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Sample records for cu damascene process

  1. Fundamental Properties of Organic Low-k Dielectrics Usable in the Cu Damascene Process

    Science.gov (United States)

    Nomura, Yutaka; Ota, Fumihiko; Kurino, Hiroyuki; Koyanagi, Mitsumasa

    2005-11-01

    The material parameters for organic low-k dielectrics usable in the damascene process were studied using two different types of polymers with similar low dielectric constants, namely, the PQ-600 thermoplastic polymer and the SiLK thermosetting polymer. The resistibility of these polymers in the damascene process was investigated through hard-mask (SiO2) deposition, etching and chemical mechanical polishing (CMP) processes using scanning probe microscopy (SPM), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and a modified edge liftoff test (m-ELT). For the PQ-600 film, damage was observed in the deposition process and dissolution of the film occurred during chemical cleaning in the etching process. On the other hand, the SiLK film was combinable with the Cu damascene process and usable as an interlayer dielectric (ILD) in one-level Cu wiring. A high glass transition temperature (Tg) and chemical resistance resulting from the thermosetting structure are considered to be the essential properties required for the desired organic low-k dielectrics. In eddition, the electrical properies of the SiLK film were investigated using a one-level test element group (TEG) formed through a single Cu damascene process. The dielectric constant of the SiLK film extracted from the Cu damascene TEG compared with that of bulk SiO2 was reduced by 24%. The leakage current measured at 1 MV/cm between the adjoining Cu lines at the TEG pattern with a hard mask was 9.7× 10-10 A/cm2, and dielectric breakdown occurred at 5.5 MV/cm.

  2. Immortality of Cu damascene interconnects

    Science.gov (United States)

    Hau-Riege, Stefan P.

    2002-04-01

    We have studied short-line effects in fully-integrated Cu damascene interconnects through electromigration experiments on lines of various lengths and embedded in different dielectric materials. We compare these results with results from analogous experiments on subtractively-etched Al-based interconnects. It is known that Al-based interconnects exhibit three different behaviors, depending on the magnitude of the product of current density, j, and line length, L: For small values of (jL), no void nucleation occurs, and the line is immortal. For intermediate values, voids nucleate, but the line does not fail because the current can flow through the higher-resistivity refractory-metal-based shunt layers. Here, the resistance of the line increases but eventually saturates, and the relative resistance increase is proportional to (jL/B), where B is the effective elastic modulus of the metallization system. For large values of (jL/B), voiding leads to an unacceptably high resistance increase, and the line is considered failed. By contrast, we observed only two regimes for Cu-based interconnects: Either the resistance of the line stays constant during the duration of the experiment, and the line is considered immortal, or the line fails due to an abrupt open-circuit failure. The absence of an intermediate regime in which the resistance saturates is due to the absence of a shunt layer that is able to support a large amount of current once voiding occurs. Since voids nucleate much more easily in Cu- than in Al-based interconnects, a small fraction of short Cu lines fails even at low current densities. It is therefore more appropriate to consider the probability of immortality in the case of Cu rather than assuming a sharp boundary between mortality and immortality. The probability of immortality decreases with increasing amount of material depleted from the cathode, which is proportional to (jL2/B) at steady state. By contrast, the immortality of Al-based interconnects is

  3. Probabilistic immortality of Cu damascene interconnects

    Science.gov (United States)

    Hau-Riege, Stefan P.

    2002-02-01

    We have studied electromigration short-line effects in Cu damascene interconnects through experiments on lines of various lengths L, stressed at a variety of current densities j, and embedded in different dielectric materials. We observed two modes of resistance evolution: Either the resistance of the lines remains constant for the duration of the test, so that the lines are considered immortal, or the lines fail due to abrupt open-circuit failure. The resistance was not observed to gradually increase and then saturate, as commonly observed in Al-based interconnects, because the barrier is too thin and resistive to serve as a redundant current path should voiding occur. The critical stress for void nucleation was found to be smaller than 41 MPa, since voiding occurred even under the mildest test conditions of j=2 MA/cm2 and L=10.5 μm at 300 °C. A small fraction of short Cu lines failed even at low current densities, which deems necessary a concept of probabilistic immortality rather than deterministic immortality. Experiments and modeling suggest that the probability of immortality is described by (jL2/B), where B is the effective elastic modulus of the metallization scheme. By contrast, the immortality of Al-based interconnects with shunt layers is described by (jL) if no voids nucleate, and (jL/B) if voids do nucleate. Even though the phenomenology of short-line effects differs for Al- and Cu-based interconnects, the immortality of interconnects of either materials system can be explained by the phenomena of nucleation barriers for void formation and void-growth saturation. The differences are due solely to the absence of a shunt layer and the low critical stress for void nucleation in the case of Cu.

  4. Dual damascene BEOL processing using multilevel step and flash imprint lithography

    Science.gov (United States)

    Chao, Brook H.; Palmieri, Frank; Jen, Wei-Lun; McMichael, D. Hale; Willson, C. Grant; Owens, Jordan; Berger, Rich; Sotoodeh, Ken; Wilks, Bruce; Pham, Joseph; Carpio, Ronald; LaBelle, Ed; Wetzel, Jeff

    2008-03-01

    Step and Flash Imprint Lithography (S-FIL®) in conjunction with Sacrificial Imprint Materials (SIM) shows promise as a cost effective solution to patterning sub 45nm features and is capable of simultaneously patterning two levels of interconnect structures, which provides a high throughput and low cost BEOL process. This paper describes the integration of S-FIL into an industry standard Cu/low-k dual damascene process that is being practiced in the ATDF at Sematech in Austin. The pattern transferring reactive ion etching (RIE) process is the most critical step and was extensively explored in this study. In addition to successful process development, the results provide useful insight into the optimal design of multilevel templates which must take into account the characteristics of both the imaging material and the dielectric layer. The template used in this study incorporates both the via and trench levels of an M2 (Metal 2) test vehicle that incorporates via chains with varying via dimensions, Kelvin test structures, serpentines, etc. The smallest vias on the template are 120nm vias with an aspect ratio of 2.0 and the smallest dense lines are 125nm/175nm with an aspect ratio of 2.9. Two inter-level dielectrics (ILD), Coral® and Black Diamond® were studied. No trench etch stop was incorporated in the ILD film stack. A multi-step, in-situ etching scheme was developed that achieves faithful pattern transfer from the sacrificial imprint material (SIM) into the underlying low k ILD with surprisingly wide process latitude. This multi-step scheme includes the following etch steps: a residual layer open, a via etch, a trench descum, a trench etch, and an SIM removal ash. Among these steps, the trench etch was found to be the most challenging to develop and it holds the key to producing high aspect ratio dual damascene features. An etching chemistry based on two fluorocarbon gases, CF 4 and C 4F 8, was found to be very effective in delivering the desired etch profiles

  5. Photonic Damascene Process for Integrated High-Q Microresonator Based Nonlinear Photonics

    CERN Document Server

    Pfeiffer, Martin H P; Brasch, Victor; Zervas, Michael; Geiselmann, Michael; Jost, John D; Kippenberg, Tobias J

    2015-01-01

    High confinement, integrated silicon nitride (SiN) waveguides have recently emerged as attractive platform for on-chip nonlinear optical devices. The fabrication of high-Q SiN microresonators with anomalous group velocity dispersion (GVD) has enabled broadband nonlinear optical frequency comb generation. Such frequency combs have been successfully applied in coherent communication and ultrashort pulse generation. However, the reliable fabrication of high confinement waveguides from stoichiometric, high stress SiN remains challenging. Here we present a novel photonic Damascene fabrication process enabling the use of substrate topography for stress control and thin film crack prevention. With close to unity sample yield we fabricate microresonators with $1.35\\,\\mu\\mathrm{m}$ thick waveguides and optical Q factors of $3.7\\times10^{6}$ and demonstrate single temporal dissipative Kerr soliton (DKS) based coherent optical frequency comb generation. Our newly developed process is interesting also for other material ...

  6. Integration Process Development for Improved Compatibility with Organic Non-Porous Ultralow-k Dielectric Fluorocarbon on Advanced Cu Interconnects

    Science.gov (United States)

    Gu, Xun; Tomita, Yugo; Nemoto, Takenao; Miyatani, Kotaro; Saito, Akane; Kobayashi, Yasuo; Teramoto, Akinobu; Kuroda, Rihito; Kuroki, Shin-Ichiro; Kawase, Kazumasa; Nozawa, Toshihisa; Matsuoka, Takaaki; Sugawa, Shigetoshi; Ohmi, Tadahiro

    2012-05-01

    Integration of an organic non-porous ultralow-k dielectric, fluorocarbon (k= 2.2), into advanced Cu interconnects was demonstrated. The challenges of process-induced damage, such as delamination and variances of both the structure and electrical properties of the fluorocarbon during fabrication, were investigated on Cu/fluorocarbon damascene interconnects. A titanium-based barrier layer, instead of a tantalum-based barrier layer, was used to avoid delamination between Cu and fluorocarbon in Cu/fluorocarbon interconnects. A moisture-hermetic dielectric protective layer was also effective to avoid damage induced by wet chemical cleaning. On the other hand, a post-etching nitrogen plasma treatment to form a stable protective layer on the surface of the fluorocarbon was proposed for the practical minimization of damage introduction to fluorocarbon in the following damascene process, such as post-etching cleaning.

  7. Electromigration of damascene copper of IC interconnect

    Science.gov (United States)

    Meyer, William Kevin

    Copper metallization patterned with multi-level damascene process is prone to electromigration failure, which affects the reliability and performance of IC interconnect. In typical products, interconnect that is not already constrained by I·R drop or Joule self-heating operates at 'near threshold' conditions. Measurement of electromigration damage near threshold is very difficult due to slow degradation requiring greatly extended stress times, or high currents that cause thermal anomalies. Software simulations of the electromigration mechanism combined with characterization of temperature profiles allows extracting material parameters and calculation of design rules to ensure reliable interconnect. Test structures capable of demonstrating Blech threshold effects while allowing thermal characterization were designed and processed. Electromigration stress tests at various conditions were performed to extract both shortline (threshold) and long-line (above threshold) performance values. The resistance increase time constant shows immortality below Je·L (product of current density and segment length) of 3200 amp/cm. Statistical analysis of times-to-failure show that long lines last 105 hours at 3.1 mA/mum2 (120°C). While this is more robust than aluminum interconnect, the semiconductor industry will be challenged to improve that performance as future products require.

  8. Damascene Array Structure of Phase Change Memory Fabricated with Chemical Mechanical Polishing Method

    Institute of Scientific and Technical Information of China (English)

    LIU Qi-Bin; SONG Zhi-Tang; ZHANG Kai-Liang; WANG Liang-Yong; FENG Song-Lin; CHEN Bomy

    2006-01-01

    @@ A damascene structure of phase change memory (PCM) is fabricated successfully with the chemical mechanical polishing (CMP) method, and the CMP of Ge2Sb2Te5 (GST) and Ti films is investigated. The polished surface of wafer is analysed by scanning electron microscopy (SEM) and an energy dispersive spectrometer (EDS). The measurements show that the damascene device structure of phase change memory is achieved by the CMP process.After the top electrode is deposited, dc sweeping test on PCM reveals that the phase change can be observed.The threshold current of array cells varies between 0.90mA and 1.15mA.

  9. Evaluation of the Cu-CMP process by TOF-SIMS and XPS: time dependence of Cu surface adsorbents and oxidation states

    Science.gov (United States)

    Nishi, A.; Sado, M.; Miki, T.; Fukui, Y.

    2003-01-01

    CMP (chemical mechanical polishing) and the post-CMP cleaning for damascene processes are necessary to produce Cu interconnects. Many kinds of additives, such as an oxidizer, an inhibitor, etching chemicals, are usually in the CMP slurries. Cu films, however, are easily oxidized and corroded by those chemicals, so it is important to choose the chemicals and to decide how long Cu films are treated with them. If we can grasp the residues on Cu films and the Cu oxidation, it will be easy to optimize the conditions of CMP processes. Then we treated Cu films with benzotriazole (BTA), a well-known Cu corrosion inhibitor, in some conditions, and we investigated the residues and the Cu oxidation. The results of TOF-SIMS measurements seem to correlate with the results of XPS measurements. Ions derived from BTA are at high relative intensities in a sample treated with high concentrated BTA, and it is not so highly oxidized. On the other hand, they are at low relative intensities in a sample treated with acids, and it is rapidly oxidized. These analysis methods can be applied in various fields.

  10. A damascene platform for controlled ultra-thin nanowire fabrication.

    Science.gov (United States)

    Guilmain, M; Labbaye, T; Dellenbach, F; Nauenheim, C; Drouin, D; Ecoffey, S

    2013-06-21

    This paper presents a damascene process for the fabrication of titanium micro/nanostructures and nanowires with adjustable thickness down to 2 nm. Their depth is precisely controlled by chemical-mechanical planarization together with in-process electrical characterization. The latter, in combination with a model of the titanium resistivity versus thickness, allows control of the metal line depth in the nanometer range. In summary, we have developed a planarization end point detection method for metal nanostructures. In addition, the model adopted covers geometrical influences like oxidation and ageing. The fabricated titanium nanowire test structures have a thickness ranging from 2 to 25 nm and a width ranging between 15 and 230 nm.

  11. Damascene patterned metal/adhesive wafer bonding for three-dimensional integration

    Science.gov (United States)

    McMahon, J. Jay

    Wafer bonding of damascene patterned metal/adhesive surfaces is explored for a new three-dimensional (3D) integration technology platform. By bonding a pair of damascene patterned metal/adhesive layers, high density micron-sized vias can be formed for interconnection of fully fabricated integrated circuit (IC) dies at the wafer-level. Such via dimensions increase the areal interconnect density by at least two orders of magnitude over current package and die-stacking approaches to 3D integration. The adhesive field-dielectric produces a high critical adhesion energy bond and has the potential to produce void-free bonded interfaces. This new technology platform has been demonstrated by fabricating and characterizing inter-wafer via-chains on 200 mm diameter Si wafers. Copper and partially cured divinylsiloxane bis-benzocyclobutene (BCB) are selected as the metal and adhesive, respectively, and unit processes for this demonstration are described. Typical alignment tolerance is ˜2 mum, and baseline bonding conditions include vacuum of 5x10-4 mbar, bonding force of 10 kN, and two step bonding temperature of 250°C for 60 min followed by 350°C for 60 min. Integration issues associated with the damascene patterning and the wafer bonding processes are discussed, particularly the resulting topography of damascene patterned Cu/BCB. Cross-sectional investigation of bonded and annealed inter-wafer interconnections provides insight into the Cu-Cu and BCB-BCB bonding interfaces. Inter-wafer specific contact resistance is measured to be on the order of 10-7 O-cm 2 for these via-chains. Several material characterization techniques have been explored to evaluate partially cured BCB as an adhesive field-dielectric. To investigate the critical adhesion energy, Gc, four-point bending is utilized to compare surfaces bonded after chemical-mechanical planarization (CMP) and various post-CMP treatments. The Gc of bonded 50% partially cured BCB is measured to be in the range of 32--44 J

  12. High resolution nanoimprint templates for dual damascene: fabrication and imprint results

    Science.gov (United States)

    Irmscher, Mathias; Butschke, Joerg; Carpio, Ron; Chao, Brook; Jen, Wei-Lun; Koepernik, Corinna; Nedelmann, Lorenz; Owens, Jordan; Palmieri, Frank; Pritschow, Marcus; Reuter, Christian; Sailer, Holger; Satoodeh, Ken; Wetzel, Jeff; Wilks, Bruce; Willson, Grant

    2008-03-01

    A dual damascene template fabrication process has been developed, which enables the structuring of high-resolution, high-aspect pillars on top of lines. Based on this technology templates with three different designs have been fabricated and characterized. Two templates are dedicated for an assessment of the fabrication process using a regular test design on one hand and an arbitrary CMOS design on the other hand. With the third template via chains shall be later realized as demonstrator for electrical tests. The templates have been imprinted in resist and sacrificial material on an Imprio 55 and an Imprio 100 tool. The usability of each fabricated template could be confirmed for the specific application. For the template manufacturing a Vistec variable shape e-beam (VSB) writer SB352HR and appropriate positive-tone and negative-tone chemically amplified resists (CAR) have been used.

  13. Simulations of Metal Cu in Heating Process

    Institute of Scientific and Technical Information of China (English)

    ZHANG, Tao(张弢); WU, Ai-Ling(吴爱玲); GUAN, Li(管立); QI, Yuan-Hua(齐元华)

    2004-01-01

    Based on the Finnis-Sinsclair (FS) many-body potential model, the melting process of a system, which consists of 500 Cu atoms, controlled by period boundary condition has been simulated. The means of pair correlation function, mean square displacement and Honeycutt-Anderson bonded pair have been used to characterize the melting behavior of Cu at different heating rates. The simulation indicates that melting point of metal Cu is 1444 K during a continuous heating process, and the calculated diffusion constant at the melting point is 4.31×10-9 m2/s. These results are better than those from the EAM method, showing that the FS potential model works well in some disordered systems.

  14. Fuzzy analytical hierarchy process and GIS for predictive cu -au ...

    African Journals Online (AJOL)

    Fuzzy analytical hierarchy process and GIS for predictive cu -au porphyry in ... process (Fuzzy AHP) that is the most popular multi-criteria decision-making techniques. ... for predictive Mineral prospectively mapping (MPM) for Cu -Au porphyry.

  15. High-performance sidewall damascened tri-gate poly-si TFTs with the strain proximity free technique and stress memorization technique

    Science.gov (United States)

    Hsieh, Dong-Ru; Kuo, Po-Yi; Lin, Jer-Yi; Chen, Yi-Hsuan; Chang, Tien-Shun; Chao, Tien-Sheng

    2017-02-01

    In this paper, strained channel-sidewall damascened tri-gate polycrystalline silicon thin-film transistors (SC-SWDTG TFTs) have been successfully fabricated and then demonstrated by an innovative process flow. This process flow without the use of advanced lithography processes combines the sidewall damascened technique (SWDT) and two strain techniques, namely, the strain proximity free technique (SPFT), and the stress memorization technique (SMT), in the poly-Si channels. It has some advantages: (1) the channel shapes and dimensions can be effectively controlled by the wet etching processes and the deposition thickness of the tetraethoxysilane (TEOS) oxide; (2) the source/drain (S/D) resistance can be significantly decreased by the formation of the raised S/D structures; (3) the SPFT, SMT, and the rapid thermal annealing (RTA) treatment can enhance the performance of the SC-SWDTG TFTs without the limitation of the highly scaling stress liner thickness in deep-submicron TFTs. Thus, the SC-SWDTG TFTs exhibit a steep subthreshold swing (S.S.) ˜ 110 mV/dec., an extremely small drain induced barrier lowing (DIBL) ˜12.2 mV V-1, and a high on/off ratio ˜107 (V D = 1 V) without plasma treatments for future three-dimensional integrated circuits (3D ICs) applications.

  16. Formation processes of CuCl and regenerated Cu crystals on bronze surfaces in neutral and acidic media

    Energy Technology Data Exchange (ETDEWEB)

    Wang Julin [Institute of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029 (China)]. E-mail: julinwang@126.com; Xu Chunchun [Institute of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029 (China); Lv Guocheng [Institute of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029 (China)

    2006-07-15

    The paper is devoted to investigating the formation of CuCl and regenerated Cu crystals on bronze. Electrochemical behaviour of bronze in simulated anoxic edaphic media and occluded cell (O.C.) solutions was studied with cycle voltammetry (CV) and X-ray diffraction (XRD). Within potential range of -800 to +800 mV, oxidation occurred was largely a process in which Cu is oxidized to CuCl and the reduction process was a reverse of it. An atomic force microscopy (AFM) was used to observe the morphology of CuCl crystals, regenerated Cu crystals and corrosion interface at nm level. The deposition of regenerated Cu on simulated archaeological bronzes was simulated under experimental conditions for the first time. CuCl could be thoroughly reduced to pure Cu if reduction time interval were sufficiently prolonged. This provided a theoretical and experimental basis for getting rid of harmful CuCl patina from archaeological bronzes with electrochemical means.

  17. Study on the Effects of Corrosion Inhibitor According to the Functional Groups for Cu Chemical Mechanical Polishing in Neutral Environment

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Won; Kim, Jae Jeong [Institute of Chemical Process, Seoul National University, Seoul (Korea, Republic of)

    2015-08-15

    As the aluminum (Al) metallization process was replaced with copper (Cu), the damascene process was introduced, which required the planarization step to eliminate over-deposited Cu with Chemical Mechanical Polishing (CMP) process. In this study, the verification of the corrosion inhibitors, one of the Cu CMP slurry components, was conducted to find out the tendency regarding the carboxyl and amino functional group in neutral environment. Through the results of etch rate, removal rate, and chemical ability of corrosion inhibitors based on 1H-1,2,4-triazole as the base corrosion inhibitor, while the amine functional group presents high Cu etching ability, carboxyl functional group shows lower Cu etching ability than base-corrosion inhibitor which means that it increases passivation effect by making strong passivation layer. It implies that the corrosion inhibitor with amine functional group was proper to apply for 1st Cu CMP slurry owing to the high etch rate and with carboxyl functional group was favorable for the 2nd Cu CMP slurry due to the high Cu removal rate/dissolution rate ratio.

  18. Fabrication of nano-imprint templates for dual-Damascene applications using a high resolution variable shape E-beam writer

    Science.gov (United States)

    Pritschow, Marcus; Butschke, Joerg; Irmscher, Mathias; Sailer, Holger; Resnick, Douglas; Thompson, Ecron

    2007-10-01

    A 3D template fabrication process has been developed, which enables the generation of high resolution, high aspect pillars on top of lines. These templates will be used to print both vias and metal lines at once for the dual damascene technology. Due to the complexity of state of the art CMOS designs only a variable shape e-beam (VSB) writer combined with chemically amplified resists (CAR) can be considered for the patterning process. We focused our work especially on the generation of high aspect pillars with a diameter below 50nm and the development of suitable overlay strategies for getting a precise alignment between the two template tiers. In this context we investigated the influence of exposure strategies on the overlay result across the entire imprint area of 25mm × 25mm. Finally, we realized templates according to the MII standard with different test designs and confirmed printability of one of them on a MII tool.

  19. Process of electroless plating Cu-Sn-Zn ternary alloy

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Cu-Sn-Zn ternary alloy layer with 10 μm thickness was prepared through electroless plating method. The influences of process conditions including the concentration of metallic salts, reductant and complex agent on Cu-Sn-Zn alloy were studied in details.The stability to bear color changes and corrosion resistance of Cu-Sn-Zn film layer were studied through air-exposure experiment and electrochemical analyses test respectively. The results show that the performances of Cu-Sn-Zn film layer are obviously superior to brass matrix. By use of SEM,EDS and XRD, the morphology, microstructure and chemical composition were investigated. The results show that complex agent can increase the content of Sn and Zn, improve the evenness and compactness and decrease needle holes, therefore the properties of electroless plating layer such as the stability to bear color changes and corrosion resistance are improved remarkably.The probable mechanism of complex agent was discussed.

  20. Reduction of nitrobenzene by the catalyzed Fe/Cu process

    Institute of Scientific and Technical Information of China (English)

    XU Wenying; LI Ping; FAN Jinhong

    2008-01-01

    The polarization behavior of the couple Fe/Cu in 100 mg/L nitrobenzene aqueous solution was studied using Evans coupling diagrams. The results indicated that the iron corrosion was limited by both anodic and cathodic half-cell reactions under the neutral conditions and cathodically controlled under the alkaline conditions. Batch experiments were performed to study the effect of solution pH, reaction duration, concentration, type of electrolyte and dissolved oxygen (DO) on the reduction of nitrobenzene by the catalyzed Fe/Cu process. This process proved effective in the pH range of 3 to 11. The conversion efficiency of nitrobenzene at pH ≈ 10.1 was almost the same as that under highly acid conditions (pH ≈ 3). The degradation of nitrobenzene fell into two phases: adsorption and surface reduction, and the influence of adsorption and mass transfer became more extensive with solution concentration. The reduction rate decreased in the presence of DO in the solution, indicating that a need for aeration was eliminated in the catalyzed Fe/Cu process. Accordingly, spending on energy consumption would be reduced. Economic analysis indicated that merely 0.05 kg was required for the treatment of a ton of nitrobenzene-containing water with pH from 3 to 11. The catalyzed Fe/Cu process is cost-effective and of practical value.

  1. Kinetic process of mechanical alloying in Fe50Cu50

    DEFF Research Database (Denmark)

    Huang, J.Y.; Jiang, Jianzhong; Yasuda, H.

    1998-01-01

    It is shown that mechanical alloying in the immiscible Fe-Cu system is governed by the atomic shear event and shear-induced diffusion process. We found that an alpha-to-gamma phase transformation, as evidenced by the Nishiyama-Wasserman orientation relationship, occurs by simultaneous shearing...... structures, until a complete fee Fe-Cu solid solution is formed. The results provide significant insight into the understanding of recent experiments showing that chemical mixing of immiscible elements can bd induced by mechanical alloying. [S0163-1829(98)51342-2]....

  2. Chemical Mechanical Planarization of Cu: Nanoscale Processes

    Science.gov (United States)

    Arthur, Michael; Fishbeck, Kelly; Muessig, Kara; McDonald, James; Williams, Christine; White, Daniel; Koeck, Deborah; Perry, Scott; Galloway, Heather

    2002-10-01

    Interconnect lines in state of the art integrated circuits are made of copper in a process that requires the repeated planarization of the copper layer. During this process the material is subjected to an aqueous slurry containing active chemicals, corrosion inhibitors and abrasive particles. A model slurry buffered to pH2, pH4 and pH6, contained nitric acid, silica particles and benzotriazole (BTA) as a corrosion inhibitor. The degree of copper planarization was investigated as a function of slurry composition and pH using atomic force microscopy. Chemical surface changes can be explained by the effect of slurry composition on the charge at the material surface. This surface charge controls the amount of friction between the abrasive and the surface which, in turn, effects the global planarization of the material. Experiments using a macroscopic polishing system with AFM characterization along with the microscopic interaction of the AFM tip and sample provide insights into the fundamental mechanisms of a planarization process.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-06-19

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

  4. Improvement of tensile properties of pure Cu and CuCrZr alloy by cryo-rolling process

    Energy Technology Data Exchange (ETDEWEB)

    Ihira, Ryota; Gwon, Hyoseong; Kasada, Ryuta, E-mail: r-kasada@iae.kyoto-u.ac.jp; Konishi, Satoshi

    2016-11-01

    Highlights: • We investigated the effect of cryo-rolling process to Cu and CuCrZr alloy by tensile test and EBSD. • Cryo-rolling process simaltaneously increased strength and ductility of Cu as previously reported. • Cryo-rolling process increased strength of CuCrZr alloy without loss-of-ductility compared with conventional cold-rolling process. • We observed heterogeneous grain size distribution in cryo-rolled Cu but not in cryo-rolled CuCrZr alloy. • We found temperature-transition of texture formation in the rolled CuCrZr alloy. - Abstract: The present study investigates the effect of cryo-rolling process, i.e. cold-rolling at liquid-nitrogen temperature followed by heat treatment, on tensile properties of pure copper and precipitation-hardened CuCrZr alloy. The cryo-rolling process resulted in a simultaneous improvement of strength and ductility of pure copper. On the other hand, a cryo-rolled CuCrZr alloy showed higher tensile strength but comparable ductility with a conventional cold-rolled CuCrZr alloy. Microstructural analysis indicates that the drastically-beneficial effect of cryo-rolling on pure copper may be due to its heterogeneous size distribution of grains which consist of cryo-rolled fine grains, residual cryo-rolled grains and recrystallized coarse grains. The modest but certain benefit of cryo-rolling on CuCrZr alloy can be explained by different texture formation compared with conventional cold-rolling. Effect of neutron irradiation on tensile properties of cryo-rolled CuCrZr alloy is also examined.

  5. Atomic diffusion behavior in Cu-Al explosive welding process

    Science.gov (United States)

    Chen, S. Y.; Wu, Z. W.; Liu, K. X.; Li, X. J.; Luo, N.; Lu, G. X.

    2013-01-01

    A hybrid method is proposed to study atomic diffusion behavior in Cu-Al explosive welding process. The method combines molecular dynamics simulation and classical diffusion theory. Cu-Al explosive welding and scanning electron microscope experiments are done to verify the method. Using the method, we find that the atomic diffusion mostly takes place in the unloading stage of the welding process. The diffusion coefficients are collision velocity-dependent, with higher velocities generating larger coefficients. When there is no transverse velocity, the diffusion coefficient is directly proportional to the longitudinal velocity. With the longitudinal velocity fixed, the diffusion coefficient is proportional to the square of the transverse velocity. The thickness of the diffusion layer is calculated from the simulation result, and it is in good agreement with the experiment result.

  6. Dislocation-mediated creep process in nanocrystalline Cu

    Institute of Scientific and Technical Information of China (English)

    Mu Jun-Wei; Sun Shi-Cheng; Jiang Zhong-Hao; Lian Jian-She; Jiang Qing

    2013-01-01

    Nanocrystalline Cu with average grain sizes ranging from ~ 24.4 to 131.3 nm were prepared by the electric brushplating technique.Nanoindentation tests were performed within a wide strain rate range,and the creep process of nanocrystalline Cu during the holding period and its relationship to dislocation and twin structures were examined.It was demonstrated that creep strain and creep strain rate are considerably significant for smaller grain sizes and higher loading strain rates,and are far higher than those predicted by the models of Cobble creep and grain boundary sliding.The analysis based on the calculations and experiments reveals that the significant creep deformation arises from the rapid absorption of high density dislocations stored in the loading regime.Our experiments imply that stored dislocations during loading are highly unstable and dislocation activity can proceed and lead to significant post-loading plasticity.

  7. Microstructure characterization of Cu processed by compression with oscillatory torsion

    Energy Technology Data Exchange (ETDEWEB)

    Rodak, K., E-mail: kinga.rodak@polsl.pl [Institute of Materials Science, Silesian University of Technology, Krasińskiego 8, 40-019 Katowice (Poland); Pawlicki, J., E-mail: jacek.pawlicki@polsl.pl [Department of Automotive Vehicle Construction, Silesian University of Technology, Krasińskiego 8, 40–019 Katowice (Poland)

    2014-08-15

    High purity Cu (99.9%) was subjected to severe plastic deformation up to a total effective strain ε{sub ft} = 130 through compression with the oscillatory torsion method at room temperature. This method produces an ultrafine grain microstructure. The microstructure evolution was investigated with respect to the value of the total effective strain using a scanning electron microscope with an electron-backscattered diffraction technique and a scanning transmission electron microscope. The results of the structural analyses show that increasing ε{sub ft} from 2 to 50 causes progress in the grain refinement. A quantitative study of the microstructure parameters, such as fraction of high angle boundaries, grain and subgrain diameter, and the area fraction of grains up to 1 μm, shows that deformation at ε{sub ft} = 45 guaranteed the best conditions for refining the microstructure of Cu. Using high values of ε{sub ft} in the range 60 to 130 restricts grain refinement because intensive recovery begins to dominate in the microstructure. - Highlights: • Cu was processed by SPD metodto an effective strain 130. • The microstructure evolution has been investigated. • The method allows to produce an ultrafine grain microstructure.

  8. Study of sedative, preanaesthetic and anti-anxiety effects of Rosa damascene herbal extract in comparison with diazepam in rat

    Directory of Open Access Journals (Sweden)

    Rezaie A

    2011-06-01

    Full Text Available "n Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Arial; mso-bidi-theme-font:minor-bidi;} Background: Rosa damascene has a special role in the Iranian traditional medicine due to its sedative, anticonvulsant and analgesic effects. Regarding its alkaloid, flavonoid and other organic compounds, this plant has always been used to reduce nervousness and treat depression and chronic insomnia. In the present time, synthetic drugs with sedative and anxiolytic properties are used for such problems but due to their side-effects and economic issues, the significance of natural medicines with fewer side-effects is of interest. Considering the importance of sedative and anxiolytic effects of Rosa damascene, we decided to compare this plant with synthetic drugs of the same properties."n"nMethods: Two different groups of male Wistar rats received either Rosa damascene extract in doses of 150, 300, 450 mg/kg or Diazepam and dimethyl sulphoxide in doses of 1.2 mg/kg intraperitoneally 30 minutes before assessing the sleep duration, sedation and preanesthetic effects induced by intraperitoneal ketamine, 40 mg/kg. The anti-anxiety effect was evaluated by using an elevated plus maze and a rota rod."n"nResults: The results showed a meaningful increase in the period of sleep induced by Ketamine (P≤0.01 and also a meaningful

  9. Microstructure and Properties of Cu Coating Fabricated onto Diamond-Cu Substrate by Low-Temperature HVOF Process

    Science.gov (United States)

    Liu, Min; Yang, Kun; Deng, Chun-ming; Deng, Chang-guang; Zhou, Ke-song

    2016-12-01

    Diamond-Cu composites have been considered to be the next generation of electronic packing materials. One of the key stumbles for such an application is the joining problem between diamond-Cu composites and other materials due to the poor wettability of the diamond particles in the composites. In order to overcome this hurdle, pure Cu powder was thermally sprayed onto diamond-Cu substrate by low-temperature high-velocity oxygen fuel spraying process. Microstructure and some fundamental properties of the coating obtained were systematically investigated, and morphologies of the single splat deposited on the diamond-Cu substrate were also observed. The splats obtained have good adhesion with the substrate as fine particles flattened sufficiently, while the coarse particles were significantly deformed. The coating was quite dense with porosity lower than 1%, oxygen content under 0.5% and thermal conductivity about 266 Wm-1 K-1 and still remained on the diamond-Cu substrate after 50 thermal shock cycles between 300 °C and water bath at room temperature. Meanwhile, the solderability of the coating was significantly improved. Therefore, Cu coating deposited on diamond-Cu substrate by low-temperature high-velocity oxygen fuel spraying process can be beneficial in electronic industry assisting with soldering and improved wettability for joining of other materials.

  10. Cu passivation for integration of gap-filling ultralow-k dielectrics

    Science.gov (United States)

    Zhang, Liping; de Marneffe, Jean-Francois; Lesniewska, Alicja; Verdonck, Patrick; Heylen, Nancy; Murdoch, Gayle; Croes, Kristof; Boemmels, Juergen; Tokei, Zsolt; De Gendt, Stefan; Baklanov, Mikhail R.

    2016-12-01

    For Cu/low-k interconnects, the reversed damascene is an alternative integration approach where the metal wires are patterned first and then the spacing filled with a flowable dielectric. In this paper, the replacement of a sacrificial template by gap-filling ultralow-k dielectrics is studied, focusing on yield and transport performance ("replacement dielectric" scheme). On non-passivated copper, the low-k curing processes induce severe damage to the metal lines, leading to the degraded electrical properties. This is confirmed by chemical inspection on the blanket Cu films and morphological inspection on patterned structures. In order to avoid Cu oxidation and out-diffusion at elevated temperature, Cu passivation by plasma-enhanced chemical vapor deposition SiCN is proposed and studied in detail. The inter-metal dielectric properties of replacement low-k are evaluated by resistance-capacitance and IV measurements using a Meander-Fork structure. By tuning the passivation layer thickness and ultraviolet curing time, high electrical yield is obtained with integrated porous low-k showing promising effective k-values (keff) and breakdown voltages (Ebd), confirming the interest of this specific integration scheme.

  11. The evaluation of antimicrobial effects of five different brands of rose water, water extract of Rosa damascene in comparison with rose oil

    OpenAIRE

    Mohammad Seddigh Ataee Bojd; Razieh Hanafi Bojd; Malaknaz Ghannadkafi; Mohammad Hasan Hasan Namaei

    2014-01-01

    Background and Aim: The use of plant compounds to treat infections is an age-old practice in a large part of the world. Members of Rosacea family have long been used for food and medicinal purposes. The aim of this study is evaluation of antimicrobial effect of five different brands of rose water, water extract of Rosa damascene in comparison with rose oil. Materials and Methods: Five different brands of rose water, water extract of rosa damascene and rose oil were tested for antibact...

  12. Aromatherapy with Rosa Damascenes in Apnea, Bradycardia and Spo2 of Preterm Infants; a Randomized Clinical Trial

    Directory of Open Access Journals (Sweden)

    Saeideh Aghagoli

    2016-06-01

    Full Text Available Background  Apnea is one of the most common problems in preterm neonates. This study aimed to evaluate the effectiveness of aromatherapy on the reduction of apnea, bradycardia, and Pulse Oximetry (SPO2 in premature infants. Materials and Methods In a clinical trial study, 60 preterm neonates randomly divided in two groups and exposed to aromatherapy with Rosa damascenes distillate or distilled water beside the routine treatment. In experimental group, two drops of 10% Rosa damascenes distillate was dropped on the pad eye in second day of birth at 6 Am. The intervention was repeated in 9 AM, 12 Am, 15 PM and 18 PM hours. A same condition applied for control group and distilled water was dropped on the pad eye. The number of apnea attacks, bradycardia and decrease in SpO2 compared between two groups using chi-square test, independent t-test and repeated measure test. Results The overall apnea attacks, bradycardia, and SPO2 in tree studied days were lower in intervention group than control group (0.47±0.13 vs. 2.6±0.41, 0.47±0.13 vs. 2.56±0.41 and 0.70±0.17 vs. 2.77±0.21, respectively. In addition, the repeated measurement test showed that the mean number of apnea attacks, decrease in heart pulse rate, and decrease in SpO2 was statistically lower in intervention group with aromatherapy than controls in first, second, third and sum of three days (P< 0.05. Conclusion Aromatherapy with Rosa damascenes distillate can reduce more and speedy the occurrence of apnea attacks, bradycardia and SPO2 in premature infants, along with other routine treatment.

  13. Effects of annealing process on electrical conductivity and mechanical property of Cu-Te alloys

    Institute of Scientific and Technical Information of China (English)

    ZHU Da-chuan; TANG Ke; SONG Ming-zhao; TU Ming-jing

    2006-01-01

    The effects of annealing process on the electrical conductivity and mechanical properties of Cu-Te alloys were studied via AG-10TA electronic universal machine, SB2230 digital electric bridge, SEM and EDS. The results show that recrystallization and precipitation occur simultaneously during the annealing process of Cu-Te alloys. Tellurium precipitates as Cu2Te second phase. The grain size increases with the increasing of annealing temperature and time. The electrical conductivity increases monotonously. The tensile strength of Cu-Te alloy is higher than that of pure copper.

  14. Ageing processes in Al-Cu-Mg alloys with different Cu/Mg ratios

    Energy Technology Data Exchange (ETDEWEB)

    Macchi, C. [IFIMAT, UNCentro and CONICET, Pinto, Tandil (Argentina); Somoza, A. [IFIMAT, UNCentro and CICPBA, Pinto, Tandil (Argentina); Ferragut, R.; Dupasquier, A. [LNESS and CNISM, Politecnico di Milano, Como (Italy); Polmear, I.J. [Emeritus Professor, Department of Materials Engineering, Monash University, Melbourne, Vic. (Australia)

    2009-11-15

    Three age-hardenable Al-Cu-Mg alloys with different Cu/Mg ratios were studied by means of positron annihilation lifetime spectroscopy and Vickers hardness as a function of the artificial ageing time at 175 C. Complementary information on the decomposition sequence was obtained by means of differential scanning calorimetry. The results are discussed in terms of the different structures that are formed during the precipitation sequence of the supersaturated solid solution. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  15. Formation process of liquid in interface of Ti/Cu contact reaction couple

    Institute of Scientific and Technical Information of China (English)

    WU Ming-fang; YU Chun; YU Zhi-shi; LI Rui-feng

    2005-01-01

    By using the Ti/Cu contact reaction couples,the dissolution behavior of Ti and Cu in the eutectic reaction process was investigated under different conditions.The results show that the formation of eutectic liquid phase has a directional property,I.e.the eutectic liquid phase forms first at the Cu side and then spreads along the depth direction of Cu.The width of the eutectic liquid zone when Ti is placed on Cu is wider than that when Ti is placed under Cu.The shape of the upside liquid zone is wave-like.This phenomenon indicates that the formation process and spreading behavior in the upside are different from those in the underside,and there exists void effect in the Cu side of underside liquid zone,this will result in the delaying phenomenon of the contact reaction between Ti and Cu,and distinctly different shapes of the both liquid zones.The formation process of Ti/Cu eutectic liquid zone is similar to that of the traditional solid-state diffusion layer,and the relationship between the width of liquid zone and holding time obeys a square root law.

  16. Surface alloying of Cu with Ti by double glow discharge process

    Institute of Scientific and Technical Information of China (English)

    袁庆龙; 池成忠; 苏永安; 徐重; 唐宾

    2004-01-01

    The surface of pure copper alloyed with Ti using double glow discharge process was investigated. The morphology, structure and forming mechanism of the Cu-Ti alloying layer were analyzed. The microhardness and wear resistance of the Cu-Ti alloying layer were measured, and compared with those of pure copper. The results indicate that the surface of copper activated by Ar and Ti ions bombardment is favorable to absorption and diffusion of Ti element. In current experimental temperature, as the Ti content increases, the liquid phase occurs between the deposited layer and diffused layer, which makes the Ti ions and atoms easy to dissolve and the thickness of Cu-Ti alloying layer increase rapidly. After cooling, the structure of the alloying layer is composed of CuTi, Cu4 Ti and Cu(Ti) solid solution. The solid solution strengthening and precipitation strengthening effects of Ti result in high surface hardness and wear resistance.

  17. Investigation on the structural variation of Co-Cu nanoparticles during the annealing process.

    Science.gov (United States)

    Ju, Shin-Pon; Lo, Yu-Chieh; Sun, Shih-Jye; Chang, Jee-Gong

    2005-11-10

    This study uses molecular dynamics simulations to investigate the crystalline process of Co-Cu nanoparticles of high and low Co concentrations (5 and 25%) during the annealing process. The modified many-body tight-binding potential involving magnetic contribution is adopted to accurately model the Cu-Cu, Co-Co, and Co-Cu pair interactions. The Co-Co bond length increases, while the Co-Cu bond length decreases as the temperature gradually drops from 2000 K to the upper melting point. During that process, the Cu-Cu bond length remains constant and the value of the first peak of the radial distribution function (RDF) increases, which indicates that Cu atoms increase their short-range order by mutual rearrangement. At temperatures lower than the upper melting point, the bond length of each pair decreases while the value of the first peak increases as the temperature is continuously reduced. Because the kinetic energy of an individual atom is not enough for rearrangement, the variations of bond length and the first RDF peak can be attributed to the shrinking effect.

  18. Effects of Cu on metabolisms and enzyme activities of microbial communities in the process of composting.

    Science.gov (United States)

    Guo, Xingliang; Gu, Jie; Gao, Hua; Qin, Qingjun; Chen, Zhixue; Shao, Li; Chen, Lin; Li, Hailong; Zhang, Weijuan; Chen, Shengnan; Liu, Jiang

    2012-03-01

    With the compost matrix of pig manure, wheat straw, and spent mushroom substrate, and then inoculated with the Compound Microbe Preparation, the study investigated the effects of the heavy metal Cu on the process of composting. Biolog EcoPlate™ test revealed that at a low content, Cu could improve the capacities of microbial communities to transform and exploit carbon sources in the form of polymer, thus speeding up the decomposition of agricultural wastes, and at a high content, Cu presented inhibiting effect on microbial communities to exploit complex macromolecular carbon sources, thus extending the decomposition of agricultural wastes. Enzyme activity testing showed that at a low content, Cu presented enzyme activity-activating effect at the early period of composting and inhibiting effect in the late period of composting, and at a high content, Cu presented enzyme activity-inhibiting effects through the process of composting.

  19. Dechlorination of carbon tetrachloride by the catalyzed Fe-Cu process

    Institute of Scientific and Technical Information of China (English)

    XU Wen-ying; GAO Ting-yao

    2007-01-01

    The electrochemical reduction characteristics of carbon tetrachloride (CT) were investigated using cyclic voltammetry in this study. In addition, the difference in reduction mechanisms of CT between Master Builders' iron and the catalyzed Fe-Cu process was discussed. The results showed that CT was reduced directly on the surface of copper rather than by atomic hydrogen produced at the cathode in the catalyzed Fe-Cu process. The reduction was realized largely by atomic hydrogen in Master Builders' iron. The entire CT in 350 ml aqueous solution with 320 mg/L was reduced to trichloromethane and dichloromethane in 2.25 h when 100 g of scrap iron with Fe/Cu ratio of 10:1 (w/w) were used. Moreover, the reduction rate slowed with time. CT could be reduced at acidic, neutral and alkaline pH from solution by Fe-Cu bimetallic media, but the mechanisms were different. The degradation rate was not significantly influenced by pH in the catalyzed Fe-Cu process; in Master Builders' iron it clearly increased with decreasing pH. The kinetics of the reductions followed pseudo-first order in both cases. Furthermore, the reductions under acidic conditions proceeded faster than that under the neutral and alkaline conditions. The catalyzed Fe-Cu process was superior to Master Builders' iron in treating CT-containing water and this advantage was particularly noticeable under alkaline conditions. The reduction was investigated in the cathode (Cu) and anode (Fe) compartments respectively, the results showed that the direct reduction pathway played an important role in the reduction by the catalyzed Fe-Cu process. The catalyzed Fe-Cu process is of practical value.

  20. Effects of processing variables on the Y2BaCuO5 size and magnetic properties of melt-processed YBa2Cu3Ox

    Science.gov (United States)

    Yang, H. F.; Varanasi, C.; Ginn, P. J. M. C.

    1995-12-01

    Samples of YBa2Cu3Ox (123) with excess Y2BaCuO5 (211) in the molar ratio of 5:1 ( 123/211) were processed using the “solid liquid melt growth” (SLMG) technique. The effect of hold time above the peritectic on the magnetic properties was examined. Extended hold times above the peritectic during processing degrade the magnetic properties of SLMG processed 123. In SLMG 123, the very fine (>100 nm) 211 particles produced by this processing route are the primarymagnetic flux pinners. Extended hold periods reduce the number and/or coarsen the average size of these fine precipitates, resulting in a reduced magnetization. These results were compared to undoped Y123 processed by the more traditional melt texture growth (MTG). In MTG processing, extended hold times above the peritectic are found to result in improved magnetic behavior because of increased defect densities.

  1. Void formation in Nb3Sn-Cu superconducting wire produced by the external tin process

    Science.gov (United States)

    Verhoeven, J. D.; Efron, A.; Gibson, E. D.; Cheng, C. C.

    1986-03-01

    The tin (Sn) diffusion step for producing Nb3Sn-Cu superconducting wire by the external Sn process was modeled in experiments where either pure Sn or a Cu-Sn alloy was plated on sheets of either pure Cu or a Cu-Sn bronze. Each stage of the three-stage solid-state diffusion process was evaluated and it was found that rows of voids are produced in stage I of the process. These voids coarsen in stages II and III and in the worst case they are observed to coalesce and cause complete spalling away of the Sn-rich diffusion layers. Methods for minimizing void formation and possible causes of the void formation are discussed.

  2. Chemistry of Cu(acac){sub 2} on Ni(110) and Cu(110) surfaces: Implications for atomic layer deposition processes

    Energy Technology Data Exchange (ETDEWEB)

    Ma Qiang; Zaera, Francisco [Department of Chemistry, University of California, Riverside, California 92521 (United States)

    2013-01-15

    The thermal chemistry of copper(II)acetylacetonate, Cu(acac){sub 2}, on Ni(110) and Cu(110) single-crystal surfaces was probed under vacuum by using x-ray photoelectron spectroscopy (XPS) and temperature programmed desorption (TPD). Some data for acetylacetone (Hacac, CH{sub 3}COCH{sub 2}COCH{sub 3}) adsorbed on Ni(110) are also reported as reference. Chemical transformations were identified in several steps covering a temperature range from 150 K to at least 630 K. The desorption of Hacac and a 3-oxobutanal (CH{sub 3}COCH{sub 2}CHO) byproduct was observed first at 150 and 180 K on Ni(110) and at 160 and 185 K on Cu(110), respectively. Partial loss of the acetylacetonate (acac) ligands and a likely change in adsorption geometry are seen next, with the possible production of HCu(acac), which desorbs at 200 and 235 K from the nickel and copper surfaces, respectively. Molecular Cu(acac){sub 2} desorption is observed on both surfaces at approximately 300 K, probably from recombination of Cu(acac) and acac surface species. The remaining copper atoms on the surface lose their remaining acac ligands to the substrate and become reduced directly to metallic copper. At the same time, the organic ligands follow a series of subsequent surface reactions, probably involving several C-C bond-scissions, to produce other fragments, additional Hacac and HCu(acac) in the gas phase in the case of the copper surface, and acetone on nickel. A significant amount of acac must nevertheless survive on the surface to high temperatures, because Hacac peaks are seen in the TPD at about 515 and 590 K and the C 1s XPS split associated with acac is seen up to close to 500 K. In terms of atomic layer deposition processes, this suggests that cycles could be design to run at such temperatures as long as an effective hydrogenation agent is used as the second reactant to remove the surface acac as Hacac. Only a small fraction of carbon is left behind on Ni after heating to 800 K, whereas more carbon

  3. Alleviation of process-induced cracking of the antireflection TiN coating (ARC-TiN) in Al-Cu and Al-Cu-Si films

    CERN Document Server

    Peng, Y C; Yang, Y R; Hsieh, W Y; Hsieh, Y F

    1999-01-01

    The alleviation of cracking of the TiN-ARC layer on Al-Cu and Al-Cu-Si films after the development process has been achieved. For the TiN-ARC/Al-Cu system, the stress-induced defects decreased with increasing TiN-ARC layer thickness. In contrast, for the TiN-ARC/Al-Cu-Si system, Si nodules formed during cooling, thereby inducing poor coverage with high aspect-ratio holes. As a result, the photoresist developer penetrated through the films. Chemical vapor deposition of TiN-ARC or predeposition of a Ti Interposing layer was used to eliminate the formation of Si nodules.

  4. The influence of precursor Cu content and two-stage processing conditions on the microstructure of Cu{sub 2}ZnSnSe{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Márquez-Prieto, J., E-mail: jose.prieto@northumbria.ac.uk [Northumbria Photovoltaic Application Centre, Faculty of Engineering and Environment, Northumbria University, Ellison Building, Newcastle upon Tyne NE1 8ST (United Kingdom); Ren, Y. [Ångström Solar Center, Solid State Electronics, Uppsala University, Uppsala 751 21 (Sweden); Miles, R.W.; Pearsall, N.; Forbes, I. [Northumbria Photovoltaic Application Centre, Faculty of Engineering and Environment, Northumbria University, Ellison Building, Newcastle upon Tyne NE1 8ST (United Kingdom)

    2015-05-01

    This paper reports the influence of processing temperature on the microstructure of Cu{sub 2}ZnSnSe{sub 4} (CZTSe) absorber layers for temperatures between 380 and 550 °C produced using a 2-stage process. X-ray diffraction analysis showed the formation of Cu{sub 2}ZnSnSe{sub 4} over this temperatures range. The Williamson-Hall method was used for microstructural analysis of the CZTSe absorbers, and this showed a progressive decrease of the micro-strain of the CZTSe with increasing selenisation temperature. The influence of precursor Cu content on the microstructure of the CZTSe was also studied. An increase of Cu content in the precursor is correlated to an increase in grain size and a decrease in micro-strain. Raman measurements show an asymmetrical broadening towards lower energies of the main 197 cm{sup −1} mode for Cu-poor compositions. This study provides an insight into the dependency of the crystallinity of CZTSe on composition and synthesis temperature. - Highlights: • We fabricate Cu{sub 2}ZnSnSe{sub 4} thin films by sputtering and post-reactive annealing. • The micro-strain of Cu{sub 2}ZnSnSe{sub 4} increases when Cu content decreases. • The micro-strain of Cu{sub 2}ZnSnSe{sub 4} decreases with increasing processing temperature. • The defect concentration of Cu{sub 2}ZnSnSe{sub 4} increases when Cu content decreases.

  5. Cu patterning on Si substrate using solution-processed Ti-Cu oxide films and electroless plating

    Science.gov (United States)

    Miyazeki, Yusuke; Horiuchi, Yoshio; Noh, Joo-Hyong; Cordonier, Christopher E. J.; Honma, Hideo; Arakawa, Taro

    2016-09-01

    We demonstrated for the first time the Cu patterning on Si using Ti and Cu oxide (TiCu-ox) films patterned by photolithography and electroless plating without etching or surface modification. The TiCu-ox films had a porous structure and acted as adhesion layers. The TiCu-ox films were patterned by photolithography on Si and glass for comparison, followed by Cu deposition by electroless plating. Fine Cu patterns on the patterned TiCu-ox films were formed. The smallest line/space widths on glass and Si were 3.2/0.8 and 3.6/4.4 µm, respectively. The deposited Cu layers had high adhesion strength and low sheet resistance.

  6. Synthesis and characterization of CuO nanoparticles using strong base electrolyte through electrochemical discharge process

    Indian Academy of Sciences (India)

    PURUSHOTTAM KUMAR SINGH; PANKAJ KUMAR; MANOWAR HUSSAIN; ALOK KUMAR DAS; GANESH CHANDRA NAYAK

    2016-04-01

    In the present study, cupric oxide (CuO) nanoparticles were synthesized by electrochemical discharge process using strong base electrolytes. The experiments were carried out separately using NaOH and KOH electrolytes.The mass output rate and the crystal size were obtained with variation of the rotation speed of magnetic stirrer for both types of electrolytes. The mass output rate of CuO nanoparticles increased with the increase in the speed of rotation, and, after an optimum speed, it started decreasing. However, the size of the particles reduced with the increase of the rotation speed. The crystal plane of the obtained CuO nanoparticles was similar for both the electrolytes whereas the yield of nanoparticles was higher in KOH as compared with NaOH under the sameexperiment conditions. In this set of experiments, the maximum output rates obtained were 21.66 mg h$^{−1}$ for NaOH and 24.66 mg h$^{−1}$ for KOH at 200 rpm for a single discharge arrangement. The average crystal size of CuO particles obtained was in the range of 13–18 nm for KOH electrolyte and 15–20 nm for NaOH electrolyte. Scanning electron microscopy images revealed that flower-like and caddice clew-shaped CuO nanocrystalline particles weresynthesized by the electrochemical discharge process. Fourier transform infrared spectrum showed that the CuO nanoparticles have a pure and monolithic phase. UV–vis–NIR spectroscopy was used to monitor oxidation course of Cu→CuO and the band gap energy was measured as 2 and 2.6 eV for CuO nanoparticle synthesized in NaOH and KOH solutions, respectively.

  7. Electromigration-induced plasticity and texture in Cu interconnects

    Energy Technology Data Exchange (ETDEWEB)

    Advanced Light Source; Tamura, Nobumichi; Budiman, A. S.; Hau-Riege, C.S.; Besser, P. R.; Marathe, A.; Joo, Y.-C.; Tamura, N.; Patel, J. R.; Nix, W. D.

    2007-10-31

    Plastic deformation has been observed in damascene Cu interconnect test structures during an in-situ electromigration experiment and before the onset of visible microstructural damage (ie. voiding) using a synchrotron technique of white beam X-ray microdiffraction. We show here that the extent of this electromigration-induced plasticity is dependent on the texture of the Cu grains in the line. In lines with strong <111> textures, the extent of plastic deformation is found to be relatively large compared to our plasticity results in the previous study [1] using another set of Cu lines with weaker textures. This is consistent with our earlier observation that the occurrence of plastic deformation in a given grain can be strongly correlated with the availability of a <112> direction of the crystal in the proximity of the direction of the electron flow in the line (within an angle of 10{sup o}). In <111> out-of-plane oriented grains in a damascene interconnect scheme, the crystal plane facing the sidewall tends to be a {l_brace}110{r_brace} plane,[2-4] so as to minimize interfacial energy. Therefore, it is deterministic rather than probabilistic that the <111> grains will have a <112> direction nearly parallel to the direction of electron flow. Thus, strong <111> textures lead to more plasticity, as we observe.

  8. Nanostructured Cu-CGO anodes fabricated using a microwave-assisted glycine-nitrate process

    Science.gov (United States)

    Shaikh, Shabana P. S.; Somalu, Mahendra R.; Muchtar, Andanastuti

    2016-11-01

    This work reports a study of nanostructured copper-doped gadolinium cermet (Cu-CGO) composite anodes prepared via conventional synthesis (CS) and microwave-synthesis (MS) involving the glycine-nitrate process (GNP). A detailed investigation on the mechanical properties, electrical conductivity and electrochemical performance of prepared Cu0.5(Ce0.9Gd0.1)0.5O2-δ anodes is included. The prepared samples were characterized by techniques, such as XRD, EDX, SEM and electrical characterizations. After reduction in 10% H2 and 90% N2, the DC conductivities of the Cu-CGO anodes prepared via CS-GNP and MS-GNP are found to be 5.43×103 and 1.09×104 S cm-1 at 700 °C, respectively. The electrochemical performances of the spin-coated anode symmetrical cells sintered at 700 °C are evaluated at cell operating temperatures of 600, 700 and 800 °C. The lowest area specific resistance (ASR) values for the Cu-CGO/CGO/Cu-CGO symmetrical cells prepared via the MS-GNP route at operating temperatures of 600, 700 and 800 °C are found to be 0.34, 0.71 and 1.10 Ω cm2, respectively. The as-prepared (via MS-GNP) Cu-CGO anode exhibits excellent electrical and electrochemical performance consistent with the uniform nanostructured morphology compared with the anode prepared via CS-GNP.

  9. The Process of TiB2-Cu Composite Phase and Structure Formation during Combustion Synthesis

    Institute of Scientific and Technical Information of China (English)

    XU Qiang; ZHANG Xinghong; HAN Jiecai; PAN Wei

    2006-01-01

    The reaction process of combustion synthesis for TiB2- Cu was investigated in detail using combustion-wave arresting experiment, X-ray diffraction (XRD) analysis, SEM analysis and differential thermal analysis ( DTA ). The XRD analysis results for the different parts of the quenched specimen shaw that TiCux intermetallic phase firstly forms with the propagation of combustion wave, and then Ti1.87 B50 and Ti3 B4 metastable phases come forth due to the diffusion of B atoms and finally the stable TiB2 phase forms because of the continuous diffusion of B atoms. The formation of TiB2 phase is not completed by one step, but undergoes several transient processes. The process of reaction synthesis for Ti-B-Cu ternary system can be divided into three main stages: melting of Cu and Ti, and the formation of Cu- Ti melt and few TiCux , TiBx intermetallic phases; large numbers of TiCux intermetallic phases formation and some fine TiB2 particles precipitation; and the TiB2 particles coarsening and the stable TiB2 and Cu two phases formation in the final product.

  10. Influence of Zn content and annealing process on electrical property of CuZn alloy

    Institute of Scientific and Technical Information of China (English)

    罗丰华; 尹志民; 汪明朴; 左铁镛

    2001-01-01

    The relationship among annealing temperature, microstructure and electrical resistivity of Cu-(8%~13%)Zn (mole fraction) alloys was studied. The results show that the relationship between the electrical resistivity of cold deformation CuZn alloy and annealing temperature is related to the recovery and recrystallization of the processes. The increments of electrical resistivity due to strain are restored mainly on the process of recovery and recrystallization. The room temperature resistivity of soft state alloys is linear to the Zn contents. The extended application of Matthissen rule on high concentration solid solution was discussed.

  11. Atomistic study of deposition process of Al thin film on Cu substrate

    Energy Technology Data Exchange (ETDEWEB)

    Cao Yongzhi, E-mail: yzcaohit@gmail.com [Center for Precision Engineering, Harbin Institute of Technology, Harbin (China); Zhang Junjie; Sun Tao; Yan Yongda; Yu Fuli [Center for Precision Engineering, Harbin Institute of Technology, Harbin (China)

    2010-08-01

    In this paper we report molecular dynamics based atomistic simulations of deposition process of Al atoms onto Cu substrate and following nanoindentation process on that nanostructured material. Effects of incident energy on the morphology of deposited thin film and mechanical property of this nanostructured material are emphasized. The results reveal that the morphology of growing film is layer-by-layer-like at incident energy of 0.1-10 eV. The epitaxy mode of film growth is observed at incident energy below 1 eV, but film-mixing mode commences when incident energy increase to 10 eV accompanying with increased disorder of film structure, which improves quality of deposited thin film. Following indentation studies indicate deposited thin films pose lower stiffness than single crystal Al due to considerable amount of defects existed in them, but Cu substrate is strengthened by the interface generated from lattice mismatch between deposited Al thin film and Cu substrate.

  12. Effect of extrusion processing on the microstructure, mechanical properties, biocorrosion properties and antibacterial properties of Ti-Cu sintered alloys.

