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Sample records for cu hg ni

  1. Theoretical study of heavy metal Cd, Cu, Hg, and Ni(II) adsorption on the kaolinite(0 0 1) surface

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Jian, E-mail: zhaojian0209@aliyun.com [Institute of Applied Physics and Computational Mathematics, PO Box 8009, Beijing 100088 (China); State Key Laboratory of Geomechanics and Deep Underground Engineering, China University of Mining and Technology, Beijing 100083 (China); He, Man-Chao [State Key Laboratory of Geomechanics and Deep Underground Engineering, China University of Mining and Technology, Beijing 100083 (China)

    2014-10-30

    Highlights: • We investigated the adsorption of Cd, Cu, Hg, and Ni(II) on kaolinite(0 0 1) surface. • The adsorption capabilities of the kaolinite for HM atoms were Ni > Cu > Cd > Hg(II). • The adsorption energy increases with the coverage for Cd, Cu, and Hg(II) atoms. • The adsorption energy decreases with the coverage for Ni(II) atoms. - Abstract: Heavy metal pollution is currently of great concern because it has been recognized as a potential threat to air, water, and soil. Adsorption was one of the most popular methods for the removal of heavy metal. The adsorption of heavy metal Cd, Cu, Hg, and Ni(II) atoms on the hydroxylated (0 0 1) surface of kaolinite was investigated using density-functional theory within the generalized gradient approximation and a supercell approach. The coverage dependence of the adsorption structures and energetics were systematically studied for a wide range of coverage Θ [from 0.11 to 1.0 monolayers (ML)] and adsorption sites. The most stable among all possible adsorption sites for Cd(II) atom was the two-fold bridge site followed by the one-fold top site, and the top site was the most favorite adsorption site for Cu and Ni(II) atoms, while the three-fold hollow site was the most stable adsorption site for Hg(II) atom followed by the two-fold bridge site. The adsorption energy increases with the coverage for Cd, Cu, and Hg(II) atoms, thus indicating the higher stability of surface adsorption and a tendency to the formation of adsorbate islands (clusters) with increasing the coverage. However, the adsorption energy of Ni(II) atoms decreases when increasing the coverage. The adsorption capabilities of the kaolinite clay for the heavy metal atoms were in the order of Ni > Cu > Cd > Hg(II). The other properties of the Cd, Cu, Hg, and Ni(II)/kaolinite(0 0 1) system including the different charge distribution, the lattice relaxation, and the electronic density of states were also studied and discussed in detail.

  2. Theoretical study of heavy metal Cd, Cu, Hg, and Ni(II) adsorption on the kaolinite(0 0 1) surface

    International Nuclear Information System (INIS)

    Zhao, Jian; He, Man-Chao

    2014-01-01

    Highlights: • We investigated the adsorption of Cd, Cu, Hg, and Ni(II) on kaolinite(0 0 1) surface. • The adsorption capabilities of the kaolinite for HM atoms were Ni > Cu > Cd > Hg(II). • The adsorption energy increases with the coverage for Cd, Cu, and Hg(II) atoms. • The adsorption energy decreases with the coverage for Ni(II) atoms. - Abstract: Heavy metal pollution is currently of great concern because it has been recognized as a potential threat to air, water, and soil. Adsorption was one of the most popular methods for the removal of heavy metal. The adsorption of heavy metal Cd, Cu, Hg, and Ni(II) atoms on the hydroxylated (0 0 1) surface of kaolinite was investigated using density-functional theory within the generalized gradient approximation and a supercell approach. The coverage dependence of the adsorption structures and energetics were systematically studied for a wide range of coverage Θ [from 0.11 to 1.0 monolayers (ML)] and adsorption sites. The most stable among all possible adsorption sites for Cd(II) atom was the two-fold bridge site followed by the one-fold top site, and the top site was the most favorite adsorption site for Cu and Ni(II) atoms, while the three-fold hollow site was the most stable adsorption site for Hg(II) atom followed by the two-fold bridge site. The adsorption energy increases with the coverage for Cd, Cu, and Hg(II) atoms, thus indicating the higher stability of surface adsorption and a tendency to the formation of adsorbate islands (clusters) with increasing the coverage. However, the adsorption energy of Ni(II) atoms decreases when increasing the coverage. The adsorption capabilities of the kaolinite clay for the heavy metal atoms were in the order of Ni > Cu > Cd > Hg(II). The other properties of the Cd, Cu, Hg, and Ni(II)/kaolinite(0 0 1) system including the different charge distribution, the lattice relaxation, and the electronic density of states were also studied and discussed in detail

  3. Adsorption of Cu(II), Hg(II), and Ni(II) ions by modified natural wool chelating fibers

    Energy Technology Data Exchange (ETDEWEB)

    Monier, M., E-mail: monierchem@yahoo.com [Chemistry Department, Drexel University, Philadelphia, PA (United States); Chemistry Department, Faculty of Science, Mansoura University, Mansoura (Egypt); Ayad, D.M.; Sarhan, A.A. [Chemistry Department, Faculty of Science, Mansoura University, Mansoura (Egypt)

    2010-04-15

    The graft copolymerization of ethyl acrylate (EA) onto natural wool fibers initiated by potassium persulphate and Mohr's salt redox initiator system in limited aqueous medium was carried out in heterogeneous media. Ester groups of the grafted copolymers were partially converted into hydrazide function groups followed by hydrazone formation through reaction with isatin. Also the application of the modified fibers for metal ion uptake was studied using Cu(II), Hg(II) and Ni(II). The modified chelating fibers were characterized using FTIR spectroscopy, SEM and X-ray diffraction.

  4. Adsorption of Cu(II), Hg(II), and Ni(II) ions by modified natural wool chelating fibers.

    Science.gov (United States)

    Monier, M; Ayad, D M; Sarhan, A A

    2010-04-15

    The graft copolymerization of ethyl acrylate (EA) onto natural wool fibers initiated by potassium persulphate and Mohr's salt redox initiator system in limited aqueous medium was carried out in heterogeneous media. Ester groups of the grafted copolymers were partially converted into hydrazide function groups followed by hydrazone formation through reaction with isatin. Also the application of the modified fibers for metal ion uptake was studied using Cu(II), Hg(II) and Ni(II). The modified chelating fibers were characterized using FTIR spectroscopy, SEM and X-ray diffraction. 2009 Elsevier B.V. All rights reserved.

  5. Adsorption of Cu(II), Hg(II), and Ni(II) ions by modified natural wool chelating fibers

    International Nuclear Information System (INIS)

    Monier, M.; Ayad, D.M.; Sarhan, A.A.

    2010-01-01

    The graft copolymerization of ethyl acrylate (EA) onto natural wool fibers initiated by potassium persulphate and Mohr's salt redox initiator system in limited aqueous medium was carried out in heterogeneous media. Ester groups of the grafted copolymers were partially converted into hydrazide function groups followed by hydrazone formation through reaction with isatin. Also the application of the modified fibers for metal ion uptake was studied using Cu(II), Hg(II) and Ni(II). The modified chelating fibers were characterized using FTIR spectroscopy, SEM and X-ray diffraction.

  6. Simultaneous determination of Hg, Pb, As, Cu, Zn and Ni in natural waters (with humic material) by energy dispersive X-ray fluorescence

    International Nuclear Information System (INIS)

    Morales S, E.A.; Zepeda L, E.

    1988-05-01

    Standardization of a method for simultaneous quantification of Hg, Pb, As, Cu, Zn and Ni in natural waters with humic acid contents was carried out. APDC for complexing free ions and silica gel as adsorber of metallic humates and further filtration were employed. X-ray fluorescence analysis was performed on filters. Good results were found for silica-gel as adsorber. Detection limits of 4 nanograms/milliliter were determined. (author)

  7. Characteristics of equilibrium, kinetics studies for adsorption of Hg(II), Cu(II), and Ni(II) ions by thiourea-modified magnetic chitosan microspheres

    International Nuclear Information System (INIS)

    Zhou Limin; Wang Yiping; Liu Zhirong; Huang Qunwu

    2009-01-01

    Magnetic chitosan microspheres were prepared and chemically modified with thiourea (TMCS) for adsorption of metal ions. TMCS obtained were investigated by means of X-ray diffraction (XRD), IR, magnetic properties and thermogravimetric analysis (TGA). The adsorption properties of TMCS toward Hg 2+ , Cu 2+ , and Ni 2+ ions were evaluated. Various factors affecting the uptake behavior such as contact time, temperature, pH and initial concentration of the metal ions were investigated. The kinetics was evaluated utilizing the pseudo-first-order, pseudo-second-order, and the intra-particle diffusion models. The equilibrium data were analyzed using the Langmuir, Freundlich, and Tempkin isotherm models. The adsorption kinetics followed the mechanism of the pseudo-second-order equation for all systems studied, evidencing chemical sorption as the rate-limiting step of adsorption mechanism and not involving a mass transfer in solution. The best interpretation for the equilibrium data was given by Langmuir isotherm, and the maximum adsorption capacities were 625.2, 66.7, and 15.3 mg/g for Hg 2+ , Cu 2+ , and Ni 2+ ions, respectively. TMCS displayed higher adsorption capacity for Hg 2+ in all pH ranges studied. The adsorption capacity of the metal ions decreased with increasing temperature. The metal ion-loaded TMCS with were regenerated with an efficiency of greater than 88% using 0.01-0.1 M ethylendiamine tetraacetic acid (EDTA)

  8. Evaluation of heavy metals (Cr, Fe, Ni, Cu, Zn, Cd, Pb and Hg) in water, sediments and water lily (Eichornia crassipes) from Jose Antonio Alzate dam

    International Nuclear Information System (INIS)

    Avila P, P.

    1995-01-01

    Water, sediments and water lily (Eichornia crassipes) from the Jose Antonio Alzate Dam were analyzed in order to determine concentrations of chromium, iron, nickel, copper, zinc, cadmium, lead and mercury. Mercury, lead, chromium and iron were found in concentrations above permissible limits in water, and in high concentrations in sediments. Cadmium, nickel, copper and zinc never were found in concentrations above permissible limits in water. The highest concentrations of heavy metals in water lily were found in the root. Accumulation factors decreased in the following order: Zn> Cr> Fe> Ni> Cu> Pb> Hg and Cd. Statistical differences (α < 0.5) between the collection samples dates was observed. High correlations between metals concentrations in superficial water, sediment and water hyacinth were also observed. These correlations could indicate that the heavy metals studied here, are originated from a natural source such as sediments or from an industrial source. (Author)

  9. Synthesis and characterization of heterobimetallic complexes of the type [Cu(pn2][MCl4] where M = Co(II, Ni(II, Cu(II, Zn(II, Cd(II, and Hg(II

    Directory of Open Access Journals (Sweden)

    Seema Yadav

    2016-11-01

    Full Text Available A series of new bimetallic transition metal complexes of the type [Cu(pn2] [MCl4] have been synthesized (where M = Co(II, Ni(II, Cu(II, Zn(II, Cd(II and Hg(II, pn = 1,3-diaminopropane and characterized by elemental analysis, molar conductance, TGA, IR and electronic spectra. All the compounds are 1:1 electrolyte in DMF. The Cu(II ion is square-planar while metal ions in the anionic moiety acquire their usual tetrahedral arrangement. On the basis of these studies it is concluded that anionic moiety is electrically stabilized by its cationic counterpart.

  10. Evaluation of heavy metals (Cr, Fe, Ni, Cu, Zn, Cd, Pb and Hg) in water, sediments and water lily (Eichornia crassipes) from Jose Antonio Alzate dam; Evaluacion de metales pesados Cr, Fe, Ni, Cu, Zn, Cd, Pb y Hg en agua, sedimento y lirio acuatico (Eichhornia crassipes) de la Presa Jose Antonio Alzate, Estado de Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Avila P, P

    1996-12-31

    Water, sediments and water lily (Eichornia crassipes) from the Jose Antonio Alzate Dam were analyzed in order to determine concentrations of chromium, iron, nickel, copper, zinc, cadmium, lead and mercury. Mercury, lead, chromium and iron were found in concentrations above permissible limits in water, and in high concentrations in sediments. Cadmium, nickel, copper and zinc never were found in concentrations above permissible limits in water. The highest concentrations of heavy metals in water lily were found in the root. Accumulation factors decreased in the following order: Zn> Cr> Fe> Ni> Cu> Pb> Hg and Cd. Statistical differences ({alpha} < 0.5) between the collection samples dates was observed. High correlations between metals concentrations in superficial water, sediment and water hyacinth were also observed. These correlations could indicate that the heavy metals studied here, are originated from a natural source such as sediments or from an industrial source. (Author).

  11. 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.

  12. Cr, Cu, Hg and Ni release from incineration bottom ash during utilization in land reclamation - based on lab-scale batch and column leaching experiments and a modeling study.

    Science.gov (United States)

    Yin, Ke; Chan, Wei Ping; Dou, Xiaomin; Ren, Fei; Wei-Chung Chang, Victor

    2018-04-01

    Incineration bottom ash (IBA) as potential material for land reclamation was investigated, based on leaching tests, sorption studies and simulation models. Based on batch and column leaching tests, Cr, Cu, Hg and Ni in the IBA leachates were measured as high as 510 μg/L, 20330 μg/L, 5.1 μg/L and 627 μg/L, respectively, presenting potential environmental risks. Sorption study was then performed with various concentrations of IBA leachates on sands and excavated materials. Partitioning coefficients of targeting metals were determined to be 6.5 (Cr), 18.4 (Cu), 16.6 (Hg), and 1.8 (Ni) for sands, while 17.4 (Cr), 13.6 (Cu), 67.1 (Hg), and 0.9 (Ni) for excavated materials, much lower than literature in favor of their transportation. Deterministic and Monte Carlo simulation was further performed under designated boundaries, combined with measured geotechnical parameters: density, porosity, permeability, partitioning coefficient, observed diffusivity, hydraulic gradient, etc., to quantitatively predict metals' fate during IBA land reclamation. Environmental risks were quantitatively unveiled in terms of predicted time of breakthrough for the targeting metals (comparing to US EPA criterion for maximum or continuous concentration). Sands were of little effects for all metals' breakthrough (1 month or less) under advection, while excavated materials sufficiently retained metals from thousands up to millions of years, under diffusion or advection. Permeability next to the IBA layer as the major risk-limiting factor, dominated transport of IBA leachates into the field. The current study provides discrimination of environmental risks associated with metals and a quantitative guidance of project design for IBA utilization in land reclamation. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. Chemical speciation of Pb(II, Cd(II, Hg(II, Co(II, Ni(II, Cu(II and Zn(II binary complexes of l-methionine in 1,2-propanediol-water mixtures

    Directory of Open Access Journals (Sweden)

    M. Padma Latha

    2007-04-01

    Full Text Available Chemical speciation of Pb(II, Cd(II, Hg(II, Co(II, Ni(II, Cu(II and Zn(II complexes of L-methionine in 0.0-60 % v/v 1,2-propanediol-water mixtures maintaining an ionic strength of 0.16 M at 303 K has been studied pH metrically. The active forms of ligand are LH2+, LH and L-. The predominant species detected are ML, MLH, ML2, ML2H, ML2H2 and MLOH. Models containing different numbers of species were refined by using the computer program MINIQUAD 75. The best-fit chemical models were arrived at based on statistical parameters. The trend in variation of complex stability constants with change in the dielectric constant of the medium is explained on the basis of electrostatic and non-electrostatic forces.

  14. Re-evaluation of microscopic and integral cross-section data for important dosimetry reactions. Re-evaluation of the excitation functions for the 24Mg(n,p)24Na, 32S(n,p)32P, 60Ni(n,p)60m+gCo, 63Cu(n,2n)62Cu, 65Cu(n,2n)64Cu, 64Zn(n,p)64Cu, 115In(n,2n)114mIn, 127I(n,2n)126I, 197Au(n,2n)196Au and 199Hg(n,n')199mHg reactions

    International Nuclear Information System (INIS)

    Zolotarev, K.I.

    2008-08-01

    Re-evaluations of cross sections and their associated covariance matrices have been carried out for ten dosimetry reactions: - excitation functions for the 63 Cu(n,2n) 62 Cu, 65 Cu(n,2n) 64 Cu, 64 Zn(n,p) 64 Cu, 115 In(n,2n) 114m In and 199 Hg(n,n') 199m Hg reactions were re-evaluated over the neutron energy range from threshold to 20 MeV; - excitation functions for the 24 Mg(n,p) 24 Na, 32 S(n,p) 32 P and 60 Ni(n,p) 60m+g Co were reevaluated in the energy range from threshold to 21 MeV; - excitation functions for the 127 I(n,2n) 126 I and 197 Au(n,2n) 196 Au reactions were reevaluated in the energy range from threshold to 32 and 40 MeV, respectively. Benchmark calculations performed for 235 U thermal fission and 252 Cf spontaneous fission neutron spectra show that the integral cross sections derived from the newly evaluated excitation functions exhibit improved agreement with related experimental data when compared with the equivalent data from the IRDF-2002 library. (author)

  15. VALIDACIÓN DE LA METODOLOGÍA PARA LA DETERMINACIÓN DE SB, AS, CD, CU, CR, HG, NI, PB Y ZN EN SEDIMENTOS POR ICO-MS

    Directory of Open Access Journals (Sweden)

    Hermógenes Rosas Rodríguez

    2004-01-01

    Full Text Available En este trabajo se presentan los resultados obtenidos en la validación de la técnica ICP-MS utilizada para la determinación de nueve elementos en sedimentos: Sb, As, Cd, Cu, Cr, Hg, Ni, Pb y Zn. Para ello se llevó a cabo el estudio de los siguientes parámetros de fiabilidad: precisión, exactitud y límites de detección y cuantificación. Para el análisis de estos elementos se utilizó un ICP-MS ELAN 6000 de Perkin Elmer®. El estudio de los distintos parámetros de validación fue muy satisfactorio para la mayoría de los analitos, alcanzándose límites de detección y de cuantificación muy bajos (inferiores a 1microg/l e incluso de 1 ng/l para el Cd. El método ICP-MS es exacto y preciso, obteniéndose para la mayoría de los elementos coeficientes de variación en torno al 2% y porcentajes de recuperación del 100%.

  16. Phase equilibria and thermodynamic functions for Ag-Hg and Cu-Hg binary systems

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yajun, E-mail: yajunliu@gatech.edu [School of Materials and Energy, Guangdong University of Technology, Guangzhou, Guangdong 510006 (China); Wang, Guan [School of Electromechanical Engineering, Guangdong University of Technology, Guangzhou, Guangdong 510006 (China); Wang, Jiang [School of Materials Science and Engineering, Guilin University of Electronic Technology, Guilin, Guangxi 541004 (China); Chen, Yang [Mining, Metallurgy and Materials Research Department, General Research Institute for Nonferrous Metals, Beijing 100088 (China); Long, Zhaohui [School of Mechanical Engineering, Xiangtan University, Xiangtan, Hunan 411105 (China)

    2012-11-10

    Highlights: Black-Right-Pointing-Pointer The thermodynamic properties of Ag-Hg and Cu-Hg are explored in order to facilitate dental materials design. Black-Right-Pointing-Pointer A self-consistent set of thermodynamic parameters is obtained. Black-Right-Pointing-Pointer The experimental information can be well reproduced by the optimized thermodynamic data. - Abstract: In order to facilitate the computational design of new amalgams for novel dental alloys, the phase equilibria, phase diagrams and thermodynamic functions for Ag-Hg and Cu-Hg binary systems are explored in this work, based on the CALPHAD framework and experimental characterizations. The Gibbs free energies of the solution phases as well as the stoichiometric phases are calculated, with the aid of enthalpies of mixing, activities, enthalpies of formation, and phase equilibrium data. The thermodynamic descriptions provided in this work enable the stabilities of each phase at various temperatures and compositions to be well described, which contribute to the establishment of a general database to design novel metallic dental materials.

  17. Adsorption of Pb, Cd, Zn, Cu and Hg ions on Formaldehyde and ...

    African Journals Online (AJOL)

    Adsorption of Pb(II), Cd(II), Zn(II), Cu(II) and Hg(II) ions on formaldehyde and Pyridine modified bean husks were determined. The adsorption capacity of formaldehyde modified bean husks (mg/g) was: Pb2+, 5.01; Cd2+, 3.63; Zn2+, 2.18; Hg2+, 1.82; Cu2+, 1.58 and that of pyridine modified bean husk was: Hg2+, 6.92; Cd2+ ...

  18. Mercury nonstoichiometry of the Hg1-xBa2CuO4+δ superconductor and the P(Hg)-P(O2)-T phase diagram of the Hg-Ba-Cu-O system

    International Nuclear Information System (INIS)

    Alyoshin, V.A.; Mikhailova, D.A.; Rudnyi, E.B.; Antipov, E.V.

    2002-01-01

    The P(Hg)-P(O 2 )-T phase diagram of the Hg-Ba-Cu-O system for the Ba:Cu=2:1 ratio was experimentally studied and followed by means of the thermodynamic modeling. It was shown that the Hg 1-x Ba 2 CuO 4+δ (Hg-1201) superconductor possesses a significant range of Hg-nonstoichiometry and exists in a certain P(Hg), P(O 2 ) and T range. Mercury nonstoichiometry of Hg-1201 was investigated in the 923≤T≤1095 K; 2.0≤P(Hg)≤8.4 atm; 0.09≤P(O 2 )≤0.86 atm ranges. It was found that the mercury content varies in the range of 0.80-0.94 under these conditions. The Gibbs energy of the Hg-1201 phase was estimated as a function of temperature and mercury concentration. The obtained results allow optimizing the synthesis conditions of Hg-1201 with a given Hg-content including preparation of the Hg-stoichiometric phase

  19. 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

  20. A Dansyl-Rhodamine Based Fluorescent Probe for Detection of Hg2+ and Cu2.

    Science.gov (United States)

    Yuan, Shizhuang; Su, Wei; Wang, Enju

    2017-09-01

    A novel fluorescent probe based on dansyl-appended rhodamine B was developed. The probe can selectively recognize and sense Hg2+ and Cu2+ from other common metal ions by showing unique fluorescence and absorption characteristics. In MeCN/HEPES buffer solution, the probe gives a ratiometric fluorescent response to Hg2+, which was ascribed to the fluorescence resonance energy transfer from dansyl moiety to the ring-opened rhodamine B moiety, while the presence of Cu2+ causes fluorescence quenching. Beside the fluorescence change, the presence of Cu2+ and Hg2+ can induce intensive absorption at about 555 nm, which resulted in a color change from colorless to pink.

  1. Fabrication and tensile properties of rapidly solidified Cu-10wt. %Ni alloy. [Cu-10Ni

    Energy Technology Data Exchange (ETDEWEB)

    Baril, D; Angers, R; Baril, J [Dept. of Mining and Metallurgy, Laval Univ., Ste-Foy, Quebec (Canada)

    1992-10-15

    Cu-10wt.%Ni ribbons were produced by melt spinning and cut into small particles with a blade cutter mill. The powders were then hot consolidated to full density by hot pressing followed by hot extrusion. Tensile properties of the resulting pieces were measured. Cu-10wt.%Ni cast ingots were also hot extruded and mechanically tested to compare with the rapidly solidified alloy and to evaluate the possible benefits brought by the rapid solidification process.

  2. Stability and diffusion of Hg implanted YBa2Cu3O6+x

    International Nuclear Information System (INIS)

    Araujo, J.P.; Correia, J.G.; Wahl, U.; Marques, J.G.; Alves, E.; Amaral, V.S.; Lourenco, A.A.; Galindo, V.; Papen, T. von; Senateur, J.P.; Weiss, F.; Vantomme, A.; Langouche, G.; Melo, A.A.; Silva, M.F. da; Soares, J.C.; Sousa, J.B.

    1999-01-01

    The radioactive isotope 197m Hg was implanted at 60 keV with low fluences (10 13 ions/cm 2 ) into YBa 2 Cu 3 O 6+x (YBCO) superconducting thin films at ISOLDE/CERN. We report on the Hg dynamics and stability inside the YBCO lattice as a function of annealing temperature up to 890 K in a vacuum or O 2 atmosphere. The perturbed angular correlation (PAC) technique was used for probing the Hg behavior at the atomic scale, while by monitoring the sample's activity in situ the Hg outdiffusion was studied. We found that Hg ions occupy unique lattice sites and that Hg should be bound to two apical oxygens. Hg diffusion occurs only for annealing temperatures above 653 K, in vacuum. The Hg migration energy was estimated to be E M =1.58±0.15 eV

  3. Stability studies of Hg implanted YBa$_{2}$Cu$_{3}$O$_{6+x}$

    CERN Document Server

    Araújo, J P; Wahl, U; Marques, J G; Alves, E; Amaral, V S; Lourenço, A A; Galindo, V; Von Papen, T; Senateur, J P; Weiss, F; Vantomme, A; Langouche, G; Melo, A A; Da Silva, M F A; Soares, J C; Sousa, J B

    1999-01-01

    High quality YBa$_{2}$Cu$_{3}$O$_{6+x}$ (YBCO) superconducting thin films were implanted with the radioactive $^{197m}$Hg (T$_{1/2}$ = 24 h) isotope to low fluences of 10$^{13}$ atoms/cm$^{2}$ and 60 keV energy. The lattice location and stability of the implanted Hg were studied combining the Perturbed Angular Correlation (PAC) and Emission Channeling (EC) techniques. We show that Hg can be introduced into the YBCO lattice by ion implantation into unique regular sites. The EC data show that Hg is located on a highly symmetric site on the YBCO lattice, while the PAC data suggests that Hg occupies the Cu(1) site. Annealing studies were performed under vacuum and O$_{2}$ atmosphere and show that Hg starts to diffuse only above 653 K.

  4. Nanostructure analysis of friction welded Pd-Ni-P/Pd-Cu-Ni-P metallic glass interface

    International Nuclear Information System (INIS)

    Ohkubo, T.; Shoji, S.; Kawamura, Y.; Hono, K.

    2005-01-01

    Friction welded Pd 40 Ni 40 P 20 /Pd 40 Cu 30 Ni 10 P 20 metallic glass interface has been characterized by energy filtering transmission electron microscopy. The interface is fully amorphous with a gradual compositional change of Cu and Ni in the range of 30 nm. By annealing above T g , the interdiffusion of Cu and Ni progressed in the supercooled liquid region, and the crystallization occurred from the Pd 40 Ni 40 P 20 glass

  5. Computer augumented modelling studies of Pb(II, Cd(II, Hg(II, Co(II, Ni(II, Cu(II and Zn(II complexes of L-glutamic acid in 1,2-propanediol–water mixtures

    Directory of Open Access Journals (Sweden)

    MAHESWARA RAO VEGI

    2008-12-01

    Full Text Available Chemical speciation of Pb(II, Cd(II, Hg(II, Co(II, Ni(II, Cu(II and Zn(II complexes of L-glutamic acid was studied at 303 K in 0–60 vol. % 1,2-propanediol–water mixtures, whereby the ionic strength was maintained at 0.16 mol dm-3. The active forms of the ligand are LH3+, LH2 and LH–. The predominant detected species were ML, ML2, MLH, ML2H and ML2H2. The trend of the variation in the stability constants with changing dielectric constant of the medium is explained based on the cation stabilizing nature of the co-solvents, specific solvent–water interactions, charge dispersion and specific interactions of the co-solvent with the solute. The effect of systematic errors in the concentrations of the substances on the stability constants is in the order alkali > > acid > ligand > metal. The bioavailability and transportation of metals are explained based on distribution diagrams and stability constants.

  6. 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.

  7. 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.

  8. 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

  9. Influence of ni thickness on oscillation coupling in Cu/Ni multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Gagorowska, B; Dus-Sitek, M [Institute of Physics, Czestochowa University of Technology, Al. Armii Krajowej 19, 42-200 Czestochowa (Poland)

    2007-08-15

    The results of investigation of magnetic properties of [Cu/Ni]x100 were presented. Samples were deposited by face-to-face sputtering method onto the silicon substrate, the thickness of Cu layer was constant (d{sub Cu} = 2 nm) and the thickness of Ni layer - variable (1 nm {<=} d{sub Ni} {<=} 6 nm). In Cu/Ni multilayers, for the thickness of Ni layer bigger than 2 nm antiferromagnetic coupling (A-F) were observed, for the thickness of Ni smaller than 2 nm A-F coupling is absent.

  10. Influence of ni thickness on oscillation coupling in Cu/Ni multilayers

    International Nuclear Information System (INIS)

    Gagorowska, B; Dus-Sitek, M

    2007-01-01

    The results of investigation of magnetic properties of [Cu/Ni]x100 were presented. Samples were deposited by face-to-face sputtering method onto the silicon substrate, the thickness of Cu layer was constant (d Cu = 2 nm) and the thickness of Ni layer - variable (1 nm ≤ d Ni ≤ 6 nm). In Cu/Ni multilayers, for the thickness of Ni layer bigger than 2 nm antiferromagnetic coupling (A-F) were observed, for the thickness of Ni smaller than 2 nm A-F coupling is absent

  11. 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

  12. 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.

  13. Enthalpy of mixing of liquid Ni-Zr and Cu-Ni-Zr alloys

    International Nuclear Information System (INIS)

    Witusiewicz, V.T.; Sommer, F.

    2000-01-01

    Since the Al-Cu-Ni-Zr system is a basis for the production of bulk amorphous materials by rapid solidification techniques from the liquid state, it is of great scientific interest to determine the partial and the integral thermodynamic functions of liquid and undercooled liquid alloys. Such data, as was pointed out previously, are important in order to understand their extremely good glass-forming ability in multicomponent metallic systems as well as for processing improvements. In order to measure the thermodynamic properties of the Al-Cu-Ni-Zr quaternary, it is necessary to have reliable thermochemical data for its constituent canaries and ternaries first. In a series of articles, the authors have reported in detail the thermodynamic properties of liquid Al-Cu, Al-Ni, Cu-Ni, Cu-Zr, Al-Zr, Al-Cu-Ni, and Al-Cu-Zr alloys. This article deals with the direct calorimetric measurements of the partial and the integral enthalpies of mixing of liquid Ni-Zr and Cu-Ni-Zr alloys and the heat capacity of liquid Ni 26 Zr 74 . In a subsequent article, the authors will present similar data for the liquid ternary Al-Ni-Zr and for the liquid quaternary Al-Cu-Ni-Zr alloys

  14. 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)

  15. Determination of As, Cd, Cr, Cu, Hg, Sb and Se concentrations by radiochemical neutron activation analysis in different Brazilian regional diets

    International Nuclear Information System (INIS)

    Favaro, D.I.T.; Maihara, V.A.; Armelin, M.J.A.; Vasconcellos, M.B.A.; Cozzolino, S.M.

    1994-01-01

    Radiochemical separation procedures developed for the determination of seven elements: As, Cd, Cr, Cu, Hg, Sb and Se in different Brazilian regional diets are described. In the case of the elements As, Hg, Sb and Se, the procedure was based on retention in inorganic exchanger TFO (tin dioxide) and determination of Hg by extraction with Ni(DDC) 2 . For determination of Cd, Cr, Cu and Se the procedure chosen was based on retention in inorganic exchanger HMD (hydrated manganese dioxide) and extraction of Cu and Cd as diethyldithiocarbamate compounds. The accuracy and precision of the methods studied were tested by means of analyses of different reference materials-Due to the lack of data on trace element levels in Brazilian foodstuffs and diets, these methods were applied to determination of these elements in different Brazilian regional diets. These s were supplied by the Food and Experimental Nutrition Department of the Faculty of Pharmaceutical Science, University of Sao Paulo. The daily intake values for these diets are presented for As, Cd, Cr, Cu, Hg, Sb and Se. (author) 21 refs.; 6 tabs

  16. Qualitative analysis of As, Ba, Cd, Cr, Zn, Fe, Mn, K, Hg, Pb y Cu, as constituents of Amatitlan Lake sediment by XRF

    International Nuclear Information System (INIS)

    Beltran, P.A.E.; Morales, E.A.

    1987-10-01

    Samples of fifteen sampling points were analyzed. Molybdenum X-ray tube with secondary excitation assembly, SiLi detector and deconvolution software AXIL were employed; self-standardization method based upon incoherent ratio was used for quantitative analysis of some elements. Ca, P, S, Ti, Mn, Fe, Cr, Zn, Cu, Ni, Ga, As, Pb, Ge, Sr and Pb, were found. As, Pb and Cu concentrations lower than 109 mg/lt, 119 mg/lt, and 500mg/lt, respectively, were measured. Hg was not detected. (author)

  17. 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

  18. Microstructure and mechanical properties of Cu-Ni-Si alloys

    International Nuclear Information System (INIS)

    Monzen, Ryoichi; Watanabe, Chihiro

    2008-01-01

    The microstructure and mechanical properties of 0.1 wt.% Mg-added and Mg-free Cu-2.0 wt.% Ni-0.5 wt.% Si alloys aged at 400 deg. C have been examined. The addition of Mg promotes the formation of disk-shaped Ni 2 Si precipitates. The Cu-Ni-Si-Mg alloy exhibits higher strength and resistance to stress relaxation than the Cu-Ni-Si alloy. The higher strength or stress relaxation resistance is attributable to the reduction in inter-precipitate spacing by the Mg addition or the drag effect of Mg atoms on dislocation motion. The Cu-Ni-Si alloy with a large grain size of 150 μm shows higher stress relaxation resistance than the alloy with a small grain size of 10 μm because of a lower density of mobile dislocations in the former alloy

  19. Microstructure and mechanical properties of Cu-Ni-Si alloys

    Energy Technology Data Exchange (ETDEWEB)

    Monzen, Ryoichi [Division of Innovative Technology and Science, Graduate School of Natural Science and Technology, Kanzawa University, Kakuma-machi, Kanazawa 920-1192 (Japan)], E-mail: monzen@t.kanazawa-u.ac.jp; Watanabe, Chihiro [Division of Innovative Technology and Science, Graduate School of Natural Science and Technology, Kanzawa University, Kakuma-machi, Kanazawa 920-1192 (Japan)

    2008-06-15

    The microstructure and mechanical properties of 0.1 wt.% Mg-added and Mg-free Cu-2.0 wt.% Ni-0.5 wt.% Si alloys aged at 400 deg. C have been examined. The addition of Mg promotes the formation of disk-shaped Ni{sub 2}Si precipitates. The Cu-Ni-Si-Mg alloy exhibits higher strength and resistance to stress relaxation than the Cu-Ni-Si alloy. The higher strength or stress relaxation resistance is attributable to the reduction in inter-precipitate spacing by the Mg addition or the drag effect of Mg atoms on dislocation motion. The Cu-Ni-Si alloy with a large grain size of 150 {mu}m shows higher stress relaxation resistance than the alloy with a small grain size of 10 {mu}m because of a lower density of mobile dislocations in the former alloy.

  20. Pixe analysis of Cu,Zn,Hg and Cd in mussels samples in bay of Algiers

    International Nuclear Information System (INIS)

    Benamar, M.A.; Tchantchane, A.; Benouali, N.; Azbouche, A.; Tobbeche, S.

    1995-01-01

    The purpose of our work is the elaboration of and absolute technique for determination of trace elements in biological matrices by means of Pixe analysis. We are interested in the determination of heavy metals in mussels samples taken from differents sits of algies coast (Cu,Zn,Cd and Hg). The reason of our choise is the element toxicity and the possible contamination of the marine environment

  1. Corrosion Resistance Of Electroless Ni-P/Cu/Ni-P Multilayer Coatings

    Directory of Open Access Journals (Sweden)

    Zhao G.L.

    2015-06-01

    Full Text Available Ni-P/Cu/Ni-P multilayer coatings were prepared by deposition of Cu layer between two Ni–P layers. The Cu layer was deposited by metal displacement reaction between Cu2+ and Fe atoms. Corrosion behavior of single-layer Ni-P coatings, double-layer Ni-P/Cu coatings, and three-layer Ni-P/Cu/Ni-P coatings were investigated by electrochemical tests in 3.5% NaCl solution. The three-layer coatings exhibited more positive Ecorr and decreased Icorr compared with conventional single-layer Ni-P coatings, which indicated an improved corrosion resistance. The polarization curves of the three-layer coatings were characterized by two passive regions. The improved corrosion resistance was not only attributed to the function of the blocked pores of Cu. The Cu interlayer also acted as a sacrificial layer instead of a barrier in the coatings, which altered the corrosion mechanism and further improved the corrosion resistance of the coatings.

  2. Sensitive and selective detection of Hg2+ and Cu2+ ions by fluorescent Ag nanoclusters synthesized via a hydrothermal method

    Science.gov (United States)

    Liu, Jing; Ren, Xiangling; Meng, Xianwei; Fang, Zheng; Tang, Fangqiong

    2013-09-01

    An easily prepared fluorescent Ag nanoclusters (Ag NCs) probe for the sensitive and selective detection of Hg2+ and Cu2+ ions was developed here. The Ag NCs were synthesized by using polymethacrylic acid sodium salt as a template via a convenient hydrothermal process. The as-prepared fluorescent Ag NCs were monodispersed, uniform and less than 2 nm in diameter, and can be quenched in the presence of mercury (Hg2+) or copper (Cu2+) ions. Excellent linear relationships existed between the quenching degree of the Ag NCs and the concentrations of Hg2+ or Cu2+ ions in the range of 10 nM to 20 μM or 10 nM to 30 μM, respectively. By using ethylenediaminetetraacetate (EDTA) as the masking agent of Cu2+, Hg2+ was exclusively detected in coexistence with Cu2+ with high sensitivity (LOD = 10 nM), which also provided a reusable detection method for Cu2+. Furthermore, the different quenching phenomena caused by the two metals ions such as changes in visible colour, shifts of UV absorbance peaks and changes in size of Ag NCs make it easy to distinguish between them. Therefore the easily synthesized fluorescent Ag NCs may have great potential as Hg2+ and Cu2+ ions sensors.An easily prepared fluorescent Ag nanoclusters (Ag NCs) probe for the sensitive and selective detection of Hg2+ and Cu2+ ions was developed here. The Ag NCs were synthesized by using polymethacrylic acid sodium salt as a template via a convenient hydrothermal process. The as-prepared fluorescent Ag NCs were monodispersed, uniform and less than 2 nm in diameter, and can be quenched in the presence of mercury (Hg2+) or copper (Cu2+) ions. Excellent linear relationships existed between the quenching degree of the Ag NCs and the concentrations of Hg2+ or Cu2+ ions in the range of 10 nM to 20 μM or 10 nM to 30 μM, respectively. By using ethylenediaminetetraacetate (EDTA) as the masking agent of Cu2+, Hg2+ was exclusively detected in coexistence with Cu2+ with high sensitivity (LOD = 10 nM), which also provided a

  3. Cd, Zn, Ni and Cu in the Indian Ocean

    NARCIS (Netherlands)

    Saager, Paul M.; Baar, Hein J.W. de; Howland, Robin J.

    1992-01-01

    Vertical profiles of dissolved Cd, Zn, Ni and Cu in the Northwest Indian Ocean (Arabian Sea) exhibit a nutrient type distribution also observed in other oceans. The area is characterized by strong seasonal upwelling and a broad oxygen minimum zone in intermediate waters. However, neither Cd, Zn, Ni

  4. 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.

  5. Mechanical properties of highly textured Cu/Ni multilayers

    International Nuclear Information System (INIS)

    Liu, Y.; Bufford, D.; Wang, H.; Sun, C.; Zhang, X.

    2011-01-01

    We report on the synthesis of highly (1 1 1) and (1 0 0) textured Cu/Ni multilayers with individual layer thicknesses, h, varying from 1 to 200 nm. When, h, decreases to 5 nm or less, X-ray diffraction spectra show epitaxial growth of Cu/Ni multilayers. High resolution transmission electron microscopy studies show the coexistence of nanotwins and coherent layer interfaces in highly (1 1 1) textured Cu/Ni multilayers with smaller h. Hardnesses of multilayer films increase with decreasing h, approach a maximum at h of a few nanometers, and show softening thereafter at smaller h. The influence of layer interfaces as well as twin interfaces on strengthening mechanisms of multilayers and the formation of twins in Ni in multilayers are discussed.

  6. A benzothiazole-based fluorescent probe for distinguishing and bioimaging of Hg{sup 2+} and Cu{sup 2+}

    Energy Technology Data Exchange (ETDEWEB)

    Gu, Biao; Huang, Liyan; Su, Wei; Duan, Xiaoli; Li, Haitao, E-mail: haitao-li@hunnu.edu.cn; Yao, Shouzhuo

    2017-02-15

    A new benzothiazole-based fluorescent probe 2-(benzo[d]thiazol-2-yl)-4-(1,3- dithian-2-yl)phenol (BT) with two different reaction sites, a thioacetal group (site 1 for Hg{sup 2+}), and O and N atoms of the benzothiazole dye (site 2 for Cu{sup 2+}), was designed and synthesized. The probe BT showed ratiometric fluorescent response to Hg{sup 2+} and fluorescence quenching behavior to Cu{sup 2+}, which induces naked-eye fluorescent color changes from green to blue and colorless, respectively. Moreover, it displayed highly sensitivity and selectivity toward Hg{sup 2+} and Cu{sup 2+} without interference from other metal ions. The sensing mechanisms were also confirmed by {sup 1}H NMR titration, mass spectrum and Job's plot analyses. Finally, probe BT was successfully used for fluorescent imaging of Hg{sup 2+} and Cu{sup 2+} in living cells, demonstrating its potential applications in biological science. - Highlights: • A benzothiazole-based probe for multiple metal ions has been firstly developed. • The differential sensing mechanisms of Hg{sup 2+} and Cu{sup 2+} relied on different reaction. • The probe could be used to monitor Hg{sup 2+} and Cu{sup 2+}in vitro and in vivo with distinct fluorescence changes.

  7. Giant magnetoimpedance effect in sputtered single layered NiFe film and meander NiFe/Cu/NiFe film

    International Nuclear Information System (INIS)

    Chen, L.; Zhou, Y.; Lei, C.; Zhou, Z.M.; Ding, W.

    2010-01-01

    Giant magnetoimpedance (GMI) effect on NiFe thin film is very promising due to its application in developing the magnetic field sensors with highly sensitivity and low cost. In this paper, the single layered NiFe thin film and NiFe/Cu/NiFe thin film with a meander structure are prepared by the MEMS technology. The influences of sputtering parameters, film structure and conductor layer width on GMI effect in NiFe single layer and meander NiFe/Cu/NiFe film are investigated. Maximum of the GMI ratio in single layer and sandwich film is 5% and 64%, respectively. The results obtained are useful for developing the high-performance magnetic sensors based on NiFe thin film.

  8. Detection and identification of Cu2+ and Hg2+ based on the cross-reactive fluorescence responses of a dansyl-functionalized film in different solvents.

    Science.gov (United States)

    Cao, Yuan; Ding, Liping; Wang, Shihuai; Liu, Yuan; Fan, Junmei; Hu, Wenting; Liu, Ping; Fang, Yu

    2014-01-08

    A dansyl-functionalized fluorescent film sensor was specially designed and prepared by assembling dansyl on a glass plate surface via a long flexible spacer containing oligo(oxyethylene) and amine units. The chemical attachment of dansyl moieties on the surface was verified by contact angle, XPS, and fluorescence measurements. Solvent effect examination revealed that the polarity-sensitivity was retained for the surface-confined dansyl moieties. Fluorescence quenching studies in water declared that the dansyl-functionalized SAM possesses a higher sensitivity towards Hg(2+) and Cu(2+) than the other tested divalent metal ions including Zn(2+), Cd(2+), Co(2+), and Pb(2+). Further measurements of the fluorescence responses of the film towards Cu(2+) and Hg(2+) in three solvents including water, acetonitrile, and THF evidenced that the present film exhibits cross-reactive responses to these two metal ions. The combined signals from the three solvents provide a recognition pattern for both metal ions at a certain concentration and realize the identification between Hg(2+) and Cu(2+). Moreover, using principle component analysis, this method can be extended to identify metal ions that are hard to detect by the film sensor in water such as Co(2+) and Ni(2+).

  9. Certification of trace element contents (As, Cd, Co, Cu, Fe, Mn, Hg, Na, Pb and Zn) in a fly ash obtained from the combustion of pulverised coal

    International Nuclear Information System (INIS)

    Griepink, B.; Colinet, E.; Guzzi, G.; Haemers, L.; Muntau, H.

    1983-01-01

    The element contents of As, Cd, Co, Cu, Fe, Mn, Hg, Na, Pb and Zn of a fly ash from pulverised coal are certified. The procedures and their results for the homogenisation, the contamination and homogeneity checks and the analytical campaign are reported. The certified mass fractions and indicative values for Cr, Ni, Th, V and water soluble sulphate are given. The work was carried out within the framework of the activities of the Community Bureau of Reference (BCR) of the Commission of the European Communities. (orig.) [de

  10. Effect of interface intermixing on giant magnetoresistance in NiFe/Cu and Co/NiFe/Co/Cu multilayers

    International Nuclear Information System (INIS)

    Nagamine, L.C.C.M.; Biondo, A.; Pereira, L.G.; Mello, A.; Schmidt, J.E.; Chimendes, T.W.; Cunha, J.B.M.; Saitovitch, E.B.

    2003-01-01

    This article reports on the important influence of the spontaneously built-in paramagnetic interfacial layers on the magnetic and magnetoresistive properties of NiFe/Cu and Co/NiFe/Co/Cu multilayers grown by magnetron sputtering. A computational simulation, based on a semiclassical model, has been used to reproduce the variations of the resistivity and of the magnetoresistance (MR) amplitude with the thickness of the NiFe, Cu, and Co layers. We showed that the compositionally intermixed layers at NiFe/Cu interfaces, which are paramagnetic, reduce the flow of polarized electrons and produce a masking on the estimated mean-free path of both types of electrons due to the reduction of their effective values, mainly for small NiFe thickness. Moreover, the transmission coefficients for the electrons decrease when Fe buffer layers are replaced by NiFe ones. This result is interpreted in terms of the variations of the interfacial intermixing and roughness at the interfaces, leading to an increase of the paramagnetic interfacial layer thickness. The effect provoked by Co deposition at the NiFe 16 A/Cu interfaces has also been investigated. The maximum of the MR amplitudes was found at 5 A of Co, resulting in the quadruplication of the MR amplitude. This result is partially attributed to the interfacial spin-dependent scattering due to the increase of the magnetic order at interfaces. Another effect observed here was the increase of the spin-dependent scattering events in the bulk NiFe due to a larger effective NiFe thickness, since the paramagnetic interfacial layer thickness is decreased

  11. 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

  12. Influence of Ni Solute segregation on the intrinsic growth stresses in Cu(Ni) thin films

    International Nuclear Information System (INIS)

    Kaub, T.M.; Felfer, P.; Cairney, J.M.; Thompson, G.B.

    2016-01-01

    Using intrinsic solute segregation in alloys, the compressive stress in a series of Cu(Ni) thin films has been studied. The highest compressive stress was noted in the 5 at.% Ni alloy, with increasing Ni concentration resulting in a subsequent reduction of stress. Atom probe tomography quantified Ni's Gibbsian interfacial excess in the grain boundaries and confirmed that once grain boundary saturation is achieved, the compressive stress was reduced. This letter provides experimental support in elucidating how interfacial segregation of excess adatoms contributes to the post-coalescence compressive stress generation mechanism in thin films. - Graphical abstract: Cu(Ni) film stress relationship with Ni additions. Atom probe characterization confirms solute enrichment in the boundaries, which was linked to stress response.

  13. 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...

  14. Tolerance and hyperaccumulation of a mixture of heavy metals (Cu, Pb, Hg, and Zn) by four aquatic macrophytes.

    Science.gov (United States)

    Romero-Hernández, Jorge Alberto; Amaya-Chávez, Araceli; Balderas-Hernández, Patricia; Roa-Morales, Gabriela; González-Rivas, Nelly; Balderas-Plata, Miguel Ángel

    2017-03-04

    In the present investigation, four macrophytes, namely Typha latifolia (L.), Lemna minor (L.), Eichhornia crassipes (Mart.) Solms-Laubach, and Myriophyllum aquaticum (Vell.) Verdc, were evaluated for their heavy metal (Cu, Pb, Hg, and Zn) hyperaccumulation potential under laboratory conditions. Tolerance analyses were performed for 7 days of exposure at five different treatments of the metals mixture (Cu +2 , Hg +2 , Pb +2 , and Zn +2 ). The production of chlorophyll and carotenoids was determined at the end of each treatment. L. minor revealed to be sensitive, because it did not survive in all the tested concentrations after 72 hours of exposure. E. crassipes and M. aquaticum displayed the highest tolerance to the metals mixture. For the most tolerant species of aquatic macrophytes, The removal kinetics of E. crassipes and M. aquaticum was carried out, using the following mixture of metals: Cu (0.5 mg/L) and Hg, Pb, and Zn 0.25 mg/L. The obtained results revealed that E. crassipes can remove 99.80% of Cu, 97.88% of Pb, 99.53% of Hg, and 94.37% of Zn. M. aquaticum withdraws 95.2% of Cu, 94.28% of Pb, 99.19% of Hg, and 91.91% of Zn. The obtained results suggest that these two species of macrophytes could be used for the phytoremediation of this mixture of heavy metals from the polluted water bodies.

  15. Promising Cu-Ni-Cr-Si alloy for first wall ITER applications

    International Nuclear Information System (INIS)

    Ivanov, A.; Abramov, V.; Rodin, M.

    1996-01-01

    Precipitation-hardened Cu-Ni-Cr-Si alloy, a promising material for ITER applications, is considered. Available commercial products, chemical composition, physical and mechanical properties are presented. Embrittlement of Cu-Ni-Cr-Si alloy at 250-300 C is observed. Mechanical properties of Cu-Ni-Cr-Si alloy neutron irradiated to a dose of ∝0.2 dpa at 293 C are investigated. Embrittlement of Cu-Ni-Cr-Si alloy can be avoided by annealing. (orig.)

  16. FABRICATION OF Cu-Al-Ni SHAPE MEMORY THIN FILM BY THERMAL EVOPRATION

    OpenAIRE

    Özkul, İskender; Canbay, Canan Aksu; Tekataş, Ayşe

    2017-01-01

    Among the functional, materials shape memory alloysare important because of their unique properties. So, these materials haveattracted more attention to be used in micro/nano electronic andelectromechanic systems. In this work, thermal evaporation method has been usedto produce CuAlNi shape memory alloy thin film. The produced CuAlNi thin filmhas been characterized and the presence of the martensite phase wasinvestigated and compared with the CuAlNi alloy sample. CuAlNi shape memoryalloy thin...

  17. Centennial record of anthropogenic impacts in Galveston Bay: Evidence from trace metals (Hg, Pb, Ni, Zn) and lignin oxidation products.

    Science.gov (United States)

    Al Mukaimi, Mohammad E; Kaiser, Karl; Williams, Joshua R; Dellapenna, Timothy M; Louchouarn, Patrick; Santschi, Peter H

    2018-06-01

    During the 20th century the impacts of industrialization and urbanization in Galveston Bay resulted in significant shifts in trace metals (Hg, Pb, Ni, Zn) and vascular plant biomarkers (lignin phenols) recorded within the surface sediments and sediment cores profile. A total of 22 sediment cores were collected in Galveston Bay in order to reconstruct the historical input of Hg, Pb, Ni, Zn and terrestrial organic matter. Total Hg (T-Hg) concentration ranged between 6 and 162 ng g -1 in surface sediments, and showed decreasing concentrations southward from the Houston Ship Channel (HSC) toward the open estuary. Core profiles of T-Hg and trace metals (Ni, Zn) showed substantial inputs starting in 1905, with peak concentrations between 1960 and 1970's, and decreasing thereafter with exception to Pb, which peaked around 1930-1940s. Stable carbon isotopes and lignin phenols showed an increasing input of terrestrial organic matter driven by urban development within the watershed in the early 1940s. Both the enrichment factor and the geoaccumulation index (I geo ) for T-Hg as a measure of the effectiveness of environmental management practices showed substantial improvements since the 1970s. The natural recovery rate in Galveston Bay since the peak input of T-Hg was non-linear and displayed a slow recovery during the twenty-first century. Copyright © 2018 Elsevier Ltd. All rights reserved.

  18. Giant Tc shift in HgBa2CaCu2O6+δ and TlBa2CaCu2O7-δ superconductors due to Hg-Tl exchange

    International Nuclear Information System (INIS)

    Gapud, A.A.; Wu, J.Z.; Kang, B.W.; Yan, S.L.; Xie, Y.Y.; Siegal, M.P.

    1999-01-01

    The irreversibility lines of epitaxial thin films of HgBa 2 CaCu 2 O 6+δ and TlBa 2 CaCu 2 O 7-δ , whether deduced from field-induced magnetoresistive broadening or onset of nonhysteretic magnetization, were found to coincide when plotted against reduced temperature, showing the same exponential-decay temperature behavior for T/T c c >0.8 (where T c is zero-field, zero-resistivity critical temperature). These results indicate that replacing Tl with Hg has no noticeable effect on the anisotropy and suggests that T c is not determined by anisotropy. copyright 1999 The American Physical Society

  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. Study of dipole interaction in micron-width NiFe/Cu/NiFe/NiO wire using exchange anisotropy

    International Nuclear Information System (INIS)

    Kimura, Takashi; Itagaki, Yoshio; Wakaya, Fujio; Gamo, Kenji

    2001-01-01

    The dipole interaction between a NiFe layer pinned by a NiO and a free NiFe layer in a micron-wide NiFe/Cu/NiFe/NiO wire was studied by changing the direction of the exchange bias from the NiO layer. The effect of the dipole interaction when the exchange bias was perpendicular to the wire axis was larger than that when the exchange bias was parallel to the wire axis, and was consistently explained by the stray field caused by the magnetic charges of the pinned layer. It was demonstrated that this method, using exchange anisotropy, is useful for investigating the dipole interaction between ferromagnetic materials separated by a nonmagnetic material in small-scale magnetic multilayers. [copyright] 2001 American Institute of Physics

  1. Study of the magnetic anisotropy in Ni/Cu and Ni/glass thin films

    Energy Technology Data Exchange (ETDEWEB)

    Cherif, S.-M. [Laboratoire PMTM, Institut Galilee, Univeriste Paris 13, Villetaneuse, 93340 (France); Layadi, A. [Departement de Physique, Universite Ferhat Abbas, Setif 19000 (Algeria)]. E-mail: a_layadi@yahoo.fr; Ben Youssef, J. [Laboratoire de Magnetisme de Bretagne, U.B.O., Brest 29238 (France); Nacereddine, C. [Departement de Physique, Universite Ferhat Abbas, Setif 19000 (Algeria); Roussigne, Y. [Laboratoire PMTM, Institut Galilee, Univeriste Paris 13, Villetaneuse, 93340 (France)

    2007-01-01

    The magnetic properties of evaporated Ni/Cu and Ni/glass thin films have been investigated by means of the vibrating sample magnetometer (VSM), the Brillouin light scattering (BLS) and magnetic force microscopy (MFM). The Ni thickness, t, ranges from 31 to 165 nm. The second- and fourth-order magnetic anisotropy constants, K {sub 1} and K {sub 2}, have been included; for the Ni/Cu series, K {sub 1} was found to decrease from 1.0x10{sup 6} to 0.18x10{sup 6} erg/cm{sup 3} as t increases from 31 to 165 nm, while K {sub 2} increased from 0.24x10{sup 6} to 0.8x10{sup 6} erg/cm{sup 3}. Over all the thickness range, the magnetization easy axis is in plane. For thinner films, there is a good agreement between anisotropy constant values inferred from VSM and BLS. Stripe domains were observed for t{>=}165 nm in Ni/glass and t{>=}90 nm in Ni/Cu.

  2. Study of the magnetic anisotropy in Ni/Cu and Ni/glass thin films

    International Nuclear Information System (INIS)

    Cherif, S.-M.; Layadi, A.; Ben Youssef, J.; Nacereddine, C.; Roussigne, Y.

    2007-01-01

    The magnetic properties of evaporated Ni/Cu and Ni/glass thin films have been investigated by means of the vibrating sample magnetometer (VSM), the Brillouin light scattering (BLS) and magnetic force microscopy (MFM). The Ni thickness, t, ranges from 31 to 165 nm. The second- and fourth-order magnetic anisotropy constants, K 1 and K 2 , have been included; for the Ni/Cu series, K 1 was found to decrease from 1.0x10 6 to 0.18x10 6 erg/cm 3 as t increases from 31 to 165 nm, while K 2 increased from 0.24x10 6 to 0.8x10 6 erg/cm 3 . Over all the thickness range, the magnetization easy axis is in plane. For thinner films, there is a good agreement between anisotropy constant values inferred from VSM and BLS. Stripe domains were observed for t≥165 nm in Ni/glass and t≥90 nm in Ni/Cu

  3. Magnetic Properties and Structural Study of Ni-Co/Cu Multilayers Prepared by Electrodeposition Method

    Directory of Open Access Journals (Sweden)

    M. Jafari Fesharaki

    2015-07-01

    Full Text Available Ni-Co/Cu multilayers have been grown by electrodeposition method from a single electrolyte (based on Ni(SO4.6H2O, Co(SO4.7H2O, Cu(SO4 and H3BO3 using galvanostatic control on titanium sublayers. The X-ray diffraction (XRD patterns confirmed the multilayered structure with the nanometer thicknesses. Also, electron diffraction x-ray (EDX  analysis confirmed the purity of deposited samples. The morphology of the samples was estimated by scanning electron microscope (SEM. Magnetoresistance (MR measurements were carried out at room temperature for the Ni-Co/Cu multilayers by measuring the resistivity in a magnetic fields varying between ±6kOe as a function of the Ni-Co and Cu layer thicknesses; (1 dCu(nm 4 and 3 dNi-Cu(nm 5. The Maximum value of giant magnetoresistance (GMR was obtained when the Ni-Co and Cu thicknesses were 4.0nm and 4.0nm respectively. The hysteresis loop of the samples at room temperature was studied using an alternating gradient force magnetometer (AGFM. Finally, the temperature dependence of magnetization for Ni-Co/Cu multilayers; (dNi-Cu(4nm/dCu(2nm and dNi-Cu(3nm/dCu(3nm measured by Faraday balance and decreasing the magnetization with increasing the temperature discussed according to electron scattering due to spin fluctuation.

  4. Low temperature interdiffusion in Cu/Ni thin films

    International Nuclear Information System (INIS)

    Lefakis, H.; Cain, J.F.; Ho, P.S.

    1983-01-01

    Interdiffusion in Cu/Ni thin films was studied by means of Auger electron spectroscopy in conjunction with Ar + ion sputter profiling. The experimental conditions used aimed at simulating those of typical chip-packaging fabrication processes. The Cu/Ni couple (from 10 μm to 60 nm thick) was produced by sequential vapor deposition on fused-silica substrates at 360, 280 and 25 0 C in 10 - 6 Torr vacuum. Diffusion anneals were performed between 280 and 405 0 C for times up to 20 min. Such conditions define grain boundary diffusion in the regimes of B- and C-type kinetics. The data were analyzed according to the Whipple-Suzuoka model. Some deviations from the assumptions of this model, as occurred in the present study, are discussed but cannot fully account for the typical data scatter. The grain boundary diffusion coefficients were determined allowing calculation of respective permeation distances. (Auth.)

  5. Phase transition study in a [Cu2 HgI4:0⋅xAgI] mixed composite system

    Indian Academy of Sciences (India)

    Administrator

    Diffraction, thermal analysis of compound, Ag2HgI4,. Cu2HgI4, Tl2HgI4 ... nitrogen atmosphere (200 ml/min) at a heating rate of. 5°C per min and a ..... Bates J B and Farington G C 1981 Proceedings of the interna- tional conference on fast ...

  6. Anomalous fast diffusion in Cu-NiFe nanolaminates.

    Energy Technology Data Exchange (ETDEWEB)

    Jankowski, Alan F. [Sandia National Laboratories (SNL-CA), Livermore, CA (United States). Energy Nanomaterials Dept.

    2017-09-01

    For this work, the decomposition of the one-dimensional composition wave in Cu-NiFe nanolaminate structures is examined using x-ray diffraction to assess the kinetics of phase decomposition. The anomalously high diffusivity value found for long-term aging at room temperature is attributed to the inherent nanostructure that features paths for short-circuit diffusion in nanolaminates as attributed to interlayer grain boundaries.

  7. Monitoring Cu nodule formation using Ni marker layers

    Energy Technology Data Exchange (ETDEWEB)

    Lafouresse, M.C., E-mail: mlafouresse@gmail.co [Department of Civil and Earth Resources Engineering, Kyoto University, Katsura, Kyoto 615-8540 (Japan); Fukunaka, Y. [Institute for Nanoscience and Nanotechnology, Waseda University, Shinjuku Ku, Tokyo 169-8555 (Japan); ISS Science Project Office, JAXA, Tsukuba-shi, Ibaraki 305-8505 (Japan); Matsuoka, T. [Department of Civil and Earth Resources Engineering, Kyoto University, Katsura, Kyoto 615-8540 (Japan); Schwarzacher, W. [H. H. Wills Physics Laboratory, Tyndall Avenue, Bristol BS8 1TL (United Kingdom)

    2011-04-30

    Highlights: {yields} Ni marker layers to monitor electrodeposited Cu nodule morphological evolution. {yields} The edges of the nodules trace out a straight line. {yields} Difference in growth between spheres and hemispheres. {yields} Nodule on nodule growth at high overpotential. {yields} No dramatic effect of the diffusion layer thickness on the film morphology. - Abstract: We have used Ni marker layers to study the evolution of the characteristic spheroidal nodule morphology in electrodeposited Cu films. Ultrathin Ni layers were electrodeposited in-between Cu layers, and cross sections prepared by electrochemical polishing. During growth of a typical spheroidal feature, the edge (i.e. where there is a discontinuity in the surface slope) traces out a straight line in the cross-sectional image. At high overpotential, the cross-sections show nodule-on-nodule growth, giving rise to the well known cauliflower morphology. Rotating disk electrode studies reveal that, surprisingly, the absolute diffusion layer thickness does not appear to play a major role in the development of spheres.

  8. Monitoring Cu nodule formation using Ni marker layers

    International Nuclear Information System (INIS)

    Lafouresse, M.C.; Fukunaka, Y.; Matsuoka, T.; Schwarzacher, W.

    2011-01-01

    Highlights: → Ni marker layers to monitor electrodeposited Cu nodule morphological evolution. → The edges of the nodules trace out a straight line. → Difference in growth between spheres and hemispheres. → Nodule on nodule growth at high overpotential. → No dramatic effect of the diffusion layer thickness on the film morphology. - Abstract: We have used Ni marker layers to study the evolution of the characteristic spheroidal nodule morphology in electrodeposited Cu films. Ultrathin Ni layers were electrodeposited in-between Cu layers, and cross sections prepared by electrochemical polishing. During growth of a typical spheroidal feature, the edge (i.e. where there is a discontinuity in the surface slope) traces out a straight line in the cross-sectional image. At high overpotential, the cross-sections show nodule-on-nodule growth, giving rise to the well known cauliflower morphology. Rotating disk electrode studies reveal that, surprisingly, the absolute diffusion layer thickness does not appear to play a major role in the development of spheres.

  9. 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)

  10. Levels determination of heavy elements (Fe, Cu, Zn, Pb and Hg) in sword fish caught from the bay of Ghazaouet

    International Nuclear Information System (INIS)

    Chalabi, A.; Malek, M.; Ghomari, M.; Benamar, M.A.; Tchantchane, A.; Azbouche, A.; Toumert, I.; Benouali, N.; Tobbeche, S. , Algiers; Algeria)

    1993-04-01

    The nuclear technics 'PIXE' and 'XRF', were used for heavy metals analysis (Fe, Cu, Zn, Pb, and Hg), in sword fish (xiphias Gladius) caught in Ghazaouet bay. Muscles, liver and gonads were analysed. The methods gave similar results. A bioaccumulation phenomenon was observed except for Hg. The high amount of concentrations found liver, especially in the case of confirms that liver is a storage organ. The high levels of Zn seem to be due to the industrial wastes from the electrolyte plant in the region. All values were lower than the admissible norms

  11. KLL resonant Auger transitions in metallic Cu and Ni

    International Nuclear Information System (INIS)

    Koever, L.; Berenyi, Z.; Cserny, I.

    2004-01-01

    Complete text of publication follows. KLL Auger spectra of 3d transition metals contain important information on the effects of the solid environment on deep core Auger transitions. Following the changes in the spectra when fine tuning the exciting photon energy across the K-shell ionization threshold with high energy resolution is informative concerning the possible resonant processes, expected to indicate the single-step nature of threshold Auger emission. The satellite structures in these spectra are strongly related to the unoccupied local electronic states above the Fermi level, as well as to the excitation, relaxation and screening processes associated with core hole ionization. In spite of the fundamental significance of the phenomena mentioned above, even non resonant high energy resolution studies of KLL Auger spectra of 3d transition metals (using laboratory X-ray sources) are very scarce due to the demanding experimental conditions requested. A very efficient tool for studying these phenomena is the Tunable High Energy XPS developed at HASYLAB which provides unique conditions, photon x and energy resolution for deep core Auger spectroscopy. Using the THE-XPS instrument at the BW2 beamline the high energy resolution (ΔE = 0.2 eV) KL 2,3 L 2,3 Auger spectra of polycrystalline Cu and Ni foils were measured with the Scienta SES-200 hemispherical analyzer. In the high energy range Cu 2p photo-electron peaks appearing in the Cu KLL Auger spectra due to the excitation by internal Cu K X-rays and trusted value for the Cu 2p3/2 binding energy were used for energy calibration. The exciting photon energy range was tuned up to about 50 eV above the K absorption edge and for the resonant energy region to 5 eV (Cu KLL) and 4 eV (Ni KLL) below threshold ensuring a photon beam with an energy width of about 1.1 eV. The evolution of the satellite structure as a function of excitation energy above threshold indicates di rent behaviour for particular satellites, making

  12. Effect of Cu Alloying on S Poisoning of Ni Surfaces and Nanoparticle Morphologies Using Ab-Initio Thermodynamics Calculations.

    Science.gov (United States)

    Kim, Ji-Su; Kim, Byung-Kook; Kim, Yeong-Cheol

    2015-10-01

    We investigated the effect of Cu alloying on S poisoning of Ni surfaces and nanoparticle morphologies using ab-initio thermodynamics calculations. Based on the Cu segregation energy and the S adsorption energy, the surface energy and nanoparticle morphology of pure Ni, pure Cu, and NiCu alloys were evaluated as functions of the chemical potential of S and the surface orientations of (100), (110), and (111). The constructed nanoparticle morphology was varied as a function of chemical potential of S. We find that the Cu added to Ni for NiCu alloys is strongly segregated into the top surface, and increases the S tolerance of the NiCu nanoparticles.

  13. 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.

  14. Fabrication of a Cu/Ni stack in supercritical carbon dioxide at low-temperature

    Energy Technology Data Exchange (ETDEWEB)

    Rasadujjaman, Md, E-mail: rasadphy@duet.ac.bd [Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 4-3-11 Takeda, Kofu, Yamanashi 400-8511 (Japan); Department of Physics, Dhaka University of Engineering & Technology, Gazipur 1700 (Bangladesh); Watanabe, Mitsuhiro [Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 4-3-11 Takeda, Kofu, Yamanashi 400-8511 (Japan); Sudoh, Hiroshi; Machida, Hideaki [Gas-Phase Growth Ltd., 2-24-16 Naka, Koganei, Tokyo 184-0012 (Japan); Kondoh, Eiichi [Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 4-3-11 Takeda, Kofu, Yamanashi 400-8511 (Japan)

    2015-09-30

    We report the low-temperature deposition of Cu on a Ni-lined substrate in supercritical carbon dioxide. A novel Cu(I) amidinate precursor was used to reduce the deposition temperature. From the temperature dependence of the growth rate, the activation energy for Cu growth on the Ni film was determined to be 0.19 eV. The films and interfaces were characterized by Auger electron spectroscopy. At low temperature (140 °C), we successfully deposited a Cu/Ni stack with a sharp Cu/Ni interface. The stack had a high adhesion strength (> 1000 mN) according to microscratch testing. The high adhesion strength originated from strong interfacial bonding between the Cu and the Ni. However, at a higher temperature (240 °C), significant interdiffusion was observed and the adhesion became weak. - Highlights: • Cu/Ni stack fabricated in supercritical CO{sub 2} at low temperature. • A novel Cu(I) amidinate precursor was used to reduce the deposition temperature. • Adhesion strength of Cu/Ni stack improved dramatically. • Fabricated Cu/Ni stack is suitable for Cu interconnections in microelectronics.

  15. 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).

  16. Enhanced Oxidation-Resistant Cu@Ni Core-Shell Nanoparticles for Printed Flexible Electrodes.

    Science.gov (United States)

    Kim, Tae Gon; Park, Hye Jin; Woo, Kyoohee; Jeong, Sunho; Choi, Youngmin; Lee, Su Yeon

    2018-01-10

    In this work, the fabrication and application of highly conductive, robust, flexible, and oxidation-resistant Cu-Ni core-shell nanoparticle (NP)-based electrodes have been reported. Cu@Ni core-shell NPs with a tunable Ni shell thickness were synthesized by varying the Cu/Ni molar ratios in the precursor solution. Through continuous spray coating and flash photonic sintering without an inert atmosphere, large-area Cu@Ni NP-based conductors were fabricated on various polymer substrates. These NP-based electrodes demonstrate a low sheet resistance of 1.3 Ω sq -1 under an optical energy dose of 1.5 J cm -2 . In addition, they exhibit highly stable sheet resistances (ΔR/R 0 flexible heater fabricated from the Cu@Ni film is demonstrated, which shows uniform heat distribution and stable temperature compared to those of a pure Cu film.

  17. Effect of solute Cu on ductile-to-brittle behavior of martensitic Fe-8% Ni alloy

    International Nuclear Information System (INIS)

    Junaidi Syarif; Tsuchiyama, Toshihiro; Takaki, Setsuo

    2007-01-01

    Effect of solute Cu on the ductile-to-brittle (DBT) behaviour of martensitic Fe-8mass%Ni alloy is investigated to understand the effect of solute Cu on mechanical properties of martensitic steel. The DBT behaviours of the Fe-8mass%Ni and the Fe-8mass%Ni-1mass%Cu alloys are almost the same. It is thought to be due to disappearance of the solid solution softening in the martensitic Fe-8mass%Ni-Cu alloys. The solute Cu gives small influence on temperature and strain rate dependences of yield stress and suppressing the twin deformation at lower temperature in the martensitic Fe-8mass%Ni alloy. Therefore, the DBT temperature of the martensitic Fe-8mass%Ni-Cu alloy was not shifted to lower side. (author)

  18. Hydrostatic pressure dependence of the superconducting transition temperature of HgBa2CaCu2O6+δ and HgBa2Ca2Cu3O8+δ

    International Nuclear Information System (INIS)

    Klehe, A.K.; Schilling, J.S.

    1994-02-01

    The dependence of the superconducting transition temperature T c (P) on purely hydrostatic pressure to 0.9 GPa has been determined in ac susceptibility studies in a He-gas pressure system for optimally doped ceramic samples of HgBa 2 CaCu 2 O 6+δ and HgBa 2 Ca 2 Cu 3 O 8+δ with superconducting transitions at T c (0) ≅ 126.6 K and 133.9 K, respectively. T c increases reversibly under hydrostatic pressure at the rates, d T c /dP ≅ +1.80 ± 0.06 K/GPa and +1.71 ± 0.05 K/GPa, respectively. Within experimental error, these values are the same as found previously for optimally doped single-layered HgBa 2 CuO 4+δ , where d T c /dP ≅ +1.72 ± 0.05 K/GPa. Remarkably, the logarithmic volume derivative of T c is nearly identical for all three compounds, dln T c /dlnV ≅ -1.20 ± 0.05, even though the bulk modulus differs by more than 30%. This provides strong evidence that a common mechanism is responsible for the pressure dependence of the superconducting state in all three compounds

  19. Catalytic hydrotreatment of fast pyrolysis oil using bimetallic Ni-Cu catalysts on various supports

    NARCIS (Netherlands)

    Ardiyanti, A. R.; Khromova, S. A.; Venderbosch, R. H.; Yakovlev, V. A.; Melian-Cabrera, I. V.; Heeres, H. J.

    2012-01-01

    Bimetallic Ni-Cu catalysts on various Supports (CeO2-ZrO2, ZrO2, SiO2, TiO2, rice husk carbon, and Sibunite) with metal contents ranging from 7.5 to 9.0 (Ni) and 3.1-3.6 wt.% (Cu) for the inorganic supports and 17.1-17.8 (Ni) and 7.1-7.8 (Cu) for the carbon supports were synthesised and screened for

  20. Structural and Transition Temperature of HgPbxBa2Ca2Cu3O8+δ Superconductor

    International Nuclear Information System (INIS)

    Hermiz, G.Y.; Abbass, M.M.

