu II lines are published for the first time. (paper)

  8. Growth and magnetic properties dependence of the Co–Cu/Cu films electrodeposited under high magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Franczak, Agnieszka, E-mail: agnieszka.franczak@mtm.kuleuven.be [Laboratoire d’Ingénierie et Sciences des Matériaux (LISM EA 4695), Université de Reims Champagne-Ardenne, UFR Sciences et Naturelles, Bat. 6, Moulin de la Housse, BP 1039, 51687 Reims Cedex 2 (France); Department of Materials Science (MTM), KU Leuven, Kasteelpark Arenberg 44, 3001 Haverlee (Leuven) (Belgium); Levesque, Alexandra [Laboratoire d’Ingénierie et Sciences des Matériaux (LISM EA 4695), Université de Reims Champagne-Ardenne, UFR Sciences et Naturelles, Bat. 6, Moulin de la Housse, BP 1039, 51687 Reims Cedex 2 (France); Zabinski, Piotr [Laboratory of Physical Chemistry and Electrochemistry, Faculty of Non-Ferrous Metals, AGH University of Science and Technology, al. A. Mickiewicza 30, 30059 Krakow (Poland); Li, Donggang [Key Laboratory of Electromagnetic Processing of Materials (Ministry of Education), Northeastern University, 314 Box, 110004 Shenyang (China); Czapkiewicz, Maciej [Department of Electronics, AGH University of Science and Technology, al. A. Mickiewicza 30, 30059 Krakow (Poland); Kowalik, Remigiusz [Laboratory of Physical Chemistry and Electrochemistry, Faculty of Non-Ferrous Metals, AGH University of Science and Technology, al. A. Mickiewicza 30, 30059 Krakow (Poland); Bohr, Frédéric [Laboratoire d’Ingénierie et Sciences des Matériaux (LISM EA 4695), Université de Reims Champagne-Ardenne, UFR Sciences et Naturelles, Bat. 6, Moulin de la Housse, BP 1039, 51687 Reims Cedex 2 (France); and others

    2015-07-15

    The present work is focused on the investigations of magnetic properties dependence on microstructure of Co–Cu/Cu films electrodeposited under superimposed high magnetic field. The experimental results indicate a strong effect of an external magnetic field on the morphology of deposited films, more precisely on the Co:Cu ratio that determines the film growth. It is shown that the Co–Cu/Cu films electrodeposited without superimposed magnetic field consisted of two clearly visible features: compact film with incorporated granular particles. Under a superimposed external high magnetic field the privilege growth of the particles was induced. As a consequence, development of the well-defined branched structure of Co–Cu/Cu film was observed. In contrary, the phase compositional investigations do not reveal any changes in the phase formation during electrodeposition under magnetic field conditions. Thus, it is assumed that a strong growth of Co–Cu/Cu films in (111) direction under magnetic or non-magnetic electrodeposition conditions is related with the growth of Cu (111) plane and embedded into it some of the Co fcc atoms of same (111) orientation, as well as the Co hcp atoms that grows in the (002) direction. This non-equilibrium growth of Co–Cu/Cu films under magnetic deposition conditions affects strongly the magnetic properties of deposited films, revealing that films obtained under magnetic fields higher than 3 T were no more magnetic materials. - Highlights: • Co–Cu/Cu electrodeposits were obtained at elevated temperature under HMFs. • The effects of HMFs on microstructure and magnetic properties were investigated. • Interesting morphological changes due to HMFs has been observed. • Changes in Co:Cu ratio due to HMFs modified the magnetic properties of deposits.

  9. Growth and magnetic properties dependence of the Co–Cu/Cu films electrodeposited under high magnetic fields

    International Nuclear Information System (INIS)

    Franczak, Agnieszka; Levesque, Alexandra; Zabinski, Piotr; Li, Donggang; Czapkiewicz, Maciej; Kowalik, Remigiusz; Bohr, Frédéric

    2015-01-01

    The present work is focused on the investigations of magnetic properties dependence on microstructure of Co–Cu/Cu films electrodeposited under superimposed high magnetic field. The experimental results indicate a strong effect of an external magnetic field on the morphology of deposited films, more precisely on the Co:Cu ratio that determines the film growth. It is shown that the Co–Cu/Cu films electrodeposited without superimposed magnetic field consisted of two clearly visible features: compact film with incorporated granular particles. Under a superimposed external high magnetic field the privilege growth of the particles was induced. As a consequence, development of the well-defined branched structure of Co–Cu/Cu film was observed. In contrary, the phase compositional investigations do not reveal any changes in the phase formation during electrodeposition under magnetic field conditions. Thus, it is assumed that a strong growth of Co–Cu/Cu films in (111) direction under magnetic or non-magnetic electrodeposition conditions is related with the growth of Cu (111) plane and embedded into it some of the Co fcc atoms of same (111) orientation, as well as the Co hcp atoms that grows in the (002) direction. This non-equilibrium growth of Co–Cu/Cu films under magnetic deposition conditions affects strongly the magnetic properties of deposited films, revealing that films obtained under magnetic fields higher than 3 T were no more magnetic materials. - Highlights: • Co–Cu/Cu electrodeposits were obtained at elevated temperature under HMFs. • The effects of HMFs on microstructure and magnetic properties were investigated. • Interesting morphological changes due to HMFs has been observed. • Changes in Co:Cu ratio due to HMFs modified the magnetic properties of deposits

  10. Effects of Cu content on the photoelectrochemistry of Cu2ZnSnS4 nanocrystal thin films

    International Nuclear Information System (INIS)

    Khoshmashrab, Saghar; Turnbull, Matthew J.; Vaccarello, Daniel; Nie, Yuting; Martin, Spencer; Love, David A.; Lau, Po K.; Sun, Xuhui; Ding, Zhifeng

    2015-01-01

    Highlights: • Two compositions of CZTS were synthesized, one yielding Cu-poor and the other Cu-stoichiometric nanocrystals (NCs). • Physical and electronic properties of both films were probed using various analytical techniques. • Films comprised of Cu-poor CZTS showed tighter packing with less defects compared to those of stoichiometric-Cu. • Photoelectrochemical measurements exhibited increased photoconversion and increased photostability of the Cu-poor films. • Intensity modulated photocurrent spectroscopy showed that the Cu-deficient NCs had half the recombination rate as that of stoichiometric-Cu films. - Abstract: Cu 2 ZnSnS 4 (CZTS) nanocrystals (NCs) were prepared via a one-pot solvothermal method. Given that the composition affects the electronic properties of this p-type semiconductor, two compositional ratios were chosen from 10 designed and synthesized analogues, one yielding Cu-poor and the other Cu-stoichiometric CZTS. NCs in which the Cu concentration was slightly below stoichiometric yielded more uniform films with greater photovoltaic performance. The lower Cu content also lead to slightly better crystallinity within the film, as demonstrated by XRD, Raman spectroscopy and transmission electron microscopy. Chronophotoelectrochemical measurements indicated that both types of NC films displayed good stability; however, with a decrease in potential, an increase in resistance for the Cu-stoichiometric film was observed. As determined by intensity modulated photocurrent spectroscopy, the product separation rate of the photoinduced holes and electrons in the Cu-poor films were more than 3 times that of the Cu-stoichiometric, confirming that the lower Cu content led to an improved photoperformance

  11. Investigation of Surface Pre-Treatment Methods for Wafer-Level Cu-Cu Thermo-Compression Bonding

    Directory of Open Access Journals (Sweden)

    Koki Tanaka

    2016-12-01

    Full Text Available To increase the yield of the wafer-level Cu-Cu thermo-compression bonding method, certain surface pre-treatment methods for Cu are studied which can be exposed to the atmosphere before bonding. To inhibit re-oxidation under atmospheric conditions, the reduced pure Cu surface is treated by H2/Ar plasma, NH3 plasma and thiol solution, respectively, and is covered by Cu hydride, Cu nitride and a self-assembled monolayer (SAM accordingly. A pair of the treated wafers is then bonded by the thermo-compression bonding method, and evaluated by the tensile test. Results show that the bond strengths of the wafers treated by NH3 plasma and SAM are not sufficient due to the remaining surface protection layers such as Cu nitride and SAMs resulting from the pre-treatment. In contrast, the H2/Ar plasma–treated wafer showed the same strength as the one with formic acid vapor treatment, even when exposed to the atmosphere for 30 min. In the thermal desorption spectroscopy (TDS measurement of the H2/Ar plasma–treated Cu sample, the total number of the detected H2 was 3.1 times more than the citric acid–treated one. Results of the TDS measurement indicate that the modified Cu surface is terminated by chemisorbed hydrogen atoms, which leads to high bonding strength.

  12. Enhancement in visible light photocatalytic activity by embedding Cu nanoparticles over CuS/MCM-41 nanocomposite

    Science.gov (United States)

    Sohrabnezhad, Sh.; Karamzadeh, M.

    2017-07-01

    This article indicate the biogenic synthesis of copper nanoparticles (Cu NPs) using the borage flowers extract of Borago officinalis over CuS/MCM-41 nanocomposite (NC). No external reducing was utilized in the developed method. The CuS-MCM-41 NC was used as stabilizing agent. The synthesis of CuS nanostructure in MCM-41 material has been realized by hydrothermal method. Their physiochemical properties have been characterized by X-ray diffraction, transmission electron microscopy (TEM), UV-Visible diffuse reflectance spectroscopy, and Fourier transform infrared spectroscopy. On the basis of TEM images, a layer of Cu NPs has been located over CuS/MCM-41 NC with average diameter of 60-80 nm. The results revealed the spherical nature of the prepared Cu NPs with diameter less than 10 nm. The DR spectra of Cu NPs in MCM-41 and CuS-MCM-41 NCs showed surface plasmon resonance bands at 570 and 500-600 nm, respectively. The photocatalytic activity was evaluated under visible light irradiation using the photocatalytic degradation of methylene blue (MB) as a model reaction. The prepared Cu/CuS/MCM-41 nanocomposite microspheres showed higher photodegradation ability for MB than CuS/MCM-41. The degradation of MB achieved up to 80% after 60 min and the nanocomposite could be recycled and reused.

  13. Growth and characterization of NixCu1-x alloy films, NixCu1-x/NiyCu1-y multilayers, and nanowires

    International Nuclear Information System (INIS)

    Kazeminezhad, I.

    2001-12-01

    It was found that it is possible to grow Ni x Cu 1-x alloy systems of arbitrary composition by electrodepositing well-defined sub-monolayer quantities of Ni and Cu in alternation using a new method based on that used previously to prepare potentiostatically deposited magnetic multilayers from a single sulphamate-based electrolyte. Following growth, the chemical composition of Ni x Cu 1-x alloy films was obtained by ZAF-corrected energy dispersive X-Ray (EDX) analysis and less than a 4% difference between the nominal and actual composition was observed. The structure of the films was investigated by high-angle X-ray diffractometry (HAXRD) and transmission electron microscopy (TEM). The films grown on polycrystalline Cu substrates had (100) texture, while those grown on Au-coated glass had (111) texture. Some evidence of Ni clustering was obtained by vibrating sample magnetometry (VSM). Self-organisation of the deposited metal was suggested for Ni potentials more positive than ∼-1.4V. The transition from a Ni/Cu multilayer to a Ni x Cu 1-x alloy was also studied and an interesting aspect, namely a plateau region in a plot of magnetisation as a function of Ni layer thickness was observed, suggesting a preferred Ni cluster size in these alloy films. Anisotropic magnetoresistance (AMR) of the films decreased with increasing Cu content at 300K and 77K. SQUID measurements for Ni 0.52 Cu 0.48 and Ni 0.62 CU 0.38 films showed that they become much more strongly ferromagnetic at low temperatures. Evidence for blocked -superparamagnetic behaviour above a blocking temperature (T B ) of the films was obtained from zero-field-cooled (ZFC) and field-cooled (FC) magnetic susceptibility measurements. Ni x Cu 1-x /Ni y Cu 1-y alloy/alloy multilayer films with short repeat distance were successfully fabricated using this method. Up to third order satellite peaks observed in HAXRD showed that the interface is sharp. Room temperature longitudinal magnetoresistance measurements showed

  14. Treatment of reverse osmosis (RO) concentrate by the combined Fe/Cu/air and Fenton process (1stFe/Cu/air-Fenton-2ndFe/Cu/air).

    Science.gov (United States)

    Ren, Yi; Yuan, Yue; Lai, Bo; Zhou, Yuexi; Wang, Juling

    2016-01-25

    To decompose or transform the toxic and refractory reverse osmosis (RO) concentrate and improve the biodegradability, 1stFe/Cu/air-Fenton-2ndFe/Cu/air were developed to treat RO concentrate obtained from an amino acid production plant in northern China. First, their operating conditions were optimized thoroughly. Furthermore, 5 control experiments were setup to confirm the superiority of 1stFe/Cu/air-Fenton-2ndFe/Cu/air and synergistic reaction between Fe/Cu/air and Fenton. The results suggest that the developed method could obtain high COD removal (65.1%) and BOD5/COD ratio (0.26) due to the synergistic reaction between Fe/Cu/air and Fenton. Under the optimal conditions, the influent and effluent of 1stFe/Cu/air-Fenton-2ndFe/Cu/air and 5 control experiments were analyzed by using UV, FTIR, EEM and LC, which confirm the superiority of 1stFe/Cu/air-Fenton-2ndFe/Cu/air. Therefore, the developed method in this study is a promising process for treatment of RO concentrate. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Magnetic dipole moments of 58Cu and 59Cu by in-source laser spectroscopy

    International Nuclear Information System (INIS)

    Stone, N. J.; Koester, U.; Stone, J. Rikovska; Fedorov, D. V.; Fedoseyev, V. N.; Flanagan, K. T.; Hass, M.; Lakshmi, S.

    2008-01-01

    Online measurements of the magnetic dipole moments and isotope shifts of 58 Cu and 59 Cu by the in-source laser spectroscopy method are reported. The results for the magnetic moments are μ ( 58 Cu) =+0.52(8) μ N ,μ( 59 Cu) =+1.84(3) μ N and for the isotope shifts δν 59,65 =1.72(22) GHz and δν 58,65 =1.99(30) GHz in the transition from the 3d 10 4s 2 S 1/2 ground state to the 3d 10 4p 2 P 1/2 state in Cu I. The magnetic moment of 58 Cu is discussed in the context of the strength of the subshell closure at 56 Ni, additivity rules and large-scale shell model calculations

  16. Hume-Rothery electron concentration rule across a whole solid solution range in a series of gamma-brasses in Cu-Zn, Cu-Cd, Cu-Al, Cu-Ga, Ni-Zn and Co-Zn alloy systems

    Science.gov (United States)

    Mizutani, U.; Noritake, T.; Ohsuna, T.; Takeuchi, T.

    2010-05-01

    The aim of the present work is to examine if the Hume-Rothery stabilisation mechanism holds across whole solid solution ranges in a series of gamma-brasses with especial attention to the role of vacancies introduced into the large unit cell. The concentration dependence of the number of atoms in the unit cell, N, for gamma-brasses in the Cu-Zn, Cu-Cd, Cu-Al, Cu-Ga, Ni-Zn and Co-Zn alloy systems was determined by measuring the density and lattice constants at room temperature. The number of itinerant electrons in the unit cell, e/uc, is evaluated by taking a product of N and the number of itinerant electrons per atom, e/a, for the transition metal element deduced earlier from the full-potential linearised augmented plane wave (FLAPW)-Fourier analysis. The results are discussed within the rigid-band model using as a host the density of states (DOS) derived earlier from the FLAPW band calculations for the stoichiometric gamma-brasses Cu5Zn8, Cu9Al4 and TM2Zn11 (TM = Co and Ni). A solid solution range of gamma-brasses in Cu-Zn, Cu-Cd, Cu-Al, Cu-Ga and Ni-Zn alloy systems is found to fall inside the existing pseudogap at the Fermi level. This is taken as confirmation of the validity of the Hume-Rothery stability mechanism for a whole solute concentration range of these gamma-brasses. An exception to this behaviour was found in the Co-Zn gamma-brasses, where orbital hybridisation effects are claimed to play a crucial role in stabilisation.

  17. Cu-capped surface alloys of Pt/Cu left brace 100 right brace

    CERN Document Server

    Alshamaileh, E; Wander, A

    2003-01-01

    The room-temperature deposition of 0.5 monolayer (ML) Pt on Cu left brace 100 right brace followed by annealing to 525 K results in a sharp c(2 x 2) low-energy electron diffraction (LEED) pattern. The structure of this surface alloy is investigated by means of symmetrized automated tensor low-energy electron diffraction (SATLEED) analysis and ab initio plane wave density functional calculations. The results are then compared with those for the similar system 0.5 ML Pd/Cu left brace 100 right brace. SATLEED results for the Pt/Cu left brace 100 right brace show that it consists of an ordered c(2 x 2) Cu-Pt second layer alloy capped with a pure Cu first layer. The first and second interlayer spacings are found to be expanded by +5.1 +- 1.7 and +3.5 +- 1.7% respectively (relative to the bulk Cu interlayer spacing of 1.807 A) due to the insertion of the 8% larger Pt atoms into the second layer. The ordered mixed layer is found to be rippled by 0.08 +- 0.06 A with Pt atoms rippled outwards towards the solid-vacuum ...

  18. Calculation of Gibbs energy of Zr-Al-Ni, Zr-Al-Cu, Al-Ni-Cu and Zr-Al-Ni-Cu liquid alloys based on quasiregular solution model

    International Nuclear Information System (INIS)

    Li, H.Q.; Yang, Y.S.; Tong, W.H.; Wang, Z.Y.

    2007-01-01

    With the effects of electronic structure and atomic size being introduced, the mixing enthalpy as well as the Gibbs energy of the ternary Zr-Al-Cu, Ni-Al-Cu, Zr-Ni-Al and quaternary Zr-Al-Ni-Cu systems are calculated based on quasiregular solution model. The computed results agree well with the experimental data. The sequence of Gibbs energies of different systems is: G Zr-Al-Ni-Cu Zr-Al-Ni Zr-Al-Cu Cu-Al-Ni . To Zr-Al-Cu, Ni-Al-Cu and Zr-Ni-Al, the lowest Gibbs energy locates in the composition range of X Zr 0.39-0.61, X Al = 0.38-0.61; X Ni = 0.39-0.61, X Al = 0.38-0.60 and X Zr = 0.32-0.67, X Al = 0.32-0.66, respectively. And to the Zr-Ni-Al-Cu system with 66.67% Zr, the lowest Gibbs energy is obtained in the region of X Al = 0.63-0.80, X Ni = 0.14-0.24

  19. Studies of the development and characterization of the Cu-Ni-Pt and Cu-Ni-Sn alloys for electro-electronic uses; Estudos do desenvolvimento e caracterizacao das ligas Cu-Ni-Pt e Cu-Ni-Sn para fins eletro-eletronicos

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Luis Carlos Elias da

    2006-07-01

    The Cu and its alloys have different applications in the owed modern society the excellent electric properties, thermal conductivity, resistance to the corrosion and other properties. These applications can be in valves, pipes, pots for absorption of solar energy, radiators for automobiles, current driver, electronic driver, thermostats elements and structural parts of nuclear reactors, as, for example, reels for field toroidal for a reactor of nuclear coalition. The alloys used in nuclear reactors, we can highlight Cu-Be, Cu-Sn and Cu-Pt. Ni and Co frequently are added to the Cu alloys so that the solubility is moved for temperatures more elevated with relationship to the binary systems of Cu-Sn and Cu-Pt. The addition of Ni-Pt or Ni-Sn to the Cu in the same or inferior percentages to 1,5% plus thermomechanical treatments changes the properties of the copper. We studied the electric conductivity and hardness Vickers of the Cu-Ni-Pt and Cu-Ni-Sn and compared with the electrolytic Cu. In the proposed flowcharts, breaking of the obtaining of the ingot, we proceeded with thermo mechanical treatments. (author)

  20. Radiolabeling and biodistribution of 62Cu-dithiocarbamate

    International Nuclear Information System (INIS)

    Matsumoto, Kazuya; Fujibayashi, Yasuhisa; Yokoyama, Akira; Konishi, Junji.

    1990-01-01

    The newly developed 62 Zn/ 62 Cu generator system has made available the production of the short-lived 62 Cu (T 1/2 = 9.8 min) positron radionuclide, eluted as 62 Cu-glycine. In the search for 62 Cu labeled radiopharmaceuticals for positron CT (PET) brain diagnostic studies, two ligands N,N-diethyl- and N,N-dimethyl-dithiocarbamic acid (DDC and DmDC) were selected, based on their Cu chelating abilities and the neutral lipophilic character of their copper chelates. In the present work, an in vitro study with non-radioactive Cu-glycine showed that both ligands easily formed the stable, neutral Cu-DDC and Cu-DmDC chelates (1:2 metal-ligand complexes) based on the ligand exchange reaction. Then the 62 Zn/ 62 Cu generator eluate, the 62 Cu-glycine was used for the radiolabeling of DDC and DmDC. The following HPLC analysis revealed that the ligand exchange reaction proceeded rapidly; the radiochemical purities of 62 Cu-DDC and 62 Cu-DmDC were extremely high (non-detectable 62 Cu-glycine) and both chelates were more lipophilic than 62 Cu-glycine. The mouse biodistribution of both radiolabeled compounds, 62 Cu-DDC and 62 Cu-DmDC indicated a brain accumlation of 2.8 and 5.3 times higher than 62 Cu-glycine, 15 min post injection, respectively. The brain accumulation observed with both 62 Cu-DDC and 62 Cu-DmDC might be due to their stable, neutral and lipophilic character; the latter enhanced by the presence of the methylated side chains. The gathered results indicated the applicability of dithiocarbamic acid derivatives in the production of new 62 Cu-labeled compounds using the 62 Zn/ 62 Cu generator system based on the ligand exchange reaction with 62 Cu-glycine eluate. Further studies with Cu-dithiocarbamic acid derivatives for development of new generator-produced 62 Cu positron radiopharmaceuticals can be recalled. (author)

  1. Influence of Cu Content on the Microstructure and Mechanical Properties of Cr-Cu-N Coatings

    Directory of Open Access Journals (Sweden)

    Ji Cheng Ding

    2018-01-01

    Full Text Available The Cr-Cu-N coatings with various Cu contents (0–25.18 (±0.17 at.% were deposited on Si wafer and stainless steel (SUS 304 substrates in reactive Ar+N2 gas mixture by a hybrid coating system combining pulsed DC and RF magnetron sputtering techniques. The influence of Cu content on the coating composition, microstructure, and mechanical properties was investigated. The microstructure of the coatings was significantly altered by the introduction of Cu. The deposited coatings exhibit solid solution structure with different compositions in all of the samples. Addition of Cu is intensively favored for preferred orientation growth along (200 direction by restricting in (111 direction. With increasing Cu content, the surface and cross-sectional morphology of coatings were changed from triangle cone-shaped, columnar feature to broccoli-like and compact glassy microstructure, respectively. The mechanical properties including the residual stress, nanohardness, and toughness of the coatings were explored on the basis of Cu content. The highest hardness was obtained at the Cu content of 1.49 (±0.10 at.%.

  2. /Cu-Al System

    Science.gov (United States)

    Kish, Orel; Froumin, Natalya; Aizenshtein, Michael; Frage, Nachum

    2014-05-01

    Wettability and interfacial interaction of the Ta2O5/Cu-Al system were studied. Pure Cu does not wet the Ta2O5 substrate, and improved spreading is achieved when relatively a high fraction of the active element (~40 at.% Al) was added. The Al2O3 and AlTaO4 phases were observed at the Ta2O5/Cu-Al interface. A thermodynamic evaluation allowed us to suggest that the lack of wetting bellow 40 at.% Al is due to the presence of a native oxide, which covers the drop. The conditions of the native oxide decomposition and the formation of the volatile Al2O suboxide strongly depend on the vacuum level during sessile drop experiments and the composition of the Cu-Al alloy. In our case, Al contents greater than 40% provides thermodynamic conditions for the formation of Al2O (as a result of Al reaction with Al2O3) and the drop spreading. It was suggested that the final contact angle in the Ta2O5/Cu-Al system (50°) is determined by Ta adsorption on the newly formed alumina interlayer.

  3. Corrosion and runoff rates of Cu and three Cu-alloys in marine environments with increasing chloride deposition rate.

    Science.gov (United States)

    Odnevall Wallinder, Inger; Zhang, Xian; Goidanich, Sara; Le Bozec, Nathalie; Herting, Gunilla; Leygraf, Christofer

    2014-02-15

    Bare copper sheet and three commercial Cu-based alloys, Cu15Zn, Cu4Sn and Cu5Al5Zn, have been exposed to four test sites in Brest, France, with strongly varying chloride deposition rates. The corrosion rates of all four materials decrease continuously with distance from the coast, i.e. with decreasing chloride load, and in the following order: Cu4Sn>Cu sheet>Cu15Zn>Cu5Al5Zn. The patina on all materials was composed of two main layers, Cu2O as the inner layer and Cu2(OH)3Cl as the outer layer, and with a discontinuous presence of CuCl in between. Additional minor patina constituents are SnO2 (Cu4Sn), Zn5(OH)6(CO3)2 (Cu15Zn and Cu5Al5Zn) and Zn6Al2(OH)16CO3·4H2O/Zn2Al(OH)6Cl·2H2O/Zn5Cl2(OH)8·H2O and Al2O3 (Cu5Al5Zn). The observed Zn- and Zn/Al-containing corrosion products might be important factors for the lower sensitivity of Cu15Zn and Cu5Al5Zn against chloride-induced atmospheric corrosion compared with Cu sheet and Cu4Sn. Decreasing corrosion rates with exposure time were observed for all materials and chloride loads and attributed to an improved adherence with time of the outer patina to the underlying inner oxide. Flaking of the outer patina layer was mainly observed on Cu4Sn and Cu sheet and associated with the gradual transformation of CuCl to Cu2(OH)3Cl of larger volume. After three years only Cu5Al5Zn remains lustrous because of a patina compared with the other materials that appeared brownish-reddish. Significantly lower release rates of metals compared with corresponding corrosion rates were observed for all materials. Very similar release rates of copper from all four materials were observed during the fifth year of marine exposure due to an outer surface patina that with time revealed similar constituents and solubility properties. Copyright © 2013 The Authors. Published by Elsevier B.V. All rights reserved.

  4. Solid phase selective separation and preconcentration of Cu(II) by Cu(II)-imprinted polymethacrylic microbeads.

    Science.gov (United States)

    Dakova, Ivanka; Karadjova, Irina; Ivanov, Ivo; Georgieva, Ventsislava; Evtimova, Bisera; Georgiev, George

    2007-02-12

    Ion-imprinted polymer (IIP) particles are prepared by copolymerization of methacrylic acid as monomer, trimethylolpropane trimethacrylate as crosslinking agent and 2,2'-azo-bis-isobutyronitrile as initiator in the presence of Cu(II), a Cu(II)-4-(2-pyridylazo)resorcinol (Cu(II)-PAR) complex, and PAR only. A batch procedure is used for the determination of the characteristics of the Cu(II) solid phase extraction from the IIP produced. The results obtained show that the Cu(II)-PAR IIP has the greatest adsorption capacity (37.4 micromol g(-1) of dry copolymer) among the IIPs investigated. The optimal pH value for the quantitative preconcentration is 7, and full desorption is achieved by 1 M HNO(3). The selectivity coefficients (S(Cu/Me)) for Me=Ni(II), Co(II) are 45.0 and 38.5, respectively. It is established that Cu(II)-PAR IIPs can be used repeatedly without a considerable adsorption capacity loss. The determination of Cu(II) ions in seawater shows that the interfering matrix does not influence the preconcentration and selectivity values of the Cu(II)-PAR IIPs. The detection and quantification limits are 0.001 micromol L(-1) (3sigma) and 0.003 micromol L(-1) (6sigma), respectively.

  5. Coupled growth of Al-Al2Cu eutectics in Al-Cu-Ag alloys

    International Nuclear Information System (INIS)

    Hecht, U; Witusiewicz, V; Drevermann, A

    2012-01-01

    Coupled eutectic growth of Al and Al 2 Cu was investigated in univariant Al-Cu-Ag alloys during solidification with planar and cellular morphology. Experiments reveal the dynamic selection of small spacings, below the minimum undercooling spacing and show that distinct morphological features pertain to nearly isotropic or anisotropic Al-Al 2 Cu interfaces.

  6. Bioaccumulation, toxicokinetics, and effects of copper from sediment spiked with aqueous Cu, nano-CuO, or micro-CuO in the deposit-feeding snail, Potamopyrgus antipodarum

    DEFF Research Database (Denmark)

    Pang, Chengfang; Selck, Henriette; Banta, Gary Thomas

    2013-01-01

    The present study examined the relative importance of copper (aqueous Cu and CuO particles of different sizes) added to sediment to determine the bioaccumulation, toxicokinetics, and effects in the deposit feeder Potamopyrgus antipodarum. In experiment 1, the bioaccumulation of Cu (240 mg Cu/g dr...

  7. Local atomic structure of Zr-Cu and Zr-Cu-Al amorphous alloys investigated by EXAFS method

    International Nuclear Information System (INIS)

    Antonowicz, J.; Pietnoczka, A.; Zalewski, W.; Bacewicz, R.; Stoica, M.; Georgarakis, K.; Yavari, A.R.

    2011-01-01

    Research highlights: → Coordination number, interatomic distances and mean square atomic displacement in Zr-Cu and Zr-Cu-Al glasses. → Icosahedral symmetry in local atomic structure. → Deviation from random mixing behavior resulting from Al addition. - Abstract: We report on extended X-ray absorption fine structure (EXAFS) study of rapidly quenched Zr-Cu and Zr-Cu-Al glassy alloys. The local atomic order around Zr and Cu atoms was investigated. From the EXAFS data fitting the values of coordination number, interatomic distances and mean square atomic displacement were obtained for wide range of compositions. It was found that icosahedral symmetry rather than that of corresponding crystalline analogs dominates in the local atomic structure of Zr-Cu and Zr-Cu-Al amorphous alloys. Judging from bonding preferences we conclude that addition of Al as an alloying element results in considerable deviation from random mixing behavior observed in binary Zr-Cu alloys.

  8. Assessment of copper nanoparticles (Cu-NPs) and copper (II) oxide (CuO) induced hemato- and hepatotoxicity in Cyprinus carpio

    Science.gov (United States)

    Noureen, Aasma; Jabeen, Farhat; Tabish, Tanveer A.; Yaqub, Sajid; Ali, Muhammad; Shakoor Chaudhry, Abdul

    2018-04-01

    Recently, Cu-based nanoparticles have drawn considerable attention for their various fascinating roles in multiple biological systems. It is recognized that their frequent use can create compatibility challenges for the recipient systems. Nevertheless, it is unclear how various biological interactions affect the compatibility of Cu oxide II (CuO) and Cu oxide nanoparticles (Cu-NPs) for different organisms. Consequently, it has been difficult to perform structured risk assessments for their use in biological systems. Therefore, this study compared the effects of different doses of waterborne Cu-NPs and CuO on the blood and liver of selected groups of Cyprinus (C) carpio. These fish while housed in suitable water tanks were exposed to one of the following treatments for 14 d: control (no added Cu) or 0.5 or 1 or 1.5 mg Cu as Cu-NPs or CuO l-1 of water. We found significant changes in all assessed blood parameters of fish in response to increasing doses from 0 to 1.5 mg of Cu-NPs or CuO. Similarly, increased levels of lipid peroxide and reduced glutathione (GSH) were also observed in the livers of C. carpio in Cu-NPs or CuO treated groups. Enhanced levels of lipid peroxidation and GSH were also recorded in the Cu-NP treated groups compared with the CuO treated groups in a dose dependent manner. The lowest catalase activity was observed in the liver of C. carpio treated with the higer dose of Cu-NPs. Cu-NP or CuO exposure induced significant histological alterations in the liver of C. carpio including focal necrosis, cloudy swelling of hepatocytes, degenerative hepatocytes, vacuolization, pyknotic nuclei, damaged central vein, nuclear hypertrophy, dilated sinusoid, vacuolated degeneration, congestion, and complete degeneration in a dose dependent manner. Substantial alterations in blood and liver specimens were observed in the Cu-NP treated fish when compared with the CuO treated fish. It appeared that the Cu-NPs were more toxic than the CuO as shown by the hemato- and

  9. Cu-Cr Literature Review

    Energy Technology Data Exchange (ETDEWEB)

    Need, Ryan F. [Los Alamos National Laboratory

    2012-08-09

    Cu-Cr alloys are part of a class of face-centered cubic (FCC)-body-centered cubic (BCC) composites that includes similar alloys, such as Cu-Nb and Cu-Ta. When heavily deformed, these FCC-BCC materials create 'in situ' composites with a characteristic structure-nanoscale BCC filaments in a ductile FCC matrix. The strength of these composites is vastly greater than predicted by the rule of mixtures, and has been shown to be inversely proportional to the filament spacing. Lower raw materials costs suggest that Cu-Cr alloys may offer more economical solution to high-strength, high-conductivity wire than either their Nb or Ta counterparts. However, Cr is also more brittle and soluble in Cu than Nb or Ta. These qualities necessitate thermal treatments to remove solute atoms from the Cu matrix, improve conductivity, and maintain the ductility of the Cr filaments. Through the use of different thermomechanical processing routes or the addition of select dopants, alloys with strength in excess of 1 GPa at 70% IACS have been achieved. To date, previous research on Cu-Cr alloys has focused on a relatively small number of alloy compositions and processing methods while the effects of dopants and ageing treatments have only been studied independently. Consequently, there remains considerable opportunity for the development and optimization of these alloys as a leading high-strength, high-conductivity material.

  10. Spatial part-set cuing facilitation.

    Science.gov (United States)

    Kelley, Matthew R; Parasiuk, Yuri; Salgado-Benz, Jennifer; Crocco, Megan

    2016-07-01

    Cole, Reysen, and Kelley [2013. Part-set cuing facilitation for spatial information. Journal of Experimental Psychology: Learning, Memory, & Cognition, 39, 1615-1620] reported robust part-set cuing facilitation for spatial information using snap circuits (a colour-coded electronics kit designed for children to create rudimentary circuit boards). In contrast, Drinkwater, Dagnall, and Parker [2006. Effects of part-set cuing on experienced and novice chess players' reconstruction of a typical chess midgame position. Perceptual and Motor Skills, 102(3), 645-653] and Watkins, Schwartz, and Lane [1984. Does part-set cuing test for memory organization? Evidence from reconstructions of chess positions. Canadian Journal of Psychology/Revue Canadienne de Psychologie, 38(3), 498-503] showed no influence of part-set cuing for spatial information when using chess boards. One key difference between the two procedures was that the snap circuit stimuli were explicitly connected to one another, whereas chess pieces were not. Two experiments examined the effects of connection type (connected vs. unconnected) and cue type (cued vs. uncued) on memory for spatial information. Using chess boards (Experiment 1) and snap circuits (Experiment 2), part-set cuing facilitation only occurred when the stimuli were explicitly connected; there was no influence of cuing with unconnected stimuli. These results are potentially consistent with the retrieval strategy disruption hypothesis, as well as the two- and three-mechanism accounts of part-set cuing.

  11. Microstructure and Mechanical Characterization of a Dissimilar Friction-Stir-Welded CuCrZr/CuNiCrSi Butt Joint

    Directory of Open Access Journals (Sweden)

    Youqing Sun

    2018-05-01

    Full Text Available Dissimilar CuNiCrSi and CuCrZr butt joints were successfully frictionstirwelded at constant welding speed of 150 mm/min and rotational speed of 1400 rpm with the CuCrZr alloy or the CuNiCrSi alloy located on the advancing side (AS. The microstructure and mechanical properties of joints were investigated. When the CuCrZr alloy was located on the AS, the area of retreating material in the nugget zone was a little bigger. The Cr solute-rich particles were found in the nugget zone on CuCrZr side (CuCrZr-NZ while a larger density of solute-rich particles identified as the concentration of Cr and Si element was found in the nugget zone on CuNiCrSi side (CuNiCrSi-NZ. The Cr precipitates and δ-Ni2Si precipitates were found in the base metal on CuNiCrSi side (CuNiCrSi-BM but only Cr precipitates can be observed in the base metal on CuCrZr side (CuCrZr-BM. Precipitates were totally dissolved into Cu matrix in both CuCrZr-NZ and CuNiCrSi-NZ, which led to a sharp decrease in both micro-hardness and tensile strength from BM to NZ. When the CuNiCrSi was located on the AS, the tensile testing results showed the fracture occurred at the CuCrZr-NZ, while the fracture was found at the mixed zone of CuNiCrSi-NZ and CuCrZr-NZ for the other case.

  12. Cu ion disordering in high ionic conductor Rb4Cu16I7Cl13

    International Nuclear Information System (INIS)

    Kawaji, Hitoshi; Atake, Tooru; Kanno, Ryoji; Izumi, Fujio; Yamamoto, Osamu.

    1993-01-01

    The properties of a high ionic conductor Rb 4 Cu 16 I 7+x Cl 13-x were studied by neutron and X-ray diffraction, and heat capacity measurements. The structure parameters of Rb 4 Cu 16 I 7.2 Cl 12.8 were obtained by the Rietveld analysis of TOF neutron diffraction data between 50 and 300 K, which showed gradual excitation of migration of Cu ions from Cu(3) site into Cu(2) site with increasing temperature from about 100 K to room temperature. The heat capacity was measured between 10 and 300 K using a high precision adiabatic calorimeter. An abnormal increase was observed in the heat capacity curve above about 100 K. The excess heat capacity showed a broad anomaly with a maximum at about 190 K. The measurements were also made of Rb 4 Cu 16 I 7 Cl 13 which showed slight different properties from Rb 4 Cu 16 I 7.2 Cl 12.8 . (author)

  13. Bonding in [CuNRR′]4 type clusters

    Institute of Scientific and Technical Information of China (English)

    WANG Bingwu; XU Guangxian; CHEN Zhida

    2004-01-01

    Many polynuclear Cu(I) compounds have been synthesized, but the problem whether there is direct or no direct Cu-Cu bonding in these compounds is not clear. The electronic structure of [CuNRR′]4 type clusters was investigated by using density functional methods. The results of geometrical optimization are in good agreement with experiment, and the localization of MO's shows that there are four Cu-Cu ( bonds to form the square Cu4 ring in addition to the four bridging Cu-N-Cu bonds. A concept of the covalence of molecular fragments is proposed to describe the bonding in these clusters.

  14. Virtual thermal expansion coefficient of Cu precipitated in the Fe95Cu5 alloy

    International Nuclear Information System (INIS)

    Koeszegi, L.; Somogyvari, Z.

    1999-01-01

    Complete text of publication follows. Precipitations on grain boundaries play very important role in the formation of material's characteristics like embrittlement, durability etc. It was already shown [1] that Cu precipitations are under different stress conditions than the bulk material. The situation is more complicated in the case when a construction is exposed to temperature changes as well. In that case not only the residual stresses during the fabrication but the different thermal expansion coefficients can produce additional problems. This situation was modelled using Fe 95 Cu 5 alloy where Cu precipitates on the grain boundaries. The alloy was produced by high-frequency melting and an extra heat treatment was used to produce a quasi-equilibrium state. Pure Cu was also measured to compare the behaviours. Cu(111) Bragg peak was measured at different temperatures by high resolution neutron diffraction. The measurements were carried out on the G5-2 spectrometer at LLB in Saclay. Measurements show that not only residual stress can be recognised on the Cu precipitates but the thermal expansion coefficient of these precipitates definitly differ from the ones of pure Cu. (author)

  15. Loss of reserves of Cu in liver when Cu supplements are withdrawn from dairy herds in the Waikato region.

    Science.gov (United States)

    Hittmann, A R; Grace, N D; Knowles, S O

    2012-03-01

    To monitor the consequences of withdrawing mineral Cu supplements from two dairy herds with initially high concentrations of Cu in liver. Two herds were selected from dairy farms in the Waikato region of New Zealand that participated in an earlier survey of Cu supplementation practices and Cu status of dairy cows. The herds were fed pasture, grass and maize silage, plus palm kernel expeller (PKE) containing 25-30 mg Cu/kg dry matter (DM) fed at 2-4 kg/cow/day. No mineral Cu supplements were supplied from January 2009. Pasture samples were collected for mineral analysis in September 2008 and April 2009. Concentration of Cu in liver biopsies from the same 9-10 cows per herd was measured on three occasions between April 2009 and May 2010. Pastures on both farms contained 10 mg Cu/kg DM, 0.1-0.5 mg Mo/kg DM and 3.5-4.0 g S/kg DM. The initial herd mean concentrations of Cu in liver were 1,500 (SD 590) and 1,250 (SD 640) μmol Cu/kg fresh tissue. In the absence of mineral Cu supplements, those mean concentrations decreased over 12 months to 705 (SD 370) and 1,120 (SD 560) μmol Cu/kg fresh tissue, respectively. For cows in the first herd, the rate of depletion of liver Cu reserves was influenced by initial concentration of Cu, such that high concentration led to faster loss according to first-order kinetics. Mineral Cu supplementation was not necessary over 12 months for two dairy herds with mean concentrations of Cu in liver >1,250 μmol Cu/kg fresh tissue, grazing pastures containing 10 mg Cu/kg DM and concentrations of Mo <1 mg/kg DM. The quantity and particularly the duration of feeding PKE appeared to be a factor in whether or not the herd lost substantial reserves of Cu in liver during the year. However, the Cu status of both herds in this study was more than adequate to support late pregnancy and mating. CLINICAL REVELANCE: Copper status of the herd should be monitored and on-farm management of Cu nutrition should take into account all sources contributing to

  16. Thermodynamic optimization of the Cu-Nd system

    International Nuclear Information System (INIS)

    Wang Peisheng; Zhou Liangcai; Du Yong; Xu Honghui; Liu Shuhong; Chen Li; Ouyang Yifang

    2011-01-01

    Research highlights: → The enthalpies of formation of the compounds Cu 6 Nd, Cu 5 Nd, Cu 2 Nd and αCuNd were calculated using DFT. → The thermodynamic constraints to eliminate the artificial phase relations were imposed during the thermodynamic optimization procedure. → The Cu-Nd system was optimized under the thermodynamic constraints. - Abstract: The thermodynamic constraints to eliminate artificial phase relations were introduced with the Cu-Nd system as an example. The enthalpies of formation of the compounds Cu 6 Nd, Cu 5 Nd, Cu 2 Nd and αCuNd are calculated using density functional theory. Taking into account all the experimental data and the first-principles calculated enthalpies of formation of these compounds, the thermodynamic optimization of the Cu-Nd system was performed under the proposed thermodynamic constraints. It is demonstrated that the thermodynamic constraints are critical to obtain a set of thermodynamic parameters for the Cu-Nd system, which can avoid the appearance of all the artificial phase relations.

  17. Cu-segregation at the Q'/α-Al interface in Al-Mg-Si-Cu alloy

    International Nuclear Information System (INIS)

    Matsuda, Kenji; Teguri, Daisuke; Uetani, Yasuhiro; Sato, Tatsuo; Ikeno, Susumu

    2002-01-01

    Cu segregation was detected at the Q ' /α-Al interface in an Al-Mg-Si-Cu alloy by energy-filtered transmission electron microscopy. By contrast, in a Cu-free Al-Mg-Si alloy no segregation was observed at the interface between the matrix and Type-C precipitate

  18. Cu and Cu(Mn) films deposited layer-by-layer via surface-limited redox replacement and underpotential deposition

    Energy Technology Data Exchange (ETDEWEB)

    Fang, J.S., E-mail: jsfang@nfu.edu.tw [Department of Materials Science and Engineering, National Formosa University, Huwei 63201, Taiwan (China); Sun, S.L. [Department of Materials Science and Engineering, National Formosa University, Huwei 63201, Taiwan (China); Cheng, Y.L. [Department of Electrical Engineering, National Chi-Nan University, Nan-Tou 54561, Taiwan (China); Chen, G.S.; Chin, T.S. [Department of Materials Science and Engineering, Feng Chia University, Taichung 40724, Taiwan (China)

    2016-02-28

    Graphical abstract: - Abstract: The present paper reports Cu and Cu(Mn) films prepared layer-by-layer using an electrochemical atomic layer deposition (ECALD) method. The structure and properties of the films were investigated to elucidate their suitability as Cu interconnects for microelectronics. Previous studies have used primarily a vacuum-based atomic layer deposition to form a Cu metallized film. Herein, an entirely wet chemical process was used to fabricate a Cu film using the ECALD process by combining underpotential deposition (UPD) and surface-limited redox replacement (SLRR). The experimental results indicated that an inadequate UPD of Pb affected the subsequent SLRR of Cu and lead to the formation of PbSO{sub 4}. A mechanism is proposed to explain the results. Layer-by-layer deposition of Cu(Mn) films was successfully performed by alternating the deposition cycle-ratios of SLRR-Cu and UPD-Mn. The proposed self-limiting growth method offers a layer-by-layer wet chemistry-based deposition capability for fabricating Cu interconnects.

  19. Reaction pathways of furfural, furfuryl alcohol and 2-methylfuran on Cu(111) and NiCu bimetallic surfaces

    Science.gov (United States)

    Xiong, Ke; Wan, Weiming; Chen, Jingguang G.

    2016-10-01

    Hydrodeoxygenation (HDO) is an important reaction for converting biomass-derived furfural to value-added 2-methylfuran, which is a promising fuel additive. In this work, the HDO of furfural to produce 2-methylfuran occurred on the NiCu bimetallic surfaces prepared on either Ni(111) or Cu(111). The reaction pathways of furfural were investigated on Cu(111) and Ni/Cu(111) surfaces using density functional theory (DFT) calculations, temperature-programmed desorption (TPD) and high-resolution electron energy loss spectroscopy (HREELS) experiments. These studies provided mechanistic insights into the effects of bimetallic formation on enhancing the HDO activity. Specifically, furfural weakly adsorbed on Cu(111), while it strongly adsorbed on Ni/Cu(111) through an η2(C,O) configuration, which led to the HDO of furfural on Ni/Cu(111). The ability to dissociate H2 on Ni/Cu(111) is also an important factor for enhancing the HDO activity over Cu(111).

  20. Sulfur induced Cu4 tetramers on Cu(111)

    DEFF Research Database (Denmark)

    Foss, M.; Feidenhans'l, R.; Nielsen, M.

    1997-01-01

    The structures of the Cu(111) and the Cu(111)(root 7 x root 7)R19.1 degrees-S reconstructions have been studied by surface X-ray diffraction and two new structural models are proposed. Although the unit cells for the two structures are quite different, a high degree of similarity has been reveale...

  1. Diffusion characteristics in the Cu-Ti system

    Energy Technology Data Exchange (ETDEWEB)

    Laik, Arijit; Kale, Gajanan Balaji [Bhabha Atomic Reseach Centre, Mumbai (India). Materials Science Div.; Bhanumurthy, Karanam [Bhabha Atomic Reseach Centre, Mumbai (India). Scientific Information Resource Div.; Kashyap, Bhagwati Prasad [Indian Institute of Technology Bombay, Mumbai (India). Dept. of Metallurgical Engineering

    2012-06-15

    The formation and growth of intermetallic compounds by diffusion reaction of Cu and Ti were investigated in the temperature range 720 - 860 C using bulk diffusion couples. Only four, out of the seven stable intermediate compounds of the Cu-Ti system, were formed in the diffusion reaction zone in the sequence CuTi, Cu{sub 4}Ti, Cu{sub 4}Ti{sub 3} and CuTi{sub 2}. The activation energies required for the growth of these compounds were determined. The diffusion characteristics of Cu{sub 4}Ti, CuTi and Cu{sub 4}Ti{sub 3} and Cu(Ti) solid solution were evaluated. The activation energies for diffusion in these compounds were 192.2, 187.7 and 209.2 kJ mol{sup -1} respectively, while in Cu(Ti), the activation energy increased linearly from 201.0 kJ mol{sup -1} to 247.5 kJ mol{sup -1} with increasing concentration of Ti, in the range 0.5 - 4.0 at.%. The impurity diffusion coefficient of Ti in Cu and its temperature dependence were also estimated. A correlation between the impurity diffusion parameters for several elements in Cu matrix has been established. (orig.)

  2. Syntheses, structures, and properties of imidazolate-bridged Cu(II)-Cu(II) and Cu(II)-Zn(II) dinuclear complexes of a single macrocyclic ligand with two hydroxyethyl pendants.

    Science.gov (United States)

    Li, Dongfeng; Li, Shuan; Yang, Dexi; Yu, Jiuhong; Huang, Jin; Li, Yizhi; Tang, Wenxia

    2003-09-22

    The imidazolate-bridged homodinuclear Cu(II)-Cu(II) complex, [(CuimCu)L]ClO(4).0.5H(2)O (1), and heterodinuclear Cu(II)-Zn(II) complex, [(CuimZnL(-)(2H))(CuimZnL(-)(H))](ClO(4))(3) (2), of a single macrocyclic ligand with two hydroxyethyl pendants, L (L = 3,6,9,16,19,22-hexaaza-6,19-bis(2-hydroxyethyl)tricyclo[22,2,2,2(11,14)]triaconta-1,11,13,24,27,29-hexaene), have been synthesized as possible models for copper-zinc superoxide dismutase (Cu(2),Zn(2)-SOD). Their crystal structures analyzed by X-ray diffraction methods have shown that the structures of the two complexes are markedly different. Complex 1 crystallizes in the orthorhombic system, containing an imidazolate-bridged dicopper(II) [Cu-im-Cu](3+) core, in which the two copper(II) ions are pentacoordinated by virtue of an N4O environment with a Cu.Cu distance of 5.999(2) A, adopting the geometry of distorted trigonal bipyramid and tetragonal pyramid, respectively. Complex 2 crystallizes in the triclinic system, containing two similar Cu-im-Zn cores in the asymmetric unit, in which both the Cu(II) and Zn(II) ions are pentacoordinated in a distorted trigonal bipyramid geometry, with the Cu.Zn distance of 5.950(1)/5.939(1) A, respectively. Interestingly, the macrocyclic ligand with two arms possesses a chairlike (anti) conformation in complex 1, but a boatlike (syn) conformation in complex 2. Magnetic measurements and ESR spectroscopy of complex 1 have revealed the presence of an antiferromagnetic exchange interaction between the two Cu(II) ions. The ESR spectrum of the Cu(II)-Zn(II) heterodinuclear complex 2 displayed a typical signal for mononuclear trigonal bipyramidal Cu(II) complexes. From pH-dependent ESR and electronic spectroscopic studies, the imidazolate bridges in the two complexes have been found to be stable over broad pH ranges. The cyclic voltammograms of the two complexes have been investigated. Both of the two complexes can catalyze the dismutation of superoxide and show rather high activity.

  3. ZrCu2P2 and HfCu2P2 phosphides and their crystal structure

    International Nuclear Information System (INIS)

    Lomnitskaya, Ya.F.

    1986-01-01

    Isostructural ZrCu 2 P 2 and HfCu 2 P 2 compounds are prepared for the first time. X-ray diffraction analysis (of powder, DRON-2.0 diffractometer, FeKsub(α) radiation) was used to study crystal structure of HfCu 2 P 2 phosphide belonging to the CaAl 2 Si 2 structural type (sp. group P anti 3 m 1, R=0.095). Lattice parameters the compounds are as follows: for ZrCu 2 P 2 a=0.3810(1), c=0.6184(5); for HfCu 2 P 2 a=0.3799(1), c=0.6160(2) (nm). Atomic parameters in the HfCu 2 P 2 structure and interatomic distances are determined

  4. Photoelectron and computational studies of the copper-nucleoside anionic complexes, Cu-(cytidine) and Cu-(uridine)

    Science.gov (United States)

    Li, Xiang; Ko, Yeon-Jae; Wang, Haopeng; Bowen, Kit H.; Guevara-García, Alfredo; Martínez, Ana

    2011-02-01

    The copper-nucleoside anions, Cu-(cytidine) and Cu-(uridine), have been generated in the gas phase and studied by both experimental (anion photoelectron spectroscopy) and theoretical (density functional calculations) methods. The photoelectron spectra of both systems are dominated by single, intense, and relatively narrow peaks. These peaks are centered at 2.63 and 2.71 eV for Cu-(cytidine) and Cu-(uridine), respectively. According to our calculations, Cu-(cytidine) and Cu-(uridine) species with these peak center [vertical detachment energy (VDE)] values correspond to structures in which copper atomic anions are bound to the sugar portions of their corresponding nucleosides largely through electrostatic interactions; the observed species are anion-molecule complexes. The combination of experiment and theory also reveal the presence of a slightly higher energy, anion-molecule complex isomer in the case of the Cu-(cytidine). Furthermore, our calculations found that chemically bond isomers of these species are much more stable than their anion-molecule complex counterparts, but since their calculated VDE values are larger than the photon energy used in these experiments, they were not observed.

  5. Photoelectron and computational studies of the copper-nucleoside anionic complexes, Cu(-)(cytidine) and Cu(-)(uridine).

    Science.gov (United States)

    Li, Xiang; Ko, Yeon-Jae; Wang, Haopeng; Bowen, Kit H; Guevara-García, Alfredo; Martínez, Ana

    2011-02-07

    The copper-nucleoside anions, Cu(-)(cytidine) and Cu(-)(uridine), have been generated in the gas phase and studied by both experimental (anion photoelectron spectroscopy) and theoretical (density functional calculations) methods. The photoelectron spectra of both systems are dominated by single, intense, and relatively narrow peaks. These peaks are centered at 2.63 and 2.71 eV for Cu(-)(cytidine) and Cu(-)(uridine), respectively. According to our calculations, Cu(-)(cytidine) and Cu(-)(uridine) species with these peak center [vertical detachment energy (VDE)] values correspond to structures in which copper atomic anions are bound to the sugar portions of their corresponding nucleosides largely through electrostatic interactions; the observed species are anion-molecule complexes. The combination of experiment and theory also reveal the presence of a slightly higher energy, anion-molecule complex isomer in the case of the Cu(-)(cytidine). Furthermore, our calculations found that chemically bond isomers of these species are much more stable than their anion-molecule complex counterparts, but since their calculated VDE values are larger than the photon energy used in these experiments, they were not observed.

  6. Impact parameter dependence of K-shell ionization in Cu-Cu collisions

    International Nuclear Information System (INIS)

    Frank, W.; Jaracz, P.; Kaun, K.-H.; Lenk, M.; Rudiger, J.; Stachura, Z.

    1980-01-01

    The impact parameter dependence of the yield of K-shell vacancy production in 1 MeV/ a.m.u. Cu-Cu collisions has been studied in an X-ray-scattered ion coincidence experiment. The results are compared with existing models for K-vacancy production

  7. Thermal stability of Py/Cu and Co/Cu giant magnetoresistance (GMR) multilayer systems

    Energy Technology Data Exchange (ETDEWEB)

    Vovk, Vitaliy

    2007-07-01

    NiFe/Cu and Co/Cu multilayer systems have been studied regarding the mechanisms of thermal degradation of the giant magnetoresistance effect (GMR). The different thermodynamics of the studied systems results in different mechanisms of the GMR degradation as shown by highest resolution nanoanalysis using the three dimensional wide angle tomographic atom probe. According to the TAP analysis, GMR deterioration in Py/Cu system occurs due to the broadening of the layer interfaces observed at 250 C. In contrast, due to the strong demixing tendency, Co/Cu multilayers remain stable up to 450 C. At higher temperatures ferromagnetic bridging of the neighboring Co layers takes place leading to the GMR breakdown. In both Py/Cu and Co/Cu systems recrystallization is induced at 350-450 C, which is accompanied by a change in the crystallographic orientation from <111> to <100> wire texture. The reaction may be utilized to produce GMR sensor layers of remarkable thermal stability. Although the systems of interest are equivalent in respect of the observed phenomenon, the Ni{sub x}Fe{sub 1-x}/Cu system is chosen for a detailed analysis because it allows a precise control of the lattice constant by varying the Fe content in the Ni{sub x}Fe{sub 1-x} layer. It is shown that the crystallographic reorientation is triggered by the minimization of lattice mismatch elastic energy. Moreover, the counteraction between the elastic and interfacial energy minimizations exerts a critical influence on the recrystallization probability. (orig.)

  8. Mechanochemical synthesis of Cu-Al and methyl orange intercalated Cu-Al layered double hydroxides

    International Nuclear Information System (INIS)

    Qu, Jun; He, Xiaoman; Chen, Min; Hu, Huimin; Zhang, Qiwu; Liu, Xinzhong

    2017-01-01

    In this study, a mechanochemical route to synthesize a Cu-Al layered double hydroxide (LDH) and a methyl orange (MO) intercalated one (MO-LDH) was introduced, in which basic cupric carbonate (Cu_2(OH)_2CO_3) and aluminum hydroxide (Al(OH)_3) with Cu/Al molar ratio at 2/1 was first dry ground for 2 h and then agitated in water or methyl orange solution for another 4 h to obtain the LDH and MO-LDH products without any heating operation. The prepared samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Thermogravimetry (TG), Differential scanning calorimetry (DSC) and Scanning electron microscopy (SEM). The products showed high crystallinity phase of Cu-Al and MO intercalated Cu-Al LDH with no evident impurities, proving that the craft introduced here was facile and effective. The new idea can be applied in other fields to produce organic-inorganic composites. - Highlights: • A facile mechanochemical route to synthesize Cu-Al and MO intercalated Cu-Al LDH. • The products possesses high crystalline of LDH phase with no impure phases. • The dry milling process induces the element substitution between the raw materials. • The agitation operation helps the grain growth of LDH.

  9. Mechanochemical synthesis of Cu-Al and methyl orange intercalated Cu-Al layered double hydroxides

    Energy Technology Data Exchange (ETDEWEB)

    Qu, Jun, E-mail: forsjun@whut.edu.cn [School of Resources and Environmental Engineering, Wuhan University of Technology, Luoshi Road 122, Wuhan, Hubei 430070 (China); He, Xiaoman; Chen, Min; Hu, Huimin [School of Resources and Environmental Engineering, Wuhan University of Technology, Luoshi Road 122, Wuhan, Hubei 430070 (China); Zhang, Qiwu, E-mail: zhangqw@whut.edu.cn [School of Resources and Environmental Engineering, Wuhan University of Technology, Luoshi Road 122, Wuhan, Hubei 430070 (China); Liu, Xinzhong [College of Ecological Environment and Urban Construction, Fujian University of Technology, Fuzhou 350118 China (China)

    2017-04-15

    In this study, a mechanochemical route to synthesize a Cu-Al layered double hydroxide (LDH) and a methyl orange (MO) intercalated one (MO-LDH) was introduced, in which basic cupric carbonate (Cu{sub 2}(OH){sub 2}CO{sub 3}) and aluminum hydroxide (Al(OH){sub 3}) with Cu/Al molar ratio at 2/1 was first dry ground for 2 h and then agitated in water or methyl orange solution for another 4 h to obtain the LDH and MO-LDH products without any heating operation. The prepared samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Thermogravimetry (TG), Differential scanning calorimetry (DSC) and Scanning electron microscopy (SEM). The products showed high crystallinity phase of Cu-Al and MO intercalated Cu-Al LDH with no evident impurities, proving that the craft introduced here was facile and effective. The new idea can be applied in other fields to produce organic-inorganic composites. - Highlights: • A facile mechanochemical route to synthesize Cu-Al and MO intercalated Cu-Al LDH. • The products possesses high crystalline of LDH phase with no impure phases. • The dry milling process induces the element substitution between the raw materials. • The agitation operation helps the grain growth of LDH.

  10. DO22-(Cu,Ni)3Sn intermetallic compound nanolayer formed in Cu/Sn-nanolayer/Ni structures

    International Nuclear Information System (INIS)

    Liu Lilin; Huang, Haiyou; Fu Ran; Liu Deming; Zhang Tongyi

    2009-01-01

    The present work conducts crystal characterization by High Resolution Transmission Electron Microscopy (HRTEM) on Cu/Sn-nanolayer/Ni sandwich structures associated with the use of Energy Dispersive X-ray (EDX) analysis. The results show that DO 22 -(Cu,Ni) 3 Sn intermetallic compound (IMC) ordered structure is formed in the sandwich structures at the as-electrodeposited state. The formed DO 22 -(Cu,Ni) 3 Sn IMC is a homogeneous layer with a thickness about 10 nm. The DO 22 -(Cu,Ni) 3 Sn IMC nanolayer is stable during annealing at 250 deg. C for 810 min. The formation and stabilization of the metastable DO 22 -(Cu,Ni) 3 Sn IMC nanolayer are attributed to the less strain energy induced by lattice mismatch between the DO 22 IMC and fcc Cu crystals in comparison with that between the equilibrium DO 3 IMC and fcc Cu crystals.

  11. Electronic states of the θ' phase in Cu-Al alloys as compared to C16-CuAl2: Cu Lα emission excited directly by undulator radiation

    Science.gov (United States)

    Dallera, C.; de Michelis, B.; Puppin, E.; Braicovich, L.; Brookes, N. B.

    1996-01-01

    The electronic states of the θ' phase formed by thermal aging in the Al-Cu (0.5 at. %) alloy are compared with those in C16-CuAl2, which is the final phase separated at equilibrium. This is done by means of Cu Lα fluorescence spectroscopy. The high brilliance of undulator radiation used as an excitation source is exploited. The spectra are taken using the first harmonic of the undulator at 1.7 keV, with a full width half maximum of ~250 eV. A narrowing of around 0.5 eV of the Cu Lα spectra in the θ' phase is found. This is explained in terms of the differences in the Cu 3d-Cu 3d interaction in the two phases and of the hybridization between Cu 3d and the nearly free-electron-like electrons. The results demonstrate the future possibilities of fluorescence spectroscopy of minority species in inhomogeneous systems.

  12. Moisture barrier properties of single-layer graphene deposited on Cu films for Cu metallization

    Science.gov (United States)

    Gomasang, Ploybussara; Abe, Takumi; Kawahara, Kenji; Wasai, Yoko; Nabatova-Gabain, Nataliya; Thanh Cuong, Nguyen; Ago, Hiroki; Okada, Susumu; Ueno, Kazuyoshi

    2018-04-01

    The moisture barrier properties of large-grain single-layer graphene (SLG) deposited on a Cu(111)/sapphire substrate are demonstrated by comparing with the bare Cu(111) surface under an accelerated degradation test (ADT) at 85 °C and 85% relative humidity (RH) for various durations. The change in surface color and the formation of Cu oxide are investigated by optical microscopy (OM) and X-ray photoelectron spectroscopy (XPS), respectively. First-principle simulation is performed to understand the mechanisms underlying the barrier properties of SLG against O diffusion. The correlation between Cu oxide thickness and SLG quality are also analyzed by spectroscopic ellipsometry (SE) measured on a non-uniform SLG film. SLG with large grains shows high performance in preventing the Cu oxidation due to moisture during ADT.

  13. Preparation of Uniform Hexapod Cu{sub 2}O and Hollow Hexapod CuO

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Youngsik; Huh, Youngduk [Dankook Univ., Yongin (Korea, Republic of)

    2013-10-15

    The filled hexapod Cu{sub 2}O precursors were also prepared under microwave irradiation for only 120 s using a commercial microwave oven. The optimal experimental conditions for the perfect and uniform hexapod-like Cu{sub 2}O precursors were examined. The control of the cooling rate by adding cold water was also examined for the elimination of further crystal growth at the end of the arm of the hexapod Cu{sub 2}O precursors due to the thermal diffusion in reaction medium. The uniform hollow structure and hexapod CuO products were also prepared from the direct thermal oxidation of the filled hexapod Cu{sub 2}O precursors. The morphology-dependent properties of inorganic materials, such as magnetic, photocatalytic, and antibacterial activities, is one of the most important experimental issues in inorganic technology. Many researchers have prepared uniform and specific shaped inorganic oxides to understand the morphology-dependent properties of inorganic oxides.

  14. Modeling Photoelectron Spectra of CuO, Cu2O, and CuO2 Anions with Equation-of-Motion Coupled-Cluster Methods: An Adventure in Fock Space.

    Science.gov (United States)

    Orms, Natalie; Krylov, Anna I

    2018-04-12

    The experimental photoelectron spectra of di- and triatomic copper oxide anions have been reported previously. We present an analysis of the experimental spectra of the CuO - , Cu 2 O - , and CuO 2 - anions using equation-of-motion coupled-cluster (EOM-CC) methods. The open-shell electronic structure of each molecule demands a unique combination of EOM-CC methods to achieve an accurate and balanced representation of the multiconfigurational anionic- and neutral-state manifolds. Analysis of the Dyson orbitals associated with photodetachment from CuO - reveals the strong non-Koopmans character of the CuO states. For the lowest detachment energy, a good agreement between theoretical and experimental values is obtained with CCSD(T) (coupled-cluster with single and double excitations and perturbative account of triple excitations). The (T) correction is particularly important for Cu 2 O - . Use of a relativistic pseudopotential and matching basis set improves the quality of results in most cases. EOM-DIP-CCSD analysis of the low-lying states of CuO 2 - reveals multiple singlet and triplet anionic states near the triplet ground state, adding an extra layer of complexity to the interpretation of the experimental CuO 2 - photoelectron spectrum.

  15. Influence of body size on Cu bioaccumulation in zebra mussels Dreissena polymorpha exposed to different sources of particle-associated Cu

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Huan, E-mail: huanzhong1982@hotmail.com [Environmental and Resource Studies Program, Trent University, Peterborough, Ontario (Canada); Nanjing University, School of Environment, State Key Laboratory of Pollution Control and Resource Reuse, Nanjing, Jiangsu Province (China); Kraemer, Lisa; Evans, Douglas [Environmental and Resource Studies Program, Trent University, Peterborough, Ontario (Canada)

    2013-10-15

    Highlights: • Mussels exposed to algal/sediment-Cu have different size-related Cu accumulation. • Size-related Cu accumulation in mussels could be more dependant on algal-Cu uptake. • Importance of algal/sediment-Cu to Cu bioaccumulation varies with mussel body size. • Cu sources (algae and sediments) should be considered in “mussel watch” programs. • Cu stable isotope offers many advantages in Cu bioaccumulation studies. -- Abstract: Size of organisms is critical in controlling metal bioavailability and bioaccumulation, while mechanisms of size-related metal bioaccumulation are not fully understood. To investigate the influences of different sources of particle-associated Cu on body size-related Cu bioavailability and bioaccumulation, zebra mussels (Dreissena polymorpha) of different sizes were exposed to stable Cu isotope ({sup 65}Cu) spiked algae (Chlorella vulgaris) or sediments in the laboratory and the Cu tissue concentration-size relationships were compared with that in unexposed mussels. Copper tissue concentrations decreased with mussel size (tissue or shell dry weight) in both unexposed and algal-exposed mussels with similar decreasing patterns, but were independent of size in sediment-exposed mussels. Furthermore, the relative contribution of Cu uptake from algae (65–91%) to Cu bioaccumulation is always higher than that from sediments (9–35%), possibly due to the higher bioavailability of algal-Cu. Therefore, the size-related ingestion of algae could be more important in influencing the size-related variations in Cu bioaccumulation. However, the relative contribution of sediment-Cu to Cu bioaccumulation increased with body size and thus sediment ingestion may also affect the size-related Cu variations in larger mussels (tissue weight >7.5 mg). This study highlights the importance of considering exposure pathways in normalization of metal concentration variation when using bivalves as biomonitors.

  16. Local Environment Sensitivity of the Cu K-Edge XANES Features in Cu-SSZ-13: Analysis from First-Principles.

    Science.gov (United States)

    Zhang, Renqin; McEwen, Jean-Sabin

    2018-05-22

    Cu K-edge X-ray absorption near-edge spectra (XANES) have been widely used to study the properties of Cu-SSZ-13. In this Letter, the sensitivity of the XANES features to the local environment for a Cu + cation with a linear configuration and a Cu 2+ cation with a square-linear configuration in Cu-SSZ-13 is reported. When a Cu + cation is bonded to H 2 O or NH 3 in a linear configuration, the XANES has a strong peak at around 8983 eV. The intensity of this peak decreases as the linear configuration is broken. As for the Cu 2+ cations in a square-planar configuration with a coordination number of 4, two peaks at around 8986 and 8993 eV are found. An intensity decrease for both peaks at around 8986 and 8993 eV is found in an NH 3 _4_Z 2 Cu model as the N-Cu-N angle changes from 180 to 100°. We correlate these features to the variation of the 4p state by PDOS analysis. In addition, the feature peaks for both the Cu + cation and Cu 2+ cation do not show a dependence on the Cu-N bond length. We further show that the feature peaks also change when the coordination number of the Cu cation is varied, while these feature peaks are independent of the zeolite topology. These findings help elucidate the experimental XANES features at an atomic and an electronic level.

  17. Bonding in d9 complexes derived from EPR: Application to CuCl2-4, CuBr2-4, and CdCl2:Cu2+

    Science.gov (United States)

    Aramburu, J. A.; Moreno, M.