    Science.gov (United States)

    Zhang, Erlin; Li, Shengyi; Ren, Jing; Zhang, Lan; Han, Yong

    2016-12-01

    Ti-Cu sintered alloys, Ti-Cu(S) alloy, have exhibited good anticorrosion resistance and strong antibacterial properties, but low ductility in previous study. In this paper, Ti-Cu(S) alloys were subjected to extrusion processing in order to improve the comprehensive property. The phase constitute, microstructure, mechanical property, biocorrosion property and antibacterial activity of the extruded alloys, Ti-Cu(E), were investigated in comparison with Ti-Cu(S) by X-ray diffraction (XRD), optical microscopy (OM), scanning electronic microscopy (SEM) with energy disperse spectroscopy (EDS), mechanical testing, electrochemical testing and plate-count method in order to reveal the effect of the extrusion process. XRD, OM and SEM results showed that the extrusion process did not change the phase constitute but refined the grain size and Ti2Cu particle significantly. Ti-Cu(E) alloys exhibited higher hardness and compressive yield strength than Ti-Cu(S) alloys due to the fine grain and Ti2Cu particles. With the consideration of the total compressive strain, it was suggested that the extrusion process could improve the ductility of Ti-Cu alloy(S) alloys. Electrochemical results have indicated that the extrusion process improved the corrosion resistance of Ti-Cu(S) alloys. Plate-count method displayed that both Ti-Cu(S) and Ti-Cu(E) exhibited strong antibacterial activity (>99%) against S. aureus. All these results demonstrated that hot forming processing, such as the extrusion in this study, refined the microstructure and densified the alloy, in turn improved the ductility and strength as well as anticorrosion properties without reduction in antibacterial properties.

  13. Low-Thermal-Budget Photonic Processing of Highly Conductive Cu Interconnects Based on CuO Nanoinks: Potential for Flexible Printed Electronics.

    Science.gov (United States)

    Rager, Matthew S; Aytug, Tolga; Veith, Gabriel M; Joshi, Pooran

    2016-01-27

    In the developing field of printed electronics, nanoparticle based inks such as CuO show great promise as a low-cost alternative to other metal-based counterparts (e.g., silver). In particular, CuO inks significantly eliminate the issue of particle oxidation before and during the sintering process that is prevalent in Cu-based formulations. We report here the scalable and low-thermal-budget photonic fabrication of Cu interconnects employing a roll-to-roll (R2R)-compatible pulse-thermal-processing (PTP) technique that enables phase reduction and subsequent sintering of ink-jet-printed CuO patterns onto flexible polymer templates. Detailed investigations of curing and sintering conditions were performed to understand the impact of PTP system conditions on the electrical performance of the Cu patterns. Specifically, the impact of energy and power of photonic pulses on print conductivity was systematically studied by varying the following key processing parameters: pulse intensity, duration, and sequence. Through optimization of such parameters, highly conductive prints were obtained in <1 s with resistivity values as low as 10 μΩ cm (corresponding to ∼17% of the International Annealed Copper Standard (IACS) conductivity) was achieved. It was also observed that the introduction of an initial ink-drying step in ambient atmosphere, after the printing and before sintering, leads to significant improvements in mechanical integrity and electrical performance of the printed Cu patterns. Moreover, the viability of CuO reactive inks, coupled with the PTP technology and pre-sintering ink-drying protocols, has also been demonstrated for the additive integration of a low-cost Cu temperature sensor onto a flexible polymer substrate.

  14. Optimization of EDM Process of (Cu-W EDM Electrodes on Different Progression

    Directory of Open Access Journals (Sweden)

    Arvind Kumar Tiwari

    2014-11-01

    Full Text Available The purpose of this research work is to determine the optimal cutting condition of EDM process of different work piece materials using different compositions of Cu-W tool Electrodes. The key cutting factors such as Discharge Current, Voltage, Pulse- On – Time, Duty Cycle, Spark Gap and flushing pressure will be optimized.

  15. Uncovering the Problem-Solving Process: Cued Retrospective Reporting Versus Concurrent and Retrospective Reporting

    Science.gov (United States)

    van Gog, Tamara; Paas, Fred; Merrienboer, Jeroen J. G.; Witte, Puk

    2005-01-01

    This study investigated the amounts of problem-solving process information ("action," "why," "how," and "metacognitive") elicited by means of concurrent, retrospective, and cued retrospective reporting. In a within-participants design, 26 participants completed electrical circuit troubleshooting tasks under different reporting conditions. The…

  16. An efficient synthesis of isocoumarins via a CuI catalyzed cascade reaction process

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    3-Alkyl isocoumarins are provided by CuI/amino acid-catalyzed Sonogashira coupling reaction of o-bromo benzoic acids and terminal alkynes and the subsequent additive cyclization. This cascade process allows synthesis of diverse isocoumarins by varying both coupling partners bearing a wide range of functional groups.

  17. FE modeling of Cu wire bond process and reliability

    NARCIS (Netherlands)

    Yuan, C.A.; Weltevreden, E.R.; Akker, P. van den; Kregting, R.; Vreugd, J. de; Zhang, G.Q.

    2011-01-01

    Copper based wire bonding technology is widely accepted by electronic packaging industry due to the world-wide cost reduction actions (compared to gold wire bond). However, the mechanical characterization of copper wire differs from the gold wire; hence the new wire bond process setting and new bond

  18. FE modeling of Cu wire bond process and reliability

    NARCIS (Netherlands)

    Yuan, C.A.; Weltevreden, E.R.; Akker, P. van den; Kregting, R.; Vreugd, J. de; Zhang, G.Q.

    2011-01-01

    Copper based wire bonding technology is widely accepted by electronic packaging industry due to the world-wide cost reduction actions (compared to gold wire bond). However, the mechanical characterization of copper wire differs from the gold wire; hence the new wire bond process setting and new bond

  19. 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.

  20. Processing and properties of silver-clad Tl-Ba-Ca-Cu-O wires and tapes

    Science.gov (United States)

    Goretta, K. C.; Wu, C. T.; Lanagan, M. T.; Boling, M. A.; Shi, D.; Miller, D. J.; Chen, Nan; Hanewald, W. G.; Sengupta, S.; Wang, Z.

    1992-03-01

    TlBa2Ca2Cu3O(sub x) and Tl2Ba2Ca2Cu3O(sub x) powders were synthesized, loaded into Ag tubes, and worked into wires and tapes by drawing and rolling. All processing outside of furnaces was in a dry-N2 glovebox. All heat treatments were performed in O2. The Ag-clad wires fabricated from these powders exhibited onset of superconductivity at approx. 18 K and critical current densities at 77 K of 2 x 10(exp 3) to 4 x 10(exp 3) A/sq cm.

  1. Synthesis of Cu-coated Graphite Powders Using a Chemical Reaction Process

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Jun-Ho; Park, Hyun-Kuk; Oh, Ik-Hyun [Korea Institute of Industrial Technology (KITECH), Gwangju (Korea, Republic of); Lim, Jae-Won [Chonbuk National University, Jeonju (Korea, Republic of)

    2017-05-15

    In this paper, Cu-coated graphite powders for a low thermal expansion coefficient and a high thermal conductivity are fabricated using a chemical reaction process. The Cu particles adhere to the irregular graphite powders and they homogeneously disperse in the graphite matrix. Cu-coated graphite powders are coarser at approximately 3-4 μm than the initial graphite powders; furthermore, their XRD patterns exhibit a low intensity in the oxide peak with low Zn powder content. For the passivation powders, the transposition solvent content has low values, and the XRD pattern of the oxide peaks is almost non-existent, but the high transposition solvent content does not exhibit a difference to the non-passivation treated powders.

  2. Research on Processes and Adhesion of Electroless Plating Ni-Cu-P Coating

    Institute of Scientific and Technical Information of China (English)

    HUANG Yan-bin; LIU Bo; ZHANG Ping; LIU De-gang; XU Xiao-li

    2004-01-01

    In order to improve the corrosion and wear resistance of the coatings of electroless plating Ni-Cu-P and broaden its application, an optimizing mathematical theory test has been applied in this research. The processing parameters have been optimized and some Ni-Cu-P coatings have been obtained with smooth and glittering appearance. At the same time,the composite complexants can prevent copper from depositing first and obtain coatings with strong adhesion. The porosity of Ni-Cu-P coating (20 μm) ranked class 9. The changing color time of the coating is more than 800 seconds with HNO3 dropthan 0.5 g/L. The surface appearance of deposition is typical cystiform cells by SEM,which rank close and neatly.

  3. Novel Processing of 81-mm Cu Shaped Charge Liners

    Energy Technology Data Exchange (ETDEWEB)

    Schwartz, A; Korzekwa, D

    2002-01-16

    A seven-step procedure was developed for producing shaped charge liner blanks by back extrusion at liquid nitrogen temperatures. Starting with a 38.1-mm diameter, 101.6-mm long cylinder at 77K, three forging steps with a flat-top die are required to produce the solid cone while maintaining low temperature. The solid cone is forged in four individual back extrusions at 77K to produce the rough liner blank. This procedure is capable of being run in batch processes to improve the time efficiency.

  4. Low-lying level structure of 56Cu and its implications for the rp process

    Science.gov (United States)

    Ong, W.-J.; Langer, C.; Montes, F.; Aprahamian, A.; Bardayan, D. W.; Bazin, D.; Brown, B. A.; Browne, J.; Crawford, H.; Cyburt, R.; Deleeuw, E. B.; Domingo-Pardo, C.; Gade, A.; George, S.; Hosmer, P.; Keek, L.; Kontos, A.; Lee, I.-Y.; Lemasson, A.; Lunderberg, E.; Maeda, Y.; Matos, M.; Meisel, Z.; Noji, S.; Nunes, F. M.; Nystrom, A.; Perdikakis, G.; Pereira, J.; Quinn, S. J.; Recchia, F.; Schatz, H.; Scott, M.; Siegl, K.; Simon, A.; Smith, M.; Spyrou, A.; Stevens, J.; Stroberg, S. R.; Weisshaar, D.; Wheeler, J.; Wimmer, K.; Zegers, R. G. T.

    2017-05-01

    The low-lying energy levels of proton-rich 56Cu have been extracted using in-beam γ -ray spectroscopy with the state-of-the-art γ -ray tracking array GRETINA in conjunction with the S800 spectrograph at the National Superconducting Cyclotron Laboratory at Michigan State University. Excited states in 56Cu serve as resonances in the 55Ni(p ,γ )56Cu reaction, which is a part of the rp process in type-I x-ray bursts. To resolve existing ambiguities in the reaction Q value, a more localized isobaric multiplet mass equation (IMME) fit is used, resulting in Q =639 ±82 keV. We derive the first experimentally constrained thermonuclear reaction rate for 55Ni(p ,γ )56Cu . We find that, with this new rate, the rp process may bypass the 56Ni waiting point via the 55Ni(p ,γ ) reaction for typical x-ray burst conditions with a branching of up to ˜40 % . We also identify additional nuclear physics uncertainties that need to be addressed before drawing final conclusions about the rp -process reaction flow in the 56Ni region.

  5. Ambient atmosphere-processable, printable Cu electrodes for flexible device applications: structural welding on a millisecond timescale of surface oxide-free Cu nanoparticles

    Science.gov (United States)

    Oh, Sang-Jin; Jo, Yejin; Lee, Eun Jung; Lee, Sun Sook; Kang, Young Hun; Jeon, Hye-Ji; Cho, Song Yun; Park, Jin-Seong; Seo, Yeong-Hui; Ryu, Beyong-Hwan; Choi, Youngmin; Jeong, Sunho

    2015-02-01

    Recently, various functional devices based on printing technologies have been of paramount interest, owing to their characteristic processing advantages along with excellent device performance. In particular, printable metallic electrodes have drawn attention in a variety of optoelectronic applications; however, research into printable metallic nanoparticles has been limited mainly to the case of an environmentally stable Ag phase. Despite its earth-abundance and highly conductive nature, the Cu phase, to date, has not been exploited as an ambient atmosphere-processable, printable material due to its critical oxidation problem in air. In this study, we demonstrate a facile route for generating highly conductive, flexible Cu electrodes in air by introducing the well-optimized photonic sintering at a time frame of 10-3 s, at which the photon energy, rather than conventional thermal energy, is instantly provided. It is elucidated here how the surface oxide-free, printed Cu particulate films undergo chemical structural/microstructural evolution depending on the instantly irradiated photon energy, and a successful demonstration is provided of large-area, flexible, printed Cu conductors on various substrates, including polyimide (PI), polyethersulfone (PES), polyethylene terephthalate (PET), and paper. The applicability of the resulting printed Cu electrodes is evaluated via implementation into both flexible capacitor devices and indium-gallium-zinc oxide (IGZO) flexible thin-film transistors.Recently, various functional devices based on printing technologies have been of paramount interest, owing to their characteristic processing advantages along with excellent device performance. In particular, printable metallic electrodes have drawn attention in a variety of optoelectronic applications; however, research into printable metallic nanoparticles has been limited mainly to the case of an environmentally stable Ag phase. Despite its earth-abundance and highly conductive

  6. Novel Ballistic Processing of Sn-0.7Cu Thick Films

    Science.gov (United States)

    Cavero, D.; Stewart, K.; Morsi, K.

    2016-11-01

    The present paper discusses a novel process (Ballistic Processing) for the ultra-rapid processing of textured and un-textured thick and potentially thin films. The effect of processing velocity (14.6 to 36.1 m/s) on the developed external structure and internal microstructure of Sn-0.7Cu thick film is discussed. Film thicknesses ranging from 6.08 to 12.79 μm were produced and characterized by two-dimensional hypoeutectic microstructures. Both film thickness and dendrite arm spacing decreased with an increase in processing velocity.

  7. Simple solution-processed CuO{sub X} as anode buffer layer for efficient organic solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Wenfei [CAS Key Laboratory of Bio-based Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 189 Songling Road, Qingdao 266101 (China); Institute of Hybrid Materials, The Growing Base for State Key Laboratory, Qingdao University, 308 Ningxia Road, Qingdao 266071 (China); Yang, Chunpeng [CAS Key Laboratory of Bio-based Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 189 Songling Road, Qingdao 266101 (China); Bao, Xichang, E-mail: baoxc@qibebt.ac.cn [CAS Key Laboratory of Bio-based Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 189 Songling Road, Qingdao 266101 (China); Sun, Liang; Wang, Ning [CAS Key Laboratory of Bio-based Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 189 Songling Road, Qingdao 266101 (China); Tang, Jianguo [Institute of Hybrid Materials, The Growing Base for State Key Laboratory, Qingdao University, 308 Ningxia Road, Qingdao 266071 (China); Chen, Weichao [CAS Key Laboratory of Bio-based Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 189 Songling Road, Qingdao 266101 (China); Yang, Renqiang, E-mail: yangrq@qibebt.ac.cn [CAS Key Laboratory of Bio-based Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 189 Songling Road, Qingdao 266101 (China)

    2015-10-15

    Graphical abstract: - Highlights: • Simple solution-processed CuO{sub X} hole transport layer for efficient organic solar cell. • Good photovoltaic performances as hole transport layer in OSCs with P3HT and PBDTTT-C as donor materials. • The device with CuO{sub X} as hole transport layer shows great improved stability compared with that of device with PEDOT:PSS as hole transport layer. - Abstract: A simple, solution-processed ultrathin CuO{sub X} anode buffer layer was fabricated for high performance organic solar cells (OSCs). XPS measurement demonstrated that the CuO{sub X} was the composite of CuO and Cu{sub 2}O. The CuO{sub X} modified ITO glass exhibit a better surface contact with the active layer. The photovoltaic performance of the devices with CuO{sub X} layer was optimized by varying the thickness of CuO{sub X} films through changing solution concentration. With P3HT:PC{sub 61}BM as the active layer, we demonstrated an enhanced PCE of 4.14% with CuO{sub X} anode buffer layer, compared with that of PEDOT:PSS layer. The CuO{sub X} layer also exhibits efficient photovoltaic performance in devices with PBDTTT-C:PC{sub 71}BM as the active layer. The long-term stability of CuO{sub X} device is better than that of PEDOT:PSS device. The results indicate that the easy solution-processed CuO{sub X} film can act as an efficient anode buffer layer for high-efficiency OSCs.

  8. Modeling Cu Migration in CdTe Solar Cells Under Device-Processing and Long-Term Stability Conditions (Poster)

    Energy Technology Data Exchange (ETDEWEB)

    Teeter, G.; Asher, S.

    2008-05-01

    An impurity migration model for systems with material interfaces is applied to Cu migration in CdTe solar cells. In the model, diffusion fluxes are calculated from the Cu chemical potential gradient. Inputs to the model include Cu diffusivities, solubilities, and segregation enthalpies in CdTe, CdS and contact materials. The model yields transient and equilibrium Cu distributions in CdTe devices during device processing and under field-deployed conditions. Preliminary results for Cu migration in CdTe PV devices using available diffusivity and solubility data from the literature show that Cu segregates in the CdS, a phenomenon that is commonly observed in devices after back-contact processing and/or stress conditions.

  9. Modeling Cu Migration in CdTe Solar Cells Under Device-Processing and Long-Term Stability Conditions: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Teeter, G.; Asher, S.

    2008-05-01

    An impurity migration model for systems with material interfaces is applied to Cu migration in CdTe solar cells. In the model, diffusion fluxes are calculated from the Cu chemical potential gradient. Inputs to the model include Cu diffusivities, solubilities, and segregation enthalpies in CdTe, CdS and contact materials. The model yields transient and equilibrium Cu distributions in CdTe devices during device processing and under field-deployed conditions. Preliminary results for Cu migration in CdTe photovoltaic devices using available diffusivity and solubility data from the literature show that Cu segregates in the CdS, a phenomenon that is commonly observed in devices after back-contact processing and/or stress conditions.

  10. 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.

  11. Manufacture of high-dispersed W-Cu composite powder by mechano-thermal process

    Institute of Scientific and Technical Information of China (English)

    李云平; 曲选辉; 郑州顺; 于澍

    2003-01-01

    In order to improve the process of co-reduction of oxide powder, a new mechano-thermal process was de-signed to produce high-dispersed W-Cu composite powder by high temperature oxidation, short time high-energymilling and reduction at lower temperature. The particle size, oxygen content and their sintering abilities of W-Cucomposite powder in different conditions were analyzed. The results show that after a quick milling of the oxidepowder for about 3-10 h, the reduction temperature of the W-Cu oxide powder can be lowered to about 650 ℃ from700-750 ℃ owning to the lowering of particle size of the oxide powder. The average particle size of W-Cu powder af-ter reduction at 650 ℃ is about 0.5 μm smaller than that reduced at 750 ℃. After sintering at 1 200 ℃ for 1 h inhydrogen atmosphere, the relative density and thermal conductivity of final products (W-20Cu) can attain 99.5%and 210 W @ m-1 @ K-1 respectively.

  12. Selective removal and patterning of a Co/Cu/Co trilayer created by femtosecond laser processing

    Energy Technology Data Exchange (ETDEWEB)

    Ulmeanu, M.; Filipescu, M.; Scarisoreanu, N.D.; Georgescu, G.; Rusen, L.; Zamfirescu, M. [National Institute for Laser, Plasma and Radiation Physics, Laser Department, Atomistilor Str. 409, P.O. Box MG-36, Magurele-Bucharest (Romania)

    2011-07-15

    The selective removal and patterning of a typical pseudo-spin-valve structure, consisting of a Co(20 nm)/ Cu(6 nm)/Co(3 nm) trilayer, by femtosecond laser has been examined in terms of irradiation parameters and layer structure. Ablation thresholds of the individual Co and Cu thin films and the SiO{sub 2}/Si substrate have been measured for single-shot irradiation with a 200 femtosecond (fs) laser pulses of a Ti:sapphire laser operating at 775 nm. Ablation of the entire trilayer structure was characterized by a sequential removal of the layers at a threshold level of fluence of 0.28 J/cm{sup 2}. Atomic Force Microscopy, optical microscopy, profilometry and Sputtered Neutral Mass Spectroscopy were employed to characterize the laser-induced single-shot laser selective removal and patterned areas. As a result, two phenomena were found to characterize the laser process: (i) selective removal of the Co and Cu layer due to the change of the laser fluence and (ii) regular pillars' area of Co/Cu/Co could be achieved in a regular manner with the lowest pillar width size of 1.5 {mu}m. Ablation through the layers was accompanied by the formation of bulges at the edges of the pillars, which was the biggest inconvenience in lowering the pillar size through the femtosecond laser process. (orig.)

  13. CdS nanowires decorated with Cu{sub 2}O nanospheres: Synthesis, formation process and enhanced photoactivity and stability

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yang; Dong, Hailiang; Jia, Husheng; Xu, Bingshe; Yu, Chunyan; Zhang, Zhuxia, E-mail: zhangzhuxia@tyut.edu.cn

    2015-09-25

    Highlights: • Novel CdS/Cu{sub 2}O heterostructural composites were synthesized by a two-step chemical method. • A formation process of CdS/Cu{sub 2}O heterostructural composites. • The CdS/Cu{sub 2}O heterostructural composites were found to have superior photocatalytic performance and stability. - Abstract: CdS/Cu{sub 2}O heterostructural materials were successfully synthesized by a solvent-thermal process followed by a chemical bath deposition process. Structures and morphologies of the obtained CdS/Cu{sub 2}O composites were characterized by XRD, SEM, and TEM; the experimental results indicate that the surface of CdS nanowires (NWs) is decorated with spherical Cu{sub 2}O whose diameter ranges from 100 to 200 nm. Through crystal shape-evolution, the formation process of these hierarchical nanostructures was rationally proposed. Briefly, in the chemical bath deposition process, Cu(OH){sub 2} colloids generate firstly, and then the colloids transform into nanobelts after adding ascorbic acid (AA). With the reaction time further increasing, nanobelts aggregate together to form the hierarchical nanospheres on the surface of CdS NWs. The photoactivity of CdS/Cu{sub 2}O composite for methyl orange (MO) photodegradation was investigated in detail. The obtained high photocatalytic efficiency can be attributed to the heterojunction structure, which results in the efficient separation of photo-generated electrons and holes.

  14. Negative quantum interference between the electronic Raman scattering processes of CuO chains and CuO2 planes of heavily overdoped (Y, Ca)Ba2Cu3O(7-delta).

    Science.gov (United States)

    Masui, T; Limonov, M; Uchiyama, H; Tajima, S; Yamanaka, A

    2005-11-11

    We found a strong X-Y anisotropy of the pair-breaking peak in the Raman scattering of heavily overdoped (Y, Ca)Ba2Cu3O(7-delta) (T(c) = 65 K). The pair-breaking peak is radically suppressed in the YY-polarized spectrum. We ascribe this anomaly to the effect of quantum interference between the Raman processes of the CuO-chain and the CuO2-plane electronic excitations that might take place as a result of the increase in the transfer matrix due to overdoping.

  15. Ultrasound assisted solidification process of ternary Cu-Sn-Sb alloy

    Institute of Scientific and Technical Information of China (English)

    Zhai Wei; Hong Zhenyu; Liu Haiman; Wei Bingbo

    2016-01-01

    It is well-known that the application of ultrasound during liquid to solid transitions for alloys can refine the solidification microstructure and thus improves the mechanical properties. How-ever, most published work focuses on single phase dendritic growth, whereas little has been con-ducted on the multiphase alloys with complicated phase transformations during solidification. In this work, the solidification process of ternary Cu40Sn45Sb15 alloy was realized within intensive ultra-sonic field with a resonant frequency of 20 kHz and ultrasound power from 0 W to 1000 W. The ultrasound refines the size of the primary e(Cu3Sn) intermetallic compound by two orders of mag-nitudes. If the ultrasound power increases to 1000 W, g(Cu6Sn5) phase nucleates and grows directly from parent liquid phase without the occurrence of peri-eutectic reaction on the top of the alloy sam-ple where the ultrasound intensity is sufficiently high. These microstructural variations lead to the enhancement of compressive strength and elasticity modulus of ternary Cu40Sn45Sb15 alloy.

  16. Neural correlates of encoding processes predicting subsequent cued recall and source memory.

    Science.gov (United States)

    Angel, Lucie; Isingrini, Michel; Bouazzaoui, Badiâa; Fay, Séverine

    2013-03-06

    In this experiment, event-related potentials were used to examine whether the neural correlates of encoding processes predicting subsequent successful recall differed from those predicting successful source memory retrieval. During encoding, participants studied lists of words and were instructed to memorize each word and the list in which it occurred. At test, they had to complete stems (the first four letters) with a studied word and then make a judgment of the initial temporal context (i.e. list). Event-related potentials recorded during encoding were segregated according to subsequent memory performance to examine subsequent memory effects (SMEs) reflecting successful cued recall (cued recall SME) and successful source retrieval (source memory SME). Data showed a cued recall SME on parietal electrode sites from 400 to 1200 ms and a late inversed cued recall SME on frontal sites in the 1200-1400 ms period. Moreover, a source memory SME was reported from 400 to 1400 ms on frontal areas. These findings indicate that patterns of encoding-related activity predicting successful recall and source memory are clearly dissociated.

  17. 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.

  18. Cu-Ni-YSZ anodes for solid oxide fuel cell by mechanical alloying processing

    Energy Technology Data Exchange (ETDEWEB)

    Guisard Restivo, Thomaz A.; Mello-Castanho, Sonia R.H. [IPEN, Inst. of Energetic and Nuclear Research, Sao Paulo, SP (Brazil)

    2010-01-15

    The work shows some results concerning a new cermet material 40 vol.% [(Cu)-Ni]-YSZ processed by mechanical alloying followed by Sintering by Activated Surface method. The projected cermet microstructure for this application is expected to possess microstructural characteristics that lead to better electric and ionic percolating, higher electrocatalytic activity and fuel reforming. The powder samples prepared by mechanical alloying optimized conditions show a homogeneous mixture. Transmission and scanning electron microscope analysis have demonstrated the powder particles are nanosized after 2 h of milling, showing lamellar internal structure aggregates. Suitable sintered pellets are obtained from these powders, within the required porosity and microstructure. Sintering kinetics studies for pellets of Ni-YSZ and Ni-Cu-YSZ indicate 2-step sintering processes. Copper additive promotes sintering and refines the microstructure. (orig.)

  19. Bulk YBa2Cu3O(x) superconductors through pressurized partial melt growth processing

    Science.gov (United States)

    Hu, S.; Hojaji, H.; Barkatt, A.; Boroomand, M.; Hung, M.; Buechele, A. C.; Thorpe, A. N.; Davis, D. D.; Alterescu, S.

    1992-01-01

    A novel pressurized partial melt growth process has been developed for producing large pieces of bulk Y-Ba-Cu-O superconductors. During long-time partial melt growth stage, an additional driving force for solidification is obtained by using pressurized oxygen gas. The microstructure and superconducting properties of the resulting samples were investigated. It was found that this new technique can eliminate porosity and inhomogeneity, promote large-scale grain-texturing, and improve interdomain coupling as well.

  20. 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)

  1. KLn Dielectronic Recombination Process of B-Through He-like Cu Ions

    Institute of Scientific and Technical Information of China (English)

    GAO Ying-Hui; ZHANG Xue-Mei; MENG Fan-Chang; CHEN Wen-Dong; CHEN Chong-Yang; ZOU Ya-Ming

    2008-01-01

    @@ The KLn dielectronic recombination processes of trapped highly charged B-like through He-like Cu ions are studied theoretically,and the theoretical results are used to analyse our previous experimental data at Heidelberg electron beam ion trap(EBIT).The theoretical resonant positions agree with the experimental resonant positions to a precision of 0.4%,in comparison with the resonant positions of those highest peaks between theory and experiment.

  2. Formation of CuInS{sub 2}-carbon multilayers in the spray ILGAR process

    Energy Technology Data Exchange (ETDEWEB)

    Camus, Christian; Abou-Ras, Daniel; Allsop, Nicholas A.; Gledhill, Sophie E.; Koehler, Tristan; Lauermann, Iver; Lux-Steiner, Martha C.; Fischer, Christian-Herbert [Helmholtz Zentrum Berlin fuer Materialien und Energie, Glienicker Str. 100, 14109 Berlin (Germany); Rappich, Joerg [Helmholtz Zentrum Berlin fuer Materialien und Energie, Kekulestr. 5, 12489 Berlin (Germany)

    2010-01-15

    In this paper, the incorporation of carbon into CuInS{sub 2} (CIS) thin films is described as observed in spray ion layer gas reaction (ILGAR) deposition of such thin films. It is shown that this carbon incorporation leads to the formation of a CIS-carbon multilayer stack. Its growth mechanism is explained by the interaction of the copper and indium precursor compounds used in the deposition process. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  3. One-step electrodeposition process of CuInSe2: Deposition time effect

    Indian Academy of Sciences (India)

    O Meglali; N Attaf; A Bouraiou; M S Aida; S Lakehal

    2014-10-01

    CuInSe2 thin films were prepared by one-step electrodeposition process using a simplified twoelectrodes system. The films were deposited, during 5, 10, 15 and 20 min, from the deionized water solution consisting of CuCl2, InCl3 and SeO2 onto ITO-coated glass substrates. As-deposited films have been annealed under vacuum at 300 °C during 30 min. The structural, optical band gap and electrical resistivity of elaborated films were studied, respectively, using X-ray diffraction (XRD), Raman spectroscopy, UV spectrophotometer and four-point probe method. The micro structural parameters like lattice constants, crystallite size, dislocation density and strain have been evaluated. The XRD investigation proved that the film deposited at 20 min present CuInSe2 single phase in its chalcopyrite structure and with preferred orientation along (1 1 2) direction, whereas the films deposited at 5, 10 and 15 min show the CuInSe2 chalcopyrite structure with the In2Se3 as secondary phase. We have found that the formation mechanism of CuInSe2 depends on the In2Se3 phase. The optical band gap of the films is found to decrease from 1.17 to 1.04 eV with increase in deposition time. All films show Raman spectra with a dominant A1 mode at 174 cm-1, confirming the chalcopyrite crystalline quality of these films. The films exhibited a range of resistivity varying from 2.3 × 10-3 to 4.4 × 10-1 cm.

  4. Growth of intermetallic phases in Al/Cu composites at various annealing temperatures during the ARB process

    Science.gov (United States)

    Hsieh, Chih-Chun; Shi, Ming-Shou; Wu, Weite

    2012-02-01

    The purpose of this study is to discuss the effect of annealing temperatures on growth of intermetallic phases in Al/Cu composites during the accumulative roll bonding (ARB) process. Pure Al (AA1100) and pure Cu (C11000) were stacked into layered structures at 8 cycles as annealed at 300 °C and 400 °C using the ARB technique. Microstructural results indicate that the necking of layered structures occur after 300 °C annealing. Intermetallic phases grow and form a smashed morphology of Al and Cu when annealed at 400 °C. From the XRD and EDS analysis results, the intermetallic phases of Al2Cu (θ) and Al4Cu9 (γ2) formed over 6 cycles and the AlCu (η2) precipitated at 8 cycles after 300 °C annealing. Three phases (Al2Cu (θ), Al4Cu9 (γ2), and AlCu (η2)) were formed over 2 cycles after 400 °C annealing.

  5. In Situ Synthesis of Al-Si-Cu Alloy During Brazing Process and Mechanical Property of Brazing Joint

    Directory of Open Access Journals (Sweden)

    LONG Wei-min

    2016-06-01

    Full Text Available The Al-Si-Cu alloy system is considered to be a promising choice of filler metal for aluminium alloys brazing due to its high strength and low melting point. The greatest obstacle is its lack of plastic forming ability and being difficult to be processed by conventional methods. This disadvantage is ascribed to the considerable amount of brittle CuAl2 intermetallic compound which forms when alloy composition is around the ternary eutectic point. In order to overcome this deficiency, authors of this article proposed to synthesize Al-Si-Cu filler metal by using in situ synthesis method, and the structure and properties of brazing joints were studied. The results show that AlSi alloy is used as the wrap layer, and CuAl alloy is used as the powder core in the composite brazing wire, the two alloys have similar melting points. The machinability of the composite brazing wire is much superior to the traditional Al-Si-Cu filler metal. During the induction brazing of 3A21 alloy, when using AlSi-CuAl composite filler wire, AlSi and CuAl alloys melt almost simultaneously, then after short time holding, Al-Si-Cu braze filler is obtained, the brazing seam has uniform composition and good bonding interface, also, the shearing strength of the brazing joints is higher than the joint brazed by conventional Al-Si-Cu filler metal.

  6. Magnetic and Hardness Analysis During Precipitation and Recovery Process of Deformed Fe-Cu Alloy

    Science.gov (United States)

    Kikuchi, Hiroaki; Sasaki, Takahiro; Murakami, Takeshi; Ito, Fumiya

    This paper describes the characteristics of the coercive force and Vickers hardness for cold-rolled and thermally aged Fe-Cu alloys with varying isothermal aging times. Fe-1 wt% Cu alloys were cold-rolled and then thermally aged at 553 or 773 K from 0 to 104 min. The coercive force for the cold-rolled specimen decreases with increasing aging time, and the slope of the reduction becomes higher with increasing aging temperature. The recovery process contributes to the change in the coercive force. In contrast, the hardness increases with increasing aging time at an early aging stage and then eventually peaks. The copper precipitates play an important role in the change in the hardness and barely have an effect on the magnetic properties.

  7. Effect of homogenization process on the hardness of Zn–Al–Cu alloys

    Institute of Scientific and Technical Information of China (English)

    Jose D. Villegas-Cardenas; Maribel L. Saucedo-Mu?oz; Victor M. Lopez-Hirata; Antonio De Ita-De la Torre; Erika O. Avila-Davila; Jorge Luis Gonzalez-Velazquez

    2015-01-01

    The effect of a homogenizing treatment on the hardness of as-cast Zn–Al–Cu alloys was investigated. Eight alloy compositions were prepared and homogenized at 350 ℃ for 180 h, and their Rockwell "B" hardness was subsequently measured. All the specimens were analyzed by X-ray diffraction and metallographically prepared for observation by optical microscopy and scanning electron microscopy. The results of the present work indicated that the hardness of both alloys (as-cast and homogenized) increased with increasing Al and Cu contents; this increased hardness is likely related to the presence of theθandτ′ phases. A regression equation was obtained to determine the hardness of the homogenized alloys as a function of their chemical composition and processing parameters, such as homogenization time and tem-perature, used in their preparation.

  8. Fabrication of Cu2ZnSn(SxSe1 - x)4 solar cells by ethanol-ammonium solution process

    Science.gov (United States)

    Xue, Cong; Li, Jianmin; Wang, Yaguang; Jiang, Guoshun; Weifeng, Liu; Zhu, Changfei

    2016-10-01

    In this paper, Cu2ZnSn(SxSe1 - x)4 precursor films were produced by doctor blade process from SnS-Cu2O-ZnS slurry. To prepare the slurry, SnS, ZnS and Cu2O precipitates, which are outgrowths of stacked layer ZnS/Cu/SnS by CBD (chemical bath deposition)-annealing route, were dissolved in the mixture solvent of ethanol and NH3·H2O. Synthesized precursor films were then annealed at different conditions. The post-annealed films were characterized by means of scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman measurements and UV-vis-NIR spectroscopy. SEM studies reveal that the rough and relatively compact absorber thin films are obtained via the sulfidation and sulfidation-selenization processes. X-ray diffraction and Raman spectrum results verify that the obtained films are composed of Cu2ZnSnS4 and Cu2ZnSnSe4 phases, which have high absorbance in visible range and direct band gap energy of 1.01-1.47 eV. The best devices yield total area power conversion efficiency of 1.99% and 2.95% corresponding to Cu2ZnSnS4 and Cu2ZnSn(SxSe1 - x)4 thin film solar cells under AM1.5 illumination without any anti-reflection layer.

  9. Measuring cognitive processes involved in the web search: log files, eye-movements and cued rertospective reports

    NARCIS (Netherlands)

    Argelagos, Esther; Jarodzka, Halszka; Pifarre, Manoli

    2011-01-01

    Argelagós, E., Jarodzka, H., & Pifarré, M. (2011, August). Measuring cognitive processes involved in web search: log files, eye-movements and cued retrospective reports compared. Presentation at EARLI, Exeter, UK.

  10. Advanced Precursor Reaction Processing for Cu(InGa)(SeS)2 Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Shafarman, William N. [Univ. of Delaware, Newark, DE (United States)

    2015-10-12

    This project “Advanced Precursor Reaction Processing for Cu(InGa)(SeS)2 Solar Cells”, completed by the Institute of Energy Conversion (IEC) at the University of Delaware in collaboration with the Department of Chemical Engineering at the University of Florida, developed the fundamental understanding and technology to increase module efficiency and improve the manufacturability of Cu(InGa)(SeS)2 films using the precursor reaction approach currently being developed by a number of companies. Key results included: (1) development of a three-step H2Se/Ar/H2S reaction process to control Ga distribution through the film and minimizes back contact MoSe2 formation; (2) Ag-alloying to improve precursor homogeneity by avoiding In phase agglomeration, faster reaction and improved adhesion to allow wider reaction process window; (3) addition of Sb, Bi, and Te interlayers at the Mo/precursor junction to produce more uniform precursor morphology and improve adhesion with reduced void formation in reacted films; (4) a precursor structure containing Se and a reaction process to reduce processing time to 5 minutes and eliminate H2Se usage, thereby increasing throughput and reducing costs. All these results were supported by detailed characterization of the film growth, reaction pathways, thermodynamic assessment and device behavior.

  11. Optimization of a Cu CMP process modeling parameters of nanometer integrated circuits

    Institute of Scientific and Technical Information of China (English)

    Ruan Wenbiao; Chen Lan; Ma Tianyu; Fang Jingjing; Zhang He; Ye Tianchun

    2012-01-01

    A copper chemical mechanical polishing (Cu CMP) process is reviewed and analyzed from the view of chemical physics.Three steps Cu CMP process modeling is set up based on the actual process of manufacturing and pattern-density-step-height (PDSH) modeling from MIT.To catch the pattern dependency,a 65 nm testing chip is designed and processed in the foundry.Following the model parameter extraction procedure,the model parameters are extracted and verified by testing data from the 65 nm testing chip.A comparison of results between the model predictions and test data show that the former has the same trend as the latter and the largest deviation is less than 5 nm.Third party testing data gives further evidence to support the great performance of model parameter optimization.Since precise CMP process modeling is used for the design of manufacturability (DFM) checks,critical hotspots are displayed and eliminated,which will assure good yield and production capacity of IC.

  12. Solution-Processed Cu2Se Nanocrystal Films with Bulk-Like Thermoelectric Performance.

    Science.gov (United States)

    Forster, Jason D; Lynch, Jared J; Coates, Nelson E; Liu, Jun; Jang, Hyejin; Zaia, Edmond; Gordon, Madeleine P; Szybowski, Maxime; Sahu, Ayaskanta; Cahill, David G; Urban, Jeffrey J

    2017-06-05

    Thermoelectric power generation can play a key role in a sustainable energy future by converting waste heat from power plants and other industrial processes into usable electrical power. Current thermoelectric devices, however, require energy intensive manufacturing processes such as alloying and spark plasma sintering. Here, we describe the fabrication of a p-type thermoelectric material, copper selenide (Cu2Se), utilizing solution-processing and thermal annealing to produce a thin film that achieves a figure of merit, ZT, which is as high as its traditionally processed counterpart, a value of 0.14 at room temperature. This is the first report of a fully solution-processed nanomaterial achieving performance equivalent to its bulk form and represents a general strategy to reduce the energy required to manufacture advanced energy conversion and harvesting materials.

  13. Devitrification process in rapidly solidified Al-Ni-Cu-Nd metallic glass

    Institute of Scientific and Technical Information of China (English)

    XIAO Yu-de(肖于德); LI Wen-xian(黎文献); D. Jacovkis; N. Clavaguera; M. T. Clavaguera-Mora; J. Rodriguez-Viejo

    2003-01-01

    In the present study, rapidly solidified ribbons of Al87 Ni7Cu3 Nd3 metallic glass was prepared by usingmelt spinning. Devitrification process of the totally amorphous ribbons was investigated by high temperature X-raydiffraction analysis, combining with differential scanning calorimetry, under continuous and isothermal heating re-gime. The X-ray diffraction intensity and full width at the half maximum (FWHM) were analyzed to investigate theincrease of crystallized amount and growth of α-Al crystal particles. The results show that under continuous heatingregime, the metallic glass devitrifies via two main stages: primary crystallization, resulting in two-phase mixture ofα-Al plus residual amorphous phase, and secondary crystallization, corresponding to rapid precipitation of some in-ter-metallic phases in the form of dispersion or eutectic mixture. Under isothermal heating regime, only Al crystalprecipitates from the Al-rich amorphous matrix at low temperature, and when heating at 280 ℃ only Al crystal pre-cipitates within a short time, and then Al8 Cu4 Nd forms, followed by Al3 Ni, in the residual amorphous phase. Whenheating at higher temperature or for longer time, Aln Nd3 forms, the amorphous phase disappears, and the ribbonsdevelop into polycrystalline morphologies with multiply phase mixture of a-Al, Al8 Cu4 Nd, Al3 Ni, and Al11 Nd3.

  14. Cu-(B4Cp metal matrix composites processed by accumulative roll-bonding

    Directory of Open Access Journals (Sweden)

    S. Mansourzadeh

    2016-12-01

    Full Text Available In this study, Cu/B4C metal matrix composites were prepared by accumulative roll-bonding (ARB. The microstructure of the processed samples was characterized by TEM, SEM and optical microscopy. The microhardness, uniaxial tensile and four-point probe tests were carried out to evaluate the mechanical properties and electrical resistivity of the ARBed monolithic and composite samples. The results showed that the reinforcement distribution was improved by increasing ARB cycles, which was quantitatively confirmed by some models. Based on TEM observations, the formation of an ultrafine grained structure in the composite matrix was also approved. It was shown that with increasing ARB cycles, the microhardness and tensile strength of the monolithic Cu samples were enhanced up to the 3rd cycle and then saturated, but the microhardness and tensile strength of the composites showed an increasing trend to the last cycle. Apart from a substantial improvement in the mechanical properties of the Cu/B4C composites, a minor decrement in electrical conductivity was detected after six ARB cycles.

  15. Laser-direct process of Cu nano-ink to coat highly conductive and adhesive metallization patterns on plastic substrate

    Science.gov (United States)

    Min, Hyungsuk; Lee, Byoungyoon; Jeong, Sooncheol; Lee, Myeongkyu

    2016-05-01

    We here present a simple, low-cost laser-direct process to fabricate conductive Cu patterns on plastic substrate. A Cu nano-ink was synthesized using Cu formate as a precursor. The Cu ink spin-coated on a polyimide substrate was selectively sintered using a pulsed ultraviolet laser beam. The unexposed regions of the coated ink could be removed by rinsing the whole film in the dispersion agent of the synthesized ink, which revealed a conductive Cu pattern. This allowed sintering and patterning to be simultaneously accomplished, with a minimum line width of ~20 μm available. The fabricated pattern remained strongly adhesive to the substrate and exhibited only a slight increase in resistance even after 1000 bending cycles to a radius of curvature of 4.8 mm.

  16. Interface morphology and solute partition during directional soldification process of Al-1.5Cu-3Zn alloy

    Energy Technology Data Exchange (ETDEWEB)

    Fuyia Chen; Wanqib Jie [State Key Lab. of Solidification Processing, Northwestern Polytechnical Univ., Xian (China)

    2005-07-01

    Interface morphology and solute partition during directional solidification process of Al-1.5Cu-3.0Zn alloy were investigated at temperature gradient of 80 K/cm and growth rate between 0.1 and 7.1 {mu}m/s. The solid-liquid interface was quenched during directional solidification and the micromorphology at the longitudinal section was examined by optic microscopy and SEM. The cellular growth interface and dendritic growth interface were observed and characterized. The distribution of Cu and Zn was measured by EDS, the equilibrium solute partition coefficients for Cu and Zn in Al-1.5Cu-3.0Zn alloy were obtained to be 0.31 and 0.58. The activity model and concentration model, developed by present authors, were used to calculate the equilibrium solute partition coefficients in Al-1.5Cu-3Zn alloy. The model-calculated results were compared with experimental data. (orig.)

  17. Structural ordering of laser-processed FePdCu thin alloy films

    Energy Technology Data Exchange (ETDEWEB)

    Perzanowski, Marcin, E-mail: Marcin.Perzanowski@ifj.edu.pl; Krupinski, Michal; Zarzycki, Arkadiusz; Zabila, Yevhen; Marszalek, Marta

    2015-10-15

    The Cu/Fe/Pd multilayers were transformed into L1{sub 0}-ordered FePdCu alloy by pulsed laser annealing. The initial multilayers were irradiated with 1, 10, 100, and 1000 laser pulses with duration time of 10 ns and energy density of 235 mJ/cm{sup 2}. The gradual change of the number of laser pulses allowed to investigate the structural and magnetic properties at early stages of the transformation and L1{sub 0}-ordering processes. The measurements were carried out using X-Ray Diffraction, SQUID magnetometry, and Magnetic Force Microscopy. We found that L1{sub 0} FePdCu (111)-oriented nanograins are formed by ordering of the coherent domains present in the as-deposited multilayer. The irradiation does not change the vertical size of the (111) crystallites. The L1{sub 0} (002)-oriented grains appear at the later stages of the transformation and their size increases with the number of applied laser pulses. Additionally, the laser annealing induces the magnetic ordering of the irradiated material, which was observed as an increase of the saturation magnetisation and the Curie temperature with the rising number of pulses. We also observed, that irradiation with 1000 pulses leads to the loss of order, which is reflected in the drop of the Curie temperature. - Highlights: • L1{sub 0}-ordered FePdCu alloy successfully fabricated by laser annealing. • The mechanism of (111) and (002) nanocrystallite formation was different. • Gradual change of annealing conditions showed early stages of transformation. • Saturation magnetisation and Curie temperature increased with the number of pulses.

  18. La-Doped CaCu3Ti4O12 Prepared By Conventional And Microwave Processing

    Science.gov (United States)

    Sharif, Nur Shafiza A.; Ahmad, Zainal A.; Hutagalung, Sabar D.

    2010-01-01

    Two processing techniques were used to prepare separate samples of undoped and La-doped CaCu3Ti4O12: the conventional furnace and microwave processing. Stoichiometric composition of undoped CaCu3Ti4O12 was produced by mixing starting materials of Ca(OH)2, CuO and TiO2 powder. The mixed powder was milled and then calcined, compacted and sintered using either a furnace (conventional) or a domestic microwave oven (microwave processing). The La2O3 was added to undoped CaCu3Ti4O12 in order to prepare the La-doped CaCu3Ti4O12 with different doping concentrations. The conventional furnace heating technique requires a calcination temperature of 900° C for 12 hours before the mixture is sintered at 1000° C for 12 hours. However, a single phase CaCu3Ti4O12 compound was successfully synthesized using a microwave oven for a calcination time of 30 minutes. Longer microwave sintering time tends to produce denser CaCu3Ti4O12 pellets.

  19. Dynamic recrystallization behavior and processing map of the Cu-Cr-Zr-Nd alloy.

    Science.gov (United States)

    Zhang, Yi; Sun, Huili; Volinsky, Alex A; Tian, Baohong; Song, Kexing; Chai, Zhe; Liu, Ping; Liu, Yong

    2016-01-01

    Hot deformation behavior of the Cu-Cr-Zr-Nd alloy was studied by hot compressive tests in the temperature range of 650-950 °C and the strain rate range of 0.001-10 s(-1) using Gleeble-1500D thermo-mechanical simulator. The results showed that the flow stress is strongly dependent on the deformation temperature and the strain rate. With the increase of temperature or the decrease of strain rate, the flow stress significantly decreases. Hot activation energy of the alloy is about 404.84 kJ/mol and the constitutive equation of the alloy based on the hyperbolic-sine equation was established. Based on the dynamic material model, the processing map was established to optimize the deformation parameters. The optimal processing parameters for the Cu-Cr-Zr-Nd alloy hot working are in the temperature range of 900-950 °C and strain rate range of 0.1-1 s(-1). A full dynamic recrystallization structure with fine and homogeneous grain size can be obtained at optimal processing conditions. The microstructure of specimens deformed at different conditions was analyzed and connected with the processing map. The surface fracture was observed to identify instability conditions.

  20. 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.

  1. Transport processes and reduction of IcRn product in YBaCuO/PrBaCuO/YBaCuO ramp-type Josephson junctions

    NARCIS (Netherlands)

    Boguslavskij, Y.M.; Gao, J.; Rijnders, A.J.H.M.; Terpstra, D.; Gerritsma, G.J.; Rogalla, H.

    1993-01-01

    The mechanisms of current passage and the causes of IcRn (critical-current normal-resistance) product reduction of YBCO/PBCO/YBCO ramp-type junctions are analyzed. At PBCO (PrBa2Cu3Ox ) barrier thicknesses L=8-20 nm the junction characteristics are determined by the thickness of the PBCO barrier and

  2. Growth mechanism of thermally processed Cu(In,Ga)S{sub 2} precursors for printed Cu(In,Ga)(S,Se){sub 2} solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Klugius, Ines; Quintilla, Aina; Friedlmeier, Theresa M.; Blazquez-Sanchez, David; Ahlswede, Erik; Powalla, Michael [Zentrum fuer Sonnenenergie- und Wasserstoff-Forschung Baden-Wuerttemberg (ZSW), Stuttgart (Germany); Miller, Rebekah [EMD Millipore, Waltham, MA (United States)

    2012-07-15

    We investigate a process used for the selenisation of particle-based precursors to prepare low-cost Cu(In,Ga)(S,Se){sub 2} (CIGS) solar cells. It is suitable for high throughput with a short optimum selenisation duration of 3-5 min and employs a rapid thermal annealing system with elemental selenium vapour. Homogeneous crack-free Cu(In,Ga)S{sub 2} precursor films of up to 1 {mu}m are obtained via doctor blading. The high selenium vapour pressure in the selenisation reaction chamber results in the formation of a compact Cu(In,Ga)(S,Se){sub 2} layer on top of a carbon-rich underlayer. In order to investigate the phase development in the film, the selenisation process was interrupted at different stages and the samples were monitored via XRD and surface-sensitive Raman measurements. We find the formation of a polycrystalline Cu(In,Ga)Se{sub 2} phase already after 1 s at the target temperature of 550 C. Furthermore, the effect of initial precursor thickness on solar cell parameters is discussed. Complete solar cells are prepared by conventional methods, leading to conversion efficiencies well above 8%. (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  3. Effect of processing condition on the microstructure of rheocast Al-Cu alloys

    Energy Technology Data Exchange (ETDEWEB)

    Prasad, P.R.; Ray, S.; Kapoor, M.L.; Gaindhar, J.L.

    1989-06-01

    The effect of processing condition of the microstructure of rheocast alloys has been theoretically analysed. The average particle size may increase, decrease or remain unaltered with the change in rheocasting temperature depending upon the prevailing nucleation and growth conditions. Experimental results of Al-Cu alloys are in agreement with the theoretical predictions. Increasing the copper content makes the transformation nucleation dominant and therefore the variation of size and distribution of /alpha/-particles with rheocasting temperature and stirring rate is a function of alloy composition. (orig.).

  4. Electrochemical properties of CuO hollow nanopowders prepared from formless Cu–C composite via nanoscale Kirkendall diffusion process

    Energy Technology Data Exchange (ETDEWEB)

    Won, Jong Min [Department of Materials Science and Engineering, Korea University, Anam-Dong, Seongbuk-Gu, Seoul 136-713 (Korea, Republic of); Kim, Jong Hwa [Daegu Center, Korea Basic Science Institute, 80 Daehakro Bukgu, Daegu 702-701 (Korea, Republic of); Choi, Yun Ju [Suncheon Center, Korea Basic Science Institute, Suncheon 540-742 (Korea, Republic of); Cho, Jung Sang [Department of Materials Science and Engineering, Korea University, Anam-Dong, Seongbuk-Gu, Seoul 136-713 (Korea, Republic of); Kang, Yun Chan, E-mail: yckang@korea.ac.kr [Department of Materials Science and Engineering, Korea University, Anam-Dong, Seongbuk-Gu, Seoul 136-713 (Korea, Republic of)

    2016-06-25

    Hollow CuO nanopowders are prepared using a simple spray drying process that relied on nanoscale Kirkendall diffusion; these nanopowders have potential applications in lithium-ion batteries. Citric acid is used as both the carbon source material and chelating agent and plays a key role in the preparation of the hollow nanopowders. The formless Cu–C composite that formed as an intermediate product transforms into slightly aggregated CuO hollow nanopowders after post-treatment at 300 and 400 °C under an air atmosphere. The CuO hollow nanopowders exhibit higher initial discharge capacities and better cycling performances than those of the filled-structured CuO nanopowders, which are prepared at a post-treatment temperature of 500 °C under an air atmosphere. The discharge capacities of the CuO nanopowders post-treated at 300, 400, and 500 °C for the 150{sup th} cycle at a current density of 1 A g{sup −1} are 793, 632, and 464 mA h g{sup −1}, respectively, and their capacity retentions calculated from the maximum discharge capacities are 88, 80, and 73%, respectively. The CuO nanopowders with hollow structures exhibit better structural stability for repeated lithium insertion and desertion processes than those with filled structures. - Highlights: • Hollow CuO nanopowders are prepared using a simple spray drying process. • Cu–C composite transforms into CuO hollow nanopowders by Kirkendall diffusion. • Hollow CuO nanopowders show good electrochemical properties for lithium-ion storage.

  5. Multi-seeding melt growth process of bulk Y-Ba-Cu-O superconductors for engineering applications

    Science.gov (United States)

    Wongsatanawarid, A.; Seki, H.; Murakami, M.

    2010-06-01

    We have prepared polycrystalline and four-domain Y-Ba-Cu-O superconductors in a molar ratio of Y123: Y211 = 10: 4 with lwt% Ce02 addition by melt-processing in air. Trapped field measurements showed that four sharp peaks were observed in a four-domain bulk sample, showing that four grains were successfully formed without defects by a multi-seeding method. Force measurements showed that a four-domain Y-Ba-Cu-O sample exhibited higher repulsive forces and smaller hysteresis loops than polycrystalline Y-Ba-Cu-O sample during the increasing and decreasing field processes, which implies higher pinning performance of the four-domain sample. With the aim of studying the transferable torque forces, we used a multi-pole magnet circuit with NSNS configuration. We confirmed that with the interaction of the magnet circuit, a four-domain Y-Ba-Cu-O sample showed larger forces than a polycrystalline sample both in the field-cooled and the zero-field-cooled mode. We also measured the torque forces acting between the magnet circuit and bulk Y-Ba-Cu-O samples by twisting the magnet circuit in the levitated state. Again a four-domain Y-Ba-Cu-O sample exhibited much higher torque forces than a polycrystalline sample. These results showed that multi-seeded Y-Ba-Cu-O sample with four-domains can be used for torque transfer apllications.

  6. Numerical Analysis of Warpage Induced by Thermo-Compression Bonding Process of Cu Pillar Bump Flip Chip Package

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Oh Young; Jung, Hoon Sun; Lee, Jung Hoon; Choa, Sung-Hoon [Seoul Nat’l Univ. of Science and Technology, Seoul (Korea, Republic of)

    2017-06-15

    In flip chip technology, the conventional solder bump has been replaced with a copper (Cu) pillar bump owing to its higher input/output (I/O) density, finer pitch, and higher reliability. However, Cu pillar bump technology faces several issues, such as interconnect shorting and higher low-k stress due to stiffer Cu pillar structure when the conventional reflow process is used. Therefore, the thermal compression bonding (TCB) process has been adopted in the flip chip attachment process in order to reduce the package warpage and stress. In this study, we investigated the package warpage induced during the TCB process using a numerical analysis. The warpage of the TCB process was compared with that of the reflow process.

  7. Dynamics of the phase formation process upon the low temperature selenization of Cu/In-multilayer stacks

    Science.gov (United States)

    Oertel, M.; Ronning, C.

    2015-03-01

    Phase reactions occurring during a low temperature selenization of thin In/Cu-multilayer stacks were investigated by ex-situ x-ray diffraction (XRD) and energy dispersive x-ray spectroscopy (EDS). Therefore, dc-sputtered In/Cu-multilayers onto molybdenum coated soda lime glass were selenized in a high vacuum system at temperatures between 260 and 340 °C with different dwell times and selenium supply. The combination of the results of the phase analysis by XRD and the measurements of the in-depth elemental distribution by EDS allowed a conclusion on the occurring reactions within the layer depth. We found two CuInSe2 formation processes depending on the applied temperature. Already, at a heater temperature of 260 °C, the CuInSe2 formation can occur by the reaction of Cu2-xSe with In4Se3 and Se. At 340 °C, CuInSe2 is formed by the reaction of Cu2-xSe with InSe and Se. Because both reactions need additional selenium, the selenium supply during the selenization can shift the reaction equilibria either to the metal binaries side or to the CuInSe2 side. Interestingly, a lower selenium supply shifts the equilibrium to the CuInSe2 side, because the amount of selenium incorporated into the metallic layer is higher for a lower selenium supply. Most likely, a larger number of grain boundaries are the reason for the stronger selenium incorporation. The results of the phase formation studies were used to design a two stage selenization process to get a defined structure of an indium selenide- and a copper selenide-layer at low temperatures as the origin for a controlled interdiffusion to form the CuInSe2-absorber-layer at higher temperatures. The approach delivers a CuInSe2 absorber which reach total area efficiencies of 11.8% (13.0% active area) in a CuInSe2-thin-film solar cell. A finished formation of CuInSe2 at low temperature was not observed in our experiments but is probably possible for longer dwell times.

  8. Dynamics of the phase formation process upon the low temperature selenization of Cu/In-multilayer stacks

    Energy Technology Data Exchange (ETDEWEB)

    Oertel, M., E-mail: michael.oertel@uni-jena.de; Ronning, C. [Institute of Solid State Physics, Friedrich-Schiller-University Jena, Max-Wien-Platz 1, 07743 Jena (Germany)

    2015-03-14

    Phase reactions occurring during a low temperature selenization of thin In/Cu-multilayer stacks were investigated by ex-situ x-ray diffraction (XRD) and energy dispersive x-ray spectroscopy (EDS). Therefore, dc-sputtered In/Cu-multilayers onto molybdenum coated soda lime glass were selenized in a high vacuum system at temperatures between 260 and 340 °C with different dwell times and selenium supply. The combination of the results of the phase analysis by XRD and the measurements of the in-depth elemental distribution by EDS allowed a conclusion on the occurring reactions within the layer depth. We found two CuInSe{sub 2} formation processes depending on the applied temperature. Already, at a heater temperature of 260 °C, the CuInSe{sub 2} formation can occur by the reaction of Cu{sub 2−x}Se with In{sub 4}Se{sub 3} and Se. At 340 °C, CuInSe{sub 2} is formed by the reaction of Cu{sub 2−x}Se with InSe and Se. Because both reactions need additional selenium, the selenium supply during the selenization can shift the reaction equilibria either to the metal binaries side or to the CuInSe{sub 2} side. Interestingly, a lower selenium supply shifts the equilibrium to the CuInSe{sub 2} side, because the amount of selenium incorporated into the metallic layer is higher for a lower selenium supply. Most likely, a larger number of grain boundaries are the reason for the stronger selenium incorporation. The results of the phase formation studies were used to design a two stage selenization process to get a defined structure of an indium selenide- and a copper selenide-layer at low temperatures as the origin for a controlled interdiffusion to form the CuInSe{sub 2}-absorber-layer at higher temperatures. The approach delivers a CuInSe{sub 2} absorber which reach total area efficiencies of 11.8% (13.0% active area) in a CuInSe{sub 2}-thin-film solar cell. A finished formation of CuInSe{sub 2} at low temperature was not observed in our experiments but is probably

  9. Stability analysis of alkaline nitrobenzene-containing wastewater by a catalyzed Fe-Cu treatment process

    Institute of Scientific and Technical Information of China (English)

    FAN Jinhong; XU Wenying; GAO Tingyao; MA Luming

    2007-01-01

    Iron and copper bimetallic system (catalyzed Fe-Cu process) is a promising technology for alkaline nitrobenzene-containing wastewater treatment.However,little is currently known about the changes of treatment efficiency with time going.This research investigated the long-term performance of the catalyzed Fe-Cu process to reduce nitrobenzene (NB) in alkaline wastewater.In addition,the changes of the metal surfaces morphologies and matters before and after the reaction were analyzed by scanning electron microscopy (SEM) in conjunction with energydispersion spectroscopy (EDS) and X-ray diffraction spectroscopy (XRD).The results showed that the surface properties of copper almost remained unchanged after weeks of operation,which spelled its strong chemical stability and resistance to poisoning.Moreover,the results indicated that there were two reasons for the treatment efficiency decreasing with time.One was the gradual iron element consumption due to corrosion.The other was iron reactivity weakened due to the precipitates accumulation on the surfaces that were mainly Fe3O4 and FeCO.