    2005-01-01

    Solid state reaction technique (SSR) was used to prepare high-T c phase in HgPb x Ba 2 Ca 2 Cu 3 O 8+δ superconductors. The effect of additional Pb to HgBa 2 Ca 2 Cu 3 O 8+δ was investigated. It has been found that the maximum transition temperature T c =133K is at x=0.1.X-ray diffraction showed a tetragonal structure with an average value of e=15.816 A . The average value of the valence of copper (v) is equal to 2.025. There is an increasing of density with the enhancement of the concentration of Pb 2

  1. Structural, electrical and magnetic properties of evaporated Ni/Cu and Ni/glass thin films

    Energy Technology Data Exchange (ETDEWEB)

    Nacereddine, C. [Departement de Physique, Universite Ferhat Abbas, Setif 19000 (Algeria); Layadi, A. [Departement de Physique, Universite Ferhat Abbas, Setif 19000 (Algeria)]. E-mail: A_Layadi@yahoo.fr; Guittoum, A. [Centre de Recherche Nucleaire d' Alger (CRNA), Alger 16000 (Algeria); Cherif, S.-M. [Laboratoire PMTM, Institut Galilee, Univeriste Paris 13, Villetaneuse 93340 (France); Chauveau, T. [Laboratoire PMTM, Institut Galilee, Univeriste Paris 13, Villetaneuse 93340 (France); Billet, D. [Laboratoire PMTM, Institut Galilee, Univeriste Paris 13, Villetaneuse 93340 (France); Youssef, J. Ben [Laboratoire de Magnetisme de Bretagne, U.B.O., Brest 29238 (France); Bourzami, A. [Departement de Physique, Universite Ferhat Abbas, Setif 19000 (Algeria); Bourahli, M.-H. [Departement d' O. M. P., Universite Ferhat Abbas, Setif 19000 (Algeria)

    2007-01-25

    The structural, electrical and magnetic properties of Ni thin films evaporated onto glass and polycrystalline Cu substrates have been investigated. The Ni thickness ranges from 31 to 165 nm. X-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM) have been used to study the structure and morphology of these systems. The Ni/Cu and Ni/glass thin films are found to be polycrystalline with a (1 1 1) texture. There is an overall increase of the grain size with increasing thickness. A negative strain was noted indicating that all the samples are under a compressive stress. Diffusion at the grain boundaries seems to be a major contribution to the electrical resistivity in this thickness range. Study of the hysteresis curves, obtained by vibrating sample magnetometer (VSM), indicates that all samples are characterized by an in-plane magnetization easy axis. Higher in-plane coercive fields seem to be associated with higher grain size, indicating that coercivity may be due to nucleation of reverse domains rather than pinning of domain walls. The saturation field and the squareness have been studied as a function of the Ni thickness.

  2. Microstructural characterization of alloys of the quasibinary Cu-NiBe system

    Energy Technology Data Exchange (ETDEWEB)

    Spaic, S.; Markoli, B. [Univ. of Ljubljana, Faculty of Natural Science and Engineering, Ljubljana (Slovenia)

    2003-08-01

    Alloys of the quasibinary section Cu-NiBe were experimentally investigated with differential thermal analysis, optical microscopy, electron microanalysis, transmission electron microscopy and X-ray diffraction. The construction of the quasibinary Cu-NiBe phase diagram was made based on the experimental results. The constitution of alloys of the whole section was studied along with the investigation of the microstructure and crystallographic relationship of the NiBe phase in aged alloys from the Cu-rich corner of the Cu-NiBe system. (orig.)

  3. Water Soluble Cationic Porphyrin Sensor for Detection of Hg2+, Pb2+, Cd2+, and Cu2+

    Directory of Open Access Journals (Sweden)

    Matibur Zamadar

    2016-01-01

    Full Text Available Here we report the sensing properties of the aqueous solution of meso-tetra(N-methyl-4-pyridylporphine tetrachloride (1 for simultaneous detection of toxic metal ions by using UV-vis spectroscopy. Cationic porphyrin 1 displayed different electronic absorptions in UV-vis region upon interacting with Hg2+, Pb2+, Cd2+, and Cu2+ ions in neutral water solution at room temperature. Quite interestingly, the porphyrin 1 showed that it can function as a single optical chemical sensor and/or metal ion receptor capable of detecting two or more toxic metal ions, particularly Hg2+, Pb2+, and Cd2+ ions coexisting in a water sample. Porphyrin 1 in an aqueous solution provides a unique UV-vis sensing system for the determination of Cd2+ in the presence of larger metal ions such as Hg2+, or Pb2+. Finally, the examination of the sensing properties of 1 demonstrated that it can operate as a Cu2+ ion selective sensor via metal displacement from the 1-Hg2+, 1-Pb2+, and 1-Cd2+.

  4. Crystallization behavior of Zr62Al8Ni13Cu17 Metallic Glass

    Directory of Open Access Journals (Sweden)

    Jo Mi Sun

    2017-06-01

    Full Text Available The crystallization behavior has been studied in Zr62Al8Ni13Cu17 metallic glass alloy. The Zr62Al8Ni13Cu17 metallic glass crystallized through two steps. The fcc Zr2Ni phase transformed from the amorphous matrix during first crystallization and then the Zr2Ni and residual amorphous matrix transformed into a mixture of tetragonal Zr2Cu and hexagonal Zr6Al2Ni phases. Johnson-Mehl-Avrami analysis of isothermal transformation data suggested that the formation of crystalline phase is primary crystallization by diffusion-controlled growth.

  5. Kinetic study of the annealing reactions in Cu-Ni-Fe alloys

    International Nuclear Information System (INIS)

    Donoso, E.

    2014-01-01

    The thermal aging of a Cu-45Ni-4Fe, Cu-34Ni-11Fe and Cu-33Ni-22Fe alloys tempered from 1173 K have been studied from Differential Scanning Calorimetry (DSC) and microhardness measurements. The analysis of DSC curves, from room temperature to 950 K, shows the presence of one exothermic reaction associated to the formation of FeNi 3 phase nucleating from a modulate structure, and one endothermic peak attributed to dissolution of this phase. Kinetic parameters were obtained using the usual Avrami-Erofeev equation, modified Kissinger method and integrated kinetic functions. Microhardness measurements confirmed the formation and dissolution of the FeNi 3 phase. (Author)

  6. Formation of Ti--Zr--Cu--Ni bulk metallic glasses

    International Nuclear Information System (INIS)

    Lin, X.H.; Johnson, W.L.

    1995-01-01

    Formation of bulk metallic glass in quaternary Ti--Zr--Cu--Ni alloys by relatively slow cooling from the melt is reported. Thick strips of metallic glass were obtained by the method of metal mold casting. The glass forming ability of the quaternary alloys exceeds that of binary or ternary alloys containing the same elements due to the complexity of the system. The best glass forming alloys such as Ti 34 Zr 11 Cu 47 Ni 8 can be cast to at least 4-mm-thick amorphous strips. The critical cooling rate for glass formation is of the order of 250 K/s or less, at least two orders of magnitude lower than that of the best ternary alloys. The glass transition, crystallization, and melting behavior of the alloys were studied by differential scanning calorimetry. The amorphous alloys exhibit a significant undercooled liquid region between the glass transition and first crystallization event. The glass forming ability of these alloys, as determined by the critical cooling rate, exceeds what is expected based on the reduced glass transition temperature. It is also found that the glass forming ability for alloys of similar reduced glass transition temperature can differ by two orders of magnitude as defined by critical cooling rates. The origins of the difference in glass forming ability of the alloys are discussed. It is found that when large composition redistribution accompanies crystallization, glass formation is enhanced. The excellent glass forming ability of alloys such as Ti 34 Zr 11 Cu 47 Ni 8 is a result of simultaneously minimizing the nucleation rate of the competing crystalline phases. The ternary/quaternary Laves phase (MgZn 2 type) shows the greatest ease of nucleation and plays a key role in determining the optimum compositions for glass formation. copyright 1995 American Institute of Physics

  7. Experimental investigation of phase equilibria in the Zr-Cu-Ni ternary system

    International Nuclear Information System (INIS)

    Yang, Mujin; Wang, Cuiping; Yang, Shuiyuan; Shi, Zhan; Han, Jiajia; Liu, Xingjun

    2017-01-01

    The phase equilibria in the Zr-Cu-Ni ternary system are investigated combined with X-ray diffraction, electron probe micro-analysis and differential scanning calorimetry. Two isothermal sections of the Zr-Cu-Ni ternary system at 1 000 C and 1 100 C are experimentally established. Most of the binary intermetallic compounds, e.g. Zr 7 Ni 10 , ZrNi, ZrNi 5 , Zr 14 Cu 51 , and Zr 2 Cu 9 , show a remarkable ternary solubility. A new ternary compound named τ 3 (Zr 31.1-30.7 . Cu 28.5-40.3 Ni 40.4-29.0 ) is detected at 1 000 C and dissolved at 1 020 C because the nearby large liquid phase field further expands. The newly determined phase equilibria will provide important information for both thermodynamic assessment and alloy design of Zr-based metallic glass.

  8. 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.

  9. The determination of the surface potential for the CdxHg1-xTe crystals and the V-CdxHg1-xTe and Ni-V-CdxMg1-xTe structures

    International Nuclear Information System (INIS)

    Veliyulin, Eh.I.; Ragimova, R.A.; Mamedov, A.A.

    1996-01-01

    Surface potential of semiconductor crystals n-Cd x Hg 1-x Te (unannealed and annealed in mercury vapors) and of the structures V-Cd x Hg 1-x Te, Ni-V-Cd x Hg 1-x Te has been defined using spectroscopy of weak-field electric reflection. It is shown that a deep penetration of vanadium atoms in near the surface region of the crystal occurs in the structures on the basis of unannealed Cd x Hg 1-x Te. 1 ref.; 4 figs

  10. 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

  11. HgO-added YBa2Cu3O7− δ superconductors

    Indian Academy of Sciences (India)

    The structural studies were carried out by neutron scattering and Rietveld analysis. The neutron scattering revealed that Hg is not incorporated in the Y-123 system and has shown optimum oxygen concentration. The significant role played by the HgO is to provide oxygen ambient through its decomposition, thus changing ...

  12. Biperiodic oscillatory coupling with the thickness of an embedded Ni layer in Co/Cu/Co/Ni/Co (100) and selection rules for the periods

    NARCIS (Netherlands)

    de Vries, J.J.; Vorst, van de M.T.H.; Johnson, M.T.; Jungblut, R.; Reinders, A.; Bloemen, P.J.H.; Coehoorn, R.; Jonge, de W.J.M.

    1996-01-01

    A biperiodic oscillation of the strength of the antiferromagnetic interlayer coupling as a function of the thickness of an embedded Ni layer has been observed in an epitaxial Cu(100)/Co/Cu/Co/Ni/Co sample with the Cu interlayer and the Ni layer in the form of wedges. As the effect originates from

  13. Chemical stabilization and high pressure synthesis of Ba-free Hg-based superconductors, (Hg,M)Sr{sub 2}Ca{sub n-1}Cu{sub n}O{sub y}(N=1{approximately}3)

    Energy Technology Data Exchange (ETDEWEB)

    Kishio, K. [Univ. of Tokyo (Japan)]|[Kyoto Univ. (Japan); Shimoyama, J.; Hahakura, S. [Univ. of Tokyo (Japan)] [and others

    1994-12-31

    A homologous series of new Hg-based HTSC compounds, (Hg,M)Sr{sub 2}Ca{sub n-1}Cu{sub n}O{sub y} with n=1 to 3, have been synthesized. The stabilization of the pure phases have been accomplished by chemical doping of third elements such as M=Cr, Mo and Re. While the Hg1201(n=1) phase was readily obtained in this way, it was necessary to simultaneously dope Y into the Ca site to stabilize the Hg1212(n=2) phase. On the other hand, single-phase Y-free Hg1212(n=2) and Hg1223(n=3) samples were synthesized only under a high pressure of 6 GPa. In sharp contrast to the Ba-containing compounds, all the samples prepared in the present study have been quite stable during the synthesis and no deterioration in air has been observed after the preparation.

  14. Grain boundary diffusion and segregation of Ni in Cu

    International Nuclear Information System (INIS)

    Divinski, Sergiy; Ribbe, Jens; Schmitz, Guido; Herzig, Christian

    2007-01-01

    Grain boundary (GB) diffusion of 63 Ni in polycrystalline Cu was investigated by the radiotracer technique in an extended temperature interval from 476 to 1156K. The independent measurements in Harrison's C and B kinetic regimes resulted in direct data of the GB diffusivity D gb and of the so-called triple product P=s.δ.D gb (s and δ are the segregation factor and the diffusional GB width, respectively). Arrhenius-type temperature dependencies for both the D gb and P values were measured, resulting in the pre-exponential factors D gb 0 =6.93x10 -7 m 2 s -1 and P 0 =1.89x10 -16 m 3 s -1 and the activation enthalpies of 90.4 and 73.8kJmol -1 , respectively. Although Ni is completely soluble in Cu, it reveals a distinct but still moderate ability to segregate copper GBs with a segregation enthalpy of about -17kJmol -1

  15. On the evolution of Cu-Ni-rich bridges of Alnico alloys with tempering

    Energy Technology Data Exchange (ETDEWEB)

    Fan, M. [Department of Materials Science and Engineering, North Carolina State University, Campus Box 7907, Raleigh, NC 27695-7907 (United States); Liu, Y. [Department of Materials Science and Engineering, North Carolina State University, Campus Box 7907, Raleigh, NC 27695-7907 (United States); Analytical Instrumentation Facility, North Carolina State University, Raleigh, NC 27695 (United States); Jha, Rajesh; Dulikravich, George S. [Departments of Mechanical and Materials Engineering, MAIDROC, Florida International University, EC3462, 10555 West Flagler Street, Miami, FL 33174 (United States); Schwartz, J.; Koch, C.C. [Department of Materials Science and Engineering, North Carolina State University, Campus Box 7907, Raleigh, NC 27695-7907 (United States)

    2016-12-15

    Tempering is a critical step in Alnico alloy processing, yet the effects of tempering on microstructure have not been well studied. Here we report these effects, and in particular the effects on the Cu-Ni bridges. Energy-dispersive X-ray spectroscopy (EDS) maps and line scans show that tempering changes the elemental distribution in the Cu-Ni bridges, but not the morphology and distribution of Cu-bridges. The Cu concentration in the Cu-Ni bridges increases after tempering while other element concentrations decrease, especially Ni and Al. Furthermore, tempering sharpens the Cu bridge boundaries. These effects are primarily related to the large 2C{sub 44}/(C{sub 11}−C{sub 12}) ratio for Cu, largest of all elements in Alnico. In addition, the Ni-Cu loops around the α{sub 1} phases become inconspicuous with tempering. The diffusion of Fe and Co to the α{sub 1} phase during tempering, which increases the difference of saturation magnetization between the α{sub 1} and α{sub 2} phases, is observed by EDS. In summary, α{sub 1}, α{sub 2} and Cu-bridges are concentrated with their major elements during tempering which improves the magnetic properties. The formation of these features formed through elemental diffusion is discussed via energy theories. - Highlights: • Tempering changes the elemental distribution in the Cu-Ni bridges, but not morphology. • Cu concentration in the Cu-Ni bridges increases after tempering while others decrease. • These effects are related to the large 2C{sub 44}/(C{sub 11}−C{sub 12}) ratio for Cu. • The Ni-Cu loops around the α{sub 1} phases become inconspicuous with tempering. • The diffusion of Fe and Co to the α{sub 1} phase during tempering is observed by EDS.

  16. Thermoelasticity and interdiffusion in CuNi multilayers

    International Nuclear Information System (INIS)

    Benoudia, M.C.; Gao, F.; Roussel, J.M.; Labat, S.; Gailhanou, M.; Thomas, O.; Beke, D.L.; Erdelyi, Z.; Langer, G.A.; Csik, A.; Kis-Varga, M.

    2012-01-01

    Complete text of publication follows. The idea of observing artificial metallic multilayers with x-ray diffraction techniques to study interdiffusion phenomena dates back to the work of DuMond and Youtz. Interestingly, these pioneering contributions even suggested that the approach could be used to measure the concentration dependence of the diffusion coefficient. This remark is precisely the subject of the present work: we aim to revisit this issue in light of recent atomistic simulation results obtained for coherent CuNi multilayers. More generally, CuNi multilayers have been extensively studied for their magnetic, mechanical, and optical properties. These physical properties depend critically on interfaces and require a good control on the evolution of composition and strain fields under heat treatment. Understanding of how interdiffusion proceeds in these nanosystems should therefore improve these practical aspects. From a theoretical viewpoint these synthetic modulated structures have been also used as valuable model systems to test the various diffusion theories accounting in particular for the influence of the alloying energy, the coherency strain, and the local concentration. Nowadays, this field remains active and has been extended with the development of atomic simulations and many microscopy techniques like atom probe tomography which give details on the intermixing mechanisms. We have performed x-ray diffraction experiments on coherent CuNi multilayers to probe thermoelasticity and interdiffusion in these samples. Kinetic mean-field simulations combined with the modeling of the x-ray spectra were also achieved to rationalize the experimental results. We have shown that classical thermoelastic arguments combined with bulk data can be used to model the x-ray scattered intensity of annealed coherent CuNi multilayers. This result provides a valuable framework to analyze the evolution of the concentration profiles at higher temperature. The typical coherent

  17. 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.

  18. Kinetic study of the annealing reactions in Cu-Ni-Fe alloys; Estudio cinetico de las reacciones de recocido en aleaciones de Cu-Ni-Fe

    Energy Technology Data Exchange (ETDEWEB)

    Donoso, E.

    2014-07-01

    The thermal aging of a Cu-45Ni-4Fe, Cu-34Ni-11Fe and Cu-33Ni-22Fe alloys tempered from 1173 K have been studied from Differential Scanning Calorimetry (DSC) and microhardness measurements. The analysis of DSC curves, from room temperature to 950 K, shows the presence of one exothermic reaction associated to the formation of FeNi{sub 3} phase nucleating from a modulate structure, and one endothermic peak attributed to dissolution of this phase. Kinetic parameters were obtained using the usual Avrami-Erofeev equation, modified Kissinger method and integrated kinetic functions. Microhardness measurements confirmed the formation and dissolution of the FeNi{sub 3} phase. (Author)

  19. Electron paramagnetic resonance studies in HgMo sub 6 S sub 8 doped with Cu sup 2 sup + : evidence for cationic mobility

    CERN Document Server

    Kadam, R M; Iyer, R M; Gopalakrishnan, I K; Yakhmi, J V

    1997-01-01

    Some of the Chevrel phase compounds are reported to exhibit unusual cationic mobilities, particularly those with transition metals. EPR evidence is presented for mobile Cu sup 2 sup + ions in Cu sup 2 sup + -doped HgMo sub 6 S sub 8. Evidence is also obtained for the existence of Hg sup + ions, giving possible support for the model correlating the site change with the reaction A sup 2 sup + + e sup -reversible A sup + during ionic conductivity. (author)

  20. Quijarroite, Cu6HgPb2Bi4Se12, a New Selenide from the El Dragόn Mine, Bolivia

    Directory of Open Access Journals (Sweden)

    Hans-Jürgen Förster

    2016-11-01

    Full Text Available Quijarroite, ideally Cu6HgPb2Bi4Se12, is a new selenide species from the El Dragόn mine, Department of Potosí, Bolivia. It most frequently occurs as lath-shaped thin plates (up to 150 µm in length and 20 µm in width intimately (subparallel intergrown with hansblockite, forming an angular network-like intersertal texture. Quijarroite is occasionally also present as sub- to anhedral grains up to 200 µm in length and 50 µm in width. It is non-fluorescent, black and opaque with a metallic luster and black streak. It is brittle, with an irregular fracture and no obvious cleavage and parting. In plane-polarized incident light, quijarroite is weakly pleochroic from cream to very slightly more brownish-cream, displaying no internal reflections. Between crossed polars, quijarroite is moderately anisotropic with pale orange-brown to blue rotation tints. Lamellar twinning on {110} is common; parquet twinning occurs rarely. The reflectance values in the air for the COM (Commission on Ore Mineralogy standard wavelengths (R1 and R2 are: 46.7, 46.8 (470 nm, 47.4, 48.2 (546 nm, 47.1, 48.5 (589 nm, and 46.6, 48.7 (650 nm. Electron-microprobe analyses yielded a mean composition of Cu 13.34, Ag 1.02, Hg 7.67, Pb 16.87, Co 0.03, Ni 0.15, Bi 27.65, Se 33.52, total 100.24 wt %. The mean empirical formula, normalized to 25 apfu (atoms per formula unit, is (Cu5.84Ag0.26Σ = 6.10(Hg1.06Ni0.07Co0.01Σ = 1.14Pb2.27Bi3.68Se11.81 (n = 24. The simplified formula is Cu6HgPb2Bi4Se12. Quijarroite is orthorhombic, space group Pmn21, with a = 9.2413(8, b = 9.0206(7, c = 9.6219(8 Å, V = 802.1(1 Å3, Z = 1. The calculated density is 5.771 g·cm−3. The five strongest X-ray powder-diffraction lines (d in Å (I/I0 (hkl are: 5.36 (55 (111, 3.785 (60 (211, 3.291 (90 (022, 3.125 (100 (212, and 2.312 (50 (400. The crystal structure of quijarroite can be considered a galena derivative and could be derived from that of bournonite. It is a primary mineral, deposited from an

  1. Deposition of Mn-Cu-Ni-enriched sediments during glacial period in the Central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Borole, D.V.

    Two siliceous sediment cores collected from the Central Indian Basin have been analysed for organic carbon, biogenic silica, Al, Mn, Ni and Cu content. The concentrations of Mn, Cu and Ni showed one order of magnitude variation (an enrichment by a...

  2. The average concentrations of As, Cd, Cr, Hg, Ni and Pb in residential soil and drinking water obtained from springs and wells in Rosia Montana area.

    Data.gov (United States)

    U.S. Environmental Protection Agency — The average concentrations of As, Cd, Cr, Hg, Ni and Pb in n=84 residential soil samples, in Rosia Montana area, analyzed by X-ray fluorescence spectrometry are...

  3. Electroplating condition for Ni nanocrystalline on metal (Ni and Cu) plates

    Energy Technology Data Exchange (ETDEWEB)

    Park, Keun Yung; Uhm, Young Rang; Son, Kwang Jae; Shim, Young Ho; Choi, Sun Ju [KAERI, Daejeon (Korea, Republic of)

    2012-10-15

    Ni 63, a beta radiation source, is prepared by the electrical deposition of radioactive Ni 63 ions on a thin non radioactive nickel foil or Cu plate. Given a half life of 100 years, a nuclear battery will still produce half of its initial starting power after 100 years. A speck of a radioisotope like nickel 63, for example, contains enough energy to power a nano nuclear battery for decades, and to do so safely. Ni 63 plating is similar to other electroplating processes that employ soluble metal anodes. It requires the passage of a direct current between two electrodes that are immersed in a conductive, aqueous solution of nickel salts. The charged Ni ions are formed by sulfate, sulfamate, chloride, and a Watts bath. However, the charged Ni 63 ions are formed by dissolving metal Ni 63. To established the coating condition of Ni 63, non radioactive metal Ni particles are dissolved an acid solution and electroplated on a Ni sheet. The nickel plating process is used extensively for decorative, engineering and electro forming purposes because the appearance and other properties of electrodeposited nickel can be varied over a wide range by controlling the composition and operating parameters of the plating solution. A continuous increase in the grain size versus current density has also been recognized in the direct current electrodeposition of nickel coating. On the other hand, A runa et al. reported that the current density has no significant effect on the grain size of nickel electro deposits. A review of the literature shows that saccharin has often been added to a nickel plating bath since the 1980s to improve the ductility and brightness, and in later periods as a grain refiner agent. In the present paper, not only the preparation of a Ni plating solution prepared by dissolving metal particles, but also an optimization of the deposition conditions, such as the current density, saccharin concentration in the bath, and different metal substrates were investigated

  4. Electroplating condition for Ni nanocrystalline on metal (Ni and Cu) plates

    International Nuclear Information System (INIS)

    Park, Keun Yung; Uhm, Young Rang; Son, Kwang Jae; Shim, Young Ho; Choi, Sun Ju

    2012-01-01

    Ni 63, a beta radiation source, is prepared by the electrical deposition of radioactive Ni 63 ions on a thin non radioactive nickel foil or Cu plate. Given a half life of 100 years, a nuclear battery will still produce half of its initial starting power after 100 years. A speck of a radioisotope like nickel 63, for example, contains enough energy to power a nano nuclear battery for decades, and to do so safely. Ni 63 plating is similar to other electroplating processes that employ soluble metal anodes. It requires the passage of a direct current between two electrodes that are immersed in a conductive, aqueous solution of nickel salts. The charged Ni ions are formed by sulfate, sulfamate, chloride, and a Watts bath. However, the charged Ni 63 ions are formed by dissolving metal Ni 63. To established the coating condition of Ni 63, non radioactive metal Ni particles are dissolved an acid solution and electroplated on a Ni sheet. The nickel plating process is used extensively for decorative, engineering and electro forming purposes because the appearance and other properties of electrodeposited nickel can be varied over a wide range by controlling the composition and operating parameters of the plating solution. A continuous increase in the grain size versus current density has also been recognized in the direct current electrodeposition of nickel coating. On the other hand, A runa et al. reported that the current density has no significant effect on the grain size of nickel electro deposits. A review of the literature shows that saccharin has often been added to a nickel plating bath since the 1980s to improve the ductility and brightness, and in later periods as a grain refiner agent. In the present paper, not only the preparation of a Ni plating solution prepared by dissolving metal particles, but also an optimization of the deposition conditions, such as the current density, saccharin concentration in the bath, and different metal substrates were investigated

  5. 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.

  6. Performance of ethanol electro-oxidation on Ni-Cu alloy nanowires through composition modulation.

    Science.gov (United States)

    Tian, Xi-Ke; Zhao, Xiao-Yu; Zhang, Li-de; Yang, Chao; Pi, Zhen-Bang; Zhang, Su-Xin

    2008-05-28

    To reduce the cost of the catalyst for direct ethanol fuel cells and improve its catalytic activity, highly ordered Ni-Cu alloy nanowire arrays have been fabricated successfully by differential pulse current electro-deposition into the pores of a porous anodic alumina membrane (AAMs). The energy dispersion spectrum, scanning and transmission electron microscopy were utilized to characterize the composition and morphology of the Ni-Cu alloy nanowire arrays. The results reveal that the nanowires in the array are uniform, well isolated and parallel to each other. The catalytic activity of the nanowire electrode arrays for ethanol oxidation was tested and the binary alloy nanowire array possesses good catalytic activity for the electro-oxidation of ethanol. The performance of ethanol electro-oxidation was controlled by varying the Cu content in the Ni-Cu alloy and the Ni-Cu alloy nanowire electrode shows much better stability than the pure Ni one.

  7. Performance of ethanol electro-oxidation on Ni-Cu alloy nanowires through composition modulation

    International Nuclear Information System (INIS)

    Tian Xike; Zhao Xiaoyu; Yang Chao; Pi Zhenbang; Zhang Lide; Zhang Suxin

    2008-01-01

    To reduce the cost of the catalyst for direct ethanol fuel cells and improve its catalytic activity, highly ordered Ni-Cu alloy nanowire arrays have been fabricated successfully by differential pulse current electro-deposition into the pores of a porous anodic alumina membrane (AAMs). The energy dispersion spectrum, scanning and transmission electron microscopy were utilized to characterize the composition and morphology of the Ni-Cu alloy nanowire arrays. The results reveal that the nanowires in the array are uniform, well isolated and parallel to each other. The catalytic activity of the nanowire electrode arrays for ethanol oxidation was tested and the binary alloy nanowire array possesses good catalytic activity for the electro-oxidation of ethanol. The performance of ethanol electro-oxidation was controlled by varying the Cu content in the Ni-Cu alloy and the Ni-Cu alloy nanowire electrode shows much better stability than the pure Ni one

  8. 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.

  9. PRECIPITATION BEHAVIOR IN A Cu-Sn-Ni-Zn-P LEAD FRAME MATERIAL

    Institute of Scientific and Technical Information of China (English)

    W.H. Tian; C.K. Yan; M.Nemoto

    2003-01-01

    Transmission electron microscopy (TEM) observations were carried out for examining the precipitation behavior in a Cu-Sn-Ni-Zn-P lead frame material. TEM observations revealed that the precipitate is hexagonal Ni5P2 and the orientation relationship between the Cu matrix and Ni5P2 precipitate is (111)fcc//(0001)hcp,[101]fcc//[11-20]hcp, where the suffix fcc denotes the Cu matrix and hcp denotes the hexagonal Ni5P2 precipitate. The NisP2 precipitate is ovoidal in shape at the beginning of aging at lower temperature. By prolonging the aging time or increasing the aging temperature, Ni5P2 precipitate grows and shows a rod-like shape. The Ni added Cu based lead frame material has a comparative mechanical properties with that of TAMAC15 which has been developed and used in electrical industry.

  10. A diffuse neutron scattering study of clustering kinetics in Cu-Ni alloys

    International Nuclear Information System (INIS)

    Vrijen, J.; Radelaar, S.; Schwahn, D.

    1977-01-01

    Diffuse scattering of thermal neutrons was used to investigate the kinetics of clustering in Cu-Ni alloys. In order to optimize the experimental conditions the isotopes 65 Cu and 62 Ni were alloyed. The time evolution of the diffuse scattered intensity at 400 0 C has been measured for eight Cu-Ni alloys, varying in composition between 30 and 80 at. pour cent Ni. The relaxation of the so called null matrix, containing 56.5 at. pour cent Ni has also been investigated at 320, 340, 425 and 450 0 C. Using Cook's model from all these measurements information has been deduced about diffusion at low temperatures and about thermodynamic properties of the Cu-Ni system. It turns out that Cook's model is not sufficiently detailed for an accurate description of the initial stages of these relaxations

  11. Wetting Behavior of Ternary Au-Ge-X (X = Sb, Sn) Alloys on Cu and Ni

    Science.gov (United States)

    Jin, S.; Valenza, F.; Novakovic, R.; Leinenbach, C.

    2013-06-01

    Au-Ge-based alloys are potential substitutes for Pb-rich solders currently used for high-temperature applications. In the present work, the wetting behavior of two Au-Ge-X (X = Sb, Sn) ternary alloys, i.e., Au-15Ge-17Sb and Au-13.7 Ge-15.3Sn (at.%), in contact with Cu and Ni substrates has been investigated. Au-13.7Ge-15.3Sn alloy showed complete wetting on both Cu and Ni substrates. Total spreading of Au-15Ge-17Sb alloy on Cu was also observed, while the final contact angle of this alloy on Ni was about 29°. Pronounced dissolution of Cu substrates into the solder alloys investigated was detected, while the formation of Ni-Ge intermetallic compounds at the interface of both solder/Ni systems suppressed the dissolution of Ni into the solder.

  12. Growth kinetics of the intermetallic phase in diffusion-soldered (Cu-5 at.%Ni)/Sn/(Cu-5 at.%Ni) interconnections

    NARCIS (Netherlands)

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

    2013-01-01

    A stereological analysis was carried out in order to obtain the kinetics parameters of the (Cu1-xNix)6Sn5 growth in the diffusion soldered (Cu–5 at.%Ni)/Sn/(Cu–5 at.%Ni) interconnections where previously anomalous fast growth of this phase was described. The n-parameter in the equation x = ktn was

  13. 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)

  14. Ostwald ripening of decomposed phases in Cu-Ni-Cr alloys

    International Nuclear Information System (INIS)

    Hernandez-Santiago, Felipe; Lopez-Hirata, Victor; Dorantes-Rosales, Hector J.; Saucedo-Munoz, Maribel L.; Gonzalez-Velazquez, Jorge L.; Paniagua-Mercado, Ana Ma.

    2008-01-01

    A study of the coarsening process of the decomposed phases was carried out in the Cu-34 wt.% Ni-4 wt.% Cr and Cu-45 wt.% Ni-10 wt.% Cr alloys using transmission electron microscopy. As aging progressed, the morphology of the coherent decomposed Ni-rich phase changed from cuboids to platelets aligned in the Cu-rich matrix directions. Prolonged aging caused the loss of coherency between the decomposed phases and the morphology of the Ni-rich phase changed to ellipsoidal. The variation of mean radius of the coherent decomposed phases with aging time followed the modified LSW theory for thermally activated growth in ternary alloy systems. The linear variation of the density number of precipitates and matrix supersaturation with aging time, also confirmed that the coarsening process followed the modified LSW theory in both alloys. The coarsening rate was faster in the symmetrical Cu-45 wt.% Ni-10 wt.% Cr alloy due to its higher volume fraction of precipitates. The activation energy for thermally activated growth was determined to be about 182 and 102 kJ mol -1 in the Cu-34 wt.% Ni-4 wt.% Cr and Cu-45 wt.% Ni-10 wt.% Cr alloys, respectively. The lower energy for the former alloy seems to be related to an increase in the atomic diffusion process as the chromium content increases. The size distributions of precipitates in the Cu-Ni-Cr alloys were broader and more symmetric than that predicted by the modified LSW theory for ternary alloys

  15. Electronic structure of benzene adsorbed on Ni and Cu surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Weinelt, M.; Nilsson, A.; Wassdahl, N. [Uppsala Univ. (Sweden)] [and others

    1997-04-01

    Benzene has for a long time served as a prototype adsorption system of large molecules. It adsorbs with the molecular plane parallel to the surface. The bonding of benzene to a transition metal is typically viewed to involve the {pi} system. Benzene adsorbs weakly on Cu and strongly on Ni. It is interesting to study how the adsorption strength is reflected in the electronic structure of the adsorbate-substrate complex. The authors have used X-ray Emission (XE) and X-ray Absorption (XA) spectroscopies to selectively study the electronic states localized on the adsorbed benzene molecule. Using XES the occupied states can be studies and with XAS the unoccupied states. The authors have used beamline 8.0 and the Swedish endstation equipped with a grazing incidence x-ray spectrometer and a partial yield absorption detector. The resolution in the XES and XAS were 0.5 eV and 0.05 eV, respectively.

  16. Thermodynamic stability of austenitic Ni-Mn-Cu cast iron

    Directory of Open Access Journals (Sweden)

    A. Janus

    2014-07-01

    Full Text Available The performed research was aimed at determining thermodynamic stability of structures of Ni-Mn-Cu cast iron castings. Examined were 35 alloys. The castings were tempered at 900 °C for 2 hours. Two cooling speeds were used: furnace-cooling and water-cooling. In the alloys with the nickel equivalent value less than 20,0 %, partial transition of austenite to martensite took place. The austenite decomposition ratio and the related growth of hardness was higher for smaller nickel equivalent value and was clearly larger in annealed castings than in hardened ones. Obtaining thermodynamically stable structure of castings requires larger than 20,0 % value of the nickel equivalent.

  17. Composition pathway in Fe-Cu-Ni alloy during coarsening

    Science.gov (United States)

    Mukherjee, Rajdip; Choudhury, Abhik; Nestler, Britta

    2013-10-01

    In this work the microstructure evolution for a two phase Fe-Cu-Ni ternary alloy is studied in order to understand the kinetic composition paths during coarsening of precipitates. We have employed a quantitative phase-field model utilizing the CALPHAD database to simulate the temporal evolution of a multi-particle system in a two-dimensional domain. The paths for the far-field matrix and for precipitate average compositions obtained from simulation are found to be rectilinear. The trends are compared with the corresponding sharp interface theory, in the context of an additional degree of freedom for determining the interface compositions due to the Gibbs-Thomson effect in a ternary alloy.

  18. Low-field spin dynamics of Cr7Ni and Cr7Ni-Cu -Cr 7Ni molecular rings as detected by μ SR

    Science.gov (United States)

    Sanna, S.; Arosio, P.; Bordonali, L.; Adelnia, F.; Mariani, M.; Garlatti, E.; Baines, C.; Amato, A.; Sabareesh, K. P. V.; Timco, G.; Winpenny, R. E. P.; Blundell, S. J.; Lascialfari, A.

    2017-11-01

    Muon spin rotation measurements were used to investigate the spin dynamics of heterometallic Cr7Ni and Cr7Ni -Cu-Cr7Ni molecular clusters. In Cr7Ni the magnetic ions are arranged in a quasiplanar ring and interact via an antiferromagnetic exchange coupling constant J , while Cr7Ni -Cu-Cr7Ni is composed of two Cr7Ni linked by a bridging moiety containing one Cu ion, that induces an inter-ring ferromagnetic interaction J'≪J . The longitudinal muon relaxation rate λ collected at low magnetic fields μ0H BPP)-like heuristic fitting model that takes into account of a distribution of electronic spin characteristic times for T >5 K, while the shoulder presented by Cr7Ni can be reproduced by a BPP function that incorporates a single electronic characteristic time theoretically predicted to dominate for T <5 K. The flattening of λ (T ) in Cr7Ni -Cu-Cr7Ni occurring at very low temperature can be tentatively attributed to field-dependent quantum effects and/or to an inelastic term in the spectral density of the electronic spin fluctuations.

  19. Highly sensitive optical sensor that detects Hg"2"+ and Cu"2"+ by immobilizing dicarboxylate 1,5-diphenyl-3-thiocarbazone on surface functionalized PVA microspheres

    International Nuclear Information System (INIS)

    Bai, Xue; Gu, Haixin; Hua, Zulin; Dai, Zhangyan; Yang, Bei; Li, Yulong

    2015-01-01

    Highlights: • PVA microspheres were chosen as carrier and DDT groups were chosen as chromophores. • The DDT–PVA microspheres could detect Hg"2"+ and Cu"2"+ simultaneously within 120 s. • The DDT–PVA microspheres had excellent detection for Hg"2"+ and Cu"2"+ ions. • The DDT–PVA microspheres had preeminent selectivity and reusability. - Abstract: A novel optical sensor to detect Hg"2"+ and Cu"2"+ is prepared by immobilizing a synthesized dicarboxylate 1,5-diphenyl-3-thiocarbazone (DDT) group on functionalized polyvinyl alcohol (PVA) microspheres. This optical sensor is successfully fabricated by extensive characterization with Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. Its colorimetric properties, selectivity, sensitivity, and reversibility are investigated as well. In this sensing system, DDT–PVA selectively recognized multiple heavy metal ions, as indicated by the changes in color from orange to scarlet for Hg"2"+ and from orange to gray for Cu"2"+. In particular, this optical sensor exhibits the most apparent color changes at pH levels of 12 and 2. Hence, Hg"2"+ and Cu"2"+ can be detected in aqueous solution at minimum detection limits of 0.053 and 0.132 μM, respectively, with a UV-vis spectrometer. Furthermore, the sensor can be regenerated by ethylene diamine tetraacetic acid and reused several times. Therefore, the optical sensor can detect Hg"2"+ because of its selectivity, sensitivity, and reversibility.

  20. Phase Equilibria of the Sn-Ni-Si Ternary System and Interfacial Reactions in Sn-(Cu)/Ni-Si Couples

    Science.gov (United States)

    Fang, Gu; Chen, Chih-chi

    2015-07-01

    Interfacial reactions in Sn/Ni-4.5 wt.%Si and Sn-Cu/Ni-4.5 wt.%Si couples at 250°C, and Sn-Ni-Si ternary phase equilibria at 250°C were investigated in this study. Ni-Si alloys, which are nonmagnetic, can be regarded as a diffusion barrier layer material in flip chip packaging. Solder/Ni-4.5 wt.%Si interfacial reactions are crucial to the reliability of soldered joints. Phase equilibria information is essential for development of solder/Ni-Si materials. No ternary compound is present in the Sn-Ni-Si ternary system at 250°C. Extended solubility of Si in the phases Ni3Sn2 and Ni3Sn is 3.8 and 6.1 at.%, respectively. As more Si dissolves in these phases their lattice constants decrease. No noticeable ternary solubility is observed for the other intermetallics. Interfacial reactions in solder/Ni-4.5 wt.%Si are similar to those for solder/Ni. Si does not alter the reaction phases. No Si solubility in the reaction phases was detected, although rates of growth of the reaction phases were reduced. Because the alloy Ni-4.5 wt.%Si reacts more slowly with solders than pure Ni, the Ni-4.5 wt.%Si alloy could be a potential new diffusion barrier layer material for flip chip packaging.

  1. The superconductor (Tl,Hg,Ca)2(Ba,Sr)2(Ca,Sr,Tl)Cu2O7.6

    International Nuclear Information System (INIS)

    Valldor, M.; Bryntse, I.; Morawski, A.

    2002-01-01

    In the title 2212-type superconductor (thallium mercury calcium barium strontium copper oxide), which contains both Tl and Hg in the charge reservoir (CR), Sr is located at both alkali-earth (AE) metal sites. Ca enters the CR at the same time as Tl shares the smaller AE site, which increases the apical Cu-Cu distance significantly. The structure causes the superconducting Cu-O layers to become significantly puckered. (orig.)

  2. Phase transformations behavior in a Cu-8.0Ni-1.8Si alloy

    Energy Technology Data Exchange (ETDEWEB)

    Lei, Q. [School of Materials Science and Engineering, Central South University, Changsha, 410083 (China); Li, Z., E-mail: lizhou6931@163.com [School of Materials Science and Engineering, Central South University, Changsha, 410083 (China) and Key Laboratory of Nonferrous Metal Materials Science and Engineering, Ministry of Education, Changsha, 410083 (China); Wang, M.P. [School of Materials Science and Engineering, Central South University, Changsha, 410083 (China); Key Laboratory of Nonferrous Metal Materials Science and Engineering, Ministry of Education, Changsha, 410083 (China); Zhang, L.; Gong, S. [School of Materials Science and Engineering, Central South University, Changsha, 410083 (China); Xiao, Z. [Department of Engineering, University of Liverpool, Liverpool, L693 GH (United Kingdom); Pan, Z.Y. [Hunan Nonferrous Metals Holding Group Co., Ltd., Changsha, 410015 (China)

    2011-02-24

    Research highlights: > High solute concentrations Cu-Ni-Si alloy with super high strength and high conductivity has a good prospect for replacing Cu-Be alloys. At least four different kinds of precipitation products (DO{sub 22} ordered structure, {beta}-Ni{sub 3}Si precipitate, {delta}-Ni{sub 2}Si precipitate and {gamma}-Ni{sub 5}Si{sub 2} precipitate) have been observed in previous investigation. Therefore, the overall phase transformation behavior of Cu-Ni-Si alloy appears to be very complex. And most previous studies on the phase transformation usually investigated the precipitation process at only one temperature or at most a few temperatures, which is far away to establish a time-temperature-transformation (TTT) diagram for Cu-Ni-Si alloy. > The phase transformation behavior of Cu-8.0Ni-1.8Si alloy has been studied systematically at wide temperature range in this paper. The results we have gained are that: after solution treatment, followed by different conditions of isothermal treatment, DO{sub 22} ordering, discontinuous precipitation and continuous precipitation were observed in the alloy; discontinuous precipitates of {beta}-Ni{sub 3}Si phase appeared when the alloy isothermal treated at 550 deg. C for short time, which had not been reported by the previous Cu-Ni-Si system alloy's researchers in their papers; two kinds of precipitates of {beta}-Ni{sub 3}Si and {delta}-Ni{sub 2}Si were determined by the TEM characterization; the orientation relationship between the two kinds of precipitates and Cu-matrix is that: (1 1 0){sub Cu}//(1 1 0){sub {beta}}//(211-bar){sub {delta}}, [112-bar]{sub Cu}//[11-bar 2]{sub {beta}}//[3 2 4]{sub {delta}}; during overaging treatment, Cu-matrix, {beta}-Ni{sub 3}Si, {delta}-Ni{sub 2}Si and {delta}'-Ni{sub 2}Si were distinguished in the samples and the orientation relationship between the precipitates and Cu-matrix can be expressed as that: (0 2 2){sub Cu}//(0 2 2){sub {beta}}//(1 0 0){sub {delta}}, (02-bar 2){sub Cu

  3. 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.%.

  4. Thermal stability and primary phase of Al-Ni(Cu)-La amorphous alloys

    International Nuclear Information System (INIS)

    Huang Zhenghua; Li Jinfu; Rao Qunli; Zhou Youhe

    2008-01-01

    Thermal stability and primary phase of Al 85+x Ni 9-x La 6 (x = 0-6) and Al 85 Ni 9-x Cu x La 6 (x = 0-9) amorphous alloys were investigated by X-ray diffraction and differential scanning calorimeter. It is revealed that replacing Ni in the Al 85 Ni 9 La 6 alloy by Cu decreases the thermal stability and makes the primary phase change from intermetallic compounds to single fcc-Al as the Cu content reaches and exceeds 4 at.%. When the Ni and La contents are fixed, replacing Al by Cu increases the thermal stability but also promotes the precipitation of single fcc-Al as the primary phase

  5. Perturbed angular correlations studies in the HgBa$_2$CaCu$_2$O$_{6+\\delta}$ high-T$_c$ superconductor

    CERN Document Server

    Mendonca, Tania Melo; Haas, Heinz; Odier, Philippe; Tavares, Pedro; SIlva, Manuel Ribeiro; Lopes, Armandina; Darie, Celine; Araujo, Joao Pedro

    2011-01-01

    The electric field gradients at $^{199m}$Hg nuclei have been measured via the perturbed angular correlation (PAC) technique, allowing a full characterization of the Hg neighborhood charge distribution at high oxygen doping on the Hg planes. The PAC technique has been applied to investigate the effect of high oxygen pressure during the measurement. Polycrystalline HgBa$_2$CaCu$_2$O$_{6+\\delta}$ (Hg-1212) samples have been annealed at 152 bar pressurized oxygen. The influence of oxygen pressure during the experiment was then investigated by measuring the samples at atmospheric pressure and under 152 bar oxygen pressure. The present set of PAC experiments shows that at high oxygen concentrations there is a non-uniform oxygen distribution. Moreover, the Hg environment is not free from oxygen and the results hint to a new type of ordering.

  6. CuNi Nanoparticles Assembled on Graphene for Catalytic Methanolysis of Ammonia Borane and Hydrogenation of Nitro/Nitrile Compounds

    International Nuclear Information System (INIS)

    Yu, Chao

    2017-01-01

    Here we report a solution phase synthesis of 16 nm CuNi nanoparticles (NPs) with the Cu/Ni composition control. These NPs are assembled on graphene (G) and show Cu/Ni composition-dependent catalysis for methanolysis of ammonia borane (AB) and hydrogenation of aromatic nitro (nitrile) compounds to primary amines in methanol at room temperature. Among five different CuNi NPs studied, the G-Cu 36 Ni 64 NPs are the best catalyst for both AB methanolysis (TOF = 49.1 mol H2 mol CuNi -1 min -1 and E a = 24.4 kJ/mol) and hydrogenation reactions (conversion yield >97%). In conclusion, the G-CuNi represents a unique noble-metal-free catalyst for hydrogenation reactions in a green environment without using pure hydrogen.

  7. Hybrid porous phosphate heterostructures as adsorbents of Hg(II) and Ni(II) from industrial sewage

    International Nuclear Information System (INIS)

    Jimenez-Jimenez, J.; Algarra, M.; Rodriguez-Castellon, E.; Jimenez-Lopez, A.; Esteves da Silva, J.C.G.

    2011-01-01

    Porous phosphate heterostructures (PPH), functionalized with different ratios of aminopropyl and mercaptopropyl groups, labelled as N x=5,25,50 -PPH and S x=5,25,50 -PPH, respectively, were tested as adsorbents for Ni(II) and Hg(II) found in industrial sewage from electroplating processes and button battery recycling. X-ray diffraction was used to study the structures. The specific surface area of the pristine material (PPH) was 620 m 2 g -1 , whereas the specific surface areas of the modified mercaptopropyl (S 5 -PPH) and aminopropyl (N 5 -PPH) were 472 and 223 m 2 g -1 , respectively. The adsorption data were fitted to a Langmuir isotherm model. The S 5 -PPH material was saturated by 120 mmol Hg(II) per 100 g of material, whereas for Ni(II) adsorption, N 25 -PPH material displayed the highest adsorption with a saturation value of 43.5 mmol per 100 g. These results suggest that functionalized PPH materials may be promising toxic metal scavengers and that they may provide an alternative environmental technology.

  8. Hybrid porous phosphate heterostructures as adsorbents of Hg(II) and Ni(II) from industrial sewage

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez-Jimenez, J., E-mail: jjimenez@uma.es [Departamento de Quimica Inorganica, Facultad de Ciencias, Universidad de Malaga, Campus de Teatinos s/n, 29071 Malaga (Spain); Algarra, M. [Centro de Geologia do Porto, Faculdade de Ciencias, Universidade do Porto. Rua do, Campo Alegre 687, 4169-007 Porto (Portugal); Rodriguez-Castellon, E.; Jimenez-Lopez, A. [Departamento de Quimica Inorganica, Facultad de Ciencias, Universidad de Malaga, Campus de Teatinos s/n, 29071 Malaga (Spain); Esteves da Silva, J.C.G. [Centro de Investigacao em Quimica (CIQ-UP), Faculdade de, Ciencias da Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto (Portugal)

    2011-06-15

    Porous phosphate heterostructures (PPH), functionalized with different ratios of aminopropyl and mercaptopropyl groups, labelled as N{sub x=5,25,50}-PPH and S{sub x=5,25,50}-PPH, respectively, were tested as adsorbents for Ni(II) and Hg(II) found in industrial sewage from electroplating processes and button battery recycling. X-ray diffraction was used to study the structures. The specific surface area of the pristine material (PPH) was 620 m{sup 2} g{sup -1}, whereas the specific surface areas of the modified mercaptopropyl (S{sub 5}-PPH) and aminopropyl (N{sub 5}-PPH) were 472 and 223 m{sup 2} g{sup -1}, respectively. The adsorption data were fitted to a Langmuir isotherm model. The S{sub 5}-PPH material was saturated by 120 mmol Hg(II) per 100 g of material, whereas for Ni(II) adsorption, N{sub 25}-PPH material displayed the highest adsorption with a saturation value of 43.5 mmol per 100 g. These results suggest that functionalized PPH materials may be promising toxic metal scavengers and that they may provide an alternative environmental technology.

  9. Influence of Ni and Cu contamination on the superconducting properties of MgB2 filaments

    International Nuclear Information System (INIS)

    Jung, A; Schlachter, S I; Runtsch, B; Ringsdorf, B; Fillinger, H; Orschulko, H; Drechsler, A; Goldacker, W

    2010-01-01

    Technical MgB 2 wires usually have a sheath composite consisting of different metals. For the inner sheath with direct contact to the superconducting filament, chemically inert Nb may be used as a reaction barrier and thermal stabilization is provided by a highly conductive metal like Cu. A mechanical reinforcement can be achieved by the addition of stainless steel. In order to illuminate the influence of defects in the reaction barrier, monofilament in situ wires with direct contact between the MgB 2 filament and frequently applied reactive sheath metals like Cu, Ni or Monel are studied. Reactions of Mg and B with a Cu-containing sheath lead to Cu-based by-products penetrating the whole filament. Reactions with Ni-containing sheaths lead to Ni-based by-products which tend to remain at the filament-sheath interface. Cu and/or Ni contamination of the filament lowers the MgB 2 -forming temperature due to the eutectic reaction between Mg, Ni and Cu. Thus, for the samples heat-treated at low temperatures J C and (partly) T C are increased compared to stainless-steel-sheathed wires. At high heat treatment temperatures uncontaminated filaments lead to the highest J C values. From the point of view of broken reaction barriers in real wires, the contamination of the filament with Cu and/or Ni does not necessarily constrain the superconductivity; it may even improve the properties of the wire, depending on the desired application.

  10. Study of Cu-Al-Ni-Ga as high-temperature shape memory alloys

    Science.gov (United States)

    Zhang, Xin; Wang, Qian; Zhao, Xu; Wang, Fang; Liu, Qingsuo

    2018-03-01

    The effect of Ga element on the microstructure, mechanical properties and shape memory effect of Cu-13.0Al-4.0Ni- xGa (wt%) high-temperature shape memory alloy was investigated by optical microscopy, SEM, XRD and compression test. The microstructure observation results showed that the Cu-13.0Al-4.0Ni- xGa ( x = 0.5 and 1.0) alloys displayed dual-phase morphology which consisted of 18R martensite and (Al, Ga)Cu phase, and their grain size was about several hundred microns, smaller than that of Cu-13.0Al-4.0Ni alloy. The compression test results proved that the mechanical properties of Cu-13.0Al-4.0Ni- xGa alloys were improved by addition of Ga element owing to the grain refinement and solid solution strengthening, and the compressive fracture strains were 11.5% for x = 0.5 and 14.9% for x = 1.0, respectively. When the pre-strain was 8%, the shape memory effect of 4.2 and 4.6% were obtained for Cu-13.0Al-4.0Ni-0.5 Ga and Cu-13.0Al-4.0Ni-1.0 Ga alloys after being heated to 400 °C for 1 min.

  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. Electroless deposition of NiCrB diffusion barrier layer film for ULSI-Cu metallization

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yuechun [School of Materials Science and Engineering, Yunnan University, Kunming (China); Chen, Xiuhua, E-mail: chenxh@ynu.edu.cn [School of Materials Science and Engineering, Yunnan University, Kunming (China); Ma, Wenhui [National Engineering Laboratory of Vacuum Metallurgy, Kunming University of Science and Technology, Kunming (China); Shang, Yudong; Lei, Zhengtao; Xiang, Fuwei [School of Materials Science and Engineering, Yunnan University, Kunming (China)

    2017-02-28

    Highlights: • In this paper, the electroless deposited NiCrB thin film was mainly in the form of NiB, CrB{sub 2} compounds and elementary Ni. • The sheet resistance of NiCrB thin film was 3.043 Ω/□, it is smaller than that of the widely used Ta, TaN and TiN diffusion barrier layers. • Annealing experiments showed that the failure temperature of NiCrB thin film regarding Cu diffusion was 900 °C. • NiCrB barrier layer crystallized after 900 °C annealing, Cu grains arrived at Si-substrate through grain boundaries, resulting in the formation of Cu{sub 3}Si. • Eelectroless deposited NiCrB film also had good oxidation resistance, it is expected to become an anti-oxidant layer of copper interconnection. - Abstract: NiCrB films were deposited on Si substrates using electroless deposition as a diffusion barrier layer for Cu interconnections. Samples of the prepared NiCrB/SiO{sub 2}/Si and NiCrB/Cu/NiCrB/SiO{sub 2}/Si were annealed at temperatures ranging from 500 °C to 900 °C. The reaction mechanism of the electroless deposition of the NiCrB film, the failure temperature and the failure mechanism of the NiCrB diffusion barrier layer were investigated. The prepared samples were subjected to XRD, XPS, FPP and AFM to determine the phases, composition, sheet resistance and surface morphology of samples before and after annealing. The results of these analyses indicated that the failure temperature of the NiCrB barrier film was 900 °C and the failure mechanism led to crystallization and grain growth of the NiCrB barrier layer after high temperature annealing. It was found that this process caused Cu grains to reach Si substrate through the grain boundaries, and then the reaction between Cu and Si resulted in the formation of highly resistive Cu{sub 3}Si.

  13. High-pressure x-ray diffraction of icosahedral Zr-Al-Ni-Cu-Ag quasicrystals

    DEFF Research Database (Denmark)

    Jiang, Jianzhong; Saksl, Karel; Rasmussen, Helge Kildahl

    2001-01-01

    temperature using synchrotron radiation. The icosahedral quasicrystal structure is retained up to the highest hydrostatic pressure used (approximately 28 GPa) and is reversible after decompression. The bulk modulus at zero pressure and its pressure derivative of the icosahedral Zr-Al-Ni-Cu-Ag quasicrystal......The effect of pressure on the structural stability of icosahedral Zr-Al-Ni-Cu-Ag quasicrystals forming from a Zr65Al7.5Ni10Cu7.5Ag10 metallic glass with a supercooled liquid region of 44 K has been investigated by in situ high-pressure angle-dispersive x-ray powder diffraction at ambient......-Al-Ni-Cu-Ag quasicrystals induced by pressure....

  14. Population health risk via dietary exposure to trace elements (Cu, Zn, Pb, Cd, Hg, and As) in Qiqihar, Northeastern China.

    Science.gov (United States)

    Luo, Jinming; Meng, Jia; Ye, Yajie; Wang, Yongjie; Bai, Lin

    2018-02-01

    The estimated daily intakes (EDIs) of six trace elements (Cu, Zn, Pb, Cd, Hg, and As) in vegetables (leafy vegetable, i.e., bok choy, fruit vegetables, i.e., cucumber and tomato, and other categories, i.e., mushroom, kidney bean, and potato), cereals (rice and wheat flour), and meats (pork, mutton, and beef) most commonly consumed by adult inhabitants of Qiqihar, Northeastern China, were determined to assess the health status of local people. The average EDIs of Cu, Zn, Pb, Cd, Hg, and As were with 20.77 μg (kg bw) -1 day -1 of Cu, 288 μg (kg bw) -1 day -1 of Zn, 2.01 μg (kg bw) -1 day -1 of Pb, 0.41 μg (kg bw) -1 day -1 of Cd, 0.01 μg (kg bw) -1 day -1 of Hg, and 0.52 μg (kg bw) -1 day -1 of As, respectively, which are below the daily allowance recommended by FAO/WHO. However, the maximum EDIs of Pb and Cd were 4.56 μg (kg bw) -1 day -1 and 1.68 μg (kg bw) -1 day -1 , respectively, which are above the recommended levels [i.e., 3.58 μg (kg bw) -1 day -1 for Pb and 1.0 μg (kg bw) -1 day -1 for Cd] by FAO/WHO. This finding indicates that the potential health risk induced by daily ingestion of Pb and Cd for the local residents should receive a significant concern. Similarly, we detected elevated Pb and Cd concentrations, i.e., with average of 13.58 and 0.60 mg kg -1 dw, respectively, in the adult scalp hairs. Consumption of rice, potato, bok choy, and wheat flour contributed to 75 and 82% of Pb and Cd daily intake from foodstuffs. Nevertheless, human scalp hair is inappropriate biological material for determination of the nutritional status of trace elements in this region.

  15. The crystallization of (NiCu)ZrTiAlSi glass/crystalline composite

    International Nuclear Information System (INIS)

    Czeppe, T.; Sypien, A.; Ochin, P.; Anastassova, S.

    2007-01-01

    Alloys of composition (Ni 1-x Cu x ) 60 Zr 18 Ti 13 A1 5 Si 4 were investigated in the form of ribbons and massive samples. The microstructure of the massive samples consists of dendritic crystals in the amorphous or nanocrystalline matrix. The amount of the amorphous phase is the lowest in the sample with the highest Cu content. The segregation in the liquid phase, leading to the local differences in density and the composition of the crystallizing dendrites in the samples crystallized in the copper mould was shown. The typical compositions of the multi-component crystals could be distinguished; one with the increased content of aluminum, the second with the high content of silicon and third, with the high content of (NiCu) and (ZrTi). The cubic phase Ni(Cu)Ti(Zr) with Cu and Zr dissolved could be identified. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

  16. Corrosion Inhibition Study of Al-Cu-Ni Alloy in Simulated Sea-Water ...

    African Journals Online (AJOL)

    A study on the inhibition of Al-Cu-Ni alloy in simulated sea-water environment was investigated using Sodium Chromate as inhibitor. The inhibitor concentration was varied as control, 0.25, 0.5, 1.0, 1.5 and 2.0 Molar. Al-Cu-Ni alloy was sand cast into cylindrical bars of 20 mm x 300 mm dimension. The corrosion of the ...

  17. 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.)

  18. Site determination of Ni atoms in Cu-Al-Ni shape memory alloys by electron channelling enhanced microanalysis

    International Nuclear Information System (INIS)

    Nakata, Yoshiyuki; Tadaki, Tsugio; Shimizu, Ken-ichi

    1990-01-01

    The crystallographic site of Ni atoms in the parent phase of differently heat-treated Cu-28.6Al-3.7Ni (at.%) shape memory alloys has been examined by electron channelling enhanced microanalysis (ALCHEMI) in order to clarify effects of heat-treatments on the Ni atom site and M s temperature. The heat-treatments were as follows: (a) Quenching into a 10% NaOH solution at 263 K, (b) Quenching into hot water at 363 K and (c) Aging at 523 K for 3.6 ks after treatment (b). The M s temperatures of specimens (a), (b) and (c) were 158, 185 and 259 K, respectively, increasing with lowering quenching rate or aging. ALCHEMI revealed that Ni atoms occupied an identical site in all the three kinds of specimens: The Ni atoms were located at the nearest neighbor sites around Al atoms. This preferential occupation of Ni atoms was attributed to the strong binding force between Ni and Al atoms. Thus, the change in M s temperature due to different heat-treatments was not directly related to the crystallographic site of Ni atoms, but might be caused by the ordering between the next nearest neighbor Cu and Al atoms. (author)

  19. Effects of Ti addition and heat treatments on mechanical and electrical properties of Cu-Ni-Si alloys

    Science.gov (United States)

    Kim, Hyung Giun; Lee, Taeg Woo; Kim, Sang Min; Han, Seung Zeon; Euh, Kwangjun; Kim, Won Yong; Lim, Sung Hwan

    2013-01-01

    The mechanical and electrical properties of Cu-5.98Ni-1.43Si and Cu-5.98Ni-1.29Si-0.24Ti alloys under heat treatment at 400 and 500 °C after hot- and cold-rolling were investigated, and a microstructural analysis using transmission electron microscopy was performed. Cu-5.98Ni-1.29Si-0.24Ti alloy displayed the combined Vickers hardness/electrical conductivity value of 315.9 Hv/57.1%IACS. This was attributed to a decrease of the solution solubility of Ni and Si in the Cu matrix by the formation of smaller and denser δ-Ni2Si precipitates. Meanwhile, the alloyed Ti was detected in the coarse Ni-Si-Ti phase particles, along with other large Ni-Si phase particles, in Cu-5.98Ni-1.29Si-0.24Ti.

  20. Local atomic and crystal structure rearrangement during the martensitic transformation in Ti50Ni25Cu25 shape memory alloy

    International Nuclear Information System (INIS)

    Menushenkov, Alexey; Grishina, Olga; Shelyakov, Alexander; Yaroslavtsev, Alexander; Zubavichus, Yan; Veligzhanin, Alexey; Bednarcik, Jozef; Chernikov, Roman; Sitnikov, Nikolay

    2014-01-01

    Highlights: • Local crystalline structure of TiNiCu SMA is investigated using EXAFS. • Peculiarities of Ni and Cu local environment are found. • Ti atoms show greater mobility relative to Ni atoms. • Ni local environment change is significant for shape memory effect. -- Abstract: The changes of crystal structure and local crystalline environment of Ti, Ni and Cu atoms in Ti 50 Ni 25 Cu 25 shape memory alloy are investigated using X-ray diffraction and extended X-ray absorption fine structure spectroscopy (EXAFS) in temperature range of martensite transformation. The analysis of the EXAFS-spectra shows that the bonds involving Ni atoms have the highest degree of disorder and the change in the local environment around Ni atoms is significant for the occurrence of the shape memory effect, while Cu atoms occupy the normal positions in the crystallographic structure and have the lowest displacement amplitude leading to the stabilization of both phases

  1. Device-quality tunnel junctions on the high Tc superconductor HgBa2CuO4+δ

    International Nuclear Information System (INIS)

    Zasadzinski, J.; Chen, J.; Romano, P.; Gray, K.E.; Wagner, J.L.; Hinks, D.G.

    1995-01-01

    SIN and SIS tunnel junction devices (e.g. photon detectors, logic elements) require quasiparticle characteristics that exhibit sharp current onsets at the gap voltage and very low sub-gap conductances. Progress is reported on the development of such junctions on High Tc cuprates using mechanical point contacts. In general, these contacts display the optimum characteristics that can be obtained from HTS native-surface tunnel barriers. Most cuprates display a sub-gap conductance which monotonically increases with voltage about the minimum value at zero bias. However, tunneling data of unusually high quality have been obtained for the recently discovered Hg-based cuprate, HgBa 2 CuO 4 (T c =96K). SIS' tunneling data using a Nb tip are presented which exhibit very low and flat sub-gap conductances and sharp conductance peaks as expected from a BCS density of states. These results are slightly improved over earlier published results with SIN junctions. Use of the experimental data to simulate the performance of a quasiparticle mixer demonstrates that noise temperatures approaching the quantum limit are possible for SIS and SIN mixers in the range 1-5 THz

  2. Low-field spin dynamics of Cr7Ni and Cr7Ni-Cu-Cr7Ni molecular rings as detected by μsR

    OpenAIRE

    Sanna, S.; Arosio, P.; Bordonali, L.; Adelnia, F.; Mariani, M.; Garlatti, E.; Baines, C.; Amato, A.; Sabareesh, K. P.V.; Timco, G.; Winpenny, R. E.P.; Blundell, S. J.; Lascialfari, A.

    2017-01-01

    Muon spin rotation measurements were used to investigate the spin dynamics of heterometallic Cr7Ni and Cr7Ni-Cu-Cr7Ni molecular clusters. In Cr7Ni the magnetic ions are arranged in a quasiplanar ring and interact via an antiferromagnetic exchange coupling constant J, while Cr7Ni-Cu-Cr7Ni is composed of two Cr7Ni linked by a bridging moiety containing one Cu ion, that induces an inter-ring ferromagnetic interaction J ≪ J. The longitudinal muon relaxation rate λ collected at low magnetic fields...

  3. Microstructure, texture and magnetic properties of Ni-Cu-W substrates for coated conductors

    DEFF Research Database (Denmark)

    Wulff, Anders Christian; Mishin, Oleg; Andersen, Niels Hessel

    2013-01-01

    concentrations of copper, increasing the Cu-content to 10 at% and 15 at% leads to increased frequencies of annealing twins in the cube-textured matrix. It is suggested that the (Ni 95W5)100-xCux alloy with x=5 at% Cu may be a good candidate material for using as a substrate for coated conductors. © 2012 Elsevier...

  4. FTIR spectroscopic study on the Hofmann -Td- type clathrates: Ni(benzoic acid)2M(CN)4.aniline (M=Zn, Cd, Hg)

    International Nuclear Information System (INIS)

    Kesan, G.; Kartal, Z.

    2010-01-01

    The Hofmann-Td-type clathrates formulated as Ni(L) 2 M(CN) 4 .nG where L is a bidentate or a pair of unidentate ligand molecule, M is Zn, Cd or Hg, G is a guest molecule and n is the number of guest molecule. The host lattice of the Hofmann-Td-type clathrates is formed from endless chains of -Ni-L-L-Ni-L-L-Ni- and M(CN) 4 ions arranged between the consecutive crossing -Ni-L-L-Ni-L-L-Ni- chains with the O-ends bound to the Ni metal atoms. These polymeric layers are held in parallel by Van der Walls interaction between ligand molecules. This structure provides α-type cavity. In this study, Ni(Benzoic Acid ) 2M(CN) 4 .Aniline (M = Zn, Cd, Hg) is obtained for the first time by means of chemical methods in powder form and their infrared spectra are reported in range of (4000-400) cm - 1. The spectral data suggest that the new clathrates are similar in structure to the Hofmann-type clathrates.

  5. Giant magnetoresistance in melt spun Cu85Co10Ni5

    DEFF Research Database (Denmark)

    Curiotto, Stefano; Johnson, Erik; Celegato, Federica

    2009-01-01

    CuCoNi rapidly solidified alloys are interesting because they display giant magnetoresistance (GMR). In the present work a Cu85Co10Ni5 alloy has been synthesized by melt spinning and analysed for GMR. The ribbons obtained have been annealed at different temperatures and the evolution of the crystal...... structure with annealing has been studied by X-ray diffraction. The. ne microstructure has been observed by TEM and related to the magnetic properties, investigated in a vibrating sample magnetometer. In the studied composition the magnetoresistance was found to be lower than in binary CuCo alloys without...

  6. Experimental investigation of phase equilibria in the Zr-Cu-Ni ternary system

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Mujin; Wang, Cuiping; Yang, Shuiyuan; Shi, Zhan; Han, Jiajia; Liu, Xingjun [Xiamen Univ. (China). College of Materials and Fujian Provincial Key Lab. of Materials Genome

    2017-08-15

    The phase equilibria in the Zr-Cu-Ni ternary system are investigated combined with X-ray diffraction, electron probe micro-analysis and differential scanning calorimetry. Two isothermal sections of the Zr-Cu-Ni ternary system at 1 000 C and 1 100 C are experimentally established. Most of the binary intermetallic compounds, e.g. Zr{sub 7}Ni{sub 10}, ZrNi, ZrNi{sub 5}, Zr{sub 14}Cu{sub 51}, and Zr{sub 2}Cu{sub 9}, show a remarkable ternary solubility. A new ternary compound named τ{sub 3} (Zr{sub 31.1-30.7} . Cu{sub 28.5-40.3}Ni{sub 40.4-29.0}) is detected at 1 000 C and dissolved at 1 020 C because the nearby large liquid phase field further expands. The newly determined phase equilibria will provide important information for both thermodynamic assessment and alloy design of Zr-based metallic glass.

  7. Copper and CuNi alloys substrates for HTS coated conductor applications protected from oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Segarra, M; Diaz, J; Xuriguera, H; Chimenos, J M; Espiell, F [Dept. of Chemical Engineering and Metallurgy, Univ. of Barcelona, Barcelona (Spain); Miralles, L [Lab. d' Investigacio en Formacions Geologiques. Dept. of Petrology, Geochemistry and Geological Prospecting, Univ. of Barcelona, Barcelona (Spain); Pinol, S [Inst. de Ciencia de Materials de Barcelona, Bellaterra (Spain)

    2003-07-01

    Copper is an interesting substrate for HTS coated conductors for its low cost compared to other metallic substrates, and for its low resistivity. Nevertheless, mechanical properties and resistance to oxidation should be improved in order to use it as substrate for YBCO deposition by non-vacuum techniques. Therefore, different cube textured CuNi tapes were prepared by RABIT as possible substrates for deposition of high critical current density YBCO films. Under the optimised conditions of deformation and annealing, all the studied CuNi alloys (2%, 5%, and 10% Ni) presented (100) left angle 001 right angle cube texture which is compatible for YBCO deposition. Textured CuNi alloys present higher tensile strength than pure copper. Oxidation resistance of CuNi tapes under different oxygen atmospheres was also studied by thermogravimetric analysis and compared to pure copper tapes. Although the presence of nickel improves mechanical properties of annealed copper, it does not improve its oxidation resistance. However, when a chromium buffer layer is electrodeposited on the tape, oxygen diffusion is slowed down. Chromium is, therefore, useful for protecting copper and CuNi alloys from oxidation although its recrystallisation texture, (110), is not suitable for coated conductors. (orig.)

  8. Synthesis and densification of Cu-coated Ni-based amorphous composite powders

    International Nuclear Information System (INIS)

    Kim, Yong-Jin; Kim, Byoung-Kee; Kim, Jin-Chun

    2007-01-01

    Spherical Ni 57 Zr 20 Ti 16 Si 2 Sn 3 (numbers indicate at.%) amorphous powders were produced by the gas atomization process, and ductile Cu phase was coated on the Ni-based amorphous powders by the spray drying process in order to increase the ductility of the consolidated amorphous alloy. The characteristics of the as-prepared powders and the consolidation behaviors of Cu-coated Ni-based amorphous composite powders were investigated. The atomization was conducted at 1450 deg. C under the vacuum of 10 -2 mbar. The Ni-based amorphous powders and Cu nitrate solution were mixed and sprayed at temperature of 130 deg. C. After spray drying and reduction treatment, the sub-micron size Cu powders were coated successfully on the surface of the atomized Ni amorphous powders. The spark plasma sintering process was applied to study the densification behavior of the Cu-coated composite powders. Thickness of the Cu layer was less than 1 μm. The compacts obtained by SPS showed high relative density of over 98% and its hardness was over 800 Hv

  9. Shape memory effect and microstructures of sputter-deposited Cu-Al-Ni films

    International Nuclear Information System (INIS)

    Minemura, T.; Andoh, H.; Kita, Y.; Ikuta, I.

    1985-01-01

    The shape memory effect has been found in many alloy systems which exhibit a thermoelastic martensite transformation. Cu-Al-Ni alloys exhibit an excellent shape memory effect in single crystalline states, but they have not yet been commercially used due to their brittle fracture along the grain boundaries in polycrystalline states. This letter reports the shape memory effect and microstructures of the sputter-deposited Cu-Al-Ni films. Cu-14%Al-4%Ni alloy ingot was prepared. A target for sputter deposition was cut from the ingot. Aluminium foils (20 μm thick) were used for the substrates of sputter deposition. The microstructures and crystal structures of the films were investigated by transmission electron microscopy (TEM) and X-ray diffraction using CuKα radiation, respectively. The effect of the sputtering conditions such as substrate temperature, partial pressure of argon gas, and the sputtering power on the structures of sputter-deposited Cu-14%Al-4%Ni films were investigated by X-ray diffraction. Results are shown and discussed. Photographs demonstrate shape memory behaviour of Cu-14%Al-4%Ni films sputter-deposited on aluminium foils from (a) liquid nitrogen temperature to (d) room temperature. (author)

  10. Oxygen ordering in the high-T$_c$ superconductor HgBa$_2$CaCu$_2$O$_{6+\\delta}$ as revealed by perturbed angular correlation

    CERN Document Server

    Mendonca, Tania Melo; Haas, Heinz; Odier, Philippe; Tavares, Pedro; Silva, Manuel Ribeiro; Lopes, Armandina; Pereira, Andre; Goncalves, Joao Nuno; Amaral, Joao; Darie, Celine; Araujo, Joao Pedro

    2011-01-01

    Lattice sites and collective ordering of oxygen atoms in HgBa$_2$CaCu$_2$O$_{6+\\delta}$ were studied using the perturbed angular correlation (PAC) technique at ISOLDE/CERN. The electric field gradients (EFG) at $^{199m}$Hg nuclei have been measured as functions of oxygen doping on the Hg planes, above and below T$_c$. In comparison with the results obtained for oxygen and fluorine doping in Hg-1201, the analysis shows a different oxygen ordering exhibited by Hg-1212. Moreover, for all studied cases, the experimental results show that at a local scale there is non-uniform oxygen distribution. A series of ab initio EFG calculations allowed to infer that at low concentrations, regions without oxygen coexist with regions where O$_{2\\delta}$ dumbbell molecules are located at the center of the Hg mesh. On the other side, at high concentrations, O$_{2\\delta}$ dumbbell molecules coexist with single O$_\\delta$ atoms occupying the center of the Hg mesh. The present results suggest that oxygen sits on the Hg planes in t...

