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Sample records for cu mo ag

  1. Ag Nanoparticles Loaded CuMoO4 Nanowires with Enhanced Photocatalytic Oxidative Activities%Ag/CuMoO4纳米线的制备及其光催化活性的研究

    Institute of Scientific and Technical Information of China (English)

    王文杰; 甄延忠

    2014-01-01

    采用水热技术获得了CuMoO4纳米线,通过光还原技术成功将Ag负载到CuMoO4纳米线材料上.利用罗丹明B模拟水中污染物,考察了CuMoO4和Ag/CuMoO4的光催化活性.研究结果表明:Ag均匀沉积在CuMoO4表面,提高了CuMoO4的光生电子-空穴对的分离效率,从而有效提高了催化剂的活性,对罗丹明B的降解率达95%.

  2. Ag/CuMoO4催化剂的水热合成以及其形貌、光催化研究

    Institute of Scientific and Technical Information of China (English)

    夏菁

    2014-01-01

    以(NH4)6Mo7O24·4H2O和CuCl2为原料,通过水热法合成了光催化剂CuMoO4以及通过光还原技术成功制备了Ag/CuMoO4的纳米线.通过XRD、SEM和UV-Vis吸收光谱等测试手段对所得催化剂形貌和催化活性进行表征.结果表明:CuMoO4在50mins可将罗丹明B降解率达到40%,Ag/CuMoO4可将罗丹明B降解率达到95%,由此说明Ag/CuMoO4是一种性能优良的光催化剂.

  3. Electronic structure and conductivity of nanocomposite metal (Au,Ag,Cu,Mo)-containing amorphous carbon films

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    Endrino, Jose L.; Horwat, David; Gago, Raul; Andersson, Joakim; Liu, Y.S.; Guo, Jinghua; Anders, Andre

    2008-05-14

    In this work, we study the influence of the incorporation of different metals (Me = Au, Ag, Cu, Mo) on the electronic structure of amorphous carbon (a-C:Me) films. The films were produced at room temperature using a novel pulsed dual-cathode arc deposition technique. Compositional analysis was performed with secondary neutral mass spectroscopy whereas X-ray diffraction was used to identify the formation of metal nanoclusters in the carbon matrix. The metal content incorporated in the nanocomposite films induces a drastic increase in the conductivity, in parallel with a decrease in the band gap corrected from Urbach energy. The electronic structure as a function of the Me content has been monitored by x-ray absorption near edge structure (XANES) at the C K-edge. XANES showed that the C host matrix has a dominant graphitic character and that it is not affected significantly by the incorporation of metal impurities, except for the case of Mo, where the modifications in the lineshape spectra indicated the formation of a carbide phase. Subtle modifications of the spectral lineshape are discussed in terms of nanocomposite formation.

  4. Timing of porphyry (Cu-Mo) and base metal (Zn-Pb-Ag-Cu) mineralisation in a magmatic-hydrothermal system—Morococha district, Peru

    Science.gov (United States)

    Catchpole, Honza; Kouzmanov, Kalin; Bendezú, Aldo; Ovtcharova, Maria; Spikings, Richard; Stein, Holly; Fontboté, Lluís

    2015-12-01

    The Morococha district in central Peru is characterised by economically important Cordilleran polymetallic (Zn-Pb-Ag-Cu) vein and replacement bodies and the large Toromocho porphyry Cu-Mo deposit in its centre. U-Pb, Re-Os, and 40Ar/39Ar geochronology data for various porphyry-related hydrothermal mineralisation styles record a 3.5-Ma multi-stage history of magmatic-hydrothermal activity in the district. In the late Miocene, three individual magmatic-hydrothermal centres were active: the Codiciada, Toromocho, and Ticlio centres, each separated in time and space. The Codiciada centre is the oldest magmatic-hydrothermal system in the district and consists of a composite porphyry stock associated with anhydrous skarn and quartz-molybdenite veins. The hydrothermal events are recorded by a titanite U-Pb age at 9.3 ± 0.2 Ma and a molybdenite Re-Os age at 9.26 ± 0.03 Ma. These ages are indistinguishable from zircon U-Pb ages for porphyry intrusions of the composite stock and indicate a time span of 0.2 Ma for magmatic-hydrothermal activity. The small Ticlio magmatic-hydrothermal centre in the west of the district has a maximum duration of 0.3 Ma, ranging from porphyry emplacement to porphyry mineralisation at 8.04 ± 0.14 Ma (40Ar/39Ar muscovite cooling age). The Toromocho magmatic-hydrothermal centre has a minimum of five recorded porphyry intrusions that span a total of 1.3 Ma and is responsible for the formation of the giant Toromocho Cu-Mo deposit. At least two hydrothermal pulses are identified. Post-dating a first pulse of molybdenite mineralisation, wide-spread hydrous skarn covers an area of over 6 km2 and is recorded by five 40Ar/39Ar cooling ages at 7.2-6.8 Ma. These ages mark the end of the slowly cooling and long-lived Toromocho magmatic-hydrothermal centre soon after last magmatic activity at 7.26 ± 0.02 Ma. District-wide (50 km2) Cordilleran base metal vein and replacement bodies post-date the youngest recorded porphyry mineralisation event at Toromocho

  5. Re-Os and U-Pb geochronology of the Laochang Pb-Zn-Ag and concealed porphyry Mo mineralization along the Changning-Menglian suture, SW China: implications for ore genesis and porphyry Cu-Mo exploration

    Science.gov (United States)

    Deng, Xiao-Dong; Li, Jian-Wei; Zhao, Xin-Fu; Wang, Hong-Qiang; Qi, Liang

    2016-02-01

    Numerous polymetallic volcanogenic massive sulfide (VMS), vein, and replacement deposits are distributed along the Changning-Menglian suture zone in Sanjiang Tethyan metallogenic province, SW China. Laochang is the largest Pb-Zn-Ag vein and replacement deposit in this area, with a proven reserve of 0.51 Mt Pb, 0.34 Mt Zn, and 1,737 t Ag. Its age and relationship to magmatic events and VMS deposits in the region, however, have long been debated. In this paper, we present pyrite Re-Os and titanite U-Pb ages aiming to provide significant insights into the timing and genesis of the Pb-Zn-Ag mineralization. Pyrite grains in textural equilibrium with galena, sphalerite, and chalcopyrite from stratabound Pb-Zn-Ag and Cu-bearing Pb-Zn-Ag orebodies have a Re-Os isochron age of 45.7 ± 3.1 Ma (2 σ, mean square weighted deviation (MSWD) = 0.45), whereas titanite grains intergrown with sulfide minerals yield a weighted mean 206Pb/238U age of 43.4 ± 1.2 Ma (2 σ, n = 8). A Mo-mineralized granitic porphyry intersected by recent drilling below the Laochang Pb-Zn-Ag ores yields a zircon U-Pb age of 44.4 ± 0.4 Ma (2 σ, n = 12). Within analytical uncertainties, the ages of the Pb-Zn-Ag deposit and the concealed Mo-mineralized porphyry are indistinguishable, indicating that they are products of a single magmatic hydrothermal system. The results show that Laochang Pb-Zn-Ag deposit is significantly younger than the host mafic volcanic rock (zircon U-Pb age of 320.8 ± 2.7 Ma; 2 σ, n = 12) and Silurian VMS deposits along the Changning-Menglian suture zone, arguing against its origin as a Carboniferous VMS deposit as many researchers claimed. The initial 187Os/188Os ratio (0.540 ± 0.012) obtained from the pyrite Re-Os isochron suggests that metals were likely derived from the granitic porphyry that formed from a hybrid magma due to mixing of crustal- and mantle-derived melts, rather than from the mafic volcanic host rocks as previously thought. Our results favor that the Laochang

  6. Optimization of TiNP/Ti Content for Si3N4/42CrMo Joints Brazed With Ag-Cu-Ti+TiNP Composite Filler

    Science.gov (United States)

    Wang, Tianpeng; Zhang, Jie; Liu, Chunfeng

    The Si3N4 ceramic was brazed to 42CrMo steel by using TiN particles modified braze, and the proportion of TiNp reinforcement and active element Ti was optimized to improve the joint strength. The brazed joints were examined by means of SEM. and EDS investigations. Microstructural examination showed that TiN+Ti5Si3 reaction layer was adjacent to Si3N4, whereas TiC was formed in 42CrMo/filler reaction layer. The Ag-Cu-Ti brazing alloy showed intimate bonding with TiNp and Cu-Ti intermetallics precipitated in the joint. The strength tests demonstrated that the mechanical properties of joints increased and then decreased by increasing the TiNp content when a low Ti content (6wt.%) was supplied. When the Ti content (>6wt.%) was offered sufficiently, the joint strength decreased firstly and then stayed stable with increasing the TiNp content. The maximum four-point bending strength (221 MPa) was obtained when the contents of TiNp and Ti were 10vol.% and 6wt.%, respectively.

  7. Interface Structure and Electrical Property of Yb0.3Co4Sb12/Mo-Cu Element Pre-pared by Welding Using Ag-Cu-Zn Solder%Yb0.3Co4Sb12/Mo-Cu热电元件的界面结构与界面电阻

    Institute of Scientific and Technical Information of China (English)

    唐云山; 柏胜强; 任都迪; 廖锦城; 张澜庭; 陈立东

    2015-01-01

    通过放电等离子烧结(SPS)实现阻挡层 Ti-Al、过渡焊接层 Ni 与热电臂 Yb0.3Co4Sb12的一体化烧结,使用Ag-Cu-Zn 共晶合金完成热电元件 Yb0.3Co4Sb12/Ti-Al/Ni 与 Mo-Cu 电极的钎焊连接。扫描电镜(SEM)显示出Yb0.3Co4Sb12/Ti-Al/Ni/Ag-Cu-Zn/Mo-Cu 接头中各界面结合良好,无裂纹,成分分析发现 Yb0.3Co4Sb12/Ti-Al 界面存在AlCo、TiCoSb及TiSb2等金属间化合物(IMC)。500℃下等温时效30 d后, Yb0.3Co4Sb12/Ti-Al界面处的金属间化合物厚度无明显变化; Ag-Cu-Zn/Ni界面处Cu、Zn扩散趋于稳定, Cu-Zn扩散层厚度达到约40μm。界面接触电阻测试结果表明,等温时效前后Yb0.3Co4Sb12/Ti-Al/Ni/Ag-Cu-Zn/Mo-Cu元件的界面接触电阻率均低于10μΩ·cm2。%The barrier layer of Ti-Al and the contact layer of Ni were joined to Yb0.3Co4Sb12 simultaneously by us-ing spark plasma sintering (SPS) technique. The Mo-Cu electrode was then welded to thermoelectric element Yb0.3Co4Sb12/Ti-Al/Ni by using Ag-Cu-Zn alloy as solder. SEM results show that there are no cracks at the inter-faces of Yb0.3Co4Sb12/Ti-Al/Ni/Ag-Cu-Zn/Mo-Cu thermoelectric joints. The EDS analysis shows that intermetallic compounds (IMCs) layer containing AlCo, TiCoSb and TiSb2 phases are formed at the interface between Yb0.3Co4Sb12 and Ti-Al. After thermal aging at 500℃ for 30 d, the inter-diffusions at both Yb0.3Co4Sb12/Ti-Al inter-face and Ag-Cu-Zn/Ni interface tend to be steady. The contact electrical resistivity of the Yb0.3Co4Sb12/ Ti-Al/Ni/Ag-Cu-Zn/Mo-Cu thermoelectric joints are about 6.1μΩ·cm2after welding, and it maintained as low as 10μΩ·cm2 even after thermal aged for 30 d.

  8. Structural and magnetic phase transitions in CeCu6<mo>-mo>xTx <mo>(mo>T<mo>=Ag,>Pd<mo>)>

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    Poudel, L.; de la Cruz, C.; Payzant, E. A.; May, A. F.; Koehler, M.; Garlea, V. O.; Taylor, A. E.; Parker, D. S.; Cao, H. B.; McGuire, M. A.; Tian, W.; Matsuda, M.; Jeen, H.; Lee, H. N.; Hong, T.; Calder, S.; Zhou, H. D.; Lumsden, M. D.; Keppens, V.; Mandrus, D.; Christianson, A. D.

    2015-12-15

    The structural and the magnetic properties of CeCu6-xAgx (0≤x≤0.85) and CeCu6-xPdx (0≤x≤0.4) have been studied using neutron diffraction, resonant ultrasound spectroscopy (RUS), x-ray diffraction measurements, and first principles calculations. The structural and magnetic phase diagrams of CeCu6-xAgx and CeCu6-xPdx as a function of Ag/Pd composition are reported. The end member, CeCu6, undergoes a structural phase transition from an orthorhombic (Pnma) to a monoclinic (P21/c) phase at 240 K. In CeCu6-xAgx, the structural phase transition temperature (Ts) decreases linearly with Ag concentration and extrapolates to zero at xS ≈0.1. The structural transition in CeCu6-xPdx remains unperturbed with Pd substitution within the range of our study. The lattice constant b slightly decreases with Ag/Pd doping, whereas a and c increase with an overall increase in the unit cell volume. Both systems, CeCu6-xAgx and CeCu6-xPdx, exhibit a magnetic quantum critical point (QCP), at x≈0.2 and x≈0.05, respectively. Near the QCP, long range antiferromagnetic ordering takes place at an incommensurate wave vector (δ10 δ2), where δ1~0.62,δ2~0.25,x=0.125 for CeCu6-xPdx and δ1~0.64,δ2~0.3,x=0.3 for CeCu6-xAgx. The magnetic structure consists of an amplitude modulation of the Ce moments which are aligned along the c axis of the orthorhombic unit cell.

  9. The role of Ag precipitates in Cu-12 wt% Ag

    Energy Technology Data Exchange (ETDEWEB)

    Yao, D.W.; Song, L.N. [Department of Materials Science and Engineering, Zhejiang University, Zheda Road No.38, Hangzhou, Zhejiang 310027 (China); Dong, A.P.; Wang, L.T. [China Railway Construction Electrification Bureau Group Co.,Ltd., Beijing 100036 (China); Zhang, L. [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Meng, L., E-mail: mengliang@zju.edu.cn [Department of Materials Science and Engineering, Zhejiang University, Zheda Road No.38, Hangzhou, Zhejiang 310027 (China)

    2012-12-15

    The Cu-12 wt% Ag was prepared to investigate the role of Ag precipitates on the properties of the alloy. Two kinds of heat treatment procedures were adopted to produce different amount of Ag precipitates in the Cu-12 wt% Ag. The microstructure of Ag precipitates was systematically observed by optical microscopy and electron microscopy. The Cu-12 wt% Ag with more Ag precipitates exhibits higher strength and lower electrical conductivity. More Ag precipitates results in more phase interface and less Ag atoms dissolved in Cu matrix. By comparing the strengthening effect and electron scattering effect of phase interface and dissolved Ag atoms, it is conclude that the interface between Cu matrix and Ag precipitates could significantly block dislocation movement and enhance electron scattering in Cu-Ag alloys.

  10. NEAR-ABSOLUTE EQUATIONS OF STATE OF DIAMOND, Ag, Al, Au, Cu, Mo, Nb, Pt, Ta, AND W FOR QUASI-HYDROSTATIC CONDITIONS

    Directory of Open Access Journals (Sweden)

    Peter I. Dorogokupets

    2015-09-01

    Full Text Available Using the modified formalism of [Dorogokupets, Oganov, 2005, 2007], equations of state are developed for diamond, Ag, Al, Au, Cu, Mo, Nb, Pt, Ta, and W by simultaneous optimization of shock-wave data, ultrasonic, X-ray, dilatometric and thermochemical measurements in the temperature range from ~100 K to the melting temperature and pressures up to several Mbar, depending on the substance. The room-temperature isotherm is given in two forms: (1 the equation from [Holzapfel, 2001, 2010] which is the interpolation between the low pressure (x≥1 and the pressure at infinite compression (x=0; it corresponds to the Thomas-Fermi model, and (2 the equation from [Vinet et al., 1987]. The volume dependence of the Grüneisen parameter is calculated according to equations from [Zharkov, Kalinin, 1971; Burakovsky, Preston, 2004] with adjustable parameters, t and δ. The room-temperature isotherm and the pressure on the Hugoniot adiabat are determined by three parameters, K', t and δ, and K0 is calculated from ultrasonic measurements. In our study, reasonably accurate descriptions of all of the basic thermodynamic functions of metals are derived from a simple equation of state with a minimal set of adjustable parameters.The pressure calculated from room-temperature isotherms can be correlated with a shift of the ruby R1 line. Simultaneous measurements of the shift and unit cell parameters of metals are conducted in mediums containing helium [Dewaele et al., 2004b; 2008; Takemura, Dewaele, 2008; Takemura, Singh, 2006], hydrogen [Chijioke et al., 2005] and argon [Tang et al., 2010]. According to [Takemura, 2001], the helium medium in diamond anvil cells provides for quasi-hydrostatic conditions; therefore, the ruby pressure scale, that is calibrated for the ten substances, can be considered close to equilibrium or almost absolute. The ruby pressure scale is given as P(GPa=1870⋅Δλ/λ0⋅(1+6⋅Δλ/λ0. The room-temperature isotherms corrected with regard

  11. A rapid, partial leach and organic separation for the sensitive determination of Ag, Bi, Cd, Cu, Mo, Pb, Sb, and Zn in surface geologic materials by flame atomic absorption

    Science.gov (United States)

    Viets, J.G.; Clark, J.R.; Campbell, W.L.

    1984-01-01

    A solution of dilute hydrochloric acid, ascorbic acid, and potassium iodide has been found to dissolve weakly bound metals in soils, stream sediments, and oxidized rocks. Silver, Bi, Cd, Cu, Mo, Pb, Sb, and Zn are selectively extracted from this solution by a mixture of Aliquat 336 (tricaprylyl methyl ammonium chloride) and MIBK (methyl isobutyl ketone). Because potentially interfering major and minor elements do not extract, the organic separation allows interference-free determinations of Ag and Cd to the 0.05 ppm level, Mo, Cu, and Zn to 0.5 ppm, and Bi, Pb, and Sb to 1 ppm in the sample using flame atomic absorption spectroscopy. The analytical absorbance values of the organic solution used in the proposed method are generally enhanced more than threefold as compared to aqueous solutions, due to more efficient atomization and burning characteristics. The leaching and extraction procedures are extremely rapid; as many as 100 samples may be analyzed per day, yielding 800 determinations, and the technique is adaptable to field use. The proposed method was compared to total digestion methods for geochemical reference samples as well as soils and stream sediments from mineralized and unmineralized areas. The partial leach showed better anomaly contrasts than did total digestions. Because the proposed method is very rapid and is sensitive to pathfinder elements for several types of ore deposits, it should be useful for reconnaissance surveys for concealed deposits. ?? 1984.

  12. Plasmonic Ag2MoO4/AgBr/Ag composite: Excellent photocatalytic performance and possible photocatalytic mechanism

    Science.gov (United States)

    Wang, Zhongliao; Zhang, Jinfeng; Lv, Jiali; Dai, Kai; Liang, Changhao

    2017-02-01

    Plasmonic Ag2MoO4/AgBr/Ag composite is fabricated by in-situ ion exchange and reduction methods at room temperature. The samples are characterized by X-ray diffraction (XRD), UV-vis diffuse reflectance (DRS), energy-dispersive X-ray spectroscopy (EDS), scanning electron microscope (SEM) and photoluminescence (PL) measurements. The results show that butterfly-like Ag2MoO4 nanosheets served as the precursor, and Ag2MoO4/AgBr/Ag is formed in phase transformation with MoO42- displaced by Br-. The ternary Ag2MoO4/AgBr/Ag composite photocatalysts show greatly enhanced photocatalytic activity in photodegrading methylene blue (MB) under visible light irradiation compared with AgBr and Ag2MoO4. The pseudo-first-order rate constant kapp of Ag2MoO4/AgBr/Ag is 0.602 min-1, which is 11.6 and 18.3 times as high as that of AgBr and Ag2MoO4, respectively. Meanwhile, the efficiency of degradation still kept 90% after ten times cyclic experiments. Eventually, possible photocatalytic mechanism was proposed.

  13. Temperature stability of AgCu nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Sopoušek, Jiří, E-mail: sopousek@mail.muni.cz; Zobač, Ondřej; Vykoukal, Vít [Masaryk University, Department of Chemistry, Faculty of Science (Czech Republic); Buršík, Jiří; Roupcová, Pavla [Institute of Physics of Materials ASCR (Czech Republic); Brož, Pavel; Pinkas, Jiří [Masaryk University, Department of Chemistry, Faculty of Science (Czech Republic); Vřešťál, Jan [Masaryk University, Central European Institute of Technology, CEITEC (Czech Republic)

    2015-12-15

    The colloidal solutions of the Ag–Cu nanoparticles (NPs, 10–32 nm) were prepared by solvothermal reactions. The samples of dried AgCu NPs and the resulting microstructures after heat treatment in air were investigated by various methods including electron microscopy (TEM, SEM) and high-temperature X-ray powder diffraction (HTXRD). The AgCu randomly mixed, Cu-rich, and Ag-rich face centred cubic crystal lattices were detected during the experiments. The temperature induced sintering was observed experimentally by HTXRD at 250 °C. The phase transformations at high temperatures were monitored by differential scanning calorimetry. The formation of the Ag-rich grains during heating in air and evolution of copper oxide microstructure were detected.Graphical abstract.

  14. Screening on binary Zr-1X (X = Ti, Nb, Mo, Cu, Au, Pd, Ag, Ru, Hf and Bi) alloys with good in vitro cytocompatibility and magnetic resonance imaging compatibility.

    Science.gov (United States)

    Zhou, F Y; Qiu, K J; Li, H F; Huang, T; Wang, B L; Li, L; Zheng, Y F

    2013-12-01

    In this study, the microstructures, mechanical properties, corrosion behaviors, in vitro cytocompatibility and magnetic susceptibility of Zr-1X alloys with various alloying elements, including Ti, Nb, Mo, Cu, Au, Pd, Ag, Ru, Hf and Bi, were systematically investigated to explore their potential use in biomedical applications. The experimental results indicated that annealed Zr-1X alloys consisted entirely or primarily of α phase. The alloying elements significantly increased the strength and hardness of pure Zr and had a relatively slight influence on elastic modulus. Ru was the most effective enhancing element and Zr-1Ru alloy had the largest elongation. The results of electrochemical corrosion indicated that adding various elements to Zr improved its corrosion resistance, as indicated by the reduced corrosion current density. The extracts of the studied Zr-1X alloys produced no significant deleterious effects on osteoblast-like cells (MG 63), indicating good in vitro cytocompatibility. All except for Zr-1Ag alloy showed decreased magnetic susceptibility compared to pure Zr, and Zr-1Ru alloy had the lowest magnetic susceptibility value, being comparable to that of α' phase Zr-Mo alloy and Zr-Nb alloy and far lower than that of Co-Cr alloy and Ti-6Al-4V alloy. Among the experimental Zr-1X alloys, Zr-1Ru alloy possessing high strength coupled with good ductility, good in vitro cytocompatibility and low magnetic susceptibility may be a good candidate alloy for medical devices within a magnetic resonance imaging environment. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  15. Dynamic Structure of Mo-O Species in Ag-Mo-P-O Catalyst for Oxidative Dehydrogenation of Propane

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The dynamic structure of Mo-O species in Ag-Mo-P-O catalyst was studied by in situ confocal microprobe laser Raman spectroscopy (LRS) and catalytic test. The results indicate Mo-O species of MoO3 transformed to Mo-O species of AgMoO2PO4 in C3H8/O2/N2 (3/1/4) flow at 773 K. This behavior is closely relative to oxidative dehydrogenation of propane and intrinsic properties of Mo-O species. The Mo-O species of AgMoO2PO4 may be active species for oxidative dehydrogenation of propane.

  16. Properties of the Mo-CuInSe2 interface

    Science.gov (United States)

    Russell, P. E.; Jamjoum, O.; Ahrenkiel, R. K.; Kazmerski, L. L.; Mickelsen, R. A.; Chen, W. S.

    1982-06-01

    Mo has been suggested and used as an ohmic back contact for CdS/p-CuInSe2 solar cells. The Mo-p-CuInSe2 interface has been studied for both polycrystalline and single-crystal CuInSe2, using electron beam induced current and capacitance-voltage techniques. The interface is found to form a Schottky barrier, thereby limiting the attainable voltage of a solar cell with Mo back contact. Au is the only known ohmic contact to p-CuInSe2.

  17. The chloridomolybdenum(III) cluster in [BMIm]4[AgMo10Cl35] with infinite chains of Ag(+)-linked [Mo10Cl35](5-) wheels.

    Science.gov (United States)

    Freudenmann, Dominic; Feldmann, Claus

    2014-10-07

    [BMIm]4[AgMo10Cl35] is prepared by reaction of MoCl5 and elemental silver in the ionic liquid [BMIm][AlCl4] ([BMIm(+)]: 1-butyl-4-methylimidazolium). Surprisingly, elemental silver is oxidized under these conditions. The title compound contains a new wheel-shaped [Mo10Cl35](5-) chlorido molybdenum(iii) species with five pairs of Mo-Mo bonds. The Mo-Mo distances are found to be 263 pm on average. The [Mo10Cl35](5-) wheels exhibit a maximum opening of 558 pm in diameter. They are interlinked via Ag(+) to form infinite [AgMo10Cl35](4-) chains. The title compound is characterized by single crystal structure analysis, EDX, FT-IR and UV-Vis spectroscopy. The wheel-type structure and Ag(+) linkage to infinite chains are a new aspect of halogenido metalates and low-valence molybdenum compounds.

  18. Ionic Conductivities of Molten CuI and AgI-CuI Mixtures

    Science.gov (United States)

    Tahara, Shuta; Shimakura, Hironori; Ohno, Satoru; Fukami, Takanori

    2017-08-01

    Ionic conductivities σ for molten CuI and AgI-CuI mixtures were measured in the temperature ranges of approximately 580-800 and 500-850 °C, respectively. The value of σ for molten CuI in the range is smaller than that for molten CuBr and CuCl. σ for molten AgI-CuI mixtures decreases with increasing CuI-concentration. The activation energies Ea for molten AgI-CuI system were determined from the analysis of temperature dependence of σ by using the by Arrhenius type equation. Ea for molten AgI-CuI gradually increase with increasing CuIconcentration.

  19. An efficient photocatalyst for degradation of various organic dyes: Ag@Ag{sub 2}MoO{sub 4}–AgBr composite

    Energy Technology Data Exchange (ETDEWEB)

    Bai, Yu-Yang; Lu, Yi; Liu, Jin-Ku, E-mail: jkliu@ecust.edu.cn

    2016-04-15

    Highlights: • Ag@Ag{sub 2}MoO{sub 4}–AgBr composite is synthesized by in-situ exchange and photo depositio nmethod. • Compared with pure Ag{sub 2}MoO{sub 4} crystal, the photocatalytic activity of Ag@Ag{sub 2}MoO{sub 4}–AgBr composite was increased by 348.4%. • Silver particles act as electron trap to enhance electron–hole separation. • This composite has the promising application to degrade organic wastewater. - Abstract: The Ag{sub 2}MoO{sub 4}-AgBr composite was prepared by a facile in-situ anion-exchange method, then the Ag nanoparticles were coated on this composite through photodeposition route to form a novel Ag@Ag{sub 2}MoO{sub 4}–AgBr composite. The in-situ Br{sup −} replacement in a crystal lattice node position of Ag{sub 2}MoO{sub 4} crystal allows for overcoming the resistance of electron transition effectively. Meanwhile silver nano-particles on the surface of Ag@Ag{sub 2}MoO{sub 4}–AgBr composite could act as electron traps to intensify the photogeneration electron-hole separation and the subsequent transfer of the trapped electron to the adsorbed O{sub 2} as an electron acceptor. As an efficient visible light catalyst, the Ag@Ag{sub 2}MoO{sub 4}–AgBr composite exhibited superior photocatalytic activity for the degradation of various organic dyes. The experimental results demonstrated superior photocatalytic rate of Ag@Ag{sub 2}MoO{sub 4}–AgBr composite compared to pure AgBr and Ag{sub 2}MoO{sub 4} crystals (37.6% and 348.4% enhancement respectively). The Ag@Ag{sub 2}MoO{sub 4}–AgBr composite cloud degraded Rhodamin B, bromophenol blue, and amino black 10b completed in 7 min.

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

    Science.gov (United States)

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

    2017-08-01

    To further improve the capacity of Cu2O to absorb I(-) anions from solution, and to understand the difference between the adsorption mechanisms of Ag/Cu2O and Cu/Cu2O adsorbents, bimetallic AgCu was doped into Cu2O through a facile solvothermal route. Samples were characterized and employed to adsorb I(-) anions under different experimental conditions. The results show that the Cu content can be tuned by adding different volumes of Ag sols. After doping bimetallic AgCu, the adsorption capacity of the samples can be increased from 0.02 mmol g(-1) to 0.52 mmol g(-1). Moreover, the optimal adsorption is reached within only 240 min. Meanwhile, the difference between the adsorption mechanisms of Ag/Cu2O and Cu/Cu2O adsorbents was verified, and the cooperative adsorption mechanism of the AgCu/Cu2O hybrid was proposed and verified. In addition, the AgCu/Cu2O hybrid showed excellent selectivity, e.g., its adsorption efficiencies are 85.1%, 81.9%, 85.9% and 85.7% in the presence of the Cl(-), CO3(2-), SO4(2-) and NO3(-) competitive anions, respectively. Furthermore, the AgCu/Cu2O hybrid can worked well in other harsh environments (e.g., acidic, alkaline and seawater environments). Therefore, this study is expected to promote the development of Cu2O into a highly efficient adsorbent for the removal of iodide from solution. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Liu Mei Lee

    2013-01-01

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

  2. Electromigration of Sn-3Ag-0.5Cu and Sn-3Ag-0.5Cu-0.5Ce-0.2Zn solder joints with Au/Ni(P)/Cu and Ag/Cu pads

    Energy Technology Data Exchange (ETDEWEB)

    Lin, H.-J., E-mail: HJLin@itri.org.t [Institute of Materials Science and Engineering, National Taiwan University, 1 Roosevelt St. Sec. 4, Taipei 106, Taiwan (China); Industrial Technology Research Institute, Mechanical and Systems Research Laboratories, Hsinchu 310, Taiwan (China); Lin, J.-S., E-mail: JohnnyLin@itri.org.t [Industrial Technology Research Institute, Mechanical and Systems Research Laboratories, Hsinchu 310, Taiwan (China); Department of Mechanical Engineering, Osaka University, Yamadaoka 2-1, Suita, Osaka 565-0871 (Japan); Chuang, T.-H., E-mail: tunghan@ntu.edu.t [Institute of Materials Science and Engineering, National Taiwan University, 1 Roosevelt St. Sec. 4, Taipei 106, Taiwan (China)

    2009-11-13

    It has previously been established that adding 0.2 wt.% Zn into a Sn-3Ag-0.5Cu-0.5Ce alloy improves the mechanical properties and eliminates the problem of rapid whisker growth. However, no detailed studies have been conducted on electromigration behavior of Sn-3Ag-0.5Cu-0.5Ce-0.2Zn alloy. The electromigration damage in solder joints of Sn-3Ag-0.5Cu and Sn-3Ag-0.5Cu-0.5Ce-0.2Zn with Ag/Cu pads and Au/Ni(P)/Cu pads was studied after current stressing at room temperature with an average current density of 3.1 x 10{sup 4} A/cm{sup 2}. With additions of 0.5 wt.% Ce and 0.2 wt.% Zn, the electromigration processes of Sn-Ag-Cu solder joints were accelerated due to refinement of the solder matrix when joint temperature was around 80 deg. C. Since Ni is more resistant than Cu to diffusion driven by electron flow, solder joints of both alloys (Sn-3Ag-0.5Cu and Sn-3Ag-0.5Cu-0.5Ce-0.2Zn) with Au/Ni(P)/Cu pads possess longer current-stressing lifetimes than those with Ag/Cu pads.

  3. A Novel Cu-Mo/ZSM-5 Catalyst for NOx Catalytic Reduction with Ammonia

    Institute of Scientific and Technical Information of China (English)

    Zhe Li; Dang Li; Wei Huang; Kechang Xie

    2005-01-01

    The Cu-Mo/ZSM-5 catalysts with different Cu/Mo ratios were prepared by wet impregnation method, and their catalytic performance for selective catalytic reduction of NOx was studied. The results showed that Cu-Mo/ZSM-5 is a very effective catalyst for NOx catalytic reduction with ammonia, especially when Cu/Mo molar ratio is about 1.5. It not only exhibited the extremely high catalytic activity, but also showed good stability for O2. The bulk phase structure of Cu-Mo/ZSM-5 catalysts was determined by XRD technique, and the results indicated that there is a maximum dispersion for Cu species when Cu/Mo molar ratio is 1.5, and an interaction between Cu and Mo along with HZSM-5 may be present in Cu-Mo/ZSM-5, which may possibly result in a special structure favorable for the catalytic reduction of NOx over Cu-Mo/ZSM-5 catalyst.

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

    OpenAIRE

    Liu Mei Lee; Ahmad Azmin Mohamad

    2013-01-01

    This paper reviews the function and importance of Sn-Ag-Cu solder alloys in electronics industry and the interfacial reaction of Sn-Ag-Cu/Cu solder joint at various solder forms and solder reflow conditions. The Sn-Ag-Cu solder alloys are examined in bulk and in thin film. It then examines the effect of soldering conditions to the formation of intermetallic compounds such as Cu substrate selection, structural phases, morphology evolution, the growth kinetics, temperature and time is also disc...

  5. Effect of Sintering Temperature of Mo Skeleton on the Contiguity and Compressive Properties of Mo-Cu IPCs

    Science.gov (United States)

    Liu, Longfei; Cao, Fuhua; Lu, Liwei; Yan, Jianhui

    2017-02-01

    Interpenetrating phase composites (IPCs) are interesting materials, in which each phase can contribute its most desirable attributes to the composite as a whole by its contiguous morphology. In the present study, molybdenum-copper (Mo-Cu) composites with interpenetrating microstructure were fabricated by open-celled porous Mo skeleton with infiltration of Cu. Effects of sintering temperature on the Mo-Mo contiguity and compressive properties of the Mo-Cu IPCs were examined. The contiguity of Mo-Mo and compressive strength increase with the sintering temperature increasing from 1473 to 1873 K, and decrease at 2073 K. Volume fraction of Cu infiltrated in Mo skeleton and failure strain of composites decrease with the sintering temperature increasing from 1473 to 1873 K and increase at 2073 K. Mutual dependency of compressive properties and contiguity of Mo-Cu IPCs are illustrated.

  6. Structural Investigations of Nanocrystalline Cu-Cr-Mo Alloy Prepared by High-Energy Ball Milling

    Science.gov (United States)

    Kumar, Avanish; Pradhan, Sunil Kumar; Jayasankar, Kalidoss; Debata, Mayadhar; Sharma, Rajendra Kumar; Mandal, Animesh

    2017-02-01

    Cu-Cr-Mo alloy could be a suitable candidate material for collector electrodes in high-power microwave tube devices. An attempt has been made to synthesize ternary Cu-Cr-Mo alloys by mechanical alloying of elemental Cu, Cr, and Mo powders, to extend the solid solubility of Cr and Mo in Cu, using a commercial planetary ball mill. For the first ternary alloy, a mixture of 80 wt.% Cu, 10 wt.% Cr, and 10 wt.% Mo was mechanically milled for 50 h. For the second ternary alloy, a mixture of 50 wt.% Cr and 50 wt.% Mo was mechanically milled for 50 h to obtain nanocrystalline Cr(Mo) alloy, which was later added to Cu powder and milled for 40 h to obtain Cu-20 wt.%Cr(Mo) alloy. Both nanocrystalline Cu-Cr-Mo ternary alloys exhibited crystallite size below 20 nm. It was concluded that, with addition of nanocrystalline Cr(Mo) to Cu, it was possible to extend the solid solubility of Cr and Mo in Cu, which otherwise was not possible by mechanical alloying of elemental powders. The resulting microstructure of the Cu-20 wt.%Cr(Mo) alloy comprised a homogeneous distribution of fine and hard (Cr, Mo) particles in a copper matrix. Furthermore, Cu-20 wt.%Cr(Mo) alloy showed better densification compared with Cu-10 wt.%Cr-10 wt.%Mo alloy.

  7. Spectroscopic studies of jet-cooled CuAg

    Science.gov (United States)

    Bishea, Gregory A.; Marak, Ninette; Morse, Michael D.

    1991-10-01

    Resonant two-photon ionization spectroscopy has been applied to jet-cooled diatomic CuAg. Four band systems have been observed, three of which have been rotationally resolved and analyzed. The ground state is X 1Σ+ in symmetry, deriving from the 3d10Cu4d10Agσ2 molecular configuration. Its bond length has been determined as r0=2.3735±0.0006 Å (1σ error limits). Based on an analysis of the possible separated atom limits, three of the excited states observed (A 0+, A' 1, and B' 0+ ) are assigned as primarily 3d9Cu4d10Agσ2σ* in character. The observation of unusually large electronic isotope shifts in the A-X, A'-X, and B'-X band systems, similar in magnitude to those previously observed in the A-X and B-X systems of Cu2 and the s←d excitations in atomic copper, provides further confirmation that these excited states derive from the 3d9Cu4d10Agσ2σ* molecular configuration. Finally, the highest energy state observed in this work is argued to be primarily ion pair in character, and is expected to have significant contributions from both the Cu+Ag- and Cu-Ag+ ion pair states.

  8. Microstructures of Sintered Mo-Cu Alloys with Mechanically Activated Powder

    Institute of Scientific and Technical Information of China (English)

    蒋凯; 张秀英; 郭崇峰

    2001-01-01

    Mechanical activation and liquid phase sintering were used to manufacture high performance Mo-Cu alloy and develop new processes. The microstructures and properties of the alloy were investigated. The experimental results showed that: (1) the ball milled Mo/Cu powder has lamellar structure, (2) the microstructures of the sintered Mo-Cu alloy were homogenous compound structures of adhesive phase Cu linking Mo grains, (3) Mo grains frequently strung or ga thered in Cu phase, and (4) the full densities of Mo-Cu alloy was achieved through sintering and special densification process. As a result, the properties of the alloy are good enough to satisfy various requirements.

  9. Distribution of Ag in Cu-sulfides in Kupferschiefer deposit, SW Poland

    Science.gov (United States)

    Kozub, Gabriela A.

    2014-05-01

    reports on high Ag content reaching 49 wt.% Ag in bornite and 1.8 wt.% Ag in chalcocite occurring due to Ag substitution in Cu-minerals without modification of their crystallographic structure (Salamon 1979; Banaś et al 2007; Kucha 2007; Piestrzyński 2007, Pieczonka 2011). Acknowledgements. This work was supported by the National Science Centre research grant (No 2011/03/N/ST10/04619). References: Kucha H and Mayer W (2007) Geochemistry. [In:] Piestrzyński A (Ed) Monografia KGHM Polska Miedź SA., pp 197-207 (In Polish) Pieczonka J (2011) Factors controlling distribution of ore minerals within copper deposit, Fore-Sudetic Monocline, SW Poland. 195 pp (In Polish) Piestrzyński A (2007) Ore minerals. [In:] Piestrzyński A (Ed) Monografia KGHM Polska Miedź SA., pp 167-197 (in Polish) Salamon W (1979) Occurrence of the Ag and Mo in the Zechstein sediments of the Fore-Sudetic Monocline. Prace Mineralogiczne, PAN 62, pp 1-52 (In Polish)

  10. Study of diffusion of Ag in Cu single crystals

    CERN Document Server

    Wang, R

    2002-01-01

    4.0 MeV sup 7 Li sup + sup + RBS and AES were used for investigations of thermal diffusion of Ag in Cu single crystals. The annealing of samples was carried out in vacuum in the temperature range from 498 to 613 K. The element depth concentration profiles transformed from RBS spectra indicate that the diffusion of Ag into Cu is a typical volume diffusion. The Arrhenius parameters corresponding to the diffusion were obtained.

  11. Mo isotope fractionation during hydrothermal evolution of porphyry Cu systems

    Science.gov (United States)

    Shafiei, Behnam; Shamanian, GholamHossein; Mathur, Ryan; Mirnejad, Hassan

    2015-03-01

    We present Mo isotope compositions of molybdenite types from three successive stages of ore deposition in several porphyry copper deposits of the Kerman region, Iran. The data provide new insights into controlling processes on Mo isotope fractionation during the hydrothermal evolution of porphyry systems. The Mo isotope compositions of 27 molybdenite samples show wide variations in δ97Mo ranging from -0.37 to +0.92 ‰. The data reveal that molybdenites in the early and transitional stages of mineralization (preferentially 2H polytypes; δ97Mo mean = 0.35 ‰) have higher δ97Mo values than late stage (mainly 3R polytypes; δ97Mo mean = 0.02 ‰) molybdenites. This trend suggests that fractionation of Mo isotopes occurred in high-temperature stages of mineralization and that hydrothermal systems generally evolve towards precipitation of molybdenite with lower δ97Mo values. Taking into account the genetic models proposed for porphyry Cu deposits along with the temperature-dependent fractionation of Mo isotope ratios, it is proposed that large variations of Mo isotopes in the early and the transitional stages of ore deposition could be controlled by the separation of the immiscible ore-forming fluid phases with different density, pH, and ƒO2 properties (i.e., brine and vapor). The fractionation of Mo isotopes during fluid boiling and Rayleigh distillation processes likely dominates the Mo isotope budget of the remaining ore-forming fluids for the late stage of mineralization. The lower δ97Mo values in the late stage of mineralization can be explained by depletion of the late ore-forming hydrothermal solutions in 97Mo, as these fluids have moved to considerable distance from the source. Finally, the relationship observed between MoS2 polytypes (2H and 3R) and their Mo isotopic compositions can be explained by the molecular vibration theory, in which heavier isotopes are preferentially partitioned into denser primary 2H MoS2 crystals.

  12. Effect of Cu concentration on morphology of Sn-Ag-Cu solders by mechanical alloying

    Science.gov (United States)

    Kao, Szu-Tsung; Duh, Jenq-Gong

    2004-12-01

    The mechanical alloying (MA) process is considered an alternative approach to produce solder materials. In this study, the effect of Cu concentration in the ternary Sn-3.5Ag-xCu (x=0.2, 0.7, and 1) solder by MA was investigated. The (Cu,Sn) solid solution was precipitated as the Cu6Sn5 intermetallic compound (IMC), which was distributed nonuniformly through the microstructure. The Cu6Sn5 IMC, which was present in the SnAgCu solder with high Cu composition, causes the as-milled MA particle to fracture to a smaller size. Appreciable distinction on morphology of as-milled MA powders with different Cu content was revealed. When the Cu concentration was low (x=0.2), MA particle aggregated to a spherical ingot with large particle size. For higher Cu concentration (x=0.7 and x=1), the MA particle turned to flakes with smaller particle size. The distinction of the milling mechanism of Sn-3.5Ag-xCu (x=0.2, 0.7, and 1) solder by the MA process was discussed. An effective approach was developed to reduce the particle size of the SnAgCu solder from 1 mm down to 10-100 µm by doping the Cu6Sn5 nanoparticle during the MA process. In addition, the differential scanning calorimetry (DSC) results also ensure the compatibility to apply the solder material for the reflow process.

  13. Evidence for enhancement of critical current by intergrain Ag in YBaCuO-Ag ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Dwir, B.; Affronte, M.; Pavuna, D.

    1989-07-24

    We report the evidence for enhancement of critical current density /ital J//sub /ital c// by /similar to/50%, which occurs when /similar to/10 wt. % Ag is added to Y/sub 1/Ba/sub 2/Cu/sub 3/O/sub 7/minus//delta// ceramics. The maximal /ital J//sub /ital c// (/similar to/700 A/cm/sup 2/ at /ital T/=77 K) appears simultaneously with maximum YBaCuO compactness in the samples. The silver fills the intergranular space (holes) without Cu substitution, and the critical temperature /ital T//sub /ital c// is not reduced from the bulk value (/similar to/91 K). Normal-state resistivity of Ag-YBaCuO samples is decreased by an order of magnitude, and samples exhibit improved contact resistance and resistance to water. While the critical density is improved by adding /similar to/10 wt. % Ag, it decreases at higher Ag concentrations.

  14. Kinetics of Ag-rich precipitates formation in Cu-Al-Ag alloys

    Energy Technology Data Exchange (ETDEWEB)

    Adorno, A.T.; Guerreiro, M.R.; Silva, R.A.G

    2004-06-15

    The kinetics of Ag-rich precipitates formation in the Cu-2 wt.% Al alloy with additions of 2, 4, 6, 8, 10 and 12 wt.% Ag was studied using microhardness changes with temperature and time, differential scanning calorimetry (DSC), differential thermal analysis (DTA), scanning electron microscopy (SEM), optical microscopy (OM), energy dispersive X-ray analysis (EDX) and X-ray diffractometry (XRD). The results indicated that an increase in the Ag content decreases the activation energy for Ag-rich precipitates formation, and that it is possible to estimate the values of the diffusion and nucleation activation energies for the Ag precipitates.

  15. Thermodynamic Alalysis of Electrodeposited Cu-Mo-Co Alloys%电镀Cu-Mo-Co合金的热力学分析

    Institute of Scientific and Technical Information of China (English)

    李远会; 王海峰; 黄碧芳; 张晓燕; 郭忠诚

    2013-01-01

    The eletrodeposited copper alloy coating without silver element on the copper substrate will be one of the emphases on the exploitation of copper based electrical contact materials.By analyzing the potential-pH diagram of Cu,Co and Mo aqueous solution system at normal temperature,the feasibility of CuMo-Co alloy coating on copper substrate is thermodynamically determined.The results showed that Cu-Co alloys could be depsoited in the aqueous solution of Cu2+ and Co2+.In the aqueous solution of Cu2+ and MoO42-,Cu-Mo alloys can not be electrodeposited.But Cu-Mo alloys can be inductively electrodeposited in the aqueous solution of Co2+ and MoO42-.So it is feasible that Cu-Mo-Co alloys could be electrodeposited in aqueous solution.%开发电镀无银铜合金镀层将是铜基电接触材料开发的重点之一.利用常温下的Cu、Mo和Co水溶液体系的φ-pH图,从热力学角度分析Cu-Mo-Co合金镀层/铜基体的可行性.结果表明,在Cu2+、Co2+的水溶液中,Cu-Co能在热力学稳定区域发生共沉积.在Cu2+、MoO42-水溶液中,Cu-Mo合金不能析出.但在Ni2+、MoO42-水溶液中,Co-Mo合金能诱导析出.因此,电镀Cu-Mo-Co合金是可能的.

  16. Ultra-Fast Synthesis for Ag2Se and CuAgSe Thermoelectric Materials

    Science.gov (United States)

    DUAN, H. Z.; LI, Y. L.; ZHAO, K. P.; QIU, P. F.; SHI, X.; CHEN, L. D.

    2016-10-01

    Ag2Se and CuAgSe have been recently reported as promising thermoelectric materials at room temperature. The traditional melting-annealing-sintering processes are used to grow Ag2Se and CuAgSe materials with the disadvantages of high costs of energy and time. In this work, phase-pure polycrystalline Ag2Se and CuAgSe compounds were synthesized from raw elemental powders directly by manual mixing followed by spark plasma sintering (MM-SPS) in a few minutes. The influence of SPS heating rate on the phase composition, microstructure, and thermoelectric properties, including Seebeck coefficient, electrical conductivity, and thermal conductivity, were investigated. The zTs of 0.8 at 390 K and 0.6 at 450 K are obtained for Ag2Se and CuAgSe, respectively, which is comparable with the values in the materials prepared by the traditional method. Furthermore, this ultrafast sample synthesis can significantly save material synthesis time and thus has the obvious advantage for large-scale production.

  17. Characterization of the MoO3/Ag grids/MoO3 sandwich electrode deposited on flexible substrate via thermal deposition method

    Science.gov (United States)

    Wang, Chen-Tao; Ting, Chu-Chi; Li, Shan-Rong; Chu, Sheng-Yuan

    2016-09-01

    In this paper, we will discuss the characteristics of the flexible sandwich electrode. We fabricate the MoO3/Ag grids/MoO3 via thermal deposition method. We will measure the bending test and the optical and electric characteristics. The conclusion of the MoO3/Ag grids/MoO3 will compare with the MoO3/Ag film/MoO3 and ITO flexible electrodes. This sandwich electrode will increase the transmittance by less silver coverage but the MoO3/Ag grids/MoO3 have lower sheet resistance compared with MoO3/Ag film/MoO3. Therefore, we propose this new electrode structure is proper for application of OLEDs.

  18. Purification of Fission 99Mo by AG1-X8 Anion Exchange Chromatography

    Institute of Scientific and Technical Information of China (English)

    LIANG; Ji-xin; WU; Yu-xuan; YU; Ning-wen; SHEN; Yi-jia; WANG; Qing-gui; GUO; Shu

    2015-01-01

    For the development of 99Mo production procedure,both of recovery yield of 99Mo and the removal of other impurities should be taken into account.Anion exchange chromatography is usually employed for purification of 99Mo from fission products.AG1-X8resin is a kind of strong

  19. Pb-free Sn-Ag-Cu ternary eutectic solder

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, I.E.; Yost, F.G.; Smith, J.F.; Miller, C.M.; Terpstra, R.L.

    1996-06-18

    A Pb-free solder includes a ternary eutectic composition consisting essentially of about 93.6 weight % Sn-about 4.7 weight % Ag-about 1.7 weight % Cu having a eutectic melting temperature of about 217 C and variants of the ternary composition wherein the relative concentrations of Sn, Ag, and Cu deviate from the ternary eutectic composition to provide a controlled melting temperature range (liquid-solid ``mushy`` zone) relative to the eutectic melting temperature (e.g. up to 15 C above the eutectic melting temperature). 5 figs.

  20. Global optimization of bimetallic cluster structures. I. Size-mismatched Ag-Cu, Ag-Ni, and Au-Cu systems

    Science.gov (United States)

    Rapallo, Arnaldo; Rossi, Giulia; Ferrando, Riccardo; Fortunelli, Alessandro; Curley, Benjamin C.; Lloyd, Lesley D.; Tarbuck, Gary M.; Johnston, Roy L.

    2005-05-01

    A genetic algorithm approach is applied to the optimization of the potential energy of a wide range of binary metallic nanoclusters, Ag-Cu, Ag-Ni, Au-Cu, Ag-Pd, Ag-Au, and Pd-Pt, modeled by a semiempirical potential. The aim of this work is to single out the driving forces that make different structural motifs the most favorable at different sizes and chemical compositions. Paper I is devoted to the analysis of size-mismatched systems, namely, Ag-Cu, Ag-Ni, and Au-Cu clusters. In Ag-Cu and Ag-Ni clusters, the large size mismatch and the tendency of Ag to segregate at the surface of Cu and Ni lead to the location of core-shell polyicosahedral minimum structures. Particularly stable polyicosahedral clusters are located at size N =34 (at the composition with 27 Ag atoms) and N =38 (at the composition with 32 and 30 Ag atoms). In Ag-Ni clusters, Ag32Ni13 is also shown to be a good energetic configuration. For Au-Cu clusters, these core-shell polyicosahedra are less common, because size mismatch is not reinforced by a strong tendency to segregation of Au at the surface of Cu, and Au atoms are not well accommodated upon the strained polyicosahedral surface.

  1. Influence of Pretreatment Conditions on Methane Aromatization Performance of Mo/HZSM-5 and Mo-Cu/HZSM-5 Catalysts

    Institute of Scientific and Technical Information of China (English)

    Yiping Zhang; Dongjie Wang; Jinhua Fei; Xiaoming Zheng

    2003-01-01

    Mo/HZSM-5 is a good catalyst for methane aromatization, and the reaction performance of Mo/HZSM-5 and Cu modified Mo/HZSM-5 catalysts under various pretreatment conditions has been studied. The results indicate that the catalyst presented a distinguished catalytic activity, benzene selectivity and a high stability when the bed temperature was raised in N2 atmosphere.

  2. Dynamic viscosities of pure tin and Sn-Ag, Sn-Cu, and Sn-Ag-Cu eutectic melts

    Science.gov (United States)

    Rozhitsina, E. V.; Gruner, S.; Kaban, I.; Hoyer, W.; Sidorov, V. E.; Popel', P. S.

    2011-02-01

    The dynamic viscosities of the melts of pure tin and eutectic Sn-Ag, Sn-Cu, and Sn-Ag-Cu alloys are studied in heating followed by cooling, and the maximum heating temperature was 1200°C. An irreversible decrease in the viscosity is found in the temperature range 800-1000°C in the polytherms of all melts. This finding is related to the loss of a local order in a melt and can be used to develop temperature regimes for the production of lead-free solders.

  3. Photoconductive properties of organic-inorganic Ag/p-CuPc/n-GaAs/Ag cell

    Institute of Scientific and Technical Information of China (English)

    Khasan Sanginovich Karimov; Muhammad Tariq Saeed; Fazal Ahmad Khalid; Zioda Mirzoevna Karieva

    2011-01-01

    A thin film of copper phthalocyanine (CuPc),a p-type semiconductor,was deposited by thermal evaporation in vacuum on an n-type gallium arsenide (GaAs) single-crystal semiconductor substrate.Then semitransparent Ag thin film was deposited onto the CuPc film also by thermal evaporation to fabricate the Ag/pCuPc/n-GaAs/Ag cell.Photoconduction of the cell was measured in photoresistive and photodiode modes of operation.It was observed that with an increase in illumination,the photoresistance decreased in reverse bias while it increased in forward bias.The photocurrent was increased in reverse bias operation.In forward bias operation with an increase in illumination,the photocurrent showed a different behavior depending on the voltage applied.

  4. Effect of Sequential Ions Implantation on Structure of Cu, Ag Nanoparticles

    Institute of Scientific and Technical Information of China (English)

    XIAO Xiang-heng; LU Zhuo-yu; GUO Li-ping; REN Feng; CHEN Dong-liang; WU Zi-yu; JIA Quan-jie

    2007-01-01

    The preparation of metal nanoparticles composites by Cu, Ag ions sequential implantation is studied. The formation of Cu, Ag nanoparticles has been evidenced by grazing incidence X-ray diffraction, extended x-ray absorption fine structure and transmission electron microscopy. With the increase of Ag ion implantation dose, the size and density of Ag nanoparticles increase significantly.

  5. Tensile properties and thermal shock reliability of Sn-Ag-Cu solder joint with indium addition.

    Science.gov (United States)

    Yu, A-Mi; Jang, Jae-Won; Lee, Jong-Hyun; Kim, Jun-Ki; Kim, Mok-Soon

    2012-04-01

    The thermal shock reliability and tensile properties of a newly developed quaternary Sn-1.2Ag-0.5Cu-0.4In (wt%) solder alloy were investigated and compared to those of ternary Sn-Ag-Cu based Pb-free solder alloys. It was revealed that the Sn-1.2Ag-0.5Cu-0.4In solder alloy shows better thermal shock reliability compared to the Sn-1.0Ag-0.5Cu and Sn-3.0Ag-0.5Cu solder alloys. The quaternary alloy has higher strength than Sn-1.0Ag-0.5Cu alloy, and higher elongation than Sn-3.0Ag-0.5Cu alloy. It was also revealed that the addition of indium promotes the formation of Ag3(Sn, In) phase in the solder joint during reflow process.

  6. Ag3Sn plate formation in the solidification of near-ternary eutectic Sn-Ag-Cu

    Science.gov (United States)

    Kang, Sung K.; Shih, Da-Yuan; Donald, Ny.; Henderson, W.; Gosselin, Timothy; Sarkhel, Amit; Charles Goldsmith, Ny.; Puttlitz, Karl J.; Choi, Won Kyoung

    2003-06-01

    Near-ternary eutectic Sn-Ag-Cu alloys are leading lead-free candidate solders for various applications. These alloys yield three phases upon solidification: β-Sn,Ag3Sn, and Cu6Sn5. Large, plate-like, pro-eutectic Ag3Sn structures can grow rapidly within the liquid phase, potentially adversely affecting the mechanical behavior and reducing the fatigue life of solder joints. This article reports on the formation of such plates in Sn-Ag-Cu solder balls and joints and demonstrates how large Ag3Sn plate formation can be minimized.

  7. Solid-liquid reactions: The effect of Cu content on Sn-Ag-Cu interconnects

    Science.gov (United States)

    Lu, Henry Y.; Balkan, Haluk; Simon, K. Y.

    2005-06-01

    The impact of copper content on the Sn-Ag-y%Cu (Ag=constant=3.5; y=0.0, 0.5, 1.0, and 2.0) interconnects was investigated in this study. The copper content and solid-liquid (S-L) reactions were used as inputs, and the outputs were the interfacial microstructure evolution and joint macro-performance. Surface microetching microscopy, cross-section microscopy, energy-dispersive x-ray analysis, shear test, and differential scanning calorimetry were used in the studies. It was discovered that as-soldered Sn-Ag-y%Cu interconnects could have different interfacial microstructures depending on copper content; no Ag3Sn plates were observed for any alloy groups. After the S-L reactions, Ag3Sn plates occurred for all groups. The magnitude of the Ag3Sn plate growth depended on copper content. This and other effects of copper content on Sn-Ag-Cu interconnects are discussed in this article.

  8. Diffusion of Six-Atom Cu Islands on Cu(111) and Ag(111)

    Institute of Scientific and Technical Information of China (English)

    Sardar Sikandar Hayat; I.Ahmad; M.Arshad Choudhry

    2011-01-01

    Diffusion of Cu hexamer islands on Cu(111) and Ag(111) is studied using a molecular dynamics simulation technique with many-body potentials obtained from the embedded atom method. Simulations are carried out at temperatures 300, 500 and 700 K, showing that shape-changing multiple-atom processes are more helpful for the diffusion rather than concerted motion of islands. Arrhenius plots of the diffusion coefficients provide effective energy barrier values of 161.29 ± 5 meV for Cu(111) and 179.34 ± 5 meV for Ag(111) surfaces. At 700K, one pop-up atom among island atoms is observed with correlative changes in the position and shape of the lower-layer adatoms.%@@ Diffusion of Cu hexamer islands on Cu(111) and Ag(111) is studied using a molecular dynamics simulation technique with many-body potentials obtained from the embedded atom method.Simulations are carried out at temperatures 300,500 and 700 K,showing that shape-changing multiple-atom processes are more helpful for the diffusion rather than concerted motion of islands.Arrhenius plots of the diffusion coefficients provide effective energy barrier values of 161.29 ± 5 meV for Cu(111) and 179.34 ± 5 meV for Ag(111) surfaces.At 700K,one pop-up atom among island atoms is observed with correlative changes in the position and shape of the lower-layer adatoms.

  9. Electrochemical behavior of Ag-Cu alloy in alkaline media

    Directory of Open Access Journals (Sweden)

    Grekulović Vesna J.

    2010-01-01

    Full Text Available Results of the investigation of electrochemical behaviour of Ag-Cu alloy containing 50 mass% Ag and 50 mass% Cu are presented in this paper. Pure silver and copper were investigated, too. Working electrodes were prepared by metallurgical process. 1 mol dm-3 and 0.5 mol dm-3 solutions of NaOH are chosen as the electrolyte. On the cyclic voltammograms, some current waves corresponding to number and quantity of phases present in the investigated electrodes appeared and they can be used for characterization of investigated alloy. On the voltammogram recorded for pure silver, two anodic and two cathodic peaks appeared. First peak consisted of two joined current waves which can be ascribed to the formation of the two different types of silver(I oxide, Ag2O. Second peak should correspond to the formation of silver(II oxide, AgO. Voltammogram obtained for pure copper exhibits one broad current wave corresponding to the formation of copper oxides, followed by a wide potential area in which copper is completely passive. At 0.4 V vs. SCE, current starts to increase again due to oxygen evolution and probably due to simultaneous dissolution of copper with formation of CuO22- as a product. In alkaline solutions copper has no significant influence on the shape and current values of the voltammograms recorded for Ag-Cu alloy; however, it has an influence only on the anodic and cathodic peak potentials, which are shifted to more negative values in comparison to Ag. It could mean an easier formation of oxides and their harder reduction. Comparing voltammograms recorded for Ag-Cu alloy in 0.5 moldm-3 NaOH and in 1 moldm-3 NaOH solutions, one can see that current waves appear at more positive potentials on the voltammograms obtained in the solution of lower concentration and with much higher current densities than those on the voltammograms obtained in the solution of higher concentration.

  10. Preparation of Mo/Cu composites by SLS method and its post-treatment techniques

    Institute of Scientific and Technical Information of China (English)

    LIU Bin; CHENG Jun; BAI Pei-kang; WANG Jian-hong

    2006-01-01

    A multi-component polymer-coated molybdenum powder was chosen for selective laser sintering(SLS). The powder was prepared by coating polymer on Mo particles and frozen by grinding techniques. The laser sintering activities and sound densification response were obtained by optimizing the process parameters. The post-treatment process of SLS samples was developed, which was high temperature sintering Mo framework combined with Cu impregnation. Then, the Mo/Cu composites are gained. The microstructure evolution of post-treatment samples was investigated by scanning electron microscopy. Mo grains frequently string together. The microstructural characterization of Mo/Cu composites is homogeneous compound structure of adhesive phase Cu linked with Mo grains. There is little ellipsoidal Mo grains singly existing around Cu phase. Between Mo grains and Cu zone, there is a medium changing zone with width of 10-20 nm. Post-treatment mechanism is Mo framework sintering of solid phase and Cu impregnation of melting/solidification. The mechanical and thermal properties concluding tensile strength, elastic modulus, elongation and linear expansion of Mo/Cu composites were studied.

  11. Synthesis, characterization and excellent photocatalytic activity of Ag/AgBr/MoO{sub 3} composite photocatalyst

    Energy Technology Data Exchange (ETDEWEB)

    Song, Jimei; Shi, Yali; Ren, Mingsong; Hu, Gang [Anhui University, Key Laboratory of Functional Inorganic Materials Chemistry of Anhui Province, College of Chemistry and Chemical Engineering, Hefei, Anhui (China)

    2014-09-15

    A novel composite photocatalyst Ag/AgBr/MoO{sub 3} was successfully synthesized via a simple precipitation method at room temperature. The obtained products were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, high-resolution transmission electron microscopy and UV-vis diffuse reflectance spectroscopy in detail. The photocatalytic activity of the samples was evaluated by monitoring the degradation of rhodamine B (RhB) solution under visible-light irradiation. The results showed that the photocatalytic activity of Ag/AgBr/MoO{sub 3} composite significantly enhanced and the degradation ratio of RhB reached 97.7 % after 15 min only. The excellent photocatalytic activity might be closely related to the large surface area, porosity structure and efficient separation of photoinduced electron-hole pairs. The possible reaction mechanism was also discussed. (orig.)

  12. Microfluidic synthesis of Ag@Cu2O core-shell nanoparticles with enhanced photocatalytic activity.

    Science.gov (United States)

    Tao, Sha; Yang, Mei; Chen, Huihui; Ren, Mingyue; Chen, Guangwen

    2017-01-15

    A microfluidic-based method for the continuous synthesis of Ag@Cu2O core-shell nanoparticles (NPs) has been developed. It only took 32s to obtain Ag@Cu2O core-shell NPs, indicating a high efficiency of this microfluidic-based method. Triangular Ag nanoprisms were employed as the cores for the overgrowth of Cu2O through the reduction of Cu(OH)4(2-) with ascorbic acid. The as-synthesized samples were characterized by XRD, TEM, SEM, HAADF-STEM, EDX, HRTEM, UV-vis spectra and N2 adsorption-desorption. The characterization results revealed that the as-synthesized Ag@Cu2O core-shell NPs exhibited a well-defined core-shell nanostructure with a polycrystalline shell, which was composed of numbers of Cu2O domains epitaxially growing on the triangular Ag nanoprism. It was concluded that the synthesis parameters such as the molar ratio of trisodium citrate to AgNO3, H2O2 to AgNO3, NaOH to CuSO4, ascorbic acid to CuSO4 and AgNO3 to CuSO4 had significant effect on the synthesis of Ag@Cu2O core-shell NPs. Moreover, Ag@Cu2O core-shell NPs exhibited superior catalytic activity in comparison with pristine Cu2O NPs towards the visible light-driven degradation of methyl orange. This enhanced photocatalytic activity of Ag@Cu2O core-shell NPs was attributed to the larger BET surface area and improved charge separation efficiency. The trapping experiment indicated that holes and superoxide anion radicals were the major reactive species in the photodegradation of methyl orange over Ag@Cu2O core-shell NPs. In addition, Ag@Cu2O core-shell NPs showed no obvious deactivation in the cyclic test.

  13. Recyclable and visible light sensitive Ag-AgBr/TiO2: Surface adsorption and photodegradation of MO

    Science.gov (United States)

    Liu, Xinxin; Zhang, Dong; Guo, Biao; Qu, Yue; Tian, Ge; Yue, Huijuan; Feng, Shouhua

    2015-10-01

    A range of highly efficient nanoheterojunction structured Ag-AgBr/TiO2 photocatalysts have been synthesized by CTAB-assisted method and characterized by X-ray diffraction (XRD), focused ion beam scanning electron microscopy (FIB-SEM), energy-dispersive spectroscopy (EDS), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectroscopy (DRS) and photoluminescence (PL). The results demonstrated that Ag-AgBr nanoparticles were successfully deposited on the surface of anatase TiO2 hierarchical spheres. The remarkable adsorptive removal of methyl orange (MO) by the uncalcined samples was investigated before evaluating its photocatalytic ability. All the calcined three-component catalysts possessed excellent photocatalytic activities for degrading MO under visible light, in which, 162.4% Ag-AgBr/TiO2 exhibited highest efficiency. The greatly enhanced activity can be attributed to the well combination of surface plasmons photocatalyst Ag-AgBr and TiO2, which can simultaneously inhibit the photo-generated electrons and holes recombination. The nanoheterojunctions architecture catalyst also showed high stability even after five consecutive cycles. Meanwhile, the possible mechanism and interpretation of the photocatalytic process were also proposed.

  14. Precipitation mechanism in Ag-8 wt.% Cu alloy

    Energy Technology Data Exchange (ETDEWEB)

    Hamana, Djamel [Phase transformations laboratory, Mentouri University of Constantine, Ain El Bey Road, Constantine 25000 (Algeria)], E-mail: d_hamana@yahoo.fr; Boumaza, Leila [Phase transformations laboratory, Mentouri University of Constantine, Ain El Bey Road, Constantine 25000 (Algeria)

    2009-05-27

    The cellular precipitation in Ag-8 wt.% Cu alloy has been studied using dilatometric analysis, differential scanning calorimetriy, optical microscopy and X-ray diffraction (XRD). Dilatometric curve presents at {approx}300 deg. C an anomaly identical to that representing an allotropic transformation, which means a formation of a new crystallographic structure. Thus the ageing temperature can affect the initiation mechanism of the reaction. At low temperature thermal migration of grain boundaries and cells formation precede boundary precipitation. At high temperature the structure consists of alternate lamellar of the {alpha} (Ag-rich) - solid solution and {beta} (Cu-rich) - solid solution phases. The activation energy E{sub act} equals to 56.5 {+-} 6.2 kJ/mol at low temperature (196 deg. C) and to 109.5 {+-} 6.7 kJ/mol at high temperature (300 deg. C)

  15. Thermodynamic properties of metastable Ag-Cu alloys

    Science.gov (United States)

    Najafabadi, R.; Srolovitz, D. J.; Ma, E.; Atzmon, M.

    1993-09-01

    The enthalpies of formation of metastable fcc Ag-Cu solid solutions, produced by ball milling of elemental powders, were determined by differential scanning calorimetry. Experimental thermodynamic data for these metastable alloys and for the equilibrium phases are compared with both calculation of phase diagrams (CALPHAD) and atomistic simulation predictions. The atomistic simulations were performed using the free-energy minimization method (FEMM). The FEMM determination of the equilibrium Ag-Cu phase diagram and the enthalpy of formation and lattice parameters of the metastable solid solutions are in good agreement with the experimental measurements. CALPHAD calculations made in the same metastable regime, however, significantly overestimate the enthalpy of formation. Thus, the FEMM is a viable alternative approach for the calculation of thermodynamic properties of equilibrium and metastable phases, provided reliable interatomic potentials are available. The FEMM is also capable of determining such properties as the lattice parameter which are not available from CALPHAD calculations.

  16. Influence of deformation and heat treatment on electrical conductivity of CuMoCr alloy

    Institute of Scientific and Technical Information of China (English)

    XIONG Xue-hui; LIU Lin; YUE Xue-qing; LIU Jian-hua; ZHANG Rui-jun

    2009-01-01

    The solution heat treatment, cold deformation and subsequent aging were performed on CuMoCr al-loy. And the influence of deformation and aging treatment on the electrical conductivity of CuMoCr alloy was studied through metallograph, transmission electron microscopy (TEM) and electrical conductivity measure-ment. Results show that deformation without subsequent aging can reduce the electrical conductivity of CuMoCr alloy, but deformation followed by the optimum aging treatment can effectively improve the electrical conductivi-ty of CuMoCr alloy. Aging at 500℃ for 4 h after 80% deformation, the much better electrical conductivity of CuMoCr alloy can be obtained. Reduction of Cr content in the Cu matrix could be the reason for the enhance-ment of electrical conductivity.

  17. Preparation and Sintering Properties of Ag27Cu2Sn Nanopaste as Die Attach Material

    Science.gov (United States)

    Liu, Xiaojian; Liu, Wei; Wang, Chunqing; Zheng, Zhen; Kong, Lingchao

    2016-10-01

    Ag27Cu2Sn nanopaste has been prepared by mixing Ag, Cu, and Sn nanoparticles with an organic solvent system. Sintering and mechanical properties of this nanopaste were characterized and investigated. Effects of sintering temperature and time on the sintered microstructure of the nanopaste and shear strength of Cu/Ag27Cu2Sn/Cu structure were analyzed. The results showed that the organic shells coated on the outside of metal nanoparticles could effectively prevent metal nanoparticles from being oxidized below 480°C. When the paste was sintered at 480°C without pressure, few voids or large particles formed within the sintered layer and distributions of Ag, Cu, and Sn were quite uniform. This sintering temperature was much lower than the eutectic temperature (779°C) of Ag-Cu bulk material. Moreover, mutual solid solubilities of Ag and Cu were increased remarkably, which may be caused by high surface activity of Ag and Cu nanoparticles and the important role of the Sn addition. Shear strength of samples with Cu/Ag27Cu2Sn/Cu structure could reach 21 MPa, which could compare with that of Ag nanopaste or conductive adhesives.

  18. Bonding property of Cu/Mo/Cu cladding metal materials by hot rolling%Cu/Mo/Cu轧制复合界面的结合特性

    Institute of Scientific and Technical Information of China (English)

    张兵; 王快社; 孙院军; 王莎

    2011-01-01

    The Cu/Mo/Cu cladding metal materials were made by hot rolling. The interface structure, fracture characteristic and the effect of rolling process parameters on bond strength were studied by optical microscope, scanning electron microscope and electron-tensile tester. The results show that the bonding interface of composite materials is tight when deformation rate is 55% for a pass with heat-treatment at 750 ℃ for 8 min, the maximum value of shearing strength is 77 Mpa. The micro-structure of Mo layer is compressed fibrous and uniform distribution. The micro-structure of Cu layer is isometric crystal. The grain size is increased from the interface to the surface, and unevenly distributed. The mechanism of bonding is typically split bonding and mechanical interlocking.%采用轧制方法制备Cu/Mo/Cu复合材料,利用金相显微镜、扫描电镜和电子拉伸机等研究Cu/Mo/Cu复合材料的界面结构、断裂特点和工艺参数对结合强度的影响.结果表明:轧制前经(750℃,8 min)热处理,道次变形量为55%,复合材料的界面结合紧密,最大剪切强度为77 MPa;钼层金属显微组织呈扁平纤维状,组织较为均匀,铜层金属的晶粒呈等轴状,由界面至表面晶粒逐渐增大,且分布很不均匀;复合机制为典型的裂口结合和机械啮合.

  19. (RE)BaCuO/Ag Composites: The Role of Silver in Bulk Materials and Joints

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    We have investigated the phase equilibria in (RE)BaCuO/Ag systems, the influence of Ag on the processing of (RE)BaCuO/Ag composites and the resulting properties. YBaCuO/Ag composites have been grown by the modified melt crystallization process with YBa2Cu3O7, Y2O3, Pt and Ag2O in the precursor. The improved strength of the YBaCuO/Ag composites compared with the conventional YBaCuO bulk material permitted us to magnetize these materials to achieve trapped fields up to 16 T (at 24 K) in the gap of a mini-magnet. The investigation of the microstructure revealed a remarkable increase of the spacing between micro-cracks especially of those perpendicular to a/b-planes when 12 wt% Ag was added. In the case of SmBaCuO/Ag composites, Ag has a strong influence on processing and causes interactions between RE123 seeds and the sample. We show the growth of single-grain SmBaCuO/Ag composites in air and discuss the influence of post-annealing on increasing Tc and Jc. Furthermore, YBaCuO/Ag composites have been shown to be appropriate materials used as a solder to join large single grains to large arrays or to "repair" grain boundaries in arrays grown by a multiseeding technique.

  20. Ferrocene-Functionalized Cu(I)/Ag(I) Dithiocarbamate Clusters.

    Science.gov (United States)

    Kishore, Pilli V V N; Liao, Jian-Hong; Hou, Hsing-Nan; Lin, Yan-Ru; Liu, C W

    2016-04-04

    A series of compounds, namely, [Cu8(μ4-H){S2CNMeCH2Fc}6](PF6) (1), [Cu7(μ4-H) {S2CN(i)PrCH2Fc}6] (2), [Cu3{S2CN(Bz) (CH2Fc)}2(dppf)2](PF6) (3), and [Ag2{S2CNMe(CH2Fc)}2(PPh3)2] (4) (dppf = 1,1'-bis(diphenylphosphino)ferrocene), supported by multiferrocene assemblies, were synthesized. All the compounds were characterized by (1)H NMR, Fourier transform infrared, elemental analysis, and electrospray ionization mass spectrometry techniques. Single-crystal X-ray structural analysis revealed that 1 is a monocationic octanuclear Cu(I) cluster and that 2 is a neutral heptanuclear Cu(I) cluster with tetracapped tetrahedral (1) and tricapped tetrahedral (2) geometries entrapped with an interstitial hydride, anchored by six ferrocene units at the periphery of the core. Compounds 3 and 4 comprise trimetallic Cu(I) and dimetallic Ag(I) cores enfolded by four and two ferrocene moieties. Interestingly both chelating and bridging modes of binding are observed for dppf ligand in 3. Further the formation and isolation of polyhydrido copper clusters [Cu28H15{S2CN(i)PrCH2Fc}12](PF6) (5) and [Cu28H15{S2CN(n)Bu2}12](PF6) (7), stabilized by bulky ferrocenyl and n-butyl dithiocarbamate ligands, was demonstrated. They are readily identified by (2)H NMR studies on their deuterium analogues, [Cu28D15{S2CN(i)PrCH2Fc}12](PF6) (6) and [Cu28D15{S2CN(n)Bu2}12](PF6) (8). Though the structure details as well as spectroscopic characterizations of 5 are yet to be investigated, the compound 7 is fully characterized by variety of spectroscopy including single-crystal X-ray diffraction. The cyclic voltammetry studies for compounds 1, 2, and 4 display irreversible redox peaks for Fe(2+)/Fe(3+) couple wherein the reduction peaks are not well-resolved due to some adsorption of the complex onto the electrode surface.

  1. CuS/MoS{sub 2} nanocomposite with high solar photocatalytic activity

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Nannan; Zhou, Yifeng, E-mail: yifengzhou@126.com; Nie, Wangyan; Song, Linyong; Chen, Pengpeng, E-mail: chenpp@ahu.edu.cn [Anhui University, Anhui Province Key Laboratory of Environment-Friendly Polymer Materials, School of Chemistry & Chemical Engineering (China)

    2015-07-15

    Two-dimensional CuS/MoS{sub 2} heterostructure with high photocatalytic activity had been successfully obtained by a simple combination of wet chemical method and hydrothermal process. CuS nanosheets had been successfully grown on the two-dimensional MoS{sub 2} nanosheets uniformly and tightly. The obtained heterostructures were well characterized through X-ray diffraction patterns, transmission electron microscopy, Fourier transform infrared spectra, ultraviolet–visible diffuse-reflectance spectra, and Zeta potential measurement. Photocatalytic performance of the CuS/MoS{sub 2} nanocomposite was evaluated toward the decomposition of methylene blue solution under natural light. The as-prepared nanocomposite showed remarkably enhanced photocatalytic activity compared with pure CuS and MoS{sub 2}. This could be attributed to the enhanced dyestuff absorption and charge transport after the conjugation between CuS and MoS{sub 2}.

  2. Synthesis of metallic glasses and metallic glass based composites in the Cu-Mo-Hf system by ion beam mixing

    Institute of Scientific and Technical Information of China (English)

    BAI Xue; WANG TongLe; CUI YuanYuan; DING Ning; LI JiaHao; LIU BaiXin

    2012-01-01

    Single-phase and dual-phase metallic glasses as well as metallic glass based composites were synthesized in the Cu-Mo-Hf ternary metal system by 200 keV xenon ion beam mixing of far-from-equilibrium.It was found that Mo-Hf-based and Cu-Mo-based single-phase metallic glasses could be obtained at compositions around Cu17Mo20Hf63 and Cu34Mo57Hf9,respectively.Interestingly,at the nearly equal-atomic stoichiometry of Cu38Mo31Hf31,a dual-phase Cu-Mo-Hf metallic glass,consisting both of the Mo-Hf-based and Cu-Mo-based phases,was first obtained at relatively low irradiation doses ranging from (1-5)×1015 Xe+/cm2,and a single-phase metallic glass was eventually obtained at a dose of 7×1015 Xe+/cm2.In addition,two glass-based composites were obtained at the compositions of Cu14Mo62Hf24 and Cu77Mo14Hf9,and they consisted of the Mo-Hf based and Cu-Mo based metallic glasses,dissolved with some uniformly distributed BCC Mo-based and FCC Cu-based crystalline solid solutions,respectively.The formation mechanism of the above described non-equilibrium alloy phases was also discussed in terms of the atomic collision theory.