  10. Photocatalytic performance of Cu2O composite octahedra prepared by a propanetriol-reduced process

    Science.gov (United States)

    Zhang, Lihui; Wang, Xiangfu

    2014-12-01

    Cu2O and Ag/Cu2O composite octahedra were synthesized via a hydrothermal reaction of CuAc2 with urea in H2O-propanetriol binary solution by adjusting the quantity of AgNO3 at 180 °C for 10 h. The influence of reaction temperature and time on the morphology and phase of the products was investigated, and a possible growth mechanism of Cu2O octahedron was also proposed. The photocatalytic activities of the as-prepared Cu2O and Ag/Cu2O octahedra for the degradation of methyl orange aqueous solution were studied. The results show that they are effective photocatalysts for the degradation of methyl orange, and the photocatalytic ability of Ag/Cu2O composite is stronger than that of Cu2O octahedra, which are expected to be useful in the treatment of wastewaters.

  11. Structural phase transformations of as-synthesized Cu-nanoferrites by annealing process

    Energy Technology Data Exchange (ETDEWEB)

    Amer, M.A., E-mail: moazamer@hotmail.com [Physics Department, Faculty of Science, Tanta University, 31527 Tanta (Egypt); Meaz, T. [Physics Department, Faculty of Science, Tanta University, 31527 Tanta (Egypt); Hashhash, A.; Attalah, S. [Reactor Physics Department, NRC, Atomic Energy Authority, 13759 Cairo (Egypt); Fakhry, F. [Physics Department, Faculty of Science, Tanta University, 31527 Tanta (Egypt)

    2015-11-15

    Samples of the as-synthesized CuFe{sub 2}O{sub 4} nanoferrites by co-precipitation route were annealed at different temperatures T. X-ray diffraction, infrared and Mössbauer spectroscopy and vibrating sample magnetometry were used for characterizing the samples. The sample structure phase was transformed from cubic-to-tetragonal-to-cubic as T increases. This transformation was attributed to the tetragonal distortion of Jahn–Teller effect of Cu{sup 2+} ions (d{sup 9}). The crystallite size R, lattice parameters, density, porosity P, strain and stiffness constant showed dependence on annealing temperature T. Seven absorption bands were observed in the IR spectra. The two characteristic bands of spinel ferrites, ν{sub 1} and ν{sub 2}, force constants and Debye temperature showed a decrease against T. The absorption bands ν{sub 1} and ν{sub 2} proved dependence on bond length; d{sub AO} and d{sub BO}, and saturation magnetization Ms, respectively. Hyperfine magnetic fields, line widths, area ratio of B- to A-sites, isomer shifts and quadrupole shifts (splitting) were deduced and discussed as functions of T, where the cation distribution were estimated. XRD patterns, Infrared spectra and RT temperature hysteresis loops proved the transformation process. Saturation magnetization showed dependence on T, P and R. - Highlights: • Amounts of as-synthesized Cu-nanoferrites were annealed at various temperatures T. • Structural phase was transformed from cubic-to-tetragonal-to-cubic with T by JTE. • IR band positions showed dependence on bond lengths and saturation magnetization Ms. • The deduced parameters showed dependence on T and affected by JTE. • Ms proved dependence on porosity and crystallite size.

  12. Electron backscatter diffraction analysis on the microstructures of electrolytic Cu deposition in the through hole filling process

    Energy Technology Data Exchange (ETDEWEB)

    Ho, C.E., E-mail: ceho1975@hotmail.com [Department of Chemical Engineering and Materials Science, Yuan Ze University, Taiwan, ROC (China); Liao, C.W. [Department of Chemical Engineering and Materials Science, Yuan Ze University, Taiwan, ROC (China); School of Physics and Technology, Wuhan University, Wuhan, Hubei 430072 (China); Pan, C.X. [School of Physics and Technology, Wuhan University, Wuhan, Hubei 430072 (China); Chen, H.J. [Department of Chemical Engineering and Materials Science, Yuan Ze University, Taiwan, ROC (China); Kuo, J.C.; Chen, D. [Department of Materials Science and Engineering, National Cheng Kung University, Taiwan, ROC (China)

    2013-10-01

    Through hole (TH) filling by electrolytic Cu deposition has become a critical process for high density interconnection technologies associated with three-dimensional packaging. In this study, the morphological and crystallographic evolutions of the electrolytic Cu TH filling with the plating time (t) were investigated using an optical microscope and a field-emission scanning electron microscope equipped with an electron backscatter diffraction (EBSD) analysis system. The Cu deposition rate in the TH was strongly dependent on t, which was established at a moderate rate of ∼ 0.3 μm/min at t = 40 min–74 min, then dramatically accelerated to ∼ 4 μm/min at t = 74 min–80 min (termed “fast deposition regime”), and subsequently decelerated in the final plating regime (t = 80 min–100 min). EBSD analyses showed that the electrolytic Cu predominantly possessed high-angle grain boundaries with strong coincidence site lattices at ∑3 (60° rotation at <111>) and ∑9 (38.9° rotation at <101>) for all t examined. Interestingly, the [111]‖TD (transverse direction) orientation displayed a relatively strong presence in the initial induction regime, while the [111]‖TD + [101]‖TD orientations with large grain sizes became dominant in the fast deposition regime (i.e., t = 74 min–80 min), and there was a very low concentration of the [111]‖TD orientation in the final deposition regime. This research offered a better understanding of the morphological and crystallographic evolutions in each stage of the electrolytic Cu TH filling. - Highlights: • Through hole (TH) filling by electrolytic Cu deposition • The Cu deposition rate is strongly dependent on the plating time in the THs. • The dominant Cu orientations were [111]‖TD (transverse direction) and [101]‖TD. • Cu possessed high angle grain boundaries with strong coincidence site lattices.

  13. Hydrogenolysis of Glycerol to Propylene Glycol on Nanosized Cu-Zn-Al Catalysts Prepared Using Microwave Process.

    Science.gov (United States)

    Kim, Dong Won; Ha, Sang Ho; Moon, Myung Jun; Lim, Kwon Taek; Ryu, Young Bok; Lee, Sun Do; Lee, Man Sig; Hong, Seong-Soo

    2015-01-01

    Cu-Zn-Al catalysts were prepared using microwave-assisted process and co-precipitation methods. The prepared catalysts were characterized by XRD, BET, XPS and TPD of ammonia and their catalytic activity for the hydrogenolysis of glycerol to propylene glycol was also examined. The XRD patterns of Cu/Zn/Al mixed catalysts show CuO and ZnO crystalline phase regardless of preparation method. The highest glycerol hydrogenolysis conversion is obtained with the catalyst having a Cu/Zn/Al ratio of 2:2:1. Hydrogen pre-reduction of catalysts significantly enhanced both glycerol conversions and selectivity to propylene glycol. The glycerol conversion increased with an increase of reaction temperature. However, the selectivity to propylene glycol increased with an increase of temperature, and then declined to 30.5% at 523 K.

  14. Mechanism of combination membrane and electro-winning process on treatment and remediation of Cu2+ polluted water body.

    Science.gov (United States)

    Zhang, Linnan; Wu, Yanjun; Qu, Xiaoyan; Li, Zhenshan; Ni, Jinren

    2009-01-01

    Mechanism of treatment and remediation of synthetic Cu2+ polluted water body by membrane and electro-winning combination process was investigated. The influences of electrolysis voltage, pH, and electrolysis time on the metal recovery efficiencies were studied. Relationship between trans-membrane pressure drop (DeltaP), additions ratio, initial Cu2+ concentration on operating efficiency, stability of membrane and the possibility of water reuse were also investigated. The morphology of membrane and electrodes were observed using scanning electron microscopy (SEM), the composition of surface deposits was ascertained using combined energy dispersive X-ray spectroscopy (EDX) and atomic absorption spectrophotometer. The results showed that using low pressure reverse osmosis (LPRO), Cu2+ concentration could increase from 20 to 100 mg/L or even higher in concentrated solutions and permeate water conductivity could be less than 20 microS/cm. The addition of sodium dodecy/sulfate sodium dodecyl sulfate improved Cu2+ removal efficiency, while EDTA had little side influence. In electro-reduction process, using plante electrode cell, Cu2+ concentration could be further reduced to 5 mg/L, and the average current efficiency ranged from 9% to 40%. Using 3D electrolysis treatment, Cu2+ concentration could be reduced to 0.5 mg/L with a current efficiency range 60%-70%.

  15. Mechnism of combination membrane and electro-winning process on treatment and remediation of Cu2+ polluted water body

    Institute of Scientific and Technical Information of China (English)

    ZHANG Linnan; WU Yanjun; QU Xiaoyan; LI Zhenshan; NI Jinren

    2009-01-01

    Mechnism of treatment and remediation of synthetic Cu2+ polluted water body by membrane and electro-winning combination process was investigated.The influnce of electrolysis voltage,pH,and electrolysis time on the metal recovery efficiencies were studied.Relationship between trans-membrane pressure drop (ΔP),additions ratio,initial Cu2+ concentration on operating efficency,stability of membrane and the possibility of water reuse were also investigated.The morphology of membrane and electrodes were observed using scanning electron microscopy (SEM),the composition of suface deposits was ascertained using combined energy dispersive X-ray spectroscopy (EDX) and atomic absorption spectrophotometer.The results showed that using low presure reverse osmosis (LPRO),the Cu2+ concentration could increase from 20 mg/L to 100 mg/L or even higher in the concentrate solutions and permeate water conductivity could be less than 20 μS/cm.The addition of SDS can improve the Cu2+ removal efficiency,while EDTA had little side influence.In electro-reduction process,using plante electrode cell,Cu2+ concentration can be further reduced to 5 mg/L,and the average current efficiency ranged from 9% to 40%.Using 3D electrolysis treatment,Cu2+ concentration could be reduced to 0.5 mg/L with a current efficiency range 60%-70%.

  16. U-Doped Y-Ba-Cu-O Melt-Processed Superconductor

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Large grain Y-Ba-Cu-O (YBCO) superconductors doped with various amounts of deplete d uranium oxide have been fabricated by top seeded melt growth (TSMG). The effec t of depleted UO2 on the large grain microstructure has been studied systemati cally in samples with and without added Pt. Addition of uranium oxide results in the formation of U-phase particles of dimensions of a few hundred nanometers w ith an approximately spherical morphology in the superconducting YBa2Cu3O 7-δ (Y-123) phase matrix. Addition of Y2O3 to the uran ium doped precursor powder, rather than Y-211, yields a significantly finer dis tribution of second phase particles. The chemical composition of the U-phase pa rticles, found in samples with no Pt addition, has been identified as Y2Ba4C u UOy, which exhibits paramagnetic behaviour. It has been confir med experimentally that this phase forms during the peritectic solidification pr ocess. Magnetic measurements show that U-doped melt processed YBCO exhibits imp roved critical current densities and trapped fields compared to un-doped material.

  17. Microstructural revolution of CIGS thin film using CuInGa ternary target during sputtering process

    Science.gov (United States)

    Liao, Kuang-Hsiang; Su, Cherng-Yuh; Ding, Yu-Ting; Pan, Cheng-Tang

    2012-12-01

    CuInGa (CIG) ternary targets were prepared by vacuum arc remelting and used to deposit CIG thin films through direct current (DC) sputtering. We adjusted the sputtering energy (1-2 kWh) by tuning both the sputtering power and the accumulative sputtering time. The impact of the varying sputtering energy on the microstructure of CIG targets and thin films was subsequently investigated. The experimental results indicated that the compositional uniformity of CIG targets is strongly influenced by this parameter. CIG thin films with a flat topography, low porosity, and dense grain boundaries were obtained when targets were accumulatively sputtered at 1 kWh. These films showed good compositional uniformity while the CIG targets were found to maintain their microstructural characteristics as compared to their as-melted counterparts. On the other hand, Cu(In,Ga)Se2 (CIGS) thin films, obtained by a selenization process, exhibited large faceted grains composed of a single chalcopyrite phase with a preferred orientation along the (1 1 2) plane. Accumulative sputtering of CIG targets at higher energies (e.g., 2 kWh) resulted in phase transformation and loss of In material as a result of an excess of residual heat budget on the surface generated by Ar ions bombardment. The CIG thin films thus showed an In-rich composition ratio, thereby potentially leading to In-rich CIGS thin films containing traces of an InSe compound.

  18. Fabrication of solution processed 3D nanostructured CuInGaS₂ thin film solar cells.

    Science.gov (United States)

    Chu, Van Ben; Cho, Jin Woo; Park, Se Jin; Hwang, Yun Jeong; Park, Hoo Keun; Do, Young Rag; Min, Byoung Koun

    2014-03-28

    In this study we demonstrate the fabrication of CuInGaS₂ (CIGS) thin film solar cells with a three-dimensional (3D) nanostructure based on indium tin oxide (ITO) nanorod films and precursor solutions (Cu, In and Ga nitrates in alcohol). To obtain solution processed 3D nanostructured CIGS thin film solar cells, two different precursor solutions were applied to complete gap filling in ITO nanorods and achieve the desirable absorber film thickness. Specifically, a coating of precursor solution without polymer binder material was first applied to fill the gap between ITO nanorods followed by deposition of the second precursor solution in the presence of a binder to generate an absorber film thickness of ∼1.3 μm. A solar cell device with a (Al, Ni)/AZO/i-ZnO/CdS/CIGS/ITO nanorod/glass structure was constructed using the CIGS film, and the highest power conversion efficiency was measured to be ∼6.3% at standard irradiation conditions, which was 22.5% higher than the planar type of CIGS solar cell on ITO substrate fabricated using the same precursor solutions.

  19. The Use of Al, Cu, and Fe in an Integrated Electrocoagulation-Ozonation Process

    Directory of Open Access Journals (Sweden)

    Carlos E. Barrera Díaz

    2015-01-01

    Full Text Available This study presents the effect of supplying electrochemically generated metallic ions (Al, Cu, and Fe during an ozonation process for treating industrial wastewater. The pollutant removal efficiencies of the electrocoagulation (EC, ozonation, and coupled EC-ozonation processes were examined by the decrease in chemical oxygen demand (COD as a function of treatment time. The EC was performed in a raw industrial wastewater, which has contributions from 39 chemical, 34 metal finishing, 22 textile, 11 leather, and 5 automotive plants, at pH (7.3 using a current density of 150 A/m2 for 60 min, giving a 45% reduction in COD. The ozonation process was more effective with the same wastewater, reducing the COD by 52% after 60 min of treatment. Combining the EC and ozonation methods resulted in a synergistic process that improves the reduction of COD in a shorter time. In just 12 min the integrated process reduced the COD by 88%. Thus, the combination of EC and ozonation processes improves noticeably the wastewater quality, decreasing the treatment time and also reducing the sludge production.

  20. Antibacterial property of CuCrO{sub 2} nanopowders prepared by a self-combustion glycine nitrate process

    Energy Technology Data Exchange (ETDEWEB)

    Nien, Yung-Tang, E-mail: ytnien@nfu.edu.tw [Deparment of Materials Science and Engineering, National Formosa University, Yunlin, 63201, Taiwan (China); Hu, Mon-Ru [Deparment of Materials Science and Engineering, National Formosa University, Yunlin, 63201, Taiwan (China); Chiu, Te-Wei [Department of Materials and Mineral Resources Engineering, National Taipei University of Technology, Taipei, 10608, Taiwan (China); Chu, Jaw-Shiow [Bioresource Collection and Research Center, Food Industry Research and Development Institute, Hsinchu, 30062, Taiwan (China)

    2016-08-15

    Porous CuCrO{sub 2} nanopowders were prepared via glycine nitrate process (GNP) at 175 °C in ambient air. The X-ray diffraction patterns showed a pure delafossite phase of CuCrO{sub 2} with numerous broad peaks, indicating a crystallite size of approximately 20 nm. The surface area of the CuCrO{sub 2} nanopowders was larger than 50 m{sup 2}/g, nearly 100 times greater than that of bulk powders (0.47 m{sup 2}/g). Pathogenic Gram-negative bacteria Escherichia coli (E. coli) were chosen as the antibacterial evaluation indicators for both the nanopowders and bulk powders. The results showed that 1750 ppm nanopowders inhibited the growth of E. coli. As a control, the bulk powders showed a normal growth profile. The antibacterial property of the CuCrO{sub 2} nanopowders can be attributed to the extremely large surface area, which induces rapid release of Cu ions and strong adhesion of nanopowders to bacteria. - Highlights: • CuCrO{sub 2} nanopowders was prepared by low-temperature glycine nitrate process. • 1250–1500 ppm of CuCrO{sub 2} nanopowders were found to depress the growth of Escherichia coli. • Bulk powders by the solid state reaction exhibited no antibacterial property. • The antibacterial property of nanopowders was attributed to rapid Cu ion releases. • Heavy adhesion of nanopowders to bacteria also resulted in antibacterial property.

  1. Decomplexation efficiency and mechanism of Cu(II)-EDTA by H2O2 coupled internal micro-electrolysis process.

    Science.gov (United States)

    Zhou, Dongfang; Hu, Yongyou; Guo, Qian; Yuan, Weiguang; Deng, Jiefan; Dang, Yapan

    2016-12-29

    Internal micro-electrolysis (IE) coupled with Fenton oxidation (IEF) was a very effective technology for copper (Cu)-ethylenediaminetetraacetic acid (EDTA) wastewater treatment. However, the mechanisms of Cu(2+) removal and EDTA degradation were scarce and lack persuasion in the IEF process. In this paper, the decomplexation and removal efficiency of Cu-EDTA and the corresponding mechanisms during the IEF process were investigated by batch test. An empirical equation and the oxidation reduction potential (ORP) index were proposed to flexibly control IE and the Fenton process, respectively. The results showed that Cu(2+), total organic carbon (TOC), and EDTA removal efficiencies were 99.6, 80.3, and 83.4%, respectively, under the proper operation conditions of iron dosage of 30 g/L, Fe/C of 3/1, initial pH of 3.0, Fe(2+)/H2O2 molar ratio of 1/4, and reaction time of 20 min, respectively for IE and the Fenton process. The contributions of IE and Fenton to Cu(2+) removal were 91.2 and 8.4%, respectively, and those to TOC and EDTA removal were 23.3, 25.1, and 57, 58.3%, respectively. It was found that Fe(2+)-based replacement-precipitation and hydroxyl radical (•OH) were the most important effects during the IEF process. •OH played an important role in the degradation of EDTA, whose yield and productive rate were 3.13 mg/L and 0.157 mg/(L min(-1)), respectively. Based on the intermediates detected by GC-MS, including acetic acid, propionic acid, pentanoic acid, amino acetic acid, 3-(diethylamino)-1,2-propanediol, and nitrilotriacetic acid (NTA), a possible degradation pathway of Cu-EDTA in the IEF process was proposed. Graphical abstract The mechanism diagram of IEF process.

  2. Phase evolution and thermal stability of 2 Mg–Cu alloys processed by mechanical alloying

    Energy Technology Data Exchange (ETDEWEB)

    Martínez, C., E-mail: carola.martinezu@usach.cl [Departamento de Ingeniería Metalúrgica, Facultad de Ingeniería, Universidad de Santiago de Chile, Av. Lib. Bernardo O’Higgins 3363, Casilla de correo 10233, Santiago (Chile); Ordoñez, S., E-mail: stella.ordonez@usach.cl [Departamento de Ingeniería Metalúrgica, Facultad de Ingeniería, Universidad de Santiago de Chile, Av. Lib. Bernardo O’Higgins 3363, Casilla de correo 10233, Santiago (Chile); Guzmán, D. [Departamento de Ingeniería en Metalurgia, Facultad de Ingeniería, Universidad de Atacama y CRIDESAT, Av. Copayapu 485, Casilla de Correo 240, Copiapó (Chile); Serafini, D. [Departamento de Física, Facultad de Ciencia, Universidad de Santiago de Chile, Av. Lib. Bernardo O’Higgins 3363, Casilla de correo 307, Santiago (Chile); Iturriza, I. [CEIT, Manuel de Lardizábal 15, 20018 San Sebastián, España (Spain); Bustos, O. [Departamento de Ingeniería Metalúrgica, Facultad de Ingeniería, Universidad de Santiago de Chile, Av. Lib. Bernardo O’Higgins 3363, Casilla de correo 10233, Santiago (Chile)

    2013-12-25

    Highlights: •Study of phase evolution of elemental powders Mg and Cu by mechanical alloying. •The presence of an amorphous precursor which crystallizes to Mg{sub 2}Cu can be observed. •Establishing the sequence of phase transformations leading to the formation of Mg{sub 2}Cu. •The feasibility to obtain Mg{sub 2}Cu by means two possible routes has been established. -- Abstract: Phase evolution during mechanical alloying (MA) of elemental Mg and Cu powders and their subsequent heat treatment is studied. Elemental Mg and Cu powders in a 2:1 atomic ratio were mechanically alloyed in a SPEX 8000D mill using a 10:1 ball-to-powder ratio. X-ray diffraction (XRD) shows that the formation of the intermetallic Mg{sub 2}Cu takes place between 3 and 4 h of milling, although traces of elemental Cu are still present after 10 h of milling. The thermal behavior of different powder mixtures was evaluated by differential scanning calorimetry (DSC). The combination of DSC, heat treatment and XRD has shown a sequence of phase transformations that results in the intermetallic Mg{sub 2}Cu from an amorphous precursor. This amorphous phase is converted into Mg{sub 2}Cu by heating at low temperature (407 K). Short MA times and the formation of the amorphous precursor, together with its subsequent transformation into Mg{sub 2}Cu at low temperatures; represent an advantageous alternative route for its preparation.

  3. Study of the adsorption and electroadsorption process of Cu (II) ions within thermally and chemically modified activated carbon.

    Science.gov (United States)

    Macías-García, A; Gómez Corzo, M; Alfaro Domínguez, M; Alexandre Franco, M; Martínez Naharro, J

    2017-04-15

    The aim of this work is to modify the porous texture and superficial groups of a commercial activated carbon through chemical and thermal treatment and subsequently study the kinetics of adsorption and electroadsorption of Cu (II) ion for these carbons. Samples of three activated carbons were used. These were a commercial activated carbon, commercial activated carbon modified thermically (C-N2-900) and finally commercial activated carbon modified chemically C-SO2-H2S-200. The activated carbons were characterized chemically and texturally and the electrical conductivity of them determined. Different kinetic models were applied. The kinetics of the adsorption and electroadsorption process of the Cu (II) ion fits a pseudo second order model and the most likely mechanism takes place in two stages. A first step through transfer of the metal mass through the boundary layer of the adsorbent and distribution of the Cu (II) on the external surface of the activated carbon and a second step that represents intraparticle diffusion and joining of the Cu (II) with the active centres of the activated carbon. Finally, the kinetics of the adsorption process are faster than the kinetics of the electroadsorption but the percentage of the Cu (II) ion retained is much higher in the electroadsorption process.

  4. Melt process of Sm-Ba-Cu-O bulk superconductors by thin film cold seeding

    Science.gov (United States)

    Fujimoto, H.; Ozaku, H.; Ohtabara, E.

    2003-10-01

    We discuss Sm123 bulks melt-processed in air and their characteristic superconducting properties for improving superconducting properties and producing a larger bulk. Isothermal undercooling growth in air with oxygen annealing and Nd123/MgO thin film cold seeding technique were applied in SmBaCuOy/Ag system to seek the high-efficiency of process, homogeneity of composition, and feasibility of batch production. We investigated process conditions such as heat treatment temperatures, compositions, seeding methods, and atmosphere. Single-domain growth of superconducting phases of a square larger than 10 mm on a side and 5 mm in thickness was achieved using this technique. Tc,onset and Tc,zero are 94 and 90 K, and Jc is 3 × 10 4 A/cm 2 at around 2 T at 77 K with a typical peak effect in the LRE system. In the case of Sm211 = 10 and 40 mol% addition, the maximum trapped magnetic field of the bulks is 1000 and 2100 G, respectively. The maximum magnetic field increases as Sm211 volume fractions increase. The result implies that melt-processed in air applying isothermal method and thin film seeding in Sm system is feasible for producing larger bulks in large scale applications.

  5. Microstructural revolution of CIGS thin film using CuInGa ternary target during sputtering process

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Kuang-Hsiang [Institute of Manufacturing Technology, National Taipei University of Technology, Taipei, 106, Taiwan (China); Su, Cherng-Yuh, E-mail: cysu@ntut.edu.tw [Institute of Manufacturing Technology, National Taipei University of Technology, Taipei, 106, Taiwan (China); Ding, Yu-Ting [Institute of Manufacturing Technology, National Taipei University of Technology, Taipei, 106, Taiwan (China); Pan, Cheng-Tang [Department of Mechanical and Electro-Mechanical Engineering, National Sun Yat-Sen University, Kaohsiung, 804, Taiwan (China)

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer CuInGa (CIG) ternary targets were prepared by vacuum arc remelting. Black-Right-Pointing-Pointer The sputtering energy has a great influence on microstructure of CIG films. Black-Right-Pointing-Pointer Increase in sputtering energy resulted in phase transformation and indium loss. Black-Right-Pointing-Pointer The surface roughness of CIGS films is determined by the morphology of precursors. Black-Right-Pointing-Pointer Rough surface enriched in In lead to poor crystalline CIGS containing InSe phases. - Abstract: CuInGa (CIG) ternary targets were prepared by vacuum arc remelting and used to deposit CIG thin films through direct current (DC) sputtering. We adjusted the sputtering energy (1-2 kWh) by tuning both the sputtering power and the accumulative sputtering time. The impact of the varying sputtering energy on the microstructure of CIG targets and thin films was subsequently investigated. The experimental results indicated that the compositional uniformity of CIG targets is strongly influenced by this parameter. CIG thin films with a flat topography, low porosity, and dense grain boundaries were obtained when targets were accumulatively sputtered at 1 kWh. These films showed good compositional uniformity while the CIG targets were found to maintain their microstructural characteristics as compared to their as-melted counterparts. On the other hand, Cu(In,Ga)Se{sub 2} (CIGS) thin films, obtained by a selenization process, exhibited large faceted grains composed of a single chalcopyrite phase with a preferred orientation along the (1 1 2) plane. Accumulative sputtering of CIG targets at higher energies (e.g., 2 kWh) resulted in phase transformation and loss of In material as a result of an excess of residual heat budget on the surface generated by Ar ions bombardment. The CIG thin films thus showed an In-rich composition ratio, thereby potentially leading to In-rich CIGS thin films containing traces of an InSe compound.

  6. The general mechanisms of Cu cluster formation in the processes of condensation from the gas phase

    Indian Academy of Sciences (India)

    I V Chepkasov; Yu Ya Gafner; S L Gafner; S P Bardakhanov

    2015-06-01

    Technological applications of metallic clusters impose very strict requirements for particle size, shape, structure and defect density. Such geometrical characteristics of nanoparticles are mainly determined by the process of their growth. This work represents the basic mechanisms of cluster formation from the gas phase that has been studied on the example of copper. The process of Cu nanoclusters synthesis has been studied by the moleculardynamics method based on tight-binding potentials. It has been shown that depending on the size and temperature of the initial nanoclusters the process of nanoparticle formation can pass through different basic scenarios. The general conditions of different types of particles formation have been defined and clear dependence of the cluster shape from collision temperature of initial conglomerates has been shown. The simulation results demonstrate a very good agreement with the available experimental data. Thus, it has been shown that depending on the specific application of the synthesized particles or in electronics, where particles of a small size with a spherical shape are required, or in catalytic reactions, where the main factor of effectiveness is the maximum surface area with the help of temperature of the system it is possible to get the realization of a certain frequency of this or that scenario of the shape formation of nanocrystalline particles.

  7. Effect of Compression with Oscillatory Torsion Processing on Structure and Properties of Cu

    Institute of Scientific and Technical Information of China (English)

    Kinga Rodak; Jacek Pawlicki

    2011-01-01

    The results presented in this study were concerned with microstructures and mechanical properties of poly- crystalline Cu subjected to plastic deformation by a compression with oscillatory torsion process. Different deformation parameters of the compression with oscillatory torsion process were adopted to study their effects on the microstructure and mechanical properties. The deformed microstructure was characterized quantitatively by electron backscattered diffraction (EBSD) and scanning transmission electron microscopy (STEM). Mechanical properties were determined on an MTS QTest/10 machine equipped with digital image correlation. From the experimental results, processes performed at high compression speed and high torsion frequency are recommended for refining the grain size. The size of structure elements, such as average grain size (D) and subgrain size (d), reached 0.42 μm and 0.30 μm, respectively, and the fraction of high angle boundaries was 35% when the sample was deformed at a torsion frequency f = 1.6 Hz and compression rate v= 0.04 mm/s. These deformation parameters led to an improvement in the strength properties. The material exhibited an ultimate tensile strength (UTS) of 434 MPa and a yield strength (YS) of 418 MPa. These values were about two times greater than those of the initial state.

  8. Coagulation-flocculation as pre-treatment for micro-scale Fe/Cu/O3 process (CF-mFe/Cu/O3) treatment of the coating wastewater from automobile manufacturing.

    Science.gov (United States)

    Xiong, Zhaokun; Cao, Jinyan; Yang, Dan; Lai, Bo; Yang, Ping

    2017-01-01

    A coagulation-flocculation as pre-treatment combined with mFe/Cu/O3 (CF-mFe/Cu/O3) process was developed to degrade the pollutants in automobile coating wastewater (ACW). In coagulation-flocculation (CF) process, high turbidity removal efficiency (97.1%) and low COD removal efficiency (10.5%) were obtained under the optimal conditions using Al2(SO4)3·18H2O and CaO. The effluent of CF process (ECF) was further disposed by mFe/Cu/O3 process, and its key operating parameters were optimized by batch experiments. Optimally, COD removal efficiency of ECF obtained by the mFe/Cu/O3 process (i.e., 87.6% after 30 min treatment) was much higher than those of mFe/Cu alone (8.3%), ozone alone (46.6%), and mFe/Cu/air (6.1%), which confirms the superiority of the mFe/Cu/O3 process. In addition, the analysis results of UV-vis, excitation-emission matrix (EEM) fluorescence spectra and GC/MS further confirm that the phenol pollutants of ECF had been effectively decomposed or transformed after CF-mFe/Cu/O3 process treatment. Meanwhile, B/C ratio of ACW increased from 0.19 to 0.56, which suggests the biodegradability was improved significantly. Finally, the operating cost of CF-mFe/Cu/O3 process was about 1.83 USD t(-1) for ACW treatment. Therefore, the combined process is a promising treatment technology for the coating wastewater from automobile manufacturing.

  9. In situ ellipsometric study of the three-stage process in CuInSe{sub 2} film deposition

    Energy Technology Data Exchange (ETDEWEB)

    Shirakata, Sho; Takahashi, Toshihiro; Matsunaga, Hiroaki [Faculty of Engineering, Ehime University, 3 Bunkyo-cho, Matsuyama (Japan)

    2013-08-15

    In Situ ellipsometric study has been carried out during the deposition of the CuInSe{sub 2} thin film by means of the three-stage process. A rotator analyzing ellipsomerter using a 632.8 nm He-Ne laser was used. Ellipsometric parameters ({Psi} and {Delta}) and reflectivity R was obtained during the entire deposition stages, in which a complex reflection coefficient is {rho}=tan{Psi} exp(i{Delta}). Cu, In and Se were deposited on the Mo-coated SLG substrate. At the first-stage (In-Se deposition), the In-Se film deposition rate and its reflactive index has been obtained on the basis of the light interference. At the second-stage, changes in both {Psi} and {Delta} are observed. Based on the X-ray diffraction measurement, these changes are related to the stoichiometric composition of the film from In-rich to Cu-rich. This signal was utilized as a process switch from the second-stage to the third-stage. At the third stage, the weak change in {Psi} has been observed showing the change of the stoichiometric composition from the Cu- rich to the In-rich. By means of the in situ ellipsometry-controlled three-stage process, the CuInSe{sub 2} layer with single phase chalcopyrite structure has successfully been prepared, which exhibits an intense near-band-edge photoluminescence at 0.998 eV at room temperature. The preliminary fabricated ZnO/CdS/CuInSe{sub 2} solar cell exhibited a conversion efficiency of 5.6%. (copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  10. Fabrication of Copper-Rich Cu-Al Alloy Using the Wire-Arc Additive Manufacturing Process

    Science.gov (United States)

    Dong, Bosheng; Pan, Zengxi; Shen, Chen; Ma, Yan; Li, Huijun

    2017-09-01

    An innovative wire-arc additive manufacturing (WAAM) process is used to fabricate Cu-9 at. pct Al on pure copper plates in situ, through separate feeding of pure Cu and Al wires into a molten pool, which is generated by the gas tungsten arc welding (GTAW) process. After overcoming several processing problems, such as opening the deposition molten pool on the extremely high-thermal conductive copper plate and conducting the Al wire into the molten pool with low feed speed, the copper-rich Cu-Al alloy was successfully produced with constant predesigned Al content above the dilution-affected area. Also, in order to homogenize the as-fabricated material and improve the mechanical properties, two further homogenization heat treatments at 1073 K (800 °C) and 1173 K (900 °C) were applied. The material and mechanical properties of as-fabricated and heat-treated samples were compared and analyzed in detail. With increased annealing temperatures, the content of precipitate phases decreased and the samples showed gradual improvements in both strength and ductility with little variation in microstructures. The present research opened a gate for in-situ fabrication of Cu-Al alloy with target chemical composition and full density using the additive manufacturing process.

  11. Fabrication of high performance Gd-Ba-Cu-O single grains in air using a practical melt processing technique

    Energy Technology Data Exchange (ETDEWEB)

    Cardwell, D.A., E-mail: dc135@cam.ac.u [Engineering Department, Trumpington Street, University of Cambridge, CB2 1PZ (United Kingdom); Shi, Y. [Engineering Department, Trumpington Street, University of Cambridge, CB2 1PZ (United Kingdom); Hari Babu, N. [Engineering Department, Trumpington Street, University of Cambridge, CB2 1PZ (United Kingdom); BCAST, Brunel University, West London UB8 3PH (United Kingdom); Iida, K. [Engineering Department, Trumpington Street, University of Cambridge, CB2 1PZ (United Kingdom)

    2009-10-15

    A practical processing route for the fabrication of LRE-Ba-Cu-O single grain superconductors has been developed at the University of Cambridge based on a generic, Mg-doped Nd-123 melt textured seed and suppression of the formation of the solid solution phase in air by enriching the precursors with higher Ba concentration. The processing of high performance Gd-Ba-Cu-O single grains using this processing route is described. The Mg-doped generic seed crystal has been used effectively to promote heterogeneous nucleation via a cold-seeding process. The Gd/Ba solid solution has been suppressed by enriching Gd-Ba-Cu-O precursor powders with two different Ba-rich compositions. This involved adding BaO{sub 2} and GdBa{sub 6}Cu{sub 3}O{sub y} (Gd-163) (a novel Ba-rich second phase) to the precursor powders, respectively. The Gd-163 phase has been observed not only to suppress formation of the solid solution phase, but also to promote increased heterogeneous grain size. A detailed further study has been carried out with an initial aim of optimizing the BaO{sub 2} and Gd-163 phase content of the precursor composition to produce a single grain almost free of solid solution. Based on the optimized parameters, large single grain Gd-Ba-Cu-O superconductors have been fabricated in an air atmosphere and demonstrated to exhibit record trapped magnetic fields for this material melt processed in air in relatively small single grain samples. The trapped fields of samples produced in air atmosphere are at least comparable to those processed under reduced oxygen partial pressure.

  12. Correlation of seawater corrosion and processing of Cu-Ni alloy tubes

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The investigetions on the effect of the initial surface and microstructure on the seawater corrosion of Cu-Ni al-loy tubes were carried out by processing, electrochemical methods and natural seawater exposure as well as SEM. Defor-mation had more impact on the final microstructure of the tubes than the annealing time did, and at the deformation of32% and annealing temperature 550~ 600 ℃ for 1 h the tubes was completely recrystallized microstructure. As increasingthe volume fraction of recrystallization, the homogeneity of microstructure and the corrosion resistance increased. Theresidual carbon film produced on the inner surface of the tubes during the processing, had higher corrosion potential thanthe alloy subatrate and good electronic conductivity, so accelerating the dissolution of the substrate in seawater, and thenon-protective and loose corrosion product film formed. Immersed in natural seawater, the tubes of incomplete recrystal-lization, consisting of deformed and recrystallized grains, displayed intergranular corrosion, which resulted from corrosionmicro-cells built between deformed and recrystallized grains and the preferable transportation of electrons on the boundariesof both the grains. In contrast, the recrystallized alloy tubes formed the uniform and compact corrosion product film underwhich no corrosion was found

  13. Effects of advanced process approaches on electromigration degradation of Cu on-chip interconnects

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, M.A.

    2007-07-12

    This thesis provides a methodology for the investigation of electromigration (EM) in Cu-based interconnects. An experimental framework based on in-situ scanning electron microscopy (SEM) investigations was developed for that purpose. It is capable to visualize the EM-induced void formation and evolution in multi-level test structures in real time. Different types of interconnects were investigated. Furthermore, stressed and unstressed samples were studied applying advanced physical analysis techniques in order to obtain additional information about the microstructure of the interconnects as well as interfaces and grain boundaries. These data were correlated to the observed degradation phenomena. Correlations of the experimental results to recently established theoretical models were highlighted. Three types of Cu-based interconnects were studied. Pure Cu interconnects were compared to Al-alloyed (CuAl) and CoWP-coated interconnects. The latter two represent potential approaches that address EM-related reliability concerns. It was found that in such interconnects the dominant diffusion path is no longer the Cu/capping layer interface for interconnects as in pure Cu interconnects. Instead, void nucleation occurs at the bottom Cu/barrier interface with significant effects from grain boundaries. Moreover, the in-situ investigations revealed that the initial void nucleation does not occur at the cathode end of the lines but several micrometers away from it. The mean times-to-failure of CuAl and CoWP-coated interconnects were increased by at least one order of magnitude compared to Cu interconnects. The improvements were attributed to the presence of foreign metal atoms at the Cu/capping layer interface. Post-mortem EBSD investigations were used to reveal the microstructure of the tested samples. The data were correlated to the in-situ observations. (orig.)

  14. P-type Cu2O/SnO bilayer thin film transistors processed at low temperatures

    KAUST Repository

    Al-Jawhari, Hala A.

    2013-10-09

    P-type Cu2O/SnO bilayer thin film transistors (TFTs) with tunable performance were fabricated using room temperature sputtered copper and tin oxides. Using Cu2O film as capping layer on top of a SnO film to control its stoichiometry, we have optimized the performance of the resulting bilayer transistor. A transistor with 10 nm/15 nm Cu2O to SnO thickness ratio (25 nm total thickness) showed the best performance using a maximum process temperature of 170 C. The bilayer transistor exhibited p-type behavior with field-effect mobility, on-to-off current ratio, and threshold voltage of 0.66 cm2 V-1 s-1, 1.5×10 2, and -5.2 V, respectively. The advantages of the bilayer structure relative to single layer transistor are discussed. © 2013 American Chemical Society.

  15. Role of estuarine natural flocculation process in removal of Cu, Mn, Ni, Pb and Zn

    Directory of Open Access Journals (Sweden)

    S. Hassani

    2017-04-01

    Full Text Available The flocculation of dissolved heavy metals is a process which has an important effect on decreasing the concentration of the colloidal elements during estuarine mixing of river water and sea or ocean water. During this important process, a large amount of colloidal elements change into particles in the form of flock and the dissolved loads decline. This study is performed to evaluate the mechanism of self-purification of heavy metals in Sardabroud's estuary. For this purpose, the effect of salinity (varying from 1 to 8.5‰ on the removal efficiency of colloidal metals (copper, zinc, lead, nickel and magnesium by flocculation process during mixing of Sardabroud River water and the Caspian Sea water was explored. The flocculation rate of Ni (25% > Zn (18.59% > Cu (16.67% > Mn(5.83% > Pb(4.86%  indicates that lead and manganese have relatively conservative behavior but nickel, zinc and copper have non-conservative behavior during Sardabroud River’s estuarine mixing. The highest removal efficiencies were obtained between salinities of 1 to 2.5%. Due to flocculation process, annual discharge of dissolved zinc, copper, lead, manganese and nickel release into the Caspian Sea via Sardabroud River would reduce from 44.30 to 36.06 ton/yr, 3.41 to 2.84 ton/yr, 10.22 to 9.7 ton/yr, 8.52 to 7.8 ton/yr and 3.41 to 2.56 ton/yr, respectively. Statistical analysis shows that the flocculation rate of Nickel is highly controlled by redox potential and dissolved oxygen. Moreover, it is found that total dissolved solid, salinity, electrical conductivity and potential of hydrogen do not have a significant influence in flocculation of studied metals.

  16. A new combined process for efficient removal of Cu(II) organic complexes from wastewater: Fe(III) displacement/UV degradation/alkaline precipitation.

    Science.gov (United States)

    Xu, Zhe; Gao, Guandao; Pan, Bingcai; Zhang, Weiming; Lv, Lu

    2015-12-15

    Efficient removal of heavy metals complexed with organic ligands from water is still an important but challenging task now. Herein, a novel combined process, i.e., Fe(III)-displacement/UV degradation/alkaline precipitation (abbreviated as Fe(III)/UV/OH) was developed to remove copper-organic complexes from synthetic solution and real electroplating effluent, and other processes including alkaline precipitation, Fe(III)/OH, UV/OH were employed for comparison. By using the Fe(III)/UV/OH process, some typical Cu(II) complexes, such as Cu(II)-ethylenediaminetetraacetic acid (EDTA), Cu(II)-nitrilotriacetic acid (NTA), Cu(II)-citrate, Cu(II)-tartrate, and Cu(II)-sorbate, each at 19.2 mg Cu/L initially, were efficiently removed from synthetic solution with the residual Cu below 1 mg/L. Simultaneously, 30-48% of total organic carbon was eliminated with exception of Cu(II)-sorbate. Comparatively, the efficiency of other processes was much lower than the Fe(III)/UV/OH process. With Cu(II)-citrate as the model complex, the optimal conditions for the combined process were obtained as: initial pH for Fe(III) displacement, 1.8-5.4; molar ratio of [Fe]/[Cu], 4:1; UV irradiation, 10 min; precipitation pH, 6.6-13. The mechanism responsible for the process involved the liberation of Cu(II) ions from organic complexes as a result of Fe(III) displacement, decarboxylation of Fe(III)-ligand complexes subjected to UV irradiation, and final coprecipitation of Cu(II) and Fe(II)/Fe(III) ions. Up to 338.1 mg/L of Cu(II) in the electroplating effluent could be efficiently removed by the process with the residual Cu(II) below 1 mg/L and the removal efficiency of ∼99.8%, whereas direct precipitation by using NaOH could only result in total Cu(II) removal of ∼8.6%. In addition, sunlight could take the place of UV to achieve similar removal efficiency with longer irradiation time (90 min).

  17. Rapid thermal processing for printed Cu(In,Ga)(S,Se){sub 2} solar cells: Comparison of precursor materials

    Energy Technology Data Exchange (ETDEWEB)

    Klugius, Ines, E-mail: ines.klugius@zsw-bw.de [Zentrum für Sonnenenergie- und Wasserstoff-Forschung Baden-Württemberg (ZSW), Industriestr. 6, 70565 Stuttgart (Germany); Miller, Rebekah [EMD Millipore, 300 2nd Avenue, Waltham, MA 02451 (United States); Quintilla, Aina; Friedlmeier, Theresa M.; Blázquez-Sánchez, David; Ahlswede, Erik; Powalla, Michael [Zentrum für Sonnenenergie- und Wasserstoff-Forschung Baden-Württemberg (ZSW), Industriestr. 6, 70565 Stuttgart (Germany)

    2013-05-01

    We investigate three different precursor types for selenisation using a rapid thermal process. Two of the precursor sample types are deposited via non-vacuum methods using particle based precursor inks, and the third precursor type investigated are films that are sputtered from a single ternary Cu–In–Ga target. The rapid thermal process is suitable for high throughput with a short optimum selenisation duration of 5 min or less and employs elemental selenium vapour. In order to investigate the phase development in the film, the selenisation process was interrupted at different stages and the samples were monitored via X-ray diffraction and surface-sensitive Raman measurements. We find different growth mechanisms for the investigated precursor types with fast CuInSe{sub 2} formation for the highly reactive elemental Cu and In particles and a slower formation of polycrystalline Cu(In,Ga)Se{sub 2} for Cu(In,Ga)S{sub 2} particle based precursors without the formation of additional phases. For selenisation of the sputtered precursor layers, we find the formation of InSe and In{sub 2}Se{sub 3} during the selenisation temperature ramp up. Using the rapid thermal selenisation process, conversion efficiencies of about 2.9% and 4.0% for the printed and 6.0% for the sputtered precursor layers could be demonstrated. - Highlights: ► Cu(In,Ga)Se{sub 2} absorber formation via rapid thermal annealing ► Growth mechanism for printed and sputtered precursor layers is investigated. ► Conversion efficiencies of about 4.0% for printed and 6.0% for sputtered layers.

  18. Pulsed Lasers: Pulsed Lasers Employing Solution-Processed Plasmonic Cu3- x P Colloidal Nanocrystals (Adv. Mater. 18/2016).

    Science.gov (United States)

    Liu, Zeke; Mu, Haoran; Xiao, Si; Wang, Rongbin; Wang, Zhiteng; Wang, Weiwei; Wang, Yongjie; Zhu, Xiangxiang; Lu, Kunyuan; Zhang, Han; Lee, Shuit-Tong; Bao, Qiaoliang; Ma, Wanli

    2016-05-01

    Q. Bao, W. Ma and co-workers demonstrate the usage of plasmonic Cu3-x P colloidal nanocrystals as a new type of tunable saturable absorber for the generation of high-energy pulses in a fiber laser. As described on page 3535, these low-cost, solution-processed, next-generation nonlinear optical materials can be harnessed for applications in signal processing and optical communication. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Environmental fatigue of an Al-Li-Cu alloy. Part 2: Microscopic hydrogen cracking processes

    Science.gov (United States)

    Piascik, Robert S.; Gangloff, Richard P.

    1992-01-01

    Based on a fractographic analysis of fatigue crack propagation (FCP) in Al-Li-Cu alloy 2090 stressed in a variety of inert and embrittling environments, microscopic crack paths are identified and correlated with intrinsic da/dN-delta K kinetics. FCP rates in 2090 are accelerated by hydrogen producing environments (pure water vapor, moist air, and aqueous NaCl), as defined in Part 1. For these cases, subgrain boundary fatigue cracking (SGC) dominates for delta K values where the crack tip process zone, a significant fraction of the cyclic plastic zone, is sufficiently large to envelop 5 micron subgrains in the unrecrystallized microstructure. SGC may be due to strong hydrogen trapping at T1 precipitates concentrated at sub-boundaries. At low delta K, the plastic zone diameter is smaller than the subgrain size and FCP progresses along (100) planes due to either local lattice decohesion or aluminum-lithium hydride cracking. For inert environments (vacuum, helium, and oxygen), or at high delta K where the hydrogen effect on da/dN is small, FCP is along (111) slip planes; this mode does not transition with increasing delta K and plastic zone size. The SGC and (100) crystallographic cracking modes, and the governing influence of the crack tip process zone volume (delta K), support hydrogen embrittlement rather than a surface film rupture and anodic dissolution mechanism for environmental FCP. Multi-sloped log da/dN-log delta K behavior is produced by changes in process zone hydrogen-microstructure interactions, and not by purely micromechanical-microstructure interactions, in contradiction to microstructural distance-based fatigue models.

  20. Development of brazing process for W-EUROFER joints using Cu-based fillers

    Science.gov (United States)

    de Prado, J.; Sánchez, M.; Ureña, A.

    2016-02-01

    A successful joint between W and EUROFER using high temperature brazing technique has been achieved for structural application in future fusion power plants. Cu-based powder alloy mixed with a polymeric binder has been used as filler. Microstructural analysis of the joints revealed that the joint consisted mainly of primary phases and acicular structures in a Cu matrix. Interaction between EUROFER and filler took place at the interface giving rise to several Cu-Ti-Fe rich layers. A loss of hardness at the EUROFER substrate close to the joint due to a diffusion phenomenon during brazing cycle was measured; however, the joints had an adequate shear strength value.

  1. Solution processed Cu2SnS3 thin films for visible and infrared photodetector applications

    Directory of Open Access Journals (Sweden)

    Sandra Dias

    2016-02-01

    Full Text Available The Cu2SnS3 thin films were deposited using an economic, solution processible, spin coating technique. The films were found to possess a tetragonal crystal structure using X-ray diffraction. The film morphology and the particle size were determined using scanning electron microscopy. The various planes in the crystal were observed using transmission electron microscopy. The optimum band gap of 1.23 eV and a high absorption coefficient of 104 cm−1 corroborate its application as a photoactive material. The visible and infrared (IR photo response was studied for various illumination intensities. The current increased by one order from a dark current of 0.31 μA to a current of 1.78 μA at 1.05 suns and 8.7 μA under 477.7 mW/cm2 IR illumination intensity, at 3 V applied bias. The responsivity, sensitivity, external quantum efficiency and specific detectivity were found to be 10.93 mA/W, 5.74, 2.47% and 3.47 × 1010 Jones respectively at 1.05 suns and 16.32 mA/W, 27.16, 2.53% and 5.10 × 1010 Jones respectively at 477.7 mW/cm2 IR illumination. The transient photoresponse was measured both for visible and IR illuminations.

  2. 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).

  3. Effect of gate dielectrics on the performance of p-type Cu2O TFTs processed at room temperature

    KAUST Repository

    Al-Jawhari, Hala A.

    2013-12-01

    Single-phase Cu2O films with p-type semiconducting properties were successfully deposited by reactive DC magnetron sputtering at room temperature followed by post annealing process at 200°C. Subsequently, such films were used to fabricate bottom gate p-channel Cu2O thin film transistors (TFTs). The effect of using high-κ SrTiO3 (STO) as a gate dielectric on the Cu2O TFT performance was investigated. The results were then compared to our baseline process which uses a 220 nm aluminum titanium oxide (ATO) dielectric deposited on a glass substrate coated with a 200 nm indium tin oxide (ITO) gate electrode. We found that with a 150 nm thick STO, the Cu2O TFTs exhibited a p-type behavior with a field-effect mobility of 0.54 cm2.V-1.s-1, an on/off ratio of around 44, threshold voltage equaling -0.62 V and a sub threshold swing of 1.64 V/dec. These values were obtained at a low operating voltage of -2V. The advantages of using STO as a gate dielectric relative to ATO are discussed. © (2014) Trans Tech Publications, Switzerland.

  4. Temperature dependency of the Ga/In distribution in Cu(In,Ga)Se2 absorbers in high temperature processes

    Science.gov (United States)

    Mueller, B. J.; Demes, T.; Lill, P. C.; Haug, V.; Hergert, F.; Zweigart, S.; Herr, U.

    2016-05-01

    The current article reports about the influence of temperature and glass substrate on Ga/In interdiffusion and chalcopyrite phase formation in the stacked elemental layer process. According to the Shockley-Queisser limit the optimum for single junction devices is near 1.4 eV, which is strongly coupled on the Ga/(Ga+In) ratio of Cu(In,Ga)Se2 thin film solar cells. To increase the Ga content in the active region of the Cu(In,Ga)Se2 a 70:30 CuGa alloy target is used. An increase of the selenization temperature leads to a more homogeneous Ga/In distribution and a less pronounced Ga agglomeration at the back contact. The Ga/In interdiffusion rates for different selenization temperatures and substrates were estimated with the model of a two layer system. At the highest selenization temperature used an absorber band gap of 1.12 eV was realized, which is similar to typical values of absorbers produced during the co-evaporation process. The Na diffusion into the Cu(In,Ga)Se2 is weakly temperature dependent but strongly influenced by the choice of the glass substrate composition.

  5. Fabrication and heat treatment of high strength Al-Cu-Mg alloy processed using selective laser melting

    Science.gov (United States)

    Zhang, Hu; Zhu, Haihong; Nie, Xiaojia; Qi, Ting; Hu, Zhiheng; Zeng, Xiaoyan

    2016-04-01

    The proposed paper illustrates the fabrication and heat treatment of high strength Al-Cu-Mg alloy produced by selective laser melting (SLM) process. Al-Cu-Mg alloy is one of the heat treatable aluminum alloys regarded as difficult to fusion weld. SLM is an additive manufacturing technique through which components are built by selectively melting powder layers with a focused laser beam. The process is characterized by short laser-powder interaction times and localized high heat input, which leads to steep thermal gradients, rapid solidification and fast cooling. In this research, 3D Al-Cu-Mg parts with relative high density of 99.8% are produced by SLM from gas atomized powders. Room temperature tensile tests reveal a remarkable mechanical behavior: the samples show yield and tensile strengths of about 276 MPa and 402 MPa, respectively, along with fracture strain of 6%. The effect of solution treatment on microstructure and related tensile properties is examined and the results demonstrate that the mechanical behavior of the SLMed Al-Cu-Mg samples can be greatly enhanced through proper heat treatment. After T4 solution treatment at 540°C, under the effect of precipitation strengthening, the tensile strength and the yield strength increase to 532 MPa and 338 MPa, respectively, and the elongation increases to 13%.

  6. Solution-processable carboxylate-capped CuO nanoparticles obtained by a simple solventless method

    Science.gov (United States)

    Estruga, Marc; Roig, Anna; Domingo, Concepción; Ayllón, José A.

    2012-08-01

    Carboxylate-capped CuO nanoparticles were obtained via a simple solventless route, based on the thermal decomposition at 120 °C of solid precursors. The reaction mixture consisted of copper acetate monohydrate, acting as the CuO precursor, and different organic carboxylic acids (lauric, phenylvaleric or 3,6,9-trioxadecanoic acid) used as the capping agent. The proposed method, in good agreement with environmentally friendly practices, produced dry nanoparticles, thereby totally eliminating the need of washing, filtration, or other downstream steps. Transmission electron micrographs show crystalline roughly spherical CuO nanoparticles with average diameters between 3.1 and 5.5 nm depending on the capping ligand. The laurate-capped CuO nanoparticles showed a paramagnetic behaviour at room temperature, while a weak ferromagnetic component was detected at low temperature (acid tail enabled the straightforward dispersibility of nanoparticles in common solvents and assisted in the deposition of the material as thin films.

  7. Optimization of the processing parameters during internal oxidation of Cu-Al alloy powders using an artificial neural network

    Energy Technology Data Exchange (ETDEWEB)

    Song Kexing; Xing Jiandong; Dong Qiming; Liu Ping; Tian Baohong; Cao Xianjie

    2005-06-15

    Internal oxidation is a commercial method for producing oxide dispersion strengthened copper (ODS Cu). In this paper, the dilute Cu-Al alloy powders containing 0.26 wt% of Al have been internally oxidized at temperatures (T) from 700 to 1000 deg. C, for holding times (t) up to 10 h. The alumina particle size has been observed and determined by electron microscopy using the two-stage preshadowed carbon replica method. By the use of backpropagation network, the non-linear relationship between internal oxidation process parameters (T,t) and alumina particle size has been established on the base of dealing with the experimental data. The results show that the well-trained backpropagation neural network can predict the alumina particle size during internal oxidation precisely and the prediction values have sufficiently mined the basic domain knowledge of internal oxidation process. Therefore, a new way of optimizing process parameters has been provided by the authors.

  8. A new manufacture process of Cu-CuNi fine thermocouple%铜-康铜微细热电偶制作新工艺

    Institute of Scientific and Technical Information of China (English)

    周艳; 孙兴华; 钱北行

    2012-01-01

    热电偶是航天器真空热试验中应用最广泛的温度传感器,它的制作工艺决定了其产品的质量和可靠性.文章以铜-康铜微细热电偶的制作工艺为例,提出并实现了一种在惰性气体保护条件下利用高压放电技术进行热电偶焊接制作的工艺方法.这种方法具有操作简单、成品率高的特点,极大提高了热电偶的制作效率,并且解决了热电偶制作过程中因氧化而引入第三种材质的问题.%The thermocouple is the most widely used temperature sensor in the vacuum thermal tests of spacecraft. Its manufacturing process directly affects the product quality and reliability. Taking the manufacturing process of Cu-CuNi fine thermocouple as an example, this paper proposes and has realized a new method to complete the welding of thermocouple by the high-pressure discharge technique under the protection of inert gas. This method is characterized by easier operation and higher rate of acceptability, which greatly improves the efficiency of thermocouple's manufacturing. Besides, the problem of introducing another material during the manufacturing process is avoided.

  9. Role of ZnO in Reduction Process of CuO-Based Catalyst for Methanol Synthesis%ZnO在CuO基甲醇合成催化剂还原过程中的作用

    Institute of Scientific and Technical Information of China (English)

    郭宪吉; 宋连卿; 郭益群

    1999-01-01

    用一步并流共沉淀法制备了一系列具有不同组成的CuO基样品,并测试了它们在合成甲醇反应中的活性.利用TG-DTG手段,对各CuO基样品的还原过程进行了考察,结果表明,ZnO组分对催化剂CuO-ZnO-Al2O3的还原行为有重要影响.依据Coats-Redfern处理方法获得了CuO基样品的还原动力学参数%A series of CuO-based samples with different compositions have been prepared and their catalytic activities for methanol synthesis have been tested.By means of TG-DTG,the reduction process of CuO-based Samples were investigated.The results indicated that the ZnO component affected the reduction behavior of the CuO-ZnO-Al2O3 sample significantly.By using Coats-Redfern,the kinetic parameters of reduction of the CuO-based samples were obtained.

  10. Development of two-step process for enhanced biorecovery of Cu-Zn-Ni from computer printed circuit boards.

    Science.gov (United States)

    Shah, Monal B; Tipre, Devayani R; Purohit, Mamta S; Dave, Shailesh R

    2015-08-01

    Metal pollution due to the huge electronic waste (E-waste) accumulation is widespread across the globe. Extraction of copper, zinc and nickel from computer printed circuit boards (c-PCB) with a two-step bleaching process using ferric sulphate generated by Leptospirillum ferriphilum dominated consortium and the factors influencing the process were investigated in the present study. The studied factors with 10 g/L pulp density showed that pH 2.0 was optimum which resulted in 87.50-97.80% Cu-Zn-Ni extraction. Pre-treatment of PCB powder with acidified distilled water and NaCl solution showed 3.80-7.98% increase in metal extraction corresponding to 94.08% Cu, 99.80% Zn and 97.99% Ni extraction. Particle size of 75 μm for Cu and Zn while 1680 μm for Ni showed 2-folds increase in metal extraction, giving 97.35-99.80% Cu-Zn-Ni extraction in 2-6 days of reaction time. Whereas; 2.76-3.12 folds increase in Cu and Zn extraction was observed with the addition of 0.1% chelating agents. When the studies were carried out with high pulp density, ferric iron concentration of 16.57 g/L was found to be optimum for metal extraction from 75 g/L c-PCB and c-PCB addition in multiple installments resulted in 8.81-26.35% increase in metal extraction compared to single addition. The studied factors can be implemented for the scale-up aimed at faster recovery of multimetals from E-waste and thereby providing a secondary source of metal in an eco-friendly manner. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  11. Preparation of high T(c) Tl-Ba-Ca-Cu-O thin films by pulsed laser evaporation and Tl2O3 vapor processing

    Science.gov (United States)

    Johs, B.; Thompson, D.; Ianno, N. J.; Woollam, John A.; Liou, S. H.

    1989-01-01

    Tl-Ba-Ca-Cu-O superconducting thin films with zero-resistance temperatures up to 115 K have been prepared using a Tl2O3 vapor process on Ba-Ca-Cu-O precursor thin films. The Ba-Ca-Cu-O thin films were made by laser deposition on Y-stabilized ZrO2 substrates. This technique minimizes problems caused by the toxicity of Tl2O3, and its subsequent decomposition to the volatile and toxic Tl2O upon heating. Therefore, it may have practical application in the fabrication of high T(c) Tl-Ba-Ca-Cu-O superconducting thin-film devices.

  12. Development of high strength W/V/Au/ODS-Cu joint using HIP process

    Directory of Open Access Journals (Sweden)

    Hiroyuki Noto

    2016-12-01

    Full Text Available A new high strength bonding method between Tungsten (W and Oxide Dispersion Strengthening copper (ODS-Cu using vanadium (V and gold (Au inserts was investigated and the resulting joints were characterized with SEM, micro-hardness and four point bending test. For the joints using thick Au inserts (300µm, a hardened reaction layer was observed in the V/Au interface region. On the other hand, the joints using thin Au inserts (0.7µm exhibited a serrated interface layer having homogeneous hardness profiles. In this case, the observed behavior is a reflection of degradation of melting point by inter-diffusion between Au and Cu. Room temperature bending test of the joints with and without 0.7µm inserts at interface between V and ODS-Cu exhibited yielding behavior with the strength of approximately 300MPa which is close to that of ODS-Cu. The joint with the thin Au insert had a serrated interface which implies appearance of liquid phase by reaction between Au and Cu.