    1985-12-01

    In this work are reported the theoretical expressions for the [g], hyperfine, and superhyperfine (shf) tensors of a d9 square-planar complex within a molecular orbital (MO) scheme. These expressions include contributions arising from crystal field and charge transfer excitations calculated up to third and second order perturbations, respectively. This makes the present framework more general than those previously used. Through those expressions we have derived from the experimental EPR and optical data the MO coefficients corresponding to the valence b1g(x2-y2), b2g(xy), and eg(xz,yz) levels and also the core polarization contribution K to the hyperfine tensor for the systems CuCl2-4, CuBr2-4, and CdCl2:Cu2+. The 3d charge obtained for CuCl2-4 is equal to 0.61, 0.83, and 0.85 for the antibonding 3b1g, 2b2g, and 2eg levels, respectively. These figures are much closer to the Xα results by Bencini and Gatteschi [J. Am. Chem. Soc. 105, 5535 (1983)] than to those by Desjardins et al. [J. Am. Chem. Soc. 105, 4590 (1983)]. The σ and π covalency for CuBr2-4 are both higher than for CuCl2-4 in accord to the lower electronegativity for bromine. However, only for the antibonding 3b1g level of CuBr2-4 have we obtained an electronic charge lying mainly on ligands. The covalency of CdCl2:Cu2+ is smaller than that found for CuCl2-4, a fact associated to a higher metal-ligand distance for the former. Evidence of this statement are also given from the analysis of crystal-field spectra and isotropic shf constant. The values of K derived for CuCl2-4 (128.1×10-4 cm-1), CuBr2-4 (103.6×10-4 cm-1), and CdCl2:Cu2+ (123.9×10-4 cm-1) point out the dependence of K on the equatorial covalency but also on the existence of axial ligands. The [g] tensor of CuBr2-4 is dominated by the charge transfer contribution while the crystal field one is negative. Finally an analysis of the importance of each one of the involved contributions to the spin-Hamiltonian parameters is reported for the

  18. Damage behavior of SnAgCu/Cu solder joints subjected to thermomechanical cycling

    International Nuclear Information System (INIS)

    Xiao, H.; Li, X.Y.; Hu, Y.; Guo, F.; Shi, Y.W.

    2013-01-01

    Highlights: •A creep–fatigue damage model based on CDM was proposed. •Designed system includes load frame, strain measure device and damage test device. •Damage evolution of solder joints was a function of accumulated inelastic strain. •Damage of solder joints is an interaction between creep and low-cycle fatigue. -- Abstract: Thermomechanical fatigue damage is a progressive process of material degradation. The objective of this study was to investigate the damage behavior of SnAgCu/Cu solder joints under thermomechanical cycling. A damage model was proposed based on continuum damage mechanics (CDM). Based upon an analysis of displacements for flip-chip solder joints subjected to thermal cycling, a special bimetallic loading frame with single-solder joint samples was designed to simulate the service conditions of actual joints in electronic packages. The assembly, which allowed for strain measurements of an individual solder joint during temperature cycling, was used to investigate the impact of stress–strain cycling on the damage behavior of SnAgCu/Cu solder joints. The characteristic parameters of the damage model were determined through thermomechanical cycling and strain measurement tests. The damage variable D = 1 − R 0 /R was selected, and values for it were obtained using a four-probe method for the single-solder joint samples every dozen cycles during thermomechanical cycling tests to verify the model. The results showed that the predicted damage was in good agreement with the experimental results. The damage evolution law proposed here is a function of inelastic strain, and the results showed that the damage rate of SnAgCu/Cu solder joints increased as the range of the applied strain increased. In addition, the microstructure evolution of the solder joints was analyzed using scanning electron microscopy, which provided the microscopic explanation for the damage evolution law of SnAgCu/Cu solder joints

  19. Damage behavior of SnAgCu/Cu solder joints subjected to thermomechanical cycling

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, H., E-mail: xiaohui2013@yahoo.com.cn; Li, X.Y.; Hu, Y.; Guo, F.; Shi, Y.W.

    2013-11-25

    Highlights: •A creep–fatigue damage model based on CDM was proposed. •Designed system includes load frame, strain measure device and damage test device. •Damage evolution of solder joints was a function of accumulated inelastic strain. •Damage of solder joints is an interaction between creep and low-cycle fatigue. -- Abstract: Thermomechanical fatigue damage is a progressive process of material degradation. The objective of this study was to investigate the damage behavior of SnAgCu/Cu solder joints under thermomechanical cycling. A damage model was proposed based on continuum damage mechanics (CDM). Based upon an analysis of displacements for flip-chip solder joints subjected to thermal cycling, a special bimetallic loading frame with single-solder joint samples was designed to simulate the service conditions of actual joints in electronic packages. The assembly, which allowed for strain measurements of an individual solder joint during temperature cycling, was used to investigate the impact of stress–strain cycling on the damage behavior of SnAgCu/Cu solder joints. The characteristic parameters of the damage model were determined through thermomechanical cycling and strain measurement tests. The damage variable D = 1 − R{sub 0}/R was selected, and values for it were obtained using a four-probe method for the single-solder joint samples every dozen cycles during thermomechanical cycling tests to verify the model. The results showed that the predicted damage was in good agreement with the experimental results. The damage evolution law proposed here is a function of inelastic strain, and the results showed that the damage rate of SnAgCu/Cu solder joints increased as the range of the applied strain increased. In addition, the microstructure evolution of the solder joints was analyzed using scanning electron microscopy, which provided the microscopic explanation for the damage evolution law of SnAgCu/Cu solder joints.

  20. Nanoporous Al sandwich foils using size effect of Al layer thickness during Cu/Al/Cu laminate rolling

    Science.gov (United States)

    Yu, Hailiang; Lu, Cheng; Tieu, A. Kiet; Li, Huijun; Godbole, Ajit; Kong, Charlie

    2018-06-01

    The roll bonding technique is one of the most widely used methods to produce metal laminate sheets. Such sheets offer interesting research opportunities for both scientists and engineers. In this paper, we report on an experimental investigation of the 'thickness effect' during laminate rolling for the first time. Using a four-high multifunction rolling mill, Cu/Al/Cu laminate sheets were fabricated with a range of thicknesses (16, 40, 70 and 130 μm) of the Al layer. The thickness of the Cu sheets was a constant 300 μm. After rolling, TEM images show good bonding quality between the Cu and Al layers. However, there are many nanoscale pores in the Al layer. The fraction of nanoscale pores in the Al layer increases with a reduction in the Al layer thickness. The finite element method was used to simulate the Cu/Al/Cu rolling process. The simulation results reveal the effect of the Al layer thickness on the deformation characteristics of the Cu/Al/Cu laminate. Finally, we propose that the size effect of the Al layer thickness during Cu/Al/Cu laminate rolling may offer a method to fabricate 'nanoporous' Al sandwich laminate foils. Such foils can be used in electromagnetic shielding of electrical devices and noisy shielding of building.

  1. Study of properties of Cu-Y and Cu-Y-Al system alloys

    International Nuclear Information System (INIS)

    Shparo, N.B.; Nikolaev, A.K.; Rozenberg, V.M.

    1978-01-01

    Investigated were the strength properties of alloys Cu(0-1.2)% Y and Cu-(10-0.5)% Al-(0-0.5)% Y after being treated under various heat conditions and tested at temperatures of 20, 400 and 600 deg C. Yttrium additions raise the temperature of recrystallization of copper and of copper-aluminium alloys. Small additions of yttrium (0.05%) increase considerably strength of Cu-Al alloys without increasing their electric resistance. Optimum properties are attained after hardening, deformation and ageing at 400 deg C

  2. Formation of layered microstructure in the Y-Ba-Cu-O and Bi-Sr-Ca-Cu-O superconductors

    International Nuclear Information System (INIS)

    Jin, S.; Kammlott, G.W.; Tiefel, T.H.; Chen, S.K.

    1992-01-01

    The layered grain microstructure is essential for overcoming the weak link problem and ensuring high transport critical currents in the cuprate superconductors. In this paper we discuss the processing and the mechanisms for layer information in Y-Ba-Cu-O and Bi-Sr-Ca-Cu-O. In melt-processed Y-Ba-Cu-O, sympathetic nucleation on previously nucleated YBa 2 Cu 3 O 7-δ plates during solidification appears to be dominant mechanism for the formation of parallel plate-shaped grains. In the Y-Ba-Cu-O and Bi-Sr-Ca-Cu-O ribbons, the interface reaction between the superconductor layer and the silvers substrate seems to be the main mechanism for the c-axis texturing of the layered grains. The drastically different critical current behavior in the c-axis textured Y-Ba-Cu-O and Bi-Sr-Ca-Cu-O ribbons is discussed in terms of possible differences in the nature of the twist and tilt grain boundaries. (orig.)

  3. Experimental Liquidus Studies of the Pb-Cu-Si-O System in Equilibrium with Metallic Pb-Cu Alloys

    Science.gov (United States)

    Shevchenko, M.; Nicol, S.; Hayes, P. C.; Jak, E.

    2018-03-01

    Phase equilibria of the Pb-Cu-Si-O system have been investigated in the temperature range from 1073 K to 1673 K (800 °C to 1400 °C) for oxide liquid (slag) in equilibrium with solid Cu metal and/or liquid Pb-Cu alloy, and solid oxide phases: (a) quartz or tridymite (SiO2) and (b) cuprite (Cu2O). High-temperature equilibration on silica or copper substrates was performed, followed by quenching, and direct measurement of Pb, Cu, and Si concentrations in the liquid and solid phases using the electron probe X-ray microanalysis has been employed to accurately characterize the system in equilibrium with Cu or Pb-Cu metal. All results are projected onto the PbO-"CuO0.5"-SiO2 plane for presentation purposes. The present study is the first-ever systematic investigation of this system to describe the slag liquidus temperatures in the silica and cuprite primary phase fields.

  4. Magnetic Moment of $^{59}$Cu

    CERN Multimedia

    2002-01-01

    Experiment IS358 uses the intense and pure beams of copper isotopes provided by the ISOLDE RILIS (resonance ionization laser ion source). The isotopes are implanted and oriented in the low temperature nuclear orientation set-up NICOLE. Magnetic moments are measured by $\\beta$-NMR. Copper (Z=29), with a single proton above the proton-magic nickel isotopes provides an ideal testground for precise shell model calculations of magnetic moments and their experimental verification. In the course of our experiments we already determined the magnetic moments of $^{67}$Ni, $^{67}$Cu, $^{68g}$Cu, $^{69}$Cu and $^{71}$Cu which provide important information on the magicity of the N=40 subshell closure. In 2001 we plan to conclude our systematic investigations by measuring the magnetic moment of the neutron-deficient isotope $^{59}$Cu. This will pave the way for a subsequent study of the magnetic moment of $^{57}$Cu with a complementary method.

  5. Optical constants of Cu(In, Ga)Se{sub 2} for arbitrary Cu and Ga compositions

    Energy Technology Data Exchange (ETDEWEB)

    Minoura, Shota; Kodera, Keita; Nakane, Akihiro; Fujiwara, Hiroyuki, E-mail: fujiwara@gifu-u.ac.jp [Center of Innovative Photovoltaic Systems (CIPS), Gifu University, 1-1 Yanagido, Gifu 501-1193 (Japan); Maekawa, Takuji [Research and Development Headquarters, ROHM Co., Ltd., 21 Saiin Mizosaki-cho, Ukyo-ku, Kyoto 615-8585 (Japan); Niki, Shigeru [Research Center for Photovoltaic Technologies, National Institute of Advanced Industrial Science and Technology (AIST), Central2, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan)

    2015-05-21

    The optical constants of Cu(In, Ga)Se{sub 2} (CIGS)-based polycrystalline layers with different Cu and Ga compositions are parameterized completely up to a photon energy of 6.5 eV assuming several Tauc-Lorentz transition peaks. Based on the modeled optical constants, we establish the calculation procedure for the CIGS optical constants in a two-dimensional compositional space of (Cu, Ga) by taking the composition-induced shift of the critical point energies into account. In particular, we find that the variation of the CIGS optical constants with the Cu composition can be modeled quite simply by a spectral-averaging method in which the dielectric function of the target Cu composition is estimated as a weighted average of the dielectric functions with higher and lower Cu compositions. To express the effect of the Ga composition, on the other hand, an energy shift model reported earlier is adopted. Our model is appropriate for a wide variety of CIGS-based materials having different Cu and Ga compositions, although the modeling error increases slightly at lower Cu compositions [Cu/(In + Ga) < 0.69]. From our model, the dielectric function, refractive index, extinction coefficient, and absorption coefficient for the arbitrary CIGS composition can readily be obtained. The optical database developed in this study is applied further for spectroscopic ellipsometry analyses of CIGS layers fabricated by single and multi-stage coevaporation processes. We demonstrate that the compositional and structural characterizations of the CIGS-based layers can be performed from established analysis methods.

  6. Influence of Cu Content on the Structure, Mechanical, Friction and Wear Properties of VCN–Cu Films

    Directory of Open Access Journals (Sweden)

    Fanjing Wu

    2018-03-01

    Full Text Available VCN–Cu films with different Cu contents were deposited by reactive magnetron sputtering technique. The films were evaluated in terms of their microstructure, elemental composition, mechanical, and tribological properties by X-ray diffraction (XRD, energy-dispersive X-ray spectroscopy (EDS, high resolution transmission electron microscopy (HR-TEM, Raman spectrometry, nano-indentation, field emission scanning electron microscope (FE-SEM, Bruker three-dimensional (3D profiler, and high-temperature ball on disc tribo-meter. The results showed that face-centered cubic (fcc VCN, hexagonal close-packed (hcp V2CN, fcc-Cu, amorphous graphite and CNx phases co-existed in VCN–Cu films. After doping with 0.6 at.% Cu, the hardness reached a maximum value of ~32 GPa. At room temperature (RT, the friction coefficient and wear rate increased with increasing Cu content. In the temperature range of 100–500 °C, the friction coefficient decreased, but the wear rate increased with the increase of Cu content.

  7. Mechanical, electronic and thermal properties of Cu{sub 5}Zr and Cu{sub 5}Hf by first-principles calculations

    Energy Technology Data Exchange (ETDEWEB)

    Yi, Guohui [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China); Zhang, Xinyu, E-mail: xyzhang@ysu.edu.cn [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China); Qin, Jiaqian, E-mail: jiaqianqin@gmail.com [Metallurgy and Materials Science Research Institute, Chulalongkorn University, Bangkok 10330 (Thailand); Ning, Jinliang; Zhang, Suhong; Ma, Mingzhen; Liu, Riping [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China)

    2015-08-15

    Highlights: • The mechanical and fundamental thermal data of Cu{sub 5}Zr and Cu{sub 5}Hf are determined. • The technologically important elastic anisotropy is obtained and discussed according to its industrial applications. • The brittle/ductile and bonding nature of Cu{sub 5}Zr and Cu{sub 5}Hf are analyzed in details. - Abstract: The structural, elastic, electronic and thermodynamic properties of Cu{sub 5}Zr and Cu{sub 5}Hf compounds are investigated by first-principles calculations combined with the quasi-harmonic Debye model. The calculated lattice parameters of cubic AuBe{sub 5}-type Cu{sub 5}Zr and Cu{sub 5}Hf agree well with available experimental and other theoretical results and the formation enthalpy calculations show that AuBe{sub 5}-type Cu{sub 5}Hf is more energetically stable than the competing hexagonal CaCu{sub 5}-type phase. The mechanical properties such as mechanical stabilities, anisotropy character, ductility (estimated from the value of B/G, Poisson’s ratio υ and Cauchy pressures C{sub 12}–C{sub 44}) and thermodynamic properties such as volume change under temperature and pressure (V/V{sub 0}), heat capacity (C{sub v}), Debye temperature (Θ), thermal expansion coefficient (α) of AuBe{sub 5}-type Cu{sub 5}Zr and Cu{sub 5}Hf are calculated together. Cu{sub 5}Hf has better performances than Cu{sub 5}Zr with higher hardness and better resistance to fracture which are rationalized from the calculated electronic structure (including density of states, charge density distributions, Mulliken’s population analysis) and we find that all ionic, covalent and metallic components exist in bonding of Cu{sub 5}Zr and Cu{sub 5}Hf but the covalent bonding in Cu{sub 5}Hf is stronger.

  8. Decomposition of NO on Cu-loaded zeolites

    Energy Technology Data Exchange (ETDEWEB)

    Sepulveda-Escribano, A; Marquez-Alvarez, C; Rodriquez-Ramos, I; Fierro, J L.G. [Instituto de Catalisis y Petroleoquimica, Madrid (Spain); Guerrero-Ruiz, A [Departamento de Quimica Inorganica, UNED, Madrid (Spain)

    1993-05-26

    Two copper ion-exchanged zeolites, Cu/NaY and Cu/NaZSM-5 have been studied by several techniques (TPR, TPD of NO, IR spectroscopy of adsorbed NO and XPS) and their catalytic activity for NO-decomposition have been determined under dynamic conditions. The results obtained here show that copper is stabilized as Cu[sup +] in Cu/NaZSM-5 after calcination in air at 673K, while in Cu/NaY the initial Cu[sup +]-ions are easier oxidized to Cu[sup 2+], this leading to a completely different catalytic behavior in the reaction of NO-decomposition. So, whereas the Cu/NaZSM-5 exhibits a high NO-conversion at the reaction temperatures (573 and 873K), the parent Cu/NaY zeolite becomes deactivated in the first stages of reaction.

  9. Synthesis, characterization and catalytic property of CuO and Ag/CuO nanoparticles for the epoxidation of styrene

    Energy Technology Data Exchange (ETDEWEB)

    Lashanizadegan, Maryam; Erfaninia, Nasrin [Alzahra University, Tehran (Iran, Islamic Republic of)

    2013-11-15

    CuO nanorodes, CuO nanoplates and Ag/CuO nanoparticles were synthesized in the presence of polyethylene glycol by depositional in alkaline environment. Oxide nanoparticles were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared absorption spectra (FT-IR). CuO and Ag/CuO nanoparticles show high catalytic activity for the selective epoxidation of styrene to styrene oxide by TBHP. Under the optimized reaction condition, the oxidation of styrene catalyzed by CuO nanorods gave 100% conversion with 60 and 35% styrene oxide and benzaldehyde, respectively. Ag/CuO gave 99% conversion and styrene oxide (71%) and benzaldehyde (12%) being the major product.

  10. Antimicrobial Cu-bearing stainless steel scaffolds

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Qiang, E-mail: mfqwang@163.com [School of Stomatology, China Medical University, Shenyang 110002 (China); Ren, Ling [Institute of Metal Research, Chinese Academy of Sciences (China); Li, Xiaopeng [School of Mechanical and Chemical Engineering, The University of Western Australia (Australia); Zhang, Shuyuan [Institute of Metal Research, Chinese Academy of Sciences (China); Sercombe, Timothy B., E-mail: tim.sercombe@uwa.edu.au [School of Mechanical and Chemical Engineering, The University of Western Australia (Australia); Yang, Ke, E-mail: kyang@imr.ac.cn [Institute of Metal Research, Chinese Academy of Sciences (China)

    2016-11-01

    Copper-bearing stainless steel scaffolds with two different structures (Body Centered Cubic and Gyroid labyrinth) at two solid fractions (25% and 40%) were fabricated from both 316L powder and a mixture of 316L and elemental Cu powder using selective laser melting, and relative 316L scaffolds were served as control group. After processing, the antimicrobial testing demonstrated that the 316L-Cu scaffolds presented excellent antimicrobial activity against Escherichia coli and Staphylococcus aureus, and the cell viability assay indicated that there was no cytotoxic effect of 316L-Cu scaffolds on rat marrow mesenchymal stem cells. As such, these have the potential to reduce implant-associated infections. The Cu was also found to homogeneously distribute within the microstructure by scanning electronic microcopy. The addition of Cu would not significantly affect its strength and stiffness compared to 316L scaffold, and the stiffness of all the scaffolds (3-20GPa) is similar to that of bone and much less than that of bulk stainless steel. Consequently, fabrication of such low stiffness porous structures, especially coupled with the addition of antimicrobial Cu, may provide a new direction for medical stainless steels. - Highlights: • 316L-Cu scaffolds were fabricated by using selective laser melting (SLM). • 316L-Cu scaffolds showed satisfied antimicrobial activities. • 316L-Cu scaffolds have no cytotoxic effect on normal cells. • Other properties of 316L-Cu scaffolds were similar to 316L scaffolds. • 316L-Cu scaffolds have the potential to be used in orthopedic applications.

  11. Antimicrobial Cu-bearing stainless steel scaffolds

    International Nuclear Information System (INIS)

    Wang, Qiang; Ren, Ling; Li, Xiaopeng; Zhang, Shuyuan; Sercombe, Timothy B.; Yang, Ke

    2016-01-01

    Copper-bearing stainless steel scaffolds with two different structures (Body Centered Cubic and Gyroid labyrinth) at two solid fractions (25% and 40%) were fabricated from both 316L powder and a mixture of 316L and elemental Cu powder using selective laser melting, and relative 316L scaffolds were served as control group. After processing, the antimicrobial testing demonstrated that the 316L-Cu scaffolds presented excellent antimicrobial activity against Escherichia coli and Staphylococcus aureus, and the cell viability assay indicated that there was no cytotoxic effect of 316L-Cu scaffolds on rat marrow mesenchymal stem cells. As such, these have the potential to reduce implant-associated infections. The Cu was also found to homogeneously distribute within the microstructure by scanning electronic microcopy. The addition of Cu would not significantly affect its strength and stiffness compared to 316L scaffold, and the stiffness of all the scaffolds (3-20GPa) is similar to that of bone and much less than that of bulk stainless steel. Consequently, fabrication of such low stiffness porous structures, especially coupled with the addition of antimicrobial Cu, may provide a new direction for medical stainless steels. - Highlights: • 316L-Cu scaffolds were fabricated by using selective laser melting (SLM). • 316L-Cu scaffolds showed satisfied antimicrobial activities. • 316L-Cu scaffolds have no cytotoxic effect on normal cells. • Other properties of 316L-Cu scaffolds were similar to 316L scaffolds. • 316L-Cu scaffolds have the potential to be used in orthopedic applications.

  12. Conducting mechanisms of forming-free TiW/Cu{sub 2}O/Cu memristive devices

    Energy Technology Data Exchange (ETDEWEB)

    Yan, P.; Li, Y.; Hui, Y. J.; Zhong, S. J.; Zhou, Y. X.; Xu, L.; Liu, N.; Qian, H.; Sun, H. J., E-mail: shj@mail.hust.edu.cn; Miao, X. S. [Wuhan National Laboratory for Optoelectronics (WNLO), Huazhong University of Science and Technology (HUST), Wuhan 430074 (China); School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2015-08-24

    P-type Cu{sub 2}O is a promising CMOS-compatible candidate to fabricate memristive devices for next-generation memory, logic and neuromorphic computing. In this letter, the microscopic switching and conducting mechanisms in TiW/Cu{sub 2}O/Cu memristive devices have been thoroughly investigated. The bipolar resistive switching behaviors without an electro-forming process are ascribed to the formation and rupture of the conducting filaments composed of copper vacancies. In the low resistive state, the transport of electrons in the filaments follows Mott's variable range hopping theory. When the devices switch back to high resistive state, the coexistence of Schottky emission at the Cu/Cu{sub 2}O interface and electron hopping between the residual filaments is found to dominate the conducting process. Our results will contribute to the further understanding and optimization of p-type memristive materials.

  13. A-site ordered perovskite CaCu3Cu2Ir2O12−δ with square-planar and octahedral coordinated Cu ions

    International Nuclear Information System (INIS)

    Zhao Qing; Wang Qing-Tao; Yin Yun-Yu; Dai Jian-Hong; Shen Xi; Yang Jun-Ye; Yu Ri-Cheng; Long You-Wen; Hu Zhi-Wei; Li Xiao-Dong

    2016-01-01

    A novel CaCu 3 Cu 2 Ir 2 O 12−δ polycrystalline sample was synthesized at 8 GPa and 1373 K. Rietveld structural analysis shows that this compound crystallizes in an -type A-site ordered perovskite structure with space group Im-3. X-ray absorption spectra reveal a +2-charge state for both the square-planar and octahedral coordinated Cu ions, and the valence state of Ir is found to be about +5. Although the A-site Ca and the A′-site Cu 2+ are 1:3 ordered at fixed atomic positions, the distribution of B-site Cu 2+ and Ir 5+ is disorderly. As a result, no long-range magnetic ordering is observed at temperatures down to 2 K. Electrical transport and heat capacity measurements demonstrate itinerant electronic behavior. The crystal structure is stable with pressure up to 35.7 GPa at room temperature. (paper)

  14. The interaction between dietary Fe, Cu and stress in Cu-67 retention and serum ceruloplasmin (Cp) activity in rats

    International Nuclear Information System (INIS)

    Pellett, L.; Kattelmann, K.; Zinn, K.; Trokey, D.; Forrester, I.; Gordon, D.T.

    1991-01-01

    The objectives of the study were to determine the effects of dietary Fe and stress on Cu-67 retention and serum Cp activity in the rat. A 2 x 2 x 2 factorial arrangement of treatments was utilized. Male Sprague Dawley weanling rats were fed AIN-76 diets ad lib containing 0.8 ppm Cu (CuD) or 5.7 ppm Cu (CuA) with 22.5 ppm Fe (FeA) or 280 ppm Fe (FeE). After 19 days, one-half of the animals of each treatment were stressed by an intramuscular injection of 0.1 ml turpentine/100 gm body weight. Forty-eight hours later, animals were gavaged with Cu-67 and counted over a 7 day period in a whole body high resolution gamma counter. Cu-67 retention was 20% higher in CuD rats compared to CuA rats. There were no significant effects caused by Fe or stress or the interaction between these variables on Cu-67 retention. In rats fed FeE-CuA diets, serum Cp activity was significantly depressed compared to rats fed FeA-CuA diets. These reductions in the acute phase protein Cp, were 85% and 70% in nonstressed and stressed rats, respectively. The results of this study suggest that the negative interaction effects of excess Fe on Cu utilization does not occur at the site of Cu absorption, but within the body and specifically in the liver

  15. Exploring Cu2O/Cu cermet as a partially inert anode to produce aluminum in a sustainable way

    International Nuclear Information System (INIS)

    Feng, Li-Chao; Xie, Ning; Shao, Wen-Zhu; Zhen, Liang; Ivanov, V.V.

    2014-01-01

    Highlights: • Cu 2 O/Cu cermet was used as a candidate partially inert anode material to produce aluminum alloys. • The thermal corrosion behavior of Cu 2 O/Cu was investigated in molten salt at 960 °C. • The corrosion rate is largely governed by the geometrical structures of Cu in the prepared samples. • The corrosion rate increases with decreasing sizes and increasing filling contents of Cu phase. • The corrosion rate was 1.8–9 cm/y and the Cu contents is less than 6.2 wt.% in the produced aluminum. - Abstract: As an energy-intensive process, aluminum production by the Hall–Héroult method accounts for significant emissions of CO 2 and some toxic greenhouse gases. The utilization of an inert anode in place of a carbon anode was considered as a revolutionary technique to solve most of the current environmental problems resulting from the Hall–Héroult process. However, the critical property requirements of the inert anode materials significantly limit the application of this technology. In light of the higher demand for aluminum alloys than for pure aluminum, a partially inert anode was designed to produce aluminum alloys in a more sustainable way. Here, Cu 2 O/Cu cermet was chosen as the material of interest. The thermal corrosion behavior of Cu 2 O/Cu was investigated in Na 3 AlF 6 –CaF 2 –Al 2 O 3 electrolyte at 960 °C to elucidate the corrosion mechanisms of this type of partially inert anode for the production of aluminum or aluminum alloys. Furthermore, the effects of the geometrical structure of the Cu phase on the thermal corrosion behavior of Cu 2 O/Cu cermet in the electrolyte were investigated as well. The thermal corrosion rate was evaluated by the weight loss method and the results show that the samples prepared with branch-like Cu have higher thermal corrosion rate than those prepared with spherical Cu, and the corrosion rate increases with decreasing size and increasing filling content of Cu phase. The calculated corrosion rate

  16. Effects of the molecule-electrode interface on the low-bias conductance of Cu-H2-Cu single-molecule junctions.

    Science.gov (United States)

    Jiang, Zhuoling; Wang, Hao; Shen, Ziyong; Sanvito, Stefano; Hou, Shimin

    2016-07-28

    The atomic structure and electronic transport properties of a single hydrogen molecule connected to both symmetric and asymmetric Cu electrodes are investigated by using the non-equilibrium Green's function formalism combined with the density functional theory. Our calculations show that in symmetric Cu-H2-Cu junctions, the low-bias conductance drops rapidly upon stretching, while asymmetric ones present a low-bias conductance spanning the 0.2-0.3 G0 interval for a wide range of electrode separations. This is in good agreement with experiments on Cu atomic contacts in a hydrogen environment. Furthermore, the distribution of the calculated vibrational energies of the two hydrogen atoms in the asymmetric Cu-H2-Cu junction is also consistent with experiments. These findings provide clear evidence for the formation of asymmetric Cu-H2-Cu molecular junctions in breaking Cu atomic contacts in the presence of hydrogen and are also helpful for the design of molecular devices with Cu electrodes.

  17. Effects of CuO nanoparticles on Lemna minor.

    Science.gov (United States)

    Song, Guanling; Hou, Wenhua; Gao, Yuan; Wang, Yan; Lin, Lin; Zhang, Zhiwei; Niu, Qiang; Ma, Rulin; Mu, Lati; Wang, Haixia

    2016-12-01

    Copper dioxide nanoparticles (NPs), which is a kind of important and widely used metal oxide NP, eventually reaches a water body through wastewater and urban runoff. Ecotoxicological studies of this kind of NPs effects on hydrophyte are very limited at present. Lemna minor was exposed to media with different concentrations of CuO NPs, bulk CuO, and two times concentration of Cu 2+ released from CuO NPs in culture media. The changes in plant growth, chlorophyll content, antioxidant defense enzyme activities [i.e., peroxidase (POD), catalase (CAT), superoxide dismutase (SOD) activities], and malondialdehyde (MDA) content were measured in the present study. The particle size of CuO NPs and the zeta potential of CuO NPs and bulk CuO in the culture media were also analyzed to complementally evaluate their toxicity on duckweed. Results showed that CuO NPs inhibited the plant growth at lower concentration than bulk CuO. L. minor roots were easily broken in CuO NPs media under the experimental condition, and the inhibition occurred only partly because CuO NPs released Cu 2+ in the culture media. The POD, SOD, and CAT activities of L. minor increased when the plants were exposed to CuO NPs, bulk CuO NPs and two times the concentration of Cu 2+ released from CuO NPs in culture media, but the increase of these enzymes were the highest in CuO NPs media among the three kinds of materials. The MDA content was significantly increased compared with that of the control from 50 mg L -1 CuO NP concentration in culture media. CuO NPs has more toxicity on L. minor compared with that of bulk CuO, and the inhibition occurred only partly because released Cu 2+ in the culture media. The plant accumulated more reactive oxygen species in the CuO NP media than in the same concentration of bulk CuO. The plant cell encountered serious damage when the CuO NP concentration reached 50 mg L -1 in culture media. The toxicology of CuO NP on hydrophytes must be considered because that hydrophytes

  18. Recycled hierarchical tripod-like CuCl from Cu-PCB waste etchant for lithium ion battery anode

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Song [Faculty of Material Science and Engineering, Kunming University of Science and Technology, Kunming 650093 China (China); Hou, Hongying, E-mail: hongyinghou@kmust.edu.cn [Faculty of Material Science and Engineering, Kunming University of Science and Technology, Kunming 650093 China (China); Liu, Xianxi [Faculty of Mechanical and Electronic Engineering, Kunming University of Science and Technology, Kunming 650093 China (China); Duan, Jixiang; Yao, Yuan; Liao, Qishu; Li, Jing; Yang, Yunzhen [Faculty of Material Science and Engineering, Kunming University of Science and Technology, Kunming 650093 China (China)

    2017-02-15

    Highlights: • High EVA CuCl was recycled with 85% recovery from Cu-PCB waste etchant. • The recycled CuCl displayed a hierarchical tripod-like morphology. • The evolution mechanism of the recycled hierarchical CuCl crystal was proposed. • The corresponding discharge capacity in LIB was 201.4 mAh/g after 100 cycles. • The results shed a new light on resource recovery and environmental protection. - Abstract: Hierarchical CuCl with high economic value added (EVA) was successfully recycled with 85% recovery from the acid Cu printed circuit board (Cu-PCB) waste etchant via facile liquid chemical reduction. The micro-structure and morphology of the recycled hierarchical CuCl were systematically characterized in terms of scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), transmission electron microscopy (TEM) and Brunauer-Emmett-Teller (BET). Furthermore, the corresponding electrochemical performances as lithium ion battery (LIB) anode were also investigated in terms of galvanostatic charge/discharge, cyclic voltammetry (CV) and AC impedance. As expected, the recycled CuCl displayed a hierarchical tripod-like structure and large specific surface area of 21.2 m{sup 2}/g. As the anode in LIB, the reversible discharge capacity was about 201.4 mAh/g even after 100 cycles, implying the satisfactory cycle performance. Clearly, the satisfactory results may open a new avenue to develop the sustainable industry, which is very important in terms of both the resource recovery and the environmental protection.

  19. Electrochemical preparation of uniform CuO/Cu2O heterojunction on β-cyclodextrin-modified carbon fibers

    KAUST Repository

    Chen, Fang-Ping

    2016-01-18

    Abstract: In this work, a uniform heterojunction of cupric oxide/cuprous oxide was decorated on the surface of carbon fibers by electrochemical method (CuO/Cu2O/CDs/CFs). Methyl-β-cyclodextrin was first grafted on the surface of carbon fibers (CDs/CFs). Cubic cuprous oxide was electrodeposited on the surface of (Cu2O/CDs/CFs) in 0.1 M KNO3, the cuprous oxide was then partly anodized to cupric oxide to form a heterojunction of cupric oxide/cuprous oxide with a burr shape (CuO/Cu2O/CDs/CFs). The obtained materials were characterized by field emission scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and electrochemical techniques. The potential application in pollution treatment was further investigated, and the prepared CuO/Cu2O/CDs/CFs could be a promising adsorbent/photocatalyst toward the uptake and degradation of 2, 6-dichlorophenol (2, 6-DCP). Graphical Abstract: [Figure not available: see fulltext.] © 2016 Springer Science+Business Media Dordrecht

  20. Computer simulations of nanoindentation in Mg-Cu and Cu-Zr metallic glasses

    DEFF Research Database (Denmark)

    Paduraru, Anca; Andersen, Ulrik Grønbjerg; Thyssen, Anders

    2010-01-01

    The formation of shear bands during plastic deformation of Cu0.50Zr0.50 and Mg0.85Cu0.15 metallic glasses is studied using atomic-scale computer simulations. The atomic interactions are described using realistic many-body potentials within the effective medium theory, and are compared with similar...... simulations using a Lennard-Jones description of the material. The metallic glasses are deformed both in simple shear and in a simulated nanoindentation experiment. Plastic shear localizes into shear bands with a width of approximately 5 nm in CuZr and 8 nm in MgCu. In simple shear, the shear band formation...... is very clear, whereas only incipient shear bands are seen in nanoindentation. The shear band formation during nanoindentation is sensitive to the indentation velocity, indenter radius and the cooling rate during the formation of the metallic glass. For comparison, a similar nanoindentation simulation...

  1. Formation and evolution of nanoporous bimetallic Ag-Cu alloy by electrochemically dealloying Mg-(Ag-Cu)-Y metallic glass

    International Nuclear Information System (INIS)

    Li, Ran; Wu, Na; Liu, Jijuan; Jin, Yu; Chen, Xiao-Bo; Zhang, Tao

    2017-01-01

    Highlights: • Uniform nanoporous Ag-Cu alloy was fabricated by dealloying Mg-based metallic glass. • The nanoporous structure was built up with numerous Ag-Cu ligaments. • The nanoporous ligaments show two-stage coarsening behavior with dealloying time. • The formation and evolution mechanisms of the nanoporous structure were clarified. • It could provide new guidance to the synthesis of nanoporous multi-component alloys. - Abstract: A three-dimensional nanoporous bimetallic Ag-Cu alloy with uniform chemical composition has been fabricated by dealloying Mg_6_5Ag_1_2_._5Cu_1_2_._5Y_1_0 metallic glass in dilute (0.04 M) H_2SO_4 aqueous solution under free-corrosion conditions. The nanoporous Ag-Cu evolves through two distinct stages. First, ligaments of the nanoporous structure, consisting of supersaturated Ag(Cu) solid solution with a constant Ag/Cu mole ratio of 1:1, are yielded. Second, with excessive immersion, some Cu atoms separate from the metastable nanoporous matrix and form spherical Cu particles on the sample surface. Formation and evolution mechanisms of the nanoporous structure are proposed.

  2. Surface studies by low energy ion beams: Cu/Ru(0001) and Cu/O/Ru(0001)

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Y.G.; O`Connor, D.J.; MacDonald, R.J. [Newcastle Univ., NSW (Australia). Dept. of Physics; Wandelt, H. [Institut fur Physikalische und Theoretische Chemie der Universitat Bonn, Bonn (Germany).; Zee, H. van [Eindhoven University of Technology, Eindhoven (Netherlands) Dept. of Physics

    1993-12-31

    The surface structure of Cu on Ru(OOO1) has been studied by low energy Li{sup +} ion scattering. It was found that Cu forms pseudomorphic islands for two layers. The effects of Cu on an O-precovered RU(OOO1) surface has also been investigated using keV He{sup +} ions. The results show that during the deposition of Cu, O is displaced from the Ru surface and migrated onto the top of the surface of the growing overlayer. The floated out O has been tested, showing a disordered overlayer. 5 refs., 3 figs.

  3. Surface studies by low energy ion beams: Cu/Ru(0001) and Cu/O/Ru(0001)

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Y G; O` Connor, D J; MacDonald, R J [Newcastle Univ., NSW (Australia). Dept. of Physics; Wandelt, H [Institut fur Physikalische und Theoretische Chemie der Universitat Bonn, Bonn (Germany).; Zee, H van [Eindhoven University of Technology, Eindhoven (Netherlands) Dept. of Physics

    1994-12-31

    The surface structure of Cu on Ru(OOO1) has been studied by low energy Li{sup +} ion scattering. It was found that Cu forms pseudomorphic islands for two layers. The effects of Cu on an O-precovered RU(OOO1) surface has also been investigated using keV He{sup +} ions. The results show that during the deposition of Cu, O is displaced from the Ru surface and migrated onto the top of the surface of the growing overlayer. The floated out O has been tested, showing a disordered overlayer. 5 refs., 3 figs.

  4. Toxic effects of Cu2+ on growth, nutrition, root morphology, and distribution of Cu in roots of Sabi grass

    International Nuclear Information System (INIS)

    Kopittke, P.M.; Asher, C.J.; Blamey, F.P.C.; Menzies, N.W.

    2009-01-01

    Sabi grass (Urochloa mosambicensis (Hack.) Dandy) (a C4 species of Poaceae) is commonly used to revegetate disturbed sites in low-rainfall environments, but comparatively little is known regarding copper (Cu) toxicity in this species. A dilute nutrient solution culture experiment was conducted for 10 d to examine the effects of elevated Cu 2+ activities ({Cu 2+ }) on the growth of Sabi grass. Growth was inhibited by high Cu in solution, with a 50% reduction in the relative fresh mass occurring at 1.0 μM {Cu 2+ } for the roots and 1.2 μM {Cu 2+ } for the shoots. In solutions containing 1.2-1.9 μM {Cu 2+ }, many of the roots ruptured due to the tearing and separation of the rhizodermis and outer cortex from the underlying tissues. Transmission electron microscopy revealed that Cu-rich deposits were found to accumulate predominantly within vacuoles. Due to limited translocation of Cu from the roots to the shoots, phytotoxicity is likely to be more of a problem in remediation of Cu-toxic sites than is Cu toxicity of fauna consuming the above-ground biomass.

  5. Use of micro-PIXE to determine spatial distributions of copper in Brassica carinata plants exposed to CuSO4 or CuEDDS

    International Nuclear Information System (INIS)

    Cestone, Benedetta; Vogel-Mikuš, Katarina; Quartacci, Mike Frank; Rascio, Nicoletta; Pongrac, Paula; Pelicon, Primož; Vavpetič, Primož; Grlj, Nataša; Jeromel, Luka; Kump, Peter; Nečemer, Marijan; Regvar, Marjana; Navari-Izzo, Flavia

    2012-01-01

    A better understanding of the mechanisms that govern copper (Cu) uptake, distribution and tolerance in Brassica carinata plants in the presence of chelators is needed before significant progress in chelate-assisted Cu phytoextraction can be made. The aims of this study were therefore to characterise (S,S)-N,N′-ethylenediamine disuccinic acid (EDDS)-assisted Cu uptake, and to compare the spatial distribution patterns of Cu in the roots and leaves of B. carinata plants. The plants were treated with 30 μM or 150 μM CuSO 4 or CuEDDS in hydroponic solution. Quantitative Cu distribution maps and concentration profiles across root and leaf cross-sections of the desorbed plants were obtained by micro-proton induced X-ray emission. In roots, the 30 μM treatments with both CuSO 4 and CuEDDS resulted in higher Cu concentrations in epidermal/cortical regions. At 150 μM CuSO 4 , Cu was mainly accumulated in root vascular bundles, whereas with 150 μM CuEDDS, Cu was detected in endodermis and the adjacent inner cortical cell layer. Under all treatments, except with a H + -ATP-ase inhibitor, the Cu in leaves was localised mainly in vascular tissues. The incubation of plants with 150 μM CuEDDS enhanced metal translocation to shoots, in comparison to the corresponding CuSO 4 treatment. Inhibition of H + -ATPase activity resulted in reduced Cu accumulation in 30 μM CuEDDS-treated roots and 150 μM CuEDDS-treated leaves, and induced changes in Cu distribution in the leaves. This indicates that active mechanisms are involved in retaining Cu in the leaf vascular tissues, which prevent its transport to photosynthetically active tissues. The physiological significance of EDDS-assisted Cu uptake is discussed. - Highlights: ► We localised Cu in Brassica carinata treated with CuSO 4 or CuEDDS by micro-PIXE. ► EDDS-assisted Cu uptake and transport resulted in preserved root endodermis. ► EDDS enhanced Cu transport from roots to shoots. ► Cu sequestration within leaf veins

  6. Enhancement of oxidation resistance in Cu and Cu(Al) thin layers

    International Nuclear Information System (INIS)

    Horvath, Z.E.; Peto, G.; Paszti, Z.; Zsoldos, E.; Szilagyi, E.; Battistig, G.; Lohner, T.; Molnar, G.L.; Gyulai, J.

    1999-01-01

    High conductivity and good resistance to electromigration makes copper a promising interconnect material in microelectronics. However, one of its disadvantages is the poor corrosion resistance. Two methods of passivation are investigated and compared: Al alloying and BF 2 + ion implantation. X-ray diffraction (XRD) and Rutherford Backscattering Spectrometry (RBS) show the oxidation inhibition of both methods, but the different ratio of CuO 2 to CuO phases suggests different mechanisms of passivation. There are no definite oxide lines in the XRD spectrum of the implanted and annealed Cu(Al) sample, so the presence of Al and the implantation together give increased protection against oxidation. The difference between the two mechanisms of oxidation inhibition is discussed briefly

  7. Time-dependent of characteristics of Cu/CuS/n-GaAs/In structure produced by SILAR method

    Energy Technology Data Exchange (ETDEWEB)

    Sağlam, M.; Güzeldir, B., E-mail: msaglam@atauni.edu.tr

    2016-09-15

    Highlights: • The CuS thin film used at Cu/n-GaAs structure is grown by SILAR method. • There has been no report on ageing of characteristics of this junction in the literature. • The properties of Cu/CuS/n-GaAs/In structure are examined with different methods. • It has been shown that Cu/CuS/n-GaAs/In structure has a stable interface. - Abstract: The aim of this study is to explain effects of the ageing on the electrical properties of Cu/n-GaAs Shottky barrier diode with Copper Sulphide (CuS) interfacial layer. CuS thin films are deposited on n-type GaAs substrate by Successive Ionic Layer Adsorption and Reaction (SILAR) method at room temperature. The structural and the morphological properties of the films have been carried out by Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD) techniques. The XRD analysis of as-grown films showed the single-phase covellite, with hexagonal crystal structure built around two preferred orientations corresponding to (102) and (108) atomic planes. The ageing effects on the electrical properties of Cu/CuS/n-GaAs/In structure have been investigated. The current–voltage (I–V) measurements at room temperature have been carried out to study the change in electrical characteristics of the devices as a function of ageing time. The main electrical parameters, such as ideality factor (n), barrier height (Φ{sub b}), series resistance (R{sub s}), leakage current (I{sub 0}), and interface states (N{sub ss}) for this structure have been calculated. The results show that the main electrical parameters of device remained virtually unchanged.

  8. Time-dependent of characteristics of Cu/CuS/n-GaAs/In structure produced by SILAR method

    International Nuclear Information System (INIS)

    Sağlam, M.; Güzeldir, B.

    2016-01-01

    Highlights: • The CuS thin film used at Cu/n-GaAs structure is grown by SILAR method. • There has been no report on ageing of characteristics of this junction in the literature. • The properties of Cu/CuS/n-GaAs/In structure are examined with different methods. • It has been shown that Cu/CuS/n-GaAs/In structure has a stable interface. - Abstract: The aim of this study is to explain effects of the ageing on the electrical properties of Cu/n-GaAs Shottky barrier diode with Copper Sulphide (CuS) interfacial layer. CuS thin films are deposited on n-type GaAs substrate by Successive Ionic Layer Adsorption and Reaction (SILAR) method at room temperature. The structural and the morphological properties of the films have been carried out by Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD) techniques. The XRD analysis of as-grown films showed the single-phase covellite, with hexagonal crystal structure built around two preferred orientations corresponding to (102) and (108) atomic planes. The ageing effects on the electrical properties of Cu/CuS/n-GaAs/In structure have been investigated. The current–voltage (I–V) measurements at room temperature have been carried out to study the change in electrical characteristics of the devices as a function of ageing time. The main electrical parameters, such as ideality factor (n), barrier height (Φ_b), series resistance (R_s), leakage current (I_0), and interface states (N_s_s) for this structure have been calculated. The results show that the main electrical parameters of device remained virtually unchanged.

  9. Degradation of contaminants by Cu{sup +}-activated molecular oxygen in aqueous solutions: Evidence for cupryl species (Cu{sup 3+})

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Yong, E-mail: fengy@hku.hk [Department of Civil Engineering, The University of Hong Kong, Pokfulam Road (Hong Kong); Lee, Po-Heng, E-mail: phlee@polyu.edu.hk [Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong); Wu, Deli, E-mail: wudeli@tongji.edu.cn [State Key Laboratory of Pollution Control and Resources Reuse, School of Environmental Science & Engineering, Tongji University, Shanghai 200092 (China); Zhou, Zhengyuan, E-mail: zzy247@hku.hk [Department of Civil Engineering, The University of Hong Kong, Pokfulam Road (Hong Kong); Li, Hangkong, E-mail: hangkong@hku.hk [Department of Civil Engineering, The University of Hong Kong, Pokfulam Road (Hong Kong); Shih, Kaimin, E-mail: kshih@hku.hk [Department of Civil Engineering, The University of Hong Kong, Pokfulam Road (Hong Kong)

    2017-06-05

    Highlights: • Sulfadiazine and methylene blue were nearly completely degraded by Cu{sup +}-O{sub 2} oxidation. • Reaction of Cu{sup +} and hydrogen peroxide produced Cu{sup 3+} as the major active species. • 5,5-dimethyl-2-hydroxypyrrolidine-N-oxyl (DMPO-OH) was found in the reaction process. • Benzoic acid and electron paramagnetic resonance are not capable to differentiate Cu{sup 3+} and ·OH. - Abstract: Copper ions (Cu{sup 2+} and Cu{sup +}) have shown potential as Fenton-like activators for the circumneutral removal of organic contaminants from aqueous solutions. However, the major active species (cupryl species (Cu{sup 3+}) versus hydroxyl radical (·OH)) produced during the activation of hydrogen peroxide by Cu{sup +} remain unclear. In this study, Cu{sup +}-O{sub 2} oxidation, in which hydrogen peroxide is produced via the activated decomposition of dissolved molecular oxygen, was used to degrade sulfadiazine, methylene blue, and benzoic acid. The results showed that both sulfadiazine and methylene blue could be efficiently degraded by Cu{sup +}-O{sub 2} oxidation in a wide effective pH range from 2.0 to 10.0. Quenching experiments with different alcohols and the effect of Br{sup −} suggested that Cu{sup 3+} rather than ·OH was the major active species. Electron paramagnetic resonance detected 5,5-dimethyl-2-hydroxypyrrolidine-N-oxyl (DMPO-OH), which was probably produced by the oxidation of DMPO by Cu{sup 3+} or ·OH formed as a product of Cu{sup 3+} decomposition. 4-hydroxybenzoic acid was produced during the degradation of benzoic acid by Cu{sup 3+}. The findings of this study may help to explain the inconsistency regarding the dominant active species produced by the interaction of Cu{sup +} and hydrogen peroxide.

  10. Proteomic response of mussels Mytilus galloprovincialis exposed to CuO NPs and Cu{sup 2+}: An exploratory biomarker discovery

    Energy Technology Data Exchange (ETDEWEB)

    Gomes, Tânia, E-mail: tania.gomes@niva.no; Chora, Suze; Pereira, Catarina G.; Cardoso, Cátia; Bebianno, Maria João

    2014-10-15

    Highlights: • Different protein expression patterns, tissue and Cu form dependent. • Different cellular mechanisms involved in CuO NPs and Cu{sup 2+} toxicity. • CuO NPs toxicity mediated by cell signalling cascades that result in apoptosis. • Caspase 3/7–1, catL, Zn-finger, precol-D as new molecular targets for both Cu forms in mussels. - Abstract: CuO NPs are one of the most used metal nanomaterials nowadays with several industrial and other commercial applications. Nevertheless, less is known about the mechanisms by which these NPs inflict toxicity in mussels and to what extent it differs from Cu{sup 2+}. The aim of this study was to investigate changes in protein expression profiles in mussels Mytilus galloprovincialis exposed for 15 days to CuO NPs and Cu{sup 2+} (10 μg L{sup −1}) using a proteomic approach. Results demonstrate that CuO NPs and Cu{sup 2+} induced major changes in protein expression in mussels’ showing several tissue and metal-dependent responses. CuO NPs showed a higher tendency to up-regulate proteins in the gills and down-regulate in the digestive gland, while Cu{sup 2+} showed the opposite tendency. Distinctive sets of differentially expressed proteins were found, either common or specific to each Cu form and tissue, reflecting different mechanisms involved in their toxicity. Fifteen of the differentially expressed proteins from both tissues were identified by MALDI-TOF-TOF. Identified proteins indicate common response mechanisms induced by CuO NPs and Cu{sup 2+}, namely in cytoskeleton and cell structure (actin, α-tubulin, paramyosin), stress response (heat shock cognate 71, putative C1q domain containing protein), transcription regulation (zinc-finger BED domain-containing protein 1, nuclear receptor subfamily 1G) and energy metabolism (ATP synthase F0 subunit 6). CuO NPs alone also had a marked effect on other biological processes, namely oxidative stress (GST), proteolysis (cathepsin L) and apoptosis (caspase 3/7-1). On

  11. Copper Selenidophosphates Cu4P2Se6, Cu4P3Se4, Cu4P4Se3, and CuP2Se, Featuring Zero-, One-, and Two-Dimensional Anions.

    Science.gov (United States)

    Kuhn, Alexander; Schoop, Leslie M; Eger, Roland; Moudrakovski, Igor; Schwarzmüller, Stefan; Duppel, Viola; Kremer, Reinhard K; Oeckler, Oliver; Lotsch, Bettina V

    2016-08-15

    Five new compounds in the Cu/P/Se phase diagram have been synthesized, and their crystal structures have been determined. The crystal structures of these compounds comprise four previously unreported zero-, one-, and two-dimensional selenidophosphate anions containing low-valent phosphorus. In addition to two new modifications of Cu4P2Se6 featuring the well-known hexaselenidohypodiphosphate(IV) ion, there are three copper selenidophosphates with low-valent P: Cu4P3Se4 contains two different new anions, (i) a monomeric (zero-dimensional) selenidophosphate anion [P2Se4](4-) and (ii) a one-dimensional selenidophosphate anion [Formula: see text], which is related to the well-known gray-Se-like [Formula: see text] Zintl anion. Cu4P4Se3 contains one-dimensional [Formula: see text] polyanions, whereas CuP2Se contains the 2D selenidophosphate [Formula: see text] polyanion. It consists of charge-neutral CuP2Se layers separated by a van der Waals gap which is very rare for a Zintl-type phase. Hence, besides black P, CuP2Se constitutes a new possible source of 2D oxidized phosphorus containing layers for intercalation or exfoliation experiments. Additionally, the electronic structures and some fundamental physical properties of the new compounds are reported. All compounds are semiconducting with indirect band gaps of the orders of around 1 eV. The phases reported here add to the structural diversity of chalcogenido phosphates. The structural variety of this family of compounds may translate into a variety of tunable physical properties.

  12. Tailoring oxides of copper-Cu_2O and CuO nanoparticles and evaluation of organic dyes degradation

    International Nuclear Information System (INIS)

    Raghav, Ragini; Aggarwal, Priyanka; Srivastava, Sudha

    2016-01-01

    We report a simple one-pot colloidal synthesis strategy tailoring cuprous or cupric nano-oxides in pure state. NaOH provided alkaline conditions (pH 12.5 -13) for nano-oxides formation, while its concentration regulated the oxidation state of the nano-oxides. The morphological, structural and optical properties of synthesized Cu_2O and CuO nanoparticles were studied by transmission electron microscopy (TEM), X-Ray diffraction (XRD) and UV-vis spectroscopy. Dye degradation capability of CuO and Cu2O nanoparticles was evaluated using four organic dyes - Malachite green, Methylene blue, Methyl orange and Methyl red. The results demonstrate effective degradation of all four dyes employing with almost comparable activity both Cu_2O and CuO nanoparticles.

  13. A novel nonenzymatic amperometric hydrogen peroxide sensor based on CuO@Cu2O nanowires embedded into poly(vinyl alcohol).

    Science.gov (United States)

    Chirizzi, Daniela; Guascito, Maria Rachele; Filippo, Emanuela; Tepore, Antonio

    2016-01-15

    A new, very simple, rapid and inexpensive nonenzymatic amperometric sensor for hydrogen peroxide (H2O2) detection is proposed. It is based on the immobilization of cupric/cuprous oxide core shell nanowires (CuO@Cu2O-NWs) in a poly(vinyl alcohol) (PVA) matrix directly drop casted on a glassy carbon electrode surface to make a CuO@Cu2O core shell like NWs PVA embedded (CuO@Cu2O-NWs/PVA) sensor. CuO nanowires with mean diameters of 120-170nm and length in the range 2-5μm were grown by a simple catalyst-free thermal oxidation process based on resistive heating of pure copper wires at ambient conditions. The oxidation process of the copper wire surface led to the formation of a three layered structure: a thick Cu2O bottom layer, a CuO thin intermediate layer and CuO nanowires. CuO nanowires were carefully scratched from Cu2O layer with a sharp knife, dispersed into ethanol and sonicated. Then, the NWs were embedded in PVA matrix. The morphological and spectroscopic characterization of synthesized CuO-NWs and CuO@Cu2O-NWs/PVA were performed by transmission electron microscopy (TEM), selected area diffraction pattern (SAD), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) analysis. Moreover a complete electrochemical characterization of these new CuO@Cu2O-NWs/PVA modified glassy carbon electrodes was performed by Cyclic Voltammetry (CV) and Cronoamperometry (CA) in phosphate buffer (pH=7; I=0.2) to investigate the sensing properties of this material against H2O2. The electrochemical performances of proposed sensors as high sensitivity, fast response, reproducibility and selectivity make them suitable for the quantitative determination of hydrogen peroxide substrate in batch analysis. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Cu-Al alloy formation by thermal annealing of Cu/Al multilayer films deposited by cyclic metal organic chemical vapor deposition

    Science.gov (United States)

    Moon, Hock Key; Yoon, Jaehong; Kim, Hyungjun; Lee, Nae-Eung

    2013-05-01

    One of the most important issues in future Cu-based interconnects is to suppress the resistivity increase in the Cu interconnect line while decreasing the line width below 30 nm. For the purpose of mitigating the resistivity increase in the nanoscale Cu line, alloying Cu with traces of other elements is investigated. The formation of a Cu alloy layer using chemical vapor deposition or electroplating has been rarely studied because of the difficulty in forming Cu alloys with elements such as Al. In this work, Cu-Al alloy films were successfully formed after thermal annealing of Cu/Al multilayers deposited by cyclic metal-organic chemical vapor deposition (C-MOCVD). After the C-MOCVD of Cu/Al multilayers without gas phase reaction between the Cu and Al precursors in the reactor, thermal annealing was used to form Cu-Al alloy films with a small Al content fraction. The resistivity of the alloy films was dependent on the Al precursor delivery time and was lower than that of the aluminum-free Cu film. No presence of intermetallic compounds were detected in the alloy films by X-ray diffraction measurements and transmission electron spectroscopy.

  15. Fundamental absorption edge in CuIn5Se8 and CuGa3Se5 single crystals

    International Nuclear Information System (INIS)

    Leon, M.; Merino, J.M.; Levcenko, S.; Nateprov, A.; Tezlevan, V.; Arushanov, E.; Syrbu, N.N.

    2006-01-01

    Optical absorption spectra of CuIn 5 Se 8 and CuGa 3 Se 5 single crystals have been investigated. The energy gap E g for CuIn 5 Se 8 (CuGa 3 Se 5 ) was found to be varied from 1.27(1.79) to 1.21(1.71) eV in the temperature range between 10 and 300 K. The temperature dependence of E g was studied by means of the Einstein model and the Paessler model. The Einstein temperature {222(267)K}, the Debye temperature {310(380)K}, a dimensionless constant related to the electron-phonon coupling {1.62(2.65)} as well as an effective energy {20 (24) meV} and a cut-off phonon energy {35(39) meV} have been estimated for CuIn 5 Se 8 (CuGa 3 Se 5 ). It was also found that the major contribution of phonons to the shift of E g versus temperature in CuIn 5 Se 8 (CuGa 3 Se 5 ) is mainly from optical phonons. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (Abstract Copyright [2006], Wiley Periodicals, Inc.)

  16. Measurements of the electric field gradient at cadmium in YBa2Cu3Ox, Y2BaCuO5 and Y2Cu2O5

    International Nuclear Information System (INIS)

    Saitovitch, H.; Silva, P.R.J.

    1990-01-01

    The electric Field Gradient (EFG) at diluted Cd sup(111) in YBa sub(2)Cu sub(3)O sub(x) was measured by Angular Correlation (AC). In order to determine the atom-probe localization, AC measurements were also, performed on Y sub(2)BaCuO sub(5). A nuclear electric quadrupole interaction frequency (NQIF) was associated with Cd sup(111) in YBa sub(2)Cu sub(3) O sub(x) Cu(1) site. (author)

  17. Spectroscopic study of the CuO chains in YBa2Cu3O7-x

    International Nuclear Information System (INIS)

    Edwards, H.; Derro, D.J.; Barr, A.L.; Markert, J.T.; de Lozanne, A.L.

    1996-01-01

    We interpret our previously published results obtained using a technique called current-imaging tunneling spectroscopy (CITS) to study the detailed electronic structure of the CuO chains in the high-temperature superconductor YBa 2 Cu 3 O 7-x near the Fermi level. Our CITS data comprise sequences of 32 simultaneously obtained images taken at bias voltages ranging from -78 to 72 mV. Cross sections of the CITS data, normalized-conductance analysis, and logarithmic-derivative analysis allow us to examine in detail the behavior of electronic modulations along the CuO chains and the energy gap in the CuO chains of YBa 2 Cu 3 O 7-x . This new analysis lends a strong foundation to our previous interpretation of the CITS data [H. L. Edwards et al., Phys. Rev. Lett. 75, 1387 (1995)]. copyright 1996 American Vacuum Society

  18. The tin-rich copper lithium stannides: Li3Cu6Sn4 and Li2CuSn2

    International Nuclear Information System (INIS)

    Fuertauer, Siegfried; Flandorfer, Hans; Effenberger, Herta S.

    2015-01-01

    The Sn rich ternary intermetallic compounds Li 3 Cu 6 Sn 4 (CSD-427097) and Li 2 CuSn 2 (CSD-427098) were synthesized from the pure elements by induction melting and annealing at 400 C. Structural investigations were performed by powder- and single-crystal XRD. Li 3 Cu 6 Sn 4 crystallizes in space group P6/mmm; it is structurally related to but not isotypic with MgFe 6 Ge 6 (a = 5.095(2) Aa, c = 9.524(3) Aa; wR 2 = 0.059; 239 unique F 2 -values, 17 free variables). Li 3 Cu 6 Sn 4 is characterized by two sites with a mixed Cu:Sn occupation. In contrast to all other Cu-Li-Sn compounds known so far, any mixed occupation was found for Cu-Li pairs only. In addition, one Li site is only half occupied. The second Sn rich phase is Li 2 CuSn 2 (space group I4 1 /amd, a = 4.4281(15) Aa, c = 19.416(4) Aa; wR 2 = 0.033; 213 unique F 2 -values, 12 atom free variables); it is the only phase in the Cu-Li-Sn system which is noted for full ordering. Both crystal structures exhibit 3D-networks which host Li atoms in channels. They are important for understanding the lithiation mechanism in Cu-Sn electrodes for Li-ion batteries.

  19. Structural and electrical properties of co-evaporated Cu(In,Ga)Se{sub 2} thin films with varied Cu contents

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Min Young; Kim, Girim; Kim, Jongwan; Park, Jae Hwan; Lim, Donggun, E-mail: dglim@ut.ac.kr

    2013-11-01

    Cu(In,Ga)Se{sub 2} (CIGS) thin films were fabricated with varying Cu contents. Cu/(Ga + In) ratios were varied between 0.4 and 1.02. Solar cells were then fabricated by co-evaporation using the CIGS layers as absorbers. The influences of Cu content on the cells' structural, optical and electrical properties were studied. The CIGS thin films were characterized by X-ray diffractometer, scanning electron microscopy, energy-dispersive spectroscopy, four-point probe measurement and Hall measurement. Grain size in the films increased with increasing Cu content. At a Cu/(Ga + In) ratio of 0.86, the (220/204) peak was stronger than the (112) peak and carrier concentration was 1.49 × 10{sup 16} cm{sup −3}. Optimizing the Cu content resulted in a CIGS solar cell with an efficiency of 16.5%. - Highlights: • Improvement of technique to form Cu(In,Ga)Se{sub 2} (CIGS) film by co-evaporation method • Cu/(In + Ga) ratio to improve the efficiency for CIGS thin film solar cell • Cu content effects have been analyzed. • Optimum condition of CIGS layer as an absorber of thin film solar cells.

  20. Enhancement of oxidation resistance in Cu and Cu(Al) thin layers

    Energy Technology Data Exchange (ETDEWEB)

    Horvath, Z.E.; Peto, G. E-mail: peto@mfa.kfki.hu; Paszti, Z.; Zsoldos, E.; Szilagyi, E.; Battistig, G.; Lohner, T.; Molnar, G.L.; Gyulai, J

    1999-01-02

    High conductivity and good resistance to electromigration makes copper a promising interconnect material in microelectronics. However, one of its disadvantages is the poor corrosion resistance. Two methods of passivation are investigated and compared: Al alloying and BF{sub 2}{sup +} ion implantation. X-ray diffraction (XRD) and Rutherford Backscattering Spectrometry (RBS) show the oxidation inhibition of both methods, but the different ratio of CuO{sub 2} to CuO phases suggests different mechanisms of passivation. There are no definite oxide lines in the XRD spectrum of the implanted and annealed Cu(Al) sample, so the presence of Al and the implantation together give increased protection against oxidation. The difference between the two mechanisms of oxidation inhibition is discussed briefly.

  1. Soldering-induced Cu diffusion and intermetallic compound formation between Ni/Cu under bump metallization and SnPb flip-chip solder bumps

    Science.gov (United States)

    Huang, Chien-Sheng; Jang, Guh-Yaw; Duh, Jenq-Gong

    2004-04-01

    Nickel-based under bump metallization (UBM) has been widely used as a diffusion barrier to prevent the rapid reaction between the Cu conductor and Sn-based solders. In this study, joints with and without solder after heat treatments were employed to evaluate the diffusion behavior of Cu in the 63Sn-37Pb/Ni/Cu/Ti/Si3N4/Si multilayer structure. The atomic flux of Cu diffused through Ni was evaluated from the concentration profiles of Cu in solder joints. During reflow, the atomic flux of Cu was on the order of 1015-1016 atoms/cm2s. However, in the assembly without solder, no Cu was detected on the surface of Ni even after ten cycles of reflow. The diffusion behavior of Cu during heat treatments was studied, and the soldering-process-induced Cu diffusion through Ni metallization was characterized. In addition, the effect of Cu content in the solder near the solder/intermetallic compound (IMC) interface on interfacial reactions between the solder and the Ni/Cu UBM was also discussed. It is evident that the (Cu,Ni)6Sn5 IMC might form as the concentration of Cu in the Sn-Cu-Ni alloy exceeds 0.6 wt.%.

  2. Diffusivities and atomic mobilities in Cu-rich fcc Al-Cu-Mn alloys

    Energy Technology Data Exchange (ETDEWEB)

    Yin, Ming; Du, Yong; Cui, Senlin; Xu, Honghui; Liu, Shuhong [Central South Univ., Changsha (China). State Key Laboratory of Powder Metallurgy; Zhang, Lijun [Bochum Univ. (DE). Interdisciplinary Centre for Advanced Materials Simulation (ICAMS)

    2012-07-15

    Via solid-solid diffusion couples, electron probe microanalysis and the Whittle and Green method, interdiffusivities in fcc Al-Cu-Mn alloys at 1 123 K were measured. The reliability of the obtained diffusivities is validated by comparing the computed diffusivities with literature data plus constraints among the diffusivities. Through assessments of experimentally determined diffusion coefficients by means of a diffusion-controlled transformations simulation package, the atomic mobilities of Al, Cu, and Mn in fcc Al-Cu-Mn alloys are obtained. Comprehensive comparisons between the model-predicted and the experimental data indicate that the presently obtained atomic mobilities can reproduce most of the diffusivities, concentration profiles, and diffusion paths reasonably. (orig.)

  3. Role of dopants in LiF:Mg,Cu, LiF:Mg,P and LiF:Mg,Cu,P detectors

    International Nuclear Information System (INIS)

    Mohammadi, Kh.; Moussavi Zarandi, A.; Afarideh, H.; Shahmaleki, S.

    2013-01-01

    In this study, electronic structure of LiF crystal doped with Mg,Cu,P impurities was studied with WIEN2k code on the basis of FPLAPW+lo method. Results show that in Mg-doped LiF composition, an electronic trap was created with impurity concentration of 1.56% and 3.125%. In this condition, the electronic trap with increasing the percentage of the impurities up to 4.687% is annihilated. It was found, that by doping of Mg and Cu or P simultaneously, a hole-trap is created in valence band. It was realized that in LiF:Mg,Cu, LiF:Mg,P and LiF:Mg,Cu,P, Cu impurity and Li atom, have a key role in creation of levels which lead to create electronic and hole traps. Mg impurity and F atom, only have a role in creation of electronic traps. In addition, P impurity has a main role in creation of the electronic and hole traps in LiF:Mg,Cu,P. The activation energy of electronic and hole trap in LiF:Mg,Cu, LiF:Mg,P and LiF:Mg,Cu,P crystalline lattice were obtained as 0.3 and 5.5 eV, 0.92 and 3.4 eV and 0.75 and 3.1 eV, respectively. - Graphical abstract: Figure (a) and (b) shows changes in electronic structure and band gap energy of LiF crystal due to presence of Mg and Cu, Mg and P ions respectively. - Highlights: • Electronic structure of LiF, LiF:Mg,Cu, LiF:Mg,P and LiF:Mg,Cu,P materials were studied with WIEN2K code. • In LiF:Mg,Cu and LiF:Mg,Cu,P, Li atom and Cu impurity have a key role in creation of levels. • F atom and Mg impurity only have a role in creation of electronic traps. • In LiF:Mg,Cu,P, P impurity has a main role in creation of electronic and hole traps

  4. Synthesis and magnetic properties of multilayer Ni/Cu and NiFe/Cu ...

    Indian Academy of Sciences (India)

    The diameter of wires can be easily varied by pore size of alumina, ranging ... saturated HgCl2 solution to remove the remaining Al, and then dipped in 5 wt% ... for NiFe alloy it is 1.3 V, that is higher than for Ni/Cu nanowires to diminish Cu.