  3. Synthesis and superconductivity of (Ag)x/CuTl-1223 composites

    Institute of Scientific and Technical Information of China (English)

    Abdul Jabbar; Irfan Qasim; M Mumtaz; K Nadeem

    2015-01-01

    Series of (Ag)x/(Cu0.5Tl0.5Ba2Ca2Cu3O10-δ) {(Ag)x/CuTl-1223} nano-superconductor composites were synthesized with different concentra-tions (i.e. x ¼ 0 ? 4.0 wt%) of silver (Ag) nanoparticles. Low anisotropic CuTl-1223 superconducting matrix was prepared by solid-state reaction and Ag nanoparticles were prepared by a sol–gel method separately. The required (Ag)x/CuTl-1223 composition was obtained by the inclusion of Ag nanoparticles in CuTl-1223 superconducting matrix. Structural, morphological, compositional and superconducting transport properties of these composites were investigated in detail by x-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive x-rays (EDX) spectroscopy and four-point probe electrical resistivity (ρ) measurements. The inclusion of Ag nanoparticles enhanced the superconducting properties without affecting the tetragonal structure of the host CuTl-1223 matrix. The improvement in superconducting properties of (Ag)x/CuTl-1223 composites is most likely due to enhanced inter-grains coupling and increased superconducting volume fraction after the addition of metallic Ag nanoparticles at the inter-crystallite sites in the samples. The presence of Ag nanoparticles at the grain-boundaries may increase the number of flux pinning centers, which were present in the form of weak-links in the pure CuTl-1223 superconducting matrix.

  4. On the concentration and separation of the trace-elements fe, cu, zn, mn, pb, mo and co : Paper chromatography

    NARCIS (Netherlands)

    Erkelens, P.C. van

    1961-01-01

    Paper chromatographic separations are described by which the minor constituents of biological ashes are separated either into: (Pb) - Mn - Co - (Pb) - Cu - Fe, Mo, Zn; or into: Cu, Mn, Co - Pb - Fe - Mo - Zn.

  5. Microstructure development in Al-Cu-Ag-Mg quaternary alloy

    Science.gov (United States)

    Zhou, Bin; Froyen, L.

    2012-01-01

    The solidification behaviour of multi-component and multi-phase systems has been largely investigated in binary and ternary alloys. In the present study, a quaternary model system is proposed based on the well known Al-Cu-Ag and Al-Cu-Mg ternary eutectic alloys. The quaternary eutectic composition and temperature were determined by EDS (Energy Dispersive Spectrometry) and DSC (Differential Scanning Calorimetry) analysis, respectively. The microstructure was then characterised by SEM (Scanning Electron Microscope). In the DSC experiments, two types of quaternary eutectics were determined according to their phase composition. For each type of eutectic, various microstructures were observed, which result in different eutectic compositions. Only one of the determined eutectic compositions was further studied by the controlled growth technique in a vertical Bridgeman type furnace. In the initial part of the directionally solidified sample, competing growth between two-phase dendrites and three-phase eutectics was obtained, which was later transformed to competing growth between three-phase and four-phase eutectics. Moreover, silver enrichment was measured at the solidification front, which is possibly caused by Ag sedimentation due to gravity and Ag rejection from dendritic and three-phase eutectic growth, and its accumulation at the solidification front.

  6. High-Reliability Low-Ag-Content Sn-Ag-Cu Solder Joints for Electronics Applications

    Science.gov (United States)

    Shnawah, Dhafer Abdulameer; Said, Suhana Binti Mohd; Sabri, Mohd Faizul Mohd; Badruddin, Irfan Anjum; Che, Fa Xing

    2012-09-01

    Sn-Ag-Cu (SAC) alloy is currently recognized as the standard lead-free solder alloy for packaging of interconnects in the electronics industry, and high- Ag-content SAC alloys are the most popular choice. However, this choice has been encumbered by the fragility of the solder joints that has been observed in drop testing as well as the high cost of the Ag itself. Therefore, low-Ag-content SAC alloy was considered as a solution for both issues. However, this approach may compromise the thermal-cycling performance of the solders. Therefore, to enhance the thermal-cycling reliability of low-Ag-content SAC alloys without sacrificing their drop-impact performance, alloying elements such as Mn, Ce, Ti, Bi, In, Sb, Ni, Zn, Al, Fe, and Co were selected as additions to these alloys. However, research reports related to these modified SAC alloys are limited. To address this paucity, the present study reviews the effect of these minor alloying elements on the solder joint reliability of low-Ag-content SAC alloys in terms of thermal cycling and drop impact. Addition of Mn, Ce, Bi, and Ni to low-Ag-content SAC solder effectively improves the thermal-cycling reliability of joints without sacrificing the drop-impact performance. Taking into consideration the improvement in the bulk alloy microstructure and mechanical properties, wetting properties, and growth suppression of the interface intermetallic compound (IMC) layers, addition of Ti, In, Sb, Zn, Al, Fe, and Co to low-Ag-content SAC solder has the potential to improve the thermal-cycling reliability of joints without sacrificing the drop-impact performance. Consequently, further investigations of both thermal-cycling and drop reliability of these modified solder joints must be carried out in future work.

  7. Structure and electronic properties of Cu nanoclusters supported on Mo2C(001) and MoC(001) surfaces

    Science.gov (United States)

    Posada-Pérez, Sergio; Viñes, Francesc; Rodríguez, José A.; Illas, Francesc

    2015-09-01

    The atomic structure and electronic properties of Cun nanoclusters (n = 4, 6, 7, and 10) supported on cubic nonpolar δ-MoC(001) and orthorhombic C- or Mo-terminated polar β-Mo2 C(001) surfaces have been investigated by means of periodic density functional theory based calculations. The electronic properties have been analyzed by means of the density of states, Bader charges, and electron localization function plots. The Cu nanoparticles supported on β-Mo2 C(001), either Mo- or C-terminated, tend to present a two-dimensional structure whereas a three-dimensional geometry is preferred when supported on δ-MoC(001), indicating that the Mo:C ratio and the surface polarity play a key role determining the structure of supported clusters. Nevertheless, calculations also reveal important differences between the C- and Mo-terminated β-Mo2 C(001) supports to the point that supported Cu particles exhibit different charge states, which opens a way to control the reactivity of these potential catalysts.

  8. Chemical structures of the Cu(In,Ga)Se2/Mo and Cu(In,Ga)(S,Se)2/Mo interfaces

    Science.gov (United States)

    Bär, M.; Weinhardt, L.; Heske, C.; Nishiwaki, S.; Shafarman, W. N.

    2008-08-01

    Using a suitable lift-off technique, we have investigated the chemical properties of the interface between Mo and chalcopyrite compound semiconductors by x-ray photoelectron spectroscopy and x-ray excited Auger-electron spectroscopy. By a systematic comparison of interfaces between S-free [ Cu(In,Ga)Se2 (CIGSe)] as well as S-containing [ Cu(In,Ga)(S,Se)2 (CIGSSe)] chalcopyrites and Mo, we find that the chemical structure at the CIG(S)Se/Mo interface is strongly influenced by the presence or absence of S. We observe an interfacial MoSe2 [Mo(SZSe1-Z)2] layer formed between CIGSe [CIGSSe] and the Mo layer. The Mo(SZSe1-Z)2 layer appears significantly thinner than the MoSe2 layer and exhibits a different S/(S+Se) ratio [Z=0.9(1)] than the CIGSSe back side [0.5(7)], giving insight into the “competition” between S and Se during contact formation. Furthermore, we find a significant Ga accumulation at the Mo back contact, which points to pronounced chemical interactions during the formation of the CIG(S)Se/Mo interface.

  9. Electrical conductivity of Cu-Ag in situ filamentary composites

    Institute of Scientific and Technical Information of China (English)

    NING Yuan-tao; ZHANG Xiao-hui; WU Yue-jun

    2007-01-01

    The electrical conductivity of Cu-10Ag in situ filamentary composite was studied during the deformation and annealing processes. The dependence of electrical resistivity of the deformed composites on the true strain presents a two-stage change with increase of the true strain. The intermediate heat treatment and the stabilized annealing treatment to the deformed composite promote the separation of Ag precipitate, and increase the electrical conductivity. The maximum conductivity of the composite experienced the stabilizing heat treatment can reach about 97% IACS with σb≥400 MPa at 550 ℃ annealing, and reach about 70% IACS with σb≥1 250 MPa at 300 ℃ annealing. The corresponded strength of the composite was reported. The microstructure reason for the changes of the conductivity was discussed.

  10. Low temperature properties of organicinorganic Ag/p-CuPc/n-GaAs/Ag photoelectric sensor

    Institute of Scientific and Technical Information of China (English)

    Kh.; S.; KARIMOV; I.; QAZI; T.; A.; KHAN; M.; I.; FEDOROV

    2008-01-01

    A thin organic film of p-type semiconducting copper phthalocynanine (CuPc) was deposited by vacuum evaporation on an n-type GaAs single-crystal semiconductor substrate. The fabricated Ag/p-CuPc/n-GaAs/Ag sensor was carried through an ageing process to stabilize the parameters. Voltage-current characteristics and photoelectrical response of the sensor were investigated at a wide temperature range of 82 to 350 K. Photoelectric characteristics were measured under non-modulated filament-lamp illumination. It was observed that such sensor parameters as rectification ratio,threshold voltage,junction,shunt and series resistances,open-circuit voltage and short circuit current are temperature-dependent. It was found that wide-range voltage-current characteristics of the sensor may be de-scribed similarly to that of a Schottky barrier diode. Using the experimental data on voltage-current characteristics and absorbance of the CuPc films,the energy-band diagram of the p-CuPc/n-GaAs heterojunction was developed. It was shown that data obtained from simulation of an equivalent circuit of photoelectric sensor agreed with experimental results.

  11. Magnetocaloric effect in Sr2FeMoO6/Ag composites

    Directory of Open Access Journals (Sweden)

    Mahmoud A. Hamad

    2015-03-01

    Full Text Available The enhanced low-field magnetocaloric effect was investigated for double perovskite Sr2FeMoO6 - silver (SFMO/Ag composites with 0, 5 and 10 wt.% of Ag. A phenomenological model was used to predict magnetocaloric properties of SFMO/Ag composites, such as magnetic entropy change, heat capacity change and relative cooling power. It was shown that magnetic entropy change (∆S M peaks of SFMO/Ag span over a wide temperature region, which can significantly improve the global efficiency of the magnetic refrigeration. Furthermore, the ∆S M distribution of the SFMO/Ag composites is much more uniform than that of gadolinium. Through these results, SFMO/Ag composite has some potential application for magnetic refrigerants in an extended high-temperature range.

  12. Cold-Sprayed Cu-MoS2 and Its Fretting Wear Behavior

    Science.gov (United States)

    Zhang, Yinyin; Descartes, Sylvie; Vo, Phuong; Chromik, Richard R.

    2016-02-01

    Cu and Cu-MoS2 coatings were fabricated by cold spray, and the fretting wear performance of the two coatings was compared. A mixture (95 wt.% Cu + 5 wt.% MoS2) was used as feedstock for the composite coating. Coatings were sprayed with identical gas flow conditions on the substrates pre-heated to approximately 170 °C. The morphology of coating top surface and polished cross sections was analyzed by scanning electron microscopy (SEM) and light optical microscopy (LOM). The influence of MoS2 on Cu deposition was examined. The local MoS2 concentration within the coating was found to affect the hardness. Fretting tests were carried out at two different normal loads, and the influence of MoS2 on friction and wear was studied. The morphology and elemental compositions of the wear scars and wear debris were observed by SEM and energy dispersive x-ray spectroscopy (EDS), respectively.

  13. Surface texturing for adaptive Ag/MoS_2 solid lubricant plating

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    The objective of this research is to prepare specially designed surface texture on hard steel surface by electrochemical micromachining (EM) and to incorporate electroless plated Ag/MoS2 solid lubricant coating into the dimples of EM textured steel surface to effectively reduce friction and wear of steel-steel contacts. The friction and wear behavior of the Ag/MoS2 solid lubricant coating on EM textured steel surface was evaluated in relation to the size and spacing of the dimples thereon. The microstructur...

  14. NaAg2Mo3O9AsO4

    Directory of Open Access Journals (Sweden)

    Ahmed Driss

    2010-10-01

    Full Text Available The title compound, sodium disilver arsenatotrimolybdate, Na0.93 (1Ag2.07 (1Mo3AsO13, was prepared by a solid-state reaction. In the crystal structure, isolated AsO4 tetrahedra share corners with groups of three edge-sharing MoO6 octahedra. This arrangement leads to the formation of anionic 1∞[Mo3AsO13]n ribbons extending parallel to [100]. The three metal sites show occupational disorder by AgI and NaI cations, each with a different Ag:Na ratio. The metal cations are situated in the space between the ribbons and are surrounded by terminal O atoms of the ribbons in the form of distorted MO7 polyhedra (M = Ag, Na for distances < 3.0 Å. The title compound shows weak ionic conductivity. Structural relationships between different compounds in the quaternary systems M–Sb–P–O, M–Nb–P–O and M–Mo–As–O (M is Ag or an alkali metal are also discussed.

  15. Electronic conductivity of mechanochemically synthesized nanocrystalline Ag1-CuI system using DC polarization technique

    Indian Academy of Sciences (India)

    D Bharathi Mohan; C S Sunandana

    2006-08-01

    A study of electronic conductivity using the DC polarization technique has been carried out for AgI and Ag1-CuI (where = 0.05, 0.15, 0.25) solid solutions over a range of temperatures from 300 K to 473 K. A diode-like current-voltage characteristics arises from microscopic p-n junctions and an enhanced electronic conductivity of the order of 10-3A is observed for undoped AgI and Cu-doped AgI. Activation energies (a) for electronic conductivity obtained from log (-1 cm-1) vs. 1000/(K-1) were 0.48, 0.6, 0.74 and 1.01 eV for AgI, Ag0.95Cu0.05I, Ag0.85Cu0.15I and Ag0.75Cu0.25I solid solutions respectively. The near-twofold increase in activation energy (1.01 eV) observed upon 25% Cu doping is due to the substantial concentration of current carriers/holes injected by Cu while replacing Ag+ in AgI.

  16. Influence of Mo/MoSe2 microstructure on the damp heat stability of the Cu(In,Ga)Se2 back contact molybdenum

    NARCIS (Netherlands)

    Theelen, M.; Harel, S.; Verschuren, M.; Tomassini, M.; Hovestad, A.; Barreau, N.; Berkum, J. van; Vroon, Z.; Zeman, M.

    2015-01-01

    The degradation behavior of Mo/MoSe2 layers have been investigated using damp heat exposure. The two studied molybdenum based films with different densities and microstructures were obtained by lifting off Cu(In,Ga)Se2 layers froma bilayer molybdenum stack on soda lime glass. Hereby, a glass/Mo/MoSe

  17. PROSES BRAZING Cu-Ag BERBAHAN BAKAR BIOGAS TERMURNIKAN

    Directory of Open Access Journals (Sweden)

    Ali Kusrijadi

    2015-01-01

    Full Text Available Pemanfaatan biogas sebagai salah satu alternatif bahan bakar  pada proses brazing merupakan langkah diversifikasi biogas, yang diharapkan dapat meningkatkan tingkat efisiensi dan keramahan teknologi. Permasalahan yang bersifat teknis dan menjadi kendala dalam pemanfaatan biogas ini adalah rendahnya konsentrasi CH4 dikarenakan adanya pengotor utama berupa air, karbondioksida dan asam disulfida. Penelitian dilakukan melalui dua tahap yaitu  tahap  pressureized storage process meliputi pemisahan komponen pengotor yang terdapat dalam biogas melalui teknik absorbsi sehingga dihasilkan biogas yang berkualitas gas alam terbarukan dan proses injeksi ke dalam suatu tangki penyimpanan, dan tahap selanjutnya adalah menggunakan biogas tersebut pada proses brazing logam Cu (tembaga dengan bahan tambah Ag (silver. Analisis hasil brazing dilakukan melalui analisis struktur mikro (metalografi untuk melihat kualitas tampak dari hasil brazing, serta analisis kekerasan mikro dan analisis parameter fisik standar terhadap hasil proses brazing. Penelitian ini telah menghasilkan perangkat alat pemurnian biogas yang dapat memurnikan biogas menjadi metana mendekati 100% dan sistem pengemasan (storage system  biogas bertekanan hingga 2 bar. Dari hasil analisis struktur mikro dan uji kekerasan mikro diketahui bahwa hasil proses brazing dengan biogas menghasilkan kualitas yang sama dengan hasil proses brazing dengan gas acetylene sehingga disimpulkan bahwa biogas dapat menjadi bahan bakar alternatif untuk proses brazing, khususnya untuk logam Cu dengan bahan tambah Ag.  Kata kunci : Biogas, Pressureized Storage, Brazing

  18. Directional solidification of Al-Cu-Ag alloy

    Energy Technology Data Exchange (ETDEWEB)

    Boeyuek, U.; Kaya, H. [Erciyes University, Department of Science Education, Education Faculty, Kayseri (Turkey); Marasli, N.; Keslioglu, K. [Erciyes University, Department of Physics, Faculty Arts and Sciences, Kayseri (Turkey); Cadirli, E. [Nigde University, Department of Physics, Faculty Arts and Sciences, Nigde (Turkey)

    2009-06-15

    Al-Cu-Ag alloy was prepared in a graphite crucible under a vacuum atmosphere. The samples were directionally solidified upwards under an argon atmosphere with different temperature gradients (G=3.99-8.79 K/mm), at a constant growth rate (V=8.30 {mu}m/s), and with different growth rates (V=1.83-498.25 {mu}m/s), at a constant gradient (G=8.79 K/mm) by using the Bridgman type directional solidification apparatus. The microstructure of Al-12.80-at.%-Cu-18.10-at.%-Ag alloy seems to be two fibrous and one lamellar structure. The interlamellar spacings ({lambda}) were measured from transverse sections of the samples. The dependence of interlamellar spacings ({lambda}) on the temperature gradient (G) and the growth rate (V) were determined by using linear regression analysis. According to these results it has been found that the value of {lambda} decreases with the increase of values of G and V. The values of {lambda} {sup 2}V were also determined by using the measured values of {lambda} and V. The experimental results were compared with two-phase growth from binary and ternary eutectic liquid. (orig.)

  19. Synthesis of few-layer MoS2 nanosheet-loaded Ag3PO4 for enhanced photocatalytic activity.

    Science.gov (United States)

    Song, Yanhua; Lei, Yucheng; Xu, Hui; Wang, Cheng; Yan, Jia; Zhao, Haozhu; Xu, Yuanguo; Xia, Jiexiang; Yin, Sheng; Li, Huaming

    2015-02-21

    Novel few-layer MoS2/Ag3PO4 composites were fabricated. The results indicated that Ag3PO4 nanoparticles were directly formed on the surface of few-layer MoS2. The physical and chemical properties of the few-layer MoS2/Ag3PO4 composite photocatalysts were tested in order to investigate the effects of few-layer MoS2 on the photocatalytic activity of Ag3PO4. The photocatalytic activity of the few-layer MoS2/Ag3PO4 composites was evaluated by the photocatalytic degradation of Rhodamine B (RhB) and bisphenol A (BPA) under visible light irradiation. The photocatalytic activity of the few-layer MoS2/Ag3PO4 composites was higher than that of pure Ag3PO4. The optimal few-layer MoS2 content for the organic pollutant degradation of the heterojunction structures was determined. The synergic effect between few-layer MoS2 and Ag3PO4 was found to lead to an improved photogenerated carrier separation. The stability and the possible photocatalytic mechanism of the composites were also discussed.

  20. Thermodynamic Analysis of In-situ Reaction Synthesis for Ag/MoS2 Composite Materials%Ag/MoS2复合材料的原位反应合成热力学分析

    Institute of Scientific and Technical Information of China (English)

    周晓龙; 郑忠; 曹建春; 陈敬超; 于杰

    2015-01-01

    通过对Ag/MoS2复合材料的热力学计算与分析,探讨了采用原位反应合成Ag/MoS2复合材料的可行性.结果表明,在同一温度条件下,S与Ag、Mo反应生成Ag2S和MoS2的标准自由焓低于Mo与Ag2S反应生成Ag和MoS2的标准自由焓,且生成的MoS2的标准自由焓最低,即从热力学角度说明Mo能够将Ag2S中的Ag置换出来;但是从Mo与Ag2S反应生成Ag和MoS2的标准自由焓来看,其标准自由焓高于S与Ag反应生成Ag2S的标准自由焓,说明若采用原位反应合成技术制备Ag/MoS2复合材料,将有部分Ag2S存在于复合材料中,不能获得完全的Ag/MoS2复合材料;因此,采用原位反应合成技术来制备完全的Ag/MoS2复合材料是不可行的.从热力学的标准自由焓与温度的关系图发现,3种化学反应中的相变能够促进反应的进行.

  1. Aging Characteristics of Sn-Ag Eutectic Solder Alloy with the Addition of Cu, In, and Mn

    Science.gov (United States)

    Ghosh, M.; Kar, Abhijit; Das, S. K.; Ray, A. K.

    2009-10-01

    In the present investigation, three types of solder alloy, i.e., Sn-Ag-Cu, Sn-Ag-In, and Sn-Ag-Cu-Mn, have been prepared and joined with Cu substrate. In the reflowed condition, the joint interface is decorated with Cu6Sn5 intermetallic in all cases. During aging at 100 °C for 50 to 200 hours, Cu3Sn formation took place in the diffusion zone of the Sn-Ag-Cu and Sn-Ag-In vs Cu assembly, which was not observed for the Sn-Ag-Cu-Mn vs Cu joint. Aging also leads to enhancement in the width of reaction layers; however, the growth is sluggish (~134 KJ/mol) for the Sn-Ag-Cu-Mn vs Cu transition joint. In the reflowed condition, the highest shear strength is obtained for the Sn-Ag-Cu-Mn vs Cu joint. Increment in aging time results in decrement in shear strength of the assemblies; yet small reduction is observed for the Sn-Ag-Cu-Mn vs Cu joint. The presence of Mn in the solder alloy is responsible for the difference in microstructure of the Sn-Ag-Cu-Mn solder alloy vs Cu assembly in the reflowed condition, which in turn influences the microstructure of the same after aging with respect to others.

  2. The Effect of Cu:Ag Atomic Ratio on the Properties of Sputtered Cu–Ag Alloy Thin Films

    Directory of Open Access Journals (Sweden)

    Janghsing Hsieh

    2016-11-01

    Full Text Available Cu–Ag thin films with various atomic ratios were prepared using a co-sputtering technique, followed by rapid thermal annealing at various temperatures. The films’ structural, mechanical, and electrical properties were then characterized using X-ray diffractometry (XRD, atomic force microscopy (AFM, FESEM, nano-indentation, and TEM as functions of compositions and annealing conditions. In the as-deposited condition, the structure of these films transformed from a one-phase to a dual-phase state, and the resistivity shows a twin-peak pattern, which can be explained in part by Nordheim’s Rule and the miscibility gap of Cu–Ag alloy. After being annealed, the films’ resistivity followed the mixture rule in general, mainly due to the formation of a dual-phase structure containing Ag-rich and Cu-rich phases. The surface morphology and structure also varied as compositions and annealing conditions changed. The recrystallization of these films varied depending on Ag–Cu compositions. The annealed films composed of 40 at % to 60 at % Cu had higher hardness and lower roughness than those with other compositions. Particularly, the Cu50Ag50 film had the highest hardness after being annealed. From the dissolution testing, it was found that the Cu-ion concentration was about 40 times higher than that of Ag. The galvanic effect and over-saturated state could be the cause of the accelerated Cu dissolution and the reduced dissolution of the Ag.

  3. Tribological properties of self-lubricating NiAl/Mo-based composites containing AgVO{sub 3} nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Eryong, E-mail: ley401@163.com [State Key Laboratory for Mechanical Behavior of Materials, School of Materials Science and Engineering, Xi' an Jiaotong University, Xi' an 710049 (China); State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Gao, Yimin, E-mail: ymgao@mail.xjtu.edu.cn [State Key Laboratory for Mechanical Behavior of Materials, School of Materials Science and Engineering, Xi' an Jiaotong University, Xi' an 710049 (China); Bai, Yaping, E-mail: jingpingxue2004@163.com [State Key Laboratory for Mechanical Behavior of Materials, School of Materials Science and Engineering, Xi' an Jiaotong University, Xi' an 710049 (China); Yi, Gewen, E-mail: gwyi@licp.cas.cn [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Wang, Wenzhen, E-mail: Wzwang@licp.cas.cn [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Zeng, Zhixiang, E-mail: zengzhx@nimte.ac.cn [Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Jia, Junhong, E-mail: jhjia@licp.cas.cn [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)

    2014-11-15

    Silver vanadate (AgVO{sub 3}) nanowires were synthesized by hydrothermal method and self-lubricating NiAl/Mo-AgVO{sub 3} composites were fabricated by powder metallurgy technique. The composition and microstructure of NiAl/Mo-based composites were characterized and the tribological properties were investigated from room temperature to 900 °C. The results showed that NiAl/Mo-based composites were consisted of nanocrystalline B2 ordered NiAl matrix, Al{sub 2}O{sub 3}, Mo{sub 2}C, metallic Ag and vanadium oxide phase. The appearance of metallic Ag and vanadium oxide phase can be attributed to the decomposition of AgVO{sub 3} during sintering. Wear testing results confirmed that NiAl/Mo-based composites have excellent tribological properties over a wide temperature range. For example, the friction coefficient and wear rate of NiAl/Mo-based composites containing AgVO{sub 3} were significantly lower than the composites containing only metallic Mo or AgVO{sub 3} lubricant when the temperature is above 300 °C, which can be attributed to the synergistic lubricating action of metallic Mo and AgVO{sub 3} lubricants. Furthermore, Raman results indicated that the composition on the worn surface of NiAl-based composites was self-adjusted after wear testing at different temperatures. For example, Ag{sub 3}VO{sub 4} and Fe{sub 3}O{sub 4} lubricants were responsible for the improvement of tribological properties at 500 °C, AgVO{sub 3}, Ag{sub 3}VO{sub 4} and molybdate for 700 °C, and AgVO{sub 3} and molybdate for 900 °C of NiAl-based composites with the addition of metallic Mo and AgVO{sub 3}. - Highlights: • NiAl/Mo-AgVO{sub 3} nanocomposites were prepared by mechanical alloying and sintering. • AgVO{sub 3} decomposed to metallic Ag and vanadium oxide during the sintering process. • NiAl/Mo-AgVO{sub 3} exhibited superior tribological properties at a board temperature range. • Phase composition on the worn surface was varied with temperatures. • Self-adjusted action

  4. Unexpected strong magnetism of Cu doped single-layer MoS₂ and its origin.

    Science.gov (United States)

    Yun, Won Seok; Lee, J D

    2014-05-21

    The magnetism of the 3d transition-metal (TM) doped single-layer (1L) MoS2, where the Mo atom is partially replaced by the 3d TM atom, is investigated using the first-principles density functional calculations. In a series of 3d TM doped 1L-MoS2's, the induced spin polarizations are negligible for Sc, Ti, and Cr dopings, while the induced spin polarizations are confirmed for V, Mn, Fe, Co, Ni, Cu, and Zn dopings and the systems become magnetic. Especially, the Cu doped system shows unexpectedly strong magnetism although Cu is nonmagnetic in its bulk state. The driving force is found to be a strong hybridization between Cu 3d states and 3p states of neighboring S, which results in an extreme unbalanced spin-population in the spin-split impurity bands near the Fermi level. Finally, we also discuss further issues of the Cu induced magnetism of 1L-MoS2 such as investigation of additional charge states, the Cu doping at the S site instead of the Mo site, and the Cu adatom on the layer (i.e., 1L-MoS2).

  5. An unusual chain constructed from heteropolyanions and isopolyanions: [{Cu(2,2'-bipy)} 6(Mo 6O 22)][SiMo 12O 40

    Science.gov (United States)

    Zhang, Chun-Jing; Zhang, Chun-Hua; Pang, Hai-Jun; Wang, Da-Peng; Kong, Qing-Jiao; Yang, Xiao-Dan; Yao, Feng; Tang, Qun; Wang, Hui-Yuan; Chen, Ya-Guang

    2010-02-01

    A new compound based on transition metal complexes modified heteropolyanions and isopolyanions: [{Cu(2,2'-bipy)} 6(Mo 6O 22)][SiMo 12O 40] ( 1) (2,2'-bipy = 2,2'-bipyridine), has been hydrothermally synthesized and characterized by elemental analysis, IR, TG and single-crystal X-ray diffraction. In compound 1, each of the [Mo 6O 22] 8- clusters is surrounded by six {Cu(2,2'-bipy)} 2+ fragments forming [{Cu(2,2'-bipy)} 6(Mo 6O 22)] 4+ cations which further alternately link the [SiMo 12O 40] 4- anions to result in an unusual 1D chain.

  6. Electrodeposition and characterisation of Sn-Ag-Cu solder alloys for flip-chip interconnection

    Energy Technology Data Exchange (ETDEWEB)

    Qin Yi [Department of Materials, Loughborough University, Leicestershire, LE11 3TU (United Kingdom); Wolfson School of Mechanical and Manufacturing Engineering, Loughborough University, Leicestershire, LE11 3TU (United Kingdom); Wilcox, G.D., E-mail: G.D.Wilcox@lboro.ac.u [Department of Materials, Loughborough University, Leicestershire, LE11 3TU (United Kingdom); Liu Changqing [Wolfson School of Mechanical and Manufacturing Engineering, Loughborough University, Leicestershire, LE11 3TU (United Kingdom)

    2010-12-15

    A pyrophosphate and iodide based bath was investigated for the electrodeposition of near-eutectic Sn-Ag-Cu alloys, which are promising lead-free solder candidates for electronics interconnection. Near-eutectic Sn-Ag-Cu electrodeposits (2.5-4.2 wt.% Ag and 0.7-1.5 wt.% Cu) were achieved from the system as measured by wavelength dispersive X-ray spectroscopy (WDS). Electroplating such near-eutectic ternary alloys at higher deposition rates was possible with the application of electrolyte agitation. Different morphologies of deposited Sn-Ag-Cu films were analysed using scanning electron microscopy (SEM). X-ray diffraction (XRD) data indicated that Sn, Ag{sub 3}Sn and Cu{sub 6}Sn{sub 5} were present in the 'as-electrodeposited' Sn-Ag-Cu film. The microstructure of the deposits and the morphology of Ag{sub 3}Sn and Cu{sub 6}Sn{sub 5} intermetallics were characterised from cross-sectional images produced from a focused ion beam scanning electron microscopy and then imaged from transmission electron microscopy (TEM) micrographs. The proposed bath proved capable of producing fine pitch near-eutectic Sn-Ag-Cu solder bumps as demonstrated on a glass test wafer.

  7. Short-range Ferromagnetism in Alloy Ribbons of Fe-Cr-Si-Nb-(Ag, Cu)

    DEFF Research Database (Denmark)

    Thanh, P. Q.; Hoa, N. Q.; Chau, N.

    2014-01-01

    We have studied the magnetic properties of two amorphous alloy ribbons Fe72Cr6Si4Nb5B12Ag1 (FCSNB-Ag) and Fe72Cr6Si4Nb5B12Cu1 (FCSNB-Cu), prepared by using a melt-spinning technique. Magnetization (M) measurements for various temperatures (T) and magnetic fields (H) indicate that ferromagnetic...

  8. [Mechanical properties of wiredrawn Ag-Pd-Cu alloys].

    Science.gov (United States)

    Hasegawa, T; Miyagawa, Y; Nakamura, K

    1989-01-01

    Nine experimental Ag-Pd-Cu ternary alloys, containing 20-30 wt% Pd and 10-20 wt% Cu, were cast into rods 4.5 mm in diameter using an original vacuum/argon-pressure oxide-free casting technique. Test samples 2.0 mm in diameter were made from the rods by wire-drawing. After softening and hardening heat treatments, mechanical properties (modulus of elasticity, elastic limit, proof stress, tensile strength, elongation, and Vickers hardness) of the samples were measured to analyze the effects of composition and fifteen sets of correlations between the mechanical properties on the condition that few internal casting defects existed. After softening heat treatment, values of hardness and strength increased with increasing Cu and Pd contents, while they increased approximately with increasing Pd content after hardening heat treatment. After softening and hardening heat treatments, tensile strength ranged from 44.4 to 60.7 and from 68.1 to 89.1 kgf/mm2, respectively. Values of elongation were more than 10% even after hardening heat treatment. Fourteen out of fifteen correlation coefficients (r) were statistically significant (p less than 0.01). One of the regression lines derived was as follows. Tensile strength (kgf/mm2) = 9.1 +/- 0.305 Hv (r = 0.990) Moreover, the mechanical properties observed in this investigation were compared with those of ordinarily cast samples with the same compositions.

  9. Electromigration of composite Sn-Ag-Cu solder bumps

    Science.gov (United States)

    Sharma, Ashutosh; Xu, Di Erick; Chow, Jasper; Mayer, Michael; Sohn, Heung-Rak; Jung, Jae Pil

    2015-11-01

    This study investigates the electromigration (EM) behavior of lead free Sn-Ag-Cu (SAC) solder alloys that were reinforced with different types of nanoparticles [Copper-coated carbon nanotubes (Cu/CNT), La2O3, Graphene, SiC, and ZrO2]. The composite solders were bumped on a Cu substrate at 220°C, and the resistance of the bumped solders was measured using a four wire setup. Current aging was carried out for 4 hours at a temperature of 160°C, and an increase in resistance was noted during this time. Of all the composite solders that were studied, La2O3 and SiC reinforced SAC solders exhibited the smallest resistances after current aging. However, the rate of change in the resistance at room temperature was lower for the SiC-reinforced SAC solder. The SAC and Graphene reinforced SAC solder bumps completely failed within 15 - 20 min of these tests. The SiC nanoparticles were reported to possibly entrap the SAC atoms better than other nanoparticles with a lower rate of EM. [Figure not available: see fulltext.

  10. Physicochemical and antibacterial characterization of ionocity Ag/Cu powder nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Nowak, A., E-mail: ana.maria.nowak@gmail.com [A. Chełkowski Institute of Physics, University of Silesia, Uniwersytecka 4, 40-007 Katowice (Poland); Silesian Center for Education and Interdisciplinary Research, 75 Pułku Piechoty 1A, 41-500 Chorzów (Poland); Szade, J. [A. Chełkowski Institute of Physics, University of Silesia, Uniwersytecka 4, 40-007 Katowice (Poland); Silesian Center for Education and Interdisciplinary Research, 75 Pułku Piechoty 1A, 41-500 Chorzów (Poland); Talik, E. [A. Chełkowski Institute of Physics, University of Silesia, Uniwersytecka 4, 40-007 Katowice (Poland); Zubko, M. [Silesian Center for Education and Interdisciplinary Research, 75 Pułku Piechoty 1A, 41-500 Chorzów (Poland); Institute of Material Science, University of Silesia, 75 Pułku Piechoty 1a, 41-500 Chórzow (Poland); Wasilkowski, D. [Department of Biochemistry, University of Silesia, Jagiellońska 28, 40-032 Katowice (Poland); Dulski, M. [Silesian Center for Education and Interdisciplinary Research, 75 Pułku Piechoty 1A, 41-500 Chorzów (Poland); Institute of Material Science, University of Silesia, 75 Pułku Piechoty 1a, 41-500 Chórzow (Poland); Balin, K. [A. Chełkowski Institute of Physics, University of Silesia, Uniwersytecka 4, 40-007 Katowice (Poland); Silesian Center for Education and Interdisciplinary Research, 75 Pułku Piechoty 1A, 41-500 Chorzów (Poland); and others

    2016-07-15

    Metal ion in bimetallic nanoparticles has shown vast potential in a variety of applications. In this paper we show the results of physical and chemical investigations of powder Ag/Cu nanoparticles obtained by chemical synthesis. Transmission electron microscopy (TEM) experiment indicated the presence of bimetallic nanoparticles in the agglomerated form. The average size of silver and copper nanoparticles is 17.1(4) nm (Ag) and 28.9(2) nm (Cu) basing on the X-ray diffraction (XRD) data. X-ray photoelectron (XPS) and Raman spectroscopies revealed the existence of metallic silver and copper as well as Cu{sub 2}O and CuO being a part of the nanoparticles. Moreover, UV–Vis spectroscopy showed surface alloy of Ag and Cu while Time of Flight Secondary Ion Mass Spectroscopy (ToF-SIMS) and Energy Dispersive X-ray Spectroscopy (EDX) showed heterogeneously distributed Ag structures placed on spherical Cu nanoparticles. The tests of antibacterial activity show promising killing/inhibiting growth behaviour for Gram positive and Gram negative bacteria. - Highlights: • Ag/Cu nanoparticles were obtained in the powder form. • The average size of nanoparticles is 17.1(4) nm (Ag) and 28.9(2) nm (Cu). • Ag/Cu powder nanoparticle shows promising antibacterial properties.

  11. Laser deposition of (Cu + Mo) alloying reinforcements on AA1200 substrate for corrosion improvement

    CSIR Research Space (South Africa)

    Popoola, API

    2011-10-01

    Full Text Available Poor corrosion performance of aluminium alloys in marine environment has been a subject of intensive research recently. Aluminium substrate was alloyed with a combination of two metallic powders (Cu + Mo) using an Nd: YAG solid state laser...

  12. Study on synthesis of ultrafine Cu-Ag core-shell powders with high electrical conductivity

    Energy Technology Data Exchange (ETDEWEB)

    Peng Yuhsien [Department of Environmental Engineering, Dayeh University, 168 University Rd., Dacun, Changhua 515, Taiwan (China); Department of Research and Development, Oriental Happy Enterprise Co., No. 27, Xin' ai Rd., South Dist., Tainan 702, Taiwan (China); Center for General Education, Kun Shan University, No. 949, Dawan Rd., Yongkang Dist., Tainan 710, Taiwan (China); Yang Chihhao [Department of Research and Development, Oriental Happy Enterprise Co., No. 27, Xin' ai Rd., South Dist., Tainan 702, Taiwan (China); Chen Kuanting, E-mail: pengyuhsien@hotmail.com [Department of Resources Engineering, National Cheng Kung University, No.1, Da-Hsueh Road, Tainan 701, Taiwan (China); Popuri, Srinivasa R. [Department of Biological and Chemical Sciences, The University of the West Indies, Cave Hill Campus 11000 (Barbados); Lee, Ching-Hwa [Department of Environmental Engineering, Dayeh University, 168 University Rd., Dacun, Changhua 515, Taiwan (China); Tang, Bo-Shin [Department of Research and Development, Oriental Happy Enterprise Co., No. 27, Xin' ai Rd., South Dist., Tainan 702, Taiwan (China)

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer This synthesis method is relatively facile, novel and eco-friendly. Black-Right-Pointing-Pointer Toxic agents were not used for chelating agent, reductant or dispersant in our method. Black-Right-Pointing-Pointer The reaction can under room temperature for energy saving purpose. Black-Right-Pointing-Pointer Cu-Ag core-shell powders with homogeneous cover-silver layer. Black-Right-Pointing-Pointer The resistivity of Cu-Ag core-shell powders has the same value as the pure silver. - Abstract: Cu-Ag composite powders with high electrical conductivity were synthesized by electroless plating of silver sulfate, copper powders with eco-friendly sodium citrate as reducing agent, dispersant and chelating agent in an aqueous system. The influences of sodium citrate/Ag ratio on Ag coatings of Cu powders were investigated. Ag was formed a dense coating on the surface of Cu powders at a molar ratio of sodium citrate/Ag = 0.07/1. SEM showed an uniformity of Ag coatings on Cu powders. SEM-EDX also revealed that Cu cores were covered by Ag shells on the whole. The surface composition analysis by XPS indicated that without Cu or Ag atoms in the surface were oxidized. The resistivity measurements of Cu-Ag paste shows that they have closer resistivity as the pure silver paste's after 250 Degree-Sign C for 30 min heat-treatment (2.55 Multiplication-Sign 10{sup -4} {Omega} cm) and 350 Degree-Sign C for 30 min heat-treatment (1.425 Multiplication-Sign 10{sup -4} {Omega} cm).

  13. The behavior and effect of CuO in Ag/SnO{sub 2} materials

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jun, E-mail: Wangjun1983@stu.xjtu.edu.cn [MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, School of Science, Xi’an Jiaotong University, Xi’an 710049 (China); Liu, Wei, E-mail: 810779396@qq.com [MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, School of Science, Xi’an Jiaotong University, Xi’an 710049 (China); Li, Dongmei, E-mail: 946346365@qq.con [MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, School of Science, Xi’an Jiaotong University, Xi’an 710049 (China); Wang, Yaping, E-mail: ypwang@mail.xjtu.edu.cn [MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, School of Science, Xi’an Jiaotong University, Xi’an 710049 (China); State Key Laboratory for Mechanical Behavior of Materials, Xi’an Jiaotong University, Xi’an 710049 (China)

    2014-03-05

    Highlights: • The crystallized monoclinic CuO in CuO-doped SnO{sub 2} nanoparticles had formed. • The crystallized monoclinic CuO distributed on the surface of SnO{sub 2} nanoparticles. • Ag/SnO{sub 2} materials adding CuO exhibited denser microstructure and better hardness. • Ag/SnO{sub 2} materials adding CuO exhibited better arc erosion resistance. • The addition of CuO can obviously inhibited the spattering loss of molten droplet. -- Abstract: In this paper, the behavior of CuO in CuO-doped SnO{sub 2} nanoparticles was investigated; the effect of the addition of CuO on physical properties and arc erosion behavior of Ag/SnO{sub 2} materials were examined. The CuO-doped SnO{sub 2} nanoparticles were structurally characterized by X-ray diffraction (XRD) and High-resolution Transmission Electron Microscope (HR-TEM). The surface morphology of arc eroded Ag/SnO{sub 2} materials was characterized by Scanning Electron Microscope (SEM). The results indicated that the crystallized monoclinic CuO in CuO-doped SnO{sub 2} nanoparticles has formed and distributed on the surface of SnO{sub 2} nanoparticles. It was found that Ag/SnO{sub 2} materials adding CuO exhibited denser microstructure and better hardness as well as better arc erosion resistance compared with Ag/SnO{sub 2} materials. The arc erosion results and theoretical analysis indicated that the addition of CuO in Ag/SnO{sub 2} materials can obviously inhibited the spattering loss of molten droplets.

  14. Effect of Ag on Sn–Cu and Sn–Zn lead free solders

    Directory of Open Access Journals (Sweden)

    Alam S.N.

    2015-06-01

    Full Text Available Lead and lead-containing compounds are considered as toxic substances due to their detrimental effect on the environment. Sn-based soldering systems, like Sn-Cu and Sn-Zn are considered as the most promising candidates to replace the eutectic Sn-Pb solder compared to other solders because of their low melting temperature and favorable properties. Eutectic Sn-0.7 wt.% Cu and near eutectic composition Sn-8 wt.% Zn solders have been considered here for study. For the Sn-Cu system, besides the eutectic Sn-0.7 wt.% Cu composition, Sn-1Cu and Sn-2Cu were studied. Three compositions containing Ag: Sn-2Ag-0.7Cu, Sn-2.5Ag-0.7Cu and Sn-4.5Ag-0.7Cu were also developed. Ag was added to the eutectic Sn-0.7 wt.% Cu composition in order to reduce the melting temperature of the eutectic alloy and to enhance the mechanical properties. For the Sn-Zn system, besides the Sn-8 wt.% Zn near eutectic composition, Sn-8Zn-0.05Ag, Sn-8Zn-0.1Ag and Sn-8Zn-0.2Ag solder alloys were developed. The structure and morphology of the solder alloys were analyzed using a scanning electron microscope (SEM, filed emission scanning electron microscope (FESEM, electron diffraction X-ray spectroscopy (EDX and X-ray diffraction (XRD. Thermal analysis of the alloys was also done using a differential scanning calorimeter (DSC. Trace additions of Ag have been found to significantly reduce the melting temperature of the Sn-0.7 wt.% Cu and Sn-8 wt.% Zn alloys.

  15. On the coexistence of copper-molybdenum bronzes: CuxMoO3 (0.2 < x < 0.25; typically x = 0.23) and CuyMoO3-z (0.1 < y < 0.2; typically y = 0.15) in the Cu-MoO2-O quasi-ternary system

    DEFF Research Database (Denmark)

    Warner, Terence Edwin; Skou, Eivind Morten

    2010-01-01

    Two copper-molybdenum bronzes: CuyMoO3-z (0.1... yields: Cu6Mo5O18, Cu and MoO2. A tentative subsolidus Cu-MoO2-O isothermal (= 25 C) phase diagram under argon is drawn from these data. Oxidation states of Cu and Mo within this system are discussed....

  16. Mo-Cu合金与1Cr18Ni9Ti不锈钢真空钎焊接头的组织性能%Microstructure characteristics of vacuum brazed joint for Mo-Cu alloy with lCrl8Ni9Ti stainless steel

    Institute of Scientific and Technical Information of China (English)

    王娟; 郑德双; 李亚江

    2013-01-01

    Mo-Cu alloy and lCrl8Ni9Ti stainless steel were joined by vacuum brazing with Ag-Cu-Ti active filler metal at 910 ℃ for 20 min and a Mo-Cu/lCrl8Ni9Ti joint with a shear strength of 75 MPa was obtained. The microstructure and performance of Mo-Cu/lCrl8Ni9Ti joint were investigated by scanning electron microscope ( SEM ) , energy dispersive spectrometer ( EDS) and microhardness test. The results indicated that Ag-Cu eutectic and Cu-rich phase were produced in the brazed joint. There were few of TiC phases near the side of lCrl8Ni9Ti stainless steel in the joint. The microhardness of brazed seam was lower than that of Mo-Cu alloy and lCrl8Ni9Ti stainless steel. There are no brittle compounds formed in the Mo-Cu/lCrl8Ni9Ti joint. The shear fracture appearance shows shear dimple feature.%采用Ag-Cu-Ti钎料,控制钎焊温度为910℃,保温时间为20 min,可以实现Mo-Cu合金与1Cr1 8Ni9Ti不锈钢的真空钎焊,接头抗剪强度为75 MPa.采用扫描电镜、能谱分析仪和显微硬度计对Mo-Cu/1 Cr18 Ni9Ti接头组织特征及性能进行分析.结果表明,钎焊接头靠近1Cr18Ni9Ti钢一侧,主要形成Ag-Cu共晶组织和少量的TiC相;靠近Mo-Cu合金一侧,Ag,Cu元素在合金与钎缝间相向扩散,共晶组织消失,以富铜相为主.钎缝的显微硬度明显低于Mo-Cu合金和1Cr18Ni9Ti不锈钢母材,无脆性化合物生成,剪切断口呈现剪切韧窝的形貌特征.

  17. Sn-Ag-Cu Nanosolders: Solder Joints Integrity and Strength

    Science.gov (United States)

    Roshanghias, Ali; Khatibi, Golta; Yakymovych, Andriy; Bernardi, Johannes; Ipser, Herbert

    2016-08-01

    Although considerable research has been dedicated to the synthesis and characterization of lead-free nanoparticle solder alloys, only very little has been reported on the reliability of the respective joints. In fact, the merit of nanoparticle solders with depressed melting temperatures close to the Sn-Pb eutectic temperature has always been challenged when compared with conventional solder joints, especially in terms of inferior solderability due to the oxide shell commonly present on the nanoparticles, as well as due to compatibility problems with common fluxing agents. Correspondingly, in the current study, Sn-Ag-Cu (SAC) nanoparticle alloys were combined with a proper fluxing vehicle to produce prototype nanosolder pastes. The reliability of the solder joints was successively investigated by means of electron microscopy and mechanical tests. As a result, the optimized condition for employing nanoparticles as a competent nanopaste and a novel procedure for surface treatment of the SAC nanoparticles to diminish the oxide shell prior to soldering are being proposed.

  18. Cellular Energy Allocation to Assess the Impact of Nanomaterials on Soil Invertebrates (Enchytraeids: The Effect of Cu and Ag

    Directory of Open Access Journals (Sweden)

    Susana I. L. Gomes

    2015-06-01

    Full Text Available The effects of several copper (Cu and silver (Ag nanomaterials were assessed using the cellular energy allocation (CEA, a methodology used to evaluate the energetic status and which relates with organisms’ overall condition and response to toxic stress. Enchytraeus crypticus (Oligochatea, was exposed to the reproduction effect concentrations EC20/50 of several Cu and Ag materials (CuNO3, Cu-Field, Cu-Nwires and Cu-NPs; AgNO3, Ag NM300K, Ag-NPs Non-coated and Ag-NPs PVP-coated for 7 days (0-3-7d. The parameters measured were the total energy reserves available (protein, carbohydrate and lipid budgets and the energy consumption (Ec integrated to obtain the CEA. Results showed that these parameters allowed a clear discrimination between Cu and Ag, but less clearly within each of the various materials. For Cu there was an increase in Ec and protein budget, while for Ag a decrease was observed. The results corroborate known mechanisms, e.g., with Cu causing an increase in metabolic rate whereas Ag induces mitochondrial damage. The various Cu forms seem to activate different mechanisms with size and shape (e.g., Cu-NPs versus Cu-Nwires, causing clearly different effects. For Ag, results are in line with a slower oxidation rate of Ag-NMs in comparison with Ag-salt and hence delayed effects.

  19. The study on interfacial bonding strength of Ag-Ni, Ag-Cu in cold pressure welding

    Institute of Scientific and Technical Information of China (English)

    李云涛; 杜则裕; 陈丽萍

    2003-01-01

    The area of combination actually is a kind of interfacial phenomena that exist on the surface or thin film. The properties of interface have important effect on the whole welded joint, even decide directly the interfacial bonding strength. The bonding strength of metals in cold pressure welding such as Ag-Ni (they are hardly mutual soluble) and Ag-Cu(they are limited soluble) are discussed in this paper. The results of the tensile test suggest that two kinds of welded joints have enough strength to satisfy with the demand for being used. Moreover, thermodynamics, crystal logy, physics and metal electronic microscopic analysis etc are adopted to further calculate the bonding strength. The results of test and theoretical analyses prove that Ag-Ni, Ag-Cu, especially, for Ag-Ni can form strong welded joint which is higher than that of the relative soft base metals in cold pressure welding.

  20. Synthesis and Structure of A Novel Quasi-Two Dimensional Organic-inorganic Hybrid Coordination Polymer:{[Cu(en)2][Ag2I4]}n

    Institute of Scientific and Technical Information of China (English)

    SUN Ling-Guo; LI Hao-Hong; CHEN Zhi-Rong; HUANG Chang-Cang; ZHAO Bin; LI Jun-Qian

    2006-01-01

    A novel coordination polymer {[Cu(en)2][Ag2I4]}n (en = ethylenediamine) was synthesized by the reaction of NaAgI2 and Cu(en)2(NO3)2·2H2O at room temperature with pH = 6.0, and the structure was characterized by X-ray single-crystal diffraction. It crystallizes in monoclinic, space group C2/m, with a=10.646(2), b = 13.304(3), c = 6.8445(14)(A), β = 118.95(3)°, C4H16N4CuAg2I4, Mr = 907.10, V = 848.3(4)(A)3, Z = 2, Dc = 3.551 g/cm3, F(000) = 806, μ(MoKα) = 10.787 mm(1, the final R1 = 0.0256 and wR2 = 0.0654 for 900 observed reflections with I > 2σ(I). According to structural analysis, the title compound consists of template cation [Cu(en)2]2+ and inorganic chain [Ag2I4]n2-. The polymeric negative chain [Ag2I4]n2- is built up from pairs of AgI4 tetrahedron by sharing one edge. Through N-H…I hydrogen-bonding interactions, the whole structure represents a quasi-two dimensional arrangement. Electrostatic attraction exists between organic cations and inorganic chains, leading to a so-called organic-inorganic hybrid structure.

  1. Evidence for improvement of critical current by Ag in YBaCuO-Ag thick films

    Science.gov (United States)

    Dwir, B.; Kellett, B.; Mieville, L.; Pavuna, D.

    1991-04-01

    The evidence is reported for enhancement of critical current density J(c) in YBa2Cu3O(7-delta) thick films with the addition of Ag, which is correlated with improvements in structural properties. An improvement of 50 percent in J(c) (up to about 500 A/sq cm at T = 4.2 K) was obtained in films made from YBCO + 60 wt pct Ag powder, fabricated by the spin-on technique on (100) SrTiO3, which is correlated with improvements in structure. The resulting films are 10 microns thick, uniform, partially textured, and show good adherence. The critical temperature Tc is improved by the addition of Ag, and a reduction in the density of microcracks and in the amount of secondary phases in the sintered films was observed. Normal-state resistivity is reduced by almost three orders of magnitude, making these films potentially useful for electronic applications in interconnects and novel hybrid circuits.

  2. Evidence for improvement of critical current by Ag in YBaCuO-Ag thick films

    Energy Technology Data Exchange (ETDEWEB)

    Dwir, B.; Kellett, B.; Mieville, L.; Pavuna, D. (Institute of Micro- and Opto-electronics, Department of Physics, Swiss Federal Institute of Technology, CH-1015 Lausanne, Switzerland (CH))

    1991-04-15

    The evidence is reported for enhancement of critical current density {ital J}{sub {ital c}} in YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} thick films with the addition of Ag, which is correlated with improvements in structural properties. An improvement of 50% in {ital J}{sub {ital c}} (up to {similar to}500 A/cm{sup 2} at {ital T}=4.2 K) was obtained in films made from YBCO+60wt % Ag powder, fabricated by the spin-on technique on (100) SrTiO{sub 3}, which is correlated with improvements in structure. The resulting films are 10 {mu}m thick, uniform, partially textured, and show good adherence. The critical temperature {ital T}{sub {ital c}} is improved by the addition of Ag, and a reduction in the density of microcracks and in the amount of secondary phases in the sintered films was observed. Normal-state resistivity is reduced by almost three orders of magnitude, making these films potentially useful for electronic applications in interconnects and novel hybrid circuits.

  3. The molecular dynamic study of anharmonic effects at Cu(111) and Ag(111) surfaces in the presence of Cu- and Ag-trimer island

    Energy Technology Data Exchange (ETDEWEB)

    Shah, Zulfiqar Ali [Department of Physics, Hazara University, Mansehra 21300 (Pakistan); Hayat, Sardar Sikandar, E-mail: sikandariub@yahoo.com [Department of Physics, Hazara University, Mansehra 21300 (Pakistan); Department of Physics, The Islamia University of Bahawalpur, Bahawalpur 63120 (Pakistan); Rehman, Z. [Department of Physics, Hazara University, Mansehra 21300 (Pakistan); Bouafia, Farida [LMPM, Mechanical Engineering Department, University of Sidi Bel Abbes, Sidi Bel Abbes 22000 (Algeria)

    2014-05-01

    The molecular dynamics (MD) technique based on semi-empirical potentials, is used to carry out the diffusion of Cu- and Ag-trimer on Cu- and Ag(111) surface at 300, 500 and 700 K temperatures. The constant energy MD simulation elaborates the anharmonic effects at the surface such as fissures, dislocations and vacancy creation, in the presence of island. The fissures and dislocations formed are in the range of 1.5–4 Å and 1–7 Å, respectively, from the island's position. The Cu and Ag islands both diffuse easily on Cu(111) surface, manipulate that the trend of diffusion is faster on Cu surface as compared to Ag surface. The process of breaking and opening of the island has also been observed. Moreover, a surface atom popped-up at 700 K by creating a vacancy near the Cu island on Ag surface. The rate of diffusion increases with the increase in temperature, both for homo- and hetero-cases.

  4. Diffusion and interface controlled reactions in {alpha}-(Cu-Al-Ag) alloys

    Energy Technology Data Exchange (ETDEWEB)

    Adorno, A.T. [Instituto de Quimica, Unesp, Departamento de Fisico-Quimica, Caixa Postal 355, 14801-970 Araraquara, SP (Brazil)]. E-mail: atadorno@iq.unesp.br; Silva, R.A.G. [Instituto de Quimica, Unesp, Departamento de Fisico-Quimica, Caixa Postal 355, 14801-970 Araraquara, SP (Brazil); Magdalena, A.G. [Instituto de Quimica, Unesp, Departamento de Fisico-Quimica, Caixa Postal 355, 14801-970 Araraquara, SP (Brazil)

    2007-08-30

    The isothermal kinetics of Ag precipitation was studied in Cu-Al-Ag alloys with concentrations ranging from 2 to 8 wt.%Al and 2 to 12 wt.%Ag, using scanning electron microscopy (SEM), X-ray energy dispersive spectroscopy (EDX) and microhardness measurements. The results indicated a change in the precipitates growing mechanism from diffusion to interface controlled process, probably due to a change in the nature of the interface with the Ag and Al enrichment of the precipitates.

  5. Synthesis and Characterization of Monometallic (Ag, Cu and Bimetallic Ag-Cu Particles for Antibacterial and Antifungal Applications

    Directory of Open Access Journals (Sweden)

    Marta Paszkiewicz

    2016-01-01

    Full Text Available In this paper, the experimental studies are concerned with the effect of the synthesis parameters on the formation of monometallic Ag and Cu nanoparticles (NPs. We consider the synthesis strategies verification for the bimetallic core-shell and alloy particles preparation. It was successfully obtained by chemical reduction method. The obtained colloidal solution is characterized by the transmission electron microscopy (TEM with energy-dispersive X-ray spectroscopy (EDX data, UV-Vis spectra, particle size distribution, and zeta potential. This work presents a comprehensive overview of experimental studies of the most stable colloidal solutions to impregnate fabrics that will exhibit a bactericidal and fungicidal activity against Candida albicans, Escherichia coli, and Staphylococcus aureus.

  6. Surface modification of oleylamine-capped Ag-Cu nanoparticles to fabricate low-temperature-sinterable Ag-Cu nanoink

    Science.gov (United States)

    Kim, Na Rae; Jong Lee, Yung; Lee, Changsoo; Koo, Jahyun; Lee, Hyuck Mo

    2016-08-01

    By treating oleylamine (OA)-capped Ag-Cu nanoparticles with tetramethylammonium hydroxide (TMAH), we obtained metal nanoparticles that are suspended in polar solvents and sinterable at low temperatures. The simple process with ultra sonication enables synthesis of monodispersed and high purity nanoparticles in an organic base, where the resulting nanoparticles are dispersible in polar solvents such as ethanol and isopropyl alcohol. To investigate the surface characteristics, we conducted Fourier-transform infrared and zeta-potential analyses. After thermal sintering at 200 °C, which is approximately 150 °C lower than the thermal decomposition temperature of OA, an electrically conductive thin film was obtained. Electrical resistivity measurements of the TMAH-treated ink demonstrate that surface modified nanoparticles have a low resistivity of 13.7 × 10-6 Ω cm. These results confirm the prospects of using low-temperature sinterable nanoparticles as the electrode layer for flexible printed electronics without damaging other stacked polymer layers.

  7. Magnetic structures of the high-pressure modifications of CoMoO{sub 4} and CuMoO{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Ehrenberg, H. [Tech. Univ., Darmstadt (Germany). Fachgebiet Strukturforschung]|[Interdisciplinary Research Centre in Superconductivity, Madingley Road, Cambridge CB3 0HE (United Kingdom); Wiesmann, M.; Weitzel, H.; Fuess, H. [Tech. Univ., Darmstadt (Germany). Fachgebiet Strukturforschung; Garcia-Jaca, J. [Departamento de Quimica Inorganica, Facultad de Ciencias Quimicas Universidad Complutense de Madrid, E-28040 Madrid (Spain)

    1998-02-01

    The magnetic structures of the high-pressure modifications CoMoO{sub 4}-II and CuMoO{sub 4}-III with wolframite structure have been determined by neutron powder diffraction and are discussed in the light of the underlying crystal structure, including the comparison with CoWO{sub 4} and CuWO{sub 4}, respectively. (orig.). 14 refs.

  8. Structural study of nanocrystalline solid solution of Cu-Mo obtained by mechanical alloying

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar, C., E-mail: claudio.aguilar@usm.cl [Departamento de Ingenieria Metalurgica y de Materiales, Universidad Tecnica Federico Santa Maria, Avenida Espana 1680, Valparaiso (Chile); Instituto de Materiales y Procesos Termomecanicos, Universidad Austral de Chile, General Lagos 2086, Valdivia (Chile); Castro, F. [Centro de Estudios e Investigaciones Tecnicas de Gipuzkoa, Paseo de Manuel Lardizabal, N Degree-Sign 15 20018, San Sebastian (Spain); Martinez, V. [TEKMETALL, Metallurgical Solutions S.L., Paseo neinor, Iribar Kalea 5, F1. B. de Igara 20018, San Sebastian (Spain); Guzman, D. [Departamento de Ingenieria en Metalurgia, Facultad de Ingenieria, Universidad de Atacama y Centro Regional de Investigacion y Desarrollo Sustentable de Atacama (CRIDESAT), Av. Copayapu 485, Copiapo (Chile); Cuevas, F. de las; Lozada, L.; Vielma, N. [Centro de Estudios e Investigaciones Tecnicas de Gipuzkoa, Paseo de Manuel Lardizabal, N Degree-Sign 15 20018, San Sebastian (Spain)

    2012-06-30

    Highlights: Black-Right-Pointing-Pointer Extension of solid solution in Cu-Mo system achieved by mechanical alloying. Black-Right-Pointing-Pointer X-ray characterization of Cu-Mo system processed by mechanical alloying. Black-Right-Pointing-Pointer Structural study of nanocrystalline solid solution of Cu-Mo obtained by mechanical alloying. - Abstract: This work studied the structural evolution of Cu-xMo (x = 5 and 8 wt.%) alloys processed by mechanical alloying using x-ray diffraction profiles, scanning electron microscopy, differential scanning calorimetric and microhardness. X-ray diffraction analysis was done using the modified Williamson-Hall and Warren-Averbach methods. These were used to determine structural properties, such as crystallite size, stacking fault probability and energy, dislocation density of metallic powder as a function of the amount of Mo and milling time. The main results obtained for both alloys were higher dislocation density and Vickers microhardness values were measured and crystallites sizes of around 10 nm were measured for both systems at 50 h of milling. Lattice defects increase the free energy and the free energy curves shift upwards, therefore the solubility limits change and Cu-Mo solid solution is formed.

  9. Microstructure and Corrosion Resistance of Electrodeposited Ni-Cu-Mo Alloy Coatings

    Science.gov (United States)

    Meng, Xinjing; Shi, Xi; Zhong, Qingdong; Shu, Mingyong; Xu, Guanquan

    2016-09-01

    This paper deals with the electrodeposition of Ni-Cu-Mo ternary alloy coatings on low-carbon steel substrate from an aqueous citrate sulfate bath. The structures and microstructure of coatings were characterized by scanning electron microscopy and x-ray diffractometry. The corrosion resistance of coatings was investigated by potentiodynamic polarization (Tafel) and electrochemical impedance spectroscopy techniques. The results show that the Ni-Cu-Mo coatings are mainly composed of fcc-Ni phase and a small amount of NiCu phase. Ni-Cu-Mo coatings exhibit a nodular surface morphology, and the roughness of electroplated coating increases with the increasing of Na2MoO4·2H2O in the bath. The corrosion performance of the coatings is significantly affected by the Mo content of the alloy coating and their surface morphology. The coating prepared in bath containing 40 g/L Na2MoO4·2H2O has the highest corrosion resistance in 3.5 wt.% NaCl solution, while that prepared in bath containing 60 g/L (or more) Na2MoO4·2H2O shows a lower corrosion resistance due to the presence of microcracks on the coating surface.

  10. Lattice sites of implanted Cu and Ag in ZnO

    CERN Document Server

    Wahl, Ulrich; Correia, J G; Agne, Thomas; Alves, E; Carvalho-Soares, João

    2006-01-01

    The group $\\textrm{I}$b impurities Cu and Ag on substitutional Zn sites are among possible candidates for p-type doping of ZnO. In order to explore possible lattice sites of Cu and Ag in ZnO the radioactive impurities $^{67}\\!$Cu and $^{111}\\!$Ag were implanted at doses of $4\\!\\times\\!10^{12}$cm$^{-2}\\to1\\!\\times\\!10^{14}$cm$^{-2}$ at 60 keV into ZnO single crystals. The emission channeling effects of $\\beta\\!^{-}$ -particles from the decay were studied by means of position-sensitive electron detectors, giving direct evidence that in the as-implanted state large fractions of Cu and Ag atoms (60--70% for Cu and 30% for Ag) occupy almost ideal substitutional Zn sites with root mean square (rms) displacements of 0.014--0.017 nm. However, following vacuum annealing at 600 °C and above both Cu and Ag were found to be located increasingly on sites that are characterized by large rms displacements (0.03--0.05 nm) from Zn sites. We conclude that in high-temperature treated ZnO Cu and Ag are most likely not simply re...

  11. Ag-Cu Colloid Synthesis: Bimetallic Nanoparticle Characterisation and Thermal Treatment

    Directory of Open Access Journals (Sweden)

    Jiří Sopoušek

    2014-01-01

    Full Text Available The Ag-Cu bimetallic colloidal nanoparticles (NPs were prepared by solvothermal synthesis from metalloorganic precursors in a mixture of organic solvents. The nanoparticles were characterized by dynamic light scattering (DLS and small angle X-ray scattering (SAXS. The properties of metallic core and organic shell of the nanoparticles were studied by direct inlet probe mass spectrometry (DIP/MS, Knudsen effusion mass spectrometry (KEMS, double-pulse laser-induced breakdown spectroscopy (DPLIBS, and differential scanning calorimetry (DSC. The transmission electron microscopy (TEM and scanning electron microscopy (SEM were used for particle characterization before and after thermal analysis. The experiment yielded results that were for AgCu nanoparticles for the first time. The detected liquidus temperature has been compared with the prediction obtained from calculation of the phase diagram of Ag-Cu nanoalloy. The experimental results show that of near-eutectic composition AgCu nanoparticles possess the fcc crystal lattice. Surprisingly, spinodal decomposition was not observed inside the AgCu nanoparticles at temperatures up to 230°C. The depression of the eutectic AgCu melting point was calculated but not observed. The eutectic AgCu microparticles are formed before melting.

  12. Inhibiting the growth of Cu3Sn and Kirkendall voids in the Cu/Sn-Ag-Cu system by minor Pd alloying

    Science.gov (United States)

    Ho, Cheng En; Kuo, Tsai Tung; Wang, Chun Chien; Wu, Wei Hsiang

    2012-10-01

    In this study, the metallurgical reaction between Cu substrates (electrolytic type) and a Sn3Ag0.5Cu-xPd alloy at 180°C was examined using a scanning electron microscope (SEM), electron probe microanalyzer (EPMA), focused ion beam (FIB) microscope, and transmission electron microscope (TEM). The results showed that the growth of Cu3Sn in the Cu/Sn-Ag-Cu solder joints was substantially suppressed by doping with a minor quantity of Pd (0.1-0.7 wt. %) in the solder alloy. The sluggish growth of Cu3Sn reduced the formation of Kirkendall voids at the Cu/Cu3Sn interface and significantly improved the mechanical reliability of the joint interface. It was argued that a minor addition of Pd into the solder stabilized the Cu6Sn5 phase and enlarged the interdiffusion coefficient of Cu6Sn5 but diminished that of the neighboring phase (Cu3Sn), thereby decreasing the Kirkendall effect in the Cu/Sn-Ag-Cu reactive system.

  13. Photoemission study on the formation of Mo contacts to CuInSe2

    Science.gov (United States)

    Nelson, A. J.; Niles, D. W.; Kazmerski, L. L.; Rioux, D.; Patel, R.; Hoechst, H.

    1992-08-01

    Synchrotron radiation soft-X-ray photoemission spectroscopy was used to investigate the development of the electronic structure at the Mo/CuInSe2 interface. Mo overlayers were e-beam deposited in steps on single-crystal n-type CuInSe2 at ambient temperature. Photoemission measurements were acquired after each growth in order to observe changes in the valence-band electronic structure as well as changes in the In 4d, Se 3d, and Mo 4d core lines. Photoemission measurements on the valence-band and core lines were also obtained after annealing. The results were used to correlate the interface chemistry with the electronic structure at this interface and to directly determine the maximum possible Schottky barrier height to be not greater than 0.2 eV at the Mo/CuInSe2 junction before annealing, thus showing that this contact is essentially ohmic.

  14. Characterization of Cu3P phase in Sn3.0Ag0.5Cu0.5P/Cu solder joints

    Institute of Scientific and Technical Information of China (English)

    Jian-xun Chen; Xing-ke Zhao; Xu-chen Zou; Ji-hua Huang; Hai-chun Hu; Hai-lian Luo

    2014-01-01

    This article reports the effects of phosphorus addition on the melting behavior, microstructure, and mechanical properties of Sn3.0Ag0.5Cu solder. The melting behavior of the solder alloys was determined by differential scanning calorimetry. The interfacial micro-structure and phase composition of solder/Cu joints were studied by scanning electron microscopy and energy dispersive spectrometry. Thermodynamics of Cu-P phase formation at the interface between Sn3.0Ag0.5Cu0.5P solder and the Cu substrate was characterized. The results indicate that P addition into Sn3.0Ag0.5Cu solder can change the microstructure and cause the appearance of rod-like Cu3P phase which is distributed randomly in the solder bulk. The Sn3.0Ag0.5Cu0.5P joint shows a mixture of ductile and brittle fracture after shear test-ing. Meanwhile, the solidus temperature of Sn3.0Ag0.5Cu solder is slightly enhanced with P addition.

  15. Creep Behavior of Lead-Free Sn-Ag-Cu + Ni-Ge Solder Alloys

    Science.gov (United States)

    Hidaka, N.; Watanabe, H.; Yoshiba, M.

    2009-05-01

    We developed a new lead-free solder alloy, an Sn-Ag-Cu base to which a small amount of Ni and Ge is added, to improve the mechanical properties of solder alloys. We examined creep deformation in bulk and through-hole (TH) form for two lead-free solder alloys, Sn-3.5Ag-0.5Cu-Ni-Ge and Sn-3.0Ag-0.5Cu, at elevated temperatures, finding that the creep rupture life of the Sn-3.5Ag-0.5Cu-Ni-Ge solder alloy was over three times better than that of the Sn-3.0Ag-0.5Cu solder at 398 K. Adding Ni to the solder appears to make microstructural development finer and more uniform. The Ni added to the solder readily combined with Cu to form stable intermetallic compounds of (Cu, Ni)6Sn5 capable of improving the creep behavior of solder alloys. Moreover, microstructural characterization based on transmission electron microscopy analyses observing creep behavior in detail showed that such particles in the Sn-3.5Ag-0.5Cu-Ni-Ge solder alloy prevent dislocation and movement.

  16. Microstructure and phase stress partition of Mo fiber reinforced CuZnAl composite

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Feng [State Key Laboratory of Heavy Oil Processing, China University of Petroleum-Beijing, Beijing 102249 (China); Department of Materials Science and Engineering, China University of Petroleum-Beijing, Beijing 102249 (China); Ni, Dingrui [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China); Hao, Shijie [State Key Laboratory of Heavy Oil Processing, China University of Petroleum-Beijing, Beijing 102249 (China); Department of Materials Science and Engineering, China University of Petroleum-Beijing, Beijing 102249 (China); Li, Sirui [Department of Materials Science and Engineering, China University of Petroleum-Beijing, Beijing 102249 (China); Ma, Zongyi [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China); Liu, Yinong [School of Mechanical and Chemical Engineering, The University of Western Australia, Crawley, WA 6009 (Australia); Feng, Chun [Department of Materials Physics and Chemistry, University of Science and Technology Beijing, Beijing 100083 (China); Cui, Lishan, E-mail: andor_20@sina.com [State Key Laboratory of Heavy Oil Processing, China University of Petroleum-Beijing, Beijing 102249 (China); Department of Materials Science and Engineering, China University of Petroleum-Beijing, Beijing 102249 (China)

    2015-03-25

    A Mo fiber reinforced CuZnAl composite was prepared by means of friction stir processing and wire drawing. Reinforcing effect of the Mo fiber and phase stress partition in the composite were investigated by means of in-situ synchrotron X-ray diffraction. The maximum elastic strain of the Mo fiber achieved was 1.8%, implying a component stress of 550 MPa on the fibers. The Mo fibers, with a volume fraction of 10%, carried 80% of stress fraction during tensile deformation. The change of modulus caused by stress-induced martensitic transformation strain resulted in redistribution of the phase stress partition between Mo fibers and CuZnAl matrix.

  17. Fabrication of W-Cu/Mo-Cu functionally graded materials by explosive consolidation

    Science.gov (United States)

    Chen, Pengwan; Jiang, Zhiming; Shen, Weiping; Yang, Jun; Huang, Fenglei

    2007-06-01

    Attempts are made to use explosive consolidation to fabricate high quality W-Cu/Mo-Cu FGMs. Tungsten powder with 99%purity and a particle size of 3˜25μm and molybdenum/copper powder with >=99% purity and a particle size of 74μm are used as starting powder. A novel technique, called bidirectional underwater shockwave explosive consolidation, is developed. Two water chambers are placed in both sides of the sample. Detonation-generated shock waves are attenuated by the water chambers before acting on the samples. Through adjusting the height of the water columns, the applied pressure can be adjusted. A self-propagating reaction system is used to provide temperature compensation and to enhance consolidation quality. Flash X-ray photography is used to observe the process of explosive consolidation. Various techniques are used to characterize the recovered samples including optical microscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), energy spectrum analysis, hardness measurement and density measurement. The explosive consolidation methods developed in the paper can be used to other hard-to-consolidate powder materials.

  18. In situ quantitative study of microstructural evolution at the interface of Sn3.0Ag0.5Cu/Cu solder joint during solid state aging

    Energy Technology Data Exchange (ETDEWEB)

    Li, Hailong [State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); An, Rong, E-mail: anr@hit.edu.cn [Key Laboratory of Micro-systems and Micro-structures Manufacturing, Harbin Institute of Technology, Ministry of Education, Harbin 150080 (China); Wang, Chunqing; Jiang, Zhi [State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China)

    2015-06-15

    Highlights: • Cu dissolution during reflowing was mainly occurred under the gaps between scallops. • Though IMC growth was diffusion-controlled, consumption of Cu substrate was not. • Growth of Cu{sub 3}Sn layer in Sn3.0Ag0.5Cu/Cu solder joint was on the both sides. • Ag and Cu lead to a thinner Cu{sub 3}Sn layer due to inhibit the diffusion of Sn into Cu. - Abstract: In situ microstructural evolution at the interface of Sn3.0Ag0.5Cu/Cu solder joint during solid state aging was quantitatively studied by nanoindentation. The morphology of Cu{sub 6}Sn{sub 5} gradually altered from scallop type to layer type. Though the growth of IMCs was diffusion-controlled, the consumption of Cu substrate was not linear with the square root of aging time. At the initial stage of solid state aging, the Cu atoms essential to the growth of IMCs were mainly from the supersaturated solder matrix. When the Cu atoms from supersaturated solder matrix were exhausted, the Cu atoms for the growth of IMCs were primarily from the Cu substrate. In addition, the IMCs formed at this state were principally used to fill up the gaps between scallops. After the gaps disappeared, the consumption of Cu substrate slowed down. Furthermore, the growth of Cu{sub 3}Sn layer in Sn3.0Ag0.5Cu/Cu solder joint was on the both sides with layer type. Since the Sn atoms were inhibited to diffuse into the Cu substrate by the alloying elements of Ag and Cu, the thickness of Cu{sub 3}Sn layer in SnAgCu/Cu solder joint was much thinner than that in pure Sn/Cu solder joint.

  19. (Ag,Cu)-Ta-O ternaries as high-temperature solid-lubricant coatings.

    Science.gov (United States)

    Gao, Hongyu; Otero-de-la-Roza, Alberto; Gu, Jingjing; Stone, D'Arcy; Aouadi, Samir M; Johnson, Erin R; Martini, Ashlie

    2015-07-22

    Ternary oxides have gained increasing attention due to their potential use as solid lubricants at elevated temperatures. In this work, the tribological properties of three ternary oxides-AgTaO3, CuTaO3, and CuTa2O6-were studied using a combination of density-functional theory (DFT), molecular dynamics (MD) simulations with newly developed empirical potential parameters, and experimental measurements (AgTaO3 and CuTa2O6 only). Our results show that the MD-predicted friction force follows the trend AgTaO3 behavior of these materials.

  20. Research on Solidification Behavior of Ag-Cu-Zn Alloys%Ag-Cu-Zn合金凝固行为的研究

    Institute of Scientific and Technical Information of China (English)

    陈永泰; 谢明; 杨有才; 张吉明; 刘满门; 王松; 王塞北; 胡洁琼; 李爱坤

    2015-01-01

    Ag-6Cu-xZn(x=0,1,2)合金铸态显微组织、物相及凝固行为进行了研究,结果表明,Zn对Ag-Cu合金的二次枝晶间距有细化作用;Ag-6Cu-xZn合金主要由α相(富Ag固溶体相)和少量的β相(富Cu和Zn固溶体相)组成,β相弥散分布于二次枝晶间;Zn的添加降低了合金及第二相的熔化温度,且 Zn 含量越高,合金熔化温度降低趋势越大,其凝固特征是一个典型的固溶体合金的非平衡凝固过程。%The as-cast microstructure, chemical phase and solidification behavior of Ag-6Cu-xZn (x=0, 1, 2) alloys were investigated. The results indicate that, the Zn in Ag-Cu alloy could refine the secondary dendrite arm spacing, but its refining effect is limited. The Ag-Cu-Zn alloy is mainly composed ofα phase (silver-rich phase) and littleβ phase ((copper, zinc)-rich phase).βphases are dispersively distributed in secondary dendrite, they will help to improve the abrasion resistance properties of materials. Adding Zn can reduce the melting temperature of the alloy and the second phase, the higher content of Zn, the greater tendency to reduce the melting temperature of the alloy, the solidification feature of Ag-Cu-Zn alloy is a typical of non-equilibrium solidification of Solid Solution.

  1. One-pot preparation of nanoporous Ag-Cu@Ag core-shell alloy with enhanced oxidative stability and robust antibacterial activity.

    Science.gov (United States)

    Liu, Xue; Du, Jing; Shao, Yang; Zhao, Shao-Fan; Yao, Ke-Fu

    2017-08-31

    Metallic core-shell nanostructures have inspired prominent research interests due to their better performances in catalytic, optical, electric, and magnetic applications as well as the less cost of noble metal than monometallic nanostructures, but limited by the complicated and expensive synthesis approaches. Development of one-pot and inexpensive method for metallic core-shell nanostructures' synthesis is therefore of great significance. A novel Cu network supported nanoporous Ag-Cu alloy with an Ag shell and an Ag-Cu core was successfully synthesized by one-pot chemical dealloying of Zr-Cu-Ag-Al-O amorphous/crystalline composite, which provides a new way to prepare metallic core-shell nanostructures by a simple method. The prepared nanoporous Ag-Cu@Ag core-shell alloy demonstrates excellent air-stability at room temperature and enhanced oxidative stability even compared with other reported Cu@Ag core-shell micro-particles. In addition, the nanoporous Ag-Cu@Ag core-shell alloy also possesses robust antibacterial activity against E. Coli DH5α. The simple and low-cost synthesis method as well as the excellent oxidative stability promises the nanoporous Ag-Cu@Ag core-shell alloy potentially wide applications.

  2. Effects of Excess Cu Addition on Photochromic Properties of AgCl-Urethane Resin Composite Films

    Directory of Open Access Journals (Sweden)

    Hidetoshi Miyazaki

    2013-01-01

    Full Text Available AgCl-resin photochromic composite films were prepared using AgNO3, HCl-EtOH, CuCl2 ethanol solutions, and a urethane resin as starting materials. The AgCl particle size in the composite films, which was confirmed via TEM observations, was 23–43 nm. The AgCl composite films showed photochromic properties: coloring induced by UV-vis irradiation and bleaching induced by cessation of UV-vis irradiation. The coloring and bleaching speed of the composite film increases with increasing CuCl2 mixing ratio.