  11. Creep behaviour of a casting titanium carbide reinforced AlSi12CuNiMg piston alloy at elevated temperatures; Hochtemperaturkriechverhalten der schmelzmetallurgisch hergestellten dispersionsverstaerkten Kolbenlegierung AlSi12CuNiMg

    Energy Technology Data Exchange (ETDEWEB)

    Michel, S.; Scholz, A. [Zentrum fuer Konstruktionswerkstoffe, TU Darmstadt (Germany); Tonn, B. [Institut fuer Metallurgie, TU Clausthal (Germany); Zak, H.

    2012-03-15

    This paper deals with the creep behaviour of the titanium carbide reinforced AlSi12CuNiMg piston alloy at 350 C and its comparison to the conventional AlSi12Cu4Ni2MgTiZr piston alloy. With only 0,02 vol-% TiC reinforcement the creep strength and creep rupture strength of the AlSi12CuNiMg piston alloy are significantly improved and reach the level of the expensive AlSi12Cu4Ni2MgTiZr alloy. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  12. Polycrystalline oxides formation during transient oxidation of (001) Cu-Ni binary alloys studied by in situ TEM and XRD

    International Nuclear Information System (INIS)

    Yang, J.C.; Li, Z.Q.; Sun, L.; Zhou, G.W.; Eastman, J.A.; Fong, D.D.; Fuoss, P.H.; Baldo, P.M.; Rehn, L.E.; Thompson, L.J.

    2009-01-01

    The nucleation and growth of Cu 2 O and NiO islands due to oxidation of Cu x Ni 1-x (001) films were monitored, at various temperatures, by in situ ultra-high vacuum (UHV) transmission electron microscopy (TEM) and in situ synchrotron X-ray diffraction (XRD). In remarkable contrast to our previous observations of Cu and Cu-Au oxidation, irregular-shaped polycrystalline oxide islands formed with respect to the Cu-Ni alloy film, and an unusual second oxide nucleation stage was noted. In situ XRD experiments revealed that NiO formed first epitaxially, then other orientations appeared, and finally polycrystalline Cu 2 O developed as the oxidation pressure was increased. The segregation of Ni and Cu towards or away, respectively, from the alloy surface during oxidation could disrupt the surface and cause polycrystalline oxide formation.

  13. Computational insight on the structural, mechanical and thermal properties of Cu2CdSnSe4 and Cu2HgSnSe4 adamantine materials

    Directory of Open Access Journals (Sweden)

    S. Bensalem

    2016-12-01

    Full Text Available Through first-principles calculation based on the density functional theory (DFT within the pseudo potential-plane wave (PP-PW approach, we studied the structural, mechanical and thermal properties of Cu2CdSnSe4 and Cu2HgSnSe4 adamantine materials. The calculated lattice parameters are in good agreement with experimental and theoretical reported data. The elastic constants are calculated for both compounds using the static finite strain scheme. The hydrostatic pressure action on the elastic constants predicts that both materials are mechanically stable up to 10 GPa. The polycrystalline mechanical parameters, i.e., the anisotropy factor (A, bulk modulus (B, shear modulus (G, Young's modulus (E, Lame's coefficient (λ and Poisson's ratio (ν have been estimated from the calculated single crystal elastic constants. The analysis of B/G ratio shows that the two studied compounds behave as ductile. Based on the calculated mechanical parameters, the Debye temperature and the thermal conductivity have been probed. In the framework of the quasi-harmonic approximation, the temperature dependence of the lattice heat capacity of both crystals has been investigated.

  14. Microstructural Characteristics and Mechanical Properties of an Electron Beam-Welded Ti/Cu/Ni Joint

    Science.gov (United States)

    Zhang, Feng; Wang, Ting; Jiang, Siyuan; Zhang, Binggang; Feng, Jicai

    2018-05-01

    Electron beam welding experiments of TA15 titanium alloy to GH600 nickel superalloy with and without a copper sheet interlayer were carried out. Surface appearance, microstructure and phase constitution of the joint were examined by optical microscopy, scanning electron microscopy and x-ray diffraction analysis. Mechanical properties of Ti/Ni and Ti/Cu/Ni joint were evaluated based on tensile strength and microhardness tests. The results showed that cracking occurred in Ti/Ni electron beam weldment for the formation of brittle Ni-Ti intermetallics, while a crack-free electron beam-welded Ti/Ni joint can be obtained by using a copper sheet as filler metal. The addition of copper into the weld affected the welding metallurgical process of the electron beam-welded Ti/Ni joint significantly and was helpful for restraining the formation of Ti-Ni intermetallics in Ti/Ni joint. The microstructure of the weld was mainly characterized by a copper-based solid solution and Ti-Cu interfacial intermetallic compounds. Ti-Ni intermetallic compounds were almost entirely suppressed. The hardness of the weld zone was significantly lower than that of Ti/Ni joint, and the tensile strength of the joint can be up to 282 MPa.

  15. Fabrication of Ti-Ni-Cu shape memory alloy powders by ball milling method

    International Nuclear Information System (INIS)

    Kang, S.; Nam, T.

    2001-01-01

    Ti-Ni and Ti-Ni-Cu shape memory alloy powders have been fabricated by ball milling method, and then alloying behavior and transformation behavior were investigated by means of optical microscopy, electron microscopy, X-ray diffraction and differential scanning calorimetry. As milled Ti-Ni powders fabricated with milling time less than 20 hrs was a mixture of pure elemental Ti and Ni, and therefore it was unable to obtain alloy powders because the combustion reaction between Ti and Ni occurred during heat treatment. Since those fabricated with milling time more than 20 hrs was a mixture of Ti-rich and Ni-rich Ti-Ni solid solution, however, it was possible to obtain alloy powders without the combustion reaction during heat treatment. Clear exothermic and endothermic peaks appeared in the cooling and heating curves, respectively in DSC curves of 20 hrs and 30 hrs milled Ti-Ni powders. On the other hand, in DSC curves of 1 hr, 10 hrs, 50 hrs and 100 hrs, the thermal peaks were almost discernible. The most optimum ball milling time for fabricating Ti-Ni alloy powders was 30 hrs. Ti-40Ni-10Cu(at%) alloy powders were fabricated successfully by ball milling conditions with rotating speed of 100 rpm and milling time of 30 hrs. (author)

  16. Ternary systems Sr-{Ni,Cu}-Si: Phase equilibria and crystal structure of ternary phases

    International Nuclear Information System (INIS)

    Nasir, Navida; Melnychenko-Koblyuk, Nataliya; Grytsiv, Andriy; Rogl, Peter; Giester, Gerald; Wosik, Jaroslaw; Nauer, Gerhard E.

    2010-01-01

    Phase relations were established in the Sr-poor part of the ternary systems Sr-Ni-Si (900 deg. C) and Sr-Cu-Si (800 deg. C) by light optical microscopy, electron probe microanalysis and X-ray diffraction on as cast and annealed alloys. Two new ternary compounds SrNiSi 3 (BaNiSn 3 -type) and SrNi 9-x Si 4+x (own-type) were found in the Sr-Ni-Si system along with previously reported Sr(Ni x Si 1-x ) 2 (AlB 2 -type). The crystal structure of SrNi 9-x Si 4+x (own-type, x=2.7, a=0.78998(3), c=1.1337(2) nm; space group P4/nbm) was determined from X-ray single crystal counter to be a low symmetry derivative of the cubic, parent NaZn 13 -type. At higher Si-content X-ray Rietveld refinements reveal the formation of a vacant site (□) corresponding to a formula SrNi 5.5 Si 6.5 □ 1.0 . Phase equilibria in the Sr-Cu-Si system are characterized by the compounds SrCu 2-x Si 2+x (ThCr 2 Si 2 -type), Sr(Cu x Si 1-x ) 2 (AlB 2 -type), SrCu 9-x Si 4+x (0≤x≤1.0; CeNi 8.5 Si 4.5 -type) and SrCu 13-x Si x (4≤x≤1.8; NaZn 13 -type). The latter two structure types appear within a continuous solid solution. Neither a type-I nor a type-IX clathrate compound was encountered in the Sr-{Cu,Ni}-Si systems. Structural details are furthermore given for about 14 new ternary compounds from related alloy systems with Ba. - Graphical abstract: The crystal structure of SrNi 9-x Si 4+x (own-type, x=2.7, a=0.78998(3), c=1.1337(2) nm; space group P4/nbm) was determined from X-ray single crystal counter to be a low symmetry derivative of the cubic, parent NaZn 13 -type and is related to CeNi 8.5 Si 4.5 -type.

  17. Hydrogen storage properties of LaMgNi3.6M0.4 (M = Ni, Co, Mn, Cu, Al) alloys

    International Nuclear Information System (INIS)

    Yang, Tai; Zhai, Tingting; Yuan, Zeming; Bu, Wengang; Xu, Sheng; Zhang, Yanghuan

    2014-01-01

    Highlights: • La–Mg–Ni system AB 2 -type alloys were prepared by induction melting. • Structures and lattice parameters were analysed by XRD. • Hydrogen absorption/desorption performances were studied. • Mechanisms of hydrogen absorption capacity fading were investigated. - Abstract: LaMgNi 3.6 M 0.4 (M = Ni, Co, Mn, Cu, Al) alloys were prepared through induction melting process. The phase compositions and crystal structures were characterised via X-ray diffraction (XRD). The hydrogen storage properties, including activation performance, hydrogen absorption capacity, cycle stability, alloy particle pulverisation and plateau pressure, were systemically investigated. Results show that Ni, Co, Mn and Cu substitution alloys exhibit multiphase structures comprising the main phase LaMgNi 4 and the secondary phase LaNi 5 . However, the secondary phase of the Al substitution alloy changes into LaAlNi 4 . The lattice parameters and cell volumes of the LaMgNi 4 phase follow the order Ni < Co < Al < Cu < Mn. Activation is simplified through partial substitution of Ni with Al, Cu and Co. The hydrogen absorption capacities of all of the alloys are approximately 1.7 wt.% at the first activation process; however, they rapidly decrease with increasing cycle number. In addition, the stabilities of hydriding and dehydriding cycles decrease in the order Al > Co > Ni > Cu > Mn. Hydriding processes result in numerous cracks and amorphisation of the LaMgNi 4 phase in the alloys. The p–c isotherms were determined by a Sieverts-type apparatus. Two plateaus were observed for the Ni, Co and Al substitution alloys, whereas only one plateau was found for Mn and Cu. This result was caused by the amorphisation of the LaMgNi 4 phase during the hydriding cycles. Reversible absorption and desorption of hydrogen are difficult to achieve. Substitutions of Ni with Co, Mn, Cu and Al significantly influence the reduction of hysteresis between hydriding and dehydriding

  18. Effect of iron content on the structure and mechanical properties of Al25Ti25Ni25Cu25 and (AlTi)60-xNi20Cu20Fex (x=15, 20) high-entropy alloys

    International Nuclear Information System (INIS)

    Fazakas, É.; Zadorozhnyy, V.; Louzguine-Luzgin, D.V.

    2015-01-01

    Highlights: • Three new refractory alloys namely: Al 25 Ti 25 Ni 25 Cu 25 , Al 22.5 Ti 22.5 Ni 20 Cu 20 Fe 15 and Al 20 Ti 20 Ni 20 Cu 20 Fe 20 , were produced by induction-melting and casting. • This kind of alloys exhibits high resistance to annealing softening. • Most the alloys in the annealed state possess even higher Vickers microhardness than the as-cast alloys. • The Al 22.5 Ti 22.5 Ni 20 Cu 20 Fe 15 and Al 20 Ti 20 Ni 20 Cu 20 Fe 20 alloys annealed at 973 K show the highest compressive stress and ductility values. - Abstract: In this work, we investigated the microstructure and mechanical properties of Al 25 Ti 25 Ni 25 C u25 Al 22.5 Ti 22.5 Ni 20 Cu 20 Fe 15 and Al 20 Ti 20 Ni 20 Cu 20 Fe 20 high entropy alloys, produced by arc melting and casting in an inert atmosphere. The structure of these alloys was studied by X-ray diffractometry and scanning electron microscopy. The as-cast alloys were heat treated at 773, 973 and 1173 K for 1800 s to investigate the effects of aging on the plasticity, hardness and elastic properties. Compared to the conventional high-entropy alloys the Al 25 Ti 25 Ni 25 Cu 25 , Al 22.5 Ti 22.5 Ni 20 Cu 20 Fe 15 and Al 20 Ti 20 Ni 20 Cu 20 Fe 20 alloys are relatively hard and ductile. Being heat treated at 973 K the Al 22.5 Ti 22.5 Ni 20 Cu 20 Fe 15 alloy shows considerably high strength and relatively homogeneous deformation under compression. The plasticity, hardness and elastic properties of the studied alloys depend on the fraction and intrinsic properties of the constituent phases. Significant hardening effect by the annealing is found.

  19. 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

  20. 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.

  1. Electrothermal vaporization inductively coupled plasma-mass spectrometry for the determination of Cr, Cu, Cd, Hg and Pb in rice flour

    International Nuclear Information System (INIS)

    Li, P.-C.; Jiang, S.-J.

    2003-01-01

    Ultrasonic slurry sampling (USS)-electrothermal vaporization (ETV) dynamic reaction cell TM (DRC) inductively coupled plasma-mass spectrometry (ICP-MS) has been applied to determine Cr, Cu, Cd, Hg and Pb in rice samples. The influences of instrument operating conditions and slurry preparation on the ion signals were reported. Ascorbic acid was used as a modifier to enhance the ion signals. The background ions at the chromium masses were reduced in intensity significantly by using 0.4 ml min -1 NH 3 as reaction cell gas in the dynamic reaction cell while a q value of 0.6 was used. Since the sensitivities of Cr, Cu, Cd, Hg and Pb in rice flour slurry and aqueous solution were quite different, standard addition and isotope dilution methods were used for the determination of Cr, Cu, Cd, Hg and Pb in these rice samples. This method has been applied to the determination of Cr, Cu, Cd, Hg and Pb in NIST SRM 1568a rice flour reference material and two rice samples purchased from the market. The analytical results for the reference material agreed with the certified values. The results for the rice samples for which no reference values were available were also found to be in good agreement between the isotope dilution and standard addition methods. The method's detection limits estimated from the standard addition plots were about 0.44, 1.7, 0.4, 0.53 and 0.69 ng g -1 for Cr, Cu, Cd, Hg and Pb, respectively, in the original rice flour

  2. Stable isotope tracing of Ni and Cu pollution in North-East Norway: Potentials and drawbacks.

    Science.gov (United States)

    Šillerová, Hana; Chrastný, Vladislav; Vítková, Martina; Francová, Anna; Jehlička, Jan; Gutsch, Marissa R; Kocourková, Jana; Aspholm, Paul E; Nilsson, Lars O; Berglen, Tore F; Jensen, Henning K B; Komárek, Michael

    2017-09-01

    The use of Ni and Cu isotopes for tracing contamination sources in the environment remains a challenging task due to the limited information about the influence of various biogeochemical processes influencing stable isotope fractionation. This work focuses on a relatively simple system in north-east Norway with two possible endmembers (smelter-bedrock) and various environmental samples (snow, soil, lichens, PM 10 ). In general, the whole area is enriched in heavy Ni and Cu isotopes highlighting the impact of the smelting activity. However, the environmental samples exhibit a large range of δ 60 Ni (-0.01 ± 0.03‰ to 1.71 ± 0.02‰) and δ 65 Cu (-0.06 ± 0.06‰ to -3.94 ± 0.3‰) values which exceeds the range of δ 60 Ni and δ 65 Cu values determined in the smelter, i.e. in feeding material and slag (δ 60 Ni from 0.56 ± 0.06‰ to 1.00 ± 0.06‰ and δ 65 Cu from -1.67 ± 0.04‰ to -1.68 ± 0.15‰). The shift toward heavier Ni and Cu δ values was the most significant in organic rich topsoil samples in the case of Ni (δ 60 Ni up to 1.71 ± 0.02‰) and in lichens and snow in the case of Cu (δ 65 Cu up to -0.06 ± 0.06‰ and -0.24 ± 0.04‰, respectively). These data suggest an important biological and biochemical fractionation (microorganisms and/or metal uptake by higher plants, organo-complexation etc.) of Ni and Cu isotopes, which should be quantified separately for each process and taken into account when using the stable isotopes for tracing contamination in the environment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Electroplating Ni-63 metal ions in chloride bath on the Cu-plate

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Kwon Mo; Uhm, Young Rang; Son, Kwang Jae; Park, Keun Yung [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    Ni-63 plating is similar to other electroplating processes that employ soluble metal anodes. The nickel plating solution described by Watts in 1916 eventually replaced all other strategies in use up to that time. Charged Ni ions are formed by sulfate, sulfamate, chloride, and a Watts bath. However, charged Ni-63 ions are formed by dissolving metal Ni-63. Specifically, it requires the passage of direct current (DC) between two electrodes that are immersed in a conductive, aqueous solution of nickel salts. The flow of a DC causes one of the electrodes (the anode) to dissolve and the other electrode (the cathode) to become covered with nickel. The nickel in the solution is present in the form of divalent positively charged ions (Ni{sup 2+}). When the current flows, the positive ions react with two electrons (2e{sup -}) and are converted into metallic nickel (Ni{sup 0}) at the cathode surface. In the present study, we optimize and established process for the electroplating Ni-63 on Cu-plate. Nanocrystalline nickel (Ni) coatings were synthesized by DC electro deposition at a current density of 15 mA/cm{sup 2}. The bath was primarily composed of 0.2 M Ni ions, prepared by dissolving Ni-63 metal particles in HCl. The prototype for electroplating radioactive Ni-63 has been established. The electroplating was carried out by two-step processes such as preparation of ionic solution including Ni-63, and coating processes on the substrate.

  4. Electroplating Ni-63 metal ions in chloride bath on the Cu-plate

    International Nuclear Information System (INIS)

    Yoo, Kwon Mo; Uhm, Young Rang; Son, Kwang Jae; Park, Keun Yung

    2014-01-01

    Ni-63 plating is similar to other electroplating processes that employ soluble metal anodes. The nickel plating solution described by Watts in 1916 eventually replaced all other strategies in use up to that time. Charged Ni ions are formed by sulfate, sulfamate, chloride, and a Watts bath. However, charged Ni-63 ions are formed by dissolving metal Ni-63. Specifically, it requires the passage of direct current (DC) between two electrodes that are immersed in a conductive, aqueous solution of nickel salts. The flow of a DC causes one of the electrodes (the anode) to dissolve and the other electrode (the cathode) to become covered with nickel. The nickel in the solution is present in the form of divalent positively charged ions (Ni 2+ ). When the current flows, the positive ions react with two electrons (2e - ) and are converted into metallic nickel (Ni 0 ) at the cathode surface. In the present study, we optimize and established process for the electroplating Ni-63 on Cu-plate. Nanocrystalline nickel (Ni) coatings were synthesized by DC electro deposition at a current density of 15 mA/cm 2 . The bath was primarily composed of 0.2 M Ni ions, prepared by dissolving Ni-63 metal particles in HCl. The prototype for electroplating radioactive Ni-63 has been established. The electroplating was carried out by two-step processes such as preparation of ionic solution including Ni-63, and coating processes on the substrate

  5. Geochemical partitioning of Cu and Ni in mangrove sediments: Relationships with their bioavailability

    International Nuclear Information System (INIS)

    Chakraborty, Parthasarathi; Ramteke, Darwin; Chakraborty, Sucharita

    2015-01-01

    Highlights: • Metal speciation controls bioavailability in mangrove ecosystem. • Bioavailability of Ni was controlled by Fe/Mn-oxyhydroxide and organic phases • Bioavailability of Cu in mangrove roots was controlled by organic phase in the sediments. • Cu interacts more strongly with organic phases than Ni in mangrove sediment. - Abstract: Sequential extraction study was performed to determine the concentrations of non-residual metal-complexes in the mangrove sediments from the Divar Island, (west coast of India). Accumulation of metal in the mangrove roots (from the same location) was determined and used as an indicator of bioavailability of metal. An attempt was made to establish a mechanistic linkage between the non-residual metal complexes and their bioavailability in the mangrove system. The non-residual fractions of Cu and Ni were mainly associated with Fe/Mn oxyhydroxide and organic phases in the sediments. A part of these metal fractions were bioavailable in the system. These two phases were the major controlling factors for Ni speciation and their bioavailability in the studied sediments. However, Cu was found to interact more strongly with the organic phases than Ni in the mangrove sediments. Organic phases in the mangrove sediments acted as buffer to control the speciation and bioavailability of Cu in the system

  6. RF magnetron sputtered TiNiCu shape memory alloy thin film

    International Nuclear Information System (INIS)

    Fu Yongqing; Du Hejun

    2003-01-01

    Shape memory alloys (SMAs) offer a unique combination of novel properties, such as shape memory effect, super-elasticity, biocompatibility and high damping capacity, and thin film SMAs have the potential to become a primary actuating mechanism for micro-actuators. In this study, TiNiCu films were successfully prepared by mix sputtering of a Ti 55 Ni 45 target with a separated Cu target. Crystalline structure, residual stress and phase transformation properties of the TiNiCu films were investigated using X-ray diffraction (XRD), differential scanning calorimeter (DSC), and curvature measurement methods. Effects of the processing parameters on the film composition, phase transformation and shape-memory effects were analyzed. Results showed that films prepared at a high Ar gas pressure exhibited a columnar structure, while films deposited at a low Ar gas pressure showed smooth and featureless structure. Chemical composition of TiNiCu thin films was dependent on the DC power of copper target. DSC, XRD and curvature measurement revealed clearly the martensitic transformation of the deposited TiNiCu films. When the free-standing film was heated and cooled, a 'two-way' shape-memory effect can be clearly observed

  7. Zr-Cu-Ni-Al bulk metallic glasses with superhigh glass-forming ability

    International Nuclear Information System (INIS)

    Sun, Y.J.; Qu, D.D.; Huang, Y.J.; Liss, K.-D.; Wei, X.S.; Xing, D.W.; Shen, J.

    2009-01-01

    Zr-Cu-Ni-Al quaternary amorphous alloy compositions with varying glass-forming ability are developed by an efficient method of proportional mixing of binary eutectics. The critical diameter of the glassy sample is improved from 6 mm for Zr 53 Cu 18.7 Ni 12 Al 16.3 to 14 mm for Zr 50.7 Cu 28 Ni 9 Al 12.3 by straightforwardly adjusting the eutectic unit's coefficients. The drastic improvement in GFA is attributed to balancing the chemical affinities of the Zr, Cu, Ni and Al components in the melt prior to solidification which makes the precipitation of competing crystalline phases more difficult. As the glass-forming ability increases, the concentration of Cu in the alloys exhibits a same trend. Based on synchrotron radiation high-energy X-ray diffraction analysis and Miracle's structural model, it is envisioned that the substitution of additional Cu atoms for Zr atoms in the investigated alloys stabilizes the efficient cluster packing structure of the amorphous alloys, leading to the pronounced increase in their glass-forming ability

  8. Solution-Based Epitaxial Growth of Magnetically Responsive Cu@Ni Nanowires

    KAUST Repository

    Zhang, Shengmao

    2010-02-23

    An experiment was conducted to show the solution-based epitaxial growth of magnetically responsive Cu@Ni nanowires. The Ni-sheathed Cu nanowires were synthesized with a one-pot approach. 30 mL of high concentration NaOH, Cu(NO3)2. 3H2O, Cu(NO3)2. 3H2O and 0.07-0.30 mL of Ni(NO3)2. 6H 2O aqueous solutions were added into a plastic reactor with a capacity of 50.0 mL. A varying amount of ethylenediamine (EDA) and hydrazine were also added sequentially, followed by thorough mixing of all reagents. The dimension, morphology, and chemical composition of the products were examined with scanning electron microscopy with energy dispersive X-ray spectroscopy. The XPS analysis on the as formed Cu nanowires confirms that there is indeed no nickel inclusion in the nanowires prior to the formation of nickel overcoat, which rules out the possibility of Cu-Ni alloy formation.

  9. Solution-Based Epitaxial Growth of Magnetically Responsive Cu@Ni Nanowires

    KAUST Repository

    Zhang, Shengmao; Zeng, Hua Chun

    2010-01-01

    An experiment was conducted to show the solution-based epitaxial growth of magnetically responsive Cu@Ni nanowires. The Ni-sheathed Cu nanowires were synthesized with a one-pot approach. 30 mL of high concentration NaOH, Cu(NO3)2. 3H2O, Cu(NO3)2. 3H2O and 0.07-0.30 mL of Ni(NO3)2. 6H 2O aqueous solutions were added into a plastic reactor with a capacity of 50.0 mL. A varying amount of ethylenediamine (EDA) and hydrazine were also added sequentially, followed by thorough mixing of all reagents. The dimension, morphology, and chemical composition of the products were examined with scanning electron microscopy with energy dispersive X-ray spectroscopy. The XPS analysis on the as formed Cu nanowires confirms that there is indeed no nickel inclusion in the nanowires prior to the formation of nickel overcoat, which rules out the possibility of Cu-Ni alloy formation.

  10. Magnetic behavior of NiCu nanowire arrays: Compositional, geometry and temperature dependence

    International Nuclear Information System (INIS)

    Palmero, E. M.; Bran, C.; Real, R. P. del; Vázquez, M.; Magén, C.

    2014-01-01

    Arrays of Ni 100−x Cu x nanowires ranging in composition 0 ≤ x ≤ 75, diameter from 35 to 80 nm, and length from 150 nm to 28 μm have been fabricated by electrochemical co-deposition of Ni and Cu into self-ordered anodic aluminum oxide membranes. As determined by X-ray diffraction and Transmission Electron Microscopy, the crystalline structure shows fcc cubic symmetry with [111] preferred texture and preferential Ni or Cu lattice depending on the composition. Their magnetic properties such as coercivity and squareness have been determined as a function of composition and geometry in a Vibrating Sample Magnetometer in the temperature range from 10 to 290 K for applied magnetic fields parallel and perpendicular to the nanowires axis. Addition of Cu into the NiCu alloy up to 50% enhances both parallel coercivity and squareness. For the higher Cu content, these properties decrease and the magnetization easy axis becomes oriented perpendicular to the wires. In addition, coercivity and squareness increase by decreasing the diameter of nanowires which is ascribed to the increase of shape anisotropy. The temperature dependent measurements reflect a complex behavior of the magnetic anisotropy as a result of energy contributions with different evolution with temperature.

  11. Coordination Compounds of Co Ni , Cu , Zn , Cd and Hg with ...

    African Journals Online (AJOL)

    CLEMENT O BEWAJI

    Bipin B. Mahapatra* and Saroj Ku. Panda. **. **P.G. Department of Chemistry, G.M. (Autonomous) College, Sambalpur – 768004 (Orissa). India. Telephone ..... Ferraro, J.R: Low Frequency Vibration of Inorganic and Co-ordination Compound Plenum press, New York. USA: (1971). 10. Sacconi. L: J. Inorg. Nucl. Chem., 18 ...

  12. Granulation of Cu-Al-Fe-Ni Bronze

    Directory of Open Access Journals (Sweden)

    Pisarek B.P.

    2014-08-01

    Full Text Available With the increase in wall thickness of the casting of iron-nickel-aluminium-bronze, by the reduction of the cooling rate the size of κII phase precipitates increases. This process, in the case of complex aluminium bronzes with additions of Cr, Mo and W is increased. Crystallization of big κII phase, during slow cooling of the casting, reduces the concentration of additives introduced to the bronze matrix and hardness. Undertaken research to develop technology of thick-walled products (g> 6 mm of complex aluminium bronzes. Particular attention was paid to the metallurgy of granules. As a result, a large cooling speed of the alloy, and also high-speed solidification casting a light weight of the granules allows: to avoid micro-and macrosegregation, decreasing the particle size, increase the dispersion of phases in multiphase alloys. Depending on the size granules as possible is to provide finished products with a wall thickness greater than 6 mm by infiltration of liquid alloy of granules (composites. Preliminary studies was conducted using drip method granulate of CuAl10Fe5Ni5 bronze melted in a INDUTHERM-VC 500 D Vacuum Pressure Casting Machine. This bronze is a starting alloy for the preparation of the complex aluminium bronzes with additions of Cr, Mo, W and C or Si. Optimizations of granulation process was carried out. As the process control parameters taken a casting temperature t (°C and the path h (mm of free-fall of the metal droplets in the surrounding atmosphere before it is intensively cooled in a container of water. The granulate was subjected to a sieve analysis. For the objective function was assume maximize of the product of Um*n, the percentage weight “Um” and the quantity of granules ‘n’ in the mesh fraction. The maximum value of the ratio obtained for mesh fraction a sieve with a mesh aperture of 6.3 mm. In the intensively cooled granule of bronze was identified microstructure composed of phases: β and fine bainite

  13. The influence of Ni additions on the relative stability of η and η′ Cu6Sn5

    KAUST Repository

    Schwingenschlögl, Udo

    2010-02-09

    We investigate how 5 at. % Ni influences the relative stability of η and η′ Cu6Sn5. Synchrotron x-ray diffraction shows that, while Cu6Sn5 exists as η′ at 25 and 150 °C and transforms to η on heating to 200 °C, Cu5.5Ni0.5Sn5 is best fit to η throughout 25–200 °C. Our first principles calculations predict that η′ is stable at T=0 K in both Cu6Sn5 and Cu5.5Ni0.5Sn5, but that the energy difference is substantially reduced from 1.21 to 0.90 eV per 22 atom cell by the Ni addition. This effect is attributed to Ni developing distinct bonding to both Cu and Sn in the η phase.

  14. Microstructure and magnetic studies of Mg-Ni-Zn-Cu ferrites

    International Nuclear Information System (INIS)

    Bachhav, S.G.; Patil, R.S.; Ahirrao, P.B.; Patil, A.M.; Patil, D.R.

    2011-01-01

    Highlights: → Ni x Mg 0.5-x Cu 0.1 Zn 0.4 Fe 2 O 4 ferrite shows spinel structure. → Lattice parameter, X-ray density, porosity increase with increase in Ni content. → The IR spectra show tetrahedral and octahedral complexes. → Initial permeability remains constant with temperature and drops to zero at certain temperature which is in close agreement with Curie temperature. → The Curie temperature shows increasing trend with Ni content. - Abstract: Soft Mg-Ni-Zn-Cu spinel ferrites having general chemical formula Ni x Mg 0.5-x Cu 0.1 Zn 0.4 Fe 2 O 4 (where x 0.1, 0.2, 0.3, 0.4 and 0.5) were prepared by standard double sintering ceramic method. The samples were characterized by X-ray diffraction at room temperature. The X-ray diffraction (XRD) study revealed that lattice parameter decreases with increase in Ni content, resulting in a reduction in lattice strain. The electrical and magnetic properties of the synthesized ferrites have been investigated as a function of temperature. The variation of initial permeability and AC susceptibility with temperature exhibits normal ferrimagnetic behavior. The variation of initial permeability with frequency is studied. The Curie temperature (T C ) in the present work was determined from initial permeability and AC susceptibility. The Curie temperature increases with Ni content.

  15. Molecular dynamics simulation of effects of twin interfaces on Cu/Ni multilayers

    International Nuclear Information System (INIS)

    Fu, Tao; Peng, Xianghe; Weng, Shayuan; Zhao, Yinbo; Gao, Fengshan; Deng, Lijun; Wang, Zhongchang

    2016-01-01

    We perform molecular dynamics simulation of the indentation on pure Cu and Ni films and Cu/Ni multilayered films with a cylindrical indenter, aimed to investigate the effects of the cubic-on-cubic interface and hetero-twin interface on their mechanical properties. We also investigate systematically the formation of twin boundary in the pure metals and the effects of the cubic-on-cubic and hetero-twin interface on mechanical properties of the multilayers. We find that the slip of the horizontal stacking fault can release the internal stress, resulting in insignificant strengthening. The change in the crystal orientation by horizontal movement of the atoms in a layer-by-layer manner is found to initiate the movement of twin boundary, and the hetero-twin interface is beneficial to the hardening of multilayers. Moreover, we also find that increasing number of hetero-twin interfaces can harden the Cu/Ni multilayers.

  16. SYNTHESIS OF ACETIC ACID FROM ETHANOL BY ELECTROOXIDATION TECHNIQUE USING Ni-Cu-PVC ELECTRODE

    Directory of Open Access Journals (Sweden)

    Riyanto Riyanto

    2017-11-01

    Full Text Available A usage of Ni-Cu-PVC electrode for the oxidation of ethanol by electrochemical technique will be reported in this paper. In this work, the effect of electrodes on the yields of acetic acid was determined. Electrode used was made of the mixtures of Ni powder, Cu powder and of polyvinyl chloride (PVC with various percentages. Electrooxidation of 0.20 M ethanol in 0.16 M KOH  (24 mL were carried out using chrono coulometry (CC at a potential of 1050 mV for 6 hours with continious stirring. Electrooxdation result obtained was analyzed using High Performance Liquid Chromatography (HPLC. The test result shows that the composition of  Ni:Cu:PVC  at 75:20:5 have higher efficiency in the electrooxidation of ethanol to acetic acid.

  17. Decreasing Ni, Cu, Cd, and Zn heavy metal magnetite-bentonite nanocomposites and adsorption isotherm study

    Science.gov (United States)

    Eskandari, M.; Zakeri Khatir, M.; Khodadadi Darban, A.; Meshkini, M.

    2018-04-01

    This present study was conducted to investigate the effect of magnetite-bentonite nanocomposite on heavy metal removal from an effluent. For this purpose, magnetite-bentonite nanocomposite was prepared through the chemical method and characterized using x-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques, followed by studying the effect of produced nanocomposite on the removal of Ni2+, Cu2+, Cd2+, and Zn2+ heavy metal ions. The results showed that adsorption capacity of magnetite-bentonite nanocomposites for the studied ions is in the order of Zn2+ > Cd2+ > Cu2+ > Ni2+. Adsorption isotherms were drawn for Ni2+, Cu2+, Cd2+, and Zn2+ cations and found that cations adsorption on nanocomposite fit into Langmuir model.

  18. Spectroscopic and DFT studies of flurbiprofen as dimer and its Cu(II) and Hg(II) complexes

    Science.gov (United States)

    Sagdinc, Seda; Pir, Hacer

    2009-07-01

    The vibrational study in the solid state of flurbiprofen and its Cu(II) and Hg(II) complexes was performed by IR and Raman spectroscopy. The changes observed between the IR and Raman spectra of the ligand and of the complexes allowed us to establish the coordination mode of the metal in both complexes. The comparative vibrational analysis of the free ligand and its complexes gave evidence that flurbiprofen binds metal (II) through the carboxylate oxygen. The fully optimized equilibrium structure of flurbiprofen and its metal complexes was obtained by density functional B3LYP method by using LanL2DZ and 6-31 G(d,p) basis sets. The harmonic vibrational frequencies, infrared intensities and Raman scattering activities of flurbiprofen were calculated by density functional B3LYP methods by using 6-31G(d,p) basis set. The scaled theoretical wavenumbers showed very good agreement with the experimental values. The electronic properties of the free molecule and its complexes were also performed at B3LYP/6-31G(d,p) level of theory. Detailed interpretations of the infrared and Raman spectra of flurbiprofen are reported. The UV-vis spectra of flurbiprofen and its metal complexes were also investigated in organic solvents.

  19. Proficiency test Plant 6 - determination of As, Cd, Cu, Hg, Pb, Se and Zn in dry mushroom powder (Suillus bovinus)

    International Nuclear Information System (INIS)

    Polkowska-Motrenko, H.; Dudek, J.; Chajduk, E.; Sypula, M.; Sadowska-Bratek, M.

    2006-01-01

    Proficiency testing scheme PLANT 6: Determination of As, Cd, Cu, Hg, Pb, Se and Zn in dry mushroom powder (Suillus bovinus) has been described. The proficiency test has been provided by the Institute of Nuclear Chemistry and Technology (Warsaw) with cooperation with POLLAB-CHEM/EURACHEM-PL and REFMAT Society. Wild mushrooms were collected in the forest in north-west Poland, cleaned, i.e. dust, soil and attached mosses were removed. Mushrooms were cut into smaller parts and air dried in a dryer. Dried mushrooms were milled in a centrifugal mill and sieved. Particles of fraction below 1 mm diameter were collected. Analytical samples of 20 g mass were prepared. The material were then characterized by homogeneity testing and determination of assigned values for concentration of elements in question. The testing samples were sent to the laboratories participating in the proficiency test. The results supplied by the participants were statistically evaluated and the calculated values of z-score and En numbers were used for the evaluation of the participating laboratory competency. (author)

  20. Crystallographic isomorphism in the structural type of α-HgI{sub 2} by example of KHgI{sub 3} · H{sub 2}O, β-Ag{sub 2}HgI{sub 4}, and β-Cu{sub 2}HgI{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Borisov, S. V., E-mail: borisov@niic.nsc.ru; Magarill, S. A.; Pervukhina, N. V. [Russian Academy of Sciences, Nikolaev Institute of Inorganic Chemistry, Siberian Branch (Russian Federation)

    2017-03-15

    The structure of KHgI{sub 3} · H{sub 2}O is assigned to the family of crystal structures having the three-layer cubic packing of iodine anions with cations in the tetrahedral voids (the structures of α-HgI{sub 2}, β-Ag{sub 2}HgI{sub 4}, and β-Cu{sub 2}HgI{sub 4} among them). Crystallographic analysis shows that the nodes of the three-layer close packing are populated by iodine anions and K cations in the ratio 3/4: 1/4. Transformation of the structure of α-HgI{sub 2} into the structure of KHgI{sub 3} · H{sub 2}O can be formally represented as the replacement of (HgI){sub n}{sup +} fragments by (KH{sub 2}O){sub n}{sup +} fragments: (Hg{sub 2}I{sub 4})–(HgI){sup +} + (KH{sub 2}O){sub n}{sup +} = KHgI{sub 3} · H{sub 2}O. Perforated layers of vertex-sharing HgI{sub 4} tetrahedra break down into parallel isolated chains. Channels formed in place of I–Hg–I–Hg–fragments are occupied by–H{sub 2}O–K–-H{sub 2}-O-K-H{sub 2}O-chains weakly bound to neighbors.

  1. Metallurgically prepared NiCu alloys as cathode materials for hydrogen evolution reaction

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Kunchan; Xia, Ming [State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083 (China); Xiao, Tao [2nd Xiangya Hospital, Central South University, Changsha 410011 (China); Lei, Ting, E-mail: tlei@mail.csu.edu.cn [State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083 (China); Yan, Weishan [State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083 (China)

    2017-01-15

    Ni−Cu bimetallic alloys with Cu content of 5, 10, 20, 30 and 50 wt% are prepared by powder metallurgy method, which consisted of powder mixing, pressing and sintering processes. The X-ray diffraction (XRD) measurement confirms that all the five Ni−Cu alloys possess the f.c.c. structure. The hydrogen evolution reaction (HER) activity of the prepared Ni−Cu alloy electrodes was studied in 6 M KOH solution by cathodic current-potential curves and electrochemical impedance spectroscopy (EIS) techniques. It was found that the electrocatalytic activity for the HER depended on the composition of Ni−Cu alloys, where Ni−10Cu alloy exhibited considerably higher HER activity than Ni plate and other Ni−Cu alloys, indicative of its chemical composition related intrinsic activity. - Highlights: • Ni−Cu alloys with various Cu contents were prepared by powder metallurgy method. • Ni−Cu alloy exhibits chemical composition related synergistic effect for HER activity. • Ni−10Cu alloy electrode presents a most efficient activity for HER. • Two time constants are observed in Nyquist curve and both of them related to the kinetics of HER.

  2. Metallurgically prepared NiCu alloys as cathode materials for hydrogen evolution reaction

    International Nuclear Information System (INIS)

    Wang, Kunchan; Xia, Ming; Xiao, Tao; Lei, Ting; Yan, Weishan

    2017-01-01

    Ni−Cu bimetallic alloys with Cu content of 5, 10, 20, 30 and 50 wt% are prepared by powder metallurgy method, which consisted of powder mixing, pressing and sintering processes. The X-ray diffraction (XRD) measurement confirms that all the five Ni−Cu alloys possess the f.c.c. structure. The hydrogen evolution reaction (HER) activity of the prepared Ni−Cu alloy electrodes was studied in 6 M KOH solution by cathodic current-potential curves and electrochemical impedance spectroscopy (EIS) techniques. It was found that the electrocatalytic activity for the HER depended on the composition of Ni−Cu alloys, where Ni−10Cu alloy exhibited considerably higher HER activity than Ni plate and other Ni−Cu alloys, indicative of its chemical composition related intrinsic activity. - Highlights: • Ni−Cu alloys with various Cu contents were prepared by powder metallurgy method. • Ni−Cu alloy exhibits chemical composition related synergistic effect for HER activity. • Ni−10Cu alloy electrode presents a most efficient activity for HER. • Two time constants are observed in Nyquist curve and both of them related to the kinetics of HER.

  3. Comparative study on hydrogenation of propanal on Ni(111) and Cu(111) from density functional theory

    Energy Technology Data Exchange (ETDEWEB)

    An, Wei, E-mail: weian@sues.edu.cn; Men, Yong; Wang, Jinguo

    2017-02-01

    Highlights: • Hydrogenation of propanal is kinetically much faster on Ni(111) than Cu(111). • Hydroxyl route is prefered over alkoxy route on Ni(111). • Alkoxy route is prefered over hydroxyl route on Cu(111). • Activation barrier for hydrogenation of carbonyl is lowered by H-tunneling effect. • η{sup 2}(C,O)-adsorption mode is beneficial for hydrogenation/dehydrogenation of aldehyde. - Abstract: Using propanal as a probe molecule, we have comparatively investigated hydrogenation of carbonyl (C=O) in short carbon-chain aldehyde on Ni(111) and Cu(111) by means of periodic density functional theory. Our focus is in particular on the differentiation of reaction route in sequential hydrogenation on Ni(111) and Cu(111) following Langmuir–Hinshelwood mechanism. Strong binding with alkoxy intermediates has great impact on altering reaction pathways on the two surfaces, where hydroxyl route via 1-hydroxyl propyl intermediate is dominant on Ni(111), but alkoxy route via propoxyl intermediate is more likely on Cu(111) due to a higher activiation barrier of initial hydrogenation in hydroxyl route. In comparison, hydrogenation of carbonyl on Ni(111) is kinetically much faster than that on Cu(111) as a result of much lower activation barrier in rate-determining step (i.e., 13.2 vs 26.8 kcal/mol) of most favorable reaction pathways. Furthermore, the discrepancy in calculated and experimental barriers can be well explained by using the concept of H-tunneling effect on bond forming with H atoms during sequential hydrogenation. The different features of electronic structure exhibited by the two metal surfaces provide insight into their catalytic behaviors.

  4. Characteristics of slowly cooled Zr-Al-Cu-Ni bulk samples with different oxygen content

    International Nuclear Information System (INIS)

    Gebert, A.; Eckert, J.; Bauer, H.-D.; Schultz, L.

    1998-01-01

    Bulk samples of the glass-forming Zr 65 Al 7.5 Cu 17.5 Ni 10 and Zr 55 Al 10 Cu 30 Ni 5 alloys with 3 mm diameter were prepared by die casting into a copper mould. The oxygen content of the samples was varied between 0.26 at.% and 0.73 at.% by adjusting the oxygen partial pressure in the argon atmosphere upon casting. Characterization of the microstructure of as-cast samples and of specimens continuously heated to 873 K was carried out by X-ray diffraction (XRD), optical microscopy (OM) and transmission electron microscopy (TEM). Thermal stability was investigated by constant-rate differential scanning calorimetry (DSC). The phase formation and the thermal stability of the slowly cooled zirconium-based bulk samples are essentially influenced by the oxygen content of the material. Furthermore, the sensitivity to oxygen depends on the composition of the alloy. In bulk Zr 65 Al 7.5 Cu 17.5 Ni 10 samples only small oxygen traces induce nucleation and crystal growth during slow cooling whereas Zr 55 Al 10 Cu 30 Ni 5 samples are completely amorphous for all oxygen contents investigated. The processes of the oxygen-induced phase formation are discussed in detail also with respect to the results obtained for the heat treated samples. With increasing oxygen content the thermal stability deteriorates, as it is obvious from a diminution of the supercooled liquid region (ΔT x = T x - T g ) which is mainly due to a reduction of the crystallization temperature T x . Furthermore, the thermal behaviour of Zr 65 Al 7.5 Cu 17.5 Ni 10 and Zr 55 Al 10 Cu 30 Ni 5 reveals significant differences. (orig.)

  5. Band spectrum transformation and temperature dependences of thermoelectric power of Hg1-xRxBa2Ca2Cu3O8+δ system

    Directory of Open Access Journals (Sweden)

    M. Vasyuk

    2011-03-01

    Full Text Available Temperature dependences of thermoelectric power S(T at T>Tc of the Hg-based high temperature superconductors Hg1-xRxBa2Ca2Cu3O8+δ (R=Re, Pb have been analyzed with accounting for strong scattering of charge carriers. Transformation of parameters of a narrow conducting band in the region of the Fermi level was studied. The existence of correlation between the effective bandwidth and the temperature of a superconductive transition Tc is shown.

  6. Magnetization reversal process and nonlinear magneto-impedance in Cu/NiFe and Nb/NiFe composite wires

    Energy Technology Data Exchange (ETDEWEB)

    Antonov, A.S.; Buznikov, N.A. E-mail: n_buznikov@mail.ru; Granovsky, A.B.; Iakubov, I.T.; Prokoshin, A.F.; Rakhmanov, A.L.; Yakunin, A.M

    2002-08-01

    The magnetization reversal of Cu/NiFe and Nb/NiFe composite wires carrying AC current is studied. The frequency spectrum of a voltage induced in a pick-up coil wound around the wire is analyzed. The frequency spectrum is shown to consist of even harmonics within a wide range of AC current amplitudes and longitudinal DC magnetic fields. The strong dependencies of the harmonic amplitudes on the DC field are found. The results obtained may be of importance for the design of weak magnetic field sensors.

  7. Magnetization reversal process and nonlinear magneto-impedance in Cu/NiFe and Nb/NiFe composite wires

    International Nuclear Information System (INIS)

    Antonov, A.S.; Buznikov, N.A.; Granovsky, A.B.; Iakubov, I.T.; Prokoshin, A.F.; Rakhmanov, A.L.; Yakunin, A.M.

    2002-01-01

    The magnetization reversal of Cu/NiFe and Nb/NiFe composite wires carrying AC current is studied. The frequency spectrum of a voltage induced in a pick-up coil wound around the wire is analyzed. The frequency spectrum is shown to consist of even harmonics within a wide range of AC current amplitudes and longitudinal DC magnetic fields. The strong dependencies of the harmonic amplitudes on the DC field are found. The results obtained may be of importance for the design of weak magnetic field sensors

  8. HEAVY METALS (Ni, Cu, Zn AND Cd CONTENT IN SERUM OF RAT FED GREEN MUSSELS

    Directory of Open Access Journals (Sweden)

    Muhammad Yudhistira Azis

    2015-11-01

    Full Text Available Green mussel (Perna viridis can playing role as bio-indicator or biomonitoring agent for heavy-metalcontaminations in the sea. In this research, the concentrations of four elements Ni, Cu, Zn and Cd in P. viridis and in the serum of rat which orally feed by P. viridis were determined by Atomic Absorption Spectrometry (AAS following dry acid digestion. Parameter analysis was evaluated by determining confidence limit for the obtained results. The result showed that there was a sequence of heavy-metal content in green mussels sample and laboratory rats serum, such as Ni < Cd < Cu < Zn. Keywords: heavy metals, green mussels, laboratory rats serum, AAS

  9. Preparation of Copper (Cu)-Nickel (Ni) Alloy Thin Films for Bilayer Graphene Growth

    Science.gov (United States)

    2016-02-01

    of each sample after annealing . Transene brand APS-100 etchant is used to completely wet etch away the unmasked portion of the Cu-Ni alloy, and...morphological changes in the metal surfaces such as roughness, grain size, and crystal orientation due to the effects of annealing temperature, hydrogen...post- annealed at 1000 °C for 30 min, 40% H2, 15 Torr.............5 Fig. 6 AFM imaging of Cu:Ni alloyed films with ratios of a) 6:1 , b) 4:1, and c) 3

  10. Formation and structure of nanocrystalline Al-Mn-Ni-Cu alloys

    International Nuclear Information System (INIS)

    Latuch, J.; Krasnowski, M.; Ciesielska, B.

    2002-01-01

    This paper reports the results of the short investigation on the effect of Cu additions upon the nanocrystallization behaviour of an Al-Mn-Ni alloy. 2 at.% Cu added to the base alloy of Al 85 Mn 10 Ni 5 alloy by substitution for Mn(mischmetal). The control of cooling rate did not cause the formation of nanocrystals of fcc-Al phase. The nanocrystalline structure fcc-Al + amorphous phase in quarternary alloy was obtained by isothermal annealing and continuous heating method, but the last technique is more effective. The volume fraction, lattice parameter, and size of Al-phase were calculated. (author)

  11. X-ray diffraction study of chalcopyrite CuFeS2, pentlandite (Fe,Ni)9S8 and Pyrrhotite Fe1-xS obtained from Cu-Ni orebodies

    International Nuclear Information System (INIS)

    Nkoma, J.S.; Ekosse, G.

    1998-05-01

    The X-ray Diffraction (XRD) technique is applied to study five samples of Cu-Ni orebodies, and it is shown that they contain chalcopyrite CuFeS 2 as the source of Cu, pentlandite (Fe,Ni) 9 S 8 as the source of Ni and pyrrhotite Fe 1-x S as a dominant compound. There are also other less dominant compounds such as bunsenite NiO, chalcocite Cu 2 S, penrosite (Ni, Cu)Se 2 and magnetite Fe 3 O 4 . Using the obtained XRD data, we obtain the lattice parameters for tetragonal chalcopyrite as a=b=5.3069A and c=10.3836A, cubic pentlandite as a=b=c=10.0487A, and hexagonal pyrrhotite as a=b=6.8820A and c=22.8037A. (author)

  12. Selective hydrogenation of furfural to cyclopentanone over Cu-Ni-Al hydrotalcite-based catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Hongyan; Zhou, Minghao; Zeng, Zuo; Xiao, Guomin; Xiao, Rui [Southeast University, Nanjing (China)

    2014-04-15

    A series of Cu-Ni-Al hydrotalcites derived oxides with a (Cu+Ni)/Al mole ratio of 3 with varied Cu/Ni mole ratio (from 0.017 to 0.5, with a Cu ratio of 0.0125 to 0.25) were prepared by co-precipitation method, then applied to the hydrogenation of furfural in aqueous. Their catalytic performance for liquid phase hydrogenation of furfural to prepare cyclopentanone was described in detail, considering reaction temperature, catalyst composition, reaction time and so on. The yield of cyclopentanone was influenced by the mole ratio of Cu-Ni-Al based heterogeneous catalyst and depended on the reaction conditions. The yield of cyclopentanone was up to 95.8% when the reaction was carried out under 413 K with H{sub 2} pressure of 40 bar for 8 h. The catalysts were characterized by X-ray powder diffraction (XRD), scanning electron microscope (SEM) and H{sub 2} temperature-programmed reduction (H{sub 2}-TPR)

  13. Fusion and characterization of an alloy Cu-Zn-Al-Ni of nuclear interest; Fusion y caracterizacion de una aleacion Cu-Zn-Al-Ni de interes nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Santana M, J.S

    2003-07-01

    The present work is the result of the study of a non ferrous quatenary alloy of Cu-Zn-Al-Ni (Foundry 3), it was chosen of a series of alloys to obtain so much information of its microstructural properties like mechanical, evaluating them and comparing them with the previously obtained ternary alloys of Cu-AI-Ni (Foundry 1) and Cu-Zn-AI (Foundry 2) identified as alloys of memory effect and superalloys. These were carried out starting from the foundry of their pure elements of Cu, Zn, Al, Ni. When physically having the ingot of each alloy, different techniques were used for their characterization. The used techniques were through the metallographic analysis, by scanning electron microscopy (SEM), X-ray dispersive energy spectroscopy (EDS), X-ray diffraction (XRD), mechanical essays and Rockwell hardness. The non ferrous quaternary alloy Cu-Zn-AI-Ni by means of the metallographic analysis didn't show significant differences in their three sections (superficial, longitudinal and transverse) since result an homogeneous alloy at the same that the both ternaries. The grain size of the quaternary alloy is the finest while the ternary alloy of Cu-AI-Ni is the one that obtained the biggest grain size. Through MEB together with the analysis by EDS and the mapping of the elements that constitute each alloy, show that the three foundries were alloyed, moreover the presence of aggregates was also observed in the Foundries 2 and 3. These results by means of the analysis of XRD corroborate that these alloys have more of two elements. Relating the microstructural properties with those mechanical show us that as minor was the grain size, better they were his mechanical properties, in this case that of the quaternary alloy. With regard to the test of Rockwell hardness the Foundry 1 were the softest with the temper treatment, while that the Foundries 2 and 3 were the hardest with this same treatment, being still harder the Foundry 2 but with very little difference, for what great

  14. Paduan Ni-Cu-Mn Sebagai Logam Alternatif Kedokteran Gigi: Efek Perendaman dalam Larutan 0,1% Sodium Sulfida

    Directory of Open Access Journals (Sweden)

    Bambang Irawan

    2015-09-01

    Full Text Available In this study, the ternary base alloys of nickel-copper-manganese (Ni-Cu-Mn alloys are prepared and these ternary alloys systems, which were constituted from higher nickel and lower copper contents than copper-base alloy ones, were evaluated by a tarnish test. Tarnish tests conducted in a 0,1% sodium sulphide solution (pH=12 at 37◦C. All test specimens were case into square paddles of 15 mm x 20 mm x 2,5 mm using the lost-wax technique with a phosphate-bonded investment. The surface of the specimens were then prepared with abrasion papers down to a 600 grit finish. Tarnish attack was quantitatively evaluated by Fibre colorimetry. The results of tarnish test showed that ternary nickel-copper-manganese alloys, such as 40Ni-30Cu-30Mn and 50Ni-30Cu-20Mn, have superior tarnishment resistance than other alloys, e.g. 20Ni-40Cu-40Mn, 30Ni-30Cu-40Mn and 30Ni-40Cu-30Mn. It was also found that 40Ni-30Cu-30Mn and 50Ni-30Cu-20Mn alloys have lower values of colour change vector than the other alloys given above.

  15. Crystal field and low energy excitations measured by high resolution RIXS at the L edge of Cu, Ni and Mn

    DEFF Research Database (Denmark)

    Ghiringhelli, G.; Piazzalunga, A.; Wang, X.

    2009-01-01

    of the 3d transition metals with unprecedented energy resolution, of the order of 100 meV for Mn, Ni and Cu. We present here some preliminary spectra on CuO, malachite, NiO, , MnO and . The dd excitations are very well resolved allowing accurate experimental evaluation of 3d state energy splitting. The low...

  16. Study on the characteristics of the impingement erosion-corrosion for Cu-Ni Alloy sprayed coating(I)

    International Nuclear Information System (INIS)

    Lee, Sang Yeol; Lim, Uh Joh; Yun, Byoung Du

    1998-01-01

    Impingement erosion-corrosion test and electrochemical corrosion test in tap water(5000Ω-cm) and seawater(25Ω-cm). Thermal spraying coated Cu-Ni alloy on the carbon steel was carried out. The impingement erosion-corrosion behavior and electrochemical corrosion characteristics of the substrate(SS41) and Cu-Ni thermal spray coating were investigated. The erosion-corrosion control efficiency of Cu-Ni coating to substrate was also estimated quantitatively. Main results obtained are as follows : 1) Under the flow velocity of 13m/s, impingement erosion-corrosion of Cu-Ni coating is under the control of electrochemical corrosion factor rather than that of mechanical erosion. 2) The corrosion potential of Cu-Ni coating becomes more noble than that of substrate, and the current density of Cu-Ni coating under the corrosion potential is drained lowly than that of substrate. 3) The erosion-corrosion control efficiency of Cu-Ni coating to substrate is excellent in the tap water of high specific resistance solution, but it becomes dull in the seawater of low specific resistance. 4) The corrosion control efficiency of Cu-Ni coating to substrate in the seawater appears to be higher than that in the tap water

  17. Crystallization of Pd40CU30Ni10P20 bulk metallic glass with and without pressure

    DEFF Research Database (Denmark)

    Yang, B.; Jiang, Jianzhong; Zhuang, Yanxin

    2007-01-01

    The glass-transition behavior of Pd40Cu30Ni10P20 bulk metallic glass was investigated by differential scanning calorimetry (DSC) and X-ray powder diffraction (XRD). The effect of pressure on the crystallization behavior of Pd40Cu30Ni10P20 bulk glass was studied by in situ high-pressure and high...

  18. The effect of intermetallic compound morphology on Cu diffusion in Sn-Ag and Sn-Pb solder bump on the Ni/Cu Under-bump metallization

    Science.gov (United States)

    Jang, Guh-Yaw; Duh, Jenq-Gong

    2005-01-01

    The eutectic Sn-Ag solder alloy is one of the candidates for the Pb-free solder, and Sn-Pb solder alloys are still widely used in today’s electronic packages. In this tudy, the interfacial reaction in the eutectic Sn-Ag and Sn-Pb solder joints was investigated with an assembly of a solder/Ni/Cu/Ti/Si3N4/Si multilayer structures. In the Sn-3.5Ag solder joints reflowed at 260°C, only the (Ni1-x,Cux)3Sn4 intermetallic compound (IMC) formed at the solder/Ni interface. For the Sn-37Pb solder reflowed at 225°C for one to ten cycles, only the (Ni1-x,Cux)3Sn4 IMC formed between the solder and the Ni/Cu under-bump metallization (UBM). Nevertheless, the (Cu1-y,Niy)6Sn5 IMC was observed in joints reflowed at 245°C after five cycles and at 265°C after three cycles. With the aid of microstructure evolution, quantitative analysis, and elemental distribution between the solder and Ni/Cu UBM, it was revealed that Cu content in the solder near the solder/IMC interface played an important role in the formation of the (Cu1-y,Niy)6Sn5 IMC. In addition, the diffusion behavior of Cu in eutectic Sn-Ag and Sn-Pb solders with the Ni/Cu UBM were probed and discussed. The atomic flux of Cu diffused through Ni was evaluated by detailed quantitative analysis in an electron probe microanalyzer (EPMA). During reflow, the atomic flux of Cu was on the order of 1016-1017 atoms/cm2sec in both the eutectic Sn-Ag and Sn-Pb systems.

  19. Determination of As, Cd, Cu, Hg and Pb in biological samples by modern electrothermal atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Sardans, Jordi; Montes, Fernando; Penuelas, Josep

    2010-01-01

    this technique that reaches figures of merit equivalent to Inductively coupled plasma mass spectrometry (ICP-MS). Herein is presented an overview of recent advances and applications of (ETAAS) for the determination of As, Cd, Cu, Hg and Pb in biological samples drawn from studies over the last decade.

  20. Determination of As, Cd, Cu, Hg and Pb in biological samples by modern electrothermal atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Sardans, Jordi, E-mail: j.sardans@creaf.uab.ca [Ecophysiological and Global Change Unit CSIC-CREAF, Edifici C, Universitat Autonoma de Barcelona, Bellaterra 08193, Barcelona (Spain); Montes, Fernando [Departamento de Ciencias Analiticas, Facultad de Ciencias, Universidad Nacional de Educacion a Distancia (UNED), C/ Senda del Rey 9. 28040 Madrid (Spain); Penuelas, Josep [Ecophysiological and Global Change Unit CSIC-CREAF, Edifici C, Universitat Autonoma de Barcelona, Bellaterra 08193, Barcelona (Spain)

    2010-02-15

    of this technique that reaches figures of merit equivalent to Inductively coupled plasma mass spectrometry (ICP-MS). Herein is presented an overview of recent advances and applications of (ETAAS) for the determination of As, Cd, Cu, Hg and Pb in biological samples drawn from studies over the last decade.

  1. Supercurrents in HgBa{sub 2}CaCu{sub 2}O{sub 6+{delta}} and TlBa{sub 2}CaCu{sub 2}O{sub 7} epitaxial thin films

    Energy Technology Data Exchange (ETDEWEB)

    Gapud, A.A.; Wu, J.Z.; Fang, L.; Yan, S.L.; Xie, Y.Y. [Department of Physics and Astronomy, University of Kansas, Lawrence, Kansas 66045-2151 (United States); Siegal, M.P.; Overmyer, D.L. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)

    1999-06-01

    The availability of high-quality epitaxial thin films of HgBa{sub 2}CaCu{sub 2}O{sub 6+{delta}} (Hg-1212) and TlBa{sub 2}CaCu{sub 2}O{sub 7} (Tl-1212) with high critical current densities (J{sub c}) has made it possible to examine and compare the J{sub c} of these species. Results reveal that the J{sub c} of 1212 species have very similar temperature behavior at low fields, strongly suggesting that the 30 K shift in critical temperature (T{sub c}) induced by the exchange of Hg and Tl in the 1212 structure is due largely to a change in charge carrier density and/or electronic band structure. {copyright} {ital 1999 American Institute of Physics.}

  2. Theoretical study of the magnetic behavior of hexanuclear Cu(II) and Ni(II) polysiloxanolato complexes.

    Science.gov (United States)

    Ruiz, Eliseo; Cano, Joan; Alvarez, Santiago; Caneschi, Andrea; Gatteschi, Dante

    2003-06-04

    A theoretical density functional study of the exchange coupling in hexanuclear polysiloxanolato-bridged complexes of Cu(II) and Ni(II) is presented. By calculating the energies of three different spin configurations, we can obtain estimates of the first-, second-, and third-neighbor exchange coupling constants. The study has been carried out for the complete structures of the Cu pristine cluster and of the chloroenclathrated Ni complex as well as for the hypotethical pristine Ni compound and for magnetically dinuclear analogues M(2)Zn(4) (M = Cu, Ni).

  3. Soft magnetic properties of hybrid ferromagnetic films with CoFe, NiFe, and NiFeCuMo layers

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jong-Gu [Eastern-western Biomedical Engineering, Sangji University, Wonju 220-702 (Korea, Republic of); Hwang, Do-Guwn [Dept. of Oriental Biomedical Engineering, Sangji University, Wonju 220-702 (Korea, Republic of); Rhee, Jang-Roh [Dept. of Physics, Sookmyung Women' s University, Seoul 140-742 (Korea, Republic of); Lee, Sang-Suk, E-mail: sslee@sangji.ac.kr [Dept. of Oriental Biomedical Engineering, Sangji University, Wonju 220-702 (Korea, Republic of)

    2011-09-30

    Two-layered ferromagnetic alloy films (NiFe and CoFe) with intermediate NiFeCuMo soft magnetic layers of different thicknesses were investigated to understand the relationship between coercivity and magnetization process by taking into account the strength of hard-axis saturation field. The thickness dependence of H{sub EC} (easy-axis coercivity), H{sub HS} (hard-axis saturation field), and {chi} (susceptibility) of the NiFeCuMo thin films in glass/Ta(5 nm)/[CoFe or NiFe(5 nm-t/2)]/NiFeCuMo(t = 0, 4, 6, 8, 10 nm)/[CoFe or NiFe(5 nm-t/2)]/Ta(5 nm) films prepared using the ion beam deposition method was determined. The magnetic properties (H{sub EC}, H{sub HS}, and {chi}) of the ferromagnetic CoFe, NiFe three-layers with an intermediate NiFeCuMo super-soft magnetic layer were strongly dependent on the thickness of the NiFeCuMo layer.

  4. Relationship between microstructure, cytotoxicity and corrosion properties of a Cu-Al-Ni shape memory alloy.

    Science.gov (United States)

    Colić, Miodrag; Rudolf, Rebeka; Stamenković, Dragoslav; Anzel, Ivan; Vucević, Dragana; Jenko, Monika; Lazić, Vojkan; Lojen, Gorazd

    2010-01-01

    Cu-Al-Ni shape memory alloys (SMAs) have been investigated as materials for medical devices, but their biomedical application is still limited. The aim of this work was to compare the microstructure, corrosion and cytotoxicity in vitro of a Cu-Al-Ni SMA. Rapidly solidified (RS) thin ribbons, manufactured via melt spinning, were used for the tests. The control alloy was a permanent mould casting of the same composition, but without shape memory effect. The results show that RS ribbons are significantly more resistant to corrosion compared with the control alloy, as judged by the lesser release of Cu and Ni into the conditioning medium. These results correlate with the finding that RS ribbons were not cytotoxic to L929 mouse fibroblasts and rat thymocytes. In addition, the RS ribbon conditioning medium inhibited cellular proliferation and IL-2 production by activated rat splenocytes to a much lesser extent. The inhibitory effects were almost completely abolished by conditioning the RS ribbons in culture medium for 4 weeks. Microstructural analysis showed that RS ribbons are martensitic, with boron particles as a minor phase. In contrast, the control Cu-Al-Ni alloy had a complex multiphase microstructure. Examination of the alloy surfaces after conditioning by energy dispersive X-ray and Auger electron spectroscopy showed the formation of Cu and Al oxide layers and confirmed that the metals in RS ribbons are less susceptible to oxidation and corrosion compared with the control alloy. In conclusion, these results suggest that rapid solidification significantly improves the corrosion stability and biocompatibility in vitro of Cu-Al-Ni SMA ribbons.

  5. 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

  6. Mechanical properties of NiTi and CuNiTi wires used in orthodontic treatment. Part 2: Microscopic surface appraisal and metallurgical characteristics

    Directory of Open Access Journals (Sweden)

    Marco Abdo Gravina

    2014-01-01

    Full Text Available OBJECTIVE: This research aimed at comparing the qualitative chemical compositions and the surface morphology of fracture regions of eight types of Nickel (Ni Titanium (Ti conventional wires, superelastic and heat-activated (GAC, TP, Ormco, Masel, Morelli and Unitek, to the wires with addition of copper (CuNiTi 27oC and 35oC, Ormco after traction test. METHODS: The analyses were performed in a scanning electronic microscope (JEOL, model JSM-5800 LV with EDS system of microanalysis (energy dispersive spectroscopy. RESULTS : The results showed that NiTi wires presented Ni and Ti as the main elements of the alloy with minimum differences in their composition. The CuNiTi wires, however, presented Ni and Ti with a significant percentage of copper (Cu. As for surface morphology, the wires that presented the lowest wire-surface roughness were the superelastic ones by Masel and Morelli, while those that presented the greatest wire-surface roughness were the CuNiTi 27oC and 35oC ones by Ormco, due to presence of microcavity formed as a result of pulling out some particles, possibly of NiTi. 4 The fracture surfaces presented characteristics of ductile fracture, with presence of microcavities. The superelastic wires by GAC and the CuNiTi 27oC and the heat-activated ones by Unitek presented the smallest microcavities and the lowest wire-surface roughness with regard to fracture, while the CuNiTi 35oC wires presented inadequate wire-surface roughness in the fracture region. CONCLUSION: CuNiTi 35oC wires did not present better morphologic characteristics in comparison to the other wires with regard to surfaces and fracture region.

  7. Trace elements (Cu, Zn, and Hg) and δ13C/δ15N in seabird subfossils from three islands of the South China Sea and its implications.

    Science.gov (United States)

    Xu, Liqiang; Liu, Xiaodong; Nie, Yaguang

    2016-05-01

    Seabird subfossils were collected on three islands of the Xisha Archipelago, South China Sea. Via elemental analysis, we identified that bird guano was a significant source for heavy metals Cu, Zn, and Hg. Cu and Zn levels in these guano samples are comparable to their levels in wildbird feces, but guano Hg was lower than previously reported. Trophic positions significantly impacted transfer efficiency of heavy metals by seabirds. Despite of a common source, trace elements, as well as stable isotopes (i.e., guano δ(13)C and collagen δ(15)N), showed island-specific characteristics. Bird subfossils on larger island had relatively greater metal concentrations and revealed higher trophic positions. Partition of element and isotope levels among the islands suggested that transfer efficacy of seabirds on different islands was different, and bird species were probably unevenly distributed among the islets. Island area is possibly a driving factor for distributions of seabird species.

  8. Structure, surface morphology and electrical properties of evaporated Ni thin films: Effect of substrates, thickness and Cu underlayer

    International Nuclear Information System (INIS)

    Hemmous, M.; Layadi, A.; Guittoum, A.; Souami, N.; Mebarki, M.; Menni, N.

    2014-01-01

    Series of Ni thin films have been deposited by thermal evaporation onto glass, Si(111), Cu, mica and Al 2 O 3 substrates with and without a Cu underlayer. The Ni thicknesses, t, are in the 4 to 163 nm range. The Cu underlayer has also been evaporated with a Cu thickness equal to 27, 52 and 90 nm. The effects of substrate, the Ni thickness and the Cu underlayer on the structural and electrical properties of Ni are investigated. Rutherford Backscattering Spectroscopy was used to probe the Ni/Substrate and Ni–Cu underlayer interfaces and to measure both Ni and Cu thicknesses. The texture, the strain and the grain size values were derived from X-ray diffraction experiments. The surface morphology is studied by means of a Scanning Electron Microscope. The electrical resistivity is measured by the four point probe. The Ni films grow with the <111> texture on all substrates. The Ni grain sizes D increase with increasing thickness for the glass, Si and mica substrates and decrease for the Cu one. The strain ε is positive for low thickness, decreases in magnitude and becomes negative as t increases. With the Cu underlayer, the growth mode goes through two phases: first, the stress (grain size) increases (decreases) up to a critical thickness t Cr , then stress is relieved and grain size increases. All these results will be discussed and correlated. - Highlights: • The structural and electrical properties of evaporated Ni thin films are studied. • The effect of thickness, substrates and Cu underlayer is investigated. • Texture, grain size, strain and surface morphology are discussed. • Growth modes are described as a function of Ni thickness

  9. Photoconducting and photocapacitance properties of Al/p-CuNiO{sub 2}-on-p-Si isotype heterojunction photodiode

    Energy Technology Data Exchange (ETDEWEB)

    Elsayed, I.A. [Physics Department, College of Science and Humanitarian Studies, Salman bin Abdulaziz University (Saudi Arabia); Physics Department, Faculty of Science, Damietta University (Egypt); Çavaş, Mehmet [Department of Mechatronics, Faculty of Technology, Firat University, Elazig (Turkey); Gupta, R. [Department of Chemistry, Pittsburg State University, Pittsburg, KS 66762 (United States); Fahmy, T. [Physics Department, College of Science and Humanitarian Studies, Salman bin Abdulaziz University (Saudi Arabia); Polymer Research Group, Physics Department, Faculty of Science, Mansoura University (Egypt); Al-Ghamdi, Ahmed A. [Department of Physics, Faculty of Science, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Yakuphanoglu, F., E-mail: fyhan@hotmail.com [Department of Physics, Faculty of Science, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Physics Department, Faculty of Science, Firat University, Elazig (Turkey)

    2015-07-25

    Highlights: • The CuNiO{sub 2} thin film was prepared by sol gel method. • The diode has a high photosensitivity value of 1.02 × 10{sup 3} under 100 mW/cm{sup 2}. • Al/p-Si/CuNiO{sub 2}/Al can used in optoelectronic device applications. - Abstract: Thin film of CuNiO{sub 2} was prepared by sol gel method to fabricate a photodiode. The surface morphology of the CuNiO{sub 2} thin film was investigated by atomic force microscopy (AFM). AFM results indicated that CuNiO{sub 2} film was formed from the nanoparticles and the average size of the nanoparticles was about 115 nm. The optical band gap of CuNiO{sub 2} film was calculated using optical data and was found to be about 2.4 eV. A photodiode having a structure of Al/p-Si/CuNiO{sub 2}/Al was prepared. The electronic parameters such as ideality factor and barrier height of the diode were determined and were obtained to be 8.23 and 0.82 eV, respectively. The interface states properties of the Al/p-Si/CuNiO{sub 2}/Al diode was performed using capacitance–voltage and conductance–voltage characteristics. The series resistance of the Al/p-Si/CuNiO{sub 2}/Al photo diode was observed to be decreasing with increasing frequency. The diode exhibited a photoconducting behavior with a high photosensitivity value of 1.02 × 10{sup 3} under 100 mW/cm{sup 2}. The obtained results indicate that Al/p-Si/CuNiO{sub 2}/Al can used in optoelectronic device applications.