  5. Phase segregation, interfacial intermetallic growth and electromigration-induced failure in Cu/In–48Sn/Cu solder interconnects under current stressing

    International Nuclear Information System (INIS)

    Li, Yi; Lim, Adeline B.Y.; Luo, Kaiming; Chen, Zhong; Wu, Fengshun; Chan, Y.C.

    2016-01-01

    The evolution of microstructure in Cu/In–48Sn/Cu solder bump interconnects at a current density of 0.7 × 10"4 A/cm"2 and ambient temperature of 55 °C has been investigated. During electromigration, tin (Sn) atoms migrated from cathode to anode, while indium (In) atoms migrated from anode to cathode. As a result, the segregation of the Sn-rich phase and the In-rich phase occurred. A Sn-rich layer and an In-rich layer were formed at the anode and the cathode, respectively. The accumulation rate of the Sn-rich layer was 1.98 × 10"−"9 cm/s. The atomic flux of Sn was calculated to be approximately 1.83 × 10"1"3 atoms/cm"2s. The product of the diffusivity and the effective charge number of Sn was determined to be approximately 3.13 × 10"−"1"0 cm"2/s. The In–48Sn/Cu IMC showed a two layer structure of Cu_6(Sn,In)_5, adjacent to the Cu, and Cu(In,Sn)_2, adjacent to the solder. Both the cathode IMC and the anode IMC thickened with increasing electromigration time. The IMC evolution during electromigration was strongly influenced by the migration of Cu atoms from cathode to anode and the accumulation of Sn-rich and In-rich layers. During electromigration, the Cu(In,Sn)_2 at the cathode interface thickened significantly, with a spalling characteristic, due to the accumulation of In-rich layer and the migration of Cu atoms - while the Cu(In,Sn)_2 at the anode interface reduced obviously, due to the accumulation of Sn-rich layer. The mechanism of electromigration-induced failure in Cu/In–48Sn/Cu interconnects was the cathode Cu dissolution-induced solder melt, which led to the rapid consumption of Cu in the cathode pad during liquid-state electromigration and this finally led to the failure. - Highlights: • Sn migrates to the anode, while In migrates to the cathode, during EM in Cu/In–48Sn/Cu. • The atomic flux of Sn has been calculated. • The interfacial IMCs were identified as: Cu_6(Sn,In)_5 + Cu(In,Sn)_2. • The interface evolution is strongly

  6. Synthesis, Crystal Structure, and Electroconducting Properties of a 1D Mixed-Valence Cu(I–Cu(II Coordination Polymer with a Dicyclohexyl Dithiocarbamate Ligand

    Directory of Open Access Journals (Sweden)

    Kenji Nakatani

    2015-04-01

    Full Text Available A new mixed-valence Cu(I–Cu(II 1D coordination polymer, [CuI4CuIIBr4(Cy2dtc2]n, with an infinite chain structure is synthesized by the reaction of Cu(Cy2dtc2 (Cy2dtc− = dicyclohexyl dithiocarbamate, C13H22NS2 with CuBr·S(CH32. The as-synthesized polymer consists of mononuclear copper(II units of CuII(Cy2dtc2 and tetranuclear copper(I cluster units, CuI4Br4. In the cluster unit, all the CuI ions have distorted trigonal pyramidal coordination geometries, and the CuI–CuI or CuI–CuII distances between the nearest copper ions are shorter than the sum of van der Waals radii for Cu–Cu.

  7. Preparation of three-dimensional porous Cu film supported on Cu foam and its electrocatalytic performance for hydrazine electrooxidation in alkaline medium

    International Nuclear Information System (INIS)

    Liu, Ran; Ye, Ke; Gao, Yinyi; Long, Ziyao; Cheng, Kui; Zhang, Wenping; Wang, Guiling; Cao, Dianxue

    2016-01-01

    Highlights: • A binder-free Cu/Cu foam electrode is prepared by an electrochemical method. • The electrode owns a novel three-dimensional porous structure. • The electrode exhibits superior catalytic activity for hydrazine electrooxidation. - Abstract: A three-dimensional porous copper film is directly deposited on Cu foam by an electrodeposition method using hydrogen bubbles as dynamic template (denoted as Cu/Cu foam). Its electrocatalytic activity toward hydrazine electrooxidation is tested by linear sweep voltammetry, chronoamperometry and electrochemical impedance spectroscopy. Compared with Cu foam, hydrazine electrooxidation on the Cu/Cu foam electrode shows that the onset oxidation potential displays a ~100 mV negative shift, the current density at −0.6 V raises about 14 times, the apparent activation energy and the charge transfer resistance reduce significantly. The increasing electrocatalytic performance for hydrazine electrooxidation is mainly caused by the highly porous structure of the Cu/Cu foam electrode which can provide a large surface area and make electrolyte access the electrocatalyst surfaces more easily. Hydrazine electrooxidation on the Cu/Cu foam electrode proceeds through a near 4-electron process.

  8. Effect of Intermetallic on Electromigration and Atomic Diffusion in Cu/SnAg3.0Cu0.5/Cu Joints: Experimental and First-Principles Study

    Science.gov (United States)

    Zhou, Wei; Liu, Lijuan; Li, Baoling; Wu, Ping

    2009-06-01

    Electromigration phenomena in a one-dimensional Cu/SnAg3.0Cu0.5/Cu joint were investigated with current stressing. The special effect of intermetallic compound (IMC) layers on the formation of serious electromigration damage induced by nonuniform current density distribution was discussed based on experimental results. Meanwhile, hillocks were observed both at the anode and near the cathode of the joint, and they were described as the result of diffusion of atoms and compressive stress released along grain boundaries to the relatively free surface. Moreover, the diffusion behavior of Cu at the cathode was analyzed with the electromigration equation, and the stability of Ag atoms in the solder during electromigration was evaluated with a first-principles method.

  9. Interplay of Cu and oxygen vacancy in optical transitions and screening of excitons in ZnO:Cu films

    International Nuclear Information System (INIS)

    Darma, Yudi; Rusydi, Andrivo; Seng Herng, Tun; Marlina, Resti; Fauziah, Resti; Ding, Jun

    2014-01-01

    We study room temperature optics and electronic structures of ZnO:Cu films as a function of Cu concentration using a combination of spectroscopic ellipsometry, photoluminescence, and ultraviolet-visible absorption spectroscopy. Mid-gap optical states, interband transitions, and excitons are observed and distinguishable. We argue that the mid-gap states are originated from interactions of Cu and oxygen vacancy (Vo). They are located below conduction band (Zn4s) and above valence band (O2p) promoting strong green emission and narrowing optical band gap. Excitonic states are screened and its intensities decrease upon Cu doping. Our results show the importance of Cu and Vo driving the electronic structures and optical transitions in ZnO:Cu films

  10. Interplay of Cu and oxygen vacancy in optical transitions and screening of excitons in ZnO:Cu films

    Science.gov (United States)

    Darma, Yudi; Seng Herng, Tun; Marlina, Resti; Fauziah, Resti; Ding, Jun; Rusydi, Andrivo

    2014-02-01

    We study room temperature optics and electronic structures of ZnO:Cu films as a function of Cu concentration using a combination of spectroscopic ellipsometry, photoluminescence, and ultraviolet-visible absorption spectroscopy. Mid-gap optical states, interband transitions, and excitons are observed and distinguishable. We argue that the mid-gap states are originated from interactions of Cu and oxygen vacancy (Vo). They are located below conduction band (Zn4s) and above valence band (O2p) promoting strong green emission and narrowing optical band gap. Excitonic states are screened and its intensities decrease upon Cu doping. Our results show the importance of Cu and Vo driving the electronic structures and optical transitions in ZnO:Cu films.

  11. Titulações potenciométricas de cátions metálicos tendo como eletrodo indicador o sistema Cu/Cu(II-EDTA Potentiometric titrations of metal cations with edta using the Cu/Cu(II-EDTA system as indicator electrode

    Directory of Open Access Journals (Sweden)

    Paulo H. Pereira da Silva

    2008-01-01

    Full Text Available In potentiometric titrations of metal cations with EDTA the Hg/HgY2- system is usually used to detect the end point. However, the use of mercury has been discouraged in analytical procedures due to its toxicity. In this work the Cu/CuY2- system was used as indicator electrode for potentiometric titrations of some metal cations with EDTA. The solutions of Cu2+, Cd2+, Mn2+, Co2+ and Zn2+ were titrated with Na2EDTA solution in the presence of a small concentration of the CuY2- complex using a copper wire as indicator electrode. The potentiometric titrations with the Cu/CuY2- system showed good correlation when compared with an Hg/HgY2- system.

  12. R&D of CuCrZr tubes for W/Cu monoblock components

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Sixiang, E-mail: sxzhao@impcas.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP), P.O. Box 1126, Hefei 230031 (China); Ma, Linsheng [State Nuclear Bao Ti Zirconium Industry Company, 206 Hi-Tech Avenue, Baoji 721013 (China); Peng, Lingjian [Advanced Technology & Materials Co., Ltd. - AT& M, Beijing 100081 (China); Gao, Bo [State Nuclear Bao Ti Zirconium Industry Company, 206 Hi-Tech Avenue, Baoji 721013 (China); Li, Chun [Laboratory of Advanced materials, School of Materials Science & Engineering, Tsinghua University, Beijing 100084 (China); Li, Qiang; Wang, Wanjing; Wei, Ran; Xu, Yuping [Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP), P.O. Box 1126, Hefei 230031 (China); Pan, Ningjie; Qin, Sigui; Shi, Yingli; Liu, Guohui; Wang, Tiejun [Advanced Technology & Materials Co., Ltd. - AT& M, Beijing 100081 (China); Luo, Guang-Nan, E-mail: gnluo@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP), P.O. Box 1126, Hefei 230031 (China); Hefei Center for Physical Science and Technology, Hefei 230031 (China); Hefei Science Center of CAS, Hefei 230031 (China)

    2016-11-15

    Highlights: • CuCrZr tubes with excellent HIP performance and good resistance to grain growth have been developed. • A circumferential ductility testing manner for small-diameter tubes has been utilized in this study. • The evolution of microstructures has been revealed throughout the new tube forming processes. - Abstract: In order to avoid the occurrence of two types of longitudinal defects (strain localization and folding flaws), which were observed in the CuCrZr tubes of EAST W/Cu upper divertor components, in the future manufacturing of monoblock components using hot isostatic pressing (HIP), a new CuCrZr tube forming protocol is proposed. The evolution of Cu grains and Cr-rich particles is monitored by scanning electron microscopy throughout the new tube forming processes. The final microstructures of the newly developed tubes are totally different from those of the EAST project previously chosen tubes and the elongation of Cr-rich precipitates has been substantially suppressed by using the new tube forming protocol. The newly developed tubes show better HIP performance than the EAST previously chosen ones. Since circumferential mechanical properties, especially ductility, are of great importance, a circumferential ductility testing manner for small-diameter tubes, which might be a supplement to longitudinal tensile testing, has been utilized and the preliminary testing results are given. The recrystallization behavior of the newly developed tubes is also investigated.

  13. Studies of the development and characterization of the Cu-Ni-Pt and Cu-Ni-Sn alloys for electro-electronic uses

    International Nuclear Information System (INIS)

    Silva, Luis Carlos Elias da

    2006-01-01

    The Cu and its alloys have different applications in the owed modern society the excellent electric properties, thermal conductivity, resistance to the corrosion and other properties. These applications can be in valves, pipes, pots for absorption of solar energy, radiators for automobiles, current driver, electronic driver, thermostats elements and structural parts of nuclear reactors, as, for example, reels for field toroidal for a reactor of nuclear coalition. The alloys used in nuclear reactors, we can highlight Cu-Be, Cu-Sn and Cu-Pt. Ni and Co frequently are added to the Cu alloys so that the solubility is moved for temperatures more elevated with relationship to the binary systems of Cu-Sn and Cu-Pt. The addition of Ni-Pt or Ni-Sn to the Cu in the same or inferior percentages to 1,5% plus thermomechanical treatments changes the properties of the copper. We studied the electric conductivity and hardness Vickers of the Cu-Ni-Pt and Cu-Ni-Sn and compared with the electrolytic Cu. In the proposed flowcharts, breaking of the obtaining of the ingot, we proceeded with thermo mechanical treatments. (author)

  14. Direct, CMOS In-Line Process Flow Compatible, Sub 100 °C Cu-Cu Thermocompression Bonding Using Stress Engineering

    Science.gov (United States)

    Panigrahi, Asisa Kumar; Ghosh, Tamal; Kumar, C. Hemanth; Singh, Shiv Govind; Vanjari, Siva Rama Krishna

    2018-03-01

    Diffusion of atoms across the boundary between two bonding layers is the key for achieving excellent thermocompression Wafer on Wafer bonding. In this paper, we demonstrate a novel mechanism to increase the diffusion across the bonding interface and also shows the CMOS in-line process flow compatible Sub 100 °C Cu-Cu bonding which is devoid of Cu surface treatment prior to bonding. The stress in sputtered Cu thin films was engineered by adjusting the Argon in-let pressure in such a way that one film had a compressive stress while the other film had tensile stress. Due to this stress gradient, a nominal pressure (2 kN) and temperature (75 °C) was enough to achieve a good quality thermocompression bonding having a bond strength of 149 MPa and very low specific contact resistance of 1.5 × 10-8 Ω-cm2. These excellent mechanical and electrical properties are resultant of a high quality Cu-Cu bonding having grain growth between the Cu films across the boundary and extended throughout the bonded region as revealed by Cross-sectional Transmission Electron Microscopy. In addition, reliability assessment of Cu-Cu bonding with stress engineering was demonstrated using multiple current stressing and temperature cycling test, suggests excellent reliable bonding without electrical performance degradation.

  15. Direct, CMOS In-Line Process Flow Compatible, Sub 100 °C Cu-Cu Thermocompression Bonding Using Stress Engineering

    Science.gov (United States)

    Panigrahi, Asisa Kumar; Ghosh, Tamal; Kumar, C. Hemanth; Singh, Shiv Govind; Vanjari, Siva Rama Krishna

    2018-05-01

    Diffusion of atoms across the boundary between two bonding layers is the key for achieving excellent thermocompression Wafer on Wafer bonding. In this paper, we demonstrate a novel mechanism to increase the diffusion across the bonding interface and also shows the CMOS in-line process flow compatible Sub 100 °C Cu-Cu bonding which is devoid of Cu surface treatment prior to bonding. The stress in sputtered Cu thin films was engineered by adjusting the Argon in-let pressure in such a way that one film had a compressive stress while the other film had tensile stress. Due to this stress gradient, a nominal pressure (2 kN) and temperature (75 °C) was enough to achieve a good quality thermocompression bonding having a bond strength of 149 MPa and very low specific contact resistance of 1.5 × 10-8 Ω-cm2. These excellent mechanical and electrical properties are resultant of a high quality Cu-Cu bonding having grain growth between the Cu films across the boundary and extended throughout the bonded region as revealed by Cross-sectional Transmission Electron Microscopy. In addition, reliability assessment of Cu-Cu bonding with stress engineering was demonstrated using multiple current stressing and temperature cycling test, suggests excellent reliable bonding without electrical performance degradation.

  16. INTERSITE INTERACTIONS IN CU L-EDGE XPS, XAS, AND XES OF DOPED AND UNDOPED CU COMPOUNDS

    NARCIS (Netherlands)

    VANVEENENDAAL, MA; SAWATZKY, GA

    1994-01-01

    The effect of interaction between different Cu atoms is studied by calculations on clusters with more Cu atoms for various kinds of spectroscopy, using a multiband Hubbard Hamiltonian. It is found that the inclusion of more Cu sites often leads to final states lower in energy than those that would

  17. Evaluation of [64Cu]Cu-DOTA and [64Cu]Cu-CB-TE2A Chelates for Targeted Positron Emission Tomography with an αvβ6-Specific Peptide

    Directory of Open Access Journals (Sweden)

    Sven H. Hausner

    2009-03-01

    Full Text Available Significant upregulation of the integrin αvβ6 has been described as a prognostic indicator in several cancers, making it an attractive target for tumor imaging. This study compares variants of a PEGylated αvβ6-targeting peptide, bearing either an [>18F]fluorobenzoyl prosthetic group ([18F]FBA-PEG-A20FMDV2 or different [64Cu]copper chelators (DOTA-PEG-A20FMDV2, CB-TE2A-PEG-A20FMDV2. The compounds were evaluated in vitro by enzyme-linked immunosorbent assay (against the integrin αvβ6 and the closely related integrin αvβ6 and by cell labeling (αvβ6-positive DX3puroβ6/αvβ6-negative DX3puro and in vivo using micro-positron emission tomography in a mouse model bearing paired DX3puroβ6/Dx3puro xenografts. In vitro, all three compounds showed excellent αvβ6-specific binding (50% inhibitory concentration [IC50](αvβ6 = 3 to g nmol/L; IC50(αvβ3 > 10 (μmol/L. In vivo, they displayed comparable, preferential uptake for the αvβ6-expressmg xenograft over the αvβ6-negative control (> 4:1 ratio at 4 hours postinjection. Whereas [64Cu]Cu-DOTA-PEG-A20FMDV2 resulted in increased levels of radioactivity in the liver, [64Cu]Cu-CB-TE2A-PEG-A20FMDV2 did not. Significantly, both 64Cu-labeled tracers showed unexpectedly high and persistent levels of radioactivity in the kidneys (> 40% injected dose/g at 4 and 12 hours postinjection. The findings underscore the potential influence of the prosthetic group on targeted in vivo imaging of clinically relevant markers such as αvβ6. Despite identical targeting peptide moiety and largely equal in vitro behavior, both 64Cu-labeled tracers displayed inferior pharmacokinetics, making them in their present form less suitable candidates than the 18F-labeled tracer for in vivo imaging of αvβ6

  18. Organic acids, amino acids compositions in the root exudates and Cu-accumulation in castor (Ricinus communis L.) Under Cu stress.

    Science.gov (United States)

    Huang, Guoyong; Guo, Guangguang; Yao, Shiyuan; Zhang, Na; Hu, Hongqing

    2016-01-01

    Ricinus communis L. is a hyperaccumulation plant newly discovered in an abandoned land of Cu mine in China. A hydroponic experiment was then carried out to determine the root exudates in the Cu-tolerant castor (Ricinus communis L.). Plants were grown in nutrient solution with increasing level of Cu doses (0, 100, 250, 500, and 750 μmol/L Cu) in the form of CuSO4. Cu accumulation in the roots and shoots of castor, and root exudates collected from the castor were measured. The results indicated that the castor had a high Cu accumulation capacity and the Cu concentrations in the shoots and roots of the castor treated with 750 μmol/L Cu were 177.1, 14586.7 mg/kg, respectively. Tartaric was the largest in the root exudates in terms of concentrations, which reached up to 329.13 μmol/g (dry plant) in the level of 750 μmol/L Cu. There was a significantly positive linear relationship between the Cu concentration in root and the concentration of succinic (R = 0.92, P < 0.05), tartaric (R = 0.96, P < 0.01), and citric (R = 0.89, P < 0.05). These results indicated that the difference in root exudation from castor could affect their Cu tolerance. What is more, significant is that the high tartaric and citric, the low oxalic and cysteine in the root exudation of castor contributed to toleration of high Cu concentrations.

  19. Ab-initio atomic level stress and role of d-orbitals in CuZr, CuZn and CuY

    Science.gov (United States)

    Ojha, Madhusudan; Nicholson, Don M.; Egami, Takeshi

    2015-03-01

    Atomic level stress offers a new tool to characterize materials within the local approximation to density functional theory (DFT). Ab-initio atomic level stresses in B2 structures of CuZr, CuZn and CuY are calculated and results are explained on the basis of d-orbital contributions to Density of States (DOS). The overlap of d-orbital DOS plays an important role in the relative magnitude of atomic level stresses in these structures. The trends in atomic level stresses that we observed in these simple B2 structures are also seen in complex structures such as liquids, glasses and solid solutions. The stresses are however modified by the different coordination and relaxed separation distances in these complex structures. We used the Locally Self-Consistent Multiple Scattering (LSMS) code and Vienna Ab-initio Simulation Package (VASP) for ab-initio calculations.

  20. Electrodeposition of Cu-In alloys for preparing CuInS sub 2 thin films

    Energy Technology Data Exchange (ETDEWEB)

    Herrero, J; Ortega, J [Inst. de Energias Renovables (CIEMAT), Madrid (Spain)

    1990-01-01

    Copper-indium alloys were prepared by electroplating from citric acid (C{sub 6}H{sub 8}O{sub 7}.H{sub 2}O) baths onto Ti substrate. Formation of the alloys was carried out by direct codeposition of the elements and by sequential electrodeposition of copper and indium. Studies of the alloy formation by electrochemical measurements and X-ray diffraction were performed. The presence of Cu{sub 7}In{sub 4} in direct deposit as well as in sequentially electrodeposited material was observed during the alloy formation. The as-deposited layers were heated in H{sub 2}S. X-ray diffraction showed the annealed layers to be CuInS{sub 2} with the chalcopyrite structure, where the CuIn{sub 5}S{sub 8} phase was included during the annealing process. Photoelectrochemical characterization of the samples allowed us to determine the photoconductivity which is related with the Cu/In ratio in the samples. The energy gap for CuInS{sub 2} photoelectrodes in polysulphide solution was 1.57 Ev. (orig.).

  1. Effect of the ITO substrate on the growth of Cu(In,Ga)Se{sub 2}, CuGa{sub 3}Se{sub 5}, CuGa{sub 5}Se{sub 8} and CuIn{sub 3}Se{sub 5} thin films by flash evaporation

    Energy Technology Data Exchange (ETDEWEB)

    Friedrich, E J; Merino, J M; Leon, M [Department of Applied Physics, Universidad Autonoma de Madrid (UAM), Cantoblanco, 28049 Madrid (Spain); Trigo, J F; Guillen, C [Department of Energy, CIEMAT, Avda Complutense, 22, 28040 Madrid (Spain); Ramiro, J, E-mail: josue.friedrich@uam.e [Department of Theory of Signal and Communications, URJC, Campus Fuenlabrada, 122, 28943 Madrid (Spain)

    2009-04-21

    Structural, compositional, electrical and morphological properties of CuIn{sub 1-x}Ga{sub x}Se{sub 2} (x = 0.15, 0.30) and ordered defect compounds (ODC) CuGa{sub 3}Se{sub 5}, CuGa{sub 5}Se{sub 8}, CuIn{sub 3}Se{sub 5} thin films grown by flash evaporation onto soda lime glass substrates (SLG) and ITO/SLG have been studied. Polycrystalline thin films with accentuated preferential orientation in the (1 1 2) plane of the tetragonal structure have been obtained. Annealing in Se atmosphere improves the structural, morphological, electrical and optical properties of the evaporated films, but provokes the formation of a CuIn{sub x}Se{sub y} phase on the surface of the films. Band gap values ranging between 1.01 and 1.21 eV have been obtained for the as-grown CuIn{sub 1-x}Ga{sub x}Se{sub 2} thin films and between 1.09 and 2.01 eV for the CuGa{sub 3}Se{sub 5}, CuGa{sub 5}Se{sub 8} and CuIn{sub 3}Se{sub 5} thin films.

  2. Influence of body size on Cu bioaccumulation in zebra mussels Dreissena polymorpha exposed to different sources of particle-associated Cu.

    Science.gov (United States)

    Zhong, Huan; Kraemer, Lisa; Evans, Douglas

    2013-10-15

    Size of organisms is critical in controlling metal bioavailability and bioaccumulation, while mechanisms of size-related metal bioaccumulation are not fully understood. To investigate the influences of different sources of particle-associated Cu on body size-related Cu bioavailability and bioaccumulation, zebra mussels (Dreissena polymorpha) of different sizes were exposed to stable Cu isotope ((65)Cu) spiked algae (Chlorella vulgaris) or sediments in the laboratory and the Cu tissue concentration-size relationships were compared with that in unexposed mussels. Copper tissue concentrations decreased with mussel size (tissue or shell dry weight) in both unexposed and algal-exposed mussels with similar decreasing patterns, but were independent of size in sediment-exposed mussels. Furthermore, the relative contribution of Cu uptake from algae (65-91%) to Cu bioaccumulation is always higher than that from sediments (9-35%), possibly due to the higher bioavailability of algal-Cu. Therefore, the size-related ingestion of algae could be more important in influencing the size-related variations in Cu bioaccumulation. However, the relative contribution of sediment-Cu to Cu bioaccumulation increased with body size and thus sediment ingestion may also affect the size-related Cu variations in larger mussels (tissue weight >7.5mg). This study highlights the importance of considering exposure pathways in normalization of metal concentration variation when using bivalves as biomonitors. Copyright © 2013 Elsevier B.V. All rights reserved.

  3. Use of micro-PIXE to determine spatial distributions of copper in Brassica carinata plants exposed to CuSO{sub 4} or CuEDDS

    Energy Technology Data Exchange (ETDEWEB)

    Cestone, Benedetta, E-mail: benedettacestone@yahoo.it [Department of Biology of Crop Plants, University of Pisa, Via del Borghetto 80, 56121 Pisa (Italy); Vogel-Mikus, Katarina [Department of Biology, Biotechnical Faculty, University of Ljubljana, Vecna pot 111, S1-1000 Ljubljana (Slovenia); Quartacci, Mike Frank [Department of Biology of Crop Plants, University of Pisa, Via del Borghetto 80, 56121 Pisa (Italy); Rascio, Nicoletta [Department of Biology, University of Padova, Via Ugo Bassi 58/B, 35121 Padova (Italy); Pongrac, Paula [Department of Biology, Biotechnical Faculty, University of Ljubljana, Vecna pot 111, S1-1000 Ljubljana (Slovenia); Pelicon, Primoz; Vavpetic, Primoz; Grlj, Natasa; Jeromel, Luka; Kump, Peter; Necemer, Marijan [Jozef Stefan Institute, Jamova 39, 1000 Ljubljana (Slovenia); Regvar, Marjana [Department of Biology, Biotechnical Faculty, University of Ljubljana, Vecna pot 111, S1-1000 Ljubljana (Slovenia); Navari-Izzo, Flavia [Department of Biology of Crop Plants, University of Pisa, Via del Borghetto 80, 56121 Pisa (Italy)

    2012-06-15

    A better understanding of the mechanisms that govern copper (Cu) uptake, distribution and tolerance in Brassica carinata plants in the presence of chelators is needed before significant progress in chelate-assisted Cu phytoextraction can be made. The aims of this study were therefore to characterise (S,S)-N,N Prime -ethylenediamine disuccinic acid (EDDS)-assisted Cu uptake, and to compare the spatial distribution patterns of Cu in the roots and leaves of B. carinata plants. The plants were treated with 30 {mu}M or 150 {mu}M CuSO{sub 4} or CuEDDS in hydroponic solution. Quantitative Cu distribution maps and concentration profiles across root and leaf cross-sections of the desorbed plants were obtained by micro-proton induced X-ray emission. In roots, the 30 {mu}M treatments with both CuSO{sub 4} and CuEDDS resulted in higher Cu concentrations in epidermal/cortical regions. At 150 {mu}M CuSO{sub 4}, Cu was mainly accumulated in root vascular bundles, whereas with 150 {mu}M CuEDDS, Cu was detected in endodermis and the adjacent inner cortical cell layer. Under all treatments, except with a H{sup +}-ATP-ase inhibitor, the Cu in leaves was localised mainly in vascular tissues. The incubation of plants with 150 {mu}M CuEDDS enhanced metal translocation to shoots, in comparison to the corresponding CuSO{sub 4} treatment. Inhibition of H{sup +}-ATPase activity resulted in reduced Cu accumulation in 30 {mu}M CuEDDS-treated roots and 150 {mu}M CuEDDS-treated leaves, and induced changes in Cu distribution in the leaves. This indicates that active mechanisms are involved in retaining Cu in the leaf vascular tissues, which prevent its transport to photosynthetically active tissues. The physiological significance of EDDS-assisted Cu uptake is discussed. - Highlights: Black-Right-Pointing-Pointer We localised Cu in Brassica carinata treated with CuSO{sub 4} or CuEDDS by micro-PIXE. Black-Right-Pointing-Pointer EDDS-assisted Cu uptake and transport resulted in preserved root

  4. Kinetics of intermetallic phase formation at the interface of Sn-Ag-Cu-X (X = Bi, In) solders with Cu substrate

    International Nuclear Information System (INIS)

    Hodulova, Erika; Palcut, Marian; Lechovic, Emil; Simekova, Beata; Ulrich, Koloman

    2011-01-01

    Highlights: → In substitutes Sn in intermetallic compounds formed at the Cu-solder interface. → Bi and In decrease the parabolic rate constant of Cu 3 Sn layer growth. → In increases the parabolic rate constant of Cu 6 Sn 5 layer growth. → High In concentrations should be avoided since they may lead to a pre-mature solder joint degradation. - Abstract: The effects of Bi and In additions on intermetallic phase formation in lead-free solder joints of Sn-3.7Ag-0.7Cu; Sn-1.0Ag-0.5Cu-1.0Bi and Sn-1.5Ag-0.7Cu-9.5In (composition given in weight %) with copper substrate are studied. Soldering of copper plate was conducted at 250 deg. C for 5 s. The joints were subsequently aged at temperatures of 130-170 deg. C for 2-16 days in a convection oven. The aged interfaces were analyzed by optical microscopy and energy dispersive X-ray spectroscopy (EDX) microanalysis. Two intermetallic layers are observed at the interface - Cu 3 Sn and Cu 6 Sn 5 . Cu 6 Sn 5 is formed during soldering. Cu 3 Sn is formed during solid state ageing. Bi and In decrease the growth rate of Cu 3 Sn since they appear to inhibit tin diffusion through the grain boundaries. Furthermore, indium was found to produce a new phase - Cu 6 (Sn,In) 5 instead of Cu 6 Sn 5 , with a higher rate constant. The mechanism of the Cu 6 (Sn,In) 5 layer growth is discussed and the conclusions for the optimal solder chemical composition are presented.

  5. Formation of closely packed Cu nanoparticle films by capillary immersion force for preparing low-resistivity Cu films at low temperature

    Energy Technology Data Exchange (ETDEWEB)

    Yokoyama, Shun, E-mail: shun.yokoyama.c2@tohoku.ac.jp; Motomiya, Kenichi; Takahashi, Hideyuki; Tohji, Kazuyuki [Tohoku University, Graduate School of Environmental Studies (Japan)

    2016-11-15

    Films made of closely packed Cu nanoparticles (NPs) were obtained by drop casting Cu NP inks. The capillary immersion force exerted during the drying of the inks caused the Cu NPs to attract each other, resulting in closely packed Cu NP films. The apparent density of the films was found to depend on the type of solvent in the ink because the capillary immersion force is affected by the solvent surface tension and dispersibility of Cu NPs in the solvent. The closely packed particulate structure facilitated the sintering of Cu NPs even at low temperature, leading to low-resistivity Cu films. The sintering was also enhanced with a decrease in the size of NPs used. We demonstrated that a closely packed particulate structure using Cu NPs with a mean diameter 61.7 nm showed lower resistivity (7.6 μΩ cm) than a traditionally made Cu NP film (162 μΩ cm) after heat treatment.

  6. Synthesis of core-shell heterostructured Cu/Cu2O nanowires monitored by in situ XRD as efficient visible-light photocatalysts

    KAUST Repository

    Chen, Wei

    2013-01-01

    Core-shell heterostructured Cu/Cu2O nanowires with a high aspect ratio were synthesized from Cu foam using a novel oxidation/reduction process. In situ XRD was used as an efficient tool to acquire phase transformation details during the temperature-programmed oxidation of Cu foam and the subsequent reduction process. Based on knowledge of the crucial phase transformation, optimal synthesis conditions for producing high-quality CuO and core-shell Cu/Cu2O nanowires were determined. In favor of efficient charge separation induced by the special core-shell heterostructure and the advanced three-dimensional spatial configuration, Cu/Cu2O nanowires exhibited superior visible-light activity in the degradation of methylene blue. The present study illustrates a novel strategy for fabricating efficiently core-shell heterostructured nanowires and provides the potential for developing their applications in electronic devices, for environmental remediation and in solar energy utilization fields. This journal is © The Royal Society of Chemistry.

  7. A TEM study of D+-implanted Cu following Ar+-ion milling: Microstructure and epitaxial Cu2O formation

    International Nuclear Information System (INIS)

    Johnson, P.B.; Corfiatis, T.; Long, N.J.; Nelson, D.G.A.; Victoria Univ., Wellington; Thomson, R.W.

    1988-01-01

    In examining the microstructure of TEM specimens prepared from D + -implanted Cu for the presence of bubbles it was found that cuprous oxide (Cu 2 O) layers had formed over large areas of the specimen surfaces. The Cu was irradiated at normal incidence with 200 keV D + ions at a temperature of 120 K to a dose of ≅ 2x10 21 D + /m 2 . Ar + ion milling at 330 K was used to erode irradiated surfaces to various depths prior to chemical back-thinning in a jet electropolishing bath. There was no evidence for the formation in the Cu of bubbles of either deuterium or argon, but dislocations at high density and planar defects were evident. Lattice fringes from {110}, {111} and {200} planes in Cu 2 O and moire patterns formed by double diffraction in the Cu and overlaid Cu 2 O film were obvious features in bright-field micrographs. The moire patterns include examples of magnified images of lattice defects. (orig.)

  8. Toxicity Action of Cu2+ on Lemna minor%Cu2+对浮萍的毒性作用

    Institute of Scientific and Technical Information of China (English)

    王爱丽; 宋志慧; 程守敬

    2004-01-01

    Cu2+作为胁迫因子研究了Cu2+对浮萍叶片数、叶绿素含量和过氧化物酶活性的影响.结果表明,Cu2+浓度低于200μg@L-1时,能刺激浮萍生长,对浮萍叶绿素含量影响不大;Cu2+浓度再增加时会抑制浮萍的生长;当Cu2+浓度为400 μg@L-1时,会严重影响浮萍的生长,对浮萍叶绿素含量的影响十分明显.Cu2+对浮萍过氧化物酶活性的影响随Cu2+浓度的升高逐渐增加.

  9. DO{sub 22}-(Cu,Ni){sub 3}Sn intermetallic compound nanolayer formed in Cu/Sn-nanolayer/Ni structures

    Energy Technology Data Exchange (ETDEWEB)

    Liu Lilin [School of Physics and Engineering, Sun Yat-Sen University, Guangzhou 510275 (China); Huang, Haiyou [Department of Mechanical Engineering, Hong Kong University of Science and Technology (HKUST) (Hong Kong); Hong Kong - Beijing Joint Research Center, HKUST Fok Ying Tung Graduate School, Nansha, Guangzhou (China); Fu Ran; Liu Deming [ASM Assembly Automation Ltd. (Hong Kong); Zhang Tongyi, E-mail: mezhangt@ust.h [Department of Mechanical Engineering, Hong Kong University of Science and Technology (HKUST) (Hong Kong); Hong Kong - Beijing Joint Research Center, HKUST Fok Ying Tung Graduate School, Nansha, Guangzhou (China)

    2009-11-03

    The present work conducts crystal characterization by High Resolution Transmission Electron Microscopy (HRTEM) on Cu/Sn-nanolayer/Ni sandwich structures associated with the use of Energy Dispersive X-ray (EDX) analysis. The results show that DO{sub 22}-(Cu,Ni){sub 3}Sn intermetallic compound (IMC) ordered structure is formed in the sandwich structures at the as-electrodeposited state. The formed DO{sub 22}-(Cu,Ni){sub 3}Sn IMC is a homogeneous layer with a thickness about 10 nm. The DO{sub 22}-(Cu,Ni){sub 3}Sn IMC nanolayer is stable during annealing at 250 deg. C for 810 min. The formation and stabilization of the metastable DO{sub 22}-(Cu,Ni){sub 3}Sn IMC nanolayer are attributed to the less strain energy induced by lattice mismatch between the DO{sub 22} IMC and fcc Cu crystals in comparison with that between the equilibrium DO{sub 3} IMC and fcc Cu crystals.

  10. Surface structure and morphology of Cu-free and Cu-covered Au(100) and Au(111) electrodes in alkaline solution

    Energy Technology Data Exchange (ETDEWEB)

    Schlaup, Christian [Technical University of Denmark, Department of Physics, Fysikvey, DK-2800 Kongens Lyngby (Denmark); Friebel, Daniel [Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, 2575 Sand Hill Rd, Menlo Park, CA 94025 (United States); Wandelt, Klaus [University of Bonn, Institute for Physical und Theoretical Chemistry, Wegelerstr. 12, D-53115 Bonn (Germany)

    2011-07-01

    For both Cu-free Au-electrodes three different phases were observed as a function of the applied electrode potential. While at low potentials the onset of surface reconstruction points towards an apparently adsorbate free surface and, thus, a weak interaction with species from the electrolyte, a Au-hydroxide and a Au-oxide phase are formed subsequently during potential increase. A similar phase behavior was also found for Cu-covered Au-electrodes, while at low potentials an apparently adsorbate free Cu layer is observed, a Cu-hydroxide coadsorbate phase and a Cu-oxide phase are formed under increased potential conditions. In addition the apparently adsorbate free Cu-film tends to form a Cu-Au alloy phase while keeping the electrode for a sufficient long time at low potential conditions.

  11. The Pd distribution and Cu flow pattern of the Pd-plated Cu wire bond and their effect on the nanoindentation

    International Nuclear Information System (INIS)

    Lin, Yu-Wei; Wang, Ren-You; Ke, Wun-Bin; Wang, I-Sheng; Chiu, Ying-Ta; Lu, Kuo-Chang; Lin, Kwang-Lung; Lai, Yi-Shao

    2012-01-01

    Highlights: ► Pd distribution in Pd-plated Cu wires reveals the whirlpool flow pattern of Cu. ► The mechanisms of the Cu flow behavior and Pd distribution are proposed. ► At Pd-rich phases, small voids formed and followed the direction of Cu flow. ► Nanoindentation studies show the Cu ball bond is harder in regions with Pd. - Abstract: The Pd plating on the 20 μm Cu wire dissolves in the free air ball (FAB) and the Cu ball bond during the wire bonding process without forming intermetallic compounds. The limiting supply of Pd and the short bonding process, 15 ms of thermosonic bonding, result in uneven distribution of Pd in the as produced Cu ball bond. Also, the Pd-rich phase may accompany small voids formed within the FAB and the wire bond, and following the direction of semi-solid Cu flow. The Pd distribution, as evidenced by the focused ion beam (FIB) and wavelength dispersive X-ray spectroscopy (WDS) mapping, reveals the whirlpool flow pattern of Cu within the FAB and the ball bond. Pd distributes within the copper ball through convective transport by the copper flow. Additionally, hardness measurements by nanoindentation testing show that the Cu ball bond is harder in the regions where Pd exists.

  12. Effect of Cu Content on TiN-Cu Nanocomposite Film Properties: Structural and Hardness Studies

    Directory of Open Access Journals (Sweden)

    M. M. Larijani

    2013-06-01

    Full Text Available Titanium nitride-Copper (TiN-Cu nanocomposite films were deposited onto stainless steel substrate using hollow cathode discharge ion plating technique. The influence of Cu content in the range of 2-7 at.% on the microstructure, morphology and mechanical properties of deposited films were investigated. Structural properties of the films were studied by X-ray diffraction pattern. Topography of the deposited films was studied using atomic force microscopy. Film hardness was estimated by a triboscope nanoindentation system. However, X-ray photoelectron spectroscopy analysis was performed to study the surface chemical bonding states. It was found that addition of soft Cu phase above 2 at.% to TiN film drastically decreased the film hardness from 30 to 2.8 Gpa due to lubricant effect of segregated copper particles. X-ray photoelectron spectroscopy results showed that Cu and TiN phases grew separately. In our case,the formation of a solid solution or chemical bonding between Cu and Ti was rejected.

  13. Subcellular differences in handling Cu excess in three freshwater fish species contributes greatly to their differences in sensitivity to Cu

    International Nuclear Information System (INIS)

    Eyckmans, Marleen; Blust, Ronny; De Boeck, Gudrun

    2012-01-01

    Since changes in metal distribution among tissues and subcellular fractions can provide insights in metal toxicity and tolerance, we investigated this partitioning of Cu in gill and liver tissue of rainbow trout (Oncorhynchus mykiss), common carp (Cyprinus carpio) and gibel carp (Carassius auratus gibelio). These fish species are known to differ in their sensitivity to Cu exposure with gibel carp being the most tolerant and rainbow trout the most sensitive. After an exposure to 50 μg/l (0.79 μM) Cu for 24 h, 3 days, 1 week and 1 month, gills and liver of control and exposed fish were submitted to a differential centrifugation procedure. Interestingly, there was a difference in accumulated Cu in the three fish species, even in control fishes. Where the liver of rainbow trout showed extremely high Cu concentrations under control conditions, the amount of Cu accumulated in their gills was much less than in common and gibel carp. At the subcellular level, the gills of rainbow trout appeared to distribute the additional Cu exclusively in the biologically active metal pool (BAM; contains heat-denaturable fraction and organelle fraction). A similar response could be seen in gill tissue of common carp, although the percentage of Cu in the BAM of common carp was lower compared to rainbow trout. Gill tissue of gibel carp accumulated more Cu in the biologically inactive metal pool (BIM compared to BAM; contains heat-stable fraction and metal-rich granule fraction). The liver of rainbow trout seemed much more adequate in handling the excess Cu (compared to its gills), since the storage of Cu in the BIM increased. Furthermore, the high % of Cu in the metal-rich granule fraction and heat-stable fraction in the liver of common carp and especially gibel carp together with the better Cu handling in gill tissue, pointed out the ability of the carp species to minimize the disadvantages related to Cu stress. The differences in Cu distribution at the subcellular level of gills and

  14. Subcellular differences in handling Cu excess in three freshwater fish species contributes greatly to their differences in sensitivity to Cu

    Energy Technology Data Exchange (ETDEWEB)

    Eyckmans, Marleen, E-mail: marleen.eyckmans@ua.ac.be [Laboratory for Ecophysiology, Biochemistry and Toxicology, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp (Belgium); Blust, Ronny; De Boeck, Gudrun [Laboratory for Ecophysiology, Biochemistry and Toxicology, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp (Belgium)

    2012-08-15

    Since changes in metal distribution among tissues and subcellular fractions can provide insights in metal toxicity and tolerance, we investigated this partitioning of Cu in gill and liver tissue of rainbow trout (Oncorhynchus mykiss), common carp (Cyprinus carpio) and gibel carp (Carassius auratus gibelio). These fish species are known to differ in their sensitivity to Cu exposure with gibel carp being the most tolerant and rainbow trout the most sensitive. After an exposure to 50 {mu}g/l (0.79 {mu}M) Cu for 24 h, 3 days, 1 week and 1 month, gills and liver of control and exposed fish were submitted to a differential centrifugation procedure. Interestingly, there was a difference in accumulated Cu in the three fish species, even in control fishes. Where the liver of rainbow trout showed extremely high Cu concentrations under control conditions, the amount of Cu accumulated in their gills was much less than in common and gibel carp. At the subcellular level, the gills of rainbow trout appeared to distribute the additional Cu exclusively in the biologically active metal pool (BAM; contains heat-denaturable fraction and organelle fraction). A similar response could be seen in gill tissue of common carp, although the percentage of Cu in the BAM of common carp was lower compared to rainbow trout. Gill tissue of gibel carp accumulated more Cu in the biologically inactive metal pool (BIM compared to BAM; contains heat-stable fraction and metal-rich granule fraction). The liver of rainbow trout seemed much more adequate in handling the excess Cu (compared to its gills), since the storage of Cu in the BIM increased. Furthermore, the high % of Cu in the metal-rich granule fraction and heat-stable fraction in the liver of common carp and especially gibel carp together with the better Cu handling in gill tissue, pointed out the ability of the carp species to minimize the disadvantages related to Cu stress. The differences in Cu distribution at the subcellular level of gills

  15. Proximity effect of Pb on CeCu6 and La0.05Ce0.95Cu6

    International Nuclear Information System (INIS)

    Chen, T.P.; Tipparachi, U.; Yang, H.D.; Wang, J.T.; Chen, B.; Chen, J.C.J.

    1999-01-01

    Heavy fermion materials have attracted a great deal of attention since 1979. These materials which contain a rare earth (U, or Ce, etc.) element exhibit unusual behavior at low temperature. The effective mass m* of the Landau quasiparticles is found to be orders of magnitude higher than that of a bare electron. Some of the Heavy Fermion materials become superconductors at low temperature. The pairing of electrons in these superconductors may not be of s symmetry like those in BCS type superconductors. The mismatch in electronic mass and the difference in pairing state between the light conventional superconducting electrons and the heavy fermion electrons have brought the coupling between light electrons (BCS type) and the heavy fermion electrons into question. Proximity effect of Pb on CeCu 6 , Pb on La 0.05 Ce 0.95 Cu 6 , and Pb on Cu was used to investigate the coupling between the conventional superconducting electrons of Pb and the heavy electrons in CeCu 6 or La 0.05 Ce 0.95 Cu 6 . In this experiment proximity effect was found between Pb and CeCu 6 , as well as between Pb and La 0.05 Ce 0.95 Cu 6 . However, the proximity effect is small when compared with that between Pb and Cu. This indicates a much shorter extrapolation length in the heavy fermion materials than in Cu. Such a phenomenon can be explained by the mismatch in effective mass between the superconducting Pb electrons and the heavy fermion electrons

  16. Cu2O/CuO Bilayered Composite as a High-Efficiency Photocathode for Photoelectrochemical Hydrogen Evolution Reaction

    Science.gov (United States)

    Yang, Yang; Xu, Di; Wu, Qingyong; Diao, Peng

    2016-10-01

    Solar powered hydrogen evolution reaction (HER) is one of the key reactions in solar-to-chemical energy conversion. It is desirable to develop photocathodic materials that exhibit high activity toward photoelectrochemical (PEC) HER at more positive potentials because a higher potential means a lower overpotential for HER. In this work, the Cu2O/CuO bilayered composites were prepared by a facile method that involved an electrodeposition and a subsequent thermal oxidation. The resulting Cu2O/CuO bilayered composites exhibited a surprisingly high activity and good stability toward PEC HER, expecially at high potentials in alkaline solution. The photocurrent density for HER was 3.15 mA·cm-2 at the potential of 0.40 V vs. RHE, which was one of the two highest reported at the same potential on copper-oxide-based photocathode. The high photoactivity of the bilayered composite was ascribed to the following three advantages of the Cu2O/CuO heterojunction: (1) the broadened light absorption band that made more efficient use of solar energy, (2) the large space-charge-region potential that enabled a high efficiency for electron-hole separation, and (3) the high majority carrier density that ensured a faster charge transportation rate. This work reveals the potential of the Cu2O/CuO bilayered composite as a promising photocathodic material for solar water splitting.

  17. Optical properties of CuCdTeO thin films sputtered from CdTe-CuO composite targets

    Energy Technology Data Exchange (ETDEWEB)

    Mendoza-Galván, A., E-mail: amendoza@qro.cinvestav.mx [Cinvestav-IPN, Unidad Querétaro, Libramiento Norponiente 2000, 76230 Querétaro (Mexico); Laboratory of Applied Optics, Department of Physics, Chemistry and Biology, Linköping University, SE-581 83 Linköping (Sweden); Arreola-Jardón, G. [Cinvestav-IPN, Unidad Querétaro, Libramiento Norponiente 2000, 76230 Querétaro (Mexico); Karlsson, L.H.; Persson, P.O.Å. [Thin Film Physics Division, Department of Physics, Chemistry and Biology, Linköping University, SE-581 83 Linköping (Sweden); Jiménez-Sandoval, S. [Cinvestav-IPN, Unidad Querétaro, Libramiento Norponiente 2000, 76230 Querétaro (Mexico)

    2014-11-28

    The effective complex dielectric function (ε) of Cu and O containing CdTe thin films is reported in the spectral range of 0.05 to 6 eV. The films were fabricated by rf sputtering from targets comprised by a mixture of CdTe and CuO powders with nominal Cu and O concentrations in the range of 2–10 at.%. Low concentration levels improved the crystalline quality of the films. Spectroscopic ellipsometry and transmittance measurements were used to determine ε. The critical point energies E{sub 1}, E{sub 1} + Δ{sub 1}, and E{sub 2} of CdTe are red-shifted with the incorporation of Cu and O. Also, an absorption band is developed in the infrared range which is associated with a mixture of CdTe and low resistivity phases Cu{sub 2−x}Te according to an effective medium analysis. The elemental distribution of the films was mapped by energy dispersive X-ray spectroscopy using scanning transmission electron microscopy. - Highlights: • Incorporation of 2 to 10 at.% of Cu and O atoms in CdTe films • Improved crystalline quality with 2 and 3 at.% of Cu and O • Complex dielectric function of Cu and O containing CdTe thin films • Effective medium modeling of below band-gap absorption.

  18. Grindability of cast Ti-Cu alloys.

    Science.gov (United States)

    Kikuchi, Masafumi; Takada, Yukyo; Kiyosue, Seigo; Yoda, Masanobu; Woldu, Margaret; Cai, Zhuo; Okuno, Osamu; Okabe, Toru

    2003-07-01

    The purpose of the present study was to evaluate the grindability of a series of cast Ti-Cu alloys in order to develop a titanium alloy with better grindability than commercially pure titanium (CP Ti), which is considered to be one of the most difficult metals to machine. Experimental Ti-Cu alloys (0.5, 1.0, 2.0, 5.0, and 10.0 mass% Cu) were made in an argon-arc melting furnace. Each alloy was cast into a magnesia mold using a centrifugal casting machine. Cast alloy slabs (3.5 mm x 8.5 mm x 30.5 mm), from which the hardened surface layer (250 microm) was removed, were ground using a SiC abrasive wheel on an electric handpiece at four circumferential speeds (500, 750, 1000, or 1250 m/min) at 0.98 N (100 gf). Grindability was evaluated by measuring the amount of metal volume removed after grinding for 1min. Data were compared to those for CP Ti and Ti-6Al-4V. For all speeds, Ti-10% Cu alloy exhibited the highest grindability. For the Ti-Cu alloys with a Cu content of 2% or less, the highest grindability corresponded to an intermediate speed. It was observed that the grindability increased with an increase in the Cu concentration compared to CP Ti, particularly for the 5 or 10% Cu alloys at a circumferential speed of 1000 m/min or above. By alloying with copper, the cast titanium exhibited better grindability at high speed. The continuous precipitation of Ti(2)Cu among the alpha-matrix grains made this material less ductile and facilitated more effective grinding because small broken segments more readily formed.

  19. Improvement of the field-trapping capabilities of bulk Nd Ba Cu O superconductors using Ba Cu O substrates

    Science.gov (United States)

    Matsui, Motohide; Nariki, Shinya; Sakai, Naomichi; Iwafuchi, Kengo; Murakami, Masato

    2006-07-01

    We used Ba-Cu-O substrates to fabricate bulk Nd-Ba-Cu-O superconductors using a top-seeded melt-growth method. There were several advantages for the use of Ba-Cu-O substrate compared to conventional substrate materials such as MgO, ZrO2, Al2O3, RE123 and RE211 (RE = rare earth). The Ba-Cu-O did not react with the precursor and minimized liquid loss. Accordingly, the introduction of large-sized cracks was suppressed. We also found that Tc values were high at the bottom regions, which was ascribed to the beneficial effect of Ba-Cu-O in suppressing Nd/Ba substitution. As a result, we obtained bulk Nd-Ba-Cu-O superconductors that exhibited fairly good field-trapping capabilities, even at the bottom surfaces.

  20. Multishelled Si@Cu Microparticles Supported on 3D Cu Current Collectors for Stable and Binder-free Anodes of Lithium-Ion Batteries.

    Science.gov (United States)

    Zhang, Zailei; Wang, Zhong Lin; Lu, Xianmao

    2018-04-24

    Silicon has proved to be a promising anode material of high-specific capacity for the next-generation lithium ion batteries (LIBs). However, during repeated discharge/charge cycles, Si-based electrodes, especially those in microscale size, pulverize and lose electrical contact with the current collectors due to large volume expansion. Here, we introduce a general method to synthesize Cu@M (M = Si, Al, C, SiO 2 , Si 3 N 4 , Ag, Ti, Ta, SnIn 2 O 5 , Au, V, Nb, W, Mg, Fe, Ni, Sn, ZnO, TiN, Al 2 O 3 , HfO 2 , and TiO 2 ) core-shell nanowire arrays on Cu substrates. The resulting Cu@Si nanowire arrays were employed as LIB anodes that can be reused via HCl etching and H 2 -reduction. Multishelled Cu@Si@Cu microparticles supported on 3D Cu current collectors were further prepared as stable and binder-free LIB anodes. This 3D Cu@Si@Cu structure allows the interior conductive Cu network to effectively accommodate the volume expansion of the electrode and facilitates the contact between the Cu@Si@Cu particles and the current collectors during the repeated insertion/extraction of lithium ions. As a result, the 3D Cu@Si@Cu microparticles at a high Si-loading of 1.08 mg/cm 2 showed a capacity retention of 81% after 200 cycles. In addition, charging tests of 3D Cu@Si@Cu-LiFePO 4 full cells by a triboelectric nanogenerator with a pulsed current demonstrated that LIBs with silicon anodes can effectively store energy delivered by mechanical energy harvesters.

  1. In-situ STM study of phosphate adsorption on Cu(111), Au(111) and Cu/Au(111) electrodes

    DEFF Research Database (Denmark)

    Schlaup, Christian; Horch, Sebastian

    2013-01-01

    The interaction of Cu(111), Au(111) and Cu-covered Au(111) electrodes with a neutral phosphate buffer solution has been studied by means of cyclic voltammetry (CV) and in situ electrochemical scanning tunneling microscopy (EC-STM). Under low potential conditions, both the Cu(111) and the Au(111......) surface appear apparently adsorbate free, indicated by the presence of a (4×4) structure and the herringbone surface reconstruction, respectively. Upon potential increase, phosphate anions adsorb on both surfaces and for Cu(111) the formation of a (√3×√3)R30° structure is found, whereas on Au(111) a "(√3......×√7)" structure is formed. For a Cu-submonolayer on Au(111), coadsorption of phosphate anions leads to the formation of a (2×2) vacancy structure within an assumed pseudomorphic structure of the Cu-submonolayer with the phosphate anions occupying the vacancies. When desorbing the phosphate anions at low...

  2. Dielectric properties of (CuO,CaO2, and BaO)y/CuTl-1223 composites

    International Nuclear Information System (INIS)

    Mumtaz, M.; Kamran, M.; Nadeem, K.; Jabbar, Abdul; Khan, Nawazish A.; Saleem, Abida; Hussain, S.Tajammul; Kamran, M.

    2013-01-01

    We synthesized (CuO, CaO 2 , and BaO) y /Cu 0.5 Tl 0.5 Ba 2 Ca 2 Cu 3 O 10-δ (y = 0, 5%, 10%, 15%) composites by solid-state reaction and characterized by x-ray diffraction, scanning electron microscopy, dc-resistivity, and Fourier transform infrared spectroscopy. Frequency and temperature dependent dielectric properties such as real and imaginary part of dielectric constant, dielectric loss, and ac-conductivity of these composites are studied by capacitance and conductance measurement as a function of frequency (10 kHz to 10 MHz) and temperature (78 to 300 K). The x-ray diffraction analysis reveals that the characteristic behavior of Cu 0.5 Tl 0.5 Ba 2 Ca 2 Cu 3 O 10-δ superconductor phase and its structure is nearly undisturbed by doping of nanoparticles. The scanning electron microscopy images show the improvement in the intergranular links among the superconducting grains with increasing nanoparticles concentration. Microcracks are healed up with the inclusion of these nanoparticles and superconducting volume fraction is also increased. The dielectric properties of these composites strongly depend upon the frequency and temperature. The zero resistivity critical temperature and dielectric properties show opposite trend with the addition of nanoparticles in Cu 0.5 Tl 0.5 Ba 2 Ca 2 Cu 3 O 10-δ superconductor matrix.

  3. CFA-13 - a bifunctional perfluorinated metal-organic framework featuring active Cu(i) and Cu(ii) sites.

    Science.gov (United States)

    Fritzsche, J; Denysenko, D; Grzywa, M; Volkmer, D

    2017-11-07

    The synthesis and crystal structure of the mixed-valent perfluorinated metal-organic framework (Me 2 NH 2 )[CFA-13] (Coordination Framework Augsburg University-13), (Me 2 NH 2 )[CuCu(tfpc) 4 ] (H 2 -tfpc = 3,5-bis(trifluoromethyl)-1H-pyrazole-4-carboxylic acid) is described. The copper-containing MOF crystallizes in the monoclinic crystal system within the space group P2 1 /n (no. 14) and the unit cell parameters are as follows: a = 22.3887(19), b = 13.6888(8), c = 21.1804(13) Å, β = 90.495(3)°, V = 6491.0(8) Å 3 . (Me 2 NH 2 )[CFA-13] features a porous 3-D structure constructed from two types of secondary building units (SBUs). Besides novel trinuclear [Cu(pz) 4 ] - coordination units, the network also exhibits Cu(ii) paddle-wheel SBUs. (Me 2 NH 2 )[CFA-13] is fully characterized by single crystal X-ray diffraction, thermogravimetric analysis, variable temperature powder X-ray diffraction, IR spectroscopy, photoluminescence, gas sorption measurements and pulse chemisorption experiments. M[CFA-13] (M = K + , Cs + ) frameworks were prepared by postsynthetic exchange of interchannel dimethylammonium cations. Moreover, it was shown that CO molecules can be selectively bound at Cu(i) sites of [Cu(pz) 4 ] - units, whereas Cu(ii) paddle-wheel units bind selectively NH 3 molecules.

  4. The Paramagnetism of Small Amounts of Mn Dissolved in Cu-Al and Cu-Ge Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Myers, H P; Westin, R

    1963-06-15

    Previous measurements of the valency of Mn in Cu-Zn alloys have been confirmed by measurements with the isoelectronic Cu-Al and Cu-Ge alloys as matrices for Mn. The valency, having the value i in pure copper, decreases slightly with increasing electron to atom ratio attaining the values 0. 9 and 0. 8 at the limiting composition in the Al and Ge alloys respectively. The apparent size of Mn in these alloys is discussed.

  5. The Paramagnetism of Small Amounts of Mn Dissolved in Cu-Al and Cu-Ge Alloys

    International Nuclear Information System (INIS)

    Myers, H.P.; Westin, R.

    1963-06-01

    Previous measurements of the valency of Mn in Cu-Zn alloys have been confirmed by measurements with the isoelectronic Cu-Al and Cu-Ge alloys as matrices for Mn. The valency, having the value i in pure copper, decreases slightly with increasing electron to atom ratio attaining the values 0. 9 and 0. 8 at the limiting composition in the Al and Ge alloys respectively. The apparent size of Mn in these alloys is discussed

  6. Effect of annealing process on the heterostructure CuO/Cu2O as a highly efficient photocathode for photoelectrochemical water reduction

    Science.gov (United States)

    Du, Fan; Chen, Qing-Yun; Wang, Yun-Hai

    2017-05-01

    CuO/Cu2O photocathodes were successfully prepared via simply annealing the electrodeposited Cu2O on fluoride doped tin oxide (FTO) substrate. They were characterized by X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscope (TEM), UV-vis absorption spectra and X-ray photoelectron spectroscopy (XPS). The results showed that the heterojunction of CuO/Cu2O was formed during the annealing process and presented the nature of p-type semiconductor. The photocurrent density and photoelectrochemical (PEC) stability of the p-type heterostructure CuO/Cu2O photocathode was improved greatly compared with the pure Cu2O, which was greatly affected by annealing time and temperature. The highest photo current density of -0.451 mA/cm2 and highest stability was obtained via annealing at 650 °C for 15 min (at -0.3 V vs. Ag/AgCl), which gave a remarkable improvement than the as-deposited Cu2O (-0.08 mA/cm2). This suggested that the CuO/Cu2O heterojunction facilitated the electron-hole pair separation and improved the photocathode's current and stability.

  7. Preparation of Cu@Cu2O Nanocatalysts by Reduction of HKUST-1 for Oxidation Reaction of Catechol

    OpenAIRE

    Seongwan Jang; Chohye Yoon; Jae Myung Lee; Sungkyun Park; Kang Hyun Park

    2016-01-01

    HKUST-1, a copper-based metal organic framework (MOF), has been investigated as a catalyst in various reactions. However, the HKUST-1 shows low catalytic activity in the oxidation of catechol. Therefore, we synthesized Fe3O4@HKUST-1 by layer-by layer assembly strategy and Cu@Cu2O by reduction of HKUST-1 for enhancement of catalytic activity. Cu@Cu2O nanoparticles exhibited highly effective catalytic activity in oxidation of 3,5-di-tert-butylcatechol. Through this method, MOF can maintain the ...

  8. Effect of Thermal Mechanical Behaviors of Cu on Stress Distribution in Cu-Filled Through-Silicon Vias Under Heat Treatment

    Science.gov (United States)

    Zhao, Xuewei; Ma, Limin; Wang, Yishu; Guo, Fu

    2018-01-01

    Through-silicon vias (TSV) are facing unexpected thermo-mechanical reliability problems due to the coefficient of thermal expansion (CTE) mismatch between various materials in TSVs. During applications, thermal stresses induced by CTE mismatch will have a negative impact on other devices connecting with TSVs, even leading to failure. Therefore, it is essential to investigate the stress distribution evolution in the TSV structure under thermal loads. In this report, TSVs were heated to 450°C at different heating rates, then cooled down to room temperature after a 30-min dwelling. After heating treatment, TSV samples exhibited different Cu deformation behaviors, including Cu intrusion and protrusion. Based on the different Cu deformation behaviors, stress in Si around Cu vias of these samples was measured and analyzed. Results analyzed by Raman spectrums showed that the stress distribution changes were associated with Cu deformation behaviors. In the area near the Cu via, Cu protrusion behavior might aggravate the stress in Si obtained from the Raman measurement, while Cu intrusion might alleviate the stress. The possible reason was that in this area, the compressive stress σ_{θ } induced by thermal loads might be the dominant stress. In the area far from the Cu via, thermal loads tended to result in a tensile stress state in Si.

  9. New insight on the local structure of Cu2+ ion in the solution of CuBr2 by EXAFS studies

    International Nuclear Information System (INIS)

    Yu Meijuan; Chu Wangsheng; Chen Xing; Wu Ziyu

    2009-01-01

    CuBr 2 solutions at different concentrations were studied by extended X-ray absorption fine structure (EXAFS) at the Cu K edge. In the saturated solution Cu 2+ ions have chemical bonds with 3.0 oxygen atoms and 0.9 Br ion at about 1.96 A and 2.42 A, respectively. It indicates that the CuBr 4 -2 configuration exists with a ratio of 25% under this condition. In the dilute solutions no evidence of Br ions contributions in the first shell around Cu 2+ ions occurs. The almost identical X-ray absorption near edge structure (XANES) and EXAFS characters address similar local environments around Cu 2+ in agreement with results of the EXAFS fit taking into account only the contributions of Cu-O bonds.

  10. Screened coulomb hybrid DFT investigation of band gap and optical absorption predictions of CuVO3, CuNbO3 and Cu 5Ta11O30 materials

    KAUST Repository

    Harb, Moussab

    2014-01-01

    We present a joint theoretical and experimental investigation of the optoelectronic properties of CuVO3, CuNbO3 and Cu 5Ta11O30 materials for potential photocatalytic and solar cell applications. In addition to the experimental results obtained by powder X-ray diffraction and UV-Vis spectroscopy of the materials synthesized under flowing N2 gas at atmospheric pressure via solid-state reactions, the electronic structure and the UV-Vis optical absorption coefficient of these compounds are predicted with high accuracy using advanced first-principles quantum methods based on DFT (including the perturbation theory approach DFPT) within the screened coulomb hybrid HSE06 exchange-correlation formalism. The calculated density of states are found to be in agreement with the UV-Vis diffuse reflectance spectra, predicting a small indirect band gap of 1.4 eV for CuVO3, a direct band gap of 2.6 eV for CuNbO3, and an indirect (direct) band gap of 2.1 (2.6) eV for Cu5Ta 11O30. It is confirmed that the Cu(i)-based multi-metal oxides possess a strong contribution of filled Cu(i) states in the valence band and of empty d0 metal states in the conduction band. Interestingly, CuVO3 with its predicted small indirect band gap of 1.4 eV shows the highest absorption coefficient in the visible range with a broad absorption edge extending to 886 nm. This novel result offers a great opportunity for this material to be an excellent candidate for solar cell applications. © the Partner Organisations 2014.

  11. Evaluation of (64)Cu-labeled DOTA-D-Phe(1)-Tyr (3)-octreotide ((64)Cu-DOTA-TOC) for imaging somatostatin receptor-expressing tumors.

    Science.gov (United States)

    Hanaoka, Hirofumi; Tominaga, Hideyuki; Yamada, Keiich; Paudyal, Pramila; Iida, Yasuhiko; Watanabe, Shigeki; Paudyal, Bishnuhari; Higuchi, Tetsuya; Oriuchi, Noboru; Endo, Keigo

    2009-08-01

    In-111 ((111)In)-labeled octreotide has been clinically used for imaging somatostatin receptor-positive tumors, and radiolabeled octreotide analogs for positron emission tomography (PET) have been developed. Cu-64 ((64)Cu; half-life, 12.7 h) is an attractive radionuclide for PET imaging and is produced with high specific activity using a small biomedical cyclotron. The aim of this study is to produce and fundamentally examine a (64)Cu-labeled octreotide analog, (64)Cu-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid-D: -Phe(1)-Tyr(3)-octreotide ((64)Cu-DOTA-TOC). (64)Cu produced using a biomedical cyclotron was reacted with DOTA-TOC for 30 min at 45 degrees C. The stability of (64)Cu-DOTA-TOC was evaluated in vitro (incubated with serum) and in vivo (blood collected after administration) by HPLC analysis. Biodistribution studies were performed in normal mice by administration of mixed solution of (64)Cu-DOTA-TOC and (111)In-DOTA-TOC and somatostatin receptor-positive U87MG tumor-bearing mice by administration of (64)Cu-DOTA-TOC or (64)Cu-1,4,8,11-tetraazacyclotetradecane-1,4,8,11-tetraacetic acid-octreotide ((64)Cu-TETA-OC). The tumor was imaged using (64)Cu-DOTA-TOC, (64)Cu-TETA-OC, and FDG with an animal PET scanner. (64)Cu-DOTA-TOC can be produced in amounts sufficient for clinical study with high radiochemical yield. (64)Cu-DOTA-TOC was stable in vitro, but time-dependent transchelation to protein was observed after injection into mice. In biodistribution studies, the radioactivity of (64)Cu was higher than that of (111)In in all organs except kidney. In tumor-bearing mice, (64)Cu-DOTA-TOC showed a high accumulation in the tumor, and the tumor-to-blood ratio reached as high as 8.81 +/- 1.17 at 6 h after administration. (64)Cu-DOTA-TOC showed significantly higher accumulation in the tumor than (64)Cu-TETA-OC. (64)Cu-DOTA-TOC PET showed a very clear image of the tumor, which was comparable to that of (18)F-FDG PET and very similar to that of (64)Cu

  12. Evaluation of 64Cu-labeled DOTA-D-Phe1-Tyr3-octreotide (64Cu-DOTA-TOC) for imaging somatostatin receptor-expressing tumors

    International Nuclear Information System (INIS)

    Hanaoka, Hirofumi; Tominaga, Hideyuki; Yamada, Keiich

    2009-01-01

    In-111 ( 111 In)-labeled octreotide has been clinically used for imaging somatostatin receptor-positive tumors, and radiolabeled octreotide analogs for positron emission tomography (PET) have been developed. Cu-64 ( 64 Cu; half-life, 12.7 h) is an attractive radionuclide for PET imaging and is produced with high specific activity using a small biomedical cyclotron. The aim of this study is to produce and fundamentally examine a 64 Cu-labeled octreotide analog, 64 Cu-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid-D-Phe 1 -Tyr 3 -octreotide ( 64 Cu-DOTA-TOC). 64 Cu produced using a biomedical cyclotron was reacted with DOTA-TOC for 30 min at 45 deg C. The stability of 64 Cu-DOTA-TOC was evaluated in vitro (incubated with serum) and in vivo (blood collected after administration) by high performance liquid chromatography (HPLC) analysis. Biodistribution studies were performed in normal mice by administration of mixed solution of 64 Cu-DOTA-TOC and 111 In-DOTA-TOC and somatostatin receptor-positive U87MG tumor-bearing mice by administration of 64 Cu-DOTA-TOC or 64 Cu-1,4,8,11-tetraazacyclotetradecane-1,4,8,11-tetraacetic acid-octreotide ( 64 Cu-TETA-OC). The tumor was imaged using 64 Cu-DOTA-TOC, 64 Cu-TETA-OC, and fluorodeoxyglucose (FDG) with an animal PET scanner. 64 Cu-DOTA-TOC can be produced in amounts sufficient for clinical study with high radiochemical yield. 64 Cu-DOTA-TOC was stable in vitro, but time-dependent transchelation to protein was observed after injection into mice. In biodistribution studies, the radioactivity of 64 Cu was higher than that of 111 In in all organs except kidney. In tumor-bearing mice, 64 Cu-DOTA-TOC showed a high accumulation in the tumor, and the tumor-to-blood ratio reached as high as 8.81±1.17 at 6 h after administration. 64 Cu-DOTA-TOC showed significantly higher accumulation in the tumor than 64 Cu-TETA-OC. 64 Cu-DOTA-TOC PET showed a very clear image of the tumor, which was comparable to that of 18 F-FDG PET and

  13. Effect of cupric salts (Cu (NO{sub 3}){sub 2}, CuSO4{sub ,} Cu(CH{sub 3}COO){sub 2}) on Cu{sub 2}(OH)PO{sub 4} morphology for photocatalytic degradation of 2,4-dichlorophenol under near-infrared light irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Chao; Li, Pei; Zhang, Wei; Che, Yanhao; Sun, Yaxin; Chi, Fangli; Ran, Songlin; Liu, Xianguo; Lv, Yaohui, E-mail: yaohui2015@163.com [School of Materials Science and Engineering, Anhui Key Laboratory of Metal Materials and Processing, Anhui University of Technology (China)

    2017-03-15

    Cu{sub 2}(OH)PO{sub 4} microstructures were synthesized by the hydrothermal method using three different types cupric salts (Cu (NO{sub 3}){sub 2}, CuSO{sub 4}, Cu(CH{sub 3}COO){sub 2}) as raw materials. The X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-visible-NIR absorption spectra were used to characterize the as-obtained products. The different anions (SO{sub 4}{sup 2-}, CH{sub 3}COO-, NO{sub 3-}) have different shapes and polarities, which can generate different interactions in reaction bath, induced the difference of structure and morphology of the prepared Cu{sub 2}(OH)PO{sub 4}. The Cu{sub 2}(OH)PO{sub 4} microstructures prepared form Cu(NO{sub 3}){sub 2} ·3H{sub 2}O showed the best photocatalytic activity induced by near-infrared light to degrade 2,4-dichlorophenol (2,4-DCP) solution. Our work suggests that the active morphological surfaces as well as different coordination environments for the metal ions has an important influence on the photocatalytic performance of Cu{sub 2}(OH)PO{sub 4} microstructure. (author)

  14. Deposition of CuIn(Se,S)2 thin films by sulfurization of selenized Cu/In alloys

    International Nuclear Information System (INIS)

    Sheppard, C.J.; Alberts, V.; Bekker, W.J.