  3. Isothermal decomposition kinetics in the Cu-9%Al-4%Ag alloy

    Energy Technology Data Exchange (ETDEWEB)

    Adorno, A.T.; Silva, R.A.G

    2004-07-28

    The influence of 4 wt.%Ag addition on the isothermal decomposition kinetics of the {beta}' phase in the Cu-9 wt.%Al alloy was studied by microhardness measurements, optical and scanning electron microscopy (SEM), energy dispersive X-ray (EDX) analysis, and X-ray diffractometry. The results showed that the presence of Ag decreases the {beta}'{yields}({alpha}+{gamma}{sub 1}) decomposition reaction rate in the Cu-9%Al-4%Ag alloy, an effect that may be associated to the {gamma}{sub 1} phase which catalyses the Ag precipitation, making it faster than the decomposition reaction, and thus, stabilizing the martensitic phase.

  4. Genesis of the Au-Bi-Cu-As, Cu-Mo ± W, and base-metal Au-Ag mineralization at the Mountain Freegold (Yukon, Canada): constraints from Ar-Ar and Re-Os geochronology and Pb and stable isotope compositions

    Science.gov (United States)

    Bineli Betsi, Thierry; Lentz, David; Chiaradia, Massimo; Kyser, Kurt; Creaser, Robert A.

    2013-12-01

    The genesis of mineralized systems across the Mountain Freegold area, in the Dawson Range Cu-Au ± Mo Belt of the Tintina Au province was constrained using Pb and stable isotope compositions and Ar-Ar and Re-Os geochronology. Pb isotope compositions of sulfides span a wide compositional range (206Pb/204Pb, 18.669-19.861; 208Pb/204Pb, 38.400-39.238) that overlaps the compositions of the spatially associated igneous rocks, thus indicating a magmatic origin for Pb and probably the other metals. Sulfur isotopic compositions of sulfide minerals are broadly similar and their δ34S (Vienna-Canyon Diablo Troilite (V-CDT)) values range from -1.4 to 3.6 ‰ consistent with the magmatic range, with the exception of stibnite from a Au-Sb-quartz vein, which has δ34S values between -8.1 and -3.1 ‰. The δ34S values of sulfates coexisting with sulfide are between 11.2 and 14.2 ‰; whereas, those from the weathering zone range from 3.7 to 4.3 ‰, indicating supergene sulfates derived from oxidation of hypogene sulfides. The δ13C (Vienna Peedee Belemnite (VPDB)) values of carbonate range from -4.9 to 1.1 ‰ and are higher than magmatic values. The δ18O (V-SMOW) values of magmatic quartz phenocrysts and magmatic least-altered rocks vary between 6.2 and 10.1 ‰ and between 5.0 and 10.1 ‰, respectively, whereas altered magmatic rocks and hydrothermal minerals (quartz and magnetite) are relatively 18O-depleted (4.2 to 7.9 ‰ and -6.3 to 1.5 ‰, respectively). Hydrogen isotope compositions of both least-altered and altered igneous rock samples are D-depleted (from -133 to -161 ‰ Vienna-Standard Mean Ocean Water (V-SMOW)), consistent with differential magma degassing and/or post-crystallization exchange between the rocks and meteoric ground water. Zircon from a chlorite-altered dike has a U-Pb crystallization age of 108.7 ± 0.4 Ma; whereas, the same sample yielded a whole-rock Ar-Ar plateau age of 76.25 ± 0.53 Ma. Likewise, molybdenite Re-Os model ages range from 75.8 to

  5. Increasing wear resistance of copper friction pair with electrically-conductive tribological Cu-Mo-S coatings

    Science.gov (United States)

    Zharkov, S. Yu.; Sergeev, V. P.; Fedorischeva, M. V.; Sergeev, O. V.; Kalashnikov, M. P.

    2016-11-01

    The composite solid lubricant Cu-Mo-S coating was produced by pulse magnetron sputtering system. The electrical resistivity of deposited Cu-Mo-S coatings was (22.8±3) × 10-8 Ohm×m. Cu-Mo-S coatings decrease the wear rate of the copper friction pair by 38 times. The decrease in the wear rate occurs owing to the formation of a transferred film on the counterface.

  6. Synthesis and characterization of LnAg(WO{sub 4})(MoO{sub 4})

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez-Martinez, F. [Universidad Politecnica de Madrid, E.U.I.T. Industrial, Ronda de Valencia 3, 28012 Madrid (Spain)], E-mail: francisco.fernandezm@upm.es; Colon, C.; Montero, J.L.; Atanes, E. [Universidad Politecnica de Madrid, E.U.I.T. Industrial, Ronda de Valencia 3, 28012 Madrid (Spain); Rivero, C. [Universidad Politecnica de Madrid, E.T.S.I. Telecomunicaciones, Avda. Complutense s/n, Ciudad Universitaria, 28040 Madrid (Spain)

    2008-02-28

    Polycrystalline LnAg(WO{sub 4})(MoO{sub 4}) powders, with Ln = La to Lu and Y, have been obtained by ceramic method. Rietveld refinement for all compounds reveals that they present tetragonal symmetry, space group I4{sub 1}/a (No. 88), where the Ln{sup 3+}/Ag{sup +} ions are located in the 4a atomic positions, since the W/Mo are randomly distributed into 4b crystal sites. In these compounds, a and b lattice parameters take values between those corresponding to tungstate and molybdate compounds. A progressive decrease in the lattice parameters is observed in going from La to Lu derivatives as a consequence of the well-known lanthanide contraction.

  7. Ethylene glycol-based Ag plating for the wet chemical fabrication of one micrometer Cu/Ag core/shell particles

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Eun Byul; Lee, Jong-Hyun, E-mail: pljh@snut.ac.kr

    2015-09-15

    Highlights: • Cu@Ag particles less than one micrometer were fabricated through Ag polyol-plating. • Ag polyol-plating was tried without using additional reagents on Cu core particles. • Continuity, uniformity, and thickness of the Ag shell depended on plating conditions. • The sample showed an excellent oxidation initiation temperature of 280 °C. • Anti-oxidation properties of Cu@Ag powders strongly depend on the Ag shell thickness. - Abstract: With the aim of preparing an inexpensive metal filler that can be added to conductive adhesives used in fine-pitch electronic applications, a polyol solution was used to fabricate Ag-coated Cu (Cu@Ag) particles with a size on the order of one micron without the need for additional reagents. The continuity, uniformity, and thickness of the Ag shell were found to be strongly dependent on the plating conditions, particularly the reaction temperature. The Ag shell prepared at a peak temperature of 180 °C from a precursor with an initial Ag concentration of 15 wt.% was judged to be an optimum one. This same sample also showed an excellent oxidation initiation temperature of approximately 280 °C. It was inferred that the oxidation resistance of the Cu@Ag powder is largely determined by the continuity, uniformity and thickness of the Ag shell.

  8. Transparent Conducting Film Fabricated by Metal Mesh Method with Ag and Cu@Ag Mixture Nanoparticle Pastes

    Directory of Open Access Journals (Sweden)

    Hyun Min Nam

    2017-05-01

    Full Text Available Transparent conducting electrode film is highly desirable for application in touch screen panels (TSPs, flexible and wearable displays, sensors, and actuators. A sputtered film of indium tin oxide (ITO shows high transmittance (90% at low sheet resistance (50 Ω/cm2. However, ITO films lack mechanical flexibility, especially under bending stress, and have limitation in application to large-area TSPs (over 15 inches due to the trade-off in high transmittance and low sheet resistance properties. One promising solution is to use metal mesh-type transparent conducting film, especially for touch panel application. In this work, we investigated such inter-related issues as UV imprinting process to make a trench layer pattern, the synthesis of core-shell-type Ag and Cu@Ag composite nanoparticles and their paste formulation, the filling of Ag and Cu@Ag mixture nanoparticle paste to the trench layer, and touch panel fabrication processes.

  9. Effect of Ag Addition on the Electrochemical Performance of Cu10Al in Artificial Saliva

    Directory of Open Access Journals (Sweden)

    R. J. Salgado-Salgado

    2016-01-01

    Full Text Available In this work we proposed to evaluate the corrosion resistance of four different alloys by electrochemical techniques, a binary alloy Cu10Al, and three ternary alloys Cu10Al-xAg (x = 5, 10, and 15 wt.% to be used like biomaterials in dental application. Biomaterials proposed were tested in artificial saliva at 37°C for 48 h. In addition, pure metals Cu, Al, Ag, and Ti as reference materials were evaluated. In general the short time tests indicated that the Ag addition increases the corrosion resistance and reduces the extent of localized attack of the binary alloy. Moreover, tests for 48 hours showed that the Ag addition increases the stability of the passive layer, thereby reducing the corrosion rate of the binary alloy. SEM analysis showed that Cu10Al alloy was preferably corroded by grain boundaries, and the Ag addition modified the form of attack of the binary alloy. Cu-rich phases reacted with SCN− anions forming a film of CuSCN, and the Ag-rich phase is prone to react with SCN− anions forming AgSCN. Thus, binary and ternary alloys are susceptible to tarnish in the presence of thiocyanate ions.

  10. Effect of Ag Addition on the Electrochemical Performance of Cu10Al in Artificial Saliva

    Science.gov (United States)

    Salgado-Salgado, R. J.; Sotelo-Mazon, O.; Rodriguez-Diaz, R. A.; Salinas-Solano, G.

    2016-01-01

    In this work we proposed to evaluate the corrosion resistance of four different alloys by electrochemical techniques, a binary alloy Cu10Al, and three ternary alloys Cu10Al-xAg (x = 5, 10, and 15 wt.%) to be used like biomaterials in dental application. Biomaterials proposed were tested in artificial saliva at 37°C for 48 h. In addition, pure metals Cu, Al, Ag, and Ti as reference materials were evaluated. In general the short time tests indicated that the Ag addition increases the corrosion resistance and reduces the extent of localized attack of the binary alloy. Moreover, tests for 48 hours showed that the Ag addition increases the stability of the passive layer, thereby reducing the corrosion rate of the binary alloy. SEM analysis showed that Cu10Al alloy was preferably corroded by grain boundaries, and the Ag addition modified the form of attack of the binary alloy. Cu-rich phases reacted with SCN− anions forming a film of CuSCN, and the Ag-rich phase is prone to react with SCN− anions forming AgSCN. Thus, binary and ternary alloys are susceptible to tarnish in the presence of thiocyanate ions. PMID:27660601

  11. Phase-dependent corrosion of titanium-to-stainless steel joints brazed by Ag-Cu eutectic alloy filler and Ag interlayer

    Science.gov (United States)

    Lee, M. K.; Park, J. J.; Lee, J. G.; Rhee, C. K.

    2013-08-01

    The electrochemical corrosion properties of Ti-STS dissimilar joints brazed by a 72Ag-28Cu alloy filler and an Ag interlayer were studied in a 3.5% NaCl solution using potentiodynamic polarization and ac impedance spectroscopy. For a joint with a layered structure of Ti(base)/TiAg/Ag solid solution/Ag-Cu eutectic/STS(base), galvanic corrosion mostly occurred in the TiAg phase with a severe material loss, indicating that the TiAg layer acted as an anode in the galvanic couple in the layered joint. The Ag-rich solid solution layer was also corroded to a certain extent, but the corrosion in this layer was dominated by the selective pitting corrosion of the eutectic Cu-rich phase. With an increase in the brazing temperature, the Cu-rich phases disappeared owing to the enhanced isothermal solidification effect, leading to an improvement of the corrosion resistance.

  12. Resistive switching effect of Ag/MoS2/FTO device

    Science.gov (United States)

    Sun, Bai; Zhao, Wenxi; Liu, Yonghong; Chen, Peng

    2015-09-01

    The electric-pulse-driven resistance change of metal/oxides/metal structure, which is called resistive switching effect, is a fascinating phenomenon for the development of next generation non-volatile memory. In this work, an outstanding bipolar resistive switching behavior of Ag/MoS2/fluorine-doped tin oxide (FTO) device is demonstrated. The device can maintain superior reversible stability over 100 cycles with an OFF/ON-state resistance ratio of about 103 at room temperature.

  13. Stability of molybdenum nanoparticles in Sn-3.8Ag-0.7Cu solder during multiple reflow and their influence on interfacial intermetallic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Haseeb, A.S.M.A., E-mail: haseeb@um.edu.my; Arafat, M.M., E-mail: arafat_mahmood@yahoo.com; Johan, Mohd Rafie, E-mail: mrafiej@um.edu.my

    2012-02-15

    This work investigates the effects of molybdenum nanoparticles on the growth of interfacial intermetallic compound between Sn-3.8Ag-0.7Cu solder and copper substrate during multiple reflow. Molybdenum nanoparticles were mixed with Sn-3.8Ag-0.7Cu solder paste by manual mixing. Solder samples were reflowed on a copper substrate in a 250 Degree-Sign C reflow oven up to six times. The molybdenum content of the bulk solder was determined by inductive coupled plasma-optical emission spectrometry. It is found that upon the addition of molybdenum nanoparticles to Sn-3.8Ag-0.7Cu solder, the interfacial intermetallic compound thickness and scallop diameter decreases under all reflow conditions. Molybdenum nanoparticles do not appear to dissolve or react with the solder. They tend to adsorb preferentially at the interface between solder and the intermetallic compound scallops. It is suggested that molybdenum nanoparticles impart their influence on the interfacial intermetallic compound as discrete particles. The intact, discrete nanoparticles, by absorbing preferentially at the interface, hinder the diffusion flux of the substrate and thereby suppress the intermetallic compound growth. - Highlights: Black-Right-Pointing-Pointer Mo nanoparticles do not dissolve or react with the SAC solder during reflow. Black-Right-Pointing-Pointer Addition of Mo nanoparticles results smaller IMC thickness and scallop diameter. Black-Right-Pointing-Pointer Mo nanoparticles influence the interfacial IMC through discrete particle effect.

  14. Cu-Ag core-shell nanoparticles with enhanced oxidation stability for printed electronics.

    Science.gov (United States)

    Lee, Changsoo; Kim, Na Rae; Koo, Jahyun; Lee, Yung Jong; Lee, Hyuck Mo

    2015-11-13

    In this work, we synthesized uniform Cu-Ag core-shell nanoparticles using a facile two-step process that consists of thermal decomposition and galvanic displacement methods. The core-shell structure of these nanoparticles was confirmed through characterization using transmission electron microscopy, energy-dispersive spectroscopy, and x-ray diffraction. Furthermore, we investigated the oxidation stability of the Cu-Ag core-shell nanoparticles in detail. Both qualitative and quantitative x-ray photoelectron spectroscopy analyses confirm that the Cu-Ag core-shell nanoparticles have considerably higher oxidation stability than Cu nanoparticles. Finally, we formulated a conductive ink using the synthesized nanoparticles and coated it onto glass substrates. Following the sintering process, we compared the resistivity of the Cu-Ag core-shell nanoparticles with that of the Cu nanoparticles. The results of this study clearly show that the Cu-Ag core-shell nanoparticles can potentially be used as an alternative to Ag nanoparticles because of their superior oxidation stability and electrical properties.

  15. Characteristics Of Sn-Zn Cast Alloys With The Addition Of Ag And Cu

    Directory of Open Access Journals (Sweden)

    Gancarz T.

    2015-09-01

    Full Text Available The aim of this work was to study the effects of Ag and Cu on the thermal properties and microstructure of Sn-Zn-Ag-Cu cast alloys. Solders based on eutectic Sn-Zn containing 0.5 to 1.0 at.% of Ag and Cu were developed for wave soldering. DSC measurements were performed to determine the melting temperatures of the alloys. TMA and electrical resistivity measurements were performed between −50 and 150°C and between 30 and 150°C, respectively. Small precipitates of Cu5Zn8, CuZn4, and AgZn3 were observed in the microstructures, and their presence was confirmed by XRD measurements. The inclusion of Ag and Cu improved the electrical resistivity and increased the melting temperature, as well as the CTE, of the alloys. However, tests performed to measure the mechanical properties of the alloys demonstratedthat the addition of Ag and Cu caused the mechanical properties to decrease.

  16. Cu-Ag core-shell nanoparticles with enhanced oxidation stability for printed electronics

    Science.gov (United States)

    Lee, Changsoo; Kim, Na Rae; Koo, Jahyun; Jong Lee, Yung; Lee, Hyuck Mo

    2015-11-01

    In this work, we synthesized uniform Cu-Ag core-shell nanoparticles using a facile two-step process that consists of thermal decomposition and galvanic displacement methods. The core-shell structure of these nanoparticles was confirmed through characterization using transmission electron microscopy, energy-dispersive spectroscopy, and x-ray diffraction. Furthermore, we investigated the oxidation stability of the Cu-Ag core-shell nanoparticles in detail. Both qualitative and quantitative x-ray photoelectron spectroscopy analyses confirm that the Cu-Ag core-shell nanoparticles have considerably higher oxidation stability than Cu nanoparticles. Finally, we formulated a conductive ink using the synthesized nanoparticles and coated it onto glass substrates. Following the sintering process, we compared the resistivity of the Cu-Ag core-shell nanoparticles with that of the Cu nanoparticles. The results of this study clearly show that the Cu-Ag core-shell nanoparticles can potentially be used as an alternative to Ag nanoparticles because of their superior oxidation stability and electrical properties.

  17. Mechanochemical Synthesis of Mo-Cu Nanocomposites Powders at Low Temperature%低温机械化学法制备Mo-Cu纳米复合粉末

    Institute of Scientific and Technical Information of China (English)

    孙翱魁; 王德志; 李翼

    2012-01-01

    Low temperature synthesis of Mo-Cu composite powders was conducted by mechanochemical treatment (hall-milling) of CuMoO4 and MoO3 mixtures followed by subsequent coreduction process. The preparation temperature of the precursors (CuMoO4-MoO3 mixtures), phases and microstructures of the Mo-Cu composites were investigated by differential scanning calorimeter (DSC), X-ray diffractometer (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM), respectively. The thermodynamical conditions at different stages of hydrogen reduction of Mo-Cu nanocotnposite powders were analyzed. Results show that the mechanochemical treatment (ball-milling) can significantly enhance the reduction activity by rbducing the particle sizes of powders and hence increasing the reaction surface area, therefore giving rise to the synthesis of Mo-Cu composite powders at relatively low temperature (680 ℃). By optimizing the experimental parameters, Mo-25 wt% Cu nanocomposite powders with superfine particles ranging from 50 to 100 nmcanbe obtained by ball-milling for 15 h followed by reduction in hydrogen at 680 ℃.%以CuMoO4-MoO3粉末为前驱体,采用机械化学-氢气共还原的方法制备出Mo-Cu纳米复合粉末.通过DSC对前躯体的制备温度进行研究,通过XRD、SEM及TEM分别对粉末的相组成、形貌和粒度进行表征,从热力学的角度对粉末的还原过程进行分析.结果表明,机械球磨可以有效地降低粉末的颗粒尺寸,增大反应面积,提高粉末还原活性,从而在低温下制备出Mo-Cu复合粉末.通过优化工艺参数,对机械球磨15h的CuMoO4-MoO3混合粉末在680℃下还原,可以得到颗粒尺寸为50~100 nm的Mo-25%Cu (质量分数)纳米复合粉末.

  18. Active control of surface plasmon resonance in MoS2-Ag hybrid nanostructures

    CERN Document Server

    Zu, Shuai; Gong, Yongji; Ajayan, Pulickel M; Fang, Zheyu

    2016-01-01

    Molybdenum disulfide (MoS2) monolayers have attracted much attention for their novel optical properties and efficient light-matter interactions. When excited by incident laser, the optical response of MoS2 monolayers was effectively modified by elementary photo-excited excitons owing to their large exciton binding energy, which can be facilitated for the optical-controllable exciton-plasmon interactions. Inspired by this concept, we experimentally investigated active light control of surface plasmon resonance (SPR) in MoS2-Ag hybrid nanostructures. The white light spectra of SPR were gradually red-shifted by increasing laser power, which was distinctly different from the one of bare Ag nanostructure. This spectroscopic tunability can be further controlled by near-field coupling strength and polarization state of light, and selectively applied to the control of plasmonic dark mode. An analytical Lorentz model for photo-excited excitons induced modulation of MoS2 dielectric function was developed to explain the...

  19. Effect of Cu Addition on the Microstructure of Ag-Ce Alloys%Cu对Ag-Ce合金组织与结构之影响

    Institute of Scientific and Technical Information of China (English)

    俞建树; 贺晓燕; 周世平; 卢绍平; 安盈志; 王佳丽; 王健

    2013-01-01

    The effects of Cu addition on the microstructure of Ag-Ce alloy were studied by SEM and EDS. The results showed that the main body of Ag-Cu-Ce alloys is silver-copper solid solution with smaller crystal grains, in which many symbiotically separated β-Cu and Ag4Ce particles were distributed diffusively. Cu addition segregation. Tensile fracture of Ag-Ce and Ag-Cu-Ce alloys was shown cone and left distinct tough pit, which is typical tough break.%利用扫描电子显微镜和能谱仪分析Cu对Ag-Ce合金组织与结构的影响。结果表明:Ag-Cu-Ce合金基体为银铜固溶体,晶粒较小,基体上弥散分布着恀多共生析出的β-Cu和Ag4Ce颗粒,Cu的加入改善了Ag4Ce的偏析现象。Ag-Ce和Ag-Cu-Ce合金的拉伸断口呈锥形,有明显的韧窝组织,为典型的韧性断裂。

  20. New bulk glassy alloys in Cu-Zr-Ag ternary system prepared by casting and milling

    Science.gov (United States)

    Janovszky, D.; Tomolya, K.; Sveda, M.; Solyom, J.; Roosz, A.

    2009-01-01

    The thermal stability, crystallization behaviour and glass forming ability of Cu-Zr-Ag system have been investigated on the basis of a ternary phase diagram. We altered the concentration of the alloys from the Cu58Zr42 to the concentration of the deep eutectic point of the Cu-Zr-Ag ternary system and we calculated the glass forming ability parameters. This paper summerises the results of the procedure during which Cu-Zr-Ag amorphous alloys with different Ag content (0-25%) were prepared by casting and ball-milling. Wedge-shaped samples were prepared from the ingots by centrifugal casting into copper mold. The supercooled liquid region (ΔTx) exceeded 75K. Following the characterization of the cast alloys, master alloys of identical composition were milled in a Fritsch Pulverisette 2 ball-mill. The powders, milled for various periods of time were analysed by XRD in order to define the amorphous fraction.

  1. Microstructure and properties of heavily deformed Cu-Ag-Ce in situ nano-filamentary composite

    Institute of Scientific and Technical Information of China (English)

    ZHANG; Xiao-hui; YAN; Lin; NING; Yuan-tao

    2005-01-01

    The microstructure and properties of heavily deformed Cu-Ag-Ce in situ nano-filamentary composite were studied in this paper. As cast, copper matrixes were dendritic and Ag-rich phases, some of which present spheroidizing tendency, were embedded in Cu dentritic arms. After heavily deforming, Agrich phases develop into fibers: the thick fibers with a size of more than 50 nm and the thin ones with a size of less than 30 nm. Strengthening of Cu-Ag-Ce in situ nano-filamentary composite could be divided into two stages and the combination of different strength and conductivity could be obtained through controlling reducing area, intermediate heat treatment and stabilizing treatment. The results revealed that heavily deformed Cu-Ag-Ce in situ nano-filamentary composite had high strength ( > 1.5GPa) and high conductivity(>65 %IACS).

  2. Prediction of Phase Formation in Nanoscale Sn-Ag-Cu Solder Alloy

    Science.gov (United States)

    Wu, Min; Lv, Bailin

    2016-01-01

    In a dynamic nonequilibrium process, the effective heat of formation allows the heat of formation to be calculated as a function of concentrations of the reacting atoms. In this work, we used the effective heat of formation rule to predict the formation and size of compound phases in a nanoscale Sn-Ag-Cu lead-free solder. We calculated the formation enthalpy and effective formation enthalpy of compounds in the Sn-Ag, Sn-Cu, and Ag-Cu systems by using the Miedema model and effective heat of formation. Our results show that, considering the surface effect of the nanoparticle, the effective heat of formation rule successfully predicts the phase formation and sizes of Ag3Sn and Cu6Sn5 compounds, which agrees well with experimental data.

  3. The compression stress-strain behavior of Sn-Ag-Cu solder

    Science.gov (United States)

    Vianco, Paul T.; Rejent, Jerome A.; Martin, Joseph J.

    2003-06-01

    The yield-stress behavior was investigated for the 95.5Sn-4.3Ag-0.2Cu (wt.%), 95.5Sn-3.9Ag-0.6Cu, and 95.5Sn-3.8Ag-0.7Cu ternary lead-free solders using the compression stress-strain test technique. Cylindrical specimens were evaluated in the as-cast or aged (125°C, 24 h) condition. The tests were performed at -25°C, 25°C, 75°C, 125°C, and 160°C using strain rates of 4.2×10-5s-1 or 8.3×10-4s-1. Specially designed Sn-Ag-0.6Cu samples were fabricated to compare the yield stress of the dendritic microstructure versus that of the equiaxed microstructure that occurs in this alloy.

  4. Correlation Between Sn Grain Orientation and Corrosion in Sn-Ag-Cu Solder Interconnects

    Science.gov (United States)

    Lee, Tae-Kyu; Liu, Bo; Zhou, Bite; Bieler, Thomas; Liu, Kuo-Chuan

    2011-09-01

    The impact of a marine environment on Sn-Ag-Cu interconnect reliability is examined using salt spray exposure followed by thermal cycling. Sn-Ag-Cu solder alloy wafer-level packages, with and without pretreatment with 5% NaCl salt spray, were thermally cycled to failure. The prior salt spray reduced the characteristic lifetime of the Sn-Ag-Cu solder joints by over 43%. Although Sn-based materials show strong resistance to corrosion, the nature of localized corroded areas at critical locations in the solder joint caused significant degradation in the Sn-Ag-Cu solder joints. An important link between the corrosion path and Sn grain orientation was observed using orientation imaging microscopy (OIM). A strong correlation between the corrosion path and grain orientation was identified, indicating that the corrosion attack preferentially followed the basal plane of the Sn lattice.

  5. On the ternary AgCu – Ga system: Electromotive force measurement and thermodynamic modeling

    Energy Technology Data Exchange (ETDEWEB)

    Gierlotka, Wojciech, E-mail: wojtek@mail.ndhu.edu.tw [Materials Science and Engineering Department, National Dong Hwa University, Hualien, Taiwan (China); Jendrzejczyk-Handzlik, Dominika; Fitzner, Krzysztof; Handzlik, Piotr [Non-Ferrous Metals Department, AGH University of Science and Technology, Krakow (Poland)

    2015-10-15

    The ternary silver–copper–gallium system found application as a solder material in jewel crafting and electronics, thus a phase diagram of this system seems to be important tool, which is necessary for a proper application of different alloys. The activity of gallium in liquid phase was determined by electromotive measurement technique and after that the equilibrium diagram of AgCu – Ga was modeled based on available experimental data using Calphad approach. A set of Gibbs energies was found and used for calculation a phase diagram and thermodynamic properties of liquid phase. The experimental data was reproduced well by calculation. - Highlights: • For the first time activity of Ga in liquid AgCu – Ga alloys was measured. • For the first time the ternary AgCu – Ga system was thermodynamically modeled. • Modeled AgCu – Ga system reproduces experimental data well.

  6. Effects of MoS2 Concentration on Performance of Cu-MoS2 Composite Coating%MoS2含量对Cu-MoS2复合镀层性能的影响

    Institute of Scientific and Technical Information of China (English)

    李斌; 孙万昌; 侯嵬玮; 张磊

    2015-01-01

    采用复合电沉积技术在Q235钢基体表面制备了Cu-MoS2复合镀层,对镀层的截面形貌和组织结构进行了观察,并考察了镀液中MoS2颗粒含量对复合镀层耐磨减摩性能和耐蚀性的影响.结果表明,MoS2颗粒均匀分布在Cu基金属中,镀层与基体结合良好,无空隙和裂纹等缺陷,镀态下镀层为晶态结构;当镀液中MoS2颗粒含量为25g/L时,镀层的减磨耐磨性达到最佳;镀层的耐蚀性,随着MoS2颗粒含量的增加逐渐升高并趋于稳定.

  7. Liquid and solid state interfacial reactions of Sn-Ag-Cu and Sn-In-Ag-Cu solders with Ni-P under bump metallization

    Energy Technology Data Exchange (ETDEWEB)

    Sharif, Ahmed [Department of Electronic Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Hong Kong (China); Chan, Y.C. [Department of Electronic Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Hong Kong (China)]. E-mail: EEYCCHAN@cityu.edu.hk

    2006-05-10

    In this study, interfacial reactions of electroless Ni(P) metallization of the ball-grid-array (BGA) substrate with the Sn-4 Ag-0.5 Cu (SAC405), Sn-3 Ag-0.5 Cu (SAC305) and Sn-9 In-3.5 Ag-0.5 Cu (SIAC) (wt.%) solder alloy were investigated, focusing on identification of the intermetallic compound (IMC) phases, the IMC growth rates and the consumption rate of the metallization layer at various liquid and solid state heat treatment conditions, e.g. extended reflow and solid state aging. A fixed volume of BGA solder ball (760 {mu}m diameter) was used on a substrate metallization pad with a diameter of 650 {mu}m. The consumption of the electroless Ni(P) in SIAC solder was also lower than in the SAC solders. The presence of indium in the solder played a major role in inhibiting the consumption of Ni(P) in the soldering reaction. The stable IMCs initially formed at the interface of the Ni(P)/In-containing solder system was the (Cu, Ni){sub 6} (Sn, In){sub 5} phase. During further reflow, the (Cu, Ni){sub 3} (Sn, In){sub 4} IMC started forming because of the limited Cu content in the solder. Bulk of the SIAC solder also contained Cu{sub 6}(Sn, In){sub 5} and Ag-In-Sn precipitates embedded in the Sn-rich matrix. It was also found that more Ag-containing SAC405 solder shows higher Ni(P) consumption than SAC305 solder at the same heat treatment condition.

  8. Investigation of the Phase Equilibria of Sn-Cu-Au Ternary and Ag-Sn-Cu-Au Quaternary Systems and Interfacial Reactions in Sn-Cu/Au Couples

    Science.gov (United States)

    Yen, Yee-Wen; Jao, Chien-Chung; Hsiao, Hsien-Ming; Lin, Chung-Yung; Lee, Chiapyng

    2007-02-01

    The phase equilibria of the Sn-Cu-Au ternary, Ag-Sn-Cu-Au quaternary systems and interfacial reactions between Sn-Cu alloys and Au were experimentally investigated at specific temperatures in this study. The experimental results indicated that there existed three ternary intermetallic compounds (IMCs) and a complete solid solubility between AuSn and Cu6Sn5 phases in the Sn-Cu-Au ternary system at 200°C. No quaternary IMC was found in the isoplethal section of the Ag-Sn-Cu-Au quaternary system. Three IMCs, AuSn, AuSn2, and AuSn4, were found in all couples. The same three IMCs and (Au,Cu)Sn/(Cu,Au)6Sn5 phases were found in all Sn-Cu/Au couples. The thickness of these reaction layers increased with increasing temperature and time. The mechanism of IMC growth can be described by using the parabolic law. In addition, when the reaction time was extended and the Cu content of the alloy was increased, the AuSn4 phase disappeared gradually. The (Au, Cu)Sn and (Cu,Au)6Sn5 layers played roles as diffusion barriers against Sn in Sn-Cu/Au reaction couple systems.

  9. CrCuAgN PVD nanocomposite coatings: Effects of annealing on coating morphology and nanostructure

    Science.gov (United States)

    Liu, Xingguang; Iamvasant, Chanon; Liu, Chang; Matthews, Allan; Leyland, Adrian

    2017-01-01

    CrCuAgN PVD nanocomposite coatings were produced using pulsed DC unbalanced magnetron sputtering. This investigation focuses on the effects of post-coat annealing on the surface morphology, phase composition and nanostructure of such coatings. In coatings with nitrogen contents up to 16 at.%, chromium exists as metallic Cr with N in supersaturated solid solution, even after 300 °C and 500 °C post-coat annealing. Annealing at 300 °C did not obviously change the phase composition of both nitrogen-free and nitrogen-containing coatings; however, 500 °C annealing resulted in significant transformation of the nitrogen-containing coatings. The formation of Ag aggregates relates to the (Cu + Ag)/Cr atomic ratio (threshold around 0.2), whereas the formation of Cu aggregates relates to the (Cu + Ag + N)/Cr atomic ratio (threshold around 0.5). The primary annealing-induced changes were reduced solubility of Cu, Ag and N in Cr, and the composition altering from a mixed ultra-fine nanocrystalline and partly amorphous phase constitution to a coarser, but still largely nanocrystalline structure. It was also found that, with sufficient Cu content (>12 at.%), annealing at a moderately high temperature (e.g. 500 °C) leads to transportation of both Cu and Ag (even at relatively low concentrations of Ag, ≤3 at.%) from inside the coating to the coating surface, which resulted in significant reductions in friction coefficient, by over 50% compared to that of the substrate (from 0.31 to 0.14 with a hemispherical diamond indenter, and from 0.83 to 0.40 with an alumina ball counterface, respectively). Results indicate that the addition of both Cu and Ag (in appropriate concentrations) to nitrogen-containing chromium is a viable strategy for the development of 'self-replenishing' silver-containing thin film architectures for temperature-dependent solid lubrication requirements or antimicrobial coating applications.

  10. Optical Limiting Properties of Ag-Cu Metal Alloy Nanoparticles Analysis by using MATLAB

    Institute of Scientific and Technical Information of China (English)

    WANG Yu-Hua; LI Hui-Qing; LU Jian-Duo; WANG Ru-Wu

    2011-01-01

    Ag-Cu alloy nanoparticles were formed by sequential ion implantation (Ag and Cu) in silica using a metal vapor vacuum arc (MEVVA) ion source.Third-order nonlinear optical properties of the nanoparticles were measured at 1064nm excitations using the Z-scan technique.Curve fitting analysis,based on the MATLAB features for Ag-Cu alloy nanoparticle optical limiting experiments,is used.The results show that Ag-Cu alloy nanoparticles display a refractive optical limiting effect at 1064 nm.Recently,increasing attention has been focused on the third-order nonlinear susceptibility and the photorefractive effect of noble-metal clusters embedded in dielectric matrices.[1-3] Third-order nonlinearities of metal/dielectric composite materials are influenced not only by the type and size of the embedded metal clusters,but also by the dielectric constant,thermal conductivity and heat capacity of the dielectric matrices.[4-6] Amongst the nanoparticles studied earlier,high nonlinear absorption and nonlinear refraction coefficients were found in copper and copper containing nanomaterials.[7,8] For silver,the nonlinear refractive index γ changes from positive to negative upon the growth of clusters.[9] Potential applications of optical limiters in the protection of sensors from intense laser pulses have motivated great efforts to design new nonlinear optical systems.[10]%Ag-Cu alloy nanoparticles were formed by sequential ion implantation (Ag and Cu) in silica using a metal vapor vacuum arc (MEVVA) ion source. Third-order nonlinear optical properties of the nanoparticles were measured at 1064 nm excitations using the Z-scan technique. Curve fitting analysis, based on the MATLAB features for Ag-Cu alloy nanoparticle optical limiting experiments, is used. The results show that Ag-Cu alloy nanoparticles display a refractive optical limiting effect at 1064 nm.

  11. Thermal Analysis of the Sn-Ag-Cu-In Solder Alloy

    DEFF Research Database (Denmark)

    Sopousek, J.; Palcut, Marián; Hodúlová, Erika

    2010-01-01

    The tin-based alloy Sn-1.5Ag-0.7Cu-9.5In (composition in wt.%) is a potential candidate for lead-free soldering at temperatures close to 200°C due to the significant amount of indium. Samples of Sn-1.5Ag-0.7Cu-9.5In were prepared by controlled melting of the pure elements, followed by quenching...

  12. STUDY OF Ag DIFFUSION INTO Cu SINGLE CRYSTALS BY RUTHERFORD BACKSCATTERING SPECTROMETRY

    Institute of Scientific and Technical Information of China (English)

    R. Wang

    2003-01-01

    4. 0Me V 7 Li++ RBS was used for investigations of thermal diffusion of Ag in Cu single crystals. The annealing of samples was carried out in vacuum in the temperature range from 498K to 613K. The element depth concentration profiles transformed fiom RBS spectra indicate that the diffusion of Ag into Cu is a typical volume diffusion. The Arrhenius parameters corresponding to the diffusion were obtained.

  13. Ag-Cu Bimetallic Nanoparticles Prepared by Microemulsion Method as Catalyst for Epoxidation of Styrene

    Directory of Open Access Journals (Sweden)

    Hong-Kui Wang

    2012-01-01

    Full Text Available Ag/Cu bimetallic nanocatalysts supported on reticulate-like γ-alumina were prepared by a microemulsion method using N2H4·H2O as the reducing agent. The catalysts were activated by calcination followed with hydrogen reduction at 873K, and the properties were confirmed using various characterization techniques. Compared with metal oxides particles, Ag-Cu particles exhibited smaller sizes (<5 nm after calcination in H2 at 873K. XPS results indicated that the binding energies changed with the Ag/Cu ratios, suggesting that increasing the copper content gave both metals a greater tendency to lose electrons. Furthermore, Ag-Cu bimetallic nanoparticles supported on γ-alumina showed better catalytic activity on the epoxidation of styrene as compared with the corresponding monometallic silver or copper. The styrene oxide selectivity could reach 76.6% at Ag/Cu molar ratio of 3/1, while the maximum conversion (up to 94.6% appeared at Ag/Cu molar ratio of 1/1 because of the maximum interaction between silver and copper.

  14. Interfacial Phenomena in Al/Al, Al/Cu, and Cu/Cu Joints Soldered Using an Al-Zn Alloy with Ag or Cu Additions

    Science.gov (United States)

    Pstruś, Janusz; Gancarz, Tomasz

    2014-05-01

    The studies of soldered joints were carried out in systems: Al/solder/Al, Al/solder/Cu, Cu/solder/Cu, where the solder was (Al-Zn)EUT, (Al-Zn)EUT with 0.5, 1.0, and 1.5 at.% of Ag and (Al-Zn)EUT with 0.5, 1.0, and 1.5 at.% of Cu addition. Brazing was performed at 500 °C for 3 min. The EDS analysis indicated that the composition of the layers starting from the Cu pad was CuZn, Cu5Zn8, and CuZn4, respectively. Wetting tests were performed at 500 °C for 3, 8, 15, and 30 min, respectively. Thickness of the layers and their kinetics of growth were measured based on the SEM micrographs. The formation of interlayers was not observed from the side of Al pads. On the contrary, dissolution of the Al substrate and migration of Al-rich particles into the bulk of the solder were observed.

  15. Morphology evolution of two-phase Cu-Ag alloys under different conditions

    Institute of Scientific and Technical Information of China (English)

    Jin-li HU; Jin-dong ZHANG; Liang MENG

    2009-01-01

    Cu-Ag filamentary microeomposites with different Ag contents were prepared by cold drawing and intermediate heat treatments. The microstructure characterization and filamentary distribution were observed for two-phase alloys under different conditions. The effect of heavy drawing strain on the microstructure evolution of Cu-Ag alloys was investigated. The results show that the microstructure components consist of Cu dendrites, eutectic colonies and secondary Ag precipitates in the alloys con-mining 6%~24% (mass fraction) Ag. With the increase in Ag content, the eutectic colonies in the microstructure increase and gradually change into a continuous net-like distribution. The Cu dendrites, eutectic colonies and secondary Ag precipitates are elongated in an axial direction and developed into the composite filamentary structure during cold drawing deformation. The eutectic colonies tend to evolve into filamentary bundles. The filamentary diameters decrease with the increase in drawing strain degree for the two-phase alloys, in particular for the alloys with low Ag content. The reduction in filamentary diameters becomes slow once the drawing strain has exceeded a certain level.

  16. Kinetics of island diffusion on Cu(111) and Ag(111) studied with variable-temperature STM

    NARCIS (Netherlands)

    Schlößer, Dietmar C.; Morgenstern, Karina; Verheij, Laurens K.; Rosenfeld, G.; Besenbacher, Flemming; Comsa, George

    2000-01-01

    The diffusion of vacancy islands on Cu(111) and Ag(111) and of adatom islands on Ag(111) has been studied using fast scanning STM. Diffusion of atoms along island edges (periphery diffusion) is much more effective in contributing to the diffusion of the islands than diffusion of atoms via terrace

  17. Adsorption behavior of {sup 99}Mo using AG1-X8 anionic resin

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Jacinete L. dos; Yamaura, Mitiko; Damasceno, Marcos O.; Forbicini, Christina A.L.G.O., E-mail: jlsantos@ipen.br, E-mail: myamaura@ipen.br, E-mail: marcos956@bol.com.br, E-mail: cforbici@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    The significant growth in demand of {sup 99}Mo in developed and developing countries, like Brazil, requires large production capacity and availability of this radioisotope. With the global crisis on its supply to Brazil rethought the need to become independent in their production and the solution was to start the Brazilian Multipurpose Reactor (RMB) project, which aims to meet the national demand of {sup 99}Mo for the medical field. This work aims to study the {sup 99}Mo adsorption in AG1-X8 strong anion resin, which is one of the intermediate steps of separation and purification, retaining it in the form of molybdate ions. In process evaluated the resin properties with respect to pH and concentration of {sup 99}Mo in the solution. The adsorbed amount of {sup 99}Mo was determined indirectly by the amount in the supernatant after adsorption and the data fitted to the Langmuir and Freundlich isotherms. Among the models, the Langmuir showed a closer relationship with the experimentally obtained data. This suggests the occurrence of monolayer adsorption and heterogeneous conditions at the surface, where both phenomena can coexist in the experimental conditions tested. (author)

  18. Synthesis and anti-bacterial activity of Cu, Ag and Cu-Ag alloy nanoparticles: A green approach

    Energy Technology Data Exchange (ETDEWEB)

    Valodkar, Mayur; Modi, Shefaly; Pal, Angshuman [Department of Chemistry, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara 390002, Gujarat (India); Thakore, Sonal, E-mail: drsonalit@gmail.com [Department of Chemistry, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara 390002, Gujarat (India)

    2011-03-15

    Research highlights: {yields} Synthesis of novel nanosized copper-silver alloys of different compositions. {yields} Completely green approach for synthesis of water soluble bimetallic nanoparticle. {yields} Interesting anti-bacterial activity of as synthesized metal and alloy nanoparticle. -- Abstract: Metallic and bimetallic nanoparticles of copper and silver in various proportions were prepared by microwave assisted chemical reduction in aqueous medium using the biopolymer, starch as a stabilizing agent. Ascorbic acid was used as the reducing agent. The silver and copper nanoparticles exhibited surface plasmon absorption resonance maxima (SPR) at 416 and 584 nm, respectively; while SPR for the Cu-Ag alloys appeared in between depending on the alloy composition. The SPR maxima for bimetallic nanoparticles changes linearly with increasing copper content in the alloy. Transmission electron micrograph (TEM) showed monodispersed particles in the range of 20 {+-} 5 nm size. Both silver and copper nanoparticles exhibited emission band at 485 and 645 nm, respectively. The starch-stabilized nanoparticles exhibited interesting antibacterial activity with both gram positive and gram negative bacteria at micromolar concentrations.

  19. Magnetically separable CuFe2O4/AgBr composite photocatalysts: Preparation, characterization, photocatalytic activity and photocatalytic mechanism under visible light

    Science.gov (United States)

    Zhao, Yalei; Lin, Cuiping; Bi, Huijie; Liu, Yonggang; Yan, Qishe

    2017-01-01

    The CuFe2O4 and CuFe2O4/AgBr composites with different CuFe2O4 contents were prepared by a facile sol-gel and hydrothermal method, respectively. The as-synthesized photocatalysts were characterized by means of powder X-ray diffraction (XRD), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), and UV-vis diffuse reflectance spectrum (UV-vis DRS). Their magnetic properties, photocatalytic degradation activities on methyl orange (MO) and tetracycline hydrochloride (TC) solution and photocatalytic mechanism were investigated in detail. The results revealed that the CuFe2O4/AgBr composites exhibited significantly higher photocatalytic activities than the pure CuFe2O4. The enhanced photocatalytic activity could be attributed to the matched band structure of two components and more effective charge transportation and separations. In addition, the quenching investigation of different scavengers demonstrated that h+, rad OH, rad O2- reactive species played different roles in the decolorization of MO and degradation of TC.

  20. Effect of the Vibrational Modes on the Ag-Cu Phase Diagram

    Institute of Scientific and Technical Information of China (English)

    DUAN Su-Qing; ZHAO Xian-Geng; LIU Shao-Jun; MA Ben-Kun

    2000-01-01

    We calculated the vibrational free energies of the selected ordered compounds in the Ag-Cu system by using two kinds of methods: (1) calculating the phonon dispersion and density of states and the consequently vibrational free energies by using the method of ab initio inverted interatomic potentials and dynamic matrix; (2) the vibrational free energies determined by a Debye-Griineisen approximation. The Ag-Cu phase diagram is calculated by the cluster variation method. The results show that the solubility at Ag-rich end of the calculated phase diagram considering vibrational modes by using the first method is in better agreement with the experimental.

  1. Adsorption of gas molecules on Cu impurities embedded monolayer MoS{sub 2}: A first- principles study

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, B.; Li, C.Y. [Hubei Nuclear Solid Physics Key Laboratory, Department of Physics, Wuhan University, Wuhan 430072 (China); Liu, L.L. [Key Lab for Special Functional Materials of Ministry of Eduaction, Henan Province, Henan University, Kaifeng 475004 (China); Zhou, B.; Zhang, Q.K. [Hubei Nuclear Solid Physics Key Laboratory, Department of Physics, Wuhan University, Wuhan 430072 (China); Chen, Z.Q., E-mail: chenzq@whu.edu.cn [Hubei Nuclear Solid Physics Key Laboratory, Department of Physics, Wuhan University, Wuhan 430072 (China); Tang, Z., E-mail: ztang@ee.ecnu.edu.cn [Key Laboratory of Polar Materials and Devices, Ministry of Education of China, East China Normal University, Shanghai 200241 (China)

    2016-09-30

    Highlights: • Embedded Cu atom is strongly constrained on the sulfur vacancy of monolayer MoS{sub 2}. • Transition-metal Cu atom can break the chemical inactivation of MoS{sub 2} surface. • MoS{sub 2}-Cu system is a promising for future application in gas molecules sensing. - Abstract: Adsorption of small gas molecules (O{sub 2}, NO, NO{sub 2} and NH{sub 3}) on transition-metal Cu atom embedded monolayer MoS{sub 2} was investigated by first-principles calculations based on the density-functional theory (DFT). The embedded Cu atom is strongly constrained on the sulfur vacancy of monolayer MoS{sub 2} with a high diffusion barrier. The stable adsorption geometry, charge transfer and electronic structures of these gas molecules on monolayer MoS{sub 2} embedded with transition-metal Cu atom are discussed in detail. It is found that the monolayer MoS{sub 2} with embedded Cu atom can effectively capture these gas molecules with high adsorption energy. The NH{sub 3} molecule acts as electron donor after adsorption, which is different from the other gas molecules (O{sub 2}, NO, and NO{sub 2}). The results suggest that MoS{sub 2}-Cu system may be promising for future applications in gas molecules sensing and catalysis, which is similar to those of the transition-metal embedded graphene.

  2. Novel PdAgCu ternary alloy: Hydrogen permeation and surface properties

    Energy Technology Data Exchange (ETDEWEB)

    Tarditi, Ana M.; Braun, Fernando [Instituto de Investigaciones en Catalisis y Petroquimica (FIQ, UNL-CONICET), Santiago del Estero 2829, 3000 Santa Fe (Argentina); Cornaglia, Laura M., E-mail: lmcornag@fiq.unl.edu.ar [Instituto de Investigaciones en Catalisis y Petroquimica (FIQ, UNL-CONICET), Santiago del Estero 2829, 3000 Santa Fe (Argentina)

    2011-05-15

    Dense PdAgCu ternary alloy composite membranes were synthesized by the sequential electroless plating of Pd, Ag and Cu on top of both disk and tubular porous stainless steel substrates. X-ray diffraction and scanning electron microscopy were employed to study the structure and morphology of the tested samples. The hydrogen permeation performance of these membranes was investigated over a 350-450 deg. C temperature range and a trans-membrane pressure up to 100 kPa. After annealing at 500 deg. C in hydrogen stream followed by permeation experiments, the alloy layer presented a FCC crystalline phase with a bulk concentration of 68% Pd, 7% Ag and 25% Cu as revealed by EDS. The PdAgCu tubular membrane was found to be stable during more than 300 h on hydrogen stream. The permeabilities of the PdAgCu ternary alloy samples were higher than the permeabilities of the PdCu alloy membranes with a FCC phase. The co-segregation of silver and copper to the membrane surface was observed after hydrogen permeation experiments at high temperature as determined by XPS.

  3. Crystal and electronic structure study of AgAu and AgCu bimetallic alloy thin films by X-ray techniques

    Energy Technology Data Exchange (ETDEWEB)

    Ozkendir, O. Murat, E-mail: ozkendir@gmail.com [Mersin University, Faculty of Technology, Energy Systems Engineering, Tarsus (Turkey); Mersin University, Institute of Natural Science, Department of Nanotechnology and Advanced Materials, Mersin (Turkey); Cengiz, E. [Karadeniz Technical University, Faculty of Science, Department of Physics, Trabzon (Turkey); Yalaz, E. [Mersin University, Institute of Natural Science, Department of Nanotechnology and Advanced Materials, Mersin (Turkey); Söğüt, Ö.; Ayas, D.H. [Kahramanmaraş Sütçü İmam Üniversitesi, Faculty of Science and Letters, Department of Physics, Kahramanmaraş (Turkey); Thammajak, B. Nirawat [Synchrotron Light Research Institute (Public Organisation), 111 University Avenue, T. Suranaree, A. Muang, Nakhon Ratchasima 30000 (Thailand)

    2016-05-15

    Highlights: • Crystal and electronic properties of bimetallic AgCu and AgAu alloy thin films were studied. • Both AgCu and AgAu bimetallic samples were determined to have cubic crystal geometry. • Strong influence of Cu and Au atoms on the electronic structure of the Ag atoms were determined. - Abstract: Crystal and electronic structure properties of bimetallic AgAu and AgCu alloy thin films were investigated by X-ray spectroscopic techniques. The aim of this study is to probe the influence of Au or Cu atoms on the electronic behaviors of Ag ions in bimetallic alloy materials that yields different crystal properties. To identify the mechanisms causing crystal phase transitions, study were supported by the collected EXAFS (Extended X-ray Absorption Fine Structure) data. Crystal structures of both Cu and Au doped bimetallic Ag samples were determined mainly in cubic geometry with “Fm3m” space group. Through the Ag–Au and Ag–Cu molecular interactions during bimetallic alloy formations, highly overlapped electronic levels that supports large molecular band formations were observed with different ionization states. Besides, traces of the d–d interactions in Au rich samples were determined as the main interplay in the broad molecular bond formations. The exact atomic locations and types in the samples were determined by EXAFS studies and supported by the performed calculations with FEFF scientific code.

  4. Theoretical and experimental study of metastable solid solutions and phase stability within the immiscible Ag-Mo binary system

    Science.gov (United States)

    Sarakinos, K.; Greczynski, G.; Elofsson, V.; Magnfält, D.; Högberg, H.; Alling, B.

    2016-03-01

    Metastable solid solutions are phases that are synthesized far from thermodynamic equilibrium and offer a versatile route to design materials with tailor-made functionalities. One of the most investigated classes of metastable solid solutions with widespread technological implications is vapor deposited ternary transition metal ceramic thin films (i.e., nitrides, carbides, and borides). The vapor-based synthesis of these ceramic phases involves complex and difficult to control chemical interactions of the vapor species with the growing film surface, which often makes the fundamental understanding of the composition-properties relations a challenging task. Hence, in the present study, we investigate the phase stability within an immiscible binary thin film system that offers a simpler synthesis chemistry, i.e., the Ag-Mo system. We employ magnetron co-sputtering to grow Ag1-xMox thin films over the entire composition range along with x-ray probes to investigate the films structure and bonding properties. Concurrently, we use density functional theory calculations to predict phase stability and determine the effect of chemical composition on the lattice volume and the electronic properties of Ag-Mo solid solutions. Our combined theoretical and experimental data show that Mo-rich films (x ≥ ˜0.54) form bcc Mo-Ag metastable solid solutions. Furthermore, for Ag-rich compositions (x ≤ ˜0.21), our data can be interpreted as Mo not being dissolved in the Ag fcc lattice. All in all, our data show an asymmetry with regards to the mutual solubility of Ag and Mo in the two crystal structures, i.e., Ag has a larger propensity for dissolving in the bcc-Mo lattice as compared to Mo in the fcc-Ag lattice. We explain these findings in light of isostructural short-range clustering that induces energy difference between the two (fcc and bcc) metastable phases. We also suggest that the phase stability can be explained by the larger atomic mobility of Ag atoms as compared to that

  5. In situ controllable synthesis of novel surface plasmon resonance-enhanced Ag2WO4/Ag/Bi2MoO6 composite for enhanced and stable visible light photocatalyst

    Science.gov (United States)

    Lv, Jiali; Dai, Kai; Zhang, Jinfeng; Lu, Luhua; Liang, Changhao; Geng, Lei; Wang, Zhongliao; Yuan, Guangyu; Zhu, Guangping

    2017-01-01

    A novel hierarchical Ag2WO4/Ag/Bi2MoO6 ternary visible-light-driven photocatalyst was successfully synthesized by in situ doping Ag2WO4 with Bi2MoO6 nanosheets through a facile hydrothermal and photochemical process. The morphology, structure, optical performance and crystallinity of the products were measured by field emission scanning electron microscope (FESEM), energy dispersive spectrometer (EDS), UV-vis diffuse reflectance spectroscopy (DRS) and X-ray diffraction (XRD). The results showed that Ag2WO4/Ag was uniformly dispersed on the surface of Bi2MoO6 nanosheets. The photocatalytic performance of Ag2WO4/Ag/Bi2MoO6 heterostructures was evaluated by the degradation of methylene blue (MB) under 410 nm LED arrays. The ternary Ag2WO4/Ag/Bi2MoO6 nanocomposite exhibits higher photocatalytic activity than Bi2MoO6 and Ag2WO4. The synergistic effect of Ag2WO4 and Bi2MoO6 could generated more heterojunctions which promoted photoelectrons transfer from Ag2WO4 to Bi2MoO6, leading to the improvement of photocatalytic performance by photoelectrons-holes recombination suppression. At the same time, the surface plasmon resonance of Ag2WO4/Ag/Bi2MoO6 is another crucial reason for the high photocatalytic performance of organic pollutants degradation. And the 20 wt% Ag2WO4-loaded Bi2MoO6 shows the optimal photocatalytic performance in the degradation of MB. In addition, the ternary composites can be easily reclaimed by precipitation and exhibits high stability of photocatalytic degradation after five recycles.

  6. Ag- and Cu-doped multifunctional bioactive nanostructured TiCaPCON films

    Energy Technology Data Exchange (ETDEWEB)

    Shtansky, D.V., E-mail: shtansky@shs.misis.ru [National University of Science and Technology “MISIS”, Leninsky prospekt 4, Moscow 119049 (Russian Federation); Batenina, I.V.; Kiryukhantsev-Korneev, Ph.V.; Sheveyko, A.N.; Kuptsov, K.A. [National University of Science and Technology “MISIS”, Leninsky prospekt 4, Moscow 119049 (Russian Federation); Zhitnyak, I.Y.; Anisimova, N.Yu.; Gloushankova, N.A. [N.N. Blokhin Russian Cancer Research Center of RAMS, Kashirskoe shosse 24, Moscow 115478 (Russian Federation)

    2013-11-15

    A key property of multicomponent bioactive nanostructured Ti(C,N)-based films doped with Ca, P, and O (TiCaPCON) that can be improved further is their antibacterial effect that should be achieved without compromising the implant bioactivity and biocompatibility. The present work is focused on the study of structure, chemical, mechanical, tribological, and biological properties of Ag- and Cu-doped TiCaPCON films. The films with Ag (0.4–4 at.%) and Cu (13 at.%) contents were obtained by simultaneous sputtering of a TiC{sub 0.5}–Ca{sub 3}(PO{sub 4}){sub 2} target and either an Ag or a Cu target. The film structure was studied using X-ray diffraction, transmission and scanning electron microscopy, energy dispersive X-ray spectroscopy, glow discharge optical emission spectroscopy, and Raman-shift and IR spectroscopy. The films were characterized in terms of their hardness, elastic modulus, dynamic impact resistance, friction coefficient and wear rate (both in air and normal saline), surface wettability, electrochemical behavior and Ag or Cu ion release in normal saline. Particular attention was paid to the influence of inorganic bactericides (Ag and Cu ions) on the bactericidal activity against unicellular yeast fungus Saccharomyces cerevisiae and gram-positive bacteria Lactobacillus acidophilus, as well as on the attachment, spreading, actin cytoskeleton organization, focal adhesions, and early stages of osteoblastic cell differentiation. The obtained results show that the Ag-doped films are more suitable for the protection of metallic surfaces against bacterial infection compared with their Cu-doped counterpart. In particular, an excellent combination of mechanical, tribological, and biological properties makes Ag-doped TiCaPCON film with 1.2 at.% of Ag very attractive material for bioengineering and modification of load-bearing metal implant surfaces.

  7. Ag- and Cu-doped multifunctional bioactive nanostructured TiCaPCON films

    Science.gov (United States)

    Shtansky, D. V.; Batenina, I. V.; Kiryukhantsev-Korneev, Ph. V.; Sheveyko, A. N.; Kuptsov, K. A.; Zhitnyak, I. Y.; Anisimova, N. Yu.; Gloushankova, N. A.

    2013-11-01

    A key property of multicomponent bioactive nanostructured Ti(C,N)-based films doped with Ca, P, and O (TiCaPCON) that can be improved further is their antibacterial effect that should be achieved without compromising the implant bioactivity and biocompatibility. The present work is focused on the study of structure, chemical, mechanical, tribological, and biological properties of Ag- and Cu-doped TiCaPCON films. The films with Ag (0.4-4 at.%) and Cu (13 at.%) contents were obtained by simultaneous sputtering of a TiC0.5-Ca3(PO4)2 target and either an Ag or a Cu target. The film structure was studied using X-ray diffraction, transmission and scanning electron microscopy, energy dispersive X-ray spectroscopy, glow discharge optical emission spectroscopy, and Raman-shift and IR spectroscopy. The films were characterized in terms of their hardness, elastic modulus, dynamic impact resistance, friction coefficient and wear rate (both in air and normal saline), surface wettability, electrochemical behavior and Ag or Cu ion release in normal saline. Particular attention was paid to the influence of inorganic bactericides (Ag and Cu ions) on the bactericidal activity against unicellular yeast fungus Saccharomyces cerevisiae and gram-positive bacteria Lactobacillus acidophilus, as well as on the attachment, spreading, actin cytoskeleton organization, focal adhesions, and early stages of osteoblastic cell differentiation. The obtained results show that the Ag-doped films are more suitable for the protection of metallic surfaces against bacterial infection compared with their Cu-doped counterpart. In particular, an excellent combination of mechanical, tribological, and biological properties makes Ag-doped TiCaPCON film with 1.2 at.% of Ag very attractive material for bioengineering and modification of load-bearing metal implant surfaces.

  8. Antimicrobial effects of metal ions (Ag+, Cu2+, Zn2+) in hydroxyapatite.

    Science.gov (United States)

    Kim, T N; Feng, Q L; Kim, J O; Wu, J; Wang, H; Chen, G C; Cui, F Z

    1998-03-01

    The antimicrobial ceramics (AC) based on hydroxyapatite (HA) were made in a wet chemical process with additions of AgNO3, Cu(NO3)2. 3H2O and Zn(NO3)2. 6H2O. The ACs were composed of metal-ion substituted hydroxyapatite and nitrate-apatite, which was identified by X-ray diffraction. The viable count and turbidity measurement was adopted to observe the antimicrobial effects of the various ACs. The aerobic Escherichia coli was used in the study. An obvious antimicrobial effect against E. coli was observed in Ag+ AC. In contrast to Ag+ AC, it was difficult to ascertain any bactericidal effect in the case of Cu2+ and Zn2+ AC. The bactericidal effect of Ag+ was observed using a dialysis tube experiment. This suggests that Ag+ dissolved out and reacted with E. coli, thus inhibiting its growth.

  9. Enhanced photocatalytic, electrochemical and photoelectrochemical properties of TiO{sub 2} nanotubes arrays modified with Cu, AgCu and Bi nanoparticles obtained via radiolytic reduction

    Energy Technology Data Exchange (ETDEWEB)

    Nischk, Michał [Department of Chemical Technology, Faculty of Chemistry, Gdansk University of Technology, 11/12 G. Narutowicza 11/12 St., 80-233 Gdansk (Poland); Department of Environmental Technology, Faculty of Chemistry, University of Gdansk, 63 Wita Stwosza St., 80-308 Gdansk (Poland); Mazierski, Paweł [Department of Environmental Technology, Faculty of Chemistry, University of Gdansk, 63 Wita Stwosza St., 80-308 Gdansk (Poland); Wei, Zhishun [Institute for Catalysis, Hokkaido University, N21, W10, 001-0021, Sapporo (Japan); Siuzdak, Katarzyna [Centre for Plasma and Laser Engineering, The Szewalski Institute of Fluid-Flow Machinery, Polish Academy of Sciences, 14 Fiszera St., 80-231 Gdansk (Poland); Kouame, Natalie Amoin [Laboratoire de Chimie Physique, CNRS—UMR 8000,Université Paris-Sud, Université Paris-Saclay, Bâtiment 349, 91405 Orsay (France); Kowalska, Ewa [Institute for Catalysis, Hokkaido University, N21, W10, 001-0021, Sapporo (Japan); Remita, Hynd [Laboratoire de Chimie Physique, CNRS—UMR 8000,Université Paris-Sud, Université Paris-Saclay, Bâtiment 349, 91405 Orsay (France); Zaleska-Medynska, Adriana, E-mail: adriana.zaleska@ug.edu.pl [Department of Environmental Technology, Faculty of Chemistry, University of Gdansk, 63 Wita Stwosza St., 80-308 Gdansk (Poland)

    2016-11-30

    Highlights: • TiO{sub 2} nanotubes were modified with Cu, AgCu, Bi nanoparticles via gamma radiolysis. • Excessive amount of deposited metal decreased photocatalytic activity. • AgCu-modified samples were more active than Cu-modified (with the same Cu content). • AgCu nanoparticles exist in a core{sub (Ag)}-shell{sub (Cu)} form. • Examined photocatalysts were resistant towards photocorrosion processes. - Abstract: TiO{sub 2} nanotubes arrays (NTs), obtained via electrochemical anodization of Ti foil, were modified with monometallic (Cu, Bi) and bimetallic (AgCu) nanoparticles. Different amounts of metals’ precursors were deposited on the surface of NTs by the spin-coating technique, and the reduction of metals was performed via gamma radiolysis. Surface modification of titania was studied by EDS and XPS analysis. The results show that AgCu nanoparticles exist in a Ag{sub core}-Cu{sub shell} form. Photocatalytic activity was examined under UV irradiation and phenol was used as a model pollutant of water. Over 95% of phenol degradation was achieved after 60 min of irradiation for almost all examined samples, but only slight difference in degradation efficiency (about 3%) between modified and bare NTs was observed. However, the initial phenol degradation rate and TOC removal efficiency was significantly enhanced for the samples modified with 0.31 and 0.63 mol% of Bi as well as for all the samples modified with Cu and AgCu nanoparticles in comparison with bare titania nanotubes. The saturated photocurrent, under the influence of simulated solar light irradiation, for the most active Bi- and AgCu-modified samples, was over two times higher than for pristine NTs. All the examined materials were resistant towards photocorrosion processes that enables their application for long term processes induced by light.

  10. Influence of Sn on Microstructure and Performance of Electric Vacuum Ag-Cu Filler Metal

    Directory of Open Access Journals (Sweden)

    SHI Lei

    2016-10-01

    Full Text Available Influence of Sn on microstructure, melting characteristic and brazing performance of electric vacuum Ag-Cu filler metal was studied by using scanning electronic microscope (SEM with energy disperse spectroscopy (EDS, differential scanning calorimetry (DSC and contrast tests. The results show that, while the addition of Sn is 4% (mass fraction,the same below, there is no brittle β-Cu phase in Ag60Cu filler metal,the effect on the processing performance is not obvious; with the increase of Sn content, the liquidus temperature of Ag60Cu filler metal decreases gradually, but the solidus temperature drops drastically,resulting in wider melting temperature range, and worse gap filling ability of filler metal. The Ag60Cu filler metal with Sn content of 4% has good spreading and metallurgical bonding abilities on copper plates, which are closer to that of BAg72Cu filler metal, and it can be processed into flake filler metal to replace the BAg72Cu flake filler metal to be used.

  11. Ag-Cu nanoalloyed film as a high-performance cathode electrocatalytic material for zinc-air battery

    OpenAIRE

    Lei, Yimin; Chen, Fuyi; Jin, Yachao; Liu, Zongwen

    2015-01-01

    A novel Ag50Cu50 film electrocatalyst for oxygen reduction reaction (ORR) was prepared by pulsed laser deposition (PLD) method. The electrocatalyst actually is Ag-Cu alloyed nanoparticles embedded in amorphous Cu film, based on transmission electron microscopy (TEM) characterization. The rotating disk electrode (RDE) measurements provide evidence that the ORR proceed via a four-electron pathway on the electrocatalysts in alkaline solution. And it is much more efficient than pure Ag catalyst. ...

  12. Reaction of Liquid Sn-Ag-Cu-Ce Solders with Solid Copper

    Science.gov (United States)

    Chriaštel'Ová, J.; Rízeková Trnková, L.; Pocisková Dimová, K.; Ožvold, M.

    2011-09-01

    Small amounts of the rare-earth element Ce were added to the Sn-rich lead-free eutectic solders Sn-3.5Ag-0.7Cu, Sn-0.7Cu, and Sn-3.5Ag to improve their properties. The microstructures of the solders without Ce and with different amounts (0.1 wt.%, 0.2 wt.%, and 0.5 wt.%) of Ce were compared. The microstructure of the solders became finer with increasing Ce content. Deviation from this rule was observed for the Sn-Ag-Cu solder with 0.2 wt.% Ce, and for the Sn-0.7Cu eutectic alloy, which showed the finest microstructure without Ce. The melting temperatures of the solders were not affected. The morphology of intermetallic compounds (IMC) formed at the interface between the liquid solders and a Cu substrate at temperatures about 40°C above the melting point of the solder for dipping times from 2 s to 256 s was studied for the basic solder and for solder with 0.5 wt.% Ce addition. The morphology of the Cu6Sn5 IMC layer developed at the interface between the solders and the substrate exhibited the typical scallop-type shape without significant difference between solders with and without Ce for the shortest dipping time. Addition of Ce decreased the thickness of the Cu6Sn5 IMC layer only at the Cu/Sn-Ag-Cu solder interface for the 2-s dipping. A different morphology of the IMC layer was observed for the 256-s dipping time: The layers were less continuous and exhibited a broken relief. Massive scallops were not observed. For longer dipping times, Cu3Sn IMC layers located near the Cu substrate were also observed.

  13. A light-modified ferroelectric resistive switching behavior in Ag/BaMoO4/FTO device at ambient temperature

    Science.gov (United States)

    Zhao, W. X.; Sun, B.; Liu, Y. H.; Wei, L. J.; Li, H. W.; Chen, P.

    2014-12-01

    BaMoO4 powder was prepared by a facile hydrothermal synthesis. And the BaMoO4/FTO device was fabricated by a spin-coated method, in which the thickness of BaMoO4 layer is about 20 μm. The bipolar resistive switching effect has been observed in Ag/BaMoO4/FTO device. Moreover, the resistive switching effect of the device is greatly improved by white light irradiation. The resistive switching behavior is explained by the polarization reversal that changes the charge distribution and modulates the Schottky barriers.

  14. 界面耦合作用对Cu(Ni)/Sn-Ag-Cu/Cu(Ni)BGA 焊点界面IMC形成与演化的影响%EFFECT OF THE CROSS-INTERACTION ON THE FORMATION AND EVOLUTION OF INTERMETALLIC COMPOUNDS IN Cu(Ni)/Sn-Ag-Cu/Cu(Ni) BGA STRUCTURE SOLDER JOINTS

    Institute of Scientific and Technical Information of China (English)

    李勋平; 周敏波; 夏建民; 马骁; 张新平

    2011-01-01

    研究了焊盘材料界面耦合作用对Cu(Ni)/Sn-3.0Ag-0.5Cu/Cu(Ni)BGA(Ball Grid Array)结构焊点焊后态和125℃等温时效过程中界面金属间化合物(IMC)的成分、形貌和生长动力学的影响.结果表明,凸点下金属层(UBM)Ni界面IMC的成分与钎料中Cu含量有关,钎料中Cu含量较高时界面IMC为(Cu,Ni)6Sn5,而Cu含量较低时,则生成(Cu,Ni)3Sn4;Cu-Ni耦合易导致Cu/Sn-3.0Ag-0.5Cu/Ni焊点中钎料/Ni界面IMC异常生长并产生剥离而进入钎料.125℃等温时效过程中,Sn-3.0Ag-0.5Cu/Cu界面IMC的生长速率常数随钎料中Cu含量增加而提高,Cu-Cu耦合降低一次回流侧IMC生长速率常数;Cu-Ni耦合和Ni-Ni耦合均导致焊点一次回流Ni侧界面IMC的生长速率常数增大,但Ni对界面IMC生长动力学的影响大于Cu;Ni有利于抑制Cu界面Cu3Sn生长,降低界面IMC生长速率,但Cu-Ni耦合对Cu界面Cu3Sn中Kirkendall空洞率无明显影响.%The formation and evolution of interfacial intermetallic compounds (IMCs) in Cu(Ni)/Sn-3.0Ag-0.5Cu/Cu(Ni) BGA (Ball Grid Array) structure solder joints both in the asreflowed state and undergoing isothermal aging at 125 C were investigated. The results show that there exists a significant cross-interaction effect of the solder pad/under bump metal (UBM) on the composition, morphology and growth kinetics of interfacial IMCs in solder joints. The reactions of solder/Ni UBM strongly depends on the Cu content of the solder, for a high Cu content, a continuous (Cu, Ni)6Sn5 layer forms at the interface, while for a low Cu content, a continuous (Ni, Cu)3Sn4 layer appears at the interface. The cross-interaction of Cu and Ni in Cu/Sn-3.0Ag-0.5Cu(SAC)/Ni solder joints has obvious influence on the composition and morphology of the interfacial IMC; and the IMC spalling phenomenon occurs at the interface of Ni side. During isothermal aging at 125 ℃, the growth rate constant of the interfacial IMC layer in SAC/Cu and Cu/SAC/Cu joints increases with

  15. Improving Efficiency of Evaporated Cu2ZnSnS4 Thin Film Solar Cells by a Thin Ag Intermediate Layer between Absorber and Back Contact

    Directory of Open Access Journals (Sweden)

    Hongtao Cui

    2015-01-01

    Full Text Available A 20 nm Ag coating on Mo back contact was adopted to improve the back contact of evaporated Cu2ZnSnS4 (CZTS solar cells. The Ag layer helped reduce the thickness of MoS2 which improves fill factor (FF significantly; additionally, it reduced secondary phases ZnS and SnS2−x, which may help carrier transport; it was also involved in the doping of the absorber layer, which compensated the intrinsic p-type doping and therefore drags down the doping level. The doping involvement may enlarge the depletion region and improve lifetime of the absorber, which led to enhancing open circuit voltage (VOC, short circuit current density (JSC, and efficiency significantly. However, it degrades the crystallinity of the material slightly.

  16. Microstructures and fatigue life of SnAgCu solder joints bearing Nano-Al particles in QFP devices

    Science.gov (United States)

    Zhang, Liang; Fan, Xi-ying; Guo, Yong-huan; He, Cheng-wen

    2014-05-01

    Microstructures and fatigue life of SnAgCu and SnAgCu bearing nano-Al particles in QFP (Quad flat package) devices were investigated, respectively. Results show that the addition of nano-Al particles into SnAgCu solder can refine the microstructures of matrix microstructure. Moreover, the nano-Al particles present in the solder matrix, act as obstacles which can create a back stress, resisting the motion of dislocations. In QFP device, it is found that the addition of nano-Al particles can increase the fatigue life by 32% compared with the SnAgCu solder joints during thermal cycling loading.

  17. The Reliability of Microalloyed Sn-Ag-Cu Solder Interconnections Under Cyclic Thermal and Mechanical Shock Loading

    Science.gov (United States)

    Mattila, Toni T.; Hokka, Jussi; Paulasto-Kröckel, Mervi

    2014-11-01

    In this study, the performance of three microalloyed Sn-Ag-Cu solder interconnection compositions (Sn-3.1Ag-0.52Cu, Sn-3.0Ag-0.52Cu-0.24Bi, and Sn-1.1Ag-0.52Cu-0.1Ni) was compared under mechanical shock loading (JESD22-B111 standard) and cyclic thermal loading (40 ± 125°C, 42 min cycle) conditions. In the drop tests, the component boards with the low-silver nickel-containing composition (Sn-Ag-Cu-Ni) showed the highest average number of drops-to-failure, while those with the bismuth-containing alloy (Sn-Ag-Cu-Bi) showed the lowest. Results of the thermal cycling tests showed that boards with Sn-Ag-Cu-Bi interconnections performed the best, while those with Sn-Ag-Cu-Ni performed the worst. Sn-Ag-Cu was placed in the middle in both tests. In this paper, we demonstrate that solder strength is an essential reliability factor and that higher strength can be beneficial for thermal cycling reliability but detrimental to drop reliability. We discuss these findings from the perspective of the microstructures and mechanical properties of the three solder interconnection compositions and, based on a comprehensive literature review, investigate how the differences in the solder compositions influence the mechanical properties of the interconnections and discuss how the differences are reflected in the failure mechanisms under both loading conditions.

  18. Atomic-scale investigation of interface-facilitated deformation twinning in severely deformed Ag-Cu nanolamellar composites

    Energy Technology Data Exchange (ETDEWEB)

    An, X. H., E-mail: anxianghai@gmail.com, E-mail: xiaozhou.liao@sydenye.edu.au; Cao, Y.; Liao, X. Z., E-mail: anxianghai@gmail.com, E-mail: xiaozhou.liao@sydenye.edu.au [School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, New South Wales 2006 (Australia); Zhu, S. M.; Nie, J. F. [Department of Materials Engineering, Monash University, Melbourne, Victoria 3800 (Australia); Kawasaki, M. [Division of Materials Science and Engineering, Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Ringer, S. P. [School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, New South Wales 2006 (Australia); Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, New South Wales 2006 (Australia); Langdon, T. G. [Departments of Aerospace and Mechanical Engineering and Materials Science, University of Southern California, Los Angeles, California 90089-1453 (United States); Materials Research Group, Faculty of Engineering and the Environment, University of Southampton, Southampton SO17 1BJ (United Kingdom); Zhu, Y. T. [Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695-7919 (United States); School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing (China)

    2015-07-06

    We report an atomic-scale investigation of interface-facilitated deformation twinning behaviour in Ag-Cu nanolamellar composites. Profuse twinning activities in Ag supply partial dislocations to directly transmit across the Ag-Cu lamellar interface that promotes deformation twinning in the neighbouring Cu lamellae although the interface is severely deformed. The trans-interface twin bands change the local structure at the interface. Our analysis suggests that the orientation relationship and interfacial structure between neighbouring Ag-Cu lamellae play a crucial role in such special interface-facilitated twinning behaviour.

  19. β-Ag2MoO4 microcrystals: Characterization, antibacterial properties and modulation analysis of antibiotic activity.

    Science.gov (United States)

    Moura, J V B; Freitas, T S; Cruz, R P; Pereira, R L S; Silva, A R P; Santos, A T L; da Silva, J H; Luz-Lima, C; Freire, P T C; Coutinho, H D M

    2017-02-01

    This study reports the antibacterial properties and modulation analysis of antibiotic activity by β-Ag2MoO4 microcrystals as well as their structural and vibrational characterization. The silver molybdate was obtained by the conventional hydrothermal method, and the structural, vibrational and morphological properties of the sample were determined using X-ray diffraction, Raman spectroscopy and scanning electron microscopy images. β-Ag2MoO4 microcrystals obtained show spinel-type cubic structure (Fd-3m) with irregular shapes. The evaluation of antibacterial and modulatory-antibiotic activity was performed using the microdilution method to determine the Minimum Inhibitory Concentration (MIC) of the β-Ag2MoO4 and antibiotics alone and associated with the silver molybdate. The β-Ag2MoO4 modulates the antibiotic activity against all bacteria assayed in a synergistic (as the norfloxacin and gentamicin against S. aureus and gentamicin against E. coli) or an antagonistic form (as the norfloxacin against E.coli and P. aeruginosa). The reversion of antibiotic resistance by combinations with Ag2MoO4 could be a novel strategy to combat infections caused by multiple drug resistance (MDR) pathogens. Our results indicate that these silver molybdates present a clinically relevant antibacterial activity and enhanced the antibiotic activity of some antibiotics against MDR strain of S. aureus and E. coli, being an interesting alternative to combat antibiotic-resistant bacterial infectious agents. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  20. In vitro cytotoxicity of Ag-Pd-Cu-based casting alloys.

    Science.gov (United States)

    Niemi, L; Hensten-Pettersen, A

    1985-01-01

    The cytotoxicity and its correlation to alloy composition, structure, corrosion, as well as galvanic coupling was studied with 12 Ag-Pd-Cu-type alloys, one conventional type III gold alloy and pure Ag, Cu, and Pd. The agar overlay cell culture technique was used. Single phase binary CuPd alloys were only slightly cytotoxic below a Cu content of 30 wt%. The tested multiphase alloys were all toxic, but no correlation between toxicity and Cu content could be observed. Solid solution annealing increased the cytotoxicity of a multiphase alloy. Exposure of a single phase alloy to an artificial saliva for 1 week prior to the test decreased its cytotoxicity significantly. Galvanic coupling of the alloys through an outer copper wire decreased their cytotoxicity.

  1. Limites de stabilité de la phase (Ag, Cu)TlTe dans le système AgCuTlTe

    Science.gov (United States)

    Brun, Gerard; Boubali, Mahjoub; Ayral, R. M.; Tedenac, Jean-Claude

    1990-12-01

    Three isopleth sections, AgTlTe(CuTlTe), AgTlTeCu 2Te, and AgTlTeCu 2TlTe 2, of the quaternary system AgCuTlTe were investigated using thermal analysis, differential scanning calorimetry, and X-ray powder diffraction. The AgTlTe-based solid solution (Ag xCu YTl zTe) limits were determined and the composition-structure relations depicted.