  10. Atom probe characterization of precipitation in an aged Cu-Ni-P alloy

    International Nuclear Information System (INIS)

    Aruga, Yasuhiro; Saxey, David W.; Marquis, Emmanuelle A.; Cerezo, Alfred; Smith, George D.W.

    2011-01-01

    A temporal evolution of clusters associated with age hardening behavior in a Cu-Ni-P alloy during ageing at 250 o C for up to 100 ks after solution treatment has been carried out. A three-dimensional atom probe (3DAP) analysis has showed that Ni-P clusters are present in the as-quenched condition, and that the cluster density increases as the ageing time increases. The clusters have a wide range of Ni/P ratios when they are relatively small, whereas larger clusters exhibit a narrow distribution of the Ni/P ratio, approaching a ratio of approximately two. These results would indicate that the clusters with various Ni/P ratios form at the early stage of precipitation and the ratio approaches a value identical to that of the equilibrium phase at 250 o C as the clusters enlarge during ageing. -- Research highlights: → We characterize the clustering behavior in a Cu-Ni-P alloy during ageing at 250 o C. → The clusters have a wide range of Ni/P ratios when they are relatively small. → Larger clusters exhibit a narrow distribution of the ratio. → Hardness increases almost linearly with the logarithm of ageing time beyond 100s. → We believe increasing density and size of the clusters leads to the age hardening.

  11. Toxicity assessment and selective leaching characteristics of Cu-Al-Ni shape memory alloys in biomaterials applications.

    Science.gov (United States)

    Chang, Shih-Hang; Chen, Bor-Yann; Lin, Jin-Xiang

    2016-04-06

    Cu-Al-Ni shape memory alloys (SMAs) possess two-way shape memory effects, superelasticity, and damping capacity. Nonetheless, Cu-Al-Ni SMAs remain promising candidates for use in biomedical applications, as they are more economical and machinable than other SMAs. Ensuring the biocompatibility of Cu-Al-Ni SMAs is crucial to their development for biomedical applications. Therefore, this study aimed to assess the toxicity of Cu-Al-Ni SMAs using a Probit dose-response model and augmented simplex design. In this study, the effects of Cu2+, Al3+ and Ni2+ metal ions on bacteria (Escherichia coli DH5α) using Probit dose-response analysis and augmented simplex design to assess the actual toxicity of the Cu-Al-Ni SMAs. Extraction and repetition of Escherichia coli DH5α solutions with high Cu2+ ion concentrations and 30-hour incubation demonstrated that Escherichia coli DH5α was able to alter its growth mechanisms in response to toxins. Metal ions leached from Cu-Al-Ni SMAs appeared in a multitude of compositions with varying degrees of toxicity, and those appearing close to a saddle region identified in the contour plot of the augmented simplex model were identified as candidates for elevated toxicity levels. When the Cu-13.5Al-4Ni SMA plate was immersed in Ringer's solution, the selective leaching rate of Ni2+ ions far exceeded that of Cu2+ and Al3+. The number of Cu2+, Al3+ and Ni2+ ions leached from Cu-Al-Ni SMAs increased with immersion time; however, at higher ratios, toxicity interactions among the metal ions had the effect of gradually reducing overall toxicity levels with regard to Escherichia coli DH5α. The quantities of Cu2+, Al3+ and Ni2+ ions leached from the Cu-13.5Al-4Ni SMA plate increased with immersion time, the toxicity interactions associated with these compositions reduced the actual toxicity to Escherichia coli DH5α.

  12. Determination of heavy metal pollutants such as Hg, Zn, Se, Cd, and Cu in aquatic environment of Thana Creek by radiochemical thermal neutron activation analysis

    International Nuclear Information System (INIS)

    khan, S.Z.; Shah, P.K.; Ramani Rao, V.; Turel, Z.r.; Haldar, B.C.

    1984-01-01

    A rapid method has been developed for the radiochemical separation of Cu, As, Se, Hg, and Zn from thermal neutron irradiated environmental samples. The concentration of the elements in the environmental samples has been ascertained by radiochemical neutron activation analysis. The accuracy, precision and sensitivity of the method has been determined. The results of the analysis indicates the location of maximum pollution of the aquatic environment and the extent of pollution in the 5 locations of Thana Creek. 1 reference, 3 tables

  13. Study of the analytic quality in the determinations of Cr, Fe, Mn, Cu, Zn, Pb and Hg through conventional and nuclear analytical techniques in mosses of the MATV

    International Nuclear Information System (INIS)

    Caballero S, B.

    2013-01-01

    To evaluate the environmental risks of air pollution and to facilitate the decision-making for control, is necessary to have the capacity to generate data with analytical quality. A comparison between nuclear (Neutron activation analysis and total reflection X-ray fluorescence spectrometry) and no nuclear analytical techniques (atomic absorption spectrometry and inductively coupled plasma optical emission spectrometry) for simultaneous determination of metal content (Cr, Cu, Fe, Hg, Mn, Pb and Zn) in mosses from Metropolitan Area of the Toluca Valley (MATV) was performed. Epiphytic mosses (Fabriona ciliaris and Leskea angustata) were sampled in two campaigns, 16 sites (urban, transition and natural) and were prepared for each technique. The biological certified reference materials were used for the quality control and to evaluate accuracy, precision, linearity, detection and quantification limits. Results show that nuclear analytical techniques and no nuclear applied in chemical analysis of Cr, Cu, Fe, Hg, Mn, Pb and Zn in moss from MATV are comparable and therefore all of these can potentially be used for this purpose. However, if its considered both, the performance parameters and economic/operational characteristics is widely recommended inductively coupled plasma optical emission spectrometry, conventional analytical technique, which showed the highest analytical grade quality. Also were observed spatial and temporal variations in the concentrations of Cr, Cu, Fe, Hg, Mn, Pb and Zn in mosses from MATV and was discussed its potential origin. The urban sites had the highest concentration of anthropogenic elements as Cr, Cu, Fe, Hg, Pb and Zn because are strongly impacted by roads with high vehicle traffic. (Author)

  14. The influence of Ni additions on the relative stability of η and η′ Cu6Sn5

    KAUST Repository

    Schwingenschlö gl, Udo; Di Paola, Cono; Gourlay, C. M.; Nogita, K.

    2010-01-01

    We investigate how 5 at. % Ni influences the relative stability of η and η′ Cu6Sn5. Synchrotron x-ray diffraction shows that, while Cu6Sn5 exists as η′ at 25 and 150 °C and transforms to η on heating to 200 °C, Cu5.5Ni0.5Sn5 is best fit to η

  15. Effect of magnetic ion Ni doping for Cu in the CuO{sub 2} plane on electronic structure and superconductivity on Y123 cuprate

    Energy Technology Data Exchange (ETDEWEB)

    Cao Shixun; Li Pinglin; Cao Guixin; Zhang Jincang

    2003-05-15

    The YBa{sub 2}Cu{sub 3-x}Ni{sub x}O{sub 7-{delta}} with x=0-0.4 have been studied using positron annihilation technique. The changes of positron annihilation parameters with the Ni substitution concentration x are given. From the change of electronic density n{sub e} and T{sub c}, it would prove that the localized carriers (electron and hole) in Cu-O chain and CuO{sub 2} planes have enormous influence on superconductivity by affecting charge transfer between the reservoir layer and CuO{sub 2} planes.

  16. Atomic ordering of the fluorine dopant in the $HgBa_{2}CuO_{4+\\delta}high-T_{c}$ superconductor

    CERN Document Server

    Correia, João Guilherme; Araújo, João Pedro; Bordet, P; Haas, Heinz; Le Floc'h, S; Lopes, A M L; Rita, E; Carvalho-Soares, João

    2005-01-01

    Lattice sites and collective ordering of fluorine atoms in oxygen- reduced samples of HgBa/sub 2/CuO/sub 4/ were investigated with the perturbed angular correlation technique by measuring the electric field gradients induced at /sup 199m/Hg nuclei. The experimental data were interpreted with the help of ab initio calculations of charge distributions for different fluorine configurations in Hg/sub m/Ba /sub 2m/Cu/sub m/O/sub 4m/F/sub n/, supercells. Internal parameters were allowed to relax, to cancel residual atomic forces due to the dopant. The experimental results show clearly that fluorine occupies only the center of the mercury mesh. For a fluorine content delta F>~0.35 the best agreement with theoretical data is obtained under the assumption that fluorine shows a tendency toward ordering along interstitial rows parallel to a, b. In conformity with experimental data from diffraction techniques the calculations show elongations of the O(2)-Hg-O(2) dumbbell and barium shifts towards the fluorine atoms as ef...

  17. Highly enhanced photocurrent of novel quantum-dot-co-sensitized PbS-Hg/CdS/Cu:ZnO thin films for photoelectrochemical applications

    International Nuclear Information System (INIS)

    Gohel, Jignasa V.; Jana, A.K.; Singh, Mohit

    2017-01-01

    A novel quantum-dot-co-sensitized PbS-Hg/CdS/Cu:ZnO thin films synthesized by low-cost process. The properties of ZnO are also enhanced by doping and co-doping. It is also compared with quantum-dot co-sensitization. Optical properties, crystal structure, morphology, and photocurrent are characterized by UV-Vis spectroscopy, XRD, SEM, and solar simulator, respectively. The bandgap is interestingly reduced highly to 2.6 eV for Ag co-doped Cu:ZnO. It is unprecedentedly reduced to 2.1 eV and even 1.97 eV for CdS and PbS-Hg QD-sensitized thin films, respectively. An exceptionally enhanced photocurrent of 17.1 mA/cm"2 is achieved with PbS-Hg-co-sensitized CdS-sensitized Cu:ZnO thin film. This is an excellent achievement, which highly supports the potential of low-cost solar conversion. (orig.)

  18. Highly enhanced photocurrent of novel quantum-dot-co-sensitized PbS-Hg/CdS/Cu:ZnO thin films for photoelectrochemical applications

    Energy Technology Data Exchange (ETDEWEB)

    Gohel, Jignasa V.; Jana, A.K.; Singh, Mohit [Sardar Vallabhbhai National Institute of Technology, Chemical Engineering Department, Surat, Gujarat (India)

    2017-08-15

    A novel quantum-dot-co-sensitized PbS-Hg/CdS/Cu:ZnO thin films synthesized by low-cost process. The properties of ZnO are also enhanced by doping and co-doping. It is also compared with quantum-dot co-sensitization. Optical properties, crystal structure, morphology, and photocurrent are characterized by UV-Vis spectroscopy, XRD, SEM, and solar simulator, respectively. The bandgap is interestingly reduced highly to 2.6 eV for Ag co-doped Cu:ZnO. It is unprecedentedly reduced to 2.1 eV and even 1.97 eV for CdS and PbS-Hg QD-sensitized thin films, respectively. An exceptionally enhanced photocurrent of 17.1 mA/cm{sup 2} is achieved with PbS-Hg-co-sensitized CdS-sensitized Cu:ZnO thin film. This is an excellent achievement, which highly supports the potential of low-cost solar conversion. (orig.)

  19. Levels Of Mn, Fe, Ni, Cu, Zn And Cd, In Effluent From A Sewage ...

    African Journals Online (AJOL)

    This study reports the results of preliminary investigation of heavy metal levels-Ni, Cd, Fe, Zn, Cu and Mn; pH; temperature and electrical conductivity in effluents from a sewage treatment oxidation pond and its receiving stream. The heavy metal concentrations were determined with Inductively Coupled Plasma-Mass ...

  20. Austenite-martensite interfaces in strained foils of CuAlNi alloy

    Czech Academy of Sciences Publication Activity Database

    Ostapovets, Andrej; Paidar, Václav; Zárubová, Niva

    2009-01-01

    Roč. 100, č. 3 (2009), 342-344 ISSN 1862-5282 R&D Projects: GA MŠk OC 149; GA AV ČR(CZ) IAA200100627 Institutional research plan: CEZ:AV0Z10100520 Keywords : martensitic transformation * CuAlNi * habit planes Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.862, year: 2009

  1. Multidimensional effects in dissociative chemisorption: H2 on Cu and Ni surfaces

    DEFF Research Database (Denmark)

    Engdahl, C.; Lundqvist, Bengt; Nielsen, U.

    1992-01-01

    It is shown that, in order to describe and understand the trends found experimentally for the variation of the H2 sticking probability with crystal face on Cu and Ni surfaces, the dynamics of all six molecular degrees of freedom must be included. The effective-medium theory is used to estimate...

  2. The response of macrophages to a Cu-Al-Ni shape memory alloy.

    Science.gov (United States)

    Colić, Miodrag; Tomić, Sergej; Rudolf, Rebeka; Anzel, Ivan; Lojen, Gorazd

    2010-09-01

    Cu-Al-Ni shape memory alloys (SMAs) have been investigated as materials for medical devices, but little is known about their biocompatibility. The aim of this work was to study the response of rat peritoneal macrophages (PMØ) to a Cu-Al-Ni SMA in vitro, by measuring the functional activity of mitochondria, necrosis, apoptosis, and production of proinflammatory cytokines. Rapidly solidified (RS) thin ribbons were used for the tests. The control alloy was a permanent mold casting of the same composition, but without the shape memory effect. Our results showed that the control alloy was severely cytotoxic, whereas RS ribbons induced neither necrosis nor apoptosis of PMØ. These findings correlated with the data that RS ribbons are significantly more resistant to corrosion compared to the control alloy, as judged by the lesser release of Cu and Ni in the conditioning medium. However, the ribbons generated intracellular reactive oxygen species and upregulated the production of IL-6 by PMØ. These effects were almost completely abolished by conditioning the RS ribbons for 5 weeks. In conclusion, RS significantly improves the corrosion stability and biocompatibility of Cu-Al-Ni SMA. The biocompatibility of this functional material could be additionally enhanced by conditioning the ribbons in cell culture medium.

  3. Dissociated Structure of Dislocation Loops with Burgers Vector alpha in Electron-Irradiated Cu-Ni

    DEFF Research Database (Denmark)

    Bilde-Sørensen, Jørgen; Leffers, Torben; Barlow, P.

    1977-01-01

    The rectangular dislocation loops with total Burgers vector a100 which are formed in Cu-Ni alloys during 1 MeV electron irradiation at elevated temperatures have been examined by weak-beam electron microscopy. The loop edges were found to take up a Hirth-lock configuration, dissociating into two ...

  4. Thermodynamic studies on the adsorption of Cu2+, Ni2+ and Cd2+ ...

    African Journals Online (AJOL)

    Amine-modified bentonite (TEPA-Bn) has been prepared with tetraethylenepentamine (TEPA) as a modifier. The structure of Ca-based bentonite (Ca-Bn), TEPA-Bn and TEPA-Bn after adsorbing Cu2+,Ni2+,Cd2+ had been characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and ...

  5. Dendritic Ni(Cu)-polypyrrole hybrid films for a pseudo-capacitor.

    Science.gov (United States)

    Choi, Bit Na; Chun, Woo Won; Qian, Aniu; Lee, So Jeong; Chung, Chan-Hwa

    2015-11-28

    Dendritic Ni(Cu)-polypyrrole hybrid films are fabricated for a pseudo-capacitor in a unique morphology using two simple methods: electro-deposition and electrochemical de-alloying. Three-dimensional structures of porous dendrites are prepared by electro-deposition within the hydrogen evolution reaction (HER) at a high cathodic potential; the high-surface-area structure provides sufficient redox reactions between the electrodes and the electrolyte. The dependence of the active-layer thickness on the super-capacitor performance is also investigated, and the 60 μm-thick Ni(Cu)PPy hybrid electrode presents the highest performance of 659.52 F g(-1) at the scan rate of 5 mV s(-1). In the thicker layers, the specific capacitance became smaller due to the diffusion limitation of the ions in an electrolyte. The polypyrrole-hybridization on the porous dendritic Ni(Cu) electrode provides superior specific capacitance and excellent cycling stability due to the improvement in electric conductivity by the addition of conducting polypyrrole in the matrices of the dendritic nano-porous Ni(Cu) layer and the synergistic effect of composite materials.

  6. Magnetic susceptibility, specific heat and magnetic structure of CuNi2(PO4)2

    International Nuclear Information System (INIS)

    Escobal, Jaione; Pizarro, Jose L.; Mesa, Jose L.; Larranaga, Aitor; Fernandez, Jesus Rodriguez; Arriortua, Maria I.; Rojo, Teofilo

    2006-01-01

    The CuNi 2 (PO 4 ) 2 phosphate has been synthesized by the ceramic method at 800 deg. C in air. The crystal structure consists of a three-dimensional skeleton constructed from MO 4 (M II =Cu and Ni) planar squares and M 2 O 8 dimers with square pyramidal geometry, which are interconnected by (PO 4 ) 3- oxoanions with tetrahedral geometry. The magnetic behavior has been studied on powdered sample by using susceptibility, specific heat and neutron diffraction data. The bimetallic copper(II)-nickel(II) orthophosphate exhibits a three-dimensional magnetic ordering at, approximately, 29.8 K. However, its complex crystal structure hampers any parametrization of the J-exchange parameter. The specific heat measurements exhibit a three-dimensional magnetic ordering (λ-type) peak at 29.5 K. The magnetic structure of this phosphate shows ferromagnetic interactions inside the Ni 2 O 8 dimers, whereas the sublattice of Cu(II) ions presents antiferromagnetic couplings along the y-axis. The change of the sign in the magnetic unit-cell, due to the [1/2, 0, 1/2] propagation vector determines a purely antiferromagnetic structure. - Graphical abstract: Magnetic structure of CuNi2(PO4)2

  7. In-situ observation of the energy dependence of defect production in Cu and Ni

    International Nuclear Information System (INIS)

    King, W.E.; Merkel, K.L.; Baily, A.C.; Haga, K.; Meshii, M.

    1983-01-01

    The damage function, the average number of Frenkel pairs created as a function of lattice atom recoil energy, was investigated in Cu and Ni using in-situ electrical-resistivity damage-rate measurements in the high-voltage electron micrscope (HVEM) at T < 10K. Electron and proton irradiations were performed in-situ on the same polycrystalline specimens using the Argonne National Laboratory HVEM-Ion Beam Interface. Both Ni and Cu exhibit a sharp rise in the damage function above the minimum threshold energy (approx. 18 eV for Cu and approx. 20 eV for Ni) as displacements in the low-threshold energy regions of the threshold energy surface become possible. A plateau is observed for both materials (0.54 Frenkel pairs for Cu and 0.46 Frenkel pairs for Ni) indicating that no further directions become productive until much higher recoil energies. These damage functions show strong deviations from simple theoretical models, such as the Modified Kinchin-Pease damage function. The results are discussed in terms of the mechanisms of defect production that govern the single-displacement regime of the damage function and are compared with results from recent molecular-dynamics simulations

  8. Adsorption of Cu 2+ and Ni 2+ ions from their aqueous solutions ...

    African Journals Online (AJOL)

    The adsorption of Cu2+ and Ni2+ions at room temperature (27°C) onto two types of biomass produced from orange mesocarp namely: untreated orange mesocarp (Me) of 250 μm particle size and xanthated orange mesocarp (XMe) produced from Me of 250 μm particle size were studied. The results obtained showed that ...

  9. Synthesis of CuO-NiO core-shell nanoparticles by homogeneous precipitation method

    International Nuclear Information System (INIS)

    Bayal, Nisha; Jeevanandam, P.

    2012-01-01

    Highlights: ► CuO-NiO core-shell nanoparticles have been synthesized using a simple homogeneous precipitation method for the first time. ► Mechanism of the formation of core-shell nanoparticles has been investigated. ► The synthesis route may be extended for the synthesis of other mixed metal oxide core-shell nanoparticles. - Abstract: Core-shell CuO–NiO mixed metal oxide nanoparticles in which CuO is the core and NiO is the shell have been successfully synthesized using homogeneous precipitation method. This is a simple synthetic method which produces first a layered double hydroxide precursor with core-shell morphology which on calcination at 350 °C yields the mixed metal oxide nanoparticles with the retention of core-shell morphology. The CuO–NiO mixed metal oxide precursor and the core-shell nanoparticles were characterized by powder X-ray diffraction, FT-IR spectroscopy, thermal gravimetric analysis, elemental analysis, scanning electron microscopy, transmission electron microscopy, and diffuse reflectance spectroscopy. The chemical reactivity of the core-shell nanoparticles was tested using catalytic reduction of 4-nitrophenol with NaBH 4 . The possible growth mechanism of the particles with core-shell morphology has also been investigated.

  10. Corrosion Inhibition Study of Al-Cu-Ni Alloy in Simulated Sea-Water ...

    African Journals Online (AJOL)

    Akorede

    ABSTRACT: A study on the inhibition of Al-Cu-Ni alloy in simulated ... which the percentage of Copper, and Nickel were kept .... proceed based on equation of reaction in eqn (4). Al .... Sodium-Modified A356.0-Type Al-Si-Mg Alloy in Simulated.

  11. Interfacial reactions in the Sb–Sn/(Cu, Ni) systems: Wetting experiments

    International Nuclear Information System (INIS)

    Novakovic, R.; Lanata, T.; Delsante, S.; Borzone, G.

    2012-01-01

    Interfacial reactions in the Sb–Sn/Cu and Sb–Sn/Ni systems have been investigated by means of wetting experiments. The wetting behaviour of two lead-free alloys, namely, Sb 2.5 Sn 97.5 and Sb 14.5 Sn 85.5 (at.%), in contact with Cu and Ni-substrates has been studied in view of possible applications as high-temperature solders in the electronics industry. The contact angle measurements on Cu and Ni plates were performed by using a sessile drop apparatus. The solder/substrate interface was characterised by the SEM-EDS analyses. -- Highlights: ► Sb–Sn alloys are used as high temperature lead-free solders. ► Sb–Sn alloys have good wetting properties on Cu and Ni substrates. ► Interfacial reactions and products are important for joint properties. ► Interfacial reactions/products data can be used to study the phase diagrams.

  12. Behaviors of heavy metals (Cd, Cu, Ni, Pb and Zn) in soil amended with composts.

    Science.gov (United States)

    Gusiatin, Zygmunt Mariusz; Kulikowska, Dorota

    2016-09-01

    This study investigated how amendment with sewage sludge compost of different maturation times (3, 6, 12 months) affected metal (Cd, Cu, Ni, Pb, Zn) bioavailability, fractionation and redistribution in highly contaminated sandy clay soil. Metal transformations during long-term soil stabilization (35 months) were determined. In the contaminated soil, Cd, Ni and Zn were predominately in the exchangeable and reducible fractions, Pb in the reducible fraction and Cu in the reducible, exchangeable and oxidizable fractions. All composts decreased the bioavailability of Cd, Ni and Zn for up to 24 months, which indicates that cyclic amendment with compost is necessary. The bioavailability of Pb and Cu was not affected by compost amendment. Based on the reduced partition index (IR), metal stability in amended soil after 35 months of stabilization was in the following order: Cu > Ni = Pb > Zn > Cd. All composts were more effective in decreasing Cd, Ni and Zn bioavailability than in redistributing the metals, and increasing Cu redistribution more than that of Pb. Thus, sewage sludge compost of as little as 3 months maturation can be used for cyclic amendment of multi-metal-contaminated soil.

  13. Recovery stress and shape memory stability in Ni-Ti-Cu thin wires at high temperatures

    Czech Academy of Sciences Publication Activity Database

    Molnár, Peter; Van Humbeeck, J.

    2011-01-01

    Roč. 102, č. 11 (2011), s. 1362-1368 ISSN 1862-5282 Institutional research plan: CEZ:AV0Z10100520 Keywords : shape memory alloys * recovery stress * Ni-Ti-Cu * stress relaxation Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.830, year: 2011 http://www.ijmr.de/directlink.asp?MK110596

  14. Discontinuous precipitation and ordering in Ni/sub 2/V-Cu alloys

    Energy Technology Data Exchange (ETDEWEB)

    Sukhanov, V D; Boyarshinova, T S; Shashkov, O D

    1986-12-01

    Ni-V-Cu system alloys were used to investigate the effect of ordering on over-saturated solid solution decomposition. It was discovered that ordering in the process of grain boundary migration (discontinuous disordering), stimulated changing of continuous precipitation mechanism for discontinuous one.

  15. Discontinuous precipitation and ordering in Ni2V-Cu alloys

    International Nuclear Information System (INIS)

    Sukhanov, V.D; Boyarshinova, T.S.; Shashkov, O.D.

    1986-01-01

    Ni-V-Cu system alloys were used to investigate the effect of ordering on over-saturated solid solution decomposition. It was discovered that ordering in the process of grain boundary migration (discontinuous disordering), stimulated changing of continuous precipitation mechanism for discontinuous one

  16. Potential of Azolla filiculoides in the removal of Ni and Cu from ...

    African Journals Online (AJOL)

    ra

    Heavy metals constitute a serious health risk because they accumulate in soils, water and organisms. One of the methods of ... The aim of this study was to verify the ability of A. filiculoides to fix Ni and Cu from polluted waters. The maximum uptake ..... due to the C–O stretching vibration of ketones, aldehydes and lactones or ...

  17. Bioaccessibility of As, Cd, Cu, Ni, Pb, and Sb in toys and low-cost jewelry.

    Science.gov (United States)

    Guney, Mert; Zagury, Gerald J

    2014-01-21

    Children can be exposed to toxic elements in toys and jewelry following ingestion. As, Cd, Cu, Ni, Pb, and Sb bioavailability was assessed (n = 24) via the in vitro gastrointestinal protocol (IVG), the physiologically based extraction test (PBET), and the European Toy Safety Standard protocol (EN 71-3), and health risks were characterized. Cd, Cu, Ni, and Pb were mobilized from 19 metallic toys and jewelry (MJ) and one crayon set. Bioaccessible Cd, Ni, or Pb exceeded EU migratable concentration limits in four to six MJ, depending on the protocol. Using two-phase (gastric + intestinal) IVG or PBET might be preferable over EN 71-3 since they better represent gastrointestinal physiology. Bioaccessible and total metal concentrations were different and not always correlated, indicating that bioaccessibility measurement may provide more accurate risk characterization. More information on impacts of multiple factors affecting metals mobilization from toys and jewelry is needed before recommending specific tests. Hazard index (HI) for Cd, Ni, or Pb were >1 for all six MJ exceeding the EU limits. For infants (6-12 mo old), 10 MJ had HI > 1 for Cd, Cu, Ni, or Pb (up to 75 for Cd and 43 for Pb). Research on prolonged exposure to MJ and comprehensive risk characterization for toys and jewelry exposure is recommended.

  18. Enhanced electrical transport and thermoelectric properties in Ni doped Cu3SbSe4

    Science.gov (United States)

    Kumar, Aparabal; Dhama, P.; Das, Anish; Sarkar, Kalyan Jyoti; Banerji, P.

    2018-05-01

    In this study, we report the enhanced thermoelectric performance of Cu3SbSe4 by Ni doping at Cu site. Cu3-xNixSbSe4 (x = 0, 0.01, 0.03, 0.05) were prepared by melt growth, ball milling followed by spark plasma sintering. Structural characterization, phase analysis and surface morphology were carried out using X-ray diffraction, field emission scanning electron microscopy and energy dispersive X-ray spectroscopy. Electrical and thermal properties of all the samples were investigated in the temperature range 300 - 650 K. Decrease in electrical resistivity with Ni doping due to increase in carrier concentration with enhanced Seebeck coefficient via increase in density of state near the Fermi level gives a remarkably high power factor. At the same time, thermal conductivity was found to decrease due to increased carrier-phonon scattering and acoustic phonon scattering. Consequently, a remarkable enhancement in the thermoelectric figure of merit (ZT˜ 0.65) of Cu3-xNixSbSe4 was achieved for x = 0.01 sample. Thus, Ni doping is an effective approach to improve the efficiency of Cu3SbSe4.

  19. A test of the stability of Cd, Cu, Hg, Pb and Zn profiles over two decades in lake sediments near the Flin Flon Smelter, Manitoba, Canada

    Energy Technology Data Exchange (ETDEWEB)

    Percival, J.B.; Outridge, P.M., E-mail: outridge@nrcan.gc.ca

    2013-06-01

    Lake sediments are valuable archives of atmospheric metal deposition, but the stability of some element profiles may possibly be affected by diagenetic changes over time. In this extensive case study, the stability of sedimentary Cd, Cu, Hg, Pb and Zn profiles was assessed in dated sediment cores that were collected in 2004 from four smelter-affected lakes near Flin Flon, Manitoba, which had previously been cored in 1985. Metal profiles determined in 1985 were in most cases clearly reproduced in the corresponding sediment layers in 2004, although small-scale spatial heterogeneity in metal distribution complicated the temporal comparisons. Pre-smelter (i.e. pre-1930) increases in metal profiles were likely the result of long-range atmospheric metal pollution, coupled with particle mixing at the 1930s sediment surface. However, the close agreement between key inflection points in the metal profiles sampled two decades apart suggests that metals in most of the lakes, and Hg and Zn in the most contaminated lake (Meridian), were stable once the sediments were buried below the surface mixed layer. Cadmium, Cu and Pb profiles in Meridian Lake did not agree as well between studies, showing evidence of upward remobilization over time. Profiles of redox-indicator elements (Fe, Mn, Mo and U) suggested that the rate of Mn oxyhydroxide recycling within sediment was more rapid in Meridian Lake, which may have caused the Cd, Cu and Pb redistribution. - Highlights: • Sedimentary Cd, Cu, Hg, Pb and Zn profiles in four lakes were mostly unchanged over 19 years. • In one lake, Cd, Cu and Pb profiles were offset relative to the originals. • The offset could indicate diagenetic upcore dispersal of these metals.

  20. 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

  1. Anodic dissolution and corrosion of alloy Cu30Ni in chloride solutions

    International Nuclear Information System (INIS)

    Zolotarev, E.I.

    1989-01-01

    The anodic and corrosion behavior of alloy Cu30Ni is studied in a solution of 3 N NaCl + 0.01 N HCl by a radiometric method using gamma isotopes of 58 Co (as a marker for Ni) and 64 Cu in combination with electrochemical measurements. It was established that under stationary conditions there was uniform dissolution of the alloy both during free corrosion and anodic polarization. The authors obtained partial anodic dissolution curves for the components of the alloy. It was shown that the dissolution kinetics differed from the mechanisms controlling dissolution of the corresponding pure metals. During corrosion of the alloy in an oxygen atmosphere a back precipitation of copper on the surface of the alloy was not observed. The characteristics observed in the corrosion-electrochemical behavior of the alloy in concentrated chloride solutions can be explained by the presence of Ni on the surface of the dissolving alloy

  2. CuNi NPs supported on MIL-101 as highly active catalysts for the hydrolysis of ammonia borane

    Science.gov (United States)

    Gao, Doudou; Zhang, Yuhong; Zhou, Liqun; Yang, Kunzhou

    2018-01-01

    The catalysts containing Cu, Ni bi-metallic nanoparticles were successfully synthesized by in-situ reduction of Cu2+ and Ni2+ salts into the highly porous and hydrothermally stable metal-organic framework MIL-101 via a simple liquid impregnation method. When the total amount of loading metal is 3 × 10-4 mol, Cu2Ni1@MIL-101 catalyst shows higher catalytic activity comparing to CuxNiy@MIL-101 with different molar ratio of Cu and Ni (x, y = 0, 0.5, 1.5, 2, 2.5, 3). Cu2Ni1@MIL-101 catalyst has the highest catalytic activity comparing to mono-metallic Cu and Ni counterparts and pure bi-metallic CuNi nanoparticles in hydrolytic dehydrogeneration of ammonia borane (AB) at room temperature. Additionally, in the hydrolysis reaction, the Cu2Ni1@MIL- 101 catalyst possesses excellent catalytic performances, which exhibit highly catalytic activity with turn over frequency (TOF) value of 20.9 mol H2 min-1 Cu mol-1 and a very low activation energy value of 32.2 kJ mol-1. The excellent catalytic activity has been successfully achieved thanks to the strong bi-metallic synergistic effects, uniform distribution of nanoparticles and the bi-functional effects between CuNi nanoparticles and the host of MIL-101. Moreover, the catalyst also displays satisfied durable stability after five cycles for the hydrolytically releasing H2 from AB. The non-noble metal catalysts have broad prospects for commercial applications in the field of hydrogen-stored materials due to the low prices and excellent catalytic activity.

  3. Linear arrangement of nano-scale magnetic particles formed in Cu-Fe-Ni alloys

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Sung, E-mail: k3201s@hotmail.co [Department of Materials Engineering (SEISAN), Yokohama National University, 79-5 Tokiwadai, Hodogayaku, Yokohama, 240-8501 (Japan); Takeda, Mahoto [Department of Materials Engineering (SEISAN), Yokohama National University, 79-5 Tokiwadai, Hodogayaku, Yokohama, 240-8501 (Japan); Takeguchi, Masaki [Advanced Electron Microscopy Group, National Institute for Materials Science (NIMS), Sakura 3-13, Tsukuba, 305-0047 (Japan); Bae, Dong-Sik [School of Nano and Advanced Materials Engineering, Changwon National University, Gyeongnam, 641-773 (Korea, Republic of)

    2010-04-30

    The structural evolution of nano-scale magnetic particles formed in Cu-Fe-Ni alloys on isothermal annealing at 878 K has been investigated by means of transmission electron microscopy (TEM), electron dispersive X-ray spectroscopy (EDS), electron energy-loss spectroscopy (EELS) and field-emission scanning electron microscopy (FE-SEM). Phase decomposition of Cu-Fe-Ni occurred after an as-quenched specimen received a short anneal, and nano-scale magnetic particles were formed randomly in the Cu-rich matrix. A striking feature that two or more nano-scale particles with a cubic shape were aligned linearly along <1,0,0> directions was observed, and the trend was more pronounced at later stages of the precipitation. Large numbers of <1,0,0> linear chains of precipitates extended in three dimensions in late stages of annealing.

  4. Moessbauer and transport studies of amorphous and icosahedral Zr-Ni-Cu-Ag-Al alloys

    International Nuclear Information System (INIS)

    Stadnik, Z.M.; Rapp, O.; Srinivas, V.; Saida, J.; Inoue, A.

    2002-01-01

    The alloy Zr 65 Al 7.5 Ni 10 Cu 7.3 Fe 0.2 Ag 10 in the amorphous and icosahedral states, and the bulk amorphous alloy Zr 65 Al 7.5 Ni 10 Cu 7.5 Ag 10 , have been studied with 57 Fe Moessbauer spectroscopy, electrical resistance and magnetoresistance techniques. The average quadrupole splitting in both alloys decreases with temperature as T 3/2 . The average quadrupole splitting in the icosahedral alloy is the largest ever reported for a metallic system. The lattice vibrations of the Fe atoms in the amorphous and icosahedral alloys are well described by a simple Debye model, with the characteristic Moessbauer temperatures of 379(29) and 439(28) K, respectively. Amorphous alloys Zr 65 Al 7. )5Ni 10 Cu 7.5 Ag 10 and Zr 65 Al 7.5 Ni 10 Cu 7.3 Fe 0.2 Ag 10 have been found to be superconducting with the transition temperature, T c , of about 1.7 K. The magnitude of Tc and the critical field slope at Tc are in agreement with previous work on Zr-based amorphous superconductors, while the low-temperature normal state resistivity is larger than typical results for binary and ternary Zr-based alloys. The resistivity of icosahedral Zr 65 Al 7.5 Ni 10 Cu 7.3 Fe 0.2 Ag 10 is larger than that for the amorphous ribbon of the same composition, as inferred both from direct measurements on the ribbons and from the observed magnetoresistance. However the icosahedral sample is non-superconducting in the measurement range down to 1.5 K. The results for the resistivity and the superconducting T c both suggest a stronger electronic disorder in the icosahedral phase than in the amorphous phase. (author)

  5. Fabrication and characterization of high-quality (Hg,Re)Ba sub 2 CaCu sub 2 O sub y thin films on LSAT substrates

    CERN Document Server

    Ogawa, A; Sugano, T; Adachi, S; Suzuki, K; Nakagaki, N; Enomoto, Y; Tanabe, K

    2002-01-01

    We have succeeded in fabricating high-quality (Hg,Re)Ba sub 2 CaCu sub 2 O sub y ((Hg,Re)-1212) thin films with a thickness of 300 nm on (LaAlO sub 3) sub 0 sub . sub 3 -(SrAl sub 0 sub . sub 5 Ta sub 0 sub . sub 5 O sub 3) sub 0 sub . sub 7 (LSAT) substrates. The films were fabricated by repeating the two-step process, which consists of the preparation of a precursor film and the heat treatment in Hg-vapour atmosphere. For the purpose of improving their crystal quality, the heat treatment in the final process was carried out in a lower Hg-vapour pressure for a longer time. The obtained films had a flat surface and no appreciable outgrowth. The films exhibited a T sub c value of 120 K and a J sub c value of 4.4 x 10 sup 6 A cm sup - sup 2 at 77 K in a self-field, which are substantially higher than those for the films fabricated in higher Hg-vapour atmosphere. Their electrical transport properties in magnetic fields up to 7 T were investigated. Their lower irreversibility fields at 77 K as well as the higher ...

  6. Potentiodynamic polarization studies of bulk amorphous alloy Zr57Cu15.4Ni12.6Al10Nb5 and Zr59Cu20Ni8Al10Ti3 in aqueous HNO3 media

    International Nuclear Information System (INIS)

    Sharma, Poonam; Dhawan, Anil; Jayraj, J.; Kamachi Mudali, U.

    2013-01-01

    The potentiodynamic polarization studies were carried out on Zr based bulk amorphous alloy Zr 57 Cu 15.4 Ni 12.6 Al 10 Nb 5 and Zr 59 Cu 20 Ni 8 Al 10 Ti 3 in solutions of 1 M, 6 M and 11.5 M HNO 3 aqueous media at room temperature. As received specimens of Zr 57 Cu 15.4 Ni 12.6 Al 10 Nb 5 (5 mm diameter rod) and Zr 59 Cu 20 Ni 8 Al 10 Ti 3 (3 mm diameter rod) were polished with SiC paper before testing them for potentiodynamic polarization studies. The amorphous nature of the specimens was checked by X-ray diffraction. The bulk amorphous alloy Zr 59 Cu 20 Ni 8 Al 10 Ti 3 shows the better corrosion resistance than Zr 57 Cu 15.4 Ni 12.6 Al 10 Nb 5 alloy in the aqueous HNO 3 media as the value of the corrosion current density (I corr ) for Zr 57 Cu 15.4 Ni 12.6 Al 10 Nb 5 alloy were found to be more than Zr 59 Cu 20 Ni 8 Al 10 Ti 3 alloy in aqueous HNO 3 media. The improved corrosion resistance of Zr 59 Cu 20 Ni 8 Al 10 Ti 3 alloy is possibly due to the presence of Ti and formation of TiO 2 during anodic oxidation. Both Zr based bulk amorphous alloys shows wider passive range at lower concentration of nitric acid and the passive region gets narrowed down with the increase in concentration. A comparison of data obtained from both the Zr-based bulk amorphous alloys is made and results are discussed in the paper. (author)

  7. Effects of Ni{sub 3}Sn{sub 4} and (Cu,Ni){sub 6}Sn{sub 5} intermetallic layers on cross-interaction between Pd and Ni in solder joints

    Energy Technology Data Exchange (ETDEWEB)

    Baek, Yong-Ho [Department of Materials Science and Engineering, Korea University, Seoul 136-713 (Korea, Republic of); Division of Advanced Circuit Interconnect, Samsung Electro-Mechanics Co., Ltd., Suwon 443-743 (Korea, Republic of); Chung, Bo-Mook [Department of Materials Science and Engineering, Korea University, Seoul 136-713 (Korea, Republic of); Department of Research and Development, KPM TECH, Ansan 425-090 (Korea, Republic of); Choi, Young-Sik [Division of Advanced Circuit Interconnect, Samsung Electro-Mechanics Co., Ltd., Suwon 443-743 (Korea, Republic of); Choi, Jaeho [Department of Advanced Metal and Materials Engineering, Gangneung-Wonju National University, Gangneung 210-702 (Korea, Republic of); Huh, Joo-Youl, E-mail: jyhuh@korea.ac.kr [Department of Materials Science and Engineering, Korea University, Seoul 136-713 (Korea, Republic of)

    2013-12-05

    Highlights: •Ni{sub 3}Sn{sub 4} acts as a source of Ni atoms, leading to a strong cross-interaction with Pd. •(Cu,Ni){sub 6}Sn{sub 5} is an effective Ni diffusion barrier, inhibiting Pd resettlement. •Dissolution kinetics of (Pd,Ni)Sn{sub 4} was interpreted based on the Sn–Ni–Pd isotherm. •Cu addition to solder alleviates the (Pd,Ni)Sn{sub 4}-related risk of reliability deterioration. -- Abstract: We examined the effects of layers of intermetallic compound (IMC) Ni{sub 3}Sn{sub 4} and (Cu,Ni){sub 6}Sn{sub 5} formed at the solder/Ni interface, on the cross-interactions between Pd and Ni during solid-state aging and reflow soldering. Two types of diffusion couples, Pd/Sn/Ni and Pd/Sn–Cu/Ni, were aged at 150 °C to study the solid-state interactions. In contrast to the Pd/Sn/Ni couples in which a Ni{sub 3}Sn{sub 4} layer formed at the Ni interface, the Pd/Sn–Cu/Ni couple where a (Cu,Ni){sub 6}Sn{sub 5} layer formed at the Ni interface exhibited no significant interaction between Pd and Ni. The (Cu,Ni){sub 6}Sn{sub 5} layer acted as an effective barrier against Ni diffusion and thus inhibited the resettlement of (Pd,Ni)Sn{sub 4} onto the Ni interface. For the interaction during reflow, Sn–3.5Ag and Sn–3.0Ag–0.5Cu solder balls were isothermally reflowed on an electroless Ni(P)/electroless Pd/immersion Au (ENEPIG) surface finish at 250 °C, and the dissolution kinetics of the (Pd,Ni)Sn{sub 4} particles converted from the 0.2-μm-thick Pd-finish layer were examined. The spalled (Pd,Ni)Sn{sub 4} particles very quickly dissolved into the molten solder when the IMC layer formed on the Ni substrate was (Cu,Ni){sub 6}Sn{sub 5} rather than Ni{sub 3}Sn{sub 4}. The dependence of the dissolution kinetics of the spalled (Pd,Ni)Sn{sub 4} particles on the IMC layers was rationalized on the basis of a Sn–Ni–Pd isotherm at 250 °C. The present study suggests that the formation of a dense (Cu,Ni){sub 6}Sn{sub 5} layer at the solder/Ni interface can effectively

  8. The evaluation of Young's modulus and residual stress of Cu films by NiFe/Cu bilayer film microbridge tests

    International Nuclear Information System (INIS)

    Zhou Zhimin; Zhou Yong; Cao Ying; Ding Wen; Mao Haiping

    2008-01-01

    This paper proposes a method to estimate the thickness limit for single-layer microbridge tests and also the thickness limit of one film on another film with known thickness for bilayer microbridge tests. To evaluate the mechanical properties of the Cu film, which could not be measured by single-layer microbridge tests, the NiFe single-layer film and NiFe/Cu bilayer film on silicon substrate are fabricated onto the microbridge by the MEMS technique. A load–deflection experiment is conducted upon the ceramic shaft adhered to the microbridge center by means of the XP nanoindenter system. From single-layer microbridge theory, Young's modulus and the residual stress of the NiFe film are deduced to be 192.74 ± 8.10 GPa and 287.75 ± 16.18 MPa, respectively. The data are introduced into bilayer microbridge theory and Young's modulus and the residual stress of the copper film are calculated to be 118.71 ± 6.54 GPa and 41.34 ± 4.42 MPa, respectively. The experimental results correspond well with those of nanoindentation

  9. CuNiO nanoparticles assembled on graphene as an effective platform for enzyme-free glucose sensing

    International Nuclear Information System (INIS)

    Zhang, Xiaohui; Liao, Qingliang; Liu, Shuo; Xu, Wei; Liu, Yichong; Zhang, Yue

    2015-01-01

    Highlights: • Hydrothermal CuNiO nanoparticles assembled on CVD synthesized graphene. • CuNiO–graphene nanocomposite was applied to construct nonenzymatic glucose sensor. • Wide linear range up to 16 mM, good selectivity and stability were achieved. - Abstract: We utilized CuNiO nanoparticles modified graphene sheets (CuNiO–graphene) to the application of enzymeless glucose sensing. The hydrothermal synthesized CuNiO nanoparticles were successfully assembled on graphene sheets. Distinct from general method, the high quality pristine graphene was produced by chemical vapor deposition (CVD) and bubbling transferred on the electrode. Incorporating the excellent electronic transport of graphene and high electrocatalytic activity of CuNiO nanoparticles, the CuNiO–graphene nanocomposite modified electrode possessed strong electrocatalytic ability toward glucose in alkaline media. The proposed nonenzymatic glucose sensor exhibited wide linear range up to 16 mM (two parts, from 0.05 to 6.9 mM and 6.9–16 mM) and high sensitivity (225.75 μA mM −1 cm −2 and 32.44 μA mM −1 cm −2 , respectively). Excellent selectivity and acceptable stability were also achieved. Such an electrode would be attractive to sensor construction for its good properties, simple operation and low expense

  10. Hydrogen storage properties of LaMgNi{sub 3.6}M{sub 0.4} (M = Ni, Co, Mn, Cu, Al) alloys

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Tai [Department of Functional Material Research, Central Iron and Steel Research Institute, Beijing 100081 (China); Key Laboratory of Integrated Exploitation of Baiyun Obo Multi-Metal Resources, Inner Mongolia University of Science and Technology, Baotou 014010 (China); Zhai, Tingting; Yuan, Zeming; Bu, Wengang [Department of Functional Material Research, Central Iron and Steel Research Institute, Beijing 100081 (China); Xu, Sheng [Key Laboratory of Integrated Exploitation of Baiyun Obo Multi-Metal Resources, Inner Mongolia University of Science and Technology, Baotou 014010 (China); Zhang, Yanghuan, E-mail: zhangyh59@sina.com [Department of Functional Material Research, Central Iron and Steel Research Institute, Beijing 100081 (China); Key Laboratory of Integrated Exploitation of Baiyun Obo Multi-Metal Resources, Inner Mongolia University of Science and Technology, Baotou 014010 (China)

    2014-12-25

    Highlights: • La–Mg–Ni system AB{sub 2}-type alloys were prepared by induction melting. • Structures and lattice parameters were analysed by XRD. • Hydrogen absorption/desorption performances were studied. • Mechanisms of hydrogen absorption capacity fading were investigated. - Abstract: LaMgNi{sub 3.6}M{sub 0.4} (M = Ni, Co, Mn, Cu, Al) alloys were prepared through induction melting process. The phase compositions and crystal structures were characterised via X-ray diffraction (XRD). The hydrogen storage properties, including activation performance, hydrogen absorption capacity, cycle stability, alloy particle pulverisation and plateau pressure, were systemically investigated. Results show that Ni, Co, Mn and Cu substitution alloys exhibit multiphase structures comprising the main phase LaMgNi{sub 4} and the secondary phase LaNi{sub 5}. However, the secondary phase of the Al substitution alloy changes into LaAlNi{sub 4}. The lattice parameters and cell volumes of the LaMgNi{sub 4} phase follow the order Ni < Co < Al < Cu < Mn. Activation is simplified through partial substitution of Ni with Al, Cu and Co. The hydrogen absorption capacities of all of the alloys are approximately 1.7 wt.% at the first activation process; however, they rapidly decrease with increasing cycle number. In addition, the stabilities of hydriding and dehydriding cycles decrease in the order Al > Co > Ni > Cu > Mn. Hydriding processes result in numerous cracks and amorphisation of the LaMgNi{sub 4} phase in the alloys. The p–c isotherms were determined by a Sieverts-type apparatus. Two plateaus were observed for the Ni, Co and Al substitution alloys, whereas only one plateau was found for Mn and Cu. This result was caused by the amorphisation of the LaMgNi{sub 4} phase during the hydriding cycles. Reversible absorption and desorption of hydrogen are difficult to achieve. Substitutions of Ni with Co, Mn, Cu and Al significantly influence the reduction of hysteresis between

  11. Interplay between interface structure and magnetism in NiFe/Cu/Ni-based pseudo-spin valves

    Science.gov (United States)

    Loving, Melissa G.; Ambrose, Thomas F.; Ermer, Henry; Miller, Don; Naaman, Ofer

    2018-05-01

    Magnetic pseudo spin valves (PSVs) with superconducting Nb electrodes, have been leading candidates for an energy-efficient memory solution compatible with cryogenic operation of ultra-low power superconducting logic. Integration of these PSV Josephson junctions in a standard multi-layer Nb process requires growing high-quality thin magnetic films on a thick Nb bottom electrode (i.e. ≥1.5kÅ, to achieve bulk superconducting properties). However, as deposited, 1.5kÅ Nb exhibits a rough surface with a characteristic rice grain morphology, which severely degrades the switching properties of subsequently deposited PSVs. Therefore, in order to achieve coherent switching throughout a PSV, the Nb interface must be modified. Here, we demonstrate that the Nb surface morphology and PSV crystallinity can be altered with the incorporation of separate 50Å Cu or 100Å Al/50Å Cu non-magnetic seed layers, and demonstrate their impact on the magnetic switching of a 15Å Ni80Fe20/50Å Cu/20Å Ni PSV, at both room temperature and at 10 K. Most notably, these results show that the incorporation of an Al seed layer leads to an improved face centered cubic templating through the bulk of the PSV, and ultimately to superior magnetic switching.

  12. Cu-Al-Ni Shape Memory Single Crystal Wires with High Transformation Temperature

    Science.gov (United States)

    Hautcoeur, Alain; Fouché, Florian; Sicre, Jacques

    2016-01-01

    CN-250X is a new material with higher performance than Nickel-Titanium Shape Memory Alloy (SMA). For space mechanisms, the main disadvantage of Nickel-Titanium Shape Memory Alloy is the limited transformation temperature. The new CN-250X Nimesis alloy is a Cu-Al-Ni single crystal wire available in large quantity because of a new industrial process. The triggering of actuators made with this Cu-Al-Ni single crystal wire can range from ambient temperature to 200 C in cycling and even to 250 C in one-shot mode. Another advantage of CN-250X is a better shape recovery (8 to 10%) than Ni-Ti (6 to 7%). Nimesis is the first company able to produce this type of material with its new special industrial process. A characterization study is presented in this work, including the two main solicitation modes for this material: tensile and torsion. Different tests measure the shape recovery of Cu-Al-Ni single crystals wires during heating from room temperature to a temperature higher than temperature of end of martensitic transformation.

  13. Glass forming ability: Miedema approach to (Zr, Ti, Hf)-(Cu, Ni) binary and ternary alloys

    Energy Technology Data Exchange (ETDEWEB)

    Basu, Joysurya [Department of Chemical, Materials and Biomolecular Engineering, 191 Auditorium Road, University of Connecticut, Storrs 06269, CT (United States)], E-mail: jbasu@engr.uconn.edu; Murty, B.S. [Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, Chennai 600036 (India); Ranganathan, S. [Department of Materials Engineering, Indian Institute of Science, Bangalore 560012 (India)

    2008-10-06

    Miedema's approach has been useful in determining the glass forming composition range for a particular alloy system. The concept of mixing enthalpy and mismatch entropy can be used in order to quantify Inoue's criteria of bulk metallic glass formation. In the present study, glass forming composition range has been determined for different binary and ternary (Zr, Ti, Hf)-(Cu, Ni) alloys based on the mixing enthalpy and mismatch entropy calculations. Though copper and nickel appear next to each other in the periodic table, the glass forming ability of the copper and nickel bearing alloys is different. Thermodynamic analysis reveals that the glass forming behaviour of Zr and Hf is similar, whereas it is different from that of Ti. The smaller atomic size of Ti and the difference in the heat of mixing of Ti, Zr, Hf with Cu and Ni leads to the observed changes in the glass forming behaviour. Enthalpy contour plots can be used to distinguish the glass forming compositions on the basis of the increasing negative enthalpy of the composition. This method reveals the high glass forming ability of binary Zr-Cu, Hf-Cu, Hf-Ni systems over a narrow composition range.

  14. Effects of Cu intercalation on the graphene/Ni(111) surface: density-functional calculations

    International Nuclear Information System (INIS)

    Kwon, Se Gab; Kang, Myung Ho

    2012-01-01

    The Cu-intercalated graphene/Ni(111) surface has been studied by using density-functional theory calculations. We find that (1) the intercalation-induced decoupling between graphene and the Ni(111) substrate begins sharply at a Cu coverage of about 0.75 ML, (2) at the optimal Cu coverage of 1 ML, graphene recovers an almost ideal Dirac-cone band structure with no band gap, and (3) the Dirac point is located at 0.17 eV below the Fermi level, indicating a small charge transfer from the substrate. Cu thus plays essentially the same role as Au in realizing quasi-free-standing graphene by intercalation. Our charge character analysis shows that the Dirac-cone bands near the Fermi level reveal a weakening of their π character when crossing the Ni d bands, suggesting that the resulting low Dirac-cone intensity could possibly be the origin of the recent photoemission report of a relatively large band gap of 0.18 eV.

  15. Temperature-dependent stability of stacking faults in Al, Cu and Ni: first-principles analysis.

    Science.gov (United States)

    Bhogra, Meha; Ramamurty, U; Waghmare, Umesh V

    2014-09-24

    We present comparative analysis of microscopic mechanisms relevant to plastic deformation of the face-centered cubic (FCC) metals Al, Cu, and Ni, through determination of the temperature-dependent free energies of intrinsic and unstable stacking faults along [1 1̄ 0] and [1 2̄ 1] on the (1 1 1) plane using first-principles density-functional-theory-based calculations. We show that vibrational contribution results in significant decrease in the free energy of barriers and intrinsic stacking faults (ISFs) of Al, Cu, and Ni with temperature, confirming an important role of thermal fluctuations in the stability of stacking faults (SFs) and deformation at elevated temperatures. In contrast to Al and Ni, the vibrational spectrum of the unstable stacking fault (USF[1 2̄ 1]) in Cu reveals structural instabilities, indicating that the energy barrier (γusf) along the (1 1 1)[1 2̄ 1] slip system in Cu, determined by typical first-principles calculations, is an overestimate, and its commonly used interpretation as the energy release rate needed for dislocation nucleation, as proposed by Rice (1992 J. Mech. Phys. Solids 40 239), should be taken with caution.

  16. Preparation and characterization of monel (70% Ni-30% Cu) metallic filters; Preparacao e caracterizacao de filtro metalico monel (70% Ni-30% Cu)

    Energy Technology Data Exchange (ETDEWEB)

    Camargo Lavos, I de

    1994-12-31

    This work investigates a process for the fabrication and characterization of monel (Ni-Cu) filters. The powder consolidation was made by vibration or by pressing at various pressures (200, 300 e 400 MPa). The sintering was carried out at 1100{sup 0} C during 1 hour under H{sub 2} atmosphere. The filter characterization was performed by measuring its density, porosity, filtering capacity and permeability. It was obtained a correlation between the processing variables (consolidation and sintering), including powder properties, and the filters characteristics. (author). 59 refs, 41 figs, 7 tabs.

  17. The Janus effect on superhydrophilic Cu mesh decorated with Ni-NiO/Ni(OH)2 core-shell nanoparticles for oil/water separation

    Science.gov (United States)

    Luo, Zhi-Yong; Lyu, Shu-Shen; Fu, Yuan-Xiang; Heng, Yi; Mo, Dong-Chuan

    2017-07-01

    Janus effect has been studied for emerging materials like Janus membranes, Janus nanoparticles, etc., and the applications including fog collection, oil/water separation, CO2 removal and stabilization of multiphasic mixtures. However, the Janus effect on oil/water separation is still unclear. Herein, Janus Cu mesh decorated with Ni-NiO/Ni(OH)2 core-shell nanoparticles is synthesized via selective electrodeposition, in which we keep one side of Cu mesh (Janus A) to be superhydrophilic, while manipulate the wettability of another side (Janus B) from hydrophobic to superhydrophilic. Experimental results indicate that Cu mesh with both-side superhydrophilic shows the superior oil/water separation performance (separation efficiency >99.5%), which is mainly due to its higher water capture percentage as well as larger oil intrusion pressure. Further, we demonstrate the orientation of Janus membranes for oil/water separation, and summarize that the wettability of the upper surface plays a more important role than the lower surface to achieve remarkable performance. Our work provides a clear insight of Janus effect on oil/water separation, it is significative to design high-performance membranes for oil/water separation and many other applications.

  18. Optimization of simultaneous electrochemical determination of Cd(II), Pb(II), Cu(II) and Hg(II) at carbon nanotube-modified graphite electrodes.

    Science.gov (United States)

    Pikna, L'ubomír; Heželová, Mária; Kováčová, Zuzana

    2015-01-01

    The health of the environment is worsening every day. Monitoring of potentially toxic elements and remediation of environmental pollution are necessary. Therefore, the research and development of simple, inexpensive, portable and effective sensors is important. Electrochemistry is a useful component of the field of environment monitoring. The present study focuses on evaluating and comparing three types of electrodes (PIGE, PIGE/MWCNT/HNO3 and PIGE/MWCNT/EDTA/HNO3) employed for the simultaneous electrochemical determination of four potentially toxic elements: Cd(II), Pb(II), Cu(II) and Hg(II). Cyclic voltammograms were measured in an acetate buffer. The LOD, LOQ, the standard and relative precisions of the method and a prediction intervals were calculated (according to the technical procedure DIN 32 645) for the three electrodes and for each measured element. The LOD for PIGE/CNT/HNO3 (the electrode with narrowest calculated prediction intervals) was 2.98 × 10(-7) mol L(-1) for Cd(II), 4.83 × 10(-7) mol L(-1) for Pb(II), 3.81 × 10(-7) mol L(-1) for Cu(II), 6.79 × 10(-7) mol L(-1) for Hg(II). One of the benefits of this study was the determination of the amount of Hg(II) in the mixture of other elements.

  19. Evolution of rapidly solidified NiAlCu(B) alloy microstructure.

    Science.gov (United States)

    Czeppe, Tomasz; Ochin, Patrick

    2006-10-01

    This study concerned phase transformations observed after rapid solidification and annealing at 500, 700 and 800 degrees C in 56.3 Ni-39.9 Al-3.8 Cu-0.06 B (E1) and 59.8 Ni-36.0 Al-4.3 Cu-0.06 B (E2) alloys (composition in at.%). Injection casting led to a homogeneous structure of very small, one-phase grains (2-4 microm in size). In both alloys, the phase observed at room temperature was martensite of L1(0) structure. The process of the formation of the Ni(5)Al(3) phase by atomic reordering proceeded at 285-394 degrees C in the case of E1 alloy and 450-550 degrees C in the case of E2 alloy. Further decomposition into NiAl (beta) and Ni(3)Al (gamma') phases, the microstructure and crystallography of the phases depended on the path of transformations, proceeding in the investigated case through the transformation of martensite crystallographic variants. This preserved precise crystallographic orientation between the subsequent phases, very stable plate-like morphology and very small beta + gamma' grains after annealing at 800 degrees C.

  20. Minor-alloyed Cu-Ni-Si alloys with high hardness and electric conductivity designed by a cluster formula approach

    Directory of Open Access Journals (Sweden)

    Dongmei Li

    2017-08-01

    Full Text Available Cu-Ni-Si alloys are widely used due to their good electrical conductivities in combination with high strength and hardness. In the present work, minor-alloying with M = (Cr, Fe, Mo, Zr was conducted for the objective of further improving their hardness while maintaining their conductivity level. A cluster-plus-glue-atom model was introduced to design the compositions of M-alloyed Cu-Ni-Si alloys, in which an ideal composition formula [(Ni,Si,M-Cu12]Cu3 (molar proportion was proposed. To guarantee the complete precipitation of solute elements in fine δ-Ni2Si precipitates, the atomic ratio of (Ni,M/Si was set as 2/1. Thus the designed alloy series of Cu93.75(Ni/Zr3.75Si2.08(Cr/Fe/Mo0.42 (at% were arc-melted into ingots under argon atmosphere, and solid-solutioned at 950 °C for 1 h plus water quenching and then aged at 450 °C for different hours. The experimental results showed that these designed alloys exhibit high hardness (HV > 1.7 GPa and good electrical conductivities (≥ 35% IACS. Specifically, the quinary Cu93.75Ni3.54Si2.08(Cr/Fe0.42Zr0.21 alloys (Cu-3.32Ni-0.93Si-0.37(Cr/Fe−0.30Zr wt% possess both a high hardness with HV = 2.5–2.7 GPa, comparable to the high-strength KLFA85 alloy (Cu-3.2Ni-0.7Si-1.1Zn wt%, HV = 2.548 GPa, and a good electrical conductivity (35–36% IACS.

  1. Thermal dependence of coercivity in granular CoNiCu glass coated microwires

    International Nuclear Information System (INIS)

    Zhukova, V.; Zhukov, A.; Palomares, F.J.; Pigazo, F.; Cebollada, F.; Del Val, J.J.; Garcia, C.; Gonzalez, J.M.; Gonzalez, J.

    2007-01-01

    Cu 80 Co 19 Ni 1 glass covered microwire samples with different geometric ratio, 0.13≤ρ≤0.5, has been investigated by using X-ray diffraction (XRD) and VSM technique. Our results show (i) the presence of FCC Co crystallites dispersed on the Cu matrix, (ii) the observation in all the samples of the coercivity, at room temperature, of the order of kA, exhibiting a maximum and decreased down to a value of the order of the room temperature one at 25 K. These results are discussed in terms of a distribution of superparamagnetic Co nanoparticles

  2. 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)

  3. Temperature effects on the generalized planar fault energies and twinnabilities of Al, Ni and Cu: First principles calculations

    KAUST Repository

    Liu, Lili

    2014-06-01

    Based on the quasiharmonic approach from first-principles phonon calculations, the volume versus temperature relations for Al, Ni and Cu are obtained. Using the equilibrium volumes at temperature T, the temperature dependences of generalized planar fault energies have also been calculated by first-principles calculations. It is found that the generalized planar fault energies reduce slightly with increasing temperature. Based on the calculated generalized planar fault energies, the twinnabilities of Al, Ni and Cu are discussed with the three typical criteria for crack tip twinning, grain boundary twinning and inherent twinning at different temperatures. The twinnabilities of Al, Ni and Cu also decrease slightly with increasing temperature. Ni and Cu have the inherent twinnabilities. But, Al does not exhibit inherent twinnability. These results are in agreement with the previous theoretical studies at 0 K and experimental observations at ambient temperature. © 2014 Elsevier B.V. All rights reserved.

  4. Temperature effects on the generalized planar fault energies and twinnabilities of Al, Ni and Cu: First principles calculations

    KAUST Repository

    Liu, Lili; Wang, Rui; Wu, Xiaozhi; Gan, Liyong; Wei, Qunyi

    2014-01-01

    Based on the quasiharmonic approach from first-principles phonon calculations, the volume versus temperature relations for Al, Ni and Cu are obtained. Using the equilibrium volumes at temperature T, the temperature dependences of generalized planar fault energies have also been calculated by first-principles calculations. It is found that the generalized planar fault energies reduce slightly with increasing temperature. Based on the calculated generalized planar fault energies, the twinnabilities of Al, Ni and Cu are discussed with the three typical criteria for crack tip twinning, grain boundary twinning and inherent twinning at different temperatures. The twinnabilities of Al, Ni and Cu also decrease slightly with increasing temperature. Ni and Cu have the inherent twinnabilities. But, Al does not exhibit inherent twinnability. These results are in agreement with the previous theoretical studies at 0 K and experimental observations at ambient temperature. © 2014 Elsevier B.V. All rights reserved.

  5. Cofiring behavior and interfacial structure of NiCuZn ferrite/PMN ferroelectrics composites for multilayer LC filters

    International Nuclear Information System (INIS)

    Miao Chunlin; Zhou Ji; Cui Xuemin; Wang Xiaohui; Yue Zhenxing; Li Longtu

    2006-01-01

    The cofiring behavior, interfacial structure and cofiring migration between NiCuZn ferrite and lead magnesium niobate (PMN)-based relaxor ferroelectric materials were investigated via thermomechanical analyzer (TMA), X-ray diffractometer (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). Mismatched sintering shrinkage between NiCuZn ferrite and PMN was modified by adding an appropriate amount of sintering aids, Bi 2 O 3 , into NiCuZn ferrite. Pyrochlore phase appeared in the mixture of NiCuZn ferrite and PMN, which is detrimental to the final electric properties of LC filters. EDS results indicated that the interdiffusion at the heterogeneous interfaces in the composites, such as Fe, Pb, Zn, existed which can strengthen combinations between ferrite layers and ferroelectrics layers

  6. Inelastic contribution to the radiation damage of Cu and Ni exposed to charged particles

    International Nuclear Information System (INIS)

    Ibragimov, Sh.Sh.; Ibragimov, R.M.; Kirsanov, V.V.; Reutov, V.F.

    1975-01-01

    The formation of radiation damage through primary knock-on atoms (PKA) in elastic interactions, and heavy nuclear reaction products in irradiation of Cu by 30 MeV protons and of Ni by 50 MeV α-particles is studied. Distributions of the mean free path of bombarding particles, of concentration and average energy of PKA and recoil nuclei are obtained. The characteristic feature of these distributions is a substantial superiority of the PKA concentration while thier average energy is much less than that of recoil nuclei. A comparison of numbers of atoms displaced by elastic and inelastic interactions is made. The contribution of inelastic processes to the total number of displacements per target atom is shown to be small for the (α, Ni) system and notable for the (p, Cu) system within the range of the mean free path where the proton energy is mainly going into ionization

  7. Fracture behaviour of Cu-Al-Ni shape memory alloys obtained by powder metallurgy

    International Nuclear Information System (INIS)

    Rodriguez, P. P.; Perez-Saez, R. B.; Recarte, V.; San Juan, J.M.; Ruano, O. A.; No, M. L.

    2001-01-01

    Polycrystalline Cu-Al-Ni shape memory alloys have been scarcely employed for technological applications due to their high brittleness. The development of a new elaboration technique based on powder metallurgy has recently overcome this problem, through the improvement of the ductility of the produced alloys without affecting its shape memory properties. The fracture behaviour of an alloy obtained using the elaboration technique has been studied by means of Scanning Electron Microscopy and mechanical testing. The results show a ductile fracture with a maximum strain close to 13%, which is the best fracture behaviour obtained for Cu-Al-Ni polycrystals. The microstructure of such alloys ha been studied by means of Transmission Electron Microscopy, showing a poligonyzed structure in which martensite plated passing through the subboundaries easily. (Author) 19 refs

  8. A study of the annealing and mechanical behaviour of electrodeposited Cu-Ni multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Pickup, C.J.

    1997-08-01

    The mechanical strength of electrodeposited Cu-Ni multilayers is known to vary with deposition wavelength. Since layered coatings are harder and more resistant to wear and abrasion than non-layered coatings, this technique is of industrial interest. Optimisation of the process requires a better understanding of the strengthening mechanisms and the microstructural changes which affect such mechanisms. The work presented in this thesis presents the characterisation a series of Cu-Ni multilayers, covering a wide range of thicknesses of the individual layers in the multilayer, using X-ray diffraction, cross-section TEM, hardness testing and tensile testing. Further, the effects of high temperature annealing on interdiffusion and on changes in internal stresses are documented. (au). 176 refs.

  9. Superconductivity and spin fluctuations in M-Zr metallic glasses (M = Cu, Ni, Co, and Fe)

    International Nuclear Information System (INIS)

    Altounian, Z.; Strom-Olsen, J.O.

    1983-01-01

    The superconducting transition temperature, upper critical field, and magnetic susceptibility have been measured in four binary metallic glass systems: Cu-Zr, Ni-Zr, Co-Zr, and Fe-Zr. For each alloy system, a full and continuous range of Zr-rich compositions accessible by melt spinning has been examined. For Cu-Zr, the range is 0.75>x>0.30; for Ni-Zr, 0.80>x>0.30; for Co-Zr, 0.80>x>0.48, and for Fe-Zr, 0.80>x>0.55 (x being the concentration of Zr in at. %). The results show clearly the influence of spin fluctuations in reducing the superconducting transition temperature. The data have been successfully analyzed using a modified form of the McMillan equation together with expressions for the Stoner enhanced magnetic susceptibility and the Ginsburg-Landau-Abrikosov-Gor'kov expression for the upper critical field

  10. Effect of Nickel Equivalent on Austenite Transition Ratio in Ni-Mn-Cu Cast Iron

    Directory of Open Access Journals (Sweden)

    Janus A.

    2013-06-01

    Full Text Available Determined was quantitative effect of nickel equivalent value on austenite decomposition degree during cooling-down castings of Ni-Mn- Cu cast iron. Chemical composition of the alloy was 1.8 to 5.0 % C, 1.3 to 3.0 % Si, 3.1 to 7.7 % Ni, 0.4 to 6.3 % Mn, 0.1 to 4.9 % Cu, 0.14 to 0.16 % P and 0.03 to 0.04 % S. Analysed were castings with representative wall thickness 10, 15 and 20 mm. Scope of the examination comprised chemical analysis (including WDS, microscopic observations (optical and scanning microscopy, image analyser, as well as Brinell hardness and HV microhardness measurements of structural components.

  11. Foam separation of Cu (II) and Ni(II) from aqueous solutions and simulated wastewaters

    International Nuclear Information System (INIS)

    Shakir, K.; Beheir, Sh.G.; Aziz, M.

    2003-01-01

    Batch experiments on the removal of Cu(II) and Ni(II) from aqueous solutions were performed through two foam separation techniques: precipitate flotation (PTF) an adsorbing colloid flotation (ACF). In ACF, Fe(III), oxyhydroxide was used as co precipitant and/or adsorbing colloid and sodium lauryl sulfate was used as a collector. ACF required a lower collector concentration than PTF. foreign ions were found to decrease the percent removal, the extent of decrease being higher by divalent ions than that by monovalent ones. However, the percent removal could be improved, even in presence of foreign ions, by addition of Al(II) as an activator. High removals could be attained for Cu(II) and Ni(II) from simulated wastewaters containing different concentrations of both metal ions. The addition of concentrations below the limits recommended by the egyptian regulations for environmental discharge

  12. Enhancement of Cu, Ni and Mo recoveries in the bulk concentrate of Jaduguda uranium bearing ore

    International Nuclear Information System (INIS)

    Rao, G.V.; Besra, L.D.

    1998-01-01

    The uranium ore treatment plant at Jaduguda, India, recovers copper, nickel and molybdenum as byproducts before the bulk flotation tailings are subjected to leaching to recover uranium values. The recoveries of these sulfide metals in this 900 TPD plant are reported to be around 60 % Cu, 25% Ni and 55% Mo in the bulk concentrate. In this article, flotation studies carried out, at the instance of M/S UCIL, with various reagents and their combination to improve the over all recoveries are presented. It was observed that material coarser than 100 microns, from the flotation feed, could not be floated even in presence of excessive reagent unless it is ground further. It was established that around 95% Cu, 75% Ni and 74% Mo values could be recovered by using either amyl xanthate or mixture of amyl xanthate and Aero Promoter 194 in place of cresylic acid that is being currently used as collector in the plant. (author)

  13. A study of the annealing and mechanical behaviour of electrodeposited Cu-Ni multilayers

    International Nuclear Information System (INIS)

    Pickup, C.J.

    1997-08-01

    The mechanical strength of electrodeposited Cu-Ni multilayers is known to vary with deposition wavelength. Since layered coatings are harder and more resistant to wear and abrasion than non-layered coatings, this technique is of industrial interest. Optimisation of the process requires a better understanding of the strengthening mechanisms and the microstructural changes which affect such mechanisms. The work presented in this thesis presents the characterisation a series of Cu-Ni multilayers, covering a wide range of thicknesses of the individual layers in the multilayer, using X-ray diffraction, cross-section TEM, hardness testing and tensile testing. Further, the effects of high temperature annealing on interdiffusion and on changes in internal stresses are documented. (au)

  14. Fusion and characterization of an alloy Cu-Zn-Al-Ni of nuclear interest

    International Nuclear Information System (INIS)

    Santana M, J.S.

    2003-01-01

    The present work is the result of the study of a non ferrous quatenary alloy of Cu-Zn-Al-Ni (Foundry 3), it was chosen of a series of alloys to obtain so much information of its microstructural properties like mechanical, evaluating them and comparing them with the previously obtained ternary alloys of Cu-AI-Ni (Foundry 1) and Cu-Zn-AI (Foundry 2) identified as alloys of memory effect and superalloys. These were carried out starting from the foundry of their pure elements of Cu, Zn, Al, Ni. When physically having the ingot of each alloy, different techniques were used for their characterization. The used techniques were through the metallographic analysis, by scanning electron microscopy (SEM), X-ray dispersive energy spectroscopy (EDS), X-ray diffraction (XRD), mechanical essays and Rockwell hardness. The non ferrous quaternary alloy Cu-Zn-AI-Ni by means of the metallographic analysis didn't show significant differences in their three sections (superficial, longitudinal and transverse) since result an homogeneous alloy at the same that the both ternaries. The grain size of the quaternary alloy is the finest while the ternary alloy of Cu-AI-Ni is the one that obtained the biggest grain size. Through MEB together with the analysis by EDS and the mapping of the elements that constitute each alloy, show that the three foundries were alloyed, moreover the presence of aggregates was also observed in the Foundries 2 and 3. These results by means of the analysis of XRD corroborate that these alloys have more of two elements. Relating the microstructural properties with those mechanical show us that as minor was the grain size, better they were his mechanical properties, in this case that of the quaternary alloy. With regard to the test of Rockwell hardness the Foundry 1 were the softest with the temper treatment, while that the Foundries 2 and 3 were the hardest with this same treatment, being still harder the Foundry 2 but with very little difference, for what great

  15. Structural stability of Pd40Cu30Ni10P20 metallic glass in supercooled liquid region

    International Nuclear Information System (INIS)

    Jiang, J.Z.; Saksl, K.