  13. Interactions between salt marsh plants and Cu nanoparticles - Effects on metal uptake and phytoremediation processes.

    Science.gov (United States)

    Andreotti, Federico; Mucha, Ana Paula; Caetano, Cátia; Rodrigues, Paula; Rocha Gomes, Carlos; Almeida, C Marisa R

    2015-10-01

    The increased use of metallic nanoparticles (NPs) raises the probability of finding NPs in the environment. A lot of information exists already regarding interactions between plants and metals, but information regarding interactions between metallic NPs and plants, including salt marsh plants, is still lacking. This work aimed to study interactions between CuO NPs and the salt marsh plants Halimione portulacoides and Phragmites australis. In addition, the potential of these plants for phytoremediation of Cu NPs was evaluated. Plants were exposed for 8 days to sediment elutriate solution doped either with CuO or with ionic Cu. Afterwards, total metal concentrations were determined in plant tissues. Both plants accumulated Cu in their roots, but this accumulation was 4 to 10 times lower when the metal was added in NP form. For P. australis, metal translocation occurred when the metal was added either in ionic or in NP form, but for H. portulacoides no metal translocation was observed when NPs were added to the medium. Therefore, interactions between plants and NPs differ with the plant species. These facts should be taken in consideration when applying these plants for phytoremediation of contaminated sediments in estuaries, as the environmental management of these very important ecological areas can be affected.

  14. Investigation of the Microstructure and the Mechanical Properties of Cu-NiC Composite Produced by Accumulative Roll Bonding and Coating Processes

    Science.gov (United States)

    Shabani, Ali; Toroghinejad, Mohammad Reza

    2015-12-01

    In the present study, Cu-1.8 wt.% NiC (nickel coating) composite was produced by the combination of two methods, including accumulative roll bonding (ARB) and electroplating processes. Electroplating process was done on copper strips in order to produce a nickel-particle-reinforced composite. Microstructure, texture, and the mechanical properties of the produced composite were evaluated during various cycles of ARB using optical and scanning electron microscopes, x-ray diffraction, microhardness, and tensile tests. In addition, the results were compared with Cu-Cu and also Cu-NiS (nickel sheet) samples. It was found that nickel layers were fractured from the first cycle of the process, and nickel fragments were distributed in the copper matrix as the number of cycles was increased. Variation of orientation density of α-, β-, and τ-fibers for the produced composite was examined in different cycles. Microhardness for different elements in different cycles of Cu-NiC was also evaluated. Also, the investigation of the mechanical properties showed that by proceeding the ARB process, the tensile strength of the produced Cu-NiC and Cu-Cu samples was increased. However, improvement in the mechanical properties of composite samples was more noticeable due to the reinforcing effect of nickel particles. The elongation of composite samples showed a decrease in the primary cycles, unlike Cu-Cu ones; however, it was then increased. Finally, by using scanning electron microscopy, the fracture surfaces of Cu-NiC composite were studied to disclose the fracture mechanism of the samples.

  15. VARIATION IN STRUCTURE AND PROPERTIES IN AN Al-Li-Cu-Mg-Zr ALLOY PRODUCED BY EXTRUSION PROCESSING

    OpenAIRE

    Mukhopadhyay, A; Flower, H.; Sheppard, T.

    1987-01-01

    The effects of extrusion processing variables on the structure and properties of an Al-Li-Cu-Mg-Zr alloy (8090 type) have been investigated. A combination of light and transmission electron microscopy have been used to characterise the as extruded microstructures and the precipitation reactions which take place on subsequent heat treatment. The corresponding mechanical properties have been determined by hardness, tensile and fracture toughness test methods. As extruded tensile properties are ...

  16. High field performance of superconducting magnets using powder metallurgy processed Cu-Nb-Sn and Nb-Al

    Energy Technology Data Exchange (ETDEWEB)

    Zaleski, A.J.; Foner, S.

    1984-06-01

    Small superconducting magnets were fabricated with powder metallurgy processed Nb-Al wire and with powder metallurgy processed multistrand Cu-Nb--Sn wire with 19 tin cores. Tests in a background field of up to 15 T showed that short sample characteristics were achieved for three coils. Upper limits of resistivity were established for both powder metallurgy processed wires. The reacted wires in the magnets gave upper limits of resistivity at 10 T of less than 1.4 x 10/sup -14/ ..cap omega.. cm for the Nb/sub 3/Sn wire, and less than 9 x 10/sup -13/ ..cap omega.. cm for the Nb-Al wire.

  17. EVOLUTION OF MICROSTRUCTURE OF Sn-Ag-Cu LEAD-FREE FLIP CHIP SOLDER JOINTS DURING AGING PROCESS

    Institute of Scientific and Technical Information of China (English)

    Y.H. Tian; C.Q. Wang; W.F. Zhou

    2006-01-01

    Flip chip bonding has become a primary technology that has found application in the chip interconnection process in the electronic manufacturing industry in recent years. The solder joints of the flip chip bonding are small and consist of complicated microstructures such as Sn solution,eutectic mixture, and intermetallic compounds (IMCs), whose mechanical performance is quite different from the original solder bulk. The evolution of microstructure of the flip chip solder joints under thermal aging was analyzed. The results show that with an increase in aging time, coarsening of solder bulk matrix and AuSn4 IMCs occurred within the solder. The IMCs that are formed at the bottom side of the flip chip bond were different from those on the top side during the aging process. ( Cu, Ni, Au )6Sn5 were formed at the interfaces of both sides, and large complicated (Au, Ni,Cu)Sn4 IMCs appeared for some time near the bottom interface after aging, but they disappeared again and thus ( Cu, Ni,Au )6Sns IMC thickness increased considerably. The influence of reflow times during the flip chip bonding (as-bonded condition) on the characteristics of interfacial IMCs was weakened when subjected to the aging process.

  18. Processing of CuAlMn Shape Memory Foams with Open Spherical Pores by Silica-Gel Beads Infiltration Method

    Science.gov (United States)

    Li, Hua; Yuan, Bin; Gao, Yan

    2016-10-01

    A molten metal infiltration process with amorphous SiO2 (silica-gel) beads as space holders was used to prepare Cu-based shape memory foams in this article. We found that the silica-gel beads with micropores inside expanded when being heated to elevated temperatures and that proper control of the expansion of silica-gel beads helped form necks between the beads with different bonding extent, which had been taken advantage of to have a good control of the foam morphology and porosity, by carefully designing suitable procedures and choosing proper parameters for the process. In addition, we studied in detail the effect of heating temperature, silica-gel bead density, and infiltration pressure of the present process on the morphology and porosity of CuAlMn shape memory foams. By coordinating these three key parameters, CuAlMn shape memory foams with open spherical pores and adjustable porosity from 66 to 85 pct were reliably produced.

  19. Processing Bi-Pb-Sr-Ca-Cu-O superconductors from amorphous state

    Science.gov (United States)

    Chiang, C. K.; Freiman, S. W.; Wong-Ng, W.; Hwang, N. M.; Shapiro, A. J.; Hill, M. D.; Cook, L. P.; Shull, R. D.; Swartzendruber, L. J.; Bennett, L. H.

    1990-01-01

    Researchers produced superconducting ceramics of the Bi-Pb-Sr-Ca-Cu-O system started from a glass. To form the glass, the mixed oxide powder was melted at 1200 C in air. The liquid was quenched rapidly by pouring it onto an aluminum plate and rapidly pressing with another plate. The quenched compound was in the form of black amorphous solid, whose x-ray powder pattern has no crystalline peaks. After heat treatment at high temperatures, the glass crystallized into a superconductor. The crystalline phases in the superconductor identified using x-ray diffraction patterns. These phases were that associated with the superconducting phases of T(sub c) = 80 K (Bi2Ca1Sr2Cu2Ox) and of T(sub c) = 110 K (Bi2Ca2Sr2Cu3Ox). The dc resistivity and the ac susceptibility of these superconductors were studied.

  20. Functional Roles of Neural Preparatory Processes in a Cued Stroop Task Revealed by Linking Electrophysiology with Behavioral Performance.

    Directory of Open Access Journals (Sweden)

    Chao Wang

    Full Text Available It is well established that cuing facilitates behavioral performance and that different aspects of instructional cues evoke specific neural preparatory processes in cued task-switching paradigms. To deduce the functional role of these neural preparatory processes the majority of studies vary aspects of the experimental paradigm and describe how these variations alter markers of neural preparatory processes. Although these studies provide important insights, they also have notable limitations, particularly in terms of understanding the causal or functional relationship of neural markers to cognitive and behavioral processes. In this study, we sought to address these limitations and uncover the functional roles of neural processes by examining how variability in the amplitude of neural preparatory processes predicts behavioral performance to subsequent stimuli. To achieve this objective 16 young adults were recruited to perform a cued Stroop task while their brain activity was measured using high-density electroencephalography. Four temporally overlapping but functionally and topographically distinct cue-triggered event related potentials (ERPs were identified: 1 A left-frontotemporal negativity (250-700 ms that was positively associated with word-reading performance; 2 a midline-frontal negativity (450-800 ms that was positively associated with color-naming and incongruent performance; 3 a left-frontal negativity (450-800 ms that was positively associated with switch trial performance; and 4 a centroparietal positivity (450-800 ms that was positively associated with performance for almost all trial types. These results suggest that at least four dissociable cognitive processes are evoked by instructional cues in the present task, including: 1 domain-specific task facilitation; 2 switch-specific task-set reconfiguration; 3 preparation for response conflict; and 4 proactive attentional control. Examining the relationship between ERPs and behavioral

  1. Investigation of Kinetics of crystallization Processes of S15-Se85, S15-Se81-Cu4 Chalcogenide glasses

    Science.gov (United States)

    Samudrala, Kavitha; Babu Devarasetty, Suresh

    2016-09-01

    In the present work, S15-Se85, S15-Se81-Cu4 chalcogenide glasses are prepared by using conventional melt quenching technique. The as-prepared samples are studied by experimental techniques like X-ray Diffraction (XRD), Differential Scanning Calorimetry (DSC). XRD studies have confirmed that the as-prepared samples are amorphous in nature. It is clear from DSC studies that the as-prepared samples are glassy in nature. Kinetic analysis of the crystallization process of as-prepared glasses is carried using DSC curves. Activation energy for glass transition and Activation energy for crystallization are determined using Kissinger method. Activation energy for glass transition of S15-Se85 and S15-Se81-Cu4 glasses is found to be 84.5076 and 275.801 KJ/Mole respectively. Activation energy for crystallization of S15-Se85 glass is found to be 106.2622 KJ/Mole for 1st peak while Activation energy for crystallization of S15-Se81-Cu4 glasses is found to be 97.93 KJ/Mole for 1st peak and 84.20 KJ/Mole for 2nd peak. Kauzmann temperature (Tk) is determined from the heating rate dependent glass transition and crystallization temperatures. Tk value for S15-Se85 glass sample is 236.680K (1st peak) and for S15-Se81-Cu4 is 283.530K (1st peak) and 286.330K (2n peak). Avrami Index (n) is also determined for as-prepared glasses. Avrami Index (n) value for S15-Se85 glass sample is 1.8 (1st peak) and for S15-Se81-Cu4 is 2.9 (1st peak) and 1.4 (2nd peak). The crystalline phases by thermal treatment of as-prepared glasses are identified using XRD patterns.

  2. New processing approaches for Cu2ZnSnSe4-based solar cells

    OpenAIRE

    López Mariño, Simón

    2016-01-01

    The present thesis focuses on the promising semiconductor material kesterite, Cu2ZnSn(S,Se)4, known as CZTS(e), which is used in the second generation of solar cells, generally known as thin film photovoltaics (PV). This material relies on earth-abundant, low-cost and low toxic elements which certainly attract the interest of both research community and industry. Kesterite could replace its well known and already commercialised thin film counterpart, CuIn(1-x)Gax(SySe1-y)2 (CIGS), since it ha...

  3. Mineralogy and skarnification processes at the Avan Cu-Fe Skarn, northeast of Kharvana, NW Iran

    Directory of Open Access Journals (Sweden)

    Mir Ali Asghar Mokhtari

    2017-02-01

    Full Text Available Introduction The Avan Cu-Fe skarn is located at the southern margin of Qaradagh batholith, about 60 km north of Tabriz. The Skarn-type metasomatic alteration is the result of Qaradagh batholith intrusion into the Upper Cretaceous impure carbonates. The studied area belongs to the Central Iranian structural zone. In regional scale, the studied area is a part of the Zangezour mineralization zone in the Lesser Caucasus. Several studies (Karimzadeh Somarin and Moayed, 2002; Calagari and Hosseinzadeh, 2005; Mokhtari, 2008; Baghban Asgharinezhad, 2012; Mokhtari, 2012 including master’s theses and research programs have been done on some skarns in the Azarbaijan area considering their petrologic and mineralization aspects. However, before this study, the Avan skarn aureole has not been studied in detail. In this paper, various geological aspects of the Avan skarn including mineralogy, bi-metasomatic alteration, metasomatism and mineralization during the progressive and retrograde stages of the skarnification processes have been studied in detail. Research Method This research consists of field and laboratory studies. Field studies include preparation of the geological map, identifying the relationship between the intrusion and the skarn aureole, identifying the relationship between different parts of the skarn zone and also collecting samples for laboratory studies. Laboratory studies include petrography, mineralography and microprobe studies. Cameca SX100 Microprobe belonging to Geological Survey of the Czech Republic was used in order to determine the chemical composition of the calc-silicate minerals such as pyroxene and garnet in garnet skarn and pyroxene- garnet skarn sub-zones. Discussion and conclusion Qaradagh batholith is composed of discrete acid to mafic phases including gabbro, diorite, quartz diorite, quartz monzonite, quartz monzodiorite, tonalite, granodiorite, monzogranite and granite porphyry which is dominated by granodiorite

  4. Preparation and characteristics of nano-crystalline Cu-Ce-Zr-O composite oxides via a green route: supercritical anti-solvent process

    Institute of Scientific and Technical Information of China (English)

    KUANG Li; HUANG Pan; SUN Huanhua; JIANG Haoxi; ZHANG Minhua

    2013-01-01

    The nano-crystalline Cu-Ce-Zr-O composite oxides were successfully prepared by the supercritical anti-solvent (SAS) process.The physicochemical properties and catalytic performances were investigated by X-ray diffraction (XRD),Raman spectroscopy,H2 temperature-programmed reduction (H2-TPR),oxygen storage capacity (OSC) measurement and catalytic activity evaluation.It was found that Cu2+ ions incorporated into CeO2-ZrO2 lattice to forn Cu-Ce-Zr-O solid solution associated with the formation of oxygen vacancies.The Cu-Ce-Zr-O catalysts prepared via the SAS process with the Cu content 2.63 mol.% showed the highest OSC index of 636.9 μmol/g.Compared with the samples prepared by impregnation method,Cu doping using SAS process could improve the dispersion of Cu2+ in the composite oxide,enhance the interaction between Cu2+ and CeO2-ZrO2,improve the reducibility of catalyst,and thus improve the OSC performance and increase the catalytic activity for CO oxidation at low temperature.

  5. Effects of temperature and operation parameters on the galvanic corrosion of Cu coupled to Au in organic solderability preservatives process

    Science.gov (United States)

    Oh, SeKwon; Kim, YoungJun; Jung, KiMin; Kim, JongSoo; Shon, MinYoung; Kwon, HyukSang

    2017-03-01

    In this work, we quantitatively examined the effects of temperature and operation parameters such as anode (Cu) to cathode (Au) area ratio, stirring speed, and Cu ion concentration on the galvanic corrosion kinetics of Cu coupled to Au (icouple ( Cu-Au)) on print circuit board in organic solderability preservative (OSP) soft etching solution. With the increase of temperature, galvanic corrosion rate (icouple ( Cu-Au) was increased; however, the degree of galvanic corrosion rate (icouple ( Cu-Au) - icorr (Cu)) was decreased owing to the lower activation energy of Cu coupled to Au, than that of Cu alone. With the increase of area ratio (cathode/anode), stirring speed of the system, icouple ( Cu-Au) was increased by the increase of cathodic reaction kinetics. And icouple ( Cu-Au) was decreased by the increase of the Cu-ion concentration in the OSP soft etching solution.

  6. Effects of temperature and operation parameters on the galvanic corrosion of Cu coupled to Au in organic solderability preservatives process

    Science.gov (United States)

    Oh, SeKwon; Kim, YoungJun; Jung, KiMin; Kim, JongSoo; Shon, MinYoung; Kwon, HyukSang

    2017-02-01

    In this work, we quantitatively examined the effects of temperature and operation parameters such as anode (Cu) to cathode (Au) area ratio, stirring speed, and Cu ion concentration on the galvanic corrosion kinetics of Cu coupled to Au (icouple (Cu-Au)) on print circuit board in organic solderability preservative (OSP) soft etching solution. With the increase of temperature, galvanic corrosion rate (icouple (Cu-Au) was increased; however, the degree of galvanic corrosion rate (icouple (Cu-Au) - icorr (Cu)) was decreased owing to the lower activation energy of Cu coupled to Au, than that of Cu alone. With the increase of area ratio (cathode/anode), stirring speed of the system, icouple (Cu-Au) was increased by the increase of cathodic reaction kinetics. And icouple (Cu-Au) was decreased by the increase of the Cu-ion concentration in the OSP soft etching solution.

  7. Formation of hierarchical CuO microcabbages as stable bionic superhydrophobic materials via a room-temperature solution-immersion process

    Science.gov (United States)

    Liu, Jinping; Huang, Xintang; Li, Yuanyuan; Li, Zikun; Chi, Qingbo; Li, Guangyun

    2008-11-01

    A new hierarchical CuO architecture consisting of densely packed nanoplates and nanoribbons was directly fabricated on Cu foils via a room-temperature solution-immersion process. The architectures resembled cabbages both in the shape and structure, and the plates and ribbons served as the leafstalks and leaves of cabbages, respectively. By carefully monitoring the growth stages, it was found that self-assembled CuO nanoplates could be firstly formed on the Cu foils, and then CuO tiny flexible nanoribbons were grown from the edges of fresh plates. The effect of NaOH concentration on the morphology of CuO structures was discussed. Importantly, stable superhydrophobicity (contact angle CA = 155°), independent of pH value of the water droplets, was successfully observed for CuO microcabbages after modification. The wettability of other CuO micro- and nanoscale hierarchical surface structures fabricated using various NaOH concentrations was also presented. The realization of superhydrophobic bionic surfaces with a new hierarchical morphology of CuO will shed new insights in both the synthesis and application fields.

  8. Solution-processable carboxylate-capped CuO nanoparticles obtained by a simple solventless method

    Energy Technology Data Exchange (ETDEWEB)

    Estruga, Marc [Universitat Autonoma de Barcelona, Department of Chemistry (Spain); Roig, Anna; Domingo, Concepcion [CSIC, Institut de Ciencia de Materials de Barcelona (Spain); Ayllon, Jose A., E-mail: joseantonio.ayllon@uab.es [Universitat Autonoma de Barcelona, Department of Chemistry (Spain)

    2012-08-15

    Carboxylate-capped CuO nanoparticles were obtained via a simple solventless route, based on the thermal decomposition at 120 Degree-Sign C of solid precursors. The reaction mixture consisted of copper acetate monohydrate, acting as the CuO precursor, and different organic carboxylic acids (lauric, phenylvaleric or 3,6,9-trioxadecanoic acid) used as the capping agent. The proposed method, in good agreement with environmentally friendly practices, produced dry nanoparticles, thereby totally eliminating the need of washing, filtration, or other downstream steps. Transmission electron micrographs show crystalline roughly spherical CuO nanoparticles with average diameters between 3.1 and 5.5 nm depending on the capping ligand. The laurate-capped CuO nanoparticles showed a paramagnetic behaviour at room temperature, while a weak ferromagnetic component was detected at low temperature (<40 K). It was also proved that the chemical structure of the carboxylic acid tail enabled the straightforward dispersibility of nanoparticles in common solvents and assisted in the deposition of the material as thin films.

  9. Effects of caffeine on anticipatory control processes : Evidence from a cued task-switch paradigm

    NARCIS (Netherlands)

    Tieges, Zoe; Snel, Jan; Kok, Albert; Plat, Niels; Ridderinkhof, Richard

    2007-01-01

    Effects of caffeine on task switching were studied using ERPs in a cued task-switch paradigm. The need for advance preparation was manipulated by varying the number of task-set aspects that required switching. In a double-blind, within-subjects experiment, caffeine reduced shift costs compared to pl

  10. Thermal storage/discharge performances of Cu-Si alloy for solar thermochemical process

    Science.gov (United States)

    Gokon, Nobuyuki; Yamaguchi, Tomoya; Cho, Hyun-seok; Bellan, Selvan; Hatamachi, Tsuyoshi; Kodama, Tatsuya

    2017-06-01

    The present authors (Niigata University, Japan) have developed a tubular reactor system using novel "double-walled" reactor/receiver tubes with carbonate molten-salt thermal storage as a phase change material (PCM) for solar reforming of natural gas and with Al-Si alloy thermal storage as a PCM for solar air receiver to produce high-temperature air. For both of the cases, the high heat capacity and large latent heat (heat of solidification) of the PCM phase circumvents the rapid temperature change of the reactor/receiver tubes at high temperatures under variable and uncontinuous characteristics of solar radiation. In this study, we examined cyclic properties of thermal storage/discharge for Cu-Si alloy in air stream in order to evaluate a potentiality of Cu-Si alloy as a PCM thermal storage material. Temperature-increasing performances of Cu-Si alloy are measured during thermal storage (or heat-charge) mode and during cooling (or heat-discharge) mode. A oxidation state of the Cu-Si alloy after the cyclic reaction was evaluated by using electron probe micro analyzer (EPMA).

  11. Positron annihilation process in Ni/sub c/Cu/sub 1-c/ alloys

    Energy Technology Data Exchange (ETDEWEB)

    Szotek, Z.; Gyorffy, B.L.; Stocks, G.M.; Temmerman, W.M.

    1982-01-01

    New, accurate, calculations of the electron momentum distribution function for the Cu/sub 60/Ni/sub 40/ random solid solution are presented and the role played by the positron wavefunction in determining the Angular Correlation of the Annihilation Radiation (ACAR) is discussed in quantitative terms.

  12. Phases in the crystallization process of Zr65Al7.5Ni10Cu17.5 metallic glass

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The crystallization process of metallic glass Zr65Al7.5Ni10Cu17.5 (atom fraction in %) were studied by transmissionelectron microscopy and X-ray diffraction. Two stages of crystallization process, which are indicated by the two exothermicpeaks in the differential scanning calorimetry diagram, were studied separately. It is found that the phases in the variousstage of the crystallization are different. In the first stage, it consists mainly of tI-CuZr2 and tP-Al2Zr3 phases, between whicha definite orientation relationship is found. While in the second stage, in addition to the above phases, phase hP2-Al2NiZr6and phase hp3-α-Zr appear, between which another orientation relationship is also found. At the same time, a comparison ismade based on the study of the phases exist in the arc-melted master ingot. The lattice parameters of the identified phaseswere determined and some interesting similarities were found. According to these similarities, all the phases were classifiedinto two groups. The first is: oB, tI-CuZr2, and hp3-α-Zr, the other is: hP2, tP-Al2Zr3 and hp1-Al2NiZr6. The relationshipsbetween phases in these two groups were investigated and the probable reasons that may result in these relationships werediscussed.

  13. Development of a hybrid sputtering/evaporation process for Cu(In,Ga)Se{sub 2} thin film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Acciarri, M.; Binetti, S.; Le Donne, A.; Lorenzi, B.; Caccamo, L.; Miglio, L. [Dipartimento di Scienza dei Materiali e Solar Energy Research Center MIB-SOLAR, Universita di Milano Bicocca, Milan (Italy); Moneta, R.; Marchionna, S.; Meschia, M. [Voltasolar s.r.l, Turate (Italy)

    2011-08-15

    In this paper we report a new method for Cu(In,Ga)Se{sub 2} deposition for solar cell application. Differently from the common co-evaporation process, an alterative approach for thin film Cu(In,Ga)Se{sub 2} has been tested: the sputtering deposition of metal elements combined with the selenium evaporation. We have studied the relationships between the growth parameters of our hybrid sputtering/evaporation method and the chemical-physical properties of the CIGS films. The cells are completed with a CdS buffer layer deposited by chemical bath deposition and ZnO + ITO deposited by RF sputtering. Test solar cells of 0.5 cm{sup 2} have shown an efficiency of 10% and 2.5% on glass and stainless steel substrate respectively. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  14. Electron microscopy study of microtexture in Cu-Al-Ni shape memory alloys processed by powder metallurgy

    Science.gov (United States)

    Rodriguez, P. P.; San Jean, J.; Iza-Mendia, A.; Recarte, V.; Pérez-Landazabal, J. J.; No, M. L.

    2003-10-01

    Cu-AI-Ni shape memory alloys processed by powder metallurgy show very good thermomechanical properties, being the mechanical behavior similar to the one observed in single crystals. In this paper we present the microstructural characterization of a sample elaborated by powder metallurgy in two different stages of the process: after being compacted by Hot Isostatic Pressing (HIP) and after compaction and hot rolling, in order to find the microscopic mechanisms responsible of their mechanical behavior. The characterization has been carried out by means of Scanning Electron Microscopy using Backscattered Electron Imaging (SEM-BSE) and Electron BackScattered Diffraction (EBSD), as well as Transmission Electron Microscopy (TEM).

  15. Microstructure and Mechanical Properties of Co21Cr22Cu22Fe21Ni14 Processed by High Pressure Torsion and Annealing

    Science.gov (United States)

    Park, Nokeun; Li, Xiang; Tsuji, Nobuhiro

    2015-08-01

    The strengthening mechanisms of Co21Cr22Cu22Fe21Ni14 multiple-principal element alloy processed by high pressure torsion (HPT) and annealing were examined. Two face-centered cubic (FCC) phases were observed in the as-cast alloy; one was a Cu-rich phase and the other was a Cu-lean one. In the HPT process, the microhardness increased from 190 HV to 470 HV at a strain of 157 due to strain hardening and grain refinement hardening. X-ray diffraction showed that the lattice parameters of the two FCC phases became closer to each other at higher HPT strain, indicating the alloying of Cu into the Cu-lean matrix. The HPT processed specimens were annealed at 500°C, 550°C, 600°C, and 650°C. The microhardness increased to 540 HV after annealing at temperatures lower than 650°C, whereas it decreased when the specimen was annealed at 650°C. The mean grain size of the specimens annealed at temperatures lower than 650°C was much smaller than 100 nm, and Cu-rich clusters with sizes ranging from 2 nm to 32 nm were distributed homogeneously. The reasons for the formation of the Cu-rich nano-clusters were discussed from a perspective of the positive mixing enthalpy of Cu in the alloy and thermalenergy for Cu diffusion at a given temperature. The dissolution and partitioning of two FCC phases played a key role in strengthening the Co21Cr22Cu22Fe21Ni14 system.

  16. Microstructural evolution and mechanical, and corrosion property evaluation of Cu-30Ni alloy formed by Direct Metal Deposition process

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharya, S., E-mail: sudipb@umich.edu [University of Michigan, 2350 Hayward Street, 2040 G.G. Brown Laboratories, Ann Arbor, MI 48109 (United States); Dinda, G.P.; Dasgupta, A.K. [Center for Advanced Technologies, Focus: HOPE, Detroit, MI 48238 (United States); Natu, H.; Dutta, B. [POM Group Inc., Auburn Hills, MI 48326 (United States); Mazumder, J. [University of Michigan, 2350 Hayward Street, 2040 G.G. Brown Laboratories, Ann Arbor, MI 48109 (United States); POM Group Inc., Auburn Hills, MI 48326 (United States)

    2011-06-02

    Research highlights: > Cu-30Ni alloy was successfully deposited with CO{sub 2} laser DMD system on C71500 substrate. > The microstructure consists of a single solid solution phase. > Columnar dendrites growing into equiaxed dendrites form layer microstructure. > Dendrite growth direction and angle relative to substrate was maintained in each layer. > Lattice parameter of solid solution phase is longer than reported lattice parameters. - Abstract: In the current investigation Cu-30Ni alloy was successfully laser deposited on a rolled C71500 plate substrate by Direct Metal Deposition technology. The microstructural investigation of the clad was performed using optical and scanning electron microscopy. The phase and crystal structure analysis was performed using X-ray diffraction technique and transmission electron microscopy. The microstructure consisted of columnar and equiaxed dendrites with face centered cubic crystal structure. The dendrites grew epitaxially from the substrate and layer and bead boundaries. Dendrites' growth direction <0 0 1> and growth angle 60{sup o} was maintained in each layer. The average primary dendritic arm spacing at the bottom part of the layers was about 7.5 {mu}m and average secondary dendritic arm spacing in the upper part of the layer varied between 2 {mu}m and 4.5 {mu}m. The lattice parameter of the identified phase was found to be longer than that reported in literature. The reported lattice parameters in literature are however from samples processed under equilibrium conditions. The microhardness of the clad was found to be less than the substrate but very consistent along the clad. Cu-30Ni clad specimen showed higher ultimate tensile strength but lower yield strength and percentage elongation as compared to the C71500 substrate. DMD Cu-30Ni clad/C71500 substrate specimen showed the worst mechanical properties. The corrosion resistance of the specimens was found to decrease in the order DMD Cu-30Ni clad, half-and-half DMD Cu

  17. Diffusion bonding process between W-Cu composite and Cu%W-Cu复合材料与Cu的扩散连接工艺

    Institute of Scientific and Technical Information of China (English)

    范景莲; 杨树忠; 刘涛; 周强

    2015-01-01

    The high mismatch on coefficient of thermal expansion between W and Cu makes the bonding between W and Cu on divertor application become a problem. The W-Cu composite and Cu were bonded by diffusion bonding in the reduced furnace with a high active Fe-Cu powder interlayer in the present paper, and the metallographical morphologies, micro-hardness, tensile strength and elements distribution of the bonded specimen were investigated. The results show that interface bonding quality of the joint is improved effectively by using an interlayer. Metallographical morphologies, micro-hardness and SEM-EDS indicate that successive and tight bonding is obtained near the joint interface of W-Cu and Cu bonded specimen. Furthermore, the average tensile strength of the joint is 168.55 MPa, which is close to the strength of Cu substrate and demonstrates the success of reaching the diffusion bonding of W-Cu and Cu by using an interlayer of active Fe-Cu composite powder.%钨、铜热膨胀系数的过度失配,使得钨、铜的连接在偏滤器上的应用成为难点。本文基于钨铜梯度材料概念对钨、铜进行连接,以高活性 Fe-Cu 粉为中间层,在还原炉中采用扩散连接的方法对 W-Cu 复合材料与 Cu进行连接,并对连接样品的金相显微形貌、显微硬度、拉伸强度和元素分布进行研究。结果表明,采用添加中间层的方法可以有效改善连接界面,提高连接质量。金相、显微硬度和能谱分析说明W-Cu与Cu连接样品的连接界面处形成了连续、紧密的结合;拉伸实验测得的平均强度为168.55 MPa,接近于Cu基材的强度,进一步证实添加中间层的方法可实现W-Cu与Cu的扩散连接。

  18. Electric field-induced hole transport in copper(i) thiocyanate (CuSCN) thin-films processed from solution at room temperature

    KAUST Repository

    Pattanasattayavong, Pichaya

    2013-01-01

    The optical, structural and charge transport properties of solution-processed films of copper(i) thiocyanate (CuSCN) are investigated in this work. As-processed CuSCN films of ∼20 nm in thickness are found to be nano-crystalline, highly transparent and exhibit intrinsic hole transporting characteristics with a maximum field-effect mobility in the range of 0.01-0.1 cm2 V-1 s-1. © 2013 The Royal Society of Chemistry.

  19. Microstructure And Mechanical Properties Of An Al-Zn-Mg-Cu Alloy Produced By Gravity Casting Process

    Directory of Open Access Journals (Sweden)

    Saikawa S.

    2015-06-01

    Full Text Available High-strength aluminum alloy are widely used for structural components in aerospace, transportation and racing car applications. The objective of this study is to enhance the strength of the Al-Zn-Mg-Cu alloy used for gravity casting process. All alloys cast into stepped-form sand mold (Sand-mold Casting; SC and Y-block shaped metal mold(Permanent mold Casting; PC C and then two –step aged at 398-423 K after solution treated at 743 K for 36 ks. The tensile strength and total elongation of the two-step aged SC alloys were 353-387 MPa and about 0.4% respectively. This low tensile properties of the SC alloys might be caused by remaining of undissolved crystallized phase such as Al2CuM, MgZn2 and Al-Fe-Cu system compounds. However, good tensile properties were obtained from PC alloys, tensile strength and 0.2% proof stress and elongation were 503-537 MPa, 474-519 MPa and 1.3-3.3%.

  20. In-situ deposition and processing of YBa2Cu3O(7-x) films and multilayers for optoelectronic devices

    Science.gov (United States)

    Villegier, J. C.; Moriceau, H.; Boucher, H.; di Cioccio, L.; Chicault, R.

    1991-03-01

    In situ direct deposition at about 700 C of thin YBa2Cu3O(7-x) superconductive films and multilayers has been done by three techniques using stoichiometric YBa2Cu3O(7-x) sintered targets. Excimer laser ablation in a dc magnetron system with hollow and planar targets leads to 0.5-, 1.2-, and 2.5-in diameter uniformly superconductive layers under static conditions. High critical current densities associated with low resistivity and good epitaxial behavior are achieved on top of MgO, SrTiO3, LaAlO3, and YSZ single-crystal wafers. High-quality c-oriented films are routinely obtained by means of a dc magnetron on large sapphire substrates covered by a YSZ RF sputtered buffer layer. The infrared properties of such films have been checked at 1.15-micron wavelength. In order to achieve active devices, small YBa2Cu3O7-YSZ-Ag tunnel junctions and arrays have been successfully patterned in the superconductor/insulator/normal-metal trilayers using SNOP (selective niobium overlap process).

  1. Process and properties of electroless Ni-Cu-P-ZrO{sub 2} nanocomposite coatings

    Energy Technology Data Exchange (ETDEWEB)

    Ranganatha, S. [Department of Studies in Chemistry, School of Chemical Sciences, Kuvempu University, Shankaraghatta 577451, Shimoga, Karnataka (India); Venkatesha, T.V., E-mail: drtvvenkatesha@yahoo.co.uk [Department of Studies in Chemistry, School of Chemical Sciences, Kuvempu University, Shankaraghatta 577451, Shimoga, Karnataka (India); Vathsala, K. [Nanotribology Laboratory, Mechanical engineering department, Indian Institute of Science, Bangalore (India)

    2012-03-15

    Highlights: Black-Right-Pointing-Pointer The Ni-P and Ni-P-Cu-ZrO{sub 2} coatings were produced by electroless technique. Black-Right-Pointing-Pointer The influence of copper and ZrO{sub 2} nanoparticles on Ni-P was studied. Black-Right-Pointing-Pointer Surface morphology, structure and electrochemical behavior were evaluated. Black-Right-Pointing-Pointer The Ni-Cu-P-ZrO{sub 2} and Ni-P-ZrO{sub 2} coatings are more resistant to corrosion than Ni-P. Black-Right-Pointing-Pointer Introduction of Cu and ZrO{sub 2} in the matrix aids to the enhancement of microhardness. -- Abstract: Electroless Ni-Cu-P-ZrO{sub 2} composite coating was successfully obtained on low carbon steel matrix by electroless plating technique. Coatings with different compositions were obtained by varying copper as ternary metal and nano sized zirconium oxide particles so as to obtain elevated corrosion resistant Ni-P coating. Microstructure, crystal structure and composition of deposits were analyzed by SEM, EDX and XRD techniques. The corrosion behavior of the deposits was studied by anodic polarization, Tafel plots and electrochemical impedance spectroscopy (EIS) in 3.5% sodium chloride solution. The ZrO{sub 2} incorporated Ni-P coating showed higher corrosion resistance than plain Ni-P. The introduction of copper metal into Ni-P-ZrO{sub 2} enhanced the protection ability against corrosion. The influence of copper metal and nanoparticles on microhardness of coatings was evaluated.

  2. Facile synthesis, characterization and magnetic property of CuFe{sub 12}O{sub 19} nanostructures via a sol–gel auto-combustion process

    Energy Technology Data Exchange (ETDEWEB)

    Ansari, Fatemeh [Institute of Nano Science and Nano Technology, University of Kashan, P.O. Box. 87317–51167, Kashan, Islamic Republic of Iran (Iran, Islamic Republic of); Sobhani, Azam, E-mail: sobhaniazam@gmail.com [Department of Chemistry, Kosar University of Bojnord, Bojnord, Islamic Republic of Iran (Iran, Islamic Republic of); Salavati-Niasari, Masoud, E-mail: salavati@kashanu.ac.ir [Institute of Nano Science and Nano Technology, University of Kashan, P.O. Box. 87317–51167, Kashan, Islamic Republic of Iran (Iran, Islamic Republic of)

    2016-03-01

    Copper hexaferrite (CuFe{sub 12}O{sub 19}) nanostructures were prepared by a simple route utilizing maltose-assisted sol–gel process. The morphology, phase structure, composition and purity of nanostructures can be controlled by type of surfactant and also adjusting the Cu:surfactant, Cu:Fe and Cu:reductant ratios. The bean-shape structures are formed in the absence of the surfactant when the molar ratio of Cu:Fe and Cu:reductant are 1:12 and 1:26, respectively. The agglomerated spherical nanoparticles with diameters ranging from 7 to 20 nm are obtained in the presence of triplex, when ratio of Cu:reductant is 1:26. In the absence of surfactant and also in the presence of triplex, the samples are found to be CuFe{sub 12}O{sub 19}. When polymer is used, there are still the peaks of CuFe{sub 12}O{sub 19} and also some boad peaks in XRD patterns, because of the small size and encapsulation of nanostructures with polymer. Magnetic measurments show superparamagnetic behavior for the all samples. The M{sub s} for the samples obtained in the presence of polymer shows that the coating of magnetic nanostructures does not always increase M{sub s}. FT-IR frequency bands in the range 463–626, 607 and 542 cm{sup −1} correspond to the formation of metal oxides in ferrites. - Highlights: • Copper hexaferrite nanostructures were synthesized for the first time. • A sol–gel auto-combustion route was used to synthesize copper hexaferrites. • Maltose was used as a new reductant. • The various polymers used to as co-fuel for completing combustion reaction. • Ideal ratios between Cu:Fe and Cu:reductant were 1:12 and 1:26, respectively.

  3. Fabrication of CuInS2-sensitized solar cells via an improved SILAR process and its interface electron recombination.

    Science.gov (United States)

    Xu, Xueqing; Wan, Qingcui; Luan, Chunyan; Mei, Fengjiao; Zhao, Qian; An, Ping; Liang, Zhurong; Xu, Gang; Zapien, Juan Antonio

    2013-11-13

    Tetragonal CuInS2 (CIS) has been successfully deposited onto mesoporous TiO2 films by in-sequence growth of InxS and CuyS via a successive ionic layer absorption and reaction (SILAR) process and postdeposition annealing in sulfur ambiance. X-ray diffraction and Raman measurements showed that the obtained tetragonal CIS consisted of a chalcopyrite phase and Cu-Au ordering, which related with the antisite defect states. For a fixed Cu-S deposition cycle, an interface layer of β-In2S3 formed at the TiO2/CIS interface with suitable excess deposition of In-S. In the meantime, the content of the Cu-Au ordering phase decreased to a reasonable level. These facts resulted in the retardance of electron recombination in the cells, which is proposed to be dominated by electron transfer from the conduction band of TiO2 to the unoccupied defect states in CIS via exponentially distributed surface states. As a result, a relatively high efficiency of ~0.92% (V(oc) = 0.35 V, J(sc) = 8.49 mA cm(-2), and FF = 0.31) has been obtained. Last, but not least, with an overloading of the sensitizers, a decrease in the interface area between the sensitized TiO2 and electrolytes resulted in deceleration of hole extraction from CIS to the electrolytes, leading to a decrease in the fill factor of the solar cells. It is indicated that the unoccupied states in CIS with energy levels below EF0 of the TiO2 films play an important role in the interface electron recombination at low potentials and has a great influence on the fill factor of the solar cells.

  4. H2 and CO oxidation process at the three-phase boundary of Cu-ceria cermet anode for solid oxide fuel cell

    Science.gov (United States)

    Zheng, Minghao; Wang, Shuang; Li, Mei; Xia, Changrong

    2017-03-01

    Cu-ceria cermets have been widely investigated as the anode materials for solid oxide fuel cells (SOFCs) that operated with hydrocarbon fuels. However, the anode reaction processes are not clear yet, especially those at the ceria-Cu-gas three phase boundary (3 PB). This work investigates samaria-doped ceria (SDC)-Cu-gas 3 PB reaction kinetics for the oxidation of H2 and CO, the products from hydrocarbons via external and internal reforming. Electrochemical conductivity relaxation measurement demonstrates that Cu is a synergistic catalyst that can significantly increase the reaction rate. The reaction at 3 PB contributes 81.3/66.8% of H2/CO oxidation when 5.4% SDC surface is covered with Cu particles. Combining with AC impedance analysis, elementary steps are proposed for the reaction at 3 PB. Water vapor combining to oxygen vacancy and carbon monoxide transforming to carbonate are the rate-determining steps for the oxidation of H2 and CO, respectively. Cu-SDC has shown much higher catalytic activity, i.e. about fivefold reaction rate, for the oxidation of CO than H2. In addition, Cu-SDC electrodes exhibit lower interfacial polarization resistance and lower activation energy for the electrochemical oxidation of CO than H2. Consequently, CO is easier to be oxidized than H2 when the Cu-ceria anode is fueled with syngas, the reforming product from hydrocarbons.

  5. Microstructure And Mechanical Properties Of An Al-Zn-Mg-Cu Alloy Produced By Gravity Casting Process

    OpenAIRE

    2015-01-01

    High-strength aluminum alloy are widely used for structural components in aerospace, transportation and racing car applications. The objective of this study is to enhance the strength of the Al-Zn-Mg-Cu alloy used for gravity casting process. All alloys cast into stepped-form sand mold (Sand-mold Casting; SC) and Y-block shaped metal mold(Permanent mold Casting; PC) C and then two –step aged at 398-423 K after solution treated at 743 K for 36 ks. The tensile strength and total elongation of t...

  6. The nature of gold in the Aitik Cu-Au deposit:implications for mineral processing and mine planning

    OpenAIRE

    Sammelin, Monika

    2011-01-01

    The Aitik mine is a large Cu-Au producer in Europe with an annual production of 28 million tons of ore and a planned expansion of production to 36 million tons of ore until year 2013. Large ongoing investments are done in the mine and a new processing plant is built to manage the capacity increase. The mine is situated 15 kilometers from the town Gällivare, in northern Norrbotten, Sweden. The ore is a large porphyry type deposit with low grades of disseminated copper (0,27 %) and gold (0,16 p...

  7. Introduction and Cultivation of Rose damascene Ⅲ in the Western Hubei%鄂西地区大马士革Ⅲ玫瑰的引种栽培

    Institute of Scientific and Technical Information of China (English)

    陈燚格; 陈芳清; 谢宗强; 樊大勇; 赵常明; 刘三峡; 印开蒲

    2012-01-01

    In order to investigate the possibility of introduction of Rosa damascene tyigintipetala in the western Hubei, a two-year introduction experiment at different sites along an attitudinal gradient was done in Xingshan, Hubei. Growth status was recorded in the first year. In the second year, photosynthesis rate (Pn), WSC, LMA, flower yield and rose oil extraction rate were measured, the phenology was recorded, too. The results showed: (1) The growth was linearly related to attitude. (2) With attitude increased, the date of leaf unfolding and flowering were later, florescence period got longer and the date of leaf-fell were earlier. (3) It began to flower in the next year of introduction, an individual plant could yield 51-517 g flowers, the average oil extraction rate in laboratory was above 0.04%. (4) Individual yield was linear related to total leaf area and WSC, but had no association with IMA and Pn.%为探讨大马士革Ⅲ玫瑰在鄂西地区引种可能性,在湖北兴山县境内选取了不同海拔梯度的试验地进行引种试验,第1年进行生长状况调查;第2年测定功能叶Pn、LMA、WSC、花产量及精油提取率,并记录其物候动态.结果显示:(1)生长状况与引种海拔线性相关;(2)随海拔的升高,展叶期、初花期逐渐后移,花期延长,落叶期提前;(3)引种第2年即开花,单株鲜花的产量在51~517 g之间,精油实验室平均提取率0.04%以上;(4)单株鲜花产量与单株总叶面积、WSC均线性相关,与LMA、功能叶Pn线性无关.

  8. Hole-transporting transistors and circuits based on the transparent inorganic semiconductor copper(I) thiocyanate (CuSCN) processed from solution at room temperature

    KAUST Repository

    Pattanasattayavong, Pichaya

    2012-12-27

    The wide bandgap and highly transparent inorganic compound copper(I) thiocyanate (CuSCN) is used for the first time to fabricate p-type thin-film transistors processed from solution at room temperature. By combining CuSCN with the high-k relaxor ferroelectric polymeric dielectric P(VDF-TrFE-CFE), we demonstrate low-voltage transistors with hole mobilities on the order of 0.1 cm2 V-1 s-1. By integrating two CuSCN transistors, unipolar logic NOT gates are also demonstrated. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Friction and wear characteristics of Al-Cu/C composites synthesized using partial liquid phase casting process

    Energy Technology Data Exchange (ETDEWEB)

    Ng, W.B.; Gupta, M.; Lim, S.C. [Department of Mechanical and Production Engineering, National University of Singapore, 10 Kent Ridge Crescent, Singapore (Singapore)

    1997-10-01

    During the sliding of aluminium alloys dispersed with graphite particulates, a layer of graphite is usually present at the sliding interface. This tribo-layer significantly reduces the amount of direct metal-to-metal contact, giving rise to low friction and a low rate of wear, making these composites useful candidate materials for anti-friction applications. Such self-lubricating composites are commonly fabricated via the squeeze casting, slurry casting or powder metallurgy route. These processes are expensive while the less-expensive conventional casting route is limited by the agglomeration of graphite particles in the composites, giving rise to poor mechanical properties. In this work, graphite particulate-reinforced Al-4.5 wt.% Cu composites with two effective graphite contents (Al-4.5 Cu/4.2 wt.% C and Al-4.5 Cu/6.8 wt.% C) were synthesized through an innovative partial liquid phase casting (rheocasting) technique, which is a modification of the conventional casting process. Unlubricated (without the use of conventional liquid lubrication) friction and wear performance of these composites as well as the un-reinforced aluminium alloy was determined using a pin-on-disk tester. The results revealed that the graphite-reinforced composites have a higher wear rate than the un-reinforced matrix alloy while their frictional characteristics are very similar within the range of testing conditions. Combining these with the information gathered from worn-surface examinations and wear-debris analysis, it is suggested that there exists a certain threshold for the amount and size of graphite particulates in these composites to enable them to have improved tribological properties. (Copyright (c) 1997 Elsevier Science B.V., Amsterdam. All rights reserved.)

  10. Optimization of thermomechanical processes in Cu-Cr-Zr lead frame alloy using neural networks and genetic algorithms

    Institute of Scientific and Technical Information of China (English)

    SU; Juanhua; LIU; Ping; DONG; Qiming; LI; Hejun

    2005-01-01

    The thermomechanical treatment process is effective in enhancing the properties of the lead frame copper alloy. In this study, an optimal pattern of the thermomechanical processes for Cu-Cr-Zr was investegated using an intelligent control technique consisting of neural networks and genetic algorithms. The input parameters of the artificial neural network (ANN) are the reduction ratio of cold rolling, aging temperature and aging time. The outputs of the ANN model are the two most important properties of hardness and conductivity. Based on the successfully trained ANN model,genetic algorithms (GA) are used to optimize the input parameters of the model and select perfect combinations of thermomechanical processing parameters and properties.The good generalization performance and optimized results of the integrated model are achieved.

  11. Investigations into alterntive substrate, absorber, and buffer layer processing for Cu(In,Ga)Se{sub 2}-based solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Tuttle, J.R.; Berens, T.A.; Keane, J. [National Renewable Energy Lab., Golden, CO (United States)] [and others

    1996-05-01

    High-performance Cu(In,Ga)Se{sub 2}(CIGS)-based solar cells are presently fabricated within a narrow range of processing options. In this contribution, alternative substrate, absorber, and buffer layer processing is considered. Cell performance varies considerably when alternative substrates are employed. These variations are narrowed with the addition of Na via a Na{sub 2}S compound. Sputtered and electrodeposited CIGS precursors and completed absorbers show promise as alternatives to evaporation. A recrystallization process is required to improve their quality. (In,Ga){sub y}Se buffer layers contribute to cell performance above 10. Further improvements in these alternatives will lead to combined cell performance greater than 10% in the near term.

  12. Hydrogen and oxygen plasma enhancement in the Cu electrodeposition and consolidation processes on BDD electrode applied to nitrate reduction

    Science.gov (United States)

    Couto, A. B.; Santos, L. C. D.; Matsushima, J. T.; Baldan, M. R.; Ferreira, N. G.

    2011-09-01

    Copper nanoparticle electrodeposition and consolidation processes were studied on boron doped diamond (BDD) electrode submitted to hydrogen and oxygen plasma treatments. The modified BDD films were applied as electrodes for nitrate electroreduction. The results showed that both treatments have a strong influence on the copper deposition and dissolution processes. For BDD treated with hydrogen plasma the copper electrodeposit was homogeneous with high particle density. This behavior was attributed to the BDD surface hydrogenation that improved its conductivity. On the other hand, the treatment with oxygen plasma was important for the copper nanoparticle consolidation on BDD surface, confirmed by the result's reproducibility for nitrate reduction. This performance may be associated with the formation of oxygen groups that can act as anchor points for Cu-clusters, enhancing the interfacial adhesion between diamond and the metal coating. The best electrochemical nitrate reduction response was obtained in acid media, where occurred the separation of the nitrate reduction process and the water reduction reaction.

  13. Effects of temporal trial-by-trial cuing on early and late stages of auditory processing: evidence from event-related potentials.

    Science.gov (United States)

    Lampar, Alexa; Lange, Kathrin

    2011-08-01

    Temporal-cuing studies show faster responding to stimuli at an attended versus unattended time point. Whether the mechanisms involved in this temporal orienting of attention are located early or late in the processing stream has not been answered unequivocally. To address this question, we measured event-related potentials in two versions of an auditory temporal cuing task: Stimuli at the uncued time point either required a response (Experiment 1) or did not (Experiment 2). In both tasks, attention was oriented to the cued time point, but attention could be selectively focused on the cued time point only in Experiment 2. In both experiments, temporal orienting was associated with a late positivity in the timerange of the P3. An early enhancement in the timerange of the auditory N1 was observed only in Experiment 2. Thus, temporal attention improves auditory processing at early sensory levels only when it can be focused selectively.

  14. Preparation of Cd(Zn)Te and CuInSe sub 2 films and devices by a two-stage process

    Energy Technology Data Exchange (ETDEWEB)

    Basol, B.M.; Kapur, V.K. (International Solar Electric Technology (ISET), Inglewood, CA (USA))

    1991-05-01

    The two-stage process was used to prepare thin films of Cd(Zn)Te and CuInSe{sub 2}. The technique involves first depositing the elemental components of the compound onto a substrate in the form of thin stacked layers and then reacting these elemental components to obtain a thin film of the desired compound. While CdTe films grown on thin CdS layers have uniform stoichiometries and sharp interfaces with the underlying CdS layers, CdZnTe films deposited onto similar substrates give rise to diffused CdZnTe-CdS interfaces because of the reactive nature of zinc. In CuInSe{sub 2} processing, the nature of the reacted compound film strongly depends on the nature of the Cu-In layers. CdS/CuInSe{sub 2} device efficiencies are also influenced by the method of deposition for the CdS window layers. (orig.).

  15. Dielectric loss, conductivity relaxation process and magnetic properties of Mg substituted Ni-Cu ferrites

    Science.gov (United States)

    Singh, Navneet; Agarwal, Ashish; Sanghi, Sujata; Khasa, Satish

    2012-08-01

    The dielectric properties, dc and ac electrical resistivities of Mg substituted Ni-Cu ferrites with general formula Ni0.5Cu0.5-xMgxFe2O4 (0.0≤x≤0.5) have been investigated as a function of frequency, temperature and composition. ac resistivity of all the samples decreases with increase in the frequency exhibiting normal ferrimagnetic behavior. The frequency dependence of dielectric loss tangent showed a maximum in between 10 Hz and 1 kHz in all the ferrites. The conductivity relaxation of the charge carriers was examined using the electrical modulus formulism, and the results indicate the presence of the non-Debye type of relaxation in the prepared ferrites. Similar values of activation energies for dc conduction and for conductivity relaxation reveal that the mechanism of electrical conduction and dielectric polarization is the same in these ferrites. A single 'master curve' for normalized plots of all the modulus isotherms observed for a given composition indicates that the distribution of relaxation time is temperature independent. The saturation magnetization and coercivity as calculated from the hysteresis loop measurement show striking dependence on composition.

  16. Studies of non-vacuum processing of Cu-chalcogenide thin films.

    Science.gov (United States)

    El Hamri, E; Meddah, M; Boulkadat, L; Elfanaoui, A; Bouabid, K; Nya, M; Portier, X; Ihlal, A

    2012-08-01

    Cu-chalcogenide thin films were prepared using a two stage method: one step electrodeposition of CuISe and CIGSe, and the sulfurisation of CISe to prepare CISSe thin films. The films were deposited on different substrates: Mo and ITO coated glass. The optimum potentials for electrodeposition of CISe and CIGSe films were respectively selected in the range -400 to -550 mV and -650 to -700 mV (vs. SCE). The electrodeposited layers were firmly adhesive. The well known chalcopyrite structure appears after annealing at 400 degrees C under Argon for CISe. The band gap value deduced from the optical measurements is close to 1 eV. To increase this value, addition of gallium in the aqueous electrolytic solution was performed. A band gap value as high as 1.26 eV was recorded on the obtained CIGSe films. Sulfurisation of CISe layers under 5% H2S/Ar atmosphere lead to a shift of the position of the principal XRD peaks indicating the substitution of selenium atoms by sulfur atoms and thus the formation of the quaternary CISSe. Optical measurements performed on this quaternary compound show that our films exhibit a band gap value scaling from 1 eV to 1.4 eV depending on the amount of sulphur incorporated into the layers during the heat treatments.

  17. Influence of process factors on shape memory effect of CuZnAl alloys

    Institute of Scientific and Technical Information of China (English)

    LIU Hai-xia; SI Nai-chao; XU Gui-fang

    2006-01-01

    Thermal cycle training of CuZnAI shape memory alloys with different transformation temperatures was carried out. The influence of different pre-strains, heat treatments and media on the shape memory effect(SME) of CuZnAl alloys with different transformation temperatures was studied by means of scanning electron microscopy(SEM) and X-ray diffractometry(XRD).Experimental results show that despite respective variation in heat treatment, medium and cycling number, the recovery rate always decreases as pre-strain increases. The decline is obvious when pre-strain is less than 2.6% but not so sharp when pre-strain exceeds 2.6%. Larger pre-strain results in more than one slip system and causes intercutting of the martensite strips among martensitic variants, then leads to the decline of SME. The SME of alloys with transformation temperatures below 347 K is larger than that of alloys beyond 361 K by 20%-40%. The recovery rate of two-step aged alloy is higher than that of step-quenched alloy by 20%-25%.During thermal cycling, the recovery rate in oil is better than that in water.

  18. Effects of Heating Rate on the Process Parameters of Superplastic Forming for Zr55Cu30Al10Ni5

    Institute of Scientific and Technical Information of China (English)

    YANG Fan; SHI Tielin; LIAO Guanglan

    2014-01-01

    We investigated the effects of heating rate on the process parameters of superplastic forming for Zr55Cu30Al10Ni5 by differential scanning calorimetry. The continuous heating and isothermal annealing analyses suggested that the temperatures of glass transition and onset crystallization are heating rate-dependent in the supercooled liquid region. Then, the time-temperature-transformation diagram under different heating rates indicates that increasing the heating rate can lead to an increase of the incubation time at the same anneal temperature in the supercooled liquid region. Based on the Arrhenius relationship, we discovered that the incubation time increases by 1.08-1.11 times with double increase of the heating rate at the same anneal temperature, and then verified it by the data of literatures and the experimental results. The obtained curve of the max available incubation time reveals that the incubation time at a certain anneal temperature in the supercooled liquid region is not infinite, and will increase with increasing heating rate until this temperature shifts out of the supercooled liquid region because of exceeding critical heating rate. It is concluded that heating rate must be an important processing parameter of superplastic forming for Zr55Cu30Al10Ni5.

  19. Effect of anions on removing Cu2+, Mn2+ and Zn2+ in electrocoagulation process using aluminum electrodes.

    Science.gov (United States)

    Hanay, Özge; Hasar, Halil

    2011-05-15

    In the present study, the performance of electrocoagulation process with aluminum electrodes in the treatment of Cu(2+), Zn(2+) and Mn(2+) containing aqueous solutions was investigated by depending on type of anion in solution, considering some operating conditions such as initial metal concentration and pH. Results obtained from synthetic wastewater showed that type of anion in solutions has a significant effect on the metal removal. The initial concentration of zinc influenced significantly the performance of electrocoagulation process as compared with the results obtained from Mn and Cu metals. Anions studied did not generate an important difference between pH variations. Best removals for three metals were achieved with increasing the pH in the presence of both anions. Total removals of copper and zinc reached almost 100% after 5 min at pH values > 7. At the end of the experiments for 35 min, the Mn removals were 85 and 80% in the presence of sulfate and chloride anions, respectively.

  20. Patterning challenges in the fabrication of 12 nm half-pitch dual damascene copper ultra low-k interconnects

    Science.gov (United States)

    Chawla, J. S.; Singh, K. J.; Myers, A.; Michalak, D. J.; Schenker, R.; Jezewski, C.; Krist, B.; Gstrein, F.; Indukuri, T. K.; Yoo, H. J.

    2014-03-01

    Earlier [1, 2] work highlighted an integrated process for electrically functional 12 nm half-pitch copper interconnects in an ultralow-k interlayer dielectric (ILD). In this paper, we focus on understanding and reducing undesired effects such as pattern asymmetry/distortion, and line undulation/ collapse. Key defect modes and possible solution paths are discussed. Line undulation can occur when the ILD feature changes shape under the stress of the sacrificial hard mask(s) (HM) during patterning, resulting in "wavy" instead of straight features. The amount of undulation is directly related to mechanical properties such as elastic modulus, residual stresses of patterned HMs and the ILD, as well as the dimensions and aspect ratio of the features. Line collapse is observed post wet-clean processing when one or more of the following is true - Insufficient ILD mechanical strength, excessive pattern aspect ratio, or non-uniform drying. Pattern asymmetry, or unequal critical dimensions (CD) of trenches defined by the same backbone, is a typical problem encountered during spacer-based pitch division. In pitch quartering (P/4), three different trench widths result from small variations in backbone lithography, spacer CD and etch bias. Symmetric patterning can be achieved through rigorous control of patterning processes like backbone definition, spacer deposition and downstream etches. Plasma-based ash and energetic metal deposition were also observed to degrade patterning fidelity of ultra low-k film, and also need to be closely managed.

  1. An investigation on supercooling directional solidification process of Cu-Ni single phase alloy

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Supercooling directional solidification (SDS) is put forward by combination of melt supercooling and conventional solidification by application of supercooling inheritance. On the self-designed SDS equipment, SDS of Cu-Ni alloy was achieved successfully. The results are as follows: (ⅰ) The primary arm spacing is about 30 m m, the growth of secondary arms are strongly suppressed. The primary arm spacing is nearly the same as LMC method (GL=25 K/mm, V=500 m m/s), the primary stems are straight, fine and completed, with an inclination angle of about 5.8o. (ⅱ) A semi-quantitative T-T model is brought forward to describe the dendrite growth rate V vs. undercooling D T. The prediction of T-T model agrees well with experimental results. The formation of fine equiaxed dendrites, transition region and dendrite region can be explained successfully by D T-V-x relation of T-T model.