  2. Interfacial reactions of Sn-Ag-Cu solders modified by minor Zn alloying addition

    Science.gov (United States)

    Kang, Sung K.; Leonard, Donovan; Shih, Da-Yuan; Gignac, Lynne; Henderson, D. W.; Cho, Sungil; Yu, Jin

    2006-03-01

    The near-ternary eutectic Sn-Ag-Cu alloys have been identified as leading Pb-free solder candidates to replace Pb-bearing solders in microelectronic applications. However, recent investigations on the processing behavior and solder joints reliability assessment have revealed several potential reliability risk factors associated with the alloy system. The formation of large Ag3Sn plates in Sn-Ag-Cu joints, especially when solidified in a relatively slow cooling rate, is one issue of concern. The implications of large Ag3Sn plates on solder joint performance and several methods to control them have been discussed in previous studies. The minor Zn addition was found to be effective in reducing the amount of undercooling required for tin solidification and thereby to suppress the formation of large Ag3Sn plates. The Zn addition also caused the changes in the bulk microstructure as well as the interfacial reaction. In this paper, an in-depth characterization of the interfacial reaction of Zn-added Sn-Ag-Cu solders on Cu and Au/Ni(P) surface finishes is reported. The effects of a Zn addition on modification of the interfacial IMCs and their growth kinetics are also discussed.

  3. Investigation of thermal, mechanical and magnetic behaviors of the Cu-11%Al alloy with Ag and Mn additions

    Energy Technology Data Exchange (ETDEWEB)

    Silva, R.A.G., E-mail: galdino.ricardo@gmail.com [Departamento de Ciencias Exatas e da Terra-UNIFESP, Diadema-SP (Brazil); Paganotti, A.; Gama, S. [Departamento de Ciencias Exatas e da Terra-UNIFESP, Diadema-SP (Brazil); Adorno, A.T.; Carvalho, T.M.; Santos, C.M.A. [Instituto de Quimica - UNESP, Araraquara-SP (Brazil)

    2013-01-15

    The investigation of thermal, mechanical and magnetic behaviors of the Cu-11%Al, Cu-11%Al-3%Ag, Cu-11%Al-10%Mn and Cu-11%Al-10%Mn-3%Ag alloys was made using microhardness measurements, differential scanning calorimetry, X-ray diffractometry, scanning electron microscopy, energy dispersion X-ray spectroscopy and magnetic moment change with applied field measurement. The results indicated that the Mn addition changes the phase stability range, the microhardness values and makes undetectable the eutectoid reaction in annealed Cu-11%Al and Cu-11%Al-3%Ag alloys while the presence of Ag does not modify the phase transformation sequence neither microhardness values of the annealed Cu-11%Al and Cu-11%Al-10%Mn alloys, but it increases the magnetic moment of this latter at about 2.7 times and decreases the rates of eutectoid and peritectoid reactions of the former. - Highlights: Black-Right-Pointing-Pointer The microstructure of Cu-Al alloy is modified in the Ag presence. Black-Right-Pointing-Pointer ({alpha} + {gamma}) phase is stabilized down to room temperature when Ag is added to Cu-Al alloy. Black-Right-Pointing-Pointer Ag-rich phase modifies the magnetic characteristics of Cu-Al-Mn alloy.

  4. Characterization and Characteristics of mechanochemically synthesized amorphous fast ionic conductor 50 SISOMO (50AgI-25Ag2O-25MoO3)

    OpenAIRE

    Dayal, Saurabh; Shahi, K.

    2012-01-01

    Mechanochemically synthesized amorphous 50SISOMO [50AgI-25Ag_2O-25MoO_3] fast ionic conductor shows high ionic conductivity of ~ 6x10^-3 {\\Omega}^-1 cm-1 at room temperature. The highest ionic conductivity is achieved for 36 h milled sample, which is more than three orders of magnitude higher than that of crystalline AgI at room temperature. The samples are thermally stable at least up to ~70 {\\deg}C. Thermoelectric power studies on 50 SISOMO amorphous fast ionic conductors (a-SIC) have been ...

  5. Electroquímica de Ag2Cu2O3 y síntesis de Ag2Cu2O4

    Directory of Open Access Journals (Sweden)

    Casan-Pastor, N.

    2002-02-01

    Full Text Available The first silver-copper mixed oxide was recently synthesized in our laboratory. Such synthesis has been possible using soft chemistry methods and low temperatures, which prevent the decomposition of silver oxides. The present work describes the electrochemical behaviour of the silver-copper mixed oxide, Ag2Cu2O3, as studied by cyclic voltametry and electrolysis, both for oxidation and for reduction reactions. This compound undergoes several redox processes when it is reduced, yielding metallic silver and metallic copper as final products. The initial oxide is not regenerated upon re-oxidation. On the other hand, when Ag2Cu2O3 is oxidized a new phase with stoichiometry Ag2Cu2O4±δ appears.The original compound can be regenerated after a new reduction.Recientemente se ha sintetizado en nuestro laboratorio el primer óxido mixto de cobre y plata. Tal síntesis ha sido posible gracias a la utilización de métodos de química suave y baja temperatura, que impiden que los óxidos de plata se descompongan. En este trabajo se describe el estudio llevado a cabo sobre el comportamiento electroquímico del óxido mixto de cobre y plata, Ag2Cu2O3 ,mediante voltametría cíclica y electrólisis tanto para los procesos de oxidación como de reducción. Dicho compuesto sufre varios procesos redox cuando es reducido, obteniéndose plata metálica y cobre metálico como productos finales, sin que se dé regeneración del óxido al volver a oxidar a éstos. En cambio al ser oxidado el Ag2Cu2O3, se observa la formación de una fase oxidada de estequiometría Ag2Cu2O4±δ a partir de la cual se puede regenerar el compuesto original.

  6. Photoemission study on the formation of Mo contacts to CuInSe sub 2

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, A.J.; Niles, D.W.; Kazmerski, L.L. (National Renewable Energy Laboratory, Golden, Colorado 80401 (United States)); Rioux, D.; Patel, R.; Hoechst, H. (Synchrotron Radiation Center, University of Wisconsin-Madison, 3731 Schneider Drive, Stoughton, Wisconsin 53589 (United States))

    1992-08-01

    Synchrotron radiation soft-x-ray photoemission spectroscopy was used to investigate the development of the electronic structure at the Mo/CuInSe{sub 2} interface. Mo overlayers were {ital e}-beam deposited in steps on single-crystal {ital n}-type CuInSe{sub 2} at ambient temperature. Photoemission measurements were acquired after each growth in order to observe changes in the valence-band electronic structure as well as changes in the In 4{ital d}, Se 3{ital d}, and Mo 4{ital d} core lines. Photoemission measurements on the valence-band and core lines were also obtained after annealing. The results were used to correlate the interface chemistry with the electronic structure at this interface and to directly determine the maximum possible Schottky barrier height {phi}{sub {ital b}} to be {le}0.2 eV at the Mo/CuInSe{sub 2} junction before annealing, thus showing that this contact is essentially ohmic.

  7. Structural and magnetic phase transitions in CeCu6 -xTx (T =Ag ,Pd )

    Science.gov (United States)

    Poudel, L.; de la Cruz, C.; Payzant, E. A.; May, A. F.; Koehler, M.; Garlea, V. O.; Taylor, A. E.; Parker, D. S.; Cao, H. B.; McGuire, M. A.; Tian, W.; Matsuda, M.; Jeen, H.; Lee, H. N.; Hong, T.; Calder, S.; Zhou, H. D.; Lumsden, M. D.; Keppens, V.; Mandrus, D.; Christianson, A. D.

    2015-12-01

    The structural and the magnetic properties of CeCu6 -xAgx (0 ≤x ≤0.85 ) and CeCu6 -xPdx (0 ≤x ≤0.4 ) have been studied using neutron diffraction, resonant ultrasound spectroscopy (RUS), x-ray diffraction measurements, and first principles calculations. The structural and magnetic phase diagrams of CeCu6 -xAgx and CeCu6 -xPdx as a function of Ag/Pd composition are reported. The end member, CeCu6, undergoes a structural phase transition from an orthorhombic (P n m a ) to a monoclinic (P 21/c ) phase at 240 K. In CeCu6 -xAgx , the structural phase transition temperature (Ts) decreases linearly with Ag concentration and extrapolates to zero at xS ≈0.1 . The structural transition in CeCu6 -xPdx remains unperturbed with Pd substitution within the range of our study. The lattice constant b slightly decreases with Ag/Pd doping, whereas a and c increase with an overall increase in the unit cell volume. Both systems, CeCu6 -xAgx and CeCu6 -xPdx , exhibit a magnetic quantum critical point (QCP), at x ≈0.2 and x ≈0.05 , respectively. Near the QCP, long range antiferromagnetic ordering takes place at an incommensurate wave vector (δ10 δ2), where δ1˜0.62 ,δ2˜0.25 ,x =0.125 for CeCu6 -xPdx and δ1˜0.64 ,δ2˜0.3 ,x =0.3 for CeCu6 -xAgx . The magnetic structure consists of an amplitude modulation of the Ce moments which are aligned along the c axis of the orthorhombic unit cell.

  8. Enlace y estereoquímica en compuestos monovalentes de Cu, Ag y Au

    OpenAIRE

    Carvajal Barba, Mª Àngels

    2004-01-01

    [spa] En esta tesis se tratan diversos aspectos de la química de Cu(I), Ag(I) y Au(I). En primer lugar se estudia sistemáticamente la capacidad de los funcionales de la densidad B3LYP, PBE0 y PBE1 para tratar las interacciones d10···d10 y otros tipos de interacciones intermoleculares, tales como enlace de hidrógeno fuerte, débil y moderado e interacciones de Van der Waals. Se estudia el problema del número de coordinación en compuestos de Cu(I), Ag(I) y Au(I): mientras que Cu(I) y Ag(I) forma...

  9. 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

    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...... 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...... are 99.10+/-1.26 GPa and 4.25+/-0.16, respectively. The compression behavior of different Bragg peaks is isotropic and the full width at half maximum of each peak remains almost unchanged during compression, indicating no anisotropic elasticity and no defects in the icosahedral Zr...

  10. Behavior and influence of Pb and Bi in Ag-Cu-Zn brazing alloy

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The effects of trace content of Pb and Bi elements on the spreading property and the strength of brazed joints of Ag-Cu-Zn filler metal have been studied. The results show that Pb has little effect on both above properties, and Bi has remarkable influence on the spreading property but little effect on the strength of brazed joint. Pb and Bi dissolve into the Ag-Cu-Zn matrix and will melt and gather at lower temperature when that alloy is being heated. Therefore a liquid forms on the surface of the Ag-Cu-Zn alloy and overlays the melting alloy, then keeps the filler metal away from the materials being joined, and so decreases the spreading property.

  11. Electromigration Behaviors of Cu Reinforced Sn-3.5Ag Composite Solder Joints

    Science.gov (United States)

    Wang, Yan; Han, Jing; Ma, Limin; Zuo, Yong; Guo, Fu

    2016-09-01

    The composite approach, by incorporating small amounts of reinforcement particles in the solder matrix, has proven to be one of the effective ways to improve the reliability of solder joints. The effects of Cu addition on electromigration were investigated in this study by incorporating 2% volume fraction Cu particles into Sn-3.5Ag eutectic solder paste by the in situ process. The one-dimensional solder joints, designed to prevent the current crowding effect, were stressed under a constant current density of 104 A/cm2 at room temperature, and the temperature of the sample could reach 105 ± 5°C due to the Joule heating effect. Doping 2 vol.% Cu was found to retard the electromigration phenomenon effectively. After electric current stressing for 528 h, the growth rate of an interfacial intermetallic compound (IMC) layer at the anode decreased 73% in contrast to that of Sn-3.5Ag solder joints, and the IMC layer at the cathode was almost unchanged. The polarization effect of Cu reinforced composite solder joints was also apparently mitigated. In addition, the surface damage of the composite solder joints was relieved by incorporating 2 vol.% Cu particles. Compared to Sn-3.5Ag solder joints, which had protruded Cu6Sn5 and wrinkles of Sn-solder matrix on the surface, the solder joints with Cu addition had a more even surface.

  12. Electromigration Behaviors of Cu Reinforced Sn-3.5Ag Composite Solder Joints

    Science.gov (United States)

    Wang, Yan; Han, Jing; Ma, Limin; Zuo, Yong; Guo, Fu

    2016-12-01

    The composite approach, by incorporating small amounts of reinforcement particles in the solder matrix, has proven to be one of the effective ways to improve the reliability of solder joints. The effects of Cu addition on electromigration were investigated in this study by incorporating 2% volume fraction Cu particles into Sn-3.5Ag eutectic solder paste by the in situ process. The one-dimensional solder joints, designed to prevent the current crowding effect, were stressed under a constant current density of 104 A/cm2 at room temperature, and the temperature of the sample could reach 105 ± 5°C due to the Joule heating effect. Doping 2 vol.% Cu was found to retard the electromigration phenomenon effectively. After electric current stressing for 528 h, the growth rate of an interfacial intermetallic compound (IMC) layer at the anode decreased 73% in contrast to that of Sn-3.5Ag solder joints, and the IMC layer at the cathode was almost unchanged. The polarization effect of Cu reinforced composite solder joints was also apparently mitigated. In addition, the surface damage of the composite solder joints was relieved by incorporating 2 vol.% Cu particles. Compared to Sn-3.5Ag solder joints, which had protruded Cu6Sn5 and wrinkles of Sn-solder matrix on the surface, the solder joints with Cu addition had a more even surface.

  13. Fabrication of Z-scheme Ag3PO4/MoS2 composites with enhanced photocatalytic activity and stability for organic pollutant degradation

    Science.gov (United States)

    Zhu, Chaosheng; Zhang, Lu; Jiang, Bo; Zheng, Jingtang; Hu, Ping; Li, Sujuan; Wu, Mingbo; Wu, Wenting

    2016-07-01

    In this study, highly efficient visible-light-driven Ag3PO4/MoS2 composite photocatalysts with different weight ratios of MoS2 were prepared via the ethanol-water mixed solvents precipitation method and characterized by ICP, XRD, HRTEM, FE-SEM, BET, XPS, UV-vis DRS and PL analysis. Under visible-light irradiation, Ag3PO4/MoS2 composites exhibit excellent photocatalytic activity towards the degradation of organic pollutants in aqueous solution. The optimal composite with 0.648 wt% MoS2 content exhibits the highest photocatalytic activity, which can degrade almost all MB under visible-light irradiation within 60 min. Recycling experiments confirmed that the Ag3PO4/MoS2 catalysts had superior cycle performance and stability. The photocatalytic activity enhancement of Ag3PO4/MoS2 photocatalysts can be mainly ascribed to the efficient separation of photogenerated charge carriers and the stronger oxidation and reduction ability through a Z-scheme system composed of Ag3PO4, Ag and MoS2, in which Ag particles act as the charge separation center. The high photocatalytic stability is due to the successful inhibition of the photocorrosion of Ag3PO4 by transferring the photogenerated electrons of Ag3PO4 to MoS2. The evidence of the Z-scheme photocatalytic mechanism of the composite photocatalysts could be obtained from the active species trapping experiments and the photoluminescence technique.

  14. Aging kinetics in the Cu-8 wt.% Al alloy with Ag additions

    Energy Technology Data Exchange (ETDEWEB)

    Adorno, A.T.; Guerreiro, M.R.; Silva, R.A.G

    2003-05-12

    The influence of additions of 2, 4, 6, 8, 10 and 12 wt.% Ag in the isothermal aging kinetics of the Cu-8 wt.% Al alloy was studied using microhardness measurements, differential scanning calorimetry, optical and scanning electron microscopy and X-ray diffractometry. The results indicate that the presence of silver is responsible for the shift of the equilibrium concentration to higher Al contents, allowing the formation of the {gamma}{sub 1} phase (Al{sub 4}Cu{sub 9}) in this alloy. For Ag additions up to 6% the dominant kinetic process is Ag precipitation and for additions from 8 to 12% Ag the nucleation of the perlitic phase dominates.

  15. Controlled growth of ultrathin Mo2C superconducting crystals on liquid Cu surface

    Science.gov (United States)

    Geng, Dechao; Zhao, Xiaoxu; Li, Linjun; Song, Peng; Tian, Bingbing; Liu, Wei; Chen, Jianyi; Shi, Dong; Lin, Ming; Zhou, Wu; Loh, Kian Ping

    2017-03-01

    Exhibiting thickness-dependent change in the critical temperature (T c) for the onset of superconductivity, Mo2C has emerged as an important new member in the family of two-dimensional atomic crystals. Controllable growth in terms of morphology and thickness is necessary to elucidate its intrinsic properties at the 2D limit. Here we demonstrate the chemical vapor deposition of ultrathin Mo2C crystals on liquid Cu surface where the morphology of the crystals can be controlled by tuning the carbon supersaturation. A unique staggered carbon vacancy ordering is discovered in Mo2C crystals having particular geometries. Thickness engineering of the crystal can be achieved by controlling the thickness of the Cu catalyst layer, which affords a facile route to grow ultrathin 2D samples. Ultrathin Mo2C crystals so obtained, have been characterized using aberration corrected scanning transmission electron microscopy annular dark field imaging, where the co-existence of both AA and AB stacking modes is observed. The high crystallinity of the Mo2C crystals synthesized in this work is attested by its characteristic sharp superconducting transition.

  16. Structure and properties of α-AgFe 2(MoO 4) 3

    Science.gov (United States)

    Balsanova, L.; Mikhailova, D.; Senyshyn, A.; Trots, D.; Fuess, H.; Lottermoser, W.; Ehrenberg, H.

    2009-06-01

    Silver diiron tris(oxomolybdate), α-AgFe 2(MoO 4) 3, was synthesized in sealed silica tubes at 1050 K and is isostructural to α-NaFe 2(MoO 4) 3, determined by single-crystal X-ray diffraction (space group P-1, a = 6.9320(7) Å, b = 6.9266(6) Å, c = 10.9732(13) Å, α = 81.197(8)°, β = 83.456(9)°, γ = 81.352(8)° at 300 K, Z = 2). The crystal structure is built up from both monomers and edge-sharing dimers of [FeO 6]-octahedra, which are linked with each other by isolated [MoO 4]-tetrahedra to a three-dimensional network. Ag ions are situated on a site with four near oxygen neighbours. Thermal expansion is most pronounced along the c-axis, while the angle α decreases with increasing temperature. Antiferromagnetic ordering is indicated by a sharp maximum in the temperature dependence of magnetization at 21.5(5) K, and a magnetic moment of 5.36(1) μ B per Fe-ion was derived from the Curie constant in the paramagnetic region. The collinear antiferromagnetic structure with propagation vector k = (0,½,½) and an ordered magnetic moment of 4.62(9) μ B per Fe-ion were deduced from neutron powder diffraction data and give evidence for an underlying magnetic interaction mechanism, resulting in rather strong and long-ranged couplings. Mössbauer spectroscopy shows a change in the electronic configuration on the two distinct Fe sites between room temperature and 150 K, accompanied by an increase of the average Fe-O distance for one site and a shrinking one for the other as expected for charge ordering in a mixed valence compound with Fe(II) and Fe(III).

  17. 一种新型的Cu-P-Ag-In-Sb钎料的研究%Investigation of new Cu-P-Ag-In-Sb filler alloy

    Institute of Scientific and Technical Information of China (English)

    王晓蓉; 余丁坤; 贺艳明; 黄世盛; 陈融; 刘美玲; 杨胜凡

    2013-01-01

    A certain mass content of Ag,In and Sb were added into Cu-P filler alloy to decrease its melting temperature and brittleness. The effect of added constituents on the melting temperature,wettability,mechanical properties and brazing properties of filler alloy were analyzed by optical microscopy, scanning electron microscopy and differential scanning calorimetry. The results indicated that the added constituents are u-niformly dispersed in the filler alloy. Compared with the traditional Cu-P filler,the melting temperature of the new Cu-P-Ag-In-Sb filler alloy is 697 ~ 711 ℃. The wettability area of the Cu-P-Ag-In-Sb filler alloy is larger than that of Cu-P filler alloy at the same experimentation temperature. The tensile tests indicated that the tensile strength of the new filler alloy can research 718. 1 MPa. In addition,the new filler alloy is used to join copper and brass,and a compact bonding is obtained at the substrates/filler alloy interface. All kinds of phases are uniformly dispersed in the brazing seam,and no defects are detected. At last,the new Cu-P-Ag-In-Sb filler alloy satisfies the requirement.%为了降低Cu-P钎料的熔化温度和改善其脆性,该研究在Cu-P钎料内复合一定质量分数的Ag,In和Sb,利用金相显微镜、扫描电镜、差热分析仪等研究了添加组元对钎料显微组织、熔化温度、铺展性、力学性能和钎焊性能的影响.结果表明,各添加组元在钎料内分布均匀,实现了预期的目标;添加3种组元后钎料的熔化温度为697 ~711℃,与传统的Cu-P钎料相比已大为降低;相同的钎焊温度下,添加Ag,In和Sb的Cu-P钎料的铺展面积明显大于Cu-P钎料;拉伸试验表明,五元系钎料的抗拉强度达到了718.1 MPa.此外,采用该钎料钎焊黄铜与紫铜得到的接头内母材/钎料界面处形成了致密的连接,无缺陷存在;钎缝组织内各相分布均匀,无气孔夹渣存在,满足使用要求.

  18. Preparation of CuO-Ag/SiO2 Nano-Composites via Adsorption Phase Reaction Technique%吸附法制备CuO-Ag/SiO2纳米复合物

    Institute of Scientific and Technical Information of China (English)

    邓辉; 蒋新

    2011-01-01

    CuO/SiO2, CuO-Ag/Si02 nanocomposites were in-situ synthesized via adsorption phase reaction technique.The influence of pre-doped nano-Ag on the preparation of CuO was discussed in different reaction systems.The results showed that the influence of Ag nanoparticles on the synthesis of CuO depended on the species of the adsorbent.Using Cu(Ac)2 as adsorbent, nano Ag showed little effect on the synthesis of CuO, while using NaOH as adsorbent, nano Ag promoted the grain size of CuO.This was absolutely different from the influence of copper species on the grain size of Ag.Via comparing the adsorption behavior of different adsorbents, the interaction between Cu(OH)2 and silica surface was considered to be responsible for this phenomena.%利用吸附法原位制备CuO/SiO2、CuO-Ag/SiO2纳米复合物,研究了不同吸附质体系中预负载的纳米Ag粒子对CuO的影响.结果表明:Ag粒子对CuO的影响因吸附质的不同而不同.以Cu(Ac)2为吸附质,纳米Ag几乎没有影响;以NaOH为吸附质,纳米Ag使得CuO的晶粒粒径增大.这一结果与铜物种对Ag晶粒粒径的影响规律完全不同.通过比较不同吸附质的吸附行为,Cu(OH)2与硅胶表面的相互作用被认为是导致这一现象的因为.

  19. Influence of Mo/MoSe{sub 2} microstructure on the damp heat stability of the Cu(In,Ga)Se{sub 2} back contact molybdenum

    Energy Technology Data Exchange (ETDEWEB)

    Theelen, Mirjam, E-mail: mirjam.theelen@tno.nl [TNO Solliance, Thin Film Technology, High Tech Campus 21, 5656 AE Eindhoven (Netherlands); Delft University of Technology, Photovoltaic Materials and Devices, Mekelweg 4, 2628 CD Delft (Netherlands); Harel, Sylvie [Institut des Matériaux Jean Rouxel (IMN)-UMR 6502, Université de Nantes, CNRS, 2 rue de la Houssinière, BP 32229, 44322 Nantes Cedex 3 (France); Verschuren, Melvin [TNO Solliance, Thin Film Technology, High Tech Campus 21, 5656 AE Eindhoven (Netherlands); Tomassini, Mathieu [Institut des Matériaux Jean Rouxel (IMN)-UMR 6502, Université de Nantes, CNRS, 2 rue de la Houssinière, BP 32229, 44322 Nantes Cedex 3 (France); Hovestad, Arjan [TNO Solliance, Thin Film Technology, High Tech Campus 21, 5656 AE Eindhoven (Netherlands); Barreau, Nicolas [Institut des Matériaux Jean Rouxel (IMN)-UMR 6502, Université de Nantes, CNRS, 2 rue de la Houssinière, BP 32229, 44322 Nantes Cedex 3 (France); Berkum, Jurgen van [Philips Innovation Services, High Tech Campus 11, 5656 AE Eindhoven (Netherlands); Vroon, Zeger [TNO Solliance, Thin Film Technology, High Tech Campus 21, 5656 AE Eindhoven (Netherlands); Zeman, Miro [Delft University of Technology, Photovoltaic Materials and Devices, Mekelweg 4, 2628 CD Delft (Netherlands)

    2016-08-01

    The degradation behavior of Mo/MoSe{sub 2} layers have been investigated using damp heat exposure. The two studied molybdenum based films with different densities and microstructures were obtained by lifting off Cu(In,Ga)Se{sub 2} layers from a bilayer molybdenum stack on soda lime glass. Hereby, a glass/Mo/MoSe{sub 2} was obtained, which resembles the back contact as present in Cu(In,Ga)Se{sub 2} solar cells. The samples were degraded for 150 h under standard damp heat conditions and analyzed before, during and after degradation. It was observed that the degradation resulted in the formation of needles and molybdenum oxide layers near the glass/Mo and the Mo/Cu(In,Ga)Se{sub 2} interfaces. X-ray Photoelectron Spectroscopy measurements have shown that the sodium was also present at the surface of the degraded material and it is proposed that the degraded material consists mostly of MoO{sub 3} with intercalated Na{sup +}. This element has likely migrated from the soda lime glass. This intercalation process could have led to the formation of Na{sub x}MoO{sub 3} ‘molybdenum bronze’ following this redox reaction: xNa{sup +} + MoO{sub 3} + xe{sup −} ↔ Na{sub x}MoO{sub 3} It is proposed that the formed oxide layer contains Na{sub x}MoO{sub 3} with different Na{sup +} contents and different grades of conductivity. This intercalation process can also explain the high mobility of Na{sup +} via the grain boundaries in molybdenum. It was also observed that the molybdenum film with a top layer deposited at a high pressure is more susceptible for damp heat degradation. - Highlights: • SLG/high pressure Mo/low pressure Mo/MoSe{sub 2} stacks were exposed to damp heat. • Molybdenum deposited at low pressure retained the best reflectivity and conductivity. • Damp heat exposure leads to a Na{sub x}MoO{sub 3}/Mo multilayer structure. • The Na{sub x}MoO{sub 3} probably consists of Na{sup +} intercalated in a (reduced) MoO{sub 3} matrix. • Intercalation can explain the

  20. Primary solidification phases of the Sn-rich Sn-Ag-Cu-Ni quaternary system

    Science.gov (United States)

    Chang, Cheng-An; Chen, Sinn-Wen; Chiu, Chen-Nan; Huang, Yu-Chih

    2005-08-01

    The eutectic and near-eutectic Sn-Ag-Cu solders are the most promising lead-free solders, and nickel is frequently used as the barrier layer material. Nickel dissolves into the molten Sn-Ag-Ni alloy during the soldering process, and the ternary solder becomes a Sn-Ag-Cu-Ni quaternary melt near the nickel substrate. Liquidus projection is the projection of the liquidus trough and it delineates the boundaries of various primary solidification phases. Information of liquidus projection is helpful for understanding the alloys’ solidification behavior. This study prepared the Sn-Ag-Cu-Ni alloys of various compositions at the Sn-rich corner. The alloys were melted at higher temperatures and solidified in air. The solidified alloys were metallographically examined to determine the phases formed, especially the primary solidification phases. No ternary or quaternary compounds were found. The knowledge of the primary solidification phases, phase formation sequences, and reaction temperatures determined in this study were put together with all of the available liquidus projections of the constituent ternary systems to determine the primary solidification phases of the quaternary Sn-Ag-Cu-Ni system at the Sn-rich corner.

  1. Thermophysical Properties of Sn-Ag-Cu Based Pb-Free Solders

    Science.gov (United States)

    Kim, Sok Won; Lee, Jaeran; Jeon, Bo-Min; Jung, Eun; Lee, Sang Hyun; Kang, Kweon Ho; Lim, Kwon Taek

    2009-06-01

    Lead-tin (Pb-Sn) alloys are the dominant solders used for electronic packaging because of their low cost and superior properties required for interconnecting electronic components. However, increasing environmental and health concerns over the toxicity of lead, combined with global legislation to limit the use of Pb in manufactured products, have led to extensive research and development studies of lead-free solders. The Sn-Ag-Cu ternary eutectic alloy is considered to be one of the promising alternatives. Except for thermal properties, much research on several properties of Sn-Ag-Cu alloy has been performed. In this study, five Sn-xAg-0.5Cu alloys with variations of Ag content x of 1.0 mass%, 2.5 mass%, 3.0 mass%, 3.5 mass%, and 4.0 mass% were prepared, and their thermal diffusivity and specific heat were measured from room temperature to 150 °C, and the thermal conductivity was calculated using the measured thermal diffusivity, specific heat, and density values. Also, the linear thermal expansion was measured from room temperature to 170 °C. The results show that Sn-3.5Ag-0.5Cu is the best candidate because it has a maximum thermal conductivity and a low thermal expansion, which are the ideal conditions to be a proper packaging alloy for effective cooling and thermostability.

  2. Topological description of mechanical behavior of Cu, Ag and Au: A first-principle study

    Directory of Open Access Journals (Sweden)

    M Saghayezhian

    2011-12-01

    Full Text Available  Mechanical properties and stress-strain curves of Cu, Ag and Au single crystals are calculated using ab initio methods. Elastic and Plastic regions are scrutinized. Yield stress and slope of these curves can shed light on brittlenesss and ductility of these metals that prove Cu, despite its high ultimate tensile strength, is less ductile than Au and Ag. Analysis of topology of charge density along with stress-strain curves shows that the elastic-plastic transition accompanies topological transition and for these metals, both transitions occur in the same strain. Some charactristics of critical point, especially bond points, are inspected.

  3. Ageing behavior in the Cu-10 wt.%Al and Cu-10 wt.%Al-4 wt.%Ag alloys

    Energy Technology Data Exchange (ETDEWEB)

    Adorno, A.T. [Departamento de Fisico-Quimica, Instituto de Quimica-Unesp, Caixa Postal 355, 14801-970 Araraquara SP (Brazil)], E-mail: atadorno@iq.unesp.br; Silva, R.A.G. [Departamento de Fisico-Quimica, Instituto de Quimica-Unesp, Caixa Postal 355, 14801-970 Araraquara SP (Brazil)

    2009-04-03

    In this work the ageing behavior in the Cu-10 wt.%Al and Cu-10 wt.%Al-4 wt.%Ag alloys was studied using microhardness measurements, differential scanning calorimetry (DSC), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX) and in situ high temperature X-ray diffractometry (XRD). The results indicated that the presence of Ag disturbs the ({alpha} + {gamma}{sub 1}) pearlitic formation in the Cu-10%Al, stabilize the martensitic phase and causes the reaction of the consumption of {alpha} phase to be the dominant process on ageing at the temperature and time ranges considered. This is due the dissolution of Cu atoms in the martensitic matrix which decreases the Al relative fraction, thus decreasing the ordering degree of the {beta}{sup '}{yields}{beta}{sup '}{sub 1} ordered martensite and making the consumption of {alpha} phase the dominant process. This process is intensified by the presence of Ag precipitates that will interfere in the Al diffusion process.

  4. Phase evolution during CuInSe{sub 2} electrodeposition on polycrystalline Mo

    Energy Technology Data Exchange (ETDEWEB)

    Saucedo, E., E-mail: edgardo.saucedo@hotmail.co [Institut de Recherche et Developement sur l' Energie Photovoltaique (IRDEP), 6 Quai Watier-BP 49, 78401 Chatou cedex (France); Ruiz, C.M.; Chassaing, E.; Jaime-Ferrer, J.S.; Grand, P.P.; Savidand, G.; Bermudez, V. [Institut de Recherche et Developement sur l' Energie Photovoltaique (IRDEP), 6 Quai Watier-BP 49, 78401 Chatou cedex (France)

    2010-05-03

    Using structural analyses means of ex-situ Raman spectroscopy and X-ray diffraction combined with electrical measurements, we study the phase evolution in the growth by electrodeposition technique of CuInSe{sub 2} on polycrystalline Mo. For this purpose the growth was stopped at different stages, and then the different layers were analysed. First growth steps seem to be controlled by the deposition of secondary phases, like elemental Se and Cu{sub 2}Se binary. After the deposition of approximately 300 nm of material, CuInSe{sub 2} ternary and ordered vacancy compounds start to adequately form. At a thickness close to 2000 nm, the formation of binary Cu{sub x}Se is observed, remaining up to the final growth process (4350 nm). All these results are compared with the kinetic model of the system under the consideration of the experimental composition evolution.

  5. Effect of microstructure on corrosion behavior of Ag-30Cu-27Sn alloy in vitro media

    Energy Technology Data Exchange (ETDEWEB)

    Salehisaki, Mehdi, E-mail: mehdisasaki@ut.ac.ir [Department of Materials Science and Engineering, University of Tehran, Tehran (Iran, Islamic Republic of); Aryana, Maryam, E-mail: maryam.aryana@yahoo.com [AGSP Engineering Company, Biomaterial Research Unit, R.N: 12786 Kerman (Iran, Islamic Republic of)

    2014-04-01

    Highlights: • High cooling rates decrease the number of Ag intermetallic particles in Cu-rich phase. • Increasing cooling rate improves corrosion behavior of Ag-30Cu-27Sn dental alloy. • Cathode/anode ratio in Cu-rich phases determines the corrosion behavior of alloy. - Abstract: In the present work, three simple heat treatment cycles were used to study the effects of microstructure on electrochemical corrosion behavior of Ag-30Cu-27Sn dental alloy. The electrochemical impedance spectroscopy (EIS) measurements and potentiodynamic polarization tests were carried out to investigate the corrosion behavior of as-cast and heat treated samples in synthetic saliva solution. The presence of intermetallic compounds were studied by X-ray diffraction method (XRD) and scanning electron microscopy (SEM) with energy dispersive X-ray detector (EDAX). The microstructural observations and electrochemical corrosion results revealed that, increasing the cooling rate improves the corrosion behavior of under investigation samples. Improvement of the corrosion behavior is attributed to reducing the area of fine distributed Ag{sub 3}Sn islands in the Cu-rich matrix which decrease the cathode/anode ratio of microgalvanic cells.

  6. Simple thermodynamic model of the extension of solid solution of Cu-Mo alloys processed by mechanical alloying

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar, C., E-mail: claudio.aguilar@usm.cl [Departamento de Ingenieria Metalurgica y de Materiales, Universidad Tecnica Federico Santa Maria, Avenida Espana 1680, Valparaiso (Chile); Guzman, D. [Departamento de Metalurgia, Facultad de Ingenieria, Universidad de Atacama, Av. Copayapu 485, Copiapo (Chile); Rojas, P.A. [Escuela de Ingenieria Mecanica, Facultad de Ingenieria, Pontificia Universidad Catolica de Valparaiso, Av. Los Carrera 01567, Quilpue (Chile); Ordonez, Stella [Departamento de Ingenieria Metalurgica, Facultad de Ingenieria, Universidad de Santiago de Chile, Av. L. Bernardo O' Higgins 3363, Santiago (Chile); Rios, R. [Instituto de Materiales y Procesos Termomecanicos, Facultad de Ciencias de la Ingenieria, Universidad Austral de Chile, General Lagos 2086, Valdivia (Chile)

    2011-08-15

    Highlights: {yields} Extension of solid solution in Cu-Mo systems achieved by mechanical alloying. {yields} Simple thermodynamic model to explain extension of solid solution of Mo in Cu. {yields} Model gives results that are consistent with the solubility limit extension reported in other works. - Abstract: The objective of this work is proposing a simple thermodynamic model to explain the increase in the solubility limit of the powders of the Cu-Mo systems or other binary systems processed by mechanical alloying. In the regular solution model, the effects of crystalline defects, such as; dislocations and grain boundary produced during milling were introduced. The model gives results that are consistent with the solubility limit extension reported in other works for the Cu-Cr, Cu-Nb and Cu-Fe systems processed by mechanical alloying.

  7. Ag-Cu-Ti合金与ZrO2陶瓷的润湿性及界面特征%Wettability and interface characteristics of Ag-Cu-Ti/ZrO2 system

    Institute of Scientific and Technical Information of China (English)

    刘玉华; 庄宇; 胡建东; 韩先贺

    2014-01-01

    Wettability and interface characteristics of Ag-Cu-Ti/ZrO2 system were studied by an improved sessile drop method. Wettability and interface morphology of Ag-Cu-Ti/ZrO2 system were investigated in detail by ADSA ( Axisymmetric drop shape analysis)-SESDROPD, X-ray diffractometer (XRD), Field emission scanning electron microscopy (FESEM) and scanning electron microscopy ( SEM) with spectrometer ( EDS) . The results show that:the wetting of molten Ag-Cu-Ti metallic glass alloy on the ZrO2 substrate belongs to the reactive wetting. With the increase in the content of Ti, the wettability of Ag-Cu-Ti/ZrO2 systems are improved significantly. There is the anomalous dependence of wettability of Ag54 Cu4 3 Ti4/ZrO2 system on the temperatures. Ag53 Cu41 Ti6 alloy has good wettability. With the increase of temperature, Ag54 Cu43 Ti4/ZrO2 and Ag53 Cu41 Ti6/ZrO2 interfaces reaction product TiO phase gradually thickening, Cu3 Ti3 O reaction layer is thinning;Ag50 Cu40 Ti10/ZrO2 interface, a big lump of intermetallic compound Cu3 Ti3 O, is easy to result in stripping of alloy and ceramic interface.%通过改良座滴法研究了 Ag-Cu-Ti/ZrO2陶瓷体系的润湿行为和界面特征[1]。采用 ADSA ( axisymmetric drop shape analysis )-SESDROPD 分析软件, X 射线衍射仪( XRD ),场发射扫描电镜( FESEM)以及配有能谱仪( EDS)的扫描电镜( SEM)测量表征了温度变化下,不同Ti含量的Ag-Cu-Ti合金在ZrO2陶瓷基板上的润湿性及其界面微观结构的影响规律。结果表明:Ag-Cu-Ti/ZrO2陶瓷体系的润湿机制为反应性润湿。 Ag-Cu-Ti合金在ZrO2陶瓷基板上的润湿性随Ti含量的增加逐渐改善。 Ag54 Cu43 Ti4合金熔体在ZrO2陶瓷基板上的润湿性对温度具有明显的反常依赖性,Ag53 Cu41 Ti6合金的润湿性较好。随温度的升高, Ag54 Cu43 Ti4/ZrO2和 Ag53 Cu41 Ti6/ZrO2界面反应产物 TiO 反应层逐渐增厚, Cu3 Ti3 O反应层有逐渐变薄的趋势。 Ag50 Cu40

  8. Low temperature properties of organic-inorganic Ag/p-CuPc/n-GaAs/Ag photoelectric sensor

    Institute of Scientific and Technical Information of China (English)

    Kh.S.KARIMOV; I.QAZI; T.A.KHAN; M.I.FEDOROV

    2008-01-01

    A thin organic film of p-type semiconducting copper phthalocynanine (CuPc) was deposited by vacuum evaporation on an n-type GaAs single-crystal semiconductor substrate. The fabricated Ag/p-CuPc/n-GaAs/Ag sensor was carried through an ageing process to stabilize the parameters. Voltage-current characteristics and photoelectrical response of the sensor were investigated at a wide temperature range of 82 to 350 K. Photoelectric characteristics were measured under nonmodulated filament-lamp illumination. It was observed that such sensor parameters as rectification ratio, threshold voltage, junction, shunt and series resistances, open-circuit voltage and short circuit current are temperature-dependent. It was found that wide-range voltage-current characteristics of the sensor may be de scribed similarly to that of a Schottky barrier diode. Using the experimental data on voltage-current characteristics and absorbance of the CuPc films, the energy-band diagram of the p-CuPc/n-GaAs heterojunction was developed. It was shown that data obtained from simulation of an equivalent circuit of photoelectric sensor agreed with experimental results.

  9. Irradiation induced dissolution of Cu and growth of Ag nanoclusters in Cu/Ag ion-exchanged soda-lime glass

    CERN Document Server

    Manikandan, D; Magudapathy, P; Nair, K G M

    2002-01-01

    Complex metal nanoclusters of Cu/Ag are formed in a soda-lime glass matrix by sequential copper and silver ion-exchange followed by ion irradiation. Optical absorption measurements showed signature of copper clusters alone in the Cu/Ag ion-exchanged sample. Irradiation of the ion-exchanged sample with He sup + ions of energy 100 keV of different fluences resulted in the growth of the silver clusters with, the optical absorption spectrum exhibiting two peaks corresponding to the surface plasmon resonance of copper and silver in the same matrix. It was found that with increase in fluence the silver clusters begin to grow while the already formed copper clusters segregate, which can be visualized from the absorption spectra, where the copper band disappears while the silver band grows with the increase in dose. Vacuum annealing of the Cu/Ag ion-exchanged samples resulted in complete disappearance of copper clusters while the silver clusters grew till they attained saturation. The glancing incidence X-ray diffrac...

  10. Global optimization and oxygen dissociation on polyicosahedral Ag32Cu6 core-shell cluster for alkaline fuel cells.

    Science.gov (United States)

    Zhang, N; Chen, F Y; Wu, X Q

    2015-07-07

    The structure of 38 atoms Ag-Cu cluster is studied by using a combination of a genetic algorithm global optimization technique and density functional theory (DFT) calculations. It is demonstrated that the truncated octahedral (TO) Ag32Cu6 core-shell cluster is less stable than the polyicosahedral (pIh) Ag32Cu6 core-shell cluster from the atomistic models and the DFT calculation shows an agreeable result, so the newfound pIh Ag32Cu6 core-shell cluster is further investigated for potential application for O2 dissociation in oxygen reduction reaction (ORR). The activation energy barrier for the O2 dissociation on pIh Ag32Cu6 core-shell cluster is 0.715 eV, where the d-band center is -3.395 eV and the density of states at the Fermi energy level is maximal for the favorable absorption site, indicating that the catalytic activity is attributed to a maximal charge transfer between an oxygen molecule and the pIh Ag32Cu6 core-shell cluster. This work revises the earlier idea that Ag32Cu6 core-shell nanoparticles are not suitable as ORR catalysts and confirms that Ag-Cu nanoalloy is a potential candidate to substitute noble Pt-based catalyst in alkaline fuel cells.

  11. Effect of La addition on the IMC of SnAgCu/Cu and Ni%La对SnAgCu/Cu及Ni界面金属间化合物的影响

    Institute of Scientific and Technical Information of China (English)

    王佳; 王丽凤; 刘学

    2011-01-01

    利用扫描电镜、能谱分析仪对Sn0.3Ag0.7Cu-xLa/Cu(x=0~0.25)和Ni界面金属间化合物(IMC)形成及长大规律进行了研究.结果表明:微量La的添加使钎焊与时效后焊点/Cu界面生成的CuSn晶粒明显细化,当X超过0.10时,CuSn晶粒的上方出现大量的粒状AgSn,晶粒表面粗化并出现孔洞.X为0.07的焊点/Ni的IMC厚度变化在时效过程中比较稳定,且超过300h时效后,其IMC厚度最小,因此,La的最佳质量分数应为0.07%.%The formation and growth of intermetallic compounds (IMC) for Sn0.3Ag0.7Cu-xLa/Cu (x = 0-0.25) and Ni were studied with the scanning electron microscope and the energy dispersive X-ray detector. The results indicate that the grain size of Cu6Sn5 in the soldering point/Cu interface is obviously refined with La addition after reflowing and aging.When x surpasses 0.10, numerous grains of Ag3Sn appear on the top of Cu6Sn5 grain, and the surface of Cu6Sn5 becomes coarsing and emerges many. holes. When x is 0.07, the thickness of IMC changes relatively stable with increment of the aging time and is minimum after 300 h aging. The optimum addition of w(La) is 0.07%.

  12. Cu-Mo2C/MCM-41: An Efficient Catalyst for the Selective Synthesis of Methanol from CO2

    Directory of Open Access Journals (Sweden)

    Xiaoran Liu

    2016-05-01

    Full Text Available Supported molybdenum carbide (yMo2C/M41 and Cu-promoted molybdenum carbide, using a mechanical mixing and co-impregnation method (xCuyMo2C/M41-M and xCuyMo2C/M41-I on a mesoporous molecular sieve MCM-41, were prepared by temperature-programmed carburization method in a CO/H2 atmosphere at 1073 K, and their catalytic performances were tested for CO2 hydrogenation to form methanol. Both catalysts, which were promoted by Cu, exhibited higher catalytic activity. In comparison to 20Cu20Mo2C/M41-M, the 20Cu20Mo2C/M41-I catalyst exhibited a stronger synergistic effect between Cu and Mo2C on the catalyst surface, which resulted in a higher selectivity for methanol in the CO2 hydrogenation reaction. Under the optimal reaction conditions, the highest selectivity (63% for methanol was obtained at a CO2 conversion of 8.8% over the 20Cu20Mo2C/M41-I catalyst.

  13. Properties and Microstructures of Sn-Ag-Cu-X Lead-Free Solder Joints in Electronic Packaging

    Directory of Open Access Journals (Sweden)

    Lei Sun

    2015-01-01

    Full Text Available SnAgCu solder alloys were considered as one of the most popular lead-free solders because of its good reliability and mechanical properties. However, there are also many problems that need to be solved for the SnAgCu solders, such as high melting point and poor wettability. In order to overcome these shortcomings, and further enhance the properties of SnAgCu solders, many researchers choose to add a series of alloying elements (In, Ti, Fe, Zn, Bi, Ni, Sb, Ga, Al, and rare earth and nanoparticles to the SnAgCu solders. In this paper, the work of SnAgCu lead-free solders containing alloying elements and nanoparticles was reviewed, and the effects of alloying elements and nanoparticles on the melting temperature, wettability, mechanical properties, hardness properties, microstructures, intermetallic compounds, and whiskers were discussed.

  14. Interfacial reactions and compound formation of Sn-Ag-Cu solders by mechanical alloying on electroless Ni-P/Cu under bump metallization

    Science.gov (United States)

    Kao, Szu-Tsung; Duh, Jenq-Gong

    2005-08-01

    Electroless Ni-P under bump metallization (UBM) has been widely used in electronic interconnections due to the good diffusion barrier between Cu and solder. In this study, the mechanical alloying (MA) process was applied to produce the SnAgCu lead-free solder pastes. Solder joints after annealing at 240°C for 15 min were employed to investigate the evolution of interfacial reaction between electroless Ni-P/Cu UBM and SnAgCu solder with various Cu concentrations ranging from 0.2 to 1.0 wt.%. After detailed quantitative analysis with an electron probe microanalyzer, the effect of Cu content on the formation of intermetallic compounds (IMCs) at SnAgCu solder/electroless Ni-P interface was evaluated. When the Cu concentration in the solder was 0.2 wt.%, only one (Ni, Cu)3Sn4 layer was observed at the solder/electroless Ni-P interface. As the Cu content increased to 0.5 wt.%, (Cu, Ni)6Sn5 formed along with (Ni, Cu)3Sn4. However, only one (Cu, Ni)6Sn5 layer was revealed, if the Cu content was up to 1 wt.%. With the aid of microstructure evolution, quantitative analysis, and elemental distribution by x-ray color mapping, the presence of the Ni-Sn-P phase and P-rich layer was evidenced.

  15. Effect of 0.5 wt % Cu addition in Sn-3.5%Ag solder on the dissolution rate of Cu metallization

    Science.gov (United States)

    Alam, M. O.; Chan, Y. C.; Tu, K. N.

    2003-12-01

    The dissolution of thin film under-bump-metallization (UBM) by molten solder has been one of the most serious processing problems in electronic packaging technology. Due to a higher melting temperature and a greater Sn content, a molten lead-free solder such as eutectic SnAg has a faster dissolution rate of thin film UBM than the eutectic SnPb. The work presented in this paper focuses on the role of 0.5 wt % Cu in the base Sn-3.5%Ag solder to reduce the dissolution of the Cu bond pad in ball grid array applications. We found that after 0.5 wt % Cu addition, the rate of dissolution of Cu in the molten Sn-3.5%Ag solder slows down dramatically. Systematic experimental work was carried out to understand the dissolution behavior of Cu by the molten Sn-3.5%Ag and Sn-3.5%Ag-0.5%Cu solders at 230-250 °C, for different time periods ranging from 1 to 10 min. From the curves of consumed Cu thickness, it was concluded that 0.5 wt % Cu addition actually reduces the concentration gradient at the Cu metallization/molten solder interface which reduces the driving force of dissolution. During the dissolution, excess Cu was found to precipitate out due to heterogeneous nucleation and growth of Cu6Sn5 at the solder melt/oxide interface. In turn, more Cu can be dissolved again. This process continues with time and leads to more dissolution of Cu from the bond pad than the amount expected from the solubility limit, but it occurs at a slower rate for the molten Sn-3.5%Ag-0.5%Cu solder.

  16. Study of tribological behavior of Cu–MoS2 and Ag–MoS2 nanocomposite lubricants

    OpenAIRE

    An, V.; Anisimov, E.; Druzyanova, V.; Burtsev, N.; Shulepov, I.; Khaskelberg, M.

    2016-01-01

    Tribological behavior of Cu–MoS2 and Ag–MoS2 nanocomposite lubricant was studied. Cu nanoparticles produced by electrical explosion of copper wires and Ag nanoparticles prepared by electrospark erosion were employed as metal cladding modifiers of MoS2 nanolamellar particles. The tribological tests showed Cu–MoS2 and Ag–MoS2 nanocomposite lubricants changed the friction coefficient of the initial grease and essentially improved its wear resistance.

  17. Photoconducting Properties of Film Composites Based on Polyvinyl Butyral and Heterometallic Cu/Mo Complexes

    Science.gov (United States)

    Davidenko, N. A.; Kokozay, V. N.; Davidenko, I. I.; Buvailo, H. I.; Makhankova, V. G.; Studzinsky, S. L.

    2016-11-01

    We have synthesized and studied novel photosensitive polymer film composites based on non-photoconducting polyvinyl butyral doped with heterometallic Cu/Mo complexes. We have established that these composites have photoconducting and photovoltaic properties and are characterized by hole-type photoconductivity. The photocurrent and the photo-EMF are higher for composites in which complexes are used that have a shorter distance between nearest-neighbor metallic copper centers, which is explained by better conditions for transport of nonequilibrium holes.

  18. Palladium, Platinum and Gold Concentrations in Fengshan Porphyry Cu-Mo Deposit, Hubei Province, China

    Institute of Scientific and Technical Information of China (English)

    WANG Minfang; DENG Xiaodong; BI Shijian; LI Zhanke

    2009-01-01

    The Fengshan porphyry-skarn copper-molybdenum (Cu-Mo) deposit is located in the south-eastern Hubei Province in east China. Cu-Mo mineralization is hosted in the Fengshan granodiorite porphyry stock that intruded the Triassic Daye Formation carbonate rocks in the early Cretaceous (~140 Ma), as well as the contact zone between granodiorite porphyry stock and carbonate rocks, forming the porphyry-type and skarn-type association. The Fengshan granodiorite stock and the immediate country rocks are strongly fractured and intensely altered by hydrothermal fluids. In addition to intense skarn alteration, the prominent alteration types are potassic, phyllic, and propylitic, whereas argillation is less common. Mineralization occurs as veins, stock works, and disseminations, and the main ore minerals are chalcopyrite, pyrite, molybdenite, bornite, and magnetite. The contents of palladium, platinum and gold (Pd, Pt and Au) are determined in nine samples from fresh and mineralized granodiorite and different types of altered rocks. The results show that the Pd content is systematically higher than Pt, which is typical for porphyry ore deposits worldwide. The Pt content ranges from 0.037 tul.765 ppb, and the Pd content ranges between 0.165and 17.979 ppb. Pd and Pt are more concentrated in porphyry mineralization than skarn mineralization, and have negative correlations with Au. The reconnaissance study presented here confirms the existence of Pd and Pt in the Fengshan porphyry-skarn Cu-Mo deposit. When compared with intracontinent and island arc geotectonic settings, the Pd, Pt, and Au contents in the Fengshan porphyry Cu-Mo deposit in the intracontinent is lower than the continental margin types and island are types. A combination of available data indicates that Pd and Pt were derived from oxidized alkaline magmas generated by the partial melting of an enriched mantle source.

  19. MoO3/Ag/MoO3 anode for organic light-emitting diodes and its carrier injection property

    Science.gov (United States)

    Banzai, Kazuki; Naka, Shigeki; Okada, Hiroyuki

    2015-05-01

    We report on the application of the dielectric/metal/dielectric (DMD) structure consisting of a molybdenum trioxide (MoO3)/silver (Ag)/MoO3 stack as the transparent electrode in organic light-emitting diodes (OLEDs). Bright emission similar to that of the indium-tin-oxide anode (ITO) device was obtained from the OLEDs with the DMD anode. Also, the barrier height at the interface of DMD/bis[N-(1-naphthyl)-N-phenyl] benzidine (α-NPD) is similar to that at the ITO/α-NPD interface. The DMD electrode is a promising anode for OLEDs.

  20. Thickness optimization of Mo films for Cu(InGa)Se2 solar cell applications

    Institute of Scientific and Technical Information of China (English)

    Li Wei; Zhao Yan-Min; Liu Xing-Jiang; Ao Jian-Ping; Sun Yun

    2011-01-01

    Mo thin films are deposited on soda lime glass (SLG) substrates using DC magnetron sputtering. The Mo film thicknesses are varied from 0.08 μm to 1.5 μm to gain a better understanding of the growth process of the film. The residual stresses and the structural properties of these films are investigated, with attention paid particularly to the film thickness dependence of these properties. Residual stress decreases and yields a typical tensile-to-compressive stress transition with the increase of film thickness at the first stages of film growth. The stress tends to be stable with the further increase of film thickness. Using the Mo film with an optimum thickness of 1 μm as the back contact, the Cu(InGa)Se2 solar cell can reach a conversion efficiency of 13.15%.

  1. Optimization of MoSe{sub 2} formation for Cu(In,Ga)Se{sub 2}-based solar cells by using thin superficial molybdenum oxide barrier layers

    Energy Technology Data Exchange (ETDEWEB)

    Duchatelet, A., E-mail: aurelien.duchatelet@edf.fr [Institute of Research and Development on Photovoltaic Energy (IRDEP), UMR 7174 EDF-CNRS-Chimie ParisTech, 6 quai Watier 78401, Chatou Cedex (France); Savidand, G. [Institute of Research and Development on Photovoltaic Energy (IRDEP), UMR 7174 EDF-CNRS-Chimie ParisTech, 6 quai Watier 78401, Chatou Cedex (France); Vannier, R.N. [Unité de Catalyse et Chimie du Solide (UCCS), UMR 8181, Ecole Nationale Supérieure de Chimie de Lille, Bat C7a-BP 90108, F-59652, Villeneuve d' Ascq (France); Lincot, D., E-mail: Daniel-Lincot@chimie-paristech.fr [Institute of Research and Development on Photovoltaic Energy (IRDEP), UMR 7174 EDF-CNRS-Chimie ParisTech, 6 quai Watier 78401, Chatou Cedex (France)

    2013-10-31

    During the formation of Cu(In,Ga)Se{sub 2} thin films deposited on Mo substrate by the selenization of Cu-In-Ga precursor, the reaction of Mo with Se can lead to a high consumption of Mo back contact and the formation of a thick MoSe{sub 2} layer, thus deteriorating the electrical properties of the back contact. In this study, the effect of thermal oxidation pre-treatment on Mo has been investigated to control the growth of MoSe{sub 2}. It has been demonstrated that a thin and covering MoO{sub 2} layer can block the selenization of Mo. Using this effect, a MoSe{sub 2} layer with controlled thickness can be formed by adding a thin and controlled Mo layer on top of an oxidized Mo substrate. In this configuration, only the Mo added on top of oxidized Mo forms MoSe{sub 2} and the whole Mo protected by MoO{sub 2} remains after selenization. Thanks to this Glass/Mo/MoO{sub 2}/Mo substrate configuration and the metallic behavior of MoO{sub 2}, the good electrical properties of the back contact are kept after selenization. - Highlights: • Selenization of Cu-In-Ga on Mo substrate produces thick detrimental MoSe{sub 2} layer. • MoO{sub 2} layer on Mo surface blocks MoSe{sub 2} formation. • Mo layer on top of MoO{sub 2}/Mo substrate enables to control MoSe{sub 2}.

  2. Microstructure and solidification behavior of multicomponent CoCrCu{sub x}FeMoNi high-entropy alloys

    Energy Technology Data Exchange (ETDEWEB)

    Wu, P.H. [School of Materials Science and Engineering, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu 212003 (China); Liu, N., E-mail: lnlynn@126.com [School of Materials Science and Engineering, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu 212003 (China); Yang, W. [School of Aeronautical Manufacturing Engineering, Nanchang Hangkong University, Nanchang, Jiangxi 330063 (China); Zhu, Z.X. [School of Materials Science and Engineering, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu 212003 (China); Lu, Y.P. [School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China); Wang, X.J. [School of Materials Science and Engineering, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu 212003 (China)

    2015-08-26

    (Fe, Co, Ni) rich dendrites nucleate primarily in CoCrFeMoNi and CoCrCu{sub 0.1}FeMoNi alloys, followed by peritetic and eutectic reactions. The quasi-peritectic reaction occurs between the primary Mo-rich dendrites and liquids in the CoCrCu{sub 0.3}FeMoNi melts, and transfers to a eutectic coupled-growth at the edge of the quasi-peritectic structure. Subsequently, eutectic reaction happens in the remnant liquids. Liquid-phase separations have occurred in CoCrCu{sub x}FeMoNi alloys when x≥0.5. Meanwhile, some nanoscale precipitates are obtained in the Cu-rich region. Two crystal structures, FCC and BCC, are identified in CoCrCu{sub x}FeMoNi high entropy alloys. Amazingly, a pretty high plastic strain (51.6%) is achieved in CoCrCu{sub 0.1}FeMoNi alloy when the compressive strength reaches to 3012 Mpa. With the increase of Cu content, atomic size difference (ΔR) and electro-negativity difference (ΔX) decrease while valence electron concentration (VEC), mixing enthalpy (ΔH) and mixing entropy (ΔS) increase. Consequently, the valence electron concentration (VEC) values range for the formation of mixture of FCC and BCC structures can be enlarged to 6.87–8.35 based on the study of this paper. It is the positive enthalpies of mixing that causes the liquid-phase separation in CoCrCu{sub x}FeMoNi high entropy alloys.

  3. Effect of Ag addition on the as-cast microstructure of Cu-8 wt.% Fe in situ composites

    Energy Technology Data Exchange (ETDEWEB)

    Xie Zhixiong [State Key Laboratory of Metal Matrix Composites, Shanghai JiaoTong University, 800 Dong Chuan Road, Shanghai 200240 (China); Gao Haiyan, E-mail: gaohaiyan@sjtu.edu.c [State Key Laboratory of Metal Matrix Composites, Shanghai JiaoTong University, 800 Dong Chuan Road, Shanghai 200240 (China); Lu Qin; Wang Jun; Sun Baode [State Key Laboratory of Metal Matrix Composites, Shanghai JiaoTong University, 800 Dong Chuan Road, Shanghai 200240 (China)

    2010-10-22

    Research highlights: {yields} Ag addition refines the primary Fe dendrites. {yields} Ag inhibits the solubility of Fe in Cu matrix at high temperature. {yields} Refinement mechanism is explained by wetting properties between Cu-Ag and {gamma}-Fe. - Abstract: Ternary copper-based composites consisting of Cu, 8 wt.% Fe and 0.1-6 wt.% Ag were prepared by inductive melting and casting. The effect of Ag addition on the as-cast microstructure was investigated using optical microscopy (OM) and scanning electron microscopy (SEM). The results show that the primary Fe dendrites in the as-cast microstructure are refined significantly with the presence of Ag. Contact angle between Cu-Ag alloy and {gamma}-Fe was measured using sessile drop technique to investigate the refinement mechanism of the primary Fe dendrites. In addition, the effect of Ag addition on the dissolution of Fe atoms in the Cu matrix at high temperature was investigated by means of energy dispersive X-ray spectroscopy (EDS). The results show that the presence of Ag inhibits the solubility of Fe in the Cu matrix at high temperature.

  4. Potential energy curves for the ground and low-lying excited states of CuAg

    Energy Technology Data Exchange (ETDEWEB)

    Alizadeh, Davood; Shayesteh, Alireza, E-mail: jamshidi@ccerci.ac.ir, E-mail: ashayesteh@ut.ac.ir [School of Chemistry, College of Science, University of Tehran, 14176 Tehran (Iran, Islamic Republic of); Jamshidi, Zahra, E-mail: jamshidi@ccerci.ac.ir, E-mail: ashayesteh@ut.ac.ir [Chemistry and Chemical Engineering Research Center of Iran, 14335-186 Tehran (Iran, Islamic Republic of)

    2014-10-21

    The ground and low-lying excited states of heteronuclear diatomic CuAg are examined by multi-reference configuration interaction (MRCI) method. Relativistic effects were treated and probed in two steps. Scalar terms were considered using the spin-free DKH Hamiltonian as a priori and spin-orbit coupling was calculated perturbatively via the spin-orbit terms of the Breit-Pauli Hamiltonian based on MRCI wavefunctions. Potential energy curves of the spin-free states and their corresponding Ω components correlating with the separated atom limits {sup 2}S(Cu) + {sup 2}S(Ag) and {sup 2}D(Cu) + {sup 2}S(Ag) are obtained. The results are in fine agreement with the experimental measurements and tentative conclusions for the ion-pair B0{sup +} state are confirmed by our theoretical calculations. Illustrative results are presented to reveal the relative importance and magnitude of the scalar and spin-orbit effects on the spectroscopic properties of this molecule. Time dependent density functional theory calculations, using the LDA, BLYP, B3LYP, and SAOP functionals have been carried out for CuAg and the accuracy of TD-DFT has been compared with ab initio results.

  5. ZnO-(Cu/Ag)TCNQ heterostructure network over flexible platform for enhanced cold cathode application

    Science.gov (United States)

    Pal, Shreyasi; Maiti, Soumen; Narayan Maiti, Uday; Chattopadhyay, Kalyan Kumar

    2016-07-01

    Multistage field emitters consisting of organic/inorganic hybrid nanostructures with branched geometry are designed via a two-step protocol: a simple wet chemical method followed by a vapor-solid-phase technique. (Cu/Ag)TCNQ (copper/silver-7,7,8,8-tetracyanoquinodimethane) nanowires (NWs) were grown hierarchically on zinc oxide (ZnO) nanorods (NRs) to form ZnO-(Cu/Ag)TCNQ heterostructure assemblies. By monitoring the metallic Cu and Ag coating thickness on ZnO NRs, precise control over the morphology and orientations of the secondary organic NWs is achieved. In-depth analysis of electron field emission (FE) behavior of the ZnO-(Cu/Ag)TCNQ-based hierarchy suggests highest emission performance with low turn-on as well as threshold fields of 1.15 and 3.75 V μm-1 respectively from the morphology-optimized hierarchy. Beneficial orientation of the branched organic NWs ensures sequential electric field enhancement in the consecutive stem and branches whereas its low work function eases electron emission; these aspects combined together render an overall enhancement in the emission behavior of the hybrid system. As compared to individual building units, the heterostructures show improved field electron emission. Additionally, successful construction of this novel hybrid over a fabric platform displays great potential in opening up new pathways in the highly-anticipated field of flexible electronics.

  6. Cu-Ag alloy Bitter type magnet for repeating pulsed field

    Energy Technology Data Exchange (ETDEWEB)

    Motokawa, M.; Nojiri, H.; Mitsudo, S. [Tohoku Univ., Sendai (Japan). Inst. for Materials Research; Arai, M.; Ubukata, K.; Fujita, M.; Arakawa, T.; Inamura, Y. [Kobe Univ. (Japan). Dept. of Physics

    1996-07-01

    Cu-Ag alloy is used for the repeating pulsed field magnets. It is found that fields up to 22 T or more will be available for this purpose instead of 16 T which is obtained with normal copper magnet used at present. This result is a big advantage for neutron diffraction experiments.

  7. Short-range ferromagnetism in alloy ribbons of Fe-Cr-Si-Nb-(Ag, Cu)

    Energy Technology Data Exchange (ETDEWEB)

    THANH, P. Q.; HOA, N. Q.; CHAU, N. [Vietnam National University, Hanoi (Viet Nam); HUU, C. X. [Danang University of Technology, Danang (Viet Nam); NGO, D. T. [Technical University of Denmark, Kgs. Lyngby (Denmark); PHAN, T. L. [Chungbuk National University, Cheongju (Korea, Republic of)

    2014-04-15

    We have studied the magnetic properties of two amorphous alloy ribbons Fe{sub 72}Cr{sub 6}Si{sub 4}Nb{sub 5}B{sub 12}Ag{sub 1} (FCSNB-Ag) and Fe{sub 72}Cr{sub 6}Si{sub 4}Nb{sub 5}B{sub 12}Cu{sub 1} (FCSNB-Cu), prepared by using a melt-spinning technique. Magnetization (M) measurements for various temperatures (T) and magnetic fields (H) indicate that ferromagnetic-paramagnetic (FM-PM) phase transitions take place in FCSNB-Ag and FCSNB-Cu at Curie temperatures (T{sub C} ) of about 308.3 K and 322.5 K, respectively. Analyses of M - H data at different temperatures in the vicinity of the FM-PM phase transition based on the modified Arrott plot method and scaling hypothesis yielded the exponent values of β = 0.369 ± 0.005, γ = 1.359 ± 0.005 and δ = 4.7 ± 0.1 for FCSNB-Ag, and β = 0.376 ± 0.002, γ = 1.315 ± 0.006 and δ = 4.5 ± 0.1 for FCSNB-Cu. Compared with the values from theoretical models, these values are close to those expected for the 3D Heisenberg model, demonstrating the existence of short-range FM order in the amorphous alloy ribbons.

  8. Fabrication of nanoporous silver by de-alloying Cu-Zr-Ag amorphous alloys

    Science.gov (United States)

    Wang, Hui; Xiao, Shang-gang; Zhang, Tao

    2016-07-01

    Nanoporous silver (NPS) with a ligament size ranging from 15 to 40 nm was fabricated by de-alloying (Cu50Zr50)100- x Ag x ( x = 10at%, 20at%, 30at%, and 40at%) amorphous ribbons in a mixed aqueous solution of hydrofluoric (HF) acid and nitric acid under free corrosion conditions. Nanoporous silver ligaments and pore sizes were able to be fine-tuned through tailoring the chemical composition, corrosion conditions, and de-alloying time. The ligament size increases with an increase in Ag content and de-alloying time, but decreases with an increase in HF concentration. This phenomenon may be attributed to the dissolution of Zr/Cu and the diffusion, aggregation, nucleation, and recrystallization of Ag, leading to an oriented attachment of adjacent nanocrystals as revealed by TEM analysis.

  9. Abundances of Ag and Cu in mantle peridotites and the implications for the behavior of chalcophile elements in the mantle

    Science.gov (United States)

    Wang, Zaicong; Becker, Harry

    2015-07-01

    Silver abundances in mantle peridotites and the behavior of Ag during high temperature mantle processes have received little attention and, as a consequence, the abundance of Ag in the bulk silicate Earth (BSE) has been poorly constrained. In order to better understand the processes that fractionate Ag and other chalcophile elements in the mantle, abundances of Ag and Cu in mantle peridotites from different geological settings (n = 68) have been obtained by isotope dilution ICP-MS methods. In peridotite tectonites and in a few suites of peridotite xenoliths which display evidence for variable extents of melt depletion and refertilization by silicate melts, Ag and Cu abundances show positive correlations with moderately incompatible elements such as S, Se, Te and Au. The mean Cu/Ag in fertile peridotites (3500 ± 1200, 1s, n = 38) is indistinguishable from the mean Cu/Ag of mid ocean ridge basalts (MORB, 3600 ± 400, 1s, n = 338) and MORB sulfide droplets. The constant mean Cu/Ag ratios indicate similar behavior of Ag and Cu during partial melting of the mantle, refertilization and magmatic fractionation, and thus should be representative of the Earth's upper mantle. The systematic fractionation of Cu, Ag, Au, S, Se and Te in peridotites and basalts is consistent with sulfide melt-silicate melt partitioning with apparent partition coefficients of platinum group elements (PGE) > Au ⩾ Te > CuAg > Se ⩾ S. Because of the effects of secondary processes, the abundances of chalcophile elements, notably S, Se, but also Cu and the PGE in many peridotite xenoliths are variable and lower than in peridotite massifs. Refertilization of peridotite may change abundances of chalcophile and lithophile elements in peridotite massifs, however, this seems to mostly occur in a systematic way. Correlations with lithophile and chalcophile elements and the overlapping mean Cu/Ag ratios of peridotites and ocean ridge basalts are used to constrain abundances of Ag and Cu in the BSE

  10. Effects of cerium on Sn-Ag-Cu alloys based on finite element simulation and experiments

    Institute of Scientific and Technical Information of China (English)

    ZHANG Liang; XUE Songbai; CHEN Yan; HAN Zongjie; WANG Jianxin; YU Shenglin; LU Fangyan

    2009-01-01

    Effect of small addition of rare earth on Sn-Ag-Cu solder was investigated by finite element method based on creep model of low stress and high stress and experiments respectively. It was found that addition of rare earths evidently improved the resistance to creep deformation of the solder, so that the reliability of Sn-Ag-Cu-Ce solder joint could be improved remarkably. Mechanical testing and microstructural analysis results showed that, mechanical properties of alloys bearing Ce were better than that of the original alloy, and the optimum content of Ce was about 0.03wt.%. After aging intermetallic compound between solder joint and Cu substrate was observed and analyzed by X-ray diffraction (XRD), scanning electron micrographs (SEM) and energy dispersive X-ray fluorescence spectrometer (EDX). Results showed that the thickness of intermetallic compound layer would became thinner when the addition of Ce was about 0.03wt.%, and the grains of intermetallic compound became finer, and the microstructure was more homogeneous than that in the original Sn-Ag-Cu/Cu interface.

  11. X-ray diffraction study of thermal parameters of Pd, Pd-Ag and Pd-Ag-Cu alloys as hydrogen purification membrane materials

    Science.gov (United States)

    Pati, Subhasis; Jat, Ram Avtar; Mukerjee, S. K.; Parida, S. C.

    2016-03-01

    High temperature X-ray diffraction measurements were carried out for pure palladium and palladium-rich alloys of compositions Pd0.77Ag0.23 and Pd0.77Ag0.10Cu0.13 in the temperature range of 298-1023 K at an interval of 50 K. The lattice parameters, coefficient of thermal expansion and X-ray Debye temperature of these materials were calculated as a function of temperature from the XRD data. The lattice parameter of Pd0.77Ag0.23 alloy was found to be higher than that of palladium, whereas the lattice parameter of Pd0.77Ag0.10Cu0.13 was found to be lower than that of palladium in the temperature range of investigation. Further, the lattice parameters of both the palladium alloys show negative deviation from Vegard's law and the deviation was found to increase with increase in temperature. The average value of coefficient of linear thermal expansion was found to follow the trend: αT (Pd)>αT (Pd0.77Ag0.23)>αT (Pd0.77Ag0.10Cu0.13). The X-ray Debye temperatures of Pd0.77Ag0.23 and Pd0.77Ag0.10Cu0.13 alloys were calculated and found to be 225±10 and 165±10 K, respectively.

  12. Influence of Dopant on Growth of Intermetallic Layers in Sn-Ag-Cu Solder Joints

    Science.gov (United States)

    Li, G. Y.; Bi, X. D.; Chen, Q.; Shi, X. Q.

    2011-02-01

    The interfacial interaction between Cu substrates and Sn-3.5Ag-0.7Cu- xSb ( x = 0, 0.2, 0.5, 0.8, 1.0, 1.5, and 2.0) solder alloys has been investigated under different isothermal aging temperatures of 100°C, 150°C, and 190°C. Scanning electron microscopy (SEM) was used to measure the thickness of the intermetallic compound (IMC) layer and observe the microstructural evolution of the solder joints. The IMC phases were identified by energy-dispersive x-ray spectroscopy (EDX) and x-ray diffractometry (XRD). The growth of both the Cu6Sn5 and Cu3Sn IMC layers at the interface between the Cu substrate and the solder fits a power-law relationship with the exponent ranging from 0.42 to 0.83, which suggests that the IMC growth is primarily controlled by diffusion but may also be influenced by interface reactions. The activation energies and interdiffusion coefficients of the IMC formation of seven solder alloys were determined. The addition of Sb has a strong influence on the growth of the Cu6Sn5 layer, but very little influence on the formation of the Cu3Sn IMC phase. The thickness of the Cu3Sn layer rapidly increases with aging time and temperature, whereas the thickness of the Cu6Sn5 layer increases slowly. This is probably due to the formation of Cu3Sn at the interface between two IMC phases, which occurs with consumption of Cu6Sn5. Adding antimony to Sn-3.5Ag-0.7Cu solder can evidently increase the activation energy of Cu6Sn5 IMC formation, reduce the atomic diffusion rate, and thus inhibit excessive growth of Cu6Sn5 IMCs. This study suggests that grain boundary pinning is one of the most important mechanisms for inhibiting the growth of Cu6Sn5 IMCs in such solder joints when Sb is added.

  13. Facile deposition of Ag{sub 3}PO{sub 4} on graphene-like MoS{sub 2} nanosheets for highly efficient photocatalysis

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Peifu [College of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai 200090 (China); Shi, Penghui, E-mail: shipenghui@shiep.edu.cn [College of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai 200090 (China); Hong, Yuanchen; Zhou, Xuejun [College of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai 200090 (China); Yao, Weifeng, E-mail: yaoweifeng@shiep.edu.cn [College of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai 200090 (China); Shanghai Key Laboratory of Materials Protection and Advanced Materials in Electric Power, Shanghai University of Electric Power, Shanghai 200090 (China)

    2015-02-15

    Graphical abstract: The photocatalytic performance of Ag{sub 3}PO{sub 4} was highly improved by the in situ deposition of Ag{sub 3}PO{sub 4} particles on graphene-like MoS{sub 2} nanosheets. - Highlights: • A novel composite photocatalyst was synthesized by depositing Ag{sub 3}PO{sub 4} on the graphene-like MoS{sub 2} nanosheets. • Ag{sub 3}PO{sub 4}/MoS{sub 2} photocatalyst exhibited a high photocatalytic activity for RhB degradation. • Graphene-like MoS{sub 2} nanosheets. • MoS{sub 2} nanosheets play an important role in photocatalytic activity by serving as an effective acceptor of the photogenerated carriers. - Abstract: A facile method for the in situ deposition of Ag{sub 3}PO{sub 4} on graphene-like MoS{sub 2} nanosheets was developed to improve the photocatalytic performance of Ag{sub 3}PO{sub 4} catalysts. The heterostructure of Ag{sub 3}PO{sub 4}/MoS{sub 2} composites was characterized by using X-ray diffraction spectra (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The prepared Ag{sub 3}PO{sub 4}/MoS{sub 2} photocatalyst exhibited a much higher photocatalytic activity than that of Ag{sub 3}PO{sub 4} for the degradation of Rhodamine B (RhB) under visible light irradiation (>400 nm). The improved photocatalytic activity of Ag{sub 3}PO{sub 4}/MoS{sub 2} is attributed to the efficient separation of photogenerated electron–hole pairs in the composite. This result provides a new perspective on the design of high-performance photocatalysts which is promising for energy applications.

  14. Structural studies of Nd$_{1.85}$Ce$_{0.15}$CuO$_{4}$ $+$ Ag superconducting system

    Indian Academy of Sciences (India)

    N RADHIKESH RAVEENDRAN; A K SINHA; R RAJARAMAN; M PREMILA; E P AMALADASS; K VINOD; J JANAKI; S KALAVATHI; AWADHESH MANI

    2016-06-01

    We have studied for the first time the effect of Ag addition (0–15 wt%) to the superconducting system, Nd$_{1.85}$Ce$_{0.15}$CuO$_{4}$, on its crystal structure and local structural features, using synchrotron X-ray diffraction(SXRD) and Raman spectroscopy, respectively. SXRD and subsequent Rietveld refinement studies on powders of Nd$_{1.85}$Ce$_{0.15}$CuO$_4$ $+$ Ag system indicate a small but significant change in lattice parameter upon Ag addition, showing evidence for possible incorporation of Ag to the extent of $\\sim$1 wt%. Raman spectroscopic studies indicate that the parent structure of Nd$_{1.85}$Ce$_{0.15}CuO$_{4}$ remains unaffected with no major local structural changes on doping with silver. However, all Raman modes show minor phonon hardening upon Ag addition, which is consistent with the unit cell volume reduction as is observed in XRD. A systematic bleaching out of the apical oxygen defect mode was also observed with increased Ag addition. Polarized Raman measurements helped to identify the asymmetric nature of the B1g Raman mode. X-ray diffraction studies on pellets of Nd$_{1.85}$Ce$_{0.15}CuO$_4$ $+$ Ag system further indicate a randomization of preferred orientation upon Ag addition. The superconductivity of the Nd$_{1.85}$Ce$_{0.15}$CuO$_4$ $+$ Ag system has been well characterized for all the compositions studied.

  15. Unconstrained solidification and characterisation of near-eutectic Al-Cu-Ag alloys

    Energy Technology Data Exchange (ETDEWEB)

    Ebzeeva, S.; Nagels, E.; Froyen, L. [Katholieke Univ. Leuven (Belgium). Dept. of Metallurgy and Materials Engineering

    2008-11-15

    This study focuses on the microstructure formation in two Al-Cu-Ag alloys with near-eutectic composition on either side of the {alpha}(Al)/{theta}-Al{sub 2}Cu groove. The alloys solidified equiaxially with two different cooling rates for each composition of alloy. The primary phases formed are {alpha}(Al) or {theta}-Al{sub 2}Cu, but univariant and invariant eutectic reactions are common. In hypoeutectic samples macrosegregation of the {alpha}(Al) phase occurred. The univariant {alpha}(Al)/{theta}-Al{sub 2}Cu eutectic in these samples is formed by coupled two-phase structures. The univariant eutectic in the samples, which exhibit primary {theta}-Al{sub 2}Cu, grew partially competitively due to the {alpha}(Al) single phase instability. It is suggested that the difference in solubility of the segregating element Ag in {alpha}(Al) and {theta}-Al{sub 2}Cu phases and processing parameters such as cooling rates determine the resulting microstructure. (orig.)