    2004-01-01

    Phase separation of bulk and ribbon Pd 40 Cu 30 Ni 10 P 20 glasses, annealed in the supercooled liquid region at ambient pressure and high pressures, has been studied by means of differential scanning calorimetry (DSC) and X-ray diffraction techniques. DSC measurements show only one glass transition event in all annealed samples, indicating that no phase separation occurs in the alloy annealed in the supercooled liquid region. Phase analyses reveal at least six crystalline phases in the crystallized sample: monoclinic, tetragonal Cu 3 Pd-like, rhombohedral, fcc-Ni 2 Pd 2 P, fcc-(Ni, Pd) solid solution, and body-centered tetragonal (bct) Ni 3 P-like phases. Annealing treatments under external pressures in the vicinity of the glass transition temperature neither induce phase separation nor alter the glass transition temperature of the Pd 40 Cu 30 Ni 10 P 20 bulk glass

  16. Ordered Phases in Cu2NiZn: A First-Principles Monte Carlo Study

    DEFF Research Database (Denmark)

    Simak, S.I.; Ruban, Andrei; Abrikosov, I.A.

    1998-01-01

    Monte Carlo simulations based on effective interactions obtained from first-principles calculations reveal the existence of three ordered phases in ternary Cu2NiZn: (i) "modified"-L1(0) (0-600 K), (ii) L1(2) (600-850 K), and (iii) L1(0) (850-1200 K). This is in contrast to the generally accepted...

  17. Designing multifunctional chemical sensors using Ni and Cu doped carbon nanotubes

    DEFF Research Database (Denmark)

    Mowbray, Duncan; García Lastra, Juan Maria; Thygesen, Kristian Sommer

    2010-01-01

    We demonstrate a “bottom up” approach to the computational design of a multifunctional chemical sensor. General techniques are employed for describing the adsorption coverage and resistance properties of the sensor based on density functional theory and non-equilibrium Green's function...... methodologies, respectively. Specifically, we show how Ni and Cu doped metallic (6,6) single-walled carbon nanotubes may work as effective multifunctional sensors for both CO and NH3....

  18. Autoradiographical Detection of Tritium in Cu-Ni Alloy by Scanning Electron Microscopy

    OpenAIRE

    高安, 紀; 中野, 美樹; 竹内, 豊三郎

    1981-01-01

    The autoradiograph of tritium dispersed in Cu-Ni alloy sheet by 6Li(n,α)3H reaction was obtained by a scanning electron microscope. Prior to the irradiation of neutrons 6Li was deposited on the sheet by evaporation. The liquid emulsion, Fuji-ER, was used in this study. The distribution of tritium was detected by the dispersion of silver grains remaining in the emulsion after the development was carried out.

  19. Complexation of Cu2+, Ni2+ and UO22+ by radiolytic degradation products of bitumen

    International Nuclear Information System (INIS)

    Loon, L.R. Van; Kopajtic, Z.

    1990-05-01

    The radiolytic degradation of bitumen was studied under conditions which reflect those which will exist in the near field of a cementitious radioactive waste repository. The potential complexation capacity of the degradation products was studied and complexation experiments with Cu 2+ , Ni 2+ and UO 2 2+ were performed. In general 1:1 complexes with Cu 2+ , Ni 2+ and UO 2 2+ , with log K values of between 5.7 and 6.0 for Cu 2+ , 4.2 for Ni 2+ and 6.1 for UO 2 2+ , were produced at an ionic strength of 0.1 M. The composition of the bitumen water was analysed by GC-MS and IC. The major proportion of the bitumen degradation products in solution were monocarboxylic acids (acetic acid, formic acid, myric acid, stearic acid ...), dicarboxylic acids (oxalic acid, phthalic acid) and carbonates. The experimentally derived log K data are in good agreement with the literature and suggest that oxalate determines the speciation of Cu 2+ , Ni 2+ and UO 2 2+ in the bitumen water below pH=7. However, under the high pH conditions typical of the near field of a cementitious repository, competition with OH-ligands will be large and oxalate, therefore, will not play a significant role in the speciation of radionuclides. The main conclusion of the study is that the radiolytic degradation products of bitumen will have no influence on radionuclide speciation in a cementitious near field and, as such, need not to be considered in the appropriate safety assessment models. (author) 12 figs., 11 tabs., 31 refs

  20. Incorporation of trace elements in Portland cement clinker: Thresholds limits for Cu, Ni, Sn or Zn

    International Nuclear Information System (INIS)

    Gineys, N.; Aouad, G.; Sorrentino, F.; Damidot, D.

    2011-01-01

    This paper aims at defining precisely, the threshold limits for several trace elements (Cu, Ni, Sn or Zn) which correspond to the maximum amount that could be incorporated into a standard clinker whilst reaching the limit of solid solution of its four major phases (C 3 S, C 2 S, C 3 A and C 4 AF). These threshold limits were investigated through laboratory synthesised clinkers that were mainly studied by X-ray Diffraction and Scanning Electron Microscopy. The reference clinker was close to a typical Portland clinker (65% C 3 S, 18% C 2 S, 8% C 3 A and 8% C 4 AF). The threshold limits for Cu, Ni, Zn and Sn are quite high with respect to the current contents in clinker and were respectively equal to 0.35, 0.5, 0.7 and 1 wt.%. It appeared that beyond the defined threshold limits, trace elements had different behaviours. Ni was associated with Mg as a magnesium nickel oxide (MgNiO 2 ) and Sn reacted with lime to form a calcium stannate (Ca 2 SnO 4 ). Cu changed the crystallisation process and affected therefore the formation of C 3 S. Indeed a high content of Cu in clinker led to the decomposition of C 3 S into C 2 S and of free lime. Zn, in turn, affected the formation of C 3 A. Ca 6 Zn 3 Al 4 O 15 was formed whilst a tremendous reduction of C 3 A content was identified. The reactivity of cements made with the clinkers at the threshold limits was followed by calorimetry and compressive strength measurements on cement paste. The results revealed that the doped cements were at least as reactive as the reference cement.

  1. Ageing effects in a Cu-Al-Ni shape memory alloy

    Czech Academy of Sciences Publication Activity Database

    Daříček, Tomáš; Lašek, Jiří; Zárubová, Niva; Novák, Václav; Bartuška, Pavel

    2001-01-01

    Roč. 11, - (2001), s. Pr8-179-Pr8-184 ISSN 1155-4339 R&D Projects: GA AV ČR IAA1010909; GA AV ČR IAA1010817 Institutional research plan: CEZ:AV0Z1010914 Keywords : Cu-Al-Ni alloy * shape memory * martensitic transformation * resistometry Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.401, year: 2001

  2. Topological model of austenite-martensite interfaces in Cu-Al-Ni alloy

    Czech Academy of Sciences Publication Activity Database

    Ostapovets, Andriy; Zárubová, Niva; Paidar, Václav

    2012-01-01

    Roč. 122, č. 3 (2012), s. 493-496 ISSN 0587-4246. [International Symposium on Physics of Materials, ISPMA /12./. Praha, 04.09.2011-08.09.2011] R&D Projects: GA AV ČR IAA100100920 Institutional research plan: CEZ:AV0Z10100520 Keywords : CuAlNi * alloy * experimental data * in-situ * topological models * transmission electron microscopy Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.531, year: 2012

  3. Study of interfacial reactions in Sn-3.5Ag-3.0Bi and Sn-8.0Zn-3.0Bi sandwich structure solder joint with Ni(P)/Cu metallization on Cu substrate

    International Nuclear Information System (INIS)

    Sun, Peng; Andersson, Cristina; Wei, Xicheng; Cheng, Zhaonian; Shangguan, Dongkai; Liu, Johan

    2007-01-01

    In this paper, the coupling effect in Sn-3.5Ag-3.0Bi and Sn-8.0Zn-3.0Bi solder joint with sandwich structure by long time reflow soldering was studied. It was found that the interfacial compound at the Cu substrate was binary Cu-Sn compound in Sn-Ag-Bi solder joint and Cu 5 Zn 8 phase in Sn-Zn-Bi solder joint. The thickness of the Cu-Zn compound layer formed at the Cu substrate was greater than or equal to that of Cu-Sn compound layer, although the reflow soldering temperature of Sn-Zn-Bi (240 o C) was lower than that of Sn-Ag-Bi (250 o C). The stable Cu-Zn compound was the absolute preferential phase in the interfacial layer between Sn-Zn-Bi and the Cu substrate. The ternary (Cu, Ni) 6 Sn 5 compound was formed at the Sn-Ag-Bi/Ni(P)-Cu metallization interface, and a complex alloy Sn-Ni-Cu-Zn was formed at the Sn-Zn-Bi/Ni(P)-Cu metallization interface. It was noted that Cu atoms could diffuse from the Cu substrate through the solder matrix to the Ni(P)-Cu metallization within 1 min reflow soldering time for both solder systems, indicating that just 30 s was long enough for Cu to go through 250 μm diffusion length in the Sn-Ag-Bi solder joint at 250 o C. The coupling effect between Ni(P)/Cu metallization and Cu substrate was confirmed as the type of IMCs at Ni(P) layer had been changed from Ni-Sn system to Cu-Sn system apparently by the diffusion effect of Cu atoms. The (Cu, Ni) 6 Sn 5 layer at the Ni(P)/Cu metallization grew significantly and its thickness was even greater than that of the Cu-Sn compound on the opposite side, however the growth of the complex alloy including Sn, Ni, Cu and Zn on the Ni(P)/Cu metallization was suppressed

  4. Preparation of Zr50Al15− xNi10Cu25Yx amorphous powders by ...

    Indian Academy of Sciences (India)

    The as-milled powders were characterized by X-ray diffraction and transmission electron microscopy. The results show that partial substitution of Al by Y can improve the glass-forming ability of Zr50Al15Ni10Cu25 alloy. Thermodynamic calculation of equivalent free energy shows that Zr50Al13.8Ni10Cu25Y1.2 alloy has the ...

  5. Nonmonotonic behaviour of superconducting critical temperature of Nb/CuNi bilayers with a nanometer range of layer thickness

    International Nuclear Information System (INIS)

    Morari, R.; Antropov, E.; Socrovisciuc, A.; Prepelitsa, A.; Zdravkov, V.I.; Tagirov, L.R.; Kupriyanov, M.Yu.; Sidorenko, A.S.

    2009-01-01

    Present work reports the result of the proximity effect investigation for superconducting Nb/CuNi-bilayers with the thickness of the ferromagnetic layer (Cu x Ni 1-x ) being in the sub-nanometer range. It was found a non-monotonic behavior of the critical temperature T c , i.e. its growth with the increasing of the ferromagnetic layer thickness dF, for the series of the samples with constant thickness of Nb layer, (d Nb = const). (authors)

  6. Determination of heavy metal deposition in the county of Obrenovac (Serbia using mosses as bioindicators, III: Copper (Cu, Iron (Fe and Mercury (Hg

    Directory of Open Access Journals (Sweden)

    Sabovljević M.

    2007-01-01

    Full Text Available In this study, the deposition of three heavy metals (Cu, Fe and Hg in four moss taxa (Bryum argenteum, Bryum capillare, Brachythecium sp. and Hypnum cupressiforme in the county of Obrenovac (Serbia is presented. The distribution of average heavy metal content in all mosses in the county of Obrenovac is presented on maps, while long-term atmospheric deposition (in the mosses Bryum argenteum and B. capillare and short-term atmospheric deposition (in the mosses Brachythecium sp. and Hypnum cupressiforme are discussed and given in a table. Areas of the highest contaminations are highlighted.

  7. Interphase Constituent of Laminated Composites Ti46Zr26Cu17Ni11

    Directory of Open Access Journals (Sweden)

    XU Bingtong

    2017-10-01

    Full Text Available Thermal analysis of the Ti46Zr26Cu17Ni11 amorphous ribbon prepared by melt spinning was conducted by using DSC. Accordingly the amorphous alloy was treated by vacuum heat treatment at 693 K (Tg, 753 K (Tg-Tx1 and 813 K (> Tx1 for different time to analyze the crystallization behavior. Taking Ti46Zr26Cu17Ni11 amorphous alloy, TA2 and pure Al as raw materials, laminated composites were fabricated by Gleeble-3500 thermal simulator at 873 K, 10 MPa and 8 h. The phase composition, precipitation order and properties of interface layers were investigated by SEM, TEM, micro hardness tester, combined thermodynamics and element diffusion theory. The results indicate that the glass transition temperature Tg of Ti46Zr26Cu17Ni11 amorphous is 720 K and the initial crystallization temperature Tx1 is 788 K. The I phase is crystallized from the amorphous at first, followed by a ternary or quaternary Laves phase and a TiNi phase precipited. After hot pressing, the interface between pure Al and crystallization layer is divided into two parts, which are Al3Ni with small thickness and Al3(Ti0.6Zr0.4 with fine grain and uniform microstructure. The interfaces are straight and there are no defects, with a thickness ratio of about 6.5:1 compared with interface layer between pure Ti with Al. The hardness of Al3(Ti0.6Zr0.4 and Al3Ti are 564.2HV and 579.8HV respectively. The plasticity of Al3(Ti0.6Zr0.4 layer is better.

  8. Intermartensitic transitions in Ni-Mn-Fe-Cu-Ga Heusler alloys

    International Nuclear Information System (INIS)

    Khan, Mahmud; Gautam, Bhoj; Pathak, Arjun; Dubenko, Igor; Stadler, Shane; Ali, Naushad

    2008-01-01

    A series of Fe doped Ni 2 Mn 0.75-x Fe x Cu 0.25 Ga Heusler alloys have been investigated by means of x-ray diffraction, magnetizations, thermal expansion, and electrical resistivity measurements. In Ni 2 Mn 0.75 Cu 0.25 Ga, martensitic and ferromagnetic transitions occur at the same temperature. Partial substitution of Mn by Fe results in a decrease of the martensitic transition temperature, T M , and an increase of the ferromagnetic transition temperature, T C , resulting in separation of the two transitions. In addition to the martensitic transition, complete thermoelastic intermartensitic transformations have been observed in the Fe doped Ni 2 Mn 0.75-x Fe x Cu 0.25 Ga samples with x>0.04. An unusual transition is observed in the alloy with x = 0.04. The magnetization curve as a function of increasing temperature shows only one first-order transition in the temperature range 5-400 K, which is identified as a typical coupled magnetostructural martensitic transformation. The magnetization curve as a function of decreasing temperature shows three different transitions, which are characterized as the ferromagnetic transition, the martensitic transition and the intermartensitic transition.

  9. Stability of an amorphous alloy of the Mm-Al-Ni-Cu system

    Directory of Open Access Journals (Sweden)

    Carlos Triveño Rios

    2012-10-01

    Full Text Available An investigation was made of the stability of melt-spun ribbons of Mm55Al25Ni10Cu10 (Mm = Mischmetal amorphous alloy. The structural transformations that occurred during heating were studied using a combination of X-ray diffraction (XRD and differential scanning calorimetry (DSC. Crystallization took place through a multi-stage process. The first stage of transformation corresponded to the formation of a metastable phase followed by cfc-Al precipitation, while in the second stage, exothermic transformations led to the formation of complex and unidentified Mm(Cu, Ni and MmAl(Cu, Ni phases. The transformation curves recorded from isothermal treatments at 226 °C and 232 °C indicated that crystallization occurred through nucleation and growth, with diffusion-controlled growth occurring in the first crystallization stage. The supercooled liquid region, ∆Tx, at 40 K/min was ~80 K. This value was obtained by the substitution of Mm (=Ce + La + Nd + Pr for La or Ce, saving chemical element-related costs.

  10. Effect of alloying elements on solidification of primary austenite in Ni-Mn-Cu cast iron

    Directory of Open Access Journals (Sweden)

    A. Janus

    2011-04-01

    Full Text Available Within the research, determined were direction and intensity of alloying elements influence on solidification way (directional orvolumetric of primary austenite dendrites in hypoeutectic austenitic cast iron Ni-Mn-Cu. 50 cast shafts dia. 20 mm were analysed.Chemical composition of the alloy was as follows: 1.7 to 3.3 % C, 1.4 to 3.1 % Si, 2.8 to 9.9 % Ni, 0.4 to 7.7 % Mn, 0 to 4.6 % Cu, 0.14 to0.16 % P and 0.03 to 0.04 % S. The discriminant analysis revealed that carbon influences solidification of primary austenite dendrites most intensively. It clearly increases the tendency to volumetric solidification. Influence of the other elements is much weaker. This means that the solidification way of primary austenite dendrites in hypoeutectic austenitic cast iron Ni-Mn-Cu does not differ from that in an unalloyed cast iron.

  11. Review of the Potential of the Ni/Cu Plating Technique for Crystalline Silicon Solar Cells

    Directory of Open Access Journals (Sweden)

    Atteq ur Rehman

    2014-02-01

    Full Text Available Developing a better method for the metallization of silicon solar cells is integral part of realizing superior efficiency. Currently, contact realization using screen printing is the leading technology in the silicon based photovoltaic industry, as it is simple and fast. However, the problem with metallization of this kind is that it has a lower aspect ratio and higher contact resistance, which limits solar cell efficiency. The mounting cost of silver pastes and decreasing silicon wafer thicknesses encourages silicon solar cell manufacturers to develop fresh metallization techniques involving a lower quantity of silver usage and not relying pressing process of screen printing. In recent times nickel/copper (Ni/Cu based metal plating has emerged as a metallization method that may solve these issues. This paper offers a detailed review and understanding of a Ni/Cu based plating technique for silicon solar cells. The formation of a Ni seed layer by adopting various deposition techniques and a Cu conducting layer using a light induced plating (LIP process are appraised. Unlike screen-printed metallization, a step involving patterning is crucial for opening the masking layer. Consequently, experimental procedures involving patterning methods are also explicated. Lastly, the issues of adhesion, back ground plating, process complexity and reliability for industrial applications are also addressed.

  12. Magnetic refrigeration capabilities of magnetocaloric Ni2Mn:75Cu:25Ga

    Science.gov (United States)

    Mishra, S. K.; Jenkins, C. A.; Dubenko, I.; Samanta, T.; Ali, N.; Roy, S.

    2013-03-01

    Doping-driven competition between energetically similar ground states leads to many exciting materials phenomena such as the emergence of high-Tc superconductivity, diluted magnetic semiconductors, and colossal magnetoresistance. Doped Ni2MnGa Heusler alloy, which is a multifunctional ferromagnetic alloy with various exotic physical properties demonstrates this notion of rich phenomenology via modified ground spin states. Adopting this generic concept, here we will present a novel doped Ni2Mn.75Cu.25Ga alloy that offers unprecedented co-existence of the magnetocaloric effect and fully controlled ferromagnetism at room temperature. Application of site engineering enables us to manipulate the ground spin state that leads to the decrease in magnetic transition temperature and also increases the delocalization of the Mn magnetism. SQUID magnetometery suggests that Cu doping enhances the saturation magnetization, coercive field and clarity of magnetic hysteresis loops. By exploiting x-ray absorption techniques and measuring element specific magnetic hysteresis loops, here we will describe the microscopic origin of enhnaced magnetocaloric properties and d-d interaction driven charge transfer effects in Ni2Mn.75Cu.25Ga This work was supported by DOE Grant No. DE-FG02-06ER46291

  13. Magnetism of coherent Co and Ni thin films on Cu(111) and Au(111) substrates: An ab initio study

    Energy Technology Data Exchange (ETDEWEB)

    Zelený, Martin, E-mail: zeleny@fme.vutbr.cz; Dlouhý, Ivo

    2017-02-15

    We present an ab initio study of structural and magnetic properties of coherent Co and Ni thin films on Cu(111) and Au(111) substrates with thicknesses of up to 6 monolayers. All studied films on Cu(111) substrates prefer structures close their ground state (hcp for Co and fcc for Ni), whereas only the hcp stacking sequence has been found for both films on Au(111) substrates. All studied films exhibit instability of the first monolayer with respect to decomposition into 2-monolayer- or 3-monolayer-high islands, which is in agreement with experimental findings. All studied films are also ferromagnetic, nevertheless the Ni/Cu(111) films reduce their magnetic moments in the layer adjacent to the substrate due to a stronger Cu–Ni interaction at the interface. The magnetic anisotropy of a Co film does not depend on the film thickness: all the studied Co/Au(111) films exhibit a perpendicular magnetic anisotropy, whereas all the Co/Cu(111) films prefer in-plane magnetization. On the other hand, both Ni films change their preference for in-plane orientation of their easy axis to out-of-plane orientation at a critical thickness of 2 monolayers, however, the magnetic anisotropy energies for films thicker than 1 monolayer are smaller than 1 meV/Ni atom. These behaviors of magnetic anisotropy do not depend on the structure of the studied films. - Highlights: • All films exhibit instability of the first monolayer and prefer grow in islands. • The Cu–Ni interaction is responsible for reduced Ni magnetic moments in Ni/Cu(111) films. • The Co/Au(111) and Co/Cu(111) films show different orientations of magnetic anisotropy. • The Ni films exhibit in-plane magnetization only for single monolayer. • Behaviors of magnetic anisotropy do not depend on the structure of the studied films.

  14. Effects of Alloying Elements (Mo, Ni, and Cu on the Austemperability of GGG-60 Ductile Cast Iron

    Directory of Open Access Journals (Sweden)

    Erkan Konca

    2017-08-01

    Full Text Available The interest in austempered ductile irons (ADI is continuously increasing due to their various advantageous properties over conventional ductile irons and some steels. This study aimed to determine the roles of alloying elements Ni, Cu, and Mo, on the austemperability of GGG-60 ductile cast iron. Two different sets of GGG-60 (EN-GJS-600-3 samples, one set alloyed with Ni and Cu and the other set alloyed with Mo, Ni, and Cu, were subjected to austempering treatments at 290 °C, 320 °C, and 350 °C. A custom design heat treatment setup, consisting of two units with the top unit (furnace serving for austenitizing and the 200 L capacity bottom unit (stirred NaNO2-KNO3 salt bath serving for isothermal treatment, was used for the experiments. It was found that austempering treatment at 290 °C increased the hardness of the Ni-Cu alloyed GGG-60 sample by about 44% without causing a loss in its ductility. In the case of the Mo-Ni-Cu alloyed sample, the increase in hardness due to austempering reached to almost 80% at the same temperature while some ductility was lost. Here, the microstructural investigation and mechanical testing results of the austempered samples are presented and the role of alloying elements (Mo, Ni, and Cu on the austemperability of GGG-60 is discussed.

  15. Assessment of Ni, Cu, Zn and Pb levels in beach and dune sands from Havana resorts, Cuba.

    Science.gov (United States)

    Díaz Rizo, Oscar; Buzón González, Fran; Arado López, Juana O

    2015-11-15

    Concentrations of nickel (Ni), copper (Cu), zinc (Zn) and lead (Pb) in beach and dune sands from thirteen Havana (Cuba) resorts were estimated by X-ray fluorescence analysis. Determined mean metal contents (in mg·kg(-1)) in beach sand samples were 28±12 for Ni, 35±12 for Cu, 31±11 for Zn and 6.0±1.8 for Pb, while for dune sands were 30±15, 38±22, 37±15 and 6.8±2.9, respectively. Metal-to-iron normalization shows moderately severe and severe enrichment by Cu. The comparison with sediment quality guidelines shows that dune sands from various resorts must be considered as heavily polluted by Cu and Ni. Almost in every resort, the Ni and Cu contents exceed their corresponding TEL values and, in some resorts, the Ni PEL value. The comparison with a Havana topsoil study indicates the possible Ni and Cu natural origin. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. The enhancement of CuO modified V2O5-WO3/TiO2 based SCR catalyst for Hg° oxidation in simulated flue gas

    Science.gov (United States)

    Chen, Chuanmin; Jia, Wenbo; Liu, Songtao; Cao, Yue

    2018-04-01

    CuO modified V2O5-WO3/TiO2 based SCR catalysts prepared by improved impregnation method were investigated to evaluate the catalytic activity for elemental mercury (Hg°) oxidation in simulated flue gas at 150-400 °C. Nitrogen adsorption, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) were used to characterize the catalysts. It was found that V0.8WTi-Cu3 catalyst exhibited the superior Hg° oxidation activity and wide operating temperature window at the gas hourly space velocity (GHSV) of 3 × 105 h-1. The BET and XRD results showed that CuO was well loaded and highly dispersed on the catalysts surface. The XPS results suggested that the addition of CuO generated abundant chemisorbed oxygen, which was due to the synergistic effect between CuO and V2O5. The existence of the redox cycle of V4+ + Cu2+ ↔ V5+ + Cu+ in V0.8WTi-Cu3 catalyst enhanced Hg° oxidation activity. The effects of flue gas components (O2, NO, SO2 and H2O) on Hg° oxidation over V0.8WTi-Cu3 catalyst were also explored. Moreover, the co-presence of NO and NH3 remarkably inhibited Hg° oxidation, which was due to the competitive adsorption and reduction effect of NH3 at SCR condition. Fortunately, this inhibiting effect was gradually scavenged with the decrease of GHSV. The mechanism of Hg° oxidation was also investigated.

  17. 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.

  18. Novel Chiral Magnetic Domain Wall Structure in Fe/Ni/Cu(001) Films

    Science.gov (United States)

    Chen, G.; Zhu, J.; Quesada, A.; Li, J.; N'Diaye, A. T.; Huo, Y.; Ma, T. P.; Chen, Y.; Kwon, H. Y.; Won, C.; Qiu, Z. Q.; Schmid, A. K.; Wu, Y. Z.

    2013-04-01

    Using spin-polarized low energy electron microscopy, we discovered a new type of domain wall structure in perpendicularly magnetized Fe/Ni bilayers grown epitaxially on Cu(100). Specifically, we observed unexpected Néel-type walls with fixed chirality in the magnetic stripe phase. Furthermore, we find that the chirality of the domain walls is determined by the film growth order with the chirality being right handed in Fe/Ni bilayers and left handed in Ni/Fe bilayers, suggesting that the underlying mechanism is the Dzyaloshinskii-Moriya interaction at the film interfaces. Our observations may open a new route to control chiral spin structures using interfacial engineering in transition metal heterostructures.

  19. Hydrogen related peaks in Cu-LaNi4.7Al0.3

    International Nuclear Information System (INIS)

    Cuscueta, D.J.; Salva, H.R.; Ghilarducci, A.A.; Ruiz, F.C.

    2009-01-01

    In this work, the effect of Ni substitution by Cu in the LaNi 4.7 Al 0.3 hydride-forming alloy was studied in order to apply it to the negative electrodes of Ni-MH batteries. SEM, EDS and X-ray diffraction techniques were used to analyze the microstructure, composition and crystalline structure of the samples. A maximum electrochemical discharge capacity of 130 mAh/g was obtained. Internal friction (IF) and shear modulus (G) were measured by means of low frequency mechanical spectroscopy, between 100 and 450 K. In the electrochemical activated sample, two main IF peaks and typical relaxation steps in G showed up at 200 and 280 K. The first is ascribed to interactions between hydrides and H atoms in solid solution and dislocations, while the last one is attributed to the β ↔ α hydride phase transformation.

  20. Magnetic properties of intermetallic compounds La(Ni,Co,Cu)3

    International Nuclear Information System (INIS)

    Tazuke, Y.; Tanikawa, H.; Okano, A.; Miyaji, T.

    2006-01-01

    LaNi 3 exhibited a metallic antiferromagnetic property with T N =30 K. La(Ni 1-x Co x ) 3 with x=0.01, 0.03 and 0.05 exhibited ferromagnetic properties, T C increasing linearly with increasing x. La(Ni 1-2z Co z Cu z ) 3 with z=0.015 exhibited a ferromagnetic property with a small T C . A La(Ni 1-y Cu y ) 3 sample with y=0.01 exhibited a Pauli-paramagnetic property; those with y=0.02, 0.03 and 0.04 exhibited gradual metamagnetic behavior and that with y=0.05 exhibited a ferromagnetic property. The gradual metamagnetic M-H variations are numerically simulated by using Landau-type free energies. The results suggest that the gradual metamagnetic behavior occurs from an antiferromagnetic state to a ferromagnetic one. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (Abstract Copyright [2006], Wiley Periodicals, Inc.)

  1. A new Ti-Zr-Hf-Cu-Ni-Si-Sn bulk amorphous alloy with high glass-forming ability

    International Nuclear Information System (INIS)

    Huang, Y.J.; Shen, J.; Sun, J.F.; Yu, X.B.

    2007-01-01

    The effect of Sn substitution for Cu on the glass-forming ability was investigated in Ti 41.5 Zr 2.5 Hf 5 Cu 42.5-x Ni 7.5 Si 1 Sn x (x = 0, 1, 3, 5, 7) alloys by using differential scanning calorimetry (DSC) and X-ray diffractometry. The alloy containing 5% Sn shows the highest glass-forming ability (GFA) among the Ti-Zr-Hf-Cu-Ni-Si-Sn system. Fully amorphous rod sample with diameters up to 6 mm could be successfully fabricated by the copper mold casting Ti 41.5 Zr 2.5 Hf 5 Cu 37.5 Ni 7.5 Si 1 Sn 5 alloy. The activation energies for glass transition and crystallization for Ti 41.5 Zr 2.5 Hf 5 Cu 37.5 Ni 7.5 Si 1 Sn 5 amorphous alloy are both larger than those values for the Sn-free alloy. The enhancement in GFA and thermal stability after the partial replacement of Cu by Sn may be contributed to the strong atomic bonding nature between Ti and Sn and the increasing of atomic packing density. The amorphous Ti 41.5 Zr 2.5 Hf 5 Cu 37.5 Ni 7.5 Si 1 Sn 5 alloy also possesses superior mechanical properties

  2. Giant T{sub c} shift in HgBa{sub 2}CaCu{sub 2}O{sub 6+{delta}} and TlBa{sub 2}CaCu{sub 2}O{sub 7{minus}{delta}} superconductors due to Hg-Tl exchange

    Energy Technology Data Exchange (ETDEWEB)

    Gapud, A.A.; Wu, J.Z.; Kang, B.W.; Yan, S.L.; Xie, Y.Y. [Department of Physics and Astronomy, University of Kansas, Lawrence, Kansas 66045-2151 (United States); Siegal, M.P. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)

    1999-01-01

    The irreversibility lines of epitaxial thin films of HgBa{sub 2}CaCu{sub 2}O{sub 6+{delta}} and TlBa{sub 2}CaCu{sub 2}O{sub 7{minus}{delta}}, whether deduced from field-induced magnetoresistive broadening or onset of nonhysteretic magnetization, were found to coincide when plotted against reduced temperature, showing the same exponential-decay temperature behavior for T/T{sub c}{lt}0.8 and power-law behavior for T/T{sub c}{gt}0.8 (where T{sub c} is zero-field, zero-resistivity critical temperature). These results indicate that replacing Tl with Hg has no noticeable effect on the anisotropy and suggests that T{sub c} is not determined by anisotropy. {copyright} {ital 1999} {ital The American Physical Society}

  3. Mechanical Deformation Behavior of Sn-Ag-Cu Solders with Minor Addition of 0.05 wt.% Ni

    Science.gov (United States)

    Hammad, A. E.; El-Taher, A. M.

    2014-11-01

    The aim of the present work is to develop a comparative evaluation of the microstructural and mechanical deformation behavior of Sn-Ag-Cu (SAC) solders with the minor addition of 0.05 wt.% Ni. Test results showed that, by adding 0.05Ni element into SAC solders, generated mainly small rod-shaped (Cu,Ni)6Sn5 intermetallic compounds (IMCs) inside the β-Sn phase. Moreover, increasing the Ag content and adding Ni could result in the change of the shape and size of the IMC precipitate. Hence, a significant improvement is observed in the mechanical properties of SAC solders with increasing Ag content and Ni addition. On the other hand, the tensile results of Ni-doped SAC solders showed that both the yield stress and ultimate tensile strengths decrease with increasing temperature and with decreasing strain rate. This behavior was attributed to the competing effects of work hardening and dynamic recovery processes. The Sn-2.0Ag-0.5Cu-0.05Ni solder displayed the highest mechanical properties due to the formation of hard (Cu,Ni)6Sn5 IMCs. Based on the obtained stress exponents and activation energies, it is suggested that the dominant deformation mechanism in SAC (205)-, SAC (0505)- and SAC (0505)-0.05Ni solders is pipe diffusion, and lattice self-diffusion in SAC (205)-0.05Ni solder. In view of these results, the Sn-2.0Ag-0.5Cu-0.05Ni alloy is a more reliable solder alloy with improved properties compared with other solder alloys tested in the present work.

  4. Temperature dependence of magnetic properties of Cu80Co19Ni1 thin microwires

    International Nuclear Information System (INIS)

    Garcia, C.; Zhukov, A.; Zhukova, V.; Larin, V.; Gonzalez, J.; Val, J.J. del; Knobel, M.

    2007-01-01

    In the present work, we report the studies of temperature dependence of magnetic properties in thin microwires with composition Cu 80 Co 19 Ni 1 . An extensive study of structural and magnetic characterization was realized. The structure was observed using X-ray diffraction with CuK α radiation. The magnetic measurements were carried out using a SQUID at temperatures between 5 and 300 K. The as-prepared Cu 80 Co 19 Ni 1 microwire presents a coercivity of about 80 Oe. The variation of the coercivity and remanent magnetization at 5-300 K were obtained from the hysteresis loops. From the difference of the ZFC and FC curves below T=100 K, we can assume the presence of small superparamagnetic grains embedded in the Cu matrix. Those superparamagnetic grains should be blocked at temperatures below the maximum of the magnetization observed below 50 K. The measurements show an unusual temperature dependence of the coercive field, consequence of a coexistence of blocked and unblocked particles, and the typical decreasing behaviour of the remanence increasing temperature

  5. The Relevant Role of Dislocations in the Martensitic Transformations in Cu-Al-Ni Single Crystals

    Science.gov (United States)

    Gastien, R.; Sade, M.; Lovey, F. C.

    2018-03-01

    The interaction between dislocations and martensitic transformations in Cu-Al-Ni alloys is shortly reviewed. Results from many researchers are critically analyzed towards a clear interpretation of the relevant role played by dislocations on the properties of shape memory alloys in Cu-based alloys. Both thermally and stress-induced transformations are considered and focus is paid on two types of transitions, the β→β' and the formation of a mixture of martensites: β→β' + γ'. After cycling in the range where both martensites are formed, the twinned γ' phase is inhibited and cycling evolves into the formation of only β'. A model which considers the difference in energy of each γ' twin variant due to the introduced dislocations quantitatively explains the inhibition of γ' in both thermally and stress-induced cycling. The type of dislocations which are mainly introduced, mixed with Burgers vector belonging to the basal plane of the β' martensite, enables also to explain the unmodified mechanical behavior during β→β' cycling. The reported behavior shows interesting advantages of Cu-Al-Ni single crystals if mechanical properties are comparatively considered with those in other Cu-based alloys.

  6. Wetting behaviour of lead-free Sn-based alloys on Cu and Ni substrates

    International Nuclear Information System (INIS)

    Amore, S.; Ricci, E.; Borzone, G.; Novakovic, R.

    2008-01-01

    The present work was carried out in the framework of the study of new lead-free solder alloys for technical applications in electronic devices. In the focus of this characterisation the wetting behaviour of several Sn-rich alloys belonging to the In-Sn, Au-Sn and Cu-Sn systems has been studied by measuring the contact angle variations on Cu and Ni substrates as a function of time and temperature. The interface between the alloy and the substrate has been analysed by the use of optical microscopy and scanning electron microscopy combined with energy-dispersive X-ray spectrometry in order to study the reaction between the alloy and the solid substrate and the possible formation of different compounds at the interface. A remarkable effect of the two different substrates on the behaviour of the contact angle as a function of temperature and on the morphology of the interface between the liquid solder and the solid substrate was observed for the In-Sn and Cu-Sn, while the Au-Sn system shows a very similar wetting behaviour on Cu and Ni

  7. Internal friction of Ti-Ni-Cu ternary shape memory alloys

    International Nuclear Information System (INIS)

    Yoshida, I.; Monma, D.; Iino, K.; Ono, T.; Otsuka, K.; Asai, M.

    2004-01-01

    Low frequency internal friction was measured on three specimens of Ti-Ni-Cu ternary alloys, the Cu content varying from 10 to 20 at.%, while Ti content was fixed at 50 at.%. The internal friction spectrum consists mainly of two peaks, a sharper one associated with the B2-B19 transformation and the other one at around 250 K, which is much broader and higher than the former. The peak height of the latter is 0.2 for the specimen containing 20% Cu, which shows that this alloy can be an excellent high damping material. Transformation behavior was studied by electrical resistivity, thermopower and DSC measurements, and was compared with the result of internal friction measurements. Solution treatment at higher temperatures lowers the internal friction peak markedly. Scanning electron microscopy observation reveals that the behaviors of precipitates are different for different solution treatment temperature, suggesting that the precipitation behavior is crucial in the damping properties

  8. Study of the analytic quality in the determinations of Cr, Fe, Mn, Cu, Zn, Pb and Hg through conventional and nuclear analytical techniques in mosses of the MATV; Estudio de la calidad analitica en las determinaciones de Cr, Fe, Mn, Cu, Zn, Pb y Hg a traves de tecnicas analiticas nucleares y convencionales en musgos de la ZMVT

    Energy Technology Data Exchange (ETDEWEB)

    Caballero S, B.

    2013-07-01

    To evaluate the environmental risks of air pollution and to facilitate the decision-making for control, is necessary to have the capacity to generate data with analytical quality. A comparison between nuclear (Neutron activation analysis and total reflection X-ray fluorescence spectrometry) and no nuclear analytical techniques (atomic absorption spectrometry and inductively coupled plasma optical emission spectrometry) for simultaneous determination of metal content (Cr, Cu, Fe, Hg, Mn, Pb and Zn) in mosses from Metropolitan Area of the Toluca Valley (MATV) was performed. Epiphytic mosses (Fabriona ciliaris and Leskea angustata) were sampled in two campaigns, 16 sites (urban, transition and natural) and were prepared for each technique. The biological certified reference materials were used for the quality control and to evaluate accuracy, precision, linearity, detection and quantification limits. Results show that nuclear analytical techniques and no nuclear applied in chemical analysis of Cr, Cu, Fe, Hg, Mn, Pb and Zn in moss from MATV are comparable and therefore all of these can potentially be used for this purpose. However, if its considered both, the performance parameters and economic/operational characteristics is widely recommended inductively coupled plasma optical emission spectrometry, conventional analytical technique, which showed the highest analytical grade quality. Also were observed spatial and temporal variations in the concentrations of Cr, Cu, Fe, Hg, Mn, Pb and Zn in mosses from MATV and was discussed its potential origin. The urban sites had the highest concentration of anthropogenic elements as Cr, Cu, Fe, Hg, Pb and Zn because are strongly impacted by roads with high vehicle traffic. (Author)

  9. Microstructure, thickness and sheet resistivity of Cu/Ni thin film produced by electroplating technique on the variation of electrolyte temperature

    Science.gov (United States)

    Toifur, M.; Yuningsih, Y.; Khusnani, A.

    2018-03-01

    In this research, it has been made Cu/Ni thin film produced with electroplating technique. The deposition process was done in the plating bath using Cu and Ni as cathode and anode respectively. The electrolyte solution was made from the mixture of HBrO3 (7.5g), NiSO4 (100g), NiCl2 (15g), and aquadest (250 ml). Electrolyte temperature was varied from 40°C up to 80°C, to make the Ni ions in the solution easy to move to Cu cathode. The deposition was done during 2 minutes on the potential of 1.5 volt. Many characterizations were done including the thickness of Ni film, microstructure, and sheet resistivity. The results showed that at all samples Ni had attacked on the Cu substrate to form Cu/Ni. The raising of electrolyte temperature affected the increasing of Ni thickness that is the Ni thickness increase with the increasing electrolyte temperature. From the EDS spectrum, it can be informed that samples already contain Ni and Cu elements and NiO and CuO compounds. Addition element and compound are found for sample Cu/Ni resulted from 70° electrolyte temperature of Ni deposition, that are Pt and PtO2. From XRD pattern, there are several phases which have crystal structure i.e. Cu, Ni, and NiO, while CuO and PtO2 have amorphous structure. The sheet resistivity linearly decreases with the increasing electrolyte temperature.

  10. Structural and magnetic properties of Co-substituted NiCu ferrite nanopowders

    Energy Technology Data Exchange (ETDEWEB)

    Li, Le-Zhong, E-mail: lezhongli@cuit.edu.cn; Zhong, Xiao-Xi; Wang, Rui; Tu, Xiao-Qiang; Peng, Long

    2017-07-01

    Highlights: • There are Fe{sub 2}O{sub 3} and CuO impurity phases when x ≤ 0.10. • The saturation magnetization and coercivity monotonically increase with the increase of Co substitution. • The anisotropy constant increases with the increase of Co substitution. • The calculated and observed values of magneton number are in close agreement with each other. - Abstract: Co-substituted NiCu ferrite nanopowders with the chemical formula Ni{sub 0.5−x}Cu{sub 0.5−x}Co{sub 2x}Fe{sub 2}O{sub 4} (0 ≤ x ≤ 0.50) were synthesized by sol-gel auto-combustion method. The effects of Co substitution on the cation distribution, structural and magnetic properties of the NiCu ferrite nanopowders have been investigated. Differential thermal analysis-thermogravimetry (DTA-TG), X-ray diffraction (XRD), transmission electron microscope (TEM) and vibrating sample magnetometer (VSM) measurements were used to characterize the chemical, structural and magnetic properties of the ferrite nanopowders, respectively. The DTA-TG results indicate that there are three steps of the combustion process. XRD results indicate that there are Fe{sub 2}O{sub 3} and CuO impurity phases when x ≤ 0.10. Furthermore, the lattice parameter increases, and the X-ray density and the average crystallite size decrease with increasing Co substitution. And the obtained particle size from TEM image is in very good agreement with the average crystallite size estimated by XRD measurements. The saturation magnetization and coercivity monotonically increase with the increase of Co substitution. The increase of the saturation magnetization is due to the substitution of Ni{sup 2+} and Cu{sup 2+} ions with lower magnetic moment by Co{sup 2+} ions with higher magnetic moment on the octahedral sites. And the increase of the coercivity is mainly due to the increase of magnetocrystalline anisotropy energy.

  11. The differential cross section and polarization for the elastic scattering of 2.9 MeV neutrons by Fe, Cu, I, Hg and Pb

    International Nuclear Information System (INIS)

    Galloway, R.B.; Waheed, A.

    1979-01-01

    Simultaneous measurements are presented of the angular dependence of polarization due to elastic scattering and of the elastic differential cross section for 2.9 MeV neutrons. The angular range covered is 20 0 to 160 0 for samples of Fe, Cu, I, Hg and Pb. The measurements are compared with the results of combining optical model and Hauser-Feshbach calculations. The optical model calculations were performed using 'global fit' parameters as well as with parameters suggested previously for the particular nuclei. The Hauser-Feshbach calculations were performed both with and without the level width fluctuation correction. It is clear that the calculations made without the level width fluctuation correction provide a better fit to the data for Fe, Cu, I and Hg and only for Pb does inclusion of the level width fluctuation correction provide a better fit. These optical model parameter sets are shown not to be very successful in fitting both differential cross-section and polarization data. The results of searches for the parameters which give the best fit for the data are presented. These parameter sets are compared with one another and with the results of 8 and 11 MeV neutron scattering studies for trends in the variation of the parameters. (Auth.)

  12. Comprehensive risk assessment and source identification of selected heavy metals (Cu, Cd, Pb, Zn, Hg, As) in tidal saltmarsh sediments of Shuangtai Estuary, China.

    Science.gov (United States)

    Liu, Chang-Fa; Li, Bing; Wang, Yi-Ting; Liu, Yuan; Cai, Heng-Jiang; Wei, Hai-Feng; Wu, Jia-Wen; Li, Jin

    2017-10-06

    Heavy metals do not degrade and can remain in the environment for a long time. In this study, we analyzed the effects of Cu, Cd, Pb, Zn, Hg, and As, on environmental quality, pollutant enrichment, ecological hazard, and source identification of elements in sediments using data collected from samples taken from Shuangtai tidal wetland. The comprehensive pollution indices were used to assess environmental quality; fuzzy similarity analysis and geoaccumulation index were used to analyze pollution accumulation; correlation matrix, principal component analysis, and clustering analysis were used to analyze pollution source; environmental risk index and ecological risk index were used to assess ecological risk. The results showed that the environmental quality was either clean or almost clean. Pollutant enrichment analysis showed that the four sub-regions had similar pollution-causing metals to the background values of the soil element of the Liao River Plain, which were ranked according to their similarity. Source identification showed that all the elements were correlated. Ecological hazard analysis showed that the environmental risk index in the study area was less than zero, posing a low ecological risk. Ecological risk of the six elements was as follows: As > Cd > Hg > Cu > Pb > Zn.

  13. Annealing temperature and O2 partial pressure dependence of T(sub c) in HgBa2CuO(4+delta)

    Science.gov (United States)

    Xiong, Q.; Cao, Y.; Chen, F.; Xue, Y. Y.; Chu, C. W.

    1994-01-01

    Samples of HgBa2CuO(4+delta) (Hg-1201) were annealed under various conditions. After carefully controlling annealing time, annealing temperature (T(sub a)) and O2 partial pressure (P(sub 0)), we were able to find the reversible annealing conditions for Hg-1201. Under 1 atm O2 at 260 C less than or equal to T(sub a) less than or equal to 400 C, the obtained T(sub c) is nearly the same (approximately 97 K). However, it decreases quickly with T(sub a) greater than 300 C in high vacuum (P(sub 0) approximately 10(exp -8) atm), and reaches zero at T(sub a) = 400 C. On the other hand, T(sub c) decreases with the decrease of T(sub a) in high-pressure O2 (approximately 500 atm) and reaches approximately 20 K at about 240 C. In the entire annealing region, the oxygen surplus varies significantly from 0.03 to 0.4, and a wide range of T(sub c) variation (0 goes to 97 K goes to 20 K) was obtained with anion doping alone.

  14. Positron annihilation characterization of free volume in micro- and macro-modified Cu0.4Co0.4Ni0.4Mn1.8O4 ceramics

    International Nuclear Information System (INIS)

    Klym, H.; Ingram, A.; Shpotyuk, O.; Hadzaman, I.; Solntsev, V.; Hotra, O.; Popov, A.

    2016-01-01

    Free volume and pore size distribution size in functional micro and macro-micro-modified Cu 0.4 Co 0.4 Ni 0.4 Mn 1.8 O 4 ceramics are characterized by positron annihilation lifetime spectroscopy in comparison with Hg-porosimetry and scanning electron microscopy technique. Positron annihilation results are interpreted in terms of model implication positron trapping and ortho-positronium decaying. It is shown that free volume of positron traps are the same type for macro and micro modified Cu 0.4 Co 0.4 Ni 0.4 Mn 1.8 O 4 ceramics. Classic Tao-Eldrup model in spherical approximation is used to calculation of the size of nanopores smaller than 2 nm using the ortho-positronium lifetime.

  15. A CuNi bimetallic cathode with nanostructured copper array for enhanced hydrodechlorination of trichloroethylene (TCE).

    Science.gov (United States)

    Liu, Bo; Zhang, Hao; Lu, Qi; Li, Guanghe; Zhang, Fang

    2018-09-01

    To address the challenges of low hydrodechlorination efficiency by non-noble metals, a CuNi bimetallic cathode with nanostructured copper array film was fabricated for effective electrochemical dechlorination of trichloroethylene (TCE) in aqueous solution. The CuNi bimetallic cathodes were prepared by a simple one-step electrodeposition of copper onto the Ni foam substrate, with various electrodeposition time of 5/10/15/20 min. The optimum electrodeposition time was 10 min when copper was coated as a uniform nanosheet array on the nickel foam substrate surface. This cathode exhibited the highest TCE removal, which was twice higher compared to that of the nickel foam cathode. At the same passed charge of 1080C, TCE removal increased from 33.9 ± 3.3% to 99.7 ± 0.1% with the increasing operation current from 5 to 20 mA cm -2 , while the normalized energy consumption decreased from 15.1 ± 1.0 to 2.6 ± 0.01 kWh log -1  m -3 . The decreased normalized energy consumption at a higher current density was due to the much higher removal efficiency at a higher current. These results suggest that CuNi cathodes prepared by simple electrodeposition method represent a promising and cost-effective approach for enhanced electrochemical dechlorination. Copyright © 2018 Elsevier B.V. All rights reserved.

  16. Response of Pinus halepensis Mill. seedlings to biosolids enriched with Cu, Ni and Zn in three Mediterranean forest soils

    International Nuclear Information System (INIS)

    Fuentes, David; Disante, Karen B.; Valdecantos, Alejandro; Cortina, Jordi; Ramon Vallejo, V.

    2007-01-01

    We investigated the response of Pinus halepensis seedlings to the application of biosolids enriched with Cu, Ni and Zn on three Mediterranean forest soils under semiarid conditions. One-year-old seedlings were planted in lysimeters on soils developed from marl, limestone and sandstone which were left unamended, amended with biosolids, or amended with biosolids enriched in Cu, Ni and Zn. Enriched biosolids increased plant heavy metal concentration, but always below phytotoxic levels. Seedlings receiving unenriched biosolids showed a weak reduction in Cu and Zn concentration in needles, negatively affecting physiological status during drought. This effect was alleviated by the application of enriched sludge. Sewage sludge with relatively high levels of Cu, Zn and Ni had minor effects on plant performance on our experimental conditions. Results suggest that micronutrient limitations in these soils may be alleviated by the application of biosolids with a higher Cu, Zn and Ni content than those established by current regulations. - Biosolid-borne Cu, Ni and Zn did not show negative effects on Pinus halepensis seedlings performance after application on three Mediterranean forest soils

  17. Ni(II) and Cu(II) binding with a 14-aminoacid sequence of Cap43 protein, TRSRSHTSEGTRSR.

    Science.gov (United States)

    Zoroddu, M A; Kowalik-Jankowska, T; Kozlowski, H; Salnikow, K; Costa, M

    2001-03-01

    The tetradecapeptide containing the 10 aminoacid repeated sequence on the C-terminus of the Ni(II)-induced Cap43 protein, was analyzed for Ni(II) and Cu(II) binding. A combined pH-metric and spectroscopic UV-VIS, EPR, CD and NMR study of Ni(II) and Cu(II) binding to the blocked CH3CO-Thr-Arg-Ser-Arg-Ser-His-Thr-Ser-Glu-Gly-Thr-Arg-Ser-Arg-NH2 (Ac-TRSRSHTSEGTRSR-Am) peptide, modeling a part of the C-terminal sequence of the Cap43 protein, revealed the formation of octahedral complexes involving imidazole nitrogen of histidine, at pH 5.5 and pH 7 for Cu(II) and Ni(II), respectively; a major square planar 4N-Ni(II) complex (about 100% at pH 9, log K* = -28.16) involving imidazole nitrogen of histidine and three deprotonated amide nitrogens of the backbone of the peptide was revealed; a 3N-Cu(II) complex (maximum about 70% at pH 7, log K*=-13.91) and a series of 4N-Cu(II) complexes starting at pH 5.5 (maximum about 90% at pH 8.7, log K* = -21.39 for CuH(-3)L), were revealed. This work supports the existence of a metal binding site at the COOH-terminal part of the Cap43 peptide.

  18. Note: Erosion of W-Ni-Fe and W-Cu alloy electrodes in repetitive spark gaps.

    Science.gov (United States)

    Wu, Jiawei; Han, Ruoyu; Ding, Weidong; Qiu, Aici; Tang, Junping

    2018-02-01

    A pair of W-Ni-Fe and W-Cu electrodes were tested under 100 kA level pulsed currents for 10 000 shots, respectively. Surface roughness and morphology characteristics of the two pairs of electrodes were obtained and compared. Experimental results indicated cracks divided the W-Cu electrode surface to polygons while the W-Ni-Fe electrode surface remained as a whole with pits and protrusions. Accordingly, the surface roughness of W-Ni-Fe electrodes increased to ∼3 μm while that of W-Cu electrodes reached ∼7 μm at the end of the test. The results reveal that the W-Ni-Fe alloy has a better erosion resistance and potential to be further applied in spark gaps.

  19. Obtainment of the alloy Cu13Al4Ni using processed by powder metallurgy; Obtencao da liga Cu13Al4Ni via metalurgia do po

    Energy Technology Data Exchange (ETDEWEB)

    Grossi, L.J.; Damasceno, N.; Muterlle, P.V., E-mail: larajgrossi@yahoo.com.br [Universidade de Brasilia (UnB), Brasilia, DF (Brazil). Departamento de Engenharia Mecanica

    2016-07-01

    The powder metallurgy is a technique environmentally advantageous that allows the production of many pieces, with a good superficial finishing and dimensional tolerance. For the production of pieces using technique, basics steps are carried out, as the characterization of powders, the mixing and homogenization, compacting and sintering. In this context, this work has as objective the obtainment of the Cu13Al4Ni alloy via powder metallurgy. For this, was made a high energy milling for 2, 4 and 8 hours. Then, the milled powder was compacted and posteriorly, sintered in an oven with controlled atmosphere. It was observed that the milling time affects directly in sintering of the pieces. The best results obtained were for the samples that were milled for 4 hours. This samples have showed 21, 52% of porosity and 6,382 g/cm³ of the density of sintered. (author)

  20. Survey of trace elements (Al, As, Cd, Cr, Co, Hg, Mn, Ni, Pb, Se, and Si) in retail samples of flavoured and bottled waters.

    Science.gov (United States)

    Barroso, M F; Ramos, S; Oliva-Teles, M T; Delerue-Matos, C; Sales, M G F; Oliveira, M B P P

    2009-01-01

    Concentrations of eleven trace elements (Al, As, Cd, Cr, Co, Hg, Mn, Ni, Pb, Se, and Si) were measured in 39 (natural and flavoured) water samples. Determinations were performed using graphite furnace electrothermetry for almost all elements (Al, As, Cd, Cr, Co, Mn, Ni, Pb, and Si). For Se determination hydride generation was used, and cold vapour generation for Hg. These techniques were coupled to atomic absorption spectrophotometry. The trace element content of still or sparkling natural waters changed from brand to brand. Significant differences between natural still and natural sparkling waters (p element was compared with the presence of flavours, preservatives, acidifying agents, fruit juice and/or sweeteners, according to the labelled composition. It was shown that flavoured waters generally increase the trace element content. The addition of preservatives and acidifying regulators had a significant influence on Mn, Co, As and Si contents (p < 0.05). Fruit juice can also be correlated to the increase of Co and As. Sweeteners did not provide any significant difference in Mn, Co, Se and Si content.

  1. Toxic metals (Ni2+, Pb2+, Hg2+) binding affinity of dissolved organic matter (DOM) derived from different ages municipal landfill leachate

    Science.gov (United States)

    Rikta, S. Y.; Tareq, Shafi M.; Uddin, M. Khabir

    2018-03-01

    Solid waste production is rapidly increasing in Bangladesh and landfill leachate is the consequence of the decomposition of this waste. These leachates contain heavy metals and significant amount of dissolved organic matter (DOM). DOM is known to have considerable role in heavy metals speciation. Hence, it is important to characterize DOM/leachate and evaluate toxic metals binding affinity of DOM. The objectives of this study were to characterize the DOM in landfill leachate through physico-chemical and optical analyses and to investigate the toxic metals (Ni2+, Pb2+ and Hg2+) binding affinity of three different ages (fresh sample L-1, young sample L-2 and mature sample L-3) DOM samples. Results suggested that leachate is a potential pollutant which contained very high organic pollutant load. Conditional stability constant (Log K) and percentages of fluorophores that correspond to metal binding (% f) values indicated that young DOM sample (L-2) had the highest binding affinity to all the three metals ions. In general, DOM samples showed the following order affinity to the metal ions; Ni2+ binding affinity: L-2 > L-3 > L-1, Pb2+ binding affinity: L-2 > L-3 > L-1 and Hg2+ binding affinity: L-2 > L-1 > L-3.

  2. Feasibility of constructed wetland planted with Leersia hexandra Swartz for removing Cr, Cu and Ni from electroplating wastewater.

    Science.gov (United States)

    You, Shao-Hong; Zhang, Xue-Hong; Liu, Jie; Zhu, Yi-Nian; Gu, Chen

    2014-01-01

    As a low-cost treatment technology for effluent, the constructed wetlands can be applied to remove the heavy metals from wastewater. Leersia hexandra Swartz is a metal-accumulating hygrophyte with great potential to remove heavy metal from water. In this study, two pilot-scale constructed wetlands planted with L. hexandra (CWL) were set up in greenhouse to treat electroplating wastewater containing Cr, Cu and Ni. The treatment performance of CWL under different hydraulic loading rates (HLR) and initial metal concentrations were also evaluated. The results showed that CWL significantly reduced the concentrations of Cr, Cu and Ni in wastewater by 84.4%, 97.1% and 94.3%, respectively. High HLR decreased the removal efficiencies of Cr, Cu and Ni; however, the heavy metal concentrations in effluent met Emission Standard of Pollutants for Electroplating in China (ESPE) at HLR less than 0.3 m3/m2 d. For the influent of 5 mg/L Cr, 10 mg/L Cu and 8 mg/L Ni, effluent concentrations were below maximum allowable concentrations in ESPE, indicating that the removal of Cr, Cu and Ni by CWL was feasible at considerably high influent metal concentrations. Mass balance showed that the primary sink for the retention of contaminants within the constructed wetland system was the sediment, which accounted for 59.5%, 83.5%, and 73.9% of the Cr, Cu and Ni, respectively. The data from the pilot wetlands support the view that CWL could be used to successfully remove Cr, Cu and Ni from electroplating wastewater.

  3. Study on the application of magnesium oxide adsorptive compound to preconcentrate trace elements (As, Cu, Co, Cr, Hg, Mn, Sb and Zn) in high salt water and neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Giang, Nguyen; Tam, Nguyen Thanh; Phuong Mai, Truong Thi; Ho Tran The Huu [Center for Analytical Techniques, Nuclear Research Institute, Dalat (Viet Nam)

    2007-12-15

    The project presents preconcentration neutron activation analysis techniques for determination of trace metals (As, Co, Cr Cu, Hg, Mn, Sb and Zn) in high salt water by adsorption of trace metals on magnesium oxide. Precipitate is collected on 0.45 {mu}m membrane filters and irradiated in pneumatic rabit system and Lazy Susan facility at flux 5.10{sup 12} n/cm{sup 2}.sec for As, Cu, Mn and 2.10{sup 12} n/cm{sup 2}.sec for Hg, Sb, Cr, Co and Zn. The radioactivities of {sup 76}As, {sup 60}Co, {sup 64}Cu, {sup 51}Cr, {sup 203}Hg, {sup 56}Mn, {sup 124}Sb and {sup 65}Zn were measured. {sup 76}As, {sup 60}Co, {sup 64}Cu, {sup 51}Cr, {sup 203}Hg, {sup 56}Mn, {sup 124}Sb and {sup 65}Zn radio traces were used to establish optimum conditions and to evaluate the chemical yield. Detection limits of this method are 0.019, 0.006, 0.044, 0.058, 0.021, 0.027, 0.012 and 0.094 {mu}g of As, Co, Cr, Cu, Hg, Mn, Sb and Zn respectively. (author)

  4. Structural characterization of two new quaternary chalcogenides: CuCo{sub 2}InTe{sub 4} and CuNi{sub 2}InTe{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Delgado, Gerzon E.; Grima-Gallardo, Pedro; Nieves, Luis, E-mail: gerzon@ula.ve [Universidad de Los Andes, Merida (Venezuela, Bolivarian Republic of); Cabrera, Humberto [Centro Multidisciplinario de Ciencias, Instituto Venezolano de Investigaciones Cientificas (IVIC), Merida (Venezuela, Bolivarian Republic of); Glenn, Jennifer R.; Aitken, Jennifer A. [Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, PA (United States)

    2016-11-15

    The crystal structure of the chalcogenide compounds CuCo{sub 2}InTe{sub 4} and CuNi{sub 2}InTe{sub 4} , two new members of the I-II{sub 2}-III-VI{sub 4} family, were characterized by Rietveld refinement using X-ray powder diffraction data. Both materials crystallize in the tetragonal space group I4-bar 2m (No. 121), Z = 2, with a stannite-type structure, with the binaries CoTe and NiTe as secondary phases. (author)

  5. The pseudoelasticity of a Ni45Ti50Cu5 alloy

    International Nuclear Information System (INIS)

    Ranucci, T.; Airoldi, G.

    2000-01-01

    Since several years the Ni (50-X) Ti 50 Cu X alloys are attentively considered for the interesting features related to the B2=>B19' transformation involved in the pseudoelastic behavior. In contrast with the binary NiTi, where two martensitic transformations, B2=>R-phase and R-phase=>B19' can overlap, in the ternary alloy a single transformation is expected with a narrower hysteresis. The pseudoelastic behavior of a Ni 45 Ti 50 Cu 5 is here thoroughly investigated both as a function of different thermal treatments and of the maximum applied strain. The minimum hysteresis width of the pseudoelastic cycle appears for a thermal treatment of 450 C and decreases with stress cycling. The stress induced transformation involves, however, a single process whenever the maximum applied strain is smaller than the transformation strain. When the attained strain exceeds the transformation strain, another transformation sets in as supported by electrical resistance measurements performed concomitantly to stress-strain tests. (orig.)

  6. Observation of martensitic structure evolution in Cu-Al-Ni single crystals with shape memory effect under external load using photoacoustic microscopy

    International Nuclear Information System (INIS)

    Muratikov, K.L.; Glazov, A.L.; Nikolaev, V.I.; Pul'nev, S.A.

    2006-01-01

    Photoacoustic microscopy is applied to observe the surface structure of Cu-Al-Ni shape-memory single crystals in both the loaded and unloaded states. Visualizing the early stages of the loading-induced martensitic transformation in Cu-Al-Ni single crystals is demonstrated to be feasible. The photoacoustic images are distinguished to advantage from the corresponding optical images by a higher contrast between different phases of the Cu-Al-Ni shape-memory alloy [ru

  7. Neutron diffraction determination of atomic mean-square displacements in cubic compounds of Ni-Al and Ni-Al-Cu systems

    International Nuclear Information System (INIS)

    Khidirov, I.; Mukhtarova, N.N.

    2002-01-01

    The atomic mean-square displacements (AMSD) are some of important characteristics of the solid and can be the main information for determination of a number of other characteristics of substances. In the work AMSD is determined for a number of cubic compounds of Ni-Al, Ni-Al-Cu systems immediately from intensities of neutron diffraction maxima. It is shown by the offered method that in all NiAl x and NiAlCu x compounds with the CsCl - type structure AMSD are near each other and they are practically constant. Therefore it is possible to assume that within the homogeneity region of these compounds the interatomic bond forces are changed insignificantly

  8. Microstructure and Tensile/Corrosion Properties Relationships of Directionally Solidified Al-Cu-Ni Alloys

    Science.gov (United States)

    Rodrigues, Adilson V.; Lima, Thiago S.; Vida, Talita A.; Brito, Crystopher; Garcia, Amauri; Cheung, Noé

    2018-03-01

    Al-Cu-Ni alloys are of scientific and technological interest due to high strength/high temperature applications, based on the reinforcement originated from the interaction between the Al-rich phase and intermetallic composites. The nature, morphology, size, volume fraction and dispersion of IMCs particles throughout the Al-rich matrix are important factors determining the resulting mechanical and chemical properties. The present work aims to evaluate the effect of the addition of 1wt%Ni into Al-5wt%Cu and Al-15wt%Cu alloys on the solidification rate, macrosegregation, microstructure features and the interrelations of such characteristics on tensile and corrosion properties. A directional solidification technique is used permitting a wide range of microstructural scales to be examined. Experimental growth laws relating the primary and secondary dendritic spacings to growth rate and solidification cooling rate are proposed, and Hall-Petch type equations are derived relating the ultimate tensile strength and elongation to the primary dendritic spacing. Considering a compromise between ultimate tensile strength and corrosion resistance of the examined alloys samples from both alloys castings it is shown that the samples having more refined microstructures are associated with the highest values of such properties.

  9. Analysis, manufacture and characterization of Ni/Cu functionally graded structures

    International Nuclear Information System (INIS)

    Rubio, Wilfredo Montealegre; Paulino, Glaucio H.; Silva, Emilio Carlos Nelli

    2012-01-01

    Highlights: ► Functionally graded structures (FGSs) of nickel and copper can be manufactured. ► The hardness curve of FGS can be used for approximating the gradation function of elastic properties. ► The graded finite element approaches with great accuracy the FGS resonance frequencies obtained experimentally. -- Abstract: In this work, an experimental and numerical analysis and characterization of functionally graded structures (FGSs) is developed. Nickel (Ni) and copper (Cu) materials are used as basic materials in the numerical modeling and experimental characterization. For modeling, a MATLAB finite element code is developed, which allows simulation of harmonic and modal analysis considering the graded finite element formulation. For experimental characterization, Ni–Cu FGSs are manufactured by using spark plasma sintering technique. Hardness and Young’s modulus are found by using microindentation and ultrasonic measurements, respectively. The effective gradation of Ni/Cu FGS is addressed by means of optical microscopy, energy dispersive spectrometry, scanning electron microscopy and hardness testing. For the purpose of comparing modeling and experimental results, the hardness curve, along the gradation direction, is used for identifying the gradation profile; accordingly, the experimental hardness curve is used for approximating the Young’s modulus variation and the graded finite element modeling is used for verification. For the first two resonance frequency values, a difference smaller than 1% between simulated and experimental results is obtained.

  10. Influence of the Si content on the microstructure and mechanical properties of Ti-Ni-Cu-Si-Sn nanocomposite alloys

    Energy Technology Data Exchange (ETDEWEB)

    Fornell, J., E-mail: Jordinafornell@gmail.com [Departament de Fisica, Universitat Autonoma de Barcelona, 08193 Bellaterra (Spain); Van Steenberge, N. [OCAS N.V., Pres. J.F. Kennedylaan 3, BE-9060 Zelzate (Belgium); Surinach, S.; Baro, M.D. [Departament de Fisica, Universitat Autonoma de Barcelona, 08193 Bellaterra (Spain); Sort, J. [Departament de Fisica, Universitat Autonoma de Barcelona, 08193 Bellaterra (Spain); Institucio Catalana de Recerca i Estudis Avancats (Spain)

    2012-09-25

    Highlights: Black-Right-Pointing-Pointer We study the effects of Si addition of Ti-Ni-Cu-Si-Sn alloy. Black-Right-Pointing-Pointer The microstructure evolution is correlated with the obtained mechanical and elastic properties. Black-Right-Pointing-Pointer Higher Young's modulus and larger hardness values are obtained in samples with higher Si contents. - Abstract: (Ti{sub 48}Ni{sub 32}Cu{sub 8}Si{sub 8}Sn{sub 4}){sub 100-x}Si{sub x} (x = 0, 2, 4 and 6) alloys were prepared by levitation melting mixtures of the high purity elements in an Ar atmosphere. Rods of 3 mm in diameter were obtained from the melt by copper mould casting. The effects of Si addition on the microstructure, elastic and mechanical properties of the Ti{sub 48}Ni{sub 32}Cu{sub 8}Si{sub 8}Sn{sub 4} alloy were investigated by scanning electron microscopy, X-ray diffraction, acoustic measurements and nanoindentation. The main phases composing the Ti{sub 48}Ni{sub 32}Cu{sub 8}Si{sub 8}Sn{sub 4} alloy are B2 NiTi, B19 Prime NiTi and tetragonal Ti{sub 2}Ni. Additional phases, like Ti{sub 5}Si{sub 3} or Ni{sub 2}Ti{sub 2}Si, become clearly visible in samples with higher Si contents. The microstructure evolution is correlated with the obtained mechanical and elastic properties. These alloys exhibit very high hardness values, which increase with the Si content, from 9 GPa (for x = 0) to around 10.5 GPa (for x = 6). The Young's modulus of Ti{sub 48}Ni{sub 32}Cu{sub 8}Si{sub 8}Sn{sub 4} (around 115 GPa) also increases significantly with Si addition, up to 160 GPa for x = 6.

  11. Fabrication and testing of a CoNiCu/Cu CPP-GMR nanowire-based microfluidic biosensor

    International Nuclear Information System (INIS)

    Bellamkonda, Ramya; John, Tom; Mathew, Bobby; DeCoster, Mark; Hegab, Hisham; Davis, Despina

    2010-01-01

    Giant magneto resistance (GMR)-based microfluidic biosensors are used in applications involving the detection, analysis, enumeration and characterization of magnetic nano-particles attached to biological mediums such as antibodies and DNA. Here we introduce a novel multilayered CoNiCu/Cu nanowire GMR-based microfluidic biosensor. The current perpendicular to the plane of multilayers (CPP)-nanowires GMR was used as the core sensing material in the biosensor which responds to magnetic fields depending on the concentration and the flow velocity of bio-nano-magnetic fluids. The device was tested with different control solutions such as DI-water, mineral oil, phosphate buffered saline (PBS), ferrofluid, polystyrene superparamagnetic beads (PSB) and Dynabeads sheep anti-rabbit IgG. The nanowire array resistance decreased with an increase in the ferrofluid concentration, and a maximum 15.8% relative GMR was observed for the undiluted ferrofluid. The sensor was also responding differently to various ferrofluid flow rates. The GMR device showed variation in the output signal when the PSB and Dynabeads of different dilutions were pumped through it. When the tests were performed with pulsing potentials (150 mV and 200 mV), an increased GMR response was identified at higher voltages for PSB and Dynabeads sheep anti-rabbit IgG.

  12. Study of hyperfine interactions in intermetallic compounds Gd(Ni,Pd,Cu)In, Tb(Ni,Pd)In, Dy(Ni,Pd)In and Ho(Ni,Pd)In; Estudo de interacoes hiperfinas em compostos intermetalicos Gd(Ni,Pd,Cu)In, Tb(Ni,Pd)In, Dy(Ni,Pd)In e Ho(Ni,Pd)In

    Energy Technology Data Exchange (ETDEWEB)

    Lapolli, Andre Luis

    2006-07-01

    Systematic behavior of magnetic hyperfine field (B{sub hf}) in the intermetallic compounds Gd(Ni,Pd,Cu)In Tb(Ni,Pd)In, Dy(Ni,Pd)In and Ho(Ni,Pd)In was studied by Perturbed Gamma-Gamma Angular Correlation spectroscopy. The measurements of B{sub hf} were carried out at the rare earth atom and in sites using the nuclear probes {sup 140}Ce and {sup 11}'1Cd respectively. The variation of hyperfine field with temperature, in most cases, follows the Brillouin function predicted from the molecular field theory. The hyperfine field values at rare earth atom sites obtained from {sup 140}Ce probe as well as at in sites obtained from {sup 111}Cd probe for each series of compounds were extrapolated to zero Kelvin B{sub hf}(T=0) from these curves. These values were compared with the values of the literature for other compounds containing the same rare earth element and all of them show a linear relationship with the ordering temperature. This indicates that the main contribution to B{sub hf} comes from the conduction electron polarization (CEP) through Fermi contact interaction and the principal mechanism of magnetic interaction in these compounds can be described by the RKKY type interaction. The values of B{sub hf}(T=0) for each family of intermetallic compounds RNiIn and RPdIn when plotted as a function of 4f spin projection of rare earth element also shows a linear relationship. Exceptions are the results for the compounds RNiIn obtained with {sup 111}Cd probe where a small deviation from linearity is observed. The results of the measurements carried out with the {sup 111}Cd probe were also analyzed to obtain the hyperfine parameters of the quadrupole interaction as a function of temperature for RPdln and GdNiIn compounds. The results show that for the compound GdPdIn there might be some Gd-In disorder at high temperature. (author)

  13. Study of hyperfine interactions in intermetallic compounds Gd(Ni,Pd,Cu)In, Tb(Ni,Pd)In, Dy(Ni,Pd)In and Ho(Ni,Pd)In; Estudo de interacoes hiperfinas em compostos intermetalicos Gd(Ni,Pd,Cu)In, Tb(Ni,Pd)In, Dy(Ni,Pd)In e Ho(Ni,Pd)In

    Energy Technology Data Exchange (ETDEWEB)

    Lapolli, Andre Luis

    2006-07-01

    Systematic behavior of magnetic hyperfine field (B{sub hf}) in the intermetallic compounds Gd(Ni,Pd,Cu)In Tb(Ni,Pd)In, Dy(Ni,Pd)In and Ho(Ni,Pd)In was studied by Perturbed Gamma-Gamma Angular Correlation spectroscopy. The measurements of B{sub hf} were carried out at the rare earth atom and in sites using the nuclear probes {sup 140}Ce and {sup 11}'1Cd respectively. The variation of hyperfine field with temperature, in most cases, follows the Brillouin function predicted from the molecular field theory. The hyperfine field values at rare earth atom sites obtained from {sup 140}Ce probe as well as at in sites obtained from {sup 111}Cd probe for each series of compounds were extrapolated to zero Kelvin B{sub hf}(T=0) from these curves. These values were compared with the values of the literature for other compounds containing the same rare earth element and all of them show a linear relationship with the ordering temperature. This indicates that the main contribution to B{sub hf} comes from the conduction electron polarization (CEP) through Fermi contact interaction and the principal mechanism of magnetic interaction in these compounds can be described by the RKKY type interaction. The values of B{sub hf}(T=0) for each family of intermetallic compounds RNiIn and RPdIn when plotted as a function of 4f spin projection of rare earth element also shows a linear relationship. Exceptions are the results for the compounds RNiIn obtained with {sup 111}Cd probe where a small deviation from linearity is observed. The results of the measurements carried out with the {sup 111}Cd probe were also analyzed to obtain the hyperfine parameters of the quadrupole interaction as a function of temperature for RPdln and GdNiIn compounds. The results show that for the compound GdPdIn there might be some Gd-In disorder at high temperature. (author)

  14. Effect of cationic size in Hg (Tl/Bi) Ba2Ca2Cu3O8+δ on ...

    Indian Academy of Sciences (India)

    In this paper we have reported investigations on the effect of simultaneous substitution of Bi and Tl at the H site in the oxygen deficient HO layer of HBa2Ca2Cu3O8+ cuprate superconductor. Bulk polycrystalline samples have been prepared by the two-step solid state reaction process (precursor route). It has been ...