  2. Electrochemical processing of high- Bi(Pb)–Sr–Ca–CuO thin films

    Indian Academy of Sciences (India)

    N V Desai; L A Ekal; D D Shivagan; S H Pawar

    2000-02-01

    Superconducting thin films of Bi(Pb)–Sr–Ca–CuO system were prepared by depositing the film onto silver substrate by d.c. electrodeposition technique with dimethyl sulphoxide bath in order to examine the effect of Pb addition to the BSCCO system. The films were deposited at the potential of – 0.8 V vs saturated calomel electrode (SCE) onto the silver substrate. The different preparative parameters such as deposition potential, deposition time were studied and optimized. These films were then oxidized electrochemically at room temperature in an alkaline (1 N KOH) solution, and also at 600°C temperature in an oxygen atmosphere. The films showed the superconducting behaviour, with values ranging between 85 K and 96 K, respectively.

  3. High-field magnetization process of granular Co-Cu alloys prepared by melt spinning

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    High solid-solubility Co15Cu35 alloys have been prepared by melt spinning and submitted to isothermal and anisothermal annealing to obtain granular alloys.The X-ray diffraction(XRD) patterns were measured to invesugate the decomposition of supersaturated solid solution induced by annealing.The atomic diffusion and structural evolution during the heat treatment were investigated.In view of the problems limiting their appllcation.the high-field magneazation curves were measured.By a fit to the high-field magnetization curves,the granuiar alloys are found hard to be magnetically saturated at the early stage of nucleation and growth.The magnetization behavior was correlaced to the annealed-induced structureal evolution and also to the magnetoresistance effect.

  4. Processing of large YBa2 Cu3Ox domains for levitation applications by a Nd1+x Ba2-x Cu3 Oy-Seeded melt-growth technique

    Science.gov (United States)

    Todt, V. R.; Sengupta, S.; Shi, Donglu; Sahm, P. R.; McGinn, P. J.; Poeppel, R. B.; Hull, J. R.

    1994-11-01

    YBa2Cu3Ox domains for levitation applications have been produced by a seeding technology that includes Nd1+x Ba2-x Cu3Oy seeds and melt-processing technologies such as conventional melt-textured growth, melt-texturing with PtO2 and Y2BaCuO5 additions, and the new solid-liquid-melt-growth technology. Large domains (˜20 mm) with high levitation forces (F1 up to 8.2 N) have been produced. The reproducibility of the results is good, and the capability of producing a large number of pellets in a single batch indicates good potential for the production of large amounts of this material.

  5. Studies on Al-Cu-Li-Mg-Ag-Zr alloy processed through vacuum induction melting (VIM) technique

    Energy Technology Data Exchange (ETDEWEB)

    Nayan, Niraj [Materials and Metallurgy Group, VSSC, Trivandrum 695022 (India)], E-mail: nirajnayan@rediffnmail.com; Govind [Materials and Metallurgy Group, VSSC, Trivandrum 695022 (India); Nair, K. Suseelan [Materials and Metallurgy Group, VSSC, Trivandrum 695022 (India); Mittal, M.C. [Materials and Metallurgy Group, VSSC, Trivandrum 695022 (India); Sudhakaran, K.N. [Materials and Metallurgy Group, VSSC, Trivandrum 695022 (India)

    2007-04-25

    A new technique of lithium addition has been adapted for the processing of Al-Cu-Li-Ag-Mg-Zr alloy, which gives more than 90% recovery of lithium throughout the billet. Processing studies on this alloy include casting, three step homogenization, to avoid incipient melting, and mechanical working particularly forging and rolling. The products in the form of sheets were subjected to various T6 (solution treatment + water quenching + aging) tempers. Mechanical properties were evaluated at room temperature and correlated with microstructure. Characterizations using optical microscope and post-fracture analysis have been carried out using Scanning electron microscope (SEM). Experimental investigation shows highest mechanical properties for the Al-1.3%Li alloy in T6 (500 deg. C/1 h + WQ + 190 deg. C/24 h) condition.

  6. Evaluating print performance of Sn-Ag-Cu lead-free solder pastes used in electronics assembly process

    Science.gov (United States)

    Mallik, S.; Bauer, R.; Hübner, F.; Ekere, N. N.

    2011-01-01

    Solder paste is the most widely used interconnection material in the electronic assembly process for attaching electronic components/devices directly onto the surface of printed circuit boards, using stencil printing process. This paper evaluates the performance of three different commercially available Sn-Ag-Cu solder pastes formulated with different particle size distributions (PSD), metal content and alloy composition. A series of stencil printing tests were carried out using a specially designed stencil of 75 μm thickness and apertures of 300×300 μm2 dimension and 500 μm pitch sizes. Solder paste printing behaviors were found related to attributes such as slumping and surface tension and printing performance was correlated with metal content and PSD. The results of the study should benefit paste manufacturers and SMT assemblers to improve their products and practices.

  7. Process Parameters Optimization for Friction Stir Welding of Pure Aluminium to Brass (CuZn30 using Taguchi Technique

    Directory of Open Access Journals (Sweden)

    Elfar O. M. R.

    2016-01-01

    Full Text Available In this research, the friction stir welding of dissimilar commercial pure aluminium and brass (CuZn30 plates was investigated and the process parameters were optimized using Taguchi L9 orthogonal array. The considered process parameters were the rotational speed, traverse speed and pin offset. The optimum setting was determined with reference to ultimate tensile strength of the joint. The predicted optimum value of ultimate tensile strength was confirmed by experimental run using optimum parameters. Analysis of variance revealed that traverse speed is the most significant factor in controlling the joint tensile strength and pin offset also plays a significant role. In this investigation, the optimum tensile strength is 50% of aluminium base metal. Metallographic examination revealed that intermetallic compounds were formed in the interface of the optimum joint where the tensile failure was observed to take place.

  8. Solution-processed highly efficient Cu2ZnSnSe4 thin film solar cells by dissolution of elemental Cu, Zn, Sn, and Se powders.

    Science.gov (United States)

    Yang, Yanchun; Wang, Gang; Zhao, Wangen; Tian, Qingwen; Huang, Lijian; Pan, Daocheng

    2015-01-14

    Solution deposition approaches play an important role in reducing the manufacturing cost of Cu2ZnSnSe4 (CZTSe) thin film solar cells. Here, we present a novel precursor-based solution approach to fabricate highly efficient CZTSe solar cells. In this approach, low-cost elemental Cu, Zn, Sn, and Se powders were simultaneously dissolved in the solution of thioglycolic acid and ethanolamine, forming a homogeneous CZTSe precursor solution to deposit CZTSe nanocrystal thin films. Based on high-quality CZTSe absorber layer, pure selenide CZTSe solar cell with a photoelectric conversion efficiency of 8.02% has been achieved without antireflection coating.

  9. Characterization of process-induced damage in Cu/low-k interconnect structure by microscopic infrared spectroscopy with polarized infrared light

    Science.gov (United States)

    Seki, Hirofumi; Hashimoto, Hideki; Ozaki, Yukihiro

    2016-09-01

    Microscopic Fourier-transform infrared (FT-IR) spectra are measured for a Cu/low-k interconnect structure using polarized IR light for different widths of low-k spaces and Cu lines, and for different heights of Cu lines, on Si substrates. Although the widths of the Cu line and the low-k space are 70 nm each, considerably smaller than the wavelength of the IR light, the FT-IR spectra of the low-k film were obtained for the Cu/low-k interconnect structure. A suitable method was established for measuring the process-induced damage in a low-k film that was not detected by the TEM-EELS (Transmission Electron Microscope-Electron Energy-Loss Spectroscopy) using microscopic IR polarized light. Based on the IR results, it was presumed that the FT-IR spectra mainly reflect the structural changes in the sidewalls of the low-k films for Cu/low-k interconnect structures, and the mechanism of generating process-induced damage involves the generation of Si-OH groups in the low-k film when the Si-CH3 bonds break during the fabrication processes. The Si-OH groups attract moisture and the OH peak intensity increases. It was concluded that the increase in the OH groups in the low-k film is a sensitive indicator of low-k damage. We achieved the characterization of the process-induced damage that was not detected by the TEM-EELS and speculated that the proposed method is applicable to interconnects with line and space widths of 70 nm/70 nm and on shorter scales of leading edge devices. The location of process-induced damage and its mechanism for the Cu/low-k interconnect structure were revealed via the measurement method.

  10. 130nm/90nm新工艺开发用的铜CMP阻挡层浆料系统%Copper CMP Barrier Slurry System for 130 nm/90 nm New Process Development

    Institute of Scientific and Technical Information of China (English)

    ChristineYe; MichaelOliver; 等

    2003-01-01

    @@ Introduction The process development of copper/low-K backends is unique in the semiconductor industry. Thereare a substantial number of alternative integrationapproaches to the dual damascene copper processthat incorporates a low-K dielectric. With the multi-plicity of integration approaches and materials, therequirements on the CMP processes are highly spe-cific to each integration scheme, in particular forwhat is labeled the second step, or copper barrierCMP step.

  11. Solution-Processed CuS NPs as an Inorganic Hole-Selective Contact Material for Inverted Planar Perovskite Solar Cells.

    Science.gov (United States)

    Rao, Haixia; Sun, Weihai; Ye, Senyun; Yan, Weibo; Li, Yunlong; Peng, Haitao; Liu, Zhiwei; Bian, Zuqiang; Huang, Chunhui

    2016-03-01

    Organic-inorganic hybrid perovskite solar cells (PSCs) have drawn worldwide intense research in recent years. Herein, we have first applied another p-type inorganic hole-selective contact material, CuS nanoparticles (CuS NPs), in an inverted planar heterojunction (PHJ) perovskite solar cell. The CuS NP-modification of indium tin oxide (ITO) has successfully tuned the surface work function from 4.9 to 5.1 eV but not affect the surface roughness and transmittance, which can effectively reduce the interfacial carrier injection barrier and facilitate high hole extraction efficiency between the perovskite and ITO layers. After optimization, the maximum power conversion efficiency (PCE) has been over 16% with low J-V hysteresis and excellent stability. Therefore, the low-cost solution-processed and stable CuS NPs would be an alternative interfacial modification material for industrial production in perovskite solar cells.

  12. Deformation behavior of Cu-12wt%AI alloy wires with continuous columnar crystals in dieless drawing process

    Institute of Scientific and Technical Information of China (English)

    LIU XueFeng; WU YuHui; XIE JianXin

    2009-01-01

    The microstructure and mechanical properties of Cu-12wt%AI alloy wires which are composed of continuous columnar crystals after dieless drawing forming at drawing speed of 1.0-1.4 mm/s and deformation temperature of 600-900℃ were analyzed,and deformation behavior of the alloy during dieless drawing forming was experimentally investigated.The results showed that in the above-mentioned conditions,recrystallization phenomenon was not found during dieless drawing forming.When a drawing speed of 1.0 mm/s was used,the grain boundaries were out of straight gradually with increasing deformation temperature from 600℃ to 900℃,and tensile strength of the dieless drawn Cu-12wt%AI alloy wires increased while elongations decreased with increasing deformation temperature.At drawing speed of 1.1-1.2 mm/s and deformation temperature of 600℃,the effect of dieless drawing forming process on the microstructure of the alloy was inconspicuous,and when drawing speed was up to 1.3-1.4 mm/s,the grain boundaries of continuous columnar crystals became zigzag while there was little effect of drawing speed of 1.1-1.4 mm/s on the elongation and tensile strength of the alloy wires.

  13. Deformation behavior of Cu-12wt%Al alloy wires with continuous columnar crystals in dieless drawing process

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The microstructure and mechanical properties of Cu-12wt%Al alloy wires which are composed of continuous columnar crystals after dieless drawing forming at drawing speed of 1.0―1.4 mm/s and deformation temperature of 600―900℃ were analyzed, and deformation behavior of the alloy during dieless drawing forming was experimentally investigated. The results showed that in the abovemen-tioned conditions, recrystallization phenomenon was not found during dieless drawing forming. When a drawing speed of 1.0 mm/s was used, the grain boundaries were out of straight gradually with increasing deformation temperature from 600℃ to 900℃, and tensile strength of the dieless drawn Cu-12wt%Al alloy wires increased while elongations decreased with increasing deformation temperature. At drawing speed of 1.1―1.2 mm/s and deformation temperature of 600℃, the effect of dieless drawing forming process on the microstructure of the alloy was inconspicuous, and when drawing speed was up to 1.3―1.4 mm/s, the grain boundaries of continuous columnar crystals became zigzag while there was little effect of drawing speed of 1.1―1.4 mm/s on the elongation and tensile strength of the alloy wires.

  14. Purification of Organic Wastewater Containing Cu2+ and Cr3+ by a Combined Process of Micro Electrolysis and Biofilm

    Institute of Scientific and Technical Information of China (English)

    李天成; 姜斌; 冯霞; 王大为; 袁绍军; 李鑫钢

    2003-01-01

    A complex process of micro electrolysis and biofilm was developed to continuously treat organic wastew-aters containing heavy metal ions such as Cu2+ and Cr3+,and the relevant purifying mechanism was also addressed. In detail,organic materials in wastewater could be consumed as nutritious source by biofilm composed of aerobes and anaerobes,However,for heavy metal ions (Cu2+,Cr3+),part was removed by electrodeposition,and some was adorbed on biofilm.In order to compare with the combined process of micro electrolysis and biofilm,the experimental data of micro electrolysis process (intermittent )or biofilm process (continuous)were provided,and the kinetic data of C6H12O6(glucose)biodegradation by cultured microbes or acclimated microbes were also obtained,These experimental results indicated that for wastewater initially consisted of C6H12O6(500 mg.L-1),Cu2+ and Cr3+(10mg.L6-1),after treatment,its concentrations of C6H12O6,Cu2+ and Cr3+ were lowered to the leve of 55-65 mg.L-1),after treatment,its concentrations of C6H12O6,Cu2+ and Cr3+ were lowered to the level of 55-65 mg.L-1,and less than 1mg.L-1,respectively,And the industrial reused water standards could be met by treated wastewater.

  15. Solution-processed inorganic copper(I) thiocyanate (CuSCN) hole transporting layers for efficient p–i–n perovskite solar cells

    KAUST Repository

    Zhao, Kui

    2015-08-27

    CuSCN is a highly transparent, highly stable, low cost and easy to solution process HTL that is proposed as a low cost replacement to existing organic and inorganic metal oxide hole transporting materials. Here, we demonstrate hybrid organic-inorganic perovskite-based p-i-n planar heterojunction solar cells using a solution-processed copper(I) thiocyanate (CuSCN) bottom hole transporting layer (HTL). CuSCN, with its high workfunction, increases the open circuit voltage (Voc) by 0.23 V to 1.06 V as compared with devices based on the well-known poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) (0.83 V), resulting in a superior power conversion efficiency (PCE) of 10.8% without any notable hysteresis. Photoluminescence measurements suggest a similar efficiency of charge transfer at HTL/perovskite interface as PEDOT:PSS. However, we observe more efficient light harvesting in the presence of CuSCN at shorter wavelengths despite PEDOT:PSS being more transparent. Further investigation of the microstructure and morphology reveals differences in the crystallographic texture of the polycrystalline perovskite film, suggesting somewhat modified perovskite growth on the surface of CuSCN. The successful demonstration of the solution-processed inorganic HTL using simple and low temperature processing routes bodes well for the development of reliable and efficient flexible p-i-n perovskite modules or for integration as a front cell in hybrid tandem solar cells.

  16. Thermocapillary flow of thin Cu-water nanoliquid film during spin coating process

    Science.gov (United States)

    Maity, Susanta

    2017-01-01

    Unsteady flow of thin Cu-water nanoliquid film over a horizontal rotating disk is studied numerically using finite difference technique under the assumption of planar interface. It is also assumed that the disk is cooling axisymmetrically from below. The effects of the nanolayer thickness and nanoparticle radius are considered for investigation. It is found that the film thinning rate decreases with increase of the nanoparticle volume fraction. It is also found that thickness of liquid decreases with increase of the thermocapillary parameter. The results show that the rate of film thinning is more for the thermal conductivity model of Yu and Choi [47] compared to the model of Maxwell [46]. It is observed that the film thinning rate increases with increase of nanolayer thickness but it decreases with the nanoparticle radius. A curve R=R_c(z,t) in R-z plane is delineated along which temperature gradient T_z is zero and positive or negative according to RR_c respectively. Furthermore, it is shown that the region for T_z>0 enlarges with increase of the nanoparticle volume fraction and the nanolayer thickness.

  17. Interface morphology and mechanical properties of Al-Cu-Al laminated composites fabricated by explosive welding and subsequent rolling process

    Science.gov (United States)

    Hoseini-Athar, M. M.; Tolaminejad, B.

    2016-07-01

    Explosive welding is a well-known solid state method for joining similar and dissimilar materials. In the present study, tri-layered Al-Cu-Al laminated composites with different interface morphologies were fabricated by explosive welding and subsequent rolling. Effects of explosive ratio and rolling thickness reduction on the morphology of interface and mechanical properties were evaluated through optical/scanning electron microscopy, micro-hardness, tensile and tensile-shear tests. Results showed that by increasing the thickness reduction, bonding strength of specimens including straight and wavy interfaces increases. However, bonding strength of the specimens with melted layer interface decreases up to a threshold thickness reduction, then rapidly increases by raising the reduction. Hardness Values of welded specimens were higher than those of original material especially near the interface and a more uniform hardness profile was obtained after rolling process.

  18. Relaxation Process of Excitonic Molecules in CuCl under the Two-Photon Resonant Excitation. II. Transverse Relaxation

    Science.gov (United States)

    Itoh, Tadashi; Katohno, Takashi; Kirihara, Toshio; Ueta, Masayasu

    1984-02-01

    Under the off-resonant excitation at the slightly higher energy side of the giant two-photon absorption band (GTA) for the direct generation of excitonic molecules (EM) in CuCl, new narrow emission bands designated as XT and XL have been found in the energy region of the MT and ML broad bands, respectively. Their photon energies increase with the decrease of the pump photon energy from the higher-energy side of the resonance and finally, at the on-resonant excitation, their bands merge into MT0 and ML0 bands, respectively, previously reported by Mita et al. Based on the detailed studies on these bands, it is found that there exists a certain kind of transverse relaxation process which acts on the EM just after their generation by the GTA and brings about the X emission as a hot luminescence.

  19. Investigation of microstructure and mechanical properties of Cu/ZnO nano composite produced by ARB process

    Science.gov (United States)

    Shahhoseyni, M.; Qods, F.

    2014-08-01

    In this study, ARB process was used to produce Cu/Nano ZnO composite and samples were subjected up to six ARB cycles. Microstructural and mechanical properties of the composite within different ARB cycles were investigated by scanning electron microscopy (SEM) and tensile and micro hardness tests. The results showed that increasing the number of cycles, not only helped the distribution of reinforcing Nano-reinforcement in the matrix, but also improved the initial bonding strength, so that at final cycles, structural integration was achieved. Mechanical experiments also showed that increasing the number of ARB cycles, increased yield and ultimate strengths as well as micro hardness. However, elongation decreased up to second cycle and then increased by later final cycles. SEM studies of the fracture surfaces after the tensile test showed that the fracture mechanism of the composite was shear ductile rupture.

  20. Multilayer Transparent Top Electrode for Solution Processed Perovskite/Cu(In,Ga)(Se,S)2 Four Terminal Tandem Solar Cells.

    Science.gov (United States)

    Yang, Yang Michael; Chen, Qi; Hsieh, Yao-Tsung; Song, Tze-Bin; Marco, Nicholas De; Zhou, Huanping; Yang, Yang

    2015-07-28

    Halide perovskites (PVSK) have attracted much attention in recent years due to their high potential as a next generation solar cell material. To further improve perovskites progress toward a state-of-the-art technology, it is desirable to create a tandem structure in which perovskite may be stacked with a current prevailing solar cell such as silicon (Si) or Cu(In,Ga)(Se,S)2 (CIGS). The transparent top electrode is one of the key components as well as challenges to realize such tandem structure. Herein, we develop a multilayer transparent top electrode for perovskite photovoltaic devices delivering an 11.5% efficiency in top illumination mode. The transparent electrode is based on a dielectric/metal/dielectric structure, featuring an ultrathin gold seeded silver layer. A four terminal tandem solar cell employing solution processed CIGS and perovskite cells is also demonstrated with over 15% efficiency.

  1. Acid etching process for fabrication of Bi2Sr2CaCu2O8+x stack

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jie; CHEN Jian; WU JingBo; KANG Lin; XU WeiWei; WU PeiHeng

    2007-01-01

    We adopted a new method, acid etching process, to fabricate the intrinsic Josephson junctions based on the Bi2Sr2CaCu2O8+x single crystals. By soaking the crystals into the dilute hydrochloric acid, we fabricated a junction stack successfully, and meantime made the surrounding area insulated. A certain concentration of hydrochloric acid was used to maintain the roughness of the modified layer. The current-voltage characteristic was achieved through the four terminal measurement. We could control the junctions' number by changing the concentration and the soaking time. We also found that the thickness of the stack was equal to the average height of the insulation layer. Such a simple, convenient and controllable fabrication method with a high yield might widen the applications of the intrinsic Josephson junctions.

  2. Processing and property assessment of NiTi and NiTiCu shape memory actuator springs

    Energy Technology Data Exchange (ETDEWEB)

    Grossmann, C.; Frenzel, J.; Depka, T.; Oppenkowski, A.; Somsen, C.; Neuking, K.; Theisen, W.; Eggeler, G. [Institut fuer Werkstoffe, Ruhr-Universitaet Bochum (Germany); Sampath, V. [Institut fuer Werkstoffe, Ruhr-Universitaet Bochum (Germany); Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, Chennai (India)

    2008-08-15

    Among the multifarious engineering applications of NiTi shape memory alloys (SMAs), their use in actuator applications stands out. In actuator applications, where the one-way effect (1WE) of NiTi SMAs is exploited, SM components are often applied as helical coil springs. Ingots are generally used as starting materials for the production of springs. But before SM actuator springs can be manufactured, the processing of appropriate wires from NiTi ingots poses a challenge because cold and hot working of NiTi SMAs strongly affect microstructure, and it is well known that the functional properties of NiTi SMAs are strongly dependent on their microstructure. The objective of the present paper is therefore to produce binary Ni{sub 50}Ti{sub 50} and ternary Ni{sub 40}Ti{sub 50}Cu{sub 10} SMA actuator springs, starting from ingots produced by vacuum induction melting. From these ingots springs are produced using swaging, rolling, wire drawing and a shape-constraining procedure in combination with appropriate heat treatments. The evolution of microstructure during processing is characterized and the mechanical properties of the wires prior to spring-making are documented. The mechanical and functional characteristics of the wires are investigated in the stress-strain-temperature space. Finally, functional fatigue testing of actuator springs is briefly described and preliminary results for NiTi and NiTiCu actuator springs are reported. (Abstract Copyright [2008], Wiley Periodicals, Inc.) [German] NiTi-Formgedaechtnislegierungen (FGL) zeichnen sich durch eine hohe Attraktivitaet fuer verschiedene Aktorik-Anwendungen aus. Dabei werden FGL haeufig in Form von zylindrischen Federn verwendet, wobei der Einwegeffekt genutzt wird. Die Herstellung von solchen Aktor-Federn ist jedoch keinesfalls trivial. Sowohl die Herstellung von geeignetem Drahtmaterial als auch die Formgebungsbehandlung stellen in gewisser Weise eine Herausforderung dar. Die funktionellen Eigenschaften von Ni

  3. Structural evolution, thermomechanical recrystallization and electrochemical corrosion properties of Ni-Cu-Mg amorphous coating on mild steel fabricated by dual-anode electrolytic processing

    Science.gov (United States)

    Abdulwahab, M.; Fayomi, O. S. I.; Popoola, A. P. I.

    2016-07-01

    The electrolytic Ni-Cu based alloy coating with admixed interfacial blend of Mg have been successfully prepared on mild steel substrate by dual anode electroplating processes over a range of applied current density and dwell time. The electrocodeposition of Ni-Cu-Mg coating was investigated in the presence of other bath additives. The influence of deposition current on surface morphology, adhesion behavior, preferred crystal orientation, surface topography and electrochemical activity of Ni-Cu-Mg alloy coating on mild steel were systematically examined. The thermal stability of the developed composite materials was examined via isothermal treatment. Scanning electron microscope equipped with EDS, X-ray diffraction, Atomic force microscope, micro-hardness tester and 3 μmetrohm Potentiostat/galvanostat were used to compare untreated and isothermally treated electrocodeposited composite. The induced activity of the Ni-Cu-Mg alloy changed the surface modification and results to crystal precipitation within the structural interface by the formation of Cu, Ni2Mg3 phase. The obtained results showed that the introduction of Mg particles in the plating bath generally modified the surface and brings an increase in the hardness and corrosion resistance of Ni-Cu-Mg layers fabricated. Equally, isothermally treated composites demonstrated an improved properties indicating 45% increase in the micro-hardness and 79.6% corrosion resistance which further showed that the developed composite is thermally stable.

  4. Preparation of a core-shell magnetic ion-imprinted polymer via a sol-gel process for selective extraction of Cu(II) from herbal medicines.

    Science.gov (United States)

    He, Huan; Xiao, Deli; He, Jia; Li, Hui; He, Hua; Dai, Hao; Peng, Jun

    2014-05-21

    A novel magnetic surface ion-imprinted polymer (c-MMWCNTs-SiO2-IIP) was synthesized for the first time using magnetic CNTs/Fe3O4 composites (c-MMWCNTs) as the core, 3-ammonium propyltriethoxysilane (APTES) as the functional monomer, tetraethylorthosilicate (TEOS) as the cross-linker and Cu(II) as the template. c-MMWCNTs-SiO2-IIP was evaluated for selective extraction of Cu(II) from herbal medicines via a magnetic solid phase extraction (M-SPE) procedure. One factor affecting the separation and preconcentration of the target heavy metal was pH. Under the optimized experimental conditions, the adsorption kinetics and adsorption capacity of c-MMWCNTs-SiO2-IIP toward Cu(II) were estimated. The results indicated that the adsorption mechanism corresponds to a pseudo-second order adsorption process, with a correlation coefficient (R(2)) of 0.985 and a maximum adsorption capacity of 42.2 mg g(-1). The relative selectivity factor (β) values of Cu(II)/Zn(II) and Cu(II)/Pb(II) were 38.5 and 34.5, respectively. c-MMWCNTs-SiO2-IIP, combined with flame atomic absorption spectrometry, was successfully applied in the extraction and detection of Cu(II) in herbal medicine, with high recoveries ranging from 95.6% to 108.4%.

  5. Processing and study of the wear and friction behaviour of discrete graded Cu hybrid composites

    Indian Academy of Sciences (India)

    T Ram Prabhu

    2015-06-01

    Discrete functionally graded composites are the novel composites which have high potential in the brake friction material applications. In this paper, we have prepared discrete functional graded Cu/10%SiC/20%graphite(Gr)/10%boron nitride (h-BN) hybrid composites by the layer stacking compaction and pressure sintering techniques.We have considered two types of composites based on h-BN particle sizes. The size ranges of h-BN used were 140–180 and 3–25 m. The friction and wear properties of the composites were evaluated in a laboratory scale brake inertial dynamometer at low (5, 10 m s−1) and high sliding speeds (30, 35 m s−1) and, high braking load (2000 N) conditions. In addition, we have performed microstructure characterization, density, hardness and flexural strength measurements.Wear surface morphology studies were also carried out using stereoscope and scanning electron microscope. Our experiments lead to the following important results: (1) the large size h-BN particle improves the densification of the hybridized composite layer and provides higher wear resistance and better braking performance at all sliding speeds, (2) the wear loss (by mass) and the stopping distance/time increase with sliding speeds due to the increase in the braking energy, (3) at low sliding speeds (5, 10 m s−1), abrasive wear is the main wear mechanism, whereas many different wear mechanisms (delamination, oxidation, abrasive) are cooccuring at higher sliding speeds (30, 35 m s−1), (4) the mechanical properties (flexural strength and surface hardness) of composites are not affected by the h-BN particle size, (5) the incorporation of copper layer in the discrete layer structure deflects and arrests the crack at the copper/composite layer interface, thus improving the fracture resistance in addition to improving the bulk thermal conductivity.

  6. Optimization of Post-selenization Process of Co-sputtered CuIn and CuGa Precursor for 11.19% Efficiency Cu(In, Ga)Se2 Solar Cells

    Science.gov (United States)

    Cheng, Ke; Han, Kaikai; Kuang, Zhongcheng; Jin, Ranran; Hu, Junxia; Guo, Longfei; Liu, Ya; Lu, Zhangbo; Du, Zuliang

    2017-04-01

    In this work, CuInGa alloy precursor films are fabricated by co-sputtering of CuIn and CuGa targets simultaneously. After selenization in a tube-type rapid thermal annealing system under a Se atmosphere, the Cu(In, Ga)Se2 (CIGS) absorber layers are obtained. Standard soda lime glass (SLG)/Mo/CIGS/CdS/i-ZnO/ITO/Ag grid structural solar cells are fabricated based on the selenized CIGS absorbers. The influences of selenization temperatures on the composition, crystallinity, and device performances are systematically investigated by x-ray energy dispersive spectroscopy, x-ray diffraction, Raman spectroscopy, and the current density-voltage ( J- V) measurement. It is found that the elemental ratio of Cu/(In + Ga) strongly depends on the selenization temperatures. Because of the appropriate elemental ratio, a 9.92% conversion efficiency is reached for the CIGS absorber selenized at 560°C. After the additional optimization by pre-annealing treatment at 280°C before the selenization, a highest conversion efficiency of 11.19% with a open-circuit ( V oc) of 456 mV, a short-circuit ( J sc) of 40.357 mA/cm2 and a fill factor of 60.82% without antireflection coating has been achieved. Above 13% efficiency improvement was achievable. Our experimental findings presented in this work demonstrate that the post-selenization of co-sputtered CuIn and CuGa precursor is a promising way to fabricate high quality CIGS absorbers.

  7. Effects of electronic relaxation processes on vibrational linewidths of adsorbates on surfaces: The case of CO/Cu(100)

    Science.gov (United States)

    Novko, D.; Alducin, M.; Blanco-Rey, M.; Juaristi, J. I.

    2016-12-01

    We investigate nonadiabatic effects for the vibrational stretch mode of the CO molecule adsorbed on the top site of the Cu(100) surface. By studying the long-wavelength (q ≈0 ) imaginary and real parts of the density functional theory based phonon self-energy due to the electron-phonon coupling Πλ we obtain the phonon linewidth and the frequency renormalization of the CO stretch mode, respectively. To simulate electronic scattering processes that lead to further damping of the phonon modes we include a phenomenological damping in the phonon self-energy, as well as in the single-electron spectral function that enters Πλ, through the momentum distribution function. For the specific case of electron-impurity scattering we explicitly show how this process opens the indirect intraband channel and broadens the linewidth of the CO stretch mode. To emphasize the importance of accounting for electronic scattering processes we compare the phonon linewidths in the clean noninteracting limit (infinite electron lifetime) and when electronic scattering processes are phenomenologically included (finite electron lifetime) with available experimental data. We find that the agreement with experiments is improved in the latter case.

  8. Preparation of Cu2Sn3S7 Thin-Film Using a Three-Step Bake-Sulfurization-Sintering Process and Film Characterization

    Directory of Open Access Journals (Sweden)

    Tai-Hsiang Lui

    2015-01-01

    Full Text Available Cu2Sn3S7 (CTS can be used as the light absorbing layer for thin-film solar cells due to its good optical properties. In this research, the powder, baking, sulfur, and sintering (PBSS process was used instead of vacuum sputtering or electrochemical preparation to form CTS. During sintering, Cu and Sn powders mixed in stoichiometric ratio were coated to form the thin-film precursor. It was sulfurized in a sulfur atmosphere to form CTS. The CTS film metallurgy mechanism was investigated. After sintering at 500°C, the thin film formed the Cu2Sn3S7 phase and no impurity phase, improving its energy band gap. The interface of CTS film is continuous and the formation of intermetallic compound layer can increase the carrier concentration and mobility. Therefore, PBSS process prepared CTS can potentially be used as a solar cell absorption layer.

  9. Latent inhibition of cued fear conditioning: an NMDA receptor-dependent process that can be established in the presence of anisomycin.

    Science.gov (United States)

    Lewis, Michael C; Gould, Thomas J

    2004-08-01

    Much of the research examining the biological basis for long-term memories has focused on mechanisms that support the formation of conditioned associations. Less information is available on biological mechanisms which underlie processes that modify the strength of conditioned associations. Latent inhibition is a phenomenon by which pre-exposure to a to-be-conditioned stimulus (CS) weakens subsequent conditioning of that CS to an unconditioned stimulus (US). Here we report that latent inhibition of cued fear conditioning is dependent on NMDA receptor activation. MK-801 (1 mg/kg), an NMDA receptor antagonist, abolished latent inhibition of cued fear conditioning. This dose of MK-801 administered before training did not disrupt cued fear conditioning. Conversely, anisomycin (150 mg/kg), a protein synthesis inhibitor, had no effect on latent inhibition of cued fear conditioning when administered 20 min before, immediately after, or 2, 4, 6, or 8 h after CS pre-exposure. Furthermore, continuous anisomycin administration (50 mg/kg, administered every 2 h for 6 h starting 20 min prior to pre-exposure) did not disrupt latent inhibition of cued fear conditioning. In addition, anisomycin had no effect on a long-lasting version of latent inhibition of cued fear conditioning that was maintained over a 7-day interval. Anisomycin administered before training, however, disrupted learning of the CS-US association. These findings suggest that latent inhibition of cued fear conditioning is a long-lasting NMDA receptor-dependent process that can develop during the inhibition of protein synthesis.

  10. An eco-friendly and inexpensive solvent for solution processable CuSCN as a hole transporting layer in organic solar cells

    Science.gov (United States)

    Chaudhary, Neeraj; Chaudhary, Rajiv; Kesari, J. P.; Patra, Asit

    2017-07-01

    During past few years, significant research on solution-processable deposition of copper(I)thiocyanate (CuSCN) as an efficient hole transporting layer (HTL) for excitonic solar cells have been successfully reported. Surprisingly, till now only two solvents diisopropyl sulfide and diethyl sulfide are known which have been used for CuSCN film deposition as a HTL for device fabrication. Here, we have used eco-friendly and inexpensive solvent dimethyl sulfoxide (DMSO) for solution processed thin film deposition of CuSCN for organic solar cells. The photovoltaic devices were fabricated using two different donor polymers PCDTBT and PTB7 blended with PC71BM as an acceptor material with device structure of ITO/CuSCN/active layer/Al. The power conversion efficiency (PCE) based on CuSCN using DMSO as a deposition solvent have been achieved up to 4.20% and 3.64% respectively, with relative higher fill factor (FF) as compared to previously reported values in literature. The resultant HTLs were characterized by UV-vis-NIR spectroscopy, X-ray diffraction (XRD), scanning electron microscope (SEM) and atomic force microscope (AFM) for better understanding.

  11. Bonding Be to Cu alloys using a proprietary Brush Wellman process and new results for bonding Be to AlBeMet

    Energy Technology Data Exchange (ETDEWEB)

    Dombrowski, D.E. [Brush Wellman Inc., Cleveland, OH (United States)

    1998-01-01

    A novel process has been investigated for bonding of beryllium to copper alloys. The process is compatible with current manufacturing capabilities and can be readily scaled up from laboratory to production scale. The effect of process variations on the bond are shown. Also shown are several new approaches for direct bonding of beryllium to an AlBeMet interlayer. Bond strengths of Be/AlBeMet 162/Cu alloy couples are presented. (author)

  12. PREPARATION OF ULTRA-FINE SUPERCONDUCTING YBa2Cu3O7-x POWDERS BY GEL COMBUSTION PROCESS%凝胶燃烧法制备超细YBa2Cu3O7-x超导粉末

    Institute of Scientific and Technical Information of China (English)

    郭建栋; 徐晓林; 王永忠; 张炎; 刘达颐; 石磊

    2005-01-01

    The ultra-fine superconducting YBa2Cu3O7-x powders were prepared by means of the gel combustion process using nitrates of Y, Ba and Cu as the starting materials and citric acid as the fuel. The resulting particle size and its superconducting properties is dependent on the nature of the auto-ignition reaction, which in turn depends upon the citrate-nitrate ratio in the gel. An attempt to determine the optimal citrate-nitrate ratio has been made in order to obtain pure, homogeneous and reasonably fine YBCO superconductor. In our experiments we found the best fuel-oxidant molar ratio to be 0.5.%纳米级细度的YBa2Cu3O7-x超导粉末有可能在第二代超导带材的研制中得到应用.超细YBa2Cu3O7-x超导粉末已经通过凝胶燃烧法制备成功.使用的起始物质是钇、钡、铜的硝酸盐以及作为燃烧剂的柠檬酸.产物颗粒的尺寸大小及其超导性能依赖于自燃过程的情况,而自燃过程又与凝胶中柠檬酸盐-硝酸盐的YBa2Cu3O7-x超导粉末.在本实验中我们发现最好的燃烧剂-氧化剂摩尔比为0.5.

  13. Reactive magnetron co-sputtering of Cu(In,Ga)Se{sub 2} absorber layers by a 2-stage process: Role of substrate type and Na-doping

    Energy Technology Data Exchange (ETDEWEB)

    Schulte, Jonas; Harbauer, Karsten; Ellmer, Klaus, E-mail: ellmer@helmholtz-berlin.de

    2015-05-01

    By simultaneous sputtering from metallic CuGa and In targets in an Ar:H{sub 2}Se atmosphere onto heated substrates, single phase and well crystallized Cu(In,Ga)Se{sub 2} thin films can be directly deposited in a single process step. However, the preparation of Cu-poor films, which are needed for high solar cell efficiencies, is impeded by the re-evaporation of excess indium, which occurs readily at moderate substrate temperatures in the range of 400 °C to 500 °C. Therefore, a significant In-excess is necessary during the second deposition stage in order to transform the final film composition into the desired Cu-poor regime ([Cu]/([In] + [Ga]) < 0.95). Higher open circuit voltages and efficiencies are achieved for absorbers produced with an intermediate Cu-rich composition and/or by using Na containing precursor films (NaF or Mo:Na). A best cell efficiency of 12.9% is achieved, which demonstrates the high potential of the investigated reactive magnetron sputtering process for solar cell manufacturing, as it is well suited for large-area, industrial applications. - Highlights: • Reactive sputtering in Ar:H{sub 2}Se allows the use of easy to fabricate targets. • Absorber quality can be improved by a 2-stage process. • The best cell has an efficiency of 12.9%. • Na-doping by NaF or Mo:Na precursors enhances the V{sub oc}.

  14. Treatment of phenol wastewater by microwave-induced ClO2-CuOx/Al2O3 catalytic oxidation process

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The catalyst of CuOx/Al2O3 was prepared by the dipping-sedimentation method using γ-Al2O3 as a carrier. CuO and Cu2O were loaded on the surface of γ-Al2O3, characterized by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). In the presence of CuOx/Al2O3, the microwave-induced chlorine dioxide (ClO2) catalytic oxidation process was conducted for the treatment of synthetic wastewater containing 100 mg/L phenol. The relationships between removal percentage and initial ClO2 concentration, catalyst dosage, microwave power, contact time, initial phenol concentration and pH were investigated and the results showed that microwave-induced ClO2-CuOx/Al2O3 process could effectively degrade contaminants in a short reaction time with a low oxidant dosage, extensive pH range. Under a given condition (ClO2 concentration 80 mg/L, microwave power 50 W, contact time 5 min, catalyst dosage 50 g/L, pH 9), phenol removal percentage approached 92.24%, corresponding to 79.13% of CODCr removal. The removal of phenol by microwave-induced ClO2-CuOx/Al2O3 catalytic oxidation process was a complicated non-homogeneous solid/water reaction, which fitted pseudo-first-order by kinetics. Compared with traditional ClO2 oxidation, ClO2 catalytic oxidation and microwave-induced ClO2 oxidation, microwave-induced ClO2 catalytic oxidation system could significantly enhance the degradation efficiency. It provides an effective technology for the removal of phenol wastewater.

  15. Efficiency loss of thin film Cu(InxGa1-x)Se(S) solar panels by lamination process

    Science.gov (United States)

    Xu, Li

    2017-04-01

    Efficiency loss of thin film Cu(InxGa1-x)Se(S) (CIGS) solar panels by lamination process has been compromising the final output power in commercial products of solar modules, but few reports have been published on such issue, as the majority of the investigation is focused on the efficiency at the circuit level, i.e., before lamination process. In this paper, we studied the effect of lamination process to the efficiency loss of thin film CIGS solar panels. It was observed that the fill factor degradation dominated the efficiency loss with the small change of Voc and Jsc. Experiments showed that neither the temperature nor the pressure, nor the two combined in the lamination process is the root cause of the efficiency loss; instead, the ethylene vinyl acetate (EVA) layer as the encapsulation material which directly contacts the solar cell devices was the major factor responsible for the efficiency loss. It was found that the gel content of the cured EVA film after lamination was highly correlated to the efficiency loss. The higher the gel content, the higher the efficiency loss. The mismatch of coefficient of thermal expansion between the EVA film and the CIGS thin film resulted in compressive stress in the device layer after lamination process. The compressive stress is speculated to affect the lattice defects, but need to be confirmed with the measurement of capacitance voltage (CV) and drive level capacitance profiling (DLCP). Three-day sun soak was then carried out and it was observed that the fill factor recovered significantly and so did the efficiency. Experiments also showed that there was no impact of chemical erosion on the front electrode of transparent conductive oxide (TCO) films by chemicals released from the EVA films during lamination.

  16. Kinetic study of the sorption process with Cu(II ions on clinoptilolite and analcime. Effects of temperature and particle size

    Directory of Open Access Journals (Sweden)

    CLAUDIA COBZARU

    2009-05-01

    Full Text Available The sorption process of the Cu(II ions on the clinoptilolite and analcime containing volcanic tuff was studied at different temperatures like 40, 60 and 80 °C. The effects of temperature and a particle size on the sorption capacity of the used zeolites were analysed.

  17. Optimisation of the solution heat treatment of Rheo-processed Al-Cu-Mg-(Ag) Alloys A206 and A201

    CSIR Research Space (South Africa)

    Masuku, EP

    2009-06-01

    Full Text Available HEAT TREATMENT OF RHEO- PROCESSED Al-Cu-Mg (Ag) ALLOYS A206 AND A201 E.P Masuku1, a, H. Möller1, b,R. Knutsen2,c L. Ivanchev1, d, G. Govender1, e 1CSIR: Materials Science and Manufacturing, P.O. Box 395, Pretoria, 0001 South Africa 2UCT...

  18. Microstructural and hardness gradients in Cu processed by high pressure surface rolling

    DEFF Research Database (Denmark)

    He, Q. Y.; Zhu, X.-M.; Mei, Q. S.

    2017-01-01

    in the topmost surface to the microscale in the bulk. The hardness varies from 1.37 GPa at the topmost surface to about 0.6 GPa in the coarse-grained matrix. The results of the investigation demonstrate that the HPSR process shows good potential for the generation of thick gradient microstructures on the surface...

  19. Fabrication of Surface Level Cu/SiCp Nanocomposites by Friction Stir Processing Route

    Directory of Open Access Journals (Sweden)

    Cartigueyen Srinivasan

    2015-01-01

    Full Text Available Friction stir processing (FSP technique has been successfully employed as low energy consumption route to prepare copper based surface level nanocomposites reinforced with nanosized silicon carbide particles (SiCp. The effect of FSP parameters such as tool rotational speed, processing speed, and tool tilt angle on microstructure and microhardness was investigated. Single pass FSP was performed based on Box-Behnken design at three factors in three levels. A cluster of blind holes 2 mm in diameter and 3 mm in depth was used as particulate deposition technique in order to reduce the agglomeration problem during composite fabrication. K-type thermocouples were used to measure temperature histories during FSP. The results suggest that the heat generation during FSP plays a significant role in deciding the microstructure and microhardness of the surface composites. Microstructural observations revealed a uniform dispersion of nanosized SiCp without any agglomeration problem and well bonded with copper matrix at different process parameter combinations. X-ray diffraction study shows that no intermetallic compound was produced after processing. The microhardness of nanocomposites was remarkably enhanced and about 95% more than that of copper matrix.

  20. Flexible Cu(In,Ga)Se2 Thin-Film Solar Cells on Polyimide Substrate by Low-Temperature Deposition Process

    Institute of Scientific and Technical Information of China (English)

    ZHANG Li; HE Qing; JIANG Wei-Long; LI Chang-Jian; SUN Yun

    2008-01-01

    The electrical and structural properties of polycrystalline Cu(In,Ga)Se2 films grown on polyimide (PI) substrates below 400℃ via one-stage and three-stage co-evaporation process have been investigated by x-ray diffraction spectra (XRD),scanning electron microscopy (SEM) and Hall effect measurement.As shown by XRD spectra,the stoichiometric CIGS films obtained by one-stage process exhibit the characteristic diffraction peaks of the (In0.68Ga0.32)2Se3 and Cu(In0.7Ga0.3)2Se.It is also found that the film structures indicate more columnar and compact than the three-stage process films from SEM images.The stoichiometric CIGS films obtained by three-stage process exhibit the coexistence of the secondary phase of (In0.68Ga0.32)2Se3,Cu2-xSe and Cu(In0.7Ga0.3)2Se.High net carrier concentration and sheet conductivity are also observed for this kind of film,related to the presence of Cu2-xSe phase.As a result,when the CIGS film growth temperature is below 400℃,the three-stage process is inefficient for solar cells.By using the one-stage co-evaporation process,the flexible CIGS solar cell on a PI substrate with the best conversion efficiency of 6.38% is demonstrated (active area 0.16cm2).

  1. In Situ Synthesis of Al-Si-Cu Alloy During Brazing Process and Mechanical Property of Brazing Joint

    OpenAIRE

    LONG Wei-min; LU Quan-bin; He, Peng; XUE Song-bai; Wu, Ming-Fang; Xue, Peng

    2016-01-01

    The Al-Si-Cu alloy system is considered to be a promising choice of filler metal for aluminium alloys brazing due to its high strength and low melting point. The greatest obstacle is its lack of plastic forming ability and being difficult to be processed by conventional methods. This disadvantage is ascribed to the considerable amount of brittle CuAl2 intermetallic compound which forms when alloy composition is around the ternary eutectic point. In order to overcome this deficiency, authors o...

  2. Optoelectronic properties of Cu(In,Ga)(S,Se){sub 2} thin film solar obtained from varied chalcogenization processes

    Energy Technology Data Exchange (ETDEWEB)

    Knecht, Robin; Knipper, Martin; Riedel, Ingo; Parisi, Juergen [Energy and Semiconductor Research Laboratory, Department of Physics, University of Oldenburg (Germany)

    2010-07-01

    Thin film solar cells made of the chalcopyrite compound semiconductor Cu(In,Ga)(S,Se){sub 2} (CIGSSe) exhibit strong potential for achieving high efficiency at relatively low production costs. While large scale production of CIGSSe-modules has been launched in different companies the transfer of high laboratory cell efficiencies to the module scale is still a major challenge. In order to improve module efficiencies optimisation of the large scale production process presents a major issue. In this work the influence of chalcogenization (selenisation and sulfurisation) parameter variation on the device characteristics was studied using temperature and illumination dependent current-voltage profiling, external quantum efficiency measurements as well as temperature dependent capacitance-voltage measurements. From these measurements we derived important characteristics of the light absorber like activation energy of the recombination current, estimation of the absorber band gap as well as the doping concentration along with the diffusion potential. These studies were completed by defect spectroscopy for analysis of defect formation in the absorber material. The results obtained from these investigations are compared for samples exposed to different conditions of the chalcogenization process.

  3. Microstructure Evolution and Hardness of an Ultra-High Strength Cu-Ni-Si Alloy During Thermo-mechanical Processing

    Science.gov (United States)

    Lei, Q.; Li, Z.; Hu, W. P.; Liu, Y.; Meng, C. L.; Derby, B.; Zhang, W.

    2016-07-01

    Microstructure evolution and hardness changes of an ultra-high strength Cu-Ni-Si alloy during thermo-mechanical processing have been investigated. For hot-compressive deformation specimens, dynamic recrystallization preferentially appeared on deformation bands. As deformation temperature increased from 750 to 900 °C, elongated grains with the Cubic texture {001} were substituted by recrystallized grains with Copper texture {112} . For the samples having undergone cold rolling followed by annealing, static recrystallization preferentially occurred in the deformation bands, and then complete recrystallization occurred. Goss, Cubic, and Brass textures remained after annealing at 600 and 700 °C for 1 h; R texture {111} and recrystallization texture {001} were formed in samples annealed at 800 and 900 °C for 1 h, respectively. For samples processed under multi-directional forging at cryogenic temperature, the hardness was increased as a result of work hardening and grain refinement strengthening. These were attributed to the formation of equiaxed sub-grain structures and a high dislocation density.

  4. Influence of Temperature on Mechanical Behavior During Static Restore Processes of Al-Zn-Mg-Cu High Strength Aluminum Alloy

    Directory of Open Access Journals (Sweden)

    ZHANG Kun

    2017-06-01

    Full Text Available Flow stress behaviors of as-cast Al-Zn-Mg-Cu high strength aluminum alloy during static restore processes were investigated by: Isothermal double-pass compression tests at temperatures of 300-400℃, strain rates of 0.01-1 s-1, strains of 33% +20% with the holding times of 0~900 s after the first pass compression. The results indicate that the deformation temperature has a dramatical effect on mechanical behaviors during static restore processes of the alloy. (1 At 300 ℃ and 330 ℃ lower temperatures, the recovery during the deformation is slow, and deformation energy stored in matrix is higher, flow stresses at the second pass deformation decreased during the recovery and recrystallization, and the stress softening phenomena is observed. Stress softening is increased with the increasing holding time; Precipitation during the holding time inhibites the stress softening. (2 At 360 ℃ and 400 ℃ higher temperatures, the recovery during deformation is rapid, and deformation energy stored in matrix is lower. Solid solubility is higher after holding, so that flow stress at the second pass deformation is increased, stress hardening phenomena is observed. Stress hardening decreased with the increasing holding time duo to the recovery and recrystallization during holding period at 360 ℃; Precipitation during holding also inhibited the stress softening. However, Stress hardening remains constant with the increasing holding time duo to the reasanenal there are no recovery and recrystallization during holding period at 400 ℃.

  5. Development of novel processes for Cu concentrates without producing sulfuric acid; Hiryusan hasseigata no atarashii doshigen shori gijutsu no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Awakura, Y.; Hirato, T. [Kyoto University, Kyoto (Japan)

    1997-02-01

    Studies are conducted to develop a new wet method for copper concentrates to replace the conventional dry smelting method for the settlement of problems involving the processing of impurities for environmental protection. A specimen of pyrites polycrystals is subjected to leaching at 80 {degree}C in a strongly acidic cupric solution. Findings are that the element sulfur generated in this process does not impede leaching and only approximately 4% of the sulfur is oxidized into sulfur ions; that the presence of more than 2g/liter of bromide ions produced during bromine-aid leaching of gold changes the structure of sulfur for the inhibition of leaching; that circulation of a bromine-containing leaching liquid is not desired since even a small amount of approximately 0.02mol/liter inhibits the leaching rate. Controlled potential electrolysis is performed for the anode in an acid solution containing CuCl, NaCl, and NaBr, for the observation of oxidation/reduction potentials predicted by Nernst`s equation. It is then disclosed that bromine is more effective than chlorine in gold leaching and that the solution potential during leaching agent regeneration enables the monitoring of solution constitution. 2 refs.

  6. Effect of ammonium hydroxide on preparation process of YBa2Cu3O7-x superconductor by sol gel method

    Directory of Open Access Journals (Sweden)

    H Arabi

    2006-09-01

    Full Text Available  In this paper the effect of ammonium hydroxide addition to the solution of metallic oxide on sol gel preparation process of YBCO is studied with differential thermal analysis, thermal graviometry and X-ray diffraction. Two samples with and without ammonium hydroxide. Ammonium hydroxide prevents both barium nitrate precipitate during the gel preparation and also unwanted reaction as well as increasing homogeneous product. After drying the gel, the samples heated up to 1050°C in DTA apparatus in order to find more accurate the type and the temperature of reaction during the preparation process. After the initial reactions in the samples, Y2Cu2O5 and 123 phases are created in the range of 780-840°C and then the 123 phase is strengthened at 900-950°C. As shown in X-ray data, 123 was the only phase after this range. In addition ammonium hydroxide support and increase the creation of 123 phase at lower temperature.

  7. L-cystine-Assisted Growth and Mechanism of CuInS2 Nanocrystallines via Solvothermal Process

    Science.gov (United States)

    Liu, Hai-Tao; Zhong, Jia-Song; Liu, Bing-Feng; Liang, Xiao-Juan; Yang, Xin-Yu; Jin, Huai-Dong; Yang, Fan; Xiang, Wei-Dong

    2011-05-01

    L-cystine is successfully used as a kind of sulfur source to grow CuInS2 nanocrystallines at 200° C for 18 h in a mixed solution made of 20 mL ethylenediamine and 20 mL distilled water. The diameter of the CuInS2 nanocrystallines ranges from 300 to 500 nm. The structure of nanocrystallines is determined to be of the tetragonal phase of CuInS2. A reasonable possible mechanism for the growth of CuInS2 nanocrystallines is proposed. The as-obtained CuInS2 products are examined using diverse techniques including x-ray powder diffraction, x-ray photoelectron spectroscopy, field-emission scanning electron microscopy, transmission electron microscopy, selected-area electron diffraction and high-resolution transmission electron microscopy.

  8. The Microstructure-Processing-Property Relationships in an Al Matrix Composite System Reinforced by Al-Cu-Fe Alloy Particles

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Fei [Iowa State Univ., Ames, IA (United States)

    2004-01-01

    Metal matrix composites (MMC), especially Al matrix composites, received a lot of attention during many years of research because of their promise for the development of automotive and aerospace materials with improved properties and performance, such as lighter weight and better structural properties, improved thermal conductivity and wear resistance. In order to make the MMC materials more viable in various applications, current research efforts on the MMCs should continue to focus on two important aspects, including improving the properties of MMCs and finding more economical techniques to produce MMCs. Solid state vacuum sintering was studied in tap densified Al powder and in hot quasi-isostatically forged samples composed of commercial inert gas atomized or high purity Al powder, generated by a gas atomization reaction synthesis (GARS) technique. The GARS process results in spherical Al powder with a far thinner surface oxide. The overall results indicated the enhanced ability of GARS-processed Al and Al alloy powders for solid state sintering, which may lead to simplification of current Al powder consolidation processing methods. Elemental Al-based composites reinforced with spherical Al-Cu-Fe alloy powders were produced by quasi-isostatic forging and vacuum hot pressing (VHP) consolidation methods. Microstructures and tensile properties of AYAl-Cu-Fe composites were characterized. It was proved that spherical Al-Cu-Fe alloy powders can serve as an effective reinforcement particulate for elemental Al-based composites, because of their high hardness and a preferred type of matrix/reinforcement interfacial bonding, with reduced strain concentration around the particles. Ultimate tensile strength and yield strength of the composites were increased over the corresponding Al matrix values, far beyond typical observations. This remarkable strengthening was achieved without precipitation hardening and without severe strain hardening during consolidation because of

  9. Welding of Al6061and Al6082-Cu composite by friction stir processing

    Science.gov (United States)

    Iyer, R. B.; Dhabale, R. B.; Jatti, V. S.

    2016-09-01

    Present study aims at investigating the influence of process parameters on the microstructure and mechanical properties such as tensile strength and hardness of the dissimilar metal without and with copper powder. Before conducting the copper powder experiments, optimum process parameters were obtained by conducting experiments without copper powder. Taguchi's experimental L9 orthogonal design layout was used to carry out the experiments without copper powder. Threaded pin tool geometry was used for conducting the experiments. Based on the experimental results and Taguchi's analysis it was found that maximum tensile strength of 66.06 MPa was obtained at 1400 rpm spindle speed and weld speed of 20 mm/min. Maximum micro hardness (92 HV) was obtained at 1400 rpm spindle speed and weld speed of 16 mm/min. At these optimal setting of process parameters aluminium alloys were welded with the copper powder. Experimental results demonstrated that the tensile strength (96.54 MPa) and micro hardness (105 HV) of FSW was notably affected by the addition of copper powder when compared with FSW joint without copper powder. Tensile failure specimen was analysed using Scanning Electron Microscopy in order to study the failure mechanism.

  10. L-cystine-Assisted Growth and Mechanism of CuInS2 Nanocrystallines via Solvothermal Process

    Institute of Scientific and Technical Information of China (English)

    LIU Hai-Tao; ZHONG Jia-Song; LIU Bing-Feng; LIANG Xiao-Juan; YANG Xin-Yu; JIN Huai-Dong; YANG Fan; XIANG Wei-Dong

    2011-01-01

    L-cystine is successfully used as a kind of sulfur source to grow CuInS2 nanocrystallines at 200℃ for 18h in a mixed solution made of 20mL ethylenediamine and 20mL distilled water. The diameter of the CuInS2 nanocrystallines ranges from 300 to 500 nm. The structure of nanocrystallines is determined to be of the tetragonal phase of CuInS2. A reasonable possible mechanism for the growth of CuInS2 nanocrystallines is proposed.The as-obtained CuInS2 products are examined using diverse techniques including x-ray powder diffraction, x-ray photoelectron spectroscopy, field-emission scanning electron microscopy, transmission electron microscopy,selected-area electron diffraction and high-resolution transmission electron microscopy.%@@ L-cystine is successfully used as a kind of sulfur source to grow CuInS2 nanocrystallines at 200°C for 18 h in a mixed solution made of 20mL ethylenediamine and 20mL distilled water.The diameter of the CuInS2 nanocrystallines ranges from 300 to 500 nm.The structure of nanocrystallines is determined to be of the tetragonal phase of CuInS2.A reasonable possible mechanism for the growth of CuInS2 nanocrystallines is proposed.The as-obtained CuInS2 products are examined using diverse techniques including x-ray powder diffraction,xray photoelectron spectroscopy,field-emission scanning electron microscopy,transmission electron microscopy,selected-area electron diffraction and high-resolution transmission electron microscopy.

  11. Self-doping processes between planes and chains in the metal-to-superconductor transition of YBa2Cu3O6.9.

    Science.gov (United States)

    Magnuson, M; Schmitt, T; Strocov, V N; Schlappa, J; Kalabukhov, A S; Duda, L-C

    2014-11-12

    The interplay between the quasi 1-dimensional CuO-chains and the 2-dimensional CuO2 planes of YBa(2)Cu(3)O(6+x) (YBCO) has been in focus for a long time. Although the CuO-chains are known to be important as charge reservoirs that enable superconductivity for a range of oxygen doping levels in YBCO, the understanding of the dynamics of its temperature-driven metal-superconductor transition (MST) remains a challenge. We present a combined study using x-ray absorption spectroscopy and resonant inelastic x-ray scattering (RIXS) revealing how a reconstruction of the apical O(4)-derived interplanar orbitals during the MST of optimally doped YBCO leads to substantial hole-transfer from the chains into the planes, i.e. self-doping. Our ionic model calculations show that localized divalent charge-transfer configurations are expected to be abundant in the chains of YBCO. While these indeed appear in the RIXS spectra from YBCO in the normal, metallic, state, they are largely suppressed in the superconducting state and, instead, signatures of Cu trivalent charge-transfer configurations in the planes become enhanced. In the quest for understanding the fundamental mechanism for high-Tc-superconductivity (HTSC) in perovskite cuprate materials, the observation of such an interplanar self-doping process in YBCO opens a unique novel channel for studying the dynamics of HTSC.

  12. Cu-Doped ZnO Thin Films Deposited by a Sol-Gel Process Using Two Copper Precursors: Gas-Sensing Performance in a Propane Atmosphere

    Directory of Open Access Journals (Sweden)

    Heberto Gómez-Pozos

    2016-01-01

    Full Text Available A study on the propane gas-sensing properties of Cu-doped ZnO thin films is presented in this work. The films were deposited on glass substrates by sol-gel and dip coating methods, using zinc acetate as a zinc precursor, copper acetate and copper chloride as precursors for doping. For higher sensitivity values, two film thickness values are controlled by the six and eight dippings, whereas for doping, three dippings were used, irrespective of the Cu precursor. The film structure was analyzed by X-ray diffractometry, and the analysis of the surface morphology and film composition was made through scanning electron microscopy (SEM and secondary ion mass spectroscopy (SIMS, respectively. The sensing properties of Cu-doped ZnO thin films were then characterized in a propane atmosphere, C3H8, at different concentration levels and different operation temperatures of 100, 200 and 300 °C. Cu-doped ZnO films doped with copper chloride presented the highest sensitivity of approximately 6 × 104, confirming a strong dependence on the dopant precursor type. The results obtained in this work show that the use of Cu as a dopant in ZnO films processed by sol-gel produces excellent catalysts for sensing C3H8 gas.