    2004-01-01

    The relatively small band gap values (close to 1eV) of CuInSe 2 thin films limits the conversion efficiencies of completed CuInSe 2 /CdS/ZnO solar cell devices. In the case of traditional two-stage growth techniques, limited success has been achieved to increase the band gap by substituting indium with gallium. In this study, sputtered copper-indium alloys were exposed to a H 2 Se/Ar atmosphere under defined conditions in order to produce partially reacted CuInSe 2 structures. These films were subsequently exposed to a H 2 S/Ar atmosphere to produce monophasic CuIn(Se, S) 2 quaternary alloys. The homogeneous incorporation of S into CuInSe 2 led to a systematic shift in the lattice parameters and band gap of the ab- sorber films. From these studies optimum selenization/sulfurization conditions were determined for the deposition of homogeneous CuIn(Se,S) 2 thin films with an optimum band gap values between 1.15 and 1.2 eV. (copyright 2004 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  15. Humidity sensing performance of in-situ fabricated Cu/Cu2O/Cu2S-polymer nanocomposite via polyphenylene sulphide cyclisation route.

    Science.gov (United States)

    Adkar, Dattatraya; Hake, Abhay; Jadkar, Sandesh; Adhyapak, Parag; Mulik, Uttamrao; Amalnerkar, Dinesh

    2011-08-01

    We herein report the feasibility of novel polymer-inorganic solid state reaction route for simultaneous in situ generation of Cu2S and Cu nanostructures in polymer network. Polyphenylene Sulphide (PPS) which is engineering thermoplastic acts as chalcogen source as well as stabilizing matrix for the resultant nano products. Typical solid state reaction was accomplished by simply heating the physical admixtures of the two reactants i.e., copper acetate and PPS by varying molar ratios mainly 1:1, 1:5, 1:10, 1:15, 1:20 at the crystalline melting temperature (285 degrees C) of PPS. The synthesized products were characterized using various physicochemical characterization techniques like X-ray Diffractometry, Field emission Scanning Electron Microscopy, Transmission Electron Microscopy, UV-Visible spectroscopy and X-ray photoelectron spectroscopy. The prima facie observations suggest occurrence of nanocrystalline Cu2S in case of product obtained with equimolar ratio, whereas remaining samples show mixture of Cu and Cu2O. The TEM analysis reveals nanoscale polydispersity (5-60 nm) and prevalence of mainly spherical morphological features in all the cases with occasional indications of plate like and cubical morphological features depending upon the molar ratio of the reactants. The humidity sensing characterization of these nanocomposites was also performed. The resistivity response with the level of humidity (20 to 70% RH) was compared for these nanocomposites. The linear response is obtained for all the samples. The sensitivity of 1:1 molar ratio sample was found to be maximum among all the samples.

  16. Ultrathin Cr added Ru film as a seedless Cu diffusion barrier for advanced Cu interconnects

    Science.gov (United States)

    Hsu, Kuo-Chung; Perng, Dung-Ching; Yeh, Jia-Bin; Wang, Yi-Chun

    2012-07-01

    A 5 nm thick Cr added Ru film has been extensively investigated as a seedless Cu diffusion barrier. High-resolution transmission electron microscopy micrograph, X-ray diffraction (XRD) pattern and Fourier transform-electron diffraction pattern reveal that a Cr contained Ru (RuCr) film has a glassy microstructure and is an amorphous-like film. XRD patterns and sheet resistance data show that the RuCr film is stable up to 650 °C, which is approximately a 200 °C improvement in thermal stability as compared to that of the pure Ru film. X-ray photoelectron spectroscopy depth profiles show that the RuCr film can successfully block Cu diffusion, even after a 30-min 650 °C annealing. The leakage current of the Cu/5 nm RuCr/porous SiOCH/Si stacked structure is about two orders of magnitude lower than that of a pristine Ru sample for electric field below 1 MV/cm. The RuCr film can be a promising Cu diffusion barrier for advanced Cu metallization.

  17. Deciphering ligands' interaction with Cu and Cu2O nanocrystal surfaces by NMR solution tools.

    Science.gov (United States)

    Glaria, Arnaud; Cure, Jérémy; Piettre, Kilian; Coppel, Yannick; Turrin, Cédric-Olivier; Chaudret, Bruno; Fau, Pierre

    2015-01-12

    The hydrogenolysis of [Cu2{(iPrN)2(CCH3)}2] in the presence of hexadecylamine (HDA) or tetradecylphosphonic acid (TDPA) in toluene leads to 6-9 nm copper nanocrystals. Solution NMR spectroscopy has been used to describe the nanoparticle surface chemistry during the dynamic phenomenon of air oxidation. The ligands are organized as multilayered shells around the nanoparticles. The shell of ligands is controlled by both their intermolecular interactions and their bonding strength on the nanocrystals. Under ambient atmosphere, the oxidation rate of colloidal copper nanocrystals closely relies on the chemical nature of the employed ligands (base or acid). Primary amine molecules behave as soft ligands for Cu atoms, but are even more strongly coordinated on surface Cu(I) sites, thus allowing a very efficient corrosion protection of the copper core. On the contrary, the TDPA ligands lead to a rapid oxidation rate of Cu nanoparticles and eventually to the re-dissolution of Cu(II) species at the expense of the nanocrystals. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Controlled Synthesis of Heterostructured SnO2-CuO Composite Hollow Microspheres as Efficient Cu-Based Catalysts for the Rochow Reaction

    Directory of Open Access Journals (Sweden)

    Hezhi Liu

    2018-04-01

    Full Text Available In this work, we report the design and synthesis of a series of heterostructured SnO2-CuO hollow microspherical catalysts (H-SnO2(x-CuO, x is the weight ratio of Sn/Cu for the Rochow reaction. The microspherical catalysts with nanosheets and nanoparticles as building blocks were prepared by a facile one-pot hydrothermal method coupled with calcination. When tested for the Rochow reaction, the prepared H-SnO2(0.2-CuO composite exhibited higher dimethyldichlorosilane selectivity (88.2% and Si conversion (36.7% than the solid CuO, hollow CuO and other H-SnO2(x-CuO microspherical samples, because in the former there is a stronger synergistic interaction between CuO and SnO2.

  19. Interaction of RBa sub 2 Cu sub 3 O sub x (R = Y or Nd) coatings with alumina and zirconia substrates. [YBaCuO; NdBaCuO

    Energy Technology Data Exchange (ETDEWEB)

    Moreau, C; Parent, L; Champagne, B; Dallaire, S [National Research Council of Canada, Industrial Materials Research Inst., Boucherville, PQ (Canada)

    1989-12-10

    As-deposited YBa{sub 2}Cu{sub 3}O{sub x} coatings by plasma spraying are not superconducting because of their inadequate crystalline structure and low oxygen content. A post-deposition heat treatment in oxygen is required to restore the appropriate superconducting YBa{sub 2}Cu{sub 3}O{sub x} structure. During heat treatment, deterimental reactions between coatings and substrates may occur and lead to the degradation or destruction of the coating superconducting properties. In the present paper, interactions of RBa{sub 2}Cu{sub 3}O{sub x} (R = Y, Nd) coatings with alumina and zirconia substrates are examined. The modifications of the coating electrical properties and microstructure are studied using X-ray diffraction, energy dispersive X-ray analysis and resistivity measurements. Coating degradation is shown to occur by diffusion of the barium atoms out of the coating leading to the formation of Y{sub 2}BaCuO{sub 5} and CuO in yttrium-based coatings, and to the formation of nonstoichiometric Nd{sub 1+y}Ba{sub 2-y}Cu{sub 3}O{sub x} and CuO in neodymium-based coatings. The coating degradation is more important on alumina substrates that on zirconia substrates for both yttrium- and neodymium-based coatings. (orig.).

  20. Strength and reliability of low temperature transient liquid phase bonded Cu-Sn-Cu interconnects

    DEFF Research Database (Denmark)

    Brincker, Mads; Söhl, Stefan; Eisele, Ronald

    2017-01-01

    As power electronic devices have tendencies to operate at higher temperatures and current densities, the demand for reliable and efficient packaging technologies are ever increasing. This paper reports the studies on application of transient liquid phase (TLP) bonding of CuSnCu systems...

  1. Chemical synthesis of flower-like hybrid Cu(OH)2/CuO electrode: Application of polyvinyl alcohol and triton X-100 to enhance supercapacitor performance.

    Science.gov (United States)

    Shinde, S K; Fulari, V J; Kim, D-Y; Maile, N C; Koli, R R; Dhaygude, H D; Ghodake, G S

    2017-08-01

    In this research article, we report hybrid nanomaterials of copper hydroxide/copper oxide (Cu(OH) 2 /CuO). A thin films were prepared by using a facile and cost-effective successive ionic layer adsorption and reaction (SILAR) method. As-synthesized and hybrid Cu(OH) 2 /CuO with two different surfactants polyvinyl alcohol (PVA) and triton-X 100 (TRX-100) was prepared having distinct morphological, structural, and supercapacitor properties. The surface of the thin film samples were examined by scanning electron microscopy (SEM). A nanoflower-like morphology of the Cu(OH) 2 /CuO nanostructures arranged vertically was evidenced on the stainless steel substrate. The surface was well covered by nanoflake-like morphology and formed a uniform Cu(OH) 2 /CuO nanostructures after treating with surfactants. X-ray diffraction patterns were used to confirm the hybrid phase of Cu(OH) 2 /CuO materials. The electrochemical properties of the pristine Cu(OH) 2 /CuO, PVA:Cu(OH) 2 /CuO, TRX-100:Cu(OH) 2 /CuO films were observed by cyclic voltammetry, galvanostatic charge/discharge, and electrochemical impedance spectroscopy technique. The electrochemical examination reveals that the Cu(OH) 2 /CuO electrode has excellent specific capacitance, 292, 533, and 443Fg -1 with pristine, PVA, and TRX-100, respectively in 1M Na 2 SO 4 electrolyte solution. The cyclic voltammograms (CV) of Cu(OH) 2 /CuO electrode shows positive role of the PVA and TRX-100 to enhance supercapacitor performance. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Resistive switching of Cu/Cu2O junction fabricated using simple thermal oxidation at 423 K for memristor application

    Science.gov (United States)

    Ani, M. H.; Helmi, F.; Herman, S. H.; Noh, S.

    2018-01-01

    Recently, extensive researches have been done on memristor to replace current memory storage technologies. Study on active layer of memristor mostly involving n-type semiconductor oxide such as TiO2 and ZnO. This paper highlight a simple water vapour oxidation method at 423 K to form Cu/Cu2O electronic junction as a new type of memristor. Cu2O is a p-type semiconductor oxide, was used as the active layer of memristor. Cu/Cu2O/Au memristor was fabricated by thermal oxidation of copper foil, followed by sputtering of gold. Structural, morphological and memristive properties were characterized using XRD, FESEM, and current-voltage, I-V measurement respectively. Its memristivity was indentified by pinch hysteresis loop and measurement of high resistance state (HRS) and low resistance state (LRS) of the sample. The Cu/Cu2O/Au memristor demonstrates comparable performances to previous studies using other methods.

  3. Non-destructive testing of CFC/Cu joints

    International Nuclear Information System (INIS)

    Casalegno, V.; Ferraris, M.; Salvo, M.; Vesprini, R.; Merola, M.

    2006-01-01

    Reliable non-destructive tests (NDT) are fundamental for the manufacturing of ITER components, especially for high heat flux plasma facing components. NDT include various techniques, which allow inspection of a component without impairing serviceability; it's important to detect and characterize defects (type, size and position) as well as the set-up of acceptance standards in order to predict their influence on the component performance in service conditions. The present study shows a description of NDT used to assess the manufacturing quality of CFC (carbon fibre reinforced carbon matrix composites)/Cu/CuCrZr joints. In the ITER divertor, armor tiles made of CFC are joined to the cooling structure made of precipitation hardened copper alloy CuCrZr; a soft pure Cu interlayer is required between the heat sink and the armour in order to mitigate the stresses at the joint interface. NDT on CFC/Cu joint are difficult because of the different behavior of CFC and copper with regard to physical excitations (e.g. ultrasonic wave) used to test the component; furthermore the response to this input must be accurately studied to identify the detachment of CFC tiles from Cu alloy. The inspected CFC/Cu/CuCrZr joints were obtained through direct casting of pure Cu on modified CFC surface and subsequently through brazing of CFC/Cu joints to CuCrZr by a Cu-based alloy. Different non-destructive methods were used for inspecting these joints: lock-in thermography, ultrasonic inspections, microtomography and microradiography. The NDT tests were followed by metallographic investigation on the samples, since the reliability of a certain non destructive test can be only validated by morphological evidence of the detected defects. This study will undertake a direct comparison of NDT used on CFC/Cu joints in terms of real flaws presence. The purpose of this work is to detect defects at the joining interface as well as in the cast copper ( for instance voids). The experimental work was

  4. First-principles study of electronic structure of CuSbS{sub 2} and CuSbSe{sub 2} photovoltaic semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Maeda, T., E-mail: tmaeda@ad.ryukoku.ac.jp; Wada, T.

    2015-05-01

    We studied the features of CuSbS{sub 2} (CAS) and CuSbSe{sub 2} (CASe), two proposed photovoltaic compounds, and clarified their electronic structures by first-principles calculations and compared them to the chalcopyrite-type CuInSe{sub 2} results. For both CAS and CASe, the calculated enthalpies of formation of the chalcostibite phases were considerably lower than those of the chalcopyrite phases. Therefore, we considered that the chalcostibite phase is more stable for CAS and CASe. In their band structure calculated with the HSE06 hybrid functional, the valence band maxima of CAS and CASe were located at the Γ-point, and the conduction band minima were located at the R-point. Their second lowest conduction band was located at the Γ-point, whose energy level nearly equaled the R-point. For CAS (CASe), the partial density of the states shows the character of the Cu 3d and S 3p (Se 4p) orbitals at the top of the valence bands and the Sb 5p and S 3p (Se 4p) orbitals at the bottom of the conduction bands. The conduction bands of CAS and CASe have a p-orbital character (Sb 5p) that differs from the s-orbital character (In 5s) of CuInSe{sub 2}. It is for the reason that CAS and CASe do not have a chalcopyrite structure but a chalcostibite-type structure. The calculated absorption coefficient of CuSbS{sub 2} (10{sup 4}-10{sup 5} cm{sup −1}) is comparable to that of CuInSe{sub 2}. - Highlights: • We studied the features of CuSbS{sub 2} and CuSbSe{sub 2}, newly proposed photovoltaic compounds. • Chalcostibite phase is more stable in CuSbS{sub 2} and CuSbSe{sub 2}. • Band structures of CuSbS{sub 2} and CuSbS{sub 2} were calculated with HSE06 hybrid functional. • Absorption coefficient of chalcostibite-type CuSbS{sub 2} is comparable to that of CuInSe{sub 2}.

  5. Development of a Low-Cost TiO2/CuO/Cu Solar Cell by using Combined Spraying and Electroplating Method

    Directory of Open Access Journals (Sweden)

    Mamat Rokhmat

    2018-03-01

    Full Text Available A simple method is proposed to develop a low-cost TiO2/CuO/Cu based solar cell. The cell is made by employing a lower grade (technical grade of TiO2 as the active material. CuO powder is synthesized using a wet chemical method and mixed with TiO2 powder to give impurity to the TiO2. A layer of TiO2/CuO is then deposited onto fluorin-doped tin oxide (FTO by spraying. Copper particles are grown on the spaces between the TiO2 and/or CuO particles by electroplating for more feasible electron migration. The TiO2/CuO/Cu solar cell is finalized by sandwiching a polymer electrolyte between the film and the counter electrode. Current-voltage measurement was performed for various parameters, such as the molarity of NaOH for producing CuO particles, the weight ratio of CuO over TiO2, and the current in the electroplating process. A highest efficiency of 1.40% and a fill factor of 0.37 were achieved by using this combined spray and electroplating method.

  6. Numerical study of the enhancement of heat transfer for hybrid CuO-Cu Nanofluids flowing in a circular pipe.

    Science.gov (United States)

    Balla, Hyder H; Abdullah, Shahrir; Mohdfaizal, Wan; Zulkifli, Rozli; Sopian, Kamaruzaman

    2013-01-01

    A numerical simulation model for laminar flow of nanofluids in a pipe with constant heat flux on the wall was built to study the effect of the Reynolds number on convective heat transfer and pressure loss. The investigation was performed for hybrid nanofluids consisting of CuO-Cu nanoparticles and compared with CuO and Cu in which the nanoparticles have a spherical shape with size 50, 50, 50nm respectively. The nanofluids were prepared, following which the thermal conductivity and dynamic viscosity were measured for a range of temperatures (10 -60°C). The numerical results obtained were compared with the existing well-established correlation. The prediction of the Nusselt number for nanofluids agrees well with the Shah correlation. The comparison of heat transfer coefficients for CuO, Cu and CuO-Cu presented an increase in thermal conductivity of the nanofluid as the convective heat transfer coefficient increased. It was found that the pressure loss increases with an increase in the Reynolds number, nanoparticle density and particle volume fraction. However, the flow demonstrates enhancement in heat transfer which becomes greater with an increase in the Reynolds number for the nanofluid flow.

  7. Insight on a novel layered semiconductors: CuTlS and CuTlSe

    Energy Technology Data Exchange (ETDEWEB)

    Aliev, Ziya S., E-mail: ziyasaliev@gmail.com [Institute of Catalysis and Inorganic Chemistry, ANAS, H.Javid ave. 113, AZ1143 Baku (Azerbaijan); Institute of Physics, ANAS, H.Javid ave. 131, AZ1143 Baku (Azerbaijan); Donostia International Physics Center (DIPC), 20080 San Sebastian (Spain); Zúñiga, Fco. Javier [Departamento de Física de la Materia Condensada, Facultad de Ciencia y Tecnología, Universidad del País Vasco, Apdo. 644, 48080 Bilbao (Spain); Koroteev, Yury M. [Institute of Strength Physics and Materials Science, Russian Academy of Sciences, Siberian Branch, 634055 Tomsk (Russian Federation); Tomsk State University, Tomsk, 634050 (Russian Federation); Breczewski, Tomasz [Departamento de Física de la Materia Condensada, Facultad de Ciencia y Tecnología, Universidad del País Vasco, Apdo. 644, 48080 Bilbao (Spain); Babanly, Nizamaddin B. [Institute of Catalysis and Inorganic Chemistry, ANAS, H.Javid ave. 113, AZ1143 Baku (Azerbaijan); Amiraslanov, Imamaddin R. [Institute of Physics, ANAS, H.Javid ave. 131, AZ1143 Baku (Azerbaijan); Politano, Antonio [Department of Physics, University of Calabria, 87036 Rende (CS) (Italy); Madariaga, Gotzon [Departamento de Física de la Materia Condensada, Facultad de Ciencia y Tecnología, Universidad del País Vasco, Apdo. 644, 48080 Bilbao (Spain); Babanly, Mahammad B. [Institute of Catalysis and Inorganic Chemistry, ANAS, H.Javid ave. 113, AZ1143 Baku (Azerbaijan); and others

    2016-10-15

    Single crystals of the ternary copper compounds CuTlS and CuTlSe have been successfully grown from stoichiometric melt by using vertical Bridgman-Stockbarger method. The crystal structure of the both compounds has been determined by powder and single crystal X-Ray diffraction. They crystallize in the PbFCl structure type with two formula units in the tetragonal system, space group P4/nmm, a=3.922(2); c=8.123(6); Z=2 and a=4.087(6); c=8.195(19) Å; Z=2, respectively. The band structure of the reported compounds has been analyzed by means of full-potential linearized augmented plane-wave (FLAPW) method based on the density functional theory (DFT). Both compounds have similar band structures and are narrow-gap semiconductors with indirect band gap. The resistivity measurements agree with a semiconductor behavior although anomalies are observed at low temperature. - Graphical abstract: The crystal structures of CuTl and CuTlSe are isostructural with the PbFCl-type and the superconductor LiFeAs-type tetragonal structure. The band structure calculations confirmed that they are narrow-gap semiconductors with indirect band gaps of 0.326 and 0.083 eV. The resistivity measurements, although confirming the semiconducting behavior of both compounds exhibit unusual anomalies at low temperatures. - Highlights: • Single crystals of CuTlS and CuTlSe have been successfully grown by Bridgman-Stockbarger method. • The crystal structure of the both compounds has been determined by single crystal XRD. • The band structure of the both compounds has been analyzed based on the density functional theory (DFT). • The resistivity measurements have been carried out from room temperature down to 10 K.

  8. Role of Cu During Sintering of Fe0.96Cu0.04 Nanoparticles

    Science.gov (United States)

    Sivaprahasam, D.; Sriramamurthy, A. M.; Bysakh, S.; Sundararajan, G.; Chattopadhyay, K.

    2018-04-01

    Nanoparticle agglomerates of passivated Fe ( n-Fe) and Fe0.96Cu0.04 ( n-Fe0.96Cu0.04), synthesized through the levitational gas condensation (LGC) process, were compacted and sintered using the conventional powder metallurgy method. The n-Fe0.96Cu0.04 agglomerates produced lower green density than n-Fe, and when compacted under pressure beyond 200 MPa, they underwent lateral cracking during ejection attributed to the presence of a passive oxide layer. Sintering under dynamic hydrogen atmosphere can produce a higher density of compact in n-Fe0.96Cu0.04 in comparison to n-Fe. Both the results of dilatometry and thermogravimetric (TG) measurements of the samples under flowing hydrogen revealed enhancement of the sintering process as soon as the reduction of oxide layers could be accomplished. The shrinkage rate of n-Fe0.96Cu0.04 reached a value three times higher than n-Fe at a low temperature of 723 K (450 °C) during heating. This enhanced shrinkage rate was the manifestation of accumulation of Cu at the surface of the particles. The formation of a thin-surface melted layer enriched with copper during heating to isothermal holding facilitated as a medium of transport for diffusion of the elements. The compacts produced by sintering at 773 K (500 °C), with relative density 82 pct, were found to be unstable and oxidized instantly when exposed to ambient atmosphere. The stable compacts of density more than 92 pct with 300- to 450-nm grain size could only be produced when sintering was carried out at 973 K (700 °C) and beyond. The 0.22 wt pct residual oxygen obtained in the sintered compact is similar to what is used for conventional ferrous powder metallurgy products.

  9. Exchange correlation length and magnetoresistance in Fe-Cu and Fe-Cu-Ni melt-spun ribbons

    International Nuclear Information System (INIS)

    El Ghannami, M.; Gomez-Polo, C.; Rivero, G.; Hernando, A.

    1994-01-01

    The magnetic properties of Fe 30 Cu 70 melt-spun ribbons are reported for the first time. In the as-cast state, the microstructure consists of b.c.c.-Fe grains immersed in a Cu-rich matrix. However, the addition of a small percentage of Ni gives rise to the appearance of new Cu-Fe-Ni phases. Under suitable thermal treatments, the microstructure of both alloys evolves towards a complete phase segregation in b.c.c-Fe and f.c.c.-Cu immiscibles phases. The temperature dependence of the magnetic properties is analysed and related to the microstructural changes produced during the thermal treatments. Remarkable magneto-resistance effects have been observed in both as-cast alloys, with maximum values of the order of 6% at low measuring temperatures. (orig.)

  10. Magneto-optical response of Cu/NiFe/Cu nanostructure under surface plasmon resonance

    Energy Technology Data Exchange (ETDEWEB)

    Mahmoodi, S. [Institute of Nanoscience and Nanotechnology, University of Kashan, Kashan, 87317 (Iran, Islamic Republic of); Moradi, M., E-mail: m.moradi@kashanu.ac.ir [Institute of Nanoscience and Nanotechnology, University of Kashan, Kashan, 87317 (Iran, Islamic Republic of); Mohseni, S.M. [Department of Physics, Shahid Beheshti University, Evin, Tehran, 19839 (Iran, Islamic Republic of)

    2016-12-15

    In this paper, we present theoretical and experimental studies about the surface plasmon resonance effects on the magneto-optical activity of Cu/NiFe/Cu nanostructures as a function of layers thickness and light incident angle. Device fabrication was done by an oblique deposition technique with RF magnetron sputtering to carefully cover fine step thickness variation of all constituted layers. Angular dependent transverse Kerr response of samples was measured in the Kretschmann configuration at a fixed wavelength of 632 nm. At an optimum layer thickness and incident angle, significant amplification of the transverse Kerr effect was observed. Enhancement in the transverse Kerr effect can be realized by hybridization of surface plasmon excitation and cavity resonance in the plasmonic nanostructure. Experimental results were in qualitative agreement with modeling based on the 4×4 transfer matrix formalism. - Highlights: • Large magneto-optical response in Cu/NiFe/Cu multilayer nanostructure is achieved. • Layer thickness and sequence are studied to find large transverse Kerr signal. • Hybridization of surface plasmon excitation and cavity resonance were done.

  11. Glass-formation and hardness of Cu-Y alloys

    International Nuclear Information System (INIS)

    Satta, Marta; Rizzi, Paola; Baricco, Marcello

    2009-01-01

    Metallic glasses exhibit particularly attractive mechanical properties, like high stresses to fracture and large elastic strain (up to 2%), but they show generally low plasticity. Aim of this work is to investigate the glass forming range in the Cu-Y system, in order to form the ductile CuY phase (CsCl structure) upon crystallization. Cu 58 Y 42 , Cu 50 Y 50 and Cu 33 Y 67 alloys have been prepared by rapid solidification and copper mould casting, obtaining ribbons and cylindrical shaped ingots, with diameter of 2 mm. Fully amorphous, partially amorphous and fully crystalline samples have been obtained for different compositions and quenching conditions. In some cases, the X-ray diffraction results, analysed using the Rietveld method, showed CuY nanocrystals embedded in an amorphous matrix. The microstructure was studied by transmission electron microscopy (TEM) and the presence of nanocrystals of the ductile phase CuY has been confirmed. Microhardness results showed a softening of the amorphous phase due to the presence of CuY nanocrystals and a hardening due to the Cu 2 Y phase.

  12. First-principles theory of short-range order in size-mismatched metal alloys: Cu-Au, Cu-Ag, and Ni-Au

    International Nuclear Information System (INIS)

    Wolverton, C.; Ozolins, V.; Zunger, A.

    1998-01-01

    We describe a first-principles technique for calculating the short-range order (SRO) in disordered alloys, even in the presence of large anharmonic atomic relaxations. The technique is applied to several alloys possessing large size mismatch: Cu-Au, Cu-Ag, Ni-Au, and Cu-Pd. We find the following: (i) The calculated SRO in Cu-Au alloys peaks at (or near) the left-angle 100 right-angle point for all compositions studied, in agreement with diffuse scattering measurements. (ii) A fourfold splitting of the X-point SRO exists in both Cu 0.75 Au 0.25 and Cu 0.70 Pd 0.30 , although qualitative differences in the calculated energetics for these two alloys demonstrate that the splitting in Cu 0.70 Pd 0.30 may be accounted for by T=0 K energetics while T≠0 K configurational entropy is necessary to account for the splitting in Cu 0.75 Au 0.25 . Cu 0.75 Au 0.25 shows a significant temperature dependence of the splitting, in agreement with recent in situ measurements, while the splitting in Cu 0.70 Pd 0.30 is predicted to have a much smaller temperature dependence. (iii) Although no measurements exist, the SRO of Cu-Ag alloys is predicted to be of clustering type with peaks at the left-angle 000 right-angle point. Streaking of the SRO peaks in the left-angle 100 right-angle and left-angle 1 (1) /(2) 0 right-angle directions for Ag- and Cu-rich compositions, respectively, is correlated with the elastically soft directions for these compositions. (iv) Even though Ni-Au phase separates at low temperatures, the calculated SRO pattern in Ni 0.4 Au 0.6 , like the measured data, shows a peak along the left-angle ζ00 right-angle direction, away from the typical clustering-type left-angle 000 right-angle point. (v) The explicit effect of atomic relaxation on SRO is investigated and it is found that atomic relaxation can produce significant qualitative changes in the SRO pattern, changing the pattern from ordering to clustering type, as in the case of Cu-Ag. copyright 1998 The American

  13. Antimicrobial activities of CuO films deposited on Cu foils by solution chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Ekthammathat, Nuengruethai [Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thongtem, Titipun, E-mail: ttpthongtem@yahoo.com [Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Materials Science Research Center, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thongtem, Somchai, E-mail: schthongtem@yahoo.com [Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Materials Science Research Center, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand)

    2013-07-15

    Monoclinic CuO thin films on Cu foils were successfully synthesized by a simple wet chemical method in alkaline solution with the pH of 13 at room temperature for different lengths of time. The as-synthesized thin films were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and selected area electron diffraction (SAED). Formation mechanism of the phase and morphologies was also discussed according to the experimental results. In this research, assemblies of pure CuO nanospindles with different orientations containing in the thin film synthesized for 2 weeks with 400 nm and 413 nm violet emissions showed better antimicrobial activity against S. aureus than E. coli.

  14. Antimicrobial activities of CuO films deposited on Cu foils by solution chemistry

    International Nuclear Information System (INIS)

    Ekthammathat, Nuengruethai; Thongtem, Titipun; Thongtem, Somchai

    2013-01-01

    Monoclinic CuO thin films on Cu foils were successfully synthesized by a simple wet chemical method in alkaline solution with the pH of 13 at room temperature for different lengths of time. The as-synthesized thin films were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and selected area electron diffraction (SAED). Formation mechanism of the phase and morphologies was also discussed according to the experimental results. In this research, assemblies of pure CuO nanospindles with different orientations containing in the thin film synthesized for 2 weeks with 400 nm and 413 nm violet emissions showed better antimicrobial activity against S. aureus than E. coli.

  15. Self-Assembled Formation of Well-Aligned Cu-Te Nano-Rods on Heavily Cu-Doped ZnTe Thin Films

    Science.gov (United States)

    Liang, Jing; Cheng, Man Kit; Lai, Ying Hoi; Wei, Guanglu; Yang, Sean Derman; Wang, Gan; Ho, Sut Kam; Tam, Kam Weng; Sou, Iam Keong

    2016-11-01

    Cu doping of ZnTe, which is an important semiconductor for various optoelectronic applications, has been successfully achieved previously by several techniques. However, besides its electrical transport characteristics, other physical and chemical properties of heavily Cu-doped ZnTe have not been reported. We found an interesting self-assembled formation of crystalline well-aligned Cu-Te nano-rods near the surface of heavily Cu-doped ZnTe thin films grown via the molecular beam epitaxy technique. A phenomenological growth model is presented based on the observed crystallographic morphology and measured chemical composition of the nano-rods using various imaging and chemical analysis techniques. When substitutional doping reaches its limit, the extra Cu atoms favor an up-migration toward the surface, leading to a one-dimensional surface modulation and formation of Cu-Te nano-rods, which explain unusual observations on the reflection high energy electron diffraction patterns and apparent resistivity of these thin films. This study provides an insight into some unexpected chemical reactions involved in the heavily Cu-doped ZnTe thin films, which may be applied to other material systems that contain a dopant having strong reactivity with the host matrix.

  16. Cu-64-pyruvaldehyde-bis-(N4-methylthiosemicarbazide) or Cu-64-PTSM as tracer for brain positron emission tomography

    International Nuclear Information System (INIS)

    Torres, E.A.; Lago Fernandez, J.L.; Casale, G.A.; Arguelles, M.G.

    1993-01-01

    Synthesis of pyruvaldehyde-bis-(N 4 -methylthiosemicarbazide) (PTSM), used for medical investigation and diagnosis, has been carried out in our Radiopharmaceutical Division in C.A.E. (Ezeiza Atomic Center). PTSM has been obtained introducing modifications to a previous synthesis published by H.G. Petering. (M.P. 236-238 degrees C). TLC, HPLC and IR spectrum controls have been performed. Cu-64 can be obtained by the Cu-63(n,α) and Zn-64(n,p) reactions. This last reaction has been chosen for the production in the RA-3 reactor since it leads to Cu-64 of high specific activity. Two different assays have been performed to obtain the chelate PTSM-Cu-64. The first one has been obtained by buffering the Cu-64 to pH 3-4; adding the PTSM solution to ethanol. The second assay has been carried out by buffering the Cu-64 solution with sodium acetate 3M and adding 100 μl of PTSM solution. Biodistribution studies have been carried out on NIH and rats showing a brain uptake of 4%, 30 minutes after injection. Thus, PTSM-Cu-64 proves a good brain diagnosis agent. (author). 1 ref

  17. Growth of CuPd nanoalloys encapsulated in carbon-shell

    Energy Technology Data Exchange (ETDEWEB)

    Kang, H. Y.; Wang, H. P., E-mail: wanghp@mail.ncku.edu.tw [National Cheng Kung University, Department of Environmental Engineering (China)

    2013-05-15

    Preparation of nanostructured copper-palladium (CuPd) alloys is getting more attention because specific catalytic properties can be tuned by controlling their composition, size, and shape. Thus, a better understanding especially in the formation mechanism of the CuPd nanoalloys is of great importance in designing the catalysts. Growth of CuPd nanoalloys encapsulated in carbon-shell (CuPd-C) was, therefore, studied by in situ synchrotron small-angle X-ray scattering during temperature-programed carbonization (TPC) of the Cu{sup 2+}- and Pd{sup 2+}-{beta}-cyclodextrin complexes. A rapid reduction of Cu{sup 2+} and Pd{sup 2+} with nucleation is found at the temperatures of <423 K, followed by coalescence at 453-573 K. The well-dispersed CuPd nanoalloys having the sizes of 7.6-7.9 nm in diameter are encapsulated in carbon-shell of 1.4-1.8 nm in thickness. The refined extended X-ray absorption fine structure spectra indicate that the bond distances of the first-shell Cu-Pd are 2.61-2.64 A with the coordination numbers of 5.1-5.6. A homogeneous CuPd alloy at the Cu/Pd atomic ratio of 1 is observed. Note that at the high Cu/Pd ratio, Cu is enriched on the CuPd nanoalloy surfaces, attributable to the relatively low surface free energy of Cu.

  18. Submillimeter and microwave residual losses in epitaxial films of Y-Ba-Cu-O and Tl-Ca-Ba-Cu-O

    International Nuclear Information System (INIS)

    Miller, D.; Richards, P.L.; Eom, C.B.; Geballe, T.H.; Etemad, S.; Inam, A.; Venkatesan, T.; Martens, J.S.; Lee, W.Y.

    1992-12-01

    We have used a novel bolometric technique and a resonant technique to obtain accurate submillimeter and microwave residual loss data for epitaxial thin films of YBa 2 Cu 3 O 7 , Tl 2 Ca 2 Ba 2 Cu 3 O 10 and Tl 2 CaBa 2 Cu 2 O 8 . For all films we obtain good agreement between the submillimeter and microwave data, with the residual losses in both the Y-Ba-Cu-O and Tl-Ca-Ba-Cu-O films scaling approximately as frequency squared below ∼ 1 THz. We are able to fit the losses in the Y-Ba-Cu-O films to a two fluid and a weakly coupled grain model for the a-b planeconductivity, in good agreement with results from a Kramers-Kronig analysis of the loss data

  19. The Y-Cu-Al system

    International Nuclear Information System (INIS)

    Krachan, T.; Stel'makhovych, B.; Kuz'ma, Yu.

    2003-01-01

    The phase diagram of the Y-Cu-Al system at 820 K has been constructed using X-ray powder diffraction. The existence of earlier known ternary aluminides has been confirmed and their homogeneity regions and atomic distributions in the structures have been determined: YCu 4.6-4.0 Al 7.4-8.0 (ThMn 12 -type R I =0.049), Y 2 Cu 12.0-10.5 Al 5.0-6.5 (Th 2 Zn 17 -type R I =0.092), YCu 1.0-1.1 Al 1.0-0.9 (Fe 2 P-type R I =0.068). It has been shown that the structure of Y(Cu,Al) 3 is characterized by an ordered distribution of the Cu and Al atoms and it should be referred as Ca 3 Cu 2 Al 7 structure type (R I =0.060) besides the PuNi 3 structure type with statistical occupancies of the smaller atoms. At the investigated temperature the compound YCu 1.0-0.25 Al 3.0-3.75 (BaAl 4 -type) was not observed. However, we found the ternary aluminide with composition Y 3 Cu 2.7-2.0 Al 8.3-9.0 and related La 3 Al 11 -type (space group Immm, a=0.4192-0.4228, b=1.2423-1.2557, c=0.9812-0.9895 nm, R I =0.069). The compounds YCu 6.8 Al 4.2 (space group Fddd, Tb(Cu 0.58 Al 0.42 ) 11 -type, a=1.42755, b=1.48587, c=0.65654 nm, R I =0.062) and YCu 6.5 Al 4.5 (space group I4 1 /amd, BaCd 11 -type, a=1.02774, c=0.65838 nm, R I =0.071) have been found and structurally refined for the first time

  20. A first-principles study of the structural, mechanical and electronic properties of precipitates of Al2Cu in Al-Cu alloys.

    Science.gov (United States)

    Ouyang, Y F; Chen, H M; Tao, X M; Gao, F; Peng, Q; Du, Y

    2018-01-03

    The properties of precipitates are important in understanding the strengthening mechanism via precipitation during heat treatment and the aging process in Al-Cu based alloys, where the formation of precipitates is sensitive to temperature and pressure. Here we report a first-principles investigation of the effect of temperature and pressure on the structural stability, elastic constants and formation free energy for precipitates of Al 2 Cu, as well as their mechanical properties. Based on the formation enthalpy of Guinier-Preston (GP(I)) zones, the size of the GP(I) zone is predicted to be about 1.4 nm in diameter, which is in good agreement with experimental observations. The formation enthalpies of the precipitates are all negative, suggesting that they are all thermodynamically stable. The present calculations reveal that entropy plays an important role in stabilizing θ-Al 2 Cu compared with θ C '-Al 2 Cu. The formation free energies of θ''-Al 3 Cu, θ C '-Al 2 Cu, θ D '-Al 5 Cu 3 and θ t '-Al 11 Cu 7 increase with temperature, while those of θ'-Al 2 Cu, θ O '-Al 2 Cu and θ-Al 2 Cu decrease. The same trend is observed with the effect of pressure. The calculated elastic constants for the considered precipitation phases indicate that they are all mechanically stable and anisotropic, except θ C '-Al 2 Cu. θ D '-Al 5 Cu 3 has the highest Vicker's hardness. The electronic structures are also calculated to gain insight into the bonding characteristics. The present results can help in understanding the formation of precipitates by different treatment processes.

  1. Infiltrated TiC/Cu composites

    International Nuclear Information System (INIS)

    Frage, N.; Froumin, N.; Rubinovich, L.; Dariel, M.P.

    2001-01-01

    One approach for the fabrication of ceramic-metal composites is based on the pressureless impregnation of a porous ceramic preform by a molten metal. Molten Cu does not react with TiC and the wetting angle is close to 90 o . Nonetheless, molten Cu readily impregnates partially sintered TiC preforms. A model that describes the dependence of the critical contact angle for spontaneous impregnation by molten metals in partially sintered preforms on the level of densification and on the morphology of the particles was developed. For high aspect ratios of the particles forming the preform, wetting angles close to 90 o still allow impregnation by the molten metal. The results of the model were confirmed by infiltration of partially sintered TiC preforms with molten Cu and by fabrication of the TiC/Cu composites with various ceramic-to metal ratios. Decreasing of the metal content in the composite from 50 vol.% to 10 vol.% leads to a hardness increase from 250 to 1800 HV, and to the decrease of the bending strength from 960 to 280 MPa. The resistivity of these TiC/Cu composites decreases from 142 ohm cm to 25 ohm cm. (author)

  2. The effect of Cu on the properties of CdO/Cu/CdO multilayer films for transparent conductive electrode applications

    Energy Technology Data Exchange (ETDEWEB)

    Raaif, M.; Mohamed, S.H. [Sohag University, Physics Department, Faculty of Science, Sohag (Egypt)

    2017-06-15

    Transparent conductive CdO/Cu/CdO multilayer films were prepared using rf plasma magnetron sputtering and electron beam evaporation techniques. The CdO layers were prepared using rf plasma magnetron sputtering, while the Cu interlayer was prepared by electron beam evaporation technique. The Cu layer thickness was varied between 1 and 10 nm. The structural and optical properties as well as the sheet resistance of the multilayer films were studied. X-ray diffraction measurements revealed the presence of cubic CdO structure and the Cu peak was only observed for the multilayers prepared with 10 nm of Cu. It has been observed that the Cu interlayer thickness has a great influence on the optical and electrical properties of the multilayers. The transmittance of the multilayer films decreased while the reflectance increased with increasing Cu interlayer thickness. The refractive index and the extinction coefficient of the multilayer films were calculated. The estimated optical band gap values were found to be decreased from 2.75 ± 0.02 to 2.40 ± 0.02 eV as the Cu interlayer thickness increased from 1 to 10 nm. The sheet resistance was sensitive to the Cu interlayer thickness and it decreased with increasing Cu interlayer thickness. A sheet resistSSance of 21.7 Ω/sq, an average transmittance (between 700 and 1000 nm) of 77%, and an optical band gap of 2.5 ± 0.02 eV were estimated for the multilayer film with 2 nm Cu layer. The multilayer film with 2 nm Cu layer has the highest figure of merit value of 3.2 x 10{sup -3} Ω{sup -1}. This indicates that the properties of this multilayer film are suitable for transparent conductive electrode applications. (orig.)

  3. Macrocyclic effects upon isomeric Cu M and M Cu cores. Formation ...

    Indian Academy of Sciences (India)

    Administrator

    from the iminic site to the aminic site in the synthesis of 10 is explained by ... Our previous studies suggest that isomeric MIICuII ... Calcd. for C24H27Br2ClCuN4NiO8: C 35⋅28; H 3⋅33; N 6⋅86; Cu 7⋅78; Ni .... Electronic absorption spectra in .... 3. 1497(1). 1452. ⋅3(5). 2992(1). 1860(2). 3206(1). Z. 2. 2. 4. 2. 4. D calcd. /g.

  4. Surface chemistry of 2-butanol and furfural on Cu, Au and Cu/Au single crystals

    OpenAIRE

    Megginson, Rory

    2016-01-01

    In this study, the adsorption of 2-butanol and furfural was investigated on Au (111), Cu (111) and Cu/Au (111) surfaces. It was hoped that by studying how these species adsorbed on these surfaces , insight would be provided into the roles of Cu and Au in the “hydrogen free” hydrogenation of furfural to furfuryl alcohol. This is a valuable process as currently furfuryl alcohol is derived from crude oil but it is possible to derive furfural from corn husk making it a greener process...

  5. Processing and characterization of composite CuO/CuO/Cu-CGO obtained by a chemical synthesis route in one step

    International Nuclear Information System (INIS)

    Sousa, A.R.O. de; Menezes, A.J.; Souza, G.S.; Lima, C.G.M. de; Souza, G.S.; Dutra, R.P.S.; Macedo, D.A.

    2016-01-01

    This paper deals with the processing and characterization of composite CuO / ceria doped with 10 mol% gadolinia (CuO-Ce0,9Gd0,1O1,95) obtained by a chemical synthesis route in one step. It was varied CuO content at 40, 50 and 60% by weight, resulting in resin precursor, which was mixed with the CGO and then heat treated at 350 ° C and subsequently calcined at 1050 deg C. The particulate materials were characterized by X-ray diffractometry using powders, it was possible to synthesize and deposit, by serigraphy, films of the anodes of the three compositions CGO electrolyte. The technique of impedance spectroscopy allowed the analysis of the electrical properties of the material, as well as the understanding of their behavior when subjected to different atmospheres of hydrogen and methane. (author)

  6. Effects of Ag addition on solid–state interfacial reactions between Sn–Ag–Cu solder and Cu substrate

    International Nuclear Information System (INIS)

    Yang, Ming; Ko, Yong-Ho; Bang, Junghwan; Kim, Taek-Soo; Lee, Chang-Woo; Li, Mingyu

    2017-01-01

    Low–Ag–content Sn–Ag–Cu (SAC) solders have attracted much recent attention in electronic packaging for their low cost. To reasonably reduce the Ag content in Pb–free solders, a deep understanding of the basic influence of Ag on the SAC solder/Cu substrate interfacial reaction is essential. Previous studies have discussed the influence of Ag on the interfacial intermetallic compound (IMC) thickness. However, because IMC growth is the joint result of multiple factors, such characterizations do not reveal the actual role of Ag. In this study, changes in interfacial IMCs after Ag introduction were systemically and quantitatively characterized in terms of coarsening behaviors, orientation evolution, and growth kinetics. The results show that Ag in the solder alloy affects the coarsening behavior, accelerates the orientation concentration, and inhibits the growth of interfacial IMCs during solid–state aging. The inhibition mechanism was quantitatively discussed considering the individual diffusion behaviors of Cu and Sn atoms, revealing that Ag inhibits interfacial IMC growth primarily by slowing the diffusion of Cu atoms through the interface. - Highlights: •Role of Ag in IMC formation during Sn–Ag–Cu soldering was investigated. •Ag affects coarsening, crystallographic orientation, and IMC growth. •Diffusion pathways of Sn and Cu are affected differently by Ag. •Ag slows Cu diffusion to inhibit IMC growth at solder/substrate interface.

  7. Electrodeposition and properties of Zn, Cu, and Cu{sub 1−x} Zn{sub x} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Özdemir, Rasim [Kilis Vocational High School, Kilis 7 Aralık University, 79000 Kilis (Turkey); Karahan, İsmail Hakkı, E-mail: ihkarahan@gmail.com [Department of Metallurgical and Materials Engineering, Faculty of Technology, Mustafa Kemal University, 31040 Hatay (Turkey)

    2014-11-01

    Highlights: • Cu, Zn and Cu–Zn deposits successfully deposited from the non-cyanide sulphate electrolyte. • The effect of alloying element was investigated on the electrical resistivity and the structure of Cu–Zn alloy. • The average crystallite size of the samples varied from 66 to 161 nm and decreased when the Zn and Cu combined in Cu–Zn. • Microstrain has been decreased with increasing crystallite size. • Electrical resistivity of alloy was obtained between the Zn and Cu films. - Abstract: The electrodeposition of Cu, Zn and Cu–Zn deposits from the non-cyanide Zn sulphate and Cu sulphate reduced by citrate at constant stirring speed has been investigated. The composition of the Cu–Zn bath was shown to influence the morphology, electrical resistivity, phase composition, and Cu and Zn content of the Cu–Zn deposits. Their structural and electrical properties have been investigated by X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDAX), cyclic voltammeter (CV) and current–voltage measurements against the temperature for electrical resistivity, respectively. XRD shows that Cu–Zn samples are polycrystalline phase. Resistivity results show that the copper film exhibits bigger residual resistivity than both the zinc and the Cu–Zn alloy. Theoretical calculations of the XRD peaks demonstrate that the average crystallite size of the Cu–Zn alloy decreased and microstrain increased when the Cu alloyed with zinc.

  8. Effects of Ag addition on solid–state interfacial reactions between Sn–Ag–Cu solder and Cu substrate

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Ming [Micro-Joining Center, Korea Institute of Industrial Technology (KITECH), Incheon 21999 (Korea, Republic of); Ko, Yong-Ho [Micro-Joining Center, Korea Institute of Industrial Technology (KITECH), Incheon 21999 (Korea, Republic of); Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291, Daehak-ro, Yuseong-gu, Daejeon 34141 (Korea, Republic of); Bang, Junghwan [Micro-Joining Center, Korea Institute of Industrial Technology (KITECH), Incheon 21999 (Korea, Republic of); Kim, Taek-Soo [Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291, Daehak-ro, Yuseong-gu, Daejeon 34141 (Korea, Republic of); Lee, Chang-Woo, E-mail: cwlee@kitech.re.kr [Micro-Joining Center, Korea Institute of Industrial Technology (KITECH), Incheon 21999 (Korea, Republic of); Li, Mingyu, E-mail: myli@hit.edu.cn [Shenzhen Key Laboratory of Advanced Materials, Harbin Institute of Technology Shenzhen Graduate School, Shenzhen 518055 (China)

    2017-02-15

    Low–Ag–content Sn–Ag–Cu (SAC) solders have attracted much recent attention in electronic packaging for their low cost. To reasonably reduce the Ag content in Pb–free solders, a deep understanding of the basic influence of Ag on the SAC solder/Cu substrate interfacial reaction is essential. Previous studies have discussed the influence of Ag on the interfacial intermetallic compound (IMC) thickness. However, because IMC growth is the joint result of multiple factors, such characterizations do not reveal the actual role of Ag. In this study, changes in interfacial IMCs after Ag introduction were systemically and quantitatively characterized in terms of coarsening behaviors, orientation evolution, and growth kinetics. The results show that Ag in the solder alloy affects the coarsening behavior, accelerates the orientation concentration, and inhibits the growth of interfacial IMCs during solid–state aging. The inhibition mechanism was quantitatively discussed considering the individual diffusion behaviors of Cu and Sn atoms, revealing that Ag inhibits interfacial IMC growth primarily by slowing the diffusion of Cu atoms through the interface. - Highlights: •Role of Ag in IMC formation during Sn–Ag–Cu soldering was investigated. •Ag affects coarsening, crystallographic orientation, and IMC growth. •Diffusion pathways of Sn and Cu are affected differently by Ag. •Ag slows Cu diffusion to inhibit IMC growth at solder/substrate interface.

  9. Cu-Ti Formation in Nb-Ti/Cu Superconducting Strand Monitored by in situ Techniques

    CERN Document Server

    Pong, I; Pong, Ian; Gerardin, Alexandre; Scheuerlein, Christian; Bottura, Luca

    2010-01-01

    In order to investigate the high temperature exposure effect on Nb-Ti/Cu superconducting strands, as might be encountered in joining by soldering and in cabling annealing, X-ray diffraction and resistometry measurements were performed in situ during heat treatment, and complemented by conventional metallography, mechanical tests and superconducting properties measurements. Changes of the Nb-Ti nanostructure at temperatures above 300 degrees C are manifested in the degradation of critical current in an applied external magnetic field, although degradation at self field was insignificant up to 400 degrees C for several minutes. Above 500 degrees C, the formation of various Cu-Ti intermetallic compounds, due to Ti diffusion from Nb-Ti into Cu, is detected by in situ XRD albeit not resolvable by SEM-EDS. There is a ductile to brittle transition near 600 degrees C, and liquid formation is observed below 900 degrees C. The formation of Cu-Ti causes a delayed reduction of the residual resistivity ratio (RRR) and adv...

  10. Small changes in Cu redox state and speciation generate large isotope fractionation during adsorption and incorporation of Cu by a phototrophic biofilm

    Science.gov (United States)

    Coutaud, Margot; Méheut, Merlin; Glatzel, Pieter; Pokrovski, Gleb S.; Viers, Jérôme; Rols, Jean-Luc; Pokrovsky, Oleg S.

    2018-01-01

    Despite the importance of phototrophic biofilms in metal cycling in freshwater systems, metal isotope fractionation linked to metal adsorption and uptake by biofilm remains very poorly constrained. Here, copper isotope fractionation by a mature phototrophic biofilm during Cu surface adsorption and incorporation was studied in batch reactor (BR) and open drip flow reactor (DFR) systems at ambient conditions. X-ray Absorption Spectroscopy (both Near Edge Structure, XANES, and Extended Fine Structure, EXAFS) at Cu K-edge of the biofilm after its interaction with Cu in BR experiments allowed characterizing the molecular structure of assimilated Cu and quantifying the degree of CuII to CuI reduction linked to Cu assimilation. For both BR and DFR experiments, Cu adsorption caused enrichment in heavy isotope at the surface of the biofilm relative to the aqueous solution, with an apparent enrichment factor for the adsorption process, ε65Cuads, of +1.1 ± 0.3‰. In contrast, the isotope enrichment factor during copper incorporation into the biofilm (ε65Cuinc) was highly variable, ranging from -0.6 to +0.8‰. This variability of the ε65Cuinc value was likely controlled by Cu cellular uptake via different transport pathways resulting in contrasting fractionation. Specifically, the CuII storage induced enrichment in heavy isotope, whereas the toxicity response of the biofilm to Cu exposure resulted in reduction of CuII to CuI, thus yielding the biofilm enrichment in light isotope. EXAFS analyses suggested that a major part of the Cu assimilated by the biofilm is bound to 5.1 ± 0.3 oxygen or nitrogen atoms, with a small proportion of Cu linked to sulfur atoms (NS biofilm exhibited a similar trend over time of exposure. Our study demonstrates the complexity of biological processes associated with live phototrophic biofilms, which produce large and contrasting isotope fractionations following rather small Cu redox and speciation changes during uptake, storage or release of

  11. Local Seebeck coefficient near the boundary in touching Cu/Bi-Te/Cu composites

    International Nuclear Information System (INIS)

    Yamashita, O.; Odahara, H.

    2007-01-01

    The thermo-emf ΔV and temperature difference ΔT across the boundary were measured as a function of r for the touching p- and n-type Cu/Bi-Te/Cu composites composed of a combination of t Bi-Te =2.0 mm and t Cu =0.3 mm, where ΔT is produced by imposing a constant voltage of 1.7 V on two Peltier modules connected in series and r is the distance from the boundary that corresponds to the interval s between two thermocouples. The resultant Seebeck coefficient α across the boundary was obtained from the relation α=ΔV/ΔT. As a result, the resultant α of the touching p- and n-type composites have surprisingly great local maximum values of 1330 and -1140 μV/K at r∼0.03 mm, respectively, and decreased rapidly with an increase of r to approach the Seebeck coefficients of the intrinsic Bi-Te compounds. The resultant maximum α of the touching p- and n-type Cu/Bi-Te/Cu composites are approximately 5.4 and 5.5 times higher in absolute value than those of the intrinsic Bi-Te compounds, respectively. It was thus clarified for the first time that the local Seebeck coefficient is enhanced most strongly in the Bi-Te region where there is an approximately 30-μm distance from the boundary, not at the boundary between Bi-Te compounds and copper. (orig.)

  12. Attempting to realize n-type BiCuSeO

    Science.gov (United States)

    Zhang, Xiaoxuan; Feng, Dan; He, Jiaqing; Zhao, Li-Dong

    2018-02-01

    As an intrinsic p-type semiconductor, BiCuSeO has been widely researched in the thermoelectric community, however, n-type BiCuSeO has not been reported so far. In this work, we successfully realized n-type BiCuSeO through carrying out several successive efforts. Seebeck coefficient of BiCuSeO was increased through introducing extra Bi/Cu to fill the Bi/Cu vacancies that may produce holes, and the maximum Seebeck coefficient was increase from +447 μVK-1 for undoped BiCuSeO to +638 μVK-1 for Bi1.04Cu1.05SeO. The Seebeck coefficient of Bi1.04Cu1.05SeO was changed from p-type to n-type through electron doping through introducing Br/I in Se sites, the maximum negative Seebeck coefficient can reach ∼ -465 μVK-1 and -543 μVK-1 for Bi1.04Cu1.05Se1-xIxO and Bi1.04Cu1.05Se1-xBrxO, respectively. Then, after compositing Bi1.04Cu1.05Se0.99Br0.01O with Ag, n-type BiCuSeO can be absolutely obtained in the whole temperature range of 300-873 K, the maximum ZT 0.05 was achieved at 475 K in the Bi1.04Cu1.05Se0.99Br0.01O+15% Ag. Our report indicates that it is possible to realize n-type conducting behaviors in BiCuSeO system.

  13. Observations of a Cast Cu-Cr-Zr Alloy

    Science.gov (United States)

    Ellis, David L.

    2006-01-01

    Prior work has demonstrated that Cu-Cr-Nb alloys have considerable advantages over the copper alloys currently used in regeneratively cooled rocket engine liners. Observations indicated that Zr and Nb have similar chemical properties and form very similar compounds. Glazov and Zakharov et al. reported the presence of Cr2Zr in Cu-Cr-Zr alloys with up to 3.5 wt% Cr and Zr though Zeng et al. calculated that Cr2Zr could not exist in a ternary Cu-Cr-Zr alloy. A cast Cu-6.15 wt% Cr-5.25 wt% Zr alloy was examined to determine if the microstructure developed would be similar to GRCop-84 (Cu-6.65 wt% Cr-5.85 wt% Nb). It was observed that the Cu-Cr-Zr system did not form any Cr2Zr even after a thermal exposure at 875 C for 176.5 h. Instead the alloy consisted of three phases: Cu, Cu5Zr, and Cr.

  14. Effect of Cu2O morphology on photocatalytic hydrogen generation and chemical stability of TiO2/Cu2O composite.

    Science.gov (United States)

    Zhu, Lihong; Zhang, Junying; Chen, Ziyu; Liu, Kejia; Gao, Hong

    2013-07-01

    Improving photocatalytic activity and stability of TiO2/Cu2O composite is a challenge in generating hydrogen from water. In this paper, the TiO2 film/Cu2O microgrid composite was prepared via a microsphere lithography technique, which possesses a remarkable performance of producing H2 under UV-vis light irradiation, in comparison with pure TiO2 film, Cu2O film and TiO2 film/Cu2O film. More interesting is that in TiO2 film/Cu2O microgrid, photo-corrosion of Cu2O can be retarded. After deposition of Pt on its surface, the photocatalytic activity of TiO2/Cu2O microgrid in producing H2 is improved greatly.

  15. Axial strain localization of CuCrZr tubes during manufacturing of ITER-like mono-block W/Cu components using HIP

    International Nuclear Information System (INIS)

    Zhao, S.X.; Peng, L.J.; Li, Q.; Wang, W.J.; Wei, R.; Qin, S.G.; Shi, Y.L.; Chang, S.P.; Xu, Y.; Liu, G.H.; Wang, T.J.; Luo, G.-N.

    2014-01-01

    Highlights: • Axial cracking and denting of CuCrZr tubes were observed. • Annealing the as-received tubes can alleviate cracking. • Denting results in the formation bonding flaws at the Cu/CuCrZr interfaces. - Abstract: Two forms of axial strain localization of CuCrZr tubes, i.e., cracking and denting, were observed during the manufacturing of ITER-like mono-block W/Cu components for EAST employing hot isostatic pressing (HIP). Microscopic investigations indicate that the occurrence of axial strain localization correlates to the heavily deformed Cu grains and elongated Cr-rich precipitates as well as highly anisotropic microstructures, which impair the circumferential ductility. Annealing the as-received tubes at 600 °C alleviates cracking due to partial recrystallization of Cu grains. However, the annealed tubes are still sensitive to wall thinning (caused by non-uniform polishing or tube bending), which results in denting. Denting may cause bonding flaws at CuCrZr/Cu interfaces and the underlying mechanisms are discussed. To some extent, denting seems do not affect the high heat flux performance of components. In this paper, we demonstrate that testing only the axial mechanical properties is not enough for manufacturers who use HIP or hot radial pressing technologies, especially for those anisotropic tubes

  16. Synthesis and characterization of micrometer Cu/PVP architectures

    International Nuclear Information System (INIS)

    Luo, Huajuan; Zhao, Yanbao; Sun, Lei

    2011-01-01

    Graphical abstract: A simple method for the synthesis of novel micrometer flower-like Cu/PVP architectures was introduced. Highlights: → Micrometer flower-like copper/polyvinylpyrrolidone architectures were obtained by a simple chemical route. → The amount of N 2 H 4 ·H 2 O, the reaction temperature, the molar ratio of CuCl 2 to PVP and different molecular weights of PVP play an important role in the controlling the morphology of the Cu/PVP architectures. → A possible mechanism of the formation of Cu/PVP architectures was discussed. -- Abstract: Micrometer-sized flower-like Cu/polyvinylpyrrolidone (PVP) architectures are synthesized by the reduction of copper (II) salt with hydrazine hydrate in aqueous solution in the presence of PVP capping agent. The resulting Cu/PVP architectures are investigated by UV-vis spectroscopy, transmission electron microscopy (TEM), X-ray powder diffraction (XRD), and scanning electron microscopy (SEM). The Cu/PVP flowers have uniform morphologies with an average diameter of 10 μm, made of several intercrossing plates. The formation of Cu/PVP flowers is a new kinetic control process, and the factors such as the amount of N 2 H 4 ·H 2 O, reaction temperature, molar ratio of CuCl 2 to PVP and molecular weight of PVP have significant effect on the morphology of Cu/PVP architectures. A possible mechanism of the formation of micrometer Cu/PVP architectures was discussed.

  17. Microstructure, impurity and metal cap effects on Cu electromigration

    Energy Technology Data Exchange (ETDEWEB)

    Hu, C.-K.; Gignac, L. G.; Ohm, J.; Breslin, C. M.; Huang, E.; Bonilla, G.; Liniger, E.; Rosenberg, R. [IBM T. J. Watson Research Center, Yorktown Heights, NY 10598 (United States); Choi, S.; Simon, A. H. [IBM Microelectronic Division, Hopewell Junction, NY 12533 (United States)

    2014-06-19

    Electromigration (EM) lifetimes and void growth of pure Cu, Cu(Mn) alloy, and pure Cu damascene lines with a CoWP cap were measured as a function of grain structure (bamboo, near bamboo, and polycrystalline) and sample temperature. The bamboo grains in a bamboo-polycrystalline grained line play the key role in reducing Cu mass flow. The variation in Cu grain size distribution among the wafers was achieved by varying the metal line height and wafer annealing process step after electroplating Cu and before or after chemical mechanical polishing. The Cu grain size was found to have a large impact on Cu EM lifetime and activation energy, especially for the lines capped with CoWP. The EM activation energy for pure Cu with a CoWP cap from near-bamboo, bamboo-polycrystalline, mostly polycrystalline to polycrystalline only line grain structures was reduced from 2.2 ± 0.2 eV, to 1.7 ± 0.1 eV, to 1.5 ± 0.1 eV, to 0.72 ± 0.05 eV, respectively. The effect of Mn in Cu grain boundary diffusion was found to be dependent on Mn concentration in Cu. The depletion of Cu at the cathode end of the Cu(Mn) line is preceded by an incubation period. Unlike pure Cu lines with void growth at the cathode end and hillocks at the anode end of the line, the hillocks grew at a starting position roughly equal to the Blech critical length from the cathode end of the Cu(Mn) polycrystalline line. The effectiveness of Mn on Cu grain boundary migration can also be qualitatively accounted for by a simple trapping model. The free migration of Cu atoms at grain boundaries is reduced by the presence of Mn due to Cu-solute binding. A large binding energy of 0.5 ± 0.1 eV was observed.

  18. Study On Nanohardness Of Phases Occurring In ZnAl22Cu3 And ZnAl40Cu3 Alloys

    Directory of Open Access Journals (Sweden)

    Michalik R.

    2015-06-01

    Full Text Available Zn-Al alloys are mainly used due to their high tribological and damping properties. A very important issue is determination of the hardness of the phases present in the Zn-Al-Cu alloys. Unfortunately, in literature there is lack of studies on the hardness of the phases present in the alloys Zn-Al-Cu. The aim of this research was to determine the hardness of the phases present in the ZnAl22Cu3Si and ZnAl40Cu3Si alloys. The scope of the research included examination of the structure, chemical composition of selected micro-regions and hardness of phases present in the examined alloys. The research carried out has shown, that CuZn4 phase is characterized by a similar hardness as the hardness of the interdendritic areas. The phases present in the structure of ZnAl40Cu3 and ZnAl22Cu3 alloys after soaking at the temperature of 185 °C are characterized by lower hardness than the phase present in the structure of the as-cast alloys.

  19. The crystallisation of Cu2ZnSnS4 thin film solar cell absorbers from co-electroplated Cu-Zn-Sn precursors

    International Nuclear Information System (INIS)

    Schurr, R.; Hoelzing, A.; Jost, S.; Hock, R.; Voss, T.; Schulze, J.; Kirbs, A.; Ennaoui, A.; Lux-Steiner, M.; Weber, A.; Koetschau, I.; Schock, H.-W.

    2009-01-01

    The best CZTS solar cell so far was produced by co-sputtering continued with vapour phase sulfurization method. Efficiencies of up to 5.74% were reached by Katagiri et al. The one step electrochemical deposition of copper, zinc, tin and subsequent sulfurization is an alternative fabrication technique for the production of Cu 2 ZnSnS 4 based thin film solar cells. A kesterite based solar cell (size 0.5 cm 2 ) with a conversion efficiency of 3.4% (AM1.5) was produced by vapour phase sulfurization of co-electroplated Cu-Zn-Sn films. We report on results of in-situ X-ray diffraction (XRD) experiments during crystallisation of kesterite thin films from electrochemically co-deposited metal films. The kesterite crystallisation is completed by the solid state reaction of Cu 2 SnS 3 and ZnS. The measurements show two different reaction paths depending on the metal ratios in the as deposited films. In copper-rich metal films Cu 3 Sn and CuZn were found after electrodeposition. In copper-poor or near stoichiometric precursors additional Cu 6 Sn 5 and Sn phases were detected. The formation mechanism of Cu 2 SnS 3 involves the binary sulphides Cu 2-x S and SnS 2 in the absence of the binary precursor phase Cu 6 Sn 5 . The presence of Cu 6 Sn 5 leads to a preferred formation of Cu 2 SnS 3 via the reaction educts Cu 2-x S and SnS 2 in the presence of a SnS 2 (Cu 4 SnS 6 ) melt. The melt phase may be advantageous in crystallising the kesterite, leading to enhanced grain growth in the presence of a liquid phase

  20. Cu2Se and Cu Nanocrystals as Local Sources of Copper in Thermally Activated In Situ Cation Exchange

    KAUST Repository

    Casu, Alberto; Genovese, Alessandro; Manna, Liberato; Longo, Paolo; Buha, Joka; Botton, Gianluigi A.; Lazar, Sorin; Kahaly, M. Upadhyay; Schwingenschlö gl, Udo; Prato, Mirko; Li, Hongbo; Ghosh, Sandeep; Palazon, Francisco; De Donato, Francesco; Lentijo Mozo, Sergio; Zuddas, Efisio; Falqui, Andrea

    2016-01-01

    Among the different synthesis approaches to colloidal nanocrystals a recently developed toolkit is represented by cation exchange reactions, where the use of template nanocrystals gives access to materials that would be hardly attainable via direct synthesis. Besides, post-synthetic treatments, such as thermally activated solid state reactions, represent a further flourishing route to promote finely controlled cation exchange. Here, we report that, upon in situ heating in a transmission electron microscope, Cu2Se nanocrystals deposited on an amorphous solid substrate undergo partial loss of Cu atoms, which are then engaged in local cation exchange reactions with Cu “acceptors” phases represented by rod- and wire- shaped CdSe nanocrystals. This thermal treatment slowly transforms the initial CdSe nanocrystals into Cu2-xSe nanocrystals, through the complete sublimation of Cd and the partial sublimation of Se atoms. Both Cu “donor” and “acceptor” particles were not always in direct contact with each other, hence the gradual transfer of Cu species from Cu2Se or metallic Cu to CdSe nanocrystals was mediated by the substrate and depended on the distance between the donor and acceptor nanostructures. Differently from what happens in the comparably faster cation exchange reactions performed in liquid solution, this study shows that slow cation exchange reactions can be performed at the solid state, and helps to shed light on the intermediate steps involved in such reactions.