  15. Influence of preparation method on supported Cu-Ni alloys and their catalytic properties in high pressure CO hydrogenation

    DEFF Research Database (Denmark)

    Wu, Qiongxiao; Eriksen, Winnie L.; Duchstein, Linus Daniel Leonhard

    2014-01-01

    (50 bar CO and 50 bar H2). These alloy catalysts are highly selective (more than 99 mol%) and active for methanol synthesis; however, loss of Ni caused by nickel carbonyl formation is found to be a serious issue. The Ni carbonyl formation should be considered, if Ni-containing catalysts (even...... high surface area silica supported catalysts (BET surface area up to 322 m2 g-1, and metal area calculated from X-ray diffraction particle size up to 29 m2 g-1). The formation of bimetallic Cu-Ni alloy nanoparticles has been studied during reduction using in situ X-ray diffraction. Compared...

  16. Corrosion aspects of Ni-Cr-Fe based and Ni-Cu based steam generator tube materials

    International Nuclear Information System (INIS)

    Dutta, R.S.

    2009-01-01

    This paper reviews corrosion related issues of Ni-Cr-Fe based (in a general sense) and Ni-Cu based steam generator tube materials for nuclear power plants those have been dealt with for last more than four decades along with some updated information on corrosion research. The materials include austenitic stainless steels (SSs), Alloy 600, Monel 400, Alloy 800 and Alloy 690. Compatibility related issues of these alloys are briefly discussed along with the alloy chemistry and microstructure. For austenitic SSs, stress corrosion cracking (SCC) behaviour in high temperature aqueous environments is discussed. For Alloy 600, intergranular cracking in high temperature water including hydrogen-induced intergranular cracking is highlighted along with the interactions of material in various environments. In case of Monel 400, intergranular corrosion and pitting corrosion at ambient temperature and SCC behaviour at elevated temperature are briefly described. For Alloy 800, the discussion covers SCC behaviour, surface characterization and microstructural aspects of pitting, whereas hydrogen-related issues are also highlighted for Alloy 690.

  17. Approach to study of Cu, Ni and Zn content in soil for ecotoxicological risk assessment

    Science.gov (United States)

    Boluda, R.; Marimon, L.; Gil, C.; Roca-Pérez, L.

    2009-04-01

    Current Spanish legislation on contaminated soils defines contaminated soil as "that whose characteristics have been negatively altered by the presence of dangerous human-derived chemical components whose concentration is such that it is an unacceptable risk for human health or the environment and has been expressly declared as such by legal ruling". Regarding heavy metals, the Spanish Autonomous Communities will promote measures to obtain generic reference values to declare a soil to be contaminated. In the Valencian Community, these reference values still do not exist. So if the protection of ecosystems is considered a priority to declare a soil to be contaminated and to assess the level of risk, emergency toxicity tests and seed growth in land plants are resorted to, or tests with aquatic organisms or other experiments with leached soils obtained by standard procedures are carried out. We studied the toxic effects of calcareous contaminated soils by Cu, Ni and Zn on marine bacterium Vibrio fisheri (MicrotoxR test assay) (1) and on barley (Hordeum vulgare L.) in plate (germination index) (2) and pot (UNE 77301) (3) experiments for the purpose of establishing the Cu, Ni and Zn concentrations in soil which may lead to toxicity in order to observe, therefore, whether there is any likelihood of these pollutants coming into contact with any receptor and if adverse effects exist for living beings and the environment. The results showed significant differences among the three types of tests done but, in all cases, the concentrations needed to reflect toxicity effect on organisms were around 20 -70 (Cu and Ni) to 1000 (Zn) times higher than the levels of the control soils. The sensitivity order of the bio-assay was: (1) < (3) < (2). We would like to thank Spanish government-MICINN for partial funding and support (MICINN, project CGL2006-09776).

  18. Assessment of Pb, Zn, Cu, Ni and Cr in vegetables grown around Zanjan

    Directory of Open Access Journals (Sweden)

    A. Afshari

    2017-05-01

    Full Text Available This study was conducted aimed to assess the potential risk of heavy metals on human health resulting from consumption of vegetables. To this end, the vegetables grown around town and industrial center of Zanjan were sampled randomly. Plant samples were digested using hydrochloric acid (HCL 2 M and concentration of elements (Pb, Zn, Cu, Ni and Cr were recorded by atomic absorption. Obtained means of heavy metals in all vegetables (N= 32 for Zn, Pb, Cu, Ni and Cr is 98.8, 31.9, 19.3, 4.4 and 2.3 mg/kg, respectively. The highest amount of metal pollution index (MPI in the basil and the lowest was observed in the garden cress (respectively 16.46 and 4.88. Daily intake (EDI for zinc, copper and chromium in all age groups was lower than the provisional tolerable daily intake (PTDI. This amount for nickel was 2, 1.6 and 1.3 %, and for Pb 28.1, 22 and 19 % higher than PTDI in children, adults and seniors, respectively. The potential risk (THQ was calculated in all age groups as Pb>>Cu>Zn>Ni>Cr. The potential risks (THQ of chromium, nickel and zinc were calculated lower than 1, for copper a bit more of 1 and for lead much higher than 1. Health index (HI for children, adults and the elderly was estimated 31.331, 24.58 and 21.14, respectively, with the largest contribution of the lead (89.7%.

  19. Comparison of properties and microstructures of Tréfimétaux CuNiBe and Hycon 3HPTM before and after neutron irradiation

    DEFF Research Database (Denmark)

    Singh, B.N.; Edwards, D.J.; Eldrup, Morten Mostgaard

    2000-01-01

    The precipitation strengthened CuNiBe alloys are among the three candidate copper alloys that are being evaluated for application in the first wall, divertor, and limiter components of ITER. Generally, CuNiBe alloys have higher strength but poorerconductivity compared to CuCrZr and Cu-A1_2O_3...... alloys. Brush-Wellman Inc. has developed an improved version of their Hycon CuNiBe alloy that has higher conductivity while maintaining a reasonable level of strength. In the present work we have investigatedthe physical and mechanical properties of the Hycon 3HPTM alloy both before and after neutron...

  20. Correlation of plastic deformation induced intermittent electromagnetic radiation characteristics with mechanical properties of Cu-Ni alloys

    International Nuclear Information System (INIS)

    Singh, Ranjana; Lal, Shree P.; Misra, Ashok

    2015-01-01

    This paper presents experimental results on intermittent electromagnetic radiation during plastic deformation of Cu-Ni alloys under tension and compression modes of deformation. On the basis of the nature of electromagnetic radiation signals, oscillatory or exponential, results show that the compression increases the viscous coefficient of Cu-Ni alloys during plastic deformation. Increasing the percentage of solute atoms in Cu-Ni alloys makes electromagnetic radiation strength higher under tension. The electromagnetic radiation emission occurs at smaller strains under compression showing early onset of plastic deformation. This is attributed to the role of high core region tensile residual stresses in the rolled Cu-Ni alloy specimens in accordance with the Bauschinger effect. The distance between the apexes of the dead metal cones during compression plays a significant role in electromagnetic radiation parameters. The dissociation of edge dislocations into partials and increase in internal stresses with increase in solute percentage in Cu-Ni alloys under compression considerably influences the electromagnetic radiation frequency.

  1. Precipitation kinetics in binary Fe–Cu and ternary Fe–Cu–Ni alloys via kMC method

    Directory of Open Access Journals (Sweden)

    Yi Wang

    2017-08-01

    Full Text Available The precipitation kinetics of coherent Cu rich precipitates (CRPs in binary Fe–Cu and ternary Fe–Cu–Ni alloys during thermal aging was modelled by the kinetic Monte Carlo method (kMC. A good agreement of the precipitation kinetics of Fe–Cu was found between the simulation and experimental results, as observed by means of advancement factor and cluster number density. This agreement was obtained owing to the correct description of the fast cluster mobility. The simulation results indicate that the effects of Ni are two-fold: Ni promotes the nucleation of Cu clusters; while the precipitation kinetics appears to be delayed by Ni addition during the coarsening stage. The apparent delayed precipitation kinetics is revealed to be related with the cluster mobility, which are reduced by Ni addition. The reduction effect of the cluster mobility weakens when the CRPs sizes increase. The results provide a view angle on the effects of solute elements upon Cu precipitation kinetics through the consideration of the non-conventional cluster growth mechanism, and kMC is verified to be a powerful approach on that.

  2. ERGO grown on Ni-Cu foam frameworks by constant potential method as high performance electrodes for supercapacitors

    Science.gov (United States)

    Mirzaee, Majid; Dehghanian, Changiz; Sabet Bokati, Kazem

    2018-04-01

    This study presents composite electrode materials based on Electrochemically Reduced graphene oxide (ERGO) and Ni-Cu Foam for supercapacitor applications. Constant potential (CP) method was used to form reduced graphene oxide on Ni-Cu foam and characterized by scanning electron microscopy (SEM), powder X-ray diffraction (XRD), X-Ray Photoelectron Spectra (XPS), Raman Spectroscopy and electrochemical measurements. ERGO improves the electrical conduction leading to decrease of the internal resistance of the heterostructure. The ERGO served as a conductive network to facilitate the collection and transportation of electrons during the cycling, improved the conductivity of Ni-Cu foam, and allowed for a larger specific surface area. The irregular porous structure allowed for the easy diffusion of the electrolyte into the inner region of the electrode. Moreover, the nanocomposite directly fabricated on Ni-Cu foam with a better adhesion and avoided the use of polymer binder. This method efficiently reduced ohmic polarization and enhanced the rate capability. As a result, the Ni-Cu foam/ERGO nanocomposite exhibited a specific capacitance of 1259.3 F g-1 at 2 A g-1and about 99.3% of the capacitance retained after 5000 cycles. The capacitance retention was about 3% when the current density increased from 2 A g-1 to 15 A g-1. This two-step process drop cast and GO reduction by potentiostatic method is nontoxic and scalable and holds promise for improved energy density from redox capacitance in comparison with the conventional double layer supercapacitors.

  3. High-performance Cu nanoparticles/three-dimensional graphene/Ni foam hybrid for catalytic and sensing applications

    Science.gov (United States)

    Zhu, Long; Guo, Xinli; Liu, Yuanyuan; Chen, Zhongtao; Zhang, Weijie; Yin, Kuibo; Li, Long; Zhang, Yao; Wang, Zengmei; Sun, Litao; Zhao, Yuhong

    2018-04-01

    A novel hybrid of Cu nanoparticles/three-dimensional graphene/Ni foam (Cu NPs/3DGr/NiF) was prepared by chemical vapor deposition, followed by a galvanic displacement reaction in Ni- and Cu-ion-containing salt solution through a one-step reaction. The as-prepared Cu NPs/3DGr/NiF hybrid is uniform, stable, recyclable and exhibits an extraordinarily high catalytic efficiency for the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) with a reduction rate constant K = 0.056 15 s-1, required time ˜30 s and excellent sensing properties for the non-enzymatic amperometric hydrogen peroxide (H2O2) with a linear range ˜50 μM-9.65 mM, response time ˜3 s, detection limit ˜1 μM. The results indicate that the as-prepared Cu NPs/3DGr/NiF hybrid can be used to replace expensive noble metals in catalysis and sensing applications.

  4. Effect of Si addition on the glass-forming ability of a NiTiZrAlCu alloy

    International Nuclear Information System (INIS)

    Liang, W.Z.; Shen, J.; Sun, J.F.

    2006-01-01

    The effect of Si addition on the glass-forming ability (GFA) of a NiTiZrAlCu alloy was investigated by using differential scanning calorimetry (DSC), differential thermal analysis (DTA), X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The maximum diameter of glassy rods increased from 0.5 mm for the Ni 42 Ti 20 Zr 25 Al 8 Cu 5 alloy (the base alloy) to 2.5 mm for the Ni 42 Ti 20 Zr 21.5 Al 8 Cu 5 Si 3.5 alloy and to 3 mm for the Ni 42 Ti 19 Zr 22.5 Al 8 Cu 5 Si 3.5 alloy, when prepared by using the copper mould casting. The GFA of the alloys can be assessed by the reduced glass transition temperature T rg (=T g /T l ) and a newly proposed parameter, δ(=T x /T l - T g ). An addition of a proper amount of Si and a minor substitution of Ti with Zr can enhance the GFA of the base alloy by suppressing the formation of primary Ni(TiZr) and (TiZr)(CuAl) 2 phases and inducing the composition close to eutectic

  5. Fine scale remobilisation of Fe, Mn, Co, Ni, Cu and Cd in contaminated marine sediment

    DEFF Research Database (Denmark)

    Tankere-Muller, Sophie; Zhang, Hao; Davison, William

    2007-01-01

    to less than 0.3 μM. With both DET and DGT measurements, there were sharply defined maxima of Cu and Cd within 2 mm of the sediment water interface, consistent with their release from organic material as it is oxidised. There was a Co maximum about 5–8 mm lower than the Cu and Cd maxima, apparently...... coincidental with Mn mobilisation. While there were clear Ni maxima, their location appeared to vary from being coincident with Co to a few mm above the Co maxima. The remobilisation of metals could not be explained by the pH gradients in the near-surface sediments. As sulphate reduction rates were appreciable...

  6. Persistence of the Z=28 Shell Gap Around ^{78}Ni: First Spectroscopy of ^{79}Cu.

    Science.gov (United States)

    Olivier, L; Franchoo, S; Niikura, M; Vajta, Z; Sohler, D; Doornenbal, P; Obertelli, A; Tsunoda, Y; Otsuka, T; Authelet, G; Baba, H; Calvet, D; Château, F; Corsi, A; Delbart, A; Gheller, J-M; Gillibert, A; Isobe, T; Lapoux, V; Matsushita, M; Momiyama, S; Motobayashi, T; Otsu, H; Péron, C; Peyaud, A; Pollacco, E C; Roussé, J-Y; Sakurai, H; Santamaria, C; Sasano, M; Shiga, Y; Takeuchi, S; Taniuchi, R; Uesaka, T; Wang, H; Yoneda, K; Browne, F; Chung, L X; Dombradi, Z; Flavigny, F; Giacoppo, F; Gottardo, A; Hadyńska-Klęk, K; Korkulu, Z; Koyama, S; Kubota, Y; Lee, J; Lettmann, M; Louchart, C; Lozeva, R; Matsui, K; Miyazaki, T; Nishimura, S; Ogata, K; Ota, S; Patel, Z; Sahin, E; Shand, C; Söderström, P-A; Stefan, I; Steppenbeck, D; Sumikama, T; Suzuki, D; Werner, V; Wu, J; Xu, Z

    2017-11-10

    In-beam γ-ray spectroscopy of ^{79}Cu is performed at the Radioactive Isotope Beam Factory of RIKEN. The nucleus of interest is produced through proton knockout from a ^{80}Zn beam at 270  MeV/nucleon. The level scheme up to 4.6 MeV is established for the first time and the results are compared to Monte Carlo shell-model calculations. We do not observe significant knockout feeding to the excited states below 2.2 MeV, which indicates that the Z=28 gap at N=50 remains large. The results show that the ^{79}Cu nucleus can be described in terms of a valence proton outside a ^{78}Ni core, implying the magic character of the latter.

  7. Characterization of a hot-rolled Cu--Al--Ni--Ti shape memory alloy

    International Nuclear Information System (INIS)

    Segui, C.; Pons, J.; Cesari, E.

    1999-01-01

    The changes in the martensitic transformation of a Cu-Al-Ni-Ti alloy hot-rolled at different temperatures have been studied in detail, covering different aspects such as ageing in the parent phase at temperatures ranging between 250 and 350 o C, stabilisation of the martensite and betatization of the previously hot-rolled specimens. Besides the evolution of transformation temperatures upon different thermal treatments, special attention has been paid to the changes in mechanical properties of the alloy, such as elastic modulus and internal friction. These results are analysed in relation to the microstructural changes as observed by transmission electron microscopy. (orig.)

  8. Local radiofrequency-induced hyperthermia using CuNi nanoparticles with therapeutically suitable Curie temperature

    International Nuclear Information System (INIS)

    Kuznetsov, Anatoly A.; Leontiev, Vladimir G.; Brukvin, Vladimir A.; Vorozhtsov, Georgy N.; Kogan, Boris Ya.; Shlyakhtin, Oleg A.; Yunin, Alexander M.; Tsybin, Oleg I.; Kuznetsov, Oleg A.

    2007-01-01

    Copper-nickel (CuNi) alloy nanoparticles with Curie temperatures (T c ) from 40 to 60 o C were synthesized by several techniques. Varying the synthesis parameters and post-treatment, as well as separations by size and T c , allow producing mediator nanoparticles for magnetic fluid hyperthermia with parametric feedback temperature control with desired parameters. In vitro and in vivo animal experiments have demonstrated the feasibility of the temperature-controlled heating of the tissue, laden with the particles, by an external alternating magnetic field

  9. Local radiofrequency-induced hyperthermia using CuNi nanoparticles with therapeutically suitable Curie temperature

    Energy Technology Data Exchange (ETDEWEB)

    Kuznetsov, Anatoly A. [Institute of Biochemical Physics, Russian Academy of Sciences (RAS), Moscow 119991 (Russian Federation); Leontiev, Vladimir G. [Institute of Metallurgy, Russian Academy of Sciences (RAS), Moscow 119991 (Russian Federation); Brukvin, Vladimir A. [Institute of Metallurgy, Russian Academy of Sciences (RAS), Moscow 119991 (Russian Federation); Vorozhtsov, Georgy N. [NIOPIK Organic Intermediates and Dyes Institute, Moscow 103787 (Russian Federation); Kogan, Boris Ya. [NIOPIK Organic Intermediates and Dyes Institute, Moscow 103787 (Russian Federation); Shlyakhtin, Oleg A. [Institute of Chemical Physics, Russian Academy of Sciences (RAS), Kosygin St. 4, Moscow 119991 (Russian Federation); Yunin, Alexander M. [Institute of Biochemical Physics, Russian Academy of Sciences (RAS), Moscow 119991 (Russian Federation); Tsybin, Oleg I. [Institute of Metallurgy, Russian Academy of Sciences (RAS), Moscow 119991 (Russian Federation); Kuznetsov, Oleg A. [Institute of Biochemical Physics, Russian Academy of Sciences (RAS), Moscow 119991 (Russian Federation)]. E-mail: kuznetsov_oa@yahoo.com

    2007-04-15

    Copper-nickel (CuNi) alloy nanoparticles with Curie temperatures (T{sub c}) from 40 to 60{sup o}C were synthesized by several techniques. Varying the synthesis parameters and post-treatment, as well as separations by size and T{sub c}, allow producing mediator nanoparticles for magnetic fluid hyperthermia with parametric feedback temperature control with desired parameters. In vitro and in vivo animal experiments have demonstrated the feasibility of the temperature-controlled heating of the tissue, laden with the particles, by an external alternating magnetic field.

  10. Time-temperature-transformation diagram of Zr-based Zr-Al-Cu-Ni metallic glasses

    International Nuclear Information System (INIS)

    Goh, T.T.; Li, Y.; Ng, S.C.

    1996-01-01

    The critical cooling rates R c for glass formation in four Zr-based Zr-Al-Cu-Ni alloys were determined using techniques developed by Uhlmann based on theories of homogeneous nucleation, crystal growth and transformation kinetics. It involves the construction of a time-temperature-transformation curve which requires the knowledge of the viscosity-temperature curve of the alloys. Two types of viscosity-temperature expressions, namely Andrade expression and Doolittle expression, were used to model the viscosity of the Zr-based alloys and the choice of the viscosity-temperature expression which gives the best estimate of the calculated time-temperature-transformation curve is discussed. (author)

  11. Chemical probes of metal cluster structure--Fe, Co, Ni, and Cu

    International Nuclear Information System (INIS)

    Parks, E.K.; Zhu, L.; Ho, J.; Riley, S.J.

    1992-01-01

    Chemical reactivity is one of the few methods currently available for investigating the geometrical structure of isolated transition metal clusters. In this paper we summarize what is currently known about the structures of clusters of four transition metals, Fe, Co, Ni, and Cu, in the size range from 13 to 180 atoms. Chemical probes used to determine structural information include reactions with H 2 (D 2 ), H 2 0, NH 3 and N 2 . Measurements at both low coverage and at saturation are discussed

  12. Nb/NiCu bilayers in single and stacked superconductive tunnel junctions: preliminary results

    International Nuclear Information System (INIS)

    Pepe, G.P.; Ruotolo, A.; Parlato, L.; Peluso, G.; Ausanio, G.; Carapella, G.; Latempa, R.

    2004-01-01

    We present preliminary experimental results concerning both single and stacked tunnel junctions in which one of the electrodes was formed by a superconductor/ferromagnet (S/F) bi-layer. In particular, in the stacked configuration a Nb/NiCu bi-layer was used as the intermediate electrode, and it was probed by tunneling on both sides. Tunnel junctions have been characterized in terms of current-voltage characteristics (IVC), and differential conductance. Preliminary steady-state injection-detection measurements performed in the stacked devices at T=4.2 K are also presented and discussed

  13. Selected characteristic of silumins with additives of Ni, Cu, Cr, Mo, W and V

    Directory of Open Access Journals (Sweden)

    S. Pietrowski

    2010-04-01

    Full Text Available The study, presents an investigation results of new grades of silumins containing of: 7,0÷17,0% Si, 4,0% Ni, 4,0% Cu and 0,5% Cr, Mo, W each as well as V. The influence tests were carried out of - antimony addition, strontium and phosphorus modification, supersaturation and ageing processes - on microstructure and silumins hardness. Revealed that investigated silumins, depending on the state, are characte-rized by hardness in the range of 80÷180 HB.

  14. Some aspects of thermally induced martensite in Fe-30% Ni-5% Cu alloy

    International Nuclear Information System (INIS)

    Guener, M.; Gueler, E.; Yasar, E.; Aktas, H.

    2007-01-01

    Kinetical, morphological, crystallographical and several thermal properties of thermally induced martensite in the austenite phase of Fe-30% Ni-5% Cu alloy were investigated. Scanning electron microscope (SEM), transmission electron microscope (TEM) and differential scanning calorimetry (DSC) techniques were used during study. Kinetics of the transformation was found to be as athermal type. SEM and TEM observations revealed α' (BCC) martensite formation in the austenite phase of alloy by thermal effect. These thermally induced α' martensites exhibited a thin plate-like morphology with twinnings

  15. Characterization of uniaxial fatigue behavior of precipitate strengthened Cu-Ni-Si alloy (SICLANIC(TM

    Directory of Open Access Journals (Sweden)

    B. Saadouki

    2018-01-01

    Full Text Available Fatigue tests were conducted on cylindrical bars specimens to understand the fatigue behavior of SICLANIC. Although it displays good resistance in monotonic tension, this material weakens and shows a softening in repeated solicitation. This has been verified through a SEM observation, the Cu-Ni-Si alloy presents transgranular failure by cleavage. The MansonCoffin diagram exhibited the plastic deformation accommodation. The plastic deformation becomes periodic and decreases progressively as the cycle number increases. The approximations of Manson Coffin give fatigue parameters values which are in good agreement with the experience

  16. Conversion of furan derivatives for preparation of biofuels over Ni-Cu/C catalyst

    DEFF Research Database (Denmark)

    Fu, Zhaolin; Wang, Z.; Lin, Weigang

    2017-01-01

    Conversions of furfural and 5-hydroxymethylfurfural as model components in bio-oil were investigated over Ni-Cu/C catalyst with formic acid as hydrogen donor in isopropanol solvent to produce biofuels. The effects of reaction temperature, feed ratio, and reaction time were studied. A high yield...... of 2-methylfuran up to 91 mol% was obtained from furfural in 8 h at 200°C, and under same conditions 80 mol% yield of 2,5-dimethylfuran could also be obtained from 5-hydroxymethylfurfural in 6 h. The results verified the catalyst performance and the availability of the reaction conditions for producing...

  17. Fatigue of thin walled tubes in copper alloy CuNi10

    DEFF Research Database (Denmark)

    Lambertsen, Søren Heide; Damkilde, Lars; Jepsen, Michael S.

    2016-01-01

    The current work concerns the investigation of the fatigue resistance of CuNi10 tubes, which are frequently used in heat exchangers of large ship engines. The lifetime performances of the exchanger tubes are greatly affected by the environmental conditions, where especially the temperature...... by means of the ASTM E739 guideline and one-sided tolerance limits factor method. The tests show good fatigue resistance and the risk for a failure is low in aspect to the case of a ship heat exchanger....

  18. Preparation and characterization of monel (70% Ni-30% Cu) metallic filters

    International Nuclear Information System (INIS)

    Camargo Lavos, I. de.

    1993-01-01

    This work investigates a process for the fabrication and characterization of monel (Ni-Cu) filters. The powder consolidation was made by vibration or by pressing at various pressures (200, 300 e 400 MPa). The sintering was carried out at 1100 0 C during 1 hour under H 2 atmosphere. The filter characterization was performed by measuring its density, porosity, filtering capacity and permeability. It was obtained a correlation between the processing variables (consolidation and sintering), including powder properties, and the filters characteristics. (author). 59 refs, 41 figs, 7 tabs

  19. Major and minor magnetostriction hysteresis loops of Co-Cu-Ni ferrite

    International Nuclear Information System (INIS)

    Bienkowski, Adam; Kaczkowski, Zbigniew

    2000-01-01

    Initial curve, major and minor magnetostriction hysteresis loops (butterfly loops) as the functions of the static magnetic field of the Co 0.004 Cu 0.12 Ni 0.866 Fe 2.01 O 4.02 ferrite were investigated. The saturation magnetostriction for the field equal to 2500 A/m was negative and equal to -11.1x10 -6 and for the field of 540 A/m (equal to 3H c ) was equal to -8.0x10 -6 . Other minor magnetostriction hysteresis loops are presented

  20. Investigation of optical properties of Cu/Ni multilayer nanowires embedded in etched ion-track template

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Lu [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100049 (China); Yao, Huijun, E-mail: Yaohuijun@impcas.ac.cn [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Duan, Jinglai; Chen, Yonghui [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Lyu, Shuangbao [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100049 (China); Maaz, Khan [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Nanomaterials Research Group, Physics Division, PINSTECH, Nilore 45650, Islamabad (Pakistan); Mo, Dan [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Liu, Jie, E-mail: J.Liu@impcas.ac.cn [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Sun, Youmei; Hou, Mingdong [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)

    2016-12-01

    Graphical abstract: The schematic diagram of measurement of extinction spectra of Cu/Ni multilayer nanowire arrays embedded in the template after removing the gold/copper substrate. - Highlights: • The optical properties of Cu/Ni multilayer nanowire arrays were first investigated by UV/Vis/NIR spectrometer and it was confirmed that the extinction peaks strongly related to the periodicity of the multilayer nanowire. • The Ni segment was thought as a kind of impurity which can change the surface electron distribution and thereby the extinction peaks of nanowire. • Current work supplied the clear layer thickness information of Cu and Ni in Cu/Ni multilayer nanowire with TEM and EDS line-scan profile analysis. - Abstract: For understanding the interaction between light and noble/magnetism multilayer nanowires, Cu/Ni multilayer nanowires are fabricated by a multi-potential step deposition technique in etched ion-track polycarbonate template. The component and the corresponding layer thickness of multilayer nanowire are confirmed by TEM and EDS line-scan analysis. By tailoring the nanowire diameter, the Cu layer thickness and the periodicity of the nanowire, the extinction spectral of nanowire arrays exhibit an extra sensitivity to the change of structural parameters. The resonance wavelength caused by surface plasmon resonance increases obviously with increasing the nanowire diameter, the Cu layer thickness and the periodicity. The observations in our work can be explained by the “impurity effect” and coupled effect and can also be optimized for developing optical devices based on multilayer nanowires.

  1. Nanoscale morphology of Ni{sub 50}Ti{sub 45}Cu{sub 5} nanoglass

    Energy Technology Data Exchange (ETDEWEB)

    Śniadecki, Z., E-mail: sniadecki@ifmpan.poznan.pl [Institute of Molecular Physics, Polish Academy of Sciences, M. Smoluchowskiego 17, 60-179 Poznań (Poland); Institute of Nanotechnology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen (Germany); Wang, D. [Institute of Nanotechnology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen (Germany); Karlsruhe Nano Micro Facility, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen (Germany); Ivanisenko, Yu. [Institute of Nanotechnology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen (Germany); Chakravadhanula, V.S.K. [Karlsruhe Nano Micro Facility, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen (Germany); Helmholtz Institute Ulm, Helmholtzstraße 11, 89081, Ulm (Germany); Joint Research Laboratory Nanomaterials (KIT-TUD), Institute of Materials Science, TU Darmstadt, Jovanka-Bontschits-Str. 2, 64287 Darmstadt (Germany); Kübel, C. [Institute of Nanotechnology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen (Germany); Karlsruhe Nano Micro Facility, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen (Germany); Hahn, H. [Institute of Nanotechnology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen (Germany); Joint Research Laboratory Nanomaterials (KIT-TUD), Institute of Materials Science, TU Darmstadt, Jovanka-Bontschits-Str. 2, 64287 Darmstadt (Germany); Nanjing University of Science and Technology, Herbert Gleiter Institute of Nanoscience, Building 340, Nanjing, Jiangsu 2 10094 (China); and others

    2016-03-15

    Nanoglasses are noncrystalline solids with a granular nano-/microstructure. In contrast to their nanocrystalline analogs, typically constituted of grains and grain boundaries, nanoglasses consist of glassy regions with a structure corresponding to melt-quenched glasses and amorphous interfaces characterized by a reduced density. Their unique properties can be controlled by modifying size and chemical composition of the granular and interfacial regions. Ni{sub 50}Ti{sub 45}Cu{sub 5} amorphous films were obtained by magnetron sputtering and analyzed to determine their nanoscale morphology and the formation mechanisms. The nanoglasses were noted to have a hierarchical nano-columnar structure with the smallest Ni-rich (Ni:Ti ratio of ca. 5:3) amorphous columns with diameters of about 8 nm and Ti-rich glassy interfacial regions with a substantially lower density. The results were obtained utilizing X-ray diffraction and different microscopic methods, e.g., atomic force microscopy and transmission electron microscopy. A detailed analysis indicates the complexity of the formation mechanisms of topologically and chemically distinguishable structural units with curvature driven surface diffusion, surface mobility, self-shadowing and internal stresses as the most important parameters. Common and simple synthesis method and the possibility for easy modification of the morphology and, consequently, the physical properties offer an opportunity for intensive studies of this new class of materials, opening the way towards possible applications. - Highlights: • Ni{sub 50}Ti{sub 45}Cu{sub 5} thin film nanoglasses were synthesized by magnetron sputtering. • Ti amorphous interfacial phase with reduced density is observed. • Stabilization of interfaces by specific local thermodynamic conditions.

  2. Simultaneous removal of NO and Hg{sup 0} over Ce-Cu modified V{sub 2}O{sub 5}/TiO{sub 2} based commercial SCR catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Chi, Guilong [School of Energy & Environmental Engineering, Hebei University of Technology, Tianjin 300401 (China); College of Environmental Science & Engineering, Nankai University, Tianjin 300350 (China); Shen, Boxiong, E-mail: shenbx@nankai.edu.cn [School of Energy & Environmental Engineering, Hebei University of Technology, Tianjin 300401 (China); Yu, Ranran [School of Energy & Environmental Engineering, Hebei University of Technology, Tianjin 300401 (China); He, Chuan; Zhang, Xiao [College of Environmental Science & Engineering, Nankai University, Tianjin 300350 (China)

    2017-05-15

    Highlights: • Simultaneous removal of NO and Hg{sup 0} over the novel modified commercial SCR catalysts. • 7% Ce-1% Cu/SCR catalyst exhibited excellent activity of NO conversion and Hg{sup 0} oxidation. • 7% Ce-1% Cu/SCR catalyst showed higher resistance to SO{sub 2} and H{sub 2}O than other catalysts. • The synergistic interaction between Ce and Cu in the catalyst improved the activity greatly. - Abstract: A series of novel Ce-Cu modified V{sub 2}O{sub 5}/TiO{sub 2} based commercial SCR catalysts were prepared via ultrasonic-assisted impregnation method for simultaneous removal of NO and elemental mercury (Hg{sup 0}). Nitrogen adsorption, X-ray diffraction (XRD), temperature programmed reduction of H{sub 2} (H{sub 2}-TPR) and X-ray photoelectron spectroscopy (XPS) were used to characterize the catalysts. 7% Ce-1% Cu/SCR catalyst exhibited the highest NO conversion efficiency (>97%) at 200–400 °C, as well as the best Hg{sup 0} oxidation activity (>75%) at 150–350 °C among all the catalysts. The XPS and H{sub 2}-TPR results indicated that 7% Ce-1% Cu/SCR possess abundant chemisorbed oxygen and good redox ability, which was due to the strong synergy between Ce and Cu in the catalyst. The existence of the redox cycle of Ce{sup 4+} + Cu{sup 1+} ↔ Ce{sup 3+} + Cu{sup 2+} could greatly improve the catalytic activity. 7% Ce-1% Cu/SCR showed higher resistance to SO{sub 2} and H{sub 2}O than other catalysts. NO has a promoting effect on Hg{sup 0} oxidation. The Hg{sup 0} oxidation activity was inhibited by the injection of NH{sub 3}, which was due to the competitive adsorption and oxidized mercury could be reduced by ammonia at temperatures greater than 325 °C. Therefore, Hg{sup 0} oxidation could easily occurred at the outlet of SCR catalyst layer due to the consumption of NH{sub 3}.

  3. Performance of 500 m3 TankCell® at Kevitsa Cu-Ni-PGM concentrator

    Directory of Open Access Journals (Sweden)

    Mattsson Toni

    2016-01-01

    Full Text Available Outotec TankCell e500 flotation cell, with 500 m3 of efficient flotation volume, has been in operation since October 2014 at Kevitsa Cu-Ni-PGM concentrator as the first Cu rougher flotation cell. The 500 m3 flotation cell has proven to provide metallurgical superiority at very low specific power. On average the cell has recovered 71% of copper contained in the flotation feed. The cell has produced the concentrate with the Cu grade equal to 17% Cu. The typical specific power for the cell is around 0.4 kW/m3 (blower power not included. After the start-up of the cell the operating parameters have varied. The mixing speed have varied from 4.9 to 7.0 m/s and the superficial gas velocity from 0.3 to 1.5 cm/s. At various operating parameters the mixing, gas dispersion and metallurgical performance of the cell have been evaluated. In this paper a review of the hydrodynamic and metallurgical performance of the cell is presented. The paper focuses on the interactions of mixing intensity, bubble size and metallurgical performance in industrial application.

  4. Effect of precipitation on the shape memory effect of Ti50Ni25Cu25 melt-spun ribbon

    International Nuclear Information System (INIS)

    Tong Yunxiang; Liu Yong; Xie Zeliang; Zarinejad, Mehrdad

    2008-01-01

    The present research aims to provide accurate understanding of the relation between precipitation (volume fraction, morphology, type) and shape memory effect of Ti 50 Ni 25 Cu 25 melt-spun ribbon. Rapid thermal annealing was used to control the microstructural development while the shape memory effect of the ribbon was determined under constraint thermal cycling. The results show that the precipitation process takes the following sequence: B11 TiCu → B11 TiCu + Ti 2 (Ni, Cu) → Ti 2 (Ni, Cu) with increasing annealing temperature or duration. The shape memory effect is found to depend on both the volume fraction and the distribution of the precipitates. The former affects the shape recovery strain through reduction of the transformation volume participating the shape recovery. The latter affects the shape recovery strain through strengthening the matrix thus reducing the martensite strain which is more predominant under low constraint stresses. Precipitation strengthening, on the other hand, reduces the tendency of dislocation generation/movement, thus reducing the irreversible strain and improving shape recovery strain. This understanding provides guidelines on the optimization of the shape memory properties of the Ti 50 Ni 25 Cu 25 melt-spun ribbon via post-processing annealing

  5. Swift heavy ion irradiation of Cu-Zn-Al and Cu-Al-Ni alloys.

    Science.gov (United States)

    Zelaya, E; Tolley, A; Condo, A M; Schumacher, G

    2009-05-06

    The effects produced by swift heavy ions in the martensitic (18R) and austenitic phase (β) of Cu based shape memory alloys were characterized. Single crystal samples with a surface normal close to [210](18R) and [001](β) were irradiated with 200 MeV of Kr(15+), 230 MeV of Xe(15+), 350 and 600 MeV of Au(26+) and Au(29+). Changes in the microstructure were studied with transmission electron microscopy (TEM) and high resolution transmission electron microscopy (HRTEM). It was found that swift heavy ion irradiation induced nanometer sized defects in the 18R martensitic phase. In contrast, a hexagonal close-packed phase formed on the irradiated surface of β phase samples. HRTEM images of the nanometer sized defects observed in the 18R martensitic phase were compared with computer simulated images in order to interpret the origin of the observed contrast. The best agreement was obtained when the defects were assumed to consist of local composition modulations.

  6. Evaluation of structural, morphological and magnetic properties of CuZnNi (Cu_xZn_0_._5_−_xNi_0_._5Fe_2O_4) nanocrystalline ferrites for core, switching and MLCI’s applications

    International Nuclear Information System (INIS)

    Akhtar, Majid Niaz; Khan, Muhammad Azhar; Ahmad, Mukhtar; Nazir, M.S.; Imran, M.; Ali, A.; Sattar, A.; Murtaza, G.

    2017-01-01

    The influence of Cu substitution on the structural and morphological characteristics of Ni–Zn nanocrystalline ferrites have been discussed in this work. The detailed and systematic magnetic characterizations were also done for Cu substituted Ni–Zn nanoferrites. The nanocrystalline ferrites of Cu substituted Cu_xZn_0_._5_−_xNi_0_._5Fe_2O_4 ferrites (x=0, 0.1, 0.2, 0.3, 0.4 and 0.5) were synthesized using sol gel self-combustion hybrid method. X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), Transmission electron microscope (TEM) and Vibrating sample magnetometer (VSM) were used to investigate the properties of Cu substituted nanocrystalline ferrites. Single phase structure of Cu substituted in Ni–Zn nanocrystalline ferrites were investigated for all the samples. Crystallite size, lattice constant and volume of the cell were found to increase by increasing Cu contents in spinel structure. The better morphology with well-organized nanocrystals of Cu–Zn–Ni ferrites at x=0 and 0.5 were observed from both FESEM and TEM analysis. The average grain size was 35–46 nm for all prepared nanocrystalline samples. Magnetic properties such as coercivity, saturation, remanence, magnetic squareness, magneto crystalline anisotropy constant (K) and Bohr magneton were measured from the recorded M–H loops. The magnetic saturation and remanence were increased by the incorporation of Cu contents. However, coercivity follow the Stoner-Wolforth model except for x=0.3 which may be due to the site occupancy and replacement of Cu contents from octahedral site. The squareness ratio confirmed the super paramgnetic behaviour of the Cu substituted in Ni–Zn nanocrystalline ferrites. Furthermore, Cu substituted Ni–Zn nanocrystalline ferrites may be suitable for many industrial and domestic applications such as components of transformers, core, switching, and MLCI’s due to variety of the soft magnetic characteristics. - Highlights: • Cu substituted

  7. Distinctive behavior of superconducting fluctuations and pseudogap in nearly optimally doped single crystal of HgBa2CuO4+δ

    International Nuclear Information System (INIS)

    Grbic, M.S.; Barisic, N.; Dulcic, A.; Kupcic, I.; Li, Y.; Zhao, X.; Yu, G.; Dressel, M.; Greven, M.; Pozek, M.

    2010-01-01

    We have applied an unconventional microwave measurement approach to a nearly optimally doped HgBa 2 CuO 4+δ single crystal. The sample geometry assured the total lateral penetration of microwaves due to weak c-axis screening currents. With this configuration, one can achieve excellent sensitivity to small changes in conductivity. The data show that the pseudogap opens at T*=185(15)K, which is almost twice the superconducting critical temperature T c =94.3 K. In contrast, the superconducting fluctuation regime is clearly confined to a narrow temperature range T c ' ∼105(2)K, far below T*. This is confirmed by the magnetic field dependence of the microwave absorption. Hence, our results support the distinction between the physical processes of pseudogap and the superconducting ordering.

  8. Neutron Diffraction Study of the High-Tc Superconductor HgBa2CaCu2O6.3 under High Pressure

    International Nuclear Information System (INIS)

    Aksenov, V.L.; Balagurov, A.M.; Savenko, B.N.; Capponi, J.J.; Glazkov, V.P.; Goncharenko, I.N.; Somenkov, V.A.

    1994-01-01

    The pressure dependence of the crystal structure of a powder sample of HgBa 2 CaCu 2 O 6.3 (T c =123 K) was studied in the pressure range of 0 to 3.6 GPa, using the DN-12 time-of-flight diffractometer at the IBR-2 pulsed reactor and a sapphire anvil cell chamber. At P=0 the results are in a good accordance with the published data. At P=3.0 and 3.6 GPa the best fit of the experimental data was achieved using the structural model with apical oxygen disordered in the (a,b) plane. The compressibility values of the lattice constants and selected bonds were calculated from the structural data. The highest absolute value of compressibility was found for the distance between the O atom layers. 12 refs., 6 figs., 3 tabs

  9. Density functional study of hypophosphite adsorption on Ni (1 1 1) and Cu (1 1 1) surfaces

    International Nuclear Information System (INIS)

    Zeng Yue; Liu Shubin; Ou Lihui; Yi Jianlong; Yu Shanci; Wang Huixian; Xiao Xiaoming

    2006-01-01

    Surface structures and electronic properties of hypophosphite, H 2 PO 2 - , molecularly adsorbed on Ni(1 1 1) and Cu(1 1 1) surfaces are investigated in this work by density functional theory at B3LYP/6-31++g(d, p) level. We employ a four-metal-atom cluster as the simplified model for the surface and have fully optimized the geometry and orientation of H 2 PO 2 - on the metal cluster. Six stable orientations have been discovered on both Ni (1 1 1) and Cu (1 1 1) surfaces. The most stable orientation of H 2 PO 2 - was found to have its two oxygen atoms interact the surface with two P-O bonds pointing downward. Results of the Mulliken population analysis showed that the back donation from 3d orbitals of the transition metal substrate to the unfilled 3d orbital of the phosphorus atom in H 2 PO 2 - and 4s orbital's acceptance of electron donation from one lone pair of the oxygen atom in H 2 PO 2 - play very important roles in the H 2 PO 2 - adsorption on the transition metals. The averaged electron configuration of Ni in Ni 4 cluster is 4s 0.63 4p 0.02 3d 9.35 and that of Cu in Cu 4 cluster is 4s 1.00 4p 0.03 3d 9.97 . Because of this subtle difference of electron configuration, the adsorption energy is larger on the Ni surface than on the Cu surface. The amount of charge transfers due to above two donations is larger from H 2 PO 2 - to the Ni surface than to the Cu surface, leading to a more positively charged P atom in Ni n H 2 PO 2 - than in Cu n H 2 PO 2 - . These results indicate that the phosphorus atom in Ni n H 2 PO 2 - complex is easier to be attacked by a nucleophile such as OH - and subsequent oxidation of H 2 PO 2 - can take place more favorably on Ni substrate than on Cu substrate

  10. 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

  11. First-principles calculation of the transition temperature Tc for HgBa2CuO4+δ high-temperature superconductors via dipolon theory

    International Nuclear Information System (INIS)

    Downs, D.; Sharma, R.R.

    1995-01-01

    First numerical evaluations of T c for oxygenated and argon-reduced single-layered HgBa 2 CuO 4+δ superconductors have been presented. Our calculations are based on the dipolon theory and are found to provide an explanation for the occurrence of superconductivity in single-layered high-T c superconductors. Relevant expressions useful for the evaluation of T c have been given. Since the polarizabilities of the ions are not known exactly for the present systems we have performed calculations making use of Pauling's as well as Tessman, Kahn, and Shockley's polarizabilities in order to estimate the uncertainties in the calculated values of T c associated with uncertainties in the polarizabilities. The effective charges on the ions required for the evaluation of dipoles and dipolon frequencies have been obtained by means of the bond-valence sums. Without fitting with any parameters, our calculations yield T c values equal to 80±21 K for the oxygenated and 50±27 K for the argon-reduced HgBa 2 CuO 4+δ superconductors, in agreement with the corresponding experimental values 95 and 59 K. The uncertainties in the calculated values of T c arise because of the uncertainties in various physical parameters (including polarizabilities) used and due to errors involved in the calculations. The present results are consistent with the observed electronic Raman-scattering intensities which show anomalously broad peaks extended up to several electron volts in cuprate high-T c superconductors. Our calculated dipolon density of states predict four optical absorption peaks at about 77 cm -1 , 195 cm -1 , 1.6 eV, and 2.5 eV

  12. Features of Crystallization of Rapidly Quenched Ni45Ti32Hf18Cu5 and Ni25Ti32Hf18Cu25 Alloys from Melt with High-Temperature Shape Memory Effect

    Science.gov (United States)

    Pushin, A. V.; Pushin, V. G.; Kuntsevich, T. E.; Kuranova, N. N.; Makarov, V. V.; Uksusnikov, A. N.; Kourov, N. I.

    2017-12-01

    A comparative study of the structure and the chemical and phase composition of Ni45Ti32Hf18Cu5 and Ni25Ti32Hf18Cu25 amorphous alloys obtained by fast-quenching of melt stream by spinning has been carried out by transmission and scanning electron microscopy and X-ray diffraction. The critical temperatures of their devitrification were determined by the data of temperatures measurements of electrical resistance. The features of the formation of ultrafine structure and the phase transformation at the vitrification depending on the regimes of heat treatment and chemical composition of alloy have been established.

  13. Effect of Zn on the structural and electrical properties of high temperature HgBa2Ca2Cu3O8+δ superconductor

    Science.gov (United States)

    Omar, Bilal A.; Fathi, Sabah J.; Jassim, Kareem A.

    2018-05-01

    Bulk polycrystalline HgBa2Ca2-yZnyCu3O8+δ compound samples with y =0.0, 0.05, 0.1, 0.15, 0.2, 0.25, and 0.3, are synthesized by a solid state reaction process. Study identifies Zinc partial substitution on superconductivity behavior. Structural properties are studied by using X-ray powder pattern, the high temperature phase superconductor (Hg-1223) of the tetragonal structure didn't change with the partial substitution of Zn ions in Ca site, lattice parameters c, c/a are established to vary Zn-substitution. The surface morphology has been studied by using atomic force microscopes (AFM), showed that all specimens have good crystalline and homogeneous surface. Also give a best nano size value is 83.29 nm at y=0.05. Four probe technique is used to measure Tc. The highest Tc and oxygen content were found to be Tc=132 K for y=0.05 after that, Tc decreases from 132 K to 115 K with increasing Zn. In addition, dielectric properties (dielectric constant, dielectric loss factor, and the alternating electrical conductivity) are characterized directly by relating with Zn concentration.

  14. A study on the cementation of Cu, Ni and Co ions with Mn powders in chloride solution

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Jae-Woo [Daejin University, Pochun-gun(Korea); Ahn, Jong-Gwan [Korea Univ., Seoul(Korea); Park, Kyung-Ho [Korea Institute of Geology Mining and Materials, Taejeon (Korea)

    2000-06-30

    A study on the cementation for the recovery of Cu, Ni and Co with Mn metallic powders in leaching solution from the manganese nodule that have removed Fe ions was studied. The results showed that the recovery efficiencies of metal ions with Mn powders increased when the temperature, pH and the concentration of chloride ions were increased in mixed solution. And the recovery efficiencies of Cu was 98% and not changed with the addition amounts of Mn powders but, in case of Co and Ni, the recovery efficiencies were increased with the addition amounts. The particle size of precipitate was about 5 {mu}m. From the results of experiment we proposed the two-step cementation process for the recovery of Cu, Ni and Co with Mn powders. (author). 9 refs., 4 tabs., 14 figs.

  15. In-situ XRD and EDS method study on the oxidation behaviour of Ni-Cu sulphide ore.

    Science.gov (United States)

    Li, Guangshi; Cheng, Hongwei; Xiong, Xiaolu; Lu, Xionggang; Xu, Cong; Lu, Changyuan; Zou, Xingli; Xu, Qian

    2017-06-12

    The oxidation mechanism of sulfides is the key issue during the sulphide-metallurgy process. In this study, the phase transformation and element migration were clearly demonstrated by in-situ laboratory-based X-ray diffraction (XRD) and energy-dispersive X-ray spectroscopy (EDS), respectively. The reaction sequence and a four-step oxidation mechanism were proposed and identified. The elemental distribution demonstrated that at a low temperature, the Fe atoms diffused outward and the Ni/Cu atoms migrated toward the inner core, whereas the opposite diffusion processes were observed at a higher temperature. Importantly, the unique visual presentation of the oxidation behaviour provided by the combination of in-situ XRD and EDS might be useful for optimising the process parameters to improve the Ni/Cu extraction efficiency during Ni-Cu sulphide metallurgy.

  16. Synthesis and Characterization of High-Entropy Alloy AlFeCoNiCuCr by Laser Cladding

    Directory of Open Access Journals (Sweden)

    Xiaoyang Ye

    2011-01-01

    Full Text Available High-entropy alloys have been recently found to have novel microstructures and unique properties. In this study, a novel AlFeCoNiCuCr high-entropy alloy was prepared by laser cladding. The microstructure, chemical composition, and constituent phases of the synthesized alloy were characterized by SEM, EDS, XRD, and TEM, respectively. High-temperature hardness was also evaluated. Experimental results demonstrate that the AlFeCoNiCuCr clad layer is composed of only BCC and FCC phases. The clad layers exhibit higher hardness at higher Al atomic content. The AlFeCoNiCuCr clad layer exhibits increased hardness at temperature between 400–700°C.

  17. Structural characterization and antioxidant properties of Cu(II) and Ni(II) complexes derived from dicyandiamide

    Science.gov (United States)

    Kertmen, Seda Nur; Gonul, Ilyas; Kose, Muhammet

    2018-01-01

    New Cu(II) and Ni(II) complexes derived from dicyandiamide were synthesized and characterised by spectroscopic and analytical methods. Molecular structures of the complexes were determined by single crystal X-ray diffraction studies. In the complexes, the Cu(II) or Ni(II) ions are four-coordinate with a slight distorted square planar geometry. The ligands (L-nPen and L-iPen) derived from dicyandiamide formed via nucleophilic addition of alcohol solvent molecule in the presence Cu(II) or Ni(II) ions. Complexes were stabilised by intricate array of hydrogen bonding interactions. Antioxidant activity of the complexes was evaluated by DPPH radical scavenging and CUPRAC methods. The complexes exhibit antioxidant activity, however, their activities were much lower than standard antioxidants (Vitamin C and trolox).

  18. Tuning the effective parameters in (Ta/Cu/[Ni/Co]x/Ta) multilayers with perpendicular magnetic anisotropy

    Science.gov (United States)

    Ayareh, Zohreh; Moradi, Mehrdad; Mahmoodi, Saman

    2018-06-01

    In this paper, we report perpendicular magnetic anisotropy (PMA) in a (Ta/Cu/[Ni/Co]x/Ta) multilayers structure. These typical structures usually include a multilayer of ferromagnetic and transition metal thin films. Usually, magnetic anisotropy is characterized by magnetization loops determined by magnetometer or magneto-optical Kerr effect (MOKE). The interface between ferromagnetic and metallic layers plays an important role in magnetic anisotropy evolution from out-of-plane to in-plane in (Ta/Cu/[Ni/Co]/Ta) structure. Obtained results from MOKE and magnetometry of these samples show that they have different easy axes due to change in thickness of Cu as spacer layer and difference in number of repetition of [Ni/Co] stacks.

  19. Hydrazine reduction of metal ions to porous submicro-structures of Ag, Pd, Cu, Ni, and Bi

    Energy Technology Data Exchange (ETDEWEB)

    Wang Yue; Shi Yongfang; Chen Yubiao [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); Wu Liming, E-mail: liming_wu@fjirsm.ac.cn [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China)

    2012-07-15

    Porous submicro-structures of Ag, Pd, Cu, Ni, and Bi with high surface area have been prepared by the reduction of hydrazine in glycerol-ethanol solution at room temperature or 120-180 Degree-Sign C. Phase purity, morphology, and specific surface area have been characterized. The reactions probably undergo three different mechanisms: simple reduction for Ag and Pd, coordination-then-reduction for Cu and Ni, and hydrolysis-then-reduction for Bi. The reductant hydrazine also plays an important role to the formation of the porous submicro-structure. The reaction temperature influences the size of the constituent particles and the overall architecture of the submicro-structure so as to influence the surface area value. The as-prepared porous metals have shown the second largest surface area ever reported, which are smaller than those made by the reduction of NaBH{sub 4}, but larger than those made by hard or soft template methods. - Graphical abstract: Porous submicro-structures of Ag, Pd, Cu, Ni, and Bi with high surface area have been prepared by the reduction of hydrazine in the glycerol-ethanol solution at room temperature or 120-180 Degree-Sign C. The reactions undergo different mechanisms: simple reduction for Ag and Pd, coordination-then-reduction for Cu and Ni, and hydrolysis-then-reduction for Bi. Highlights: Black-Right-Pointing-Pointer Syntheses of porous Ag, Pd, Cu, Ni, and Bi with high surface area. Black-Right-Pointing-Pointer Ag and Pd undergo simple reduction. Black-Right-Pointing-Pointer Cu and Ni undergo coordination-then-reduction. Black-Right-Pointing-Pointer Bi undergoes hydrolysis-then-reduction. Black-Right-Pointing-Pointer The as-prepared metals have shown the second largest surface area ever reported.

  20. Magnetic nanoparticles of NiCuZn tested in different conditions in catalysis for biodiesel

    International Nuclear Information System (INIS)

    Dantas, J.; Silva, F.N.; Silva, A.S.; Pereira, K.R.O.; Costa, A.C.F.M.

    2014-01-01

    In this work it was used magnetic nanoparticles Ni_0_,_2Cu_0_,_3Zn_0_,_5Fe_2O_4, chemical and thermally stable, under different conditions in catalysis for biodiesel. The magnetic characteristic of such material allows the catalyst recovery after the reactions by applying a permanent magnet. It was proposed to evaluate the performance of the nanomagnetic catalyst Ni_0_,_2Cu_0_,_3Zn_0_,_5Fe_2O_4 in the transesterification, modifying the processing variables (temperature, time, molar ratio of oil:alcohol and catalyst amount). The nanoparticles were synthesized by combustion reaction and characterized by XRD, TG, BET, magnetic measurements and gas chromatography. The results revealed the formation of inverse spinel phase, type B(AB)_2O_4, presenting isotherm profile classified as type V, with hysteresis loop of type 3 (H3). The magnetic hysteresis curve showed a characteristic behavior of soft magnetic material. GC analysis confirmed that nanoparticles were catalytically active, since they were superior to the reaction conducted without the catalyst presence. Besides, the reactions suffered considerable influence due to the changes of the independent variables. (author)

  1. Hydrographic parameters and distribution of dissolved Cu, Ni, Zn and nutrients near Jeddah desalination plant

    Directory of Open Access Journals (Sweden)

    Fallatah Mohammad M.

    2018-04-01

    Full Text Available The development of safe desalination plants with low environmental impact is as important an issue as the supply of drinking water. The desalination plant in Jeddah (Saudi Arabia, Red Sea coast produces freshwater from seawater by multi-stage flash distillation (MSFD and reverse osmosis (RO. The process produces brine as by-product, which is dumped into the sea. The aim of this study was to assess the impact of Jeddah desalination plant on the coastal water in the nearby of the plant. Total concentrations of dissolved Cu, Ni, Zn and nutrients in several locations around the plant were analyzed by cathodic stripping voltammetry. The average levels of dissolved Cu, Ni, and Zn on surface in the sampling locations were 15.02, 11.02, and 68.03 nM respectively, whereas the levels at the seafloor near the discharging point were much higher. Distribution of temperature, salinity, nutrients and dissolved oxygen were quite normal both on surface and in depth.

  2. Design and characterization of FeCrNiCoAlCu and FeCrNiCo(AlCu){sub 0,5} multicomponent alloys; Previsao e caracterizacao de ligas multicomponentes FeCrNiCoAlCu e FeCrNiCo(AlCu){sub 0,5}

    Energy Technology Data Exchange (ETDEWEB)

    Triveno Rios, Carlos; Artacho, Victor Falcao [Universidade Federal do ABC (CECS/UFABC), Santo Andre, SP (Brazil). Engenharia de Materiais

    2014-07-01

    High entropy alloys using multi-element main quasi-equivalent atomic proportions and generally forms single-phase solid solution and has the ability to enhance levels of strain hardening combined with high levels of plastic deformation at room temperature. In this work two high-entropy alloys with almost similar composition were studied and the factors influencing the formation of solid solution phases (δ atomic radius difference, ΔH{sub mix} mixing enthalpy, ΔS{sub mix} mixing entropy) were evaluated. The microstructure as-cast and the compositions of phases in the two alloys were analyzed by SEM and XRD. The mechanical characterization was realized by measurements of microhardness and cold compression test. The results showed that FeCrNiCo(AlCu){sub 0,5} and FeCrNiCoAlCu alloys with δ equal to 5,7 and 4,9, respectively, form alloys with solid solutions of high entropy. However, the presence of FC and BCCC structures greatly influence the mechanical properties. (author)

  3. Screening of various types of lignin products for biosorption of heavy metals (Cu, Ni, Zn)

    Energy Technology Data Exchange (ETDEWEB)

    Gouda, H [Nile Research Inst., National Water Research Center, El Qanater (Egypt)

    2000-07-01

    This paper discussed the need to develop new technologies and approaches to meet strict environmental legislation and standards regarding the discharge of heavy metals to the environment by industry. A study was conducted to determine the feasibility of using different lignin materials for heavy metal removal using the BioElecDetox process. This process uses an unique combination of existing water and wastewater equipment and technology. The heavy metal removal efficiencies of grape stalks, pine bark, larch bark, pine sawdust, broccoli stems, and paper pulp were tested for their biosorption capacity, sedimentation, desorption and recycling for single solutions of copper, nickel and zinc (Cu, Ni and Zn respectively). Results showed that the grape stalk was the best biosorbent among the biomasses examined for Cu, Ni and Zn ions from single solution. The biomass biosorption capacity was determined using the Langmuir equation. Pine bark also gave good results and was considered to be the second best biosorbent. The biosorption for single metal solution was high for all metals. Biomass recycling had no impact on the efficiency of biosorption. It was recommended that future experiments should be conducted for industrial effluent using different biomasses at laboratory scale for the BioElecDetox process. 5 refs., 1 tab., 2 figs.

  4. High temperature dielectric studies of indium-substituted NiCuZn nanoferrites

    Science.gov (United States)

    Hashim, Mohd.; Raghasudha, M.; Shah, Jyoti; Shirsath, Sagar E.; Ravinder, D.; Kumar, Shalendra; Meena, Sher Singh; Bhatt, Pramod; Alimuddin; Kumar, Ravi; Kotnala, R. K.

    2018-01-01

    In this study, indium (In3+)-substituted NiCuZn nanostructured ceramic ferrites with a chemical composition of Ni0.5Cu0.25Zn0.25Fe2-xInxO4 (0.0 ≤ x ≤ 0.5) were prepared by chemical synthesis involving sol-gel chemistry. Single phased cubic spinel structure materials were prepared successfully according to X-ray diffraction and transmission electron microscopy analyses. The dielectric properties of the prepared ferrites were measured using an LCR HiTester at temperatures ranging from room temperature to 300 °C at different frequencies from 102 Hz to 5 × 106 Hz. The variations in the dielectric parameters ε‧ and (tanδ) with temperature demonstrated the frequency- and temperature-dependent characteristics due to electron hopping between the ions. The materials had low dielectric loss values in the high frequency range at all temperatures, which makes them suitable for high frequency microwave applications. A qualitative explanation is provided for the dependences of the dielectric constant and dielectric loss tangent on the frequency, temperature, and composition. Mӧssbauer spectroscopy was employed at room temperature to characterize the magnetic behavior.

  5. Phase formation in as-solidified and heat-treated Al-Si-Cu-Mg-Ni alloys: Thermodynamic assessment and experimental investigation for alloy design

    Energy Technology Data Exchange (ETDEWEB)

    Farkoosh, A.R., E-mail: amir.rezaeifarkoosh@mail.mcgill.ca [Department of Mining and Materials Engineering, McGill University, 3610 University, Aluminum Research Center - REGAL, Montreal, Quebec, Canada H3A 2B2 (Canada); Javidani, M. [Laval University, Department of Mining, Metallurgy and Materials Engineering, Aluminum Research Center - REGAL, 1065 Ave de la Medecine, Quebec, Canada G1V 0A6 (Canada); Hoseini, M. [Department of Mining and Materials Engineering, McGill University, 3610 University, Aluminum Research Center - REGAL, Montreal, Quebec, Canada H3A 2B2 (Canada); Larouche, D. [Laval University, Department of Mining, Metallurgy and Materials Engineering, Aluminum Research Center - REGAL, 1065 Ave de la Medecine, Quebec, Canada G1V 0A6 (Canada); Pekguleryuz, M. [Department of Mining and Materials Engineering, McGill University, 3610 University, Aluminum Research Center - REGAL, Montreal, Quebec, Canada H3A 2B2 (Canada)

    2013-02-25

    Highlights: Black-Right-Pointing-Pointer Phase formation in Al-Si-Ni-Cu-Mg-Fe system have been investigated. Black-Right-Pointing-Pointer T-Al{sub 9}FeNi, {gamma}-Al{sub 7}Cu{sub 4}Ni, {delta}-Al{sub 3}CuNi and {epsilon}-Al{sub 3}Ni are formed at different Ni levels. Black-Right-Pointing-Pointer Thermally stable Ni-bearing precipitates improved the overaged hardness. Black-Right-Pointing-Pointer It was found that Ni:Cu and Ni:Fe ratios control the precipitation. Black-Right-Pointing-Pointer {delta}-Al{sub 3}CuNi phase has more contribution to strength compare to other precipitates. - Abstract: Thermodynamic simulations based on the CALPHAD method have been carried out to assess the phase formation in Al-7Si-(0-1)Ni-0.5Cu-0.35Mg alloys (in wt.%) under equilibrium and non-equilibrium (Scheil cooling) conditions. Calculations showed that the T-Al{sub 9}FeNi, {gamma}-Al{sub 7}Cu{sub 4}Ni, {delta}-Al{sub 3}CuNi and {epsilon}-Al{sub 3}Ni phases are formed at different Ni levels. By analyzing the calculated isothermal sections of the phase diagrams it was revealed that the Ni:Cu and Ni:Fe ratios control precipitation in this alloy system. In order to verify the simulation results, microstructural investigations in as-cast, solution treated and aged conditions were carried out using electron probe microanalysis (EPMA), scanning electron microscopy (SEM), X-ray diffraction (XRD) and transmission electron microscopy (TEM). Furthermore, cooling curve analysis (CCA) was also performed to determine the freezing range of the new alloys and porosity formation during solidification. Hardness measurements of the overaged samples showed that in this alloy system the {delta}-Al{sub 3}CuNi phase has a greater influence on the overall strength of the alloys compared to the other Ni-bearing precipitates.

  6. Facile Synthesis of Cu2O/RGO/Ni(OH)2 Nanocomposite and its Double Synergistic Effect on Supercapacitor Performance

    International Nuclear Information System (INIS)

    Wang, Kun; Zhao, Chongjun; Min, Shudi; Qian, Xiuzhen

    2015-01-01

    ABSTRACT: A nanocomposite for supercapacitor electrode materials was designed and developed by integrating partially disabled Cu 2 O (low specific capacity, but high cycling ability) and Ni(OH) 2 (low cyclability and high specific capacity) in the presence of reduced graphene oxide (RGO) nanosheets. Nanocomposite of Cu 2 O/RGO/Ni(OH) 2 was directly grown on nickel foam (NF) through a facile one-pot hydrothermal process without any other reductant or oxidant, in which nickel foam acted as both a reductant of GO and Ni source, and a substrate for nanocomposite. The resultant Cu 2 O/RGO/Ni(OH) 2 nanocomposites were characterized by X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectrometer (XPS), field emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM). The electrochemical performance of the as-synthesized Cu 2 O/RGO/Ni(OH) 2 /NF electrodes were evaluated using cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectrometry (EIS) in 6 mol L −1 KOH aqueous solution. This Cu 2 O/RGO/Ni(OH) 2 nanocomposite exhibits superior capacitive performance: high capability (3969.3 mF cm −2 at 30 mA cm −2 , i.e., 923.1 F g −1 at 7.0 A g −1 ), excellent cycling stability (92.4% retention even after 4,000 cycles, for RGO/Ni(OH) 2 /NF, 92.3% after 1,000 cycles), and good rate capacitance (50.3% capacity remaining at 200 mA cm −2 )

  7. A new Ti-Zr-Hf-Cu-Ni-Si-Sn bulk amorphous alloy with high glass-forming ability

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Y.J. [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Shen, J. [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China)]. E-mail: junshen@hit.edu.cn; Sun, J.F. [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Yu, X.B. [Lab of Energy Science and Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China)]. E-mail: yuxuebin@hotmail.com

    2007-01-16

    The effect of Sn substitution for Cu on the glass-forming ability was investigated in Ti{sub 41.5}Zr{sub 2.5}Hf{sub 5}Cu{sub 42.5-x}Ni{sub 7.5}Si{sub 1}Sn {sub x} (x = 0, 1, 3, 5, 7) alloys by using differential scanning calorimetry (DSC) and X-ray diffractometry. The alloy containing 5% Sn shows the highest glass-forming ability (GFA) among the Ti-Zr-Hf-Cu-Ni-Si-Sn system. Fully amorphous rod sample with diameters up to 6 mm could be successfully fabricated by the copper mold casting Ti{sub 41.5}Zr{sub 2.5}Hf{sub 5}Cu{sub 37.5}Ni{sub 7.5}Si{sub 1}Sn{sub 5} alloy. The activation energies for glass transition and crystallization for Ti{sub 41.5}Zr{sub 2.5}Hf{sub 5}Cu{sub 37.5}Ni{sub 7.5}Si{sub 1}Sn{sub 5} amorphous alloy are both larger than those values for the Sn-free alloy. The enhancement in GFA and thermal stability after the partial replacement of Cu by Sn may be contributed to the strong atomic bonding nature between Ti and Sn and the increasing of atomic packing density. The amorphous Ti{sub 41.5}Zr{sub 2.5}Hf{sub 5}Cu{sub 37.5}Ni{sub 7.5}Si{sub 1}Sn{sub 5} alloy also possesses superior mechanical properties.

  8. Pulsed Nd:YAG laser welding of Cu54Ni6Zr22Ti18 bulk metallic glass

    International Nuclear Information System (INIS)

    Kim, Jong Hyun; Lee, Changhee; Lee, D.M.; Sun, J.H.; Shin, S.Y.; Bae, J.C.

    2007-01-01

    Pulsed Nd:YAG laser was used to weld Cu 54 Ni 6 Zr 22 Ti 18 (numbers indicate at.%) metallic glass with glass forming ability of 6 mm. Through a single pulse irradiation on the glassy plate, the pulse condition for welding without crystallization was investigated. Under the selected pulse condition, the Cu 54 Ni 6 Zr 22 Ti 18 plate was periodically welded with different welding speeds. For the welding speed of 60 mm/min, no crystallization was observed in both weldment and heat-affected zone. For the 20 mm/min, the crystallized areas with a band shape were observed along the welding direction

  9. Effect of surface shear on cube texture formation in heavy cold-rolled Cu-45 at%Ni alloy substrates

    DEFF Research Database (Denmark)

    Tian, Hui; Suo, Hongli; Liang, Yaru

    2015-01-01

    Two types of Cu-45 at%Ni alloy thin tapes with and without surface shear were obtained by different heavy cold rolling processes. The deformation and recrystallization textures of the two tapes were thoroughly investigated by electron back scattering diffraction technique. The results showed...... that a shear texture mainly covered the surface of the heavy deformed tapes because of the fraction between the surface of rolling mills and the thin tapes when the rolling force strongly reduced at high strain, which significantly reduced the fraction of rolling texture on the surface of the Cu-45at %Ni alloy...

  10. Coordination Behavior of Ni2+, Cu2+, and Zn2+ in Tetrahedral 1-Methylimidazole Complexes: A DFT/CSD Study

    OpenAIRE

    Tetteh, Samuel

    2018-01-01

    The interaction between nickel (Ni2+), copper (Cu2+), and zinc (Zn2+) ions and 1-methylimidazole has been studied by exploring the geometries of eleven crystal structures in the Cambridge Structural Database (CSD). The coordination behavior of the respective ions was further investigated by means of density functional theory (DFT) methods. The gas-phase complexes were fully optimized using B3LYP/GENECP functionals with 6-31G∗ and LANL2DZ basis sets. The Ni2+ and Cu2+ complexes show distorted ...

  11. Sequestration of Cu(II), Ni(II), and Co(II) by ethyleneimine immobilized on silica

    International Nuclear Information System (INIS)

    Arakaki, Luiza N.H.; Alves, Ana Paula M.; Silva Filho, Edson C. da; Fonseca, Maria G.; Oliveira, Severino F.; Espinola, Jose Geraldo P.; Airoldi, Claudio

    2007-01-01

    Thermodynamic data on interaction of Cu(II), Ni(II), and Co(II) with silica modified with ethyleneimine are obtained by calorimetric titration. The amount of ethyleneimine anchored on silica surface was estimated to be 0.70 mmol g -1 . The enthalpies of binding Ni(II), Cu(II) and Co(II), are -3.59 ± 0.001, -4.88 ± 0.001, and -7.75 ± 0.003 kJ mol -1 , respectively

  12. Long-term superelastic cycling at nano-scale in Cu-Al-Ni shape memory alloy micropillars

    Energy Technology Data Exchange (ETDEWEB)

    San Juan, J., E-mail: jose.sanjuan@ehu.es; Gómez-Cortés, J. F. [Dpto. Física Materia Condensada, Facultad de Ciencia y Tecnología, Univ. del País Vasco UPV/EHU, Apdo. 644, 48080 Bilbao (Spain); López, G. A.; Nó, M. L. [Dpto. Física Aplicada II, Facultad de Ciencia y Tecnología, Univ. del País Vasco UPV/EHU, Apdo. 644, 48080 Bilbao (Spain); Jiao, C. [FEI, Achtseweg Noord 5, 5651 GG Eindhoven (Netherlands)

    2014-01-06

    Superelastic behavior at nano-scale has been studied along cycling in Cu-Al-Ni shape memory alloy micropillars. Arrays of square micropillars were produced by focused ion beam milling, on slides of [001] oriented Cu-Al-Ni single crystals. Superelastic behavior of micropillars, due to the stress-induced martensitic transformation, has been studied by nano-compression tests during thousand cycles, and its evolution has been followed along cycling. Each pillar has undergone more than thousand cycles without any detrimental evolution. Moreover, we demonstrate that after thousand cycles they exhibit a perfectly reproducible and completely recoverable superelastic behavior.

  13. GRAIN-REFINEMENT AND THE RELATED PHENOMENA IN QUATERNARY Cu-Al-Ni-Ti SHAPE MEMORY ALLOYS

    OpenAIRE

    Sugimoto , K.; Kamei , K.; Matsumoto , H.; Komatsu , S.; Akamatsu , K.; Sugimoto , T.