  16. Phase transitions in CuS-Ag2S nanoparticle system

    Science.gov (United States)

    Sheela Christy, R.; Thanka Kumaran, J. T.; Bansal, C.; Brightson, M.

    2016-02-01

    (Ag2)xCu1-xS, x = .2, .4, .6 and .8 nanoparticles were synthesized by the solvothermal method. The as-synthesized nanoparticles were characterized by X-ray diffraction to study the crystal structure and size. The surface morphologies of the above samples were studied using scanning electron microscope. As there is continuous shift in the lower wavelength absorption edge of the UV-VIS spectrum of these samples with concentration, (Ag2)xCu1-xS nanoparticles can be tuned to different band gap energies by varying the composition. The D.C. electrical resistance was measured in the temperature range 310-485 K. As Ag2S transforms from monoclinic to bcc at around 450 K, copper sulfide nanoparticles also shows a phase transition at around 470 K, the effects of these two transitions are seen in the resistance measurements and in the UV-VIS spectra of the entire system. The electrical resistance of (Ag2)xCu1-xS nanoparticles rapidly reduces as more and more copper sulfide is added.

  17. Mo-Cu metal cluster formation and binding in an orange protein isolated from Desulfovibrio gigas.

    Science.gov (United States)

    Carepo, Marta S P; Pauleta, Sofia R; Wedd, Anthony G; Moura, José J G; Moura, Isabel

    2014-06-01

    The orange protein (ORP) isolated from the sulfate-reducing bacterium Desulfovibrio gigas (11.8 kDa) contains a mixed-metal sulfide cluster of the type [S2MoS2CuS2MoS2](3-) noncovalently bound to the polypeptide chain. The D. gigas ORP was heterologously produced in Escherichia coli in the apo form. Different strategies were used to reconstitute the metal cluster into apo-ORP and obtain insights into the metal cluster synthesis: (1) incorporation of a synthesized inorganic analogue of the native metal cluster and (2) the in situ synthesis of the metal cluster on the addition to apo-ORP of copper chloride and tetrathiomolybdate or tetrathiotungstate. This latter procedure was successful, and the visible spectrum of the Mo-Cu reconstituted ORP is identical to the one reported for the native protein with absorption maxima at 340 and 480 nm. The (1)H-(15)N heteronuclear single quantum coherence spectra of the reconstituted ORP obtained by strategy 2, in contrast to strategy 1, exhibited large changes, which required sequential assignment in order to identify, by chemical shift differences, the residues affected by the incorporation of the cluster, which is stabilized inside the protein by both electrostatic and hydrophobic interactions.

  18. Research on Physical Properties of Sn-Ag-Cu-Sb Solder%Sn-Ag-Cu-Sb无铅焊料物理性能

    Institute of Scientific and Technical Information of China (English)

    桂太龙; 袁力鹏; 郝龙; 贾伟; 董小丽

    2011-01-01

    为了获得不同性能的电子封装焊料,制备了掺杂Sb(锑)的Sn-3.35Ag-0.7Cu无铅焊料合金,并对其密度、杨氏模量、硬度等重要物理性能进行了测定.测得该无铅焊料的密度为7.2106g/cm3,杨氏模量为43 GPa,硬度为96.7 N/mm2.实验结果表明,同未掺杂Sn-3.35Ag-0.7Cu焊料合金相比,硬度略有降低,熔点下降不明显,但密度有显著降低,杨氏模量、润湿性有明显的提高.%We prepare of the doped Sb (antimony) of the Sn-3.35Ag-0. 7Cu lead-free solder alloy. Its important physical properties were measured: density, Young's modulus, hardness and so on. The density is 7. 210 6g/cm3, Young' s modulus is 43GPa, and the hardness is 96.7 N/mm2. The experimental results show that nondoped with Sn -3.35Ag -0. 7Cu solder alloys, the hardness slightly lower, the melting points do not drop obviously than that not doped. However, there is a significant reduction in density. Young's modulus and wetting p properties are significantly improved.

  19. A correlative experimental and ab initio approach to improve the fracture behavior of Mo thin films by alloying with Cu

    Science.gov (United States)

    Jörg, Tanja; Music, Denis; Cordill, Megan J.; Franz, Robert; Köstenbauer, Harald; Linke, Christian; Winkler, Jörg; Schneider, Jochen M.; Mitterer, Christian

    2017-09-01

    The effect of Cu alloying on the deformation behavior of Mo thin films is investigated as a feasible concept to overcome their poor ductility, which severely limits performance in flexible electronics. 50 nm thick Mo1-xCux films (with 0 ≤ x ≤ 0.51) were sputter-deposited on polyimide substrates and subjected to uniaxial tensile loading while measuring their electrical resistance in situ. A significant ductility enhancement is experimentally observed with increasing Cu content. This can be rationalized by considering the associated changes in bond character as the Cu additions weaken the covalent and hence shear resistant contribution to the overall bond character.

  20. Dissolution behavior of Cu in Cu-Ag and Cu-P brazing alloys using weld brazing%溶解钎焊时Cu在Cu-Ag及Cu-P合金钎料中的溶解行为

    Institute of Scientific and Technical Information of China (English)

    李一楠; 王长文; 彭子龙; 闫久春; 刘雪松

    2011-01-01

    研究溶解钎焊条件下母材Cu在Cu-Ag及Cu-P合金钎料中的溶解行为.测量了在800~920℃的温度范围内铜箔在Cu-P和Cu-Ag合金中的溶解厚度.推导并计算出Cu在这两种合金钎料中的溶解速度常数存在如下关系:kCu-p(T)=10kCu-A(T).结果表明,采用溶解钎焊工艺时在相同条件下液态Cu-P合金对母材Cu的溶解量大于Cu-Ag合金的.由于溶解钎焊工艺在一个热循环内具有反应时间短和温度变化快的特点,因此Cu在液态钎料中快的溶解反应速度是实现溶解钎焊的根本原因.同时,P元素与Ag元素相比具有加速溶解母材的作用,是实现溶解钎焊必不可少的合金元素.研究了合金元素的添加对焊接接头力学性能的影响,提出了获得良好力学性能的钎料成分设计原则.%The dissolution behavior of base metal Cu in the Cu-Ag and Cu-P brazing alloys using weld brazing was researched.The thickness loss of Cu foil in contact with Cu-P and Cu-Ag alloys at 800-920 ℃ was measured.And the dissolution rate constants in both alloys were calculated as the following relation:kcu-p(T)=1 0kCu.Ag(T),which explains the special phenomenon that the dissolving amount of copper in Cu-P liquid alloys is larger than that in Cu-Ag alloys under the same condition.As weld brazing has its own characteristics of short reaction time and quick temperature variation in one thermal cycle,the quick dissolution rate of copper in filler metals is the main reason to achieve weld brazing.It can be concluded that element P is indispensable in filler metals compared with element Ag as the function of accelerating dissolution during weld brazing.Finally,the influences of the addition of alloy element on mechanical performance of the welding joints were studied and the design principles of filler metals for weld brazing were proposed to achieve good mechanical performance.

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

    Science.gov (United States)

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

    2015-03-01

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

  2. Study on AgCuTi Brazing Al2O3/Nb%AgCuTi钎焊Al2O3/Nb的研究

    Institute of Scientific and Technical Information of China (English)

    吴铭方; 于治水

    2000-01-01

    在钎焊温度1 043~1 393 K、钎焊时间3~60 min条件下,对Al2O3/(Ag72Cu28)97Ti3/Nb接头进行了钎焊试验.经SEM、EDS、XRD检测,界面产物为TiO、Ti2O.在1 093 K、15 min条件下,接头剪切强度最高可达223 MPa.

  3. Visible light degradation of textile effluent using nanostructured TiO2/Ag/CuO photocatalysts

    OpenAIRE

    Karthikeyan, N.; Narayanan, V.; Stephen, A

    2016-01-01

    TiO2, Ag and CuO nanomaterials, and nanostructured TiO2/Ag/CuO photocatalytic materials coupled in different weight percentages were synthesized. The prepared materials were characterized by XRD, SEM, EDX and UV-Vis diffuse reflectance spectroscopy. Photocatalytic degrading capabilities of the pure, as well as the nanostructured TiO2/Ag/CuO photocatalytic materials were tested on the dye effluent collected from the textile industries. The samples collected during the photocatalytic degradatio...

  4. Mechanical Characterization of Lead-Free Sn-Ag-Cu Solder Joints by High-Temperature Nanoindentation

    OpenAIRE

    Lotfian, S.; Molina Aldareguía, Jon M.; Yazzie, K. E.; Llorca Martinez, Francisco Javier; Chawla, N

    2013-01-01

    The reliability of Pb-free solder joints is controlled by their microstructural constituents. Therefore, knowledge of the solder microconstituents’ mechanical properties as a function of temperature is required. Sn-Ag-Cu lead-free solder alloy contains three phases: a Sn-rich phase, and the intermetallic compounds (IMCs) Cu6Sn5 and Ag3Sn. Typically, the Sn-rich phase is surrounded by a eutectic mixture of β-Sn, Cu6Sn5, and Ag3Sn. In this paper, we report on the Young’s modulus and hardness of...

  5. Copper-silver bimetallic system on natural clinoptilolite: thermal reduction of Cu2+ and Ag+ exchanged.

    Science.gov (United States)

    Rodríguez-Iznaga, Inocente; Petranovskii, Vitalii; Castillón-Barraza, Felipe; Concepción-Rosabal, Beatriz

    2011-06-01

    Copper-silver bimetallic system supported on natural clinoptilolite from Tasajeras deposit (Cuba) was studied. Bimetallic samples were prepared by simultaneous ion exchange, and reduced in a wide temperature range in a hydrogen flow. The main goal of the work was analysis of the mutual influence of both metals on their reduction process and the properties of the resultant particles. Analysis was done by combined use of XRD and UV-Vis spectroscopy. The reduction of Cu2+ and Ag+ cations shows existence of notable inter-influence between both cations during this process. The Cu2+ reduction is favored by the presence of Ag+, which should be related with the synergetic influence of silver cations and/or clusters formed on the first stages of reduction on Cu(2+)-framework interaction, facilitating the Cu2+ reduction even at low temperature (25 and 50 degrees C). The aggregation of the reduced highly dispersed species both for copper and silver is limited in this bimetallic system. The introduction of Ag+ as the second cation in the copper-exchanged zeolites favors the copper reduction at lower temperatures (25 and 50 degrees C), and appears to be the efficient tool for the control of the size of the resultant reduced nanoparticles (it means their dispersion).

  6. Active Brazing of C/C Composite to Copper by AgCuTi Filler Metal

    Science.gov (United States)

    Zhang, Kexiang; Xia, Lihong; Zhang, Fuqin; He, Lianlong

    2016-05-01

    Brazing between the carbon-fiber-reinforced carbon composite (C/C composite) and copper has gained increasing interest because of its important application in thermal management systems in nuclear fusion reactors and in the aerospace industry. In order to examine the "interfacial shape effect" on the mechanical properties of the joint, straight and conical interfacial configurations were designed and machined on the surface of C/C composites before joining to copper using an Ag-68.8Cu-4.5Ti (wt pct) alloy. The microstructure and interfacial microchemistry of C/C composite/AgCuTi/Cu brazed joints were comprehensively investigated by using high-resolution transmission electron microscopy. The results indicate that the joint region of both straight and conical joints can be described as a bilayer. Reaction products of Cu3Ti3O and γ-TiO were formed near the copper side in a conical interface joint, while no reaction products were found in the straight case. The effect of Ag on the interfacial reaction was discussed, and the formation mechanism of the joints during brazing was proposed. On the basis of the detailed microstructure presented, the mechanical performance of the brazed joints was discussed in terms of reaction and morphology across the joint.

  7. Room temperature nanojoining of Cu-Ag core-shell nanoparticles and nanowires

    Science.gov (United States)

    Wang, Jiaqi; Shin, Seungha

    2017-02-01

    Room temperature ( T room, 300 K) nanojoining of Ag has been widely employed in fabrication of microelectronic applications where the shapes and structures of microelectronic components must be maintained. In this research, the joining processes of pure Ag nanoparticles (NPs), Cu-Ag core-shell NPs, and nanowires (NWs) are studied using molecular dynamics simulations at T room. The evolution of densification, potential energy, and structural deformation during joining process are analyzed to identify joining mechanisms. Depending on geometry, different joining mechanisms including crystallization-amorphization, reorientation, Shockley partial dislocation are determined. A three-stage joining scenario is observed in both joining process of NPs and NWs. Besides, the Cu core does not participate in all joining processes, however, it enhances the mobility of Ag shell atoms, contributing to a higher densification and bonding strength at T room, compared with pure Ag nanomaterials. The tensile test shows that the nanojoint bears higher rupture strength than the core-shell NW itself. This study deepens understanding in the underlying joining mechanisms and thus nanojoint with desirable thermal, electrical, and mechanical properties could be potentially achieved.

  8. Vacuum Brazing of WC-8Co Cemented Carbides to Carbon Steel Using Pure Cu and Ag-28Cu as Filler Metal

    Science.gov (United States)

    Zhang, X. Z.; Liu, G. W.; Tao, J. N.; Shao, H. C.; Fu, H.; Pan, T. Z.; Qiao, G. J.

    2017-02-01

    The wetting and spreading behavior of commercial pure Cu and Ag-28Cu alloy on WC-8Co cemented carbide were investigated by the sessile drop technique. The contact angle of both systems obviously decreases with moderately increasing the wetting temperature. Vacuum brazing of the WC-8Co cemented carbide to SAE1045 steel using the pure Cu or Ag-28Cu as filler metal was further carried out based on the wetting results. The interfacial interactions and joint mechanical behavior involving microhardness, shear strength and fracture were analyzed and discussed. An obvious Fe-Cu-Co transition layer is detected at the WC-8Co/Cu interface, while no obvious reaction layer is observed at the whole WC-8Co/Ag-28Cu/SAE1045 brazing seam. The microhardness values of the two interlayers and the steel substrate near the two interlayers increase more or less, while those of WC-8Co cemented carbide substrates adjacent to the two interlayers decrease. The WC-8Co/SAE1045 joints using pure Cu and Ag-28Cu alloy as filler metals obtain average shear strength values of about 172 and 136 MPa, and both of the joint fractures occur in the interlayers.

  9. Vacuum Brazing of WC-8Co Cemented Carbides to Carbon Steel Using Pure Cu and Ag-28Cu as Filler Metal

    Science.gov (United States)

    Zhang, X. Z.; Liu, G. W.; Tao, J. N.; Shao, H. C.; Fu, H.; Pan, T. Z.; Qiao, G. J.

    2016-12-01

    The wetting and spreading behavior of commercial pure Cu and Ag-28Cu alloy on WC-8Co cemented carbide were investigated by the sessile drop technique. The contact angle of both systems obviously decreases with moderately increasing the wetting temperature. Vacuum brazing of the WC-8Co cemented carbide to SAE1045 steel using the pure Cu or Ag-28Cu as filler metal was further carried out based on the wetting results. The interfacial interactions and joint mechanical behavior involving microhardness, shear strength and fracture were analyzed and discussed. An obvious Fe-Cu-Co transition layer is detected at the WC-8Co/Cu interface, while no obvious reaction layer is observed at the whole WC-8Co/Ag-28Cu/SAE1045 brazing seam. The microhardness values of the two interlayers and the steel substrate near the two interlayers increase more or less, while those of WC-8Co cemented carbide substrates adjacent to the two interlayers decrease. The WC-8Co/SAE1045 joints using pure Cu and Ag-28Cu alloy as filler metals obtain average shear strength values of about 172 and 136 MPa, and both of the joint fractures occur in the interlayers.

  10. Thiophene hydrodesulfurization over CoMo/Al2O3-CuY catalysts: Temperature effect study

    Directory of Open Access Journals (Sweden)

    Yamina Boukoberine

    2016-09-01

    Full Text Available CoMo/γ-Al2O3-CuY catalysts are prepared by physically mixing CoMo/γ-Al2O3 catalyst with Cu-exchanged Y zeolite. The CuY zeolite is prepared by the solid state ion exchange technique. The thiophene hydrodesulfurization is performed in a fixed bed reactor at high temperature and atmospheric pressure. The results show that the presence of CuY zeolite particles in CoMo/Al2O3 catalyst can have a noticeable effect on both the conversion and product selectivities. An increasing zeolite loading in catalyst results in a decrease of the thiophene HDS activity. This decrease is probably caused by the formation of heavy compounds and the deactivation of the zeolite at high temperatures.

  11. High resolution electron microscopy study of a high Cu variant of Weldalite (tm) 049 and a high strength Al-Cu-Ag-Mg-Zr alloy

    Science.gov (United States)

    Herring, R. A.; Gayle, Frank W.; Pickens, Joseph R.

    1991-01-01

    Weldalite (trademark) 049 is an Al-Cu-Li-Ag-Mg alloy that is strengthened in artificially aged tempers primarily by very thin plate-like precipitates lying on the set of (111) matrix planes. This precipitate might be expected to be the T(sub 1) phase, Al2CuLi, which has been observed in Al-Cu-Li alloys. However, in several ways this precipitate is similar to the omega phase which also appears as the set of (111) planes plates and is found in Al-Cu-Ag-Mg alloys. The study was undertaken to identify the set of (111) planes precipitate or precipitates in Weldalite (trademark) 049 in the T8 (stretched and artificially aged) temper, and to determine whether T(sub 1), omega, or some other phase is primarily responsible for the high strength (i.e., 700 MPa tensile strength) in this Al-Cu-Li-Ag-Mg alloy.

  12. Solderability and intermetallic compounds formation of Sn-9Zn-xAg lead-free solders wetted on Cu substrate

    Institute of Scientific and Technical Information of China (English)

    CHEN Wenxue; XUE Songbai; WANG Hui; WANG Jianxin; HAN Zongjie

    2009-01-01

    The eutectie Sn-9Zn alloy was doped with Ag (0 wt.%-1 wt.%) to form Sn-9Zn-xAg lead-free solder alloys. The effect of the addition of Ag on the microstructure and solderability of this alloy was investigated and intermetallic compounds (IMCs) formed at the solder/Cu interface were also examined in this study. The results show that, due to the addition of Ag, the microstructure of the solder changes. When the quan-tity of Ag is lower than 0.3 wt.%, the needle-like Zn-rich phase decreases gradually. However, when the quantity of Ag is 0.5 wt.%-1 wt.%, Ag-Zn intermetallic compounds appear in the solder. In particular, adding 0.3 wt.% Ag improves the wetting behavior due to the better oxi-dation resistance of the Sn-9Zn solder. The addition of an excessive amount of Ag will deteriorate the wetting property because the gluti-nosity and fluidity of Sn-9Zn-(0.5, 1)Ag solder decrease. The results also indicate that the addition of Ag to the Sn-Zn solder leads to the pre-cipitation of ε-AgZn_3 from the liquid solder on preformed interracial intermetallics (Cu_5Zn_8). The peripheral AgZn_3, nodular on the Cu_5Zn_8 IMCs layer, is likely to be generated by a peritectic reaction L+γ-Ag_5Zn8→ε-AgZn_3 and the following crystallization of AgZn_3.

  13. Intermetallic compound formation in Sn-Co-Cu, Sn-Ag-Cu and eutectic Sn-Cu solder joints on electroless Ni(P) immersion Au surface finish after reflow soldering

    Energy Technology Data Exchange (ETDEWEB)

    Sun Peng [Key State Lab for New Displays and System Integration (Chinese Ministry of Education), SMIT Center, Shanghai University, 200072 Shanghai (China) and Department of Microtechnology and Nanoscience, SMIT Center, Chalmers University of Technology, 412-96 Goeteborg (Sweden)]. E-mail: peng.sun@mc2.chalmers.se; Andersson, Cristina [Department of Microtechnology and Nanoscience, SMIT Center, Chalmers University of Technology, 412-96 Goeteborg (Sweden); Wei Xicheng [Key State Lab for New Displays and System Integration (Chinese Ministry of Education), SMIT Center, Shanghai University, 200072 Shanghai (China); Cheng Zhaonian [Department of Microtechnology and Nanoscience, SMIT Center, Chalmers University of Technology, 412-96 Goeteborg (Sweden); Shangguan Dongkai [Flextronics International, San Jose, CA (United States); Liu Johan [Key State Lab for New Displays and System Integration (Chinese Ministry of Education), SMIT Center, Shanghai University, 200072 Shanghai (China); Department of Microtechnology and Nanoscience, SMIT Center, Chalmers University of Technology, 412-96 Goeteborg (Sweden)

    2006-11-25

    The interfacial reactions between Sn-0.4Co-0.7Cu eutectic alloy and immersion Au/electroless Ni(P)/Cu substrate were investigated after reflow soldering at 260 deg. C for 2 min. Common Sn-4.0Ag-0.5Cu and eutectic Sn-0.7Cu solders were used as reference. Two types of intermetallic compounds (IMC) were found in the solder matrix of the Sn-0.4Co-0.7Cu alloy, namely coarser CoSn{sub 2} and finer Cu{sub 6}Sn{sub 5} particles, while only one ternary (Cu, Ni){sub 6}Sn{sub 5} interfacial compound was detected between the solder alloy and the electroless nickel and immersion gold (ENIG) coated substrate. The same trend was also observed for the Sn-Ag-Cu and Sn-Cu solder joints. Compared with the CoSn{sub 2} particles found in the Sn-Co-Cu solder and the Ag{sub 3}Sn particles found in the Sn-Ag-Cu solder, the Cu{sub 6}Sn{sub 5} particles found in both solder systems exhibited finer structure and more uniform distribution. It was noted that the thickness of the interfacial IMCs for the Sn-Co-Cu, Sn-Ag-Cu and Sn-Cu alloys was 3.5 {mu}m, 4.3 {mu}m and 4.1 {mu}m, respectively, as a result of longer reflow time above the alloy's melting temperature since the Sn-Ag-Cu solder alloy has the lowest melting point.

  14. High temperature phase equilibria studies in the Bi-Sr-Ca-Cu-O-Ag system

    Energy Technology Data Exchange (ETDEWEB)

    Margulies, Lawrence

    1999-11-08

    A variety of experimental techniques were utilized to examine the high temperature phase equilibria in the Bi-Sr-Ca-Cu-O-Ag system. Quenching studies were used to determine the liquid solubility of Ag in the Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8} (Bi2212) melt and the details of the peritectic decomposition pathway of Bi2212 as a function on Ag content and oxygen partial pressure (PO{sub 2}). A liquid immiscibility region between oxide and Ag liquids in the 8--98 at% range was found above 900 C. Two eutectics were found in the Bi2212-Ag pseudobinary. On the oxide rich side, a eutectic exists at approximately 4 at% Ag. On the Ag rich side, a eutectic exists at approximately 98 at% Ag at a temperature of 15 C below the melting point of pure Ag. Six distinct solid phases were found to be in equilibrium with the partial melt within the Ag content and PO{sub 2} range studied. The stability of these solid phases were found to be highly sensitive to PO{sub 2}, and to a much lesser extent Ag content. High temperature x-ray diffraction (HTXRD) studies of this system are in conflict with these results. It is suggested that these discrepancies are due to experimental artifacts caused by the significant thermal gradients and lack of full bulk sampling which is inherent in conventional HTXRD designs. In part 2, a new furnace design compatible with synchrotron radiation sources is introduced to address these problems. This design allows for full bulk sampling in a low thermal gradient environment using Debye-Scherrer transmission geometry. Sample spinning is also introduced in the design to eliminate preferred orientation and incomplete powder averaging and allow for quantitative phase analysis and structural refinement. Studies on model systems are presented to demonstrate the capabilities for high resolution structural studies (Al{sub 2}O{sub 3}) and time resolved phase transformation studies (SrCO{sub 3}). Finally, the Bi2212 system is examined to confirm the quenching results

  15. Sn-Ag-xCu-Bi-Ni/Cu焊点界面IMC演变%Evolution of the Interfacial IMC in Sn-Ag-xCu-Bi-Ni/Cu Solder Joints

    Institute of Scientific and Technical Information of China (English)

    孙凤莲; 汪洋; 刘洋; 王国军

    2012-01-01

    为了研究低银无铅焊点界面金属间化合物(IMC)的形成与演变,以低银无铅焊点Sn-Ag-xCu-Bi-Ni/Cu为研究对象,研究了钎料中Cu质量分数对界面IMC厚度、形貌和成分的影响.实验结果表明,随着钎料中Cu质量分数的增加,回流焊后焊点IMC层厚度变薄,IMC晶粒尺寸增大,IMC晶粒形貌由颗粒状转变为棱柱状以及鹅卵石状,同时界面IMC成分发生由(Cu,Ni)6Sn5向Cu6Sns的转变.高温时效后,界面IMC层厚度增长.当钎料中Cu质量分数超过1%时,时效后生成较厚的Cu3Sn化合物层,对焊点可靠性不利.钎料中Cu质量分数应控制在1%以下.%In order to study the formation and evolution of the intermetallic compounds (IMC) in low-Ag lead-free solder joints, the effect of Cu content on the thickness, morphology, and constituent of the interfacial IMC in Sn-Ag-xCu-Bi-Ni/Cu solder joints was investigated. Experimental results indicated that the thickness of IMC layer decreased but the grain size of which increased as the concentration of Cu increased in the solder alloys. Meanwhile , the appearance of IMC grains transformed from tiny grains to prisms and cobbles, and the constituent of IMC transformed from (Cu,Ni)6Sn5to Cu6Sn5. The thickness of IMC layer increased during high temperature storage ( HTS) aging. Thick Cu3Sn layer formed during aging when the Cu content was higher than 1% in the solder. Due to reliability concern, the content of Cu in the solder should be controlled less than 1 %.

  16. Crystal structure of novel compounds in the systems Zr-Cu-Al, Mo-Pd-Al and partial phase equilibria in the Mo-Pd-Al system.

    Science.gov (United States)

    Khan, Atta U; Rogl, P; Giester, G

    2012-02-28

    The crystal structures of three Al-rich compounds have been solved from X-ray single crystal diffractometry: τ(1)-MoPd(2-x)Al(8+x) (x = 0.067); τ(7)-Zr(Cu(1-x)Al(x))(12) (x = 0.514) and τ(9)-ZrCu(1-x)Al(4) (x = 0.144). τ(1)-MoPd(2-x)Al(8+x) adopts a unique structure type (space group Pbcm; lattice parameters a = 0.78153(2), b = 1.02643(3) and c = 0.86098(2) nm), which can be conceived as a superstructure of the Mo(Cu(x)Al(1-x))(6)Al(4) type. Whereas Mo-atoms occupy the 4d site, Pd(2) occupies the 4c site, Al and Pd(1) atoms randomly share the 4d position and the rest of the positions are fully occupied by Al. A Bärnighausen tree documents the crystallographic group-subgroup relation between the structure types of Mo(Cu(x)Al(1-x))(6)Al(4) and τ(1). τ(7)-Zr(Cu(1-x)Al(x))(12) (x = 0.514) has been confirmed to crystallize with the ThMn(12) type (space group I4/mmm; lattice parameters a = 0.85243(2) and c = 0.50862(3) nm). In total, 4 crystallographic sites were defined, out of which, Zr occupies site 2a, the 8f site is fully occupied by Cu, the 8i site is entirely occupied by Al, but the 8j site turned out to comprise a random mixture of Cu and Al atoms. The compound τ(9)-ZrCu(1-x)Al(4) (x = 0.144) crystallizes in a unique structure type (space group P4/nmm; lattice parameters a = 0.40275(3) and c = 1.17688(4) nm) which exhibits full atom order but a vacancy (14.4%) on the 2c site, shared with Cu atoms. τ(9)-ZrCu(1-x)Al(4) is a superstructure of Cu with an arrangement of three unit cells of Cu in the direction of the c-axis. A Bärnighausen tree documents this relationship. The ZrCu(1-x)Al(4) type (n = 3) is part of a series of structures which follow this building principle: Cu (n = 1), TiAl(3) (n = 2), τ(5)-TiNi(2-x)Al(5) (n = 4), HfGa(2) (n = 6) and Cu(3)Pd (n = 7). A partial isothermal section for the Al-rich part of the Mo-Pd-Al system at 860 °C has been established with two ternary compounds τ(1)-MoPd(2-x)Al(8+x) and τ(2) (unknown structure). The

  17. Synthesis, surface and optical properties of Ag{sub 2}Cu(VO{sub 3}){sub 4} and Cu(VO{sub 3}){sub 2} vanadates

    Energy Technology Data Exchange (ETDEWEB)

    Qiao, Xuebin [Jiangsu Key Laboratory of Advanced Laser Materials and Devices, School of Physics and Electronic Engineering, Jiangsu Normal University, Xuzhou 221116 (China); Wan, Yingpeng; Li, Yuze [College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123 (China); Qin, Lin [Department of Physics and Interdisciplinary Program of Biomedical, Mechanical & Electrical Engineering, Pukyong National University, Busan 608-737 (Korea, Republic of); Seo, Hyo Jin, E-mail: hjseo@pknu.ac.kr [Department of Physics and Interdisciplinary Program of Biomedical, Mechanical & Electrical Engineering, Pukyong National University, Busan 608-737 (Korea, Republic of)

    2016-04-15

    Graphical abstract: - Highlights: • The well-developed Ag{sub 2}Cu(VO{sub 3}){sub 4} and Cu(VO{sub 3}){sub 2} were developed. • The vanadates show typical indirect allowed transitions narrow band energy. • Ag{sub 2}Cu(VO{sub 3}){sub 4} and Cu(VO{sub 3}){sub 2} present photocatalytic activity driven by visible-light. • Photocatalysis was discussed on the band energy and positions. - Abstract: Ag{sub 2}Cu(VO{sub 3}){sub 4} and Cu(VO{sub 3}){sub 2} were prepared via the sol–gel chemical synthesis. The phase formation was confirmed by X-ray powder polycrystalline diffraction (XRD) measurements. The surface properties were measured with the scanning electron microscope (SEM), energy dispersive spectra (EDS), transmission electron microscopy (TEM), and nitrogen adsorption–desorption isotherms. The optical properties and the band-gap structures were investigated. The vanadates have efficient optical absorption in the UV to visible wavelength region with an indirect allowed transition. Ag{sub 2}Cu(VO{sub 3}){sub 4} has smaller band gap (1.85 eV) than that of Cu(VO{sub 3}){sub 2} (2.03 eV). The narrowed band gap is due to the hybridization between the Ag-4d and O-2p in the valence band. The photocatalysis was investigated by photodegradation of methylene blue (MB) solutions excited by the light with wavelength longer than 420 nm. Correspondingly Ag{sub 2}Cu(VO{sub 3}){sub 4} has more efficient photocatalytic activity on MB photodegradation than that of Cu(VO{sub 3}){sub 2}. The photocatalytic mechanisms were suggested according to the band positions and the trapping experiments.

  18. Controlling Ag3Sn plate formation in near-ternary-eutectic Sn-Ag-Cu solder by minor Zn alloying

    Science.gov (United States)

    Kang, Sung K.; Shih, Da-Yuan; Leonard, Donovan; Henderson, Donald W.; Gosselin, Timothy; Cho, Sung-Il; Yu, Jin; Choi, Won K.

    2004-06-01

    As a result of extensive studies, nearternary-eutectic Sn-Ag-Cu (SAC) alloys have been identified as the leading lead-free solder candidates to replace lead-bearing solders for ball-grid array module assembly. However, recent studies revealed several potential reliability risk factors associated with the alloy system. The formation of large Ag3Sn plates in solder joints, especially when solidified at a relatively slow cooling rate, poses a reliability concern. In this study, the effect of adding a minor amount of zinc in SAC alloy was investigated. The minor zinc addition was shown to reduce the amount of undercooling during solidification and thereby suppress the formation of large Ag3Sn plates. In addition, the zinc was found to cause changes in both the microstructure and interfacial reaction of the solder joint. The interaction of zinc with other alloying elements in the solder was also investigated for a better understanding of the role of zinc during solidification of the nearternary-eutectic alloys.

  19. Protein-Assisted Formation of Molybdenum Heterometallic Clusters: Evidence for the Formation of S2MoS2-M-S2MoS2 Clusters with M = Fe, Co, Ni, Cu, or Cd within the Orange Protein.

    Science.gov (United States)

    Maiti, Biplab K; Maia, Luisa B; Pauleta, Sofia R; Moura, Isabel; Moura, José J G

    2017-02-20

    The Orange Protein (ORP) is a small bacterial protein, of unknown function, that harbors a unique molybdenum/copper (Mo/Cu) heterometallic cluster, [S2Mo(VI)S2Cu(I)S2Mo(VI)S2](3-), noncovalently bound. The apo-ORP is able to promote the formation and stabilization of this cluster, using Cu(II)- and Mo(VI)S4(2-) salts as starting metallic reagents, to yield a Mo/Cu-ORP that is virtually identical to the native ORP. In this work, we explored the ORP capability of promoting protein-assisted synthesis to prepare novel protein derivatives harboring molybdenum heterometallic clusters containing iron, cobalt, nickel, or cadmium in place of the "central" copper (Mo/Fe-ORP, Mo/Co-ORP, Mo/Ni-ORP, or Mo/Cd-ORP). For that, the previously described protein-assisted synthesis protocol was extended to other metals and the Mo/M-ORP derivatives (M = Cu, Fe, Co, Ni, or Cd) were spectroscopically (UV-visible and electron paramagnetic resonance (EPR)) characterized. The Mo/Cu-ORP and Mo/Cd-ORP derivatives are stable under oxic conditions, while the Mo/Fe-ORP, Mo/Co-ORP, and Mo/Ni-ORP derivatives are dioxygen-sensitive and stable only under anoxic conditions. The metal and protein quantification shows the formation of 2Mo:1M:1ORP derivatives, and the visible spectra suggest that the expected {S2MoS2MS2MoS2} complexes are formed. The Mo/Cu-ORP, Mo/Co-ORP, and Mo/Cd-ORP are EPR-silent. The Mo/Fe-ORP derivative shows an EPR S = (3)/2 signal (E/D ≈ 0.27, g ≈ 5.3, 2.5, and 1.7 for the lower M= ±(1)/2 doublet, and g ≈ 5.7 and 1.7 (1.3 predicted) for the upper M = ±(3)/2 doublet), consistent with the presence of either one S = (5)/2 Fe(III) antiferromagnetically coupled to two S = (1)/2 Mo(V) or one S = (3)/2 Fe(I) and two S = 0 Mo(VI) ions, in both cases in a tetrahedral geometry. The Mo/Ni-ORP shows an EPR axial S = (1)/2 signal consistent with either one S = (1)/2 Ni(I) and two S = 0 Mo(VI) or one S = (1)/2 Ni(III) antiferromagnetically coupled to two S = (1)/2 Mo(V) ions, in both

  20. Microstructure and mechanical properties of CuNiMo austempered ductile iron

    OpenAIRE

    Erić Olivera; Jovanović Marina P.; Šiđanin Leposava P.; Rajnović Dragan M.

    2004-01-01

    Microstructure and mechanical properties of Cu, Ni and Mo alloyed cast ductile iron have been investigated after austempering. Samples were austenitised at 860oC for 1h and then austempered at 320oC and 400oC in the interval from 0,5 to 5h. The X-ray diffraction technique and the light microscopy were utilized to investigate the bainitic transformation, while tensile and impact tests were performed for characterization of mechanical properties. By austempering at 320oC in the range between 2 ...

  1. Effect of Cu, Mo, Si on the content of retained austenite of austempered ductile iron

    Energy Technology Data Exchange (ETDEWEB)

    Mi, Y. [Zhejiang Univ., Hangzhou (China). Dept. of Materials Science and Engineering

    1995-05-01

    In this paper, the effects of Cu, Mo, Si contents on the volume fraction of retained austenite of austempered ductile iron (ADI) are analyzed exactly by X-ray diffraction, and the fracture modes of test samples with different volume fraction of retained austenite are investigated by SEM. It is shown that the retained austenite content increases with the content of copper, decreases with the content of molybdenum, and reaches the maximum with a certain content of silicon. When the retained austenite content decreases, the fracture modes of test samples change from ductile fracture to cleavage fracture.

  2. Subsurface structure and magnetic parameters of Fe-Mo-Cu-B metallic glass

    Directory of Open Access Journals (Sweden)

    Miglierini Marcel

    2015-03-01

    Full Text Available Subsurface properties of 57Fe81Mo9Cu1B9 metallic glass were studied by conversion electron and conversion X-ray Mössbauer spectrometry. They were applied to both surfaces of the ribbons. Deviations in structural surface features are exhibited via different contents of crystalline phases, which were identified as bcc-Fe and magnetite. The presence of small ferromagnetic particles was also suggested from magnetic measurements. An influence of irradiation with 130-keV N+ ions on surface properties of the as-quenched alloy is also discussed.

  3. Kinetics of Silver Dissolution in Nitric Acid from Ag-Au0.04-Cu0.10 and Ag-Cu0.23 Scraps

    Institute of Scientific and Technical Information of China (English)

    S.K.Sadrnezhaad; E.Ahmadi; M.Mozammel

    2006-01-01

    Kinetics of dissolution of silver present in precious metal scraps in HNO3 was studied in temperature range of 26~85℃. Dissolution rate of silver was much faster than that of copper at all temperatures. Effects of particle size, stirring speed, acid concentration and temperature on the rate of dissolving of silver were evaluated.Dissolution rate decreases with particle size and increases with temperature. Dissolving was accelerated with acid concentrations less than 10 mol/L. Concentrations greater than 10 mol/L resulted in slowing down of the dissolution rate. Shrinking core model with internal diffusion equation t/τ=1-3(1-x)2/3+2(1-x)could be used to explain the mechanism of the reaction. Silver extraction resulted in activation energies of 33.95 k J/mol for Ag-Au0.04-Cu0.10 and 68.87 k J/mol for Ag-Cu0.23 particles. Inter-diffusion of silver and nitrate ions through the porous region of the insoluble alloying layer was the main resistance to the dissolving process. Results were tangible for applications in recycling of the material from electronic silver-bearing scraps, dental alloys,jewelry, silverware and anodic slime precious metal recovery.

  4. Flow Stress Behavior and Processing Map of Al-Cu-Mg-Ag Alloy during Hot Compression

    Institute of Scientific and Technical Information of China (English)

    YANG Sheng; YI Danqing; ZHANG Hong; YAO Sujuan

    2008-01-01

    The hot deformation behavior of Al-Cu-Mg-Ag was studied by isothermal hot compression tests in the temperature range of 573-773 K and strain rate range of 0.001-1 s-1 on a Gleeble 1500 D thermal mechanical simulator. The results show the flow stress of Al-Cu-Mg-Ag alloy increases with strain rate and decreases after a peak value, indicating dynamic recovery and recrystallization. A hyperbolic sine relationship is found to correlate well the flow stress with the strain rate and temperature, the flow stress equation is estimated to illustrate the relation of strain rate and stress and temperature during high temperature deformation process. The processing maps exhibit two domains as optimum fields for hot deformation at different strains, including the high strain rate domain in 623-773 K and the low strain rate domain in 573-673 K.

  5. Molecular Dynamics Study of Surface Anisotropy in Ag_{60} Cu_{40} Alloy at Nanoscale

    Science.gov (United States)

    Imran, Muhammad; Hussain, Fayyaz; Rashid, Muhammad; Kousar, Farhana; Javid, M. Arshad; Ullah, Hafeez; Ahmad, Ejaz; Ahmad, S. A.

    2017-03-01

    In the present study, molecular dynamics simulation has been performed to investigate the anisotropic behavior of free standing Ag_{60} Cu_{40} nanorods. We choose different orientations with various cross sections to study the dynamics of thermal behavior of Ag_{60} Cu_{40} nanorods. The system is modeled using embedded atom method potentials. The radial distribution functions are analyzed to reveal the dynamic evolution of the structural behavior of nanorods with different orientations and sample sizes. The total energy and mean square displacement is also calculated to characterize the melting phenomenon of various samples. The melting temperature of the nanorods is found to be significantly size and orientation dependent, and it increases with the increase in cross-sectional area. The nanorods with low-index crystallographic surfaces such as (110) exhibit lowest melting temperature as compared to compact surfaces (111).

  6. Green Synthesis of Ag-Cu Nanoalloys Using Opuntia ficus- indica

    Science.gov (United States)

    Rocha-Rocha, O.; Cortez-Valadez, M.; Hernández-Martínez, A. R.; Gámez-Corrales, R.; Alvarez, Ramón A. B.; Britto-Hurtado, R.; Delgado-Beleño, Y.; Martinez-Nuñez, C. E.; Pérez-Rodríguez, A.; Arizpe-Chávez, H.; Flores-Acosta, M.

    2017-02-01

    Bimetallic Ag/Cu nanoparticles have been obtained by green synthesis using Opuntia ficus- indica plant extract. Two synthesis methods were applied to obtain nanoparticles with core-shell and Janus morphologies by reversing the order of precursors. Transmission electronic microscopy revealed size of 10 nm and 20 nm for the core-shell and Janus nanoparticles, respectively. Other small particles with size of up to 2 nm were also observed. Absorption bands attributed to surface plasmon resonance were detected at 440 nm and 500 nm for the core-shell and Janus nanoparticles, respectively. Density functional theory predicted a breathing mode type (BMT) located at low wavenumber due to small, low-energy clusters of (AgCu) n with n = 2 to 9, showing a certain correlation with the experimental one (at 220 cm-1). The dependence of the BMT on the number of atoms constituting the cluster is also studied.

  7. LPG sensing performance of CuO–Ag2O bimetallic oxide nanoparticles

    Directory of Open Access Journals (Sweden)

    K.R. Nemade

    2015-10-01

    Full Text Available In the present article, we synthesized CuO–Ag2O bimetallic oxide nanoparticles by using microwave assisted and solid state diffusion routes. The structural, morphological, optical and thermal study of as-synthesized materials were done through X-ray diffractometer (XRD, scanning electron microscope (SEM, Fourier transform infrared (FTIR, ultraviolet–visible (UV–vis and thermogravimetric analysis (TGA, respectively. Comparatively different sensing parameters such as sensing response at room temperature, operating temperature, response and recovery time and stability characteristics were investigated and discussed for liquefied petroleum gas (LPG. The CuO–Ag2O bimetallic oxide nanoparticles synthesized by microwave assisted route shows good gas sensing properties.

  8. Adsorption of gas molecules on Cu impurities embedded monolayer MoS2: A first- principles study

    Science.gov (United States)

    Zhao, B.; Li, C. Y.; Liu, L. L.; Zhou, B.; Zhang, Q. K.; Chen, Z. Q.; Tang, Z.

    2016-09-01

    Adsorption of small gas molecules (O2, NO, NO2 and NH3) on transition-metal Cu atom embedded monolayer MoS2 was investigated by first-principles calculations based on the density-functional theory (DFT). The embedded Cu atom is strongly constrained on the sulfur vacancy of monolayer MoS2 with a high diffusion barrier. The stable adsorption geometry, charge transfer and electronic structures of these gas molecules on monolayer MoS2 embedded with transition-metal Cu atom are discussed in detail. It is found that the monolayer MoS2 with embedded Cu atom can effectively capture these gas molecules with high adsorption energy. The NH3 molecule acts as electron donor after adsorption, which is different from the other gas molecules (O2, NO, and NO2). The results suggest that MoS2-Cu system may be promising for future applications in gas molecules sensing and catalysis, which is similar to those of the transition-metal embedded graphene.

  9. Size and alloying induced shift in core and valence bands of Pd-Ag and Pd-Cu nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Sengar, Saurabh K.; Mehta, B. R., E-mail: brmehta@physics.iitd.ac.in [Thin Film Laboratory, Department of Physics, Indian Institute of Technology Delhi, New Delhi 110016 (India); Govind [Surface Physics Group, National Physical Laboratory (CSIR), New Delhi 110012 (India)

    2014-03-28

    In this report, X-ray photoelectron spectroscopy studies have been carried out on Pd, Ag, Cu, Pd-Ag, and Pd-Cu nanoparticles having identical sizes corresponding to mobility equivalent diameters of 60, 40, and 20 nm. The nanoparticles were prepared by the gas phase synthesis method. The effect of size on valence and core levels in metal and alloy nanoparticles has been studied by comparing the values to those with the 60 nm nanoparticles. The effect of alloying has been investigated by comparing the valence and core level binding energies of Pd-Cu and Pd-Ag alloy nanoparticles with the corresponding values for Pd, Ag, and Cu nanoparticles of identical sizes. These effects have been explained in terms of size induced lattice contractions, alloying induced charge transfer, and hybridization effects. The observation of alloying and size induced binding energy shifts in bimetallic nanoparticles is important from the point of view of hydrogen reactivity.

  10. Effect of Be addition on the precipitation behaviors and mechanical properties in Al-Cu-Li-Mg-Zr-(Ag) alloys

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J.K. [Dept. of Materials Engineering, Miryang National Univ. (Korea); Chung, D.S. [Dept. of Materials, Ulsan Polytechnic Coll. (Korea); Park, H.S. [Jisung Precision Inc. Ltd, Changwon, Kyungnam (Korea); Enoki, M. [Dept. of Materials Engineering, Univ. of Tokyo (Japan)

    2005-07-01

    The effect of beryllium (Be) on the precipitation behaviors and mechanical properties of Al-Cu-Li-Mg-Zr-(Ag) alloys was investigated. The results show that adding 0.02%Be to Al-Cu-Li-Mg-Zr-(Ag) alloys, the elongation of the alloy increased without significant decrease in strength and the aging response was accelerated. In a Al-Cu-Li-Mg-Zr-(Ag) alloy, G.P. zone was formed at early aging time (2 h) and T{sub 1} and {theta}' phases were formed at peak-aging and over-aging times, while in Al-Cu-Li-Mg-Zr-(Ag)-Be alloys T{sub 1} and {theta}' phases were formed at early aging time (2 h) and the density of {theta}' phase was very low and fine T{sub 1} phases were homogeneously distributed at peak-aging and over-aging times. (orig.)

  11. Ag-Cu nanoalloyed film as a high-performance cathode electrocatalytic material for zinc-air battery

    Science.gov (United States)

    Lei, Yimin; Chen, Fuyi; Jin, Yachao; Liu, Zongwen

    2015-04-01

    A novel Ag50Cu50 film electrocatalyst for oxygen reduction reaction (ORR) was prepared by pulsed laser deposition (PLD) method. The electrocatalyst actually is Ag-Cu alloyed nanoparticles embedded in amorphous Cu film, based on transmission electron microscopy (TEM) characterization. The rotating disk electrode (RDE) measurements provide evidence that the ORR proceed via a four-electron pathway on the electrocatalysts in alkaline solution. And it is much more efficient than pure Ag catalyst. The catalytic layer has maximum power density of 67 mW cm-2 and an acceptable cell voltage at 0.863 V when current densities increased up to 100 mA cm-2 in the Ag50Cu50-based primary zinc-air battery. The resulting rechargeable zinc-air battery exhibits low charge-discharge voltage polarization of 1.1 V at 20 mAcm-2 and high durability over 100 cycles in natural air.

  12. Effects of Composition and Thermal Cycle on Transformation Behaviors, Thermal Stability and Mechanical Properties of CuAlAg Alloy

    Institute of Scientific and Technical Information of China (English)

    Yunqing MA; Chengbao JIANG; Lifen DENG; Huibin XU

    2003-01-01

    The phase transformation behavior, mechanical properties, and the thermal stability of CuAlAg alloy were studied andminor rare earth (0.1 wt pct La+Ce) was added to improve the mechanical property of the studied alloy. It was foundthat Ag addition in the CuAl binary alloy can improve the stability of martensitic transformation and high Al contentleads to the disappearing of martensitic transformation. The tensile strength and strain of the Cu-10.6Al-5.8Ag (wtpct) alloy were measured to be 383.5 MPa and 0.86%, respectively. With rare earth addition, the tensile strainincreased from 0.86% to 1.47%. The CuAlAg alloy did not exhibit martensitic transformation on the second heatingprocess. Its poor thermal stability still needs to be improved.

  13. Influence of thermomechanical processing on the structure and properties of Cu-Ag alloy in situ composites

    Institute of Scientific and Technical Information of China (English)

    NING; Yuan-tao; ZHANG; Xiao-hui; ZHANG; Jie

    2005-01-01

    The influences of the thermomechanical processing, including the solidification conditions, the cold deformation and the intermediate annealing treatment, on the structure and properties of the Cu-10Ag alloy in situ composite were studied in this paper. The cast structure and the structural changes in the cold deformation and intermediate annealing process were observed. The properties including the ultimate tensile strength (UTS) and the electrical conductivity were determined. A two-stage strain strengthening effect for the Cu-10Ag alloy in situ filamentary composite was observed. The factors influencing the UTS and conductivity were discussed. The solidification conditions in the range of 10-1000 K/s cooling rates and the intermediate heat treatment showed obviously influence on the structure and properties on the Cu-10Ag alloy in situ filamentary composite. The typical properties of the Cu-Ag alloy in situ filamentary composites through thermomechanical processing were reported.

  14. Molecular Dynamics Study on Interfacial Energy and Atomic Structure of Ag/Ni and Cu/Ni Heterophase System

    Institute of Scientific and Technical Information of China (English)

    Haijiang LIU; Shaoqing WANG; An DU; Caibei ZHANG

    2004-01-01

    The results of molecular dynamics calculations on the interfacial energies and atomic structures of Ag/Ni and Cu/Ni interaces are presented. Calculation on Ag/Ni interfaces with low-index planes shows that those containing the (111) plane have the lowest energies, which is in agreement with the experiments. Comparing surface energy with interracial energy, it is found the order of the interfacial energies of Ag/Ni and Cu/Ni containing the planes fall in the same order as solid-vapor surface energies of Ag, Cu and Ni. In this MD simulation, the relaxed atomic structure and dislocation network of (110)Ag||(110)Ni interface are coincident to HREM observations.

  15. Thermodynamic measurements on Ag - 28% Cu nanopowders processed by mechanical alloying route

    Energy Technology Data Exchange (ETDEWEB)

    Milea, A., E-mail: milea_alexandru@icf.ro [“Ilie Murgulescu” Institute of Physical Chemistry of the Romanian Academy, 202 Splaiul Independentei, 060021 Bucharest (Romania); Gingu, O., E-mail: oanagingu@yahoo.com [University of Craiova, Romania, 13 A.I. Cuza, 200585 Craiova (Romania); Preda, S., E-mail: predas01@yahoo.co.uk [“Ilie Murgulescu” Institute of Physical Chemistry of the Romanian Academy, 202 Splaiul Independentei, 060021 Bucharest (Romania); Sima, G., E-mail: gsima2001@yahoo.com [University of Craiova, Romania, 13 A.I. Cuza, 200585 Craiova (Romania); Nicolicescu, C., E-mail: nicolicescu_claudiu@yahoo.com [University of Craiova, Romania, 13 A.I. Cuza, 200585 Craiova (Romania); Tanasescu, S., E-mail: stanasescu2004@yahoo.com [“Ilie Murgulescu” Institute of Physical Chemistry of the Romanian Academy, 202 Splaiul Independentei, 060021 Bucharest (Romania)

    2015-04-25

    Graphical abstract: Crystallite size (XRD measurements) and enthalpy increment (H{sub T} − H{sub 298}) (drop calorimetry data) of the nanozised Ag - 28% Cu powders as a function of temperature. - Highlights: • We report relevant data for thermodynamic stability of mechanical alloyed Ag - 28% Cu nanopowders. • Enthalpy increment and heat capacity data have been measured by drop calorimetry. • The effect of milling time on the particle size and energetic parameters is evidenced. • Correlation between thermodynamic and structural data of Ag - 28% Cu nanopowders is discussed. - Abstract: The paper is devoted to the investigation of the thermodynamic properties of Ag - 28% Cu powders processed by mechanical alloying route at two different milling times (20 and 80 h). Thermodynamic properties represented by the heat capacity (C{sub p}) and the enthalpy increment (H{sub T} − H{sub 298}) have been obtained in the temperature range from ambient to 1073 K by drop calorimetry using a multi-detector high temperature calorimeter SETARAM MHTC-96. A critical comparison of the isothermal enthalpy measurements with the dynamic differential scanning calorimetric (DSC) results has been made to reveal the occurrence of the micro-relaxation process, as well as of the correlative effects of decomposition and growth processes. New features related to the effect of the milling time and crystallite size on the thermal behavior and energetic parameters were evidenced. The correlation between thermal stability and microstructure of the sample obtained after 80 h processing has been investigated by the evaluation of the in situ controlled annealing powder X-ray diffraction patterns (XRD)

  16. Microstructure evaluation of long-term aged binary Ag-Cu alloy

    OpenAIRE

    K. Labisz; Z. Rdzawski; M. Pawlyta

    2011-01-01

    Purpose: In this work there are presented microstructure investigation results of the long aged Ag-Cu alloy used for monetary production. The purpose of this work was to determine the microstructural phase changes after 30 year ageing time, with appliance of transmission electron microscopy. Mainly the possibility of spinodal decomposition process occurrence was investigated.Design/methodology/approach: The investigations were performed using optical microscopy for the microstructure determin...

  17. LPG sensing performance of CuO–Ag2O bimetallic oxide nanoparticles

    OpenAIRE

    K.R. Nemade; S.A. Waghuley

    2015-01-01

    In the present article, we synthesized CuO–Ag2O bimetallic oxide nanoparticles by using microwave assisted and solid state diffusion routes. The structural, morphological, optical and thermal study of as-synthesized materials were done through X-ray diffractometer (XRD), scanning electron microscope (SEM), Fourier transform infrared (FTIR), ultraviolet–visible (UV–vis) and thermogravimetric analysis (TGA), respectively. Comparatively different sensing parameters such as sensing response at ro...

  18. [Determination of Ag, Cu, Zn and Cd in silver brazing filler metals by ICP-AES].

    Science.gov (United States)

    Yang, X

    1997-06-01

    A method of simultaneous and direct determination for Ag, Cu, Zn and Cd in silver brazing filler metals by ICP-AES is reported. The spectral interferences and effect of acidity have been investigated. Working conditions were optimized. The method has been applied to the analysis of silver brazing filler metals with RSD of 4-7% and recovery of 94-105%. This method was accurate, simple and rapid.

  19. Mo/Cu(In, Ga)Se{sub 2} back interface chemical and optical properties for ultrathin CIGSe solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Erfurth, F.; Jehl, Z. [Institut de Recherche et Developpement sur l' Energie Photovoltaieque IRDEP (EDF/CNRS/Chimie-ParisTech UMR 7174), 6 quai Watier, 78401 Chatou (France); Bouttemy, M. [ILV - UMR 8180, Universite de Versailles St Quentin, 45 Av. des Etats Unis, 78035 Versailles (France); Dahan, N. [Institut d' Optique, CNRS, Campus Polytechnique, RD 128, 91127 Palaiseau Cedex (France); Tran-Van, P.; Gerard, I.; Etcheberry, A. [ILV - UMR 8180, Universite de Versailles St Quentin, 45 Av. des Etats Unis, 78035 Versailles (France); Greffet, J.-J. [Institut d' Optique, CNRS, Campus Polytechnique, RD 128, 91127 Palaiseau Cedex (France); Powalla, M. [Zentrum fuer Sonnenenergie- und Wasserstoff-Forschung (ZSW), Industriestr. 6, 70565 Stuttgart (Germany); Voorwinden, G. [Wuerth Elektronik Research GmbH, Industriestr. 4, 70565 Stuttgart (Germany); Lincot, D.; Guillemoles, J.F. [Institut de Recherche et Developpement sur l' Energie Photovoltaieque IRDEP (EDF/CNRS/Chimie-ParisTech UMR 7174), 6 quai Watier, 78401 Chatou (France); Naghavi, N., E-mail: negar.naghavi@edf.fr [Institut de Recherche et Developpement sur l' Energie Photovoltaieque IRDEP (EDF/CNRS/Chimie-ParisTech UMR 7174), 6 quai Watier, 78401 Chatou (France)

    2012-01-15

    Chemical and optical properties of the interface between a coevaporated Cu(In,Ga)Se{sub 2} (CIGSe) absorber thin film and the Mo back contact are investigated with the objective to reduce markedly the thickness of CIGSe layers from two microns down to about 100 nm. First a mechanical lift off technique allowed to separate Mo and CIGSe layers and perform X-ray photoelectron spectroscopy (XPS) and elipsometry studies on as prepared surfaces. On the Mo side small amounts of In and Ga are observed together with the formation of an MoSe{sub 2} layer. There is no evidence of the presence of Cu. On the opposite CIGSe side a clear depletion of Cu together with an enrichment of Ga is evidenced. There is no evidence of Mo. Optical reflectivity of the interface CIGSe/Mo is studied by ellipsometry showing a low reflectivity of the interface attributed to the formation of MoSe{sub 2} layer. The enhance light absorption in ultrathin absorbers using alternative, highly reflective back contacts are finally discussed.

  20. Mo/Cu(In, Ga)Se 2 back interface chemical and optical properties for ultrathin CIGSe solar cells

    Science.gov (United States)

    Erfurth, F.; Jehl, Z.; Bouttemy, M.; Dahan, N.; Tran-Van, P.; Gerard, I.; Etcheberry, A.; Greffet, J.-J.; Powalla, M.; Voorwinden, G.; Lincot, D.; Guillemoles, J. F.; Naghavi, N.

    2012-01-01

    Chemical and optical properties of the interface between a coevaporated Cu(In,Ga)Se2 (CIGSe) absorber thin film and the Mo back contact are investigated with the objective to reduce markedly the thickness of CIGSe layers from two microns down to about 100 nm. First a mechanical lift off technique allowed to separate Mo and CIGSe layers and perform X-ray photoelectron spectroscopy (XPS) and elipsometry studies on as prepared surfaces. On the Mo side small amounts of In and Ga are observed together with the formation of an MoSe2 layer. There is no evidence of the presence of Cu. On the opposite CIGSe side a clear depletion of Cu together with an enrichment of Ga is evidenced. There is no evidence of Mo. Optical reflectivity of the interface CIGSe/Mo is studied by ellipsometry showing a low reflectivity of the interface attributed to the formation of MoSe2 layer. The enhance light absorption in ultrathin absorbers using alternative, highly reflective back contacts are finally discussed.

  1. mo explicar física cuántica con un gato zombi

    CERN Document Server

    Gonzalez Buron, Helena; Marimon Garrido, Oriol; Barrrecheguran Manero, Pablo; Luri Carrascoso, Xavier; Puerto Gimenez, Irene; Saenz de Cabezon Irigarai, Eduardo

    2016-01-01

    ¿Sabías que el teletransporte es real? ¿Que a veces un electrón tiene probabilidades de atravesar una pared? ¿Que dos partículas pueden influenciarse mutuamente aunque estén a años luz de distancia? ¿Y que las partículas cuánticas son como Clark Kent y disimulan sus poderes cuando los científicos las están observando? En Cómo explicar la física cuántica con un gato zombi descubrirás que, aunque no lo parezca, la física cuántica está por todas partes en nuestra vida cotidiana. Y además aprenderás... ...¡los principios más locos y flipantes de la física cuántica! ...¡experimentos low cost que puedes hacer en tu casa! ...que los científicos están un poco pallá, ¿lo sabías? ...y que los gatos tampoco son muy normales que digamos...

  2. Sputtered Ni-Zn under bump metallurgy (UBM) for Sn-Ag-Cu solders

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tae Jin; Kim, Young Min [Division of Materials Science and Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Kim, Young-Ho, E-mail: kimyh@hanyang.ac.kr [Division of Materials Science and Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of)

    2012-09-15

    Highlights: Black-Right-Pointing-Pointer Ni-Zn UBM can effectively suppress the growth of IMCs and the consumption of UBM. Black-Right-Pointing-Pointer The growth of (Ni, Cu){sub 3}Sn{sub 4} was retarded at the SAC305/Ni-Zn interface after aging. Black-Right-Pointing-Pointer Only a single (Cu, Ni){sub 6}Sn{sub 5} formed at the SAC107/Ni-Zn interface after aging. Black-Right-Pointing-Pointer Segregated Zn atoms on IMC layers retarded the interdiffusion of Cu, Ni, and Sn. Black-Right-Pointing-Pointer Sputtered Ni-Zn UBM is promising for Pb-free solder flip chip applications. - Abstract: We developed a new sputtered under bump metallurgy (UBM) based on Ni-20wt% Zn thin films for Pb-free solders. This study focuses on the interfacial reactions between two Pb-free solders (Sn3.0Ag0.5Cu and Sn1.0Ag0.7Cu) and a Ni-Zn alloy UBM. By adding Zn to Ni UBM, Zn is incorporated into intermetallic compounds (IMCs) to form a quaternary Cu-Ni-Zn-Sn phase at the solder/Ni-Zn interface after reflow and subsequent isothermal aging. The Ni-Zn UBM sufficiently reduces the interfacial reaction and IMCs formation rates as well as UBM consumption rates compared to a Ni UBM. In particular, the formation of (Ni, Cu){sub 3}Sn{sub 4} IMC was significantly retarded by adding Zn into UBM.

  3. Thermodynamic modeling of the Na-X (X = Si, Ag, Cu, Cr systems

    Directory of Open Access Journals (Sweden)

    Hao D.

    2012-01-01

    Full Text Available The Na-X (X = Si, Ag, Cu, Cr systems have been critically reviewed and modeled by means of the CALPHAD approach. The two compounds, NaSi and Ag2Na, are treated as stoichiometric ones. By means of first-principles calculations, the enthalpies of formation at 0 K for the LT-NaSi (low temperature form of NaSi and Ag2Na have been computed to be -5210 and -29821.8 Jmol-1, respectively, with the desire to assist thermodynamic modeling. One set of self-consistent thermodynamic parameters is obtained for each of these binary systems. Comparisons between calculated and measured phase diagrams show that most of the experimental information can be satisfactorily accounted for by the present thermodynamic descriptions.

  4. Correlation between mechanical properties and structural changes of the sintered Cu-4 at% Ag alloy during thermomechanical treatment

    OpenAIRE

    Rangelov Ivana I.; Nestorović Svetlana D.; Marković Desimir D.

    2008-01-01

    Influence of thermomechanical treatment on micro structure and strength (hardness and microhardness) of the sintered copper based Cu-4 at% Ag alloy was investigated using Vickers hardness and microhardness measurements, and optical microscopy. After sintering at 790°C, samples of Cu-4 at% Ag alloy were subjected to thermomechanical treatment by cold rolling with 20, 40 and 60% deformation degrees, and annealing below and over the recrystallization temperature. It was shown that microstructure...

  5. Combinatorial development of antibacterial Zr-Cu-Al-Ag thin film metallic glasses

    Science.gov (United States)

    Liu, Yanhui; Padmanabhan, Jagannath; Cheung, Bettina; Liu, Jingbei; Chen, Zheng; Scanley, B. Ellen; Wesolowski, Donna; Pressley, Mariyah; Broadbridge, Christine C.; Altman, Sidney; Schwarz, Udo D.; Kyriakides, Themis R.; Schroers, Jan

    2016-05-01

    Metallic alloys are normally composed of multiple constituent elements in order to achieve integration of a plurality of properties required in technological applications. However, conventional alloy development paradigm, by sequential trial-and-error approach, requires completely unrelated strategies to optimize compositions out of a vast phase space, making alloy development time consuming and labor intensive. Here, we challenge the conventional paradigm by proposing a combinatorial strategy that enables parallel screening of a multitude of alloys. Utilizing a typical metallic glass forming alloy system Zr-Cu-Al-Ag as an example, we demonstrate how glass formation and antibacterial activity, two unrelated properties, can be simultaneously characterized and the optimal composition can be efficiently identified. We found that in the Zr-Cu-Al-Ag alloy system fully glassy phase can be obtained in a wide compositional range by co-sputtering, and antibacterial activity is strongly dependent on alloy compositions. Our results indicate that antibacterial activity is sensitive to Cu and Ag while essentially remains unchanged within a wide range of Zr and Al. The proposed strategy not only facilitates development of high-performing alloys, but also provides a tool to unveil the composition dependence of properties in a highly parallel fashion, which helps the development of new materials by design.

  6. Energetics of small clusters of group IB metals (Cu, Ag, and Au) adsorbed on graphene

    Science.gov (United States)

    Kaur, Gagandeep; Gupta, Shuchi; Dharamvir, Keya

    2013-06-01

    The 2D structure of graphene maximizes the interaction of adsorbate on the layer. Many experiments have been devised to form stable metallic clusters of different sizes. We study the structure and binding energies of group IB clusters Mn (M=Au, Ag, Cu n=1, 3) adsorbed on graphene using Gupta potential [1] (for M-M interaction) and Lennard-Jones potential [2] (for metal-carbon interaction). The total energy of the system has been obtained by placing each of Mn cluster a certain distance above the graphene sheet at various positions and in various orientations. The minimized energy configurations, for all Mn clusters, lie above the center of a hexagon and parallel to the graphene sheet. Binding energy per atom for Ag and Cu metal clusters are less than those of respective Au indicating the lower stability of Ag/Cu metal-graphene system. Using various energy barriers, we can calculate the energy required to move small cluster from one position of minimum energy to another on graphene.

  7. Effect of microstructure on thermal conductivity of Cu, Ag thin films.

    Science.gov (United States)

    Ryu, Sang; Juhng, Woonam; Kim, Youngman

    2010-05-01

    Thin film type materials are widely used in modern industries, such as semiconductor devices, functional superconductors, machining tools, and so on. The thermal properties of material in semiconductor are very important factors for stable operation because the heat generated during device operation may increase clock frequency. Even though thermal properties of thin films may play a major role in assessing reliability of parts, the measurement methods of thin film thermal properties are generally known to be complex to devise. In this study, a temperature distribution method was applied for the measurement of thermal conductivity of Cu and Ag thin film on borosilicate glass substrate. Cu and Ag thin films were deposited on borosilicate glass using thermal evaporation processes. To measure the thermal conductivity changes according to the microstructure of metallic thin film, the processing variables for the Cu and Ag thin film deposition were changed. To minimize the effect of film thickness, the film thickness was fixed to the thickness of approximately 500 nm throughout experiments. The thermal conductivities of thin films were measured to be much lower than those of bulk materials. Thin film with larger grain size showed higher thermal conductivity probably due to the lower number density of grain boundary. Weidman-Franz law could be applied to thin films produced in this study. Thermal conductivity was also estimated from the resistivity of thin film and Lorenz number of bulk material.

  8. Corrosion properties of Ag-Au-Cu-Pd system alloys containing indium.

    Science.gov (United States)

    Hattori, Masayuki; Tokizaki, Teruhiko; Matsumoto, Michihiko; Oda, Yutaka

    2010-01-01

    In this study, the corrosion resistance of Ag-Au-Cu-Pd system alloys consisting of 5 or 10 mass% indium was evaluated. Levels of element release and tarnish were determined and electrochemical measurements performed. Results were compared with those for commercial silver-palladium-gold alloy. In terms of electrochemical behavior, the transpassive potential of these experimental alloys was 168-248mV. Experimental alloys with 25 mass% Au showed similar corrosion resistance to control gold-silver-palladium alloy. Amount of released elements was 14-130microg/cm(2) at 7 days, which is in the allowable range for dental alloys. Addition of indium to Ag-Au-Cu-10mass%Pd system alloys was effective in increasing resistance to tarnish and alloys containing 10 mass% of indium showed a minimal decrease in L(*) values after immersion. These findings indicate that 25Au-37.5Ag-15Cu-10Pd-2Zn-10In-0.5Ir alloy is applicable in dental practice.

  9. 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.

  10. Electromigration-induced cracks in Cu/Sn3.5Ag/Cu solder reaction couple at room temperature

    Institute of Scientific and Technical Information of China (English)

    He Hongwen; Xu Guangchen; Guo Fu

    2009-01-01

    Electromigration (EM) behavior of Cu/Sn3.5Ag/Cu solder reaction couple was investigated with a high current density of 5× 103 A/cm2 at room temperature. One dimensional structure, copper wire/solder ball/copper wire SRC was designed and fabricated to dissipate the Joule heating induced by the current flow. In addition, thermomigration effect was excluded due to the symmetrical structure of the SRC. The experimental results in-dicated that micro-cracks initially appeared near the cathode interface between solder matrix and copper substrate after 474 h current stressing. With current stressing time increased, the cracks propagated and extended along the cathode interface. It should be noted that the continuous Cu6Sn5 intcrmetallic compounds (LMCs) layer both at the anode and at the cathode remained their sizes. Interestingly, tiny cracks appeared at the root of some long column-type Cu6Sn5 at the cathode interface due to the thermal stress.

  11. Electromigration-induced cracks in Cu/Sn3.5Ag/Cu solder reaction couple at room temperature

    Science.gov (United States)

    Hongwen, He; Guangchen, Xu; Fu, Guo

    2009-03-01

    Electromigration (EM) behavior of Cu/Sn3.5Ag/Cu solder reaction couple was investigated with a high current density of 5 × 103 A/cm2 at room temperature. One dimensional structure, copper wire/solder ball/copper wire SRC was designed and fabricated to dissipate the Joule heating induced by the current flow. In addition, thermomigration effect was excluded due to the symmetrical structure of the SRC. The experimental results indicated that micro-cracks initially appeared near the cathode interface between solder matrix and copper substrate after 474 h current stressing. With current stressing time increased, the cracks propagated and extended along the cathode interface. It should be noted that the continuous Cu6Sn5 intermetallic compounds (IMCs) layer both at the anode and at the cathode remained their sizes. Interestingly, tiny cracks appeared at the root of some long column-type Cu6Sn5 at the cathode interface due to the thermal stress.

  12. Intermetallic compound formation at Sn-3.0Ag-0.5Cu-1.0Zn lead-free solder alloy/Cu interface during as-soldered and as-aged conditions

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Feng-Jiang [Department of Materials Science and Engineering, Shanghai University of Engineering Science, Shanghai 201620 (China)]. E-mail: wangfjy@yahoo.com.cn; Yu, Zhi-Shui [Department of Materials Science and Engineering, Shanghai University of Engineering Science, Shanghai 201620 (China); Qi, Kai [Department of Materials Science and Engineering, Shanghai University of Engineering Science, Shanghai 201620 (China)

    2007-07-12

    Intermetallic formations of Sn-3.0Ag-0.5Cu solder alloy with additional 1.0 wt% Zn were investigated for Cu-substrate during soldering and isothermal aging. During soldering condition, the Cu{sub 5}Zn{sub 8} compound with granular-type morphology is the interfacial IMC for Sn-3.0Ag-0.5Cu-1.0Zn solder, while the Cu{sub 6}Sn{sub 5} compound with scallop-type morphology is the interfacial IMC for Sn-3.0Ag-0.5Cu solder. During thermal aging, the final interfacial structure for Sn-3.0Ag-0.5Cu-1.0Zn solder is solder/Cu{sub 5}Zn{sub 8}/Cu{sub 6}Sn{sub 5}/Cu{sub 3}Sn/Cu, different from the solder/Cu{sub 6}Sn{sub 5}/Cu{sub 3}Sn/Cu for Sn-3.0Ag-0.5Cu solder. The thickness of Cu-Sn IMC layers increases, while the thickness of Cu{sub 5}Zn{sub 8} compound layer decreases with increasing aging time due to the decomposition of the Cu{sub 5}Zn{sub 8} layer by the diffusion of Cu and Zn atoms into the solder and Cu{sub 6}Sn{sub 5} at higher aging temperature. For Sn-3.0Ag-0.5Cu-1.0Zn solder, at higher aging temperature of 150 or 175 {sup o}C, with the formation of Cu{sub 3}Sn at Cu{sub 6}Sn{sub 5}/Cu, Kirkendall voids can be observed at the interface of Cu{sub 3}Sn/Cu.

  13. EFFECT OF BRAZING TIME ON TiC CERMET/IRON JOINT BRAZED WITH Ag-Cu-Zn FILLER METAL

    Institute of Scientific and Technical Information of China (English)

    L.X. Zhang; J.C. Feng; Z.R. Li; H.J. Liu

    2004-01-01

    The brazing of TiC cermet to iron was carried out at 1223K for 5-20min using Ag-Cu-Zn filler metal. The formation phase and interface structure of the joints were investigated by electron probe microanalysis (EPMA), scanning electron microscopy (SEM) and X-ray diffraction (XRD), and the joint strength was tested by shearing method. The results showed: there occurred three new formation phases, Cu(s.s), FeNi and Ag(s.s) in TiC cermet/iron joint. The interface structure was expressed as TiC cermet/Cu(s.s)+FeNi/Ag(s.s)+a little Cu(s.s)+a little FeNi/Cu(s.s)+ FeNi/iron. With brazing time increasing, there appeared highest shear strength of the joints, the value of which was up to 252.2MPa when brazing time was 10min.

  14. Structural evolution of Ag-Cu nano-alloys confined between AlN nano-layers upon fast heating.

    Science.gov (United States)

    Janczak-Rusch, J; Chiodi, M; Cancellieri, C; Moszner, F; Hauert, R; Pigozzi, G; Jeurgens, L P H

    2015-11-14

    The structural evolution of a Ag-Cu/AlN nano-multilayer (NML), as prepared by magnetron-sputtering on a α-Al2O3 substrate, was monitored during fast heating by real-time in situ XRD analysis (at the synchrotron), as well as by ex situ microstructural analysis using SEM, XPS and in-house XRD. The as-deposited NML is constituted of alternating nano-layers (thickness ≈ 10 nm) of a chemically inert AlN barrier and a eutectic Ag-Cu(40at%) nano-alloy. The nano-alloy in the as-deposited state is composed of a fcc matrix of Ag nano-grains (≈6 nm), which are supersaturated by Cu, and some smaller embedded Cu rich nano-grains (≈4 nm). Heating up to 265 °C activates segregation of Cu out of the supersaturated Ag nano-grains phase, thus initiating phase separation. At T > 265 °C, the phase-separated Cu metal partially migrates to the top NML surface, thereby relaxing thermally-accumulated compressive stresses in the confined alloy nano-layers and facilitating grain coarsening of (still confined) phase-separated nano-crystallites. Further heating and annealing up to 420 °C results in complete phase separation, forming extended Ag and Cu domains with well-defined coherent Ag/AlN interfaces. The observed outflow of Cu well below the eutectic melting point of the bulk Ag-Cu alloy might provide new pathways for designing low-temperature nano-structured brazing materials.

  15. Ag-Pd-Cu alloy inserted transparent indium tin oxide electrodes for organic solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyo-Joong; Seo, Ki-Won; Kim, Han-Ki, E-mail: imdlhkkim@khu.ac.kr [Department of Advanced Materials Engineering for Information and Electronics, Kyung-Hee University, 1 Seocheon-dong, Yongin-si, Gyeonggi-do 446-701 (Korea, Republic of); Noh, Yong-Jin; Na, Seok-In [Graduate School of Flexible and Printable Electronics, Chonbuk National University, 664-14, Deokjin-dong, Jeonju-si, Jeollabuk-do 561-756 (Korea, Republic of)

    2014-09-01

    The authors report on the characteristics of Ag-Pd-Cu (APC) alloy-inserted indium tin oxide (ITO) films sputtered on a glass substrate at room temperature for application as transparent anodes in organic solar cells (OSCs). The effect of the APC interlayer thickness on the electrical, optical, structural, and morphological properties of the ITO/APC/ITO multilayer were investigated and compared to those of ITO/Ag/ITO multilayer electrodes. At the optimized APC thickness of 8 nm, the ITO/APC/ITO multilayer exhibited a resistivity of 8.55 × 10{sup −5} Ω cm, an optical transmittance of 82.63%, and a figure-of-merit value of 13.54 × 10{sup −3} Ω{sup −1}, comparable to those of the ITO/Ag/ITO multilayer. Unlike the ITO/Ag/ITO multilayer, agglomeration of the metal interlayer was effectively relieved with APC interlayer due to existence of Pd and Cu elements in the thin region of the APC interlayer. The OSCs fabricated on the ITO/APC/ITO multilayer showed higher power conversion efficiency than that of OSCs prepared on the ITO/Ag/ITO multilayer below 10 nm due to the flatness of the APC layer. The improved performance of the OSCs with ITO/APC/ITO multilayer electrodes indicates that the APC alloy interlayer prevents the agglomeration of the Ag-based metal interlayer and can decrease the thickness of the metal interlayer in the oxide-metal-oxide multilayer of high-performance OSCs.

  16. In-situ synthesis of AgCu/Cu{sub 2}O nanocomposite by mechanical alloying: The effect of the processing on the thermal behavior

    Energy Technology Data Exchange (ETDEWEB)

    Gingu, Oana [University of Craiova, Department IMST, 1st Calugareni, 220037 Drobeta Turnu Severin (Romania); Rotaru, P., E-mail: protaru@central.ucv.ro [University of Craiova, Department of Physics, 13 A.I. Cuza Street, 200585 Craiova (Romania); Milea, A.; Marin, A. [Institute of Physical Chemistry “Ilie Murgulescu” of the Romanian Academy, 202 Splaiul Independentei, P.O. Box 194, 060021 Bucharest (Romania); Nicolicescu, C.; Sima, Gabriela [University of Craiova, Department IMST, 1st Calugareni, 220037 Drobeta Turnu Severin (Romania); Tanasescu, Speranta [Institute of Physical Chemistry “Ilie Murgulescu” of the Romanian Academy, 202 Splaiul Independentei, P.O. Box 194, 060021 Bucharest (Romania)

    2015-04-20

    TG heating curves for Ag–Cu samples vs. the milling time, recorded during the heating. The samples’ mass variation is strongly dependent on the powders’ specific surface, respectively the milling time. - Highlights: • AgCu bimetallic composites reinforced by Cu{sub 2}O has been studied. • The milling time influences the particle size distribution of the particles. • The thermal behavior of the mixtures has been studied by TG and DSC, in argon. • Correlation of thermal stability with thermal expansion properties was made. - Abstract: The influence of the mechanical alloying processing parameters on the elaboration of AgCu-based bimetallic matrix composites reinforced by in-situ synthesized Cu{sub 2}O has been studied. The milling time (20, 45 and 80 h) of the initial 72% mass Ag + 28% mass Cu micrometric powders mixture influences the particle size distribution of the obtained composite particles. After 80 h of mechanical alloying, AgCu/Cu{sub 2}O nanoparticles of 60–80 nm are obtained and their chemical composition at bulk/surface level has been determined by X-ray diffraction and photoelectron spectroscopy. The effect of milling time on the thermal behavior of the powders samples has been studied by thermogravimetry and differential scanning calorimetry measurements in argon atmosphere. The argon chemosorbtive reaction from the particles surface has been identified and the binding energy (0.9–1.99 eV) has been calculated. The isothermal drop calorimetry and the linear thermal expansion measurements were used to evaluate the correlation between thermal stability and thermal expansion properties of the in-situ synthesized AgCu/Cu{sub 2}O nanocomposite.

  17. 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.