  1. Cu2Se and Cu Nanocrystals as Local Sources of Copper in Thermally Activated In Situ Cation Exchange

    KAUST Repository

    Casu, Alberto

    2016-01-27

    Among the different synthesis approaches to colloidal nanocrystals a recently developed toolkit is represented by cation exchange reactions, where the use of template nanocrystals gives access to materials that would be hardly attainable via direct synthesis. Besides, post-synthetic treatments, such as thermally activated solid state reactions, represent a further flourishing route to promote finely controlled cation exchange. Here, we report that, upon in situ heating in a transmission electron microscope, Cu2Se nanocrystals deposited on an amorphous solid substrate undergo partial loss of Cu atoms, which are then engaged in local cation exchange reactions with Cu “acceptors” phases represented by rod- and wire- shaped CdSe nanocrystals. This thermal treatment slowly transforms the initial CdSe nanocrystals into Cu2-xSe nanocrystals, through the complete sublimation of Cd and the partial sublimation of Se atoms. Both Cu “donor” and “acceptor” particles were not always in direct contact with each other, hence the gradual transfer of Cu species from Cu2Se or metallic Cu to CdSe nanocrystals was mediated by the substrate and depended on the distance between the donor and acceptor nanostructures. Differently from what happens in the comparably faster cation exchange reactions performed in liquid solution, this study shows that slow cation exchange reactions can be performed at the solid state, and helps to shed light on the intermediate steps involved in such reactions.

  2. Glass-formation and hardness of Cu-Y alloys

    Energy Technology Data Exchange (ETDEWEB)

    Satta, Marta; Rizzi, Paola [Dipartimento di Chimica IFM and NIS/INSTM/CNISM, Universita di Torino, v. Giuria 9, I-10125 Torino (Italy); Baricco, Marcello, E-mail: marcello.baricco@unito.i [Dipartimento di Chimica IFM and NIS/INSTM/CNISM, Universita di Torino, v. Giuria 9, I-10125 Torino (Italy)

    2009-08-26

    Metallic glasses exhibit particularly attractive mechanical properties, like high stresses to fracture and large elastic strain (up to 2%), but they show generally low plasticity. Aim of this work is to investigate the glass forming range in the Cu-Y system, in order to form the ductile CuY phase (CsCl structure) upon crystallization. Cu{sub 58}Y{sub 42}, Cu{sub 50}Y{sub 50} and Cu{sub 33}Y{sub 67} alloys have been prepared by rapid solidification and copper mould casting, obtaining ribbons and cylindrical shaped ingots, with diameter of 2 mm. Fully amorphous, partially amorphous and fully crystalline samples have been obtained for different compositions and quenching conditions. In some cases, the X-ray diffraction results, analysed using the Rietveld method, showed CuY nanocrystals embedded in an amorphous matrix. The microstructure was studied by transmission electron microscopy (TEM) and the presence of nanocrystals of the ductile phase CuY has been confirmed. Microhardness results showed a softening of the amorphous phase due to the presence of CuY nanocrystals and a hardening due to the Cu{sub 2}Y phase.

  3. Influence of Cu diffusion conditions on the switching of Cu-SiO2-based resistive memory devices

    International Nuclear Information System (INIS)

    Thermadam, S. Puthen; Bhagat, S.K.; Alford, T.L.; Sakaguchi, Y.; Kozicki, M.N.; Mitkova, M.

    2010-01-01

    This paper presents a study of Cu diffusion at various temperatures in thin SiO 2 films and the influence of diffusion conditions on the switching of Programmable Metallization Cell (PMC) devices formed from such Cu-doped films. Film composition and diffusion products were analyzed using secondary ion mass spectroscopy, Rutherford backscattering spectrometry, X-ray diffraction and Raman spectroscopy methods. We found a strong dependence of the diffused Cu concentration, which varied between 0.8 at.% and 10 -3 at.%, on the annealing temperature. X-ray diffraction and Raman studies revealed that Cu does not react with the SiO 2 network and remains in elemental form after diffusion for the annealing conditions used. PMC resistive memory cells were fabricated with such Cu-diffused SiO 2 films and device performance, including the stability of the switching voltage, is discussed in the context of the material characteristics.

  4. Selective synthesis of clinoatacamite Cu2(OH)3Cl and tenorite CuO nanoparticles by pH control

    DEFF Research Database (Denmark)

    Engelbrekt, Christian; Malcho, Phillip; Andersen, Jonas

    2014-01-01

    , it directed the growth of Cu2(OH)3Cl to provide pure clinoatacamite without the presence of related poly- morphs. The products were characterized by transmission electron microscopy, infrared spectroscopy, ultraviolet–visible light spectroscopy, X-ray powder diffraction (XRD), scanning transmission X......-ray microscopy and atomic force microscopy. Infrared spectroscopy was essential for characterization of closely related polymorphs of Cu2(OH)3Cl indistinguishable by XRD. A plausible mechanism has been proposed and discussed for the formation of the CuO and Cu2(OH)3Cl nanostructures....

  5. Preparation of Cu@Cu2O Nanocatalysts by Reduction of HKUST-1 for Oxidation Reaction of Catechol

    Directory of Open Access Journals (Sweden)

    Seongwan Jang

    2016-11-01

    Full Text Available HKUST-1, a copper-based metal organic framework (MOF, has been investigated as a catalyst in various reactions. However, the HKUST-1 shows low catalytic activity in the oxidation of catechol. Therefore, we synthesized Fe3O4@HKUST-1 by layer-by layer assembly strategy and Cu@Cu2O by reduction of HKUST-1 for enhancement of catalytic activity. Cu@Cu2O nanoparticles exhibited highly effective catalytic activity in oxidation of 3,5-di-tert-butylcatechol. Through this method, MOF can maintain the original core-shell structure and be used in various other reactions with enhanced catalytic activity.

  6. Formation of uniform carrot-like Cu31S16-CuInS2 heteronanostructures assisted by citric acid at the oil/aqueous interface.

    Science.gov (United States)

    Li, Yongjie; Tang, Aiwei; Liu, Zhenyang; Peng, Lan; Yuan, Yi; Shi, Xifeng; Yang, Chunhe; Teng, Feng

    2018-01-07

    A simple two-phase strategy was developed to prepare Cu 31 S 16 -CuInS 2 heterostructures (HNS) at the oil/aqueous interface, in which the In(OH) 3 phase was often obtained in the products due to the reaction between indium ions and hydroxyl ions in the aqueous phase. To prevent the formation of the In(OH) 3 phase, citric acid was incorporated into the aqueous phase to assist in the synthesis of uniform carrot-like Cu 31 S 16 -CuInS 2 semiconductor HNS at the oil/aqueous interface for the first time. By manipulating the dosage of citric acid and Cu/In precursor ratios, the morphology of the Cu 31 S 16 -CuInS 2 HNS could be tailored from mushroom to carrot-like, and the presence of citric acid played a critical role in the synthesis of high-quality Cu 31 S 16 -CuInS 2 HNS, which inhibited the formation of the In(OH) 3 phase due to the formation of the indium(iii)-citric acid complex. The formation mechanism was studied by monitoring the morphology and phase evolution of the Cu 31 S 16 -CuInS 2 HNS with reaction time, which revealed that the Cu 31 S 16 seeds were first formed and then the cation-exchange reaction directed the subsequent anisotropic growth of the Cu 31 S 16 -CuInS 2 HNS.

  7. Compound cuing in free recall.

    Science.gov (United States)

    Lohnas, Lynn J; Kahana, Michael J

    2014-01-01

    According to the retrieved context theory of episodic memory, the cue for recall of an item is a weighted sum of recently activated cognitive states, including previously recalled and studied items as well as their associations. We show that this theory predicts there should be compound cuing in free recall. Specifically, the temporal contiguity effect should be greater when the 2 most recently recalled items were studied in contiguous list positions. A meta-analysis of published free recall experiments demonstrates evidence for compound cuing in both conditional response probabilities and interresponse times. To help rule out a rehearsal-based account of these compound cuing effects, we conducted an experiment with immediate, delayed, and continual-distractor free recall conditions. Consistent with retrieved context theory but not with a rehearsal-based account, compound cuing was present in all conditions, and was not significantly influenced by the presence of interitem distractors.

  8. Corrosion behavior of Cu during graphene growth by CVD

    International Nuclear Information System (INIS)

    Dong, Yuhua; Liu, Qingqing; Zhou, Qiong

    2014-01-01

    Highlights: • Graphene films were deposited on the Cu by chemical vapor deposition method. • Annealing affects the corrosion property of Cu. • Graphene films improve corrosion performance of Cu for a short period of time. - Abstract: The corrosion performance of Cu samples may be affected by annealing at high temperatures during graphene growth via the chemical vapor deposition method. In this study, multiple graphene films were deposited on Cu and characterized by Raman spectroscopy and transmission electron microscopy. The corrosion behavior of Cu immersed in 3.5 wt.% NaCl solution was investigated using electrochemical impedance spectroscopy. The Cu morphology was observed by optical microscopy and scanning electron microscopy. Results indicated that annealing affects the corrosion process of Cu. The presence of graphene films on the Cu substrate improved the corrosion performance of the material for a short period of time

  9. Evidence of icosahedral short-range order in Zr70Cu30 and Zr70Cu29Pd1 metallic glasses

    DEFF Research Database (Denmark)

    Saksl, K.; Franz, H.; Jovari, P.

    2003-01-01

    Change in local atomic environment during crystallization of Zr-based glassy alloys was studied by extended x-ray absorption fine structure (EXAFS) spectroscopy. The formation of icosahedral quasicrystalline phase followed by crystallization of tetragonal CuZr2 has been observed in the Zr70Cu29Pd1...... glassy alloy during annealing up to 850 K. On the other hand, the binary Zr70Cu30 alloy shows a single glassy to crystalline CuZr2 phase transformation. The local atomic environment of as-quenched Zr70Cu30 alloy is matched to an icosahedral local atomic configuration, which is similar to that of the as......-quenched Zr70Cu29Pd1 alloy and the alloy annealed at 593 K containing icosahedral phase. Considering that the supercooled liquid region appears prior to crystallization in the Zr70Cu30 glassy alloy, the observed results support the theory claiming a strong correlation between the existence of local...

  10. Structural and electronic properties of Cu2Q and CuQ (Q = O, S, Se, and Te) studied by first-principles calculations

    Science.gov (United States)

    Zhao, Ting; Wang, Yu-An; Zhao, Zong-Yan; Liu, Qiang; Liu, Qing-Ju

    2018-01-01

    In order to explore the similarity, difference, and tendency of binary copper-based chalcogenides, the crystal structure, electronic structure, and optical properties of eight compounds of Cu2Q and CuQ (Q = O, S, Se, and Te) have been calculated by density functional theory with HSE06 method. According to the calculated results, the electronic structure and optical properties of Cu2Q and CuQ present certain similarities and tendencies, with the increase of atomic number of Q elements: the interactions between Cu-Q, Cu-Cu, and Q-Q are gradually enhancing; the value of band gap is gradually decreasing, due to the down-shifting of Cu-4p states; the covalent feature of Cu atoms is gradually strengthening, while their ionic feature is gradually weakening; the absorption coefficient in the visible-light region is also increasing. On the other hand, some differences can be found, owing to the different crystal structure and component, for example: CuO presents the characteristics of multi-band gap, which is very favorable to absorb infrared-light; the electron transfer in CuQ is stronger than that in Cu2Q; the absorption peaks and intensity are very strong in the ultraviolet-light region and infrared-light region. The findings in the present work will help to understand the underlying physical mechanism of binary copper-based chalcogenides, and available to design novel copper-based chalcogenides photo-electronics materials and devices.

  11. Texturization of diamond-wire-sawn multicrystalline silicon wafer using Cu, Ag, or Ag/Cu as a metal catalyst

    Science.gov (United States)

    Wang, Shing-Dar; Chen, Ting-Wei

    2018-06-01

    In this work, Cu, Ag, or Ag/Cu was used as a metal catalyst to study the surface texturization of diamond-wire-sawn (DWS) multi-crystalline silicon (mc-Si) wafer by a metal-assisted chemical etching (MACE) method. The DWS wafer was first etched by standard HF-HNO3 acidic etching, and it was labeled as AE-DWS wafer. The effects of ratios of Cu(NO3)2:HF, AgNO3:HF, and AgNO3:Cu(NO3)2 on the morphology of AE-DWS wafer were investigated. After the process of MACE, the wafer was treated with a NaF/H2O2 solution. In this process, H2O2 etched the nanostructure, and NaF removed the oxidation layer. The Si {1 1 1} plane was revealed by etching the wafer in a mixture of 0.03 M Cu(NO3)2 and 1 M HF at 55 °C for 2.5 min. These parallel Si {1 1 1} planes replaced some parallel saw marks on the surface of AE-DWS wafers without forming a positive pyramid or an inverted pyramid structure. The main topography of the wafer is comprised of silicon nanowires grown in direction when Ag or Ag/Cu was used as a metal catalyst. When silicon is etched in a mixed solution of Cu(NO3)2, AgNO3, HF and H2O2 at 55 °C with a concentration ratio of [Cu2+]/[Ag+] of 50 or at 65 °C with a concentration ratio of [Cu2+]/[Ag+] of 33, a quasi-inverted pyramid structure can be obtained. The reflectivity of the AE-DWS wafers treated with MACE is lower than that of the multiwire-slurry-sawn (MWSS) mc-Si wafers treated with traditional HF + HNO3 etching.

  12. Preparation of Cu Nanoclusters within Dendrimer Templates

    National Research Council Canada - National Science Library

    Zhao, M

    1998-01-01

    ... (16-atom Cu cluster in G4 and 64-atom Cu cluster in G6 dendrimers). The clusters remain trapped within the dendrimers for extended periods of time, do not agglomerate, and do not precipitate. The clusters can also be oxidized to yield dendrimer-encapsulated Cu(2+).

  13. Heating induced microstructural changes in graphene/Cu nanocomposites

    International Nuclear Information System (INIS)

    Solá, F; Niu, J; Xia, Z H

    2013-01-01

    Dynamic heating experiments on graphene/Cu nanocomposites by in situ scanning electron microscopy were conducted to observe the evolution of the morphology and size of the Cu nanoparticles. Microstructural characterization showed that the graphene/Cu nanocomposites system consists of graphene sheets decorated with Cu-based nanoparticles with different chemistries (Cu, Cu 2 O), shapes (cube, rod, triangle, etc) and sizes. Evidence of neck evolution, coalescence, sublimation and Ostwald ripening were observed. Interestingly, some of the events occurred at the edges of the graphene sheets. The quantitative data of necking evolution deviates from the classical continuum theory indicating that intrinsic faceting and the shape of the nanoparticles played an important role in the necking process. This was supported by molecular dynamics simulations. Experimental data of liquid-spherical nanoparticles on graphene suggested that Cu did not wet graphene. Based on sublimation experiments and surface stability, we propose that graphene decorated with Cu nanoparticles enclosed by {111} facets are the most stable nanocomposite at high temperatures. The growth mechanism of nanoparticles on graphene is discussed.

  14. Effect of the existing form of Cu element on the mechanical properties, bio-corrosion and antibacterial properties of Ti-Cu alloys for biomedical application.

    Science.gov (United States)

    Zhang, Erlin; Wang, Xiaoyan; Chen, Mian; Hou, Bing

    2016-12-01

    Ti-Cu alloys have exhibited strong antibacterial ability, but Ti-Cu alloys prepared by different processes showed different antibacterial ability. In order to reveal the controlling mechanism, Ti-Cu alloys with different existing forms of Cu element were prepared in this paper. The effects of the Cu existing form on the microstructure, mechanical, corrosion and antibacterial properties of Ti-Cu alloys have been systematically investigated. Results have shown that the as-cast Ti-Cu alloys showed a higher hardness and mechanical strength as well as a higher antibacterial rate (51-64%) but a relatively lower corrosion resistance than pure titanium. Treatment at 900°C/2h (T4) significantly increased the hardness and the strength, improved the corrosion resistance but had little effect on the antibacterial property. Treatment at 900°C/2h+400°C/12h (T6) increased further the hardness and the mechanical strength, improved the corrosion resistance and but also enhanced the antibacterial rate (>90%) significantly. It was demonstrated that the Cu element in solid solution state showed high strengthening ability but low antibacterial property while Cu element in Ti2Cu phase exhibited strong strengthening ability and strong antibacterial property. Ti2Cu phase played a key role in the antibacterial mechanism. The antibacterial ability of Ti-Cu alloy was strongly proportional to the Cu content and the surface area of Ti2Cu phase. High Cu content and fine Ti2Cu phase would contribute to a high strength and a strong antibacterial ability. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Displacement waves in La2CuO(4-delta) and La(1.85)Sr(0.15)CuO(4-delta)

    Science.gov (United States)

    Kajitani, Tsuyoshi; Onozuka, Takashi; Yamaguchi, Yasuo; Hirabayashi, Makoto; Syono, Yasuhiko

    1987-11-01

    Structural investigation of orthorhombic La2CuO(4-delta) and La(1.85)Sr(0.15)CuO(4-delta) was carried out by means of X-ray and neutron diffraction on the basis of the space group Cmmm. The periodic expansion/contraction type distortion of CuO6 octahedra was found in both orthorhombic compounds. The distortion is nearly one-dimensional in La2CuO(4-delta) but is two-dimensional in La(1.85)Sr(0.15)CuO(4-delta). The existence of a charge-density wave is highly possible in the structures.

  16. Cu charge fluctuations and anomalous behaviour in the phonon spectrum of La2CuO4

    International Nuclear Information System (INIS)

    Dobry, A.; Greco, A.; Migoni, R.; Stachiotti, M.

    1991-09-01

    The additional excitation observed in the phonon spectrum of La 2 CuO 4 is shown to arise from Cu charge fluctuations. A nonlinear breathing shell model is formulated for the coupling of these fluctuations with the lattice. The harmonic dynamics and exact nonlinear solutions are studied in a 2-D model of the CuO 2 planes. A molecular dynamics simulation shows an additional peak of nonphononic character originated by the nonlinear lattice dynamics. (author). 20 refs, 3 figs

  17. Highly stable carbon-doped Cu films on barrierless Si

    International Nuclear Information System (INIS)

    Zhang, X.Y.; Li, X.N.; Nie, L.F.; Chu, J.P.; Wang, Q.; Lin, C.H.; Dong, C.

    2011-01-01

    Electrical resistivities and thermal stabilities of carbon-doped Cu films on silicon have been investigated. The films were prepared by magnetron sputtering using a Cu-C alloy target. After annealing at 400 deg. C for 1 h, the resistivity maintains a low level at 2.7 μΩ-cm and no Cu-Si reaction is detected in the film by X-ray diffraction (XRD) and transmission electron microscopy (TEM) observations. According to the secondary ion mass spectroscopy (SIMS) results, carbon is enriched near the interfacial region of Cu(C)/Si, and is considered responsible for the growth of an amorphous Cu(C)/Si interlayer that inhibits the Cu-Si inter-diffusion. Fine Cu grains, less than 100 nm, were present in the Cu(C) films after long-term and high-temperature annealings. The effect of C shows a combination of forming a self-passivated interface barrier layer and maintaining a fine-grained structure of Cu. A low current leakage measured on this Cu(C) film also provides further evidence for the carbon-induced diffusion barrier interlayer performance.

  18. Minor-Cu doped soft magnetic Fe-based FeCoBCSiCu amorphous alloys with high saturation magnetization

    Science.gov (United States)

    Li, Yanhui; Wang, Zhenmin; Zhang, Wei

    2018-05-01

    The effects of Cu alloying on the amorphous-forming ability (AFA) and magnetic properties of the P-free Fe81Co5B11C2Si1 amorphous alloy were investigated. Addition of ≤ 1.0 at.% Cu enhances the AFA of the base alloy without significant deterioration of the soft magnetic properties. The Fe80.5Co5B11C2Si1Cu0.5 alloy with the largest critical thickness for amorphous formation of ˜35 μm possesses a high saturation magnetization (Bs) of ˜1.78 T, low coercivity of ˜14.6 A/m, and good bending ductility upon annealing in a wide temperature range of 513-553 K with maintaining the amorphous state. The fabrication of the new high-Fe-content Fe-Co-B-C-Si-Cu amorphous alloys by minor doping of Cu gives a guideline to developing high Bs amorphous alloys with excellent AFA.

  19. Simulations on Nickel target preparation and separation of Ni(II)-Cu(II) matrix for production of radioisotope "6"4Cu

    International Nuclear Information System (INIS)

    Sunarhadijoso Soenarjo; Wira Y Rahman; Sriyono; Triyanto

    2011-01-01

    The simulations on Nickel target preparation and separation of Ni(II)-Cu(II) matrix has been carried out as a preliminary study for production of medical radioisotope Cu-64 based on nuclear reaction of "6"4Ni (p,n) "6"4Cu. The nickel target preparation was performed by means of electroplating method using acidic solution of nickel chloride - boric acid mixture and basic solution of nickel sulphate - nickel chloride mixture on a silver - surfaced-target holder. The simulated solution of Ni(II) - Cu(II) matrix was considered as the solution of post-proton-irradiated nickel target containing both irradiated nickel and radioactive copper, but in the presented work the proton irradiation of nickel target was omitted, while the radioactive copper was originally obtained from neutron irradiation of CuO target. The separation of radioactive copper from the nickel target matrix was based on anion exchange column chromatography in which the radiocopper was conditioned to form anion complex CuCl_4"2"- and retained on the column while the nickel was kept in the form of Ni"2"+ cation and eluted off from the column. The retained radioactive copper was then eluted out the column in the condition of dilute HCl changing back the copper anion complex into Cu"2"+ cation. It was found that the electroplating result from the acidic solution was more satisfied than that from the basic solution. By conditioning the matrix solution at HCl 6 M, the radioactive copper was found in the forms of Cu"2"+ and CuCl_4"2"- while the nickel was totally in the form of Ni"2"+. In the condition of HCl 9 M, the radioactive copper was mostly in the form of CuCl_4"2"- while the nickel was found as both Ni"2"+ and NiCl_4"2"-. The best condition of separation was in HCl 8 M in which the radioactive copper was mostly in the form of CuCl_4"2"- while the nickel was mostly in the form of Ni"2"+. The retained CuCl_4"2"- was then changed back into Cu_2_+ cation form and eluted out the column by using HCl 0.05 M

  20. Solvothermal Synthesis of Three-Dimensional Hierarchical CuS Microspheres from a Cu-Based Ionic Liquid Precursor for High-Performance Asymmetric Supercapacitors.

    Science.gov (United States)

    Zhang, Jing; Feng, Huijie; Yang, Jiaqin; Qin, Qing; Fan, Hongmin; Wei, Caiying; Zheng, Wenjun

    2015-10-07

    It is meaningful to exploit copper sulfide materials with desired structure as well as potential application due to their cheapness and low toxicity. A low-temperature and facile solvothermal method for preparing three-dimensional (3D) hierarchical covellite (CuS) microspheres from an ionic liquid precursor [Bmim]2Cu2Cl6 (Bmim = 1-butyl-3-methylimidazolium) is reported. The formation of CuS nanostructures was achieved by decomposition of intermediate complex Cu(Tu)3Cl (thiourea = Tu), which produced CuS microspheres with diameters of 2.5-4 μm assembled by nanosheets with thicknesses of 10-15 nm. The ionic liquid, as an "all-in-one" medium, played a key role for the fabrication and self-assembly of CuS nanosheets. The alkylimidazolium rings ([Bmim](+)) were found to adsorb onto the (001) facets of CuS crystals, which inhibited the crystal growth along the [001] direction, while the alkyl chain had influence on the assembly of CuS nanosheets. The CuS microspheres showed enhanced electrochemical performance and high stability for the application in supercapacitors due to intriguing structural design and large specific surface area. When this well-defined CuS electrode was assembled into an asymmetric supercapacitor (ASC) with an activated carbon (AC) electrode, the CuS//AC-ASC demonstrated good cycle performance (∼88% capacitance after 4000 cycles) and high energy density (15.06 W h kg(-1) at a power density of 392.9 W kg(-1)). This work provides new insights into the use of copper sulfide electrode materials for asymmetric supercapacitors and other electrochemical devices.

  1. CO2 activation on bimetallic CuNi nanoparticles

    Directory of Open Access Journals (Sweden)

    Natalie Austin

    2016-10-01

    Full Text Available Density functional theory calculations have been performed to investigate the structural, electronic, and CO2 adsorption properties of 55-atom bimetallic CuNi nanoparticles (NPs in core-shell and decorated architectures, as well as of their monometallic counterparts. Our results revealed that with respect to the monometallic Cu55 and Ni55 parents, the formation of decorated Cu12Ni43 and core-shell Cu42Ni13 are energetically favorable. We found that CO2 chemisorbs on monometallic Ni55, core-shell Cu13Ni42, and decorated Cu12Ni43 and Cu43Ni12, whereas, it physisorbs on monometallic Cu55 and core-shell Cu42Ni13. The presence of surface Ni on the NPs is key in strongly adsorbing and activating the CO2 molecule (linear to bent transition and elongation of C˭O bonds. This activation occurs through a charge transfer from the NPs to the CO2 molecule, where the local metal d-orbital density localization on surface Ni plays a pivotal role. This work identifies insightful structure-property relationships for CO2 activation and highlights the importance of keeping a balance between NP stability and CO2 adsorption behavior in designing catalytic bimetallic NPs that activate CO2.

  2. Processing of R-Ba-Cu-O superconductors

    International Nuclear Information System (INIS)

    Wu, H.

    1998-01-01

    Precipitation processes were developed to introduce second phases as flux pinning centers in Gd-Ba-Cu-O and Nd-Ba-Cu-O superconductors. In Gd-Ba-Cu-O, precipitation is caused by the decrease of the upper solubility limit of Gd 1+x Ba 2-x Cu 3 O 7 solid solution (Gd123ss) in low oxygen partial pressure. Processing of supersaturated Gd 1.2 Ba 1.8 Cu 3 O 7 in low oxygen partial pressure can produce dispersed second phases. Gd211 is formed as a separate phase while extensive Gd124 type stacking fault is formed instead of a separate CuO phase. As a result of the precipitation reaction, the transition temperature and critical current density are increased. In Nd-Ba-Cu-O, precipitation is caused by the decrease of the lower solubility limit of Nd 1+x Ba 2-x Cu 3 O 7 solid solution (Nd123ss) in oxygen. DTA results reveal the relative stability of Nd123ss in different oxygen partial pressures. In 1 bar oxygen partial pressure, Nd123ss with x = 0.1 is the most stable phase. In lower oxygen partial pressures, the most stable composition shifts towards the stoichiometric composition. The relative stability changes faster with decreasing oxygen partial pressure. Therefore, processing in oxygen and air tends to produce broad superconducting transitions but sharp transitions can be achieved in 0.01 bar and 0.001 bar oxygen partial pressures. While the lower solubility limits in 0.01 bar and 0.001 bar oxygen partial pressures remain at x = 0.00, the solubility limits in oxygen and air show a narrowing with decreasing temperature. Because of the narrowing of the solubility range in oxygen, oxygen annealing of Nd123 initially processed in low oxygen partial pressures will result in precipitation of second phases. The equilibrium second phase is BaCuO 2 for temperature above 608 C, and at lower temperatures the equilibrium second phases are Ba 2 CuO 3.3 and Ba 2 Cu 3 O 5+y . However, annealing at low temperature may produce a fine metastable transition phase. A coherent intermediate

  3. Construction of Hierarchical CuO/Cu2O@NiCo2S4 Nanowire Arrays on Copper Foam for High Performance Supercapacitor Electrodes

    Science.gov (United States)

    Zhou, Luoxiao; He, Ying; Jia, Congpu; Pavlinek, Vladimir; Saha, Petr; Cheng, Qilin

    2017-01-01

    Hierarchical copper oxide @ ternary nickel cobalt sulfide (CuO/Cu2O@NiCo2S4) core-shell nanowire arrays on Cu foam have been successfully constructed by a facile two-step strategy. Vertically aligned CuO/Cu2O nanowire arrays are firstly grown on Cu foam by one-step thermal oxidation of Cu foam, followed by electrodeposition of NiCo2S4 nanosheets on the surface of CuO/Cu2O nanowires to form the CuO/Cu2O@NiCo2S4 core-shell nanostructures. Structural and morphological characterizations indicate that the average thickness of the NiCo2S4 nanosheets is ~20 nm and the diameter of CuO/Cu2O core is ~50 nm. Electrochemical properties of the hierarchical composites as integrated binder-free electrodes for supercapacitor were evaluated by various electrochemical methods. The hierarchical composite electrodes could achieve ultrahigh specific capacitance of 3.186 F cm−2 at 10 mA cm−2, good rate capability (82.06% capacitance retention at the current density from 2 to 50 mA cm−2) and excellent cycling stability, with capacitance retention of 96.73% after 2000 cycles at 10 mA cm−2. These results demonstrate the significance of optimized design and fabrication of electrode materials with more sufficient electrolyte-electrode interface, robust structural integrity and fast ion/electron transfer. PMID:28914819

  4. Construction of Hierarchical CuO/Cu2O@NiCo2S4 Nanowire Arrays on Copper Foam for High Performance Supercapacitor Electrodes

    Directory of Open Access Journals (Sweden)

    Luoxiao Zhou

    2017-09-01

    Full Text Available Hierarchical copper oxide @ ternary nickel cobalt sulfide (CuO/Cu2O@NiCo2S4 core-shell nanowire arrays on Cu foam have been successfully constructed by a facile two-step strategy. Vertically aligned CuO/Cu2O nanowire arrays are firstly grown on Cu foam by one-step thermal oxidation of Cu foam, followed by electrodeposition of NiCo2S4 nanosheets on the surface of CuO/Cu2O nanowires to form the CuO/Cu2O@NiCo2S4 core-shell nanostructures. Structural and morphological characterizations indicate that the average thickness of the NiCo2S4 nanosheets is ~20 nm and the diameter of CuO/Cu2O core is ~50 nm. Electrochemical properties of the hierarchical composites as integrated binder-free electrodes for supercapacitor were evaluated by various electrochemical methods. The hierarchical composite electrodes could achieve ultrahigh specific capacitance of 3.186 F cm−2 at 10 mA cm−2, good rate capability (82.06% capacitance retention at the current density from 2 to 50 mA cm−2 and excellent cycling stability, with capacitance retention of 96.73% after 2000 cycles at 10 mA cm−2. These results demonstrate the significance of optimized design and fabrication of electrode materials with more sufficient electrolyte-electrode interface, robust structural integrity and fast ion/electron transfer.

  5. Effect of Cooling Rate on the Longitudinal Modulus of Cu3Sn Phase of Ag-Sn-Cu Amalgam Alloy (Part II

    Directory of Open Access Journals (Sweden)

    R. H. Rusli

    2015-10-01

    Full Text Available Effects of cooling rate (at the time of solidification on the elastic constants of Cu3Sn phase of Ag-Sn-Cu dental amalgam alloy were studied. In this study, three types of alloys were made, with the composition Cu-38-37 wt% Sn by means of casting, where each alloy was subjected to different cooling rate, such as cooling on the air (AC, air blown (AB, and quenched in the water (WQ. X-ray diffraction, metallography, and Scanning Electron Microscopy with Energy Dispersive Spectroscopy studies of three alloys indicated the existence of Cu3Sn phase. Determination of the modulus of elasticity of Cu3Sn (ε phase was carried out by the measurement of longitudinal and transversal waves velocity using ultrasonic technique. The result shows that Cu3Sn (ε phase on AC gives higher modulus of elasticity values than those of Cu3Sn (ε on AB and WQ. The high modulus of elasticity value will produce a strong Ag-Sn-Cu dental amalagam alloy.

  6. A first-principles study of the possible magnetism of Rh in the Cu/Rh/Cu(001) system

    CERN Document Server

    Jang, Y R; Chang, C S; Cho, L H; Lee, J I

    1999-01-01

    Possible 4d magnetism of a Rh monolayer in a Cu/Rh/Cu(001) system is investigated using the full-potential linearized augmented-plane-wave (FLAPW) energy band method based on the local-spin-density approximation (LSDA). We have calculated the total energy of the Cu/Rh/Cu(001) system and have found that the Rh monolayer is ferromagnetic (FM) with a tiny magnetic moment. However, the total energy difference between the ferromagnetic and the paramagnetic states is found to be very small, and thus which state can be realized at room temperature is uncertain. The calculated charge densities and layer-projected density of states (LDOS) are presented and discussed in relation to the magnetic properties.

  7. First-principle Calculations of Mechanical Properties of Al2Cu, Al2CuMg and MgZn2 Intermetallics in High Strength Aluminum Alloys

    Directory of Open Access Journals (Sweden)

    LIAO Fei

    2016-12-01

    Full Text Available Structural stabilities, mechanical properties and electronic structures of Al2Cu, Al2CuMg and MgZn2 intermetallics in Al-Zn-Mg-Cu aluminum alloys were determined from the first-principle calculations by VASP based on the density functional theory. The results show that the cohesive energy (Ecoh decreases in the order MgZn2 > Al2CuMg > Al2Cu, whereas the formation enthalpy (ΔH decreases in the order MgZn2 > Al2Cu > Al2CuMg. Al2Cu can act as a strengthening phase for its ductile and high Young's modulus. The Al2CuMg phase exhibits elastic anisotropy and may act as a crack initiation point. MgZn2 has good plasticity and low melting point, which is the main strengthening phase in the Al-Zn-Mg-Cu aluminum alloys. Metallic bonding mode coexists with a fractional ionic interaction in Al2Cu, Al2CuMg and MgZn2, and that improves the structural stability. In order to improve the alloys' performance further, the generation of MgZn2 phase should be promoted by increasing Zn content while Mg and Cu contents are decreased properly.

  8. Oxygen potentials and phase equilibria of the quaternary Y-Ba-Cu-O system in the region involving the YBa2Cu3O7-x phase

    International Nuclear Information System (INIS)

    Fitzner, K.; Musbah, O.; Hsieh Kerchang; Zhang Minxian; Chang, Y.A.

    1993-01-01

    The equilibrium oxygen potentials of four-phase equilibria (counting only the condensed phases) in the CuO-Cu 2 O-BaCuO 2 -Y 2 BaCuO 5 (211)-YBa 2 Cu 3 O 7-x (123) phase region were determined using the following solid-oxide electrolyte e.m.f. cell: Pt10Rh, air (psub(O 2 )=0.21 atm) vertical stroke ZrO 2 +Y 2 O 3 vertical stroke mixtures of oxides, Pt. The oxide mixtures whose oxygen potentials were measured were CuO-Cu 2 O-211-123, CuO-Cu 2 O-BaCuO 2 -123, Cu 2 O-BaCuO 2 -211-123 and CuO-BaCuO 2 -211-123. The phase in some of the mixtures were identified by X-ray diffraction. These data were analyzed and are presented using stability diagrams, i.e., oxygen potential as a function of the reciprocal of the temperature. Extrapolation of these data for the four four-phase equilibra to high temperatures yields a metastable five-phase equilibrium, i.e., 123=CuO+Cu 2 O+BaCuO 2 +211, at ∼1243 K (970 ) and log psub(O 2 ) ∼ -1.21 (psub(O 2 )∼0.062 atm). (orig.)

  9. Magnetic excitations in CuO

    International Nuclear Information System (INIS)

    Ain, M.; Reichardt, W.; Hennion, B.; Pepy, G.; Wanklyn, B.M.

    1989-01-01

    The authors have studied the magnetic excitations of CuO both in the ordered and the paramagnetic phase. Their results demonstrate the dominance of the magnetic interaction along the 10-1 Cu-O zigzag chains. In this direction the slope of the acoustic branch is 550 neV Angstrom

  10. Is the High Cu Tolerance of Trichoderma atroviride Isolated from the Cu-Polluted Sediment Due to Adaptation? An In Vitro Toxicological Study

    International Nuclear Information System (INIS)

    Yap, C.K.; Yazdani, M.; Abdullah, F.; Tan, S.G.

    2011-01-01

    The tolerance of Cu by Trichoderma atroviride, a tolerant fungus isolated from the drainage surface sediment of the Serdang Industrial Area was investigated under in vitro conditions. Only this fungus species can tolerate up to 600 mg/ L of Cu on solid medium Potato Dextrose Agar based on the isolation of the most tolerant fungus from the polluted sediment. Toxicity test performed on T. atroviride, showed a maximum tolerance at 300 mg/L of Cu concentration when grown in liquid medium Potato Dextrose Broth (PDB). The EC 50 value of the isolate was 287.73 mg/ L of Cu concentration in PDB. The Cu concentration in the drainage surface sediment, where the T. atroviride was isolated from, was 347.64 μg/ g while the geochemical distributions of the non-resistant and resistant fractions of Cu were 99.6 and 0.4 %, respectively. The sediment data indicated that the drainage had greatly received anthropogenic Cu from the nearby industries which are involved in the manufacturing of plastics and electronic products. The present findings indicate that the high Cu tolerance showed by T. atroviride could be due to the well adaptation of the fungus to the Cu polluted sediment. Therefore, T. atroviride could be a potential bioremediator of Cu pollution in the freshwater ecosystem. (author)

  11. Synthesis of CuInSe2 thin films from electrodeposited Cu11In9 precursors by two-step annealing

    Directory of Open Access Journals (Sweden)

    TSUNG-WEI CHANG

    2014-02-01

    Full Text Available In this study, copper indium selenide (CIS films were synthesized from electrodeposited Cu-In-Se precursors by two-step annealing. The agglomeration phenomenon of the electrodeposited In layer usually occurred on the Cu surface. A thermal process was adopted to turn Cu-In precursors into uniform Cu11In9 binary compounds. After deposition of the Se layer, annealing was employed to form chalcopyrite CIS. However, synthesis of CIS from Cu11In9 requires sufficient thermal energy. Annealing temperature and time were investigated to grow high quality CIS film. Various electrodeposition conditions were investigated to achieve the proper atomic ratio of CIS. The properties of the CIS films were characterized by scanning electron microscopy (SEM, X-ray Diffraction (XRD, and Raman spectra.

  12. Inhibiting properties of benzimidazole films for Cu(II)/Cu(I) reduction in chloride media studied by RDE and EQCN techniques

    Energy Technology Data Exchange (ETDEWEB)

    Scendo, M. [Institute of Chemistry, Saint Cross Academy, ul. Checinska 5, 25020 Kielce (Poland)]. E-mail: scendo@pu.kielce.pl; Hepel, M. [Department of Chemistry, State University of New York, Potsdam, NY 13676, USA (United States)

    2007-08-15

    The effects of benzimidazole (BIM) and 2-methylbenzimidazole (MBIM) on the electroreduction of Cu(II) on a rotating Pt disk electrode in chloride media were investigated. These studies were undertaken in conjunction with earlier observation that these imidazole derivatives act as inhibitors of copper corrosion processes and are non-toxic. We have found that BIM and MBIM also form adsorption films on Pt, which are able to inhibit one-electron reduction of Cu(II) to Cu(I) and prevent the development of convective diffusion limiting current wave. The inhibition was found to be controlled by field-assisted mass transfer in the film. The ingress of Cu(II) species into the film was detected using the EQCN technique. The EQCN measurements indicate that small fraction of Cu(I) formed in the film by reduction of Cu(II) is retained in the film, most likely in the form of CuCl. The uptake of CuCl by inhibitor films diminishes in strongly inhibiting films (e.g., in acidic medium). The inhibition effectiveness of Cu(II) reduction process by Pt vertical bar BIM and Pt vertical bar MBIM films increases strongly with increasing acidity of the medium in the pH range from 3.0 to 1.0. The mechanism of this remarkable pH effect has been proposed. It is based on charge and pH-induced film restructuring, including changes in orientation and protonation of BIM molecules in the film.

  13. The optoelectronic properties and role of Cu concentration on the structural and electrical properties of Cu doped ZnO nanoparticles

    Science.gov (United States)

    Omri, K.; Bettaibi, A.; Khirouni, K.; El Mir, L.

    2018-05-01

    In the current study, we synthesized a Cu-doped ZnO (CZO) nanoparticles material using a sol-gel method with different doping concentrations of Cu (0, 2, 3 and 4 at.%). The control of the Cu concentration on structural, electrical and optical properties of CZO nanoparticles was investigated in detail. The XRD analysis of the CZO nanoparticles reveals the formation of ZnO hexagonal wurtzite structure for all samples which confirm the incorporation of Cu2+ ions into the ZnO lattice by substitution. Furthermore, CZO nanoparticles showed a small red shift of absorption band with the incorporation of Cu from 0 to 4 at.%; i.e. a decreased band gap value from 3.34 eV to 3.27 eV with increasing of Cu doping content. The frequency dispersion of the electric conductivity were studied using the Jonscher universal power law, according to relation σ(ω) = σDC + A ωs(T). Alternative current conductivity increases with increasing Cu content in spite of the decrease the activation energy with copper loading. It was found that the conductivity reached its maximum value for critical Cu concentration of 3 at.%. The frequency relaxation phenomenon was also investigated and all results were discussed in term of the copper doping concentration.

  14. Temperature stability of AgCu nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Sopoušek, Jiří, E-mail: sopousek@mail.muni.cz; Zobač, Ondřej; Vykoukal, Vít [Masaryk University, Department of Chemistry, Faculty of Science (Czech Republic); Buršík, Jiří; Roupcová, Pavla [Institute of Physics of Materials ASCR (Czech Republic); Brož, Pavel; Pinkas, Jiří [Masaryk University, Department of Chemistry, Faculty of Science (Czech Republic); Vřešťál, Jan [Masaryk University, Central European Institute of Technology, CEITEC (Czech Republic)

    2015-12-15

    The colloidal solutions of the Ag–Cu nanoparticles (NPs, 10–32 nm) were prepared by solvothermal reactions. The samples of dried AgCu NPs and the resulting microstructures after heat treatment in air were investigated by various methods including electron microscopy (TEM, SEM) and high-temperature X-ray powder diffraction (HTXRD). The AgCu randomly mixed, Cu-rich, and Ag-rich face centred cubic crystal lattices were detected during the experiments. The temperature induced sintering was observed experimentally by HTXRD at 250 °C. The phase transformations at high temperatures were monitored by differential scanning calorimetry. The formation of the Ag-rich grains during heating in air and evolution of copper oxide microstructure were detected.Graphical abstract.

  15. Thermodynamic analysis of the Cu2S-Cu2Te system using dissociation pressure data

    International Nuclear Information System (INIS)

    Glazov, V.M.; Pashinkin, A.S.; Burkhanov, A.S.; Saleeva, N.M.

    1978-01-01

    The Knudsen effusive method has been used for studying the dissociation pressure in the Cu 2 S-Cu 2 Te system, and on the basis of the experimental data obtained, the tellurium activity in the system and the mixing energy have been calculated. The dissociation pressure of pure components and alloys containing 10, 30, 50, 70, and 90 mol% of copper telluride within the temperature range of 750-1200 deg C has been studied. A smooth character of the concentration dependence of tellurium activity is observed, which points to the formation of a continuous series of solid solutions in the Cu 2 S-Cu 2 Te system within the temperature range studied. The data on the mixing energy in the system show a good agreement of the values obtained from the dissociation pressure with those determined from the fusibility diagram. The results indicate that the system in question is described well within the framework of the model of regular solutions

  16. Oxygen isotope effect in YBa2Cu3O7 prepared by burning YBa2Cu3 in 16O and 18O

    Science.gov (United States)

    Yvon, Pascal J.; Schwarz, R. B.; Pierce, C. B.; Bernardez, L.; Conners, A.; Meisenheimer, R.

    1989-04-01

    We prepared YBa2Cu3 powder by ball milling a 2:1 molar mixture of the intermetallics BaCu and CuY. We synthesized YBa2Cu3(16O)7-x and YBa2Cu3(18O)7-x by oxidizing the YBa2Cu3 powder in 16O and 18O. The 16O/18O ratios were determined by laser-ionization and sputtering-ionization mass spectroscopy. The YBa2Cu3(160)7-x sample had 99.8 at. %16O, and the YBa2Cu3(18O)7-x sample had 96.5 at. %18O. Susceptibility measurements of the superconducting transition temperature (Tc=91.7 K for 16O; half-point transition at 84 K show an isotope effect of 0.4+/-0.1 K.

  17. Transient and modulated charge separation at CuInSe{sub 2}/C{sub 60} and CuInSe{sub 2}/ZnPc hybrid interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Morzé, Natascha von, E-mail: natascha.von_morze@helmholtz-berlin.de; Dittrich, Thomas, E-mail: dittrich@helmholtz-berlin.de; Calvet, Wolfram, E-mail: wolfram.calvet@helmholtz-berlin.de; Lauermann, Iver, E-mail: iver.lauermann@helmholtz-berlin.de; Rusu, Marin, E-mail: rusu@helmholtz-berlin.de

    2017-02-28

    Highlights: • Surface physical properties of non- and Na-treated CuInSe{sub 2} layers studied. • Evidence of exciton dissociation and charge separation at CuInSe{sub 2}/ZnPc interface. • Strong band bending at the CuInSe{sub 2} surface in contact with C{sub 60} observed. • No evidence for exciton dissociation at the CuInSe{sub 2}/C{sub 60} interface found. • Cu-poor phase at CuInSe{sub 2}/organic interface crucial for charge separation. - Abstract: Spectral dependent charge transfer and exciton dissociation have been investigated at hybrid interfaces between inorganic polycrystalline CuInSe{sub 2} (untreated and Na-conditioned) thin films and organic C{sub 60} as well as zinc phthalocyanine (ZnPc) layers by transient and modulated surface photovoltage measurements. The stoichiometry and electronic properties of the bare CuInSe{sub 2} surface were characterized by photoelectron spectroscopy which revealed a Cu-poor phase with n-type features. After the deposition of the C{sub 60} layer, a strong band bending at the CuInSe{sub 2} surface was observed. Evidence for dissociation of excitons followed by charge separation was found at the CuInSe{sub 2}/ZnPc interface. The Cu-poor layer at the CuInSe{sub 2} surface was found to be crucial for transient and modulated charge separation at CuInSe{sub 2}/organic hybrid interfaces.

  18. Phase Equilibria of Sn-Co-Cu Ternary System

    Science.gov (United States)

    Chen, Yu-Kai; Hsu, Chia-Ming; Chen, Sinn-Wen; Chen, Chih-Ming; Huang, Yu-Chih

    2012-10-01

    Sn-Co-Cu ternary alloys are promising lead-free solders, and isothermal sections of Sn-Co-Cu phase equilibria are fundamentally important for the alloys' development and applications. Sn-Co-Cu ternary alloys were prepared and equilibrated at 523 K, 1073 K, and 1273 K (250 °C, 800 °C, and 1000 °C), and the equilibrium phases were experimentally determined. In addition to the terminal solid solutions and binary intermetallic compounds, a new ternary compound, Sn3Co2Cu8, was found. The solubilities of Cu in the α-CoSn3 and CoSn2 phases at 523 K (250 °C) are 4.2 and 1.6 at. pct, respectively, while the Cu solubility in the α-Co3Sn2 phase is as high as 20.0 at. pct. The Cu solubility increases with temperature and is around 30.0 at. pct in the β-Co3Sn2 at 1073 K (800 °C). The Co solubility in the η-Cu6Sn5 phase is also significant and is 15.5 at. pct at 523 K (250 °C).

  19. Surface plasmon resonance enhanced visible-light-driven photocatalytic activity in Cu nanoparticles covered Cu{sub 2}O microspheres for degrading organic pollutants

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Yahui, E-mail: chengyahui@nankai.edu.cn [Department of Electronics and Key Laboratory of Photo-Electronic Thin Film Devices and Technology of Tianjin, Nankai University, Tianjin 300071 (China); Lin, Yuanjing [Department of Electronics and Key Laboratory of Photo-Electronic Thin Film Devices and Technology of Tianjin, Nankai University, Tianjin 300071 (China); Xu, Jianping [Institute of Material Physics, Key Laboratory of Display Materials and Photoelectric Devices, Ministry of Education, Tianjin University of Technology, Tianjin 300384 (China); He, Jie; Wang, Tianzhao; Yu, Guojun; Shao, Dawei; Wang, Wei-Hua; Lu, Feng [Department of Electronics and Key Laboratory of Photo-Electronic Thin Film Devices and Technology of Tianjin, Nankai University, Tianjin 300071 (China); Li, Lan [Institute of Material Physics, Key Laboratory of Display Materials and Photoelectric Devices, Ministry of Education, Tianjin University of Technology, Tianjin 300384 (China); Du, Xiwen [School of Material Science and Engineering, Tianjin University, Tianjin 300072 (China); Wang, Weichao [Department of Electronics and Key Laboratory of Photo-Electronic Thin Film Devices and Technology of Tianjin, Nankai University, Tianjin 300071 (China); Liu, Hui, E-mail: liuhui@nankai.edu.cn [Department of Electronics and Key Laboratory of Photo-Electronic Thin Film Devices and Technology of Tianjin, Nankai University, Tianjin 300071 (China); Zheng, Rongkun [School of Physics, The University of Sydney, Sydney, NSW 2006 (Australia)

    2016-03-15

    Graphical abstract: - Highlights: • Cu NPs introduce the SPR and result in an increase of visible light absorption. • The photocatalytic activity of Cu{sub 2}O/Cu improves greatly due to the SPR effect. • A dark catalytic activity is observed stemming from the Fenton-like reaction. • The • O{sub 2}{sup −} and • OH radicals contribute to the photocatalytic process. • The • OH radicals contribute to the dark catalytic process. - Abstract: Micron-sized Cu{sub 2}O with different coverage of Cu nanoparticles (NPs) on the sphere has been synthesized by a redox procedure. The absorption spectra show that Cu NPs induce the surface plasmon resonance (SPR) at the wavelength of ∼565 nm. Methylene blue (MB) photodegrading experiments under visible-light display that the Cu{sub 2}O–Cu–H{sub 2}O{sub 2} system exhibits a superior photocatalytic activity to Cu{sub 2}O–H{sub 2}O{sub 2} or pure H{sub 2}O{sub 2} with an evident dependency on Cu coverage. The maximum photodegradation rate is 88% after visible-light irradiating for 60 min. The role of the Cu NPs is clarified through photodegradation experiments under 420 nm light irradiation, which is different from the SPR wavelength of Cu NPs (∼565 nm). By excluding the SPR effect, it proves that Cu SPR plays a key role in the photodegradation. Besides, a dark catalytic activity is observed stemming from the Fenton-like reaction with the aid of H{sub 2}O{sub 2}. The radical quenching experiments indicate that both • O{sub 2}{sup −} and • OH radicals contribute to the photocatalysis, while the dark catalysis is only governed by the • OH radicals, leading to a lower activity comparing with the photocatalysis. Therefore, with introducing Cu NPs and H{sub 2}O{sub 2}, the Cu{sub 2}O-based photocatalytic activity could be significantly improved due to the SPR effect and dark catalysis.

  20. Preparation of 64Cu based on nuclear reaction of 64Ni (p,n) 64Cu: Simulations of target preparation and radionuclidic separation

    International Nuclear Information System (INIS)

    Sunarhadijoso Soenarjo; Wira Y Rahman; Sriyono; Triyanto

    2010-01-01

    As a preliminary study for production technology of 64 Cu based on nuclear reaction of 64 Ni (p,n) 64 Cu, the nickel targets were prepared by electroplating method using acidic solution of nickel chloride - boric acid and basic solution of nickel sulphate - nickel chloride mixtures on a silver-surfaced target holder. The simulated solution of Ni(II) - Cu(II) matrix was considered as the solution of post-proton-irradiated nickel containing radioactive copper. In the presented work the irradiation of nickel target was omitted, while the radioactive copper was obtained from neutron irradiation of CuO target. The separation of radioactive copper was based on anion exchange column chromatography in which the radiocopper was conditioned to form CuCl 4 2- anion complex, while the nickel was kept as Ni 2+ cation. It was found that the electroplating deposit from the acidic solution was better than that form the basic solution. By conditioning the matrix solution in 6 M HCl, the radioactive copper was indicated in the forms of Cu 2+ and CuCl 4 2- while the nickel was in the form of Ni 2+ . In the condition of 9 M HCl, the radioactive copper was in the form of CuCl 4 2- , while the nickel was found as both Ni 2+ and CuCl 4 2- . The best condition of separation was in 8 M HCl in which the radioactive copper was in the form of CuCl 4 2- , while the nickel was in the form of Ni 2+ . The retained CuCl 4 2- was then changed back into Cu 2+ cation and eluted out from the column by using 0.05 M HCl. The γ-spectrometric analysis showed a single strong peak at 511 keV in accordance to γ-annihilation peak coming from positron decay of 64 Cu, and a very weak peak at 1346 keV related to γ-ray from internal energy transition of 64 Cu. (author)

  1. 27Al, 63Cu NMR spectroscopy and electrical transport in Heusler Cu-Mn-Al alloy powders

    Science.gov (United States)

    Nadutov, V. M.; Perekos, A. O.; Kokorin, V. V.; Trachevskii, V. V.; Konoplyuk, S. M.; Vashchuk, D. L.

    2018-02-01

    The ultrafine powder of the Heusler Cu-13,1Mn-12,6Al (wt.%) alloy produced by electrical spark dispersion (ESD) in ethanol and the pellets prepared by pressing of the powders and aged in various gas environment (air, Ar, vacuum) were studied by XRD, nuclear magnetic resonance, magnetic and electric transport methods. The constituent phases were identified as b.c.c. α-Cu-Mn-Al, f.c.c. γ-Cu-Mn-Al, Cu2MnAl, and oxides. The sizes of the coherently scattering domains (CSD) and the saturation magnetizations were in the range of 4-90 nm and 0-1.5 Am2/kg, respectively. 27Al and 63Cu NMR spectra of the powders and pellets have shown hyperfine structure caused by contributions from atomic nuclei of the constituent phases. The aging of pellets in different gas environments had effect on their phase composition but no effect on dispersion of the phases. In contrast to the as-cast alloy, electrical resistance of the pellets evidenced semiconducting behavior at elevated temperatures due to the presence of metal oxides formed on the surfaces of nanoparticles.

  2. New insight on the local structure of Cu{sup 2+} ion in the solution of CuBr{sub 2} by EXAFS studies

    Energy Technology Data Exchange (ETDEWEB)

    Yu Meijuan; Chu Wangsheng; Chen Xing; Wu Ziyu, E-mail: wuzy@ustc.edu.c [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049 (China)

    2009-11-15

    CuBr{sub 2} solutions at different concentrations were studied by extended X-ray absorption fine structure (EXAFS) at the Cu K edge. In the saturated solution Cu{sup 2+} ions have chemical bonds with 3.0 oxygen atoms and 0.9 Br ion at about 1.96 A and 2.42 A, respectively. It indicates that the CuBr{sub 4}{sup -2} configuration exists with a ratio of 25% under this condition. In the dilute solutions no evidence of Br ions contributions in the first shell around Cu{sup 2+} ions occurs. The almost identical X-ray absorption near edge structure (XANES) and EXAFS characters address similar local environments around Cu{sup 2+} in agreement with results of the EXAFS fit taking into account only the contributions of Cu-O bonds.

  3. Superparamagnetism in CuFeInTe{sub 3} and CuFeGaTe{sub 3} alloys

    Energy Technology Data Exchange (ETDEWEB)

    Grima-Gallardo, P.; Alvarado, F.; Munoz, M.; Duran, S.; Quintero, M.; Nieves, L.; Quintero, E.; Tovar, R.; Morocoima, M. [Centro de Estudios en Semiconductores (CES), Fac. Ciencias, Dpto. Fisica, Universidad de Los Andes, Merida (Venezuela); Ramos, M.A. [Laboratorio de Difraccion y Fluorescencia de Rayos-X, Instituto Zuliano de Investigaciones Tecnologicas (INZIT), La Canada de Urdaneta, Estado Zulia (Venezuela)

    2012-06-15

    The temperature dependencies of DC magnetic susceptibilities, {chi}(T), of CuFeInTe{sub 3} and CuFeGaTe{sub 3} alloys were measured in a SQUID apparatus using the protocol of field cooling (FC) and zero FC (ZFC). The FC curves of both samples reflect a weak ferromagnetic (or ferrimagnetic) behavior with a nearly constant value of {chi}(T) in the measured temperature range (2-300 K) indicating that the critical temperatures (T{sub c}) are >300 K. The ZFC curves diverges from FC, showing irreversibility temperatures (T{sub irr}) of {proportional_to}250 K for CuFeInTe{sub 3} and >300 K for CuFeGaTe{sub 3}, suggesting that we are dealing with cluster-glass systems in a superparamagnetic state. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  4. Chemical reactivities of the superconducting oxides, YBa2Cu3Oy and BiSrCaCu2Oy

    International Nuclear Information System (INIS)

    Toyama, Hisashi; Mizuno, Noritaka; Misono, Makoto

    1989-01-01

    The chemical reactivities of YBa 2 Cu 3 O y and BiSrCaCu 2 O y with various gases have been studied. It was found that large quantities of NO, CO, and NO 2 were rapidly absorbed (or intercalated) in the bulk of YBa 2 Cu 3 O y (T c : 90 K) at 573 K. The amount absorbed was in the order NO ∼ CO ∼ NO 2 > O 2 ∼ CO 2 > N 2 O ∼ 0. The amount for NO was more than two times the amount of YBa 2 Cu 3 O y in molar ratio and elongation by about 0.2 angstrom along c-axis was observed. NO absorbed was almost completely recovered as NO by the evacuation at 773 K. This absorption-desorption cycle proceeded reversively. The electronic resistivity at 573 K of YBa 2 Cu 3 O y increased upon the NO absorption and was restored by the evacuation at 773 K. CO was also absorbed rapidly accompanied by evolution of CO 2 . BiSrCaCu 2 O y did not absorb either NO or CO

  5. Zr-(Cu,Ag)-Al bulk metallic glasses

    International Nuclear Information System (INIS)

    Jiang, Q.K.; Wang, X.D.; Nie, X.P.; Zhang, G.Q.; Ma, H.; Fecht, H.-J.; Bendnarcik, J.; Franz, H.; Liu, Y.G.; Cao, Q.P.; Jiang, J.Z.

    2008-01-01

    In this paper, we report the formation of a series Zr-(Cu,Ag)-Al bulk metallic glasses (BMGs) with diameters at least 20 mm and demonstrate the formation of about 25 g amorphous metallic ingots in a wide Zr-(Cu,Ag)-Al composition range using a conventional arc-melting machine. The origin of high glass-forming ability (GFA) of the Zr-(Cu,Ag)-Al alloy system has been investigated from the structural, thermodynamic and kinetic points of view. The high GFA of the Zr-(Cu,Ag)-Al system is attributed to denser local atomic packing and the smaller difference in Gibbs free energy between amorphous and crystalline phases. The thermal, mechanical and corrosion properties, as well as elastic constants for the newly developed Zr-(Cu,Ag)-Al BMGs, are also presented. These newly developed Ni-free Zr-(Cu,Ag)-Al BMGs exhibit excellent combined properties: strong GFA, high strength, high compressive plasticity, cheap and non-toxic raw materials and biocompatible property, as compared with other BMGs, leading to their potential industrial applications

  6. Electronic structures of the YBa2Cu3O7-x surface and its modification by sputtering and adatoms of Ti and Cu

    Science.gov (United States)

    Meyer, H. M., III; Hill, D. M.; Wagener, T. J.; Gao, Y.; Weaver, J. H.; Capone, D. W., II; Goretta, K. C.

    1988-10-01

    We present x-ray and inverse photoemission results for fractured surfaces of YBa2Cu3O6.9 before and after surface modification by Ar ion bombardment and the deposition of adatoms of Ti and Cu. Representative results are compared for samples prepared in three different ways. Two of the sample types exhibit substantial emission from grain-boundary phases because of both intergranular and transgranular fracture; they produce results that are very similar to those presented thus far in the literature. A third type was nearly free of contamination and clearly showed spectral features characteristic of the superconductor. Comparison of these nearly contamination-free valence-band results to those for clean La1.85Sr0.15CuO4 shows remarkably similar x-ray photoemission spectroscopy densities of states, with subtle differences near the Fermi level and at 3 eV. Inverse photoemission results show the top of the Cu-O hybrid orbitals to be 2 eV above EF and the empty states of Y and Ba at higher energy. Comparison with one-electron densities of states shows reasonable agreement, but there are large differences within the set of calculated results, and it is unclear from the valence bands alone how to account for final-state Cu d-d Coulomb correlation effects (satellite features show these effects very clearly). Argon sputtering for both types of samples shows destruction of the superconductor, with differences that can be related to sample surface quality. The deposition of adatoms of Ti and Cu results in reaction associated with oxygen withdrawal from the near-surface region. Studies of the Cu 2p3/2 line shape show that the deposition of as little as ~1 monolayer equivalent of Ti or Cu reduces the formal Cu2+ emission within the probed volume (30-50 Å deep). Core-level analysis shows that this chemical reduction of Cu is accompanied by crystal-structure modifications as well. Studies of Cu adatom interactions reveal the progression from Cu2+ to Cu1+ and ultimately, to Cu

  7. Basic characterization of 64Cu-ATSM as a radiotherapy agent

    International Nuclear Information System (INIS)

    Obata, Atsushi; Kasamatsu, Shingo; Lewis, Jason S.; Furukawa, Takako; Takamatsu, Shinji; Toyohara, Jun; Asai, Tatsuya; Welch, Michael J.; Adams, Susan G.; Saji, Hideo; Yonekura, Yoshiharu; Fujibayashi, Yasuhisa

    2005-01-01

    64 Cu-diacetyl-bis(N 4 -methylthiosemicarbazone) ( 64 Cu-ATSM) is a promising radiotherapy agent for the treatment of hypoxic tumors. In an attempt to elucidate the radiobiological basis of 64 Cu-ATSM radiotherapy, we have investigated the cellular response patterns in vitro cell line models. Cells were incubated with 64 Cu-ATSM, and the dose-response curves were obtained by performing a clonogenic survival assay. Radiation-induced damage in DNA was evaluated using the alkali comet assay and apoptotic cells were detected using Annexin V-FITC and propidium iodide staining methods. Washout rate and subcellular distribution of 64 Cu in cells were investigated to further assess the effectiveness of 64 Cu-ATSM therapy on a molecular basis. A direct comparison of subcellular localization of Cu-ATSM was made with the flow tracer analog Cu-pyruvladehyde-bis(N 4 -methylthiosemicarbazone). In this study, 64 Cu-ATSM was shown to reduce the clonogenic survival rate of tumor cells in a dose-dependent manner. Under hypoxic conditions, cells took up 64 Cu-ATSM and radioactive 64 Cu was highly accumulated in the cells. In the 64 Cu-ATSM-treated cells, DNA damage by the radiation emitted from 64 Cu was detected, and inhibition of cell proliferation and induction of apoptosis was observed at 24 and 36 h after the treatment. The typical features of postmitotic apoptosis induced by radiation were observed following 64 Cu-ATSM treatment. The majority of the 64 Cu taken up into the cells remained in the postmitochondrial supernatant (the cellular residue after removal of the nuclei and mitochondria), which indicates that the β - particle emitted from 64 Cu may be as effective as the Auger electrons in 64 Cu-ATSM therapy. These data allow us to postulate that 64 Cu-ATSM will be able to attack the hypoxic tumor cells directly, as well as potentially affecting the peripheral nonhypoxic regions indirectly by the β - particle decay of 64 Cu

  8. Formation of aluminium nitride and segregation of Cu impurity atoms in aluminium implanted by high dose nitrogen ions

    International Nuclear Information System (INIS)

    Lin Chenglu; Hemment, P.L.F.; Li Jinhua; Zou Shichang

    1994-01-01

    Aluminium films with a thickness of 7000 A (containing 0.85% copper) were deposited on silicon substrates. 400 keV N 2 + or 350 keV N + ions were implanted into the aluminium films or at the interface between the aluminium and silicon, respectively. Automatic spreading resistance (ASR), Fourier transform infrared spectroscopy (FTIR) and Rutherford backscattering (RBS) and channelling were used to characterize the formation of aluminium nitride and the depth distribution of the Cu impurity in the aluminium films after ion implantation and post-annealing. The formation of a stoichiometric AlN layer with high resistance was evident from ASR, RBS analysis and FTIR measurements by the presence of the absorption band at 650 cm -1 . When the implanted nitrogen is near the interface between the aluminium and silicon, a multilayer structure can be obtained, which consists of aluminium, aluminium nitride and the silicon substrate. Cu, which is a background impurity in the deposited aluminium films, segregated into the synthesised aluminium nitride during high dose nitrogen ion implantation. This is due to irradiation-induced segregation during ion implantation. (orig.)

  9. CuO cauliflowers for supercapacitor application: Novel potentiodynamic deposition

    International Nuclear Information System (INIS)

    Dubal, Deepak P.; Gund, Girish S.; Lokhande, Chandrakant D.; Holze, Rudolf

    2013-01-01

    Graphical abstract: Schematic experimental setup used for the potentiodynamic mode of electrodeposition for the synthesis of CuO cauliflower onto stainless steel substrate. Highlights: ► Synthesis of CuO using potentiodynamic mode of electrodeposition. ► Uniformly spread cauliflower-like nanostructure. ► CuO cauliflowers provide high specific capacitance with good stability. ► CuO cauliflowers show high power and energy density values. -- Abstract: In present investigation, synthesis and characterization of novel cauliflower-like copper oxide (CuO) and its electrochemical properties have been performed. The utilized CuO cauliflowers were prepared by potentiodyanamic mode from an aqueous alkaline bath. X-ray diffraction pattern confirm the formation of monoclinic CuO cauliflowers. Scanning electron micrograph analysis reveals that CuO cauliflowers are uniformly spread all over the substrate surface with the surface area of 49 m 2 g −1 with bimodal pore size distribution. Electrochemical analysis shows that CuO cauliflower exhibits high specific capacitance of 179 Fg −1 in 1 M Na 2 SO 4 electrolyte with 81% capacity retention after 2000 cycles. The Ragone plot discovers better power and energy densities of cauliflowers-like CuO sample. Present investigation illustrates that the potentiodynamic approach for the direct growth of cauliflower-like CuO is simple and cost-effective and can be applied for synthesis of other metal oxides, polymers etc.

  10. ECAE-processed Cu-Nb and Cu-Ag nanocomposite wires for pulse magnet applications

    International Nuclear Information System (INIS)

    Edgecumbe Summers, T.S.; Walsh, R.P.; Pernambuco-Wise, P.

    1997-01-01

    Cu-Nb and Cu-Ag nanocomposites have recently become of interest to pulse magnet designers because of their unusual combination of high strength with reasonable conductivity. In the as-cast condition, these conductors consist of two phases, one of almost pure Nb (or Ag) and the other almost pure Cu. When these castings are cold worked as in a wire-drawing operation for example, the two phases are drawn into very fine filaments which produce considerable strengthening without an unacceptable decrease in conductivity. Unfortunately, any increase in strength with operations such as wire drawing is accompanied by a reduction in the cross section of the billet, and thus far, no wires with strengths on the order of 1.5 GPa or more have been produced with cross sections large enough to be useful in magnet applications. Equal Channel Angular Extrusion (ECAE) is an innovative technique which allows for the refinement of the as-cast ingot structure without a reduction in the cross sectional dimensions. Samples processed by the ECAE technique prior to wire drawing should be stronger at a given wire diameter than those processed by wire drawing alone. The tensile properties of wire-drawn Cu-18%Nb and Cu-25%Ag both with and without prior ECAE processing were tested and compared at both room temperature and 77K. All samples were found to have resistivities consistent with their strengths, and the strengths of the ECAE-processed wires were significantly higher than their as-cast and drawn counterparts. Therefore, with ECAE processing prior to wire drawing, it appears to be possible to make high-strength conductors with adequately large cross sections for pulse magnets

  11. Cu-O network dependence of optical charge-transfer gaps and spin-pair excitations in single-CuO2-layer compounds

    International Nuclear Information System (INIS)

    Tokura, Y.; Koshihara, S.; Arima, T.; Takagi, H.; Ishibashi, S.; Ido, T.; Uchida, S.