    1982-01-01

    It was reported that the addition of a small amount of titanium (0.5 - 3.99%) to a Cu-13.93%Al-3.36%Ni ternary alloy resulted in a remarkable grain-refining. The original grain-size of about 750 microns under hot-rolled and quenched conditions of the ternary alloy was reduced to that of the order of about 100 microns by addition of tiatanium. It was suggested that several technical improvements of the mechanical properties of Cu-Al-Ni shape memory alloys, such as better formability, less crac...

  14. Morphological characteristic of the conventional and melt-spun Al-10Ni-5.6Cu (in wt.%) alloy

    Energy Technology Data Exchange (ETDEWEB)

    Karakoese, Ercan [Erciyes University, Institute of Science and Technology, Department of Physics, 38039 Kayseri (Turkey); Keskin, Mustafa, E-mail: keskin@erciyes.edu.tr [Erciyes University, Faculty of Arts and Sciences, Department of Physics, 38039 Kayseri (Turkey)

    2009-12-15

    The Al-10Ni-5.6Cu alloy was prepared by conventional casting and further processed melt-spinning technique. The resulting conventional cast and melt-spun ribbons were characterized using X-ray diffraction, optical microscopy, scanning electron microscopy together with energy dispersive spectroscopy, differential scanning calorimetry and microhardness techniques. The X-ray diffraction analysis indicated that ingot samples were {alpha}-Al, intermetallic Al{sub 3}Ni and Al{sub 2}Cu phases. The optical microscopy and scanning electron microscopy results show that the microstructures of rapidly solidified ribbons are clearly different from their ingot alloy. Al-10Ni-5.6Cu ribbons reveal a very fine cellular structure with intermetallic Al{sub 3}Ni particles. Moreover, at high solidification rates the melt-spun ribbons have a polygonal structure dispersed in a supersaturated aluminum matrix. The differential scanning calorimetry measurements revealed that exothermic reaction was between 290 deg. C and 440 deg. C which are more pronounced in the ternary Al-10Ni-5.6Cu alloy.

  15. Morphological characteristic of the conventional and melt-spun Al-10Ni-5.6Cu (in wt.%) alloy

    International Nuclear Information System (INIS)

    Karakoese, Ercan; Keskin, Mustafa

    2009-01-01

    The Al-10Ni-5.6Cu alloy was prepared by conventional casting and further processed melt-spinning technique. The resulting conventional cast and melt-spun ribbons were characterized using X-ray diffraction, optical microscopy, scanning electron microscopy together with energy dispersive spectroscopy, differential scanning calorimetry and microhardness techniques. The X-ray diffraction analysis indicated that ingot samples were α-Al, intermetallic Al 3 Ni and Al 2 Cu phases. The optical microscopy and scanning electron microscopy results show that the microstructures of rapidly solidified ribbons are clearly different from their ingot alloy. Al-10Ni-5.6Cu ribbons reveal a very fine cellular structure with intermetallic Al 3 Ni particles. Moreover, at high solidification rates the melt-spun ribbons have a polygonal structure dispersed in a supersaturated aluminum matrix. The differential scanning calorimetry measurements revealed that exothermic reaction was between 290 deg. C and 440 deg. C which are more pronounced in the ternary Al-10Ni-5.6Cu alloy.

  16. Highly sensitive optical sensor that detects Hg{sup 2+} and Cu{sup 2+} by immobilizing dicarboxylate 1,5-diphenyl-3-thiocarbazone on surface functionalized PVA microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Bai, Xue, E-mail: baixue@hhu.edu.cn; Gu, Haixin; Hua, Zulin; Dai, Zhangyan; Yang, Bei; Li, Yulong

    2015-11-15

    Highlights: • PVA microspheres were chosen as carrier and DDT groups were chosen as chromophores. • The DDT–PVA microspheres could detect Hg{sup 2+} and Cu{sup 2+} simultaneously within 120 s. • The DDT–PVA microspheres had excellent detection for Hg{sup 2+} and Cu{sup 2+} ions. • The DDT–PVA microspheres had preeminent selectivity and reusability. - Abstract: A novel optical sensor to detect Hg{sup 2+} and Cu{sup 2+} is prepared by immobilizing a synthesized dicarboxylate 1,5-diphenyl-3-thiocarbazone (DDT) group on functionalized polyvinyl alcohol (PVA) microspheres. This optical sensor is successfully fabricated by extensive characterization with Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. Its colorimetric properties, selectivity, sensitivity, and reversibility are investigated as well. In this sensing system, DDT–PVA selectively recognized multiple heavy metal ions, as indicated by the changes in color from orange to scarlet for Hg{sup 2+} and from orange to gray for Cu{sup 2+}. In particular, this optical sensor exhibits the most apparent color changes at pH levels of 12 and 2. Hence, Hg{sup 2+} and Cu{sup 2+} can be detected in aqueous solution at minimum detection limits of 0.053 and 0.132 μM, respectively, with a UV-vis spectrometer. Furthermore, the sensor can be regenerated by ethylene diamine tetraacetic acid and reused several times. Therefore, the optical sensor can detect Hg{sup 2+} because of its selectivity, sensitivity, and reversibility.

  17. Distribution and accumulation of Cd, Cu, Hg, Pb and Zn in the surface sediments of El Tobari Lagoon, central-East Gulf of California: An ecosystem associated with agriculture and aquaculture activities.

    Science.gov (United States)

    Jara-Marini, M E; Tapia-Alcaraz, J N; Dumer-Gutiérrez, J A; García-Rico, L; García-Hernández, J; Páez-Osuna, F

    2013-01-01

    The purpose of this research is to provide a comprehensive assessment of the concentration levels and spatial variability of cadmium (Cd), copper (Cu), mercury (Hg), lead (Pb) and zinc (Zn) in El Tobari Lagoon in surface sediments during two seasons for several geochemical variables that could explain the observed heavy metal variability. Seventy-two surface sediments samples were collected in 12 different sites of the El Tobari Lagoon. Sediment samples were dried and subjected to acid extraction using a microwave system and five metals (Cd, Cu, Hg, Pb and Zn) were measured using atomic adsorption spectrometry. A certificate sediment material and blanks were used as quality control purposes. The enrichment factor (EF) and the index of geoaccumulation (Igeo) were calculated as index of metals contamination for the sediments, using aluminum as the conservative element. The five metals examined in sediments from El Tobari Lagoon exhibited a linear correlation with Al as result of the large specific surface areas of these sediment components and the chemical affinities between them. The metals contents in sites of the El Tobari Lagoon were variable, and Cd, Cu and Hg presented a seasonal behavior. The enrichment factor and index of geoaccumulation analysis indicated that Cd and Hg exhibited a certain extent (EF for Cd ranged from 4.10 to 10.29; EF for Hg ranged from 2.77 to 12.89) of anthropogenic pollution, while Cu showed sporadic (EF ranged from 0.43 to 2.54) anthropogenic contamination. The highest concentrations of Cd, Cu and Hg were found in the sites that regularly received discharge effluents from agriculture and aquaculture.

  18. Raman study of HgBa 2Ca n-1 Cu nO 2 n+2+ δ ( n=1,2,3,4 and 5) superconductors

    Science.gov (United States)

    Zhou, Xingjiang; Cardona, M.; Chu, C. W.; Lin, Q. M.; Loureiro, S. M.; Marezio, M.

    1996-02-01

    Polarized micro-Raman scattering measurements have been performed on the five members of the HgBa 2Ca n-1 Cu nO 2 n+2+ δ ( n=1,2,3,4 and 5) high- Tc superconductor family using different laser frequencies. Local laser annealing measurements were carried out to investigate the variation of the Raman spectra with the excess oxygen content, δ. A systematic evolution of the spectra, which display mainly peaks near 590, 570, 540 and 470 cm -1, with increasing number of CuO 2 layers has been observed; its origin has been shown to lie in the variation of the interstitial oxygen content. In addition to confirming that the 590 cm -1 mode represents vibration of apical oxygens in the absence of neighboring excess oxygen, the 570 cm -1 mode, which may be composed of some finer structures, has been assigned to the vibration of the apical oxygen modified by the presence of the neighboring excess oxygens. The 540 and 470 cm -1 modes may represent the direct vibration of excess oxygens. The implication of possible different distribution sites of excess oxygens is discussed. All other observed lower-frequency modes are also assigned.

  19. Synthesis, structural and physico-chemical studies of the monocrystal superconductor oxides Hg Ba{sub 2} Ca{sub n-1} Cu{sub n} O{sub 2n+2+{delta}}; Synthese, etudes structurales et physico-chimiques de monocristaux d`oxydes supraconducteurs Hg Ba{sub 2} Ca{sub n-1} Cu{sub n} O{sub 2n+2+{delta}}

    Energy Technology Data Exchange (ETDEWEB)

    Viallet-Guillen, Virginie [Dept. de Recherche sur l` Etat Condense, CEA Centre d` Etudes de Saclay, 91 - Gif-sur-Yvette (France)

    1998-01-01

    The thesis presents the synthesis and the structural and physico-chemical properties of the mercury-based monocrystal superconductor oxides. The results reported in the first chapter refer to the first three members of the mercury cuprate series Hg-1201, Hg-1212 and Hg-1223. In the second chapter detailed results concerning the structure of these compounds are given highlighting the features common to all cuprates and pointing out the peculiarities of mercury phases. The third chapter presents the phase diagrams ({delta}, T, p(O{sub 2})) of the compounds HgBa{sub 2}CuO{sub 4+{delta}} and HgBa{sub 2}Ca{sub 2}Cu{sub 3}O{sub 8+{delta}} obtained by thermogravimetry under controlled atmosphere between 150 deg.C and 500 deg.C and thermodynamic equilibrium conditions. In the case of Hg-1201, the critical temperature shows a variation close to a parabolic law, with an optimal Tc of 96 K ({delta}{approx_equal}0.10) while in Hg-1223 the Tc increases linearly with the O content up to the optimal Tc of 135 K ({delta}{approx_equal}0.19) and decreases only by 2 K in the over-doped regime. Finally, in the fourth chapter different physical properties are reviewed. The obtained monocrystals allowed studying the resistive transitory anisotropy, the torque, the specific heat, the nuclear magnetic resonance and the Raman diffusion 212 refs., 106 figs., 30 tabs.

  20. A dilute Cu(Ni) alloy for synthesis of large-area Bernal stacked bilayer graphene using atmospheric pressure chemical vapour deposition

    Energy Technology Data Exchange (ETDEWEB)

    Madito, M. J.; Bello, A.; Dangbegnon, J. K.; Momodu, D. Y.; Masikhwa, T. M.; Barzegar, F.; Manyala, N., E-mail: ncholu.manyala@up.ac.za [Department of Physics, Institute of Applied Materials, SARCHI Chair in Carbon Technology and Materials, University of Pretoria, Pretoria 0028 (South Africa); Oliphant, C. J.; Jordaan, W. A. [National Metrology Institute of South Africa, Private Bag X34, Lynwood Ridge, Pretoria 0040 (South Africa); Fabiane, M. [Department of Physics, Institute of Applied Materials, SARCHI Chair in Carbon Technology and Materials, University of Pretoria, Pretoria 0028 (South Africa); Department of Physics, National University of Lesotho, P.O. Roma 180 (Lesotho)

    2016-01-07

    A bilayer graphene film obtained on copper (Cu) foil is known to have a significant fraction of non-Bernal (AB) stacking and on copper/nickel (Cu/Ni) thin films is known to grow over a large-area with AB stacking. In this study, annealed Cu foils for graphene growth were doped with small concentrations of Ni to obtain dilute Cu(Ni) alloys in which the hydrocarbon decomposition rate of Cu will be enhanced by Ni during synthesis of large-area AB-stacked bilayer graphene using atmospheric pressure chemical vapour deposition. The Ni doped concentration and the Ni homogeneous distribution in Cu foil were confirmed with inductively coupled plasma optical emission spectrometry and proton-induced X-ray emission. An electron backscatter diffraction map showed that Cu foils have a single (001) surface orientation which leads to a uniform growth rate on Cu surface in early stages of graphene growth and also leads to a uniform Ni surface concentration distribution through segregation kinetics. The increase in Ni surface concentration in foils was investigated with time-of-flight secondary ion mass spectrometry. The quality of graphene, the number of graphene layers, and the layers stacking order in synthesized bilayer graphene films were confirmed by Raman and electron diffraction measurements. A four point probe station was used to measure the sheet resistance of graphene films. As compared to Cu foil, the prepared dilute Cu(Ni) alloy demonstrated the good capability of growing large-area AB-stacked bilayer graphene film by increasing Ni content in Cu surface layer.

  1. Martensitic transformations of Cu-Al-Ni single crystals in tension/compression

    Energy Technology Data Exchange (ETDEWEB)

    Novak, V.; Sittner, P. [Academy of Sciences of the Czech Republic, Prague (Czech Republic). Inst. of Physics; Humbeeck, J. van [Academy of Sciences of the Czech Republic, Prague (Czech Republic). Inst. of Physics; Catholic Univ. of Leuven, Heverlee (Belgium). MTM Dept.

    2001-11-01

    Cu-Al-Ni alloys, similarly as other Cu-base shape memory alloys, transform into more martensitic structures {alpha}{sub 1}' (6R), {beta}{sub 1}' (18R) and {gamma}{sub 1}' (2H), depending on the temperature, stress, load axis orientation, sense of loading and composition. The transformation stress-temperature conditions at which individual transitions take place are beneficially represented in so called non-equilibrium stress-temperature phase diagrams. On the basis of the {sigma}-T diagrams, complex history dependent thermomechanical behaviors of SMA single crystals undergoing sequentially multiple solid state transitions can be easily understood and predicted. Since chemical composition of the alloy crystals affects mainly the equilibrium transformation temperatures, T{sub 0}, and only slightly the slopes of the transformation lines in the {sigma}-T diagrams, the diagrams mainly shift in the temperature range (over {proportional_to}200K) with the compositional variations. The shape of the diagrams, however, may change significantly when the T{sub 0} shifts for individual transitions are different. Knowledge of the compositional dependence of {sigma}-T diagrams would be beneficial for the development of shape memory alloys with specific required thermomechanical properties. The aim of the present work is experimental investigation of the martensitic transformations and construction of the {sigma}-T diagram for Cu-Al-Ni alloy with lower Al content (T{sub 0}>363K) and comparison with our previous results obtained on alloys with higher Al content (T{sub 0}<263K). (orig.)

  2. Search for positron localization near transition-metal solutes of negative effective charge in Ni and Cu

    International Nuclear Information System (INIS)

    Hunter, D.M.; Grynszpan, R.I.; Arrott, A.S.

    1993-01-01

    Results of an early (1973) angular correlation (ACAR) study of dilute (0.5 at.%) Cu based alloys by a Japanese group were interpreted in terms of an attraction of e + by transition metal solutes of effective negative charge. Doppler Broadening (DB) measurements reveal no such an effect for Cu(Mn) and Cu(Ni) solid solutions as well as for Ni alloys with 3d, 4d and 5d transition metal solutes (0.1 to 1.5 at.%) i.e. no evidence of e + localization near these impurities is seen. Our results strongly suggest that the ACAR results are due to the metallurgical state of the samples. In contrast, significant DB lineshape parameter variations, observed for our Ni(Zr) alloys, are attributed to positron trapping in and near Ni 5 Zr precipitates. Our DB results for a series of Ni(Au) alloys are understood in terms of a combination of the effect of an overall lattice expansion and a positron preference for clusters of Au atoms. The above comparison between DB and ACAR results is supported by our 'spin polarized' DB results for a (001) Ni single crystal which resemble those obtained by other groups using a 'spin polarized' 2D-ACAR technique. (orig.)

  3. Microscopy modifications in an aged Cu-Al-Ni-Mn alloy; Modificacoes microestruturais em uma liga Cu-Al-Ni-Mn submetida ao envelhecimento

    Energy Technology Data Exchange (ETDEWEB)

    Gama, J.L.L. [Instituto Federal de Alagoas (IFAL), Maceio, AL (Brazil); Ferreira, R.A.S., E-mail: jorgelauriano@gmail.co [Universidade Federal de Pernambuco (DEM/UFPE), Recife, PE (Brazil). Dept. de Engenharia Mecanica

    2010-07-01

    An Cu-12Al-4Ni-3Mn shape memory alloy have been manufactured using an induction furnace of 24 KVA. After melting, chemical analyse was performed by X-ray fluorescence (XRF). The phase transformation of this alloy was studied in the different sequences produced during thermomechanic treatments. After homogenization, the ingot was solution treated at 850 deg C. At 750 deg C samples were submitted to a reduction by rolling to about 30% in thickness, followed by water quenching. In sequence, the ingot was cold-rolled at different thicknesses. In deformed state, sample of this alloy was submitted to the thermal analyse-DTA for identification of the phase transformation domains. For each identified domain, ageing was carried out, at different times, to evaluate the presence of the different phases. Samples were characterized ray-X diffraction. The results showed that the microstructural evolutions are of a complex nature. At 425 deg C temperature both recrystallization and precipitation of different phases were simultaneously observed. (author)

  4. SAE 1045 steel/WC-Co/Ni-Cu-Ni/SAE 1045 steel joints prepared by dynamic diffusion bonding: Microelectrochemical studies in 0.6 M NaCl solution

    International Nuclear Information System (INIS)

    Andreatta, Francesco; Matesanz, Laura; Akita, Adriano H.; Paussa, Luca; Fedrizzi, Lorenzo; Fugivara, Cecilio S.; Gomez de Salazar, Jose M.; Benedetti, Assis V.

    2009-01-01

    Corrosion of SAE 1045 steel/WC-Co/Ni-Cu-Ni/SAE 1045 steel interfaces was investigated in 0.6 M NaCl solution using an electrochemical microcell, which enables local electrochemical characterization at the micrometer scale. Two pieces of steel, one with a WC-Co coating covered with Ni (12 μm) and Cu (5 μm) layers, and the other with a Ni (15 μm) layer, were welded by dynamic diffusion bonding. A WC-Co coating was applied to the steel by the high velocity oxygen-fuel process, and Ni-Cu and Ni layers by electroplating. Polarization curves were recorded using an electrochemical microcell. Different regions of welded samples were investigated, including steel, cermet coating, and steel/cermet and steel/Ni-Cu-Ni/cermet interfaces. Optical and electronic microscopes were employed to study the corroded regions. Potentiodynamic polarization curves obtained using the microcell revealed that the base metal was more susceptible to corrosion than the cermet. In addition, cermet steel/cermet and steel/Ni-Cu-Ni/cermet joints exhibited different breakdown potentials. Steel was strongly corroded in the regions adjacent to the interfaces, while the cermet was less corroded. Iron oxides/hydroxides and chloride salts were the main corrosion products of steel. After removal of the superficial layer of corrosion products, iron oxides were mainly observed. Chloride ions were detected mainly on a copper-enriched layer placed between two Ni-enriched layers.

  5. Hydrogen induced structural and magnetic transformations in magnetic regenerator materials ErNi n (n=1, 2) and HoCu2

    International Nuclear Information System (INIS)

    Wang Dong; Li Yanli; Long Yi; Ye Rongchang; Chang Yongqin; Wan Farong

    2007-01-01

    The effect of hydrogenation on the structures and magnetic properties of magnetic regenerators HoCu 2 (CeCu 2 -type), ErNi 2 (MgCu 2 -type) and ErNi (FeB-type) has been investigated. All these compounds can form crystalline hydrides which remain in the structure of the original compound. In the case of ErNi 2 , hydrogenation induces volume expansion up to 13% compared with the parent compound. The magnetic moment and the Curie temperature of the crystalline hydrides decreases as the hydrogen content increases. In the case of ErNi and HoCu 2 , there is a little change in the lattice parameters and magnetic properties of the crystalline hydrides compared with original compounds. Amorphous hydrides are also observed after the hydrogenation of ErNi 2 and HoCu 2 compounds

  6. Chemically modified activated carbon with 1-acylthiosemicarbazide for selective solid-phase extraction and preconcentration of trace Cu(II), Hg(II) and Pb(II) from water samples.

    Science.gov (United States)

    Gao, Ru; Hu, Zheng; Chang, Xijun; He, Qun; Zhang, Lijun; Tu, Zhifeng; Shi, Jianping

    2009-12-15

    A new sorbent 1-acylthiosemicarbazide-modified activated carbon (AC-ATSC) was prepared as a solid-phase extractant and applied for removing of trace Cu(II), Hg(II) and Pb(II) prior to their determination by inductively coupled plasma optical emission spectrometry (ICP-OES). The separation/preconcentration conditions of analytes were investigated, including effects of pH, the shaking time, the sample flow rate and volume, the elution condition and the interfering ions. At pH 3, the maximum static adsorption capacity of Cu(II), Hg(II) and Pb(II) onto the AC-ATSC were 78.20, 67.80 and 48.56 mg g(-1), respectively. The adsorbed metal ions were quantitatively eluted by 3.0 mL of 2% CS(NH2)2 and 2.0 mol L(-1) HCl solution. Common coexisting ions did not interfere with the separation. According to the definition of IUPAC, the detection limits (3sigma) of this method for Cu(II), Hg(II) and Pb(II) were 0.20, 0.12 and 0.45 ng mL(-1), respectively. The relative standard deviation under optimum conditions is less than 4.0% (n=8). The prepared sorbent was applied for the preconcentration of trace Cu(II), Hg(II) and Pb(II) in certified and water samples with satisfactory results.

  7. Plant community and litter composition in temperate deciduous woodlots along two field gradients of soil Ni, Cu and Co concentrations

    International Nuclear Information System (INIS)

    Hale, Beverley; Robertson, Paul

    2016-01-01

    Perennial plant communities in the proximity of metal smelters and refineries may receive substantial inputs of base metal particulate as well as sulphate from the co-emission of sulphur dioxide. The Ni refinery at Port Colborne (Canada) operated by Inco (now Vale Canada Ltd.) emitted Ni, Co and Cu, along with sulphur dioxide, between 1918 and 1984. The objectives were to determine if vascular plant community composition, including standing litter, in twenty-one woodlots on clay or organic soil, were related to soil Ni concentration which decreased in concentration with distance from the Ni refinery. The soil Ni concentration in the clay woodlots ranged from 16 to 4130 mg Ni/kg, and in the organic woodlots, ranged from 98 to 22,700 mg Ni/kg. The concentrations of Co and Cu in the soils were also elevated, and highly correlated with soil Ni concentration. In consequence, each series of woodlots constituted a ‘fixed ratio ray’ of metal mixture exposure. For each of the woodlots, there were 16 independent measurements of ‘woodlot status’ which were correlated with elevated soil Ni concentration. Of the 32 combinations, there were eight linear correlations with soil Ni concentration, considerably more than would be expected by chance alone at a p-value of 0.05. With the exception of mean crown rating for shrubs at the clay sites, the correlations were consistent with the hypothesis that increased soil metal concentrations would be correlated with decreased diversity, plant community health or fitness, and increased accumulation of litter. Only five of the eight linear correlations were from the organic woodlots, suggesting that the observations were not confounded with soil type nor range in soil metal concentrations. - Highlights: • Temperate woodlots on organic or clay soils with gradient of soil Ni were studied. • Soil Ni ranged up to 4100 mg/kg on clay and up to 22,700 mg/kg on organic. • Most indices of plant community status were not correlated

  8. Impact of deposition rate on the structural and magnetic properties of sputtered Ni/Cu multilayer thin films

    Energy Technology Data Exchange (ETDEWEB)

    Karpuz, Ali [Karamanoglu Mehmetbey Univ., Karaman (Turkey). Dept. of Physics; Colmekci, Salih; Kockar, Hakan; Kuru, Hilal; Uckun, Mehmet [Balikesir Univ. (Turkey). Dept. of Physics

    2018-04-01

    The structural and corresponding magnetic properties of Ni/Cu films sputtered at low and high deposition rates were investigated as there is a limited number of related studies in this field. 5[Ni(10 nm)/Cu(30 nm)] multilayer thin films were deposited using two DC sputtering sources at low (0.02 nm/s) and high (0.10 nm/s) deposition rates of Ni layers. A face centered cubic phase was detected for both films. The surface of the film sputtered at the low deposition rate has a lot of micro-grains distributed uniformly and with sizes from 0.1 to 0.4 μm. Also, it has a vertical acicular morphology. At high deposition rate, the number of micro-grains considerably decreased, and some of their sizes increased up to 1 μm. The surface of the Ni/Cu multilayer deposited at the low rate has a relatively more grainy and rugged structure, whereas the surface of the film deposited at the high rate has a relatively larger lateral size of surface grains with a relatively fine morphology. Saturation magnetisation, M{sub s}, values were 90 and 138 emu/cm{sup 3} for deposition rates of 0.02 and 0.10 nm/s, respectively. Remanence, M{sub r}, values were also found to be 48 and 71 emu/cm{sup 3} for the low and high deposition rates, respectively. The coercivity, H{sub c}, values were 46 and 65 Oe for the low and high Ni deposition rates, respectively. The changes in the film surfaces provoked the changes in the H{sub c} values. The M{sub s}, M{sub r}, and H{sub c} values of the 5[Ni(10 nm)/Cu(30 nm)] films can be adjusted considering the surface morphologies and film contents caused by the different Ni deposition rates.

  9. Teores de Fe, Mn, Zn, Cu, Ni E Co em solos de referência de Pernambuco Concentrations of Fe, Mn, Zn, Cu, Ni and Co in benchmark soils of Pernambuco, Brazil

    Directory of Open Access Journals (Sweden)

    Caroline Miranda Biondi

    2011-06-01

    Full Text Available Metais pesados formam um grupo de elementos com particularidades relevantes e de ocorrência natural no ambiente, como elementos acessórios na constituição de rochas. Esses elementos, apesar de associados à toxidez, exigem tratamento diferenciado em relação aos xenobióticos, uma vez que diversos metais possuem essencialidade (Fe, Mn, Cu, Zn e Ni e benefício (Co comprovados para as plantas. Nesse contexto, o objetivo deste trabalho foi determinar os teores naturais dos metais Fe, Mn, Zn, Ni, Cu e Co nos solos de referência de Pernambuco. Foram coletadas amostras de solo nas três regiões fisiográficas (Zona da Mata, Agreste e Sertão, dos dois primeiros horizontes dos 35 solos de referência do Estado de Pernambuco. A digestão das amostras baseou-se no método 3051A (USEPA, 1998, e a determinação foi efetuada em ICP-OES. Correlações significativas foram estabelecidas entre os metais e entre estes e a fração argila do solo, em ambos os horizontes, indicando a associação comum da maioria dos metais com solos mais argilosos. A maioria dos solos apresentou teores de Fe, Mn, Zn, Cu, Ni e Co menores que os de solos de outras regiões do País, com litologia mais máfica, o que corrobora o fato de que os teores desses elementos são mais diretamente relacionados aos minerais Fe-magnesianos. Os resultados indicam baixo potencial dos solos de Pernambuco em liberar Cu, Co e Ni para plantas, enquanto deficiências de Zn, Fe e Mn são menos prováveis. Os teores naturais de Fe, Mn, Zn, Cu, Ni e Co determinados podem ser utilizados como base para definição dos Valores de Referência de Qualidade para os solos de Pernambuco, de acordo com o preconizado pela legislação nacional.Heavy metals are a group of elements with specific features and natural occurrence in the environment, representing an accessory in the formation of rocks. These elements, although associated with toxicity, must be treated different from xenobiotics, since many

  10. Electronic structure of Pd42.5Ni7.5Cu30P20, an excellent bulk metallic glass former: Comparison to the Pd40Ni40P20 reference glass

    International Nuclear Information System (INIS)

    Hosokawa, S.; Sato, H.; Happo, N.; Mimura, K.; Tezuka, Y.; Ichitsubo, T.; Matsubara, E.; Nishiyama, N.

    2007-01-01

    In-house photoemission and inverse-photoemission spectra (PES and IPES) were measured on Pd 42.5 Ni 7.5 Cu 30 P 20 and Pd 40 Ni 40 P 20 bulk metallic glasses in order to clarify the origin of excellent glass-forming ability from the viewpoint of electronic structure. Minima are observed for both the metallic glasses at a slightly higher energy than the Fermi level. Incident photon-energy dependent PES spectra were obtained using synchrotron radiation and the Pd 4d partial density of states (DOS) was estimated from the PES data. Soft X-ray emission spectra were also measured near the Ni and Cu 2p 3/2 absorption edges to evaluate, respectively, the Ni and Cu 3d partial DOS in the valence band. The Pd 4d and the Ni and Cu 3d partials in the conduction band were obtained from X-ray absorption spectra around the Pd 3p 3/2 and Ni and Cu 2p 3/2 absorption edges, respectively. It was found that the Pd 4d partial DOS near the Fermi energy largely decreases and becomes localized by replacing the Ni atoms with the Cu atoms, which may be closely related to the excellent glass-forming ability of the Pd 42.5 Ni 7.5 Cu 30 P 20 bulk metallic glass due to a selective formation of Pd-P covalent bonds

  11. Ni Nanobuffer Layer Provides Light-Weight CNT/Cu Fibers with Superior Robustness, Conductivity, and Ampacity.

    Science.gov (United States)

    Zou, Jingyun; Liu, Dandan; Zhao, Jingna; Hou, Ligan; Liu, Tong; Zhang, Xiaohua; Zhao, Yonghao; Zhu, Yuntian T; Li, Qingwen

    2018-03-07

    Carbon nanotube (CNT) fiber has not shown its advantage as next-generation light-weight conductor due to the large contact resistance between CNTs, as reflected by its low conductivity and ampacity. Coating CNT fiber with a metal layer like Cu has become an effective solution to this problem. However, the weak CNT-Cu interfacial bonding significantly limits the mechanical and electrical performances. Here, we report that a strong CNT-Cu interface can be formed by introducing a Ni nanobuffer layer before depositing the Cu layer. The Ni nanobuffer layer remarkably promotes the load and heat transfer efficiencies between the CNT fiber and Cu layer and improves the quality of the deposited Cu layer. As a result, the new composite fiber with a 2 μm thick Cu layer can exhibit a superhigh effective strength >800 MPa, electrical conductivity >2 × 10 7 S/m, and ampacity >1 × 10 5 A/cm 2 . The composite fiber can also sustain 10 000 times of bending and continuously work for 100 h at 90% ampacity.

  12. Morphology, optical and electrical properties of Cu-Ni nanoparticles in a-C:H prepared by co-deposition of RF-sputtering and RF-PECVD

    Energy Technology Data Exchange (ETDEWEB)

    Ghodselahi, T., E-mail: ghodselahi@ipm.ir [School of Physics, Institute for Research in Fundamental Sciences (IPM), P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of); Vesaghi, M.A. [School of Physics, Institute for Research in Fundamental Sciences (IPM), P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of); Department of Physics, Sharif University of Technology, P.O. Box 11365-9161, Tehran (Iran, Islamic Republic of); Gelali, A.; Zahrabi, H.; Solaymani, S. [Young Researchers Club, Islamic Azad University, Kermanshah Branch, Kermanshah (Iran, Islamic Republic of)

    2011-11-01

    We report optical and electrical properties of Cu-Ni nanoparticles in hydrogenated amorphous carbon (Cu-Ni NPs - a-C:H) with different surface morphology. Ni NPs with layer thicknesses of 5, 10 and 15 nm over Cu NPs - a-C:H were prepared by co-deposition of RF-sputtering and RF-Plasma Enhanced Chemical Vapor Deposition (RF-PECVD) from acetylene gas and Cu and Ni targets. A nonmetal-metal transition was observed as the thickness of Ni over layer increases. The surface morphology of the sample was described by a two dimensional (2D) Gaussian self-affine fractal, except the sample with 10 nm thickness of Ni over layer, which is in the nonmetal-metal transition region. X-ray diffraction profile indicates that Cu NPs and Ni NPs with fcc crystalline structure are formed in these films. Localized Surface Plasmon Resonance (LSPR) peak of Cu NPs is observed around 600 nm in visible spectra, which is widen and shifted to lower wavelengths as the thickness of Ni over layer increases. The variation of LSPR peak width correlates with conductivity variation of these bilayers. We assign both effects to surface electron delocalization of Cu NPs.

  13. Microstructural evolution of direct chill cast Al-15.5Si-4Cu-1Mg-1Ni-0.5Cr alloy during solution treatment

    Directory of Open Access Journals (Sweden)

    He Kezhun

    2011-08-01

    Full Text Available Heat treatment has important influence on the microstructure and mechanical properties of Al-Si alloys. The most common used heat treatment method for these alloys is solution treatment followed by age-hardening. This paper investigates the microstructural evolution of a direct chill (DC cast Al-15.5Si-4Cu-1Mg-1Ni-0.5Cr alloy after solution treated at 500, 510, 520 and 530℃, respectively for different times. The major phases observed in the as-cast alloy are α-aluminum dendrite, primary Si particle, eutectic Si, Al7Cu4Ni, Al5Cu2Mg8Si6, Al15(Cr, Fe, Ni, Cu4Si2 and Al2Cu. The Al2Cu phase dissolves completely after being solution treated for 2 h at 500℃, while the eutectic Si, Al5Cu2Mg8Si6 and Al15(Cr, Fe, Ni, Cu4Si2 phases are insoluble. In addition, the Al7Cu4Ni phase is substituted by the Al3CuNi phase. The α-aluminum dendrite network disappears when the solution temperature is increased to 530℃. Incipient melting of the Al2Cu-rich eutectic mixture occurrs at 520℃, and melting of the Al5Cu2Mg8Si6 and Al3CuNi phases is observed at a solution temperature of 530℃. The void formation of the structure and deterioration of the mechanical properties are found in samples solution treated at 530℃.

  14. In situ TEM observation of stress-induced martensitictransformations and twinning processes in CuAlNi single crystals

    Czech Academy of Sciences Publication Activity Database

    Zárubová, Niva; Gemperlová, Juliana; Gemperle, Antonín; Dlabáček, Zdeněk; Šittner, Petr; Novák, Václav

    2010-01-01

    Roč. 58, č. 15 (2010), s. 5109-5119 ISSN 1359-6454 R&D Projects: GA AV ČR(CZ) IAA200100627 Institutional research plan: CEZ:AV0Z10100520 Keywords : CuAlNi shape memory alloy * martensitic transformation * in situ TEM straining Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.781, year: 2010

  15. Studies of the magnetic properties of Ni-Zn-Cu ferrite and its synthesis by using metal nitrate salts

    International Nuclear Information System (INIS)

    Koh, Jae Gui

    2004-01-01

    Ni-Zn-Cu ferrite was synthesized by decomposing the metal nitrates Ni(NO 3 ) 2 ·6H 2 O, Cu(NO 3 ) 2 ·6H 2 O, Zn(NO 3 ) 2 ·6H 2 O, and Fe(NO 3 ) 3 ·9H 2 O at 200 .deg. C for 20 hours. The ferrite powder was calcined at 400 .deg. C and pulverized for 3, 6, 9, or 12 hours in a steel ball mill. Then, it was sintered from 700 .deg. C to 1000 .deg. C in 100 .deg. C steps for 1 hour at each step. Thus, we could study the effects of the synthesis conditions on the microstructure and magnetic properties of Ni-Zn-Cu ferrite. We could chemically bond initial specimens in liquid at a low-temperature of 150 .deg. C owing to the low melting points, less than 200 .deg. C, of the metal nitrates instead of mechanical ball-mill pulverization, thus narrowing the distance between the particles a molecular one and lowering the sintering point at least by 200 .deg. C to 300 .deg. C. The initial permeability was 50 to 470, and the maximum magnetic induction and coercive force were 0.2410 T and 39.79 A/m to 95.496 A/m, respectively, which are similar to values for Ni-Zn-Cu ferrite synthesized using a conventional process.

  16. Synthesis and characterisation of Cu(II), Ni(II), Mn(II), Zn(II) and VO(II ...

    Indian Academy of Sciences (India)

    Unknown

    Synthesis and characterisation of Cu(II), Ni(II), Mn(II), Zn(II) and VO(II) Schiff base complexes derived from o-phenylenediamine and acetoacetanilide. N RAMAN*, Y PITCHAIKANI RAJA and A KULANDAISAMY. Department of Chemistry, VHNSN College, Virudhunagar 626 001, India e-mail: ra_man@123india.com.

  17. Variability of Mn, Fe, Ni, Cu and Co in manganese nodules from the Central Indian Ocean Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Jauhari, P.

    clays which contain higher Fe and Co. Clustering of analysed shows that Ni and Cu are geochemically associated with Mn, and Co with in both sediment types. However, the degree of correlation between all the elements is higher in the nodules from red clay...

  18. Geochronology and characteristics of Ni-Cu-(PGE) mineralization at Rožany, Lusatian Granitoid Complex, Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Haluzová, Eva; Ackerman, Lukáš; Pašava, J.; Jonášová, Šárka; Svojtka, Martin; Hrstka, Tomáš; Veselovský, F.

    2015-01-01

    Roč. 60, č. 4 (2015), s. 219-236 ISSN 1802-6222 R&D Projects: GA ČR GA13-15390S Institutional support: RVO:67985831 Keywords : Ni-Cu-(PGE) * Lusatia * Re-Os * Bohemian Massif * sulphur Subject RIV: DD - Geochemistry Impact factor: 1.326, year: 2015

  19. Texture development and anisotropic behaviour of a TI-44.2NI4.9CU (AT.%) shape memory alloy

    NARCIS (Netherlands)

    Zhao, L.

    1997-01-01

    The objective of this work was to determine the relationship between texture development and anisotropy of shape memory properties. A commercial Ti-45Ni-5Cu (at.%) shape memory alloy was selected. Textures were developed by controlling rolling parameters, such as rolling temperature, intermediate

  20. Thermal behaviour of Cu-Mg-Mn and Ni-Mg-Mn layered double hydroxides and characterization of formed oxides

    Czech Academy of Sciences Publication Activity Database

    Kovanda, F.; Grygar, Tomáš; Dorničák, V.; Rojka, T.; Bezdička, Petr; Jirátová, Květa

    2005-01-01

    Roč. 28, 1-4 (2005), s. 121-136 ISSN 0169-1317 Institutional research plan: CEZ:AV0Z40320502 Keywords : Cu-Mg-Mn basic carbonates * Ni-Mg-Mn hydrotalcite Subject RIV: CA - Inorganic Chemistry Impact factor: 1.324, year: 2005

  1. Twinning processes in Cu-Al-Ni martensite single crystals investigated by neutron single crystal diffraction method

    Czech Academy of Sciences Publication Activity Database

    Molnar, P.; Šittner, P.; Novák, V.; Lukáš, Petr

    2008-01-01

    Roč. 481, Sp.Iss.SI (2008), s. 513-517 ISSN 0921-5093 R&D Projects: GA AV ČR IAA100480704 Institutional research plan: CEZ:AV0Z10480505 Keywords : Cu-Al-Ni * single crystals * neutron diffraction Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.806, year: 2008

  2. Generation of covariance files for the isotopes of Cr, Fe, Ni, Cu, and Pb in ENDF/B-VI

    International Nuclear Information System (INIS)

    Hetrick, D.M.; Larson, D.C.; Fu, C.Y.

    1991-02-01

    The considerations that governed the development of the uncertainty files for the isotopes of Cr, Fe, Ni, Cu, and Pb in ENDF/B-VI are summarized. Four different approaches were used in providing the covariance information. Some examples are given which show the standard deviations as a function of incident energy and the corresponding correlation matrices. 11 refs., 5 tabs

  3. The synthesis and the spectroscopic, thermal, and structural properties of the M2[(fumarate)Ni(CN)4]·2(1,4-Dioxane) clathrate (M = Co, Ni, Cd and Hg)

    Science.gov (United States)

    Kartal, Zeki; Yavuz, Abdülkerim

    2018-03-01

    In this study, the clathrates of fumarate-tetracyanonickel-dioxane, given by the formula M2[(fumarate)Ni(CN)4]·2(1,4-Dioxane) (M = Co, Ni, Cd and Hg), have been obtained for the first time through chemical methods. These clathrates have been characterized by elemental, thermal, FT-IR, and FT-Raman spectroscopies. The parameters of structures of clathrates have been determined by X-ray powder diffraction. The thermal behaviors of these clathrates have been also investigated by thermo-gravimetric analysis (TGA), differential thermal analysis (DTA), and derivative thermal gravimetric analysis (DTG) in the range of 20-900 °C. X-ray powder diffraction data have been recorded at ambient temperature in the 2θ range 5-50°. The FT-IR and FT-Raman spectra of clathrates have been recorded in the region of 4000-400 cm-1 and 4000-100 cm-1, respectively. The results of the spectral and thermal analyses of the newly synthesized clathrates of fumarate-tetracyanonickel-dioxane suggest that these clathrates are new examples of the Hofmann-type dioxane clathrates. In our study, the Hofmann-type dioxane clathrates, which are formed by bounding electrons of oxygen-donor atoms of fumarate ion ligand molecule to transition metal atoms, consist of the corrugated |M-Ni(CN)4|∞ polymeric layers, which are held in parallel through the chain of (-M-fumarate-M-).

  4. Thermo-chemical characterization of a Al nanoparticle and NiO nanowire composite modified by Cu powder

    International Nuclear Information System (INIS)

    Bohlouli-Zanjani, Golnaz; Wen, John Z.; Hu, Anming; Persic, John; Ringuette, Sophie; Zhou, Y. Norman

    2013-01-01

    Highlights: • First study on the copper modified powder-type Al nanoparticle and NiO nanowire composites. • Experimental findings were unique in identifying the AlNi formation and comparing with the Al/CuO thermite. • Potential applications in material joining and bonding. - Abstract: Thermo-chemical properties of the Al nanoparticle and NiO nanowire composites modified by the micro-sized copper additive were investigated experimentally. Their onset temperatures of ignition and energy release data per mass were characterized using differential thermal analysis measurements. These microstructures and chemical compositions of reaction products were analyzed using scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffraction. The fuel-rich Al/NiO/Cu composites produced two types of metallic spheres. Copper spheres were formed from melting and solidification of the copper additive, while AlNi composite spheres were identified by the energy dispersive X-ray spectroscopy and X-ray diffraction analyses. It was found that the amount of the copper additive did not significantly influence the onset temperature of thermite peaks, but caused a dramatic change in energy release. The aforementioned ignition and energetic properties were compared with these from the Al nanoparticle and CuO nanowire composites

  5. Giant magnetic coercivity in YNi{sub 4}B-type SmNi{sub 3}TB (T=Mn–Cu) solid solutions

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Jinlei; Yan, Chang [Research Center for Solid State Physics and Materials, School of Mathematics and Physics, Suzhou University of Science and Technology, Suzhou 215009 (China); Yapaskurt, V.O. [Department of Petrology, Geological Faculty Moscow State University, Leninskie Gory, Moscow 119992 (Russian Federation); Morozkin, A.V., E-mail: morozkin@tech.chem.msu.ru [Department of Chemistry, Moscow State University, Leninskie Gory, House 1, Building 3, GSP-2, Moscow 119992 (Russian Federation)

    2016-12-01

    The effects of transition metal substitution for Ni on the magnetic properties of the YNi{sub 4}B-type SmNi{sub 4}B via SmNi{sub 3}TB (T=Mn, Fe, Co, Cu) solid solutions have been investigated. SmNi{sub 4}B, SmNi{sub 3}MnB, SmNi{sub 3}FeB, SmNi{sub 3}CoB and SmNi{sub 3}CuB show ferromagnetic ordering at 40 K, 210 K, 322 K, 90 K and 57 K and field sensitive metamagnetic-like transitions at 15 K, 100 K, 185 K, 55 K and 15 K in a magnetic field of 10 kOe, respectively. The magnetocaloric effects of SmNi{sub 3}TB (T=Mn–Cu) were calculated in terms of isothermal magnetic entropy change (ΔS{sub m}). The magnetic entropy ΔS{sub m} reaches value of –0.94 J/kg K at 40 K for SmNi{sub 4}B, –1.5 J/kg K at 205 K for SmNi{sub 3}MnB, –0.54 J/kg K at 320 K for SmNi{sub 3}FeB, –0.49 J/kg K at 90 K for SmNi{sub 3}CoB and –0.54 J/kg K at 60 K for SmNi{sub 3}CuB in field change of 0–50 kOe around the Curie temperature. They show positive ΔS{sub m} of +0.71 J/kg K at ~10 K for SmNi{sub 4}B, +1.69 J/kg K at 30 K for SmNi{sub 3}MnB, +0.89 J/kg K at 110 K for SmNi{sub 3}FeB, +1.08 J/kg K at 25 K for SmNi{sub 3}CoB and +1.12 J/kg K at 10 K for SmNi{sub 3}CuB in field change of 0–50 kOe around the low temperature metamagnetic-like transition. Below the field induced transition temperature (change of magnetic structure), SmNi{sub 3}TB (T=Mn–Cu) exhibits giant magnetic coercivity of 74 kOe at 5 K for SmNi{sub 4}B, 69 kOe at 20 K (90 kOe at 10 K) for SmNi{sub 3}MnB, 77 kOe at 60 K for SmNi{sub 3}FeB, 88 kOe at 20 K for SmNi{sub 3}CoB and 52 kOe at 5 K for SmNi{sub 3}CuB. - Highlights: • YNi{sub 4}B-type SmNi{sub 3}{Mn, Fe, Co, Ni, Cu}B exhibit the Curie points at 39–322 K. • SmNi{sub 3}{Mn, Fe, Co, Ni, Cu}B show field induced transition at 15–185 K. • SmNi{sub 3}MnB shows huge magnetic hysteresis with coercive field of 69 kOe at 20 K. • SmNi{sub 3}FeB shows huge magnetic hysteresis with coercive field of 77 kOe at 60 K. • SmNi{sub 3}CoB shows giant coercive

  6. Effect of preparation conditions on the diffusion parameters of Cu/Ni thin films

    Energy Technology Data Exchange (ETDEWEB)

    Rammo, N.N.; Makadsi, M.N. [College of Science, Baghdad University, Baghdad (Iraq); Abdul-Lettif, A.M. [College of Science, Babylon University, Hilla (Iraq)

    2004-11-01

    Diffusion coefficients of vacuum-deposited Cu/Ni bilayer thin films were determined in the temperature range 200-500 C using X-ray photoelectron spectroscopy, sheet resistance measurements, and X-ray diffraction analysis. The difference between the results of the present work and those of previous relevant investigations may be attributed to the difference in the film microstructure, which is controlled by the preparation conditions. Therefore, the effects of deposition rate, substrate temperature, film thickness, and substrate structure on the diffusion parameters were separately investigated. It is shown that the diffusion activation energy (Q) decreases as deposition rate increases, whereas Q increases as substrate temperature and film thickness increase. The value of Q for films deposited on amorphous substrates is less than that for films deposited on single-crystal substrates. (copyright 2004 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  7. Precipitation hardening in a 12%Cr-9%Ni-4%Mo-2%Cu stainless steel

    International Nuclear Information System (INIS)

    Haettestrand, Mats; Nilsson, Jan-Olof; Stiller, Krystyna; Liu Ping; Andersson, Marcus

    2004-01-01

    A combination of complementary techniques including one-dimensional and three-dimensional atom probe, energy-filtered transmission electron microscopy and conventional transmission electron microscopy has been used to assess the precipitation reactions at 475 deg. C in a 12%Cr-9%Ni-4%Mo-2%Cu precipitation hardening stainless steel. The continuous hardening up to at least 1000 h of ageing was attributed to a sequence of precipitation reactions involving nickel-rich precipitates nucleating at copper clusters followed by molybdenum-rich quasicrystalline precipitates and nickel-rich precipitates of type L1 0 . An estimate of the relative contributions to the strength increment during tempering based on measurements of particle densities was performed. Nickel-rich precipitates were found to play the most important role up to about 40 h of ageing after which the effect of quasicrystalline particles became increasingly important

  8. Magnetocaloric behavior of Mn rich Ni46Cu2Mn43In11 alloy

    Science.gov (United States)

    Ray, Mayukh K.; Obaidat, I. M.; Banerjee, Sangam

    2018-02-01

    In this work, we studied the magnetic entropy change (ΔSM) across the martensite transformation (MT) in Mn-rich Ni46Cu2Mn43ln11 alloy. This compound undergoes a MT and a magnetic phase transition around the temperatures (TM=) 272 K and (TCA=) 325 K, respectively. A large field induced shift (=0.28 K/kOe) of the MT temperatures is observed. An application of magnetic field (H =) of 50 kOe causes a large ΔSM of 20 J/kg-K and -4.4 J/kg-K around TM and TCA, respectively. We also found that the change in magnetic field induced isothermal ΔSM(H)T is mainly depends on the induced austenite phase fraction by the applied magnetic field at that temperature. Possible reasons for the observed behaviours are comprehensively discussed.

  9. Sintered Fe-Ni-Cu-Sn-C Alloys Made of Ball-Milled Powders

    Directory of Open Access Journals (Sweden)

    Romański A.

    2014-10-01

    Full Text Available The main objective of this paper was to perform sinterability studies of ball-milled Fe-12%Ni-6.4%Cu-1.6%Sn-0.6%C powders. A mixture of precisely weighed amounts of elemental iron, nickel and graphite, and pre-alloyed 80/20 bronze powders was ball-milled for 8, 30 and 120 hours. After cold-pressing at 400 MPa the specimens were sintered at 900oC for 30 minutes in a reducing atmosphere and subsequently tested for density and hardness as well as subjected to structural studies using scanning electron microscopy (SEM and X-ray diffraction (XRD analysis.

  10. Comparative study of Ni and Cu doped ZnO nanoparticles: Structural and optical properties

    Science.gov (United States)

    Thakur, Shaveta; Thakur, Samita; Sharma, Jyoti; Kumar, Sanjay

    2018-05-01

    Nanoparticles of undoped and doped (0.1 M Ni2+ and Cu2+) ZnO are synthesized using chemical precipitation method. The crystallite size, morphology, chemical bonding and optical properties of as prepared nanoparticles are determined by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy and UV-visible spectra. XRD analysis shows that the prepared samples are single phase and have hexagonal wurtzite structure. The crystallite size of the doped and undoped nanoparticles is determined using Scherrer method. The crystallite size is found to be increased with concentration of nickel and copper. All stretching and vibrational bands are observed at their specific positions through FTIR. The increase in band gap can be attributed to the different chemical nature of dopant and host cation.

  11. Thermophysical Properties Measurements of Zr62Cu20Al10Ni8

    Science.gov (United States)

    Bradshaw, Richard C.; Waren, Mary; Rogers, Jan R.; Rathz, Thomas J.; Gangopadhyay, Anup K.; Kelton, Ken F.; Hyers, Robert W.

    2006-01-01

    Thermophysical property studies performed at high temperature can prove challenging because of reactivity problems brought on by the elevated temperatures. Contaminants from measuring devices and container walls can cause changes in properties. To prevent this, containerless processing techniques can be employed to isolate a sample during study. A common method used for this is levitation. Typical levitation methods used for containerless processing are, aerodynamically, electromagnetically and electrostatically based. All levitation methods reduce heterogeneous nucleation sites, 'which in turn provide access to metastable undercooled phases. In particular, electrostatic levitation is appealing because sample motion and stirring are minimized; and by combining it with optically based non-contact measuring techniques, many thermophysical properties can be measured. Applying some of these techniques, surface tension, viscosity and density have been measured for the glass forming alloy Zr62Cu20Al10Ni8 and will be presented with a brief overview of the non-contact measuring method used.

  12. L-shell photoabsorption spectroscopy for solid metals: Ti, V, Cr, Fe, Ni, Cu

    International Nuclear Information System (INIS)

    Del Grande, N.K.

    1989-01-01

    Synchrotron radiation measurements of near-threshold and broad-range (400--1500 eV) absolute photoabsorption cross sections were made for five transition metals with ±10% overall uncertainties. Fine structure details of 2p-3d autoionizing resonances are shown with better than 1.0 eV resolution for solid metals: Ti, V, Cr, Fe, Ni, and Cu. Fine structure similar to what we measured can be produced using a multi-configuration Dirac Fock (MCDF) model if a statistical distribution is assumed for the initial atomic states. Calculations were performed in intermediate coupling with configuration interactions by Mau H. Chen. The results are compared with other experimental work and theoretical methodologies. 18 refs., 7 figs

  13. Obtainment of the alloy Cu13Al4Ni using processed by powder metallurgy

    International Nuclear Information System (INIS)

    Grossi, L.J.; Damasceno, N.; Muterlle, P.V.

    2016-01-01

    The powder metallurgy is a technique environmentally advantageous that allows the production of many pieces, with a good superficial finishing and dimensional tolerance. For the production of pieces using technique, basics steps are carried out, as the characterization of powders, the mixing and homogenization, compacting and sintering. In this context, this work has as objective the obtainment of the Cu13Al4Ni alloy via powder metallurgy. For this, was made a high energy milling for 2, 4 and 8 hours. Then, the milled powder was compacted and posteriorly, sintered in an oven with controlled atmosphere. It was observed that the milling time affects directly in sintering of the pieces. The best results obtained were for the samples that were milled for 4 hours. This samples have showed 21, 52% of porosity and 6,382 g/cm³ of the density of sintered. (author)

  14. Structural Transformations in High-Capacity Li 2 Cu 0.5 Ni 0.5 O 2 Cathodes

    Energy Technology Data Exchange (ETDEWEB)

    Ruther, Rose; Pandian, Amaresh S.; Yan, Pengfei; Weker, Johanna N.; Wang, Chongmin; Nanda, Jagjit

    2017-03-21

    Cathode materials that can cycle > 1 Li+ per transition metal are of substantial interest to increase the overall energy density of lithium-ion batteries. Li2Cu0.5Ni0.5O2 has a very high theoretical capacity of ~ 500 mAh/g assuming both Li+ are cycled reversibly. The Cu2+/3+ and Ni2+/3+/4+ redox couples are also at high voltage, which could further boost the energy density of this system. Despite such promise, Li2Cu0.5Ni0.5O2 undergoes irreversible phase changes during charge (delithiation) that result in large first-cycle irreversible loss and poor long-term cycling stability. Oxygen is evolved before the Cu2+/3+ or Ni3+/4+ transitions are accessed. In this contribution, XRD, TEM, and TXM-XANES are used to follow the chemical and structural changes that occur in Li2Cu0.5Ni0.5O2 during electrochemical cycling. Li2Cu0.5Ni0.5O2 is a solid solution of orthorhombic Li2CuO2 and Li2NiO2, but the structural changes more closely mimic the Li2NiO2 endmember. Li2Cu0.5Ni0.5O2 loses long-range order during charge, but TEM analysis provides clear evidence for particle exfoliation and the transformation from orthorhombic to a partially layered structure. Linear combination fitting and principal component analysis of TXM-XANES are used to map the different phases that emerge during cycling ex situ and in situ. Significant changes in the XANES at the Cu and Ni K-edges correlate with the onset of oxygen evolution.

  15. Two-dimensional nano-lattice in Fe-Co-Ni-Al-Cu alloys

    International Nuclear Information System (INIS)

    Kalanov, M.U.; Ibragimova, E.M.; Khamraeva, R.N.; Rustamova, V.M.; Ummatov, H.D.

    2007-01-01

    Full text: The high coercive strength of the dispersionally solidified alloys on the base of Fe-Co-Ni-Al-Cu system appears as a result of the special thermomagnetic annealing, when particles of the strong magnetic phase are distinguished in non-magnetic matrix along an external magnetic field direction. The neutron studying allows one to reveal the correlation between magnetization and inclusion axes, and also existence of magnetic microcell and perfectness of the lattice. This work presents results of neutron diffraction study with a double-crystal spectrometer (0.145 nm). Plate like samples of size 18 12 4 mm 3 were cut from a single crystal of alloy UNDK35 T5 along (100) plane. Magnetic field of 6 kOe was applied perpendicular to the neutron beam. Zero-field spectrum had only random variation of the background. Under the applied magnetic field two maxima appeared at the angles of 12 and 24 minute. In the case of the magnetic field directed in parallel to the scattering vector, the two maxima disappeared as expected. It is evidence that nuclear scattering is less than magnetic one and the observed maxima correspond to (10) and (20) reflections from a two dimensional ferro-magnetic microcell. The cell parameter of the magnetic microcell was found 40.6 nm. The coherent scattering region size was 120-160 nm. The ferro-magnetic rod diameter estimated from the peak widths was 16 nm. The diffraction pattern for the demagnetized sample strongly differs from the initial magnetized sample, where a diffuse reflection was observed near Bragg reflection and related with residual magnetization. So, the magnetic inclusions created in the Fe-Co-Ni-Al-Cu system at the thermomagnetic annealing by means of disintegration of the solid solution are strong ferro-magnetic and one-domain. These particles form the two-dimensional magnetic microcell and interact each to other within 3-4 periods of the cell. (authors)

  16. 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.

  17. Dissolved trace metal (Cu, Cd, Co, Ni, and Ag) distribution and Cu speciation in the southern Yellow Sea and Bohai Sea, China

    Science.gov (United States)

    Li, Li; Xiaojing, Wang; Jihua, Liu; Xuefa, Shi

    2017-02-01

    Trace metals play an important role in biogeochemical cycling in ocean systems. However, because the use of trace metal clean sampling and analytical techniques has been limited in coastal China, there are few accurate trace metal data for that region. This work studied spatial distribution of selected dissolved trace metals (Ag, Cu, Co, Cd, and Ni) and Cu speciation in the southern Yellow Sea (SYS) and Bohai Sea (BS). In general, the average metal (Cu, Co, Cd, and Ni) concentrations found in the SYS were lower by a factor of two than those in BS, and they are comparable to dissolved trace metal concentrations in coastal seawater of the United States and Europe. Possible sources and sinks and physical and biological processes that influenced the distribution of these trace metals in the study region were further examined. Close relationships were found between the trace metal spatial distribution with local freshwater discharge and processes such as sediment resuspension and biological uptake. Ag, owing to its extremely low concentrations, exhibited a unique distribution pattern that magnified the influences from the physical and biological processes. Cu speciation in the water column showed that, in the study region, Cu was strongly complexed with organic ligands and concentrations of free cupric ion were in the range of 10-12.6-10-13.2 mol L-1. The distribution of Cu-complexing ligand, indicated by values of the side reaction coefficient α', was similar to the Chl a distribution, suggesting that in situ biota production may be one main source of Cu-complexing organic ligand.

  18. 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.

  19. Preparation and microwave-infrared absorption of reduced graphene oxide/Cu-Ni ferrite/Al2O3 composites

    Science.gov (United States)

    De-yue, Ma; Xiao-xia, Li; Yu-xiang, Guo; Yu-run, Zeng

    2018-01-01

    Reduced graphene oxide (RGO)/Cu-Ni ferrite/Al2O3 composite was prepared by solvothermal method, and its properties were characterized by SEM, x-ray diffraction, energy-dispersive x-ray spectroscopy and FTIR. The electromagnetic parameters in 2-18 GHz and mid-infrared (IR) spectral transmittance of the composite were measured, respectively. The results show that Cu0.7Ni0.3Fe2O4 nanoparticles with an average size of tens nanometers adsorb on surface of RGO, and meanwhile, Al2O3 nanoparticles adhere to the surface of Cu0.7Ni0.3Fe2O4 nanoparticles and RGO. The composite has both dielectric and magnetic loss mechanism. Its reflection loss is lower than -19 dB in 2-18 GHz, and the maximum of -23.2 dB occurs at 15.6 GHz. With the increasing of Al2O3 amount, its reflection loss becomes lower and the maximum moves towards low frequency slightly. Compared with RGO/Cu-Ni ferrite composites, its magnetic loss and reflection loss slightly reduce with the increasing of Al2O3 amount, and the maximum of reflection loss shifts from a low frequency to a high one. However, its broadband IR absorption is significantly enhanced owing to nano-Al2O3. Therefore, RGO/Cu-Ni ferrite/Al2O3 composites can be used as excellent broadband microwave and IR absorbing materials, and maybe have broad application prospect in electromagnetic shielding, IR absorbing and coating materials.

  20. Effect of heat treatment on the physical properties of bimetallic doped catalyst, Cu-Ni/TiO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Bashiri, Robabeh, E-mail: noranimuti-mohamed@petronas.com.my; Sufian, Suriati [Chemical Engineering Dept. Universiti Teknologi PETRONAS, 31750 Tronoh, Perak (Malaysia); Mohamed, Norani Muti, E-mail: noranimuti-mohamed@petronas.com.my; Kait, Chong Fai, E-mail: chongfaikait@petronas.com.my [Fundamental and Applied Sciences Dept., Universiti Teknologi PETRONAS, 31750 Tronoh, Perak (Malaysia)

    2015-07-22

    Post heat treatment is critical for the doped semiconductor oxide in order to improve its photocatalytic performance. Thus work had been carried out to understand the effect of different calcination temperature (400, 450 and 500°C) on the physical properties of nanosized Cu-Ni/TiO{sub 2}Cu-Ni doped TiO{sub 2} nanoparticles prepared using a combined method of sol-gel and hydrothermal. The treated samples were characterized using Raman spectroscopy, Brunauer–Emmett–teller (BET) measurement, high resolution transmission electron microscopy (HRTEM), field-emission scanning electron microscopy (FESEM), and diffuse reflectance UV-Vis spectroscopy (DR-UV-Vis). Raman analysis showed that all samples displayed anatase (101) phase of TiO{sub 2}, which is in good agreement with the TEM results. BET data showed that all prepared Cu-Ni/TiO{sub 2} with different calcination temperature are mesoporous. SEM images displayed spherical particles with typical size of about 15 to 20 nm. UV-Vis spectra illustrated that the absorbance edge of all prepared Cu-Ni/TiO{sub 2} have extended to the visible region with bandgap energies (2-2.1 eV) less than the pure anatase TiO{sub 2} (3.2 eV). Calcination temperature of 450°C is considered to be the optimum as it converts the synthesized Cu-Ni/TiO{sub 2} sample to have smaller average particle size with higher surface area that lead to more absorbance in the visible region and lower bandgap energy.

  1. Study on the occurrence of platinum in Xinjie Cu-Ni sulfide deposits by a combination of SPM and NAA

    International Nuclear Information System (INIS)

    Li Xiaolin; Zhu Jieqing; Lu Rongrong; Gu Yingmei; Wu Xiankang; Chen Youhong

    1997-01-01

    A combination of neutron-activation analysis (NAA) and scanning proton microprobe (SPM) was used to study the distribution of platinum-group elements (PGEs) in rocks and ores from Xinjie Cu-Ni deposit. The minimum detection limits of PGEs by NAA had been much improved by means of a nickel-sulfide fire-assay technique for pre-concentration of PGEs in the ore samples. A simple and effective method was developed for true element mapping in SPM experiments. A pair of moveable absorption filters was set up in the target chamber for high sensitivities of both major and trace elements. The bulk analysis results by NNA indicated that the PGE mineralization occurred at the base of Xinjie layered intrusion in clino-pyroxenite rocks and the Cu-Ni sulfide minerals disseminated within the rocks had high abundance level of PGEs. However, the micro-PIXE analysis of the Cu-Ni sulfide mineral grains did not find PGEs above the MDL of (6-9) x 10 -6 for Rh, Ru and Pd, and 6- x 10 -6 for Pt. The search for platinum occurrence in sulfide minerals was followed by scanning analysis of SPM when some smaller platinum enriched grains were found in the sulfide minerals. The microscopic analysis results suggested that platinum occurred in the Cu-Ni sulfide matrix as independent arsenide mineral grains. The chemical formula of the arsenide sperrylite was PtAs2. The information of the platinum occurrence was helpful to future mineralogical research and mineral processing and beneficiation of the Cu-Ni deposit

  2. Effect of heat treatment on the physical properties of bimetallic doped catalyst, Cu-Ni/TiO2

    International Nuclear Information System (INIS)

    Bashiri, Robabeh; Sufian, Suriati; Mohamed, Norani Muti; Kait, Chong Fai

    2015-01-01

    Post heat treatment is critical for the doped semiconductor oxide in order to improve its photocatalytic performance. Thus work had been carried out to understand the effect of different calcination temperature (400, 450 and 500°C) on the physical properties of nanosized Cu-Ni/TiO 2 Cu-Ni doped TiO 2 nanoparticles prepared using a combined method of sol-gel and hydrothermal. The treated samples were characterized using Raman spectroscopy, Brunauer–Emmett–teller (BET) measurement, high resolution transmission electron microscopy (HRTEM), field-emission scanning electron microscopy (FESEM), and diffuse reflectance UV-Vis spectroscopy (DR-UV-Vis). Raman analysis showed that all samples displayed anatase (101) phase of TiO 2 , which is in good agreement with the TEM results. BET data showed that all prepared Cu-Ni/TiO 2 with different calcination temperature are mesoporous. SEM images displayed spherical particles with typical size of about 15 to 20 nm. UV-Vis spectra illustrated that the absorbance edge of all prepared Cu-Ni/TiO 2 have extended to the visible region with bandgap energies (2-2.1 eV) less than the pure anatase TiO 2 (3.2 eV). Calcination temperature of 450°C is considered to be the optimum as it converts the synthesized Cu-Ni/TiO 2 sample to have smaller average particle size with higher surface area that lead to more absorbance in the visible region and lower bandgap energy

  3. Simultaneous decomplexation in blended Cu(II)/Ni(II)-EDTA systems by electro-Fenton process using iron sacrificing electrodes.

    Science.gov (United States)

    Zhao, Zilong; Dong, Wenyi; Wang, Hongjie; Chen, Guanhan; Tang, Junyi; Wu, Yang

    2018-05-15

    This research explored the application of electro-Fenton (E-Fenton) technique for the simultaneous decomplexation in blended Cu(II)/Ni(II)-EDTA systems by using iron sacrificing electrodes. Standard discharge (0.3 mg L -1 for Cu and 0.1 mg L -1 for Ni in China) could be achieved after 30 min reaction under the optimum conditions (i.e. initial solution pH of 2.0, H 2 O 2 dosage of 6 mL L -1  h -1 , current density of 20 mA/cm 2 , inter-electrode distance of 2 cm, and sulfate electrolyte concentration of 2000 mg L -1 ). The distinct differences in apparent kinetic rate constants (k app ) and intermediate removal efficiencies corresponding to mere and blended systems indicated the mutual promotion effect toward the decomplexation between Cu(II) and Ni(II). Massive accumulation of Fe(Ⅲ) favored the further removal of Cu(II) and Ni(II) by metal ion substitution. Species distribution results demonstrated that the decomplexation of metal-EDTA in E-Fenton process was mainly contributed to the combination of various reactions, including Fenton reaction together with the anodic oxidation, electro-coagulation (E-coagulation) and electrodeposition. Unlike hypophosphite and citrate, the presence of chlorine ion displayed favorable effects on the removal efficiencies of Cu(II) and Ni(II) at low dosage, but facilitated the ammonia nitrogen (NH 4 + -N) removal only at high dosage. Copyright © 2018 Elsevier B.V. All rights reserved.

  4. Copper-based alloys, crystallographic and crystallochemical parameters of alloys in binary systems Cu-Me (Me=Co, Rh, Ir, Cu, Ag, Au, Ni, Pd, Pt)

    Energy Technology Data Exchange (ETDEWEB)

    Porobova, Svetlana, E-mail: porobova.sveta@yandex.ru; Loskutov, Oleg, E-mail: lom58@mail.ru [Tomsk State University of Architecture and Building, Russia, Tomsk, 2 Solyanaya sq, Tomsk, 634003 (Russian Federation); Markova, Tat’jana, E-mail: patriot-rf@mail.ru [Siberian State Industrial University. 42 Kirov St., Novokuznetsk, 654007 (Russian Federation); Klopotov, Vladimir, E-mail: vdklopotov@mail.ru [Research Tomsk Polytechnic University, 30 Lenin Ave., Tomsk, 634050 (Russian Federation); Klopotov, Anatoliy, E-mail: klopotovaa@tsuab.ru [Tomsk State University of Architecture and Building, Russia, Tomsk, 2 Solyanaya sq, Tomsk, 634003 (Russian Federation); National Research Tomsk State University, 36, Lenin Ave., Tomsk, 634050 (Russian Federation); Vlasov, Viktor, E-mail: vik@tsuab.ru [Tomsk State University of Architecture and Building, Russia, Tomsk, 2 Solyanaya sq, Tomsk, 634003 (Russian Federation); Research Tomsk Polytechnic University, 30 Lenin Ave., Tomsk, 634050 (Russian Federation)

    2016-01-15

    The article presents the results of the analysis of phase equilibrium of ordered phases in binary systems based on copper Cu- Me (where Me - Co, Rh, Ir, Ag, Au, Ni, Pd, Pt) to find correlations of crystallochemical and crystallographic factors. It is established that the packing index in disordered solid solutions in binary systems based on copper is close to the value of 0.74 against the background of an insignificant deviation of atomic volumes from the Zen’s law.

  5. Magnetostatic coupling of 900 domain walls in Fe19Ni81/Cu/Co trilayers

    International Nuclear Information System (INIS)

    Kurde, J; Miguel, J; Kuch, W; Bayer, D; Aeschlimann, M; Sanchez-Barriga, J; Kronast, F; Duerr, H A

    2011-01-01

    The magnetic interlayer coupling of Fe 19 Ni 81 /Cu/Co trilayered microstructures has been studied by means of x-ray magnetic circular dichroism in combination with photoelectron emission microscopy (XMCD-PEEM). We find that a parallel coupling between magnetic domains coexists with a non-parallel coupling between magnetic domain walls (DWs) of each ferromagnetic layer. We attribute the non-parallel coupling of the two magnetic layers to local magnetic stray fields arising at DWs in the magnetically harder Co layer. In the magnetically softer FeNi layer, non-ordinary DWs, such as 270 0 and 90 0 DWs with overshoot of the magnetization either inwards or outwards relative to the turning direction of the Co magnetization, are identified. Micromagnetic simulations reveal that in the absence of magnetic anisotropy, both types of overshooting DWs are energetically equivalent. However, if a uniaxial in-plane anisotropy is present, the relative orientation of the DWs with respect to the anisotropy axis determines which of these DWs is energetically favorable.

  6. Glass formation and crystallization of Zr53Cu21Al10Ni8Ti8 alloy

    International Nuclear Information System (INIS)

    Neogy, S.; Tewari, R.; Srivastava, D.; Dey, G.K.; Banerjee, S.; Vaibhaw, K.; Ranganathan, S.

    2010-01-01

    In the present study, transmission electron microscopy techniques, like micro-diffraction, high resolution and fluctuation microscopy, have been employed to carry out detailed investigation of as-solidified and crystallized microstructures of the Zr 53 Cu 21 Al 10 Ni 8 Ti 8 alloy synthesized using melt spinning, suction casting and copper mould casting techniques. Samples produced by copper mould casting technique showed partially crystalline microstructure whereas the other techniques resulted in complete amorphous microstructures. High-resolution microscopy established that the dendrites of the big cube phase in partially crystalline glass grew by atomistic ledges. The other crystalline bct Zr 2 Ni phase, present in partially crystalline glass and also in all the crystallized microstructures, showed various types of internal faults depending upon the crystallite size. Fluctuation microscopy established that oxygen plays a major role in determining the degree of medium range order in glassy phases. In addition, variation in oxygen content changed the crystallization behaviour of glasses from a single to multiple events

  7. Investigation of magnetoimpedance effect on electrodeposited NiFe/Cu wire using inductance spectroscopy

    International Nuclear Information System (INIS)

    Mishra, Amaresh Chandra; Sahoo, Trilochan; Srinivas, V.; Thakur, Awalendra K.

    2011-01-01

    In this report, inductance spectroscopy (IS) has been used as a tool to investigate the thickness dependence of magnetoimpedance (MI) on electrodeposited NiFe thin films. An MI value as high as 140% has been observed under an applied magnetic field of 76 Oe at 300 kHz frequency for a film thickness of 6.8 μm. This result is in sharp contrast to earlier reports in literature showing monotonous increase in MI as a function of thickness. Maximum of MI was found at an optimum film thickness whose position varies with frequency. These reports exhibiting strong frequency dependence of MI prompted us to investigate the underlying physics using IS. The origin of MI lies in the combined effect of domain wall motion and spin rotation, which contributes to permeability. A parallel inductance and resistance (LR) circuit in series with series LR circuit model has been proposed as an equivalent electrical model to describe the property of these coated wires. The circuit elements have been linked with the phenomenon of domain wall motion and spin rotation. The experimental results obtained appear to be consistent with the proposed equivalent circuit model. -- Research Highlights: →GMI study on electrodeposited NiFe/Cu wire has been done to resolve the existing controversies. →Inductance spectroscopy has been used to evaluate the magnetic character. →The sample has been modeled as an equivalent electrical circuit. →A correlation between circuit parameters and GMI has been achieved.