  18. Effects of rare earth element Ce on solderabilities of micron-powdered Sn-Ag-Cu solder

    Institute of Scientific and Technical Information of China (English)

    XUE Song-bai; YU Sheng-lin; WANG Xu-yan; LIU lin; HU Yong-fang; YAO Li-hua

    2005-01-01

    Several important properties of the micron-powdered Sn-Ag-Cu-Ce solder, including the spreadability, spreading ratio, wetting time, and melting point, were investigated for verifying the effects of rare earth element Ce on solderabilities of micron-powdered Sn-Ag-Cu solder. The solidus and the liquidus of the micron-powdered Sn-Ag-Cu-Ce solder are 193.6℃ and 218.4℃, respectively, about 28℃ and 3℃ lower than the melting point of the block Sn-Ag-Cu solder, which reminds the existence of the surface effect of the micron-powdered solder. By adding Ce into Sn-Ag-Cu alloy, its wetting time on pure copper can be obviously decreased. For the Sn-Ag-Cu-0.03%Ce, the soldering temperature is 250℃, and the wetting time on pure copper is close to 1s, with the soldering temperature approaching to 260℃, the wetting time is dropped to 0.8s, which is close to the wetting time, 0.68s, of Sn-Pb solder at 235℃.

  19. Effect of Silver Content on Microstructure and Properties of Brass/steel Induction Brazing Joint Using Ag-Cu-Zn-Sn Filler Metal

    Institute of Scientific and Technical Information of China (English)

    J. Cao; L.X. Zhang; H.Q. Wang; L.Z. Wu; C. Feng

    2011-01-01

    The induction brazing of brass to steel using Ag-Cu-Zn-Sn filler metal was investigated in this study. The influence of Ag content on the microstructure and properties were analyzed by means of optical microscopy, scanning electron microscopy and electron probe microanalysis. Defect free joint was achieved using Ag-Cu-Zn-Sn filler metal. The microstructure of the joint was mainly composed of Ag-based solid solution and Cu-based solid solution. The increase of Ag content and the cooling rate both led to the increase of the needle like eutectic structure. The tensile strength decreased with the increase of Ag content. The tensile strength at room temperature using Ag25CuZnSn filler metal reached 445 MPa. All fractures using Ag-Cu-Zn-Sn filler metal presented ductile characteristic.

  20. 合金元素 Ag 含量对 Sn-Ag-Cu无铅焊料焊接性能的影响%Effect of Ag concentration on soldering properties of Sn-Ag-Cu lead-free solder alloy

    Institute of Scientific and Technical Information of China (English)

    高瑞军; 张宇航; 康宇; 韩振峰; 孙福林; 钟茂山

    2015-01-01

    The paper has investigated that different amount of pure Ag are added into Sn-Ag-Cu lead-free solders,and the effect on soldering properties was also discussed.The results show that Ag can improve spreadability and wettability of Cu alloy further.When 0.5% of Ag added,both Sn-0.7Cu and Sn-0.5Ag-0.5Cu solder alloys exhibited similar properties.%探讨了合金元素 Ag 含量对 Sn-Ag-Cu 无铅合金焊料熔化温度、铺展性及润湿性的影响.结果表明,随着 Ag 含量的增加,Sn-Ag-Cu 合金焊料的熔化温度降低,铺展性和润湿性提高,当 w(Ag)≤0.5%时,Sn-0.7Cu 焊料与 Sn-0.5Ag-0.5Cu 焊料的焊接性能十分接近.

  1. Wear behavior of an austempered ductile iron containing Mo-Ni-Cu

    Energy Technology Data Exchange (ETDEWEB)

    Yazdani, S.; Rahimi, M.A. [Faculty of Materials Engineering, Sahand Univ. of Technology, Tabriz (Iran)

    2005-07-01

    The aim of the this investigation is to study the influence of Ni on tribiological behavior of an austempered ductile iron (ADI) containing Mo, Ni and Cu. Ductile irons with chemical composition Fe-3.56%C-2.67%Si -0.25%Mo-0.5%Cu and Ni contents of 0.8 and 1.5% were cast into standard Y-blocks. Wear test samples were machined off from the bottom section of blocks. Austenitizing heat treatment was carried out at 870 C temperature followed by austempering at 270, 320, and 370 C for 5-1140 minutes. The wear test was carried out by using block-on-ring test machine. Sliding dry wear behavior was studied under applied loads of 50, 100 and 150 N. The results show that wear resistance is independent of austempering temperature with an applied load of 50 N, but there is a strong dependence at higher austempering temperatures with applied loads of 100 and 150 N. Wear mechanism is described as being due to subsurface fatigue, with cracks nucleated at plastically, deformed graphite interfaces. The wear controlling mechanism is the crack growth when wear shows a dependence on applied load and austempering temperature. (orig.)

  2. Photocatalytic performances and activities of Ag-doped CuFe{sub 2}O{sub 4} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Zhengru, E-mail: zhengruzhu@gmail.com [Research Center of Hydrology and Water Source, School of Urban and Environment, Liaoning Normal University, Dalian, 116029 (China); State Key Laboratory of Fine Chemical, Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Dalian, 116024 (China); Li, Xinyong; Zhao, Qidong [State Key Laboratory of Fine Chemical, Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Dalian, 116024 (China); Li, Yonghua; Sun, Caizhi; Cao, Yongqiang [Research Center of Hydrology and Water Source, School of Urban and Environment, Liaoning Normal University, Dalian, 116029 (China)

    2013-08-01

    Graphical abstract: - Highlights: • CuFe{sub 2}O{sub 4} nanocrystals were synthesized by a co-precipitation method. • Ag/CuFe{sub 2}O{sub 4} catalyst was prepared by the wetness impregnation strategy. • The structural properties of Ag/CuFe{sub 2}O{sub 4} were investigated by XRD, TEM, DRS, and XPS techniques. • Ag/CuFe{sub 2}O{sub 4} has higher photocatalytic activity. - Abstract: In this work, CuFe{sub 2}O{sub 4} nanoparticles were synthesized by a chemical co-precipitation route. The Ag/CuFe{sub 2}O{sub 4} catalyst was prepared based on the CuFe{sub 2}O{sub 4} nanoparticles by the incipient wetness impregnation strategy, which showed excellent photoelectric property and catalytic activity. The structural properties of these samples were systematically investigated by X-ray powder diffraction (XRD), transmission electronic microscopy (TEM), UV–vis diffuse reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FT-IR) techniques. The photo-induced charge separation in the samples was demonstrated by surface photovoltage (SPV) measurement. The photocatalytic degradation of 4-CP by the Ag/CuFe{sub 2}O{sub 4} and CuFe{sub 2}O{sub 4} samples were comparatively studied under xenon lamp irradiation. The results indicate that the Ag/CuFe{sub 2}O{sub 4} sample exhibited the higher efficiency for the degradation of 4-CP.

  3. Semitransparent inverted polymer solar cells employing a sol-gel-derived TiO2 electron-selective layer on FTO and MoO3/Ag/MoO3 transparent electrode.

    Science.gov (United States)

    Li, Fumin; Chen, Chong; Tan, Furui; Li, Chunxi; Yue, Gentian; Shen, Liang; Zhang, Weifeng

    2014-01-01

    We report a new semitransparent inverted polymer solar cell (PSC) with a structure of glass/FTO/nc-TiO2/P3HT:PCBM/MoO3/Ag/MoO3. Because high-temperature annealing which decreased the conductivity of indium tin oxide (ITO) must be handled in the process of preparation of nanocrystalline titanium oxide (nc-TiO2), we replace glass/ITO with a glass/fluorine-doped tin oxide (FTO) substrate to improve the device performance. The experimental results show that the replacing FTO substrate enhances light transmittance between 400 and 600 nm and does not change sheet resistance after annealing treatment. The dependence of device performances on resistivity, light transmittance, and thickness of the MoO3/Ag/MoO3 film was investigated. High power conversion efficiency (PCE) was achieved for FTO substrate inverted PSCs, which showed about 75% increase compared to our previously reported ITO substrate device at different thicknesses of the MoO3/Ag/MoO3 transparent electrode films illuminated from the FTO side (bottom side) and about 150% increase illuminated from the MoO3/Ag/MoO3 side (top side).

  4. Electrical characterization of the organic semiconductor Ag/CuPc/Au Schottky diode

    Institute of Scientific and Technical Information of China (English)

    Mutabar Shah; M. H. Sayyad; Kh. S. Karimov

    2011-01-01

    This paper reports on the fabrication and investigation of a surface-type organic semiconductor copper phthalocyanine (CuPc) based diode. A thin film of CuPc of thickness 100 nm was thermally sublimed onto a glass substrate with preliminary deposited metallic electrodes to form a surface-type Ag/CuPc/Au Schottky diode. The current-voltage characteristics were measured at room temperature under dark conditions. The barrier height was calculated as 1.05 eV. The values of mobility and conductivity was found to be 1.74 x l0-9 cm2/(V.s) and 5.5 x 10-6 Ω-1. cm-1, respectively. At low voltages the device showed ohmic conduction and the space charge limited current conduction mechanisms were dominated at higher voltages.

  5. An exploration hydrogeochemical study at the giant Pebble porphyry Cu-Au-Mo deposit, Alaska, USA, using high-resolution ICP-MS

    Science.gov (United States)

    Eppinger, Robert G.; Fey, David L.; Giles, Stuart A.; Kelley, Karen D.; Smith, Steven M.

    2012-01-01

    A hydrogeochemical study using high resolution ICP-MS was undertaken at the giant Pebble porphyry Cu-Au-Mo deposit and surrounding mineral occurrences. Surface water and groundwater samples from regional background and the deposit area were collected at 168 sites. Rigorous quality control reveals impressive results at low nanogram per litre (ng/l) levels. Sites with pH values below 5.1 are from ponds in the Pebble West area, where sulphide-bearing rubble crop is thinly covered. Relative to other study area waters, anomalous concentrations of Cu, Cd, K, Ni, Re, the REE, Tl, SO42− and F− are present in water samples from Pebble West. Samples from circum-neutral waters at Pebble East and parts of Pebble West, where cover is much thicker, have anomalous concentrations of Ag, As, In, Mn, Mo, Sb, Th, U, V, and W. Low-level anomalous concentrations for most of these elements were also found in waters surrounding nearby porphyry and skarn mineral occurrences. Many of these elements are present in low ng/l concentration ranges and would not have been detected using traditional quadrupole ICP-MS. Hydrogeochemical exploration paired with high resolution ICP-MS is a powerful new tool in the search for concealed deposits.

  6. Effect of the oxygen flow rate on the structure and the properties of Ag-Cu-O sputtered films deposited using a Ag/Cu target with eutectic composition

    Energy Technology Data Exchange (ETDEWEB)

    Pierson, J.F. [Laboratoire de Science et Genie des Surfaces (UMR CNRS 7570), Ecole des Mines, Parc de Saurupt, CS 14234, 54042 Nancy Cedex (France)], E-mail: jean-francois.pierson@mines.inpl-nancy.fr; Rolin, E.; Clement-Gendarme, C.; Petitjean, C.; Horwat, D. [Laboratoire de Science et Genie des Surfaces (UMR CNRS 7570), Ecole des Mines, Parc de Saurupt, CS 14234, 54042 Nancy Cedex (France)

    2008-08-15

    Ag-Cu-O films were deposited on glass substrates by reactive sputtering of a composite Ag{sub 60}Cu{sub 40} target in various Ar-O{sub 2} mixtures. The films were characterised by energy dispersive X-ray analysis, X-ray diffraction, UV-visible spectroscopy and using the four point probe method. The structure of the films is strongly dependent on the oxygen flow rate introduced in the deposition chamber. The variation of the oxygen flow rate allows the deposition of the following structures: Ag-Cu-(O) solid solution, nc-Ag + nc-Cu{sub 2}O, nc-Ag + nc-(Ag,Cu){sub 2}O and finally X-ray amorphous. UV-visible reflectance measurements confirm the occurrence of metallic silver into the deposited films. The increase of the oxygen flow rate induces a continuous increase of the film oxygen concentration that can be correlated to the evolution of the film reflectance and the film electrical resistivity. Finally, the structural changes vs. the oxygen content are discussed in terms of reactivity of sputtered atoms with oxygen.

  7. Research on Microstructure and Properties of AgCuZnNi Alloy%AgCuZnNi合金的显微组织与性能研究

    Institute of Scientific and Technical Information of China (English)

    陈永泰; 谢明; 杨有才; 张吉明; 王松; 王塞北; 胡洁琼; 李爱坤

    2015-01-01

    AgCuZnNi合金的物相以及变形过程中合金的显微组织、力恘、电恘性能进行了悁究.悁究结果表明:合金主要由富Ag固溶体以及富Cu相组成,Zn与Ni主要存在于富Cu相中.变形量较小时,基体中的富Cu相发生位移、转动和破碎,随着变形量的继恋增加,大颗粒的富Cu相先产生变形,最后全部转变为纤维组织.抗拉强度和硬度随变形量的增加而增加,是形变强化、晶界强化和纤维强化共同作用的结果.电阻率随变形量的增加而增加,晶体缺陷及界面增多是电阻率增加的主要原因.%The phase composition and microstructure, mechanical properties, electrical properties during deformation of AgCuZnNi alloy were analyzed. The results show that the AgCuZnNi alloy is mainly composed of silver-rich phase and copper-rich phase, Zn and Ni mainly exist in copper-rich phase. The displacement, rotation and broken of the copper-rich phase take place only when the deformation is small. With the increase of deformation, large particles of copper-rich phase first produce deformation, finally, all particles of copper-rich phase completely convert to fibrous tissue. Tensile strength and hardness increase with the increase of deformation, which attributed to the joint actions of deformation strengthening, grain boundary strengthening and fiber strengthening. Resistivity decreases with the increase of deformation, due to the increase of crystal defects and grain boundary.

  8. Experimental determination of interfacial energies for Ag2A1 solid solution in the CuAl2-Ag2Al system

    Institute of Scientific and Technical Information of China (English)

    Ocak Y; Akbulut S; Keslio(g)lu K; Mara(s)ll N; (C)adlrll E; Kaya H

    2009-01-01

    The equilibrated grain boundary groove shapes of solid solution Ag2Al in equilibrium with an Al-Cu-Ag liquid were observed from a quenched sample with a radial heat flow apparatus. The Gibbs-Thomson coefficient,solid-liquid interfacial energy and grain boundary energy of the solid solution Ag2Al have been determined from the observed grain boundary groove shapes. The thermal conductivity of the solid phase and the thermal conductivity ratio of the liquid phase to solid phase for Ag2Al-28.3 at the %CuAl2 alloy at the melting temperature have also been measured with a radial heat flow apparatus and Bridgman type growth apparatus,separately.

  9. Ag2O-Bi2MoO6:制备及光催化降解富里酸%Ag2O Doped Bi2MoO6: Preparation and Photocatalytic Activity for Fulvic Acid Degradation

    Institute of Scientific and Technical Information of China (English)

    张月; 赵雪姣; 段元首; 苏秀荣

    2015-01-01

    以钼酸铵、硝酸铋和硝酸银为原料,以十六烷基三甲基溴化铵(CTAB)为辅助活性剂,采用水热法合成了Ag2O-Bi2MoO6光催化剂.用X射线粉末衍射、扫描电镜及紫外-可见吸收光谱等进行表征,并对水中天然有机物富里酸进行了光催化氧化研究.结果表明:未掺杂钼酸铋表面平滑,Ag2O-Bi2MoO6表面有明显的小块颗粒存在,分布集中,且其XRD图出现Ag2O的衍射峰.与未掺杂样品相比,掺杂Ag2O后Bi2MoO6的可见光催化活性提高,当掺银量为1.5%时活性最高.实验最佳催化剂浓度为0.6 g·L-1,在溶液pH值减小、富里酸初始浓度减小时有助于富里酸的去除.富里酸降解过程符合一级反应动力学方程,拟合方程为y=-0.019 5x.对富里酸降解产物进行发光菌生物毒性测试,发现光催化2h后降解产物比处理前毒性降低约90%.

  10. Reassessment of Atomic Mobilities in fcc Cu-Ag-Sn System Aiming at Establishment of an Atomic Mobility Database in Sn-Ag-Cu-In-Sb-Bi-Pb Solder Alloys

    Science.gov (United States)

    Xu, Huixia; Zhang, Lijun; Cheng, Kaiming; Chen, Weimin; Du, Yong

    2017-04-01

    To establish an accurate atomic mobility database in solder alloys, a reassessment of atomic mobilities in the fcc (face centered cubic) Cu-Ag-Sn system was performed as reported in the present work. The work entailed initial preparation of three fcc Cu-Sn diffusion couples, which were used to determine the composition-dependent interdiffusivities at 873 K, 923 K, and 973 K, to validate the literature data and provide new experimental data at low temperatures. Then, atomic mobilities in three boundary binaries, fcc Cu-Sn, fcc Ag-Sn, and fcc Cu-Ag, were updated based on the data for various experimental diffusivities obtained from the literature and the present work, together with the available thermodynamic database for solder alloys. Finally, based on the large number of interdiffusivities recently measured from the present authors, atomic mobilities in the fcc Cu-Ag-Sn ternary system were carefully evaluated. A comprehensive comparison between various calculated/model-predicted diffusion properties and the experimental data was used to validate the reliability of the obtained atomic mobilities in ternary fcc Cu-Ag-Sn alloys.

  11. Metallogenic system of Machangqing Cu-Mo-Au polymetallic ore concentration area in Yunnan Province%云南省马厂箐Cu-Mo-Au多金属矿集区成矿系统

    Institute of Scientific and Technical Information of China (English)

    郭晓东; 牛翠袆; 王治华; 王梁; 夏锐

    2012-01-01

    As a typical porphyry Cu-Mo-Au ore concentration area related to alkaline-rich intrusive rocks in western Yunnan ore belt, Machangqing has many mineralization types such as porphyry Cu-Mo mineralization, contact metasomatic Cu-Mo-Au mineralization and hydrothermal Au-Ag-Pb-Zn lodes. Alteration-mineralization types and ore-forming element associations show clear spatial zones around the porphyry. The magmatic activity is synchronous to Cu-Mo-Au mineralization. The three types are genetically controlled by the Machangqing porphyry magma system which supplied material, fluid and dynamic force for the mineralization. Based on a detailed analysis of the mineralization evidence and the structure of the ore system, the authors have concluded that the thermal dynamic force from Machangqing intrusion caused the migration of the are-forming fluid from the magma outwards, With the variation of physical and chemical conditions of fissures in the intrusive body as well as contact structures and fracture zones in the wall rock, there occurred different mineralization types and metallogenic element associations under different conditions. In general, with the evolution of hydrothermal mineralization, the mineralization was developed from porphyry through the contact zone to the wall rock, and from high-T to low-T correspondingly. The establishment of the Cu-Mo-Au polymetallic metallogenic system for the Machangqing ore concentration area will help the study of mineralization theory and the exploration practice in the west Yunnan metallogenic belt.%马厂箐地区是滇西成矿带内一个典型的与喜马拉雅期富碱侵入岩有关的斑岩型铜-钼-金多金属矿集区,发育有斑岩型钼铜、接触交代型铜钼(金)和热液脉型金银铅锌等多种类型矿化.其矿化和蚀变类型及成矿元素组合,在空间上具有明显的以岩体为中心的分带性;岩浆活动与铜钼金成矿作用具有同时性.这3种矿化类型的形成受控于马厂箐

  12. Direct Observation of Long-Term Durability of Superconductivity in YBa2Cu3O7-Ag2O Composites

    Science.gov (United States)

    Lin, Juhn-Jong; Lin, Yong-Han; Huang, Shiu-Ming; Lee, Tsang-Chou; Chen, Teng-Ming

    2003-10-01

    We report direct observation of long-term durability of superconductivity of several YBa2Cu3O7-Ag2O composites that were first prepared and studied almost fourteen years ago [J. J. Lin et al.: Jpn. J. Appl. Phys. 29 (1990) 497]. Remeasurements performed recently on both resistances and magnetizations indicate a sharp critical transition temperature at 91 K. We also find that such long-term environmental stability of high-temperature superconductivity can only be achieved in YBa2Cu3O7 with Ag2O addition, but not with pure Ag addition.

  13. Mechanical properties and microstructure investigation of Sn-Ag-Cu lead free solder for electronic package applications

    Science.gov (United States)

    Wang, Qing

    While the electronics industry appears to be focusing on Sn-Ag-Cu as the alloy of choice for lead free electronics assembly, the exact composition varies by geographic region, supplier and user. Add to that dissolved copper and silver from the printed circuit board traces and surface finish, and there can be significant variation in the final solder joint composition. A systematic study of the mechanical and microstructural properties of Sn-Ag-Cu alloys with Ag varying from 2wt% to 4wt% and Cu varying from 0.5wt% to 1.5wt%, was investigated in this research study. Different sample preparation techniques (water quenched, oil quenched and water quenched followed by reflow) were explored and the resulting microstructure compared to that of a typical reflowed lead free chip scale package (CSP) solder joint. Tensile properties such as tensile strength, 0.2% yield strength and the ultimate tensile strength and creep behavior of selected alloy compositions (Sn-4Ag-1.5Cu, Sn-4Ag-0.5Cu, Sn-2Ag-1.5Cu, Sn-2Ag-0.5Cu, Sn-3.5Ag-0.8Cu) were performed for three conditions: as-cast; aged for 100 hours at 125°C; and aged for 250 hours at 125°C. The microstructures of these alloys were examined using light and scanning electron microscopy (LM and SEM) respectively and SEM based energy dispersive x-ray spectroscopy (EDS). Fracture surface and cross-section analysis were performed on the specimens after creep testing. The creep testing results and the effect of high temperature aging on mechanical properties will also be presented for the oil quenched samples. A hyperbolic-sine creep model was adopted and used to fit the creep experiment data. The effect of adding the quaternary element bismuth to the Sn-3.5Ag-0.8Cu alloy on the mechanical properties was measured and compared with the mechanical properties of the ternary alloys. The results of this research study provide necessary data for the modeling of solder joint reliability for a range of Sn-Ag-Cu compositions and a baseline

  14. Mechanism of unique hardening of dental Ag-Pd-Au-Cu alloys in relation with constitutional phases

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yonghwan [Department of Materials Science, Graduate School of Engineering, Tohoku University, 6-6 Aoba, Aramaki Aza, Aoba-ku, Sendai 980-8579 (Japan); Niinomi, Mitsuo, E-mail: niinomi@imr.tohoku.ac.jp [Department of Biomaterials Science, Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan); Nakai, Masaaki; Akahori, Toshikazu [Department of Biomaterials Science, Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan); Kanno, Toru [Department of Materials Science, Graduate School of Engineering, Tohoku University, 6-6 Aoba, Aramaki Aza, Aoba-ku, Sendai 980-8579 (Japan); Fukui, Hisao [Department of Dental Materials Science, School of Dentistry, Aichi-Gakuin University, 1-100 Kusumoto-cho, Chikusa-ku, Nagoya 464-8650 (Japan)

    2012-04-05

    Highlights: Black-Right-Pointing-Pointer The unique hardening behavior on Ag-Pd-Au-Cu alloys by solution treatment was investigated. Black-Right-Pointing-Pointer The Cu-rich {alpha}{sub 1} phase and Ag-rich {alpha}{sub 2} phase decomposed by solution treatment contributed weakly to the change of hardness. Black-Right-Pointing-Pointer The fine {beta} phases precipitated by aging treatment caused great increase in hardness. Black-Right-Pointing-Pointer The fine L1{sub 0}-type ordered {beta} Prime phase precipitated by solution treatment may contribute to the unique hardening behavior. - Abstract: The objective of this research was to investigate the effect of constitutional phases on the unique hardening behavior of as-solutionized dental Ag-Pd-Au-Cu alloy fabricated by cold rolling. The commercial dental Ag-Pd-Au-Cu alloy fabricated by cold rolling consists of Cu-rich {alpha}{sub 1}, Ag-rich {alpha}{sub 2}, and {beta} phases. On the other hand, the Ag-Pd-Au-Cu alloy fabricated by the liquid rapid solidification (LRS) method consists of single {alpha} phase. They were subjected to various heat treatments, respectively. The microstructures were observed by scanning electron microscope, transmission electron microscope and X-ray diffraction. The hardness was evaluated by a Vickers micro-hardness tester. In the Ag-Pd-Au-Cu alloy fabricated by cold rolling, the fine L1{sub 0}-type-ordered {beta} Prime phase is precipitated and the coarse {beta} phase is remained after solution treatment at 1123 K. The hardness increases drastically. On the other hand, in the Ag-Pd-Au-Cu alloy fabricated by LRS method, the single {alpha} phase was decomposed into the {alpha}{sub 1} phase and the {alpha}{sub 2} phase after solution treatment at 1023 K and its hardness change was small. However, after aging treatment at 673 K, the fine {beta} phase is precipitated in the {alpha} phase and the hardness increases greatly even in the Ag-Pd-Au-Cu alloy fabricated by LRS method. It is considered

  15. Bonding of Cf/SiC composite to Invar alloy using an active cement, Ag-Cu eutectic and Cu interlayer

    Science.gov (United States)

    Lei, Zhao; Xiaohong, Li; Jinbao, Hou; Qiang, Sun; Fuli, Zhang

    2012-10-01

    The interfacial microstructures and mechanical properties of the joints formed by active cement added brazing in vacuum of Cf/SiC composite to Invar alloy, using Ag-Cu eutectic alloy and pure copper foil as braze alloy and interlayer respectively, were investigated. CuTi, Cu4Ti3, Fe2Ti and the reaction layer of TiC and Si were the predominant components at the joint interface. The maximum shear strength of the joint was 77 MPa for brazing at 850 °C for 15 min. The results show that active cement added brazing in vacuum using Ag-Cu eutectic alloy and Cu interlayer can be used successfully for joining Cf/SiC composites to Invar alloy.

  16. Synthesis and crystal structure and nonlinear optical properties of polymeric W (Mo)-Cu-S cluster

    Institute of Scientific and Technical Information of China (English)

    ZHOU Jian-liang; CHEN Qi-yuan; GU Ying-ying; ZHONG Shi-an

    2006-01-01

    The polymeric chalcogenide [W2O2S6Cu4(NCMe)4]n (compound 1) was synthesized by the self-assembly reaction of (NH4)2(WOS3) with CuBr in MeCN in the presence of tricyclohexylphosphane (PCy3) under a purified nitrogen atmosphere using standard Schlenk techniques. It gives rise to a novel 1D polymeric compound 1 with solvent MeCN coordinated to the copper atom. This situation is unprecedented in the W(Mo)/Cu/S system. The crystals were characterized by elemental analysis,IR and single-crystal X-ray crystallography. The configuration of the polymeric compound can be viewed as a helical chain which is propagated along the crystallographic c axis. The excited state absorption and refraction of compound 1 in CH3CN solution were studied by using the Z-scan technique with laser pulses of 40 ps pulse-width at a wavelength of 532 nm. The polymeric compound possesses an optical self-focusing performance. The positive nonlinear refraction is attributed to population transitions between singlet states. Compound 1 displays a strong excited-state absorption.

  17. Effects of Ag, Ag{sub 2}O and AgNO{sub 3} addition on the superconducting properties of Tl{sub 2}Ba{sub 2}CaCu{sub 2}O{sub 8}

    Energy Technology Data Exchange (ETDEWEB)

    Salleh, Faizah M.; Yahya, A.K.; Imad, H.; Abd-Shukor, R

    2003-02-25

    The effects of 5 wt.% Ag additions in the form of Ag powder, Ag{sub 2}O and AgNO{sub 3} on phase formation and superconductivity of Tl-2212 is reported. Samples were prepared using two different solid state synthesis routes: (a) addition of 5 wt.% Ag to presynthesized (PS) Tl-2212 powder and (b) premixing (PM) of 5 wt.% Ag to unreacted powders with starting composition of Tl{sub 2}Ba{sub 2}CaCu{sub 2}O{sub 8}. For PS samples, addition of Ag showed little effect on T{sub c} values. For PM samples, addition of Ag in the form of Ag powder and AgNO{sub 3} showed a lowering of T{sub czero} to around 70 K. In the case of Ag{sub 2}O the deterioration is severe and the sample was not superconducting down to 10 K. X-ray diffraction patterns of PM samples showed existence of Tl-2212 phase and a substantial amount of unreacted Tl{sub 2}O{sub 3}. We also report results of microstructural investigations using scanning electron microscope and Vickers Microhardness measurements and their variation with the synthesis methods and the different forms of Ag-additives. The different forms of starting silver give rise to varied Tl-2212 properties and the PS AgNO{sub 3} sample showed the best improvement in normal state conductivity compared to metallic silver and silver oxide powders.

  18. Improvement on the microstructure stability, mechanical and wetting properties of Sn-Ag-Cu lead-free solder with the addition of rare earth elements

    Energy Technology Data Exchange (ETDEWEB)

    Yu, D.Q.; Zhao, J.; Wang, L

    2004-08-11

    Ternary lead-free solder alloys Sn-Ag-Cu were considered as the potential alternatives to lead-tin alloys comparing with other solders. In this paper, microstructure and mechanical properties of Sn-2.5Ag-0.7Cu, Sn-3.5Ag-0.7Cu, Sn-3.5Ag-0.7Cu-0.1RE, and Sn-3.5Ag-0.7Cu-0.25RE alloys were researched. Coarse {beta}-Sn grains were formed in Sn-2.5Ag-0.7Cu and Sn-3.5Ag-0.7Cu alloys and bulky Ag{sub 3}Sn intermetallics were found in Sn-3.5Ag-0.7Cu alloy. With the addition of trace rare earth (RE) elements the coarse {beta}-Sn grains were refrained, at the same time, Cu{sub 6}Sn{sub 5} and Ag{sub 3}Sn intermetallics were finer according to the adsorption affection of the active rare earth elements. Due to the fine and uniform microstructure, the tensile strength and elongation were improved. In addition, the wetting properties were also enhanced. All these results indicated that adding trace rare earth elements was an efficient way to develop new solders.

  19. Interfacial reactions of BGA Sn-3.5%Ag-0.5%Cu and Sn-3.5%Ag solders during high-temperature aging with Ni/Au metallization

    Energy Technology Data Exchange (ETDEWEB)

    Sharif, Ahmed [Department of Electronic Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Hong Kong (China); Islam, M.N. [Department of Electronic Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Hong Kong (China); Chan, Y.C. [Department of Electronic Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Hong Kong (China)]. E-mail: eeycchan@cityu.edu.hk

    2004-11-15

    The joint strength and the microstructure of Sn-3.5Ag and Sn-3.5Ag-0.5Cu (wt.%) solders on Cu/Ni/Au ball-grid-array (BGA) pad metallization were investigated after high-temperature solid-state aging at 190 deg. C (around 0.86T{sup m} of solder alloys). Sn-Ag solder gave better results in terms of shear strength on high-temperature aging than Sn-Ag-Cu. Very high consumption of Ni was observed in the case of Sn-Ag-Cu solder alloys. After 16 days of aging at the afore mentioned temperature, 5 {mu}m Ni layer was fully consumed from the substrate pad and a thick layer of Cu-Sn intermetallic compounds (IMCs) was found at the base of the interfacial IMCs. Much less consumption of Ni substrate was observed for Sn-3.5Ag solder during high-temperature aging for longer time. The mean thickness of the intermetallics at the interface was higher for Sn-Ag-Cu solder alloy. For both cases Ni diffused through the interfacial IMCs and formed quaternary compounds for Sn-Ag-Cu system and ternary compounds for Sn-Ag system within the bulk solder. It appeared that Sn-Ag-Cu solder alloy was more vulnerable in high-temperature solid-state aging.

  20. Interpretation of dc and ac conductivity of Ag{sub 2}O–SeO{sub 2}–MoO{sub 3} glass-nanocomposite-semiconductor

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharya, Sanjib, E-mail: sanjib_ssp@yahoo.co.in [Department of Engineering Sciences and Humanities, Siliguri Institute of Technology, Darjeeeling 734009, West Bengal (India); Kundu, Ranadip [Department of Engineering Sciences and Humanities, Siliguri Institute of Technology, Darjeeeling 734009, West Bengal (India); Department of Mechanical Engineering, Jadavpur University, Jadavpur, Kolkata 700032 (India); Das, Anindya Sundar [Department of Mechanical Engineering, Jadavpur University, Jadavpur, Kolkata 700032 (India); Department of Electronics and Communication Engineering, Regent Education and Research Foundation, Barrackpore, Kolkata 7000121 (India); Roy, Debasish [Department of Mechanical Engineering, Jadavpur University, Jadavpur, Kolkata 700032 (India)

    2015-07-15

    Highlights: • Polaron hopping. • Dc and ac conductivity. • Mott's model and Greave's model. • Ag{sub 2}MoO{sub 4}, Ag{sub 2}Mo{sub 2}O{sub 7} and Ag{sub 6}Mo{sub 10}O{sub 33} nanoparticles and SeO{sub 3} and SeO{sub 4} nanoclusters. • XRD and FESEM studies. - Abstract: A new type of semiconducting glass-nanocomposites 0.3Ag{sub 2}O–0.7 (xMoO{sub 3}–(1 − x) SeO{sub 2}) is prepared by melt-quenching route. The formation of Ag{sub 2}MoO{sub 4}, Ag{sub 2}Mo{sub 2}O{sub 7} and Ag{sub 6}Mo{sub 10}O{sub 33} nanoparticles and SeO{sub 3} and SeO{sub 4} nanoclusters in glass-nanocomposites has been confirmed from X-ray diffraction (XRD) and field emission scanning electron microscopic (FESEM) studies. Fourier transform infrared (FTIR) spectroscopy is employed to find out Se−O stretching vibration as well as stretching vibrations of Mo{sub 2}O{sub 7}{sup 2−} ions. The dc conductivity of them is studied on the light of polaron hopping approach in a wide temperature range. At low temperatures, variable range hopping model (Mott's model) is employed to analyze the conductivity data. Greave's model is used to predict temperature dependent variable range hopping in the high temperature region. Frequency dependent ac conductivity is well explained on the basis of tunneling. I–V characteristics of the as-prepared samples have also been investigated.

  1. Characteristics of intermetallics and micromechanical properties during thermal ageing of Sn-Ag-Cu flip-chip solder interconnects

    Energy Technology Data Exchange (ETDEWEB)

    Li Dezhi [Wolfson School of Mechanical and Manufacturing Engineering, Loughborough University, Loughborough, Leicestershire LE11 3TU (United Kingdom); Liu Changqing [Wolfson School of Mechanical and Manufacturing Engineering, Loughborough University, Loughborough, Leicestershire LE11 3TU (United Kingdom)]. E-mail: c.liu@lboro.ac.uk; Conway, Paul P. [Wolfson School of Mechanical and Manufacturing Engineering, Loughborough University, Loughborough, Leicestershire LE11 3TU (United Kingdom)

    2005-01-25

    Sn-3.8 wt.% Ag-0.7 wt.% Cu solder was applied to Al-1 wt.% Cu bond pads with an electroless nickel (Ni-P) interlayer as an under bump metallisation (UBM). The microstructure and micromechanical properties were studied after ageing at 80 deg. C and 150 deg. C. Two types of intermetallic compounds (IMCs) were identified by electron back-scattered diffraction (EBSD), these being a (Cu, Ni){sub 6}Sn{sub 5} formed at the solder-UBM interface and Ag{sub 3}Sn in the bulk solder. The (Cu, Ni){sub 6}Sn{sub 5} layer grew very slowly during the ageing process, with no Kirkendall voids found by scanning electron microscopy (SEM) after ageing at 80 deg. C. Nano-indentation was used to analyse the mechanical properties of different phases in the solder. Both (Cu, Ni){sub 6}Sn{sub 5} and Ag{sub 3}Sn were harder and more brittle than the {beta}-Sn matrix of the Sn-Ag-Cu alloy. The branch-like morphology of the Ag{sub 3}Sn IMC, especially at the solder-UBM interface, could ultimately be detrimental to the mechanical integrity of the solder when assembled in flip-chip joints.

  2. Enhanced photocatalytic, electrochemical and photoelectrochemical properties of TiO2 nanotubes arrays modified with Cu, AgCu and Bi nanoparticles obtained via radiolytic reduction

    Science.gov (United States)

    Nischk, Michał; Mazierski, Paweł; Wei, Zhishun; Siuzdak, Katarzyna; Kouame, Natalie Amoin; Kowalska, Ewa; Remita, Hynd; Zaleska-Medynska, Adriana

    2016-11-01

    TiO2 nanotubes arrays (NTs), obtained via electrochemical anodization of Ti foil, were modified with monometallic (Cu, Bi) and bimetallic (AgCu) nanoparticles. Different amounts of metals' precursors were deposited on the surface of NTs by the spin-coating technique, and the reduction of metals was performed via gamma radiolysis. Surface modification of titania was studied by EDS and XPS analysis. The results show that AgCu nanoparticles exist in a Agcore-Cushell form. Photocatalytic activity was examined under UV irradiation and phenol was used as a model pollutant of water. Over 95% of phenol degradation was achieved after 60 min of irradiation for almost all examined samples, but only slight difference in degradation efficiency (about 3%) between modified and bare NTs was observed. However, the initial phenol degradation rate and TOC removal efficiency was significantly enhanced for the samples modified with 0.31 and 0.63 mol% of Bi as well as for all the samples modified with Cu and AgCu nanoparticles in comparison with bare titania nanotubes. The saturated photocurrent, under the influence of simulated solar light irradiation, for the most active Bi- and AgCu-modified samples, was over two times higher than for pristine NTs. All the examined materials were resistant towards photocorrosion processes that enables their application for long term processes induced by light.

  3. Transparent ITO/Ag-Pd-Cu/ITO multilayer cathode use in inverted organic solar cells

    Science.gov (United States)

    Kim, Hyo-Joong; Lee, Hyun Hwi; Kal, Jinha; Hahn, Jungseok; Kim, Han-Ki

    2015-10-01

    The characteristics of transparent ITO/Ag-Pd-Cu (APC)/ITO multilayer cathodes were investigated for use in inverted organic solar cells (IOSCs). The insertion of an APC interlayer into the ITO film effectively led to crystallization of the top ITO layer, unlike that in the Ag interlayer, and resulted in a low sheet resistance of 6.55 Ohm/square and a high optical transmittance of 84.14% without post annealing. In addition, the alloying of the Pd and Cu elements into Ag prevented agglomeration and oxidization of the metal interlayer and led to more stable ITO/APC/ITO films under ambient conditions. The microstructure and interfacial structure of the transparent ITO/APC/ITO cathode in the IOSCs were examined in detail by synchrotron X-ray scattering and high resolution transmission electron microscopy. Furthermore, we suggested a possible mechanism to explain the lower PCE of the IOSCs with an ITO/APC/ITO cathode than that of a reference IOSC with a crystalline ITO cathode using the external quantum efficiency of the IOSCs.

  4. Transparent ITO/Ag-Pd-Cu/ITO multilayer cathode use in inverted organic solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyo-Joong; Kim, Han-Ki, E-mail: imdlhkkim@khu.ac.kr [Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, 1 Seocheon-dong, Yongin-si, Gyeonggi-do 446-701 (Korea, Republic of); Lee, Hyun Hwi [Pohang Accelerator Laboratory, POSTECH, Jigokro-127beon-gil, Nam-gu, Pohang 790-784 (Korea, Republic of); Kal, Jinha; Hahn, Jungseok [Future Technology Research Group, Kolon Central Research Park, 154 Mabukro, Giheung-ku, Yongin-si, Kyunggi-do, 16910 (Korea, Republic of)

    2015-10-15

    The characteristics of transparent ITO/Ag-Pd-Cu (APC)/ITO multilayer cathodes were investigated for use in inverted organic solar cells (IOSCs). The insertion of an APC interlayer into the ITO film effectively led to crystallization of the top ITO layer, unlike that in the Ag interlayer, and resulted in a low sheet resistance of 6.55 Ohm/square and a high optical transmittance of 84.14% without post annealing. In addition, the alloying of the Pd and Cu elements into Ag prevented agglomeration and oxidization of the metal interlayer and led to more stable ITO/APC/ITO films under ambient conditions. The microstructure and interfacial structure of the transparent ITO/APC/ITO cathode in the IOSCs were examined in detail by synchrotron X-ray scattering and high resolution transmission electron microscopy. Furthermore, we suggested a possible mechanism to explain the lower PCE of the IOSCs with an ITO/APC/ITO cathode than that of a reference IOSC with a crystalline ITO cathode using the external quantum efficiency of the IOSCs.

  5. Transparent ITO/Ag-Pd-Cu/ITO multilayer cathode use in inverted organic solar cells

    Directory of Open Access Journals (Sweden)

    Hyo-Joong Kim

    2015-10-01

    Full Text Available The characteristics of transparent ITO/Ag-Pd-Cu (APC/ITO multilayer cathodes were investigated for use in inverted organic solar cells (IOSCs. The insertion of an APC interlayer into the ITO film effectively led to crystallization of the top ITO layer, unlike that in the Ag interlayer, and resulted in a low sheet resistance of 6.55 Ohm/square and a high optical transmittance of 84.14% without post annealing. In addition, the alloying of the Pd and Cu elements into Ag prevented agglomeration and oxidization of the metal interlayer and led to more stable ITO/APC/ITO films under ambient conditions. The microstructure and interfacial structure of the transparent ITO/APC/ITO cathode in the IOSCs were examined in detail by synchrotron X-ray scattering and high resolution transmission electron microscopy. Furthermore, we suggested a possible mechanism to explain the lower PCE of the IOSCs with an ITO/APC/ITO cathode than that of a reference IOSC with a crystalline ITO cathode using the external quantum efficiency of the IOSCs.

  6. Characterization of Ag-Cu-S Thin Layers Formed on Low Density Polyethylene Film

    Directory of Open Access Journals (Sweden)

    Ingrida ANCUTIENĖ

    2011-09-01

    Full Text Available The Ag-Cu-S layer formed on PE demonstrated a wide variation in thickness. The cross-section showed the average thickness of sulfide layers on PE increase from 1.9 mm to 5.6 mm with the increase in the sulfurization time and from 1.9 mm to 3.9 mm with the increase of treating time in the solution of copper salts. The electronic micrographs of the sulfide layers indicate the creation of an irregular but continuous base of small dendrites and agglomerates. With the increase in the sulfurization time and treating time in copper (II/I salt solution observed an increase of the agglomerates size. Energy dispersive spectroscopy results indicate that modified layers are poor in copper (0.5 at. % - 1.5 at. %. The atomic ratios of Ag/Cu/S, calculated from the quantification of the peaks (excluded C and O elements give the values (% of 8.3:1.5:4.4, 8.7:0.5:4.3 and 23:1.2:10.9, respectively. In all cases, energy dispersive spectroscopy measurements revealed the modified layers are nearly stoichiometric Ag2S.http://dx.doi.org/10.5755/j01.ms.17.3.584

  7. The formation of Luoboling porphyry Cu-Mo deposit: Constraints from zircon and apatite

    Science.gov (United States)

    Li, Cong-ying; Hao, Xi-luo; Liu, Ji-qiang; Ling, Ming-xing; Ding, Xing; Zhang, Hong; Sun, Wei-dong

    2017-02-01

    The Luobuling porphyry Cu-Mo deposit belongs to the Late Cretaceous Zijinshan Cu-Au-Mo mineralization field in southeastern China. Due to intensive hydrothermal alteration and weathering, it is very difficult to collect fresh whole rock samples for geochemical and isotopic studies in Luobuling. Zircon and apatite are accessory minerals that are resistant to hydrothermal alterations. In this study, we compared the trace element and isotope compositions of zircon and apatite from ore-bearing and barren samples to understand the formation of the Luoboling Cu-Mo deposit. Zircon U-Pb LA-ICP-MS dating shows that the Luoboling porphyries formed at 100 Ma (100.3 ± 1.2 Ma, 100.6 ± 1.5 Ma and 98.6 ± 1.2 Ma), which belongs to the late stage mineralization of the Zijinshan mineralization field. Zhongliao porphyritic granodiorite has the same age as the deposit (99.5 ± 1.6 Ma). The age of barren Sifang granodiorite is slightly older (109.7 ± 0.8 Ma). All these zircon grains have high Ce4+/Ce3+ ratios, indicating high oxygen fugacities. The ore-bearing samples show variable εHf(t) of - 7.3 to 0.2, suggesting either heterogeneous sources or mixing of two different magmas. Interestingly, the Hf isotope composition of barren samples is systematically higher (εHf(t) of - 3.6 to 5.5), implying a lower contribution of crustal materials. The OH mole percent of apatite grains from barren samples (LBL22-03 and SF09-05) is 0.5, which is higher than that of apatite from the ore-bearing samples (LBL20-01 LBL20-02 and LBL22-02), indicating lower F, Cl contents or higher water contents in the magma. In apatite from the ore-bearing samples, Sr is high, indicating the absence of plagioclase crystallization. In contrast, barren samples have varied and lower Sr, indicating that apatite crystallization was accompanied by plagioclase. These patterns were controlled by water contents because the crystallization of plagioclase is suppressed by high water contents in magmas. It also suggests

  8. Photocatalytic comparison of Cu- and Ag-doped TiO2/GF for bioaerosol disinfection under visible light

    Science.gov (United States)

    Pham, Thanh-Dong; Lee, Byeong-Kyu

    2015-12-01

    Photocatalysts, TiO2/glass fiber (TiO2/GF), Cu-doped TiO2/glass fiber (Cu-TiO2/GF) and Ag-doped TiO2/glass fiber (Ag-TiO2/GF), were synthesized by a sol-gel method. They were then used to disinfect Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) in bioaerosols under visible light irradiation. TiO2/GF did not show any significant disinfection effect. Both Cu and Ag acted as intermediate agents to enhance separation efficiency of electron-hole pairs of TiO2, leading to improved photocatalytic activity of Cu-TiO2/GF and Ag-TiO2/GF under visible light. Cu in Cu-TiO2/GF acted as a defective agent, increasing the internal quantum efficiency of TiO2, while Ag in Ag-TiO2/GF acted as a sensitive agent, enhancing the transfer efficiency of the electrons generated. The highest disinfection efficiencies of E. coli and S. aureus by Cu-TiO2/GF were 84.85% and 65.21%, respectively. The highest disinfection efficiencies of E. coli and S. aureus by Ag-TiO2/GF were 94.46% and 73.12%, respectively. Among three humidity conditions - 40±5% (dry), 60±5% (moderate), and 80±5% (humid) - the moderate humidity condition showed the highest disinfection efficiency for both E. coli and S. aureus. This study also showed that a Gram-negative bacterium (E. coli) were more readily disinfected by the photocatalysts than a Gram-positive bacterium (S. aureus).

  9. Preparation and characterization of sub-20 nm Cu{sub X}@Ag{sub 1} core-shell nanoparticles by changing concentration of silver precursor

    Energy Technology Data Exchange (ETDEWEB)

    Chee, Sang-Soo; Lee, Jong-Hyun, E-mail: pljh@snut.ac.kr

    2017-01-01

    Ultrafine Ag-coated Cu (Cu@Ag) nanoparticles (NPs) less than 20 nm in diameter were prepared. After synthesizing ultrafine Cu NPs using a solvothermal method to serve as the core particles, Cu@Ag NPs were fabricated with different initial Ag precursor concentrations, resulting in different thicknesses, densities, and uniformities of Ag shells. The average thickness and density of the Ag shell increased with increasing initial Ag precursor concentration in a Cu:Ag atomic ratio from 6:1 to 1:1. However, excessive Ag precursor concentrations induced homogeneous nucleation and growth of surplus fine pure NPs. Ag dewetting behavior and Cu oxidation in the Cu{sub 4}@Ag{sub 1} NPs were observed, they occurred during heating at 200 and 250 °C, respectively. The electrical resistivities of sintered Cu{sub 4}@Ag{sub 1} films decreased with increasing temperature from 200 to 240 °C. The resistivity after washing the OA and sintering for 60 min at 240 °C in air was measured to be 4.96 × 10{sup −3} Ω cm. The film was sintered in nitrogen using the ink containing non-washed Cu{sub 4}@Ag{sub 1} NPs indicated the lower resistivity of 2.70 × 10{sup −3} Ω cm owing to the non-oxidation atmosphere, although the chemically capped oleylamine in the core-shell NPs hindered the sintering behavior. - Highlights: • Ultrafine Ag-coated Cu nanoparticles less than 20 nm in diameter were fabricated. • Different Ag precursor concentrations influenced thickness and density of Ag shell. • Excessive Ag precursor concentrations induced formation of surplus fine pure NPs. • Ag dewetting behavior and Cu oxidation in Cu{sub 4}@Ag{sub 1} nanoparticles were observed. • Electrical resistivities of sintered Cu{sub 4}@Ag{sub 1} films were 2.70–4.96 × 10{sup −3} Ω cm.

  10. Microstructure and Interfacial Reactions During Vacuum Brazing of Stainless Steel to Titanium Using Ag-28 pct Cu Alloy

    Science.gov (United States)

    Laik, A.; Shirzadi, A. A.; Sharma, G.; Tewari, R.; Jayakumar, T.; Dey, G. K.

    2015-02-01

    Microstructural evolution and interfacial reactions during vacuum brazing of grade-2 Ti and 304L-type stainless steel (SS) using eutectic alloy Ag-28 wt pct Cu were investigated. A thin Ni-depleted zone of -Fe(Cr, Ni) solid solution formed on the SS-side of the braze zone (BZ). Cu from the braze alloy, in combination with the dissolved Fe and Ti from the base materials, formed a layer of ternary compound , adjacent to Ti in the BZ. In addition, four binary intermetallic compounds, CuTi, CuTi, CuTi and CuTi formed as parallel contiguous layers in the BZ. The unreacted Ag solidified as islands within the layers of CuTi and CuTi. Formation of an amorphous phase at certain locations in the BZ could be revealed. The -Ti(Cu) layer, formed due to diffusion of Cu into Ti-based material, transformed to an -Ti + CuTi eutectoid with lamellar morphology. Tensile test showed that the brazed joints had strength of 112 MPa and failed at the BZ. The possible sequence of events that led to the final microstructure and the mode of failure of these joints were delineated.

  11. Ehrlich-Schwöbel barriers and adsorption of Au, Cu and Ag stepped (100) surfaces

    Science.gov (United States)

    Benlattar, M.; Elkoraychy, E.; Sbiaai, K.; Mazroui, M.; Boughaleb, Y.

    2017-02-01

    We use a combination of quenched molecular dynamics and embedded atom method to calculate the activation energy barriers for the hopping and exchange mechanisms of Au, Ag or Cu on Au(100), Ag(100) or Cu(100) stepped surfaces. Our findings show that the Ehrlich-Schwöbel (ES) barriers for an adatom to undergo jump or exchange at a step edge are found to be dependent of the nature of substrate stepped surfaces. We also find that the ES barriers for the hopping processes are too high, except for Cu/Au(100). While for exchange process the Ehrlich-Schwöbel barriers are found to be very low and even negative. These ES barriers can explain the difference in the growth modes for the different systems. On the other hand, we calculated the adsorption energies at the most stable adsorption sites near step edges. In particular, we wish to clarify the relation between the adatom diffusion energy barriers and the adatom adsorption energies. These results may serve as some guiding rules for studying stepped surface morphologies, which are of importance to surface nanoengineering.

  12. Thermodynamic properties of the liquid Ag-Bi-Cu-Sn lead-free solder alloys

    Directory of Open Access Journals (Sweden)

    Garzel G.

    2014-01-01

    Full Text Available The electromotive force measurement method was employed to determine the thermodynamic properties of liquid Ag-Bi-Cu-Sn alloys using solid electrolyte galvanic cells as shown below: Kanthal+Re, Ag-Bi-Cu-Sn, SnO2 | Yttria Stabilized Zirconia | air, Pt, Experiments were made within temperature interval: 950 - 1300K along four composition paths of constant ratios: XAg : XBi : XCu = 1, XAg : (XBi + XCu = 3:2 for XBi = XCu, XBi : (XAg + XCu = 3:2 for XAg = XCu and XCu : (XAg + XBi = 3:2 for XAg = XBi and tin concentration changing from 0.1 to 0.9 mole fractions, every 0.1. Almost all the results were approximated by straight line equations: EMF vs T, and tin activities were then calculated in arbitrary temperature; measurement results were presented by graphs. Unusual activity plot for XBi : (XAg + XCu = 3:2 composition path was most probably caused by miscibility gap detected earlier in Bi-Cu-Sn ternary liquid alloys.

  13. Microgalvanic Corrosion Behavior of Cu-Ag Active Braze Alloys Investigated with SKPFM

    Directory of Open Access Journals (Sweden)

    Armen Kvryan

    2016-04-01

    Full Text Available The nature of microgalvanic couple driven corrosion of brazed joints was investigated. 316L stainless steel samples were joined using Cu-Ag-Ti and Cu-Ag-In-Ti braze alloys. Phase and elemental composition across each braze and parent metal interface was characterized and scanning Kelvin probe force microscopy (SKPFM was used to map the Volta potential differences. Co-localization of SKPFM with Energy Dispersive Spectroscopy (EDS measurements enabled spatially resolved correlation of potential differences with composition and subsequent galvanic corrosion behavior. Following exposure to the aggressive solution, corrosion damage morphology was characterized to determine the mode of attack and likely initiation areas. When exposed to 0.6 M NaCl, corrosion occurred at the braze-316L interface preceded by preferential dissolution of the Cu-rich phase within the braze alloy. Braze corrosion was driven by galvanic couples between the braze alloys and stainless steel as well as between different phases within the braze microstructure. Microgalvanic corrosion between phases of the braze alloys was investigated via SKPFM to determine how corrosion of the brazed joints developed.

  14. Optical Property Characterization of Novel Graphene-X (X=Ag, Au and Cu Nanoparticle Hybrids

    Directory of Open Access Journals (Sweden)

    Sumit Ranjan Sahu

    2013-01-01

    Full Text Available The present investigation reports new results on optical properties of graphene-metal nanocomposites. These composites were prepared by a solution-based chemical approach. Graphene has been prepared by thermal reduction of graphene oxide (GO at 90°C by hydrazine hydrate in an ammoniacal medium. This ammoniacal solution acts as a solvent as well as a basic medium where agglomeration of graphene can be prevented. This graphene solution has further been used for functionalization with Ag, Au, and Cu nanoparticles (NPs. The samples were characterized by X-ray diffraction (XRD, Raman spectroscopy, UV-Vis spectroscopy, scanning electron microscopy (SEM, and transmission electron microscopy (TEM to reveal the nature and type of interaction of metal nanoparticles with graphene. The results indicate distinct shift of graphene bands both in Raman and UV-Vis spectroscopies due to the presence of the metal nanoparticles. Raman spectroscopic analysis indicates blue shift of D and G bands in Raman spectra of graphene due to the presence of metal nanoparticles except for the G band of Cu-G, which undergoes red shift, reflecting the charge transfer interaction between graphene sheets and metal nanoparticles. UV-Vis spectroscopic analysis also indicates blue shift of graphene absorption peak in the hybrids. The plasmon peak position undergoes blue shift in Ag-G, whereas red shift is observed in Au-G and Cu-G.

  15. Al2O3/SUS304 Brazing via AgCuTi-W Composite as Active Filler

    Science.gov (United States)

    Su, Cherng-Yuh; Zhuang, Xie-Zongyang; Pan, Cheng-Tang

    2014-03-01

    Alumina ceramic (α-Al2O3) was brazed to stainless steel (SUS304) using an Ag-Cu-Ti + W composite filler and a traditional active brazing filler alloy (CuSil-ABA). Then, the effects of the presence of W particles and of the brazing parameters on the microstructures and mechanical properties of the brazed joints were investigated. The maximum tensile strength of the joints obtained using Ag-Cu-Ti + W composite filler was 13.2 MPa, which is similar to that obtained using CuSil-ABA filler (13.5 MPa). When the joint was brazed at 930 °C for 30 min, the tensile strengths decreased for both kinds of fillers, although the strength was slightly higher for the Ag-Cu-Ti + W composite filler than for the Ag-Cu-Ti filler. The interfacial microstructure results show that the Ti reacts with W to form a Ti-W-O compound in the brazing alloy. When there are more W particles in the brazing alloy, the thickness of the Ti X O Y reaction layer near the alumina ceramic decreases. Moreover, W particles added to the brazing alloy can reduce the coefficient of thermal expansion of the brazing alloy, which results in lower residual stress between the Al2O3 and SUS304 in the brazing joints and thus yields higher tensile strengths as compared to those obtained using the CuSil-ABA brazing alloy.

  16. Bifunctional MoO3-WO3/Ag/MoO3-WO3 Films for Efficient ITO-Free Electrochromic Devices.

    Science.gov (United States)

    Dong, Wenjie; Lv, Ying; Xiao, Lili; Fan, Yi; Zhang, Nan; Liu, Xingyuan

    2016-12-14

    Dielectric-metal-dielectric (DMD) trilayer films, served as both electrochromic (EC) film and transparent conductor (TC), have exhibited great potential application in low-cost, ITO-free electrochromic devices (ECDs). However, recent reports on the DMD-based ECDs revealed that the response time and the optical modulation properties were not very satisfactory. Here, the mixed MoO3-WO3 materials were first introduced as the dielectric layer to construct an EC-TC bifunctional MoO3-WO3/Ag/MoO3-WO3 (MWAMW) film, which demonstrates strong and broad-band optical modulation in the visible light region, fast color-switching time (2.7 s for coloration and 4.1 s for bleaching), along with high coloration efficiency (70 cm(2) C(-1)). The electrical structure and electrochemical reaction kinetics analysis revealed that the improved EC performances are associated with the increased electron intervalence transition together with the fast charge-transfer and ion-diffusion dynamics.

  17. Modification of trace metal accumulation in the green mussel Perna viridis by exposure to Ag, Cu, and Zn

    Energy Technology Data Exchange (ETDEWEB)

    Shi Dalin [Department of Biology, The Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon, Hong Kong (China); Wang Wenxiong [Department of Biology, The Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon, Hong Kong (China)]. E-mail: wwang@ust.hk

    2004-11-01

    To examine the Cd, Hg, Ag, and Zn accumulation in the green mussel Perna viridis affected by previous exposure to Cu, Ag, or Zn, the dietary metal assimilation efficiency (AE) and the uptake rate from the dissolved phase were quantified. The mussel's filtration rate, metallothionein (MT) concentration, and metal tissue burden as well as the metal subcellular partitioning were also determined to illustrate the potential mechanisms underlying the influences caused by one metal pre-exposure on the bioaccumulation of the other metals. The green mussels were pre-exposed to Cu, Ag, or Zn for different periods (1-5 weeks) and the bioaccumulation of Cd, Hg, Ag, and Zn were concurrently determined. Pre-exposure to the three metals did not result in any significant increase in MT concentration in the green mussels. Ag concentration in the insoluble fraction increased with increasing Ag exposure period and Ag ambient concentration. Our data indicated that Cd assimilation were not influenced by the mussel's pre-exposure to the three metals (Cu, Ag, and Zn), but its dissolved uptake was depressed by Ag and Zn exposure. Although Hg assimilation from food was not affected by the metal pre-exposure, its influx rate from solution was generally inhibited by the exposure to Cu, Ag, and Zn. Ag bioaccumulation was affected the most obviously, in which its AE increased with increasing Ag tissue concentration, and its dissolved uptake decreased with increasing tissue concentrations of Ag and Cu. As an essential metal, Zn bioaccumulation remained relatively stable following the metal pre-exposure, suggesting the regulatory ability of Zn uptake in the mussels. Zn AE was not affected by metal pre-exposure, but its dissolved uptake was depressed by Ag and Zn pre-exposure. All these results indicated that the influences of one metal pre-exposure on the bioaccumulation of other metals were metal-specific due to the differential binding and toxicity of metals to the mussels. Such

  18. Structure cristalline de la triple molybdate Ag0.90Al1.06Co2.94(MoO45

    Directory of Open Access Journals (Sweden)

    Rawia Nasri

    2015-04-01

    Full Text Available Silver(I aluminiun tricobalt(II pentakis[tetraoxidomolybdate(VI], Ag0.90Al1.06Co2.94(MoO45, was synthesized using a solid-state reaction at 845 K. The structure can be described as a three-dimensional framework formed from dimeric M2O10 (M = Co/Al and trimeric M3O14 units linked to MoO4 tetrahedra by sharing corners, with the cavities occupied by disordered Ag+ cations. It is shown that the Co and Al atoms occupy common positions with different occupancies. The Ag+ cations are located at two different sites with occupancies of 0.486 (1 and 0.408 (1. The title coumpond is isotypic with NaMg3Al(MoO45 and NaFe4(MoO45. Differences and similarities with other related structures are discussed.

  19. Microstructural evolution of ternary Ag33Cu42Ge25 eutectic alloy inside ultrasonic field

    Directory of Open Access Journals (Sweden)

    Wei Zhai

    2014-12-01

    Full Text Available Ultrasonic field with a frequency of 20 kHz is introduced into the solidification process of ternary Ag33Cu42Ge25 eutectic alloy from the sample bottom to its top. The ultrasound stimulates the nucleation of alloy melt and prevents its bulk undercooling. At low ultrasound power of 250 W, the primary ε2 phase in the whole alloy sample grows into non-faceted equiaxed grains, which differs to its faceted morphology of long strip under static condition. The pseudobinary (Ag+ε2 eutectic transits from dendrite shape grain composed of rod type eutectic to equiaxed chrysanthemus shape formed by lamellar structure. By contrast, the ultrasound produces no obvious variation in the morphology of ternary (Ag+Ge+ε2 eutectic except a coarsening effect. When ultrasound power rises to 500 W, divorced ternary (Ag+Ge+ε2 eutectic forms at the sample bottom. However, in the upper part, the ultrasonic energy weakens, and it only brings about prominent refining effect to primary ε2 phase. The microstructural evolution mechanism is investigated on the cavitation, acoustic streaming and acoustic attenuation.

  20. Microstructural evolution of ternary Ag33Cu42Ge25 eutectic alloy inside ultrasonic field

    Institute of Scientific and Technical Information of China (English)

    Wei Zhai; Xiaoyu Lu; Bingbo Wei

    2014-01-01

    Ultrasonic field with a frequency of 20 kHz is introduced into the solidification process of ternary Ag33Cu42Ge25 eutectic alloy from the sample bottom to its top. The ultrasound stimulates the nucleation of alloy melt and prevents its bulk undercooling. At low ultrasound power of 250 W, the primary ε2 phase in the whole alloy sample grows into non-faceted equiaxed grains, which differs to its faceted morphology of long strip under static condition. The pseudobinary (Ag+ε2) eutectic transits from dendrite shape grain composed of rod type eutectic to equiaxed chrysanthemus shape formed by lamellar structure. By contrast, the ultrasound produces no obvious variation in the morphology of ternary (Ag+Ge+ε2) eutectic except a coarsening effect. When ultrasound power rises to 500 W, divorced ternary (Ag+Ge+ε2) eutectic forms at the sample bottom. However, in the upper part, the ultrasonic energy weakens, and it only brings about prominent refining effect to primaryε2 phase. The microstructural evolution mechanism is investigated on the cavitation, acoustic streaming and acoustic attenuation.

  1. Precipitation hardening in a 12%Cr-9%Ni-4%Mo-2%Cu stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Haettestrand, Mats; Nilsson, Jan-Olof; Stiller, Krystyna; Liu Ping; Andersson, Marcus

    2004-02-23

    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{sub 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.

  2. Mechanical alloying in Fe2O3-MO (M: Zn, Ni, Cu, Mg) systems

    DEFF Research Database (Denmark)

    Jiang, Jianzhong; Gerward, Leif; Mørup, Steen

    1999-01-01

    of MFe2O4 ferrites are critically discussed. No significant with respect to ferrite formation rates was observed in open and closed containers used here. In the Fe2O3/ZnO system, a single ferrite phase can be synthesized but in other systems no significant amounts of ferrites are formed by high......Mechanical alloying processes in four Fe2O3MO (M: Zn, Ni, Cu, Mg) systems by high-energy ball milling from simple oxide powder mixtures in both open and closed tungsten carbide containers have been investigated by x-ray powder diffraction and Mossbauer spectroscopy. Mechanisms for the formation......-energy ball milling under the conditions used here. The dominant alloying mechanism depends on the interdiffusion at relatively low temperatures. The experimental results may also be explained by the crystal structures of the reactants and the ferrites....

  3. An orientation soil survey at the Pebble Cu-Au-Mo porphyry deposit, Alaska

    Science.gov (United States)

    Smith, Steven M.; Eppinger, Robert G.; Fey, David L.; Kelley, Karen D.; Giles, S.A.

    2009-01-01

    Soil samples were collected in 2007 and 2008 along three traverses across the giant Pebble Cu-Au-Mo porphyry deposit. Within each soil pit, four subsamples were collected following recommended protocols for each of ten commonly-used and proprietary leach/digestion techniques. The significance of geochemical patterns generated by these techniques was classified by visual inspection of plots showing individual element concentration by each analytical method along the 2007 traverse. A simple matrix by element versus method, populated with a value based on the significance classification, provides a method for ranking the utility of methods and elements at this deposit. The interpretation of a complex multi-element dataset derived from multiple analytical techniques is challenging. An example of vanadium results from a single leach technique is used to illustrate the several possible interpretations of the data.

  4. Phase transformation and tribological properties of Ag-MoO3 contained NiCrAlY based composite coatings fabricated by laser cladding

    Science.gov (United States)

    Wang, Lingqian; Zhou, Jiansong; Xin, Benbin; Yu, Youjun; Ren, Shufang; Li, Zhen

    2017-08-01

    Ag-MoO3 contained NiCrAlY based composite coating was successfully prepared on GH4169 stainless steel substrate by high energy ball milling and laser cladding. The microstructure and phase transformation were investigated by scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS) and X-ray diffraction spectrum (XRD). The tribological behavior and mechanism from room temperature to 800 °C were investigated. Results showed that MoO3 in the composite powders transformed to Mo2C reinforcement under the high energy density of laser, and a series of opposite transformation occurred during friction process. The coating showed the lowest friction coefficient and low wear rate at 600 °C and 800 °C due to the generation of Ag2MoO4 during tribo-chemical reactions and the formation of lubrication glaze on the worn surface. Ag made effective lubrication when the temperature rose up to 200 °C. The coating displayed a relatively high friction coefficient (about 0.51) at 400 °C, because though MoO3 (oxidation products of Mo2C) and Ag2MoO4 were detected on the worn surface, they could not realize effective lubrication at this temperature. Abrasive wear, adhesive wear and plastic deformation contributed to the increased friction and wear.

  5. Measurements of the work function of single-walled carbon nanotubes encapsulated by AgI, AgCl, and CuBr using Kelvin probe technique with different kinds of probes

    Energy Technology Data Exchange (ETDEWEB)

    Zhukov, A. A., E-mail: azhukov@issp.ac.ru [Russian Academy of Science, Institute of Solid State Physics (Russian Federation); Chernysheva, M. V.; Eliseev, A. A. [Moscow State University, Department of Materials Science (Russian Federation)

    2016-07-15

    We report the results on the measurements of the work function of single-walled carbon nanotubes encapsulated by Agl (AgI@SWCNT), AgCl (AgCl@SWCNT), and CuBr (CuBr@SWCNT) by the local Kelvin probe technique. We found the values of the work function of tubes encapsulated with AgI and AgCl (Φ(AgI@SWCNT) = 5.08 ± 0.02, Φ(AgCl@SWCNT) = 5.10 ± 0.02 eV) to exceed substantially that of pristine carbon nanotubes, and the value of the work function of carbon nanotubes encapsulated with CuBr is Φ(CuBr@SWCNT) = 4.89 ± 0.03 (eV). The measurements are carried out using different kinds of microscope probes including multi-walled carbon nanotube tips.

  6. Effects of FeCo magnetic nanoparticles on microstructure of Sn-Ag-Cu alloys

    Science.gov (United States)

    Xu, Siyang; Habib, Ashfaque H.; Prasitthipayong, Anya; McHenry, Michael E.

    2013-05-01

    Sn-Ag-Cu (SAC) alloys have been regarded as the most promising candidates for lead-free solders in the electronic packaging industry. We prepared SAC solder-FeCo magnetic nanoparticles (MNPs) composite paste with different MNP concentration and used AC magnetic fields localized heating to cause their reflow. Differential scanning calorimetry results show a reduced undercooling of the composite paste with the addition of MNPs. Transmission electron microscope prove that the FeCo MNPs are distributed in Sn matrix of the reflowed solder composites. Optical micrographs show a decrease in the amount of primary Ag3Sn and β-Sn dendrites, and an increase in the amount of eutectic microconstituents with increasing MNPs. The addition of FeCo MNPs is considered to promote the solidification of β-Sn by providing more heterogeneous nucleation sites at a relatively low undercooling, which results in the microstructural refinement in the as-prepared solder joints.

  7. Improved galvanic replacement growth of Ag microstructures on Cu micro-grid for enhanced SERS detection of organic molecules

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Tian-Long [Key Laboratory for Anisotropy and Texture of Materials, School of Materials and Metallurgy, Northeastern University, Shenyang 110819 (China); Advanced Materials Processing Unit, National Institute for Materials Science, Namiki 1–1, Tsukuba, Ibaraki 305-0044 (Japan); Li, Ji-Guang, E-mail: LI.Jiguang@nims.go.jp [Key Laboratory for Anisotropy and Texture of Materials, School of Materials and Metallurgy, Northeastern University, Shenyang 110819 (China); Advanced Materials Processing Unit, National Institute for Materials Science, Namiki 1–1, Tsukuba, Ibaraki 305-0044 (Japan); Sun, Xudong, E-mail: xdsun@mail.neu.edu.cn [Key Laboratory for Anisotropy and Texture of Materials, School of Materials and Metallurgy, Northeastern University, Shenyang 110819 (China); Sakka, Yoshio [Advanced Materials Processing Unit, National Institute for Materials Science, Namiki 1–1, Tsukuba, Ibaraki 305-0044 (Japan)

    2016-04-01

    Galvanic growth of Ag nano/micro-structures on Cu micro-grid was systematically studied for surface-enhanced Raman scattering (SERS) applications. Detailed characterizations via FE-SEM and HR-TEM showed that processing parameters, (reaction time, Ag{sup +} concentration, and PVP addition) all substantially affect thermodynamics/kinetics of the replacement reaction to yield substrates of significantly different microstructures/homogeneities and thus varied SERS performances (sensitivity, enhancement factor, and reproducibility) of the Ag substrates in the detection of R6G analyte. PVP as an additive was shown to notably alter nucleation/growth behaviors of the Ag crystals and promote the deposition of dense and uniform Ag films of nearly monodisperse polyhedrons/nanoplates through suppressing dendrites crystallization. Under optimized synthesis (50 mM of Ag{sup +}, 30 s of reaction, and 700 wt.% of PVP), Ag substrates exhibiting a high Raman signal enhancement factor of ~ 1.1 × 10{sup 6} and a low relative standard deviation of ~ 0.13 in the repeated detection of 10 μM R6G were obtained. The facile deposition and excellent performance reported in this work may allow the Ag microstructures to find wider SERS applications. Moreover, growth mechanisms of the different Ag nano/micro-structures were discussed based on extensive FE-SEM and HR-TEM analysis. - Highlights: • A facile synthetic technique of growing SERS active Ag substrates onto Cu micro-grid has been systematically studied. • Changing processing parameters has yielded Ag crystals of various morphologies and SERS performances. • PVP additive was observed to suppress Ag dendrite crystallization for nearly monodispersed Ag polyhedrons/nanoplates. • PVP modified SERS substrate exhibits excellent EF and RSD values in the repeated detection of 10 μM R6G analyte.

  8. Effect of Yttrium on the Fracture Strength of the Sn-1.0Ag-0.5Cu Solder Joints

    Science.gov (United States)

    Choi, Hyelim; Kaplan, Wayne D.; Choe, Heeman

    2016-07-01

    This is a preliminary investigation on the mechanical properties of Pb-free Sn-1.0Ag-0.5Cu solder joints containing 0.02 wt.% to 0.1 wt.% Y under a range of thermal aging and reflow conditions. Despite the significantly thicker intermetallic compound (IMC) formed at the solder joint, the 0.1 wt.% Y-doped joint exhibited a higher fracture strength than its baseline Sn-1.0Ag-0.5Cu counterpart under most aging and reflow conditions. This may be associated with the formation of Y-Cu IMCs formed at the interface between the solder and the Cu substrate, because the Y-Cu IMCs have recently been referred to as relatively `ductile' IMCs.

  9. Investigating Quantum Oscillations in the Thermal Coefficient of Resistivity of Ultra-thin Ag Capping Layers on Cu for IC Interconnect Applications

    Science.gov (United States)

    Tatem, Elroy

    As the semiconductor industry continues to scale feature sizes, scattering from phonons, surfaces, and grain boundaries result in an increase of metal interconnect resistivity in state-of-the-art integrated circuits (ICs). The interconnect chapter of the 2011 International Technology Roadmap for Semiconductors (ITRS) stated that there are currently no manufacturable solutions in the near term for suitable Cu replacements. Previous studies of thin Ag films deposited on Cu demonstrated oscillations in the electron-phonon interactions within the bilayer system. This thesis investigates oscillations in the resistive properties of the Ag/Cu bilayer system and discusses the applicability of these oscillations to the resistivity challenges facing metal-based IC interconnects. Ag/Cu bilayer films were prepared by physical vapor deposition (PVD). The films were characterized by measuring the electrical resistance of the films at various temperatures and calculating the thermal coefficient of resistance (TCR) for various Ag capping layer thicknesses. Films were further characterized by atomic force microscopy (AFM), Rutherford backscattering (RBS), and scanning electron microscopy (SEM). Patterned Ag-capped Cu lines were fabricated, which exhibited resistive behavior similar to that of the Ag/Cu films. Compared to bare Cu, the resistances of Ag-capped Cu lines and films were lower and exhibited a reduced dependence on temperature. Smaller thermal coefficients of resistivity were also observed for Ag-capped Cu films and patterned lines when compared to Cu alone.

  10. Preparation of Cu, Ag, Fe and Al nanoparticles by the exploding wire technique

    Indian Academy of Sciences (India)

    P Sen; Joyee Ghosh; Alqudami Abdullah; Prashant Kumar; Vandana

    2003-10-01

    We describe a novel process for the production of nanoparticles of Cu, Ag, Fe and Al which involves exploding their respective wires, triggered by large current densities in the wires. The particles are characterised by X-ray diffraction (XRD) and atomic force microscopy (AFM). Particle sizes in the range 20-100nm were obtained employing this technique. The XRD results reveal that the nanoparticles continue to retain lattice periodicity at reduced particle sizes, displaying in some cases evidence of lattice strain and preferential orientation. In the case of Fe, Mossbauer spectroscopy reveals loss of ferromagnetism as a result of the reduced size of the particles.

  11. Wettability in the liquid Cu-Ag alloy – fireproof material – gas phase system

    Directory of Open Access Journals (Sweden)

    G. Siwiec

    2013-07-01

    Full Text Available In the present paper, results of wettability studies on the liquid metal – fireproof material – gas phase system using copper and Cu-Ag alloys as well as typical fireproof materials, i.e. aluminium oxide, magnesium oxide and graphite, are presented. Contact angle measurements were conducted at 1 373–1 573 K by means of a high-temperature microscope coupled with a camera and a computer equipped with a program for recording and analysing images. For the measurements, the sessile drop method was used.

  12. Study on the Correlation between Microstructure Corrosion and Wear Resistance of Ag-Cu-Ge Alloys

    Directory of Open Access Journals (Sweden)

    Antonio Cusma

    2015-03-01

    Full Text Available In this work, a morphological and structural characterization of a ternary Ag-Cu-Ge alloy of known composition was performed with the aim of evaluating how the passivation parameters (time and temperature influence the morphological features of the material surface. A nanomechanical characterization was performed in order to correlate the morphology and microstructure of the alloy with its tarnish, wear, and scratch resistance. It was found that the addition of germanium to the alloy not only provides the material with tarnish and fire-stain resistance, but it also improves the scratch and wear resistance owing to the formation of a dense and stable thin oxide layer.

  13. Ammonia synthesis on Au modified Fe(111) and Ag and Cu modified Fe(100) surfaces

    DEFF Research Database (Denmark)

    Lytken, Ole; Waltenburg, Hanne Neergaard; Chorkendorff, Ib

    2003-01-01

    In order to investigate any influence of steps and possible positive effects of making surface alloys the ammonia synthesis has been investigated over Au modified Fe(111) and Ag and Cu modified Fe(100) single crystals in the temperature range 603-773 K, using a system combining ultra-high vacuum...... and a high-pressure cell. Ammonia was synthesized from a stoichiometric (N-2:3H(2)) gas mixture at a pressure of 2 bar. By deposition of small amounts of An, the ammonia production activity of the Fe(1 1 1) surface can be enhanced. More important, for the gold modified surface, the reaction order in ammonia...

  14. Spasmodic growth during the rapid solidification of undercooled Ag-Cu eutectic melts

    Science.gov (United States)

    Clopet, C. R.; Cochrane, R. F.; Mullis, A. M.

    2013-01-01

    A melt fluxing technique has been used to undercool Ag-Cu eutectic alloy by 10-70 K and the subsequent recalescence has been studied using high speed imaging. Spasmodic growth of the solidification front was observed, in which the growth front would make a series of quasi-periodic jumps separated by extended periods during which time growth appeared to arrest. Evidence of this previously unreported mode of growth is presented. The high speed images and microstructural evidence support the theory that anomalous eutectics form by the growth and subsequent remelting of eutectic dendrites.

  15. Thermodynamic Description of the Quaternary Ag-Bi-Cu-Sn System

    Science.gov (United States)

    Gierlotka, Wojciech

    2017-09-01

    Lead-free soldering is an important part of electronic devices production. New lead-free solders that replace classical Sn-37Pb solder are still under development. Thermodynamic modeling makes the development process faster, cheaper and more environmentally friendly due to predictions of phases stabilities and phases transformations. In this work, the thermodynamic description of quaternary Ag-Bi-Cu-Sn system is presented. The thermodynamic assessment of promising lead-free quaternary solder was prepared using the Calphad approach. A good agreement between available experimental data and calculation was found.

  16. Correlation between mechanical properties and structural changes of the sintered Cu-4 at% Ag alloy during thermomechanical treatment

    Directory of Open Access Journals (Sweden)

    Rangelov Ivana I.

    2008-01-01

    Full Text Available Influence of thermomechanical treatment on micro structure and strength (hardness and microhardness of the sintered copper based Cu-4 at% Ag alloy was investigated using Vickers hardness and microhardness measurements, and optical microscopy. After sintering at 790°C, samples of Cu-4 at% Ag alloy were subjected to thermomechanical treatment by cold rolling with 20, 40 and 60% deformation degrees, and annealing below and over the recrystallization temperature. It was shown that microstructure of Cu-4 at% Ag alloy changed with thermomechanical treatment, which directly causes changes of mechanical properties. Optical microphotograph of the sintered Cu-4 at% Ag alloy shows relatively homogeneous structure with spherical pores presented. The strength (hardness and microhardness of the sintered Cu-4 at% Ag alloy during cold rolling increases with deformation degree due to deformation strengthening. Maximum values of hardness and microhardness were for 60% deformation. The porosity still exists in spite of the fact that compacting was carried out during the cold rolling. The hardness and microhardness continue to increase after annealing at temperature bellow recrystallization temperature due to anneal hardening effect which occurs in a temperature range of 160-350°C. It was concluded that solute segregation to dislocations, analogous to the formation of Cottrel atmosphere in interstitial solid solutions, is primarily responsible for anneal hardening phenomenon. Annealing at higher temperatures (higher than 400°C results in strength decrease due to beginning of alloy recrystallization.