    1990-01-01

    Spectra of optical conductivity and magnon Raman scattering have been investigated in single crystals of a parent family of cuprate superconductors with various types of Cu-O single-layer networks. The analysis of the spectra shows the systematic dependence of the charge-transfer gaps and covalent character of Cu-O bonds on the pattern of the Cu-O network, while the spin-exchange energy is rather convergent for all the single-CuO 2 -sheet compounds

  12. 139La and 63Cu NMR investigation of charge order in La2CuO4 +y (Tc=42 K)

    Science.gov (United States)

    Imai, T.; Lee, Y. S.

    2018-03-01

    We report 139La and 63Cu NMR investigation of the successive charge order, spin order, and superconducting transitions in superoxygenated La2CuO4 +y single crystal with stage-4 excess oxygen order at Tstage≃290 K. We show that the stage-4 order induces tilting of CuO6 octahedra below Tstage, which in turn causes 139La NMR line broadening. The structural distortion continues to develop far below Tstage, and completes at Tcharge≃60 K, where charge order sets in. This sequence is reminiscent of the the charge-order transition in Nd codoped La1.88Sr0.12CuO4 that sets in once the low-temperature tetragonal phase is established. We also show that the paramagnetic 63Cu NMR signals are progressively wiped out below Tcharge due to enhanced low-frequency spin fluctuations in charge-ordered domains, but the residual 63Cu NMR signals continue to exhibit the characteristics expected for optimally doped superconducting CuO2 planes. This indicates that charge order in La2CuO4 +y does not take place uniformly in space. In addition, unlike the typical second-order magnetic phase transitions, low-frequency Cu spin fluctuations as probed by 139La nuclear spin-lattice relaxation rate do not exhibit critical divergence at Tspin(≃Tc ) =42 K. These findings, including the spatially inhomogeneous nature of the charge-ordered state, are qualitatively similar to the case of La1.885Sr0.115CuO4 [Imai et al., Phys. Rev. B 96, 224508 (2017), 10.1103/PhysRevB.96.224508 and Arsenault et al., Phys. Rev. B 97, 064511 (2018), 10.1103/PhysRevB.97.064511], but both charge and spin order take place more sharply in the present case.

  13. High spin states in 62Cu

    International Nuclear Information System (INIS)

    Tsan Ung Chan; Agard, M.; Bruandet, J.F.; Giorni, A.; Glasser, F.; Longequeue, J.P.; Morand, C.

    1977-06-01

    The 62 Cu nucleus has been studied via the reactions 60 Ni(α,pnγ), 63 Cu(p,pnγ), 52 Cr( 14 N,2p2nγ) using different in beam γ-spectroscopy techniques. The intensity of the principal γ-lines observed in different reactions leading to the 62 Cu has been compared. A brief discussion is made in terms of the independent particle model. A level scheme including levels with spin up to 9 + is proposed [fr

  14. Cohesion strength and atomic structure of W-Cu graded interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Liang, C.P.; Fan, J.L.; Gong, H.R., E-mail: gonghr@csu.edu.cn

    2017-04-15

    W-Cu graded interface is a solution to big differences of properties between W and Cu, while the number and composition of graded layers in the literature are quite different. The present first principles calculation reveals that W-rich graded interfaces possess higher strength and lower interface energy than Cu-rich counterparts. It shows that the differences of thermal expansion and Young’s modulus between overlayer and substrate are decisive factors in the design of Cu-rich and W-rich graded interfaces, respectively. A graded structure of W{sub 8}Cu{sub 1}/W{sub 7}Cu{sub 2}/W{sub 6}Cu{sub 3}/Cu{sub 6}W{sub 3}/Cu{sub 8}W{sub 1} is therefore suggested theoretically.

  15. Cu-NMR study on disordered Sr14Cu24O41

    International Nuclear Information System (INIS)

    Ohsugi, S.; Matsumoto, S.; Kitaoka, Y.; Matsuda, M.; Uehara, M.; Akimitsu, J.; Nagata, T.

    2002-01-01

    The ladder-Cu NMR spectrum of a structural disordered single crystal Sr 14 Cu 24 O 41 (Sr14-B) under a magnetic field H∝11 T gradually splits into two spectra with Curie-like broadening as T decreases from T SP ∝150 K. Short-range (SR) staggered polarization (SP) on the ladder planes, originating from single-hole localization, occurs. The separation of the Sr14-B spectrum ΔH deviates from the Curie-like T dependence below 20 K. This assures that spontaneous moments appear below T N ∝20 K in H∝11 T. (orig.)

  16. Lack of dependence between intrinsic magnetic damping and perpendicular magnetic anisotropy in Cu(t{sub Cu})/[Ni/Co]{sub N} multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Minghong [Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Department of Optical Science and Engineering, Fudan University, Shanghai 200433 (China); Li, Wei [State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062 (China); Ren, Yang [School of Physics and Astronomy, Yunnan University, Kunming 650000 (China); Zhang, Zongzhi, E-mail: zzzhang@fudan.edu.cn [Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Department of Optical Science and Engineering, Fudan University, Shanghai 200433 (China); Jin, Q.Y. [Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Department of Optical Science and Engineering, Fudan University, Shanghai 200433 (China)

    2017-04-15

    The correlation between magnetic damping and perpendicular magnetic anisotropy has been investigated in Cu(t{sub Cu})/[Ni/Co]{sub N} multilayers by time-resolved magneto-optical Kerr effect. The uniaxial magnetic anisotropy constant K{sub u} is varied in the range of 3.0–3.6 Merg/cm{sup 3} by tuning either multilayer repetition number N or Cu thickness t{sub Cu}. It is found that the PMA strength K{sub u} increases with the increase of N, while the damping constant α{sub 0} keeps nearly a constant of 0.025, implying the intrinsic damping is independent of the K{sub u} tuned by N. In contrast, as t{sub Cu} increases from 2.5 to 20 nm, the α{sub 0} value rises continuously up to 0.040, in spite of the rather weak enhancement in K{sub u} and its non-monotonic variation behavior. We consider the constant α{sub 0} with N is due to the unchanged spin-orbit coupling strength at each Co/Ni interface, while the obvious enhancement in α{sub 0} with t{sub Cu} results mainly from the increased degree of spin disordering at the rougher Cu/Ni interface. - Highlights: • The perpendicular magnetic anisotropy K{sub u} is tuned in Cu(t{sub Cu})/[Ni/Co]{sub N} system. • The intrinsic magnetic damping is found to be independent K{sub u}. • Extrinsic damping increases with t{sub Cu} due to large interfacial spin disordering.

  17. Near-Infrared Emitting CuInSe2/CuInS2 Dot Core/Rod Shell Heteronanorods by Sequential Cation Exchange

    Science.gov (United States)

    2015-01-01

    The direct synthesis of heteronanocrystals (HNCs) combining different ternary semiconductors is challenging and has not yet been successful. Here, we report a sequential topotactic cation exchange (CE) pathway that yields CuInSe2/CuInS2 dot core/rod shell nanorods with near-infrared luminescence. In our approach, the Cu+ extraction rate is coupled to the In3+ incorporation rate by the use of a stoichiometric trioctylphosphine-InCl3 complex, which fulfills the roles of both In-source and Cu-extracting agent. In this way, Cu+ ions can be extracted by trioctylphosphine ligands only when the In–P bond is broken. This results in readily available In3+ ions at the same surface site from which the Cu+ is extracted, making the process a direct place exchange reaction and shifting the overall energy balance in favor of the CE. Consequently, controlled cation exchange can occur even in large and anisotropic heterostructured nanocrystals with preservation of the size, shape, and heterostructuring of the template NCs into the product NCs. The cation exchange is self-limited, stopping when the ternary core/shell CuInSe2/CuInS2 composition is reached. The method is very versatile, successfully yielding a variety of luminescent CuInX2 (X = S, Se, and Te) quantum dots, nanorods, and HNCs, by using Cd-chalcogenide NCs and HNCs as templates. The approach reported here thus opens up routes toward materials with unprecedented properties, which would otherwise remain inaccessible. PMID:26449673

  18. Effects of Cu interlayer on the wettability of aluminum on carbon

    Energy Technology Data Exchange (ETDEWEB)

    Ko, Young Jin [School of Advanced Material Engineering, Yonsei University, Seoul 120-749 (Korea, Republic of); Yoon, Juil [Department of Mechanical Systems Engineering, Hansung University, Seoul 136-792 (Korea, Republic of); Lee, Joonho [Department of Materials Science and Engineering, Korea University, Seoul 136-701 (Korea, Republic of); Han, Jun Hyun, E-mail: jhhan@cnu.ac.kr [Department of Nano Materials Engineering, Chungnam National University, Daejeon 305-764 (Korea, Republic of)

    2013-10-15

    Highlights: •The enhancement of wettability of Al on the Cu-coated graphite was restricted by the dewetting of the Cu layer. •The pre-sputtering of Cu could enhanced the wettability of Al more than the Cu single layer coating using electroless plating. •A thick Cu coating layer is needed to enhance the wettability of Al on graphite with time without dewetting of the Al droplet. -- Abstract: Wettability of Al on Cu coated graphites and the interfacial reactions between Al and the Cu coating were analyzed to examine in depth the effect of the Cu coating layer used to enhance the wettability of Al on carbon. The wetting behaviors of Al according to Cu coating method and Cu thickness were also investigated. The Cu/Cu double layer coated by sputtering the Cu single layer coated by electroless plating because it improved the stability of the Cu layer coated on graphite at high temperature. In order to suppress the dewetting of Al on graphite and improve the wettability of Al on graphite, a thick Cu coating layer to supply sufficient Cu atoms for saturation in an Al droplet is needed.

  19. Effects of Cu interlayer on the wettability of aluminum on carbon

    International Nuclear Information System (INIS)

    Ko, Young Jin; Yoon, Juil; Lee, Joonho; Han, Jun Hyun

    2013-01-01

    Highlights: •The enhancement of wettability of Al on the Cu-coated graphite was restricted by the dewetting of the Cu layer. •The pre-sputtering of Cu could enhanced the wettability of Al more than the Cu single layer coating using electroless plating. •A thick Cu coating layer is needed to enhance the wettability of Al on graphite with time without dewetting of the Al droplet. -- Abstract: Wettability of Al on Cu coated graphites and the interfacial reactions between Al and the Cu coating were analyzed to examine in depth the effect of the Cu coating layer used to enhance the wettability of Al on carbon. The wetting behaviors of Al according to Cu coating method and Cu thickness were also investigated. The Cu/Cu double layer coated by sputtering the Cu single layer coated by electroless plating because it improved the stability of the Cu layer coated on graphite at high temperature. In order to suppress the dewetting of Al on graphite and improve the wettability of Al on graphite, a thick Cu coating layer to supply sufficient Cu atoms for saturation in an Al droplet is needed

  20. The thermo-mechanical behaviour of W-Cu metal matrix composites for fusion heat sink applications: The influence of the Cu content

    Science.gov (United States)

    Tejado, E.; Müller, A. v.; You, J.-H.; Pastor, J. Y.

    2018-01-01

    Copper and its alloys are used as heat sink materials for next generation fusion devices and will be joined to tungsten as an armour material. However, the joint of W and Cu experiences high thermal stresses when exposed to high heat loads so an interlayer material could effectively ensure the lifetime of the component by reducing the thermal mismatch. Many researchers have published results on the production of W-Cu composites aiming attention at its thermal conductivity; nevertheless, the mechanical performance of these composites remains poor. This paper reports the characterization of the thermo-mechanical behaviour of W-Cu composites produced via a liquid Cu melt infiltration of porous W preform. This technique was applied to produce composites with 15, 30 and 40 wt% Cu. The microstructure, thermal properties, and mechanical performance were investigated and measured from RT to 800 °C. The results demonstrated that high densification and superior mechanical properties can indeed be achieved via this manufacturing route. The mechanical properties (elastic modulus, fracture toughness, and strength) of the composites show a certain dependency on the Cu content; fracture mode shifts from the dominantly brittle fracture of W particles with constrained deformation of the Cu phase at low Cu content to the predominance of the ductile fracture of Cu when its ratio is higher. Though strong degradation is observed at 800 °C, the mechanical properties at operational temperatures, i.e. below 350 °C, remain rather high-even better than W/Cu materials reported previously. In addition, we demonstrated that the elastic modulus, and therefore the coefficient of thermal expansion, can be tailored via control of the W skeleton's porosity. As a result, the W-Cu composites presented here would successfully drive away heat produced in the fusion chamber avoiding the mismatch between materials while contributing to the structural support of the system.

  1. Investigations on Cu-Ni and Cu-Al systems with secondary ion mass spectrometry (SIMS)

    International Nuclear Information System (INIS)

    Rodriguez-Murcia, H.; Beske, H.E.

    1976-04-01

    The ratio of the ionization coefficients of secondary atomic ions emitted from the two component systems Cu-Ni and Cu-Al was investigated as a function of the concentration of the two components. In the low concentration range the ratio of the ionization coefficients is a constant. An influence of the phase composition on the ratio of the ionization coefficients was found in the Cu-Al system. In addition, the cluster ion emission was investigated as a function of the concentration and the phase composition of the samples. The secondary atomic ion intensity was influenced by the presence of cluster ions. The importance of the cluster ions in quantitative analysis and phase determination by means of secondary ion mass spectrometry are discussed. (orig.) [de

  2. Synthesis of Thermally Spherical CuO Nanoparticles

    Directory of Open Access Journals (Sweden)

    Nittaya Tamaekong

    2014-01-01

    Full Text Available Copper oxide (CuO nanoparticles were successfully synthesized by a thermal method. The CuO nanoparticles were further characterized by thermogravimetric analysis (TGA, differential thermal analysis (DTA, X-ray diffraction (XRD, scanning electron microscopy (SEM, energy dispersive X-ray spectrometry (EDS, and high resolution transmission electron microscopy (HRTEM, respectively. The specific surface area (SSABET of CuO nanoparticles was determined by nitrogen adsorption. The SSABET was found to be 99.67 m2/g (dBET of 9.5 nm. The average diameter of the spherical CuO nanoparticles was approximately 6–9 nm.

  3. Displacement waves in La/sub 2/CuO(4-delta) and La(1. 85)Sr(0. 15)CuO(4-delta)

    Energy Technology Data Exchange (ETDEWEB)

    Kajitani, T.; Onozuka, T.; Yamaguchi, Y.; Hirabayashi, M.; Syono, Y.

    1987-11-01

    Structural investigation of orthorhombic La/sub 2/CuO(4-delta) and La(1.85)Sr(0.15)CuO(4-delta) was carried out by means of X-ray and neutron diffraction on the basis of the space group Cmmm. The periodic expansion/contraction type distortion of CuO6 octahedra was found in both orthorhombic compounds. The distortion is nearly one-dimensional in La/sub 2/CuO(4-delta) but is two-dimensional in La(1.85)Sr(0.15)CuO(4-delta). The existence of a charge-density wave is highly possible in the structures. 20 references.

  4. Microstructure and tribological properties of Ti–Cu intermetallic compound coating

    International Nuclear Information System (INIS)

    Guo, Chun; Zhou, Jiansong; Yu, Youjun; Wang, Lingqian; Zhou, Huidi; Chen, Jianmin

    2012-01-01

    Highlights: ► Ti–Cu coating has been synthesized on pure Ti substrate by laser cladding. ► Microstructure and tribological properties of Ti–Cu coating were analyzed. ► The prepared Ti–Cu intermetallic compound coating has excellent wear resistance. -- Abstract: Ti–Cu intermetallic compound coating has been in situ synthesized successfully on pure Ti substrate by laser cladding using copper powder as the precursor. It has been found that the prepared coating mainly contains of TiCu, TiCu 3 , Ti 3 Cu, and Ti phases. The transmission electron microscopy results conform further the existence of Ti–Cu intermetallic compound in the fabricated coating. Tribological properties of the prepared Ti–Cu intermetallic compound coating were systematically evaluated. It was found that normal loads and sliding speeds have a strong influence on the friction coefficient and wear rate of Ti–Cu intermetallic compound coating. Namely, the friction coefficient of the Ti–Cu intermetallic compound coating decreased with increasing normal load and sliding speed. The wear rate of the Ti–Cu intermetallic compound coating decreased rapidly with increasing sliding speed, while the wear rate increased as the normal load increased.

  5. Analysis on dynamic tensile extrusion behavior of UFG OFHC Cu

    Science.gov (United States)

    Park, Kyung-Tae; Park, Leeju; Kim, Hak Jun; Kim, Seok Bong; Lee, Chong Soo

    2014-08-01

    Dynamic tensile extrusion (DTE) tests with the strain rate order of ~105 s-1 were conducted on coarse grained (CG) Cu and ultrafine grained (UFG) Cu. ECAP of 16 passes with route Bc was employed to fabricate UFG Cu. DTE tests were carried out by launching the sphere samples to the conical extrusion die at a speed of ~475 m/sec in a vacuumed gas gun system. UFG Cu was fragmented into 3 pieces and showed a DTE elongation of ~340%. CG Cu exhibited a larger DTE elongation of ~490% with fragmentation of 4 pieces. During DTE tests, dynamic recrystallization occurred in UFG Cu, but not in CG Cu. In order to examine the DTE behavior of CG Cu and UFG Cu under very high strain rates, a numerical analysis was undertaken by using a commercial finite element code (LS-DYNA 2D axis-symmetric model) with the Johnson - Cook model. The numerical analysis correctly predicted fragmentation and DTE elongation of CG Cu. But, the experimental DTE elongation of UFG Cu was much smaller than that predicted by the numerical analysis. This difference is discussed in terms of microstructural evolution of UFG Cu during DTE tests.

  6. Differences in soil solution chemistry between soils amended with nanosized CuO or Cu reference materials: implications for nanotoxicity tests.

    Science.gov (United States)

    McShane, Heather V A; Sunahara, Geoffrey I; Whalen, Joann K; Hendershot, William H

    2014-07-15

    Soil toxicity tests for metal oxide nanoparticles often include micrometer-sized oxide and metal salt treatments to distinguish between toxicity from nanometer-sized particles, non-nanometer-sized particles, and dissolved ions. Test result will be confounded if each chemical form has different effects on soil solution chemistry. We report on changes in soil solution chemistry over 56 days-the duration of some standard soil toxicity tests-in three soils amended with 500 mg/kg Cu as nanometer-sized CuO (nano), micrometer-sized CuO (micrometer), or Cu(NO3)2 (salt). In the CuO-amended soils, the log Cu2+ activity was initially low (minimum -9.48) and increased with time (maximum -5.20), whereas in the salt-amended soils it was initially high (maximum -4.80) and decreased with time (minimum -6.10). The Cu2+ activity in the nano-amended soils was higher than in the micrometer-amended soils for at least the first 11 days, and lower than in the salt-amended soils for at least 28 d. The pH, and dissolved Ca and Mg concentrations in the CuO-amended soils were similar, but the salt-amended soils had lower pH for at least 14 d, and higher Ca and Mg concentrations throughout the test. Soil pretreatments such as leaching and aging prior to toxicity tests are suggested.

  7. Facile Large-scale synthesis of stable CuO nanoparticles

    Science.gov (United States)

    Nazari, P.; Abdollahi-Nejand, B.; Eskandari, M.; Kohnehpoushi, S.

    2018-04-01

    In this work, a novel approach in synthesizing the CuO nanoparticles was introduced. A sequential corrosion and detaching was proposed in the growth and dispersion of CuO nanoparticles in the optimum pH value of eight. The produced CuO nanoparticles showed six nm (±2 nm) in diameter and spherical feather with a high crystallinity and uniformity in size. In this method, a large-scale production of CuO nanoparticles (120 grams in an experimental batch) from Cu micro-particles was achieved which may met the market criteria for large-scale production of CuO nanoparticles.

  8. Amorphous Cu-Ag films with high stability

    International Nuclear Information System (INIS)

    Reda, I.M.; Hafner, J.; Pongratz, P.; Wagendristel, A.; Bangert, H.; Bhat, P.K.

    1982-06-01

    Films produced by quenching Cu-Ag vapour onto cooled substrates at liquid nitrogen temperature have been investigated using electron microscopy, electron diffraction and electrical resistivity measurements. In the composition range from 30 to 70 at% Cu the as quenched films are amorphous, and within the range of 35 to 63 at% Cu the amorphous phase is stable above room temperature with a maximum crystallization temperature Tsub(c)=381 K at 47.5 at% Cu. Crystallization results in the formation of a supersaturated fcc solid solution which decomposes in a second crystallization step. The effect of deposition rate, film thickness, temperature and surface of the substrate, and most importantly of the composition on the transition temperatures has been investigated. A comparative study of the formation of amorphous phases in a wide variety of Cu-based alloys is presented. (author)

  9. Epitaxial growth of Cu on Cu(001): Experiments and simulations

    International Nuclear Information System (INIS)

    Furman, Itay; Biham, Ofer; Zuo, Jiang-Kai; Swan, Anna K.; Wendelken, John

    2000-01-01

    A quantitative comparison between experimental and Monte Carlo simulation results for the epitaxial growth of Cu/Cu(001) in the submonolayer regime is presented. The simulations take into account a complete set of hopping processes whose activation energies are derived from semiempirical calculations using the embedded-atom method. The island separation is measured as a function of the incoming flux and the temperature. A good quantitative agreement between the experiment and simulation is found for the island separation, the activation energies for the dominant processes, and the exponents that characterize the growth. The simulation results are then analyzed at lower coverages, which are not accessible experimentally, providing good agreement with theoretical predictions as well

  10. N4H9Cu7S4: a hydrazinium-based salt with a layered Cu7S4- framework.

    Science.gov (United States)

    Mitzi, David B

    2007-02-05

    Crystals of a hydrazinium-based copper(I) sulfide salt, N4H9Cu7S4 (1), have been isolated by an ambient temperature solution-based process. In contrast to previously reported hydrazinium salts of main-group metal chalcogenides, which consist of isolated metal chalcogenide anions, and ACu7S4 (A = NH4+, Rb+, Tl+, K+), which contains a more three-dimensional Cu7S4- framework with partial Cu-site occupancy, the structure of 1 [P21, a = 6.8621(4) A, b = 7.9851(4) A, c = 10.0983(5) A, beta = 99.360(1) degrees , Z = 2] is composed of extended two-dimensional Cu7S4- slabs with full Cu-site occupancy. The Cu7S4- slabs are separated by a mixture of hydrazinium and hydrazine moieties. Thermal decomposition of 1 into copper(I) sulfide proceeds at a significantly lower temperature than that observed for analogous hydrazinium salts of previously considered metal chalcogenides, completing the transition at temperatures as low as 120 degrees C. Solutions of 1 may be used in the solution deposition of a range of Cu-containing chalcogenide films.

  11. CuO nanoparticles and their antimicrobial activity against nosocomial strains

    Directory of Open Access Journals (Sweden)

    Mónica Marcela Gómez León

    2017-09-01

    Full Text Available Using a prototype reactor, CuO nanoparticles (NPs were synthetized through the precipitation method, starting from CuSO2·5H2O and Cu(CH3COO2·H2O. The obtained NPs were characterized by XDR, FT-IR, SEM, and TEM. The antimicrobial activity of the NPs was determined by the plate diffusion method, placing 20 mg of NPs onto four nosocomial strains obtained from north Lima national hospital Intensive-Care Unit (Staphylococcus epidermidis, Aerococcus viridans, Ochrobactrum anthropic, and Micrococcus lylae. NPs characterization revealed that those synthetized from acetate (CuO–Acet shown pure CuO phase, while those synthetized from sulphate CuO–Sulf shown two phases where CuO was the predominant one, having more than 84%. The crystal domains for CuO–Acet and CuO–Sulf were 15 and 19 nm, respectively. The inhibition halos for the studied strains were larger for CuO–Sulf NPs than CuO–Acet NPs, only Ochrobactrum anthropi displayed similar inhibition halos for both types of NPs.

  12. Influence of Material Coating on the Heat Transfer in a Layered Cu-SiC-Cu Systems

    Directory of Open Access Journals (Sweden)

    Strojny-Nędza A.

    2017-06-01

    Full Text Available This paper describes the process of obtaining Cu-SiC-Cu systems by way of spark plasma sintering. A monocrystalline form of silicon carbide (6H-SiC type was applied in the experiment. Additionally, silicon carbide samples were covered with a layer of tungsten and molybdenum using chemical vapour deposition (CVD technique. Microstructural examinations and thermal properties measurements were performed. A special attention was put to the metal-ceramic interface. During annealing at a high temperature, copper reacts with silicon carbide. To prevent the decomposition of silicon carbide two types of coating (tungsten and molybdenum were applied. The effect of covering SiC with the aforementioned elements on the composite’s thermal conductivity was analyzed. Results were compared with the numerical modelling of heat transfer in Cu-SiC-Cu systems. Certain possible reasons behind differences in measurements and modelling results were discussed.

  13. MOFzyme: Intrinsic protease-like activity of Cu-MOF

    Science.gov (United States)

    Li, Bin; Chen, Daomei; Wang, Jiaqiang; Yan, Zhiying; Jiang, Liang; Deliang Duan; He, Jiao; Luo, Zhongrui; Zhang, Jinping; Yuan, Fagui

    2014-10-01

    The construction of efficient enzyme mimetics for the hydrolysis of peptide bonds in proteins is challenging due to the high stability of peptide bonds and the importance of proteases in biology and industry. Metal-organic frameworks (MOFs) consisting of infinite crystalline lattices with metal clusters and organic linkers may provide opportunities for protease mimic which has remained unknown. Herein, we report that Cu2(C9H3O6)4/3 MOF (which is well known as HKUST-1 and denoted as Cu-MOF here), possesses an intrinsic enzyme mimicking activity similar to that found in natural trypsin to bovine serum albumin (BSA) and casein. The Michaelis constant (Km) of Cu-MOF is about 26,000-fold smaller than that of free trypsin indicating a much higher affinity of BSA for Cu-MOF surface. Cu-MOF also exhibited significantly higher catalytic efficiency than homogeneous artificial metalloprotease Cu(II) complexes and could be reused for ten times without losing in its activity. Moreover, Cu-MOF was successfully used to simulate trypsinization in cell culture since it dissociated cells in culture even without EDTA.

  14. Efficient Destruction of Pollutants in Water by a Dual-Reaction-Center Fenton-like Process over Carbon Nitride Compounds-Complexed Cu(II)-CuAlO2.

    Science.gov (United States)

    Lyu, Lai; Yan, Dengbiao; Yu, Guangfei; Cao, Wenrui; Hu, Chun

    2018-04-03

    Carbon nitride compounds (CN) complexed with the in-situ-produced Cu(II) on the surface of CuAlO 2 substrate (CN-Cu(II)-CuAlO 2 ) is prepared via a surface growth process for the first time and exhibits exceptionally high activity and efficiency for the degradation of the refractory pollutants in water through a Fenton-like process in a wide pH range. The reaction rate for bisphenol A removal is ∼25 times higher than that of the CuAlO 2 . According to the characterization, Cu(II) generation on the surface of CuAlO 2 during the surface growth process results in the marked decrease of the surface oxygen vacancies and the formation of the C-O-Cu bridges between CN and Cu(II)-CuAlO 2 in the catalyst. The electron paramagnetic resonance (EPR) analysis and density functional theory (DFT) calculations demonstrate that the dual reaction centers are produced around the Cu and C sites due to the cation-π interactions through the C-O-Cu bridges in CN-Cu(II)-CuAlO 2 . During the Fenton-like reactions, the electron-rich center around Cu is responsible for the efficient reduction of H 2 O 2 to • OH, and the electron-poor center around C captures electrons from H 2 O 2 or pollutants and diverts them to the electron-rich area via the C-O-Cu bridge. Thus, the catalyst exhibits excellent catalytic performance for the refractory pollutant degradation. This study can deepen our understanding on the enhanced Fenton reactivity for water purification through functionalizing with organic solid-phase ligands on the catalyst surface.

  15. CuO cauliflowers for supercapacitor application: Novel potentiodynamic deposition

    Energy Technology Data Exchange (ETDEWEB)

    Dubal, Deepak P., E-mail: deepak.dubal@chemie.tu-chemnitz.de [Technische Universität Chemnitz, Institut für Chemie, AG Elektrochemie, D-09107 Chemnitz (Germany); Gund, Girish S.; Lokhande, Chandrakant D. [Thin Film Physics Laboratory, Department of Physics, Shivaji University, Kolhapur, 416004 (M.S) (India); Holze, Rudolf, E-mail: rudolf.holze@chemie.tu-chemnitz.de [Technische Universität Chemnitz, Institut für Chemie, AG Elektrochemie, D-09107 Chemnitz (Germany)

    2013-02-15

    Graphical abstract: Schematic experimental setup used for the potentiodynamic mode of electrodeposition for the synthesis of CuO cauliflower onto stainless steel substrate. Highlights: ► Synthesis of CuO using potentiodynamic mode of electrodeposition. ► Uniformly spread cauliflower-like nanostructure. ► CuO cauliflowers provide high specific capacitance with good stability. ► CuO cauliflowers show high power and energy density values. -- Abstract: In present investigation, synthesis and characterization of novel cauliflower-like copper oxide (CuO) and its electrochemical properties have been performed. The utilized CuO cauliflowers were prepared by potentiodyanamic mode from an aqueous alkaline bath. X-ray diffraction pattern confirm the formation of monoclinic CuO cauliflowers. Scanning electron micrograph analysis reveals that CuO cauliflowers are uniformly spread all over the substrate surface with the surface area of 49 m{sup 2} g{sup −1} with bimodal pore size distribution. Electrochemical analysis shows that CuO cauliflower exhibits high specific capacitance of 179 Fg{sup −1} in 1 M Na{sub 2}SO{sub 4} electrolyte with 81% capacity retention after 2000 cycles. The Ragone plot discovers better power and energy densities of cauliflowers-like CuO sample. Present investigation illustrates that the potentiodynamic approach for the direct growth of cauliflower-like CuO is simple and cost-effective and can be applied for synthesis of other metal oxides, polymers etc.

  16. Microscopic evidence for magnetic ordering in NdCu3Ru4O12 : 63,65Cu nuclear quadrupole resonance study

    Science.gov (United States)

    Yogi, M.; Niki, H.; Hedo, M.; Komesu, S.; Nakama, T.

    2018-05-01

    We have conducted 63,65Cu nuclear quadrupole resonance (NQR) measurements on A-site ordered perovskite compounds LaCu3Ru4O12 and NdCu3Ru4O12 to investigate their ground state and spin fluctuations. While there is only one Cu site in the crystal structure, multiple NQR resonance lines were observed. This is presumed to be due to the presence of slight distortion and lattice defects in the samples. The nuclear spin-lattice relaxation rate divided by temperature, 1 /T1 T , for LaCu3Ru4O12 showed almost constant value indicating the Fermi-liquid state. A remarkable increase in 1 /T1 T due to spin fluctuations was observed in NdCu3Ru4O12 . Furthermore, an evident magnetic phase transition at TM = 0.6 K was revealed from the distinct peak of 1 /T1 T and the broadening of the NQR spectrum.

  17. Syntheses, crystal structures, and characterization of two new Tl{sup +}-Cu{sup 2+}-Te{sup 6+} oxides: Tl{sub 4}CuTeO{sub 6} and Tl{sub 6}CuTe{sub 2}O{sub 10}

    Energy Technology Data Exchange (ETDEWEB)

    Yeon, Jeongho; Kim, Sang-Hwan [Department of Chemistry, University of Houston, 136 Fleming Building, Houston, TX 77204-5003 (United States); Green, Mark A. [Department of Materials Science and Engineering, University of Maryland, College Park, MD, 20742-2115 and NIST Center for Neutron Research, National Institute of Standard and Technology, 100 Bureau Drive, Gaithersburg, MD 20899-6103 (United States); Bhatti, Kanwal Preet; Leighton, C. [Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455-0132 (United States); Shiv Halasyamani, P., E-mail: psh@uh.edu [Department of Chemistry, University of Houston, 136 Fleming Building, Houston, TX 77204-5003 (United States)

    2012-12-15

    Crystals and polycrystalline powders of two new oxide materials, Tl{sub 4}CuTeO{sub 6} and Tl{sub 6}CuTe{sub 2}O{sub 10}, have been synthesized by hydrothermal and solid-state methods. The materials were structurally characterized by single-crystal X-ray diffraction. Tl{sub 4}CuTeO{sub 6} and Tl{sub 6}CuTe{sub 2}O{sub 10} exhibit one dimensional anionic slabs of [CuTeO{sub 6}]{sup 4-} and [CuTe{sub 2}O{sub 10}]{sup 6-}, respectively. Common to both slabs is the occurrence of Cu{sup 2+}O{sub 4} distorted squares and Te{sup 6+}O{sub 6} octahedra. The slabs are separated by Tl{sup +} cations. For Tl{sub 4}CuTeO{sub 6}, magnetic measurements indicate a maximum at {approx}8 K in the temperature dependence of the susceptibility. Low temperature neutron diffraction data confirm no long-range magnetic ordering occurs and the susceptibility was adequately accounted for by fits to a Heisenberg alternating chain model. For Tl{sub 6}CuTe{sub 2}O{sub 10} on the other hand, magnetic measurements revealed paramagnetism with no evidence of long-range magnetic ordering. Infrared, UV-vis spectra, thermogravimetric, and differential thermal analyses are also reported. Crystal data: Tl{sub 4}CuTeO{sub 6}, Triclinic, space group P-1 (No. 2), a=5.8629(8) A, b=8.7848(11) A, c=9.2572(12) A, {alpha}=66.0460(10), {beta}=74.2010(10), {gamma}=79.254(2), V=417.70(9) A{sup 3}, and Z=2; Tl{sub 6}CuTe{sub 2}O{sub 10}, orthorhombic, space group Pnma (No. 62), a=10.8628(6) A, b=11.4962(7) A, c=10.7238(6) A, V=1339.20(13) A{sup 3}, and Z=4. - Graphical Abstract: Two new oxide materials, Tl{sub 4}CuTeO{sub 6} and Tl{sub 6}CuTe{sub 2}O{sub 10}, have been synthesized and characterized. The materials exhibit one dimensional crystal structures consisting of CuO{sub 4} and TeO{sub 6} polyhedra. Highlights: Black-Right-Pointing-Pointer Two New Tl-Te-Cu-oxides have been synthesized and structurally characterized. Black-Right-Pointing-Pointer For Tl{sub 4}CuTeO{sub 6}, magnetic measurements indicate a

  18. Diffusion and adhesion properties of Cu films on polyimide substrates

    International Nuclear Information System (INIS)

    Liang, T.X.; Liu, Y.Q.; Fu, Z.Q.; Luo, T.Y.; Zhang, K.Y.

    2005-01-01

    Copper thin films were prepared on polyimide (PI) substrates by physical vapor deposition (PVD) and chemical vapor deposition (CVD). Titanium nitride (TiN) diffusion barrier layers were deposited between the copper films and the PI substrates by PVD. Auger electron spectroscopy compositional depth profile showed that TiN barrier layer was very effective in preventing copper diffusion into PI substrate even after the Cu/TiN/PI samples were annealed at 300 deg. C for 5 h. For the as-deposited CVD-Cu/PI, CVD-Cu/TiN/PI, and as-deposited PVD-Cu/PI samples, the residual stress in Cu films was very small. Relatively larger residual stress existed in Cu films for PVD-Cu/TiN/PI samples. For PVD-Cu/TiN/PI samples, annealing can increase the peeling strength to the level observed without a diffusion barrier. The adhesion improvement of Cu films by annealing treatment can be attributed to lowering of the residual tensile stress in Cu films

  19. Explanation of the photocurrent quantum efficiency (Φ) enhancements through the CAN's model equation for the p-CuI sensitized methylviolet-C18 LB films in the photoelectrochemical cells (PECs) and Cu/n-Cu2O/M-C18/p-CuI solid-state photovoltaic cells

    International Nuclear Information System (INIS)

    Fernando, C A N; Liyanaarachchi, U S; AARajapaksha, R D

    2013-01-01

    Photocurrent enhancements in a dye sensitized photoelectrochemical cell (PEC) with a Cu/p-CuI/M-C 18 photoelectrode and a dye sensitized solid state photovoltaic cell (DSSC) with Cu/n-Cu 2 O/M-C 18 /p-CuI are studied by controlling the formation of dye aggregates of M-C 18 Langmuir–Blodgett (LB) films on the p-CuI layer. LB films of M-C 18 are deposited under biasing conditions during the LB deposition process on Cu/p-CuI, Cu/n-Cu 2 O/p-CuI and conductive glass plates with the three-electrode configuration setup coupling to the LB trough. LB films prepared under positive biasing conditions enhance the photocurrent quantum efficiencies for both PECs and DSSCs controlling and minimizing the formation of dye aggregates. The electrolyte used for LB deposition and photocurrent measurements is (10 −2 M) Fe 2+ + Fe 3+ (10 −2 M) and (10 −2 M) NaH 2 PO 4 –Na 2 HPO 4 , pH = 6 buffer solution. Maximum photocurrent quantum efficiencies (φmax%) obtained are ≈22% for PEC and ≈20% for DSSCs, where the M-C 18 LB film deposition applied potentials +0.3 V versus Ag/AgCl. The mechanism of the photocurrent enhancement is discussed through the CAN's model equation, φ = AD 0 –BD 0 2 , where A = k 1 k 2 /F, B = I k 1 2 k 2 [2k 6 /F 3 + k 2 k 4 /k 3 2 X 2 F 2 ], F = k 2 + k 5 Y + k 7 + k 1 I [1 + k 2 /k 3 X], presented from our previous study [1]. Experimental evidence for the formation of the aggregates of M-C 18 LB films for the negative applied potentials and suppression of the aggregates with positive applied potentials are presented from absorption spectra, AFM pictures and fluorescence measurements of the samples. Conversion efficiency obtained is ≈2.5%, V oc ≈750 mV and I sc ≈ 5.8 mA cm −2 for DSSC fabricated with +0.3 V versus Ag/AgCl applied deposition potential of M-C 18 LB films. (paper)

  20. Explanation of the photocurrent quantum efficiency (Φ) enhancements through the CAN's model equation for the p-CuI sensitized methylviolet-C18 LB films in the photoelectrochemical cells (PECs) and Cu/n-Cu2O/M-C18/p-CuI solid-state photovoltaic cells

    Science.gov (United States)

    Fernando, C. A. N.; Liyanaarachchi, U. S.; AARajapaksha, R. D.

    2013-04-01

    Photocurrent enhancements in a dye sensitized photoelectrochemical cell (PEC) with a Cu/p-CuI/M-C18 photoelectrode and a dye sensitized solid state photovoltaic cell (DSSC) with Cu/n-Cu2O/M-C18/p-CuI are studied by controlling the formation of dye aggregates of M-C18 Langmuir-Blodgett (LB) films on the p-CuI layer. LB films of M-C18 are deposited under biasing conditions during the LB deposition process on Cu/p-CuI, Cu/n-Cu2O/p-CuI and conductive glass plates with the three-electrode configuration setup coupling to the LB trough. LB films prepared under positive biasing conditions enhance the photocurrent quantum efficiencies for both PECs and DSSCs controlling and minimizing the formation of dye aggregates. The electrolyte used for LB deposition and photocurrent measurements is (10-2 M) Fe2+ + Fe3+ (10-2 M) and (10-2 M) NaH2PO4-Na2HPO4, pH = 6 buffer solution. Maximum photocurrent quantum efficiencies (Фmax%) obtained are ≈22% for PEC and ≈20% for DSSCs, where the M-C18 LB film deposition applied potentials +0.3 V versus Ag/AgCl. The mechanism of the photocurrent enhancement is discussed through the CAN's model equation, Ф = AD0-BD02, where A = k1k2/F, B = I k12 k2[2k6/F3 + k2k4/k32 X2F2], F = k2 + k5Y + k7 + k1 I [1 + k2/k3 X], presented from our previous study [1]. Experimental evidence for the formation of the aggregates of M-C18 LB films for the negative applied potentials and suppression of the aggregates with positive applied potentials are presented from absorption spectra, AFM pictures and fluorescence measurements of the samples. Conversion efficiency obtained is ≈2.5%, Voc ≈750 mV and Isc ≈ 5.8 mA cm-2 for DSSC fabricated with +0.3 V versus Ag/AgCl applied deposition potential of M-C18 LB films.

  1. Role of interlayer coupling for the power factor of CuSbS2 and CuSbSe2

    KAUST Repository

    Alsaleh, Najebah Mohammed Abdullah; Singh, Nirpendra; Schwingenschlö gl, Udo

    2016-01-01

    The electronic and transport properties of bulk and monolayer CuSbS2 and CuSbSe2 are determined by using density functional theory and semiclassical Boltzmann transport theory, in order to investigate the role of interlayer coupling for the thermoelectric properties. The calculated band gaps of the bulk compounds are in agreement with experiments and significantly higher than those of the monolayers, which thus show lower Seebeck coefficients. Since also the electrical conductivity is lower, the monolayers are characterized by lower power factors. Therefore, interlayer coupling is found to be essential for the excellent thermoelectric response of CuSbS2 and CuSbSe2, even though it is weak.

  2. Role of interlayer coupling for the power factor of CuSbS2 and CuSbSe2

    KAUST Repository

    Alsaleh, Najebah Mohammed Abdullah

    2017-01-08

    The electronic and transport properties of bulk and monolayer CuSbS2 and CuSbSe2 are determined by using density functional theory and semiclassical Boltzmann transport theory, in order to investigate the role of interlayer coupling for the thermoelectric properties. The calculated band gaps of the bulk compounds are in agreement with experiments and significantly higher than those of the monolayers, which thus show lower Seebeck coefficients. Since also the electrical conductivity is lower, the monolayers are characterized by lower power factors. Therefore, interlayer coupling is found to be essential for the excellent thermoelectric response of CuSbS2 and CuSbSe2, even though it is weak.

  3. Role of interlayer coupling for the power factor of CuSbS2 and CuSbSe2

    KAUST Repository

    Alsaleh, Najebah M.

    2016-09-26

    The electronic and transport properties of bulk and monolayer CuSbS2 and CuSbSe2 are determined by using density functional theory and semiclassical Boltzmann transport theory, in order to investigate the role of interlayer coupling for the thermoelectric properties. The calculated band gaps of the bulk compounds are in agreement with experiments and significantly higher than those of the monolayers, which thus show lower Seebeck coefficients. Since also the electrical conductivity is lower, the monolayers are characterized by lower power factors. Therefore, interlayer coupling is found to be essential for the excellent thermoelectric response of CuSbS2 and CuSbSe2, even though it is weak.

  4. Chemical synthesis of Cu2Se nanoparticles at room temperature

    International Nuclear Information System (INIS)

    Rong, Fengxia; Bai, Yan; Chen, Tianfeng; Zheng, Wenjie

    2012-01-01

    Graphical abstract: The Cu 2 Se nanoparticles were synthesized by a simple and rapid method at room temperature. The TEM and SEM images show that the Cu 2 Se nanoparticles were spherical. Highlights: ► Cu 2 Se nanoparticles were synthesized by the reaction of nanoSe 0 sol with Cu + ions. ► The Cu 2 Se nanoparticles were spherical with cubic structure and well crystallized. ► Optical and electrochemical properties of Cu 2 Se nanoparticles were observed. ► The formation mechanism of Cu 2 Se nanoparticles was proposed. -- Abstract: A simple and rapid method has been developed to synthesize cuprous selenide (Cu 2 Se) nanoparticles by the reaction of selenium nanoparticles sol with copper sulfate solution containing ascorbic acid at room temperature. Cu 2 Se nanoparticles were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and energy dispersive X-ray analysis (EDX). The results indicated that Cu 2 Se nanoparticles were cubic crystal structure and spherical with the diameter about 75 nm. The ultraviolet–visible absorption spectrum (UV–vis) and cyclic voltammetry of Cu 2 Se nanoparticles were also investigated. The optical band gap energy of Cu 2 Se nanoparticles was 1.94 eV. On the basis of a series of experiments and characterizations, the formation mechanism of Cu 2 Se nanoparticles was discussed.

  5. Geometric distribution of CuO chains in YBa2Cu3O6+x

    International Nuclear Information System (INIS)

    Matic, V.M.; Lazarov, N.Dj.

    2006-01-01

    Statistics of CuO chains in basal planes of YBa 2 Cu 3 O 6+x high-T c superconductor has been studied in terms of two dimensional asymmetric next-to-nearest-neighbor Ising (ASYNNNI) model, with accentuation on distribution of CuO chains per different chain lengths. It has been shown that the fraction p(l) of CuO chains containing l oxygen ions (i.e., having the length equal to l), satisfies so-called ''law of geometric distribution''p(l)=ω(1-ω) l-1 , where the quantity ω is equal to the inverse of average chain length l av in the system, for given values of oxygen content x and temperature T. In the case of ortho-II (OII) structural phase, the geometric chain probability distribution is shown to hold separately for each of two different sublattices of oxygen sites, commonly known as α 1 and α 2 , with respectively defined l av α 1 (x,T) and l av α 2 (x,T). The theoretically derived result of the chain probability distribution p(l) is shown to be in a remarkable agreement with the results obtained out of extensive Monte Carlo calculations that were made within region of stability of orthorhombic structural phases in (x,T) space. The relevance of chain length distribution for accurate count of the number of transferred electronic holes to superconducting CuO 2 layers has been pointed out and expression for hole concentration has been derived. The concept of critical chain length for charge transfer mechanism was briefly discussed

  6. Beta decay of Cu-56

    NARCIS (Netherlands)

    Borcea, R; Aysto, J; Caurier, E; Dendooven, P; Doring, J; Gierlik, M; Gorska, M; Grawe, H; Hellstrom, M; Janas, Z; Jokinen, A; Karny, M; Kirchner, R; La Commara, M; Langanke, K; Martinez-Pinedo, G; Mayet, P; Nieminen, A; Nowacki, F; Penttila, H; Plochocki, A; Rejmund, M; Roeckl, E; Schlegel, C; Schmidt, K; Schwengner, R; Sawicka, M

    2001-01-01

    The proton-rich isotope Cu-56 was produced at the GSI On-Line Mass Separator by means of the Si-28(S-32, p3n) fusion-evaporation reaction. Its beta -decay properties were studied by detecting beta -delayed gamma rays and protons. A half-Life of 93 +/- 3 ms was determined for Cu-56. Compared to the

  7. The crystallisation of Cu{sub 2}ZnSnS{sub 4} thin film solar cell absorbers from co-electroplated Cu-Zn-Sn precursors

    Energy Technology Data Exchange (ETDEWEB)

    Schurr, R. [Chair for Crystallography and Structural Physics, University of Erlangen-Nuernberg, Staudtstrasse 3, D-91058 Erlangen (Germany)], E-mail: schurr@krist.uni-erlangen.de; Hoelzing, A.; Jost, S.; Hock, R. [Chair for Crystallography and Structural Physics, University of Erlangen-Nuernberg, Staudtstrasse 3, D-91058 Erlangen (Germany); Voss, T.; Schulze, J.; Kirbs, A. [Atotech Deutschland GmbH, Erasmusstrasse 20, D-10553 Berlin (Germany); Ennaoui, A.; Lux-Steiner, M. [Heterogeneous Material Systems SE II, Hahn-Meitner-Institut, Glienickerstr.100, D-14109 Berlin (Germany); Weber, A.; Koetschau, I.; Schock, H.-W. [Technology SE III, Hahn-Meitner-Institut, Glienickerstr.100, D-14109 Berlin (Germany)

    2009-02-02

    The best CZTS solar cell so far was produced by co-sputtering continued with vapour phase sulfurization method. Efficiencies of up to 5.74% were reached by Katagiri et al. The one step electrochemical deposition of copper, zinc, tin and subsequent sulfurization is an alternative fabrication technique for the production of Cu{sub 2}ZnSnS{sub 4} based thin film solar cells. A kesterite based solar cell (size 0.5 cm{sup 2}) with a conversion efficiency of 3.4% (AM1.5) was produced by vapour phase sulfurization of co-electroplated Cu-Zn-Sn films. We report on results of in-situ X-ray diffraction (XRD) experiments during crystallisation of kesterite thin films from electrochemically co-deposited metal films. The kesterite crystallisation is completed by the solid state reaction of Cu{sub 2}SnS{sub 3} and ZnS. The measurements show two different reaction paths depending on the metal ratios in the as deposited films. In copper-rich metal films Cu{sub 3}Sn and CuZn were found after electrodeposition. In copper-poor or near stoichiometric precursors additional Cu{sub 6}Sn{sub 5} and Sn phases were detected. The formation mechanism of Cu{sub 2}SnS{sub 3} involves the binary sulphides Cu{sub 2-x}S and SnS{sub 2} in the absence of the binary precursor phase Cu{sub 6}Sn{sub 5}. The presence of Cu{sub 6}Sn{sub 5} leads to a preferred formation of Cu{sub 2}SnS{sub 3} via the reaction educts Cu{sub 2-x}S and SnS{sub 2} in the presence of a SnS{sub 2}(Cu{sub 4}SnS{sub 6}) melt. The melt phase may be advantageous in crystallising the kesterite, leading to enhanced grain growth in the presence of a liquid phase.

  8. Electron tunneling measurements in LaSrCuO and YBaCuO

    International Nuclear Information System (INIS)

    Moreland, J.; Ekin, J.W.; Goodrich, L.F.; Capobianco, T.E.; Clark, A.F.

    1987-01-01

    The break junction technique whereby vacuum tunneling occurs within the fracture of a bulk sample is used to study the LaSrCuO and YBaCuO perovskite superconductors. Structure in the current versus voltage characteristics is reminiscent of previous quasiparticle curves obtained for BCS superconducting materials. Some curves have anomalous qualities, including large dips in the junction conductance with increasing voltage just above a well defined tunneling gap edge linearly increasing junction conductance with an applied bias, along with features occurring near the voltage intervals with the 1, 3, 5 pattern

  9. CHARGED PARTICLE MULTIPLICITIES IN ULTRA-RELATIVISTIC AU+AU AND CU+CU COLLISIONS

    Science.gov (United States)

    Back, B. B.; Alver, B.; Back, B. B.; Baker, M. D.; Ballintijn, M.; Barton, D. S.; Betts, R. R.; Bickley, A. A.; Bindel, R.; Busza, W.; Carroll, A.; Chai, Z.; Chetluru, V.; Decowski, M. P.; Garcia, E.; Gburek, T.; George, N.; Gulbrandsen, K.; Halliwell, C.; Hamblen, J.; Harnarine, I.; Hauer, M.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Holynski, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Khan, N.; Kulinich, P.; Kuo, C. M.; Li, W.; Lin, W. T.; Loizides, C.; Manly, S.; Mignerey, A. C.; Nouicer, R.; Olszewski, A.; Pak, R.; Reed, C.; Richardson, E.; Roland, C.; Roland, G.; Sagerer, J.; Seals, H.; Sedykh, I.; Smith, C. E.; Stankiewicz, M. A.; Steinberg, P.; Stephans, G. S. F.; Sukhanov, A.; Szostak, A.; Tonjes, M. B.; Trzupek, A.; Vale, C.; Vannieuwenhuizen, G. J.; Vaurynovich, S. S.; Verdier, R.; Veres, G. I.; Walters, P.; Wenger, E.; Willhelm, D.; Wolfs, F. L. H.; Wosiek, B.; Wozniak, K.; Wyngaardt, S.; Wyslouch, B.

    The PHOBOS collaboration has carried out a systematic study of charged particle multiplicities in Cu+Cu and Au+Au collisions at the Relativistic Heavy-Ion Collider (RHIC) at Brookhaven National Laboratory. A unique feature of the PHOBOS detector is its ability to measure charged particles over a very wide angular range from 0.5° to 179.5° corresponding to |η| <5.4. The general features of the charged particle multiplicity distributions as a function of pseudo-rapidity, collision energy and centrality, as well as system size, are discussed.

  10. Synthesis of Cu3N from CuO and NaNH2

    Directory of Open Access Journals (Sweden)

    Akira Miura

    2014-12-01

    Full Text Available We report on the low-temperature synthesis of submicron-sized Cu3N powder produced from CuO and NaNH2 powder mixture by heating at 150–190 °C in a Teflon-sealed autoclave. The structure was the anti-RuO3 type with a lattice parameter of 0.3814(1 nm, and strong optical absorption was observed below ∼1.9 eV. This synthesis method has the potential of facile control of the reaction with less use of ammonia sources.

  11. CuInSe2 nano-crystallite reaction kinetics using solid state reaction from Cu2Se and In2Se3 powders

    International Nuclear Information System (INIS)

    Hsiang, Hsing-I; Lu, Li-Hsin; Chang, Yu-Lun; Ray, Dahtong; Yen, Fu-Su

    2011-01-01

    Highlights: → CuInSe 2 phase increased gradually accompanied with a decrease in γ-In 2 Se 3 and no intermediate phase during calcination. → CuInSe 2 formation from Cu 2 Se and In 2 Se 3 powders follows a one-dimensional diffusion-controlled reaction with apparent activation energy of about 122.5 kJ/mol. → The solid reaction kinetics may be dominated by the diffusion of In 3+ ions. - Abstract: The reaction mechanism and CuInSe 2 formation kinetics using a solid state reaction from Cu 2 Se and In 2 Se 3 powders synthesized using a heating up process were investigated using X-ray diffractomy (XRD) and transmission electron microscopy (TEM). It was observed that the CuInSe 2 phase increased gradually, accompanied with a decrease in γ-In 2 Se 3 with no intermediate phase as the calcination temperature and soaking time were increased. The reaction kinetics was analyzed using the Avrami and polynomial kinetic model, suggesting that CuInSe 2 formation from Cu 2 Se and In 2 Se 3 powders follows a diffusion-controlled reaction with an apparent activation energy of about 122.5-182.3 kJ/mol. Cu 2 Se and In 2 Se 3 phases react and directly transform into CIS without the occurrence of any intermediate phase and the size of the newly formed CuInSe 2 crystallites was close to that of the Cu 2 Se reactant particle based on the TEM results, which indicated that the solid reaction kinetics may be dominated by the diffusion of In 3+ ions.

  12. Revisiting 63Cu NMR evidence for charge order in superconducting La1.885Sr0.115CuO4

    Science.gov (United States)

    Imai, T.; Takahashi, S. K.; Arsenault, A.; Acton, A. W.; Lee, D.; He, W.; Lee, Y. S.; Fujita, M.

    2017-12-01

    The presence of charge and spin stripe order in the La2CuO4 -based family of superconductors continues to lead to new insight on the unusual ground-state properties of high-Tc cuprates. Soon after the discovery of charge stripe order at Tcharge≃65 K in Nd3 + co-doped La1.48Nd0.4Sr0.12CuO4 (Tc≃6 K) [Tranquada et al., Nature (London) 375, 561 (1995), 10.1038/375561a0], Hunt et al. demonstrated that La1.48Nd0.4Sr0.12CuO4 and superconducting La2 -xSrxCuO4 with x ˜1 /8 (Tc≃30 K) share nearly identical NMR anomalies near Tcharge of the former [Phys. Rev. Lett. 82, 4300 (1999), 10.1103/PhysRevLett.82.4300]. Their inevitable conclusion that La1.885Sr0.115CuO4 also undergoes charge order at a comparable temperature became controversial, because diffraction measurements at the time were unable to detect Bragg peaks associated with charge order. Recent advances in x-ray diffraction techniques finally led to definitive confirmations of the charge order Bragg peaks in La1.885Sr0.115CuO4 with an onset at as high as Tcharge≃80 K. Meanwhile, improved instrumental technology has enabled routine NMR measurements that were not feasible two decades ago. Motivated by these new developments, we revisit the charge order transition of a La1.885Sr0.115CuO4 single crystal based on 63Cu NMR techniques. We demonstrate that 63Cu NMR properties of the nuclear spin Iz=-1/2 to +1/2 central transition below Tcharge exhibit unprecedentedly strong dependence on the measurement time scale set by the separation time τ between the 90∘ and 180∘ radio-frequency pulses; a new kind of anomalous, very broad winglike 63Cu NMR signals gradually emerge below Tcharge only for extremely short τ ≲4 μ s , while the spectral weight INormal of the normal NMR signals is progressively wiped out. The NMR linewidth and relaxation rates depend strongly on τ below Tcharge, and their enhancement in the charge ordered state indicates that charge order turns on strong but inhomogeneous growth of Cu spin

  13. The influence of precursor Cu content and two-stage processing conditions on the microstructure of Cu{sub 2}ZnSnSe{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Márquez-Prieto, J., E-mail: jose.prieto@northumbria.ac.uk [Northumbria Photovoltaic Application Centre, Faculty of Engineering and Environment, Northumbria University, Ellison Building, Newcastle upon Tyne NE1 8ST (United Kingdom); Ren, Y. [Ångström Solar Center, Solid State Electronics, Uppsala University, Uppsala 751 21 (Sweden); Miles, R.W.; Pearsall, N.; Forbes, I. [Northumbria Photovoltaic Application Centre, Faculty of Engineering and Environment, Northumbria University, Ellison Building, Newcastle upon Tyne NE1 8ST (United Kingdom)

    2015-05-01

    This paper reports the influence of processing temperature on the microstructure of Cu{sub 2}ZnSnSe{sub 4} (CZTSe) absorber layers for temperatures between 380 and 550 °C produced using a 2-stage process. X-ray diffraction analysis showed the formation of Cu{sub 2}ZnSnSe{sub 4} over this temperatures range. The Williamson-Hall method was used for microstructural analysis of the CZTSe absorbers, and this showed a progressive decrease of the micro-strain of the CZTSe with increasing selenisation temperature. The influence of precursor Cu content on the microstructure of the CZTSe was also studied. An increase of Cu content in the precursor is correlated to an increase in grain size and a decrease in micro-strain. Raman measurements show an asymmetrical broadening towards lower energies of the main 197 cm{sup −1} mode for Cu-poor compositions. This study provides an insight into the dependency of the crystallinity of CZTSe on composition and synthesis temperature. - Highlights: • We fabricate Cu{sub 2}ZnSnSe{sub 4} thin films by sputtering and post-reactive annealing. • The micro-strain of Cu{sub 2}ZnSnSe{sub 4} increases when Cu content decreases. • The micro-strain of Cu{sub 2}ZnSnSe{sub 4} decreases with increasing processing temperature. • The defect concentration of Cu{sub 2}ZnSnSe{sub 4} increases when Cu content decreases.

  14. Local Electrical Response in Alkaline-Doped Electrodeposited CuInSe2/Cu Films

    Directory of Open Access Journals (Sweden)

    Javier A. Barón-Miranda

    2016-12-01

    Full Text Available The local electrical response in alkaline-doped CuInSe2 films prepared by single-step electrodeposition onto Cu substrates was studied by current-sensing atomic force microscopy. The CuInSe2 (CIS films were prepared from single baths containing the dopant ions (Li, Na, K or Cs and were studied by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy and photocurrent response. Increased crystallinity and surface texturing as the ion size increased were observed, as well as an enhanced photocurrent response in Cs-doped CIS. Li- and Na-doped films had larger conductivity than the undoped film while the K- and Cs-doped samples displayed shorter currents and the current images indicated strong charge accumulation in the K- and Cs-doped films, forming surface capacitors. Corrected current-sensing AFM IV curves were adjusted with the Shockley equation.

  15. Optical properties of Cu implanted ZnO

    International Nuclear Information System (INIS)

    Cetin, A.; Kibar, R.; Ayvacikli, M.; Can, N.; Buchal, Ch.; Townsend, P.D.; Stepanov, A.L.; Karali, T.; Selvi, S.

    2006-01-01

    Nanoparticles of Cu have been made in zinc oxide crystals by ion implantation. The Cu ions were implanted at 400 keV into the (0 0 0 1) face of a single crystal. After implantation and after post-irradiation annealing there are numerous changes in the luminescence responses which include a variety of green and yellow emission bands. Following annealing at temperatures up to 1000 o C a green luminescence near 525 nm was observed which has been associated with the isolated Cu ions. The changes between as implanted and annealed luminescence signals suggests that the implants generate clustering or nanoparticle formation of Cu but anneals dissociate them

  16. Kinetics of photocurrent generation and an efficient charge separation of a dye-sensitized n-Cu2O/p-CuSCN junction photoelectrode in a solid-state photovoltaic cell

    International Nuclear Information System (INIS)

    Fernando, C A N; Kumara, N T R N; Gamage, T N

    2010-01-01

    A Cu/n-Cu 2 O/dye/p-CuSCN junction photoelectrode is fabricated to produce a solid-state dye-sensitized photovoltaic cell. Samples are characterized by XRD, SEM and surface resistivity measurements. Photocurrent generation is found due to light absorption of n-Cu 2 O thin film and dye sensitization between p-CuSCN and the dye. Kinetics of the photocurrent generation of the dye sensitization is studied solving the rate equations by the iteration method obtaining a relationship for the photocurrent quantum efficiency (Φ) depending on the surface concentration (D o ) of the dye and the rate constants of the reactions with connection to the dye sensitization process. The solution obtained in the steady state by iteration is found to be of the form Φ = AD o −BD o 2 (A and B are constants related to the reaction rates of the photocurrent generation process and the concentration of the n-Cu 2 O film). The variation of the n-Cu 2 O concentration with photocurrent is presented. A photocurrent enhancement is observed for the Cu/n-Cu 2 O/dye/p-CuSCN photovoltaic cell compared to that of Cu/n-Cu 2 O, Cu/p-CuSCN/dye and Cu/n-Cu 2 O/p-CuSCN photovoltaic cells. Good rectification characteristics are observed for the Cu/n-Cu 2 O/p-CuSCN photoelectrode compared to that of Cu/n-Cu 2 O and Cu/p-CuSCN photoelectrodes. Photocurrent enhancement is found due to the efficient charge separation process at the n–p junction. Energy band structures of the n–p junction are proposed according to the onset potentials which are used to discuss the mechanism of the efficient charge separation suppressing the recombination process

  17. Large magnetoresistance in intercalated Cu oxides

    OpenAIRE

    Grigoryan, L.; Furusawa, M.; Hori, H.; Tokumoto, M.

    1997-01-01

    Magnetism and electrical resistance as a function of magnetic field, temperature, and chemical composition are studied in Cu oxides intercalated with metal phthalocyanines MPc, where M is Fe or Ni, and Pc is C_H_N_. An unusually large positive magnetoresistance (MR) of ~ 1200% is observed in FePc-intercalated Bi_Sr_Ca_Cu_O_ samples with two Cu-O layers in the unit cell (n=2). The magnitude of the MR decreased to 40% and ~ 0% in the FePc-intercalated n=3 and n=4 samples, respectively, and to ~...

  18. Development of cold sprayed Cu coating for canister

    International Nuclear Information System (INIS)

    Kim, Hyung Jun; Kang, Yoon Ha

    2010-01-01

    Cold sprayed Cu deposition was studied for the application of outer part of canister for high level nuclear waste. Five commercially available pure Cu powders were analyzed and sprayed by high pressure cold spray system. Electrochemical corrosion test using potentiostat in 3.5% NaCl solution was conducted as well as microstructural analysis including hardness and oxygen content measurements. Overall evaluation of corrosion performance of cold sprayed Cu deposition is inferior to forged and extruded Cu plates, but some of Cu depositions are comparable to Cu plates. The simulated corrosion test in 200m underground cave is still in progress. The effect of cold spray process parameters was also studied and the results show that the type of nozzle is the most important other than powder feed rate, spray distance, and scan speed. 1/10 scale miniature of canister was manufactured confirming that the production of full scale canister is possible

  19. Scalable production of Cu@C composites for cross-coupling catalysis

    Energy Technology Data Exchange (ETDEWEB)

    Bu, Lijuan [Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081 (China); Ming, Hai, E-mail: lunaticmh@163.com [College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123 (China)

    2015-10-15

    Highlights: • Cu@C core–shell composite was prepared by reduction of [Cu(NH{sub 3}){sub 4}]{sup 2+} with glucose. • The carbon shell in Cu@C can be tuned to the different degree of carbonization. • The Cu@C composites were utilized to catalyze the C−N cross coupling reaction. • The catalytic ability of Cu@C depends on the degree of shell-carbonization. - Abstract: A novel Cu@C core–shell microstructure was prepared by reduction of [Cu(NH{sub 3}){sub 4}]{sup 2+} with glucose using a mild hydrothermal process. The carbon shell of such Cu@C composite can be tuned to different carbonization degrees just through varying the calcination conditions. The structural properties of as-prepared Cu@C were investigated in detail by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron micrographs (TEM) and Raman spectra. In addition, these Cu@C composites were firstly used to catalyze the C−N cross coupling of amines with iodobenzene. Among them, the catalytic ability of Cu@C composites increased as their surface carbon’s carburization degree improved.

  20. Generalized stacking fault energies, cleavage energies, ionicity and brittleness of Cu(Al/Ga/In)Se2 and CuGa(S/Se/Te)2

    Science.gov (United States)

    Xue, H. T.; Tang, F. L.; Gruhn, T.; Lu, W. J.; Wan, F. C.; Rui, Z. Y.; Feng, Y. D.

    2014-04-01

    We calculate the generalized stacking fault (GSF) energies and cleavage energies γcl of the chalcopyrite compounds CuAlSe2, CuGaSe2, CuInSe2, CuGaS2 and CuGaTe2 using first principles. From the GSF energies, we obtain the unstable stacking fault energies γus and intrinsic stacking fault energies γisf. By analyzing γus and γisf, we find that the \\langle \\bar{{1}}\\,1\\,0\\rangle (1 1 2) direction is the easiest slip direction for these five compounds. Also, for CuInSe2, it is most possible to undergo a dislocation-nucleation-induced plastic deformation along the \\langle \\bar{{1}}\\,1\\,0\\rangle (1 1 2) slip direction. We show that the (1 1 2) plane is the preferable plane for fracture in the five compounds by comparing γcl of the (0 0 1) and (1 1 2) planes. It is also found that both γus and γcl decrease as the cationic or anionic radius increases in these chalcopyrites, i.e. along the sequences CuAlSe2 → CuGaSe2 → CuInSe2 and CuGaS2 → CuGaSe2 → CuGaTe2. Based on the values of the ratio γcl/γus, we discuss the brittle-ductile properties of these compounds. All of the compounds can be considered as brittle materials. In addition, a strong relationship between γcl/γus and the total proportion of ionic bonding in these compounds is found.

  1. Enhanced photocatalytic, electrochemical and photoelectrochemical properties of TiO2 nanotubes arrays modified with Cu, AgCu and Bi nanoparticles obtained via radiolytic reduction

    International Nuclear Information System (INIS)

    Nischk, Michał; Mazierski, Paweł; Wei, Zhishun; Siuzdak, Katarzyna; Kouame, Natalie Amoin; Kowalska, Ewa; Remita, Hynd; Zaleska-Medynska, Adriana

    2016-01-01

    Highlights: • TiO 2 nanotubes were modified with Cu, AgCu, Bi nanoparticles via gamma radiolysis. • Excessive amount of deposited metal decreased photocatalytic activity. • AgCu-modified samples were more active than Cu-modified (with the same Cu content). • AgCu nanoparticles exist in a core (Ag) -shell (Cu) form. • Examined photocatalysts were resistant towards photocorrosion processes. - Abstract: TiO 2 nanotubes arrays (NTs), obtained via electrochemical anodization of Ti foil, were modified with monometallic (Cu, Bi) and bimetallic (AgCu) nanoparticles. Different amounts of metals’ precursors were deposited on the surface of NTs by the spin-coating technique, and the reduction of metals was performed via gamma radiolysis. Surface modification of titania was studied by EDS and XPS analysis. The results show that AgCu nanoparticles exist in a Ag core -Cu shell form. Photocatalytic activity was examined under UV irradiation and phenol was used as a model pollutant of water. Over 95% of phenol degradation was achieved after 60 min of irradiation for almost all examined samples, but only slight difference in degradation efficiency (about 3%) between modified and bare NTs was observed. However, the initial phenol degradation rate and TOC removal efficiency was significantly enhanced for the samples modified with 0.31 and 0.63 mol% of Bi as well as for all the samples modified with Cu and AgCu nanoparticles in comparison with bare titania nanotubes. The saturated photocurrent, under the influence of simulated solar light irradiation, for the most active Bi- and AgCu-modified samples, was over two times higher than for pristine NTs. All the examined materials were resistant towards photocorrosion processes that enables their application for long term processes induced by light.

  2. CuLi2Sn and Cu2LiSn: Characterization by single crystal XRD and structural discussion towards new anode materials for Li-ion batteries.