  8. Magnetostatic coupling of 90 domain walls in FeNi/Cu/Co trilayers

    Energy Technology Data Exchange (ETDEWEB)

    Kurde, Julia; Miguel, Jorge; Kuch, Wolfgang [Freie Universitaet, Berlin (Germany); Bayer, Daniela; Aeschlimann, Martin [Technische Universitaet, Kaiserslautern (Germany); Sanchez-Barriga, Jaime; Kronast, Florian; Duerr, Herrmann A. [Helmholtz-Zentrum Berlin fuer Materialien und Energie (Germany)

    2011-07-01

    The magnetic interlayer coupling of FeNi/Cu/Co trilayered microstructures has been studied by means of X-ray magnetic circular dichroism in combination with photoelectron emission microscopy (XMCD-PEEM). We find that a parallel coupling between magnetic domains coexists with a non-parallel coupling between magnetic domain walls of each ferromagnetic layer. We attribute the non-parallel coupling of the two magnetic layers to local magnetic stray fields arising at domain walls in the magnetically harder Co layer. In the magnetically softer FeNi layer non-ordinary domain walls such as 270 and 90 domain walls with overshoot of the magnetization either inwards or outwards relative to the turning direction of the Co magnetization are identified. Micromagnetic simulations reveal that in the absence of magnetocrystalline anisotropy, both types of overshooting domain walls are energetically equivalent. However, if a uniaxial in-plane anisotropy is present, the relative orientation of the domain walls with respect to the anisotropy axis determines which of these domain walls is energetically favorable.

  9. Influence of cold isostatic pressing on the magnetic properties of Ni-Zn-Cu ferrite

    Science.gov (United States)

    Le, Trong Trung; Valdez-Nava, Zarel; Lebey, Thierry; Mazaleyrat, Frédéric

    2018-04-01

    In power electronics, there is the need to develop solutions to increase the power density of converters. Interleaved multicellular transformers allow interleaving many switching cells and, as a result, a possible increase in the power density. This converter is often composed of a magnetic core having the function of an intercell transformer (ICT) and, depending on the complexity of the designed architecture, its shape could be extremely complex. The switching frequencies (1-10 MHz) for the new wide band gap semiconductors (SiC, GaN) allow to interleave switching cell at higher frequencies than silicon-based semiconductors (materials, but their limit in frequency drive raises the need of higher frequency magnetic materials, such Ni-Zn ferrites. These materials can operate in medium and high power converters up to 10 MHz. We propose to use Ni0,30Zn0,57Cu0,15Fe2O4 ferrite and to compress it by cold isostatic pressing (CIP) into a a green ceramic block and to machine it to obtain the desired ICT of complex shape prior sintering. We compare the magnetic permeability spectra and hysteresis loops the CIP and uniaxially pressed ferrites. The effect of temperature and sintering time as well as high-pressure on properties will be presented in detail. The magnetic properties of the sintered cores are strongly dependent on the microstructure obtained.

  10. Brazing of zirconia to titanium using Ag-Cu and Au-Ni filler alloys

    Directory of Open Access Journals (Sweden)

    Jean S. Pimenta

    2013-12-01

    Full Text Available Advanced ceramic is usually joined to metal by the well-known direct brazing process, where costly active filler alloys can be considered a limitation. Brazing using active-metal-free filler alloy as insert between the joint components is an attempt to overcome it. The active metal diffusion from the titanium member through the bulk of molten filler to the ceramic was responsible to produce an active filler alloy in loco and promote reduction of the zirconium oxide to improve wetting on the ceramic surface. Unalloyed titanium was joined in a high-vacuum furnace (<3x10-5 mbar to yttria-tetragonal zirconia polycristals (Y-TZP and zirconia partially stabilized with magnesia (Mg-PSZ, where commercial fillers Ag-28Cu and Au-18Ni with respective thermal cycles were evaluated. Helium gas leak detection test was performed at the ceramic/metal interface at room temperature; samples from reliable vacuum tight joints were examined by microstructural analysis techniques and energy dispersive X-ray analysis at the joint cross-section. Tight joints were produced with eutectic Ag-Cu filler, revealing an intermetallic layer and a dark reaction layer near the ceramic surface; titanium diffusion was efficient for superficial chemical interactions between individual components. Brazing joints were also tested using three-point flexure testing.

  11. First stage of the structural evolution of austenite in Cu-Al-Ni shape memory alloys

    International Nuclear Information System (INIS)

    Pelosin, V.; Gerland, M.; Riviere, A.

    2001-01-01

    Two shape memory Cu-Al-Ni alloys, a polycrystal and a single crystal, exhibiting a martensitic transformation close to 130 C (in the as-quenched state) have been studied. Specimens have been quenched after heat treatment at 850 C. The structural evolutions of the high temperature phase (austenite) have been studied for thermal treatments performed below 200 C. Investigations have been carried out using electrical resistivity measurements, TEM (transmission electron microscopy) observations and X-ray diffraction analysis. The main structural modifications are observed in the polycrystalline alloy and concern first, the reordering process of the austenite structure (B2→L2 1 ), and second, the precipitation of the (Cu 9 Al 4 ) γ 2 phase. In the single crystal alloy, the evolutions are very slight and localized on the structural defects. Particular attention is paid to the role of the quenched-in vacancy elimination on the observed mechanisms. In addition, the incidence of the structural evolution on the transformation temperatures is also discussed. (orig.)

  12. Magnetoimpedance effect of the Ni80Fe20/Cu composite wires: The influence of DC current imposed on the Cu base

    Directory of Open Access Journals (Sweden)

    Delu Chen

    2014-06-01

    Full Text Available In this paper, the copper composite wires of 75 μm in diameter with a sputtered layer of Ni80Fe20 permalloy were prepared, with a DC current applied to the basal Cu terminals during the fabrication process. The influence of the DC current on the magnetic configuration and Magneto-Impedance (MI effect was studied. The results indicate that both the current amplitude and actuation duration have significant effect on the magnetic properties of the Ni80Fe20 layer. With appropriate current applied, the induced magnetic field leads to a circumferential magnetic domain structure and reduces significantly the equivalent anisotropy field of Ni80Fe20 layer. Then, the GMI ratio of the composite wires was significantly increased. A maximum GMI of 194.8% can be reached when the current was fixed at 100 mA and the Ni80Fe20 thickness is 780 nm. If the Ni80Fe20 thickness is above 780 nm, the coercivity of the coating layer increases while the GMI ratio of the composite wire reduces, since the magnetic anisotropy of the Ni80Fe20 layer varies from circumferential to longitudinal. The results were explained combining the thermal and magnetic effects of current.

  13. Effect of neodymium substitutions on electromagnetic properties in low temperature sintered NiCuZn ferrite

    Science.gov (United States)

    Wu, C. P.; Tung, M. J.; Ko, W. S.; Wang, Y. P.; Tong, S. Y.; Yang, M. D.

    2015-11-01

    Nd3+ ions substituted Ni0.37Cu0.14Zn0.52Fe2O4 (Nd3+ ions content=0, 0.01, 0.04, 0.6, 1.5 wt%) were prepared by the usual standard ceramic method at 1030 °C sintering temperature, and the composition dependence of the physical and magnetic properties has been investigated. SEM micrographs and EDX analysis revealed that it is no obvious impurities up to Nd3+ ions content wt%=0.04. For higher Nd3+ ions content samples (0.6 and 1.5 wt%), there are two kind of impurities Cu-rich and Nd-rich iron oxide phase. The saturation magnetization of the 0.01 wt% Nd3+ions content sample is higher as result of that the A-B sites distance and YK-angles are shorter and smaller. The saturation magnetization of 0.04-1.5 wt% Nd3+ ion content sample are reduced, since the total magnetic moments of the AB site are decreased. For the 0.6 wt% sample, the Curie temperature increasing is as result of the Cu-rich iron oxide separating out. The maximum enhancements of permeability μ‧ are improved to 11.2% (0.04 wt%) and 29.2% (0.6 wt%) at the 6.7 and 13.8 MHz, respectively. However, it is notice that small amount substitutions of Nd3+ increase the high frequency electromagnetic characteristics, can be applied to NFC technology and WPT technologies.

  14. Effect of neodymium substitutions on electromagnetic properties in low temperature sintered NiCuZn ferrite

    Energy Technology Data Exchange (ETDEWEB)

    Wu, C.P., E-mail: itria20161@itri.org.tw; Tung, M.J.; Ko, W.S.; Wang, Y.P.; Tong, S.Y.; Yang, M.D.

    2015-11-01

    Nd{sup 3+} ions substituted Ni{sub 0.37}Cu{sub 0.14}Zn{sub 0.52}Fe{sub 2}O{sub 4} (Nd{sup 3+} ions content=0, 0.01, 0.04, 0.6, 1.5 wt%) were prepared by the usual standard ceramic method at 1030 °C sintering temperature, and the composition dependence of the physical and magnetic properties has been investigated. SEM micrographs and EDX analysis revealed that it is no obvious impurities up to Nd{sup 3+} ions content wt%=0.04. For higher Nd{sup 3+} ions content samples (0.6 and 1.5 wt%), there are two kind of impurities Cu-rich and Nd-rich iron oxide phase. The saturation magnetization of the 0.01 wt% Nd{sup 3+}ions content sample is higher as result of that the A–B sites distance and YK-angles are shorter and smaller. The saturation magnetization of 0.04–1.5 wt% Nd{sup 3+} ion content sample are reduced, since the total magnetic moments of the AB site are decreased. For the 0.6 wt% sample, the Curie temperature increasing is as result of the Cu-rich iron oxide separating out. The maximum enhancements of permeability μ′ are improved to 11.2% (0.04 wt%) and 29.2% (0.6 wt%) at the 6.7 and 13.8 MHz, respectively. However, it is notice that small amount substitutions of Nd{sup 3+} increase the high frequency electromagnetic characteristics, can be applied to NFC technology and WPT technologies.

  15. High efficient conversion of furfural to 2-methylfuran over Ni-Cu/Al2O3 catalyst with formic acid as a hydrogen donor

    DEFF Research Database (Denmark)

    Fu, Zhaolin; Wang, Ze; Lin, Weigang

    2017-01-01

    Conversion of furfural to 2-methylfuran over Cu/Al2O3, Ni/Al2O3 and Ni-Cu/Al2O3 catalysts were investigated with formic acid as a hydrogen donor. Ni/Al2O3 showed a high catalytic activity but a moderate selectivity to 2-methylfuran. Contrarily, Cu/Al2O3 showed a low catalytic activity but a high...... selectivity for carbonyl reduction. Over the bimetallic catalysts Ni-10%Cu/Al2O3, by increasing Ni content, more furfural was converted with the reduction of carbonyl primarily. The effect of reaction solvent and the fraction of formic acid were also studied. The result showed that isopropanol solvent could...

  16. Direct production of carbon nanofibers decorated with Cu2O by thermal chemical vapor deposition on Ni catalyst electroplated on a copper substrate

    Directory of Open Access Journals (Sweden)

    MA Vesaghi

    2012-12-01

    Full Text Available  Carbon nanofibers (CNFs decorated with Cu2O particles were grown on a Ni catalyst layer deposited on a Cu substrate by thermal. chemical vapor deposition from liquid petroleum gas. Ni catalyst nanoparticles with different sizes were produced in an electroplating system at 35˚C. These nanoparticles provide the nucleation sites for CNF growth, removing the need for a buffer layer. High temperature surface segregation of the Cu substrate into the Ni catalyst layer and its exposition to O2 at atmospheric environment, during the CNFs growth, lead to the production of CNFs decorated with Cu2O particles. The surface morphology of the Ni catalyst films and grown CNFs over it was studied by scanning electron microscopy. Transmission electron microscopy and Raman spectroscopy revealed the formation of CNFs. The selected area electron diffraction pattern and electron diffraction studies show that these CNFs were decorated with Cu2O nanoparticles.

  17. Effects of Fabrication Parameters on Interface of Zirconia and Ti-6Al-4V Joints Using Zr55Cu30Al10Ni5 Amorphous Filler

    Science.gov (United States)

    Liu, Yuhua; Hu, Jiandong; Shen, Ping; Guo, Zuoxing; Liu, Huijie

    2013-09-01

    ZrO2 was brazed to Ti-6Al-4V using a Zr55Cu30Al10Ni5 (at.%) amorphous filler in a high vacuum at 1173-1273 K. The influences of brazing temperature, holding time, and cooling rate on the microstructure and shear strength of the joints were investigated. The interfacial microstructures can be characterized as ZrO2/ZrO2- x + TiO/(Zr,Ti)2(Cu,Ni)/(Zr,Ti)2(Cu,Ni,Al)/acicular Widmanstäten structure/Ti-6Al-4V. With the increase in the brazing temperature, both the thickness of the ZrO2- x + TiO layer and the content of the (Zr,Ti)2(Cu,Ni) phase decreased. However, the acicular Widmanstäten structure gradually increased. With the increase in the holding time, the (Zr,Ti)2(Cu,Ni) phase decreased, and the thickness of the (Zr,Ti)2(Cu,Ni) + (Zr,Ti)2(Cu,Ni,Al) layer decreased. In addition, cracks formed adjacent to the ZrO2 side under rapid cooling. The microstructures produced under various fabrication parameters directly influence the shear strength of the joints. When ZrO2 and Ti-6Al-4V couples were brazed at 1173 K for 10 min and then cooled at a rate of 5 K/min, the maximum shear strength of 95 MPa was obtained.

  18. On the Path to Optimizing the Al-Co-Cr-Cu-Fe-Ni-Ti High Entropy Alloy Family for High Temperature Applications

    Directory of Open Access Journals (Sweden)

    Anna M. Manzoni

    2016-03-01

    Full Text Available The most commonly investigated high entropy alloy, AlCoCrCuFeNi, has been chosen for optimization of its microstructural and mechanical properties by means of compositional changes and heat treatments. Among the different available optimization paths, the decrease of segregating element Cu, the increase of oxidation protective elements Al and Cr and the approach towards a γ-γ′ microstructure like in Ni-based superalloys have been probed and compared. Microscopical observations have been made for every optimization step. Vickers microhardness measurements and/or tensile/compression test have been carried out when the alloy was appropriate. Five derived alloys AlCoCrFeNi, Al23Co15Cr23Cu8Fe15Ni16, Al8Co17Cr17Cu8Fe17Ni33, Al8Co17Cr14Cu8Fe17Ni34.8Mo0.1Ti1W0.1 and Al10Co25Cr8Fe15Ni36Ti6 (all at.% have been compared to the original AlCoCrCuFeNi and the most promising one has been selected for further investigation.

  19. Understanding lattice defects to influence ferromagnetic order of ZnO nanoparticles by Ni, Cu, Ce ions

    Energy Technology Data Exchange (ETDEWEB)

    Verma, Kuldeep Chand, E-mail: dkuldeep.physics@gmail.com [Department of Physics, Panjab University, Chandigarh 160014 (India); Kotnala, R.K., E-mail: rkkotnala@gmail.com [CSIR-National Physical Laboratory, New Delhi 110012 (India)

    2017-02-15

    Future spintronics technologies based on diluted magnetic semiconductors (DMS) will rely heavily on a sound understanding of the microscopic origins of ferromagnetism in such materials. It remains unclear, however, whether the ferromagnetism in DMS is intrinsic - a precondition for spintronics - or due to dopant clustering. For this, we include a simultaneous doping from transition metal (Ni, Cu) and rare earth (Ce) ions in ZnO nanoparticles that increase the antiferromagnetic ordering to achieve high-T{sub c} ferromagnetism. Rietveld refinement of XRD patterns indicate that the dopant ions in ZnO had a wurtzite structure and the dopants, Ni{sup 2+}, Cu{sup 2+}, Ce{sup 3+} ions, are highly influenced the lattice constants to induce lattice defects. The Ni, Cu, Ce ions in ZnO have nanoparticles formation than nanorods was observed in pure sample. FTIR involve some organic groups to induce lattice defects and the metal-oxygen bonding of Zn, Ni, Cu, Ce and O atoms to confirm wurtzite structure. Raman analysis evaluates the crystalline quality, structural disorder and defects in ZnO lattice with doping. Photoluminescence spectra have strong near-band-edge emission and visible emission bands responsible for defects due to oxygen vacancies. The energy band gap is calculated using Tauc relation. Room temperature ferromagnetism has been described due to bound magnetic polarons formation with Ni{sup 2+}, Cu{sup 2+}, Ce{sup 3+} ions in ZnO via oxygen vacancies. The zero field and field cooling SQUID measurement confirm the strength of antiferromagnetism in ZnO. The field cooling magnetization is studied by Curie-Weiss law that include antiferromagnetic interactions up to low temperature. The XPS spectra have involve +3/+4 oxidation states of Ce ions to influence the observed ferromagnetism. - Graphical abstract: The lattice defects/vacancies attributed by Ni and Ce ions in the wurtzite ZnO structure are responsible in high T{sub c} -ferromagnetism due to long-range magnetic

  20. High salinity volatile phases in magmatic Ni-Cu-platinum group element deposits

    Science.gov (United States)

    Hanley, J. J.; Mungall, J. E.

    2004-12-01

    The role of "deuteric" fluids (exsolved magmatic volatile phases) in the development of Ni-Cu-PGE (platinum group element) deposits in mafic-ultramafic igneous systems is poorly understood. Although considerable field evidence demonstrates unambiguously that fluids modified most large primary Ni-Cu-PGE concentrations, models which hypothesize that fluids alone were largely responsible for the economic concentration of the base and precious metals are not widely accepted. Determination of the trace element composition of magmatic volatile phases in such ore-forming systems can offer considerable insight into the origin of potentially mineralizing fluids in such igneous environments. Laser ablation ICP-MS microanalysis allows researchers to confirm the original metal budget of magmatic volatile phases and quantify the behavior of trace ore metals in the fluid phase in the absence of well-constrained theoretical or experimental predictions of ore metal solubility. In this study, we present new evidence from major deposits (Sudbury, Ontario, Canada; Stillwater Complex, Montana, U.S.A.) that compositionally distinct magmatic brines and halide melt phases were exsolved from crystallizing residual silicate melt and trapped within high-T fluid conduits now comprised of evolved rock compositions (albite-quartz graphic granite, orthoclase-quartz granophyre). Petrographic evidence demonstrates that brines and halide melts coexisted with immiscible carbonic phases at the time of entrapment (light aliphatic hydrocarbons, CO2). Brine and halide melt inclusions are rich in Na, Fe, Mn, K, Pb, Zn, Ba, Sr, Al and Cl, and homogenize by either halite dissolution at high T ( ˜450-700° C) or by melting of the salt phase (700-800° C). LA-ICPMS analyses of single inclusions demonstrate that high salinity volatile phases contained abundant base metals (Cu, Fe, Sn, Bi) and precious metals (Pt, Pd, Au, Ag) at the time of entrapment. Notably, precious metal concentrations in the inclusions

  1. Three-dimensional rigid multiphase networks providing high-temperature strength to cast AlSi10Cu5Ni1-2 piston alloys

    International Nuclear Information System (INIS)

    Asghar, Z.; Requena, G.; Boller, E.

    2011-01-01

    The three-dimensional (3-D) architecture of rigid multiphase networks present in AlSi10Cu5Ni1 and AlSi10Cu5Ni2 piston alloys in as-cast condition and after 4 h spheroidization treatment is characterized by synchrotron tomography in terms of the volume fraction of rigid phases, interconnectivity, contiguity and morphology. The architecture of both alloys consists of α-Al matrix and a rigid long-range 3-D network of Al 7 Cu 4 Ni, Al 4 Cu 2 Mg 8 Si 7 , Al 2 Cu, Al 15 Si 2 (FeMn) 3 and AlSiFeNiCu aluminides and Si. The investigated architectural parameters of both alloys studied are correlated with room-temperature and high-temperature (300 deg. C) strengths as a function of solution treatment time. The AlSi10Cu5Ni1 and AlSi10Cu5Ni2 alloys behave like metal matrix composites with 16 and 20 vol.% reinforcement, respectively. Both alloys have similar strengths in the as-cast condition, but the AlSi10Cu5Ni2 is able to retain ∼15% higher high temperature strength than the AlSi10Cu5Ni1 alloy after more than 4 h of spheroidization treatment. This is due to the preservation of the 3-D interconnectivity and the morphology of the rigid network, which is governed by the higher degree of contiguity between aluminides and Si.

  2. Heterospin systems constructed from [Cu2Ln]3+ and [Ni(mnt)2]1-,2- Tectons: First 3p-3d-4f complexes (mnt = maleonitriledithiolato).

    Science.gov (United States)

    Madalan, Augustin M; Avarvari, Narcis; Fourmigué, Marc; Clérac, Rodolphe; Chibotaru, Liviu F; Clima, Sergiu; Andruh, Marius

    2008-02-04

    New heterospin complexes have been obtained by combining the binuclear complexes [{Cu(H(2)O)L(1)}Ln(O(2)NO)(3)] or [{CuL(2)}Ln(O(2)NO)(3)] (L(1) = N,N'-propylene-di(3-methoxysalicylideneiminato); L(2) = N,N'-ethylene-di(3-methoxysalicylideneiminato); Ln = Gd(3+), Sm(3+), Tb(3+)), with the mononuclear [CuL(1)(2)] and the nickel dithiolene complexes [Ni(mnt)(2)](q)- (q = 1, 2; mnt = maleonitriledithiolate), as follows: (1)infinity[{CuL(1)}(2)Ln(O(2)NO){Ni(mnt)(2)}].Solv.CH(3)CN (Ln = Gd(3+), Solv = CH(3)OH (1), Ln = Sm(3+), Solv = CH(3)CN (2)) and [{(CH(3)OH)CuL(2)}(2)Sm(O(2)NO)][Ni(mnt)(2)] (3) with [Ni(mnt)2]2-, [{(CH(3)CN)CuL(1)}(2)Ln(H(2)O)][Ni(mnt)(2)]3.2CH(3)CN (Ln = Gd(3+) (4), Sm(3+) (5), Tb(3+) (6)), and [{(CH(3)OH)CuL(2)}{CuL(2)}Gd(O(2)NO){Ni(mnt)(2)}][Ni(mnt)(2)].CH(2)Cl(2) (7) with [Ni(mnt))(2]*-. Trinuclear, almost linear, [CuLnCu] motifs are found in all the compounds. In the isostructural 1 and 2, two trans cyano groups from a [Ni(mnt)2]2- unit bridge two trimetallic nodes through axial coordination to the Cu centers, thus leading to the establishment of infinite chains. 3 is an ionic compound, containing discrete [{(CH(3)OH)CuL(2)}(2)Sm(O(2)NO)](2+) cations and [Ni(mnt)(2)](2-) anions. Within the series 4-6, layers of discrete [CuLnCu](3+) motifs alternate with stacks of interacting [Ni(mnt)(2)](*-) radical anions, for which two overlap modes, providing two different types of stacks, can be disclosed. The strength of the intermolecular interactions between the open-shell species is estimated through extended Hückel calculations. In compound 7, [Ni(mnt)(2)](*-) radical anions coordinate group one of the Cu centers of a trinuclear [Cu(2)Gd] motif through a CN, while discrete [Ni(mnt)(2)](*-) units are also present, overlapping in between, but also with the coordinated ones. Furthermore, the [Cu(2)Gd] moieties dimerize each other upon linkage by two nitrato groups, both acting as chelate toward the gadolinium ion from one unit and monodentate toward a

  3. Effects of microstructure and CaO addition on the magnetic and mechanical properties of NiCuZn ferrites

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Sea-Fue, E-mail: sfwang@ntut.edu.tw; Hsu, Yung-Fu; Liu, Yi-Xin; Hsieh, Chung-Kai

    2015-11-15

    In this study, the effects of grain size and the addition of CaCO{sub 3} on the magnetic and mechanical properties of Ni{sub 0.5}Cu{sub 0.3}Zn{sub 0.2}Fe{sub 2}O{sub 4} ceramics were investigated. The bending strength of the ferrites increased from 66 to 84 MPa as the grain size of the sintered ceramics decreased from 10.25 μm to 7.53 μm, while the change in hardness was insignificant. The addition of various amounts of CaCO{sub 3} densified the Ni{sub 0.5}Cu{sub 0.3}Zn{sub 0.2}Fe{sub 2}O{sub 4} ceramics at 1075 °C. In the pure Ni{sub 0.5}Cu{sub 0.3}Zn{sub 0.2}Fe{sub 2}O{sub 4} ceramic, second phase CuO was segregated at the grain boundaries. With the CaCO{sub 3} content ≥1.5 wt%, a small amount of discrete plate-like second phase Fe{sub 2}CaO{sub 4} was observed, together with the disappearance of the second phase CuO. The grain size of the Ni{sub 0.5}Cu{sub 0.3}Zn{sub 0.2}Fe{sub 2}O{sub 4} ceramic dropped from 7.80 μm to 4.68 μm, and the grain size distribution widened as the CaCO{sub 3} content increased from 0 to 5 wt%. Initially rising to 807 after CaCO{sub 3} addition up to 2.0 wt%, due to a reduced grain size, the Vickers hardness began to drop as the CaCO{sub 3} content increased. The bending strength grew linearly with the CaCO{sub 3} content and reached twice the value for the Ni{sub 0.5}Cu{sub 0.3}Zn{sub 0.2}Fe{sub 2}O{sub 4} ceramic with an addition of 5.0 wt% CaCO{sub 3}. The initial permeability of the Ni{sub 0.5}Cu{sub 0.3}Zn{sub 0.2}Fe{sub 2}O{sub 4} ceramic decreased substantially from 402 to 103 as the addition of CaCO{sub 3} in ferrite increased from 0 to 5 wt%, and the quality factor of the Ni{sub 0.5}Cu{sub 0.3}Zn{sub 0.2}Fe{sub 2}O{sub 4} ceramic was maximized at 95 for 1.0 wt% CaCO{sub 3} addition. - Highlights: • Effects of grain size and CaCO{sub 3} on the properties of NiCuZn ferrite were studied. • Bending strength increased with grain size of the ferrite but not in the hardness. • Bending strength reached a twice value for

  4. Effects of Cu and Ni additions on the heat affected zone (HAZ) microstructure and mechanical properties of a C-Mn niobium microalloyed steel

    International Nuclear Information System (INIS)

    Ale, Ricardo Miranda; Rebello, Joao Marques A.; Charlier, Jacques

    1996-01-01

    The influence of small additions of Cu and Ni on the heat affected zone microstructure and mechanical properties, particularly toughness, of C-Mn microalloyed steel has been evaluated. Cu and Ni additions improved the toughness of both coarse grained region and coarse grained region reheated intercritically due to the formation of lower bainite and avoiding Nb precipitation hardening, respectively. With Cu and Ni additions the embrittlement of the coarse grained region reheated intercritically, due to MA constituent, is counterbalanced by the formation of fine ferrite recrystallized grains near the prior austenite grain boundaries and the stabilisation of austenite between ferrite laths. (author)

  5. Percolation-induced plasmonic state and double negative electromagnetic properties of Ni-Zn Ferrite/Cu granular composite materials

    Science.gov (United States)

    Massango, Herieta; Kono, Koji; Tsutaoka, Takanori; Kasagi, Teruhiro; Yamamoto, Shinichiro; Hatakeyama, Kenichi

    2018-05-01

    Complex permeability and permittivity spectra of Ni-Zn Ferrite/Cu hybrid granular composite materials have been studied in the RF to microwave frequency range. The electrical conductivity σ shows insulating properties in the volume fraction of Cu particles below φ = 0.14. A large jump in conductivity was observed between φ = 0.14 and 0.24 indicating that the Cu particles make metallic conduction between this interval. Hence, the percolation threshold φC, was estimated to be 0.14. A percolation-induced low frequency plasmonic state with negative permittivity spectrum was observed from φ = 0.14-0.24. Meanwhile the negative permeability was observed at φ = 0.16, 0.19 and 0.24. Hence the DNG characteristic was realized in these Cu volume content in the frequency range from 105 MHz to 2 GHz.

  6. The Structure and Mechanical Properties of Ni-Mo PM Steels with Addition of Mn And Cu

    Science.gov (United States)

    Lichańska, E.; Kulecki, P.; Pańcikiewicz, K.

    2017-12-01

    The aim of the study was to evaluate the effect of chemical composition on the structure and mechanical properties of Mn-Ni-Mo and Ni-Mo-Cu PM steels. Pre-alloyed powder Astaloy 85Mo, diffusion alloyed powders Distaloy AQ and Distaloy AB produced by Höganäs, low carbon ferromanganese, carbonyl nickel powder T255 with three-dimensional filamentary structure and graphite CU-F have been used as the basic powders. Three mixtures with compositions of Fe-1%Mn-(0.5/1.75)%Ni-(0.5/0.85)%Mo-0.8%C and Fe-1.75%Ni-0.5%Mo-1.5%Cu-0.8%C were prepared in a Turbula mixer. Green compacts were single pressed in a steel die at 660 MPa according to PN-EN ISO 2740 standard. Sinterhardening was carried out at 1250°C in a mixture of 95% N2+5% H2 for 60 minutes. Mechanical tests (tensile, bend, hardness) and microstructural investigations were performed. Additionally, XRD and EDS analysis, fractographic investigations were carried out. The microstructures of steels investigated were mainly bainitic or bainitic-martensitic. Addition 1% Mn to Distaloy AQ based steel caused increase of tensile properties (YS from 422 to 489 MPa, UTS from 522 to 638 MPa, TRS from 901 to 1096 MPa) and decrease of plasticity (elongation from 3.65 to 2.84%).

  7. Characterisation of the early stages of solute clustering in 1Ni-1.3Mn welds containing Cu

    Energy Technology Data Exchange (ETDEWEB)

    Hyde, J.M., E-mail: jonathan.hyde@materials.ox.ac.uk [Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH (United Kingdom); National Nuclear Laboratory Ltd, B168 Harwell, Didcot, Oxon OX11 0QJ (United Kingdom); Burke, M.G. [Bechtel Bettis Inc., 814 Pittsburgh-McKeesport Blvd, West Mifflin, Pittsburgh 15122-0079 (United States); Boothby, R.M.; English, C.A. [National Nuclear Laboratory Ltd, B168 Harwell, Didcot, Oxon OX11 0QJ (United Kingdom)

    2009-04-15

    Microstructural characterisation of neutron irradiated low alloy steels is important for developing mechanistic understanding of irradiation embrittlement. This work is focused on the early stages of irradiation-induced clustering in a low Cu (0.03 wt%), high Ni ({approx}1 wt%) weld. The weld was irradiated at a very high dose rate and then examined by atom probe (energy-compensated position-sensitive atom probe (ECOPoSAP) and local electrode atom probe (LEAP)) with supporting microstructural information obtained by small angle neutron scattering (SANS) and positron annihilation (PALA). It was demonstrated that extreme care must be taken optimising parameters used to characterise the extent of clustering. This is particularly important during the early stages of irradiation-damage when the clusters are poorly defined and significant compositional variations are present in what is traditionally described as matrix. Analysis of the irradiated materials showed increasing clustering of Cu, Mn, Ni and Si with dose. In the low Cu steel the results showed that initially the irradiation damage results in clustering of Mn, Ni and Si, but at very high doses, at very high dose rates, redistribution of Si is significantly more advanced than that for Mn and Ni.

  8. In-situ GISAXS study on the oxidation behavior of liquid Ga on Ni(Cu)/Si substrates

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Weidong [College of Materials Science and Engineering, Qiqihar University, Qiqihar 161006 (China); Liu, Mingling [Department of Mechanical and Electrical Engineering, Qinhuangdao Institute of Technology, Qinhuangdao 066100 (China); Wu, Zhaojun [Department of Practice Teaching and Equipment Management, Qiqihar University, Qiqihar 161006 (China); Xing, Xueqing; Mo, Guang; Wu, Zhonghua [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Liu, Hong, E-mail: lhong68@sina.com.cn [School of Biomedical Engineering, Capital Medical University, Beijing 100069 (China)

    2015-11-01

    Liquid Ga could be used as a flexible heat-transfer medium or contact medium in the synchrotron-radiation-based instruments. The chemical stability of liquid Ga on other metal surface determines the serviceability of liquid Ga. In this paper, the oxidation evolutions of liquid Ga on Ni and Cu substrates have been investigated by in-situ grazing incidence small angle X-ray scattering (GISAXS) as a function of substrate temperature. The liquid Ga on Ni and Cu substrates shows different oxidation behaviors. A successive and slower oxidation from oxide clusters to oxide layer takes place with temperature increasing from 25 to 190 °C on the surface of the Ga/Ni/Si specimen, but a quick oxidation occurs on the entire surface of the Ga/Cu/Si specimen at the initial 25 °C. The subsequent heating increases the surface roughness of both liquid Ga, but increases simultaneously the surface curvature of the Ga/Cu/Si specimen. The understanding of the substrate-dependent oxidation behavior of liquid Ga is beneficial to its application as a heat-transfer medium.

  9. The Effect of Surfactant Content over Cu-Ni Coatings Electroplated by the sc-CO₂ Technique.

    Science.gov (United States)

    Chuang, Ho-Chiao; Sánchez, Jorge; Cheng, Hsiang-Yun

    2017-04-19

    Co-plating of Cu-Ni coatings by supercritical CO₂ (sc-CO₂) and conventional electroplating processes was studied in this work. 1,4-butynediol was chosen as the surfactant and the effects of adjusting the surfactant content were described. Although the sc-CO₂ process displayed lower current efficiency, it effectively removed excess hydrogen that causes defects on the coating surface, refined grain size, reduced surface roughness, and increased electrochemical resistance. Surface roughness of coatings fabricated by the sc-CO₂ process was reduced by an average of 10%, and a maximum of 55%, compared to conventional process at different fabrication parameters. Cu-Ni coatings produced by the sc-CO₂ process displayed increased corrosion potential of ~0.05 V over Cu-Ni coatings produced by the conventional process, and 0.175 V over pure Cu coatings produced by the conventional process. For coatings ~10 µm thick, internal stress developed from the sc-CO₂ process were ~20 MPa lower than conventional process. Finally, the preferred crystal orientation of the fabricated coatings remained in the (111) direction regardless of the process used or surfactant content.

  10. Creep and Oxidation Behavior of Modified CF8C-Plus with W, Cu, Ni, and Cr

    Science.gov (United States)

    Unocic, Kinga A.; Dryepondt, Sebastien; Yamamoto, Yukinori; Maziasz, Philip J.

    2016-04-01

    The microstructures of modified CF8C-Plus (Fe-19Cr-12Ni-0.4W-3.8Mn-0.2Mo-0.6Nb-0.5Si-0.9C) with W and Cu (CF8CPWCu) and CF8CPWCu enhanced with 21Cr + 15Ni or 22Cr + 17.5Ni were characterized in the as-cast condition and after creep testing. When imaged at lower magnifications, the as-cast microstructure was similar among all three alloys as they all contained a Nb-rich interdendritic phase and Mn-based inclusions. Transmission electron microscopy (TEM) analysis showed the presence of nanoscale Cu-rich nanoprecipitates distributed uniformly throughout the matrix of CF8CPWCu, whereas in CF8CPWCu22/17, Cu precipitates were found primarily at the grain boundaries. The presence of these nanoscale Cu-rich particles, in addition to W-rich Cr23C6, nanoscale Nb carbides, and Z-phase (Nb2Cr2N2), improved the creep strength of the CF8CPWCu steel. Modification of CF8CPWCu with Cr and Ni contents slightly decreased the creep strength but significantly improved the oxidation behavior at 1073 K (800 °C). In particular, the addition of 22Cr and 17.5Ni strongly enhanced the oxidation resistance of the stainless steel resulting in a 100 degrees or greater temperature improvement, and this composition provided the best balance between improving both mechanical properties and oxidation resistance.

  11. Effect of protein adsorption on the corrosion behavior of 70Cu-30Ni alloy in artificial seawater.

    Science.gov (United States)

    Torres Bautista, Blanca E; Carvalho, Maria L; Seyeux, Antoine; Zanna, Sandrine; Cristiani, Pierangela; Tribollet, Bernard; Marcus, Philippe; Frateur, Isabelle

    2014-06-01

    Copper alloys often used in cooling circuits of industrial plants can be affected by biocorrosion induced by biofilm formation. The objective of this work was to study the influence of protein adsorption, which is the first step in biofilm formation, on the electrochemical behavior of 70Cu-30Ni (wt.%) alloy in static artificial seawater and on the chemical composition of oxide layers. For that purpose, electrochemical measurements performed after 1h of immersion were combined to surface analyses. A model is proposed to analyze impedance data. In the presence of bovine serum albumin (BSA, model protein), the anodic charge transfer resistance deduced from EIS data at Ecorr is slightly higher, corresponding to lower corrosion current. Without BSA, two oxidized layers are shown by XPS and ToF-SIMS: an outer layer mainly composed of copper oxide (Cu2O redeposited layer) and an inner layer mainly composed of oxidized nickel, with a global thickness of ~30nm. The presence of BSA leads to a mixed oxide layer (CuO, Cu2O, Ni(OH)2) with a lower thickness (~10nm). Thus, the protein induces a decrease of the dissolution rate at Ecorr and hence a decrease of the amount of redeposited Cu2O and of the oxide layer thickness. © 2013.

  12. Nonlinear elastic properties of bulk metallic glasses Zr52.5Ti5Cu17.9Ni14.6Al10 and Pd40Cu30Ni10P20

    International Nuclear Information System (INIS)

    Kobelev, N.P.; Kolyvanov, E.L.; Khonik, V.A.

    2005-01-01

    The influence of uniaxial compression on the propagation of ultrasonic vibrations in Zr 52.5 Ti 5 Cu 17.9 Ni 14.6 Al 10 and Pd 40 Cu 30 Ni 10 P 20 bulk metallic glasses produced by melt quenching at a rate of 100 K/s is investigated. Elastic deformation was realized by compression of the samples along their long axis up to strains of about 1 GPa. Deriving of major ratios used during the calculation of the third-order elastic moduli of the glasses is described in brief, the results of the calculations being provided. A qualitative agreement between the calculated results and available data on the influence of the uniform pressure on the sound wave propagation rate was obtained [ru

  13. Analysis of the influence of structure on mechanical properties of multilayer Ni/Cu thin films for use in microelectronic technologies

    Directory of Open Access Journals (Sweden)

    Lamovec Jelena S.

    2015-01-01

    Full Text Available Multilayer Ni/Cu thin films were produced by dual-bath electrodeposition technique (DBT on polycrystalline cold-rolled Cu substrate. Different Ni/Cu multilayer structures were realized by changing of process parameters such as total film thickness, sublayer thickness and Ni/Cu sublayer thickness ratio. The mechanical properties of Vickers microhardness and interfacial adhesion in the films were investigated. Decreasing of sublayer thickness down to 300 nm and increasing of Ni:Cu sublayer thickness ratio to 1:4, lead to higher values of Vickers microhardness compared to monolayer metal films. Thin films with sublayer thicknesses from 75 nm to 5 μm show strong interfacial adhesion. A weak adhesion and sublayer exfoliation for the films with sublayer thickness greater than 5μm were found. Three-dimensional Ni microstructures can be fabricated using multilayer Ni/Cu film by selective etching of Cu layers in an acidic thiourea solution ('surface micromachining' technique.

  14. Toward the existence of ultrafast diffusion paths in Cu with a gradient microstructure: Room temperature diffusion of Ni

    Science.gov (United States)

    Wang, Z. B.; Lu, K.; Wilde, G.; Divinski, S.

    2008-09-01

    Room temperature diffusion of Ni63 in Cu with a gradient microstructure prepared by surface mechanical attrition treatment (SMAT) was investigated by applying the radiotracer technique. The results reveal significant penetration of Ni into the nanostructured layer. The relevant diffusivity is higher than that along the conventional high-angle grain boundaries by about six orders of magnitude. This behavior is associated with a higher energy state of internal interfaces produced via plastic deformation. The diffusivity in the top surface layer is somewhat smaller than that in the subsurface layer. This fact is related to nanotwin formation in the former during SMAT.

  15. KINETIKA MIKRO DEKOMPOSISI METANA MENJADI KARBON NANOTUBE PADA PERMUKAAN KATALIS Ni-Cu-Al

    Directory of Open Access Journals (Sweden)

    Praswasti Pembangun Dyah Kencana Wulan

    2012-04-01

    Full Text Available MICRO KINETICS OF DECOMPOSITION OF METHANE TO CARBON NANOTUBES OVER NI-CU-AL CATALYST. The main focus of this research was to obtain micro kinetics decomposition of methane producing carbon nanotube on the surface of the Ni-Cu-Al catalyst. Experimental kinetics data collected at a temperature range of 650-750oC and pressure of one atmosphere. The preliminary test was conducted to obtain the kinetics are not influenced by external and internal diffusion limitations as well as inter-phase transfer. Kinetics data were tested by micro kinetic model derived from the catalyst surface reaction mechanism. The most appropriate kinetic model becomes the rate-limiting step of methane decomposition reaction. Results of preliminary experiment showed that the kinetics of the external diffusion effect is negligible at flow rates above 150 mL/min. Internal diffusion can be ignored with a catalyst under 0.25 mm in diameter with a weight of 0.04 grams of catalyst and contact time 2.5x10-4. Rate equation analysis shows that the rate-limiting step is the adsorption which indicates that intermediate consumption (CH4I + I Û CH3I + HI is faster than the formation of intermediate (adsorption of methane, CH4 + I Û CH4I. The activation energy obtained for 34.628 kJ/mol and pre-exponential factor of 6.583x106.  Fokus utama penelitian ini adalah memperoleh kinetika mikro dekomposisi metana yang menghasilkan Carbon Nanotube pada permukaan  katalis Ni-Cu-Al. Data kinetika eksperimen diambil pada rentang temperatur 650-750oC dan tekanan 1 atmosfer. Percobaan pendahuluan dilakukan untuk memperoleh daerah kinetika yang tidak dipengaruhi oleh limitasi difusi eksternal dan internal serta perpindahan antar fasa.  Data kinetika  diuji dengan model kinetika mikro yang diturunkan dari mekanisme reaksi permukaan katalis. Model kinetika yang paling sesuai menjadi tahap pembatas laju reaksi dekomposisi metana. Hasil percobaan pendahuluan kinetika menunjukkan bahwa pengaruh

  16. Ferromagnetic half-metallic characteristic in bulk Ni 0.5M 0.5O (M=Cu, Zn and Cd): A GGAU study

    KAUST Repository

    Mi, Wenbo

    2012-07-01

    Ferromagnetic half metallicity with a high spin polarization of 100% was predicted in the bulk Ni 0.5Cu 0.5O using density-functional theory method. The band gap of majority spin is 3.45 eV for Ni 0.5Cu 0.5O. The density of states of minority spin at the Fermi level are mainly from Cu 3d and O 2p in the Ni 0.5Cu 0.5O. The magnetic moments are from Ni 3d states. Ni 0.5Zn 0.5O and Ni 0.5Cd 0.5O systems are ferromagnetic insulators, but the magnetic moment of Ni 2 ions is enhanced by the Zn and Cd incorporation. Therefore, Ni 0.5Cu 0.5O is the potential candidate for spintronics devices because of the predicted high spin polarization. © 2012 Elsevier Ltd. All rights reserved.

  17. Ferromagnetic half-metallic characteristic in bulk Ni 0.5M 0.5O (M=Cu, Zn and Cd): A GGAU study

    KAUST Repository

    Mi, Wenbo; Yang, Hua; Cheng, Yingchun; Bai, Haili

    2012-01-01

    Ferromagnetic half metallicity with a high spin polarization of 100% was predicted in the bulk Ni 0.5Cu 0.5O using density-functional theory method. The band gap of majority spin is 3.45 eV for Ni 0.5Cu 0.5O. The density of states of minority spin at the Fermi level are mainly from Cu 3d and O 2p in the Ni 0.5Cu 0.5O. The magnetic moments are from Ni 3d states. Ni 0.5Zn 0.5O and Ni 0.5Cd 0.5O systems are ferromagnetic insulators, but the magnetic moment of Ni 2 ions is enhanced by the Zn and Cd incorporation. Therefore, Ni 0.5Cu 0.5O is the potential candidate for spintronics devices because of the predicted high spin polarization. © 2012 Elsevier Ltd. All rights reserved.

  18. Efficient CH3NH3PbI3 perovskite/fullerene planar heterojunction hybrid solar cells with oxidized Ni/Au/Cu transparent electrode

    Science.gov (United States)

    Lai, Wei-Chih; Lin, Kun-Wei; Guo, Tzung-Fang; Chen, Peter; Liao, Yuan-Yu

    2018-02-01

    We demonstrated the performance of inverted CH3NH3PbI3 perovskite-based solar cells (SCs) with a thermally oxidized nickel/gold/copper (Ni/Au/Cu) trilayer transparent electrode. Oxidized Ni/Au/Cu is a high transparent layer and has less resistance than the oxidized Ni/Au layer. Like the oxidized Ni/Au layer, oxidized Ni and Cu in oxidized Ni/Au/Cu could perform as a hole transport layer of the perovskite-based SCs. It leads to improved perovskite SC performance on an open circuit voltage of 1.01 V, a short circuit current density of 14.36 mA/cm2, a fill factor of 76.7%, and a power conversion efficiency (η%) of 11.1%. The η% of perovskite SCs with oxidized Ni (10 nm)/Au (6 nm)/Cu (1 nm) improved by approximately 10% compared with that of perovskite SCs with oxidized Ni/Au.

  19. Contributions of Cu-rich clusters, dislocation loops and nanovoids to the irradiation-induced hardening of Cu-bearing low-Ni reactor pressure vessel steels

    Energy Technology Data Exchange (ETDEWEB)

    Bergner, F., E-mail: f.bergner@hzdr.de [Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstr. 400, 01328 Dresden (Germany); Gillemot, F. [Centre for Energy Research of the Hungarian Academy of Sciences, 29-33 Konkoly-Thege street, 1121 Budapest XII (Hungary); Hernández-Mayoral, M.; Serrano, M. [Division of Materials, CIEMAT, Avenida Complutense 22, 28040 Madrid (Spain); Török, G. [Wigner Research Center for Physics of the Hungarian Academy of Sciences, 29-33 Konkoly-Thege street, 1121 Budapest XII (Hungary); Ulbricht, A.; Altstadt, E. [Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstr. 400, 01328 Dresden (Germany)

    2015-06-15

    Highlights: • TEM and SANS were applied to estimate mean size and number density of loops, nanovoids and Cu-rich clusters. • A three-feature dispersed-barrier hardening model was applied to estimate the yield stress increase. • The values and errors of the dimensionless obstacle strength were estimated in a consistent way. • Nanovoids are stronger obstacles for dislocation glide than dislocation loops, loops are stronger than Cu-rich clusters. • For reactor-relevant conditions, Cu-rich clusters contribute most to hardening due to their high number density. - Abstract: Dislocation loops, nanovoids and Cu-rich clusters (CRPs) are known to represent obstacles for dislocation glide in neutron-irradiated reactor pressure vessel (RPV) steels, but a consistent experimental determination of the respective obstacle strengths is still missing. A set of Cu-bearing low-Ni RPV steels and model alloys was characterized by means of SANS and TEM in order to specify mean size and number density of loops, nanovoids and CRPs. The obstacle strengths of these families were estimated by solving an over-determined set of linear equations. We have found that nanovoids are stronger than loops and loops are stronger than CRPs. Nevertheless, CRPs contribute most to irradiation hardening because of their high number density. Nanovoids were only observed for neutron fluences beyond typical end-of-life conditions of RPVs. The estimates of the obstacle strength are critically compared with reported literature data.

  20. Le gisement de sulfures à Ni-Cu-Au d'Älgliden, ceinture de Skellefte, en Suède : un gisement magmatique de Ni-Cu en zone de subduction

    OpenAIRE

    Coin , Kévin

    2017-01-01

    Most major sulfide Ni-Cu deposits originated from komatiitic or tholeiitic magmas that formed in association with mantle plumes. Their genesis involves the segregation of a immiscible sulfide liquid, reaction of the sulfide liquid with silicate melt to upgrade the sulfide in chalcophile elements, and the concentration of the sulfide liquid in economic amounts. Saturation in sulfide is commonly achieved by lowering the sulfide solubility via assimilation of siliceous wall rock or by increasing...

  1. Influence of cold isostatic pressing on the magnetic properties of Ni-Zn-Cu ferrite

    Directory of Open Access Journals (Sweden)

    Trong Trung Le

    2018-04-01

    Full Text Available In power electronics, there is the need to develop solutions to increase the power density of converters. Interleaved multicellular transformers allow interleaving many switching cells and, as a result, a possible increase in the power density. This converter is often composed of a magnetic core having the function of an intercell transformer (ICT and, depending on the complexity of the designed architecture, its shape could be extremely complex. The switching frequencies (1-10 MHz for the new wide band gap semiconductors (SiC, GaN allow to interleave switching cell at higher frequencies than silicon-based semiconductors (<1 MHz. Intercell transformers must follow this increase in frequency times-fold the number of switching cells. Current applications for ICT transformers use Mn-Zn based materials, but their limit in frequency drive raises the need of higher frequency magnetic materials, such Ni-Zn ferrites. These materials can operate in medium and high power converters up to 10 MHz. We propose to use Ni0,30Zn0,57Cu0,15Fe2O4 ferrite and to compress it by cold isostatic pressing (CIP into a a green ceramic block and to machine it to obtain the desired ICT of complex shape prior sintering. We compare the magnetic permeability spectra and hysteresis loops the CIP and uniaxially pressed ferrites. The effect of temperature and sintering time as well as high-pressure on properties will be presented in detail. The magnetic properties of the sintered cores are strongly dependent on the microstructure obtained.

  2. Synthesis and molecular structure of [Cu(NH3)4][Ni(CN)4]: A missing piece in the [Cu(NH3)n][Ni(CN)4] story

    Science.gov (United States)

    Solanki, Dina; Hogarth, Graeme

    2015-11-01

    Reaction of CuCl2·2H2O and K2[Ni(CN)4]·2H2O in aqueous ammonia gave blue rod-like crystals of [Cu(NH3)4][Ni(CN)4]. An X-ray crystallographic reveals that square-planar anions and cations are weakly associated through coordination of a cis pair of cyanide ligands to copper, with one short and one long contact and thus the copper centre is best described as a square-based pyramid. Crystals lose ammonia readily upon removal from the solvent and this has been probed by TGA and DSC measurements. For comparison we have also re-determined the structure of the related ethylenediamine (en) complex [Cu(en)2][Ni(CN)4] at 150 K. This consists of a 1D chain in which a trans pair of cyanide ligands bind to copper such that the latter has an overall tetragonally distorted octahedral coordination geometry.

  3. Theoretical analysis of experimental tracer and interdiffusion data in Cu-Ni-Fe alloys

    International Nuclear Information System (INIS)

    Belova, I.V.; Murch, G.E.; Filipek, R.; Danielewski, M.

    2005-01-01

    In this paper, we present strategies to extract fundamental atomistic information from measured diffusion coefficients in a ternary alloy system. The strategies are exemplified with Cu-Ni-Fe alloys at 1271 K where recent extensive interdiffusion coefficients and tracer diffusion coefficients for all three components have become available. We develop new defining phenomenological expressions for the vacancy-wind factors in terms of the diffusion coefficients. We show that the measured tracer diffusion coefficients can be processed using the Manning and Moleko, Allnatt and Allnatt random alloy diffusion kinetics formalisms (with and without the assumption of the Gibbs-Duhem relation between the thermodynamic activities) to give jump frequencies, tracer correlation factors, vacancy-wind factors and phenomenological coefficients. It is shown for example that Cu is generally the most correlated component in its diffusion behavior and that the off-diagonal phenomenological coefficients can be as high as 64% of the smallest of the diagonal phenomenological coefficients. It is also shown that the Darken formalism (which ignores off-diagonal phenomenological coefficients) is in fact a reasonable approximation for expressing the diagonal phenomenological coefficients in terms of the tracer diffusion coefficients. It is then shown how the measured interdiffusivities can be processed with these formalisms to give tracer diffusivities, vacancy-wind factors and phenomenological coefficients. Finally, we show how a straightforward strategy starting with the Darken analysis that is then followed by the Manning or Moleko, Allnatt and Allnatt analysis can be used to gain access to the vacancy-wind factors and the off-diagonal phenomenological coefficients

  4. 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.

  5. Can heavy metal pollution defend seed germination against heat stress? Effect of heavy metals (Cu(2+), Cd(2+) and Hg(2+)) on maize seed germination under high temperature.

    Science.gov (United States)

    Deng, Benliang; Yang, Kejun; Zhang, Yifei; Li, Zuotong

    2016-09-01

    Heavy metal pollution, as well as greenhouse effect, has become a serious threat today. Both heavy metal and heat stresses can arrest seed germination. What response can be expected for seed germination under both stress conditions? Here, the effects of heavy metals (Cu(2+), Cd(2+) and Hg(2+)) on maize seed germination were investigated at 20 °C and 40 °C. Compared with 20 °C, heat stress induced thermodormancy. However, this thermodormancy could be significantly alleviated by the addition of a low concentration of heavy metals. Heavy metals, as well as heat stress induced H2O2 accumulation in germinating seeds. Interestingly, this low concentration of heavy metal that promoted seed germination could be partly blocked by DMTU (a specific ROS scavenger), irrespective of temperature. Accordingly, H2O2 addition reinforced this promoting effect on seed germination, which was induced by a low concentration of heavy metal. Furthermore, we found that the NADPH oxidase derived ROS was required for seed germination promoted by the heavy metals. Subsequently, treatment of seeds with fluridone (a specific inhibitor of ABA) or ABA significantly alleviated or aggravated thermodormancy, respectively. However, this alleviation or aggravation could be partly attenuated by a low concentration of heavy metals. In addition, germination that was inhibited by high concentrations of heavy metals was also partly reversed by fluridone. The obtained results support the idea that heavy metal-mediated ROS and hormone interaction can finally affect the thermodormancy release or not. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. DNA damage and transcriptional changes in the gills of mytilus galloprovincialis exposed to nanomolar doses of combined metal salts (Cd, Cu, Hg.

    Directory of Open Access Journals (Sweden)

    Laura Varotto

    Full Text Available Aiming at an integrated and mechanistic view of the early biological effects of selected metals in the marine sentinel organism Mytilus galloprovincialis, we exposed mussels for 48 hours to 50, 100 and 200 nM solutions of equimolar Cd, Cu and Hg salts and measured cytological and molecular biomarkers in parallel. Focusing on the mussel gills, first target of toxic water contaminants and actively proliferating tissue, we detected significant dose-related increases of cells with micronuclei and other nuclear abnormalities in the treated mussels, with differences in the bioconcentration of the three metals determined in the mussel flesh by atomic absorption spectrometry. Gene expression profiles, determined in the same individual gills in parallel, revealed some transcriptional changes at the 50 nM dose, and substantial increases of differentially expressed genes at the 100 and 200 nM doses, with roughly similar amounts of up- and down-regulated genes. The functional annotation of gill transcripts with consistent expression trends and significantly altered at least in one dose point disclosed the complexity of the induced cell response. The most evident transcriptional changes concerned protein synthesis and turnover, ion homeostasis, cell cycle regulation and apoptosis, and intracellular trafficking (transcript sequences denoting heat shock proteins, metal binding thioneins, sequestosome 1 and proteasome subunits, and GADD45 exemplify up-regulated genes while transcript sequences denoting actin, tubulins and the apoptosis inhibitor 1 exemplify down-regulated genes. Overall, nanomolar doses of co-occurring free metal ions have induced significant structural and functional changes in the mussel gills: the intensity of response to the stimulus measured in laboratory supports the additional validation of molecular markers of metal exposure to be used in Mussel Watch programs.

  7. Preparation of Zr50Al15-xNi10Cu25Yx amorphous powders by mechanical alloying and thermodynamic calculation

    International Nuclear Information System (INIS)

    Long, Woyun; Li, Jing; Lu, Anxian

    2013-01-01

    Amorphous Zr 50 Al 15-x Ni 10 Cu 25 Y x powders were fabricated by mechanical alloying at a low rotation speed from commercial pure element powders. The beneficial effect of Al partially substituted by Y in Zr 50 Al 15 Ni 10 Cu 25 on glass-forming ability was investigated. The as-milled powders were characterized by X-ray diffraction and transmission electron microscopy. The results show that partial substitution of Al by Y can improve the glass-forming ability of Zr 50 Al 15 Ni 10 Cu 25 Y alloy. Thermodynamic calculation of equivalent free energy shows that Zr 50 Al 13.8 Ni 10 Cu 25 Y 1.2 alloy has the highest glass-forming ability, which is in good agreement with the report of orthogonal experiments. (author)

  8. Effects of Glucopone 215 CSUP Concentration on Size and Magnetic Property of Co-Ni-Cu Nanoparticles Prepared by Electrodeposition Method

    International Nuclear Information System (INIS)

    Abdul Razak Daud; Setia Budi; Shahidan Radiman

    2011-01-01

    Co-Ni-Cu nanoparticles were prepared by electrodeposition method at co-deposition potential of -925 mV (SCE) from sulphate solution (0.018 M Co 2+ + 0.180 M Ni 2+ + 0.002 M Cu 2+ ), both in the presence and in the absence of surfactant, Glucopone 215 CSUP. The effect of surfactant concentration on size and magnetic properties of Co-Ni-Cu nanoparticles produced was investigated. Surface morphology was analyzed using a field emission scanning electron microscope (FESEM) while its magnetic properties were investigated by a vibrating sampel magnetometer (VSM). Co-Ni-Cu nanoparticles prepared from the Glucopone 215 CSUP- containing solution were spherical with nanometer size. The finest particles were about 50 nm obtained when 5 v% of surfactant was used which was the highest surfactant concentration studied in this work. Coercivity (H c ) of the samples prepared from electrolytes containing surfactant was higher than those of prepared without surfactant. (author)

  9. Chemical ordering around open-volume regions in bulk metallic glass Zr52.5Ti5Al10Cu17.9Ni14.6

    International Nuclear Information System (INIS)

    Asoka-Kumar, P.; Hartley, J.; Howell, R.; Sterne, P. A.; Nieh, T. G.

    2000-01-01

    We provide direct experimental evidence for a nonrandom distribution of atomic constituents in Zr 52.5 Ti 5 Al 10 Cu 17.9 Ni 14.6 bulk metallic glass using positron annihilation spectroscopy. The Ti content around the open-volume regions is significantly enhanced at the expense of Ni and Cu. Our results indicate that Ni and Cu atoms closely occupy the volume bounded by their neighboring atoms while Al, Ti, and Zr are less closely packed, and more likely to be associated with the open-volume regions. The overall distribution of elements seen by the positron is not significantly altered by annealing or by crystallization. Theoretical calculations indicate that the observed elemental distribution is not consistent with the known crystalline phases Zr 2 Cu and NiZr 2 , while Al 3 Zr 4 shows some of the characteristics seen in the experiment. (c) 2000 American Institute of Physics

  10. Fabrication and application of a new modified electrochemical sensor using nano-silica and a newly synthesized Schiff base for simultaneous determination of Cd2+, Cu2+ and Hg2+ ions in water and some foodstuff samples

    International Nuclear Information System (INIS)

    Afkhami, Abbas; Soltani-Felehgari, Farzaneh; Madrakian, Tayyebeh; Ghaedi, Hamed; Rezaeivala, Majid

    2013-01-01

    Highlights: ► A new modified electrochemical sensor was constructed and used. ► A new Schiff base coated nano-silica was used as modifier. ► The electrochemical properties of electrode were studied. ► This modifier enhanced the electrochemical properties of electrode. ► The electrode was used for simultaneous determination of Cd 2+ , Cu 2+ and Hg 2+ ions. -- Abstract: A new chemically modified carbon paste electrode was constructed and used for rapid, simple, accurate, selective and highly sensitive simultaneous determination of cadmium, copper and mercury using square wave anodic stripping voltammetry (SWASV). The carbon paste electrode was modified by N,N′-bis(3-(2-thenylidenimino)propyl)piperazine coated silica nanoparticles. Compared with carbon paste electrode, the stripping peak currents had a significant increase at the modified electrode. Under the optimized conditions (deposition potential, −1.100 V vs. Ag/AgCl; deposition time, 60 s; resting time, 10 s; SW frequency, 25 Hz; pulse amplitude, 0.15 V; dc voltage step height, 4.4 mV), the detection limit was 0.3, 0.1 and 0.05 ng mL −1 for the determination of Cd 2+ , Cu 2+ and Hg 2+ , respectively. The complexation reaction of the ligand with several metal cations in methanol was studied and the stability constants of the complexes were obtained. The effects of different cations and anions on the simultaneous determination of metal ions were studied and it was found that the electrode is highly selective for the simultaneous determination of Cd 2+ , Cu 2+ and Hg 2+ . Furthermore, the present method was applied to the determination of Cd 2+ , Cu 2+ and Hg 2+ in water and some foodstuff samples

  11. Photocatalytic Degradation of DIPA Using Bimetallic Cu-Ni/TiO2 Photocatalyst under Visible Light Irradiation

    Science.gov (United States)

    Bustam, Mohamad Azmi; Chong, Fai Kait; Man, Zakaria B.; Khan, Muhammad Saqib; Shariff, Azmi M.

    2014-01-01

    Bimetallic Cu-Ni/TiO2 photocatalysts were synthesized using wet impregnation (WI) method with TiO2 (Degussa-P25) as support and calcined at different temperatures (180, 200, and 300°C) for the photodegradation of DIPA under visible light. The photocatalysts were characterized using TGA, FESEM, UV-Vis diffuse reflectance spectroscopy, fourier transform infrared spectroscopy (FTIR) and temperature programmed reduction (TPR). The results from the photodegradation experiments revealed that the Cu-Ni/TiO2 photocatalysts exhibited much higher photocatalytic activities compared to bare TiO2. It was found that photocatalyst calcined at 200°C had the highest photocatalyst activities with highest chemical oxygen demand (COD) removal (86.82%). According to the structural and surface analysis, the enhanced photocatalytic activity could be attributed to its strong absorption into the visible region and high metal dispersion. PMID:25105158

  12. Photocatalytic Degradation of DIPA Using Bimetallic Cu-Ni/TiO2 Photocatalyst under Visible Light Irradiation

    Directory of Open Access Journals (Sweden)

    Nadia Riaz

    2014-01-01

    Full Text Available Bimetallic Cu-Ni/TiO2 photocatalysts were synthesized using wet impregnation (WI method with TiO2 (Degussa-P25 as support and calcined at different temperatures (180, 200, and 300°C for the photodegradation of DIPA under visible light. The photocatalysts were characterized using TGA, FESEM, UV-Vis diffuse reflectance spectroscopy, fourier transform infrared spectroscopy (FTIR and temperature programmed reduction (TPR. The results from the photodegradation experiments revealed that the Cu-Ni/TiO2 photocatalysts exhibited much higher photocatalytic activities compared to bare TiO2. It was found that photocatalyst calcined at 200°C had the highest photocatalyst activities with highest chemical oxygen demand (COD removal (86.82%. According to the structural and surface analysis, the enhanced photocatalytic activity could be attributed to its strong absorption into the visible region and high metal dispersion.

  13. Regularity in the formation of compounds in ternary R-Me-Sn systems, R - REM, Me - Fe, Co, Ni, Cu

    International Nuclear Information System (INIS)

    Skolozdra, R.V.; Komarovskaya, L.P.; Koretskaya, O.Eh.

    1992-01-01

    For the ternary alloy systems of (La, Y, Gd, Lu)-Fe-Sn, (Ce, Y, Gd)-Co-Sn, (Ce, Y, Gd, Lu)-Ni-Sn and (Pr, Gd, Lu)-Cu-Sn isothermal sections of phase diagrams were plotted within the range of 670 to 870 K. It was revealed that substitution of transition metal in the kFe-Co-Ni-Cu series led to changes both in a number of ternary stannides and their structural types. A tendency was observed in change of stannide numbers depending on quantity ratio of R and Me components. Crystallochemical analysis of compounds obtained showed that they could be treated as interstitial structures or lsuperstructures with respect to them. The results of magnetic properties measurements were used for explanation of structural features of ternary compounds considered

  14. Ion scattering studies of ordered alloy surfaces: CuAu(1 0 0) and NiAl

    International Nuclear Information System (INIS)

    Beikler, R.; Taglauer, E.

    2000-01-01

    The composition and structure of alloy surfaces can differ from the corresponding bulk properties due to segregation and relaxation effects. We studied the (1 0 0) surface of the ordered alloy CuAu and amorphous Ni and Al by low-energy Ne + and Na + ion scattering. The interpretation of the experimental results is supported by numerical simulations using the MARLOWE code. In the CuAu system a certain geometry was found to be very sensitive to Au presence in the 2nd layer. Comparison with MARLOWE results also allows to study variations in the ion yields arising from neutralization effects. By trajectory analysis ion survival probabilities are estimated for Ni and Al

  15. Structural behavior of Pd40Cu30Ni10P20 bulk metallic glass below and above the glass transition

    DEFF Research Database (Denmark)

    Mattern, N.; Hermann, H.; Roth, S.

    2003-01-01

    The thermal behavior of the structure of Pd40Cu30Ni10P20 bulk metallic glass has been investigated in situ through the glass transition by means of high-temperature x-ray synchrotron diffraction. The dependence of the x-ray structure factor S(q) of the Pd40Cu30Ni10P20 glass on temperature follows...... the Debye theory up to the glass transition with a Debye temperature theta=296 K. Above the glass transition temperature T-g, the temperature dependence of S(q) is altered, pointing to a continuous development of structural changes in the liquid with temperature. The atomic pair correlation functions g......(r) indicate changes in short-range-order parameters of the first and the second neighborhood with temperature. The temperature dependence of structural parameters is different in glass and in supercooled liquid, with a continuous behavior through the glass transition. The nearest-neighbor distance decreases...

  16. Breakdown of Shape Memory Effect in Bent Cu-Al-Ni Nanopillars: When Twin Boundaries Become Stacking Faults.

    Science.gov (United States)

    Liu, Lifeng; Ding, Xiangdong; Sun, Jun; Li, Suzhi; Salje, Ekhard K H

    2016-01-13

    Bent Cu-Al-Ni nanopillars (diameters 90-750 nm) show a shape memory effect, SME, for diameters D > 300 nm. The SME and the associated twinning are located in a small deformed section of the nanopillar. Thick nanopillars (D > 300 nm) transform to austenite under heating, including the deformed region. Thin nanopillars (D faults in the deformed region. No SME occurs and heating converts only the undeformed regions into austenite. The defect-rich, deformed region remains in the martensite phase even after prolonged heating in the stability field of austenite. A complex mixture of twins and stacking faults was found for diameters 130 nm < D < 300 nm. The size effect of the SME in Cu-Al-Ni nanopillars consists of an approximately linear reduction of the SME between 300 and 130 nm when the SME completely vanishes for smaller diameters.

  17. Study of hyperfine interactions in intermetallic compounds Gd(Ni,Pd,Cu)In, Tb(Ni,Pd)In, Dy(Ni,Pd)In and Ho(Ni,Pd)In

    International Nuclear Information System (INIS)

    Lapolli, Andre Luis

    2006-01-01

    Systematic behavior of magnetic hyperfine field (B hf ) in the intermetallic compounds Gd(Ni,Pd,Cu)In Tb(Ni,Pd)In, Dy(Ni,Pd)In and Ho(Ni,Pd)In was studied by Perturbed Gamma-Gamma Angular Correlation spectroscopy. The measurements of B hf were carried out at the rare earth atom and in sites using the nuclear probes 140 Ce and 11 '1Cd respectively. The variation of hyperfine field with temperature, in most cases, follows the Brillouin function predicted from the molecular field theory. The hyperfine field values at rare earth atom sites obtained from 140 Ce probe as well as at in sites obtained from 111 Cd probe for each series of compounds were extrapolated to zero Kelvin B hf (T=0) from these curves. These values were compared with the values of the literature for other compounds containing the same rare earth element and all of them show a linear relationship with the ordering temperature. This indicates that the main contribution to B hf comes from the conduction electron polarization (CEP) through Fermi contact interaction and the principal mechanism of magnetic interaction in these compounds can be described by the RKKY type interaction. The values of B hf (T=0) for each family of intermetallic compounds RNiIn and RPdIn when plotted as a function of 4f spin projection of rare earth element also shows a linear relationship. Exceptions are the results for the compounds RNiIn obtained with 111 Cd probe where a small deviation from linearity is observed. The results of the measurements carried out with the 111 Cd probe were also analyzed to obtain the hyperfine parameters of the quadrupole interaction as a function of temperature for RPdln and GdNiIn compounds. The results show that for the compound GdPdIn there might be some Gd-In disorder at high temperature. (author)

  18. Laser surface remelting of a Cu-Al-Ni-Mn shape memory alloy

    Energy Technology Data Exchange (ETDEWEB)

    Romero da Silva, Murillo, E-mail: murilloromero_@hotmail.com [Postgraduate Program in Materials Science and Engineering, Federal University of São Carlos, Rodovia Washington Luís, km 235, São Carlos, SP 13565-905 (Brazil); Gargarella, Piter [Department of Materials Engineering, Federal University of São Carlos, Rodovia Washington Luís, km 235, São Carlos, SP 13565-905 (Brazil); Gustmann, Tobias [IFW Dresden, Institute for Complex Materials, Helmholtzstraße 20, d-01069 Dresden (Germany); Botta Filho, Walter José; Kiminami, Claudio S. [Department of Materials Engineering, Federal University of São Carlos, Rodovia Washington Luís, km 235, São Carlos, SP 13565-905 (Brazil); Eckert, Jürgen [Erich Schmid Institute of Materials Science, Austrian Academy of Sciences, Jahnstraße 12, A-8700 Leoben (Austria); Department Materials Physics, Montanuniversität Leoben, Jahnstraße 12, A-8700 Leoben (Austria); Pauly, Simon [IFW Dresden, Institute for Complex Materials, Helmholtzstraße 20, d-01069 Dresden (Germany); Bolfarini, Claudemiro [Department of Materials Engineering, Federal University of São Carlos, Rodovia Washington Luís, km 235, São Carlos, SP 13565-905 (Brazil)

    2016-04-20

    Cu-based shape memory alloys (SMAs) show better thermal and electrical conductivity, lower cost and are easier to process than traditional Ti-based SMAs, but they exhibit a lower ductility and lower fatigue life. These properties can be improved by decreasing the grain size and reducing microstructural segregations, which may be obtained using laser surface remelting treatments. The aim of the present work was to produce and characterize laser remelted Cu-11.85Al-3.2Ni-3Mn SMA plates. Twelve plates with the dimensions of 50×10×1.5 mm were produced by suction casting in a first step. The surface of the plates was remelted afterwards with a laser beam power of 300 W, hatching of 50% and using three different scanning speeds: 100, 300 and 500 mm/s. The plates were characterized by optical and scanning electron microscopy, X-ray diffraction, differential scanning calorimetry as well as by tensile and microhardness tests. The remelted region showed a T morphology, with average thickness of 52, 29 and 23 µm for the plates remelted with scanning speeds of 100, 300 and 500 mm/s, respectively. In the plates remelted with 100 and 300 mm/s, some pores were found around the center of the track, due to the keyhole instability. The same phase formed in the as-cast sample was obtained in the laser remelted coatings: the monoclinic β′{sub 1} martensitic phase with zig-zag morphology. However, the laser treated samples exhibit lower transformation temperatures than the as-cast sample, due to grain refinement at the surface. They also show an improvement in the mechanical properties, with an increase of up to 162 MPa in fracture stress, up to 2.2% in ductility and up to 20.9 HV in microhardness when compared with the as-cast sample, which makes the laser surface remelting a promising method for improving the mechanical properties of Cu-based SMAs.

  19. Stability of nanosized alloy thin films: Faulting and phase separation in metastable Ni/Cu/Ag-W films

    International Nuclear Information System (INIS)

    Csiszár, G.; Kurz, S.J.B.; Mittemeijer, E.J.

    2016-01-01

    A comparative study of Me(=Ni/Cu/Ag)-based, W-alloyed, nanocrystalline, heavily faulted thin films was carried out to identify parameters stabilizing the nanocrystalline nature upon thermal treatment. The three systems, initially of comparably, heavily twinned (twin boundaries at spacings of 1–5 nm) microstructures showed similarities but also strikingly different behaviours upon annealing, as observed by application of in particular X-ray diffraction (line-broadening) analysis and (high resolution) transmission electron microscopy. During annealing in the range of 30–600 °C, (i) segregation at the planar faults (for Me = Ni) and at grain boundaries (for Me = Ni,Cu,Ag), as well as nanoscale phase separation (for Me = Cu,Ag) take place, (ii) distinct grain growth does not occur and (iii) the twin boundaries either are largely preserved ((Ni(W) and Ag(W)) or disappear totally (Cu(W))), which was ascribed to an altered faulting energy, due to change of the amount of W segregated at the twin boundaries, and to the evolution of nano-precipitates. The nanosized films exhibit very large internal (macro)stresses parallel to the surface, which change during annealing in the range of 1 GPa (tensile) to −3 GPa (compressive) and thus are sensitive to the microstructural changes in the films (decomposition and relaxation) that happen on a nanoscale. The results are discussed in terms of thermodynamic and/or kinetic constraints controlling these processes and thus the thermal stability of the systems concerned.

  20. Distribution and Behaviors of Cd, Cu, and Ni in the East China Sea Surface Water off the Changjiang Estuary

    OpenAIRE

    Kuo-Tung Jiann; Liang-Saw Wen; Gwo-Ching Gong

    2009-01-01

    Trace metal (Cd, Cu, and Ni) dis tri bu tions and be hav iors in sur face waters of the East China Sea continental shelf were investigated during an expeditioncon ducted in June 2004. Dissolved and particulate trace metal con centrations, as well as fractions of dissolved trace metals, fraction ated based on their different chemical affinities to ion exchangers, were determined using ultra-clean techniques and graphite furnace atomic absorption spectrometry (GFAAS). Large variations of dissol...