  17. The effects of deposition time on surface morphology, structural, electrical and optical properties of sputtered Ag-Cu thin films

    Science.gov (United States)

    Ahmadpourian, Azin; Luna, Carlos; Boochani, Arash; Arman, Ali; Achour, Amine; Rezaee, Sahare; Naderi, Sirvan

    2016-10-01

    The preparation of designed nanostructured thin films combining nano grains of different compositions and physical properties represents a promising avenue for the exploration of novel collective behaviors with technological potentials. Herein, nanostructured Ag-Cu thin films with different surface morphology properties were grown by magnetron sputtering varying the deposition time (4-24 min) and fixing the other deposition conditions. X-ray diffraction studies corroborated that Cu and Ag tend to appear as separated phases with nanometric sizes due to the fact that these elements are rather immiscible. The deposited Cu tended to be partially oxidized with crystal sizes of several tens of nm, whereas the deposited Ag phase displayed a poor crystallinity with an average crystal size of around 3nm. However, at deposition time of few minutes, the formation of Ag-Cu crystals with a preferable crystallization orientation along the [111] direction was detected. The surface morphology of the obtained thin films was studied by atomic force microscopy determining the surface roughness and average particle sizes of the samples. These parameters were correlated with the plasmon resonance extinction bands of the different Ag-Cu films and their electrical properties, providing a reproducible route to obtain thin films with tuned electrical resistances and optical properties.

  18. Antimicrobial effect of TiO2 doped with Ag and Cu on Escherichia coli and Pseudomonas putida

    Science.gov (United States)

    Angelov, O.; Stoyanova, D.; Ivanova, I.

    2016-10-01

    Antimicrobial effect of TiO2 doped with Ag and Cu on Gram-negative bacteria Escherichia coli and Pseudomonas putida is studied. The thin films are deposited on glass substrates without heating during the deposition by r.f. magnetron co-sputtering of TiO2 target and pieces of Ag and Cu. The studied films, thickness about 65 nm, were as deposited and annealed (5200C, 4h, N2+5%H2, 4Pa). The as deposited thin films TiO2:Ag:Cu have band gap energy of 3.56 eV little higher than the band gap of crystalline anatase TiO2 which can be explained with the quantum effect of the granular structure of r.f. magnetron sputtered films. The annealed samples have band gap of 2.52 eV due to formation of donor levels from Ag and Cu atoms near the bottom of the conduction band. The toxic effect was determined through the classical Koch's method and the optical density measurements at λ=610 nm. The as deposited TiO2:Ag:Cu thin films demonstrate stronger inhibition effect - bactericidal for P. putida and bacteriostatic for E. coli (up to the 6th hour) in comparison with the annealed samples. The both methods of study show the same trends of the bacterial growth independently of their different sensitivity which confirms the observed effect.

  19. A colorimetric assay for measuring iodide using Au@Ag core–shell nanoparticles coupled with Cu{sup 2+}

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Jingbin, E-mail: xmuzjb@163.com [State Key Laboratory of Heavy Oil Processing & College of Science, China University of Petroleum (East China), Qingdao 266555 (China); Cao, Yingying [State Key Laboratory of Heavy Oil Processing & College of Science, China University of Petroleum (East China), Qingdao 266555 (China); Lu, Chun-Hua [The Key Laboratory of Analysis and Detection Technology for Food Safety of the MOE, College of Chemistry, Fuzhou University, Fuzhou 350002 (China); Wang, Xu-dong [Karlsruhe Institute of Technology (KIT), Institute for Biological Interfaces (IBG-1), Hermann-von-Helmholtz-Platz, 76344 Eggenstein-Leopoldshafen (Germany); Wang, Qianru; Wen, Cong-ying; Qu, Jian-Bo; Yuan, Cunguang [State Key Laboratory of Heavy Oil Processing & College of Science, China University of Petroleum (East China), Qingdao 266555 (China); Yan, Zi-feng, E-mail: zfyancat@upc.edu.cn [State Key Laboratory of Heavy Oil Processing & College of Science, China University of Petroleum (East China), Qingdao 266555 (China); Chen, Xi [Department of Chemistry and the MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005 (China)

    2015-09-03

    Au@Ag core–shell nanoparticles (NPs) were synthesized and coupled with copper ion (Cu{sup 2+}) for the colorimetric sensing of iodide ion (I{sup −}). This assay relies on the fact that the absorption spectra and the color of metallic core–shell NPs are sensitive to their chemical ingredient and dimensional core-to-shell ratio. When I{sup −} was added to the Au@Ag core–shell NPs-Cu{sup 2+} system/solution, Cu{sup 2+} can oxidize I{sup −} into iodine (I{sub 2}), which can further oxidize silver shells to form silver iodide (AgI). The generated Au@AgI core–shell NPs led to color changes from yellow to purple, which was utilized for the colorimetric sensing of I{sup −}. The assay only took 10 min with a lowest detectable concentration of 0.5 μM, and it exhibited excellent selectivity for I{sup −} over other common anions tested. Furthermore, Au@Ag core–shell NPs-Cu{sup 2+} was embedded into agarose gels as inexpensive and portable “test strips”, which were successfully used for the semi-quantitation of I{sup −} in dried kelps. - Highlights: • Au@Ag core–shell NPs were synthesized and coupled with Cu{sup 2+} for the colorimetric I{sup −} sensing. • This assay is simple, rapid and selective. • Au@Ag core–shell NPs-Cu{sup 2+} were embedded into agarose gels as test strips.

  20. Abrasive and corrosive behaviors of Cu-Zr-Al-Ag-Nb bulk metallic glasses

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, J L; Shek, C H [Department of Physics and Materials Science, City University of Hong Kong (Hong Kong); Lu, J X, E-mail: apchshek@cityu.edu.h

    2009-01-01

    The present work investigated effects of Nb (1-5 at.%) on CuZrAlAg bulk metallic glasses. The addition of Nb did not change the amorphous structure but affected the thermal behaviors significantly. The corrosion resistances of the BMGs with addition of 5 at% Nb in 0.5 N H{sub 2}SO{sub 4} solutions was the best among the samples. Pin-on-disk measurements showed that the hardest sample, viz. the one with 3 at% Nb exhibited the best wear resistance. Mechanical properties were also investigated using a nanoindentation technique. It was found that the addition of Nb may improved corrosion resistance and wear resistance of the Cu-based BMG, but not in a simple and systematic manner.

  1. Abrasive and corrosive behaviors of Cu-Zr-Al-Ag-Nb bulk metallic glasses

    Science.gov (United States)

    Zhang, J. L.; Lu, J. X.; Shek, C. H.

    2009-01-01

    The present work investigated effects of Nb (1-5 at.%) on CuZrAlAg bulk metallic glasses. The addition of Nb did not change the amorphous structure but affected the thermal behaviors significantly. The corrosion resistances of the BMGs with addition of 5 at% Nb in 0.5 N H2SO4 solutions was the best among the samples. Pin-on-disk measurements showed that the hardest sample, viz. the one with 3 at% Nb exhibited the best wear resistance. Mechanical properties were also investigated using a nanoindentation technique. It was found that the addition of Nb may improved corrosion resistance and wear resistance of the Cu-based BMG, but not in a simple and systematic manner.

  2. Thermodynamics of the eutectic alloy Ag38. 5 Cu33. 4 Ge28. 1

    Energy Technology Data Exchange (ETDEWEB)

    Battezzati, L.; Riontino, G. (Turin Univ. (Italy). Dipt. di Chimica Inorganica, Chimica Fisica e Chimica dei Materiali); Baricco, M. (Istituto Elettrotecnico Nazionale, Turin (Italy))

    1989-08-01

    The heat of fusion and the specific heat of the liquid and crystalline Ag{sub 38.5}Cu{sub 33.4}Ge{sub 28.1} eutectic alloy have been determined by DSC. The specific heat of the solid follows the Neumann-Kopp rule, with an additional contribution which is shown to be due to Cu{sub 3}Ge dissolution. The specific heat of the liquid decreases with increasing temperature and exceeds that of the solid at the melting point and in the undercooled regime. An amorphous alloy of the same composition was prepared by melt spinning and the heat of crystallization was measured. The set of thermodynamic data is used to discuss glass formation in this system. The role of the excess specific heat of the liquid phase with respect to the crystalline phases is outlined. (orig.).

  3. Synthesis of [MoOS3Cu3U(3,5-diMePy)4]·CH3CN and(Et4N)4[Mo4Cu8O4S12{(Ph2PS)2N}4]from Solid State Product[Et4N]4[Mo2O2S6Cu6I4Br2]%从固相反应产物[NEt4]4[Mo2O2S6Cu6I4Br2]合成原子簇[MoOS3Cu3I(3,5-diMePy)4]·CH3CN和(EtN)4[Mo4Cu8O4S12{(Ph2PS)2}4](英文)

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@ Treatment of iodide-bridged dimer [NEt4] 4[Mo2O2S6Cu6I4Br2] 1 with 3, 5-bimethylpyridine or with K[(Ph2PS) 2N] in CH3CN afforded the tetranuclear cluster [MoOS3Cu3I(3,5-diMePy)4]·CH3CN 2 and dodecanuclear cluster (Et4N)4[Mo4Cu8O4S12{(Ph2PS)2N}4] 3. Monomeric 2 possess a nest-shaped skeleton.The structure of oligomeric 3 can be regarded as a tetramer of nest-shaped MoCu3OS3[(Ph2PS)aN]groups co-polymerized by sharing the limbic Cu atoms.

  4. Influence of the Ag concentration on the medium-range order in a CuZrAlAg bulk metallic glass

    Science.gov (United States)

    Gammer, C.; Escher, B.; Ebner, C.; Minor, A. M.; Karnthaler, H. P.; Eckert, J.; Pauly, S.; Rentenberger, C.

    2017-03-01

    Fluctuation electron microscopy of bulk metallic glasses of CuZrAl(Ag) demonstrates that medium-range order is sensitive to minor compositional changes. By analyzing nanodiffraction patterns medium-range order is detected with crystal-like motifs based on the B2 CuZr structure and its distorted structures resembling the martensitic ones. This result demonstrates some structural homology between the metallic glass and its high temperature crystalline phase. The amount of medium-range order seems slightly affected with increasing Ag concentration (0, 2, 5 at.%) but the structural motifs of the medium-range ordered clusters become more diverse at the highest Ag concentration. The decrease of dominant clusters is consistent with the destabilization of the B2 structure measured by calorimetry and accounts for the increased glass-forming ability.

  5. The preparation of thermally stable TiNx/Ag(Mo)/TiNx ultrathin films by magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Loka, Chadrasekhar; Yu, Ho Tak; Lee, Kee-Sun, E-mail: kslee@kongju.ac.kr

    2014-11-03

    Thermally stable optically selective coatings are indispensable for low emissivity (low-e) applications. Low-e coatings effectively reduce energy loss from the building glazing systems by allowing high visible transmittance and reflecting most near-infrared radiation of the solar spectrum. In the present study, we investigated the thermal stability and optical properties of TiNx/Ag(Mo)/TiNx films deposited on glass substrates by using rf and dc magnetron sputtering at room temperature. The deposited multilayer stacks were annealed up to 873 K for 1 h in air ambient and a rigorous analysis was presented on the structure, microstructure, topography, chemical composition, and optical properties by grazing incidence X-ray diffraction, high resolution transmission electron microscopy, scanning electron microscopy, atomic force microscopy, Auger electron spectroscopy, and Ultraviolet–visible–near infrared spectrophotometer, respectively. The results revealed that the proposed structure was thermally stable with dense and smooth microstructure until 773 K; in addition, noteworthy inward/outward diffusion of silver was not observed due to the good diffusion barrier performance of TiNx. An abrupt rise in root mean square roughness and locally isolated islands like structures was observed at 873 K annealing temperature. The deposited films showed high transmittance in the visible region and high reflectance in the infrared region of the solar radiation spectrum. - Highlights: • TiNx/Ag(Mo)/TiNx/films were thermally durable until 773 K. • High visible transmittance was obtained by adopting the amorphous TiNx films. • Ag(Mo) film was protected until 773 K by partial oxidation of TiNx layers.

  6. Specific heat and related thermophysical properties of liquid Fe-Cu-Mo alloy

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The specific heat and related thermophysical properties of liquid Fe77.5Cu13Mo9.5 monotectic alloy were investigated by an electromagnetic levitation drop calo-rimeter over a wide temperature range from 1482 to 1818 K.A maximum under-cooling of 221 K(0.13 Tm)was achieved and the specific heat was determined as 44.71 J·mol1·K1.The excess specific heat,enthalpy change,entropy change and Gibbs free energy difference of this alloy were calculated on the basis of experimental results.It was found that the calculated results by traditional esti-mating methods can only describe the solidification process under low under-cooling conditions.Only the experimental results can reflect the reality under high undercooling conditions.Meanwhile,the thermal diffusivity,thermal conductivity,and sound speed were derived from the present experimental results.Furthermore,the solidified microstructural morphology was examined,which consists of(Fe)and(Cu)phases.The calculated interface energy was applied to exploring the correlation between competitive nucleation and solidification microstructure within monotectic alloy.

  7. Specific heat and related thermophysical properties of liquid Fe-Cu-Mo alloy

    Institute of Scientific and Technical Information of China (English)

    WANG HaiPeng; LUO BingChi; CHANG Jian; WEI BingBo

    2007-01-01

    The specific heat and related thermophysical properties of liquid Fe77.5Cu13Mo9.5 monotectic alloy were investigated by an electromagnetic levitation drop calorimeter over a wide temperature range from 1482 to 1818 K. A maximum undercooling of 221 K (0.13 Tm) was achieved and the specific heat was determined as 44.71 J·mol-1·K-1. The excess specific heat, enthalpy change, entropy change and Gibbs free energy difference of this alloy were calculated on the basis of experimental results. It was found that the calculated results by traditional estimating methods can only describe the solidification process under low undercooling conditions. Only the experimental results can reflect the reality under high undercooling conditions. Meanwhile, the thermal diffusivity, thermal conductivity, and sound speed were derived from the present experimental results. Furthermore, the solidified microstructural morphology was examined, which consists of (Fe) and (Cu) phases. The calculated interface energy was applied to exploring the correlation between competitive nucleation and solidification microstructure within monotectic alloy.

  8. Highly Efficient and Air Stable Inverted Polymer Solar Cells Using LiF-Modified ITO Cathode and MoO3/AgAl Alloy Anode.

    Science.gov (United States)

    Jia, Xiangkun; Jiang, Ziyao; Chen, Xiaohong; Zhou, Jianping; Pan, Likun; Zhu, Furong; Sun, Zhuo; Huang, Sumei

    2016-02-17

    The performance and air stability of inverted polymer solar cells (PSCs) were greatly improved using a combination of LiF-modified ITO cathode and a MoO3/AgAl alloy anode. The power conversion efficiency (PCE) of PSCs with AgAl contact reached 9.4%, which is higher than that of the cells with Ag (8.8%) and Al electrode (7.6%). The PCE of AgAl-based PSCs can further increase up to 10.3% through incorporating an ultrathin LiF-modified ITO. AgAl-based cells also exhibit a superior stability compared to the cells with Ag and Al contacts. PCE of the AgAl-based cells without encapsulation remains 78% of its original value after the cells were aged for 380 days in air. The presence of a LiF-modified ZnO interlayer between ITO and the organic active layer improves the charge collection. The improvement in PCE and stability of the AgAl-based cells is primarily attributed to the formation of AlOx at the MoO3/AgAl interface, preventing Ag diffusion and improving the built-in potential across the active layer in the cells.

  9. Epitaxial Cu(001) films grown on a Cr/Ag/Fe/GaAs(001) buffer system

    Energy Technology Data Exchange (ETDEWEB)

    Gottlob, Daniel M., E-mail: d.gottlob@fz-juelich.de [Peter Grünberg Institut, Electronic Properties (PGI-6), Forschungszentrum Jülich, 52425 Jülich (Germany); Fakultät für Physik and Center for Nanointegration Duisburg-Essen (CeNIDE), Universität Duisburg-Essen, 47048 Duisburg (Germany); Jansen, Thomas [Peter Grünberg Institut, Electronic Properties (PGI-6), Forschungszentrum Jülich, 52425 Jülich (Germany); Jülich-Aachen Research Alliance, Fundamentals for Future Information Technology (JARA-FIT), Forschungszentrum Jülich, 52425 Jülich (Germany); Hoppe, Michael [Peter Grünberg Institut, Electronic Properties (PGI-6), Forschungszentrum Jülich, 52425 Jülich (Germany); Bürgler, Daniel E. [Peter Grünberg Institut, Electronic Properties (PGI-6), Forschungszentrum Jülich, 52425 Jülich (Germany); Jülich-Aachen Research Alliance, Fundamentals for Future Information Technology (JARA-FIT), Forschungszentrum Jülich, 52425 Jülich (Germany); and others

    2014-07-01

    We present a procedure to prepare single-crystalline, high-purity Cu(001) films (templates) suitable as substrates for subsequent epitaxial thin-film growth. The template films were grown in a dedicated molecular-beam epitaxy system on a Cr/Ag/Fe/GaAs(001) buffer layer system. Low-energy electron diffraction and X-ray diffraction were applied to determine the surface orientation and the epitaxial relationship between all layers of the stack. Post-annealing at moderate temperatures enhances the quality of the film as shown by low-energy electron diffraction and atomic force microscopy. X-ray photoemission and Auger electron spectroscopy confirm that no atoms of the buffer layers diffuse into the Cu film during the initial preparation and the post-annealing treatment. The completed Cu(001) template system can be exposed to air and afterwards refurbished by Ar{sup +}-ion bombardment and annealing, enabling the transfer between vacuum systems. The procedure provides suitable conductive thin film templates for studies of epitaxial thin films, e.g. on the magnetic and magnetotransport properties of Co and Ni based films and multilayers. - Highlights: • Preparation of epitaxial Cu(001) template films on an insulating substrate • Characterization of template structure, orientation, cleanness, and roughness • Template films can be exposed to air and refurbished in different vacuum system. • Template films are suitable for further thin film growth at up to 570 K.

  10. CuO and Ag2O/CuO Catalyzed Oxidation of Aldehydes to the Corresponding Carboxylic Acids by Molecular Oxygen

    Directory of Open Access Journals (Sweden)

    Yaowu Sha

    2008-04-01

    Full Text Available Furfural was oxidized to furoic acid by molecular oxygen under catalysis by 150nm-sized Ag2O/CuO (92% or simply CuO (86.6%. When 30 nm-size catalyst was used,the main product was a furfural Diels-Alder adduct. Detailed reaction conditions andregeneration of catalysts were investigated. Under optimal conditions, a series of aromaticand aliphatic aldehydes were oxidized to the corresponding acids in good yields.

  11. M atom (M = Cu, Ag and Au) interaction with Ag and Au substrates: a first-principles study using cluster and slab models.

    Science.gov (United States)

    Nigam, Sandeep; Majumder, Chiranjib

    2010-11-03

    Using state-of-the-art first-principles calculations we report the interaction of M atoms (M = Cu, Ag and Au) with small Ag(n), Au(n) clusters (n = 3 and 6) and periodic Ag(111) and Au(111) surfaces. All calculations were performed using the plane wave pseudo-potential approach under the spin polarized version of the generalized gradient approximation scheme. The result shows that the equilibrium geometry of all MAg(3) and MAu(3) clusters favor a planar rhombus structure. From the charge distribution analysis of MAg(n)/MAu(n) clusters it is found that, while Cu and Ag donates electronic charge towards the host clusters, the Au atom acts as an acceptor, thus creating charge polarization in the system. The difference in orbital decomposed charges before and after the M interaction reveals that enhanced s-d hybridization is responsible for keeping the MAu(6) cluster planar, and increased p-orbital participation induces three-dimensional configurations in MAg(6) clusters. The optimization of M atom deposition on the Ag(111) and Au(111) surfaces shows that M atoms prefer to adsorb on the threefold fcc site over other well-defined sites. From the orbital decomposed charge analysis it is inferred that, although there is significant difference in the absolute magnitude of the interaction energy between M atoms and the Ag or Au substrates, the nature of chemical bonding is similar for the finite size clusters as well as in slab models.

  12. Ag7+ ion induced modification of morphology, optical and luminescence behaviour of charge compensated CaMoO4 nanophosphor

    Science.gov (United States)

    Dutta, S.; Som, S.; Kunti, A. K.; Sharma, S. K.; Kumar, Vijay; Swart, H. C.; Visser, H. G.

    2016-10-01

    The present paper reports on the swift heavy ion (SHI) induced structural, optical and luminescence properties of CaMoO4:Dy3+/K+ nanophosphor synthesized via hydrothermal route. Herein 100 MeV Ag7+ ion beam was used varying fluence from 1 × 1011 to 1 × 1013 ions/cm2. The depth profile of the Ag7+ ions was estimated using SRIM code. XRD and FESEM results revealed the loss of crystallinity and reduction in particle size after SHI irradiations. The XPS technique confirmed the stability of oxidation states of the elements. Reflectance spectra exhibited a red shift in the absorption band, followed by a decrease in band gap. Decrease in the intensity of the photoluminescence peaks without any change in band positions was also obtained after ion irradiation. The thermoluminescence (TL) characteristics were discussed in detail, and the trapping parameter was calculated. The results were compared on the grounds of linear energy transfer of the irradiated ions.

  13. Characteristics of Laser Reflow Bumping of Sn3.5Ag and Sn3.5Ag0.5Cu Lead-Free Solder Balls

    Institute of Scientific and Technical Information of China (English)

    Yanhong TIAN; Chunqing WANG; Yarong CHEN

    2008-01-01

    Lead-free Sn3.5Ag and Sn3.5Ag0.5Cu solder balls were reflowed by laser to form solder bumps. Shear test was performed on the solder bumps, and SEM/EDX (scanning electron microscopy/energy dispersive X-ray spectrometer) was used to analyze the formation of intermetallic compounds (IMCs) at interface region. A finite element modeling on the temperature gradient and distribution at the interface of solder bump during laser reflow process was conducted to elucidate the mechanism of the IMCs growth direction. The results show that the parameters window for laser reflow bumping of Sn3.5Ag0.5Cu was wider than that of Sn3.5Ag. The shear strength of Sn3.5Ag0.5Cu solder bump was comparable to that of Sn3.5Ag solder bump, and was not affected obviously by laser power and irradiation time when appropriate parameters were used. Both laser power and heating time had a significant effect on the formation of IMCs. A continuous AuSn4 interrnetallic compound layer and some needle-like AuSn4 were observed at the interface of solder and Au/Ni/Cu metallization layer when the laser power is small. The formation of needle-like AuSn4 was due to temperature gradient at the interface, and the direction of temperature gradient was the preferred growth direction of AuSn4. With increasing the laser power and heating time, the needle-like AuSn4 IMCs dissolved into the bulk solder, and precipitated out once again during solidification along the grain boundary of the solder bump.

  14. Experimental and finite element analysis of the shear speed effects on the Sn-Ag and Sn-Ag-Cu BGA solder joints

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong-Woong; Jung, Seung-Boo

    2004-04-25

    An experimental investigation was combined with a non-linear finite element analysis using an elastic-viscoplastic constitutive model to study the effect of ball shear speed on the shear forces of BGA solder joints. Two solder compositions were examined in this work: Sn-3.5Ag and Sn-3.5Ag-0.75Cu. The Cu substrates had been surface finished electrolytically with a 7 {mu}m thick Ni diffusion barrier followed by an 0.5 {mu}m thick Au layer to enhance solderability. Ag{sub 3}Sn and a few AuSn{sub 4} intermetallic compound (IMC) particles were found inside the two solders. Only a continuous Ni{sub 3}Sn{sub 4} layer was observed at the interface between the Au/Ni plated layer and the Sn-3.5Ag, while a continuous (Ni{sub 1-x}Cu{sub x}){sub 3}Sn{sub 4} layer and a small amount of discontinuous (Cu{sub 1-y}Ni{sub y}){sub 6}Sn{sub 5} particles were formed at the interface between the substrate and the Sn-3.5Ag-0.75Cu. The IMC was identified using energy dispersive spectrometer (EDS) and electron probe micro analysis (EPMA). Shear tests were carried out over a shear speed range from 10 to 700 {mu}m/s at a shear ram height of 50 {mu}m. The shear force was observed to linearly increase with shear speed and reach a maximum value at the highest shear speed in both the experimental and the computational results. All test specimens fractured in a ductile mode. The failure mechanisms were discussed in terms of von Mises stresses and plastic strain energy density distributions.

  15. Antimicrobial activity and biocompatibility of Ag{sup +}- and Cu{sup 2+}-doped biphasic hydroxyapatite/α-tricalcium phosphate obtained from hydrothermally synthesized Ag{sup +}- and Cu{sup 2+}-doped hydroxyapatite

    Energy Technology Data Exchange (ETDEWEB)

    Radovanović, Željko, E-mail: zradovanovic@tmf.bg.ac.rs [Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11000 Belgrade (Serbia); Jokić, Bojan; Veljović, Djordje; Dimitrijević, Suzana [Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11000 Belgrade (Serbia); Kojić, Vesna [Oncology Institute of Vojvodina, Institutski put 4, 21204 Sremska Kamenica (Serbia); Petrović, Rada; Janaćković, Djordje [Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11000 Belgrade (Serbia)

    2014-07-01

    Hydroxyapatite (HAp) powders doped with Ag{sup +} or Cu{sup 2+} were synthesized by a hydrothermal method in order to obtain biomaterial with an antimicrobial effect. The synthesis was performed with two contents of dopant (Ag{sup +} or Cu{sup 2+}) by considering both the antimicrobial activities and biocompatibility of the powders. The doped HAp was annealed at 1200 °C for 2 h with the intention of investigating the influence of doping with Ag{sup +} and Cu{sup 2+} on the creation of the biphasic HAp/α-tricalcium phosphate (HAp/α-TCP) and determining the antimicrobial activity and biocompatibility of the obtained biphasic powders. Analyses of all powders, undoped and doped HAp and HAp/α-TCP, were performed by Field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), atomic absorption spectroscopy (AAS) and energy-dispersive X-ray spectroscopy (EDS). The in vitro antibacterial activities of the powders were evaluated against: Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Candida albicans. All powders showed good antimicrobial activity but generally the powders of doped HAp/α-TCP had more uniform results against all pathogenic microorganisms than the powders of doped HAp. In vitro biocompatibility tests, MTT and DET, were used to evaluate the biocompatibility of Ag{sup +}- and Cu{sup 2+}-doped HAp/α-TCP with MRC-5 human fibroblast cells. These tests confirmed that powders do not have a cytotoxic effect. The HAp/α-TCP powders doped with the lower content of Ag{sup +} and Cu{sup 2+} showed especially good biocompatibility. Antimicrobial and biocompatibility tests recommend the Ag{sup +}- and Cu{sup 2+}-doped HAp/α-TCP as promising material for use in reconstructive surgery of bone.

  16. Mechanical Behavior of Sn-3.0Ag-0.5Cu/Cu Solder Joints After Isothermal Aging

    Science.gov (United States)

    Nguyen, Van Luong; Chung, Chin-Sung; Kim, Ho-Kyung

    2016-01-01

    The tensile impact behavior of lead-free Sn-3Ag-0.5Cu/Cu solder joints aged at 413 K and 453 K for times ranging from 24 h to 1000 h has been investigated in this study. The activation energy for growth of the intermetallic compound (IMC) layer was estimated and compared with literature values. Additionally, the tensile strength of solder joints with IMC thickness of 17.6 μm was found to be more sensitive to the strain rate as compared with solder joints with thinner IMC layers. Equations representing the relationships among the effective stress, strain rate, aging time, and aging temperature as well as IMC thickness were established using matrix laboratory (MATLAB) software. These equations show that the tensile strength decreases with increase in the IMC thickness to about 8 μm, after which it becomes nearly constant when the IMC thickness is between approximately 8 μm and 14 μm, before decreasing significantly when the IMC thickness exceeds 14 μm. The main reason for these characteristics was excessive increase in the IMC thickness of solder joints, causing a change in the stress concentration of the tensile load from the protruding region to the inside of the IMC layer at the same tested strain rate.

  17. Effect of Cooling Rate on the Longitudinal Modulus of Cu3Sn Phase of Ag-Sn-Cu Amalgam Alloy (Part II

    Directory of Open Access Journals (Sweden)

    R. H. Rusli

    2015-10-01

    Full Text Available Effects of cooling rate (at the time of solidification on the elastic constants of Cu3Sn phase of Ag-Sn-Cu dental amalgam alloy were studied. In this study, three types of alloys were made, with the composition Cu-38-37 wt% Sn by means of casting, where each alloy was subjected to different cooling rate, such as cooling on the air (AC, air blown (AB, and quenched in the water (WQ. X-ray diffraction, metallography, and Scanning Electron Microscopy with Energy Dispersive Spectroscopy studies of three alloys indicated the existence of Cu3Sn phase. Determination of the modulus of elasticity of Cu3Sn (ε phase was carried out by the measurement of longitudinal and transversal waves velocity using ultrasonic technique. The result shows that Cu3Sn (ε phase on AC gives higher modulus of elasticity values than those of Cu3Sn (ε on AB and WQ. The high modulus of elasticity value will produce a strong Ag-Sn-Cu dental amalagam alloy.

  18. Two Liquid Phases Separation of Fe-Cu-B and Fe-Cu-Ag-B systems at 1873 and 1523 K

    Science.gov (United States)

    Ono-Nakazato, Hideki; Yamaguchi, Katsuhiro; Agawa, Shingo; Taguchi, Kenji; Usui, Tateo

    In recycling of steel scraps, the accumulation of tramp element in steel has been one of serious problems. Because copper in steel causes hot-shortness, the copper content of steel scraps is strictly adjusted under the upper limiting value in steelmaking process. In addition, recycling of steel scrap is necessary for energy savings and to realize a recycling-oriented society. In the present study,it was found that addition of boron could separate a single liquid in Fe-Cu system into Fe-rich and Cu-rich phases. Equilibrium experiments in Fe-Cu-B ternary system at 1873 and 1523 K showed that the copper content in Fe-rich phase decreased to 4.3 mass%. Subsequently, equilibrium experiments in Fe-Cu-Ag-B system were carried out and the copper was observed to be distributed between Fe-B and Ag phases. The distribution ratio of [mass%Cu](in Ag) / [mass%Cu](in Fe) was about 6 at 1873 K, regardless of copper content. It was found that the copper content of iron could be decreased by using silver as the solvent.

  19. Mechanical Characterization of Lead-Free Sn-Ag-Cu Solder Joints by High-Temperature Nanoindentation

    Science.gov (United States)

    Lotfian, S.; Molina-Aldareguia, J. M.; Yazzie, K. E.; Llorca, J.; Chawla, N.

    2013-06-01

    The reliability of Pb-free solder joints is controlled by their microstructural constituents. Therefore, knowledge of the solder microconstituents' mechanical properties as a function of temperature is required. Sn-Ag-Cu lead-free solder alloy contains three phases: a Sn-rich phase, and the intermetallic compounds (IMCs) Cu6Sn5 and Ag3Sn. Typically, the Sn-rich phase is surrounded by a eutectic mixture of β-Sn, Cu6Sn5, and Ag3Sn. In this paper, we report on the Young's modulus and hardness of the Cu6Sn5 and Cu3Sn IMCs, the β-Sn phase, and the eutectic compound, as measured by nanoindentation at elevated temperatures. For both the β-Sn phase and the eutectic compound, the hardness and Young's modulus exhibited strong temperature dependence. In the case of the intermetallics, this temperature dependence is observed for Cu6Sn5, but the mechanical properties of Cu3Sn are more stable up to 200°C.

  20. Adsorption of Ag, Cu and Hg from aqueous solutions using expanded perlite.

    Science.gov (United States)

    Ghassabzadeh, Hamid; Mohadespour, Ahmad; Torab-Mostaedi, Meisam; Zaheri, Parisa; Maragheh, Mohammad Ghannadi; Taheri, Hossein

    2010-05-15

    The aim of the present work was to investigate the ability of expanded perlite (EP) to remove of silver, copper and mercury ions from aqueous solutions. Batch adsorption experiments were carried out and the effect of pH, adsorbent dosage, contact time and temperature of solution on the removal process has been investigated. The optimum pH for the adsorption was found to be 6.5. Adsorption of these metal ions reached their equilibrium concentration in 120, 240 and 180 min for Ag (I), Cu (II) and Hg (II) ions, respectively. Experimental data were also evaluated in terms of kinetic characteristics of adsorption and it was found that adsorption process for these metal ions followed well pseudo-second-order kinetics. Using Langmuir isotherm model, maximum adsorption capacity of EP was found to be 8.46, 1.95 and 0.35 mg/g for Ag (I), Cu (II) and Hg (II) ions, respectively. Finally, the thermodynamic parameters including, the change of free energy (DeltaG degrees ), enthalpy (DeltaH degrees ) and entropy (DeltaS degrees ) of adsorption were calculated for each metal ion. The results showed that the adsorption of these metal ions on EP was feasible and exothermic at 20-50 degrees C.

  1. Electrochemical depositions of fluorohydroxyapatite doped by Cu2+, Zn2+, Ag+ on stainless steel substrates

    Science.gov (United States)

    Bir, F.; Khireddine, H.; Touati, A.; Sidane, D.; Yala, S.; Oudadesse, H.

    2012-07-01

    Fluoridated hydroxyapatite (FHA, Ca10(PO4)6(OH)2-xFx where 0 < x < 2 is the degree of fluoridation) and inorganic ions (Zn2+, Cu2+, Ag+) substituted fluoridated hydroxyapatite coatings (M-FHA) were deposited on the surface of medical grade 316L stainless steel samples by electrochemical deposition technique. The FHA coatings were co-substituted with antibacterial ions (Zn2+, Cu2+ or Ag+) by co-precipitation and ion-exchange methods. Characterization studies of coatings from X-ray diffraction (XRD), Scanning electron microscopy (SEM) and Energy dispersive X-ray spectroscopy (EDX) showed that the obtained layers are monophase crystals FHA and did not contain any discernible crystalline impurity. The particles of all samples are of nano size that gives thin layers. The surface morphology, microstructure and Ca/P atomic ratio of the FHA coatings can be regulated by varying electrolyte temperature. This later affects the porosity of the coating surface and the chemical compositions of the deposits. Quantitative elemental analysis indicates that the copper, zinc and silver ions are incorporated into the Fluorohydroxyapatite. The antimicrobial effects of doped fluorohydroxyapatite coatings against pathogen bacterial strains Staphylococcus aureus were tested in liquid media. The results are promising and demonstrated that all doped FHA samples exhibit excellent antimicrobial activity "in vitro" against the microorganism, so the antimicrobial properties of the coatings developed are improved.

  2. The Role of Pd in Sn-Ag-Cu Solder Interconnect Mechanical Shock Performance

    Science.gov (United States)

    Lee, Tae-Kyu; Zhou, Bite; Bieler, Thomas R.; Tseng, Chien-Fu; Duh, Jeng-Gong

    2013-02-01

    The mechanical stability of solder joints with Pd added to Sn-Ag-Cu alloy with different aging conditions was investigated in a high- G level shock environment. A test vehicle with three different strain and shock level conditions in one board was used to identify the joint stability and failure modes. The results revealed that Pd provided stability at the package-side interface with an overall shock performance improvement of over 65% compared with the Sn-Ag-Cu alloy without Pd. A dependency on the pad structure was also identified. However, the strengthening mechanism was only observed in the non-solder mask defined (NSMD) pad design, whereas the solder mask defined (SMD) pad design boards showed no improvement in shock performance with Pd-added solders. The effects of Sn grain orientation on shock performance, interconnect stability, and crack propagation path with and without Pd are discussed. The SAC305 + Pd solder joints showed more grain refinements, recrystallization, and especially mechanical twin deformation during the shock test, which provides a partial explanation for the ability of SAC305 + Pd to absorb more shock-induced energy through active deformation compared with SAC305.

  3. Nucleation promotion of Sn-Ag-Cu lead-free solder alloys via micro alloying

    Science.gov (United States)

    Mao, Jie

    Sn-Ag-Cu (SAC) alloy system is widely accepted as a viable Pb-free alternative to Sn-Pb alloys for microelectronics packaging applications. Compared with its Pb-containing predecessor SAC alloys tend to have coarse grain structure, which is believed to be caused by high undercooling prior to nucleation. This work explores the possibility of modifying the nucleation process and reducing the undercooling of SAC alloys via introducing minor alloying elements. The mechanisms through which effective alloying elements influenced the nucleation process of SAC alloys are investigated with microstructural and chemical analyses. Minor alloying elements (Mn and Zn) are found promoting beta-Sn nucleation and reducing the undercooling of SAC. Manganese promotes beta-Sn primary phase nucleation through the formation of MnSn2 intermetallic compound. Experimental results in this work support the claim by previous researchers that zinc promotes beta-Sn primary phase nucleation through the formation of zinc oxide. In addition to nucleation, this work also assesses the microstructural impact of minor elements on Sn-Ag-Cu based alloys. Methods have been developed to quantify and compare microstructural impacts of minor elements and efficiently study their partitioning behaviors. LA-ICPMS was introduced to SAC alloy application to efficiently study partitioning behaviors of minor elements.

  4. Atomic structure of water/Au, Ag, Cu and Pt atomic junctions.

    Science.gov (United States)

    Li, Yu; Kaneko, Satoshi; Fujii, Shintaro; Nishino, Tomoaki; Kiguchi, Manabu

    2017-02-08

    Much progress has been made in understanding the transport properties of atomic-scale conductors. We prepared atomic-scale metal contacts of Cu, Ag, Au and Pt using a mechanically controllable break junction method at 10 K in a cryogenic vacuum. Water molecules were exposed to the metal atomic contacts and the effect of molecular adsorption was investigated by electronic conductance measurements. Statistical analysis of the electronic conductance showed that the water molecule(s) interacted with the surface of the inert Au contact and the reactive Cu ant Pt contacts, where molecular adsorption decreased the electronic conductance. A clear conductance signature of water adsorption was not apparent at the Ag contact. Detailed analysis of the conductance behaviour during a contact-stretching process indicated that metal atomic wires were formed for the Au and Pt contacts. The formation of an Au atomic wire consisting of low coordination number atoms leads to increased reactivity of the inert Au surface towards the adsorption of water.

  5. 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.

  6. Synthesis, crystal structure and charge-distribution validation of β-Na4Cu(MoO43 adopting the alluadite structure-type

    Directory of Open Access Journals (Sweden)

    Wassim Dridi

    2016-08-01

    Full Text Available Single crystals of a new variety of tetrasodium copper(II tris[molybdate(VI], Na4Cu(MoO43, have been synthesized by solid-state reactions and characterized by single-crystal X-ray diffraction. This alluaudite structure-type is characterized by the presence of infinite layers of composition (Cu/Na2Mo3O14 parallel to the (100 plane, which are linked by MoO4 tetrahedra, forming a three-dimensional framework containing two types of hexagonal channels in which Na+ cations reside. The Cu2+ and Na2+ cations are located at the same general site with occupancies of 0.5. All atoms are on general positions except for one Mo, two Na (site symmetry 2 and another Na (site symmetry -1 atom. One O atom is split into two separate positions with occupancies of 0.5. The title compound is isotypic with Na5Sc(MoO44 and Na3In2As3O12. The structure model is supported by bond-valence-sum (BVS and charge-distribution CHARDI methods. β-Na4Cu(MoO43 is compared and discussed with the K4Cu(MoO43 and α-Na4Cu(MoO43 structures.

  7. Trigonal prismatic Cu(I) and Ag(I) pyrazolato nanocage hosts: encapsulation of S8 and hydrocarbon guests.

    Science.gov (United States)

    Duan, Peng-Cheng; Wang, Zhao-Yang; Chen, Jing-Huo; Yang, Guang; Raptis, Raphael G

    2013-11-14

    Two neutral hexanuclear trigonal prismatic cage molecules have been synthesized by coupling two planar triangular M3pz3-panels, M = Cu(I) and Ag(I), in eclipsed geometry. The ~230 Å(3) cage volume can be either vacant or occupied by neutral guests. The crystal structures of the M6-cyclohexane and Ag6-S8 host-guest species have been determined.

  8. Vacancy-solute interactions during multiple-step ageing of an Al-Cu-Mg-Ag alloy

    Energy Technology Data Exchange (ETDEWEB)

    Ferragut, R. [L-NESS, Dipartimento di Fisica, Politecnico di Milano, Anzani 42, I-22100 Como (Italy)], E-mail: rafael.ferragut@polimi.it; Dupasquier, A. [L-NESS, Dipartimento di Fisica, Politecnico di Milano, Anzani 42, I-22100 Como (Italy); Macchi, C.E. [IFIMAT, UNCentro and CONICET, Pinto 399, B7000GHG Tandil (Argentina); Somoza, A. [IFIMAT, UNCentro and CICPBA, Pinto 399, B7000GHG Tandil (Argentina); Lumley, R.N. [CSIRO Light Metals Flagship, Locked Bag 33, Clayton South, MDC, Vic. 3169 (Australia); Polmear, I.J. [Department of Materials Engineering, Monash University, Melbourne, Vic. 3800 (Australia)

    2009-02-15

    Small additions of Ag and Mg stimulate nucleation of the {omega} phase in artificially aged Al-Cu alloys, after which these elements segregate to the {omega}/matrix interfaces. In this work, positron spectroscopy results show that vacancies accompany the Ag (and Mg) atoms at the interface during precipitate formation, after which they are released back into the matrix and facilitate secondary ageing at ambient temperature.

  9. Effect of adding Ce on interfacial reactions between Sn-3.0Ag-0.5Cu solder and Cu substrate

    Institute of Scientific and Technical Information of China (English)

    LU Bin; LI Hui; WANG Juan-hui; ZHU Hua-wei; JIAO Xian-he

    2008-01-01

    The formation and the growth of Cu-Sn intermetallic compound (IMC) layer at the interface between Sn-3.0Ag-0.5Cu-xCe solder and Cu substrate during soldering and aging were studied. The results show that Cu6Sn5 IMC is observed at the interface between solder and Cu substrate in all conditions. After aging for 120h, the Cu3Sn IMC is then obtained. With increasing aging time, the scalloped Cu6Sn5 structure changes to a plate structure. The Cu3Sn film always forms with a relatively planar interface. By adding a small amount of the rare earth element Ce (only 0.1%, mass fraction) into the Sn-3.0Ago0.5Cu solder alloy, the growth rate of the Cu-Sn IMC at the interface of solder alloy system is decreased. When the time exponent is approximately 0.5, the growth of the IMC layer is mainly controlled by a diffusion over the studied time range.

  10. Processing and fabrication of YBa2Cu3O(x)/Ag composite wires and coils

    Science.gov (United States)

    Ferrando, W. A.; Divecha, A. P.; Mansour, A. N.; Karmarkar, S. D.; Balachandran, U.; Dorris, S. E.; Dusek, J. T.; Picciolo, J. J.; Singh, J. P.; Poeppel, R. B.

    1990-11-01

    Silver was added to YBa2Cu3O(x) (123) powder by a melt technique using AgNO3 and heated to approx. 600 C to decompose the nitrate. This process yields 123 powder that is uniformly coated with Ag, as indicated by optical and scanning electron microscopy (SEM). The composite power is formed into rods (approx. 4 mm diameter) via drawing and swaging through conical converging dies. Wires of finer diameter (approx. 1 mm) and substantially greater linear uniformity were produced by slurry extrusion of the composite powder in a polymeric vehicle. Transport critical current density, J sub c, of these wires at present is about 750 A/sq cm. This value may be expected to rise due to further reduction of second phase impurities localized at grain boundaries and better understanding of the Ag/superconductor interface. The wire fabrication is described in some detail and discusses the results of microscopic analyses by scanning electron microscopy (SEM), x ray photoemission spectroscopy (XPS), and x ray diffraction (XRD).

  11. Equivalent Activity Coefficient Phenomenon of Cerium Reacting with Lead or Bismuth in Ag, Cu and Zn Alloy

    Institute of Scientific and Technical Information of China (English)

    薛松柏; 钱乙余; 董健

    2002-01-01

    The relation between contents of cerium and impurity lead or bismuth to their activity coefficient in Ag, Cu and Zn-base alloy was calculated and analyzed by using the ternary system Chou model. The thermodynamic calculation results show that the "equivalent activity coefficient phenomenon" emerges among the activity coefficient of solute in a certain range of cerium (or at a certain point) for the Ce-Pb-X and Ce-Bi-X (X=Ag, Cu or Zn) ternary alloy system. Under this condition, the activity coefficient of solute has nothing to do with its own concentration. The preliminary theoretical analysis to this phenomenon was also made.

  12. The effect of immersion time in a benzotriazole solution on anodic behaviour of AgCu50 alloy

    OpenAIRE

    Grekulović, Vesna; Rajčić-Vujasinović, Mirjana; Stević, Zoran; id_orcid 0000-0002-1867-9360

    2016-01-01

    Electrochemical behavior of silver ,copper and AgCu50 alloy after their immersion in 0.01 mol/dm3 benzotriazole solution for 30, 360, 720 i 1440 minutes, was investigated in 0.1 mol/dm3 NaOH using the cyclic voltammetry method. Currents on cyclic voltammograms for both, pure silver, pure copper and AgCu50 alloy recorded after imemersion in the benzotriazole solution are lower than the corresponding currents obtained without the contact of the metals with BTA. During the immersion of electrode...

  13. Comparison of Extensive Thermal Cycling Effects on Microstructure Development in Micro-alloyed Sn-Ag-Cu Solder Joints

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Iver E.; Boesenberg, Adam; Harringa, Joel; Riegner, David; Steinmetz, Andrew; Hillman, David

    2011-09-28

    Pb-free solder alloys based on the Sn-Ag-Cu (SAC) ternary eutectic have promise for widespread adoption across assembly conditions and operating environments, but enhanced microstructural control is needed. Micro-alloying with elements such as Zn was demonstrated for promoting a preferred solidification path and joint microstructure earlier in simple (Cu/Cu) solder joints studies for different cooling rates. This beneficial behavior now has been verified in reworked ball grid array (BGA) joints, using dissimilar SAC305 (Sn-3.0Ag-0.5Cu, wt.%) solder paste. After industrial assembly, BGA components joined with Sn-3.5Ag-0.74Cu-0.21Zn solder were tested in thermal cycling (-55 C/+125 C) along with baseline SAC305 BGA joints beyond 3000 cycles with continuous failure monitoring. Weibull analysis of the results demonstrated that BGA components joined with SAC + Zn/SAC305 have less joint integrity than SAC305 joints, but their lifetime is sufficient for severe applications in consumer, defense, and avionics electronic product field environments. Failure analysis of the BGA joints revealed that cracking did not deviate from the typical top area (BGA component side) of each joint, in spite of different Ag3Sn blade content. Thus, SAC + Zn solder has not shown any advantage over SAC305 solder in these thermal cycling trials, but other characteristics of SAC + Zn solder may make it more attractive for use across the full range of harsh conditions of avionics or defense applications.

  14. Cu含量对Ag-Cu钎料钎焊透氧膜界面结构的影响%Effect of Cu Content on Interface Microstructures of Oxygen-Permeable Membrane Brazed with Ag-Cu Brazing Filler

    Institute of Scientific and Technical Information of China (English)

    王方; 张玉文; 丁伟中; 鲁雄刚

    2011-01-01

    采用Ag-Cu钎料用于透氧膜与不锈钢支撑体之间的封接,研究了Cu含量对Ag-Cu钎料钎焊透氧膜界面结构的影响.利用SEM对连接界面的显微组织进行观察,并用EDS对界面的相组成进行分析.结果表明:纯Ag与透氧膜陶瓷之间的连接界面无元素互扩散;Ag中少量1 at%Cu的添加并未明显改善钎焊连接界面:当Cu含量增加到3.3 at%时,在透氧膜一侧生成一层由Cu和Ag扩散所致的厚度约200 μm的反应层,反应层的生成表明Ag-3.3Cu钎料与透氧膜之间具有良好的润湿性和界面结合.%Ag-Cu brazing filler were adopted to seal oxygen-permeable membrane ceramics and stainless steel support, and the effect of Cu content on interface microstructure of oxygen-permeable membrane brazed with Ag-Cu brazing filler was investigated. The microstructure of the interface was observed by SEM and the constituent phases were analyzed by EDS. The results show that no elemental interdiffusion occurs in the interface of pure Ag and oxygen-permeable membrane; the addition of 1 at%Cu doesn't improve the bonding of the interface obviously; when the Cu content reaches 3.3 at%, a reaction layer of about 200μrn in thickness forms on the membrane side due to the diffusion of Cu and Ag, which indicates the good wetting ability and interface bonding between Ag-3.3Cu brazing filler and oxygen-permeable membrane.

  15. Enhancement of broad-band light absorption in monolayer MoS2 using Ag grating hybrid with distributed Bragg reflector

    Science.gov (United States)

    Cao, Jintao; Wang, Jin; Yang, Guofeng; Lu, Yann; Sun, Rui; Yan, Pengfei; Gao, Shumei

    2017-10-01

    A hybrid novel structure of monolayer MoS2 with Ag nanograting and DBR on Si substrate has been proposed to obtain broad-band absorption response for two-dimensional (2D) materials. It is effective to reduce light loss and reflect the incident light efficiently for monolayer MoS2 absorption with DBR dielectric layers. Moreover, by combining Ag nanograting with DBR structure, the average absorption achieves as high as 59% within broad wavelength ranging from 420 to 700 nm, which is attributed to the plasmonic resonant effect of metal nanostripes. The absorption would be affected by the duty ratio and period of the Ag nanograting, and shows incident angle dependent characteristics, while an average absorption higher than 60% has been obtained at the incident angle around 40°. These results indicate that 2D MoS2 in combination with DBR and metal nanograting have a promising potential applications for optical nano-devices.

  16. Microstructural evolution during aging of an Al-Cu-Li-Ag-Mg-Zr alloy

    Science.gov (United States)

    Kumar, K. S.; Brown, S. A.; Pickens, Joseph R.

    1991-01-01

    Alloys in the Al-Cu-Li Ag-Mg subsystem were developed that exhibit desirable combinations of strength and ductility. These Weldalite (trademark) alloys, are unique for Al-Cu-Li alloys in that with or without a prior cold stretching operation, they obtain excellent strength-ductility combinations upon natural and artificial aging. This is significant because it enables complex, near-net shape products such as forgings and super plastically formed parts to be heat treated to ultra-high strengths. On the other hand, commercial extrusions, rolled plates and sheets of other Al-Cu-Li alloys are typically subjected to a cold stretching operation before artificial aging to the highest strength tempers to introduce dislocations that provide low-energy nucleation sites for strengthening precipitates such as the T(sub 1) phase. The variation in yield strength (YS) with Li content in the near-peak aged condition for these Weldalite (trademark) alloys and the associated microstructures were examined, and the results are discussed.

  17. Vibrational states on vicinal surfaces of Al, Ag, Cu and Pd

    Science.gov (United States)

    Sklyadneva, I. Yu.; Rusina, G. G.; Chulkov, E. V.

    1998-10-01

    We present the calculation of vibrational modes and lattice relaxation for the (110), (211), (311), (511), (331) and (221) surfaces of Al, Ag, Cu and Pd. The surface phonon frequencies and polarizations are obtained for relaxed and unrelaxed surfaces using embedded atom model potentials. On all surfaces studied step-localized vibrational modes and surface states localized on terrace atoms are found. It is shown that as the terrace width increases so does the number of surface phonons. It is found that interlayer relaxation leads to a shift in the frequencies of the surface states and to a change in the number and localization. In particular, it may cause the appearance or disappearance of step modes. It is shown that the character of relaxation on vicinal surfaces is determined by the number of atoms on a terrace. A comparison of the results with the available experimental data for the Al(221), Cu(211), and Cu(511) surfaces indicates that there is a good agreement with the experimental data.

  18. Corrosion behavior of Cu-Ni-Ag-Al alloy anodes in aluminium electrolysis

    Institute of Scientific and Technical Information of China (English)

    徐君莉; 石忠宁; 邱竹贤

    2004-01-01

    The behavior of Cu-Ni-Ag-Al alloy used as anode for aluminum electrolysis was directly visualized in a two-compartment see-through cell during electrolysis, and its performances were tested at 850℃ in acidic electrolyte molten salts consisting of 39.3 % NaF-43.7 % AlF3-8 % NaCl-5 % CAF2-4 % Al2 O3 for 40 h in a laboratory cell. The results show that nascent oxygen oxidizes the anodic surface to form oxide film at the beginning of electrolysis. X-ray diffraction analysis of alloy surface show that the oxide film on the anodic surface consists of CuO, NiO, Al2O3,CuAl2 O4 and NiAl2 O4. However, SEM image shows the oxide film is porous, loose and easy to fall into electrolyte and to contaminate aluminum. The corrosion mechanism of metal anodes was analyzed.

  19. Cu-Fe-MoS2复合材料的摩擦学特性研究%Research on Tribological Properties of Cu-Fe-MoS2 Composites

    Institute of Scientific and Technical Information of China (English)

    付传起; 王宙

    2011-01-01

    通过基体组元合金化和添加不同含量的MoS2,采用感应热压烧结的方法制备了具有良好高温自润滑性能的Cu-Fe-MoS2 复合材料.通过力学性能试验和摩擦磨损试验,考察了从室温到800℃条件下复合材料的力学和摩擦学性能.利用XRD,EDS和SEM分析了复合材料的相组成和表面形貌,探讨了复合材料的磨损机理.试验结果表明:感应加热频率和MoS2含量对复合材料的力学和摩擦性能具有一定的影响,当感应加热频率为35Hz和MoS2 质量分数(含量)为4 %时.复合材料具有良好的力学和摩擦学性能.%Cu-Fe-MoS2 composites with various amounts of MoS2 additives were prepared by induction heating sintering method combined with the alloying of the Cu-Fe matrix with various metallic elements. As the temperature was increased from room temperature to 800 ℃, the mechanical and tribological properties of the composites were measured using the universal test and MRH-3 friction-wear test. The phase compositions and worn surface morphologies of the composites were analyzed by means of X-ray diffraction (XRD) and scanning electron microscopy (SEM). Meanwhile, wear mechanisms were discussed. Experimental results show that there are some effects on mechanical and frictional properties of composite between induction frequency and content of MoS2. Meanwhile, composite possess excellent mechanical and frictional properties with induction frequency of 35 Hz and MoS2 of 4%.

  20. [Quantitative surface analysis of Pt-Co, Cu-Au and Cu-Ag alloy films by XPS and AES].

    Science.gov (United States)

    Li, Lian-Zhong; Zhuo, Shang-Jun; Shen, Ru-Xiang; Qian, Rong; Gao, Jie

    2013-11-01

    In order to improve the quantitative analysis accuracy of AES, We associated XPS with AES and studied the method to reduce the error of AES quantitative analysis, selected Pt-Co, Cu-Au and Cu-Ag binary alloy thin-films as the samples, used XPS to correct AES quantitative analysis results by changing the auger sensitivity factors to make their quantitative analysis results more similar. Then we verified the accuracy of the quantitative analysis of AES when using the revised sensitivity factors by other samples with different composition ratio, and the results showed that the corrected relative sensitivity factors can reduce the error in quantitative analysis of AES to less than 10%. Peak defining is difficult in the form of the integral spectrum of AES analysis since choosing the starting point and ending point when determining the characteristic auger peak intensity area with great uncertainty, and to make analysis easier, we also processed data in the form of the differential spectrum, made quantitative analysis on the basis of peak to peak height instead of peak area, corrected the relative sensitivity factors, and verified the accuracy of quantitative analysis by the other samples with different composition ratio. The result showed that the analytical error in quantitative analysis of AES reduced to less than 9%. It showed that the accuracy of AES quantitative analysis can be highly improved by the way of associating XPS with AES to correct the auger sensitivity factors since the matrix effects are taken into account. Good consistency was presented, proving the feasibility of this method.

  1. Evolution of a high local strain in rolling up MoS2 sheets decorated with Ag and Au nanoparticles for surface-enhanced Raman scattering

    Science.gov (United States)

    Hwang, Da Young; Hack Suh, Dong

    2017-01-01

    We report that a high local strain was obtained for multilayer MoS2 nanoscrolls decorated with noble nanoparticles (Ag and Au NPs) using a rolling process beyond breaking or slipping of MoS2. The local strain was estimated through the bending strain in the nanoscrolls and the extent of coverage of Ag and Au NPs decorated on MoS2, exhibiting magnified surface-enhanced Raman scattering. TEM images showed that the MoS2-Ag and MoS2-Au nanoscrolls have a tube-like morphology decorated with NPs on the inner and outer sides of the MoS2 nanoscrolls. In the Raman spectra, we confirmed the red shift and broadness of the FWHM for nanoscrolls in the eigenvectors of the {{{E}}}{2{{g}}+}1 and {{{E}}}{2g+}1 modes. From the Grüneisen parameter γ and the shear deformation potential β, we obtained peak shifts of ˜4.9 cm-1/% at {{{E}}}{2g-}1 and ˜1.1 cm-1/% strain at {{{E}}}{2g+}1 for free-standing MoS2. According to the obtained relationship of the Raman shift and the induced uniaxial tensile strain, the {{{E}}}{2g-}1 and {{{E}}}{2g+}1 peaks shifted upwards to around -12.8 cm-1 and -2.9 cm-1, respectively, and can be converted to an induced uniaxial tensile strain of about 2.6% for MoS2-Ag nanoscrolls.

  2. Hierarchical Fe3O4@MoS2/Ag3PO4 magnetic nanocomposites: Enhanced and stable photocatalytic performance for water purification under visible light irradiation

    Science.gov (United States)

    Guo, Na; Li, Haiyan; Xu, Xingjian; Yu, Hongwen

    2016-12-01

    Novel hierarchical Fe3O4@MoS2/Ag3PO4 magnetic nanophotocatalyst with remarkable photocatalytic capability were prepared by simply depositing the Ag3PO4 onto the surface of crumpled Fe3O4@MoS2 nanosphere. The nanocomposites were characterized by XRD, TEM, HRTEM, XPS, BET, and UV-vis DRS. The outcome of the photocatalytic experiments demonstrated that Fe3O4@MoS2/Ag3PO4 with 6 wt% content of Ag3PO4 (FM/A-6%) showed the highest photocatalytic activity upon the degradation Congo red (CR) and Rhodamine B (RhB) under both visible light and simulated sunlight irradiation. In addition, FM/A-6% possessed larger specific surface area (76.56 m2/g) and excellent optical property. The possible Z-scheme charge carriers transfer mechanism for the enhanced photocatalytic properties of the FM/A-6% was also discussed. The Z-scheme charge carriers transfer mechanism established between MoS2 and Ag3PO4 facilitate the charge separation efficiency. Moreover, FM/A-6% can be separated and collected easily by external magnetic field and maintain high activity after five times photoreaction cycles. Given the remarkable photocatalytic performance and high stability of FM/A-6% nanocomposite, it is looking forward to exhibit great potential for applications in water purification.

  3. Cube-like Cu2MoS4 photocatalysts for visible light-driven degradation of methyl orange

    Directory of Open Access Journals (Sweden)

    Ke Zhang

    2015-07-01

    Full Text Available Cube-like Cu2MoS4 nanoparticles with low-index facets and high crystallinity were fabricated via a hydrothermal method. The as-obtained nanocubes with an average size of 40-60 nm are composed of stacking-Cu2MoS4 layers separated by a weak Van der Waals gap of 0.5 nm. A strong absorption at visible light region is observed in the nanocube aqueous solution, indicating its optical-band gap of 1.78 eV. The photocatalytic measurements reveal that the nanocubes can thoroughly induce the degradation of methyl orange under visible light irradiation with good structural stability. Our finding may provide a way in design and fabrication of transition metal dichalcogenide nanostructures for practical applications.

  4. Bi对Sn-0.3Ag-0.7Cu-xBi/Ni焊点IMC的影响%Influence of Bi on IMC of Sn-0.3Ag-0.7Cu-xBi/Ni Solder

    Institute of Scientific and Technical Information of China (English)

    权延慧; 李锋

    2011-01-01

    无铅钎料和基板间金属间化合物(1MC)的生长对元器件的可靠性有重要影响.使用Sn-0.3Ag-0.7Cu-xBi无铅钎料与Ni盘进行焊接,并对焊点进行了180℃时效试验,时效时间分别为O、24、96、216和384h.采用金相显微镜、扫描电镜和能谱仪观察分析了钎料与Ni界面IMC的生长及形貌变化,并对其焊点IMC层Ni的分布进行了分析,同时对其界面生长速率进行了拟合.结果表明:Sn-0.3Ag-0.7Cu焊料与Ni焊盘之间的IMC是棒状的(CuxNi1-x)6Sn5,Bi的加入并没有起到很好的抑制作用,而是随着Bi含量的增加IMC先增加后减少.Sn-O.3Ag-0.7Cu/Ni焊点IMC中Ni的平均含量(wN)分为15%、5%两区域.由近Ni向钎料基体方向呈下降趋势.但是Sn-O.3Ag-0.7Cu-3.0Bi/Ni焊点IMC中Ni的平均含量在7%左右.时效后IMC层的厚度会随着老化时间的延长而增加,但是Sn-0.3Ag-0.7Cu-xBi/Ni焊点由于Bi的析出IMC增长得缓慢;Sn-0.3Ag-0.7Cu/Ni焊点(CuxNi1-x)6Sn5中15%Ni的含量区域逐渐过渡到5%区域,但是Sn-0.3Ag-0.7Cu-xBi/Ni焊点IMC中Ni的平均含量维持9%较时效前有所增加.通过生长速率计算,Sn-O.3Ag-0.7Cu-xBi/Ni焊点IMC的生长速率随着Bi含量的增加而减少.%The growth of intermetallic compounds (IMC) between lead-free solder and pad has an important influence on the reliability of primary device. Ni substrate was welded by Sn-0.3Ag-0.7Cu-xBi lead-free solder, and the joints were aging-treated at 180C, aging time was 0, 24, 95, 216 and 384 h respectively, The growth and morphology characteristics of the IMCs were investigated by metallographic microscope, SEM and EDX. The content change of Ni in the IMC was also analysed, meanwhile, the IMC growth rates were fitted by experimental data. The results show that the IMC between Sn-0.3Ag-0.7Cu-xBi and Ni substrate is (CuxNi1-x)6Sn5- The effect of controlling the thickness of IMC is not very good after the addition of Bi, with the increase of Bi content, the thickness of IMC

  5. Calibrations of MoNA-LISA VANDLE 56Ni(d,n)57Cu Experiment

    Science.gov (United States)

    Ikeyama, R.; Cizewski, J. A.; Peters, W. A.; Bergstrom, Z. J.; Paulauskas, S. V.; Deyoung, P. A.; Hinnefeld, J.; Rogers, W.; Baumann, T.; Jones, M.; Smith, J. K.; Lesher, S. R.; Ribens Collaboration; Vandle Collaboration; Mona Collaboration

    2013-10-01

    A (d,n) proton transfer experiment, in inverse kinematics, was conducted at the National Superconducting Cyclotron Laboratory using a 35 MeV/nucleon beam of 56Ni. This experiment used both the Versatile Array of Neutron Detectors at Low Energy (VANDLE) at back angles to detect neutrons with less than 20 MeV and the MoNA-LISA array at forward angles for higher energy neutrons and to cover a large angular range. The experiment attempts to measure the spectroscopic factors of the 57Cu resonance important in the rp -process, and determination of the reaction rate. Precise calibrations of all the detector subsystems are crucial for identifying the kinematic signature of the ejected neutrons and the extracting the spectroscopic factors to the different energy levels. Calibrations of the charged particle detectors and the neutron detector arrays are ongoing. Preliminary results pertaining to detector calibrations will be presented as well as details of the experimental setup. This work was supported in part by the U.S. DOE, the NNSA, and the NSF.

  6. Mechanical Property Stability of Cu-Mo-Ni Alloyed Austempered Ductile Iron

    Institute of Scientific and Technical Information of China (English)

    LIU Sheng-fa; WANG Zhong-fan

    2005-01-01

    The aim of present work is to investigate the influencing factors on mechanical property stability of Cu-Mo-Ni alloyed austempered ductile iron (ADI). The results show that after austenitized at 900 ℃ for 2 h followed by austempered at 370 ℃ for another 2 h, the mechanical property of the alloyed ADI can reach the Germanite GGG-100 standard, i.e.σb≮1 000 MPa, δ≮5%, at 95% confidence level. And the satisfactory mechanical properties were obtained when the alloyed ADI was austenitized at 850 ℃ to 1 000 ℃ for 1-4 h, and austempered at 355 ℃ to 400 ℃ for another 1 h to 4 h. The microstructures, including nodule number, white bright zone content (martensite-containing interdendritic segregation zone) and retained austenite content, can significantly influence the mechanical properties of the ADI. In order to obtain the good combinations of strength and ductility, the volume fraction of white bright zone should be less than 5%, and the retained austenite contents maintain between 30 % and 40 %. The application of inoculation techniques to increase graphite nodule number can effectively reduce the white bright zone content in the structure.

  7. Microstructural and mechanical characteristics of low alloyed Ni-Mo-Cu austempered ductile iron

    Energy Technology Data Exchange (ETDEWEB)

    Bosnjak, B.

    2000-12-01

    The present study investigated the effect of austempering temperature and austempering time on the microstructure and mechanical properties of low alloyed Ni-Mo-Cu ductile iron. The effect of austempering parameters and alloying additions on the austemperability of treated ductile iron has been estimated, too. Specimens were austenitised at 900 degree C for 120 mm, then austempered for 10, 30, 60, 120, 240 and 360 mm at 300, 350 and 400 degree C respectively, and examined by light and scanning electron microscopy. The structure consisted of bainitic ferrite containing retained austenite. the amount of which increased, and the carbon content of which decreased, with increasing austempering temperature. The carbon content of austenite has been evaluated by measuring the lattice parameter by X-ray diffraction. After short periods of austempering time in iron, the carbon content of the retained austenite decreases and on subsequent cooling to room temperature it transforms to martensite. The volume fractions of retained austenite, bainitic ferrite, martensite and austenite carbon content was correlated with microstructural changes and mechanical properties. Optimum properties are obtained at intermediate austempering periods (120-240 mm) when both the amount of retained austenite and austenite carbon content are maximum. (author)

  8. Microstructure and mechanical properties of CuNiMo austempered ductile iron

    Directory of Open Access Journals (Sweden)

    Erić Olivera

    2004-01-01

    Full Text Available Microstructure and mechanical properties of Cu, Ni and Mo alloyed cast ductile iron have been investigated after austempering. Samples were austenitised at 860oC for 1h and then austempered at 320oC and 400oC in the interval from 0,5 to 5h. The X-ray diffraction technique and the light microscopy were utilized to investigate the bainitic transformation, while tensile and impact tests were performed for characterization of mechanical properties. By austempering at 320oC in the range between 2 and 5h, a microstructure typical for austempered ductile iron was produced, i.e. a mixture of free bainitic ferrite and highly carbon enriched retained austenite. The characteristic of the whole range of austempering at 400oC is the appearance of martensitic structure. The maximum impact energy (133 J coincides with the maximum value of volume fraction of retained austenite that was obtained after 2,5h of austempering at 320oC. The appearance of martensite during austempering at 400oC is the main cause for much lower tensile properties than at 320oC.

  9. Geochronological framework of the early Paleozoic Bainaimiao Cu-Mo-Au deposit, NE China, and its tectonic implications

    Science.gov (United States)

    Zhou, Zhen-Hua; Mao, Jing-Wen; Ma, Xing-Hua; Che, He-Wei; Ou'yang, He-Gen; Gao, Xu

    2017-08-01

    The Bainaimiao Cu-Mo-Au deposit of NE China is an important ore deposit in the middle section of the northern margin of the North China Craton. The early Paleozoic Bainaimiao Group is the main ore-hosting rock. The mineralization at the deposit shows features of porphyry alteration and late-stage orogenesis and transformation. Zircon LA-ICP-MS U-Pb age data indicate that the ages of the Third and Fifth formations of the Bainaimiao Group are 492.7 ± 2.9 Ma (MSWD = 0.53) and 488.9 ± 3.1 Ma (MSWD = 0.92), respectively. The age of quartz diorite that intrudes the Bainaimiao Group is 459.3 ± 6.4 Ma (MSWD = 2.20). Molybdenite samples from massive Cu-Mo-bearing ores and quartz veins in the southern ore belt yield a Re-Os isochron age of 438.2 ± 2.7 Ma (MSWD = 0.16), which is consistent with the Re-Os isochron age of molybdenite in the northern ore belt, implying that the two ore belts belong to the same mineralization system. Muscovite from a post-magmatic Cu-Mo-bearing quartz-calcite vein yields an Ar-Ar isochron age of 422.5 ± 3.9 Ma (MSWD = 0.64) with an initial 40Ar/36Ar ratio of 286 ± 21. The well-defined plateau age of the muscovite is 422.4 ± 2.6 Ma (MSWD = 0.05), which represents the time of the post-magmatic orogenic transformation event. Based on our new age data and previous findings, we propose that the Bainaimiao Cu-Mo-Au deposit formed in an active continental margin setting and experienced four stages of ore mineralization: (1) a Late Cambrian-Middle Ordovician volcanic-sedimentary stage; (2) a Late Ordovician porphyry mineralization stage; (3) a Late Silurian regional metamorphism stage; and (4) an orogenic transformation stage. Subhedral and euhedral Paleoproterozoic (2402-1810 Ma) inherited zircons indicate that the Bainaimiao Group has a tectonic affinity with the North China Craton. The Central Asian Orogenic Belt, which is closely related to the complex closure of the Paleo-Asian Ocean, is favorable for prospecting for Paleozoic porphyry Cu-Mo

  10. Television as Textbook: "Cuéntame cómo pasó" in the Spanish (Literature) Classroom

    Science.gov (United States)

    Bartlett, Linda; Manyé, Lourdes

    2015-01-01

    The long-running Spanish television program "Cuéntame cómo pasó" represents not only a wildly successful series for Radio Televisión Española, but also an excellent example of the project of historical memory. Premiering in 2001 (but set, in the first season, in 1968), the story of the multigenerational Alcántara family forms a…

  11. Effect Of Heat Treatment Parameters On The Formation Of ADI Microstructure With Additions Of Ni, Cu, Mo

    Directory of Open Access Journals (Sweden)

    Mrzygłód B.

    2015-09-01

    Full Text Available Metallographic examinations and mechanical tests were carried out on the ductile iron with additions of Ni, Cu and Mo in as-cast state and after austempering. TTT and CCT diagrams were plotted. The heat treatment was performed in six different variants. Studies included qualitative assessment of the microstructure and testing of mechanical properties such as R0,2, Rm, A, Z, HRC, KC. An analysis of the obtained results was also presented.

  12. Stopping Power of Be, Al, Cu, Ag, Pt, and Au for 5-12-MeV Protons and Deuterons

    DEFF Research Database (Denmark)

    Andersen, H.H.; Hanke, C.; Sørensen, H.;

    1967-01-01

    Recent measurements on stopping power of aluminum have been continued with the stopping materials Be, Cu, Ag, Pt, and Au. The method of measuring stopping powers utilizing a thermometric compensation technique working at liquid-helium temperature has been used. Results are obtained with a standar...

  13. Stopping Power of Al, Cu, Ag, Au, Pb, and U for 5-18-MeV Protons and Deuterons

    DEFF Research Database (Denmark)

    Sørensen, H.; Andersen, Hans Henrik

    1973-01-01

    High energy protons and deuterons of energies between 9 and 18 MeV have been used to extend earlier measurements of the stopping power of Al, Cu, Ag and Au and the stopping powers of Pb and U in the range 5-18 MeV have been determined for the first time. Mean excitation potentials have been...

  14. Localized surface plasmon behavior of Ag-Cu alloy nanoparticles stabilized by rice-starch and gelatin

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Manish Kumar; Mandal, R. K., E-mail: rkmandal.met@itbhu.ac.in [Department of Metallurgical Engineering, IIT (BHU), Varanasi and DST Unit on Nanoscience and Technology, BHU, Varanasi-221 005 (India); Manda, Premkumar; Singh, A. K. [DefenceMetallurgical Research Laboratory, KanchanBagh, Hyderabad-500058 (India)

    2015-10-15

    The purpose of this communication was to understand localized surface plasmon behavior of a series of Ag-Cu alloy nanoparticles capped by rice-starch and gelatin. The structures of dried powders were investigated with the help of X-ray diffraction. The analysis revealed Ag-rich and Cu-rich phases with maximum solid solubility of Cu ∼9 atom per cent; 8 atom per cent and Ag ∼ 16 atom per cent; 14 atom per cent in rice-starch and gelatin capped samples respectively. Transmission electron microscope was used for knowing the particle size as well as to supplement FCC phase formations of Ag-rich and Cu-rich solid phases arrived at based on X-ray diffraction studies. The UV-Vis spectra of sols were examined for the formation and stability of alloy nanoparticles. The temporal evolution of LSPR curves gave us to assert that the sol is stable for more than two months. Small angle X-ray scattering in the sol state was extensively utilized to understand nature of suspensions in terms of fractals. Such a study is important for having a correlation between LSPR behaviors with those of nanoparticle dispersion in aqueous media. It is believed that this work will be a contribution to the emerging field of plasmonics that include applications in the area of photophysical processes and photochemical reactions.

  15. The Effects of Adding Elements of Zinc and Magnesium on Ag-Cu Eutectic Alloy for Warming Acupuncture

    Directory of Open Access Journals (Sweden)

    Yu Kyoung Kim

    2013-01-01

    Full Text Available The warming acupuncture for hyperthermia therapy is made of STS304. However, its needle point cannot be reached to a desirable temperature due to heat loss caused by low thermal conductivity, and the quantification of stimulation condition and the effective standard establishment of warming acupuncture are required as a heat source. Accordingly, in this study, after Ag-Cu alloys with different composition ratios were casted and then mixed with additives to improve their physical and mechanical properties, the thermal conductivity and biocompatibility of the alloy specimens were evaluated for selecting suitable material. Ag-Cu binary alloys and ternary alloys added 5 wt% Zn or 2 wt% Mg were casted and then cold drawn to manufacture needles for acupuncture, and their physical properties, thermal conductivity, and biocompatibility were evaluated for their potential use in warming acupuncture. The results of this study showed that the physical and mechanical properties of the Ag-Cu alloys were improved by additives and that the thermal conductivity, machinability, and biocompatibility of the Ag-Cu alloys were improved by Mg addition.

  16. Effect of cerium on microstructure and mechanical properties of Sn-Ag-Cu system lead-free solder alloys

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The melting point, spreading property, mechanical properties and microstructures of Sn-3.0Ag-2.8Cu solder alloys added with micro-variable-Ce were studied by means of optical microscopy, scanning electron microscopy(SEM) and energy dispersive X-ray(EDX). The results indicate that the melting point of Sn-3.0Ag-2.8Cu solder is enhanced by Ce addition; a small amount of Ce will remarkably prolong the creep-tupture life of Sn-3.0Ag-2.8Cu solder joint at room temperature, especially when the content of Ce is 0.1%, the creep-rupture life will be 9 times or more than that of the solder joint without Ce addition; the elongation of Sn-3.0Ag-2.gCu solder is also obviously improved even up to 15.7%. In sum, the optimum content of Ce is within 0.05%-0.1%.

  17. Energy Reflection Coefficients for 5-10 keV He Ions Incident on Au, Ag, and Cu

    DEFF Research Database (Denmark)

    Schou, Jørgen; Sørensen, H.; Littmark, U.

    1978-01-01

    The calorimetric deuterium-film method was used for measurements of the energy reflection coefficient γ for normal incidence of 5-10 keV He ions on Cu, Ag and Au. A theoretical calculation of γ by means of transport theory gives fair agreement with the experimental results. The experimental data ...

  18. Interfacial energy and match of cold pressure welded Ag/Ni and Al/Cu

    Institute of Scientific and Technical Information of China (English)

    李云涛; 杜则裕; 马成勇

    2002-01-01

    The technology of cold pressure welding was adopted to achieve the bonding of Al/Cu(limited soluble and forming compounds), Ag/Ni (hardly mutual soluble), and the relative state of interface was tested by HREM. The results indicate that stable interface is always corresponding to the low interfacial energy value; the stable interface is not coherent but partly-coherent because of the twisting of grain boundary caused by pressure, meanwhile existing dislocation. Namely, the interfacial match and other states under the condition of cold pressure welding are different from the situation that under the condition of thermal action. Moreover, theoretical analyses and calculation on the base of thermodynamics, crystallogeny, solid physics etc, were discussed.

  19. ANTIMICROBIAL ACTIVITY OF Ag+, Cu2+, Zn2+, Mg2+ IONS DOPED CHITOSAN NANOPARTICLES

    Directory of Open Access Journals (Sweden)

    Sukhodub LB

    2015-04-01

    Full Text Available Modification by polymers and inorganic ions of the bioactive materials for orthopedic implants with the purpose of initiating controlled reactions in tissues that surround the implant, is one of the modern approaches in medical materials. A key feature of functional polymers is their ability to form complexes with various metal ions in solution. Chitosan is natural biopolymer with pronounced affinity to transition metal ions. Some researches prove the higher antimicrobial activity of Chitosan-metal complexes compared with pure Chitosan. The purpose of this work was the study of antimicrobial activity of Chitosan nanoparticles modified by metal ions Ag+, Cu2+, Zn2+, Mg2+ against reference strains S. aureus 25923 ATSS, E. coli ATCC 25922, C. albicans ATCC 885653 for their further use as components of the composite biomaterials for medical purpose.Chitosan nanoparticles suspension was prepared by known method based on the ionotropic gelation between chitosan and sodium tripolyphosphate.To obtain Chitosan-metal nanoparticles to the Chitosan suspension were added the corresponding metal ions aqueous solutions in quantity to match the concentration of metal ions of 200 ppm . Antibacterial activities of Ag+, Cu2+, Zn2+, Mg2+ ions doped Chitosan nanoparticles, pure Chitosan nanoparticles, metal ions and 1% (v/v acetic acid solution (it was used as solvent for Chitosan against bacteria were evaluated by determination of minimum inhibitory concentration (MIC and minimum bactericidal concentration (MBC in vitro. Muller– Hinton (MH broth and MH agar (Russia were used as growth media. The bacteria suspension for further use was prepared with concentration that corresponded 0,5units by McFarland scale. The MIC was determined by a broth dilution method. The results were read after 24 hours of experimental tubes incubation at 37 oC as equivalent to the concentration of the tube without visible growth. To evaluate MBC, a sample of 0,1 ml was transferred from

  20. Development of a new Pb-free solder: Sn-Ag-Cu

    Energy Technology Data Exchange (ETDEWEB)

    Miller, C.M.