  13. Influence of cold-rolling on the precipitation processes in Cu-4 at. % Ti alloy; Influencia de la deformacion en frio sobre el proceso de precipitacion en una aleacion de Cu-4 at. % Ti

    Energy Technology Data Exchange (ETDEWEB)

    Donoso, E.

    2008-07-01

    By using differential scanning calorimetry (DSC), energetic and kinetic measurements associated with the different peaks displayed during linear heating of Cu-4 at. % Ti were made, employing quenched and cold-work material at different percentages of cold-rolling. Unlike to the situation observed in the quenched alloy in which precipitation is developed, in the deformed alloys such process is inhibited by the segregation of the solute atoms to partial dislocations. For calculating the dislocation density an expression governing the energy release accompanying recrystallization was applied, in order to determine, by appropriate models, the energy evolved during the pinning process. (Author) 35 refs.

  14. Thick film processing of YBa sub 2 Cu sub 3 O sub 7 sub - sub x

    CERN Document Server

    Wells, J J

    2000-01-01

    texture in the substrates used. A J sub c of approx 10 sup 4 Acm sup - sup 2 77K, 0T, was obtained with a precursor solution of 0.00375 mol/dm sup 3. The current carrying length scale was measured to be approx 1 mm showing there is good connectivity between the 1-2 mu m diameter grains. A route for producing textured silver substrates, and two techniques for producing YBCO thick films have been studied with a view to demonstrating an economical route for the fabrication of long lengths of YBCO tape. Silver ingots cold rolled to a deformation of 98 % and recrystallised at 800 deg C for 24 hours gave a left brace 110 right brace texture with a FWHM in phi of approx 20deg. These were used as substrates for the epitaxial growth of YBCO by both a low pO sub 2 melt processing technique and an ultrasonic spray pyrolysis technique. The low pO sub 2 melt processing technique enabled the melting point of YBCO to be lowered to 945 degC at a pO sub 2 of 5x10 sup - sup 3 atm such that the YBCO could be resolidified from t...

  15. Texture Analysis of Cu-Cr-Zr Alloy in Process of Deformation%Cu-Cr-Zr系合金变形过程中的织构分析

    Institute of Scientific and Technical Information of China (English)

    朱永兵; 慕思国; 李华清; 郭富安

    2009-01-01

    The Cu-Cr-Zr alloy was treated by hot rolling, solution and cold rolling. The types and the evolution of texture in the different state were investigated using X-ray diffraction. The results show that the main solution and the cube texture disappears. In the condition of cold rolling, the intensity of texture enhances with the increasing of the deformation. The main textures during the cold rolling are C, B and S texture. In the early stage of the cold rolling, it appears the%对Cu-Cr-Zr系合金铸锭进行热轧、固溶和冷轧,利用X射线衍射仪测试合金材料不同状态下的织构,分析各个状态下的织构种类及其演变规律.结果表明:热轧后材料中主要织构为Copper{112}〈111〉(C)织构、Brass{011}〈211〉(B)织构和S{123}〈634〉织构,存在微弱的立方织构{001}〈100〉;固溶后材料中织构的强度降低,立方织构消失;冷轧后材料中织构的强度随着变形量的增加而强度增加,冷轧过程中主要织构也是C织构、B织构和S织构,在冷轧初期出现Goss{011}〈100〉(G)织构,随后G织构慢慢减弱,直至消失.

  16. Properties, Phases and Microstructure of Microwave Sintered W-20Cu Composites from Spray Pyrolysiscontinuous Reduction Processed Powders

    Institute of Scientific and Technical Information of China (English)

    TAO Jianqing; SHI Xiaoliang

    2012-01-01

    The effects of microwave sintering on the properties,phases and microstructure of W-20Cu alloy,using composite powder fabricated by spray pyrolysis-continuous reduction technology,were investigated.Compared with the conventional hot-press sintering,microwave sintering to W-20Cu composites could be achieved with lower sintering temperature and shorter sintering time.Furthermore,microwave sintered W-Cu composites with high densification,homogenous microstructure and excellent properties were obtained.Microwave sintering could also result in finer microstructures.

  17. Preparation, Processing and Tunneling in YBa2Cu3O7-δ-Pb Native-Barrier Structures

    Science.gov (United States)

    Frangi, Francesca; Dwir, Benjamin; James, Jonathan H.; Gauzzi, Andrea; Pavuna, Davor

    1993-06-01

    We have developed a procedure for the preparation of small (40× 40 μm2) window-type YBa2Cu3O7-δ-Pb junctions with YSZ insulator and native tunnel barrier. We present the patterning technique of the two electrodes based on photolithography and wet etching. The nature of the barrier is found to be semiconducting. The tunneling measurements show gap-like feature of YBa2Cu3O7-δ at 8.5 meV and some additional features related to Pb and YBa2Cu3O7-δ phonon spectra.

  18. In situ heating SEM observation of the bainitic transformation process in Cu-17Al-11Mn (at.%) alloys.

    Science.gov (United States)

    Motomura, Shunichi; Soejima, Yohei; Miyoshi, Takayuki; Hara, Toru; Omori, Toshihiro; Kainuma, Ryosuke; Nishida, Minoru

    2016-04-01

    To understand the bainitic transformation behavior in Cu-17Al-11Mn (at.%) alloys, dynamicin situobservation during heating was carried out in a scanning electron microscope (SEM). In this study, after optimizing the sample preparation method and observation conditions, we successfully observed the transformation process with sufficient resolution and contrast. From the observation results, bainite is first formed preferentially at the grain boundaries of the parent phase. Bainite is also formed inside the grains to relax the elastic strain generated by the initial bainite. Regarding the growth mode, in the early stage of the transformation, bainite grows along the longitudinal direction, and in the late stage, it grows along the lateral direction. The growth rate of the bainite was also evaluated by continuous observation of the same plate. Dynamicin situobservation of a martensitic transformation in the same alloy was also performed to compare the growth mode with that of bainite, and it was found that the behavior is considerably different between bainitic and the martensitic transformations. © The Author 2015. Published by Oxford University Press on behalf of The Japanese Society of Microscopy. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  19. Development of novel processes for Cu concentrates without producing sulfuric acid; Hiryusan hasseigata no atarashii doshigen shori gijutsu no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, T.; Noguchi, F.; Takasu, T.; Ito, H. [Kyushu Inst. of Technology, Kitakyushu (Japan). Faculty of Engineering

    1997-02-01

    In the refining process for the production of copper from pyrites, heat treatment is carried out in a neutral atmosphere so that part of the sulphur will be collected in the form of simple sulfur and that pyrites naturally low in reactivity will be made active. A basic study is also conducted of a very high speed electrolytic method. The chemical aspects of pyrites which are various in composition (mainly CuFeS2) are clarified by X-ray diffraction, and then is subjected to heat-treatment in a 773K-1073K argon atmosphere. There is a decrease in the amount of sulfur at a temperatures not lower than 973K. The X-ray main diffraction line splits for the emergence of some lower angle diffraction lines. The specimen is then subjected to a leach test in a copper chloride base liquor, to disclose that leachability grows remarkably higher in the presence of a great change in the X-ray diffraction lattice constant. An experiment follows in which an electrolyte is allowed to flow at a high speed for accelerating the rate of electrolytic refining in an effort to prevent the passivation of anode and deposition of dendrite on the cathode that is apt to occur when the current density is high. Passivation is prevented when the flow rate is 10m/min or higher in the vicinity of the anode surface for the formation of a smooth electrodeposited surface. 2 refs., 2 figs., 2 tabs.

  20. Processing and properties of Cu based micro- and nano-composites

    Indian Academy of Sciences (India)

    S Panda; K Dash; B C Ray

    2014-04-01

    Nano-composites of 1, 3, 5 and 7 vol% Al2O3 (average size < 50 nm) and microcomposites having compositions 5, 10, 15, 20 vol% of Al2O3 (average size ∼ 10 m) reinforced in copper matrix were fabricated by powder metallurgy route. All the specimens were sintered at different sintering temperatures (850, 900 and 1000°C) to study the effect of temperature on the process and progress of sinterability of the reinforced micro- and nanoparticles in the matrix. These micro- and nano-composites were characterized using X-ray diffraction and scanning electron microscopy followed by density, microhardness and wear measurements. The compression and flexural tests were also carried out in order to investigate the mechanical behaviour of the micro- and nano-composites for a fixed optimum sintering temperature. Fractography of the 3-point bend specimens was performed to investigate the fracture behaviour of the micro- and nano-composites. The flexural test results showed that the ultimate flexural strength decreases and flexural modulus increases with the increase in reinforcement content.

  1. Solution processible Cu{sub 2}SnS{sub 3} thin films for cost effective photovoltaics: Characterization

    Energy Technology Data Exchange (ETDEWEB)

    Dias, Sandra, E-mail: dias.sandra123@gmail.com; Murali, Banavoth; Krupanidhi, S.B.

    2015-11-01

    Thin films of Cu{sub 2}SnS{sub 3} (CTS) were deposited by the facile solution processed sol–gel route followed by a low-temperature annealing. The Cu–Sn-thiourea complex formation was analysed using Fourier Transform Infrared spectrophotometer (FTIR). The various phase transformations and the deposition temperature range for the initial precursor solution was determined using Thermogravimetric analysis (TGA) and Differential Scanning Calorimetry (DSC). X-Ray Diffraction (XRD) studies revealed the tetragonal phase formation of the CTS annealed films. Raman spectroscopy studies further confirmed the tetragonal phase formation and the absence of any deterioratory secondary phases. The morphological investigations and compositional analysis of the films were determined using Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS) respectively. Atomic Force Microscopy (AFM) was used to estimate the surface roughness of 1.3 nm. The absorption coefficient was found to be 10{sup 4} cm{sup −1} and bandgap 1.3 eV which qualifies CTS to be a potential candidate for photovoltaic applications. The refractive index, extinction coefficient and relative permittivity of the film were measured by Spectroscopic ellipsometry. Hall effect measurements, indicated the p type nature of the films with a hole concentration of 2 × 10{sup 18} cm{sup −3}, electrical conductivity of 9 S/cm and a hole mobility of 29 cm{sup 2}/V. The properties of CTS as deduced from the current study, present CTS as a potential absorber layer material for thin film solar cells. - Highlights: • Cu{sub 2}SnS{sub 3} thin films have been synthesized by spin coating of a precursor solution. • The Cu–Sn-thiourea complex precursor was analysed. • The structural, optical and electrical properties of the thin films were studied. • Totally 24 infra-red, 30 optical, 29 Raman and 30 hyper Raman modes are active. • Refractive index, extinction coefficient and relative

  2. Preparation and characterization of Cu2ZnSnSe4 thin films grown from ZnSe and Cu2SnS3 precursors in a two stage process

    Science.gov (United States)

    Moreno, R.; Leguizamon, A.; Hurtado, M.; Guzmán, F.; Gordillo, G.

    2014-04-01

    Compound of the kesterite familie has been considered as an alternative absorber layer in the manufacture of thin film solar cells due to its earth abundant and environmental friendly constituents and high absorption coefficient. In this work we propose a new route to grow single phase Cu2ZnSnSe4 (CZTSe) thin films with tetragonal-kesterite type structure; this consist in sequential evaporation of thin films of CuSe, SnSe and ZnSe in a two stage process. Measurements of X-ray diffraction (XRD) revealed the formation of the Cu2ZnSnSe4 compound, grown with tetragonal Kësterite type structure. Optical characterization performed through spectral transmittance measurements established that this compound has high absorption (absorption coefficient > 104 cm-1) and a forbidden energy gap of 1.46 eV; these results indicate that the CZTSe thin films we have prepared has properties suitable for later use as absorber layer in solar cells. Results regarding electrical transport properties determined from temperature dependent conductivity measurements are also reported.

  3. Processing and characterization of B4C/Cu graded composite as plasma facing component for fusion reactors

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A new approach for fabricating B4C/Cu graded composite by rapid self-resistance sintering under ultra-high pressure was presented, by which a near dense B4C/Cu graded composite with a compositional spectrum of 0-100% was successfully fabricated. Plasma relevant performances ofsintered B4C/Cu composite were preliminarily characterized, it is found that its chemical sputtering yield is 70% lower than that of SMF800 nuclear graphite under 2.7 keV D+ irradiation, and almost no damages after 66 shots of in situ plasma discharge in HL-1 Tokamak facility, which indicates B4C/Cu plasma facing component has a good physical and chemical sputtering resistance performance compared with nuclear graphite.

  4. Local atomic structure and oxidation processes of Cu(I) binding site in amyloid beta peptide: XAS Study

    Science.gov (United States)

    Kremennaya, M. A.; Soldatov, M. A.; Streltsov, V. A.; Soldatov, A. V.

    2016-05-01

    There are two different motifs of X-ray absorption spectra for Cu(I) K-edge in amyloid-β peptide which could be due to two different configurations of local Cu(I) environment. Two or three histidine ligands can coordinate copper ion in varying conformations. On the other hand, oxidation of amyloid-β peptide could play an additional role in local copper environment. In order to explore the peculiarities of local atomic and electronic structure of Cu(I) binding sites in amyloid-β peptide the x-ray absorption spectra were simulated for various Cu(I) environments including oxidized amyloid-β and compared with experimental data.

  5. Preparation of YBa 2Cu 3O 7-x crystals by verneuil process with laser-heating

    Science.gov (United States)

    Nakada, I.; Itoh, M.; Ogura, I.; Koga, K.; Sato, S.

    1989-09-01

    Premelted YBa 2Cu 3O 7- x was mixed with a BaCuO 2-CuO flux and formed into a boule melting the fed powder under laser-heating. Holding the boule at 910°C, the surplus flux was removed by melting and YBa 2Cu 3O 7- x crystals were extracted. The size of the crystals was from 0.01×0.01 to 0.5×0.5 mm with 0.02V0.04mm in thickness. After annealing at 600°C the crystals became superconducting with the transition temperature at 92 K. Interference contrast microscopy revealed microstep line structures on the as-grown crystal surfaces as well as domain structures in the orthorhombic phase. It was found that the crystallographic orientation of the orthorhombic lattice could be determined from the contrast of the domains in the microscope.

  6. Catalytic Gas-Phase Glycerol Processing over SiO2-, Cu-, Ni- and Fe- Supported Au Nanoparticles.

    Directory of Open Access Journals (Sweden)

    Maciej Kapkowski

    Full Text Available In this study, we investigated different metal pairings of Au nanoparticles (NPs as potential catalysts for glycerol dehydration for the first time. All of the systems preferred the formation of hydroxyacetone (HYNE. Although the bimetallics that were tested, i.e., Au NPs supported on Ni, Fe and Cu appeared to be more active than the Au/SiO2 system, only Cu supported Au NPs gave high conversion (ca. 63% and selectivity (ca. 70% to HYNE.

  7. Anticipatory processes in brain state switching - evidence from a novel cued-switching task implicating default mode and salience networks.

    Science.gov (United States)

    Sidlauskaite, Justina; Wiersema, Jan R; Roeyers, Herbert; Krebs, Ruth M; Vassena, Eliana; Fias, Wim; Brass, Marcel; Achten, Eric; Sonuga-Barke, Edmund

    2014-09-01

    The default mode network (DMN) is the core brain system supporting internally oriented cognition. The ability to attenuate the DMN when switching to externally oriented processing is a prerequisite for effective performance and adaptive self-regulation. Right anterior insula (rAI), a core hub of the salience network (SN), has been proposed to control the switching from DMN to task-relevant brain networks. Little is currently known about the extent of anticipatory processes subserved by DMN and SN during switching. We investigated anticipatory DMN and SN modulation using a novel cued-switching task of between-state (rest-to-task/task-to-rest) and within-state (task-to-task) transitions. Twenty healthy adults performed the task implemented in an event-related functional magnetic resonance imaging (fMRI) design. Increases in activity were observed in the DMN regions in response to cues signalling upcoming rest. DMN attenuation was observed for rest-to-task switch cues. Obversely, DMN was up-regulated by task-to-rest cues. The strongest rAI response was observed to rest-to-task switch cues. Task-to-task switch cues elicited smaller rAI activation, whereas no significant rAI activation occurred for task-to-rest switches. Our data provide the first evidence that DMN modulation occurs rapidly and can be elicited by short duration cues signalling rest- and task-related state switches. The role of rAI appears to be limited to certain switch types - those implicating transition from a resting state and to tasks involving active cognitive engagement.

  8. The calculation of specific heats for some important solid components in hydrogen production process based on CuCl cycle

    Directory of Open Access Journals (Sweden)

    Avsec Jurij

    2014-01-01

    Full Text Available Hydrogen is one of the most promising energy sources of the future enabling direct production of power and heat in fuel cells, hydrogen engines or furnaces with hydrogen burners. One of the last remainder problems in hydrogen technology is how to produce a sufficient amount of cheap hydrogen. One of the best options is large scale thermochemical production of hydrogen in combination with nuclear power plant. copper-chlorine (CuCl cycle is the most promissible thermochemical cycle to produce cheap hydrogen.This paper focuses on a CuCl cycle, and the describes the models how to calculate thermodynamic properties. Unfortunately, for many components in CuCl cycle the thermochemical functions of state have never been measured. This is the reason that we have tried to calculate some very important thermophysical properties. This paper discusses the mathematical model for computing the thermodynamic properties for pure substances and their mixtures such as CuCl, HCl, Cu2OCl2 important in CuCl hydrogen production in their fluid and solid phase with an aid of statistical thermodynamics. For the solid phase, we have developed the mathematical model for the calculation of thermodynamic properties for polyatomic crystals. In this way, we have used Debye functions and Einstein function for acoustical modes and optical modes of vibrations to take into account vibration of atoms. The influence of intermolecular energy we have solved on the basis of Murnaghan equation of state and statistical thermodynamics.

  9. PROCESS AND MECHANISM OF MICROWAVE SINTERING OF SiC-Cu/Al COMPOSITES%微波烧结SiC-Cu/Al复合材料的工艺及机理

    Institute of Scientific and Technical Information of China (English)

    王海龙; 张锐; 汪长安; 何小波; 黄勇; 胡行

    2006-01-01

    Aluminum matrix composites reinforced by silicon carbide/copper coated particles (SiC-Cu/Al) were prepared using microwave sintering. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques were used to characterize the sintered compacts. The process and mechanism of microwave sintering were discussed. It was found that the assistant-heating structure which was set up by mullite heat-preservation material, silicon carbide (SiC) rods and alumina crucible can effectively enhance the process of densification during sintering. The highest density of SiC-Cu/Al composites was 2.53 g/cm3 at 720 ℃. The saddle-shaped profile of the hardness with sintering temperature was detected. Correspondingly, different microstructures were observed at different temperatures. The uniformity of disturbed phases decreased with increasing temperature. Segregation of SiC grains occurred at high temperatures. Induction losses caused by both eddy currents and interfacial polarization were contributed to successful sintering.%用微波烧结工艺成功制备了铜包裹碳化硅颗粒增强铝基(SiC-Cu/Al)复合材料,利用扫描电镜和X射线衍射分析仪对烧结样品进行表征,并讨论了烧结过程及机理.研究表明:采用多晶莫来石纤维棉、硅碳棒和氧化铝坩锅组合设计的保温结构能很好地促进烧结.烧结温度为720℃时,SiC-Cu/Al复合材料的密度取得最大值为2.53g/cm3.SiC-Cu/Al复合材料的硬度随烧结温度的升高的变化成马鞍状.烧结温度对样品显微结构的影响较大,随着烧结温度的升高,相分布的均匀性降低,在较高的烧结温度下会出现SiC颗粒的偏聚.涡流损耗和界面极化损耗是促进微波烧结的主要动力.

  10. The mechanism of degradation of bisphenol A using the magnetically separable CuFe{sub 2}O{sub 4}/peroxymonosulfate heterogeneous oxidation process

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Yin; Ai, Jia [Department of Environmental Engineering, Wuhan University, Wuhan 430079 (China); Shenzhen Research Institute of Wuhan University, Shenzhen 518057 (China); Zhang, Hui, E-mail: eeng@whu.edu.cn [Department of Environmental Engineering, Wuhan University, Wuhan 430079 (China); Shenzhen Research Institute of Wuhan University, Shenzhen 518057 (China)

    2016-05-15

    Highlights: • Copper ferrite (CuFe{sub 2}O{sub 4}) was fabricated and utilized in heterogeneous PMS process. • The influence of reaction parameters for the mineralization of BPA were evaluated. • Possible reaction mechanism and the stability of CuFe{sub 2}O{sub 4} were investigated. • Surface bound radicals (mainly ·OH) may be responsible for the BPA degradation. - Abstract: The removal of bisphenol A (BPA) in aqueous solution by an oxidation process involving peroxymonosulfate (PMS) activated by CuFe{sub 2}O{sub 4} magnetic nanoparticles (MNPs) is reported herein. The effects of PMS concentration, CuFe{sub 2}O{sub 4} dosage, initial pH, initial BPA concentration, catalyst addition mode, and anions (Cl{sup −}, F{sup −}, ClO{sub 4}{sup −} and H{sub 2}PO{sub 4}{sup −}) on BPA degradation were investigated. Results indicate that nearly complete removal of BPA (50 mg/L) within 60 min and 84.0% TOC removal in 120 min could be achieved at neutral pH by using 0.6 g/L CuFe{sub 2}O{sub 4} MNPs and 0.3 g/L PMS. The generation of reactive radicals (mainly hydroxyl radicals) was confirmed using electron paramagnetic resonance (EPR). Possible mechanisms on the radical generation from CuFe{sub 2}O{sub 4}/PMS system are proposed based on the results of radical identification tests and XPS analysis. The lack of inhibition of the reaction by free radical scavengers such as methanol and tert-butyl alcohol suggests that these species may not be generated in the bulk solution, and methylene blue probe experiments confirm that this process does not involve free radical generation. Surface-bound, rather than free radicals generated by a surface catalyzed-redox cycle involving both Fe(III) and Cu(II), are postulated to be responsible for the mineralization of bisphenol A.

  11. Processus de réorientation des variantes de martensite dans un monocristal de Cu Al NiReorientation process of martensite variants in a Cu Al Ni monocrystal

    Science.gov (United States)

    Blanc, Pascal; Lexcellent, Christian

    2003-04-01

    On the one hand, Chu (Thesis, Minnesota, 1993), Abeyaratne et al. (Philos. Mag. A 73 (2) (1996) 457-497) performed biaxial tensile tests on a single crystal Cu-Al-Ni plate, in order to analyze the reorientation process of martensite variants. On the other hand, use is made of a constitutive model with n+1 internal variables (the volume fractions of austenite and of the n martensite variants) specific to the thermomechanical behavior of SMA single crystals in order to simulate the martensite variant reorientation. The comparison between experimental results and model prediction is fairly good. To cite this article: P. Blanc, C. Lexcellent, C. R. Mecanique 331 (2003).

  12. Structure–mechanical property relationship in a low carbon Nb–Cu microalloyed steel processed through a three-step heat treatment: The effect of tempering process

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, W.H. [School of Materials Science and Engineering, University of Science and Technology, Beijing (China); Challa, V.S.A. [Department of Metallurgical and Materials Engineering, University of Texas El Paso, TX 799968 (United States); Guo, H. [School of Materials Science and Engineering, University of Science and Technology, Beijing (China); Shang, C.J., E-mail: cjshang@ustb.edu.cn [School of Materials Science and Engineering, University of Science and Technology, Beijing (China); Misra, R.D.K. [Department of Metallurgical and Materials Engineering, University of Texas El Paso, TX 799968 (United States)

    2015-01-03

    We describe here the impact of tempering temperature and tempering time on the microstructure and mechanical property in a low carbon Nb–Cu microalloyed steel via a three-step heat treatment. After tempering process, the microstructure primarily comprised of ferrite, retained austenite and tempered bainite/martensite. The ferrite matrix with ultrafine grain size was film-like and enriched with nanometer-sized niobium-containing and copper precipitates. The volume fraction of ferrite increased with the increase in tempering temperature and tempering time. Retained austenite had average grain size less than 1 μm and was enriched with copper precipitates that contributes to enhance the stability of austenite. The retained austenite revealed high thermal stability and remained stable in the range of 20–30% when tempering temperature and time changed. High strength and good ductility were obtained in the tempering temperature range of 450–550 °C, or by prolonging tempering time at 500 °C, where the yield strength was ∼750 MPa and the product of tensile strength and % elongation was ∼32 GPa%, which is attributed to the cooperation of multiphase microstructure, stable retained austenite and nanometer-sized precipitates.

  13. Characterization and photoluminescence properties of ultrafine copper molybdate (α-CuMoO4) powders prepared via a combustion-like process

    Institute of Scientific and Technical Information of China (English)

    Mohamed Benchikhi; Rachida El Ouatib; Sophie Guillemet-Fritsch; Lahcen Er-Rakho; and Bernard Durand

    2016-01-01

    We report a simple method for preparing copper(II) molybdate (CuMoO4) powders via a combustion-like process. A gel was first prepared by the polymerizable complex method, where citric acid was used as a complexing and polymerizing agent and nitric acid was used as an oxidizing agent. The thermal decomposition behavior of the (CuMo)-precursor gel was studied by thermogravimetry–differential ther-mal analysis (TG–DTA), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). We observed that the crystallization of CuMoO4 powder was completed at 450°C. The obtained homogeneous powder was composed of grains with sizes in the range from 150 to 500 nm and exhibited a specific surface area of approximately 5 m2/g. The average grain size increased with increasing annealing tem-perature. The as-prepared CuMoO4 crystals showed a strong green photoluminescence emission at room temperature under excitation at 290 nm, which we mainly interpreted on the basis of the Jahn-Teller effect on [MoO42−] complex anions. We also observed that the photolumi-nescence intensity increased with increasing crystallite size.

  14. Nanoparticle-induced grain growth of carbon-free solution-processed CuIn(S,Se)2 solar cell with 6% efficiency.

    Science.gov (United States)

    Cai, Yongan; Ho, John C W; Batabyal, Sudip K; Liu, Wei; Sun, Yun; Mhaisalkar, Subodh G; Wong, Lydia H

    2013-03-13

    Chalcopyrite-based solar cell deposited by solution processes is of great research interest because of the ease of fabrication and cost effectiveness. Despite the initial promising results, most of the reported methods encounter challenges such as limited grain growth, carbon-rich interlayer, high thermal budget, and the presence of secondary Cu-rich phases, which limit the power conversion efficiency (PCE). In this paper, we develop a new technique to deposit large grain, carbon-free CISSe absorber layers from aqueous nanoparticle/precursor mixture which resulted in a solar cell with PCE of 6.2%. CuCl2, InCl3, and thiourea were mixed with CuS and In2S3 nanoparticles in water to form the unique nanoparticle/precursor solution. The Carbon layer formation was prevented because organic solvents were not used in the precursor. The copper-rich (CuS) nanoparticles were intentionally introduced as nucleation sites which accelerate grain growth. In the presence of nanoparticles, the grain size of CISSe film increased by a factor of 7 and the power conversion efficiency of the solar cell is 85% higher than the device without nanoparticle. This idea of using nanoparticles as a means to promote grain growth can be further exploited for other types of chalcopyrite thin film deposited by solution methods.

  15. Characterization and photoluminescence properties of ultrafine copper molybdate (α-CuMoO4) powders prepared via a combustion-like process

    Science.gov (United States)

    Benchikhi, Mohamed; El Ouatib, Rachida; Guillemet-Fritsch, Sophie; Er-Rakho, Lahcen; Durand, Bernard

    2016-11-01

    We report a simple method for preparing copper(II) molybdate (CuMoO4) powders via a combustion-like process. A gel was first prepared by the polymerizable complex method, where citric acid was used as a complexing and polymerizing agent and nitric acid was used as an oxidizing agent. The thermal decomposition behavior of the (CuMo)-precursor gel was studied by thermogravimetry-differential thermal analysis (TG-DTA), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). We observed that the crystallization of CuMoO4 powder was completed at 450°C. The obtained homogeneous powder was composed of grains with sizes in the range from 150 to 500 nm and exhibited a specific surface area of approximately 5 m2/g. The average grain size increased with increasing annealing temperature. The as-prepared CuMoO4 crystals showed a strong green photoluminescence emission at room temperature under excitation at 290 nm, which we mainly interpreted on the basis of the Jahn-Teller effect on [MoO 4 2- ] complex anions. We also observed that the photoluminescence intensity increased with increasing crystallite size.

  16. Fabrication of Cu2SnS3 thin films by ethanol-ammonium solution process by doctor-blade technique

    Science.gov (United States)

    Wang, Yaguang; Li, Jianmin; Xue, Cong; Zhang, Yan; Jiang, Guoshun; Liu, Weifeng; Zhu, Changfei

    2017-06-01

    In the present study, a low-cost and simple method is applied to fabricate Cu2SnS3 (CTS) thin films. Namely CTS thin films are prepared by a doctor-blade method with a slurry dissolving the Cu2O and SnS powders obtained from CBD reaction solution into ethanol-ammonium solvents. Series of characterization methods including XRD, Raman spectra, SEM and UV-Vis analyses are introduced to investigate the phase structure, morphology and optical properties of CTS thin films. As a result, monoclinic CTS films have been obtained with the disappearance of binary phases CuS and SnS2 while increasing the annealing temperature and time, high quality monoclinic CTS thin films consisting of compact and large grains have been successfully prepared by this ethanol-ammonium method. Moreover, the secondary phase Cu2Sn3S7 is also observed during the annealing process. In addition, the post-annealed CTS film with a band-gap about 0.89 eV shows excellent absorbance between 400 and 1200 nm, which is proper for the bottom layer in multi-junction thin film solar cells. [Figure not available: see fulltext.

  17. Moessbauer spectrometry and X-ray diffraction studies of the Fe sub 8 sub 7 Zr sub 6 B sub 6 Cu sub 1 nanocrystallization process

    CERN Document Server

    Bibicu, I; Plazaola, F; Apinaniz, E

    2001-01-01

    Fe sub 8 sub 7 Zr sub 6 B sub 6 Cu sub 1 amorphous ribbon were obtained by the melt spinning technique under a controlled atmosphere. One-hour isothermal treatments at different temperatures were performed in a differential thermal analyzer apparatus in an Ar atmosphere. The Conversion Electron Moessbauer Spectrometry (CEMS) and X-ray diffraction measurements of the Fe sub 8 sub 7 Zr sub 6 B sub 6 Cu sub 1 sample in different steps of the nanocrystallization process have been performed. The results have been compared with those obtained by means of Transmission Moessbauer Spectrometry (TMS) technique. The X-ray diffraction patterns and CEMS spectra of the studied samples present systematically higher crystallized fractions than those corresponding to spectra obtained by transmission geometry. As these techniques offer us information about different regions of the sample, the differences among the obtained results have been related to an inhomogenization of the crystallization process into the sample induced b...

  18. Effect of the burn-out step on the microstructure of the solution-processed Cu(In,Ga)Se-2 solar cells

    OpenAIRE

    Batuk, Maria; Buffiere, Marie; Zaghi, Armin E.; Lenaers, Nick; Verbist, Christophe; Khelifi, Samira; Vleugels, Jef; Meuris, Marc; Hadermann, Joke

    2015-01-01

    For the development of the photovoltaic industry cheap methods for the synthesis of Cu(In,Ga)Se-2 (CIGSe) based solar cells are required. In this work, CIGSe thin films were obtained by a solution-based method using oxygen-bearing derivatives. With the aimof improving the morphology of the printed CIGSe layers, we investigated two different annealing conditions of the precursor layer, consisting of (1) a direct selenization step (reference process), and (2) a pre-treatment thermal step prior ...

  19. An Efficient and Practical Process for Pd/Cu Cocatalyzed Homocoupling Reaction of Terminal Alkynes Using Sodium Percarbonate as a Dual Reagent in Aqueous Media

    Institute of Scientific and Technical Information of China (English)

    ZHOU, Lei; ZHAN, Hai-Ying; LIU, Hai-Ling; JIANG, Huan-Feng

    2007-01-01

    A new process for the Pd/Cu co-catalyzed homocoupling reaction of terminal alkynes was developed. The reaction was carried out in aqueous media with sodium percarbonate as both a clean oxidant and a base. Meanwhile, a palladium complex immobilized on a synthetic PS-PEG400-PPh2 resin was used as the catalyst, which may be recovered by simple filtration and reused for several times with high activity.

  20. Consolidation of powders of the superconductor YBa/sub 2/Cu/sub 3/O/sub 7-. delta. / by high energy-high rate processing

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J.Y.; Persad, C.; Swinnea, J.S.; Marcus, H.L.; Steinfink, H. (Texas Univ., Austin, TX (USA). Center for Materials Science and Engineering)

    1988-01-01

    The consolidation response of powders of the superconducting compound YBa/sub 2/Cu/sub 3/O/sub 7-{delta}/ by itself and admixed with metal powders is reported. The processing approach relies on short duration (

  1. Large levitation force due to flux pinning in YBaCuO superconductors fabricated by Melt-Powder-Melt-Growth process

    Science.gov (United States)

    Murakami, Masato; Oyama, Terutugu; Fujimoto, Hiroyuki; Taguchi, Takahiro; Gotoh, Satoshi

    1990-11-01

    An extremely large levitation force of as high as 30 N at a height of 1 mm was achieved in Ag-doped YBaCuO fabricated by the Melt-Powder-Melt-Growth process using a repulsive force against a 0.4 T rare-earth magnet at 77 K. The combination of a large Jc value and large shielding current loop is the source of such a large levitation force.

  2. Análises térmicas e processo de sinterização da cerâmica KSr2Nb5O15 dopada com CuO Thermal analysis and sintering process of KSr2Nb5O15 ceramic doped with CuO

    Directory of Open Access Journals (Sweden)

    Delia do Carmo Vieira

    2009-01-01

    Full Text Available KSr2Nb5O15 is a ferroelectric material. The sintering process of the KSr2Nb5O15 ceramic doped with different amounts of CuO was investigated in this research. It was found that CuO is effective as promoter of the densification process of the KSN ceramic. The developed microstructures were different due to the amount of CuO and secondary phases were observed in the microstructures. However, the results of X - ray diffraction showed that only the tetragonal tungsten bronze (TTB structure was identified in all the investigated ceramic systems. The thermal behavior of CuO and also of the CuO - KSN phase mixture was investigated by thermal analysis.

  3. Thermal analysis and sintering process of KSr{sub 2}Nb{sub 5}O{sub 15} ceramic doped with CuO; Analises termicas e processo de sinterizacao da ceramica KSr{sub 2}Nb{sub 5}O{sub 15} dopada com CuO

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, Delia do Carmo; Cardoso, Celso Xavier [Universidade Estadual Paulista (UNESP), Presidente Prudente, SP (Brazil). Fac. de Ciencias e Tecnologia. Dept. de Fisica, Quimica e Biologia], e-mail: dcvieira@fct.unesp.br; Duran, Rafael Matos [Universidad de Oriente, Santiago de Cuba (Cuba). Facultad de Ingenieria Quimica

    2009-07-01

    KSr{sub 2}Nb{sub 5}O{sub 15} is a ferroelectric material. The sintering process of the KSr{sub 2}Nb{sub 5}O{sub 15} ceramic doped with different amounts of CuO was investigated in this research. It was found that CuO is effective as promoter of the densification process of the KSN ceramic. The developed microstructures were different due to the amount of CuO and secondary phases were observed in the microstructures. However, the results of X - ray diffraction showed that only the tetragonal tungsten bronze (TTB) structure was identified in all the investigated ceramic systems. The thermal behavior of CuO and also of the CuO - KSN phase mixture was investigated by thermal analysis. (author)

  4. Half-lives and branchings for {\\beta}-delayed neutron emission for neutron-rich Co-Cu isotopes in the r-process

    CERN Document Server

    Hosmer, P; Aprahamian, A; Arndt, O; Clement, R R C; Estrade, A; Farouqi, K; Kratz, K -L; Liddick, S N; Lisetskiy, A F; Mantica, P F; Möller, P; Mueller, W F; Montes, F; Morton, A C; Ouellette, M; Pellegrini, E; Pereira, J; Pfeiffer, B; Reeder, P; Santi, P; Steiner, M; Stolz, A; Tomlin, B E; Walters, W B; Wöhr, A; 10.1103/PhysRevC.82.025806

    2010-01-01

    The {\\beta} decays of very neutron-rich nuclides in the Co-Zn region were studied experimentally at the National Superconducting Cyclotron Laboratory using the NSCL {\\beta}-counting station in conjunction with the neutron detector NERO. We measured the branchings for {\\beta}-delayed neutron emission (Pn values) for 74Co (18 +/- 15%) and 75-77Ni (10 +/- 2.8%, 14 +/- 3.6%, and 30 +/- 24%, respectively) for the first time, and remeasured the Pn values of 77-79Cu, 79,81Zn, and 82Ga. For 77-79Cu and for 81Zn we obtain significantly larger Pn values compared to previous work. While the new half-lives for the Ni isotopes from this experiment had been reported before, we present here in addition the first half-life measurements of 75Co (30 +/- 11 ms) and 80Cu (170+110 -50 ms). Our results are compared with theoretical predictions, and their impact on various types of models for the astrophysical rapid neutron-capture process (r-process) is explored. We find that with our new data, the classical r-process model is bet...

  5. High critical current density in powder-in-tube processed MgB2/Ta/Cu wire

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The magnetization of dense MgB2/Ta/Cu wires prepared by the powder-in-tube method is measured by a SQUID magnetometer. The results indicate that the critical temperature of MgB2/Ta/Cu is around 38.4 K with a sharp transition width of 0.6 K. The MgB2/Ta/Cu wire shows a strong flux pinning and the critical current density is higher than 105 A/cm2 (5 K, self-field) and 104 A/cm2 (20 K, 1 T). Also, the irreversibility field of the sample reaches 6.6 T at 5 K.

  6. Structures,properties and responses to heat treatment of deformation processed Cu-15%Cr composite powders prepared by mechanical milling

    Institute of Scientific and Technical Information of China (English)

    刘京雷; 刘祖岩; 王尔德; 线恒泽

    2002-01-01

    Cu-15%Cr composite powders were produced from elemental powders by mechanical milling technique. The structures, properties and thermal stability of the composite powders were characterized by scanning and transmission electron microscopy (SEM and TEM, respectively), electron probe microanalysis(EPMA), X-ray diffractometry and microhardness testing. The results show that powders are first flattened into thin discs at the initial stage of milling and then evolved into spheroid on further milling. Lamellar structure in powders is produced after intermediate milling. The Cr laminas degenerate into particles uniformizing in Cu matrix with excessive milling. The microhardness values and internal strain sharply increase with increasing milling time. Nano-sized Cu grains were found by TEM analysis. The microstructural observations suggested that the composite powders have high thermal stability and both spherodisation and thermal grooving contribute to the instability of Cr laminas.

  7. Solid state reactions and diffusion processes during rapid thermal processing of Cu-In-S based semiconductors; Festkoerperreaktionen und Diffusionsprozesse bei der schnellen Bildung von Halbleiterschichten im System Cu-In-S

    Energy Technology Data Exchange (ETDEWEB)

    Enzenhofer, T.

    2007-12-14

    In this thesis thin layers of the system Cu-In-S were studied for the photovoltaic application by means of structural and electro-optical procedures. The effect of small quantities of group II elements on the absorber and component properties could be explained by a widely appointed study. The motivation to insert extraneous elements into CuInS{sub 2} absorber layers results from the too low zero-current voltage of CuInS{sub 2} based solar cells. It could be shown that by addition of small quantities of Zn and/or Mg (<1 at.%) the zero-current voltage can be increased by 90 mV. The best doped CuInS{sub 2} solar cells aimed efficiencies, which were also determined for the reference system. As limiting factor in the doped system the zero-current has been proved. The intensive analysis of the absorber properties showed the the extraneous atoms effect in the bulk and on the surface different modifications.

  8. Effect of citric acid on formation of oxides of Cu and Zn in modified sol-gel process: A comparative study

    Indian Academy of Sciences (India)

    KAMARAJ MAHENDRAPRABHU; PERUMAL ELUMALAI

    2016-05-01

    We report here the influence of citric acid concentration on the formation of sol-gel products ineach of Cu and Zn systems by using respective metal nitrate as precursor and citric acid as gelling agent. Thesynthesized sol-gel products were characterized by X-ray diffraction (XRD), scanning electron microscope(SEM), energy dispersive X-ray analysis (EDX), Fourier transform infra-red (FT-IR) spectroscopy and UVVisiblediffused reflectance spectroscopy (UV-Vis DRS). The influence of citric acid concentration on theformation of metal/metal oxide in each case was primarily investigated by varying the molar ratio of each metalnitrate (N) and citric (C) acid (N:C = 1:1, 1:2, 1:4, 1:6 and 1:8). It was observed that at low N:C molar ratios(1:1) and (1:2), the Cu system had only CuO and at high N:C molar ratio, lower oxidation state of copper(Cu2O and Cu) has resulted. Distinctly, irrespective of the N:C molar ratio, the sol-gel product of Zn systemwas only single phase of ZnO. The SEM observations confirmed that the grains of these two metal systemswere spherical in nature. In each metal system, at high N:C molar ratio, small grain size has resulted. At highN:C ratio, lower oxidation state of metal ion is resulted where the metal system is susceptible for reduction. Thesusceptibility of metal ions to undergo reduction controlled the formation of end products in the sol-gel process.

  9. cuGWAM: Genome-wide association multifactor dimensionality reduction using CUDA-enabled high-performance graphics processing unit.

    Science.gov (United States)

    Kwon, Min-Seok; Kim, Kyunga; Lee, Sungyoung; Park, Taesung

    2012-01-01

    Multifactor dimensionality reduction (MDR) method has been widely applied to detect gene-gene interactions that are well recognized as playing an important role in understanding complex traits. However, because of an exhaustive analysis of MDR, the current MDR software has some limitations to be extended to the genome-wide association studies (GWAS) with a large number of genetic markers up to approximately 1 million. To overcome this computational problem, we developed CUDA (Compute Unified Device Architecture) based genome-wide association MDR (cuGWAM) software using efficient hardware accelerators, cuGWAM has better performance than CPU-based MDR methods and other GPU-based methods.

  10. Surface-reconstructed Cu Electrode via a Facile Electrochemical Anodization-Reduction Process for Low Overpotential CO 2 reduction

    KAUST Repository

    Min, Shixiong

    2017-03-21

    A high-surface-area Cu electrode, fabricated by a simple electrochemical anodization-reduction method, exhibits high activity and selectivity for CO2 reduction at low overpotential in 0.1 M KHCO3 solution. A faradaic efficiency of 37% for HCOOH and 27% for CO production was achieved with the current density of 1.5 mA cm-2 at −0.64 V vs. RHE, much higher than that of polycrystalline Cu. The enhanced catalytic performance is a result of the formation of the high electrochemical active surface area and high density of preferred low-index facets.

  11. Synthesis of Solution-Processed Cu{sub 2}ZnSnSe{sub 4} Thin Films on Transparent Conducting Oxide Glass Substrates

    Energy Technology Data Exchange (ETDEWEB)

    Ismail, Agus; Cho, Jin Woo; Park, Se Jin; Hwang, Yun Jeong; Min, Byoung Koun [Korea Institute of Science and Technology, Seoul (Korea, Republic of)

    2014-07-15

    Received February 10, 2014, Accepted March 7, 2014 Cu{sub 2}ZnSnSe{sub 4} (CZTSe) thin films were synthesized on transparent conducting oxide glass substrates via a simple, non-toxic, and low-cost process using a precursor solution paste. A three-step heating process (oxidation, sulfurization, and selenization) was employed to synthesize a CZTSe thin film as an absorber layer for use in thin-film solar cells. In particular, we focused on the effects of sulfurization conditions on CZTSe film formation. We found that sulfurization at 400 .deg. C involves the formation of secondary phases such as CuSe{sub 2} and Cu{sub 2}SnSe{sub 3}, but they gradually disappeared when the temperature was increased. The formed CZTSe thin films showed homogenous and good crystallinity with grain sizes of approximately 600 nm. A solar cell device was tentatively fabricated and showed a power conversion efficiency of 2.2% on an active area of 0.44 cm{sup 2} with an open circuit voltage of 365 mV, a short current density of 20.6 mA/cm{sup 2}, and a fill factor of 28.7%.

  12. Consolidation of powders of the oxide superconductor YBa/sub 2/Cu/sub 3/Ox by high energy-high rate processing

    Energy Technology Data Exchange (ETDEWEB)

    Persad, C.; Lee, S.J.; Peterson, D.R.; Swinnea, J.S.; Schmerling, M.

    1988-01-01

    The consolidation response of powders of the superconducting compound YBa/sub 2/Cu/sub 3/Ox is reported. Copper, silver, tin, and Cu-based metallic glass infiltrates have also been employed in preliminary fabricability studies. The processing approach relies on short-duration (< 1s), high-current-density 10000 A/sq.cm, pulse-resistive heating of powders under applied pressures of 200 MPa to 400 MPa. Powders and fabricated disk compacts were characterized by X-ray diffraction, optical and scanning electron microscopy, and resistivity measurements. X-ray diffraction comparisons of starting powder and consolidated material show retention of the single phase 1-2-3 structure and the development of a preferred orientation. In the consolidated pure YBa/sub 2/Cu/sub 3/0x, Tc onsets of 87K were accompanied by broad transitions. Iodometric analyses indicated oxygen depletion in the as-consolidated disks. Observed oxygen-content profiles across the sample thickness had values 0.11< x <0.35. The variation in the peak processing temperature within the disk was found to correlate with the oxygen content profile.

  13. Understanding the densification process of Bi2Sr2CaCu2O x round wires with overpressure processing and its effect on critical current density

    Science.gov (United States)

    Matras, M. R.; Jiang, J.; Larbalestier, D. C.; Hellstrom, E. E.

    2016-10-01

    Overpressure (OP) processing increases the critical current density ({{\\boldsymbol{J}}}{{C}}) of Bi2Sr2CaCu2O x (2212) round wires by shrinking the surrounding Ag matrix around the 2212 filaments, driving them close to full density and greatly increasing the 2212 grain connectivity. Indeed densification is vital for attaining the highest {{\\boldsymbol{J}}}{{C}}. Here, we investigate the time and temperature dependence of the wire densification. We find that the wire diameter decreases by 3.8 ± 0.3% after full heat treatment at 50 atm and 100 atm OP. At 50 atm OP pressure, the filaments start densifying above 700 °C and reach a 3.30 ± 0.07% smaller diameter after 2 h at 820 °C, which is below the melting point of 2212 powder. The densification is homogeneous and does not change the filament shape before melting. The growth of non-superconducting phases is observed at 820 °C, suggesting that time should be minimized at high temperature prior to melting the 2212 powder. Study of an open-ended 2.2 m long wire sample shows that full densification and the high OP {{\\boldsymbol{J}}}{{C}} ({{\\boldsymbol{J}}}{{C}} varies by about 3.1 times over the 2.2 m long wire) is reached about 1 m from the open ends, thus showing that coil-length wires can be protected from leaky seals by adding at least 1 m of sacrificial wire at each end.

  14. Removal of Cu, Pb and Zn by foam fractionation and a soil washing process from contaminated industrial soils using soapberry-derived saponin: a comparative effectiveness assessment.

    Science.gov (United States)

    Maity, Jyoti Prakash; Huang, Yuh Ming; Hsu, Chun-Mei; Wu, Ching-I; Chen, Chien-Cheng; Li, Chun-Yi; Jean, Jiin-Shuh; Chang, Young-Fo; Chen, Chen-Yen

    2013-08-01

    The feasibility of using the eco-friendly biodegradable surfactant saponin (a plant-based surfactant) from soapberry and surfactin from Bacillus subtilis (BBK006) for the removal of heavy metals from contaminated industrial soil (6511mgkg(-1) copper, 4955mgkg(-1) lead, and 15090mgkg(-1) zinc) by foam fractionation and a soil flushing process was evaluated under variation of fundamental factors (surfactant concentration, pH, temperature and time). The results of latter process showed that 1-2% Pb, 16-17% Cu and 21-24% Zn was removed by surfactin after 48h, whereas the removal of Pb, Cu and Zn was increased from 40% to 47%, 30% to 36% and 16% to 18% in presence of saponin with an increase from 24 to 72h at room temperature by the soil washing process at pH 4. In the foam fractionation process, the metal removal efficiencies were increased with increases in the saponin concentration (0.075-0.15gL(-1)) and time (24-72h), whereas the efficiency was decreased with increasing pH (4-10) and temperature (>40°C). The removal efficiencies of Pb, Cu and Zn were increased significantly from 57% to 98%, 85% to 95% and 55% to 56% with an increase in the flow rate from 0.2 to 1.0Lmin(-1) at 0.15gL(-1) saponin (pH 4 and 30°C). The present investigation indicated that the foam fractionation process is more efficient for the removal of heavy metal from contaminated industrial soil in comparison to the soil washing process. The plant-based eco-friendly biodegradable biosurfactant saponin can be used for environmental cleanup and pollution management.

  15. Layer growth and electronic defect properties of CuInS{sub 2} absorber layers from the sequence process; Schichtwachstum und elektronische Defekteigenschaften von CuInS{sub 2}-Absorberschichten aus dem sequentiellen Prozess

    Energy Technology Data Exchange (ETDEWEB)

    Siemer, K.

    2000-10-01

    The following topics were covered: synthesis of CuInS{sub 2} solar cells, layer growth of CuInS{sub 2} absorbers, electrical characterization, C-V and DLTS spectroscopy, defect spectroscopy of CuInS{sub 2} solar cells.

  16. In-situ optical emission spectroscopy for a better control of hybrid sputtering/evaporation process for the deposition of Cu(In,Ga)Se{sub 2} layers

    Energy Technology Data Exchange (ETDEWEB)

    Posada, Jorge; Jubault, Marie [Institute of Research and Development on Photovoltaic Energy (IRDEP), EDF-CNRS-Chimie ParisTech, UMR 7174, 6 Quai Watier, 78401 Chatou (France); Bousquet, Angélique; Tomasella, Eric [Clermont Université, Université Blaise Pascal, Institute of Chemistry of Clermont-Ferrand (ICCF), CNRS-UMR 6296, 24 Avenue des Landais, 63171 Aubière (France); Lincot, Daniel [Institute of Research and Development on Photovoltaic Energy (IRDEP), EDF-CNRS-Chimie ParisTech, UMR 7174, 6 Quai Watier, 78401 Chatou (France)

    2015-05-01

    In this work, we have developed a hybrid one-step co-sputtering/evaporation Cu(In,Ga)Se{sub 2} (CIGS) process, where Cu, In and Ga are sputtered simultaneously with the thermal evaporation of selenium, thus avoiding the H{sub 2}Se use. An appropriate control of the selenium flux is very important to prevent the target poisoning and hence some material flux variations. Indeed, the control of the CIGS composition must be rigorous to ensure reproducible solar cell properties. In this regard, a study of the correlations between plasma species and thin film composition, structure and morphology has been performed by varying power values and Se evaporation temperature in the 170 to 230 °C range. We started by studying the plasma with a powerful technique: optical emission spectroscopy, following light emissions from different plasma species: sputtered Cu, Ga, In but also evaporated Se. Hence, we determined the Se flow threshold avoiding target poisoning and the main parameter controlling the CIGS composition. Obviously, we also focused our interest on the material. We measured film composition and thickness of the samples with X-ray fluorescence and by energy dispersive X-ray. Different phases formed during the process were identified by Raman spectroscopy and X-ray diffraction. The optoelectronic cell properties showed promising efficiency of 10.3% for an absorber with composition ratios of [Cu]/([In] + [Ga]) = 1.02 and [Ga]/([In] + [Ga]) = 0.44. Finally, this work shows that we are able to control this hybrid process and thus the structure and composition of CIGS thin film for industrial transfer in the photovoltaic field. - Highlights: • We have developed a hybrid one-step co-sputtering/evaporation Cu(In,Ga)Se{sub 2} process. • Correlations between plasma species and thin film composition have been performed. • We determined the Se flow threshold avoiding target poisoning. • Efficient small-area CIGS cells with 10.3% efficiency were fabricated.

  17. Preparation of (Bi,Pb)2Sr2Ca2Cu3Ox precursor powders by a modified polyethylene glycol based sol-gel process

    DEFF Research Database (Denmark)

    Grivel, Jean-Claude; Andersen, N.H.

    2002-01-01

    A modified sol-gel process based on polyethylene glycol has been developed for preparing (Bi,Pb)(2)Sr2Ca2Cu3Ox precursor powders in view of Ag-sheeted tape manufacture. A careful control of the pH and concentration temperature yields an amorphous gel, which can be converted to a fine and extremely...... reactive powder. The reactions taking place during the process were studied. Various calcination conditions were used in order to obtain precursor powders having different characteristics (grain size distribution. phase assembly). The influence of precursor preparation parameters on the formation...

  18. The microstructure infl uence on the chip formation process of Al-Cu alloy cast conventionally and in semi solid state

    Directory of Open Access Journals (Sweden)

    P. Kovač

    2012-01-01

    Full Text Available For many metal alloys, the process of metal cutting is accompanied by extensive plastic deformation and fracture. To study this process, quick stop sectional samples of hypoeutectic Al-Cu alloy chip formation, either as conventionally cast alloy or as “semi solid metal” are used. The type of chip formation is classifi ed according to crack formation mechanism and propagation. During cutting, in all specimens used, quasi-continuous chips with built-up edge (BUE are obtained. The formation of BUE is undesirable since it is a highly deformed body with a semi stable top which periodically breaks away giving rise to poor workpiece surface quality.

  19. Solidification process of Cu66Ti34 amorphous alloysimulated by molecular dynamics%Cu66Ti34非晶合金凝固过程的分子动力学模拟

    Institute of Scientific and Technical Information of China (English)

    邱克强; 厉虹; 孙晶; 尤俊华; 任英磊; 李庆丰

    2011-01-01

    采用分子动力学模拟了二元合金Cu66Ti34的凝固过程.原子间作用采用GEAM势,利用偶关联函数,均方位移(MSD)等分析方法,研究Cu66Ti34合金在4×1013 K/s冷却速度下的玻璃化转变温度、原子的扩散行为.结果表明,通过偶分布函数第一谷的最小值与第一峰最大值之比获得的玻璃转变温度为600 K,与相近成分Cu50Ti50的实验值接近;在800 K时,Cu和Ti的MSD最大值均小于1×10-2 nnm2,合金熔体很粘稠;在600 K时,曲线的斜率降低,在动力学上合金熔体已经凝固.定压比热容与温度成二次分布关系,存在一个峰值温度为892 K的热力学玻璃转变温度,证明了用动力学方法和用热力学方法获得的玻璃转变温度之间的差异.%The solidification process of Cu66Ti34 binary alloy was studied by molecular dynamics simulation. The general embedded atomic (GEAM) potential was selected as many-body interaction. The analytical methods, such as pair correction function (PCF) and mean square displacement (MSD), were employed to calculate the glass transition temperature (Tg) and the diffusion behaviors of atoms at cooling rate of 4×l013 K/s. The results show that the glass transition temperature obtained from inflection point of the curve is 600 K, which is the ratio of minimum to maximum of the first peak of PCF for Cu66Ti34 alloy, and is comparable to that of Cu50Ti50 alloy. The maximum of MSD is lower than 1× 10-2nm2 when the temperature is 800 K, showing that the melt is very sticky. However, when the temperature reaches 600 K, the slope of the curve becomes smaller, showing that the melt is frozen dynamically, which shows that the glass transition temperature varies possibly in certain range due to dynamical factor. Simultaneously, the calculated specific heat capacity (cp) at constant pressure shows that it distributes in secondary order vs temperature. The peak temperature or the glass transition temperature is 892 K, which shows the

  20. Electroreflectance of CuInS{sub 2}-solar cells for the optimization of the process parameters during the absorbers production process; Elektroreflexion an CuInS{sub 2}-Solarzellen im Hinblick auf die Optimierung der Prozessparameter bei der Absorber-Herstellung

    Energy Technology Data Exchange (ETDEWEB)

    Henninger, R.

    2002-07-01

    CuInS{sub 2} thin film solar cells were prepared by a new sequential process. The quality of these layers and the conversion efficiency of the solar cells depends on the process parameters of the sequential process. Electroreflectance measurements are used to characterize these solar cells. This method is suitable to measure optical properties like band gap energy and to detect secondary phases in the vicinity of the heterojunction and defects in the semiconductor. Electroreflectance measurements of the thin film solar cells shows clearly a dependence of film growth from the process parameters copper to indium ratio and sulfurization temperature. From the correlation of electroreflectance results with photoluminescence, X-ray-diffraction and external quantum efficiency measurements a model of film growth was derived. Solar cells made from optimized CuInS{sub 2} films reach an active area efficiency of 12,5%. This is the best efficiency reported so far for this type of solar cell. (orig.) [German] Mit einem neuen sequentiellen Verfahren wurden CuInS{sub 2}-Duennfilme fuer die Solarzellen-Anwendung hergestellt. Die Qualitaet dieser Schichten und damit der Solarzellenwirkungsgrad haengen von den Prozessparametern des sequentiellen Prozesses ab. Elektroreflexion wurde als Messverfahren zur Charakterisierung der fertigen Solarzellen eingesetzt. Dieses Verfahren ist geeignet um optische Eigenschaften, wie die Bandlueckenenergie, zu bestimmen und Fremdphasen in der Naehe des pn-Ueberganges sowie Defekte im Halbleiter nachzuweisen. In Elektroreflexionsmessungen an den hergestellten Duennfilmsolarzellen zeigte sich deutlich eine Abhaengigkeit des Schichtwachstums von den Prozessparametern Kupfer-Indium-Verhaeltnis und Sulfurisierungstemperatur. Aus der Korrelation der Elektroreflexionsergebnisse mit Photolumineszenz-, Roentgenbeugungs- und Quantenausbeutemessungen wurde ein Modell zur Schichtbildung von CuInS{sub 2} abgeleitet. Solarzellen aus optimierten CuInS{sub 2

  1. Processing of W-Cu functionally graded materials (FGM) through the powder metallurgy route: application as plasma facing components for ITER-like thermonuclear fusion reactor; Elaboration de materiaux W-Cu a gradient de proprietes fonctionnelles (FGM) par metallurgie des poudres: application en tant que composants face au plasma de machines de fusion thermonucleaire de type Iter

    Energy Technology Data Exchange (ETDEWEB)

    Raharijaona, J.J.

    2009-11-15

    The aim of this study was to study and optimize the sintering of W-Cu graded composition materials, for first wall of ITER-like thermonuclear reactor application. The graded composition in the material generates graded functional properties (Functionally Graded Materials - FGM). Rough thermomechanical calculations have shown the interest of W-Cu FGM to improve the lifetime of Plasma Facing Components (PFC). To process W-Cu FGM, powder metallurgy route was analyzed and optimized from W-CuO powder mixtures. The influence of oxide reduction on the sintering of powder mixtures was highlighted. An optimal heating treatment under He/H{sub 2} atmosphere was determined. The sintering mechanisms were deduced from the analysis of the effect of the Cu-content. Sintering of W-Cu materials with a graded composition and grain size has revealed two liquid migration steps: i) capillary migration, after the Cu-melting and, ii) expulsion of liquid, at the end of sintering, from the dense part to the porous part, due to the continuation of W-skeleton sintering. These two steps were confirmed by a model based on capillary pressure calculation. In addition, thermal conductivity measurements were conducted on sintered parts and showed values which gradually increase with the Cu-content. Hardness tests on a polished cross-section in the bulk are consistent with the composition profiles obtained and the differential grain size. (author)

  2. La_2CuO_4微晶的溶胶-凝胶法制备及合成活化能%Preparation and Activation Energy of La_2CuO_4 Micro-crystallites Synthesized by Sol–Gel Process

    Institute of Scientific and Technical Information of China (English)

    李意峰; 黄剑锋; 曹丽云; 吴建鹏

    2011-01-01

    以硝酸镧和硝酸铜为起始原料、水为溶剂、柠檬酸为络合剂,采用溶胶-凝胶法制备La2CuO4微晶。通过热重-差热分析、X射线衍射、红外光谱和透射电子显微镜等表征前驱物凝胶粉体及La2CuO4粉体的热性能、物相组成、官能团及显微结构,用Kissinger法研究La2CuO4微晶的合成活化能。结果表明采用溶胶-凝胶法可以成功制备La2CuO4微晶:600℃煅烧2h可获得单一物相的La2CuO4;煅烧温度升至700℃后,La2CuO4晶粒形状为正交晶型结构,晶粒尺寸100~120nm,晶粒分布比较均匀。计算得到La2CuO4微晶的合成活化能为147.0kJ/mol。%Micro-crystallite La2CuO4 was prepared via a sol–gel process using lanthanum nitrate and cupric nitrate as raw materials,distilled water as solvent,and citric acid as complexing agent.Thermal properties,phase composition,functional group,and micro-structure of the as-prepared La2CuO4 were characterized by thermogravimetric–differential thermal analysis,X-ray diffraction,infra-red spectroscopy,and transmission electron microscopy.Synthesis activation energy of La2CuO4 was investigated by Kissinger method.Results show that La2CuO4 can be successfully prepared by the sol–gel process,and pure La2CuO4 can be obtained by cal-cining at 600 ℃ for 2 h.When calcination temperature is increased to 700 ℃,the La2CuO4 exhibits an orthogonal structure,the grain distribution is uniform and the size is about 100–120 nm.The preparation activation energy of La2CuO4 is calculated to be 147.0 kJ/mol.