    Science.gov (United States)

    Fürtauer, Siegfried; Effenberger, Herta S; Flandorfer, Hans

    2014-12-01

    The stannides CuLi 2 Sn (CSD-427095) and Cu 2 LiSn (CSD-427096) were synthesized by induction melting of the pure elements and annealing at 400 °C. The phases were reinvestigated by X-ray powder and single-crystal X-ray diffractometry. Within both crystal structures the ordered CuSn and Cu 2 Sn lattices form channels which host Cu and Li atoms at partly mixed occupied positions exhibiting extensive vacancies. For CuLi 2 Sn, the space group F-43m. was verified (structure type CuHg 2 Ti; a =6.295(2) Å; wR 2 ( F ²)=0.0355 for 78 unique reflections). The 4( c ) and 4( d ) positions are occupied by Cu atoms and Cu+Li atoms, respectively. For Cu 2 LiSn, the space group P 6 3 / mmc was confirmed (structure type InPt 2 Gd; a =4.3022(15) Å, c =7.618(3) Å; wR 2 ( F ²)=0.060 for 199 unique reflections). The Cu and Li atoms exhibit extensive disorder; they are distributed over the partly occupied positions 2( a ), 2( b ) and 4( e ). Both phases seem to be interesting in terms of application of Cu-Sn alloys as anode materials for Li-ion batteries.

  3. Electromigration-induced cracks in Cu/Sn3.5Ag/Cu solder reaction couple at room temperature

    International Nuclear Information System (INIS)

    He Hongwen; Xu Guangchen; Guo Fu

    2009-01-01

    Electromigration (EM) behavior of Cu/Sn 3.5 Ag/Cu solder reaction couple was investigated with a high current density of 5 x 10 3 A/cm 2 at room temperature. One dimensional structure, copper wire/solder ball/copper wire SRC was designed and fabricated to dissipate the Joule heating induced by the current flow. In addition, thermomigration effect was excluded due to the symmetrical structure of the SRC. The experimental results indicated that micro-cracks initially appeared near the cathode interface between solder matrix and copper substrate after 474 h current stressing. With current stressing time increased, the cracks propagated and extended along the cathode interface. It should be noted that the continuous Cu 6 Sn 5 intermetallic compounds (IMCs) layer both at the anode and at the cathode remained their sizes. Interestingly, tiny cracks appeared at the root of some long column-type Cu 6 Sn 5 at the cathode interface due to the thermal stress.

  4. Magnetism of CuCl{sub 2}·2D{sub 2}O and CuCl{sub 2}·2H{sub 2}O, and of CuBr{sub 2}·6H{sub 2}O

    Energy Technology Data Exchange (ETDEWEB)

    DeFotis, G.C., E-mail: gxdefo@wm.edu [Department of Chemistry, College of William and Mary, Williamsburg, VA 23187 (United States); Hampton, A.S.; Van Dongen, M.J.; Komatsu, C.H.; Benday, N.S.; Davis, C.M. [Department of Chemistry, College of William and Mary, Williamsburg, VA 23187 (United States); Hays, K.; Wagner, M.J. [Department of Chemistry, George Washington University, Washington, D.C. 20052 (United States)

    2017-07-15

    Highlights: • CuCl{sub 2}·2D{sub 2}O is examined magnetically and compared with CuCl{sub 2}·2H{sub 2}O. • Slightly lower magnetic characteristic temperatures occur for deuterated dihydrate. • The new compound CuBr{sub 2}·6H{sub 2}O is examined magnetically. • Unexpected relationships appears between magnetic behaviors of CuBr{sub 2}·6H{sub 2}O and CuBr{sub 2}. • Two alternative monoclinic unit cells can account for diffraction data on CuBr{sub 2}·6H{sub 2}O. - Abstract: The magnetic properties of little examined CuCl{sub 2}·2D{sub 2}O are studied and compared with those of CuCl{sub 2}·2H{sub 2}O. New CuBr{sub 2}·6H{sub 2}O is also examined. Susceptibility maxima appear for chlorides at 5.35 and 5.50 K, in the above order, with estimated antiferromagnetic ordering at 4.15 and 4.25 K. Curie-Weiss fits yield g of 2.210 and 2.205, and Weiss θ of −6.0 and −4.7 K, respectively, in χ{sub M} = C/(T − θ). One-dimensional Heisenberg model fits to susceptibilities, including interchain exchange in a mean-field approximation, are performed. Interchain exchange is significant but much weaker than intrachain. The bromide hexahydrate strongly differs magnetically from any chloride hydrate, but exhibits notable similarities and differences compared to previously studied CuBr{sub 2}. A broad susceptibility maximum occurs near 218 K, only 4% lower than for CuBr{sub 2}, but with almost twice the magnitude. Powder X-ray diffraction data for CuBr{sub 2}·6H{sub 2}O may be best accounted for by a monoclinic unit cell that is metrically orthorhombic. The volume per formula unit is consistent with trends in metal ionic radii. However, an alternative monoclinic cell with 5% smaller volume more readily rationalizes the magnetism.

  5. Effect of Cu{sup 2+}/Al{sup 3+} mole ratio on structure of Cu-Al bimetallic nanoparticles prepared by radiation induced method

    Energy Technology Data Exchange (ETDEWEB)

    Abedini, Alam; Larki, Farhad; Saion, Elias; Noroozi, Monir [Putra Malaysia Univ., Serdang, Selangor (Malaysia). Dept. of Physics

    2013-07-15

    Cu-Al bimetallic nanoparticles were synthesized by gamma irradiation technique in aqueous solutions containing metal chlorides as precursors, polyvinyl alcohol (PVA) as a capping agent, isopropanol as a radical scavenger, and distilled water as a solvent. The Cu-Al bimetallic nanoparticles were characterized by transmission electron microscopy (TEM), UV-visible absorption spectrometry, powder X-ray diffractometer (XRD), and Energy-dispersive X-ray spectroscopy (EDX). The TEM, XRD, EDX, and absorption analyses confirmed the formation of core-shell structure of Cu-Al bimetallic nanoparticles at lower Cu{sup 2+}/Al{sup 3+} mole ratio, and the formation of Cu-Al alloy nanoparticles at higher Cu{sup 2+}/Al{sup 3+} mole ratio. The TEM analysis for particle size and size distribution revealed that the average particle size of Cu-Al bimetallic nanoparticles decreased with the increase of absorbed dose. It may be explained due to the competition between nucleation and aggregation processes in the formation of metallic nanoparticles under irradiation. (orig.)

  6. Mechanical properties and electrical conductivity of Cu-Cr and Cu-Cr-4% SiC nanocomposites for thermo-electric applications

    International Nuclear Information System (INIS)

    Mula, Suhrit; Sahani, Pankajini; Pratihar, S.K.; Mal, Siddhartha; Koch, Carl C.

    2011-01-01

    Highlights: → Ball-milled Cu-Cr and Cu-Cr-SiC nanopowders successfully consolidated by microwave sintering. → Addition of nanosize SiC in Cu-Cr leads to enhanced sintered density, wear and hardness. → A good combination of wear resistance, hardness and electrical conductivity resulted in Cu 94 Cr 6 -4% SiC. → Microwave suscepting SiC particles played a pivotal role in good densification retaining matrix grains 99 Cr 1 , Cu 94 Cr 6 , Cu 99 Cr 1 -4 wt.% SiC and Cu 94 Cr 6 -4 wt.% SiC (average particle size ∼30 nm). The 50 h ball-milled samples were uniaxially pressed, and then pellets were sintered at 800 deg. C, 900 deg. C and 1000 deg. C for a constant soaking period of 30 min by microwave sintering technique. Microstructural characterization was carried out by X-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM). Sintered compacts resulted a highly densified compacts (∼95% relative density) while retaining ultra-fine grains (100-200 nm) in the matrix. The mechanical properties, namely, hardness and wear resistance, and electrical conductivity of the sintered specimens were also evaluated. The best combination of mechanical properties (e.g. hardness ∼2.4 GPa) and electrical conductivity (60.3% of IACS) were obtained for Cu 94 Cr 6 -4 wt.% SiC sintered at 900 deg. C. This is possibly due to presence of ultra-fine grains in the bulk samples, good densification and proper bonding between particles. The results were analyzed in the light of interactions of microwaves between metallic matrix and microwave susceptive SiC particulates.

  7. Interfacial Reaction and IMC Growth of an Ultrasonically Soldered Cu/SAC305/Cu Structure during Isothermal Aging

    Directory of Open Access Journals (Sweden)

    Yulong Li

    2018-01-01

    Full Text Available In order to accelerate the growth of interfacial intermetallic compound (IMC layers in a soldering structure, Cu/SAC305/Cu was first ultrasonically spot soldered and then subjected to isothermal aging. Relatively short vibration times, i.e., 400 ms and 800 ms, were used for the ultrasonic soldering. The isothermal aging was conducted at 150 °C for 0, 120, 240, and 360 h. The evolution of microstructure, the IMC layer growth mechanism during aging, and the shear strength of the joints after aging were systemically investigated. Results showed the following. (i Formation of intermetallic compounds was accelerated by ultrasonic cavitation and streaming effects, the thickness of the interfacial Cu6Sn5 layer increased with aging time, and a thin Cu3Sn layer was identified after aging for 360 h. (ii The growth of the interfacial IMC layer of the ultrasonically soldered Cu/SAC305/Cu joints followed a linear function of the square root of the aging time, revealing a diffusion-controlled mechanism. (iii The tensile shear strength of the joint decreased to a small extent with increasing aging time, owing to the combined effects of IMC grain coarsening and the increase of the interfacial IMC. (iv Finally, although the fracture surfaces and failure locations of the joint soldered with 400 ms and 800 ms vibration times show similar characteristics, they are influenced by the aging time.

  8. Dietary bioavailability of Cu adsorbed to colloidal hydrous ferric oxide

    Science.gov (United States)

    Cain, Daniel J.; Croteau, Marie-Noële; Fuller, Christopher C.

    2013-01-01

    The dietary bioavailability of copper (Cu) adsorbed to synthetic colloidal hydrous ferric oxide (HFO) was evaluated from the assimilation of 65Cu by two benthic grazers, a gastropod and a larval mayfly. HFO was synthesized, labeled with 65Cu to achieve a Cu/Fe ratio comparable to that determined in naturally formed HFO, and then aged. The labeled colloids were mixed with a food source (the diatom Nitzschia palea) to yield dietary 65Cu concentrations ranging from 211 to 2204 nmol/g (dry weight). Animals were pulse fed the contaminated diet and assimilation of 65Cu from HFO was determined following 1–3 days of depuration. Mass transfer of 65Cu from HFO to the diatom was less than 1%, indicating that HFO was the source of 65Cu to the grazers. Estimates of assimilation efficiency indicated that the majority of Cu ingested as HFO was assimilated (values >70%), implying that colloidal HFO potentially represents a source of dietary Cu to benthic grazers, especially where there is active formation and infiltration of these particles into benthic substrates.

  9. Electrodeposition and Thermoelectric Properties of Cu-Se Binary Compound Films

    Science.gov (United States)

    Yang, Mengqian; Shen, Zhengwu; Liu, Xiaoqing; Wang, Wei

    2016-03-01

    Cu-Se binary compound films have been prepared by electrodeposition from solutions containing CuSO4, H2SeO3, and H2SO4 and their composition, structure, and thermoelectric performance analyzed. Moving the depositing potential negatively increased the Cu content in the film, remarkably so for relatively low Cu2+ concentration in the solution. X-ray diffraction analysis showed that the phase composition of the films varied with their Cu content. Cu-Se binary compound films electrodeposited from solutions with different concentration ratios of CuSO4 to H2SeO3 showed two different phases: α-Cu2- x Se (monoclinic) with Se content in the range of 33.3 at.% to 33.8 at.%, and β-Cu2Se (cubic) with Se content in the range of 35.3 at.% to 36.0 at.%. The highest power factor for electrodeposited Cu2- x Se film was 0.13 mW/(K2 m) with Seebeck coefficient of 56.0 μV/K.

  10. In situ observation of Cu-Ni alloy nanoparticle formation by X-ray diffraction, X-ray absorption spectroscopy, and transmission electron microscopy: Influence of Cu/Ni ratio

    DEFF Research Database (Denmark)

    Wu, Qiongxiao; Duchstein, Linus Daniel Leonhard; Chiarello, Gian Luca

    2014-01-01

    Silica-supported, bimetallic Cu-Ni nanomaterials were prepared with different ratios of Cu to Ni by incipient wetness impregnation without a specific calcination step before reduction. Different in situ characterization techniques, in particular transmission electron microscopy (TEM), X-ray...... diffraction (XRD), and X-ray absorption spectroscopy (XAS), were applied to follow the reduction and alloying process of Cu-Ni nanoparticles on silica. In situ reduction of Cu-Ni samples with structural characterization by combined synchrotron XRD and XAS reveals a strong interaction between Cu and Ni species......, which results in improved reducibility of the Ni species compared with monometallic Ni. At high Ni concentrations silica-supported Cu-Ni alloys form a homogeneous solid solution of Cu and Ni, whereas at lower Ni contents Cu and Ni are partly segregated and form metallic Cu and Cu-Ni alloy phases. Under...

  11. Interdiffusion within model TiN/Cu and TiTaN/Cu systems synthesized by combinatorial thin film deposition

    International Nuclear Information System (INIS)

    Mühlbacher, M.

    2015-01-01

    Continued device miniaturization in microelectronics calls for a fundamental understanding of diffusion processes and damage mechanisms in the Cu metallization/TiN barrier layer system. Thus, the starting point of the present study is a combined experimental and theoretical examination of lattice diffusion in ideal single-crystal TiN/Cu stacks grown on MgO(001) by unbalanced DC magnetron sputter deposition. After a 12 h annealing treatment at 1000 °C, a uniform Cu diffusion layer of 7-12 nm is observed by scanning transmission electron microscopy and atom probe tomography (APT). Density-functional theory calculations predict a stoichiometry-dependent atomic diffusion mechanism of Cu in bulk TiN, with Cu diffusing on the N sublattice for the experimental N/Ti ratio of 0.92. These findings are extended to a comparison of grain boundary diffusion of Cu in dense polycrystalline TiN sputter-deposited on Si at 700 °C and underdense polycrystalline TiN grown on Si without external substrate heating. While the Cu diffusion path along dense TiN grain boundaries can be restricted to approximately 30 nm after a 1 h annealing treatment at 900 °C as visualized by 3D APT reconstructions, it already exceeds 500 nm after annealing at 700 °C in the underdense low-temperature TiN barrier. In this case, the formation of the Cu3Si phase, which characteristically grows along the close-packed directions in Si, is identified as the main damage mechanism leading to complete barrier failure. To meet the low-temperature processing needs of semiconductor industry and at the same time exploit the improved performance of dense polycrystalline barrier layers, deposition of TiTaN barriers on Si is demonstrated by a reactive hybrid high-power impulse/DC magnetron sputtering process, where barrier densification is achieved by pulsed irradiation of the growth surface with only a few at.% of energetic Ta ions without external substrate heating. These barrier layers delay the onset of Cu grain

  12. Satellite NMR in Cu doped with transition impurities

    International Nuclear Information System (INIS)

    Slichter, C.P.

    1979-01-01

    Measurements were made of the conduction electron spin magnetization density, M/sub sigma/(R vector) near iron group atoms (Sc through Ni) in Cu. M/sub sigma/(R vector) produces an additional effective local field which shifts the NMR frequency of nearby shells of Cu nuclei relative to Cu nuclei far from all impurities. Resonances of nearby shells appear as weak satellites to the strong resonance of distant Cu nuclei (the main line). M/sub sigma/(R vector) at a given site is proportional through know constants to the splitting of the satellite from the main line. The shell was identified giving rise to the satellite in many cases by use of single crystals. A good approximation M/sub sigma/(R vector) is proportional to the spin susceptibility chi/sub s/ of the impurity. For CuCr we find a large temperature independent chi/sub s/, in contrast to CuMn and CuFe. The results lead to a picture of the electronic structure of Cr, Mn, and Fe along the lines of Schrieffer and Hirst as ions with integral numbers of d-electrons, possessing crystal field and spin-orbit couplings

  13. Low temperature formation of CuIn{sub 1−x}Ga{sub x}Se{sub 2} solar cell absorbers by all printed multiple species nanoparticulate Se + Cu-In + Cu-Ga precursors

    Energy Technology Data Exchange (ETDEWEB)

    Möckel, Stefan A., E-mail: Stefan.A.Moeckel@FAU.de [Department of Materials Science, Chair of Materials for Electronics and Energy Technology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Martensstr, 7, 91058 Erlangen (Germany); Wernicke, Tobias; Arzig, Matthias; Köder, Philipp [Department of Materials Science, Chair of Materials for Electronics and Energy Technology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Martensstr, 7, 91058 Erlangen (Germany); Brandl, Marco [Chair for Crystallography and Structural Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Staudtstr. 3, 91058 Erlangen (Germany); Ahmad, Rameez; Distaso, Monica; Peukert, Wolfgang [Institute of Particle Technology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Cauerstr. 4, 91058 Erlangen (Germany); Hock, Rainer [Chair for Crystallography and Structural Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Staudtstr. 3, 91058 Erlangen (Germany); Wellmann, Peter J. [Department of Materials Science, Chair of Materials for Electronics and Energy Technology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Martensstr, 7, 91058 Erlangen (Germany)

    2015-05-01

    In this work an all nanoparticulate precursor for application in Cu(In{sub 1−x}Ga{sub x})Se{sub 2} solar cell absorbers is presented. Binary Cu-In nanoparticles, Cu-Ga powder and elemental Se nanoparticles were mixed in dispersion and deposited on Mo-coated substrates. Research was focused on Cu(In{sub 1−x}Ga{sub x})Se{sub 2} layer formation kinetics, phase composition characterised by differential scanning calorimetry and in-situ X-ray diffraction (XRD). Furthermore phase composition and morphology were studied by ex-situ XRD, Raman spectroscopy and scanning electron microscopy. The results revealed a fast consumption of the precursor and the formation of CuInSe{sub 2} below 340 °C. Binary secondary phases were not observed at any temperature. - Highlights: • All printable precursor for CIGSe • Formation of Ga droplets • Complete consumption below 340 °C.

  14. A facile and low cost synthesis of earth abundant element Cu{sub 2}ZnSnS{sub 4} (CZTS) nanocrystals: Effect of Cu concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Seung Wook; Han, Jun Hee [Department of Materials Science and Engineering, KAIST, 335 Gwahangno, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Park, Chan Yeong; Kim, Sae-Rok; Park, Yeon Chan; Agawane, G.L. [Photonics Technology Research Institute, Department of Materials Science and Engineering, Chonnam National University, 300 Yongbong-Dong, Buk-Gu, Gwangju 500-757 (Korea, Republic of); Moholkar, A.V. [Electrochemical Mat. Lab, Department of Physics, Shivaji University, Kolhapur 416-004 (India); Yun, Jae Ho [Photovoltaic Research Group, Korea Institute of Energy Research, 71-2 Jang-Dong, Yuseong-Gu, Daejeon 305-343 (Korea, Republic of); Jeong, Chae Hwan [Solar City Center, Development of Advanced Components and Materials Korea Institute of Industrial Technology, Gwangju 500-480 (Korea, Republic of); Lee, Jeong Yong, E-mail: j.y.lee@kaist.ac.kr [Department of Materials Science and Engineering, KAIST, 335 Gwahangno, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Kim, Jin Hyeok, E-mail: jinhyeok@chonnam.ac.kr [Photonics Technology Research Institute, Department of Materials Science and Engineering, Chonnam National University, 300 Yongbong-Dong, Buk-Gu, Gwangju 500-757 (Korea, Republic of)

    2012-11-15

    Highlights: Black-Right-Pointing-Pointer Cu{sub 2}ZnSnS{sub 4} (CZTS) nanocrystals (NCs) were prepared by sulfurization of microwave assisted precursor without toxic chemicals. Black-Right-Pointing-Pointer Effect of Cu concentration on the properties of CZTS NCs was investigated using various analysis methods. Black-Right-Pointing-Pointer The properties of CZTS NCs was strongly related to the Cu concentrations. - Abstract: Cu{sub 2}ZnSnS{sub 4} (CZTS) nanocrystals (NCs) were synthesized by sulfurization of microwave assisted precursor powders without toxic chemicals. The effects of different Cu concentration from 0.01 to 0.025 M on the structural, morphological, compositional, chemical and optical properties of CZTS NCs were investigated. X-ray diffraction patterns, X-ray photoelectron spectroscopy and transmission electron microscopy results showed that the precursor powder contains several broad peaks that could not be assigned to CZTS, ZnS, Cu{sub 2-x}S, Sn{sub 2}S{sub 3} and Cu{sub 2}SnS{sub 3}. However, the sulfurized NCs showed both kesterite CZTS and Cu- and Sn-based secondary phases except for that formed at Cu concentration of 0.02 M. Inductively coupled plasma (ICP) results showed that the presence of Cu in the sulfurized CZTS NCs increased with increasing Cu concentration from 16.57 to 32.94 at.% while Zn and Sn in the sulfurized CZTS NCs decreased with increasing Cu concentration. UV-Vis spectroscopy results showed that the absorption coefficient of the sulfurized NCs was over 10{sup 4} cm{sup -1} in the visible region and band gap energy of the sulfurized CZTS NCs decreased from 1.65 to 1.28 eV with increasing Cu concentration.

  15. RbCuFe(PO42

    Directory of Open Access Journals (Sweden)

    Mongi Ben Amara

    2013-08-01

    Full Text Available A new iron phosphate, rubidium copper(II iron(III bis(phosphate, RbCuFe(PO42, has been synthesized as single crystals by the flux method. This compound is isostructural with KCuFe(PO42 [Badri et al. (2011, J. Solid State Chem. 184, 937–944]. Its structure is built up from Cu2O8 units of edge-sharing CuO5 polyhedra, interconnected by FeO6 octahedra through common corners to form undulating chains that extend infinitely along the [011] and [01-1] directions. The linkage of such chains is ensured by the PO4 tetraedra and the resulting three-dimensional framework forms quasi-elliptic tunnels parallel to the [101] direction in which the Rb+ cations are located.

  16. Photonuclear spallation reactions in Cu

    International Nuclear Information System (INIS)

    Shibata, S.; Imamura, M.; Miyachi, T.

    1986-06-01

    Formation yields of 24 radioactive nuclides by the interaction of bremsstrahlung in the maximum end-point energies of 100 MeV - 1 GeV with Cu have been measured by direct γ-ray counting of irradiated targets. The yields in the mass range of 42 to 60 except for 60 Cu were analysed by non-linear least-squares fit to construct the mass yield and charge dispersion curves in spallation reactions. From the parameter values obtained, the energy dependence of the slope of the mass yield curve and the relationship between target N/Z and the most probable product N/Z were investigated in comparison with the results of proton, α and heavy ion-induced spallations of Cu. The characteristics of photon-induced spallations are discussed. (author)

  17. Phase equilibria in Dy-Cu-Al system at 500 deg C

    International Nuclear Information System (INIS)

    Kuz'ma, Yu.B.; Milyan, V.V.

    1989-01-01

    Using the methods of X-ray diffraction analysis a diagram of phase equilibria in Dy-Cu-Al system at 500 deg C is plotted. Boundaries of solid solutions on the basis of DyCu 2 , DyCu and DyAl 2 compounds are determined and homogeneity regions of ternary compounds Dy 2 (Cu, Al) 7 and Dy(CuAl) 5 are ascertained. Compounds DyCuAl 3 , Dy 4 Cu 4 Al 11 and Dy 5 Cu 6 Al 9 have been detected for the first time

  18. Organic photovoltaic effects depending on CuPc layer thickness

    International Nuclear Information System (INIS)

    Hur, Sung Woo; Kim, Tae Wan; Chung, Dong Hoe; Oh, Hyun Seok; Kim, Chung Hyeok; Lee, Joon Ung; Park, Jong Wook

    2004-01-01

    Organic photovoltaic effects were studied in device structures of ITO/CuPc/Al and ITO/CuPc/C 60 /BCP/Al by varying the CuPc layer thickness. Since the exciton diffusion length is relatively short in organic semiconductors, a study on the thickness-dependent photovoltaic effects is important. The thickness of the CuPc layer was varied from 10 nm to 50 nm. We found that the optimum CuPc layer thickness was around 40 nm from the analysis of the current density-voltage characteristics in an ITO/CuPc/Al photovoltaic cell. The efficiency of the device shows that the multi-layered heterojunction structure is more appropriate for photovoltaic cells.

  19. Magnetoelectric Coupling in CuO Nanoparticles for Spintronics Applications

    Science.gov (United States)

    Kaur, Mandeep; Tovstolytkin, Alexandr; Lotey, Gurmeet Singh

    2018-05-01

    Multiferroic copper oxide (CuO) nanoparticles have been synthesized by colloidal synthesis method. The morphological, structural, magnetic, dielectric and magnetodielectric property has been investigated. The structural study reveals the monoclinic structure of CuO nanoparticles. Transmission electron microscopy images disclose that the size of the CuO nanoparticles is 18 nm and the synthesized nanoparticles are uniform in size and dispersion. Magnetic study tells the weak ferromagnetic character of CuO nanoparticles with coercivity and retentivity value 206 Oe and 0.060 emu/g respectively. Dielectric study confirms that the dielectric constant of CuO nanoparticles is around 1091 at low frequency. The magnetoelectric coupling in the synthesized CuO nanoparticles has been calculated by measuring magnetodielectric coupling coefficient.

  20. Comparison of Two Kinds of 64Cu Labelled Octreotide Analogues

    Directory of Open Access Journals (Sweden)

    HAN Zhen-yi1;LIANG Ji-xin1;HU Ji2;LUO Hong-yi1;QING Jing2;CHEN Yu-qing2;LI Guang2;LI Hong-yu1,2

    2016-10-01

    Full Text Available Octreotide analogues DOTA-TOC and DOTA-TATE were labeled with 64Cu. The influences of the ratio of peptide mass to 64Cu activity, pH value, temperature and reaction time on labeling yield were investigated. The optimum labeling was determined. In vitro stability tests in saline and 10% bovine serum had been carried out. Biodistribution of the two radiolabelled compounds in normal mice and Micro PET imaging in nude mice bearing U87MG tumor had been evaluated. The results showed that the labeling yields of 64Cu-DOTA-TOC and 64Cu-DOTA-TATE were higher than 95%. Two kinds of octreotide analogues labeled with 64Cu were quite stable in saline and decomposed slowly in 10% bovine serum at 37 ℃. Biodistribution results in normal mice showed that two 64Cu labelled tracers had similar profiles. Both of the compounds washed out from the blood quickly. High uptake of radioactivity in liver and kidneys indicated the tracers were excreted via both hepatobiliary system and renal system. At the same time, compared to 64Cu-DOTA-TOC, higher radioactivity accumulation of 64Cu-DOTA-TATE in liver and kidneys was observed. Micro PET images of U87MG tumor-bearing nude mice with 64Cu-DOTA-TOC and 64Cu-DOTA-TATE showed the tumors very clearly. The radioactivity uptake of 64Cu-DOTA-TATE in tumor was higher than that of 64Cu-DOTA-TOC. This work has paved the way for further preclinical and clinical application of 64Cu-DOTA-TOC and 64Cu-DOTA-TATE as PET tumor imaging agents.

  1. Low-lying isomeric levels in Cu75

    Science.gov (United States)

    Daugas, J. M.; Faul, T.; Grawe, H.; Pfützner, M.; Grzywacz, R.; Lewitowicz, M.; Achouri, N. L.; Angélique, J. C.; Baiborodin, D.; Bentida, R.; Béraud, R.; Borcea, C.; Bingham, C. R.; Catford, W. N.; Emsallem, A.; de France, G.; Grzywacz, K. L.; Lemmon, R. C.; Lopez Jimenez, M. J.; de Oliveira Santos, F.; Regan, P. H.; Rykaczewski, K.; Sauvestre, J. E.; Sawicka, M.; Stanoiu, M.; Sieja, K.; Nowacki, F.

    2010-03-01

    Isomeric low-lying states were identified and investigated in the Cu75 nucleus. Two states at 61.8(5)- and 128.3(7)-keV excitation energies with half-lives of 370(40)- and 170(15)-ns were assigned as Cu75m1 and Cu75m2, respectively. The measured half-lives combined with the recent spin assignment of the ground state allow one to deduce tentatively spin and parity of the two isomers and the dominant multipolarities of the isomeric transitions with respect to the systematics of the Cu isotopes. Shell-model calculations using an up-to-date effective interaction reproduce the evolution of the 1/2-, 3/2-, and 5/2- states for the neutron-rich odd-mass Cu isotopes when filling the νg9/2. The results indicate a significant change in the nuclear structure in this region, where a single-particle 5/2- state coexists with more and more collective 3/2- and 1/2- levels at low excitation energies.

  2. Growth and transport properties of multilayer superconducting films of Nd1.83Co0.17CuOx/YBa2Cu3O7-δ

    International Nuclear Information System (INIS)

    Gupta, A.; Gross, R.; Olsson, E.; Segmuller, A.; Koren, G.

    1990-01-01

    This paper reports on strained multilayer thin films of YBa 2 Cu 3 O 7-δ /Nd 1.83 Ce 0.17 CuO x that have been prepared by laser ablation deposition. For individual layers below a critical layer thickness of about 250 Angstrom, coherency strain compresses the Nd 1.83 Ce 0.17 CuO x lattice and expands the YBa 2 Cu 3 O 7-δ lattice. The orthorhombic distortion in the YBa 2 Cu 3 O 7-δ layers is also removed. Depending on their oxygen content, either the YBa 2 Cu 3 O 7-δ , or the Nd 1.83 Ce 0.17 CuO x layers are superconducting in these multilayers. The strain-induced structural modification has a significant influence on the superconducting transition temperature and critical current density of the YBa 2 Cu 3 O 7-δ layers. Zero field critical current densities as high as 1.1 x 10 7 A/cm 2 at 77K have been measured for the YBa 2 Cu 3 O 7-δ layers

  3. Crystal structures of CCa2CuO5 and CSr1.9Ca1.1Cu2O7 refined from single crystal data

    International Nuclear Information System (INIS)

    Kopnin, E.M.; Matveev, A.T.; Salamakha, P.S.; Sato, A.; Takayama-Muromachi, E.

    2003-01-01

    Single crystals were grown for new layered oxycarbonates CCa 2 CuO 5 and CSr 1.9 Ca 1.1 Cu 2 O 7 at 6 GPa using a belt-type apparatus. Their crystal structures were determined using single crystal X-ray diffraction data with R1(wR2)=0.0294(0.0659) and 0.0199(0.0457) for CCa 2 CuO 5 and CSr 1.9 Ca 1.1 Cu 2 O 7 , respectively. These phases crystallize in the space group P4/mmm (No. 123), Z=1 with a=3.8157(1) Angst, c=7.1426(3) Angst for CCa 2 CuO 5 and a=3.8753(1) Angst, c=10.6765(5) Angst for CSr 1.9 Ca 1.1 Cu 2 O 7 . In contrast to CSr 2 CuO 5 , no ordering in the orientation of the triangular CO 3 groups was revealed in CCa 2 CuO 5 and CSr 1.9 Ca 1.1 Cu 2 O 7

  4. Purity of targets prepared on Cu substrates

    Science.gov (United States)

    Méens, A.; Rossini, I.; Sens, J. C.

    1993-09-01

    The purity of several elemental self-supporting targets usually prepared by evaporation onto soluble Cu substrates has been studied. The targets were analysed by Rutherford backscattering and instrumental neutron activation analysis. Because of the high percentage of Cu observed in some Si targets, further measurements, including transmission electron microscopy, have been performed on Si targets deposited by e-gun bombardment onto Cu and ion-beam sputtering onto betaine.

  5. Tribological properties of self-lubricating Ta-Cu films

    Science.gov (United States)

    Qin, Wen; Fu, Licai; Zhu, Jiajun; Yang, Wulin; Li, Deyi; Zhou, Lingping

    2018-03-01

    In this paper, Ta and TaCu films were deposited by using magnetron sputtering, and the tribological properties of the films against Si3N4 balls were investigated under the loads of 2 N and 5 N. The average grain sizes of both films are below 25 nm. Ta and TaCu films have approximate hardness. While the wear rate of TaCu film is much smaller than that of Ta film. Post-wear testing XRD, Raman and XPS revealed the formation of tantalum oxide on the worn surface of both Ta and TaCu films. Tantalum oxidation is effectively lubricating to reduce friction coefficient. So the friction coefficient of both Ta and TaCu film is about 0.45 under different applied loads. Meanwhile, the addition of Cu could increase the toughness of the film, and avoid the generation of wear debris, resulting in a significant increase in wear resistance.

  6. A water soluble Cu(I)-NHC for CuAAC ligation of unprotected peptides under open air conditions.

    Science.gov (United States)

    Gaulier, Christelle; Hospital, Audrey; Legeret, Bertrand; Delmas, Agnès F; Aucagne, Vincent; Cisnetti, Federico; Gautier, Arnaud

    2012-04-25

    A reducing agent-free version of CuAAC able to operate under open air conditions is reported. A readily-synthesizable, hydrophilic and highly stable Cu(I)-NHC allows the clean ligations of unprotected peptides comprising sensitive side chains, at millimolar concentrations.

  7. Toxicity and transfer of CuO Nanoparticles on Arabidopsis thaliana

    Science.gov (United States)

    Zhao, Shilin; Dai, Yanhui; Xu, Lina

    2018-02-01

    CuO engineered nanoparticles (ENPs) are widely used in commercial applications. With increasing CuO ENPs production, CuO ENPs are likely to present in the environment and cause a potential threaten to ecosystem. In this work, Arabidopsis thaliana (Bay-0) was chosen to take the toxic experiment after exposed to CuO ENPs (0, 20, and 50 mg/L) and Cu2+ (0.15 mg/L). And the copper content of shoots at 50 mg/L CuO ENPs was about 20 times of control, indicating that CuO ENPs could be absorbed into Arabidopsis thaliana seedlings and transfered from root to shoot in a certain way.

  8. Thermoelectric and mechanical properties of spark plasma sintered Cu3SbSe3 and Cu3SbSe4: Promising thermoelectric materials

    Science.gov (United States)

    Tyagi, Kriti; Gahtori, Bhasker; Bathula, Sivaiah; Toutam, Vijaykumar; Sharma, Sakshi; Singh, Niraj Kumar; Dhar, Ajay

    2014-12-01

    We report the synthesis of thermoelectric compounds, Cu3SbSe3 and Cu3SbSe4, employing the conventional fusion method followed by spark plasma sintering. Their thermoelectric properties indicated that despite its higher thermal conductivity, Cu3SbSe4 exhibited a much larger value of thermoelectric figure-of-merit as compared to Cu3SbSe3, which is primarily due to its higher electrical conductivity. The thermoelectric compatibility factor of Cu3SbSe4 was found to be ˜1.2 as compared to 0.2 V-1 for Cu3SbSe3 at 550 K. The results of the mechanical properties of these two compounds indicated that their microhardness and fracture toughness values were far superior to the other competing state-of-the-art thermoelectric materials.

  9. The crystal structure of (Nb$_{0.75}$Cu$_{0.25}$)Sn$_{2}$ in the Cu-Nb-Sn system

    CERN Document Server

    Martin, Stefan; Nolze, Gert; Leineweber, Andreas; Leaux, Floriane; Scheuerlein, Christian

    2017-01-01

    During the processing of superconducting Nb$_{3}$Sn wire, several intermediate intermetallic phases including a previously encountered Cu-Nb-Sn phase show up. The yet unknown crystal structure of this phase is now identified by a combination of different experimental techniques and database search to be of the hexagonal NiMg2 type with a proposed composition of about (Nb0.75Cu0.25)Sn2. The structure determination started from an evaluation of the lattice parameters from EBSD Kikuchi patterns from quenched material suggesting hexagonal or orthorhombic symmetry. A database search then led to the hexagonal NiMg2 type structure, the presence of which was confirmed by a Rietveld analysis on the basis of high energy synchrotron X-ray powder diffraction data. Assuming a partial substitution of Nb in orthorhombic NbSn2 by Cu, the change of the valence electron concentration provokes a structural transformation from the CuMg2 type for NbSn2 to the NiMg2 type for (Nb0.75Cu0.25)Sn2. In the previous literature the (Nb0.7...

  10. The determination of extinction coefficient of CuInS2, and ZnCuInS3 multinary nanocrystals.

    Science.gov (United States)

    Qin, Lei; Li, Dongze; Zhang, Zhuolei; Wang, Kefei; Ding, Hong; Xie, Renguo; Yang, Wensheng

    2012-10-21

    A pioneering work for determining the extinction coefficient of colloidal semiconductor nanocrystals (NCs) has been cited over 1500 times (W. Yu, W. Guo, X. G. Peng, Chem. Mater., 2003, 15, 2854-2860), indicating the importance of calculating NC concentration for further research and applications. In this study, the size-dependent nature of the molar extinction coefficient of "greener" CuInS(2) and ZnCuInS(3) NCs with emission covering the whole visible to near infrared (NIR) is presented. With the increase of NC size, the resulting quantitative values of the extinction coefficients of ternary CuInS(2) and quaternary ZnCuInS(3) NCs are found to follow a power function with exponents of 2.1 and 2.5, respectively. Obviously, a larger value of extinction coefficient is observed in quaternary NCs for the same size of particles. The difference of the extinction coefficient from both samples is clearly demonstrated due to incorporating ZnS with a much larger extinction coefficient into CuInS(2) NCs.

  11. Ca doping of TSMTG-YBa2Cu3O7-δ/Y2BaCuO5 composites

    International Nuclear Information System (INIS)

    Delorme, F.; Harnois, C.; Monot-Laffez, I.; Marinel, S.

    2002-01-01

    Calcium doped YBa 2 Cu 3 O 7-δ /Y 2 BaCuO 5 bulk samples have been synthesised by the top-seeding-melt-texture growth (TSMTG) process up to 1 wt.% of CaCO 3 . Calcium additions up to 0.25 wt.% of CaCO 3 do not change the decomposition temperature whereas additions of 1 wt.% of CaCO 3 lead to an increase of the decomposition temperature of about 10 deg. C. This difference is not important enough to change the thermal cycle used to process YBa 2 Cu 3 O 7-δ undoped bulk samples. Microstructure studies show that no precursor or secondary phases containing calcium are present in the samples. Energy dispersive spectroscopy analyses have shown that Ca is present both in the YBa 2 Cu 3 O 7-δ matrix and the Y 2 BaCuO 5 particles. The position of the calcium atoms in the superconducting matrix is discussed. The calcium doped samples present slightly depressed critical temperatures but drastically depressed critical current densities

  12. Electricity generation from banana peels in an alkaline fuel cell with a Cu2O-Cu modified activated carbon cathode.

    Science.gov (United States)

    Liu, Peng; Liu, Xianhua; Dong, Feng; Lin, Qingxia; Tong, Yindong; Li, Yang; Zhang, Pingping

    2018-08-01

    Low-cost and highly active catalyst for oxygen reduction reaction is of great importance in the design of alkaline fuel cells. In this work, Cu 2 O-Cu composite catalyst has been fabricated by a facile laser-irradiation method. The addition of Cu 2 O-Cu composite in activated carbon air-cathode greatly improves the performance of the cathode. Our results indicate the enhanced performance is likely attributed to the synergistic effect of high conductivity of Cu and the catalytic activity of Cu 2 O towards the oxygen reduction reaction. Furthermore, an alkaline fuel cell equipped with the composite air-cathode has been built to turn banana peels into electricity. Peak power density of 16.12Wm -2 is obtained under the condition of 3M KOH and 22.04gL -1 reducing sugar, which is higher than other reported low-temperature direct biomass alkaline fuel cells. HPLC results indicate the main oxidation products in the alkaline fuel cell were small organic acids. Copyright © 2018 Elsevier B.V. All rights reserved.

  13. Electrochemical capacitor behavior of copper sulfide (CuS) nanoplatelets

    Energy Technology Data Exchange (ETDEWEB)

    Justin Raj, C.; Kim, Byung Chul; Cho, Won-Je; Lee, Won-Gil; Seo, Yongseong; Yu, Kook-Hyun, E-mail: yukook@dongguk.edu

    2014-02-15

    Highlights: • The electrochemical supercapacitor electrode was fabricated using CuS nanoplatelets. • CuS electrodes shows better electrochemical properties in aqueous LiClO{sub 4} electrolyte. • The heat treated CuS electrode shows an excellent pseudocapacitance performance than bare CuS electrode. -- Abstract: Copper sulfide (CuS) nanoplatelets have been fabricated by simple low temperature chemical bath deposition technique for electrochemical supercapacitor electrodes. The morphology and structural properties of the electrodes were analyzed using scanning electron microscopy and X-ray diffraction. The effect of heat treatment on electrochemical properties of CuS electrodes were examined by cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic charge/discharge tests. Results show that bare and heat treated CuS has pseudocapacitive characteristic within the potential range of −0.6 to 0.3 V (vs. Ag/AgCl) in aqueous 1 M LiClO{sub 4} solution. The pseudocapacitance is induced mainly by lithium ions insertion/extraction with the CuS electrodes. The specific capacitance of 72.85 F g{sup −1} was delivered by heat treated CuS film at a scan rate of 5 mV s{sup −1} with an energy and power density of 6.23 W h kg{sup −1} and 1.75 kW kg{sup −1} at 3 Ag{sup −1} constant discharge current which is comparatively higher than that of as deposited CuS electrode.

  14. Microstructure and opto-electric properties of Cu/ITO thin films

    International Nuclear Information System (INIS)

    Wang Xian; Li Junlei; Shi Shiwei; Song Xueping; Cui Jingbiao; Sun Zhaoqi

    2012-01-01

    Highlights: ► We prepared Cu/ITO films with different Cu layer thickness. ► We analyzed the relation between opto-electric properties and roughness of the films. ► The Cu-16.1 nm/ITO film shows excellent optical and electric properties. ► Cu/ITO films have great application prospects in new-type transflective displays. - Abstract: Cu/ITO thin films were deposited on glass and silicon substrates by DC and RF magnetron sputtering at room temperature. X-ray diffraction results showed that the films were amorphous. Both of SEM images and 3D Profilometer images indicated that the surface morphology of the ITO films had been affected by the Cu layer. The optical and electric properties of the Cu/ITO films changed significantly with the variation of Cu layer thickness. Cu-5.4 nm/ITO film exhibited the highest optical transmittance of 62.9% at 550 nm and the lowest sheet resistance of 96 Ω/□, whereas Cu-16.1 nm/ITO film showed the highest average reflectance of 24.0% and the lowest resistance of 27.4 Ω/□. Based on our analysis, it was evaluated that Cu layer had an important effect on the electrical and optical properties of ITO thin films.

  15. Un acercamiento al paradigma cuántico

    OpenAIRE

    Zapata Mesa, John Fernando

    2009-01-01

    En este breve escrito se hace algunos comentarios sobre la física cuántica con el objetivo de hacer un acercamiento al lector a este nuevo paradigma y de motivar una reflexión en esta línea.La física cuántica es la ciencia más desarrollada y mejor fundamentada hasta el momento junto con la teoría de la relatividad de Einstein. Toda la tecnología actual es una consecuencia directa de la física cuántica, es decir sin física cuántica no hubiese sido posible la construcción de un láser, computado...

  16. The natural aging and precipitation hardening behaviour of Al-Mg-Si-Cu alloys with different Mg/Si ratios and Cu additions

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Lipeng [College of Materials Science and Engineering, Chongqing University, Chongqing 400044 China (China); Jia, Zhihong, E-mail: zhihongjia@cqu.edu.cn [College of Materials Science and Engineering, Chongqing University, Chongqing 400044 China (China); Zhang, Zhiqing; Sanders, Robert E.; Liu, Qing [College of Materials Science and Engineering, Chongqing University, Chongqing 400044 China (China); Yang, Guang [Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education and International Centre for Dielectric Research, Xi’an Jiaotong University, Xi’an 710049 (China)

    2015-03-11

    The natural aging and artificial aging behaviours of Al-Mg-Si-Cu alloys with different Mg/Si ratios and Cu additions were investigated using Vickers microhardness measurements, differential scanning calorimetry (DSC) analysis and transmission electron microscopy (TEM) characterisation. Excess Si and Cu additions enhanced the alloy hardening ability during natural (NA) and artificial aging (AA). Alloys with low Cu and high Si contents exhibited higher precipitation hardening than alloys rich in Mg during artificial aging. In contrast, the alloys with high amounts of Cu were less dependent on the Mg/Si ratio during precipitation hardening due to their similar aging kinetics. The main precipitate phases that contributed to the peak-aging hardness were the L, Q′ and β″ phases. In the over-aging conditions, the alloys rich in Mg and Cu had finer and more numerous precipitates than their Si-rich equivalents due to the preferential precipitation of the L phase. The combination of excess Mg and high Cu resulted in an alloy with a relatively low hardness in T4 temper and a relatively higher hardness after the paint baking cycle. Thus, this alloy has good potential for use in auto body panel applications.

  17. Theoretical investigation of the Fermi surface of La2-xSrxCuO4 and YBa2Cu3O7

    International Nuclear Information System (INIS)

    Antonov, V.N.; Antonov, V.N.; Bar'yakhtar, V.G.

    1989-01-01

    The theoretical investigation of both the Fermi surface (FS) form and isoenergetic surfaces near the Fermi energy of La 2-x Sr x CuO 4 and YBa 2 Cu 3 O 7 is carried out by selfconsistent LMTO/method in an atomic sphere approximation. The FS of these compounds is established to have an essential two-dimensional character. The FS La 2 CuO 4 is a corrugated rounded box centered in Γ point. The FS YBa 2 Cu 3 O 7 consists of four plates: an electron ''cushion'' in Γ point and three embeded hole surfaces centered in S point. In this case the ''cushion'' and one of the hole surfaces are vigorously corrugated along the z-direction. A comparison between both the FS calculated theoretically of La 2 CuO 4 and YBa 2 Cu 3 O 7 and experimental data on electron-positron annihilation is carried out. The electron-rate maps and numerical results of various characteristics, i.e., plate areas, mean rates, mean squares of the rates, partial densities of states for each plate of the FS YBa 2 Cu 3 O 7 are given

  18. Chelator induced phytoextraction and in situ soil washing of Cu

    International Nuclear Information System (INIS)

    Kos, Bostjan; Lestan, Domen

    2004-01-01

    In a soil column experiment, we investigated the effect of 5 mmol kg -1 soil addition of citric acid, ethylenediamine tetraacetate (EDTA), diethylenetriamine-pentaacetate (DTPA) and [S,S]-stereoisomer of ethylenediamine-disuccinate (EDDS) on phytoextraction of Cu from a vineyard soil with 162.6 mg kg -1 Cu, into the test plant Brassica rapa var. pekinensis. We also examined the use of a horizontal permeable barrier, composed of layers of nutrient enriched sawdust and apatite, for reduction of chelator induced Cu leaching. The addition of all chelators, except citric acid, enhanced Cu mobility and caused leaching of 19.5-23% of initial total Cu from the soil column. However, Cu plant uptake did not increase accordingly; the most effective was the EDDS treatment, in which plant Cu concentration reached 37.8±1.3 mg kg -1 Cu and increased by 3.3-times over the control treatment. The addition of none of the chelators in the concentration range from 5 to 15 mmol kg -1 exerted any toxic effect on respiratory soil microorganisms. When EDDS was applied into the columns with horizontal permeable barriers, only 0.53±0.32% of the initial total Cu was leached. Cu (36.7%) was washed from the 18 cm soil layer above the barrier and accumulated in the barrier. Our results indicate that rather than for a reduction of Cu leaching during rather ineffective chelate induced Cu phytoextraction, horizontal permeable barriers could be more effective in a new remediation technique of controlled in situ soil washing of Cu with biodegradable chelates

  19. Kinematic viscosity of liquid Al-Cu alloys

    International Nuclear Information System (INIS)

    Konstantinova, N Yu; Popel, P S

    2008-01-01

    Temperature dependences of kinematic viscosity n of liquid Al 100-x -Cu x alloys (x = 0.0, 10.0, 17.1, 25.0, 32.2, 40.0 and 50.0 at.%) were measured. A technique based on registration of the period and the decrement of damping of rotating oscillations of a cylindrical crucible with a melt was used. Viscosity was calculated in low viscous liquids approximation. Measurements were carried out in vacuum in crucibles of BeO with a temperature step of 30 deg. C and isothermal expositions of 10 to 15 minutes during both heating up to 1100-1250 deg. C and subsequent cooling. We have discovered branching of heating and cooling curves v(T) (hysteresis of viscosity) below temperatures depending on the copper content: 950 deg. C at 10 and 17.1 at.% Cu, 1050 deg. C at 25 and 40 at.% Cu, 850 deg. C at 32.2 at.% Cu. For samples with 10 and 17.1 at.% Cu the cooling curve 'returns' to the heating one near 700 deg. C. An abnormally high spreading of results at repeated decrement measurements was fixed at heating of the alloy containing 50 at.% Cu above 1000 deg. C. During subsequent cooling the effect disappeared. Isotherms of kinematic viscosity have been fitted for several temperatures

  20. Conventional and inverse magnetocaloric effect in Pr2CuSi3 and Gd2CuSi3 compounds

    International Nuclear Information System (INIS)

    Wang, Fang; Yuan, Feng-ying; Wang, Jin-zhi; Feng, Tang-fu; Hu, Guo-qi

    2014-01-01

    Highlights: • Two phase transitions in a narrow temperature range were observed and studied. • Both typical and inverse magnetocaloric effect were observed and discussed. • The inverse magnetocaloric effect was attributed to the spin-glass behavior. - Abstract: Magnetic properties and magnetocaloric effect (MCE) in Pr 2 CuSi 3 and Gd 2 CuSi 3 compounds were investigated systematically. Both Pr 2 CuSi 3 and Gd 2 CuSi 3 compounds experienced two phase transitions in a relatively narrow temperature range: first a paramagnet (PM)–ferromagnet (FM) second-order phase transition at 12 and 26 K and then a FM–spin glass (SG) transition at 6 K and 7.5 K, respectively. The magnetic entropy change (ΔS M ) was calculated based on Maxwell relation using the collected magnetization data. The maximum of ΔS M for Pr 2 CuSi 3 and Gd 2 CuSi 3 compounds was 7.6 and 5 J kg −1 K −1 , respectively, at the applied filed change of 0–5 T. The shape of the temperature dependence of ΔS M (ΔS M –T) curve was obviously different from that of the conventional magnetic materials undergoing only one typical phase transition. In the left half part of ΔS M –T curve, ΔS M is not very sensitive to the applied field and they tend to intersect with the decrease of temperature. Both typical conventional and inverse MCE behavior were observed in Gd 2 CuSi 3 , which would be originated from the two transition features at the low temperatures

  1. Density-functional study of the methoxy intermediates at Cu(111), Cu(110) and Cu(001) surfaces

    Czech Academy of Sciences Publication Activity Database

    Pick, Štěpán

    2010-01-01

    Roč. 22, č. 39 (2010), s. 395002 ISSN 0953-8984 Institutional research plan: CEZ:AV0Z40400503 Keywords : Cu surfaces * methoxy group CH3O- * physical chemistry Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.332, year: 2010

  2. Theoretical investigation of the Fermi surfaces of La2-xSrxCuO4 and YBa2Cu3O7

    International Nuclear Information System (INIS)

    Antonov, V.N.; Antonov, Vl.N.; Bar'yakhtar, V.G.; Baglyuk, A.I.; Maksimov, E.G.; Nemoshkalenko, V.V.; Perlov, A.Ya.; Savrasov, S.Yu.; Uspenskii, Yu.A.

    1989-01-01

    A theoretical investigation is made of the shape of the Fermi surface and of the constant-energy surfaces near the Fermi energy of the La 2-x Sr x CuO 4 and YBa 2 Cu 3 O 7 oxides by a self-consistent linear muffin-tin orbital method in the atomic sphere approximation (OMTO-ASA). It is shown that the Fermi surfaces of these compounds are strongly two-dimensional. The Fermi surface of La 2-x Sr x CuO 4 is a corrugated rounded box centered at the point Λ. The Fermi surface of YBa 2 Cu 3 O 7 consists of four sheets: an electron cushion at the point Λ and three nested hole surfaces centered at the point S. The electron cushion and one of the hole surfaces are strongly corrugated along the z direction. The theoretically calculated Fermi surfaces of La 2 CuO 4 and YBa 2 Cu 3 O 7 are compared with the experimental data on electron-positron annihilation

  3. Crystallization-mediated amorphous Cu_xO (x = 1, 2)/crystalline CuI p–p type heterojunctions with visible light enhanced and ultraviolet light restrained photocatalytic dye degradation performance

    International Nuclear Information System (INIS)

    Wang, Hongli; Cai, Yun; Zhou, Jian; Fang, Jun; Yang, Yang

    2017-01-01

    Highlights: • Cu_xO(x = 1, 2)/CuI p–p type heterojunctions were facilely constructed via crystallization-mediated approaches. • Cu_xO/CuI heterojunctions exhibit effective visible-light-driven photocatalytic activity for dye degradation. • The Cu_xO/CuI interface can enhance the spatial separation of the photogenerated electron–hole pairs. • This work represents a critical step for mass production of functional semiconductor heterojunctions in a mild manner. - Abstract: We report simple and cost-effective fabrication of amorphous Cu_xO (x = 1, 2)/crystalline CuI p–p type heterojunctions based on crystallization-mediated approaches including antisolvent crystallization and crystal reconstruction. Starting from CuI acetonitrile solution, large crystals in commercial CuI can be easily converted to aggregates consisting of small particles by the crystallization processes while the spontaneous oxidation of CuI by atmospheric/dissolved oxygen can induce the formation of trace Cu_xO on CuI surface. As a proof of concept, the as-fabricated Cu_xO/CuI heterojunctions exhibit effective photocatalytic activity towards the degradation of methyl blue and other organic pollutants under visible light irradiation, although the wide band-gap semiconductor CuI is insensible to visible light. Unexpectedly, the Cu_xO/CuI heterojunctions exhibit restrained photocatalytic activity when ultraviolet light is applied in addition to the visible. It is suggested that the Cu_xO/CuI interface can enhance the spatial separation of the electron–hole pairs with the excitation of Cu_xO under visible light and prolong the lifetime of photogenerated charges with high redox ability. The present work represents a critically important step in advancing the crystallization technique for potential mass production of semiconductor heterojunctions in a mild manner.

  4. Importance of the Cu oxidation state for the SO2-poisoning of a Cu-SAPO-34 catalyst in the NH3-SCR reaction

    DEFF Research Database (Denmark)

    Hammershøi, Peter S.; Vennestrøm, Peter N. R.; Falsig, Hanne

    2018-01-01

    behavior and mechanisms of a Cu-SAPO-34 catalyst were studied with reactor tests and DFT calculations. Exposure of the catalyst to two different SO2 concentrations and durations, but with the same total SO2 exposure, calculated as the product of partial pressure of SO2 and exposure time, lead to the same...... degree of deactivation. Exposure of the Cu-SAPO-34 catalyst to SO2 in the presence and absence of NO and NH3 at different temperatures between 200–600 °C showed different trends for the deactivation. Below 400 °C, the S/Cu ratio on the catalyst increased with temperature in absence of NO and NH3, while...... showing that SO2 and SO3, which is possibly formed by oxidation of SO2 over Cu sites, interact similar with Cu in Cu-SAPO-34 and Cu-SSZ-13....

  5. Performance of WCN diffusion barrier for Cu multilevel interconnects

    Science.gov (United States)

    Lee, Seung Yeon; Ju, Byeong-Kwon; Kim, Yong Tae

    2018-04-01

    The electrical and thermal properties of a WCN diffusion barrier have been studied for Cu multilevel interconnects. The WCN has been prepared using an atomic layer deposition system with WF6-CH4-NH3-H2 gases and has a very low resistivity of 100 µΩ cm and 96.9% step coverage on the high-aspect-ratio vias. The thermally stable WCN maintains an amorphous state at 800 °C and Cu/WCN contact resistance remains within a 10% deviation from the initial value after 700 °C. The mean time to failure suggests that the Cu/WCN interconnects have a longer lifetime than Cu/TaN and Cu/WN interconnects because WCN prevents Cu migration owing to the stress evolution from tensile to compressive.

  6. Charging effects and surface potential variations of Cu-based nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Nunes, D., E-mail: daniela.gomes@fct.unl.pt [i3N/CENIMAT, Department of Materials Science, Faculty of Science and Technology, Universidade NOVA de Lisboa, Campus de Caparica, 2829-516 Caparica (Portugal); Calmeiro, T.R.; Nandy, S.; Pinto, J.V.; Pimentel, A.; Barquinha, P. [i3N/CENIMAT, Department of Materials Science, Faculty of Science and Technology, Universidade NOVA de Lisboa, Campus de Caparica, 2829-516 Caparica (Portugal); Carvalho, P.A. [SINTEF Materials and Chemistry, PB 124 Blindern, NO-0314, Oslo (Norway); CeFEMA, Instituto Superior Técnico, Universidade de Lisboa, 1049-001, Lisboa (Portugal); Walmsley, J.C. [SINTEF Materials and Chemistry, Materials and Nanotechnology, Høgskoleringen 5, 7034 Trondheim (Norway); Fortunato, E., E-mail: emf@fct.unl.pt [i3N/CENIMAT, Department of Materials Science, Faculty of Science and Technology, Universidade NOVA de Lisboa, Campus de Caparica, 2829-516 Caparica (Portugal); Martins, R., E-mail: rm@uninova.pt [i3N/CENIMAT, Department of Materials Science, Faculty of Science and Technology, Universidade NOVA de Lisboa, Campus de Caparica, 2829-516 Caparica (Portugal)

    2016-02-29

    The present work reports charging effects and surface potential variations in pure copper, cuprous oxide and cupric oxide nanowires observed by electrostatic force microscopy (EFM) and Kelvin probe force microscopy (KPFM). The copper nanowires were produced by wet synthesis, oxidation into cuprous oxide nanowires was achieved through microwave irradiation and cupric oxide nanowires were obtained via furnace annealing in atmospheric conditions. Structural characterization of the nanowires was carried out by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and energy dispersive X-ray spectroscopy. During the EFM experiments the electrostatic field of the positive probe charged negatively the Cu-based nanowires, which in turn polarized the SiO{sub 2} dielectric substrate. Both the probe/nanowire capacitance as well as the substrate polarization increased with the applied bias. Cu{sub 2}O and CuO nanowires behaved distinctively during the EFM measurements in accordance with their band gap energies. The work functions (WF) of the Cu-based nanowires, obtained by KPFM measurements, yielded WF{sub CuO} > WF{sub Cu} > WF{sub Cu{sub 2O}}. - Highlights: • Charge distribution study in Cu, Cu{sub 2}O and CuO nanowires through electrostatic force microscopy • Structural/surface defect role on the charge distribution along the Cu nanowires • Determination of the nanowire work functions by Kelvin probe force microscopy • Three types of nanowires give a broad idea of charge behavior on Cu based-nanowires.

  7. In-source laser spectroscopy of $^{75, 77, 78}$Cu Direct evidence for a change in the quasiparticle energy sequence in $^{75, 77}$Cu and an absence of longer-lived isomers in $^{78}$Cu

    CERN Document Server

    Koster, U; Serot, O; Fedosseev, V N; Kratz, K L; Stone, N J; Sjodin, A M; Materna, T; Flanagan, K T; Molkanov, P L; Stone, J R; Seliverstov, M D; Mathieu, L; Marsh, B A

    2011-01-01

    This paper describes measurements on the isotopes (75,77,78)Cu by the technique of in-source laser spectroscopy, at the ISOLDE facility, CERN. The role of this technique is briefly discussed in the context of this and other, higher resolution, methods applied to copper isotopes in the range (57-78)Cu. The data, analyzed in comparison with previous results on the lighter isotopes (59,63)Cu, establish the ground-state nuclear spin of (75,77)Cu as 5/2 and yield their magnetic dipole moments as +1.01(5)mu(N) and +1.61(5)mu(N), respectively. The results on (78)Cu show no evidence for long-lived isomerism at this mass number and are consistent with a spin in the range 3-6 and moment of 0.0(4) mu(N)

  8. Experimental and thermodynamic investigation of Al-Cu-Nd ternary system

    Energy Technology Data Exchange (ETDEWEB)

    Bai, W.M. [School of Materials Science and Engineering, Central South University, Changsha, 410083 (China); Jiang, Y. [Hunan Sushi Guangbo Testing Techniques Co. LTD, Changsha (China); Guo, Z.Y.; Zeng, L.J.; Tan, M.Y. [School of Materials Science and Engineering, Central South University, Changsha, 410083 (China); Meggs, C. [School of Metallurgy and Materials, The University of Birmingham, Edgbaston, Birmingham, B15 2TT (United Kingdom); Zhang, L.G., E-mail: ligangzhang@csu.edu.cn [School of Materials Science and Engineering, Central South University, Changsha, 410083 (China); Liu, L.B., E-mail: pdc@csu.edu.cn [School of Materials Science and Engineering, Central South University, Changsha, 410083 (China); Jin, Z.P. [School of Materials Science and Engineering, Central South University, Changsha, 410083 (China)

    2017-07-01

    The phase relationships in the Al–Cu-Nd ternary system at 673 K have been investigated by X-ray powder diffraction (XRD) and scanning electron microscope (SEM) with energy disperse X-ray spectroscopy (EDS) in backscattered electron imaging (BSE) modes. The existence of six ternary Stoichiometric compounds, namely τ{sub 1}-Al{sub 8}Cu{sub 4}Nd, τ{sub 2}-Al{sub 9}Cu{sub 8}Nd{sub 2}, τ{sub 3}-Al{sub 6}Cu{sub 7}Nd, τ{sub 4}-Al{sub 2.4}Cu{sub 8.6}Nd, τ{sub 5}-Al{sub 3}CuNd, τ{sub 6}-AlCuNd, have been confirmed. A complete thermodynamic description of the Al–Cu-Nd ternary system coupled with the CALPHAD method is obtained based on experimental results and first-principles calculations. The calculated phase equilibria were in agreement with the available experimental data. - Highlights: • Phase relationships in the Al-Cu-Nd system has been systematically investigated. • 9 three-phase regions and 4 two-phase regions are confirmed. • A complete thermodynamic description of the Al-Cu-Nd system is obtained. • Results of first-principle calculation consist with thermodynamic calculation.

  9. Investigation of new type Cu-Hf-Al bulk glassy alloys

    International Nuclear Information System (INIS)

    Nagy, E; Ronto, V; Solyom, J; Roosz, A

    2009-01-01

    In the last years new type Cu-Hf-Al ternary alloys were developed with high glass forming ability and ductility. The addition of Al to Cu-Hf alloys results in improvements in glass formation, thermal stability and mechanical properties of these alloys. We have investigated new Cu-based bulk amorphous alloys in Cu-Hf-Al ternary system. The alloys with Cu 49 Hf 42 Al 9 , Cu 46 Hf 45 Al 9 , Cu 50 Hf 42.5 Al 7.5 and Cu 50 Hf 45 Al 5 compositions were prepared by arc melting. The samples were made by centrifugal casting and were investigated by X-ray diffraction method. Thermodynamic properties were examined by differential scanning calorimetry and the structure of the crystallising phases by scanning electron microscopy. The determination of liquidus temperatures of alloys were measured by differential thermal analysis.

  10. Cubic-to-Tetragonal Phase Transitions in Ag-Cu Nano rods

    International Nuclear Information System (INIS)

    Delogu, F.; Mascia, M.

    2012-01-01

    Molecular dynamics simulations have been used to investigate the structural behavior of nano rods with square cross section. The nano rods consist of pure Ag and Cu phases or of three Ag and Cu domains in the sequence Ag-Cu-Ag or Cu-Ag-Cu. Ag and Cu domains are separated by coherent interfaces. Depending on the side length and the size of individual domains, Ag and Cu can undergo a transition from the usual face-centered cubic structure to a body-centered tetragonal one. Such transition can involve the whole nano rod, or only the Ag domains. In the latter case, the transition is accompanied by a loss of coherency at the Ag-Cu interfaces, with a consequent release of elastic energy. The observed behaviors are connected with the stresses developed at the nano rod surfaces.

  11. Effect of Ni addition to the Cu substrate on the interfacial reaction and IMC growth with Sn3.0Ag0.5Cu solder

    Science.gov (United States)

    Zhang, Xudong; Hu, Xiaowu; Jiang, Xiongxin; Li, Yulong

    2018-04-01

    The formation and growth of intermetallic compound (IMC) layer at the interface between Sn3.0Ag0.5Cu (SAC305) solder and Cu- xNi ( x = 0, 0.5, 1.5, 5, 10 wt%) substrate during reflowing and aging were investigated. The soldering was conducted at 270 °C using reflowing method, following by aging treatment at 150 °C for up to 360 h. The experimental results indicated that the total thickness of IMC increased with increasing aging time. The scallop-like Cu6Sn5 and planar-like Cu3Sn IMC layer were observed between SAC305 solder and purely Cu substrate. As the content of Ni element in Cu substrate was 0.5% or 1.5%, the scallop-like Cu6Sn5 and planar-like Cu3Sn IMC layer were still found between solder and Cu-Ni substrate and the total thickness of IMC layer decreased with the increasing Ni content. Besides, when the Ni content was up to 5%, the long prismatic (Cu,Ni)6Sn5 phase was the only product between solder and substrate and the total thickness of IMC layer increased significantly. Interestingly, the total thickness of IMC decreased slightly as the Ni addition was up to 10%. In the end, the grains of interfacial IMC layer became coarser with aging time increasing while the addition of Ni in Cu substrate could refine IMC grains.

  12. Properties of different temperature annealed Cu(In,Ga)Se{sub 2} and Cu(In,Ga){sub 2}Se{sub 3.5} films prepared by RF sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Yu Zhou; Liu Lian; Yan Yong; Zhang Yanxia; Li Shasha; Yan Chuanpeng; Zhang Yong [Key Laboratory of Magnetic Suspension Technology and Maglev Vehicle, Ministry of Education of China, Superconductivity and New Energy R and D Center (SNERDC), Mail Stop 165, Southwest Jiaotong University, Chengdu 610031 (China); Zhao Yong, E-mail: yzhao@swjtu.edu.cn [Key Laboratory of Magnetic Suspension Technology and Maglev Vehicle, Ministry of Education of China, Superconductivity and New Energy R and D Center (SNERDC), Mail Stop 165, Southwest Jiaotong University, Chengdu 610031 (China); School of Materials Science and Engineering, University of New South Wales, Sydney 2052, NSW (Australia)

    2012-11-15

    Highlights: Black-Right-Pointing-Pointer The Cu(In,Ga)Se{sub 2} and Cu(In,Ga)2Se{sub 3.5} films follow different process to form CIGS phase. Black-Right-Pointing-Pointer Composition loss of the annealed Cu(In,Ga)Se{sub 2} and Cu(In,Ga){sub 2}Se{sub 3.5} films are different. Black-Right-Pointing-Pointer Hexagonal CuSe phase exhibits unique transport feature. Black-Right-Pointing-Pointer Conductivity of the CIGS films is affected by the 'variable range hopping' mechanism. - Abstract: We have investigated the effect of annealing temperature on structural, compositional, electrical properties of the one-step RF sputtered Cu(In,Ga)Se{sub 2} and Cu(In,Ga){sub 2}Se{sub 3.5} films. After the annealing at various temperatures, loss of Se element is significant for the Cu(In,Ga)Se{sub 2} films and meanwhile composition of the annealed Cu(In,Ga){sub 2}Se{sub 3.5} films keeps almost constant. The as-deposited Cu(In,Ga)Se{sub 2} and Cu(In,Ga){sub 2}Se{sub 3.5} films show amorphous structure and they follow different transformation process to form chalcopyrite structure. Electrical conductivity of the annealed CIGS films related to their chemical composition. Cu(In,Ga)Se{sub 2} films annealed at 150 Degree-Sign C show unique electron transport mechanism for the formation of hexagonal CuSe phase. Electrical conductivity of the chalcopyrite structure films are dominated by the 'variable range hopping' transport mechanism. The annealed Cu(In,Ga){sub 2}Se{sub 3.5} films present higher density of disorders than the annealed Cu(In,Ga)Se{sub 2} films for their significant Cu deficient composition.

  13. Praseodymium valency from crystal structure in Pr-Ba-Cu-O and (Y-Pr)-Ba-Cu-O single crystals

    International Nuclear Information System (INIS)

    Collin, G.; Albouy, P.A.; Monod, P.; Ribault, M.