    1995-02-10

    With the ever increasing awareness of the toxicity of Pb, significant pressure has been put on the electronics industry to get the Pb out of solder. This work pertains to the development and characterization of an alloy which is Pb-free, yet retains the proven positive qualities of current Sn-Pb solders while enhancing the shortcomings of Sn-Pb solder. The solder studied is the Sn-4.7Ag-1.7Cu wt% alloy. By utilizing a variety of experimental techniques the alloy was characterized. The alloy has a melting temperature of 217{degrees}C and exhibits eutectic melting behavior. The solder was examined by subjecting to different annealing schedules and examining the microstructural stability. The effect of cooling rate on the microstructure of the solder was also examined. Overall, this solder alloy shows great promise as a viable alternative to Pb-bearing solders and, as such, an application for a patent has been filed.

  1. Structure and age of the Cerro de Pasco Cu-Zn-Pb-Ag deposit, Peru

    Science.gov (United States)

    Cheney, E. S.

    1991-04-01

    The world-famous Cu-Zn-Pb-Ag deposit at Cerro de Pasco, Peru, consists of texturally massive pyrite, texturally massive sphalerite-galena-pyrite, and veins containing pyrite and enargite. Historically the deposit has been considered to be the hydrothermal product of the adjacent Miocene volcanic and intrusive complex (locally known as the “Vent”). However, both the texturally massive sulfides of the deposit and the pre-Miocene strata are cut by the Longitudinal fault, one of the largest faults in the district, but the Vent is not. Imbrication by the Longitudinal fault zone (duplex structures) has thickened the deposit so that it is amenable to open-pit mining. Dikes and pyrite-enargite veins pass from the Vent into the massive sulfides; fragments of massive pyrite occur in the Vent. Thus, no matter what their origin, the texturally massive sulfides are older and, therefore, genetically unrelated to the Vent.

  2. Hydrogen mimicking the properties of coinage metal atoms in Cu and Ag monohydride clusters.

    Science.gov (United States)

    Vetter, Karsten; Proch, Sebastian; Ganteför, Gerd F; Behera, Swayamprabha; Jena, Puru

    2013-12-28

    A systematic study of the electronic structure and equilibrium geometries of Cun, Cun-1H, Agn, and Agn-1H; n = 2-5 clusters is carried out using photoelectron spectroscopy (PES) experiments and density functional theory based calculations. Our objective is to see if the substitution of a coinage metal atom by hydrogen would retain the electronic structure of the parent metal cluster since both systems are isoelectronic. For clusters with n ≥ 3, we find that the measured PES and vertical detachment energies (VDEs) (i.e. energies necessary to remove an electron from the anionic Mn(-) (M = Cu, Ag) clusters without changing their geometries) are close to those of Mn-1H(-) clusters, suggesting that substitution of a metal atom with hydrogen does not perturb the electronic structure of the parent cluster anion significantly. Calculated VDEs agree very well with experiment validating the theoretical methods used as well as the geometries of the neutral and anionic clusters.

  3. Effect of thin Mo2C layer on thermal stability of Si/SiO2/Ti/Cu system

    Indian Academy of Sciences (India)

    C C Tripathi; Mukesh Kumar; Dinesh Kumar

    2011-12-01

    The effect of introducing a thin Mo2C (30 nm) layer between Ti and Cu on the thermal stability of Si/SiO2/Ti/Cu system was studied using four-point probe (FPP), scanning electron microscopy (SEM), energydispersive X-ray spectroscopy (EDAX) and X-ray diffraction (XRD) techniques. The measured value of the sheet resistance in the bi-layered diffusion barrier structure does not show any change up to an annealing temperature of 750°C. The sheet resistance when measured after annealing at 800°C marginally increases but less than twice its value at room temperature. The XRD analysis indicated no copper diffusion and the formation of Cu3Si phase up to 800°C. The bi-layered barrier structure annealed at elevated temperature shows copper-depleted and agglomerated regions. The sheet resistance measurement, study of surface morphology and the XRD analysis confirm that the insertion of thin Mo2C layer increases the thermal stability of the system from 400°C to 750°C. The increased thermal stability of the system is ascribed to longer diffusion path length in the bi-layered system probably because of grain boundaries mismatch at Ti–Mo2C interface.

  4. Pronounced Plasticity Caused by Phase Separation and β-relaxation Synergistically in Zr-Cu-Al-Mo Bulk Metallic Glasses.

    Science.gov (United States)

    Wang, Tuo; Wang, Lu; Wang, Qinjia; Liu, Yanhui; Hui, Xidong

    2017-04-27

    Bulk metallic glasses (BMGs) are known to have extraordinary merits such as ultrahigh strength and dynamic toughness etc. but tied to the detrimental brittleness, which has become a critical issue to the engineering application and understanding the glass nature. In this article, we report a new class of Zr-Cu-Al-Mo BMGs with extraordinary plastic strain above 20%. "Work-hardening" effect after yielding in a wide range of plastic deformation process has been detected for this kind of BMGs. Compositional heterogeneity, which can be classified into ZrMo- and Cu-rich zones, was differentiated in this kind of BMG. Pronounced humps have been observed on the high frequency kinetic spectrum in Mo containing BMGs, which is the indicator of β-relaxation transition. The underlying mechanism for the excellent plastic deforming ability of this class of BMGs is ascribed to the synergistic effects of soft ZrMo-rich glass formed through phase separation and abundant flow units which related to β-relaxation.

  5. Study on the Characteristics of Ag Doped CuO-BaTiO3 CO2 Sensors

    Directory of Open Access Journals (Sweden)

    Jinhuai Liu

    2002-09-01

    Full Text Available In this paper the characteristics of a CuO-BaTiO3 based CO2 gas sensor was investigated. The sensitivity of the CuO-BaTiO3 based CO2 sensor was influenced by doping various metal elements such as Au, Ag, Pt, Pd, Ce, Mg, Sr, La, Zn, Fe and Bi, which were added as a pure metal or in the form of metal oxides. It was found that Ag is the most suitable additive among all substances tested. The Ag-doped CO2 gas sensor has better sensitivity and lower operating temperature, with a detection concentration range of from 100 ppm to 10%. The sensor also shows good stability.

  6. Geology, mineralogy and fluid inclusion data from the Arapucan Pb Zn Cu Ag deposit, Canakkale, Turkey

    Science.gov (United States)

    Orgün, Yüksel; Gültekin, Ali Haydar; Onal, Ayten

    2005-07-01

    The Arapucan Pb-Zn-Cu-Ag deposit occurs as hydrothermal veins in diabase and altered Triassic metasandstones adjacent to calc-alkaline intrusive igneous rocks. The deposit is an important commercial source of base metal in northwestern Turkey. Potential by-products are silver and gold. The geology of the area includes a Paleozoic metamorphic basement, Triassic sedimentary rocks with carbonate blocks, Tertiary granitoids and Neogene volcanics. The mineral assemblage includes galena, quartz, calcite, sphalerite, chalcopyrite and pyrite as well as minor bismuthinite, tetrahedrite, pyrolusite, hematite, scheelite, malachite, magnetite, limonite and rutile. Silver is associated with tetrahedrite. Early hydrothermal activity was responsible for the formation of three hypogene alteration types of decreasing intensity: silicification, sericitization and argillic alteration. These alteration styles show a rough spatial zonation. The ore stage clearly postdates hydrothermal alteration, as indicated by the occurrence of ore minerals in vuggy cavities and fractures in silica bodies. The deposit contains evidence of at least two periods of hypogene mineralization separated by a period of faulting. In addition to Pb, Zn, Cu, Ag and Au, the ores contain substantial quantities of W, Bi, Sb and Te. Average δ 34S values for galena and pyrite are -3.95 and -2.24‰, respectively, suggesting an igneous source for both the sulphur and metals. However, geological and geochemical interpretations suggest that at least some of the metals were leached from the metasandstones and diabases. Fluid inclusions in main-stage sphalerite homogenize at 229-384 °C with salinities ranging from 1.7 to 18.5 eq.wt% NaCl. The deposits formed as the result of the interaction of two aqueous fluids: a higher-salinity fluid (probably magmatic) and a dilute meteoric fluid. The narrow range of δ 34S (galena and pyrite) values (-5.2 to -1.2‰ CDT) suggests that the sulphur source of the hydrothermal fluids

  7. Core/shell Cu@Ag nanoparticle: a versatile platform for colorimetric visualization of inorganic anions.

    Science.gov (United States)

    Zhang, Jia; Yuan, Yue; Xu, Xiaowen; Wang, Xiaolei; Yang, Xiurong

    2011-10-01

    Recognition and sensing of anions in aqueous media have been of considerable interest while remaining a challenging task up to date. In this document, we wish to present a simple yet sensitive method to detect inorganic anions by colorimetry based on the citrate-stabilized core/shell Cu@Ag nanoparticle (NP). It was found that the NP could discriminate some specific anions (Cl(-), Br(-), I(-), S(2-), and SCN(-)) from a wide range of environmentally dominant anions (F(-), SO(4)(2-), H(2)PO(4)(-), CO(3)(2-), NO(3)(-), etc), identified by the change in the color of the buffered NP solution or the surface plasmon resonance (SPR) absorbance band in the UV-vis spectrum. Among the recognized anions, four types of variation in the SPR absorption band were revealed. It was strongly enhanced for Cl(-) and Br(-) and was strongly damped for S(2-). For I(-), it first was slightly enhanced at lower concentrations and then gradually was damped at higher concentrations. For SCN(-), it first was slightly damped at lower concentrations and then was strongly enhanced at higher concentrations. In response to the optical change, the color of the NP solution turned from brown to bright yellow for Cl(-) (1 mM), Br(-) (10 μM), and SCN(-) (50 μM) to brownish orange for I(-) (10 μM) and to reddish orange for S(2-) (50 μM). The reason for these phenomena was postulated by the evidence of transmission electron microscope (TEM) images, X-ray photoelectron spectroscopy (XPS), and zeta potentials. In view of the importance of anions in the environment and for human health, the Cu@Ag NP colorimetric platform may have some applications, such as discriminating household table salt (NaCl) from industrial salt (NaNO(2)), testing the quality and extent of a variety of waters, and so forth.

  8. The Low-Lying States of AlCu and AlAg

    Science.gov (United States)

    Bauschlicher, Charles W., Jr.; Langhoff, Stephen R.; Partridge, Harry

    1994-01-01

    The singlet and triplet states of AlCu and AlAg below about 32 000/cm are studied using the internally contracted multireference configuration-interaction method. A more elaborate study of the X(sup 1)Sum(sup +) ground state of AlCu is undertaken using extended Gaussian basis sets, including the effect of inner-shell correlation and including a perturbational estimate of relativistic effects. Our best estimate of the spectroscopic constants (r(sub 0), DeltaG(sub 1/2), and D(sub 0)) for the X(sup 1)Sum(sup+) state with the experimental values in parentheses are: 4.416(4.420) a(sub 0), 295 (294) /cm, and 2.318 (2.315) eV. The calculations definitively assign the upper state in the observed transition at 14 892/cm to the lowest (sup 1)Prod state. The calculated spectroscopic constants and radiative lifetime for the (sup 1)Prod state are in good agreement with experiment. The calculations support the tentative assignments of Behm et al. for three band systems observed in the visible region between 25 000 and 28 000 / cm. However, the computed spectroscopic constants are in very poor agreement with those deduced from an analysis of the spectra. Analogous theoretical results for AlAg suggest that the (2)(sup 3)Prod, (3)(sup 3)Prod, and (3)(sup 1)Sum(sup +) states account for the bands observed, but not assigned, by Duncan and co-workers.

  9. Phase transition study in a [Cu2HgI4 : 0.AgI] mixed composite system

    Indian Academy of Sciences (India)

    Noorussaba; Afaq Ahmad

    2010-08-01

    A novel composite superionic system, [Cu2HgI4 : 0.AgI], ( = 0.2, 0.4, 0.6 mol wt.%), was prepared. A [Cu2HgI4] system was used as the host. Electrical conductivity was measured to study the transition behaviour at frequencies of 100 Hz, 120 Hz, 1 kHz and 10 kHz in the temperature range 90–170°C using a Gen Rad 1659 RLC Digibridge. Conductivity increased sharply during the – phase transition. Upon increasing the dopant-to-host ratio, the conductivity of the superionic system exhibited Arrhenius (thermally activated)-type behaviour. DTA, DTG, TGA and X-ray powder diffraction were performed to confirm doping effect and transition in the host. The phase transition temperature increased with an increase in the dopant concentration. Activation energies in eV for pre- and post-transition phase behaviour are also reported. Due to an interaction between [Cu2HgI4] and AgI, the addition of AgI to [Cu2HgI4] shifted the phase transition of the host [Cu2HgI4].

  10. Micelle-Directing Synthesis of Ag-Doped WO3 and MoO3 Composites for Photocatalytic Water Oxidation and Organic-Dye Adsorption.

    Science.gov (United States)

    Bate, Nasen; Shi, Hongfei; Chen, Li; Wang, Jiabo; Xu, Shasha; Chen, Weilin; Li, Jianping; Wang, Enbo

    2017-07-20

    In this paper, an Ag-doped WO3 (and MoO3 ) composite has been prepared by following a simple micelle-directed method and high-temperature sintering route. The as-prepared samples were characterized by X-ray diffraction, inductively coupled plasma, transmission electron microscopy, X-ray photoelectron spectroscopy, UV/Vis diffuse reflectance spectroscopy, Brunauer-Emmett-Teller, photoluminescence spectroscopy, and electrochemical impedance spectroscopy techniques. The photocatalytic experiments reveal that their oxygen-production rates are up to 95.43 μmol (75.45 μmol) for Ag-doped WO3 (MoO3 ), which is 9.5 (7.3) times higher than that of pure WO3 : 9.012 μmol (MoO3 : 9.00 μmol) under visible-light illumination (λ≥420 nm), respectively. The improvement of their photocatalytic activity is attributed to the enhancement of their visible-light absorption and the separation efficiency of photogenerated carriers by Ag doping. Moreover, Ag-doped WO3 (MoO3 ) also shows excellent adsorption of rhodamine B (RhB) and methylene blue (MB) in aqueous solution, with maximum adsorption capacities towards RhB and MB of 822 and 820 mg g(-1) for Ag-doped WO3 , and 642 and 805 mg g(-1) for Ag-doped MoO3 , respectively. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Mechanical properties of FeCo magnetic particles-based Sn-Ag-Cu solder composites

    Science.gov (United States)

    Xu, Siyang; Prasitthipayong, Anya; Pickel, Andrea D.; Habib, Ashfaque H.; McHenry, Michael E.

    2013-06-01

    We demonstrate magnetic nanoparticles (MNPs) in enabling lead-free solder reflow in RF fields and improved mechanical properties that impact solder joint reliability. Here, we report on Sn-Ag-Cu (SAC) alloys. SAC solder-FeCo MNP composites with 0, 1, 2, 3, and 4 wt. % FeCo MNP and the use of AC magnetic fields to achieve localized reflow. Electron microscopy of the as-reflowed samples show a decrease in the volume of Sn dendrite regions as well as smaller and more homogeneously dispersed Ag3Sn intermetallic compounds (IMCs) with increasing MNP concentrations. Mechanical properties of the composites were measured by nanoindentation. In pure solder samples and solder composites with 4 wt. % MNP, hardness values increased from 0.18 GPa to 0.20 GPa and the modulus increased from 39.22 GPa to 71.22 GPa. The stress exponent, reflecting creep resistance, increased from 12.85 of pure solder to 16.47 for solder composites with 4 wt. % MNP. Enhanced mechanical properties as compared with the as-prepared solder joints are explained in terms of grain boundary and dispersion strengthening resulting from the microstructural refinement.

  12. 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.

  13. Evolution of Intermetallic Compounds between Sn-0.3Ag-0.7Cu Low-silver Lead-free Solder and Cu Substrate during Thermal Aging

    Institute of Scientific and Technical Information of China (English)

    Niwat Mookam; Kannachai Kanlayasiri

    2012-01-01

    The growth, transformation, and lattice structure of intermetallic compounds formed between Sn-0.3Ag-0.7Cu lead-free solder and copper substrate were investigated. Dip soldering was used to initiate the reaction between the solder and substrate. An r/-Cu6Sn5 intermetallic phase possessing a hexagonal lattice structure was found at the as-soldered interface. Thermal aging at a number of conditions resulted in the formation of a CuaSn intermetallic phase between the Cu6Sn5 layer and the copper substrate, e-Cu3Sn with an orthorhombic lattice structure was found together with hexagonal CusSn. Subsequently, the activation energies of the intermetallic phases were calculated and compared to results obtained from the literature. The comparison showed that good agreement existed between the findings from this study and literature data within a similar temperature range.

  14. Microstructure and Shear Strength in Brazing Joint of Mo-Cu Composite with 304 Stainless Steel by Ni-Cr-P Filler Metal

    Science.gov (United States)

    Wang, Juan; Wang, Jiteng; Li, Yajiang; Zheng, Deshuang

    2015-07-01

    The brazing of Mo-Cu composite and 304 stainless steel was carried out in vacuum with Ni-Cr-P filler metal at 980 °C for 20 min. Microstructure in Mo-Cu/304 stainless steel joint was investigated by field-emission scanning electron microscope (FE-SEM) with energy dispersive spectrometer (EDS) and shear strength was measured by shearing test. The results indicate that shear strength of the Mo-Cu/304 stainless steel joint is about 155 MPa. There forms eutectic structure of γ-Ni solid solution with Ni3P in the braze seam. Ni-Cu(Mo) and Ni-Fe solid solution are at the interface beside Mo-Cu composite and 304 stainless steel, respectively. Shear fracture exhibits mixed ductile-brittle fracture feature with trans-granular fracture, ductile dimples and tearing edges. Fracture originates from the interface between brazing seam and Mo-Cu composite and it propagates to the braze seam due to the formation of brittle Ni5P2 and Cr3P precipitation.

  15. Utilization of a Porous Cu Interlayer for the Enhancement of Pb-Free Sn-3.0Ag-0.5Cu Solder Joint

    Directory of Open Access Journals (Sweden)

    Nashrah Hani Jamadon

    2016-09-01

    Full Text Available The joining of lead-free Sn-3.0Ag-0.5Cu (SAC305 solder alloy to metal substrate with the addition of a porous Cu interlayer was investigated. Two types of porous Cu interlayers, namely 15 ppi—pore per inch (P15 and 25 ppi (P25 were sandwiched in between SAC305/Cu substrate. The soldering process was carried out at soldering time of 60, 180, and 300 s at three temperature levels of 267, 287, and 307 °C. The joint strength was evaluated by tensile testing. The highest strength for solder joints with addition of P25 and P15 porous Cu was 51 MPa (at 180 s and 307 °C and 54 MPa (at 300 s and 307 °C , respectively. The fractography of the solder joint was analyzed by optical microscope (OM and scanning electron microscopy (SEM. The results showed that the propagation of fracture during tensile tests for solder with a porous Cu interlayer occurred in three regions: (i SAC305/Cu interface; (ii inside SAC305 solder alloy; and (iii inside porous Cu. Energy dispersive X-ray spectroscopy (EDX was used to identify intermetallic phases. Cu6Sn5 phase with scallop-liked morphology was observed at the interface of the SAC305/Cu substrate. In contrast, the scallop-liked intermetallic phase together with more uniform but a less defined scallop-liked phase was observed at the interface of porous Cu and solder alloy.

  16. Structures and phase transitions of the A7PSe6 (A = Ag, Cu) argyrodite-type ionic conductors. II. Beta- and gamma-Cu7PSe6

    Science.gov (United States)

    Gaudin; Boucher; Petricek; Taulelle; Evain

    2000-06-01

    The crystal structures of two of the three polymorphic forms of the Cu7PSe6 argyrodite compound are determined by means of single-crystal X-ray diffraction. In the high-temperature form, at 353 K, i.e. 33 K above the first phase transition, gamma-Cu7PSe6 crystallizes in cubic symmetry, space group F43m. The full-matrix least-squares refinement of the structure leads to the residual factors R = 0.0201 and wR = 0.0245 for 31 parameters and 300 observed independent reflections. In the intermediate form, at room temperature, beta-Cu7PSe6 crystallizes again in cubic symmetry, but with space group P2(1)3. Taking into account a merohedric twinning, the refinement of the beta-Cu7PSe6 structure leads to the residual factors R = 0.0297 and wR = 0.0317 for 70 parameters and 874 observed, independent reflections. The combination of a Gram-Charlier development of the Debye-Waller factor and a split model for copper cations reveals the possible diffusion paths of the d10 species in the gamma-Cu7PSe6 ionic conducting phase. The partial ordering of the Cu+ d10 element at the phase transition is found in concordance with the highest probability density sites of the high-temperature phase diffusion paths. A comparison between the two Cu7PSe6 and Ag7PSe6 analogues is carried out, stressing the different mobility of Cu+ and Ag+ and their relative stability in low-coordination chalcogenide environments.

  17. Comparative modular analysis of two complex sulfosalt structures: sterryite, Cu(Ag,Cu)3Pb19(Sb,As)22(As-As)S56, and parasterryite, Ag4Pb20(Sb,As)24S58.

    Science.gov (United States)

    Moëlo, Yves; Guillot-Deudon, Catherine; Evain, Michel; Orlandi, Paolo; Biagioni, Cristian

    2012-10-01

    The crystal structures of two very close, but distinct complex minerals of the lead sulfosalt group have been solved: sterryite, Cu(Ag,Cu)(3)Pb(19)(Sb,As)(22)(As-As)S(56), and parasterryite, Ag(4)Pb(20)(Sb,As)(24)S(58). They are analyzed and compared according to modular analysis. The fundamental building block is a complex column centred on a Pb(6)S(12) triangular prismatic core, with two additional long and short arms. The main chemical and topological differences relate to the short arm, which induces a relative a/4 shift (~2 Å along the elongation parameter) of the constitutive rod layers, as illustrated by distinct cell settings within the same space group (P2(1)/n and P2(1)/c, respectively). Selection of the shortest (i.e. strongest) (Sb,As)-S bonds permitted to enhance the polymeric organization of (Sb,As) atoms with triangular pyramidal coordination. These two quasi-homeotypic structures are expanded derivatives of owyheeite, Ag(3)Pb(10)Sb(11)S(28). The hierarchy of organization levels from zero- to three-dimensional entities is subordinated to building operators, which appear as the driving force for the construction of such complex structures. Minor cations (Ag, Cu) or the As-As pair in sterryite secure the final locking, which favours the formation of one or the other compound.

  18. Photocatalytic removal of M(2+) (Ni(2+), Cu(2+), Zn(2+), Cd(2+), Hg(2+) and Ag(+)) over new catalyst CuCrO(2).

    Science.gov (United States)

    Ketir, W; Bouguelia, A; Trari, M

    2008-10-30

    The metal ions M(2+) (Ni(2+), Cu(2+), Zn(2+), Cd(2+), Hg(2+) and Ag(+)) are potentially toxic. Their electro deposition has been carried out in aqueous air-equilibrated CuCrO(2) suspension upon visible illumination. The delafossite CuCrO(2) is p-type semiconductor characterized by a low band gap (1.28 eV) and a long-term chemical stability. The corrosion rate is found to be 10(-2) micromol m(-2)month(-1) in aqua regia. The oxide has been elaborated through nitrate route where the specific surface area is increased via the surface/bulk ratio. A correlation exists between the dark M(2+) adsorption, the redox potential of M(2+/0) couple and the conduction band of CuCrO(2) positioned at -1.06 V(SCE). Ag(+) cannot be photoreduced because of its positive potential located far above the valence band. By contrast, Zn(2+) is efficiently deposited due to the large driving force at the interface. The improved photoactivity of copper with a deposition percentage (90%) is attributed to the strong dark adsorption onto the surface catalyst. The results indicate a competitive effect with the water reduction; it has been observed that the M(2+) deposition goes parallel with the hydrogen evolution. Such behavior is attributed to the low H(2) over voltage when ultra fine aggregate of M islands are photodeposited onto CuCrO(2) substrate.

  19. Chemical stability at noble metal M/YBa 2Cu 3O 6.8 interfaces (M = Pt, Ag, Au)

    Science.gov (United States)

    Bohnenkamp-Weiss, Ruth; Schmid-Fetzer, Rainer

    1994-02-01

    The chemical compatibility between YBa 2Cu 3O 6.8 (Y123) and Pt, Ag or Au was studied using quasi-infinite diffusion couples which were encapsulated and annealed at 650 to 800°C for 5 to 80 h. The phase formation at the interface was analyzed in cross sections of these couples using optical and scanning electron microscopy together with energy- and wavelength dispersive X-ray microanalysis. In addition, bulk powder mixtures of Y123 with Pt, Ag or Au were annealed at 800°C for 100 h and phase analysis was performed using X-ray diffraction. At the Pt/Y123 interface a reaction zone grows slowly but decisively at 800°C. Its microstructure is multiphase with YCu-oxides and a fine-grained dispersion of Y 2BaCuO 5 (Y211) with BaCu-oxides. Additional BaPt oxides and other phases are seen in powder mixtures annealed for longer times. Barium is suspected to diffuse out from the superconductor along grain boundaries from as deep as 1 mm, causing the decomposition of Y123 into YCu-oxides in the depleted regions. Ag and Au form a stable contact at the interface to Y123 with no reaction zone or new phases. Interdiffusion at the Ag/Y123 interface at 800°C was too low to be clearly detected. In contrast, Au diffuses very fast into Y123 and at 800°C the solubility is 4.2 mass% Au. Yttrium and barium diffuse much slower into the (Au) phase, Cu diffusion was not detected. Weak traces of decomposition products, mostly Y211 and BaCu-oxides, were observed in bulk powder mixtures of Y123 with Ag or Au annealed at 800°C for 100 h in closed capsules. These decomposition products are considered to be due to the high oxygen pressure in the closed capsule, exceeding the stability limit of Y123, and not due to the reduction of Y123. Both Ag and Au are virtually non-reactive with Y123.

  20. The Effect of Ag Addition on the Enhancement of the Thermal and Mechanical Properties of CuZrAl Bulk Metallic Glasses

    Directory of Open Access Journals (Sweden)

    Tsan-Man Chung

    2016-09-01

    Full Text Available In this study, the thermal and mechanical properties of Cu50−xZr43Al7Agx (x = 0, 3, 4, 5, 6 bulk metallic glasses (BMGs are investigated by using an X-ray diffractometer (XRD, a differential scanning calorimeter (DSC, differential thermal analysis (DTA, a Vickers hardness tester, a material test system (MTS, scanning electron microscopy (SEM, and transmission electron microscopy (TEM. Cu50−xZr43Al7Agx (x = 0, 3, 4, 5, 6 BMGs were made by arc-melting and an injection casting process. The results revealed that the glass transition temperature (Tg and the crystallization temperature (Tx of CuZrAl alloy decreased with the Ag addition. Hence, the supercooled liquid region and γ of Cu45Zr43Al7Ag5 alloy increased to 76 K and 0.42, respectively. The thermal stability and glass forming ability of CuZrAlAg BMG alloys were enhanced by the microalloyed Ag content. The room temperature compressive fracture strength and strain measured of Cu47Zr43Al7Ag3 were about 2200 MPa and 2.1%, respectively. The distribution of vein patterns and the formation of nanocrystalline phases on the fracture surface of Cu47Zr43Al7Ag3 alloy can be observed by SEM and TEM to be significant, indicating a typical ductile fracture behavior and an improved plasticity of alloys with the addition of microalloyed Ag from 0 to 6 atom %.

  1. 两相热法处理Cyanex301-Ag+/Cu2+萃取体系制备纳米Ag2S和微米CuS材料%Preparation of Ag2S Nanoparticles and CuS Microstructures from the Solvent Extraction Systems by a Two-phase Thermal Method

    Institute of Scientific and Technical Information of China (English)

    孙霞; 刘玉炳; 李艳玲; 廖伍平

    2011-01-01

    以Cyanex 301萃取剂为硫源,分别萃取Ag+和Cu2+,两相热法制备了Ag2S纳米颗粒和CuS微结构,采用X射线粉末衍射、紫外可见光谱、红外光谱以及电子显微镜对产物进行了表征.表明制得的Ag2S和CuS分别为单斜相和六方相.产物粒径随着反应温度的升高而增大,因而可通过加热温度调控产物尺寸,另外还考虑了其它反应条件对产物的影响.%Monoclinic Ag2S nanoparticles and hexagonal CuS microstructures have been successfully prepared from solvent-extraction systems by a two-phase thermal method. In these systems, the extractant Cyanex 301 (di-(2,4,4-trimethylpentyl) dithiophosphinic acid) acts as not only the surfactant but also the sulfur source. The products were characterized by powder X-ray diffraction (XRD) , UV-Visible spectroscopy(UV-Vis) , FT-infrared spectroscopy(FTIR) and transmission/scanning electron microscopy (TEM/SEM). It is found that the size of Ag2S nanoparticles becomes bigger with the increasing temperature and the morphology and size of CuS microstructures can be controlled by the feed concentration or temperature.

  2. Growth behavior of intermetallic compounds at Sn–Ag/Cu joint interfaces revealed by 3D imaging

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Q.K., E-mail: qkzhang@alum.imr.ac.cn [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); State Key Laboratory of Advanced Brazing Filler Metals & Technology, Zhengzhou Research Institute of Mechanical Engineering, Zhengzhou 450001 (China); Long, W.M. [State Key Laboratory of Advanced Brazing Filler Metals & Technology, Zhengzhou Research Institute of Mechanical Engineering, Zhengzhou 450001 (China); Zhang, Z.F., E-mail: zhfzhang@imr.ac.cn [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China)

    2015-10-15

    In this study, the morphologies of intermetallic compounds (IMCs) at the as-soldered and thermal aged Sn–Ag/Cu joint interfaces were observed by SEM and measured using Laser Confocal Microscope, and their three-dimensional (3D) shapes were revealed using 3D imaging technology. The observation reveal that during the soldering process the Cu{sub 6}Sn{sub 5} grains at the joint interface evolve from hemispheroid to a bamboo shoot-shaped body with increasing liquid state reacting time, and their grain size increases sharply. After thermal aging, the Cu{sub 6}Sn{sub 5} grains change into equiaxed grains, while the top of some prominent Cu{sub 6}Sn{sub 5} grains changes little. Due to the higher active energy of the Sn atoms at the grain boundary, the growth rate of IMC grains around the grain boundaries of the solder is higher during the aging process. From the evolution in morphology of the IMC layer, it is demonstrated that the IMC layer grows through grain boundary diffusion of the Cu and Sn atoms during the aging process, and the volume diffusion is very little. The 3D imaging technology is used to reveal the shape and dimension of the IMC grains. - Highlights: • Morphologies of IMCs at the Sn–Ag/Cu interface were revealed by 3D imaging. • Preferential growth of IMCs around the solder grain boundaries was observed. • Growth behaviors of IMCs during reflowing and aging process were investigated.

  3. A one-dimensional polyoxometalate-based polymer [Cu(DMF)₆][PMo(V)Mo(VI)₁₁O₄₀Cu(DMF)₄]·DMF: crystal structure and luminescent properties.

    Science.gov (United States)

    Bai, Yan; Zheng, Guang-Shui; Dang, Dong-Bin; Gao, Hui; Qi, Ze-Yan; Niu, Jing-Yang

    2010-11-01

    The polyoxometalate-based 1D coordination polymer [[Cu(DMF)₆][PMo(V)Mo(VI)₁₁O₄₀Cu(DMF)₄]·DMF1 was synthesized and characterized by IR, UV spectroscopy and single-crystal X-ray diffraction analysis. Each Cu(II) center has a distorted octahedral coordination geometry. Cu(1) center interconnects with two [PMo(V)Mo(VI)₁₁O₄₀]⁴⁻ anion subunits and each [PMo(V)Mo(VI)(11)O(40)]⁴⁻ polyoxoanion acts as a didentate ligand to link two Cu centers through two terminal oxygen atoms to form a one-dimensional chain structure. The luminescent properties of 1 in the solution and in the solid state were investigated, respectively. Copyright © 2010 Elsevier B.V. All rights reserved.

  4. Structural and superconducting properties of YBa2Cu3-xMxOy (M=Ag, Al

    Directory of Open Access Journals (Sweden)

    S Falahati

    2009-08-01

    Full Text Available   Samples of YBa2Cu3-xAgxOy with x=0, 0.1, 0.15, 0.2, 0.3 and samples of YBa2Cu3-xAlxOy with x=0, 0.01, 0.02, 0.03 and 0.045 are prepared by the sol-gel method. Structural and superconducting properties of samples are studied by electrical resistivity (R-T, X-ray diffraction (XRD and scanning electron microscopy (SEM. All the samples show transition to superconducting state and the transition temperatures of the samples increased with increasing Ag doping up to x=0.15. R-T measurements show a small decrease of TC (zero with increasing Al doping up to x=0.02, and followed by a faster decrease with increasing doping concentration. YBCO grains are better linked with increasing Ag doping. So, Ag has positive effects in superconducting properties of YBCO. The crystal structure of samples was refined by MAUD. These results show tha, Ag is substituted for Cu(1 in YBCO. According to these analysis, we introduce x=0.15 as the optimum value for doping concentration .

  5. Effect of Ag Content and the Minor Alloying Element Fe on the Mechanical Properties and Microstructural Stability of Sn-Ag-Cu Solder Alloy Under High-Temperature Annealing

    Science.gov (United States)

    Shnawah, Dhafer Abdulameer; Sabri, Mohd Faizul Mohd; Badruddin, Irfan Anjum; Said, Suhana Binti Mohd; Ariga, Tadashi; Che, Fa Xing

    2013-03-01

    This study compares the high-Ag-content Sn-3Ag-0.5Cu with the low- Ag-content Sn-1Ag-0.5Cu solder alloy and the three quaternary solder alloys Sn-1Ag-0.5Cu-0.1Fe, Sn-1Ag-0.5Cu-0.3Fe, and Sn-1Ag-0.5Cu-0.5Fe to understand the beneficial effects of Fe on the microstructural stability, mechanical properties, and thermal behavior of the low-Ag-content Sn-1Ag-0.5Cu solder alloy. The results indicate that the Sn-3Ag-0.5Cu solder alloy possesses small primary β-Sn dendrites and wide interdendritic regions consisting of a large number of fine Ag3Sn intermetallic compound (IMC) particles. However, the Sn-1Ag-0.5Cu solder alloy possesses large primary β-Sn dendrites and narrow interdendritic regions of sparsely distributed Ag3Sn IMC particles. The Fe-bearing SAC105 solder alloys possess large primary β-Sn dendrites and narrow interdendritic regions of sparsely distributed Ag3Sn IMC particles containing a small amount of Fe. Moreover, the addition of Fe leads to the formation of large circular FeSn2 IMC particles located in the interdendritic regions. On the one hand, tensile tests indicate that the elastic modulus, yield strength, and ultimate tensile strength (UTS) increase with increasing Ag content. On the other hand, increasing the Ag content reduces the total elongation. The addition of Fe decreases the elastic modulus, yield strength, and UTS, while the total elongation is still maintained at the Sn-1Ag-0.5Cu level. The effect of aging on the mechanical behavior was studied. After 720 h and 24 h of aging at 100°C and 180°C, respectively, the Sn-1Ag-0.5Cu solder alloy experienced a large degradation in its mechanical properties after both of the aging conditions, whereas the mechanical properties of the Sn-3Ag-0.5Cu solder alloy degraded more dramatically after 24 h of aging at 180°C. However, the Fe-bearing SAC105 solder alloys exhibited only slight changes in their mechanical properties after both aging procedures. The inclusion of Fe in the Ag3Sn IMC particles

  6. 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.

  7. PANI-Ag-Cu Nanocomposite Thin Films Based Impedimetric Microbial Sensor for Detection of E. coli Bacteria

    Directory of Open Access Journals (Sweden)

    Huda Abdullah

    2014-01-01

    Full Text Available PANI-Ag-Cu nanocomposite thin films were prepared by sol-gel method and deposited on the glass substrate using spin coating technique. Polyaniline was synthesized by chemical oxidative polymerization of aniline monomer in the presence of nitric acid. The films were characterized using XRD, FTIR, and UV-Visible spectroscopy. The performance of the sensor was conducted using electrochemical impedance spectroscopy to obtain the change in impedance of the sensor film before and after incubation with E. coli bacteria in water. The peaks in XRD pattern confirm the presence of Ag and Cu nanoparticles in face-centered cubic structure. FTIR analysis shows the stretching of N–H in the polyaniline structure. The absorption band from UV-Visible spectroscopy shows high peaks between 400 nm and 500 nm which indicate the presence of Ag and Cu nanoparticles, respectively. Impedance analysis indicates that the change in impedance of the films decreases with the presence of E. coli. The sensitivity on E. coli increases for the sample with high concentration of Cu.

  8. The annealing effects on the micro-structure and properties of RuMoC films as seedless barrier for advanced Cu metallization

    Energy Technology Data Exchange (ETDEWEB)

    Zou, Jianxiong; Liu, Bo, E-mail: liubo2009@scu.edu.cn, E-mail: gh.jiao@siat.ac.cn [Key Laboratory of Radiation Physics and Technology of Ministry of Education, Institute of Nuclear Science and Technology, Sichuan University, Chengdu 610064 (China); Jiao, Guohua, E-mail: liubo2009@scu.edu.cn, E-mail: gh.jiao@siat.ac.cn; Lu, Yuanfu; Dong, Yuming [Shenzhen Institutes of Advanced Technology Chinese Academy of Sciences, Shenzhen 518055 (China); The Chinese University of Hong Kong, Hong Kong (China); Li, Qiran [Institut d' Electronique Fondamentale, CNRS-Université Paris Sud UMR 8622, 91405 Orsay (France)

    2016-09-07

    100 nm thick RuMoC films and 5 nm thick RuMoC films with Cu capping have been deposited on Si(111) by magnetron co-sputtering with Ru and MoC confocal targets. The samples were subsequently annealed at temperatures ranging from 450 to 650 °C in vacuum at a pressure of 3 × 10{sup −4} Pa to study the annealing effects on the microstructures and properties of RuMoC films for advanced seedless Cu metallization applications. The sheet resistances, residual oxygen contents, and microstructures of the RuMoC films have close correlation with the doping contents of Mo and C, which can be easily controlled by the deposition power ratio of MoC versus Ru targets (DPR). When DPR was 0.5, amorphous RuMoC film (marked as RuMoC II) with low sheet resistances and residual oxygen contents was obtained. The fundamental relationship between the annealing temperatures with the microstructures and properties of the RuMoC films was investigated, and a critical temperature point was revealed at about 550 °C where the components and microstructures of the RuMoC II films changed obviously. Results indicated that below 550 °C, the RuMoC II films remained amorphous due to the well-preserved C-Ru and C-Mo bonds. However, above 550 °C, the microstructures of RuMoC II films transformed from amorphous to nano-composite structure due to the breakage of Ru-C bonds, while the supersaturated solid solution MoC segregated out along the grain boundaries of Ru, thus hindering the diffusion of Cu and O atoms. This is the main mechanism of the excellent thermal stability of the RuMoC films after annealing at high temperatures. The results indicated great prospects of amorphous RuMoC films in advanced seedless Cu metallization applications.

  9. Investigation of thermoluminescence in Li2B4O7 phosphors doped with Cu, Ag and Mg

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Li2B4O7 (LBO):Cu,Ag,Mg phosphors have been prepared by the sintering technique. The roles of the Ag and Mg dopants in the phosphors have been studied using the methods of thermoluminescence (TL) glow curves and TL 3D spectra. The results indicated that proper concentrations of Ag and Mg can enhance the TL of LBO:Cu. It was also indicated that the intensity of TL peak at 130℃ is reduced with the in- creasing Ag concentration, and enhanced with the increasing Mg concentration. From the TL 3D spectra, three emission bands (λ1 = 421 nm, λ2 = 380 nm, λ3 = 350 nm) were observed: the intensity of low energy emission band is reduced and that of the high energy is enhanced with the increasing dopant Ag; on the contrary, the intensity of low energy emission band is enhanced and that of the high energy one is reduced with the increasing dopant Mg.

  10. Investigation of thermoluminescence in Li2B4O7 phosphors doped with Cu, Ag and Mg

    Institute of Scientific and Technical Information of China (English)

    XIONG ZhengYe; TANG Qiang; ZHANG ChunXiang

    2007-01-01

    Li2B4O7 (LBO):Cu,Ag,Mg phosphors have been prepared by the sintering technique.The roles of the Ag and Mg dopants in the phosphors have been studied using the methods of thermoluminescence (TL) glow curves and TL 3D spectra. The results indicated that proper concentrations of Ag and Mg can enhance the TL of LBO:Cu.It was also indicated that the intensity of TL peak at ~130℃ is reduced with the increasing Ag concentration, and enhanced with the increasing Mg concentration.From the TL 3D spectra, three emission bands (λ1 = 421 nm,λ2 = 380 nm, λ3 = 350nm) were observed: the intensity of low energy emission band is reduced and that of the high energy is enhanced with the increasing dopant Ag; on the contrary, the intensity of low energy emission band is enhanced and that of the high energy one is reduced with the increasing dopant Mg.

  11. Geochemical element mobility during the hydrothermal alteration in the Tepeoba porphyry Cu-Mo-Au deposits at Balikesir, NW Turkey

    Science.gov (United States)

    Abdelnasser, Amr; Kiran Yildirim, Demet; Doner, Zeynep; Kumral, Mustafa

    2016-04-01

    The Tepeoba porphyry Cu-Mo-Au deposit represents one of the important copper source and mineral deposits in the Anatolian tectonic belt at Balikesir province, NW Turkey. It considered as a vein-type deposit locally associated with intense hydrothermal alteration within the brecciation, quartz stockwork veining, and brittle fracture zones in the main host rock that represented by hornfels, as well as generally related to the shallow intermediate to silicic intrusive Eybek pluton. Based on the field and geologic relationships and types of ore mineral assemblages and the accompanied alteration types, there are two mineralization zones; hypogene (primary) and oxidation/supergene zones are observed associated with three alteration zones; potassic, phyllic, and propylitic zones related to this porphyry deposit. The phyllic and propylitic alterations locally surrounded the potassic alteration. The ore minerals related to the hypogene zone represented by mostly chalcopyrite, Molybdenite, and pyrite with subordinate amount of marcasite, enargite, and gold. On the other hand they include mainly cuprite with chalcopyrite, pyrite and gold as well as hematite and goethite at the oxidation/supergene zone. This study deals with the quantitative calculations of the mass/volume changes (gains and losses) of the major and trace elements during the different episodes of alteration in this porphyry deposit. These mass balance data reveal that the potassic alteration zone that the main Cu- and Mo-enriched zone, has enrichment of K, Si, Fe, and Mg, and depletion of Na referring to replacement of plagioclase and amphibole by K-feldspar, sericite and biotite. While the propylitic alteration that is the main Mo- and Au-enriched zone is accompanied with K and Na depletion with enrichment of Si, Fe, Mg, and Ca forming chlorite, epidote, carbonate and pyrite. On the other hand the phyllic alteration that occurred in the outer part around the potassic alteration, characterized by less amount

  12. Comparison of Extensive Thermal Cycling Effects on Microstructure Development in Micro-alloyed Sn-Ag-Cu Solder Joints

    Science.gov (United States)

    Anderson, Iver E.; Boesenberg, Adam; Harringa, Joel; Riegner, David; Steinmetz, Andrew; Hillman, David

    2012-02-01

    Pb-free solder alloys based on the Sn-Ag-Cu (SAC) ternary eutectic have promise for widespread adoption across assembly conditions and operating environments, but enhanced microstructural control is needed. Micro-alloying with elements such as Zn was demonstrated for promoting a preferred solidification path and joint microstructure earlier in simple (Cu/Cu) solder joints studies for different cooling rates. This beneficial behavior now has been verified in reworked ball grid array (BGA) joints, using dissimilar SAC305 (Sn-3.0Ag-0.5Cu, wt.%) solder paste. After industrial assembly, BGA components joined with Sn-3.5Ag-0.74Cu-0.21Zn solder were tested in thermal cycling (-55°C/+125°C) along with baseline SAC305 BGA joints beyond 3000 cycles with continuous failure monitoring. Weibull analysis of the results demonstrated that BGA components joined with SAC + Zn/SAC305 have less joint integrity than SAC305 joints, but their lifetime is sufficient for severe applications in consumer, defense, and avionics electronic product field environments. Failure analysis of the BGA joints revealed that cracking did not deviate from the typical top area (BGA component side) of each joint, in spite of different Ag3Sn blade content. Thus, SAC + Zn solder has not shown any advantage over SAC305 solder in these thermal cycling trials, but other characteristics of SAC + Zn solder may make it more attractive for use across the full range of harsh conditions of avionics or defense applications.

  13. 超音速电弧熔化气雾化CuAg10粉末的特性%Characteristics of CuAg10 Powders by Ultrasonic Arc Gas Atomization Process

    Institute of Scientific and Technical Information of China (English)

    蔡宏中; 秦国义; 赵永坤

    2008-01-01

    利用超音速电弧熔化气雾化法制备了CuAg10合金粉末,对合金粉末的组织结构、粒度分布特征、X射线衍射特性、晶格常数及形貌特征等进行了系统研究.结果表明:粉末组织为二次枝晶臂间距很小的枝晶,雾化时的冷却速度达105K/s;合金粉末粒度均匀细小,形状多为球形、类球状, 平均尺寸为44μm;在雾化过程中形成了过饱和(Cu)和(Ag).

  14. PEMANFAATAN KARBON AKTIF ARANG BATUBARA (KAAB UNTUK MENURUNKAN KADAR ION LOGAM BERAT Cu2+ DAN Ag+ PADA LIMBAH CAIR INDUSTRI

    Directory of Open Access Journals (Sweden)

    Kusmiyati Kusmiyati

    2012-05-01

    Full Text Available UTILIZATION OF CHAR COAL ACTIVATED CARBON (CCAB FOR HEAVY IONS (Cu2+ AND Ag+ REDUCTION FROM INDUSTRIAL WASTE WATER. Industrial wastewater may contain heavy metals such as Cu and Ag those are harmful to the environment if discharged without pretreatment. One of the methods to reduce heavy metals in wastewater is adsorption, to separate certain components from liquid to the surface of solids. Adsorption is a simple method, but most of the adsorbents are expensive, therefore a cheaper adsorbent is required to reduce the cost of the adsorption process. This work utilized bottom ash as an adsorbent. Bottom ash is a waste of combustion products in the coal industry, which contain potentially harmful materials. Activation of bottom ash was made by soaking in peroxide and continuing by heating at a temperature of 500oC. This study was aimed to determine the influence of process parameters (concentration, pH and processing time to the percentage of amount heavy metals adsorbed, to study the equation isotherm adsorption using Langmuir and Freundlich models, and to calculate the kinetic constants of adsorption based on pseudo -first- order and pseudo-second-order kinetic model. The experiment was conducted in the batch system, where 10 grams bottom ash was mixed with 400 ml of synthetic waste. AAS was used to determine the heavy metals content in the waste solution. The results showed that bottom ash can be used to reduce heavy metals of Cu2+ and Ag+, the optimum condition when the concentration of 25 ppm under acidic conditions, bottom ash was able to adsorb Cu2+ metals ion by 62.79-80.25% at pH 4, and 65.54-85.98% at neutral pH with the same adsorption time of 300 min. For the ion metals Ag+, at acidic solution the metals ion can be adsorbed by 56.51-82.21%, while at neutral pH conditions 59.92-87.55%. Adsorption of bottom ash follows the model of Freundlich isotherm adsorption at acidic and neutral condition, the correlation coefficient (R2obtained was

  15. Effect of Rare-Earth (La, Ce, and Y) Additions on the Microstructure and Mechanical Behavior of Sn-3.9Ag-0.7Cu Solder Alloy

    Science.gov (United States)

    Dudek, M. A.; Chawla, N.

    2010-03-01

    In this article, we report on the microstructure and mechanical properties of Ce- and Y-containing Sn-3.9Ag-0.7Cu solders. The microstructures of both as-processed solder and solder joints containing rare-earth (RE) elements (up to 0.5 wt pct) are more refined compared to conventional Sn-3.9Ag-0.7Cu, with decreases in secondary Sn dendrite size and spacing and a thinner Cu6Sn5 intermetallic layer at the Cu/solder interface. These results agree well with similar observations seen in La-containing solders reported previously. The monotonic shear behavior of reflowed Sn-3.9Ag-0.7Cu- X(Ce, Y)/Cu lap shear joints was studied as well as the creep behavior at 368 K (95 °C). The data were compared with results obtained for Sn-3.9Ag-0.7Cu and Sn-3.9Ag-0.7Cu- XLa alloys. All RE-containing alloys exhibited creep behavior similar to Sn-3.9Ag-0.7Cu. Alloys with Ce additions exhibited a small decrease in ultimate shear strength but higher elongations compared with Sn-Ag-Cu. Similar observations were seen in La-containing solders. The influence of the RE-containing intermetallics (CeSn3 and YSn3) that form in these alloys on the microstructural refinement, solidification behavior, and mechanical performance of these novel materials is discussed.

  16. Structural, vibrational and thermodynamic properties of Ag(n)Cu(34-n) nanoparticles.

    Science.gov (United States)

    Yildirim, Handan; Kara, Abdelkader; Rahman, Talat S

    2009-02-25

    We report results of a systematic study of structural, vibrational and thermodynamical properties of 34-atom bimetallic nanoparticles from the Ag(n)Cu(34-n) family using model interaction potentials as derived from the embedded atom method and invoking the harmonic approximation of lattice dynamics. Systematic trends in the bond length and dynamical properties can be explained largely from arguments based on local coordination and elemental environment. Thus an increase in the number of silver atoms in a given neighborhood introduces a monotonic increase in bond length, while an increase of the copper content does the reverse. Moreover, for the bond lengths of the lowest-coordinated (six and eight) copper atoms with their nearest neighbors (Cu atoms), we find that the nanoparticles divide into two groups with the average bond length either close to (∼2.58 Å) or smaller than (∼2.48 Å) that in bulk copper, accompanied by characteristic features in their vibrational density of states. For the entire set of nanoparticles, we find vibrational modes above the bulk bands of copper/silver. We trace a blue shift in the high-frequency end of the spectrum that occurs as the number of copper atoms increases in the nanoparticles, leading to shrinkage of the bond lengths from those in the bulk. The vibrational densities of states at the low-frequency end of the spectrum scale linearly with frequency as for single-element nanoparticles, with a more pronounced effect for these nanoalloys. The Debye temperature is found to be about one-third of that of the bulk for pure copper and silver nanoparticles, with a non-linear increase as copper atoms increase in the nanoalloy.

  17. Pt74Ag26 nanoparticle-decorated ultrathin MoS2 nanosheets as novel peroxidase mimics for highly selective colorimetric detection of H2O2 and glucose

    Science.gov (United States)

    Cai, Shuangfei; Han, Qiusen; Qi, Cui; Lian, Zheng; Jia, Xinghang; Yang, Rong; Wang, Chen

    2016-02-01

    To extend the functionalities of two-dimensional graphene-like layered compounds as versatile materials, the modification of transition metal dichalcogenide nanosheets such as MoS2 with metal nanoparticles is of great and widespread interest. However, few studies are available on the preparation of bimetallic nanoparticles supported on MoS2. Herein, a facile and efficient method to synthesize MoS2-PtAg nanohybrids by decorating ultrathin MoS2 nanosheets with octahedral Pt74Ag26 alloy nanoparticles has been reported. The as-prepared MoS2-Pt74Ag26 nanohybrids were investigated as novel peroxidase mimics to catalyze the oxidation of classical peroxidase substrate 3,3',5,5'-tetramethylbenzidine (TMB) in the presence of H2O2, producing a blue colored reaction and exhibiting typical Michaelis-Menten kinetics. MoS2-Pt74Ag26 has a higher affinity for H2O2 than horseradish peroxidase (HRP) and a higher vmax value with TMB as the substrate than MoS2. The improved catalytic activity of hybrids for colorimetric reactions could be attributed to the synergistic effects of octahedral Pt74Ag26 nanoparticles and ultrathin MoS2 nanosheets as supports. Meanwhile, the generation of active oxygen species (&z.rad;OH) by H2O2 decomposition with MoS2-Pt74Ag26 was responsible for the oxidation of TMB. On the basis of these findings, a colorimetric method based on MoS2-Pt74Ag26 nanohybrids that is highly sensitive and selective was developed for glucose detection. Lower values of the limit of detection (LOD) were obtained, which is more sensitive than MoS2 nanosheets.To extend the functionalities of two-dimensional graphene-like layered compounds as versatile materials, the modification of transition metal dichalcogenide nanosheets such as MoS2 with metal nanoparticles is of great and widespread interest. However, few studies are available on the preparation of bimetallic nanoparticles supported on MoS2. Herein, a facile and efficient method to synthesize MoS2-PtAg nanohybrids by decorating

  18. Sn-6Bi-2Ag(Cu, Sb)无铅钎料合金微观组织分析%Microstructures of Sn-6Bi-2Ag(Cu,Sb) lead-free solder alloys

    Institute of Scientific and Technical Information of China (English)

    黄明亮; 于大全; 王来; 王富岗

    2002-01-01

    利用差示扫描量热计(DSC)测定了Sn-6Bi-2 Ag, Sn-6Bi-2Ag-0.5Cu, Sn-6Bi-2Ag -2.5Sb三种新无铅钎料合金的熔化温度. 结果表明, 少量Cu的加入能降低Sn-Bi-Ag系无铅钎料合金的熔化温度, 而Sb的加入使合金的熔化温度升高.利用光学显微镜(OM)、扫描电子显微镜(SEM)、能谱分析(EDX)对合金的微观组织进行了分析与比较, 钎料合金的微观组织与冷却条件和合金元素的含量有关, Sb的加入使析出相的尺寸细化.硬度测定表明Sn-Bi-Ag(C u, Sb)无铅钎料合金的硬度远大于纯Sn的硬度, 加入少量的Cu(0.5%), Sb(2.5%)对Sn -Bi-Ag系钎料合金的硬度影响较小.

  19. Biosynthesis of Cu, ZVI, and Ag nanoparticles using Dodonaea viscosa extract for antibacterial activity against human pathogens

    Science.gov (United States)

    Kiruba Daniel, S. C. G.; Vinothini, G.; Subramanian, N.; Nehru, K.; Sivakumar, M.

    2013-01-01

    Biosynthesis of copper, zero-valent iron (ZVI), and silver nanoparticles using leaf extract of Dodonaea viscosa has been investigated in this report. There are no additional surfactants/polymers used as capping or reducing agents for these syntheses. The synthesized nanoparticles were characterized by UV-Vis spectroscopy, X-ray diffraction, atomic force microscopy, and high-resolution transmission electron microscopy. The phase analysis was performed using selected area electron diffraction. The pH dependence of surface plasmon resonance and subsequent size variation has been determined. The synthesized nanoparticles showed spherical morphology and the average size of 29, 27, and 16 nm for Cu, ZVI, and Ag nanoparticles, respectively. Finally, biosynthesized Cu, ZVI, and Ag nanoparticles were tested against human pathogens viz. Gram-negative Escherichia coli, Klebsiella pneumonia, Pseudomonas fluorescens and Gram-positive Staphylococcus aureus and Bacillus subtilis, and showed good antimicrobial activity.

  20. Mineralogical data on angelaite, Cu2AgPbBiS4, from the Los Manantiales District, Chubut, Argentina

    DEFF Research Database (Denmark)

    Topa, D.; Paar, W.H.; Putz, H.

    2010-01-01

    , native gold and galena; less common associates are aikinite, wittichenite, miharaite and cervelleite. Angelaite forms subhedral, commonly oriented inclusions in galena; these may attain a size of up to 200 3 50 mm. The mineral is grey in color with a brownish tint, opaque, and lacks internal reflections...... is strongly anisotropic, with rotation tints in shades of pale grey, deep green and deep blue. We provide the measured values of reflectance in air and oil. The average of 23 electron-microprobe analyses is: Cu 16.7(3), Ag 13.4(2), Pb 27.8(6), Bi 26.6(5), S 16.0(2), total 100.5(5) wt.%, equivalent to Cu2.07Ag...

  1. AgCu Bimetallic Nanoparticles under Effect of Low Intensity Ultrasound: The Cell Viability Study In Vitro

    Directory of Open Access Journals (Sweden)

    Vladan Bernard

    2014-01-01

    Full Text Available The effects of metallic nanoparticles as cytotoxicity or antibacterial activity are widely known. It is also obvious that ultrasound is one of the most widely used therapeutic modalities in medicine. The effect of application of therapeutical ultrasonic field in the presence of metallic nanoparticles AgCu <100 nm modified by phenanthroline or polyvinyl alcohol was examined on human ovarian carcinoma cells A2780. Metallic nanoparticles were characterized by electron microscopy and by measuring of zeta potential. The cell viability was tested by MTT test. The experimental results indicate a significant decrease of cell viability, which was affected by a combined action of ultrasound field and AgCu nanoparticles. The maximum decrease of cells viability was observed for nanoparticles modified by phenanthroline. The effect of metallic nanoparticles on human cell in presence of ultrasound exposure was found—a potential health risk or medical advantage of targeted therapy in the future.

  2. Biosynthesis of Cu, ZVI, and Ag nanoparticles using Dodonaea viscosa extract for antibacterial activity against human pathogens

    Energy Technology Data Exchange (ETDEWEB)

    Kiruba Daniel, S. C. G.; Vinothini, G. [Anna University of Technology, Tiruchirappalli, Department of Nanoscience and Technology (India); Subramanian, N. [Anna University of Technology, Tiruchirappalli, Department of Pharmaceutical Technology (India); Nehru, K. [Anna University of Technology, Tiruchirappalli, Department of Chemistry (India); Sivakumar, M., E-mail: muthusiva@gmail.com [Anna University of Technology, Tiruchirappalli, Department of Nanoscience and Technology (India)

    2013-01-15

    Biosynthesis of copper, zero-valent iron (ZVI), and silver nanoparticles using leaf extract of Dodonaea viscosa has been investigated in this report. There are no additional surfactants/polymers used as capping or reducing agents for these syntheses. The synthesized nanoparticles were characterized by UV-Vis spectroscopy, X-ray diffraction, atomic force microscopy, and high-resolution transmission electron microscopy. The phase analysis was performed using selected area electron diffraction. The pH dependence of surface plasmon resonance and subsequent size variation has been determined. The synthesized nanoparticles showed spherical morphology and the average size of 29, 27, and 16 nm for Cu, ZVI, and Ag nanoparticles, respectively. Finally, biosynthesized Cu, ZVI, and Ag nanoparticles were tested against human pathogens viz. Gram-negative Escherichia coli, Klebsiella pneumonia, Pseudomonas fluorescens and Gram-positive Staphylococcus aureus and Bacillus subtilis, and showed good antimicrobial activity.

  3. In Situ Scanning Electron Microscopy Observation of Tensile Deformation in Sn-Ag-Cu Alloys Containing Rare-Earth Elements

    Science.gov (United States)

    Xiao, Wei Min; Shi, Yao Wu; Lei, Yong Ping; Xia, Zhi Dong; Guo, Fu

    2008-11-01

    The effects of rare-earth (RE) element additions on the tensile deformation mechanism of the Sn-3.8Ag-0.7Cu solder alloy have been investigated. The results show that adding RE elements can remarkably improve the tensile strength and elongation of the Sn-3.8Ag-0.7Cu alloy. The increase in the mechanical properties are attributed to the constraints of microcrack growth and grain boundary sliding in the eutectic phase as well as the relaxation of stress concentration in the β-Sn phase due to the addition of the RE elements. It is considered that the RE elements strengthen the eutectic phase and increase the deformation resistance of this alloy.

  4. Correlations between IMC thickness and three factors in Sn-3Ag-0.5Cu alloy system

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The effects of Ni content, soldering temperature and time on the IMC thickness in Sn-3Ag-0.5Cu and Sn-3Ag-0.5Cu-0.2Co alloys were researched using uniform design method and computer programs. For each alloy, the factors were divided into three levels in the experiment. Two correlative equations are given by regression. They indicate that the effects of three factors on the function are in the mutual and quadratic forms. And the analysis of variance shows the equations are sound and meaningful. Using the equations, it is easy to search, predict and control the IMC thickness. The existence of element Co accelerates the crystallization and growing up of IMC.

  5. Effect of Sb Addition on the Solidification of Deeply Undercooled Ag-28.1 wt. % Cu Eutectic Alloy

    Directory of Open Access Journals (Sweden)

    Su Zhao

    2016-02-01

    Full Text Available Ag-28.1 wt. % Cu eutectic alloy solidifies in the form of eutectic dendrite at undercooling above 76 K. The remelting and ripening of the original lamellar eutectics result in the formation of the anomalous eutectics in the final microstructure. The addition of the third element Sb (0.5 and 1 wt. % does not change the growth mode, but enlarges the volume fraction of anomalous eutectics because of the increasing recalescence rate. The additional constitutional supercooling owing to the Sb enrichment ahead of the eutectic interface promotes the branching of the interface and as a result fine lamellar eutectic arms form around the anomalous eutectics in the Sb-added Ag-28.1 wt. % Cu eutectic alloy.

  6. Electrochemical Performance and Storage Mechanism of Ag2 Mo2 O7 Micro-rods as the Anode Material for Lithium-Ion Batteries.

    Science.gov (United States)

    Zhang, Meina; Gao, Yu; Chen, Nan; Ge, Xin; Chen, Hong; Wei, Yingjin; Du, Fei; Chen, Gang; Wang, Chunzhong

    2017-04-11

    Ag2 Mo2 O7 micro-rods are prepared by one-step hydrothermal method and their lithium electrochemical properties, as the anode for lithium-ion batteries, are comprehensively studied in terms of galvanostatic charge-discharge cycling, cyclic voltammetry, and rate performance measurements. The electrode delivers a high reversible capacity of 825 mAh g(-1) at a current density of 100 mA g(-1) and a superior rate capability with a discharge capacity of 263 mAh g(-1) under the high current density of 2 Ag(-1) . The structural transition and phase evolution of Ag2 Mo2 O7 were investigated by using ex situ XRD and TEM. The Ag2 Mo2 O7 electrode is likely to be decomposed into amorphous molybdenum, Li2 O, and metallic silver based on the conversion reaction. Silver nanoparticles are not involved in the subsequent electrochemical cycles to form a homogeneous conducting network. Such in situ decomposition behavior provides an insight into the mechanism of the electrochemical reaction for the anode materials and would contribute to the design of new electrode materials in future. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. The late Oligocene Cevizlidere Cu-Au-Mo deposit, Tunceli Province, eastern Turkey

    Science.gov (United States)

    İmer, Ali; Richards, Jeremy P.; Creaser, Robert A.; Spell, Terry L.

    2015-02-01

    The Cevizlidere deposit, located in the Tunceli Province of eastern Anatolia, is the largest porphyry Cu-Au-Mo system in Turkey. The deposit is spatially related to a composite stock, which was emplaced into Paleozoic limestones and Paleogene andesitic rocks to the southeast of the Munzur mountains, near the southwestern margin of the Ovacık pull-apart basin. The host plutonic rocks at Cevizlidere are porphyritic, medium-K calc-alkaline diorites and granodiorites. 40Ar/39Ar incremental step-heating analysis of two igneous biotite separates obtained from syn-mineral diorite porphyry yielded late Oligocene cooling ages of 25.49 ± 0.10 and 25.10 ± 0.14 Ma, whereas hydrothermal biotite yielded an age of 24.73 ± 0.08 Ma. Re-Os ages obtained from two molybdenite separates (24.90 ± 0.10 and 24.78 ± 0.10 Ma) indicate that porphyry-style alteration and mineralization developed shortly after magma emplacement. The whole-rock geochemical composition of the Cevizlidere porphyry intrusions is consistent with derivation from partial melting of the metasomatized supra-subduction zone mantle. However, based on regional tectonic reconstructions, Oligocene magmatic activity in this area appears to be related to a major kinematic reorganization that took place at around 25 Ma, during the switch from subduction to collisional tectonics in eastern Anatolia. This kinematic switch may be attributed to break-off of the Southern Neo-Tethys oceanic slab prior to the Arabia-Eurasia continent-continent collision (~12-10 Ma) following widespread middle Eocene (50-43 Ma) arc/back-arc magmatism. In this respect, the subduction-related tectonic setting of the late Oligocene Cevizlidere porphyry deposit is similar to that of the middle Eocene Çöpler epithermal Au deposit. The late timing of Cevizlidere with respect to the Southern Neo-Tethys subduction may be comparable to some early to late Miocene porphyry-epithermal systems that lie within the contiguous Urumieh-Dokhtar belt in central

  8. The crystal structure of Gabrielite, Tl2AgCu2As3S7, a new species of Thallium Sulfosalt from Lengenbach, Switzerland

    DEFF Research Database (Denmark)

    Balic-Zunic, Tonci; Makovicky, Emil; Karanovic, Ljiljana

    2006-01-01

    Gabrielite, Tl2AgCu2As3S7, is a new species of sulfosalt mineral occurring in the famous Lengenbach locality, at Binntal, Canton Valais, Switzerland. It was discovered in association with numerous other As sulfosalts, such as hutchinsonite, hatchite, edenharterite, trechmannite, tennantite...... formula Tl6(Ag,Cu)3IV(Cu,Ag)6III[(As,Sb)S3]3[(As,Sb)2S4]3; the empirical formula obtained from the microprobe data is Tl5.95(Ag2.56Cu6.46) 9.02(As8.23Sb0.48) 8.71S21. The name of the mineral honors Walter Gabriel, of Basel, Switzerland, well-known mineral photographer and expert of Lengenbach minerals....

  9. Efficient enhancement of hydrogen production by Ag/Cu{sub 2}O/ZnO tandem triple-junction photoelectrochemical cell

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ying; Ren, Feng, E-mail: fren@whu.edu.cn; Chen, Chao; Liu, Chang; Xing, Zhuo; Liu, Dan; Xiao, Xiangheng; Wu, Wei; Zheng, Xudong; Liu, Yichao; Jiang, Changzhong [Center for Ion Beam Application and Center for Electron Microscopy, School of Physics and Technology, Wuhan University, Wuhan 430072 (China); Shen, Shaohua; Fu, Yanming [International Research Center for Renewable Energy, State Key Laboratory of Multiphase Flow in Power Engineering, Xi' an Jiaotong University, Xi' an 710049 (China)

    2015-03-23

    Highly efficient semiconductor photoelectrodes for solar hydrogen production through photocatalytic water splitting are a promising and challenge solution to solve the energy problems. In this work, Ag/Cu{sub 2}O/ZnO tandem triple-junction photoelectrode was designed and prepared. An increase of 11 times of photocurrent is achieved in the Ag/Cu{sub 2}O/ZnO photoelectrode comparing to that of the Cu{sub 2}O film. The high performance of the Ag/Cu{sub 2}O/ZnO film is due to the optimized design of the tandem triple-junction structure, where the localized surface Plasmon resonance of Ag and the hetero-junctions efficiently absorb solar energy, produce, and separate electron-hole pairs in the photocathode.

  10. A series of novel Mo(W)/Cu/S heterobimetallic clusters containing SBu(t-) linkages. Synthesis, structure and spectroscopic characterisation.

    Science.gov (United States)

    Li, Zhihua; Du, Shaowu; Wu, Xintao

    2004-08-21

    Six new copper(I) clusters, [Et4N]2[(MOS3)2Cu4(mu-SBu(t))2](1a: M = Mo; 1b: M = W), [Et4N][(MOS3)2Cu6(mu-SBu(t))3](2a: M = Mo; 2b: M = W) and [Bu4N]2[(MOS3)3Cu9(mu-SBu(t))3(mu3-SBu(t))][I](3a: M = Mo; 3b: M = W) have been prepared by the reactions of thiomolybdates and thiotungstates with CuSBu(t) under various conditions. The [(MOS3)2Cu4(mu-SBu(t))2](2-) dianions in 1a and 1b represent the first examples of double butterfly-shaped Mo(W)/Cu/S clusters. Addition of more Cu atoms to 1a or 1b resulted in the formation of incomplete double cubane-like clusters 2a or 2b. Single crystal structural studies showed that the anions of 2a and 2b are formed in a mouth-to-mouth fashion by two incomplete cubanes [MOS3Cu3](M = Mo, W) with three mu-SBu(t-) linkages. In the molecular structure of 3b, the SBu(t-) ligands act as mu- and mu3-bridges which link three WOS3Cu3 incomplete cubane-like fragments. An iodide ion crystallises in the cavity defined by the three incomplete cubanes in 3b. The spectroscopic and electrochemical properties of all the clusters are also studied.

  11. Pt74Ag26 nanoparticle-decorated ultrathin MoS2 nanosheets as novel peroxidase mimics for highly selective colorimetric detection of H2O2 and glucose.

    Science.gov (United States)

    Cai, Shuangfei; Han, Qiusen; Qi, Cui; Lian, Zheng; Jia, Xinghang; Yang, Rong; Wang, Chen

    2016-02-14

    To extend the functionalities of two-dimensional graphene-like layered compounds as versatile materials, the modification of transition metal dichalcogenide nanosheets such as MoS2 with metal nanoparticles is of great and widespread interest. However, few studies are available on the preparation of bimetallic nanoparticles supported on MoS2. Herein, a facile and efficient method to synthesize MoS2-PtAg nanohybrids by decorating ultrathin MoS2 nanosheets with octahedral Pt74Ag26 alloy nanoparticles has been reported. The as-prepared MoS2-Pt74Ag26 nanohybrids were investigated as novel peroxidase mimics to catalyze the oxidation of classical peroxidase substrate 3,3',5,5'-tetramethylbenzidine (TMB) in the presence of H2O2, producing a blue colored reaction and exhibiting typical Michaelis-Menten kinetics. MoS2-Pt74Ag26 has a higher affinity for H2O2 than horseradish peroxidase (HRP) and a higher vmax value with TMB as the substrate than MoS2. The improved catalytic activity of hybrids for colorimetric reactions could be attributed to the synergistic effects of octahedral Pt74Ag26 nanoparticles and ultrathin MoS2 nanosheets as supports. Meanwhile, the generation of active oxygen species (˙OH) by H2O2 decomposition with MoS2-Pt74Ag26 was responsible for the oxidation of TMB. On the basis of these findings, a colorimetric method based on MoS2-Pt74Ag26 nanohybrids that is highly sensitive and selective was developed for glucose detection. Lower values of the limit of detection (LOD) were obtained, which is more sensitive than MoS2 nanosheets.

  12. Distributions of dissolved trace metals (Cd, Cu, Mn, Pb, Ag in the southeastern Atlantic and the Southern Ocean

    Directory of Open Access Journals (Sweden)

    M. Boye

    2012-03-01

    Full Text Available Comprehensive synoptic datasets (surface water down to 4000 m of dissolved cadmium (Cd, copper (Cu, manganese (Mn, lead (Pb and silver (Ag are presented along a section between 34° S and 57° S in the southeastern Atlantic Ocean and the Southern Ocean to the south off South Africa. The vertical distributions of Cu, Ag, and of Cd display nutrient-like profiles similar to silicic acid, and phosphate, respectively. The distribution of Mn shows a subsurface maximum in the oxygen minimum zone, whereas Pb concentrations are rather invariable with depth. Dry deposition of aerosols is thought to be an important source of Pb to surface waters close to South Africa, and dry deposition and snowfall may have been significant sources of Cu and Mn at the higher latitudes. Furthermore, the advection of water-masses enriched in trace metals following contact with continental margins appeared to be an important source of trace elements to the surface, intermediate and deep waters in the southeastern Atlantic Ocean and the Antarctic Circumpolar Current. Hydrothermal inputs appeared to have formed a source of trace metals to the deep waters over the Bouvet Triple Junction ridge crest, as suggested by relatively enhanced dissolved Mn concentrations. The biological utilization of Cu and Ag was proportional to that of silicic acid across the section, suggesting that diatoms formed an important control over the removal of Cu and Ag from surface waters. However uptake by dino- and nano-flagelattes may have influenced the distribution of Cu and Ag in the surface waters of the subtropical Atlantic domain. Cadmium correlated strongly with phosphate (P, yielding lower Cd/P ratios in the subtropical surface waters where phosphate concentrations were below 0.95 μM. The greater depletion of Cd relative to P observed in the Weddell Gyre compared to the Antarctic Circumpolar Current could be due to increase Cd-uptake induced by iron-limiting conditions in these High

  13. Cathode catalysis performance of SmBaCuMO_(5+δ) (M=Fe, Co, Ni) in ammonia synthesis

    Institute of Scientific and Technical Information of China (English)

    张正方; 钟正平; 刘瑞泉

    2010-01-01

    The SmBaCuMO5+δ (M=Fe, Co, Ni) (SBCM) powders were synthesized by the citrate sol-gel method and the powders were sintered to ceramic pellets. The powders and sintered ceramic pellets were characterized with XRD, TEM and SEM measurements. The cathode catalytic performances of SBCM ceramic pellets for ammonia synthesis were studied from wet hydrogen and dry nitrogen at atmospheric pressure and low temperature, using SBCM ceramic pellets as cathode, Nafion proton exchange membrane as electrolyte, Ni-Ce0.8Sm0....

  14. 57Fe75Mo8Cu1B16 metallic glass studied by CEMS, CXMS and HEXRD

    Science.gov (United States)

    Cesnek, Martin; Miglierini, Marcel; Bednarčík, Jozef

    2016-10-01

    57Fe75Mo8Cu1B16 metallic glass prepared by single roller melt spinning was investigated by conversion electron Mössbauer spectroscopy, conversion X-ray Mössbauer spectroscopy and high-energy X-ray diffraction. All methods confirmed presence of amorphous structure without traces of a crystalline phase. Results obtained by Mössbauer spectrometry suggest predominant appearance of magnetic regions on side of the ribbon which was in contact with the quenching wheel. In situ High-energy X-ray diffraction experiment revealed transition from ferromagnetic to paramagnetic state and it was even possible to estimate the Curie temperature.

  15. Precipitation Hardening and Statistical Modeling of the Aging Parameters and Alloy Compositions in Al-Cu-Mg-Ag Alloys

    Science.gov (United States)

    Al-Obaisi, A. M.; El-Danaf, E. A.; Ragab, A. E.; Soliman, M. S.

    2016-06-01

    The addition of Ag to Al-Cu-Mg systems has been proposed to replace the existing high-strength 2xxx and 7xxx Al alloys. The aged Al-Cu-Mg-Ag alloys exhibited promising properties, due to special type of precipitates named Ω, which cooperate with other precipitates to enhance the mechanical properties significantly. In the present investigation, the effect of changing percentages of alloying elements, aging time, and aging temperature on the hardness values was studied based on a factorial design. According to this design of experiments (DOE)—23 factorial design, eight alloys were cast and hot rolled, where (Cu, Mg, and Ag) were added to aluminum with two different levels for each alloying element. These alloys were aged at different temperatures (160, 190, and 220 °C) over a wide range of time intervals from 10 min. to 64 h. The resulting hardness data were used as an input for Minitab software to model and relate the process variables with hardness through a regression analysis. Modifying the alloying elements' weight percentages to the high level enhanced the hardness of the alloy with about 40% as compared to the alloy containing the low level of all alloying elements. Through analysis of variance (ANOVA), it was figured out that altering the fraction of Cu had the greatest effect on the hardness values with a contribution of about 49%. Also, second-level interaction terms had about 21% of impact on the hardness values. Aging time, quadratic terms, and third-level interaction terms had almost the same level of influence on hardness values (about 10% contribution). Furthermore, the results have shown that small addition of Mg and Ag was enough to improve the mechanical properties of the alloy significantly. The statistical model formulated interpreted about 80% of the variation in hardness values.

  16. CuAg Sıvı Metalinde Amorf Oluşumunun Moleküler Dinamik Benzetimi

    Directory of Open Access Journals (Sweden)

    Burcu BOZKURT ÇIRAK

    2014-02-01

    Full Text Available Çok cisim potansiyellerini tanımlamada yaygın olarak kullanılan yaklaşımlardan gömülmüş atom yöntemi (Embedded Atom Method, EAM, atomlar arasındaki fiziksel etkileşmeleri modellemek için kullanılır. EAM yaklaşımında kristal içindeki bir atomun enerjisi, itici ve çekici etkileşme fonksiyonuna bağlı olarak hesaplanmaktadır. Bu çalışmada, CuAg sıvı metalinin hızlı soğutulması sonucu elde edilen amorf yapı, moleküler dinamik benzetim yöntemi ile incelenmiştir. Cu, Ag ve CuAg için Sutton-Chen EAM fonksiyonlarının e, c, ao, m ve n parametreleri kullanılmıştır. Benzetim çalışmasında, CuAg alaşımının 200-1600 K sıcaklık aralığında üç farklı soğutma hızı için bazı termodinamik özellikleri incelenmiştir. Bu işlemler sırasında meydana gelen yapısal değişimler radyal dağılım fonksiyonu (RDF eğrileri yardımıyla analiz edilmiştir. Anahtar Kelimeler: Metal Camlar, Moleküler Dinamik Benzetim, Gömülmüş Atom Yöntemi, Sutton-Chen Potansiyeli

  17. Constitutive Behavior of Mixed Sn-Pb/Sn-3.0Ag-0.5Cu Solder Alloys

    Science.gov (United States)

    Tucker, J. P.; Chan, D. K.; Subbarayan, G.; Handwerker, C. A.

    2012-03-01

    During the transition from Pb-containing solders to Pb-free solders, joints composed of a mixture of Sn-Pb and Sn-Ag-Cu often result from either mixed assemblies or rework. Comprehensive characterization of the mechanical behavior of these mixed solder alloys resulting in a deformationally complete constitutive description is necessary to predict failure of mixed alloy solder joints. Three alloys with 1 wt.%, 5 wt.%, and 20 wt.% Pb were selected so as to represent reasonable ranges of Pb contamination expected from different 63Sn-37Pb components mixed with Sn-3.0Ag-0.5Cu. Creep and displacement-controlled tests were performed on specially designed assemblies at temperatures of 25°C, 75°C, and 125°C using a double lap shear test setup that ensures a nearly homogeneous state of plastic strain at the joint interface. The observed changes in creep and tensile behavior with Pb additions were related to phase equilibria and microstructure differences observed through differential scanning calorimetric and scanning electron microscopic cross-sectional analysis. As Pb content increased, the steady-state creep strain rates increased, and primary creep decreased. Even 1 wt.% Pb addition was sufficient to induce substantially large creep strains relative to the Sn-3.0Ag-0.5Cu alloy. We describe rate-dependent constitutive models for Pb-contaminated Sn-Ag-Cu solder alloys, ranging from the traditional time-hardening creep model to the viscoplastic Anand model. We illustrate the utility of these constitutive models by examining the inelastic response of a chip-scale package (CSP) under thermomechanical loading through finite-element analysis. The models predict that, as Pb content increases, total inelastic dissipation decreases.

  18. Electronic and structural properties of A Al 2Se 4 ( A=Ag, Cu, Cd, Zn) chalcopyrite semiconductors

    Science.gov (United States)

    Mishra, S.; Ganguli, B.

    2011-07-01

    We have studied the structural and electronic proper