  3. Nonlinear optical processes at quadrupole polariton resonance in Cu2O as probed by a Z-scan technique

    Science.gov (United States)

    Mani, S.; Jang, J. I.; Ketterson, J. B.

    2010-09-01

    Employing a modified Z-scan technique at 2 K, we monitor not only the fundamental (ω) but also the frequency-doubled (2ω) and tripled (3ω) Z-scan responses in Cu2O when the input laser frequency ω is tuned to the two-photon quadrupole polariton resonance. The Z-scan response at ω allows us to accurately estimate the absolute number of polaritons generated via two-photon absorption. A striking dip is observed near the 2ω Z-scan focus which basically arises from Auger-type recombination of polaritons. Under high excitation levels, the 3ω Z-scan shows strong third harmonic generation. Based on the nonlinear optical parameters determined, we estimate the experimental polariton density achievable and propose a direction for polariton-based Bose-Einstein condensation in Cu2O .

  4. Phase formation and reaction kinetics during the processing of the chalkopyrite-solar-cell-material Cu(In,Ga)(Se,S){sub 2}; Phasenbildung und Reaktionskinetik bei der Herstellung des Chalkopyrit-Solarzellenmaterials Cu(In,Ga)(Se,S){sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Purwins, Michael

    2010-02-05

    The SEL/RTP-procedure (Stacked-Elemental-Layer/Rapid-Thermal-Process) is a method which is used to produce CuInSe{sub 2}-based absorbers/semiconductors for the application in thin film solar cells and modules, respectively. The SEL/RTP-procedure consists of two consecutive steps. During the first step a stack of several layers of the metals Cu, Ga and In as well as Se and/or S are deposited onto a substrate to form the so called precursor. By annealing the precursor, reaching temperatures of about 550 C, the stacked layers are converted into the compound semiconductor Cu(In{sub 1-x}Ga{sub x})(S{sub 1-y}Se{sub y}){sub 2} (CIGSSe). During the thermal process the central component of the later solar cell, the highly light absorbing, photoelectric active layer is formed. Thus, the second step is of great importance. This is not only because of the fact that the absorbers physical properties are established by the thermal process. Additionally the profitability of the whole manufacturing process is affected. To be able to optimize the SEL/RTP-procedure a deep and comprehensive understanding of the occurring phase formation processes and reaction kinetic mechanisms associated with them is necessary. This was the goal of the present thesis which therefore deals with the phase formation processes during the deposition of the precursor and its reaction kinetics during the following selenization and sulfurization process. Therefore the influence of different sputtering parameters on the formation of phases and the evolution of the precursor's morphology during its production by sputtering alternating stacked layers of Cu:Ga-alloys (i.e. Cu{sub 85}Ga{sub 15}, Cu{sub 75}Ga{sub 25} and CuGa{sub 2}) and/or the elements Cu and In was investigated. It was found that the deposition of Cu{sub 75/85}Ga{sub 25/15} onto In leads to the formation of CuIn{sub 2} and/or a metastable Cu(In,Ga)-alloy that is rich in copper. This deposition sequence is crucial for the precursor

  5. Effect of Se flux on CuGaSe2 absorbers deposited on ITO-coated SLG substrates by using a three-stage co-evaporation process

    Science.gov (United States)

    Yoo, Jinsu; Eo, Young-Joo; Cho, Jun-Sik; Yun, Jae-Ho; Choi, Jang Hun; Kim, Kihwan; Park, Ju Hyung; Kong, Seong Ho

    2016-11-01

    As the key factor for top-cell application in a tandem structure, wide-bandgap chalcopyrite CuGaSe2 (CGS) absorbers were deposited at a thickness of 2 μm on soda-lime glass (SLG) which was coated with radio-frequency sputtered indium-tin-oxide (ITO) films. The semi-transparent CGS absorbers with a bandgap energy of 1.65 eV were grown by using a three-stage co-evaporation process with Cu, Ga, and Se elemental sources. During CGS absorber growth, the composition ratio [Cu]/[Ga] was fixed at about 0.85 and the Se-to-Ga flux ratio P [ Se]/[ Ga] was varied from 22 to 61 by increasing the temperature of the Se source. In this study, the compositional, structural, optical and electrical properties of top-cell CGS absorbers, which absorbed the short wavelength range of the solar spectrums for tandem solar cell application, were investigated as a function of the Se flux. On the basis of our experimental results, the highest CGS solar cell efficiency of 4.7 % in the cell structure described as Al/ZnO:Al/i-ZnO/CdS/CGS/ITO/SLG was demonstrated using a P [ Se]/[ Ga] value of 22.

  6. Totally solution-processed CuInS2 solar cells based on chloride inks: reduced metastable phases and improved current density

    Science.gov (United States)

    Dehghani, Mehdi; Behjat, Abbas; Tajabadi, Fariba; Taghavinia, Nima

    2015-03-01

    Planar superstrate CuInS2 (CIS) solar cell devices are fabricated using totally solution-processed deposition methods. These Cd-free devices are structured by FTO/TiO2/In2S3/CIS/carbon, where TiO2 and In2S3 are deposited by spray pyrolysis, and a CIS film is deposited using spin-coating followed by annealing at 250 °C. The pasted carbon layer is utilized as the anode. No further sulfurization or selenization is employed. The Cu/In ratio in the ink is found as a critical factor affecting the morphology and crystallinity of the film as well as the photovoltaic performance of the device. An optimum Cu/In = 1.05 results in large-grain films with sharp diffraction peaks and, subsequently, optimal series resistance and shunt conductance. It is also found that the chloride-based ink results in CIS films with considerably reduced metastable phases, compared to the conventional acetate-based inks. A current density of 23.6 mA cm-2 is obtained for the best devices, leading to a conversion efficiency of 4.1%.

  7. Reaction Time and Film Thickness Effects on Phase Formation and Optical Properties of Solution Processed Cu2ZnSnS4 Thin Films

    Science.gov (United States)

    Safdar, Amna; Islam, Mohammad; Akram, Muhammad Aftab; Mujahid, Mohammad; Khalid, Yasir; Shah, S. Ismat

    2016-02-01

    Copper-zinc-tin-sulfide (Cu2ZnSnS4 or CZTS) is a promising p-type semiconductor material as absorber layer in thin film solar cells. The sulfides of copper and tin as well as zinc and sulfur powders were dissolved in hydrazine. The effect of chemical reaction between precursor species, at room temperature, was assessed for 6 to 22 h. For 22 h reaction time, the effect of spin coated film thickness on the resulting composition, after annealing under N2 flow at 500 °C for 1 h, was investigated. The morphology, composition, and optical properties of the annealed films were determined by means of x-ray diffraction, scanning electron microscope, and spectrophotometer studies. It was found that, for less than optimal reaction time of 22 h or film thickness below 1.2 µm, other ternary phases namely Cu4SnS4, Cu5Sn2S7, and ZnS co-exist in different proportions besides CZTS. Formation of phase-pure CZTS films also exhibited a tendency to minimize film cracking during annealing. Depending on the processing conditions, the band gap ( E g) values were determined to be in the range of 1.55 to 1.97 eV. For phase-pure annealed CZTS film, an increase in the E g value may be attributed to quantum confinement effect due to small crystallite size.

  8. Effect of preparation conditions on the properties of Cu{sub 3}BiS{sub 3} thin films grown by a two - step process

    Energy Technology Data Exchange (ETDEWEB)

    Mesa, F; Gordillo, G, E-mail: fgmesar@unal.edu.c, E-mail: ggordillog@unal.edu.c [Departamento de Fisica, Universidad Nacional de Colombia, Bogota Cr.30 No 45-03 (Colombia)

    2009-05-01

    Cu{sub 3}BiS{sub 3} thin films were prepared on soda-lime glass substrates by co-evaporation of the precursors in a two-step process; for that, the metallic precursors were evaporated from a tungsten boat in presence of elemental sulfur evaporated from a tantalum effusion cell. The films were characterized by spectral transmittance, atomic force microscopy AFM and x-ray diffraction (XRD) measurements to investigate the effect of the growth conditions on the optical, morphological and structural properties. The results revealed that, independently of the deposition conditions, the films grow only in the orthorhombic Cu{sub 3}BiS{sub 3} phase. It was also found that the Cu{sub 3}BiS{sub 3} films present p-type conductivity, a high absorption coefficient (greater than 10{sup 4} cm{sup -1}) and an energy band gap Eg of about 1.41 eV, indicating that this compound has good properties to perform as absorbent layer in thin film solar cells.

  9. Improved efficiency of a large-area Cu(In,Ga)Se₂ solar cell by a nontoxic hydrogen-assisted solid Se vapor selenization process.

    Science.gov (United States)

    Wu, Tsung-Ta; Hu, Fan; Huang, Jyun-Hong; Chang, Chia-ho; Lai, Chih-chung; Yen, Yu-Ting; Huang, Hou-Ying; Hong, Hwen-Fen; Wang, Zhiming M; Shen, Chang-Hong; Shieh, Jia-Min; Chueh, Yu-Lun

    2014-04-01

    A nontoxic hydrogen-assisted solid Se vapor selenization process (HASVS) technique to achieve a large-area (40 × 30 cm(2)) Cu(In,Ga)Se2 (CIGS) solar panel with enhanced efficiencies from 7.1 to 10.8% (12.0% for active area) was demonstrated. The remarkable improvement of efficiency and fill factor comes from improved open circuit voltage (Voc) and reduced dark current due to (1) decreased interface recombination raised from the formation of a widened buried homojunction with n-type Cd(Cu) participation and (2) enhanced separation of electron and hole carriers resulting from the accumulation of Na atoms on the surface of the CIGS film. The effects of microstructural, compositional, and electrical characteristics with hydrogen-assisted Se vapor selenization, including interdiffusion of atoms and formation of buried homojunction, were examined in detail. This methodology can be also applied to CIS (CuInSe2) thin film solar cells with enhanced efficiencies from 5.3% to 8.5% (9.4% for active area) and provides a facile approach to improve quality of CIGS and stimulate the nontoxic progress in the large scale CIGS PV industry.

  10. Surface-Mechanical Properties of Electrodeposited Cu-Al2O3 Composite Coating and Effects of Processing Parameters

    Science.gov (United States)

    Maharana, H. S.; Ashok, Akarapu; Pal, S.; Basu, A.

    2016-01-01

    Cu/Al2O3 composite coatings were prepared from acidic copper sulfate bath containing ultrafine Al2O3 particles by direct current plating method to increase the surface-mechanical property of Cu for its possible use as electrical contact. Effect of ultrafine Al2O3 particle concentration in electrolyte and deposition current density on the surface-mechanical properties of the coatings was investigated. Coatings were characterized by scanning electron microscopy and X-ray diffraction (XRD) techniques for the purpose of surface morphology and phase study. From XRD data, crystallographic texture of the coating was also analyzed. To study the mechanical properties, microhardness testing, adhesion, and wear test were carried out. Improved hardness of the resultant coatings was observed and was correlated with the wt pct of ultrafine particle in the Cu matrix, matrix structure, and crystallographic orientation. Better wear property of the composite coating was also reported from the wear plot and wear track morphology. Altogether, better coating property was attributed toward finer matrix, hard reinforced phase, and preferred orientation in selected conditions. Electrical conductivity of the coating was affected by grain size and second-phase concentration, and the values obtained were in the usable range required for electrical applications.

  11. Electron spin relaxation governed by Raman processes both for Cu²⁺ ions and carbonate radicals in KHCO₃ crystals: EPR and electron spin echo studies.

    Science.gov (United States)

    Hoffmann, Stanislaw K; Goslar, Janina; Lijewski, Stefan

    2012-08-01

    EPR studies of Cu²⁺ and two free radicals formed by γ-radiation were performed for KHCO₃ single crystal at room temperature. From the rotational EPR results we concluded that Cu²⁺ is chelated by two carbonate molecules in a square planar configuration with spin-Hamiltonian parameters g(||)=2.2349 and A(||)=18.2 mT. Free radicals were identified as neutral HOCO· with unpaired electron localized on the carbon atom and a radical anion CO₃·⁻ with unpaired electron localized on two oxygen atoms. The hyperfine splitting of the EPR lines by an interaction with a single hydrogen atom of HOCO· was observed with isotropic coupling constants a₀=0.31 mT. Two differently oriented radical sites were identified in the crystal unit cell. Electron spin-lattice relaxation measured by electron spin echo methods shows that both Cu²⁺ and free radicals relax via two-phonon Raman processes with almost the same relaxation rate. The temperature dependence of the relaxation rate 1/T₁ is well described with the effective Debye temperature Θ(D)=175 K obtained from a fit to the Debye-type phonon spectrum. We calculated a more realistic Debye temperature value from available elastic constant values of the crystal as Θ(D)=246 K. This Θ(D)-value and the Debye phonon spectrum approximation give a much worse fit to the experimental results. Possible contributions from a local mode or an optical mode are considered and it is suggested that the real phonon spectrum should be used for the relaxation data interpretation. It is unusual that free radicals in KHCO₃ relax similarly to the well localized Cu²⁺ ions, which suggests a small destruction of the host crystal lattice by the ionizing irradiation allowing well coupling between radical and lattice dynamics.

  12. Electron spin relaxation governed by Raman processes both for Cu2+ ions and carbonate radicals in KHCO3 crystals: EPR and electron spin echo studies

    Science.gov (United States)

    Hoffmann, Stanislaw K.; Goslar, Janina; Lijewski, Stefan

    2012-08-01

    EPR studies of Cu2+ and two free radicals formed by γ-radiation were performed for KHCO3 single crystal at room temperature. From the rotational EPR results we concluded that Cu2+ is chelated by two carbonate molecules in a square planar configuration with spin-Hamiltonian parameters g|| = 2.2349 and A|| = 18.2 mT. Free radicals were identified as neutral HOCOrad with unpaired electron localized on the carbon atom and a radical anion CO3·- with unpaired electron localized on two oxygen atoms. The hyperfine splitting of the EPR lines by an interaction with a single hydrogen atom of HOCOrad was observed with isotropic coupling constants ao = 0.31 mT. Two differently oriented radical sites were identified in the crystal unit cell. Electron spin-lattice relaxation measured by electron spin echo methods shows that both Cu2+ and free radicals relax via two-phonon Raman processes with almost the same relaxation rate. The temperature dependence of the relaxation rate 1/T1 is well described with the effective Debye temperature ΘD = 175 K obtained from a fit to the Debye-type phonon spectrum. We calculated a more realistic Debye temperature value from available elastic constant values of the crystal as ΘD = 246 K. This ΘD-value and the Debye phonon spectrum approximation give a much worse fit to the experimental results. Possible contributions from a local mode or an optical mode are considered and it is suggested that the real phonon spectrum should be used for the relaxation data interpretation. It is unusual that free radicals in KHCO3 relax similarly to the well localized Cu2+ ions, which suggests a small destruction of the host crystal lattice by the ionizing irradiation allowing well coupling between radical and lattice dynamics.

  13. Distribution of Bioactive Trace Metals (Fe, Co, Ni, Cu and Zn) in the semiarid Kuwait Bay, stressed by natural and anthropogenic processes

    Science.gov (United States)

    Al-Said, T. F.; Pokavanich, T.; Al-Hashem, A.; Kedila, R.

    2016-02-01

    Kuwait is in the northwestern part of the Arabian Gulf and receives flow from Shatt Al-Arab River as the main fresh water input to the Gulf. Kuwait's waters can be described as eutrophic, euphotic, and highly saline waters. The main objective of the study is to assess spatial and temporal distribution of Cu, Co, Zn, Fe and Ni, nutrients such as nitrate and phosphate, chlorophyll-a and physical variables along transects in Kuwait's Waters. No systematic research on bioactive metals has been studied in the region. Concentration of trace metal in the shallow Kuwait Bay was relatively high and decreased towards the southern water. This is attributed to higher sewage input, domestic and industrial effluents, dust storms and human activities. Cu, Ni, Fe, Zn and Co levels were measured using proven tested methodology i.e., Adsorptive Cathodic Stripping Voltammetry (Ad-CSV) and Flow Injection Analyzer (FIA). Surface seawater samples were collected from 26 stations using clean polyethylene sampling devices from four transects during two seasons in 2015. Average concentrations of Copper, Nickel, Cobalt, Zinc and chlorophyll-a corresponded to 14.99, 22.32, 0.74, 14.56 nM and 3.05µg/L during June 2015. These values indicated lower concentrations compared to previously published values from Kuwait's waters: Cu 48.52, Ni 26.12, Co 4.69, Zn 93.86 nM. Two transects conducted during summer 2015 showed positive relationship between metals (Cu, Co and Ni) and chlorophyll. Strong and apparent correlation was observed between cobalt and chlorophyll-a in Kuwait Bay indicating that these micronutrient are abundant and higher than phytoplankton essential requirements. Recent measured Fe concentration 7.95nM in Kuwait Bay was comparable to values found in similar coastal water. Latest results obtained during the transactional surveys and processes involved in Kuwait's waters will be shown and discussed during the presentation.

  14. Study of the Effect of Process Parameters on Mechanical Properties and Microstructure of Al-Cu and SiCp Reinforced Metal Matrix Composite

    Directory of Open Access Journals (Sweden)

    SERAJUL HAQUE

    2012-12-01

    Full Text Available The high cost of fabrication hindered the actual application of metal matrix composite (MMC despite of their high stiffness, strength, corrosion resistance, wear resistance, non-reactivity with chemicals and so many other tailored quality which are never obtained in alloy of metals. In this study, a modest attempt has been made to find out the process parameters at which best mechanical properties of Al6061, 4%Cu and reinforced 5% SiCp ceramic MMC can be obtained. Addition of 4% Cu in Al6061 is more or less comparable to the composition of duralumin, which is widely used in aerospace applications. SiCp is hard and having linear thermal expansion at high temperature. With reinforcement of SiCp in Al-Cu alloy, it can be postulated thathardness of MMC retains at high temperature applications. An analysis of Variance (ANOVA was used for analysis of data with the help of SPSS (Version-17.0 software. Independent parameters are three levels of pouring rates (1.5cm/s, 2.5 cm/s and 3.5 cm/s, material type (Al6061+4%Cu alloy and Al+4%Cu, reinforced 5%SiCp MMC processed using stir casting technique and dependent parameters are hardness and impact strength, which is found that at different pouring rates material hardness and impact strength are highly significant. At pouring rate of 2.5 cm/s and 700±5°C pouring temperature, optimum values of hardness and impact strength are observed as compared to other values of pouring rates (1.5 cm/s and 3.5 cm/s. With reinforcement of 5% SiC trend of mechanical properties is same, buthardness and impact strength of MMCs are increased by 25% and 20% respectively. Also it is observed from scanning electron microscopy (SEM that at pouring rate 2.5 cm/s a better homogeneity can be obtained.

  15. Differential Scanning Calorimetry (DSC) and Thermodynamic Prediction of Liquid Fraction vs Temperature for Two High-Performance Alloys for Semi-Solid Processing (Al-Si-Cu-Mg (319s) and Al-Cu-Ag (201))

    Science.gov (United States)

    Zhang, Duyao; Atkinson, Helen V.; Dong, Hongbiao; Zhu, Qiang

    2017-10-01

    There is a need to extend the application of semi-solid processing (SSP) to higher performance alloys such as 319s (Al-Si-Cu-Mg) and 201 (Al-Cu-Ag). The melting of these two alloys was investigated using differential scanning calorimetry (DSC) and thermodynamic prediction. The alloys had been processed by magneto-hydrodynamic (MHD) stirring before receipt to produce a microstructure suitable for SSP. The DSC results for the as-received MHD material were compared with those for material which has been taken through a complete DSC cycle and then reheated for a second DSC run. The effects of microsegregation were then analyzed. A higher liquid fraction for a particular temperature is found in the second DSC run than the first. Microstructural observations suggest this is because the intermetallics which form during the first cooling cycle tend to co-located. Quaternary and ternary reactions then occur during the second DSC heat and the co-location leads to enhanced peaks. The calculated liquid fraction is lower with 10 K/min DSC heating rate comparing with 3 K/min at a given temperature. The DSC scan rate must therefore be carefully considered if it is to be used to identify temperature parameters or the suitability of alloys for SSP. In addition, the starting material for DSC must represent the starting material for the SSP. With thermodynamic prediction, the equilibrium condition will provide better guidance for the thixoforming of MHD stirred starting material than the Scheil condition. The Scheil mode approximates more closely with a strongly microsegregated state.

  16. A rapid process of Yba2Cu3O7-δ thin film fabrication using trifluoroacetate metal-organic deposition with polyethylene glycol additive

    DEFF Research Database (Denmark)

    Wu, Wei; Feng, Feng; Shi, Kai

    2013-01-01

    and oxygenation processes, mass percentage and molecular weight of PEG additive, YBCO thin films with Jc of about 4.5 MA cm-2 (77 K, self-field) could be routinely fabricated using (20-30) wt% PEG(1000-2000) additive with a total treatment time of about 2 h including the 15 min pyrolysis process time. The effects......Trifluoroacetate metal-organic deposition (TFA-MOD) is a promising technique to fabricate YBa2Cu3O7-δ (YBCO) superconducting films. However, its slow pyrolysis process, which usually takes more than 10 h, constitutes a barrier for industrial production. In this study, polyethylene glycol (PEG......) was utilized to reduce the stress generation inside the coated films when the strong pyrolysis reactions happen. With the addition of 30 wt% PEG2000 to the precursor solution, a smooth film surface could be obtained through a rapid pyrolysis process of 15 min. After the optimizations of the crystallization...

  17. Electromagnetic Stirring versus ECAP: Morphological Comparison of Al-Si-Cu Alloys to Make the Microstructural Refinement for Use in SSM Processing

    Directory of Open Access Journals (Sweden)

    Luis Vanderlei Torres

    2016-01-01

    Full Text Available This work evaluates the morphological evolution at the semisolid state of the Al-4.0wt%Si-2.5wt%Cu alloy produced by direct chill casting under electromagnetic stirring (EMS and by one equal channel angular pressing (ECAP pass. The ECAP emerged as a promising technique capable of reduction and homogeneous metals microstructure imposing large deformations occurs in a matrix that contains two channels of the same cross-sectional area and forms an angle of 120°. The materials were submitted to reheating treatment in condition of 60% solid fraction at treatment times of 0, 30, and 90 s. Comparing the two cases, we have the presented ECAP process that had an excellent response to the recovery and recrystallization mechanisms, and refined microstructures ideal for thixoforming were produced. Primary particle sizes of about 45 μm and grain sizes of about 75 μm and a circularity shape factor of more than 0.60 were obtained. The low silicon alloy, Al-4.0wt%Si-2.5wt%Cu, presented excellent refinement when processed via equal channel angular pressing, presenting good morphological stability at the semisolid state, without significant changes in size or shape of the solid particles. This fully globular structure is favourable for thixoforming processes.

  18. 热型连铸Cu-Cr合金铸态下的组织与性能%Microstructure and Properties of As-cast Cu-Cr Alloy Made by Heated Mold Continuous Casting Process

    Institute of Scientific and Technical Information of China (English)

    陈先朝; 李林升; 余业球; 黎沃光

    2004-01-01

    用热型连铸法制备过共晶Cu-Cr合金线,探讨了其在铸态下的微观组织形态、力学性能和导电性能.结果表明:随着含Cr量的增加,Cu-Cr合金的抗拉强度增加;拉铸速度增加,Cu-Cr合金的导电性增加.

  19. Variable mineralization processes during the formation of the Permian Hulu Ni-Cu sulfide deposit, Xinjiang, Northwestern China

    Science.gov (United States)

    Zhao, Yun; Xue, Chunji; Zhao, Xiaobo; Yang, Yongqiang; Ke, Junjun; Zu, Bo

    2016-08-01

    The Permian Hulu Ni-Cu sulfide deposit is located at the southern margin of the Central Asian Orogenic Belt (CAOB) in Northern Xinjiang, Northwestern China. The host intrusion of the Hulu deposit is composed of a layered mafic-ultramafic sequence and a dike-like unit. The layered sequence is composed of harzburgite, lherzolite, pyroxenite, gabbro, gabbrodiorite and diorite. The dike-like body comprises lherzolite and gabbro. Sulfide orebodies occur mainly within the harzburgite, pyroxenite and lherzolite at the base of the layered sequence and within the lherzolite in the dike-like body. Sulfide mineralization from the Hulu deposit shows significant depletion of PGE relative to Cu and Ni. These elements show good positive correlations with S in the sulfide mineralization from the dike-like unit but relatively weak correlations in the sulfide mineralization from the layered sequence. The sulfide mineralization from the layered unit shows excellent positive correlations between Ir and Os, Ru or Rh, and poor relationships between Ir and Pt or Pd. On the contrary, sulfide mineralization from the dike-like unit shows good correlations in the diagrams of Os, Ru, Rh, Pt and Pd against Ir. Both high Cu/Pd ratios (8855-481,398) and our modeling indicate that PGE depletion resulted from sulfide removal in a deep staging magma chamber. The evolved PGE-depleted magmas then ascended to the shallower magma chamber and became sulfide saturation due to crustal contamination. Both low Se/S ratios (33.5 × 10-6-487.5 × 10-6) and a negative correlation between Se/S and Cu/Pd ratios are consistent with the addition of crustal S. A large number of sulfide liquids segregated with minor crystallization of monosulfide solid solution (MSS) in the shallower magma chamber. When new magma pulses with unfractionated sulfide droplets entered the shallower magma chamber, the sulfide slurry containing crystallized MSS may be disrupted and mixed with the unfractionated sulfide droplets. The

  20. Membrane Fouling in Cu2+ Removal Process of Ultrafiltration of PEI-Cu2+ Complex in Water%聚乙烯亚胺(PEI)络合-超滤处理水中Cu2+过程中的膜污染

    Institute of Scientific and Technical Information of China (English)

    赵倩

    2011-01-01

    该文依据膜流动电位及zeta电位的测定原理设计了一套试验装置,可对中空纤维膜的流动电位进行测定.通过该装置研究了聚偏氟乙烯(PVDF)中空纤维超滤膜的动电现象在聚乙烯亚胺(PEI)络合-超滤处理水中Cu2+过程中的作用及规律,以此分析膜污染发生的过程与机理,为如何减轻和清洗超滤膜污染提供了依据.%According to the theories of membrane streaming potential and zeta potential, an experimental device was designed to measure streaming potential of hollow fiber membranes. By this design, the process of uItrafiltration of PEI-Cu2+ complex in water, changes of removal rate of Cu2* and streaming potential of the membrane were examined. The electrokinetic phenomenon and mechanism of poly vinylidine fluoride (PVDF) hollow fiber membrane pollution were studied and data for the reduction and cleaning of the membrane contamination were given in this paper.

  1. Temperature field in the hot-top during casting a new super-high strength Al-Zn-Mg-Cu alloy by low frequency electromagnetic process

    Directory of Open Access Journals (Sweden)

    Yubo ZUO

    2005-08-01

    Full Text Available The billets of a new super-high strength Al-Zn-Mg-Cu alloy in 200 mm diameter were produced by the processed of low frequency electromagnetic casting (LFEC and conventional direct chill(DCcasting, respectively. The effects of low frequency electromagnetic field on temperature field of the melt in the hot-top were investigated by temperature thermocouples into the casting during the processes. The results show that during LFEC process the temperature field in the melt applying the hot-top is very uniform, which is helpful to reduce the difference of thermal gradients between the surface and the center, and then to reduce the thermal stress and to eliminate casting crack.

  2. Temperature field in the hot-top during casting a new super-high strength Al-Zn-Mg-Cu alloy by low frequency electromagnetic process

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The billets of a new super-high strength Al-Zn-Mg-Cu alloy in 200mm diameter were produced by the processes of low frequency electromagnetic casting (LFEC) and conventional direct chill (DC) casting, respectively. The effects of low frequency electromagnetic field on temperature field of the melt in the hot-top were investigated by temperature measurement method. Temperature curves were measured from the surface to the center of the billets by locating type K thermocouples into the casting during the processes. The results show that during LFEC process the temperature field in the melt applying the hot-top is very uniform, which is helpful to reduce the difference of thermal gradients between the surface and the center, and then to reduce the thermal stress and to eliminate casting crack.

  3. Preparation and Characterization of Zn x Cu(1- x)O Composite Films on Glass Substrates Through SILAR Processing

    Science.gov (United States)

    Bayansal, Fatİh; Şahİn, Bünyamİn; Yüksel, Mustafa

    2015-07-01

    CuO composite thin films with and without Zn-doping are deposited onto glass substrates by the SILAR method. All the films are characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), UV-Vis spectrophotometry, temperature dependent dc conductivity, and X-ray diffraction (XRD) measurements. SEM results show that the particle size decreases from 27 to 16 nm with increasing Zn-doping. EDX analysis evidences the amount of Zn in CuO films, which increases with increasing Zn concentration in the growth solutions. Transmittance, optical band gap, and activation energy values of the films are found to be increasing from the UV-Vis and temperature dependent dc conductivity measurements with increasing Zn-doping. It also is found from the XRD patterns that mean crystallite size of the films decreases from 18.94 to 13.70 nm with increasing Zn-doping. Moreover, increase in Zn concentration results peak shifts to lower 2 θ values.

  4. Investigation of sol-gel processed CuO/SiO2 nanocomposite as a potential photoanode material

    Directory of Open Access Journals (Sweden)

    Tenkyong Tenzin

    2015-12-01

    Full Text Available Synthesis and characterization of a highly efficient photoconductive nanocomposite comprising of two common metal oxides: copper oxide (CuO and silicon dioxide (SiO2 are being reported in this paper. The CuO/SiO2 nanocomposite has been synthesized using a cost-effective and facile sol gel route. The structural, chemical and optical properties of the prepared samples have been studied using various characterization techniques. The UV-Vis analysis revealed better absorption in the case of the nanocomposite as compared to its parent materials. X-ray diffraction (XRD analysis has been employed to determine the structural formation of the nanocomposite and the crystallite size with the use of Scherrer’s formula. The photo conductivity study of the sample showed enhanced photocurrent in the case of nanocomposite as compared to its single components, thus, presenting it as a potential candidate for solar cell applications, especially as photoanode material in the dye-sensitized solar cells (DSSC.

  5. Preparation, processing and tunneling in YBa2Cu3O(7-[delta])-Pb native-barrier structures

    Energy Technology Data Exchange (ETDEWEB)

    Frangi, F.; Dwir, B.; James, J. H.; Gauzzi, A.; Pavuna, D. (Swiss Federal Institute of Technology, Lausanne (Switzerland). Institute of Micro- and Optoelectonics)

    1993-06-15

    In this study, a procedure for the preparation of small (40[times]40[mu]m[sup 2]) window-type YBa2Cu3O(7-[delta])-Pb junctions with YSZ (yttrium-stabilized zirconium-oxide) insulator and native tunnel barrier has been developed. This paper presents the patterning technique of the two electrodes based on photolithography and wet etching. From the device characteristics, the nature of the barrier was found to be semiconducting. The tunneling I-V curves showed a behavior dominated by the Pb gap at 1.3 meV below 7.2 K. The dI/dV curve also showed an additional feature at 5.3 meV, which disappeared above Tc of Pb, and was attributed to longitudinal Pb phonons. Furthermore, another structure at 8.5 meV that persisted at temperatures above the critical temperature of Pb was attributed to the YBa2Cu3O(7-[delta]) gap. 15 refs., 7 figs.

  6. Microfluidic reactor synthesis and photocatalytic behavior of Cu@Cu{sub 2}O nanocomposite

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Lei, E-mail: xulei_kmust@aliyun.com [National Local Joint Laboratory of Engineering Application of Microwave Energy and Equipment Technology, Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093 (China); Mechanical Engineering, University of Washington, Seattle, WA 98195 (United States); Srinivasakannan, C. [Chemical Engineering Program, The Petroleum Institute, PO Box 253, Abu Dhabi (United Arab Emirates); Peng, Jinhui, E-mail: jhpeng@kmust.edu.cn [National Local Joint Laboratory of Engineering Application of Microwave Energy and Equipment Technology, Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093 (China); Yan, Mi [Faculty of Mathematical and Physical Sciences, University College London, London WC1E 6BT (United Kingdom); Zhang, Di [Mechanical Engineering, University of Washington, Seattle, WA 98195 (United States); Zhang, Libo [National Local Joint Laboratory of Engineering Application of Microwave Energy and Equipment Technology, Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093 (China)

    2015-03-15

    Highlights: • The Cu@Cu{sub 2}O nanocomposites were synthesized in microfluidic reactor followed by oxidation process. • The Cu@Cu{sub 2}O composite particle is on nanoscale exhibiting an open bicontinuous structure. • The amount of Cu{sub 2}O can be controlled by varying drying temperature. • The binary Cu@Cu{sub 2}O–H{sub 2}O{sub 2} systems exhibit an excellent photocatalyst for degradation methylene blue under UV irradiation. - Abstract: The Cu@Cu{sub 2}O nanocomposites were synthesized by solution-phase synthesis of Cu nanoparticles in microfluidic reactor at room temperature, followed by controlling the oxidation process. The size, morphology, elemental compositions, and the chemical composition on the surface of Cu@Cu{sub 2}O nanocomposite were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Experimental results demonstrated that the surface of the Cu nanoparticles was oxidized to Cu{sub 2}O which serves as the shell of nanoparticle. The amount of Cu{sub 2}O can be controlled by varying the drying temperature. Additionally the binary Cu@Cu{sub 2}O nanocomposite along with H{sub 2}O{sub 2} exhibited its potential as an excellent photocatalyst for degradation of methylene blue (MB) under UV irradiation.

  7. A Low-Temperature, Solution-Processable, Cu-Doped Nickel Oxide Hole-Transporting Layer via the Combustion Method for High-Performance Thin-Film Perovskite Solar Cells.

    Science.gov (United States)

    Jung, Jae Woong; Chueh, Chu-Chen; Jen, Alex K-Y

    2015-12-16

    Low-temperature, solution-processable Cu-doped NiOX (Cu:NiOx ), prepared via combustion chemistry, is demonstrated as an excellent hole-transporting layer (HTL) for thin-film perovskite solar cells (PVSCs). Its good crystallinity, conductivity, and hole-extraction properties enable the derived PVSC to have a high power conversion efficiency (PCE) of 17.74%. Its general applicability for various elecrode materials is also revealed.

  8. Correlation between product purity and process parameters for the synthesis of Cu2ZnSnS4 nanoparticles using microwave irradiation

    Science.gov (United States)

    Ahmad, R.; Nicholson, K. S.; Nawaz, Q.; Peukert, W.; Distaso, M.

    2017-07-01

    Kesterites (CZT(S,Se)4) emerged as a favourable photovoltaic material, leading to solar cell efficiencies as high as 12.7%. The development of sustainable roll-to-roll printing processes that make use of Cu2ZnSnS4 (CZTS) nanoparticle inks requires the proper design of synthetic approaches and the understanding of the relation between process parameters and product purity. In the current paper, we developed this relationship by calculating a specific energy factor. A microwave-assisted synthetic method that operates at atmospheric pressure and makes use of eco-friendly solvents is established. Four solvents, i.e. ethylene glycol (EG), diethylene glycol (di-EG), triethylene glycol (tri-EG) and tetraethylene glycol (tet-EG) are compared and the temperature during the reaction is assessed by two different methods. In particular, two by-products have been identified, i.e. Cu2 - x S and a hexagonal phase. We show that the variation of reaction parameters such as power irradiation, type of solvent and precursor concentration influences the nanoparticles' sizes (from 12 to 6 nm) and also the temperature-time profile of reaction which, in turn, can be related to phase purity of CZTS nanoparticles. The results suggest that the product purity scales with the specific energy factor providing a useful tool to a rational design of high-quality CZTS nanoparticles.

  9. Influence of cobalt and chromium additions on the precipitation processes in a Cu-4Ti alloys; Influencia de la adicion de cobalto y cromo en el proceso de precipitacion en una aleacion de Cu-4Ti

    Energy Technology Data Exchange (ETDEWEB)

    Donoso, E.

    2010-07-01

    The influence of 0.5% atomic cobalt and 1% atomic chromium additions on the precipitation hardening of Cu-4Ti alloy was studied by differential scanning calorimetry (DSC) and microhardness measurements. The analysis of the calorimetric curves, for binary alloy, shows the presence of two overlapping exothermic reactions (stages 1 and 2) attributed to the formation of Cu{sub 4}Ti and Cu{sub 3}Ti particles in the copper matrix, respectively. DSC curves for Cu-4Ti-0.5Co alloy shows three exothermic effects (overlapping stages 3 and 4 and stage 5) associated to the formation of phases Ti{sub 2}Co, TiCo and Cu{sub 4}Ti, respectively. DSC curves for Cu-4Ti1Cr alloy shows three exothermic reactions (stages 6, 7 and 9) and one endothermic peak (stage 8). The exothermic reactions correspond to the formation of phases Cr{sub 2}Ti, Cu{sub 4}Ti and Cu{sub 3}Ti, respectively, and the endothermic reactions are attributed to the Cr{sub 2}Ti dissolution. The activation energies calculated using the modified Kissinger method were lower than the ones corresponding to diffusion of cobalt, chromium, and titanium in copper. Kinetic parameters were obtained by a convolution method based on the Johnson-Mehl-Avrami (JMA) formalism. Microhardness measurements confirmed the formation of the mentioned phases. Also, these measurements confirmed the effect of cobalt and chromium addition on the binary alloy hardness. (Author). 31 refs.

  10. Development of a Cost-Effective Process for the Fabrication of Single Grain YBa{sub 2}Cu{sub 3}O{sub 7-y} Bulk Superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Park, Soon Dong; Kim, Kwang Mo; Jun, Byung Hyuk [Neutron Science Division, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Han, Young Hee; Kim, Chan Joong [Green Growth Laboratory, Korea Electric Power Research Institute, Daejeon (Korea, Republic of)

    2011-12-15

    To reduce the processing cost of the single grain REBCO (RE: Rare-earth elements) bulk superconductors, a cost-effective process should be developed. One possible way of developing the cost-effective process is the use of low-cost precursor powders. In this study, the single grain YBCO superconductors were fabricated using a home made powder. YBa{sub 2}Cu{sub 3}O{sub 7-y} (Y123) powders were synthesized at in air by the powder calcination method with repeated crushing and heat treatment steps. The processing parameters for the fabrication of single grain Y123 bulk superconductors, T{sub max} (maximum temperature), Tp (peritectic temperature) and a cooling rate through Tp were optimized. To enhance the flux pinning capacity of the single grain Y123 samples, YBa{sub 2}Cu{sub 3}O{sub 5} (Y211) particles were dispersed in the Y123 matrix by adding Y{sub 2}O{sub 3} powder to the calcined Y123 powder. Applying the optimized processing condition, the single grain Y123 superconductors with Tc=91 K and Jc-1.5x10{sup 4} A/cm{sup 2} at 2 T were successfully fabricated using a home made powder. The levitation forces and trapped magnetic field at 77 K measured using a Nd-B-Fe permanent magnet of 5300 G were 47 N and 3000 G, respectively, which are comparable to those obtained for the samples fabricated using a commercial grade Y123 powders.

  11. Slurry Chemical Corrosion and Galvanic Corrosion during Copper Chemical Mechanical Polishing

    Science.gov (United States)

    Kondo, Seiichi; Sakuma, Noriyuki; Homma, Yoshio; Ohashi, Naofumi

    2000-11-01

    Copper (Cu) corrosion during chemical mechanical polishing (CMP) was controlled in order to improve the Cu damascene interconnect process. Slurry chemical corrosion was found to be enhanced when the slurry was diluted by deionized (DI) water during rinsing just after CMP@. Since the corrosion inhibitor, benzotriazole (BTA), reduces the Cu removal rate, adding it to the rinse solution prevents chemical corrosion more effectively than adding it to the slurry. On the other hand, galvanic corrosion occurs at the interface between Cu and the barrier metal, and it can be prevented by selecting appropriate barrier metals. Because the difference between the electrochemical potentials of Cu and the barrier metal is small in the slurry, refractory metals such as Ta, TaN, and TiN were found to be appropriate barrier metals. On the other hand, W, WN, and Ti have large potential differences, so galvanic corrosion was clearly observed when Cu/W damascene interconnects were fabricated.

  12. Double-graded bandgap in Cu(In,Ga)Se2 thin film solar cells by low toxicity selenization process

    Science.gov (United States)

    Wang, Yi-Chih; Shieh, Han-Ping D.

    2014-08-01

    A low-toxic selenization with post gallium diffusion (PGD) treatment has been demonstrated to increase the bandgap in the surface Cu(In,Ga)Se2 (CIGSe) absorbers and to form double-graded bandgap profiles to improve the cell efficiency. The CIGSe absorber with PGD for 5 min increased open-circuit voltage from 0.49 to 0.66 V and efficiency from 9.2% to 13.2%, contributed by the enhancement of carrier recombination in the space-charge region. The reduction in short-circuit current from 30.8 to 29.9 mA/cm2, attributed to the absorption loss in long-wavelength regions, can be potentially improved by further optimization of the minimum bandgap value in gradient valley.

  13. Properties of grain boundaries in bulk, melt processed Y-Ba-Cu-O fabricated using bridge-shaped seeds

    Science.gov (United States)

    Shi, Y.-H.; Durrell, J. H.; Dennis, A. R.; Babu, N. Hari; Mancini, C. E.; Cardwell, D. A.

    2012-04-01

    Single grain RE-Ba-Cu-O ((RE)BCO, where RE is a rare earth element or yttrium) bulk superconducting materials have significant potential for a variety of engineering applications due to their ability to trap high magnetic fields. However, it is well known that the presence of grain boundaries coupled with a high angle of misorientation (typically 5°) significantly reduces the critical current density, Jc, in all forms of high temperature superconducting materials. It is of considerable fundamental and technological interest, therefore, to investigate the grain boundary properties of bulk, film and tape (RE)BCO. We report a successful multi-seeding technique for the fabrication of fully aligned, artificial (0° misalignment) grain boundaries within large grain YBCO bulk superconductors using bridge-shaped seeds. The microstructure and critical current densities of the grain boundaries produced by this technique have been studied in detail.

  14. Highly conductive Cu2-xS nanoparticle films through room-temperature processing and an order of magnitude enhancement of conductivity via electrophoretic deposition.

    Science.gov (United States)

    Otelaja, Obafemi O; Ha, Don-Hyung; Ly, Tiffany; Zhang, Haitao; Robinson, Richard D

    2014-11-12

    A facile room-temperature method for assembling colloidal copper sulfide (Cu2-xS) nanoparticles into highly electrically conducting films is presented. Ammonium sulfide is utilized for connecting the nanoparticles via ligand removal, which transforms the as-deposited insulating films into highly conducting films. Electronic properties of the treated films are characterized with a combination of Hall effect measurements, field-effect transistor measurements, temperature-dependent conductivity measurements, and capacitance-voltage measurements, revealing their highly doped p-type semiconducting nature. The spin-cast nanoparticle films have carrier concentration of ∼ 10(19) cm(-3), Hall mobilities of ∼ 3 to 4 cm(2) V(-1) s(-1), and electrical conductivities of ∼ 5 to 6 S · cm(-1). Our films have hole mobilities that are 1-4 orders of magnitude higher than hole mobilities previously reported for heat-treated nanoparticle films of HgTe, InSb, PbS, PbTe, and PbSe. We show that electrophoretic deposition (EPD) as a method for nanoparticle film assembly leads to an order of magnitude enhancement in film conductivity (∼ 75 S · cm(-1)) over conventional spin-casting, creating copper sulfide nanoparticle films with conductivities comparable to bulk films formed through physical deposition methods. The X-ray diffraction patterns of the Cu2-xS films, with and without ligand removal, match the Djurleite phase (Cu(1.94)S) of copper sulfide and show that the nanoparticles maintain finite size after the ammonium sulfide processing. The high conductivities reported are attributed to better interparticle coupling through the ammonium sulfide treatment. This approach presents a scalable room-temperature route for fabricating highly conducting nanoparticle assemblies for large-area electronic and optoelectronic applications.

  15. Highly Conductive Cu 2– x S Nanoparticle Films through Room-Temperature Processing and an Order of Magnitude Enhancement of Conductivity via Electrophoretic Deposition

    KAUST Repository

    Otelaja, Obafemi O.

    2014-11-12

    © 2014 American Chemical Society. A facile room-temperature method for assembling colloidal copper sulfide (Cu2-xS) nanoparticles into highly electrically conducting films is presented. Ammonium sulfide is utilized for connecting the nanoparticles via ligand removal, which transforms the as-deposited insulating films into highly conducting films. Electronic properties of the treated films are characterized with a combination of Hall effect measurements, field-effect transistor measurements, temperature-dependent conductivity measurements, and capacitance-voltage measurements, revealing their highly doped p-type semiconducting nature. The spin-cast nanoparticle films have carrier concentration of ∼1019 cm-3, Hall mobilities of ∼3 to 4 cm2 V-1 s-1, and electrical conductivities of ∼5 to 6 S·cm-1. Our films have hole mobilities that are 1-4 orders of magnitude higher than hole mobilities previously reported for heat-treated nanoparticle films of HgTe, InSb, PbS, PbTe, and PbSe. We show that electrophoretic deposition (EPD) as a method for nanoparticle film assembly leads to an order of magnitude enhancement in film conductivity (∼75 S·cm-1) over conventional spin-casting, creating copper sulfide nanoparticle films with conductivities comparable to bulk films formed through physical deposition methods. The X-ray diffraction patterns of the Cu2-xS films, with and without ligand removal, match the Djurleite phase (Cu1.94S) of copper sulfide and show that the nanoparticles maintain finite size after the ammonium sulfide processing. The high conductivities reported are attributed to better interparticle coupling through the ammonium sulfide treatment. This approach presents a scalable room-temperature route for fabricating highly conducting nanoparticle assemblies for large-area electronic and optoelectronic applications.

  16. CuO and ZnO Nanoparticles Modify Interkingdom Cell Signaling Processes Relevant to Crop Production.

    Science.gov (United States)

    Anderson, Anne J; McLean, Joan E; Jacobson, Astrid R; Britt, David W

    2017-05-12

    As the world population increases, strategies for sustainable agriculture are needed to fulfill the global need for plants for food and other commercial products. Nanoparticle formulations are likely to be part of the developing strategies. CuO and ZnO nanoparticles (NPs) offer potential as fertilizers, as they provide bioavailable essential metals, and as pesticides, because of dose-dependent toxicity. Effects of these metal oxide NPs on rhizosphere functions are the focus of this review. These NPs at doses of ≥10 mg metal/kg change the production of key metabolites involved in plant protection in a root-associated microbe, Pseudomonas chlororaphis O6. Altered synthesis occurs in the microbe for phenazines, which function in plant resistance to pathogens, the pyoverdine-like siderophore that enhances Fe bioavailability in the rhizosphere and indole-3-acetic acid affecting plant growth. In wheat seedlings, reprogramming of root morphology involves increases in root hair proliferation (CuO NPs) and lateral root formation (ZnO NPs). Systemic changes in wheat shoot gene expression point to altered regulation for metal stress resilience as well as the potential for enhanced survival under stress commonly encountered in the field. These responses to the NPs cross kingdoms involving the bacteria, fungi, and plants in the rhizosphere. Our challenge is to learn how to understand the value of these potential changes and successfully formulate the NPs for optimal activity in the rhizosphere of crop plants. These formulations may be integrated into developing practices to ensure the sustainability of crop production.

  17. Shape memory characteristics and mechanical properties of powder metallurgy processed Ti50Ni40Cu10 alloy.

    Science.gov (United States)

    Kim, Yeon-Wook

    2014-10-01

    Ti-Ni-Cu alloy powders were prepared by gas atomization and porous bulk specimens were fabricated by spark plasma sintering (SPS). The microstructure of as-solidified powders exhibited a cellular structure and they contained a high density of nano-sized porosities which were located in the intercellular regions. XRD analysis showed that one-step martensitic transformation of B2-B19 occurred in all alloy powders and SPS specimens. When the martensitic transformation start temperature (M(s)) and austenite transformation finish temperature (A(f)) were determined in order to analyze the dependence of powder size on transformation temperatures, the M(s) increased slightly from -17.5 degrees C to - 14.6 degrees C as increasing the powder size ranging from between 25 and 50 μm to ranging between 100 and 150 μm. However, the M(s) and A(f) of the as-atomized powders is much smaller than those of SPS specimens and the M(s) of porous specimen was about 10.9 degrees C. Loading-unloading compressive tests were carried out to investigate the mechanical properties of porous Ti-Ni-Cu specimen. The specimen was compressed to the strain of 6% at a temperature higher than A,. After unloading, the residual strain was 2.1%. After the compressed specimen was heated to 60 degrees C and held for 30 minutes and then cooled to room temperature, the changes in the length of the specimens were measured. Then it was found that the recovered strain ascribed to shape memory effect was 1.5%.

  18. Kesterite Cu2ZnSn(S,Se)4 Solar Cells with beyond 8% Efficiency by a Sol-Gel and Selenization Process.

    Science.gov (United States)

    Liu, Fangyang; Zeng, Fangqin; Song, Ning; Jiang, Liangxing; Han, Zili; Su, Zhenghua; Yan, Chang; Wen, Xiaoming; Hao, Xiaojing; Liu, Yexiang

    2015-07-08

    A facile sol-gel and selenization process has been demonstrated to fabricate high-quality single-phase earth abundant kesterite Cu2ZnSn(S,Se)4 (CZTSSe) photovoltaic absorbers. The structure and band gap of the fabricated CZTSSe can be readily tuned by varying the [S]/([S] + [Se]) ratios via selenization condition control. The effects of [S]/([S] + [Se]) ratio on device performance have been presented. The best device shows 8.25% total area efficiency without antireflection coating. Low fill factor is the main limitation for the current device efficiency compared to record efficiency device due to high series resistance and interface recombination. By improving film uniformity, eliminating voids, and reducing the Mo(S,Se)2 interfacial layer, a further boost of the device efficiency is expected, enabling the proposed process for fabricating one of the most promising candidates for kesterite solar cells.

  19. Investigation of the temperature dependence of the critical state in melt processed YBa2Cu3O7-∂ thick films

    Science.gov (United States)

    Dewhurst, C. D.; Cardwell, D. A.; Alford, N. McN.

    1995-03-01

    The inter- and intra-grain critical current densities of melt processed YBa2Cu3O7-∂ (YBCO) thick films have been measured as a function of temperature using vibrating sample magnetometry. The width of the M-H hysteresis curve has been observed to scale with the cube of the sample width for temperatures up to ˜70 K and applied fields of greater than 1 T which implies that current flows on the length scale of the sample over this temperature and field regime. An exponential decrease of magnetic moment hysteresis with temperature up to ˜70 K and between ˜80 K and Tc has been observed and attributed to the dominance of inter- and intra-granular current, respectively. An empirical model is presented to account for the observed dependence of the critical current density on temperature, based upon weak link behavior within the ``Hub and Spoke'' like morphology characteristic of melt processed YBCO thick films.

  20. Anomalous behavior of linear resistivity arising in intergrain ordering process of weak-sintered ceramic system YBa{sub 2}Cu{sub 4}O{sub 8}

    Energy Technology Data Exchange (ETDEWEB)

    Hagiwara, M., E-mail: hag@kit.ac.jp [Kyoto Institute of Technology, Sakyo-ku, Kyoto 606-8585 (Japan); Fujii, A.; Hayashi, T.; Shima, T. [Kyoto Institute of Technology, Sakyo-ku, Kyoto 606-8585 (Japan); Deguchi, H. [Kyushu Institute of Technology, Tobata-Ku, Kitakyusyu 804-8550 (Japan)

    2011-11-15

    Ceramic system of YBa{sub 2}Cu{sub 4}O{sub 8} (Y124) shows intergrain ordering affected by frustration. Novel vanishing process of electric resistivity is caused by the frustration effect. Almost vanished resistivity around the critical temp. is restored below the region. Faint peak of resistivity appears certainly below the ordering point decided magnetically. Faint electric resistivity behavior is searched experimentally near and below intergrain ordering temperature of weakly sintered ceramic YBa{sub 2}Cu{sub 4}O{sub 8} (Y124). For this purpose, a new method to detect linear and nonlinear resistivity sensitively by combination of pulse delta method and numerical Fourier-transformation has been designed. Making use of the experimental system for several weak sintered Y124 samples, it is revealed that linear resistivity just above the intergrain ordering point first drops toward zero steeply with decreasing temperature, and then turns abruptly upward to forms faint maximum at lower temperature. Such a novel behavior of 'revival of resistivity' is confirmed to be reproducible, and considered to be an essential frustration effect for d-wave type grain system with irregular or inhomogeneous ceramic structure.

  1. 8.3% efficient Cu{sub 2}ZnSn(S,Se){sub 4} solar cells processed from sodium-containing solution precursors in a closed reactor

    Energy Technology Data Exchange (ETDEWEB)

    Werner, M., E-mail: melanie.werner@empa.ch; Sutter-Fella, C.M.; Romanyuk, Y.E.; Tiwari, A.N.

    2015-05-01

    Solution-processed Cu-Zn-Sn-S precursors are annealed under reactive Se atmosphere in different reactors in order to investigate the effects on metal composition and morphology. It is possible to minimize metal losses, specifically of Sn, by changing from open reactor to closed graphite reactor. The Cu{sub 2}ZnSn(S,Se){sub 4} (CZTS,Se) films annealed in the closed reactor exhibit a bi-layer structure with a dense top crust, whereas the other samples are more porous. The densification of the surface and suppression of Sn loss from the sample leads to an increased open circuit-voltage (V{sub oc}) = 419 mV for soda lime glass/Mo/CZTSSe/CdS/i-ZnO/ZnO:Al solar cell device. When NaCl is added to the initial precursor solution the device efficiency can be further improved to 8.3% mainly due to an increase in V{sub oc} = 450 mV and fill factor = 59%. - Highlights: • Closed reactor design results in large-grained top layer. • NaCl in the solution increases solar cell performance. • Highest conversion efficiency of 8.3% is achieved.

  2. Application of Taguchi approach to optimize the sol-gel process of the quaternary Cu2ZnSnS4 with good optical properties

    Science.gov (United States)

    Nkuissi Tchognia, Joël Hervé; Hartiti, Bouchaib; Ridah, Abderraouf; Ndjaka, Jean-Marie; Thevenin, Philippe

    2016-07-01

    Present research deals with the optimal deposition parameters configuration for the synthesis of Cu2ZnSnS4 (CZTS) thin films using the sol-gel method associated to spin coating on ordinary glass substrates without sulfurization. The Taguchi design with a L9 (34) orthogonal array, a signal-to-noise (S/N) ratio and an analysis of variance (ANOVA) are used to optimize the performance characteristic (optical band gap) of CZTS thin films. Four deposition parameters called factors namely the annealing temperature, the annealing time, the ratios Cu/(Zn + Sn) and Zn/Sn were chosen. To conduct the tests using the Taguchi method, three levels were chosen for each factor. The effects of the deposition parameters on structural and optical properties are studied. The determination of the most significant factors of the deposition process on optical properties of as-prepared films is also done. The results showed that the significant parameters are Zn/Sn ratio and the annealing temperature by applying the Taguchi method.

  3. Solution-Processed Cu(In, Ga)(S, Se)2 Nanocrystal as Inorganic Hole-Transporting Material for Efficient and Stable Perovskite Solar Cells.

    Science.gov (United States)

    Xu, Lu; Deng, Lin-Long; Cao, Jing; Wang, Xin; Chen, Wei-Yi; Jiang, Zhiyuan

    2017-12-01

    Perovskite solar cells are emerging as one of the most promising candidates for solar energy harvesting. To date, most of the high-performance perovskite solar cells have exclusively employed organic hole-transporting materials (HTMs) such as 2,2',7,7'-tetrakis-(N,N-di-p-methoxyphenylamine)-9,9'-spirobifluorene (spiro-OMeTAD) or polytriarylamine (PTAA) which are often expensive and have low hole mobility. Almost all these HTMs reported needed lithium salt, e.g., lithium bis(trifluoromethylsulfonyl)imide (Li-TFSI) doping, to improve hole mobility and performance. However, the use of Li-TFSI should be avoided because the hygroscopic nature of Li-TFSI could cause decomposition of perovskite and reduce device stability. Herein, we employed solution-processed CuIn0.1Ga0.9(S0.9Se0.1)2 (CIGSSe) nanocrystals as a novel inorganic HTM in perovskite solar cells. A power conversion efficiency of 9.15% was obtained for CIGSSe-based devices with improved stability, compared to devices using spiro-OMeTAD as HTM. This work offers a promising candidate of Cu-based inorganic HTM for efficient and stable perovskite solar cells.

  4. Magnetic Flux-Trapping of Anisotropic-Grown Y-Ba-Cu-O Bulk Superconductors during and after Pulsed-Field Magnetizing Processes

    Science.gov (United States)

    Oka, T.; Yamada, Y.; Horiuchi, T.; Ogawa, J.; Fukui, S.; Sato, T.; Yokoyama, K.; Langer, M.

    2014-05-01

    The magnetic flux penetration into the melt-textured Y-Ba-Cu-O high temperature superconducting bulk magnets were precisely evaluated during and after the pulsed field magnetization processes operated at 30 K. The bulk magnets were carefully fabricated by the cold seeding method with use of a single and a pair of seed crystals composed of the Nd-Ba-Cu-O thin films. These seed crystals were put on the top surfaces of the precursors to let the large grains grow during the heat treatments. We observed the flux penetrations which occurred in the lower applied-field regions at around 3.1 T for the samples bearing the twin seeds than those of the single-seeded crystals at around 3.8 T. This means that the magnetic fluxes are capable of invading into the twin-seeded samples more easily than the single-seeds. It suggests that the anisotropic grain growths of parallel and normal to the rows of seed crystals affects the variations of Jc values with different distributions of the pinning centers, results in the preferential paths for the invading magnetic fluxes.

  5. Solution-processed p-type copper(I) thiocyanate (CuSCN) for low-voltage flexible thin-film transistors and integrated inverter circuits

    Science.gov (United States)

    Petti, Luisa; Pattanasattayavong, Pichaya; Lin, Yen-Hung; Münzenrieder, Niko; Cantarella, Giuseppe; Yaacobi-Gross, Nir; Yan, Feng; Tröster, Gerhard; Anthopoulos, Thomas D.

    2017-03-01

    We report on low operating voltage thin-film transistors (TFTs) and integrated inverters based on copper(I) thiocyanate (CuSCN) layers processed from solution at low temperature on free-standing plastic foils. As-fabricated coplanar bottom-gate and staggered top-gate TFTs exhibit hole-transporting characteristics with average mobility values of 0.0016 cm2 V-1 s-1 and 0.013 cm2 V-1 s-1, respectively, current on/off ratio in the range 102-104, and maximum operating voltages between -3.5 and -10 V, depending on the gate dielectric employed. The promising TFT characteristics enable fabrication of unipolar NOT gates on flexible free-standing plastic substrates with voltage gain of 3.4 at voltages as low as -3.5 V. Importantly, discrete CuSCN transistors and integrated logic inverters remain fully functional even when mechanically bent to a tensile radius of 4 mm, demonstrating the potential of the technology for flexible electronics.

  6. Solution-Processed Cu(In, Ga)(S, Se)2 Nanocrystal as Inorganic Hole-Transporting Material for Efficient and Stable Perovskite Solar Cells

    Science.gov (United States)

    Xu, Lu; Deng, Lin-Long; Cao, Jing; Wang, Xin; Chen, Wei-Yi; Jiang, Zhiyuan

    2017-02-01

    Perovskite solar cells are emerging as one of the most promising candidates for solar energy harvesting. To date, most of the high-performance perovskite solar cells have exclusively employed organic hole-transporting materials (HTMs) such as 2,2',7,7'-tetrakis-( N, N-di- p-methoxyphenylamine)-9,9'-spirobifluorene (spiro-OMeTAD) or polytriarylamine (PTAA) which are often expensive and have low hole mobility. Almost all these HTMs reported needed lithium salt, e.g., lithium bis(trifluoromethylsulfonyl)imide (Li-TFSI) doping, to improve hole mobility and performance. However, the use of Li-TFSI should be avoided because the hygroscopic nature of Li-TFSI could cause decomposition of perovskite and reduce device stability. Herein, we employed solution-processed CuIn0.1Ga0.9(S0.9Se0.1)2 (CIGSSe) nanocrystals as a novel inorganic HTM in perovskite solar cells. A power conversion efficiency of 9.15% was obtained for CIGSSe-based devices with improved stability, compared to devices using spiro-OMeTAD as HTM. This work offers a promising candidate of Cu-based inorganic HTM for efficient and stable perovskite solar cells.