    1990-01-01

    The substitution of Pr to Y leads to materials with a general formula (Y 1-v Pr v ) (Ba 2-x Pr x ) (Cu 3-y vac y ) O 6+x/2-y+z and with a structural transition around v + x' ∼ 0.5. For v + x 0.5 the crystals are tetragonal, La 1.5 Ba 1.5 Cu 3 O 7±z type, with the characteristic tri-twinning of this phase. The Pr valency, in the range 3-3.2 + depending on preparation conditions, is determined from interatomic distances. Orthorhombic crystals of Pr Ba Cu O prepared at high temperatures exhibit a high amount of defects, y ∼ 0.25 on the Cu(1) site and are semiconductors with a T -1/4 activation law attributed to the praseodymium valence fluctuation

  14. Electrochemical performance of electroactive poly(amic acid)-Cu{sup 2+} composites

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Ying [Alan G. MacDiarmid Institute, College of Chemistry, Jilin University, Changchun, 130012 (China); Li, Fangfei [State Key Lab of Superhard Materials, Jilin University, Changchun 130012 (China); Hanlon, Ashley M.; Berda, Erik B. [Department of Chemistry and Materials Science Program, University of New Hampshire, Durham, New Hampshire 03824 (United States); Liu, Xincai; Wang, Ce [Alan G. MacDiarmid Institute, College of Chemistry, Jilin University, Changchun, 130012 (China); Chao, Danming, E-mail: chaodanming@jlu.edu.cn [Alan G. MacDiarmid Institute, College of Chemistry, Jilin University, Changchun, 130012 (China)

    2017-01-15

    Graphical abstract: Electroactive poly(amic acid)-Cu{sup 2+} (EPAA-Cu) composites on the substrates have been prepared, whose electrochemical properties, including electroactivity, electrochromism and anticorrosion, reveal drastic enhancement after incorporation of Cu{sup 2+} ions. - Highlights: • The electroactive poly(amic acid)-Cu{sup 2+} (EPAA-Cu) composites were prepared. • A significant current enhancement phenomenon of EPAA-Cu/ITO electrodes was observed. • EPAA-Cu/ITO electrochromic electrodes reveals a shorter switching times. • Excellent corrosive protection for the CS was achieved by incorporating Cu{sup 2+} ions. - Abstract: Electroactive poly(amic acid)-Cu{sup 2+} (EPAA-Cu) composites on substrates were successfully prepared via nucleophilic polycondensation followed by the use of an immersing method. Analysis of the structure properties of EPAA-Cu composites was performed using scanning electron microscopy (SEM), X-ray photoelectron spectra (XPS) and Fourier-transform infrared spectra (FTIR). A significant current enhancement phenomenon of EPAA-Cu/ITO electrodes was found as evident from cyclic voltammetry (CV) measurements. In addition, Cu{sup 2+} ions were incorporated into the composites and had a positive effect on their electrochromic behaviors decreasing their switching times. The anticorrosive performance of EPAA-Cu composites coatings on the carbon steel in 3.5 wt% NaCl solution were also investigated in detail using tafel plots analysis and electrochemical impedance spectroscopy. The anticorrosive ability of these coatings significantly enhanced through the incorporation of Cu{sup 2+} ions.

  15. Time-dependent protection of ground and polished Cu using graphene film

    International Nuclear Information System (INIS)

    Dong, Yuhua; Liu, Qingqing; Zhou, Qiong

    2015-01-01

    Highlights: • Graphene was deposited on polished and ground Cu sheets by CVD. • Graphene films provide better protection to polished Cu for short time. • Multilayer graphene films provide better protection for short time. - Abstract: Graphene was deposited on Cu sheets with different morphologies by chemical vapor deposition. Scanning electron microscopy (SEM) analysis indicated that the morphology of the Cu sheet affected the graphene film properties. Electrochemical impedance spectroscopy measurements showed that the graphene film did not effectively protect Cu against corrosion because of prolonged exposure to ionic environments (3.5 wt.% NaCl solution). For short durations, graphene films provided better protection to polished Cu than ground Cu. Prolonged electrolyte immersion of graphene-coated Cu samples showed that the graphene film from the polished Cu surface was detached more easily than that from ground Cu

  16. Heteroepitaxial growth of strained multilayer superconducting thin films of Nd1.83Ce0.17CuOx/YBa2Cu3O7-δ

    International Nuclear Information System (INIS)

    Gupta, A.; Gross, R.; Olsson, E.; Segmueller, A.; Koren, G.; Tsuei, C.C.

    1990-01-01

    Heteroepitaxial growth of strained multilayer thin films of YBa 2 Cu 3 O 7-δ /Nd 1.83 Ce 0.17 CuO x by pulsed-laser deposition is reported. The coherency strain results in biaxial compression of the tetragonal Nd 1.83 Ce 0.17 CuO x layers, whereas the biaxial tension in the YBa 2 Cu 3 O 7-δ layers removes the orthorhombic distortion and makes the unit cell isotropic in the basal plane (a=b). Depending on their oxygen content, either the YBa 2 Cu 3 O 7-δ or the Nd 1.83 Ce 0.17 CuO x layers are superconducting in these multilayers. The strain-induced structural modification has a significant influence on the superconducting transition temperature of the YBa 2 Cu 3 O 7-δ layers

  17. Enhanced photocatalytic, electrochemical and photoelectrochemical properties of TiO{sub 2} nanotubes arrays modified with Cu, AgCu and Bi nanoparticles obtained via radiolytic reduction

    Energy Technology Data Exchange (ETDEWEB)

    Nischk, Michał [Department of Chemical Technology, Faculty of Chemistry, Gdansk University of Technology, 11/12 G. Narutowicza 11/12 St., 80-233 Gdansk (Poland); Department of Environmental Technology, Faculty of Chemistry, University of Gdansk, 63 Wita Stwosza St., 80-308 Gdansk (Poland); Mazierski, Paweł [Department of Environmental Technology, Faculty of Chemistry, University of Gdansk, 63 Wita Stwosza St., 80-308 Gdansk (Poland); Wei, Zhishun [Institute for Catalysis, Hokkaido University, N21, W10, 001-0021, Sapporo (Japan); Siuzdak, Katarzyna [Centre for Plasma and Laser Engineering, The Szewalski Institute of Fluid-Flow Machinery, Polish Academy of Sciences, 14 Fiszera St., 80-231 Gdansk (Poland); Kouame, Natalie Amoin [Laboratoire de Chimie Physique, CNRS—UMR 8000,Université Paris-Sud, Université Paris-Saclay, Bâtiment 349, 91405 Orsay (France); Kowalska, Ewa [Institute for Catalysis, Hokkaido University, N21, W10, 001-0021, Sapporo (Japan); Remita, Hynd [Laboratoire de Chimie Physique, CNRS—UMR 8000,Université Paris-Sud, Université Paris-Saclay, Bâtiment 349, 91405 Orsay (France); Zaleska-Medynska, Adriana, E-mail: adriana.zaleska@ug.edu.pl [Department of Environmental Technology, Faculty of Chemistry, University of Gdansk, 63 Wita Stwosza St., 80-308 Gdansk (Poland)

    2016-11-30

    Highlights: • TiO{sub 2} nanotubes were modified with Cu, AgCu, Bi nanoparticles via gamma radiolysis. • Excessive amount of deposited metal decreased photocatalytic activity. • AgCu-modified samples were more active than Cu-modified (with the same Cu content). • AgCu nanoparticles exist in a core{sub (Ag)}-shell{sub (Cu)} form. • Examined photocatalysts were resistant towards photocorrosion processes. - Abstract: TiO{sub 2} nanotubes arrays (NTs), obtained via electrochemical anodization of Ti foil, were modified with monometallic (Cu, Bi) and bimetallic (AgCu) nanoparticles. Different amounts of metals’ precursors were deposited on the surface of NTs by the spin-coating technique, and the reduction of metals was performed via gamma radiolysis. Surface modification of titania was studied by EDS and XPS analysis. The results show that AgCu nanoparticles exist in a Ag{sub core}-Cu{sub shell} form. Photocatalytic activity was examined under UV irradiation and phenol was used as a model pollutant of water. Over 95% of phenol degradation was achieved after 60 min of irradiation for almost all examined samples, but only slight difference in degradation efficiency (about 3%) between modified and bare NTs was observed. However, the initial phenol degradation rate and TOC removal efficiency was significantly enhanced for the samples modified with 0.31 and 0.63 mol% of Bi as well as for all the samples modified with Cu and AgCu nanoparticles in comparison with bare titania nanotubes. The saturated photocurrent, under the influence of simulated solar light irradiation, for the most active Bi- and AgCu-modified samples, was over two times higher than for pristine NTs. All the examined materials were resistant towards photocorrosion processes that enables their application for long term processes induced by light.

  18. Transport properties of YBa2Cu3O7/PrBa2Cu3O7 superlattices

    International Nuclear Information System (INIS)

    Jakob, G.; Hahn, T.; Stoelzel, C.; Tome-Rosa, C.; Adrian, H.

    1992-01-01

    We investigated the transport properties of high-quality YBa 2 Cu 3 O 7 /PrBa 2 Cu 3 O 7 superlattices. The exceptional structural order of the superlattices resulted in satellite peaks up to the ninth order in X-ray diffraction diagrams and high Tc values. We find high superconducting critical transport current densities j c even for ultrafine modulated superlattices which proves the existence of nearly continuous YBa 2 Cu 3 O 7 layers. The activation energy U is found to be constant or to have a linear temperatures dependence over a wide temperature range. (orig.)

  19. Brazing of Cu with Pd-based metallic glass filler

    Energy Technology Data Exchange (ETDEWEB)

    Terajima, Takeshi [Joining and Welding Research Institute, Osaka University, 11-1 Mihogaoka, Ibaraki, Osaka 567-0047 (Japan)], E-mail: terajima@jwri.osaka-u.ac.jp; Nakata, Kazuhiro [Joining and Welding Research Institute, Osaka University, 11-1 Mihogaoka, Ibaraki, Osaka 567-0047 (Japan); Matsumoto, Yuji [Materials and Structures Laboratory, Tokyo Institute of Technology (Japan); Zhang, Wei; Kimura, Hisamichi; Inoue, Akihisa [Institute for Materials Research, Tohoku University (Japan)

    2008-02-25

    Metallic glass has several unique properties, including high mechanical strength, small solidification shrinkage, small elastic modulus and supercooling state, all of which are well suited as a residual stress buffer for metal and ceramic joining. In the present preliminary study, we demonstrated brazing of Cu rods with Pd{sub 40}Cu{sub 30}Ni{sub 10}P{sub 20} metallic glass filler. The brazing was carried out at 873 K for 1 min in a vacuum atmosphere (1 x 10{sup -3} Pa), and then the specimens were quenched at the rate of 30 K/s by blowing He. The metallic glass brazing of Cu using Pd{sub 40}Cu{sub 30}Ni{sub 10}P{sub 20} filler was successful, with the exception that several voids remained in the filler. According to micro-focused X-ray diffraction, no diffraction patterns were observed at both the center of the Pd{sub 40}Cu{sub 30}Ni{sub 10}P{sub 20} filler and the Cu/Pd{sub 40}Cu{sub 30}Ni{sub 10}P{sub 20} interface. The result showed that the Cu specimens were joined with Pd{sub 40}Cu{sub 30}Ni{sub 10}P{sub 20} filler in the glassy state. The tensile fracture strength of the brazed specimens ranged from 20 to 250 MPa. The crack extension from the voids in the Pd{sub 40}Cu{sub 30}Ni{sub 10}P{sub 20} filler may have caused the results to be uneven and very low compared to the strength of Pd-based bulk metallic glass.

  20. EPR of CU+2:Mb single crystal

    International Nuclear Information System (INIS)

    Nascimento, O.R.; Ribeiro, S.C.; Bemski, G.

    1976-01-01

    Copper introduced into met-myoglobin crystals occupies various sites as indicated by EPR parameters. CU 2+ (A) is probably liganded to histidine A10, lysine A14 and asparagine GH4 (Banaszak, 1965) and shows super-hyperfine interaction with a single (imidazole) nitrogen. Cu 2+ (B) and Cu 2+ (C) correspond to other anisotropic sites described with lesser details. Cu 2+ (A) exhibits a transition to an isotropic form with a transition temperature of 40.5 0 C. This transition is indicative of a conformational change in myoglobin and could correspond to a motion of A helix away from the GH section. The transition temperature is 7 0 C higher than the previously reported (Atanasov, 1971) one for myoglobin in solution

  1. Intratumoral distribution of CU-ATSM and FDG: immunohistochemical characterization of the region with high CU-ATSM or FDG accumulation

    Energy Technology Data Exchange (ETDEWEB)

    Takako, Furukawa; Tsuneo, Saga; Yasuhisa, Fujibayashi [Institute of Radiological Sciences, Dept. of Diagnostic Imaging, Molecular Imaging Center, Nationa, Chiba (Japan); Takako, Furukawa; Takeshi, Tanaka; Yasuhisa, Fujibayashi [Fukui Univ., Biomedica Imaging Research Center (Japan)

    2006-07-01

    Intratumoral distribution of [Cu-64]Cu-di-acetyl-bis (N4-methyl-thio-semi-carbazone ) ({sup 64}Cu-ATSM) and fluorine-18 2-fluoro-2-deoxyglucose ({sup 18}FDG) in mice bearing tumors of four different origins, LLC1 (Lewis lung carcinoma), Meth-A (sarcoma), B16 (melanoma) and colon26 (adenocarcinoma), were compared to the immunohistochemical staining for proliferating cells (Ki67), blood vessels (CD34 or von Willebrand Factor (vWF)) and apoptotic cells (terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) method). With all the cell lines, {sup 64}Cu-ATSM and {sup 18}FDG were distributed to different regions of the tumor mass. The immunohistochemical study demonstrated that the high {sup 64}Cu-ASTM uptake regions were hypo-vascular and consisted of tumor cells arrested in cell cycle, while the high {sup 18}FGD uptake regions were hyper-vascular and consisted of proliferating cells. Through our study, it was revealed that one tumor mass contains two regions of different characteristics, which can be distinguished by {sup 64}Cu-ATSM and {sup 18}FDG. Since hypoxia and cell cycle arrest are critical factors to reduce the sensitivity of tumor to radiation and conventional chemotherapy, regions with such characteristics in tumor should be treated intensively as one of the primary targets. {sup 64}Cu-ATSM which can delineate hypoxic and cell cycle arrested regions in tumors can provide valuable information for cancer treatment as well as the possibility to treat such regions directly as an internal radiotherapy reagent. (author)

  2. Fabrication and characterization of Pd/Cu doped ZnO/Si and Ni/Cu doped ZnO/Si Schottky diodes

    Energy Technology Data Exchange (ETDEWEB)

    Agarwal, Lucky; Singh, Brijesh Kumar; Tripathi, Shweta [Department of Electronics & Communication Engineering, Motilal Nehru National Institute of Technology, Allahabad 211004 (India); Chakrabarti, P., E-mail: pchakrabarti.ece@iitbhu.ac.in [Department of Electronics & Communication Engineering, Motilal Nehru National Institute of Technology, Allahabad 211004 (India); Department of Electronics Engineering, Indian Institute of Technology (Banaras Hindu University), Varanasi 221005 (India)

    2016-08-01

    In this paper, fabrication and characterization of copper doped ZnO (Cu doped ZnO) based Schottky devices have been reported. Cu doped ZnO thin films have been deposited on p-Si (100) samples by the sol-gel spin coating method. X-Ray diffraction (XRD) and atomic force microscopy (AFM) studies have been done in order to evaluate the structural and morphological properties of the film. The optical properties of the film have been determined by using variable angle ellipsometry. Further, Seebeck measurement of the deposited Cu doped ZnO film leads to positive Seebeck coefficient confirming the p-type conductivity of the sample. The resistivity and acceptor concentration of the film has also been evaluated using four probe measurement system. Pd and Ni metals have been deposited on separate Cu doped ZnO thin film samples using low cost thermal evaporation method to form Schottky contacts. The electrical characterization of the Schottky diode has been performed by semiconductor device analyzer (SDA). Electrical parameters such as barrier height, ideality factor, reverse saturation current and rectification ratio have also been determined for the as-prepared Schottky diode using conventional thermionic emission model and Cheung's method. - Highlights: • Fabrication of sol-gel derived Cu doped ZnO (p-type) Schottky contact proposed. • The p-type Conductivity of the sample confirmed by Seebeck Measurement. • Pd and Ni deposited on Cu doped ZnO film to form Schottky contacts. • Cu doped ZnO expected to emerge as a potential material for thin film solar cells.

  3. Fabrication and characterization of Pd/Cu doped ZnO/Si and Ni/Cu doped ZnO/Si Schottky diodes

    International Nuclear Information System (INIS)

    Agarwal, Lucky; Singh, Brijesh Kumar; Tripathi, Shweta; Chakrabarti, P.

    2016-01-01

    In this paper, fabrication and characterization of copper doped ZnO (Cu doped ZnO) based Schottky devices have been reported. Cu doped ZnO thin films have been deposited on p-Si (100) samples by the sol-gel spin coating method. X-Ray diffraction (XRD) and atomic force microscopy (AFM) studies have been done in order to evaluate the structural and morphological properties of the film. The optical properties of the film have been determined by using variable angle ellipsometry. Further, Seebeck measurement of the deposited Cu doped ZnO film leads to positive Seebeck coefficient confirming the p-type conductivity of the sample. The resistivity and acceptor concentration of the film has also been evaluated using four probe measurement system. Pd and Ni metals have been deposited on separate Cu doped ZnO thin film samples using low cost thermal evaporation method to form Schottky contacts. The electrical characterization of the Schottky diode has been performed by semiconductor device analyzer (SDA). Electrical parameters such as barrier height, ideality factor, reverse saturation current and rectification ratio have also been determined for the as-prepared Schottky diode using conventional thermionic emission model and Cheung's method. - Highlights: • Fabrication of sol-gel derived Cu doped ZnO (p-type) Schottky contact proposed. • The p-type Conductivity of the sample confirmed by Seebeck Measurement. • Pd and Ni deposited on Cu doped ZnO film to form Schottky contacts. • Cu doped ZnO expected to emerge as a potential material for thin film solar cells.

  4. Diffusion of 64Cu in copper-containing chalcogenide glasses

    International Nuclear Information System (INIS)

    Vlasov, Yu.G.; Bychkov, E.A.; Bolotov, A.M.; Tsegel'nik, V.S.; Gavrilov, Yu.A.

    1996-01-01

    Diffusion experiments with 64 Cu radioactive tracer for a number of copper-containing chalcogenide glasses CuI-As 2 Se 3 , Cu-SbI 3 -As 2 Se 3 , CuI-PbI 2 -As 2 Se 3 , CuI-PbI 2 -SbI 3 -As 2 Se 3 and Cu 2 Se-As 2 Se 3 are carried out for the first time. The results of diffusion and electrodiffusion measurements are in correspondence with information on electroconductivity and diffusion in a limited space (cage diffusion) from the Moessbauer spectroscopy on 124 I. It is shown for the first time that the Cheivin factor index for copper-conducting glasses in by 2-3 times higher as compared to silver-conducting glasses with approximate diffusion coefficients indices. 27 refs., 3 figs., 1 tab

  5. NQR study in superconducting La2CuO4+δ

    International Nuclear Information System (INIS)

    Ueda, K.; Sugata, T.; Kohori, Y.; Oda, Y.; Kohara, T.

    1992-01-01

    Cu NQR signals were observed around 33.1 and 36.0 MHz together with the antiferromagnetic Cu NMR signals in the superconducting La 2 CuO 4+ δ obtained by annealing in high pressure oxygen gas. The NQR intensity increases with increasing oxygen contents. The nuclear spin-lattice relaxation time, T 1 , of Cu NQR indicates that the paramagnetic phase is in the superconducting state at low temperatures. These results show that the NQR and NMR signals were coming from the Cu sites in the superconducting phase and the antiferromagnetic phase, respectively. No appreciable differences were observed in the Cu NQR spectrum and the relaxation time between the superconducting La 2 CuO 4 + δ samples annealed under the oxygen pressure of 400 ≅ 1200 bar. (orig.)

  6. Effects of processing parameters on Be/CuCrZr joining

    International Nuclear Information System (INIS)

    Park, Jeong-Yong; Lee, Jung-Suk; Choi, Byung-Kwon; Park, Sang-Yun; Hong, Bong Guen; Jeong, Yong Hwan; Jung, Ki-Jung

    2007-01-01

    A joining of Be/CuCrZr has been considered as the key technology for the fabrication of the ITER first wall. Among the joining methods, Hot isostatic pressing (HIP), which is one of the diffusion bonding methods, is the most feasible method to join the Be and CuCrZr alloy. In the HIP joining of Be and CuCrZr, the interlayer was used to prevent the formation of brittle intermetallic compounds in the interface. Therefore, it is crucial to select a suitable interlayer for a joining of Be and CuCrZr. On the other hand, the diffusion between Be and CuCrZr would be enhanced with an increase of the HIP joining temperature, thereby increasing the joint strength. However, the HIP joining temperature is limited by the mechanical properties of CuCrZr. During the fabrication process of the ITER first wall, CuCrZr is subjected to several thermal cycles including a solution annealing, a cooling and an aging. The HIP joining of Be and CuCrZr corresponds to the aging of CuCrZr. The HIP joining at a higher temperature would cause a degradation of the mechanical properties of CuCrZr by an overaging effect although it is preferable for an improvement of the joint strength. In this study, the effect of the cooling rate on the mechanical properties of aged CuCrZr was investigated to find the maximum HIP temperature without a degradation of the mechanical properties of CuCrZr

  7. Fe and Cu isotope mass balances in the human body

    Science.gov (United States)

    Balter, V.; Albarede, F.; Jaouen, K.

    2011-12-01

    The ranges of the Fe and Cu isotope compositions in the human body are large, i.e. ~3% and ~2%, respectively. Both isotopic fractionations appear to be mainly controlled by redox conditions. The Fe and Cu isotope compositions of the tissues analyzed so far plot on a mixing hyperbolae between a reduced and an oxidized metals pools. The reduced metals pool is composed by erythrocytes, where Fe is bounded to hemoglobin as Fe(II) and Cu to superoxide-dismutase as Cu(I). The oxidized metals pool is composed by hepatocytes, where Fe and Cu are stored as Fe(III) ferritin and as Cu(II) ceruloplasmine, respectively. The position of each biological component in the δ56Fe-δ65Cu diagram therefore reflects the oxidation state of Fe and Cu of the predominant metal carrier protein and allows to quantify Fe and Cu fluxes between organs using mass balance calculations. For instance, serum and clot Fe and Cu isotope compositions show that current biological models of erythropoiesis violates mass conservation requirements, and suggest hidden Fe and Cu pathways during red blood cells synthesis. The results also show that a coupled Fe-Cu strong gender isotopic effect is observed in various organs. The isotopic difference between men and women is unlikely to be due to differential dietary uptake or endometrium loss, but rather reflects the effect of menstrual losses and a correlative solicitation of hepatic stores. We speculate that thorough studies of the metabolism of stable isotopes in normal conditions is a prerequisite for the understanding of the pathological dysregulations.

  8. Surface segregation as a means of gettering Cu in liquid-phase-epitaxy silicon thin layers grown from Al-Cu-Si solutions

    Energy Technology Data Exchange (ETDEWEB)

    Wang, T.H.; Ciszek, T.F.; Reedy, R.; Asher, S.; King, D. [National Renewable Energy Lab., Golden, CO (United States)

    1996-05-01

    The authors demonstrate that, by using the natural surface segregation phenomenon, Cu can be gettered to the surface from the bulk of silicon layers so that its concentrations in the liquid-phase-epitaxy (LPE) layers are much lower than its solubility at the layer growth temperature and the reported 10{sup 17} cm{sup {minus}3} degradation threshold for solar-cell performance. Secondary-ion mass spectroscopy (SIMS) analysis indicates that, within a micron-deep sub-surface region, Cu accumulates even in as-grown LPE samples. Slower cooling after growth to room temperature enhances this Cu enrichment. X-ray photoelectron spectroscopy (XPS) measurement shows as much as 3.2% Cu in a surface region of about 50 {Angstrom}. More surface-sensitive, ion-scattering spectroscopy (ISS) analysis further reveals about 7% of Cu at the top surface. These results translate to an areal gettering capacity of about 1.0 x 10{sup 16} cm{sup {minus}2}, which is higher than the available total-area density of Cu in the layer and substrate (3.6 x 10{sup 15} cm{sup {minus}2} for a uniform 1.2 x 10{sup 17}cm{sup {minus}3} Cu throughout the layer and substrate with a total thickness of 300 {mu}m).

  9. The tin-rich copper lithium stannides: Li{sub 3}Cu{sub 6}Sn{sub 4} and Li{sub 2}CuSn{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Fuertauer, Siegfried; Flandorfer, Hans [Vienna Univ. (Austria). Inst. of Inorganic Chemistry (Materials Chemisrty); Effenberger, Herta S. [Vienna Univ. (Austria). Inst. of Mineralogy and Crystallography

    2015-05-01

    The Sn rich ternary intermetallic compounds Li{sub 3}Cu{sub 6}Sn{sub 4} (CSD-427097) and Li{sub 2}CuSn{sub 2} (CSD-427098) were synthesized from the pure elements by induction melting and annealing at 400 C. Structural investigations were performed by powder- and single-crystal XRD. Li{sub 3}Cu{sub 6}Sn{sub 4} crystallizes in space group P6/mmm; it is structurally related to but not isotypic with MgFe{sub 6}Ge{sub 6} (a = 5.095(2) Aa, c = 9.524(3) Aa; wR{sub 2} = 0.059; 239 unique F{sup 2}-values, 17 free variables). Li{sub 3}Cu{sub 6}Sn{sub 4} is characterized by two sites with a mixed Cu:Sn occupation. In contrast to all other Cu-Li-Sn compounds known so far, any mixed occupation was found for Cu-Li pairs only. In addition, one Li site is only half occupied. The second Sn rich phase is Li{sub 2}CuSn{sub 2} (space group I4{sub 1}/amd, a = 4.4281(15) Aa, c = 19.416(4) Aa; wR{sub 2} = 0.033; 213 unique F{sup 2}-values, 12 atom free variables); it is the only phase in the Cu-Li-Sn system which is noted for full ordering. Both crystal structures exhibit 3D-networks which host Li atoms in channels. They are important for understanding the lithiation mechanism in Cu-Sn electrodes for Li-ion batteries.

  10. Structure and phase composition of Al-Ce-Cu system alloys in range of quasi-binary Al-Al8CeCu4 section

    International Nuclear Information System (INIS)

    Belov, N.A.; Khvan, A.V.

    2007-01-01

    The phase diagram of the Al-Cu-Ce system in the quasibinary section area of Al-Al 8 CeCu 4 has been investigated by metallographic, thermal, micro-X-ray spectral and X-ray structural analyses. The parameters of the eutectic reaction L→(Al)+CeCu 4 Al 8 : T=610 Deg C were found out; the composition was 14% Cu and 7% Ce. This eutectics is of a disperse structure and the ternary compound contained is capable of fragmentation and spheroidizing in the heating process (starting from 540 Deg C). It was demonstrated that the area of optimal (Al)+CeCu 4 Al 8 eutectics-based alloy compositions was within the narrow limits. That is related to the fact that at a comparatively little variation of the Cu:Ce=2 ratio solidus sharply decreases and, as a result, the crystallization interval considerably extends [ru

  11. Inelastic Neutron Scattering Cross Sections of Cu-63 and Cu-65 in the Energy Region 0.7 to 1.4 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Holmqvist, B; Wiedling, T

    1964-08-15

    The gamma ray spectra from, the {sup 63}Cu (n, n'{gamma}) and {sup 65}Cu (n, n'{gamma}) reactions have been studied for seven neutron energies in the energy range 0.7 - 1.4 MeV using a Nal(Tl) scintillation spectrometer and time-of-flight techniques. Scatterers of natural copper have been used. Experimental excitation curves have been obtained for the two lowest excited levels in each of the Cu and Cu isotopes. The experimental (n, n') cross sections for the individual levels at 668 keV and 961 keV in {sup 63}Cu and 764 keV and 1114 keV in {sup 65}Cu have been compared to a modified Hauser-Feshbach theory for inelastic neutron scattering. This experiment has confirmed by other methods determined spins of these levels, i.e. 1/2{sup -} and 5/2{sup -} respectively.

  12. Hydrogenation of furfural at the dynamic Cu surface of CuOCeO2/Al2O3 in vapor phase packed bed reactor

    Science.gov (United States)

    The hydrogenation of furfural to furfuryl alcohol over a CuOCeO2/'-Al2O3 catalyst in a flow reactor is reported. The catalyst was prepared by the wet impregnation of Cu onto a CeO2/'-Al2O3 precursor. The calcined catalyst was then treated with HNO3 to remove surface CuO resulting in a mixed CuCe oxi...

  13. Solidification of Bi2Sr2Ca1Cu2Oy and Bi2Sr1.75Ca0.25CuOy

    International Nuclear Information System (INIS)

    Holesinger, T.G.; Miller, D.J.; Viswanathan, H.K.; Chumbley, L.S.

    1993-01-01

    The solidification processes for the compositions Bi 2 Sr 2 CaCu 2 O y (2212) and Bi 2 Sr 1.75 Ca 0.25 CuO y (2201) were determined as a function of oxygen partial pressure. During solidification in argon, the superconducting phases were generally not observed to form for either composition. In both cases, the solidus is lowered to approximately 750 degree C. Solidification of Bi 2 Sr 1.75 Ca 0.25 CuO y in Ar resulted in a divorced eutectic structure of Bi 2 Sr 2-x Ca x O y (22x) and Cu 2 O while solidification of Bi 2 Sr 2 CaCu 2 O y in Ar resulted in a divorced eutectic structure of Bi 2 Sr 3-x Ca x O y (23x) and Cu 2 O. Solidification of Bi 2 Sr 1.75 Ca 0.25 CuO y in O 2 resulted in large grains of 2201 interspersed with small regions containing the eutectic structure of 22x and CuO/Cu 2 O. Solidification of Bi 2 Sr 2 CaCu 2 O y in partial pressures of 1%, 20%, and 100% oxygen resulted in multiphase samples consisting of 2212, 2201, some alkaline-earth cuprates, and both divorced eutectic structures found during solidification in Ar. For both compositions, these latter structures can be attributed to oxygen deficiencies present in the melt regardless of the overpressure of oxygen. These eutectic structures are unstable and convert into the superconducting phases during subsequent anneals in oxygen. The formation process of the 2212 phase during solidification from the melt was determined to proceed through an intermediate state involving the 2201 phase

  14. Plant Mediated Green Synthesis of CuO Nanoparticles: Comparison of Toxicity of Engineered and Plant Mediated CuO Nanoparticles towards Daphnia magna

    Directory of Open Access Journals (Sweden)

    Sadia Saif

    2016-11-01

    Full Text Available Research on green production methods for metal oxide nanoparticles (NPs is growing, with the objective to overcome the potential hazards of these chemicals for a safer environment. In this study, facile, ecofriendly synthesis of copper oxide (CuO nanoparticles was successfully achieved using aqueous extract of Pterospermum acerifolium leaves. P. acerifolium-fabricated CuO nanoparticles were further characterized by UV-Visible spectroscopy, field emission scanning electron microscopy (FE-SEM, energy dispersive X-ray (EDX, Fourier transform infrared spectroscopy (FTIR, X-ray photoelectron spectroscopy (XPS and dynamic light scattering (DLS. Plant-mediated CuO nanoparticles were found to be oval shaped and well dispersed in suspension. XPS confirmed the elemental composition of P. acerifolium-mediated copper nanoparticles as comprised purely of copper and oxygen. DLS measurements and ion release profile showed that P. acerifolium-mediated copper nanoparticles were more stable than the engineered CuO NPs. Copper oxide nanoparticles are used in many applications; therefore, their potential toxicity cannot be ignored. A comparative study was performed to investigate the bio-toxic impacts of plant-synthesized and engineered CuO nanoparticles on water flea Daphnia. Experiments were conducted to investigate the 48-h acute toxicity of engineered CuO NPs and plant-synthesized nanoparticles. Lower EC50 value 0.102 ± 0.019 mg/L was observed for engineered CuO NPs, while 0.69 ± 0.226 mg/L was observed for plant-synthesized CuO NPs. Additionally, ion release from CuO nanoparticles and 48-h accumulation of these nano CuOs in daphnids were also calculated. Our findings thus suggest that the contribution of released ions from nanoparticles and particles/ions accumulation in Daphnia needs to be interpreted with care.

  15. Cu(I)/Cu(II) mixed-valence surface complexes of S-[(2-hydroxyamino)-2-oxoethyl]-N,N-dibutyldithiocarbamate: Hydrophobic mechanism to malachite flotation.

    Science.gov (United States)

    Liu, Sheng; Zhong, Hong; Liu, Guangyi; Xu, Zhenghe

    2018-02-15

    Hydroxamate and sulfhydryl surfactants are effective collectors for flotation of copper minerals. The combination application of hydroxamate and sulfhydryl collectors has been proved to be an effective approach for improving the flotation recovery of non-sulfide copper minerals. A surfactant owing both hydroxamate and dithiocarbamate groups might exhibit strong affinity to non-sulfide copper minerals through double sites adsorption, rendering an enhanced hydrophobization to non-sulfide copper minerals flotation. The flotation performance of S-[(2-hydroxyamino)-2-oxoethyl]- N,N-dibutyldithiocarbamate (HABTC) to malachite, calcite and quartz were first evaluated through systematic micro-flotation experiments. HABTC's hydrophobic mechanism to malachite was further investigated and analyzed by zeta potential, Fourier transform infrared spectroscopy (FTIR), time-of-flight secondary ion mass spectrometry (ToF-SIMS) and X-ray photoelectron spectroscopy (XPS). The micro-flotation results demonstrated HABTC was an excellent collector for malachite flotation and exhibited favorable selectivity for flotation separation of malachite from quartz or calcite under pH 8.5-10.3. Zeta potential and FTIR implied that HABTC might bond with the surface copper atoms of malachite, with releasing the H + ions of its hydroxamate group into pulp. ToF-SIMS provided clear evidences that the Cu-hydroxamate and Cu-dithiocarbamate groups were formed on malachite surfaces after HABTC adsorption. XPS revealed that Cu(I)/Cu(II) mixed-valence surface complexes of HABTC anchored on malachite through formation of Cu(I)S and Cu(II)O bonds, accompanying with reduction of partial surface Cu(II) to Cu(I). The Cu(I)/Cu(II) mixed-valence double chelating character and "chair"-shape N,N-dibutyldithiocarbamate hydrophobic group, resulting in an enhanced affinity and hydrophobization of HABTC to malachite flotation. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Multifilamentar superconductor wires of Cu-Nb-Al and Cu-Nb3Sn obtained by a new method

    International Nuclear Information System (INIS)

    Lima, O.F. de

    1985-01-01

    A new method to prepare multifilamentar wires of Cu-Nb 3 Sn which is based on power metallurgy is developed. Wires of Cu+xw%Nb++2wt%Al (x =10,30) were tinned and heat treated for Sn diffusion and reaction (T = 700 0 C), leading to the Nb 3 Sn A 15 phase. Final wires showed microfilament density around 8 x 10 4 mm -2 . The superconducting properties (T sup(c), J sup(c) x H), mechanical properties (tau x epsilon) and eletrical resistivity for Cu-Nb-Al wires were as normally expected. The Cu-Nb 3 Sn wires showed high T sub(c) approx. 17.9 K, very near that for the pure A 15 phase. J sub(c) x H curves were approx. 4 times lower than typical published results for wires prepared by other methods. The experimental evidence shows that J sub(c) increases when decreases the initial Nb particle size. (Author) [pt

  17. Measurements of low photon doses using LiF:Mg,Cu,P and CaF{sub 2}:Cu dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    Prokert, K [Dresden Univ. of Technology (Germany). Inst. of Radiation Protection Physics; Mann, G [Dresden Univ. of Technology (Germany). Inst. of Radiation Protection Physics

    1997-03-01

    The new thermoluminophors LiF:Mg, Cu, P and CaF{sub 2}:Cu in form of pellets exhibit a significantly higher TL-response than the well-known dosimeters of the types TLD-100 (LiF:Mg, Ti), TLD-400 (CaF{sub 2}:Mn), TLD-900 (CaSO{sub 4}:Dy), etc. Furthermore, the thermoluminophor LiF:Mg, Cu, P shows besides its high sensitivity a good tissue equivalence and therefore, only a small variation of the dose response with the photon energy. The lower limits of detection of these new materials are about 5 {mu}Gy and 0.2 {mu}Gy resp. Therefore, short term measurements of absorbed dose can be realised in radiation fields at very low dose rates (environmental radiation, scattering radiation at medical equipment`s etc.) with an accuracy of {+-}10%. In the field of environmental monitoring the period of exposure can be limited to about 10 days. Using CaF{sub 2}:Cu detectors an exposure of 24 hours is sufficient for dose measurements with lower accuracy. The reusability of CaF{sub 2}:Cu pellets is guaranteed without loss of sensitivity independently of the application of different reading and annealing procedures. In the case of LiF:Mg, Cu, P detectors special procedures are needed in order to keep constant TL-properties. The results of dose measurements at low dose levels in different radiation fields demonstrate the advantages of these detector types. (orig.)

  18. Spectrophotometric Determination of the CuSO4 Soret Coefficient of a CuSO4-H2O Binary Solutions System

    Directory of Open Access Journals (Sweden)

    Ijang Rohman

    2010-06-01

    Full Text Available A spectrophotometric technique for the determination of the CuSO4 soret coefficient of a CuSO4-water binary solutions system is described. A short column of solutions is placed between horizontal metal plates that are held at different temperatures. The subsequent changes in composition due to thermal diffusion are followed by monitoring changes of transmittance near the end of the solutions column. In water, CuSO4 diffuses to the warm compartment of column. The soret coefficient of CuSO4 0.0254 molal in water agrees with the appropriate theory, i.e. 17.60x10-3 °C-1 on the average.

  19. Homogeneous (Cu, Ni)6Sn5 intermetallic compound joints rapidly formed in asymmetrical Ni/Sn/Cu system using ultrasound-induced transient liquid phase soldering process.

    Science.gov (United States)

    Li, Z L; Dong, H J; Song, X G; Zhao, H Y; Tian, H; Liu, J H; Feng, J C; Yan, J C

    2018-04-01

    Homogeneous (Cu, Ni) 6 Sn 5 intermetallic compound (IMC) joints were rapidly formed in asymmetrical Ni/Sn/Cu system by an ultrasound-induced transient liquid phase (TLP) soldering process. In the traditional TLP soldering process, the intermetallic joints formed in Ni/Sn/Cu system consisted of major (Cu, Ni) 6 Sn 5 and minor Cu 3 Sn IMCs, and the grain morphology of (Cu, Ni) 6 Sn 5 IMCs subsequently exhibited fine rounded, needlelike and coarse rounded shapes from the Ni side to the Cu side, which was highly in accordance with the Ni concentration gradient across the joints. However, in the ultrasound-induced TLP soldering process, the intermetallic joints formed in Ni/Sn/Cu system only consisted of the (Cu, Ni) 6 Sn 5 IMCs which exhibited an uniform grain morphology of rounded shape with a remarkably narrowed Ni concentration gradient. The ultrasound-induced homogeneous intermetallic joints exhibited higher shear strength (61.6 MPa) than the traditional heterogeneous intermetallic joints (49.8 MPa). Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Oxidation of Cu(II) aminopolycarboxylates by carbonate radical. A flash photolysis study

    International Nuclear Information System (INIS)

    Mandal, P.C.; Bardhan, D.K.

    1999-01-01

    Reactions of carbonate radical (CO 3 -. ) generated by photolysis or by radiolysis of a carbonate solution, with Cu(II) complexes of aminopolycarboxylic acids viz., Cu(II)ethylenediamine tetraacetate [Cu II EDTA] 2- and Cu(II)-iminodiacetate [Cu II IDA] were studied at pH 10.5 and ionic strength 0.2 mol x dm -3 . Time-resolved spectroscopy and kinetics for the transients were studied using flash photolysis and stable products arising from the ligand degradation of the complex were ascertained by steady-state radiolysis experiments. From the kinetic data it is observed that CO 3 -. radical reacts initially with Cu II -complex to form a transient intermediate having maximum absorption at 335 nm and 430 nm. From the subsequent reactions of this intermediate it was assigned to be Cu III .species. This Cu(III) species undergoes intermolecular electron transfer with the Cu II -complex to give a radical intermediate which again slowly reacts with Cu II -complex to give a long lived species containing Cu-C bond. This long lived species, however, slowly decomposed to give glyoxalic reaction between Cu III -complex and a suitable donor, the one electron reduction potential for [Cu III EDTA] 1- /[Cu II EDTA] 2- and [Cu III IDA] +1 /Cu II IDA was determined. (author)

  1. Electronic Topological Transitions in CuNiMnAl and CuNiMnSn under pressure from first principles study

    Science.gov (United States)

    Rambabu, P.; Kanchana, V.

    2018-06-01

    A detailed study on quaternary ordered full Heusler alloys CuNiMnAl and CuNiMnSn at ambient and under different compressions is presented using first principles electronic structure calculations. Both the compounds are found to possess ferromagnetic nature at ambient with magnetic moment of Mn being 3.14 μB and 3.35 μB respectively in CuNiMnAl and CuNiMnSn. The total magnetic moment for both the compounds is found to decrease under compression. Fermi surface (FS) topology change is observed in both compounds under pressure at V/V0 = 0.90, further leading to Electronic Topological Transitions (ETTs) and is evidenced by the anomalies visualized in density of states and elastic constants under compression.

  2. Synthesis of Cu2O, CuCl, and Cu2OCl2 nanoparticles by ultrafast ...

    Indian Academy of Sciences (India)

    2014-02-13

    Feb 13, 2014 ... 800 nm and ∼2 ps laser pulses. Cu2O NPs exhibited two-photon absorption at lower peak intensities while three-photon absorption was observed at higher peak intensities. Other samples exhibited two-photon absorption at all peak intensities. Keywords. Picosecond; laser ablation; copper complex; ...

  3. A density functional theory study of partial oxidation of propylene on Cu2O(0 0 1) and CuO(0 0 1) surfaces

    International Nuclear Information System (INIS)

    Düzenli, Derya; Atmaca, Deniz Onay; Gezer, Miray Gülbiter; Onal, Isik

    2015-01-01

    Graphical abstract: - Highlights: • Propylene epoxidation mechanism on Cu 2 O(0 0 1) and CuO(0 0 1) surfaces is investigated using DFT method. • Acrolein is found to be a thermodynamically more favorable product for both surfaces especially over CuO surface. • The more basic property of the surface oxygen increases the probability of acrolein formation over CuO(0 0 1) surface. - Abstract: This work theoretically investigates propylene epoxidation reaction on Cu 2 O(0 0 1) and CuO(0 0 1) surfaces using periodical DFT method to determine the active copper species within the reaction mechanism. The transition states and energy profiles are calculated for the formation of surface intermediates such as oxametallopropylene (OMP) over Cu 2 O(0 0 1) and oxygen bridging (OB) over CuO(0 0 1) and allylic H-stripping reaction (AHS) over both surfaces as well as for formation of products. Propylene oxide (PO) and acetone are obtained through OMP and OB surface intermediates and acrolein generation is observed through allylic H-stripping reaction (AHS). The calculations revealed that the corresponding surface intermediates for epoxidation reaction need to overcome an activation barrier of 13 kcal/mol over CuO surface whereas they occur without an energy barrier over Cu 2 O surface indicating the higher activity of Cu + species. Acrolein is also found to be a thermodynamically more favorable product for both surfaces especially over CuO surface due to the presence of more surface oxygen atoms on which the basicity has been evaluated by the adsorption of sulfur dioxide. This indicates that the lattice oxygen inherent in both surface types does not participate in PO production.

  4. Influence of Nitrogen Partial Pressure on Microstructure and Tribological Properties of Mo-Cu-V-N Composite Coatings with High Cu Content

    Directory of Open Access Journals (Sweden)

    Haijuan Mei

    2018-01-01

    Full Text Available In this study, Mo-Cu-V-N composite coatings with high Cu content of ~18 at.% were deposited on 316L stainless steel and YT14 cemented carbide substrates by high power impulse magnetron sputtering in Ar–N2 gas mixtures. The influence of N2 partial pressure was investigated with respect to the microstructure and tribological properties of the coatings. The results indicated that the Mo-Cu-V-N composite coatings exhibited FCC B1-MoN phase with a strong (200 preferred orientation, and Cu phase was found to exist as metallic species. As the N2 partial pressure increased from 0.11 to 0.35 Pa, the peak intensity of (200 plane decreased gradually and simultaneous peak broadening was observed, which was typical for grain refinement. With increasing the N2 partial pressure, the columnar microstructure became much coarser, which led to the decrease of residual stress and hardness. The Mo-Cu-V-N composite coatings with high Cu content exhibited a relatively low wear rate of 10−8 mm3/N·m at 25 °C, which was believed to be attributed to the mixed lubricious oxides of MoO2, CuO and V2O5 formed during tribo-oxidation, which cannot be formed in the coatings with low Cu content. When the wear temperature was increased up to 400 °C, the wear rate increased sharply up to 10−6 mm3/N·m despite the formation of lubricious oxides of MoO3/CuMoO4 and V2O5. This could be due to the loss of nitrogen and pronounced oxidation at high temperatures, which led the wear mechanism to be transformed from mild oxidation wear to severe oxidation wear.

  5. Critical current density in (YBa2Cu3O7-δ)1-x-(PrBa2Cu3O7-δ)x melt-textured composites

    Science.gov (United States)

    Opata, Yuri Aparecido; Monteiro, João Frederico Haas Leandro; Jurelo, Alcione Roberto; Siqueira, Ezequiel Costa

    2018-06-01

    Melt textured (YBa2Cu3O7-δ)1-x-(PrBa2Cu3O7-δ)x composites (x = 0.00 and x = 0.05) were grown using the top seeding method. The effect of the PrBa2Cu3O7-δ phase on the growth process and the modification of the microstructure as well as on the physical properties was analyzed. X-ray analyses indicated that both pure and Pr-doped samples present an orthorhombic superconducting phase. From resistivity measurements for YBa2Cu3O7-δ and (YBa2Cu3O7-δ)0.95-(PrBa2Cu3O7-δ)0.05 samples, the Tcab did not change and was around 90.5 K. However, from magnetic measurements, the superconductivity was observed in critical temperatures TC = 92.9 K and 92.4 K for YBa2Cu3O7-δ and (YBa2Cu3O7-δ)0.95-(PrBa2Cu3O7-δ)0.05 samples, respectively. The YBa2Cu3O7-δ sample showed higher critical current densities than those shown by the (YBa2Cu3O7-δ)0.95-(PrBa2Cu3O7-δ)0.05 sample, with values of JC = 5.85 × 105 A/cm2 and 4.72 × 105 A/cm2, respectively. This paper also discusses the importance of Pr substitution on nano- and micro-meter scales to enhance JC(H).

  6. Average and local structure of α-CuI by configurational averaging

    International Nuclear Information System (INIS)

    Mohn, Chris E; Stoelen, Svein

    2007-01-01

    Configurational Boltzmann averaging together with density functional theory are used to study in detail the average and local structure of the superionic α-CuI. We find that the coppers are spread out with peaks in the atom-density at the tetrahedral sites of the fcc sublattice of iodines. We calculate Cu-Cu, Cu-I and I-I pair radial distribution functions, the distribution of coordination numbers and the distribution of Cu-I-Cu, I-Cu-I and Cu-Cu-Cu bond-angles. The partial pair distribution functions are in good agreement with experimental neutron diffraction-reverse Monte Carlo, extended x-ray absorption fine structure and ab initio molecular dynamics results. In particular, our results confirm the presence of a prominent peak at around 2.7 A in the Cu-Cu pair distribution function as well as a broader, less intense peak at roughly 4.3 A. We find highly flexible bonds and a range of coordination numbers for both iodines and coppers. This structural flexibility is of key importance in order to understand the exceptional conductivity of coppers in α-CuI; the iodines can easily respond to changes in the local environment as the coppers diffuse, and a myriad of different diffusion-pathways is expected due to the large variation in the local motifs

  7. Crystal structure, Raman scattering and magnetic properties of CuCr2-xZrxSe4 and CuCr2-xSnxSe4 selenospinels

    Science.gov (United States)

    Pinto, C.; Galdámez, A.; Barahona, P.; Moris, S.; Peña, O.

    2018-06-01

    Selenospinels, CuCr2-xMxSe4 (M = Zr and Sn), were synthesized via conventional solid-state reactions. The crystal structure of CuCr1.5Sn0.5Se4, CuCr1.7Sn0.3Se4, CuCr1.5Zr0.5Se4, and CuCr1.8Zr0.2Se4 were determined using single-crystal X-ray diffraction. All the phases crystallized in a cubic spinel-type structure. The chemical compositions of the single-crystals were examined using energy-dispersive X-ray analysis (EDS). Powder X-ray diffraction patterns of CuCr1.3Sn0.7Se4 and CuCr1.7Sn0.3Se4 were consistent with phases belonging to the Fd 3 bar m Space group. An analysis of the vibrational properties on the single-crystals was performed using Raman scattering measurements. The magnetic properties showed a spin glass behavior with increasing Sn content and ferromagnetic order for CuCr1.7Sn0.3Se4.

  8. Role of interlayer coupling for the power factor of CuSbS2 and CuSbSe2

    KAUST Repository

    Alsaleh, Najebah Mohammed Abdullah; Singh, Nirpendra; Schwingenschlö gl, Udo

    2017-01-01

    The electronic and transport properties of bulk and monolayer CuSbS2 and CuSbSe2 are determined by using density functional theory and semiclassical Boltzmann transport theory, in order to investigate the role of interlayer coupling

  9. Feeding reduces waterborne Cu bioaccumulation in a marine rabbitfish Siganus oramin

    International Nuclear Information System (INIS)

    Guo, Zhiqiang; Zhang, Wei; Du, Sen; Zhou, Yanyan; Gao, Na; Zhang, Li; Green, Iain

    2016-01-01

    Waterborne metal uptake has been extensively studied and dietary metal assimilation is increasingly recognized in fish, whilst the interaction between the two uptake routes is largely overlooked. This study compared the waterborne Cu bioaccumulation ("6"5Cu as tracer) in a juvenile rabbitfish at different feeding regimes (starvation (SG), feeding normal diet (NDG) or diet supplemented with extra Cu (DCG)) to test the hypothesis that feeding can influence waterborne metal uptake in marine fish. NDG and DCG diet was fed as a single meal and then all fish were exposed to waterborne "6"5Cu for 48 h, during which the time course sampling was conducted to determine "6"5Cu bioaccumulation, chyme flow and dietary Cu assimilation. The results revealed that SG fish accumulated the highest "6"5Cu, followed by NDG (61% of SG), whilst DCG fish accumulated the lowest "6"5Cu (34% of SG). These results suggested a protective effect of feeding against waterborne Cu bioaccumulation. This effect was most notable between 10 min and 16 h when there was chyme in gastrointestinal tract (GT). Dietary Cu assimilation mainly occurred before 16 h after feeding. Waterborne "6"5Cu influx rate in the GT was positively correlated with "6"5Cu contents of chyme in NDG, whereas it was largely negatively correlated with "6"5Cu contents of chyme in DCG. The waterborne Cu uptake in the GT was mainly influenced by the chyme flow and dietary Cu assimilation. Overall, our findings suggested that feeding has an important effect on waterborne metal uptake and that both the feeding status of the fish and the relative metal exposure through water and food should be considered in prediction of the metal bioaccumulation and biomonitoring programs. - Highlights: • Feeding shows a protective effect against waterborne Cu uptake in fish. • The elevated dietary Cu can greatly suppress the waterborne Cu uptake. • The presence of chyme reduces Cu uptake in the gastrointestinal tract. • Feeding status has

  10. Crystal structure and phase transition studies in perovskite-type oxides using powder-diffraction techniques and symmetry-mode analysis : SrLnMRuO6 (Ln=La,Pr,Nd; M=Zn,Co,Mg,Ni,Fe) and ALn2CuTi2O9 (A=Ca,Ba; Ln=La,Pr,Nd,Sm)

    OpenAIRE

    Iturbe Zabalo, Edurne

    2013-01-01

    La tesis se ha centrado en la síntesis y caracterización estructural de materiales tipo perovskita: SrLnMRuO6 (Ln=La,Pr,Nd; M=Zn,Co,Mg,Ni,Fe) y ALn2CuTi2O9 (A=Ca,Ba; Ln=La,Pr,Nd,Sm). El estudio de las estructuras de los materiales se ha realizado mediante el análisis de los patrones de difracción en polvo de rayos-X, sincrotrón y/o neutrones. En el refinamiento por el método de Rietveld de las estructuras se han sustituido las coordenadas atómicas (el método más común), por coordenadas colect...

  11. Effect of the Cu and Ni content on the crystallization temperature and crystallization mechanism of La–Al–Cu(Ni metallic glasses

    Directory of Open Access Journals (Sweden)

    Peiyou Li

    2016-02-01

    Full Text Available The effect of the Cu and Ni content on the crystallization mechanism and the crystallization temperatures of La–Al–Cu(Ni metallic glasses (MGs was studied by differential scanning calorimetry (DSC. The experimental results have shown that the DSC curves obtained for the La–Al–Cu and La–Al–Ni MGs exhibit two and three crystallization temperatures, respectively. The crystallization temperatures of the La–Al–Cu and La–Al–Ni MGs result from the merging and splitting of thermal events related to the corresponding eutectic atomic pairs in the La72Cu28 and La81.6Al18.4 MGs, and La72Ni28 and La81.6Al18.4 MGs, respectively. In addition, Al- and Ni-containing clusters with weak or strong atomic interaction in the Al–Ni atomic pairs strongly affect the crystallization mechanism and thus the crystallization temperature of La–Al–Ni MGs. This study provides a novel understanding of the relation between the crystallization temperature and the underlying crystallization mechanisms in La–Al–Cu(Ni MGs.

  12. Crystallization-mediated amorphous Cu{sub x}O (x = 1, 2)/crystalline CuI p–p type heterojunctions with visible light enhanced and ultraviolet light restrained photocatalytic dye degradation performance

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hongli; Cai, Yun; Zhou, Jian; Fang, Jun, E-mail: fangjun@njtech.edu.cn; Yang, Yang, E-mail: yangy@njtech.edu.cn

    2017-04-30

    Highlights: • Cu{sub x}O(x = 1, 2)/CuI p–p type heterojunctions were facilely constructed via crystallization-mediated approaches. • Cu{sub x}O/CuI heterojunctions exhibit effective visible-light-driven photocatalytic activity for dye degradation. • The Cu{sub x}O/CuI interface can enhance the spatial separation of the photogenerated electron–hole pairs. • This work represents a critical step for mass production of functional semiconductor heterojunctions in a mild manner. - Abstract: We report simple and cost-effective fabrication of amorphous Cu{sub x}O (x = 1, 2)/crystalline CuI p–p type heterojunctions based on crystallization-mediated approaches including antisolvent crystallization and crystal reconstruction. Starting from CuI acetonitrile solution, large crystals in commercial CuI can be easily converted to aggregates consisting of small particles by the crystallization processes while the spontaneous oxidation of CuI by atmospheric/dissolved oxygen can induce the formation of trace Cu{sub x}O on CuI surface. As a proof of concept, the as-fabricated Cu{sub x}O/CuI heterojunctions exhibit effective photocatalytic activity towards the degradation of methyl blue and other organic pollutants under visible light irradiation, although the wide band-gap semiconductor CuI is insensible to visible light. Unexpectedly, the Cu{sub x}O/CuI heterojunctions exhibit restrained photocatalytic activity when ultraviolet light is applied in addition to the visible. It is suggested that the Cu{sub x}O/CuI interface can enhance the spatial separation of the electron–hole pairs with the excitation of Cu{sub x}O under visible light and prolong the lifetime of photogenerated charges with high redox ability. The present work represents a critically important step in advancing the crystallization technique for potential mass production of semiconductor heterojunctions in a mild manner.

  13. Calculations of oxide formation on low-index Cu surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Lian, Xin; Liu, Renlong, E-mail: lrl@cqu.edu.cn, E-mail: henkelman@utexas.edu [College of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400030 (China); Xiao, Penghao; Yang, Sheng-Che; Henkelman, Graeme, E-mail: lrl@cqu.edu.cn, E-mail: henkelman@utexas.edu [Department of Chemistry and the Institute for Computational and Engineering Sciences, University of Texas at Austin, Austin, Texas 78712-0165 (United States)

    2016-07-28

    Density-functional theory is used to evaluate the mechanism of copper surface oxidation. Reaction pathways of O{sub 2} dissociation on the surface and oxidation of the sub-surface are found on the Cu(100), Cu(110), and Cu(111) facets. At low oxygen coverage, all three surfaces dissociate O{sub 2} spontaneously. As oxygen accumulates on the surfaces, O{sub 2} dissociation becomes more difficult. A bottleneck to further oxidation occurs when the surfaces are saturated with oxygen. The barriers for O{sub 2} dissociation on the O-saturated Cu(100)-c(2×2)-0.5 monolayer (ML) and Cu(100) missing-row structures are 0.97 eV and 0.75 eV, respectively; significantly lower than those have been reported previously. Oxidation of Cu(110)-c(6×2), the most stable (110) surface oxide, has a barrier of 0.72 eV. As the reconstructions grow from step edges, clean Cu(110) surfaces can dissociatively adsorb oxygen until the surface Cu atoms are saturated. After slight rearrangements, these surface areas form a “1 ML” oxide structure which has not been reported in the literature. The barrier for further oxidation of this “1 ML” phase is only 0.31 eV. Finally the oxidized Cu(111) surface has a relatively low reaction energy barrier for O{sub 2} dissociation, even at high oxygen coverage, and allows for facile oxidation of the subsurface by fast O diffusion through the surface oxide. The kinetic mechanisms found provide a qualitative explanation of the observed oxidation of the low-index Cu surfaces.

  14. Measurement of thermoelectric power of Fe-Cu binary alloys

    International Nuclear Information System (INIS)

    Joubouji, Katsuo

    2007-01-01

    In INSS, non-destructive evaluation (NDE) of irradiation embrittlement of low alloy steel using thermoelectric power (TEP) measurement has been considered, as well as NDE of thermal aging of cast duplex stainless steel which has been studied in recent years. Material degradation is evaluated based on a relation between progress of the degradation and change in TEP due to change in material structure caused by the degradation event. So it is necessary for NDE of irradiation embrittlement to measure the change in TEP due to precipitation of Cu contained as an impurity, which is known as one of the reasons for the embrittlement. In this study, TEP of Fe-Cu binary alloys with different Cu content was measured for investigation of the relationship between TEP of the alloys and Cu content. In addition, appropriateness of measuring TEP of Fe-Cu binary alloy in the same way to measure TEP of duplex stainless steel was examined. It was found that increment of Cu contained in the alloys changed TEP in a negative direction and the rate was evaluated as -6.6μV/K/wt%Cu. There were the cases that it took 20 minutes for measurement values to become stable in measurement of Fe-Cu binary alloys. It was much longer than the time taken in measurement of duplex stainless steel. So the measurement time per a point was extended to 60 minutes in case of Fe-Cu binary alloys. (author)

  15. Susceptibility of 169 USA300 methicillin-resistant Staphylococcus aureus isolates to two copper-based biocides, CuAL42 and CuWB50.

    Science.gov (United States)

    Luna, Vicki Ann; Hall, Tony J; King, Debbie S; Cannons, Andrew C

    2010-05-01

    To test the activity of two copper-based biocides, CuAL42 and CuWB50, and benzalkonium chloride against 169 isolates of methicillin-resistant Staphylococcus aureus (MRSA) pulsotype USA300, a virulent, multiply resistant, widespread clone in the USA. Tests including MIC, MBC and time-kill studies were performed multiple times. The MIC range, MIC(50) and MIC(90) (0.59-18.75, 4.69 and 4.69 ppm, respectively) and the MBC range, MBC(50) and MBC(90) (1.17-18.75, 4.69 and 9.38 ppm, respectively) for CuAL42 were identical with those obtained with CuWB50, except that the MBC range for CuWB50 was wider (0.59-37.5 ppm). In time-kill studies, a 6 log(10) reduction of cfu was achieved within 1 h (150 ppm) and 0.5 h (300 ppm) for CuAL42, and 1.5 h (150 ppm) and 0.75 h (300 ppm) for CuWB50. Both copper-based biocides can effectively kill USA300 MRSA and may facilitate the eradication of the organism from healthcare settings.

  16. Comparison of the Isothermal Oxidation Behavior of As-Cast Cu-17%Cr and Cu-17%Cr-5%Al. Part 1; Oxidation Kinetics

    Science.gov (United States)

    Raj. Sai V.

    2008-01-01

    The isothermal oxidation kinetics of as-cast Cu-17%Cr and Cu-17%Cr-5%Al in air were studied between 773 and 1173 K under atmospheric pressure. These observations reveal that Cu- 17%Cr-5%Al oxidizes at significantly slower rates than Cu-17%Cr. The rate constants for the alloys were determined from generalized analyses of the data without an a priori assumption of the nature of the oxidation kinetics. Detailed analyses of the isothermal thermogravimetric weight change data revealed that Cu-17%Cr exhibited parabolic oxidation kinetics with an activation energy of 165.9 9.5 kJ mol-1. In contrast, the oxidation kinetics for the Cu-17%Cr- 5%Al alloy exhibited a parabolic oxidation kinetics during the initial stages followed by a quartic relationship in the later stages of oxidation. Alternatively, the oxidation behavior of Cu-17%CR- 5%Al could be better represented by a logarithmic relationship. The parabolic rate constants and activation energy data for the two alloys are compared with literature data to gain insights on the nature of the oxidation mechanisms dominant in these alloys.

  17. Cu hydrotalcite-like compounds: Morphological, structural and microstructural properties

    Energy Technology Data Exchange (ETDEWEB)

    Suarez, D. Rosales [Instituto Politecnico Nacional, ESIQIE, Av. IPN s/n, Edif. 8, UPALM, Mexico D.F. 07738 (Mexico); Zeifert, B.H. [Instituto Politecnico Nacional, ESIQIE, Av. IPN s/n, Edif. 8, UPALM, Mexico D.F. 07738 (Mexico)]. E-mail: bzeifert@yahoo.com; Garduno, M. Hesiquio [Instituto Politecnico Nacional, ESFM, Av. IPN s/n, Edif. 9, UPALM, Mexico D.F. 07738 (Mexico)]. E-mail: miguelhg@esfm.ipn.mx; Blasquez, J. Salmones [Instituto Politecnico Nacional, ESIQIE, Av. IPN s/n, Edif. 8, UPALM, Mexico D.F. 07738 (Mexico)]. E-mail: jose_salmones@yahoo.com.mx; Serrano, A. Romero [Instituto Politecnico Nacional, ESIQIE, Av. IPN s/n, Edif. 8, UPALM, Mexico D.F. 07738 (Mexico)

    2007-05-31

    Copper containing mixed oxides are widely employed as catalysts for the synthesis of methanol, higher alcohol, hydrocarbons from syngas at low temperature and pressure, and for NiO {sub x} reduction. In this work, a series of Mg-Al-Cu, as hydrotalcite-like compounds (Cu-HTlcs) precursors of mixed oxides were synthesized by direct coprecipitation. The effect of pH, Cu content and mechanical milling on the structure and texture of these materials was investigated. The obtained materials were characterized by X-ray diffraction, differential scanning calorimetry, scanning and transmission electron microscopy and BET surface area measurements. The results showed that the materials were nanocrystalline powders. The Cu-HTlcs has a hexagonal unit cell. The a and c parameters increased as a function of the Cu content in both milled and non-milled samples. Crystallite size also increased with Cu content in both cases and smaller for non-milled samples. In contrast, microstrain values were greater for milled samples. BET area decreased with Cu content and showed that materials synthesized were mesoporous type. Mechanical milling did not destroy the morphology of the samples.

  18. Cu hydrotalcite-like compounds: Morphological, structural and microstructural properties

    International Nuclear Information System (INIS)

    Suarez, D. Rosales; Zeifert, B.H.; Garduno, M. Hesiquio; Blasquez, J. Salmones; Serrano, A. Romero

    2007-01-01

    Copper containing mixed oxides are widely employed as catalysts for the synthesis of methanol, higher alcohol, hydrocarbons from syngas at low temperature and pressure, and for NiO x reduction. In this work, a series of Mg-Al-Cu, as hydrotalcite-like compounds (Cu-HTlcs) precursors of mixed oxides were synthesized by direct coprecipitation. The effect of pH, Cu content and mechanical milling on the structure and texture of these materials was investigated. The obtained materials were characterized by X-ray diffraction, differential scanning calorimetry, scanning and transmission electron microscopy and BET surface area measurements. The results showed that the materials were nanocrystalline powders. The Cu-HTlcs has a hexagonal unit cell. The a and c parameters increased as a function of the Cu content in both milled and non-milled samples. Crystallite size also increased with Cu content in both cases and smaller for non-milled samples. In contrast, microstrain values were greater for milled samples. BET area decreased with Cu content and showed that materials synthesized were mesoporous type. Mechanical milling did not destroy the morphology of the samples

  19. Antibacterial ability and angiogenic activity of Cu-Ti-O nanotube arrays

    International Nuclear Information System (INIS)

    Zong, Mingxiang; Bai, Long; Liu, Yanlian; Wang, Xin; Zhang, Xiangyu; Huang, Xiaobo; Hang, Ruiqiang; Tang, Bin

    2017-01-01

    Bacterial infection and loosening of orthopedic implants remain two disastrously postoperative complications. Angiogenesis is critical important to facilitate implant osseointegration in vivo. TiO 2 nanotubes arrays (NTAs) with proper dimensions possess good osseointegration ability. Accordingly, the present work incorporated copper (Cu) into TiO 2 NTAs (Cu-Ti-O NTAs) to enhance their antibacterial ability and angiogenesis activity, which was realized through anodizing magnetron-sputtered TiCu coatings with different Cu contents on pure titanium (Ti). Our results show ordered Cu-Ti-O NTAs can be produced under proper Cu content (< 15.14%) in TiCu coatings. The NTAs possess excellent long-term antibacterial ability against Staphylococcus aureus (S. aureus), which may be ascribed to sustained release of Cu 2+ . The cytotoxicity of Cu-Ti-O NTAs to endothelial cells (ECs) could be negligible and can even promote cell proliferation as revealed by live/dead staining and MTT. Meanwhile, Cu-Ti-O NTAs can up-regulate nitric oxide (NO) synthesis and vascular endothelial growth factors (VEGF) secretion of ECs on the sample surfaces compared with that of pure TiO 2 NTAs (control). Furthermore, the angiogenic activity is also enhanced in ionic extracts of Cu-Ti-O NTAs compared with the control. The excellent long-term antibacterial ability and favorable angiogenic activity render Cu-Ti-O NTAs to be promising implant coatings. - Highlights: • Cu-Ti-O NTAs possess long-term antibacterial ability against Staphylococcus aureus. • Cu-Ti-O NTAs can up-regulate nitric oxide synthesis and vascular endothelial growth factors secretion of endothelial cells. • Cu-Ti-O NTAs can enhance in vitro angiogenesis activity of endothelial cells.

  20. Antibacterial ability and angiogenic activity of Cu-Ti-O nanotube arrays

    Energy Technology Data Exchange (ETDEWEB)

    Zong, Mingxiang; Bai, Long; Liu, Yanlian; Wang, Xin; Zhang, Xiangyu; Huang, Xiaobo; Hang, Ruiqiang, E-mail: hangruiqiang@tyut.edu.cn; Tang, Bin

    2017-02-01

    Bacterial infection and loosening of orthopedic implants remain two disastrously postoperative complications. Angiogenesis is critical important to facilitate implant osseointegration in vivo. TiO{sub 2} nanotubes arrays (NTAs) with proper dimensions possess good osseointegration ability. Accordingly, the present work incorporated copper (Cu) into TiO{sub 2} NTAs (Cu-Ti-O NTAs) to enhance their antibacterial ability and angiogenesis activity, which was realized through anodizing magnetron-sputtered TiCu coatings with different Cu contents on pure titanium (Ti). Our results show ordered Cu-Ti-O NTAs can be produced under proper Cu content (< 15.14%) in TiCu coatings. The NTAs possess excellent long-term antibacterial ability against Staphylococcus aureus (S. aureus), which may be ascribed to sustained release of Cu{sup 2+}. The cytotoxicity of Cu-Ti-O NTAs to endothelial cells (ECs) could be negligible and can even promote cell proliferation as revealed by live/dead staining and MTT. Meanwhile, Cu-Ti-O NTAs can up-regulate nitric oxide (NO) synthesis and vascular endothelial growth factors (VEGF) secretion of ECs on the sample surfaces compared with that of pure TiO{sub 2} NTAs (control). Furthermore, the angiogenic activity is also enhanced in ionic extracts of Cu-Ti-O NTAs compared with the control. The excellent long-term antibacterial ability and favorable angiogenic activity render Cu-Ti-O NTAs to be promising implant coatings. - Highlights: • Cu-Ti-O NTAs possess long-term antibacterial ability against Staphylococcus aureus. • Cu-Ti-O NTAs can up-regulate nitric oxide synthesis and vascular endothelial growth factors secretion of endothelial cells. • Cu-Ti-O NTAs can enhance in vitro angiogenesis activity of endothelial cells.