  7. Solution-processed p-type copper(I) thiocyanate (CuSCN) for low-voltage flexible thin-film transistors and integrated inverter circuits

    KAUST Repository

    Petti, Luisa

    2017-03-17

    We report on low operating voltage thin-film transistors (TFTs) and integrated inverters based on copper(I) thiocyanate (CuSCN) layers processed from solution at low temperature on free-standing plastic foils. As-fabricated coplanar bottom-gate and staggered top-gate TFTs exhibit hole-transporting characteristics with average mobility values of 0.0016 cm2 V−1 s−1 and 0.013 cm2 V−1 s−1, respectively, current on/off ratio in the range 102–104, and maximum operating voltages between −3.5 and −10 V, depending on the gate dielectric employed. The promising TFT characteristics enable fabrication of unipolar NOT gates on flexible free-standing plastic substrates with voltage gain of 3.4 at voltages as low as −3.5 V. Importantly, discrete CuSCN transistors and integrated logic inverters remain fully functional even when mechanically bent to a tensile radius of 4 mm, demonstrating the potential of the technology for flexible electronics.

  8. Preparation of PtSnCu/C and PtSn/C electrocatalysts and activation by dealloying processes for ethanol electrooxidation; Preparacao de eletrocatalisadores PtSnCu/C e PtSn/C e ativacao por processos de dealloying para aplicacao na oxidacao eletroquuimica do etanol

    Energy Technology Data Exchange (ETDEWEB)

    Crisafulli, Rudy

    2013-06-01

    PtSnCu/C (with different Pt:Sn:Cu atomic ratios) and PtSn/C (50:50) electrocatalysts were prepared by borohydride (BR) and alcohol-reduction (AR) processes using H{sub 2}PtCl{sub 6}.6H{sub 2}O, SnCl{sub 2}.2H{sub 2}O and CuCl{sub 2}.2H{sub 2}O as metal sources, NaBH{sub 4} and ethylene glycol as reducing agents, 2-propanol and ethylene glycol/water as solvents and carbon black as support. In a further step, these electrocatalysts were activated by chemical (CD) and electrochemical (ED) dealloying processes through acid treatment and thin porous coating technique, respectively. These materials were characterized by energy dispersive X-ray, Xray diffraction, transmission electron microscopy, line scan energy dispersive Xray and cyclic voltammetry. Electrochemical studies for ethanol electro-oxidation were performed by cyclic voltammetry, chronoamperometry and in single Direct Ethanol Fuel Cell using Membrane Electrode Assembly (MEA). The anodic effluents were analysed by gas chromatography. The X-ray diffractograms of the as-synthesized electrocatalysts showed the typical face-centered cubic structure (FCC) of platinum and its alloys. After dealloying, the X-ray diffractograms showed that the Pt FCC structure was preserved. The crystallite sizes of the assynthesized electrocatalysts were in the range of <=2 nm to 3 nm and after dealloying there were no significant variations in sizes. The energy dispersive Xray analysis of the as-synthesized electrocatalysts showed a Pt:Sn and Pt:Sn:Cu atomic ratios similar to the nominal values. After chemical and electrochemical dealloying of the electrocatalysts the ranged Pt:Sn and Pt:Sn:Cu atomic ratios showed that Cu and Sn atoms were removed. However, chemical dealloying process proved to be more efficient for removing Cu and electrochemical dealloying for removing Sn. The line scan energy dispersive X-ray analysis showed that acid and electrochemical treatments were efficient to dealloying Cu and/or Sn superficial atoms of

  9. Primary crystallization process of rapidly solidified Al-Ni-Cu-Nd metallic glasses under continuous heating regime

    Institute of Scientific and Technical Information of China (English)

    XIAO YU-de(肖于德); LI Wen-xian(黎文献); D. Jacovkis; N. Clavaguera; M. T. Clavaguera-Mora; J. Rodriguez-Viejo

    2003-01-01

    Rapidly solidified Al87Ni7Cu3Nd3 metallic glasses were prepared by using melt spinning. Its calorimetric behavior was characterized by using differential scanning calorimeter. The metallic glasses were partially crystallized under continuous heating regime. Primary crystallization was studied through structural characterization of the amorphous and partially crystallized ribbons by means of conventional X-ray diffraction and transmission electron microscopy with selected area electron diffraction. The results show that, the as-spun ribbons are fully amorphous and homogeneous on the micron scale, but contain high density of nanoscale quenched-in clusters or crystallite embryos. Primary crystallization mainly leads to formation of two-phase mixture of α-Al nanocrystalline and residual amorphous phase. Precipitation of α-Al nanoparticles is limited by build-up and overlapped diffusion field of solute atoms with low diffusion rate. At the earlier stage of primary crystallization the crystal nuclei exhibit high density and growth rate. With the α-Al crystal growing, the crystal growth rate decreases, and even at the later stage further crystallization into α-Al crystal becomes difficult to occur due to thermal stabilization of the residual nickel and neodymium-enriched amorphous phase, the saturated values of crystallized volume fraction and α-Al crystal diameter getting to 20%-30% and 5-15 nm.

  10. Effect of austempering process on microstructure and wear behavior of ductile iron containing Mn-Ni-Cu-Mo

    Science.gov (United States)

    PourAsiabi, HaMiD; Saghafian, Hasan; Pourasiabi, Hamed

    2013-01-01

    In this work, the effects of austempering time and temperature on the microstructure and sliding wear behavior of a Mn-Ni-Cu-Mo alloyed ductile iron were investigated. Ductile iron samples with the desired chemical composition were cast according to ASTM A897M-1990 Y-block. Wear test samples austenitized at 900 °C for 90 min, were austempered at 260, 290 and 320 °C for 30, 60, 90 and 120 min. The wear tests on samples were conducted by Block-on-Ring testing machine according to ASTM G77-98 standard, at the applied load of 75N and the displacement speed of 3.27 m/s. The results showed that the sample austempered at 260 °C for 90 min exhibited the maximum relative wear resistance in comparison with the as-cast sample. The X-ray diffraction patterns of wear debris and the SEM observations of worn surfaces and crosssection of worn surfaces together with wear debris showed that delamination associated with oxidation is the dominant wear mechanism in the samples.

  11. Effects of improved process for CuO-doped NKN lead-free ceramics on high-power piezoelectric transformers.

    Science.gov (United States)

    Yang, Song-Ling; Tsai, Cheng-Che; Liou, Yi-Cheng; Hong, Cheng-Shong; Li, Bing-Jing; Chu, Sheng-Yuan

    2011-12-01

    In this paper, the effects of the electrical proper- ties of CuO-doped (Na(0.5)K(0.5))NbO(3) (NKN) ceramics prepared separately using the B-site oxide precursor method (BO method) and conventional mixed-oxide method (MO method) on high-power piezoelectric transformers (PTs) were investigated. The performances of PTs made with these two substrates were compared. Experimental results showed that the output power and temperature stability of PTs could be enhanced because of the lower resonant impedance of the ceramics prepared using the BO method. In addition, the output power of PTs was more affected by the resonant impedance than by the mechanical quality factor (Q(m)) of the ceramics. The PTs fabricated with ceramics prepared using the BO method showed a high efficiency of more than 94% and a maximum output power of 8.98 W (power density: 18.3 W/cm(3)) with temperature increase of 3°C under the optimum load resistance (5 kΩ) and an input voltage of 150 V(pp). This output power of the lead-free disk-type PTs is the best reported so far.

  12. Magnetic Properties of GdBa{sub 2}Cu{sub 3}O{sub 7-y} Bulk Superconductors Fabricated by a Top-seeded Melt Growth Process

    Energy Technology Data Exchange (ETDEWEB)

    Kim, K. M.; Park, S. D.; Jun, B. H.; Kim, C. J. [Neutron Science Division, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Ko, T. K. [Dept. of Electrical and Eletronic Engineering, Yonsei University, Seoul (Korea, Republic of)

    2012-08-15

    The fabrications condition and superconducting properties of top-seeded melt growth (TSMG) processed GdBa{sub 2}Cu{sub 3}O{sub 7-y} (Gd123) bulk superconductors were studied. Processing parameters (a maximum temperature (T{sub max}), a temperature for crystal growth (T{sub G}) and a cooling rate (R{sub G}) through a peritectic temperature (T{sub P}) for the fabrication of single grain Gd123 superconductors were optimized. The magnetic levitation forces, trapped magnetic fields, superconducting transition temperature (Tc) and critical current density (Jc) of the Gd123 bulks superconductors were estimated. Single grain Gd123 bulk superconductors were successfully fabricated at the optimized processing condition. The Tc of a TSMG processed Gd123 sample was 92.5 K and the Jc at 77 K and 0 T was approximately 50{kappa}A/cm{sup 2}. The trapped magnetic field contour and magnetic levitation forces were dependent on the top surface morphology of TSMG processed Gd123 samples. The single grain Gd123 samples, field-cooled at 77 K using a Nd-B-Fe permanent magnet with 5.27 kG and 30 mm dia., showed the trapped magnetic field contour of a single grain with a maximum of 4 kG at the sample center. The maximum magnetic levitation forces of the single grain Gd123 sample, field-cooled or zero field-cooled, were 40 N and 107 N, respectively.

  13. Process the Experimental Data of Time-resolved Photoluminescence Lifetime Spectra on Cu2 O Nanowires by Origin%用Origin拟合Cu2 O纳米线时间分辨荧光光谱寿命

    Institute of Scientific and Technical Information of China (English)

    王鹏

    2015-01-01

    The time-resolved photoluminescence spectra of synthesized Cu2 O nanowires are fitted by the func-tion of exponential decay in Origin. The time-resolved photoluminescence lifetimes of the Cu2 O nanowires are obtained in the temperature region of 77-300 K.%基于用Origin软件的指数衰减拟合函数对制备得到的Cu2 O纳米线的时间分辨荧光光谱进行拟合,得到了Cu2 O纳米线在77-300 K温度范围内的瞬态荧光寿命值。

  14. Chemical welding of binary nanoparticles: room temperature sintering of CuSe and In2S3 nanoparticles for solution-processed CuInS(x)Se(1-x) solar cells.

    Science.gov (United States)

    Min Lim, Hui; Batabyal, Sudip K; Pramana, Stevin S; Wong, L H; Magdassi, Shlomo; Mhaisalkar, S G

    2013-06-14

    Chemical welding of oppositely charged dissimilar metal chalcogenide nanomaterials is reported to produce a quaternary metal chalcogenide. CuSe and In2S3 nanoparticles were synthesized with opposite surface charges by stabilizing with polyacrylic acid and polydiallyldimethylammonium chloride. Upon mixing these nanoparticles at room temperature, the electrostatic attraction induced coalescence of these nanoparticles and led to the formation of CuInSxSe1-x nanoparticles.

  15. Non-linear effects of initial melt temperatures on microstructures and mechanical properties during quenching process of liquid Cu46Zr54 alloy

    Science.gov (United States)

    Mo, Yun-Fei; Liu, Rang-Su; Tian, Ze-An; Liang, Yong-Chao; Zhang, Hai-Tao; Hou, Zhao-Yang; Liu, Hai-Rong; Zhang, Ai-long; Zhou, Li-Li; Peng, Ping; Xie, Zhong

    2015-05-01

    A MD simulation of liquid Cu46Zr54 alloys has been performed for understanding the effects of initial melt temperatures on the microstructural evolution and mechanical properties during quenching process. By using several microstructural analyzing methods, it is found that the icosahedral and defective icosahedral clusters play a key role in the microstructure transition. All the final solidification structures obtained at different initial melt temperatures are of amorphous structures, and their structural and mechanical properties are non-linearly related to the initial melt temperatures, and fluctuated in a certain range. Especially, there exists a best initial melt temperature, from which the glass configuration possesses the highest packing density, the optimal elastic constants, and the smaller extent of structural softening under deforming.

  16. Investigation on preparation of CuO-SnO2-CeO2/γ-Al2O3 catalysts for catalytic wet air oxidation process and their catalytic activity for degradation of phenol

    Institute of Scientific and Technical Information of China (English)

    SUN Xiao-jun; ZHANG Mi-lin; WAN Jia-feng; XIA Zhi; LIU Xiao-hui; LIU hui

    2008-01-01

    Catalytic Wet Air Oxidation process is an efficient measure for treatment of wastewater with great strength which is not biodegradable. Heterocatalysts now become the key investigation subject of catalytic wet air oxidation process due to their good stability and easy separation. In the paper, CuO-SnOE-CeO2/γ-Al2O3 catalysts are prepared by impregnation method, with SnO2 as a doping component, CuO as an active component, CeO2 as a structure stabilizer, γ-Al2O3 as a substrate. XPS test is carried out to investigate the effect of Sn on the chemical surrounding of Cu and O element on the catalyst surface and their catalytic activity. It is shown that the right do-ping of Sn can increase Cu+ content on the catalyst surface, as a result the quantity of adsorption oxygen is also increased. It is found that Cu + content on the catalyst surface is one of the primary factors that determin catalytic activity of catalyst through analyzing the catalytic wet air oxidation process of phenol.

  17. Effect of temperature on mechanical alloying of Cu-Zn and Cu-Cr system

    Institute of Scientific and Technical Information of China (English)

    ZUO Ke-sheng; XI Sheng-qi; ZHOU Jin-gen

    2009-01-01

    Cu-Zn and Cu-Cr powders were milled with an attritor mill at room temperature, -10, -20 and -30 ℃, respectively. Phase transformation and morphology evolution of the alloyed powder were investigated by X-ray diffractometry(XRD), X-ray photoelectron spectroscopy(XPS) and scanning electron microscopy(SEM). The results show that lowering temperature can delay mechanical alloying(MA) process of Cu-Zn system with negative mixing enthalpy, and promote MA process of Cu-Cr system with positive mixing enthalpy. As for Cu-Cr and Cu-Zn powders milled at -10 ℃, lamellar structures are firstly formed, while fewer lamellar particles can be found when the powder is milled at -20 ℃. When the alloyed powder is annealed at 1 000 ℃, Cu(Cr) solid solution is decomposed and Cr precipitates from Cu matrix, whereas Cu(Zn) solid solution keeps stable.

  18. Microstructure of shear-induced thixoformed Al- 4.5Cu-1.5Mg alloy via RAP and SSTT processes

    Directory of Open Access Journals (Sweden)

    Siamak Nikzad

    2017-07-01

    Full Text Available In this research, the effect of the thixoforming temperature on the microstructure and mechanical properties was investigated in the thixoforming of the feedstock produced by the RAP (recrystallization and partial melting and SSTT (semi-solid thermal transformation processes for Al-4.5Cu-1.5Mg alloy. In the RAP process, the percentage reduction in area was approximately 35%. Thixoforming was done at 610, 620, and 630 °C. Globular microstructure was observed at all temperatures and conditions. The minimum average globule size was 39 μm, and it was obtained in the thixoforming of the feedstock produced by the RAP process in the section of 4 mm in diameter at 620 ° C after applying shear. Its corresponding compressive strength was -877.44 MPa. The maximum average globule size was 136 μm, and it was obtained in the thixoforming of the feedstock produced by the SSTT process in the section of 10 mm in diameter at 630 °C before applying shear. Its corresponding compressive strength was -769.18 MPa. The finest and most spherical globules, as well as the highest compressive strength were obtained at 620 °C in both RAP and SSTT states.

  19. Scanning and Deep Processing of Information in Hypertext: An Eye Tracking and Cued Retrospective Think-Aloud Study

    Science.gov (United States)

    Salmerón, L.; Naumann, J.; García, V.; Fajardo, I.

    2017-01-01

    When students solve problems on the Internet, they have to find a balance between quickly scanning large sections of information in web pages and deeply processing those that are relevant for the task. We studied how high school students articulate scanning and deeper processing of information while answering questions using a Wikipedia document,…

  20. Mapping processing strategies in learning from expository text: an exploratory eye tracking study followed by a cued recall

    NARCIS (Netherlands)

    Catrysse, Leen; Gijbels, D.; Donche, V.; de Maeyer, Sven; van den Bossche, Piet; Gommers, L.

    2016-01-01

    This study starts from the observation that current empirical research on students' processing strategies in higher education has mainly focused on the use of self-report instruments to measure students' general preferences towards processing strategies. In contrast, there is a rather limited use of

  1. Mapping Processing Strategies in Learning from Expository Text: An Exploratory Eye Tracking Study Followed by a Cued Recall

    Science.gov (United States)

    Catrysse, Leen; Gijbels, David; Donche, Vincent; De Maeyer, Sven; Van den Bossche, Piet; Gommers, Luci

    2016-01-01

    This study starts from the observation that current empirical research on students' processing strategies in higher education has mainly focused on the use of self-report instruments to measure students' general preferences towards processing strategies. In contrast, there is a rather limited use of more direct and online observation techniques to…

  2. Dynamics of CO and D{sub 2}O on Cu(111). Laser induced and thermally induced processes Dynamik von CO und D{sub 2}O auf Cu(111); Dynamik von CO und D{sub 2}O auf Cu(111). Laserinduzierte und thermisch induzierte Prozesse

    Energy Technology Data Exchange (ETDEWEB)

    Mehlhorn, M.

    2005-07-15

    molecules in crystalline ice clusters on Cu(111) is investigated as an example for a surfaces reaction induced by electrons from the tunneling tip. Two processes could be separated. The first is the dissociation of single water molecules in the cluster surface by electron attachment. The second process is the dissociation at the interface between dissociated and crystalline regions. This process is also mediated by electron injection into the conduction band. (orig.)

  3. Crystallisation process in Mg{sub 60}Cu{sub 30}Gd{sub 10-x}Nd{sub x}(x = 0, 8.5) amorphous alloys

    Energy Technology Data Exchange (ETDEWEB)

    Rizzi, P; Satta, M; Baricco, M [Dip. Chimica IFM and NIS/CNISM/INSTM, Universita di Torino, V. Giuria 7, 10125 Torino (Italy); Enzo, S [Dipartimento di Chimica, Universita di Sassari, Via Vienna 2, 07100 Sassari (Italy); Georgarakis, K; Yavari, A R, E-mail: paola.rizzi@unito.i [Institut National Polytechnique de Grenoble, 1130 rue de la Piscine, BP 75, 38402 Grenoble (France)

    2009-01-01

    Mg{sub 60}Cu{sub 30}Gd{sub 10} and Mg{sub 60}Cu{sub 30}Gd{sub 1.5}Nd{sub 8.5} ribbons were obtained by melt spinning. For both compositions, a fully amorphous phase was found and a clear Tg was observed. In-situ XRD measurements were carried out during heating of ribbons at the ID11 synchrotron beamline of ESRF, Grenoble (France). In order to identify the crystallisation products, an annealed Mg{sub 60}Cu{sub 30}Gd{sub 10} master alloy was analysed by SEM/EDS and XRD. The existence of new ternary compounds (MgCu{sub 4}Gd and Mg{sub 2}CuGd) in the Mg-Cu-Gd system is suggested.

  4. Phase equilibria in the YBCuO system and melt processing of Ag clad Y 1Ba 2Cu 3O 7- x tapes at reduced oxygen partial pressures

    Science.gov (United States)

    MacManus-Driscoll, J. L.; Bravman, J. C.; Beyers, R. B.

    1995-02-01

    We have undertaken phase-stability studies of Y 1Ba 2Cu 3O 7- x(+Ag) and BaCu 2O 2 (+Ag) over the temperature range 780°C-950°C and oxygen partial pressure range 1.0 × 10 -6-2.0 × 10 -1 atm. Ag was found to have no effect on the thermodynamic stability of either phase. Partial melting of YBCO was found at temperatures as low as 800°C ± 10°C, with significant peritectic melting at temperatures as low as 900°C ± 10°C. These thermochemical studies have enabled us to determine the optimum conditions for reduced temperature and pressure (RTP) processing of Ag clad Y 1Ba 2Cu 3O 7- x pellets and tapes. The classic domain structure with strong texturing over short lengths was produced in samples melt processed by controlling oxygen partial pressure at a fixed temperature. The RTP method has the advantage that the second phase Y 2BaCuO 5 particle size can be controlled. Moreover, the technique offers the promise of long lengths of flexible Y 1Ba 2Cu 3O 7- x tapes with high current carrying capability.

  5. 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.

  6. Thermodynamic Modelling on the Mutual Effect of Copper, Manganese and Iron Addition in Al-Si-Cu For Semisolid Processing

    OpenAIRE

    Salleh, M. S.; Omar,M.Z.; J. Syarif; M. N. Mohammed

    2012-01-01

    Semisolid metal (SSM) processing or Thixoforming is a new method for forming alloys in the semisolid state to near net shaped products. All the alloys which have been used to date for thixoforming were developed originally for either casting or forging operations. Thus, there is a lack of specific alloys for semi solid processing that present good fluidity, low viscosity and small grain size. Thermodynamic calculation software, such as Java-based Material Properties (JMatPro), provides a tool...

  7. The influence of a grain boundary on the thermal transport properties of bulk, melt-processed Y-Ba-Cu-O

    Science.gov (United States)

    Marchal, C.; Fagnard, J. F.; Shi, Y. H.; Cardwell, D. A.; Mucha, J.; Misiorek, H.; Cloots, R.; Vertruyen, B.; Vanderbemden, P.

    2013-01-01

    We report the dependence of thermal conductivity, thermoelectric power and electrical resistivity on temperature for a bulk, large grain melt-processed Y-Ba-Cu-O (YBCO) high temperature superconductor (HTS) containing two grains separated by a well-defined grain boundary. Transport measurements at temperatures between 10 and 300 K were carried out both within one single grain (intra-granular properties) and across the grain boundary (inter-granular properties). The influence of an applied external magnetic field of up to 8 T on the measured sample properties was also investigated. The presence of the grain boundary is found to affect strongly the electrical resistivity of the melt-processed bulk sample, but has almost no effect on its thermoelectric power and thermal conductivity, within experimental error. The results of this study provide direct evidence that the heat flow in multi-granular melt-processed YBCO bulk samples should be virtually unaffected by the presence of grain boundaries in the material.

  8. High-Temperature Deformation Processing Map Approach for Obtaining the Desired Microstructure in a Multi-component (Ni-Ti-Cu-Fe) Alloy

    Science.gov (United States)

    Nayan, Niraj; Singh, Gaurav; Narayana Murty, S. V. S.; Jha, Abhay K.; Pant, Bhanu; George, Koshy M.

    2015-05-01

    An equiatomic NiTiCuFe multi-component alloy with simple body-centered cubic (bcc) and face-centered cubic solid-solution phases in the microstructure was processed by vacuum induction melting furnace under dynamic Ar atmosphere. High-temperature uniaxial compression experiments were conducted on it in the temperature range of 1073 K to 1303 K (800 °C to 1030 °C) and strain rate range of 10-3 to 10-1 s-1. The data generated were analyzed with the aid of the dynamic materials model through which power dissipation efficiency and instability maps were generated so as to identify the governing deformation mechanisms that are operative in different temperature-strain rate regimes with the aid of complementary microstructural analysis of the deformed specimens. Results indicate that the stable domain for the high temperature deformation of the multi-component alloy occurs in the temperature range of 1173 K to 1303 K (900 °C to 1030 °C) and range of 10-3 to 10-1.2 s-1, and the deformation is unstable at T = 1073 K to 1153 K (800 °C to 880 °C) and = 10-3 to 10-1.4 s-1 as well as T = 1223 K to 1293 K (950 °C to 1020 °C) and = 10-1.4 to 10-1 s-1, with adiabatic shear banding, localized plastic flow, or cracking being the unstable mechanisms. A constitutive equation that describes the flow stress of NiTiCuFe multi-component alloy as a function of strain rate and deformation temperature was also determined.

  9. Influence of tin additions on the precipitation processes in a Cu-Ni-Zn alloys; Influencia de la adicion de estano en el proceso de precipitacion en una aleacion de Cu-Ni-Zn

    Energy Technology Data Exchange (ETDEWEB)

    Donoso, E. C.; Dianez, M. J.; Criado, J. M.; Espinoza, R.; Mosquera, E.

    2016-05-01

    The influence of 1.1 wt% tin additions on the precipitation hardening of Cu-11 wt% Ni-20 wt% Zn alloy was studied by Differential Scanning Calorimetry (DSC), microhardeness measurements and High Resolution Transmission Electron Microscopy (HRTEM). The calorimetric curves, in the range of temperatures analyzed, show the presence of two exothermic reactions in the ternary alloy, associated to the short-range-order development assisted by migration of excess vacancies. On the other hand, one exothermic and one endothermic reaction are observed in the quaternary alloy, associated to the formation and dissolution of Cu{sub 2}NiZn precipitates, respectively. It has been show that an addition of 1.1% tin plays an important role in the formation of Cu{sub 2}NiZn precipitates, responsible for the precipitation hardening of the ternary alloy. (Author)

  10. Effect of some process parameters on geometric errors in twopoint incremental forming for Al-Cu-Mg Aluminum Alloy

    Science.gov (United States)

    Li, Xiaoqiang; Han, Kai; Yu, Honghan; Zhang, Yongsheng; Li, Dongsheng

    2016-08-01

    Two point incremental forming receives widespread study with its advantages of economy and flexibility in small batch products, such as aircraft parts. Aircraft parts, however, are rigorous in their shape errors. In this paper, one real airplane part is selected and formed with different process parameters to investigate the shape error level of part. Comparing the geometric errors caused by different process parameters, such as tool diameter, step size, feed rate and tool path, it is found that the geometric errors reduce as tool diameter increases. Meanwhile, the effect of step size is not linear. Influence law of feed rate is various with different other parameters. The bidirectional tool path, having opposite processing direction at adjacent layer, reduces the errors.

  11. Improvements in the processing of large grain, bulk Y-Ba-Cu-O superconductors via the use of additional liquid phase

    Science.gov (United States)

    Congreve, Jasmin V. J.; Shi, Yunhua; Dennis, Anthony R.; Durrell, John H.; Cardwell, David A.

    2017-01-01

    A major limitation to the widespread application of Y-Ba-Cu-O (YBCO) bulk superconductors is the relative complexity and low yield of the top seeded melt growth (TSMG) process, by which these materials are commonly fabricated. It has been demonstrated in previous work on the recycling of samples in which the primary growth had failed, that the provision of an additional liquid-rich phase to replenish liquid lost during the failed growth process leads to the reliable growth of relatively high quality recycled samples. In this paper we describe the adaptation of the liquid phase enrichment technique to the primary TSMG fabrication process. We further describe the observed differences between the microstructure and superconducting properties of samples grown with additional liquid-rich phase and control samples grown using a conventional TSMG process. We observe that the introduction of the additional liquid-rich phase leads to the formation of a higher concentration of Y species at the growth front, which leads, in turn, to a more uniform composition at the growth front. Importantly, the increased uniformity at the growth front leads directly to an increased homogeneity in the distribution of the Y-211 inclusions in the superconducting Y-123 phase matrix and to a more uniform Y-123 phase itself. Overall, the provision of an additional liquid-rich phase improves significantly both the reliability of grain growth through the sample thickness and the magnitude and homogeneity of the superconducting properties of these samples compared to those fabricated by a conventional TSMG process.

  12. Electrochemical behavior of Cu in the (NaCl-KCl-CuCl)molten salt

    Institute of Scientific and Technical Information of China (English)

    Yungang LI; Jie LI; Kuai ZHANG; Limin LIU

    2011-01-01

    The electrochemical reaction mechanism and electrocrystallization process of Cu on copper electrode in the eutectic NaC1-KC1-CuC1 molten salt were investigated by means of cyclic voltammetry,chronopotentiometry and chronoamperometry technique at 710 ℃.The results show that the electrochemical reaction process of Cu is a quasi-reversible process mix-controlled by Cu+ diffusion rate and electron transport rate; the electrochemical reduction mechanism is Cu++e→Cu; the electrocrystallization process of copper is an instantaneous hemispheroid three-dimensional nucleation process; the Cu+ diffusion coefficient is 4.3×10-4 cm2·s-1 under the experimental conditions.

  13. Fabrication of Cu{sub 2}ZnSn(S{sub x}Se{sub 1−x}){sub 4} solar cells by ethanol-ammonium solution process

    Energy Technology Data Exchange (ETDEWEB)

    Xue, Cong; Li, Jianmin; Wang, Yaguang; Jiang, Guoshun; Weifeng, Liu, E-mail: liuwf@ustc.edu.cn; Zhu, Changfei, E-mail: cfzhu@ustc.edu.cn

    2016-10-15

    Highlights: • The CBD precipitates were utilized to fabricate the CZTS/CZTSSe solar cells. • A solvent mixture of ethanol and ammonium hydroxide was used to form SnS-Cu2O-ZnS slurry. • Formation of CZTS/CZTSSe with good crystalline quality confirmed by XRD and Raman spectra. • CZTS and CZTSSe thin film solar cells obtained the best PCE of 1.99% and 2.95%, respectively. - Abstract: In this paper, Cu{sub 2}ZnSn(S{sub x}Se{sub 1−x}){sub 4} precursor films were produced by doctor blade process from SnS-Cu{sub 2}O-ZnS slurry. To prepare the slurry, SnS, ZnS and Cu{sub 2}O precipitates, which are outgrowths of stacked layer ZnS/Cu/SnS by CBD (chemical bath deposition)-annealing route, were dissolved in the mixture solvent of ethanol and NH{sub 3}·H{sub 2}O. Synthesized precursor films were then annealed at different conditions. The post-annealed films were characterized by means of scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman measurements and UV–vis–NIR spectroscopy. SEM studies reveal that the rough and relatively compact absorber thin films are obtained via the sulfidation and sulfidation-selenization processes. X-ray diffraction and Raman spectrum results verify that the obtained films are composed of Cu{sub 2}ZnSnS{sub 4} and Cu{sub 2}ZnSnSe{sub 4} phases, which have high absorbance in visible range and direct band gap energy of 1.01–1.47 eV. The best devices yield total area power conversion efficiency of 1.99% and 2.95% corresponding to Cu{sub 2}ZnSnS{sub 4} and Cu{sub 2}ZnSn(S{sub x}Se{sub 1−x}){sub 4} thin film solar cells under AM1.5 illumination without any anti-reflection layer.

  14. Crystallite-growth, phase transition, magnetic properties, and sintering behaviour of nano-CuFe{sub 2}O{sub 4} powders prepared by a combustion-like process

    Energy Technology Data Exchange (ETDEWEB)

    Köferstein, Roberto, E-mail: roberto.koeferstein@chemie.uni-halle.de [Institute of Chemistry, Martin-Luther-University Halle-Wittenberg, Kurt-Mothes-Strasse 2, 06120 Halle (Germany); Walther, Till [Institute of Chemistry, Martin-Luther-University Halle-Wittenberg, Kurt-Mothes-Strasse 2, 06120 Halle (Germany); Hesse, Dietrich [Max Planck Institute of Microstructure Physics, Weinberg 2, 06120 Halle (Germany); Ebbinghaus, Stefan G. [Institute of Chemistry, Martin-Luther-University Halle-Wittenberg, Kurt-Mothes-Strasse 2, 06120 Halle (Germany)

    2014-05-01

    The synthesis of nano-crystalline CuFe{sub 2}O{sub 4} powders by a combustion-like process is described herein. Phase formation and evolution of the crystallite size during the decomposition process of a (CuFe{sub 2})—precursor gel were monitored up to 1000 °C. Phase-pure nano-sized CuFe{sub 2}O{sub 4} powders were obtained after reaction at 750 °C for 2 h resulting in a crystallite size of 36 nm, which increases to 96 nm after calcining at 1000 °C. The activation energy of the crystallite growth process was calculated as 389 kJ mol{sup −1}. The tetragonal⇄cubic phase transition occurs between 402 and 419 °C and the enthalpy change (ΔH) was found to range between 1020 and 1229 J mol{sup −1} depending on the calcination temperature. The optical band gap depends on the calcination temperature and was found between 2.03 and 1.89 eV. The shrinkage and sintering behaviour of compacted powders were examined. Dense ceramic bodies can be obtained either after conventional sintering at 950 °C or after a two-step sintering process at 800 °C. Magnetic measurements of both powders and corresponding ceramic bodies show that the saturation magnetization rises with increasing calcination-/sintering temperature up to 49.1 emu g{sup −1} (2.1 µ{sub B} fu{sup −1}), whereas the coercivity and remanence values decrease. - Graphical abstract: A cheap one-pot synthesis was developed to obtain CuFe{sub 2}O{sub 4} nano-powders with different crystallite sizes (36–96 nm). The optical band gaps, phase transition temperatures and enthalpies were determined depending on the particle size. The sintering behaviour of nano CuFe{sub 2}O{sub 4} was studied in different sintering procedures. The magnetic behaviour of the nano-powders as well as the corresponding ceramic bodies were investigated. - Highlights: • Eco-friendly and simple synthesis for nano CuFe{sub 2}O{sub 4} powder using starch as polymerization agent. • Monitoring the phase evolution and crystallite growth

  15. Effect of milling duration on the evolution of shape memory properties in a powder processed Cu-Al-Ni-Ti alloy

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Mohit; Gupta, Gaurav K.; Shafeeq, Muhamed M.; Modi, Om P.; Prasad, Braj K. [CSIR - Advanced Materials and Processes Research Institute, Bhopal (India)

    2013-09-15

    The present work describes the effect of milling duration on the properties of a powder metallurgy processed Cu-Al-Ni-Ti shape memory alloy employing mechanical alloying. Powder mixtures milled for different durations were sintered in order to investigate the formation of solid solution and evolution of martensitic structure. The idea was to optimize the duration of milling (mechanical alloying) to obtain chemical homogeneity as well as shape memory properties in the processed material without undergoing extensive post homogenization treatment. The martensitic structure was noted to evolve in the powder mix milled for at least 16 hrs, whereas complete transformation to martensite occurred after milling for 40 hrs. Interestingly, the dissolution of alloying elements (to form the {beta} phase prior to the formation of martensite) was noted to complete partially only during mechanical alloying for 40 hrs and remaining during subsequent sintering for 1 hr. The hot pressed compacts of the powders milled for 40 hrs were chemically homogeneous and consisted of fully martensite phase, which is essential for the realization of shape memory properties. They also revealed almost 100% shape recovery at the applied pre-strain levels of 1 and 2%. (orig.)

  16. Cu(In,Ga)Se{sub 2} absorber thinning and the homo-interface model: Influence of Mo back contact and 3-stage process on device characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Leonard, E.; Arzel, L.; Tomassini, M.; Barreau, N., E-mail: nicolas.barreau@univ-nantes.fr [Institut des Matériaux Jean Rouxel (IMN)-UMR 6502, Université de Nantes, CNRS, 2 rue de la Houssinière, BP 32229, 44322 Nantes Cedex 3 (France); Zabierowski, P. [Faculty of Physics, Warsaw University of Technology, Koszykowa 75, PL 00-662 Warsaw (Poland); Fuertes Marrón, D. [Instituto de Energía Solar–ETSIT, Technical University of Madrid, Ciudad Universitaria s.n., 28040 Madrid (Spain)

    2014-08-21

    Thinning the absorber layer is one of the possibilities envisaged to further decrease the production costs of Cu(In,Ga)Se{sub 2} (CIGSe) thin films solar cell technology. In the present study, the electronic transport in submicron CIGSe-based devices has been investigated and compared to that of standard devices. It is observed that when the absorber is around 0.5 μm-thick, tunnelling enhanced interface recombination dominates, which harms cells energy conversion efficiency. It is also shown that by varying either the properties of the Mo back contact or the characteristics of 3-stage growth processing, one can shift the dominating recombination mechanism from interface to space charge region and thereby improve the cells efficiency. Discussions on these experimental facts led to the conclusions that 3-stage process implies the formation of a CIGSe/CIGSe homo-interface, whose location as well as properties rule the device operation; its influence is enhanced in submicron CIGSe based solar cells.

  17. Cu(In,Ga)Se2 absorber thinning and the homo-interface model: Influence of Mo back contact and 3-stage process on device characteristics

    Science.gov (United States)

    Leonard, E.; Arzel, L.; Tomassini, M.; Zabierowski, P.; Fuertes Marrón, D.; Barreau, N.

    2014-08-01

    Thinning the absorber layer is one of the possibilities envisaged to further decrease the production costs of Cu(In,Ga)Se2 (CIGSe) thin films solar cell technology. In the present study, the electronic transport in submicron CIGSe-based devices has been investigated and compared to that of standard devices. It is observed that when the absorber is around 0.5 μm-thick, tunnelling enhanced interface recombination dominates, which harms cells energy conversion efficiency. It is also shown that by varying either the properties of the Mo back contact or the characteristics of 3-stage growth processing, one can shift the dominating recombination mechanism from interface to space charge region and thereby improve the cells efficiency. Discussions on these experimental facts led to the conclusions that 3-stage process implies the formation of a CIGSe/CIGSe homo-interface, whose location as well as properties rule the device operation; its influence is enhanced in submicron CIGSe based solar cells.

  18. Influence of Ga-notch position on recombination processes in Cu(In,Ga)Se-2-based solar cells investigated by means of photoluminescence

    Science.gov (United States)

    Pawłowski, M.; Zabierowski, P.; Bacewicz, R.; Barreau, N.

    2013-05-01

    One of the consequences of the deposition of Cu(In,Ga)Se-2 (CIGSe) absorber by a three stage process is a non-uniform Ga distribution. It takes the form of the so-called Ga-notch and is considered to be crucial for achieving highly efficient CIGSe solar cells. However, the influence of this sequential element co-evaporation on defect related properties of the absorber is not fully understood. In this paper, we use voltage dependent photoluminescence (PLV) to investigate the impact of a different Ga-notch position on recombination processes in CIGSe-based solar cells. The most striking difference between investigated samples is the increased sensitivity of the photoluminescence signal to blue light, as the position of the Ga-notch moves away from the CdS/CIGSe interface. Such metastable behavior of PLV characteristics and its close correlation with changes observed in capacitance-voltage curves suggest an increased concentration of deep defects in the top CIGSe layer. We propose that the observed changes of PLV characteristics can be explained by electrical field redistribution within the junction due to charging of deep metastable defects.

  19. Effect of Thermomechanical Processing on Microstructure, Texture Evolution, and Mechanical Properties of Al-Mg-Si-Cu Alloys with Different Zn Contents

    Science.gov (United States)

    Wang, X. F.; Guo, M. X.; Chen, Y.; Zhu, J.; Zhang, J. S.; Zhuang, L. Z.

    2017-07-01

    The effect of thermomechanical processing on microstructure, texture evolution, and mechanical properties of Al-Mg-Si-Cu alloys with different Zn contents was studied by mechanical properties, microstructure, and texture characterization in the present study. The results show that thermomechanical processing has a significant influence on the evolution of microstructure and texture and on the final mechanical properties, independently of Zn contents. Compared with the T4P-treated (first preaged at 353 K (80 °C) for 12 hours and then naturally aged for 14 days) sheets with high final cold rolling reduction, the T4P-treated sheets with low final cold rolling reduction possess almost identical strength and elongation and higher average r values. Compared with the intermediate annealed sheets with high final cold rolling reduction, the intermediate annealed sheets with low final cold rolling reduction contain a higher number of particles with a smaller size. After solution treatment, in contrast to the sheets with high final cold rolling reduction, the sheets with low final cold rolling reduction possess finer grain structure and tend to form a weaker recrystallization texture. The recrystallization texture may be affected by particle distribution, grain size, and final cold rolling texture. Finally, the visco-plastic self-consistent (VPSC) model was used to predict r values.

  20. Effect of Alloying Elements and Intermediate Annealing on Microstructure and Properties of Cu-Cr Deformation Processed in situ Composites%合金元素及中间退火对Cu-Cr系形变原位复合材料组织和性能的影响

    Institute of Scientific and Technical Information of China (English)

    毕莉明; 刘平; 陈小红; 刘新宽; 马凤仓; 李伟

    2013-01-01

    采用冷拔结合中间退火工艺制备出Cu-13%Cr-0.24%Zr、Cu-15%Cr-0.24%Zr和Cu-15%Cr形变原位复合线材.研究了Cr含量、Zr元素、中间退火温度及次数对线材极限抗拉强度及导电性能的影响.结果表明:Zr元素可显著提高材料的强度,且对其导电性能影响不大:提高Cr元素含量,对材料的强度有一定贡献,但效果不明显.增加中间退火次数和提高中间退火温度都会使材料的极限抗拉强度降低,导电率升高.本实验中,通过两次500℃中间退火工艺制备的Cu-15%Cr-0.24%Zr线材获得较为优异的综合性能,抗拉强度达到1056MPa,导电率达到73 %IACS.%Cu-13%Cr-0.24%Zr,Cu-15%Cr-0.24%Zr and Cu-15%Cr deformation in situ composite wires were prepared by cold drawing combined with intermediate heat treatments.The effects of Zr element,Cr content,intermediate annealing temperature and times on the ultimate tensile strength (UTS) and electrical conductivity of Cu-Cr composites were investigated.Results show that Zr element can significantly enhance the UTS,while its effect on the electrical conductivity is modest.With the increase of mass friction of the Cr element,the UTS tends to increase a bit,and it has little impact on the electrical conductivity.Increasing annealing temperature or times can decrease the UTS and improve the electrical conductivity.In the experiment Cu-15%Cr-0.24%Zr in situ deformation wires with excellent comprehensive properties were obtained through the process of twice intermediate annealing at 500 ℃,whose UTS reaches 1056 MPa and whose electrical conductivity reaches 73%IACS.

  1. 电化学阻抗谱法研究温度对三维多孔Cu6Sn5合金电极嵌锂过程的影响%Electrochemical Impedance Spectroscopy Study on Effects of Temperature on the Lithiation Process of 3-Dimensional Porous Cu6Sns Alloy Electrode

    Institute of Scientific and Technical Information of China (English)

    樊小勇; 王晶晶; 李严; 曹桂铭; 史晓媛; 黄令; 孙世刚; 李东林

    2011-01-01

    Porous Cu was fabricated by electrodepositing using hydrogen bubbles as the dynamic template,and subsequently treated by annealing to increase the structural stability. The 3-dimensional porous Cu6Sn5 alloy electrode was prepared by electrodepositing using the porous Cu as the substrate. The lithiation/delithiation potentials of 3-dimensional porous Cu6Sn5 were investigated by cyclic voltammetry. The initial lithiation process of 3-dimensional porous Cu6Sn5 alloy electrode at different temperature was studied by electrochemical impedance spectroscopy. The results indicate that the Nyquist plots are composed of three regions in the main lithiation range: high frequency arc represents solid electrolyte interphase(SEI) impedance, middle frequency arc represents charge transfer impedance, and low frequency arc represents phase transformation impedance.The variation of the electrochemical impedance versus temperature was analyzed by simulating the experimental data using appropriate equivalent circuit.%采用氢气泡为动力学模板电沉积获得多孔铜,通过热处理增强其结构稳定性,并以该多孔铜为基底电沉积获得三维多孔Cu6Sn5合金电极.采用循环伏安法研究了三维多孔Cu6Sn5合金电极的嵌/脱锂电位.采用电化学阻抗谱研究了三维多孔Cu6Sn5合金电极在不同温度下的首次嵌锂过程.结果显示,在主要的嵌锂区间内,三维多孔Cu6Sn5合金电极的Nyquist图由锂离子穿过电极表面SEI膜阻抗的高频圆弧、电荷传递阻抗的中频圆弧和相变阻抗的低频圆弧3部分组成.因此,选择合适的等效电路对阻抗谱进行了模拟,并分析了其随温度的变化规律.

  2. Nitridation process effect on crystal structure and magnetic properties of TbCu7-type SmFe9 alloys

    Institute of Scientific and Technical Information of China (English)

    吕彬彬; 于敦波; 张世荣; 罗阳; 靳金玲; 闫文龙; 李红卫

    2013-01-01

    The effect of nitridation process, i.e. temperature and time, on crystal structure and magnetic properties of SmFe9Nx inter-stitial compounds was systematically investigated. After nitridation treatment, nitrogen atoms were incorporated into SmFe9 alloys to form SmFe9Nx interstitial compounds, which increased the distance of Fe-Fe and enhanced Fe-Fe interaction. As a result, SmFe9Nx interstitial compounds had a higher Curie temperature and more excellent magnetic properties than SmFe9 alloys. The relationships between nitridation temperature, nitridation time, nitriding efficiency, magnetic properties and phase transition were researched. It could be concluded that nitriding efficiency was strongly associated with magnetic properties and phase transition at different tem-peratures. The nitriding efficiency also had a connection with magnetic properties under different time, while no obvious phase transi-tion was found during that process. By studying nitridation process under a series of temperatures and time in this experiment, a suit-able nitridation temperature (713 K) and an ideal length of nitridation time (8 h) was decided, which would produce the optimal mag-netic behavior of SmFe9Nx interstitial compounds.

  3. The effects of different particle raze Y2Ba4CuBiOy nanoparticles doped on the properties of single domain YBCO bulk superconductors by TSIG process%不同粒径纳米Y2Ba4CuBiOy相掺杂对TSIG法单畴YBCO超导块材性能的影响

    Institute of Scientific and Technical Information of China (English)

    王妙; 杨万民; 张晓菊; 唐艳妮; 王高峰

    2012-01-01

    Single domain YBCO bulk superconductors are fabricated by the top-seeded infiltration and growth process(TSIG). The effects of different particle size Y2Ba4CuBiOy nanoparticles doped on the growth morphology, microstrncture and levitation force of single domain YBCO bulk superconductors are investigated. The mean diameters of the initial Y2Ba4CuBiOy nanoparticles respectively are 283 nm, 170.4 nm and 82.5 nm, and the amount of Y2Ba4CuBiOyadded to Y2BaCuO5 is 2 wt%. The results show that the single domain YBCO bulk superconductors can be fabricated, and the surface of the sample has significant cross pattern and four single domain sectors become smooth and flat. The second phase Y2Ba4CuBiOy nanoparticles are well-distributed into the single domain YBCO bulk samples, and the particles sizes of Y2Ba4CuBiOy nanoparticles in the YBCO bulk sample are respectively 270 nm, 150 nm and 50 nm, smaller than that the initial powder. The magnetic levitation forces of the samples increase gradually with the decrease of initial powders of Y2Ba4CuBiOy nanoparticles, which are respectively 10 N, 17 N and 22 N. The results are very important for further studying the method of flux pinning of nanoparticles and improving the properties of YBCO bulk superconductors.%本文采用顶部籽晶熔渗方法(TSIG),研究了不同粒径纳米Y2Ba4CuBiOy粒子对单畴YBCO超导块材的生长形貌、微观结构及其磁悬浮力的影响.实验所用纳米Y2Ba4CuBiOy粉体的平均粒度分别为283.0nm,170.4nm以及82.5nm,每种粉体在YBCO超导块材中的含量均为2wt%.研究结果表明:在掺杂量为2wt%的情况下,Y2Ba4CuBiOy粉体的粒度并不影响样品的宏观形貌,均可制备出单畴YBCO块材;并且成功地将纳米Y2Ba4CuBiOy粒子引入单畴YBCO块材中,且使其均匀分布,但样品中的Y2Ba4CuBiOy粒子均小于其初始粉体的粒度,分别减小到270nm,150nm和50nm;随着Y2Ba4CuBiOy粉体初始粒度

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

    Science.gov (United States)

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

    2016-12-01

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

  5. Application of Zr/Ti-Pic in the adsorption process of Cu(II), Co(II) and Ni(II) using adsorption physico-chemical models and thermodynamics of the process; Aplicacao de Zr/Ti-PILC no processo de adsorcao de Cu(II), Co(II) e Ni(II) utilizando modelos fisico-quimicos de adsorcao e termodinamica do processo

    Energy Technology Data Exchange (ETDEWEB)

    Guerra, Denis Lima; Airoldi, Claudio [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Inst. de Quimica. Dept. de Quimica Inorganica]. E-mail: dlguerra@iqm.unicamp.br; Lemos, Vanda Porpino; Angelica, Romulo Simoes [Universidade Federal do Para (UFPa), Belem (Brazil); Viana, Rubia Ribeiro [Universidade Federal do Mato Grosso (UFMT), Cuiaba (Brazil). Inst. de Ciencias Exatas e da Terra. Dept. de Recursos Minerais

    2008-07-01

    The aim of this investigation is to study how Zr/Ti-Pic adsorbs metals. The physico-chemical proprieties of Zr/Ti-Pic have been optimized with pillarization processes and Cu(II), Ni(II) and Co(II) adsorption from aqueous solution has been carried out, with maximum adsorption values of 8.85, 8.30 and 7.78 x-1 mmol g{sup -1}, respectively. The Langmuir, Freundlich and Temkin adsorption isotherm models have been applied to fit the experimental data with a linear regression process. The energetic effect caused by metal interaction was determined through calorimetric titration at the solid-liquid interface and gave a net thermal effect that enabled the calculation of the exothermic values and the equilibrium constant. (author)

  6. Cu-Cr Literature Review

    Energy Technology Data Exchange (ETDEWEB)

    Need, Ryan F. [Los Alamos National Laboratory

    2012-08-09

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

  7. Literature review on the properties of cuprous oxide Cu{sub 2}O and the process of copper oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Korzhavyi, P. A.; Johansson, B. (Department of Materials Science and Engineering, Royal Institute of Technology, Stockholm (Sweden))

    2011-10-15

    The purpose of the present review is to provide a reference guide to the most recent data on the properties of copper(I) oxide as well as on the atomic processes involved in the initial stages of oxidation of copper. The data on the structure of surfaces, as obtained from atomic-resolution microscopy studies (for example, STM) or from first-principles calculations, are reviewed. Information of this kind may be useful for understanding the atomic mechanisms of corrosion and stress-corrosion cracking of copper

  8. Advanced processing of CdTe- and CuIn{sub x}Ga{sub 1{minus}x}Se{sub 2}-based solar cells. Phase 1 annual subcontract report, 18 April 1995--17 April 1996

    Energy Technology Data Exchange (ETDEWEB)

    Morel, D L; Ferekides, C S [Univ. of South Florida, Tampa, FL (United States)

    1997-03-01

    The main objective of this project to develop high-efficiency CdTe solar cells based on processing conditions favorable for manufacturing processes. This report presents the results on work performed during the first phase of this project. One of the major issues addressed is the use of soda-lime glass substrates in place of the borosilicate glass often used for laboratory devices; another task is the preparation of Cu(In, Ga) Se{sub 2} solar cells by selenizing suitable precursor films. Emphasis is placed on processing and how different reaction schemes affect device performance. It was found that different reaction schemes not only change the bulk properties of Cu(In, Ga) Se{sub 2}, but also its surface properties, which critically affect device performance. Although the objective is to optimize processing to meet the manufacturing constraints, work has not been limited within these requirements.

  9. Fabrication of Cu(In,Ga)Se{sub 2} thin films by a combination of mechanochemical and screen-printing/sintering processes

    Energy Technology Data Exchange (ETDEWEB)

    Wada, T.; Matsuo, Y.; Nomura, S. [Department of Materials Chemistry, Ryukoku University, Seta, Otsu 520-2194 (Japan); Nakamura, Y.; Miyamura, A. [Department of Metallurgy and Ceramics Science, Tokyo Institute of Technology (Japan); Chiba, Y.; Konagai, M. [Department of Physical Electronics, Tokyo Institute of Technology (Japan); Yamada, A. [Quantum Nanoelectronics Research Center, Tokyo Institute of Technology (Japan)

    2006-09-15

    We prepared fine Cu(In,Ga)Se{sub 2} (CIGS) powder suitable for screen printing using a mechanochemical process. Particulate precursors were deposited in a thin layer by a screen-printing technique, the remaining organic solvent was removed from the screen-printed CIGS film and finally the porous precursor layer was sintered into a dense polycrystalline film by atmospheric-pressure firing. The crystal structure of the film was analyzed by X-ray diffraction and the microstructure was observed in a SEM. The thickness of the film was 5-10 {mu}m with a grain size of about 2 {mu}m. The films were also observed in a TEM. The grain size of the as-prepared powder was less than 1 {mu}m; however, it enlarged to 2-3 {mu}m after firing at 575 C under a Se ambient. Preliminary CIGS solar cells with our standard Al grid/B-doped ZnO/i-ZnO/ CdS/CIGS/Mo/soda-lime glass structure were fabricated. An efficiency of 2.7%, a V{sub oc} of 0.325 V, a J{sub sc} of 28.3 mA/cm{sup 2} and a FF of 0.295 was obtained. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (Abstract Copyright [2006], Wiley Periodicals, Inc.)

  10. DOE applied to study the effect of process parameters on silicon spacing in lost foam Al-Si-Cu alloy casting

    Science.gov (United States)

    Shayganpour, A.; Idris, M. H.; Izman, S.; Jafari, H.

    2012-09-01

    Lost foam casting as a relatively new manufacturing process is extensively employed to produce sound complicated castings. In this study, an experimental investigation on lost foam casting of an Al-Si-Cu aluminium cast alloy was conducted. The research was aimed in evaluating the effect of different pouring temperatures, slurry viscosities, vibration durations and sand grain sizes on eutectic silicon spacing of thin-wall castings. A stepped-pattern was used in the study and the focus of the investigations was at the thinnest 3 mm section. A full two-level factorial design experimental technique was used to plan the experiments and afterwards identify the significant factors affecting casting silicon spacing. The results showed that pouring temperature and its interaction with vibration time have pronounced effect on eutectic silicon phase size. Increasing pouring temperature coarsened the eutectic silicon spacing while the higher vibration time diminished coarsening effect. Moreover, no significant effects on silicon spacing were found with variation of sand size and slurry viscosity.

  11. Microstructure and corrosion behavior of a Zr-Sn-Nb-Fe-Cu-O alloy fabricated by α+β quenching processing

    Science.gov (United States)

    Chen, Liangyu; Zhang, Lina; Chai, Linjiang; Yang, Wenlong; Wang, Liqiang; lu, Weijie

    2017-03-01

    In this work, the microstructure of a Zr-Sn-Nb-Fe-Cu-O alloy fabricated by α+β quenching processing (ABQ sample) was investigated by the combined utilization of scanning electron microscopy, electron backscatter diffraction and transmission electron microscopy. The results showed that the polygonal grains evenly distributed in ABQ sample and triangular grains distributed at triple junctions of polygonal grains with densely second phase particles (SPPs). The textures of directions tilted approximately 25° from normal direction and the rolling direction spreading along the {-} were found in the sample, which was also detected in the regularly cold rolled and annealed sample. The occurrence of corrosion kinetics transition of ABQ sample was sight earlier than that of RAX sample. Due to a higher solid solubility of β-Zr, SPPs re-dissolved into β-Zr during α+β annealing and precipitated out afterward in those areas. Finally, discrepant corrosion rate of metal matrix and SPPs led to the formation of protrusions of matrix, which could concentrate stress and generate cracks in the oxide.

  12. Solution-Processed One-Dimensional ZnO@CdS Heterojunction toward Efficient Cu2ZnSnS4 Solar Cell with Inverted Structure

    Science.gov (United States)

    Chen, Rongrong; Fan, Jiandong; Liu, Chong; Zhang, Xing; Shen, Yanjiao; Mai, Yaohua

    2016-10-01

    Kesterite Cu2ZnSnS4 (CZTS) semiconductor has been demonstrated to be a promising alternative absorber in thin film solar cell in virtue of its earth-abundant, non-toxic element, suitable optical and electrical properties. Herein, a low-cost and non-toxic method that based on the thermal decomposition and reaction of metal-thiourea-oxygen sol-gel complexes to synthesize CZTS thin film was developed. The low-dimensional ZnO@CdS heterojunction nano-arrays coupling with the as-prepared CZTS thin film were employed to fabricate a novel solar cell with inverted structure. The vertically aligned nanowires (NWs) allow facilitating the charge carrier collection/separation/transfer with large interface areas. By optimizing the parameters including the annealing temperature of CZTS absorber, the thickness of CdS buffer layer and the morphology of ZnO NWs, an open-circuit voltage (VOC) as high as 589 mV was obtained by such solar cell with inverted structure. The all-solution-processed technic allows the realization of CZTS solar cell with extremely low cost.

  13. van der Waals-corrected Density Functional Theory simulation of adsorption processes on noble-metal surfaces: Xe on Ag(111), Au(111), and Cu(111)

    CERN Document Server

    Silvestrelli, Pier Luigi

    2016-01-01

    The DFT/vdW-WF2s1 method based on the generation of localized Wannier functions, recently developed to include the van der Waals interactions in the Density Functional Theory and describe adsorption processes on metal surfaces by taking metal-screening effects into account, is applied to the case of the interaction of Xe with noble-metal surfaces, namely Ag(111), Au(111), and Cu(111). The study is also repeated by adopting the DFT/vdW-QHO-WF variant relying on the Quantum Harmonic Oscillator model which describes well many-body effects. Comparison of the computed equilibrium binding energies and distances, and the $C_3$ coefficients characterizing the adatom-surface van der Waals interactions, with available experimental and theoretical reference data shows that the methods perform well and elucidate the importance of properly including screening effects. The results are also compared with those obtained by other vdW-corrected DFT schemes, including PBE-D, vdW-DF, vdW-DF2, rVV10, and by the simpler Local Dens...

  14. Solution-Processed One-Dimensional ZnO@CdS Heterojunction toward Efficient Cu2ZnSnS4 Solar Cell with Inverted Structure.

    Science.gov (United States)

    Chen, Rongrong; Fan, Jiandong; Liu, Chong; Zhang, Xing; Shen, Yanjiao; Mai, Yaohua

    2016-10-13

    Kesterite Cu2ZnSnS4 (CZTS) semiconductor has been demonstrated to be a promising alternative absorber in thin film solar cell in virtue of its earth-abundant, non-toxic element, suitable optical and electrical properties. Herein, a low-cost and non-toxic method that based on the thermal decomposition and reaction of metal-thiourea-oxygen sol-gel complexes to synthesize CZTS thin film was developed. The low-dimensional ZnO@CdS heterojunction nano-arrays coupling with the as-prepared CZTS thin film were employed to fabricate a novel solar cell with inverted structure. The vertically aligned nanowires (NWs) allow facilitating the charge carrier collection/separation/transfer with large interface areas. By optimizing the parameters including the annealing temperature of CZTS absorber, the thickness of CdS buffer layer and the morphology of ZnO NWs, an open-circuit voltage (VOC) as high as 589 mV was obtained by such solar cell with inverted structure. The all-solution-processed technic allows the realization of CZTS solar cell with extremely low cost.

  15. Non-vacuum processed Cu{sub 2}ZnSnS{sub 4} thin films: Influence of copper precursor on structural, optical and morphological properties

    Energy Technology Data Exchange (ETDEWEB)

    Aslan, Ferhat, E-mail: ferhataslan@harran.edu.tr; Tumbul, Ahmet

    2014-11-05

    Highlights: • Non-vacuum sol–gel prepared CZTS thin films. • CZTS has been prepared with different copper precursors. • The remarkable effect of copper precursor on the CZTS films was identified. • The CZTS films exhibited kesterite phase with a (1 1 2) plane preferred orientation. - Abstract: In this study, thin film of Cu{sub 2}ZnSnS{sub 4} (CZTS) has been successfully deposited by sol–gel dip-coating method on glass substrates. In the sol–gel process, glacial acetic acid, ethanol and triethanolamine were used as solvent and stabilizer. Three different copper precursors of copper (III) nitrate hemipentahydrate, copper (II) 2-ethylhexanoate and copper (II) acetate in the solution were used to obtain CZTS thin films. Effect of copper precursor on the structural, morphological and optical properties was investigated. X-ray diffraction (XRD) and Raman spectroscopy studies showed that CZTS thin films exhibited kesterite structure with a (1 1 2) plane preferred orientation and Raman shift of 336 cm{sup −1}, respectively.

  16. Thermal plasma properties for Ar-Al, Ar-Fe and Ar-Cu mixtures used in welding plasmas processes: I. Net emission coefficients at atmospheric pressure

    Science.gov (United States)

    Cressault, Y.; Gleizes, A.

    2013-10-01

    This article is devoted to the calculation of the net emission coefficient (NEC) of Ar-Al, Ar-Fe and Ar-Cu mixtures at atmospheric pressure for arc welding processes. The results are given in data tables for temperatures between 3 kK and 30 kK, for five plasma thicknesses (0, 0.5, 1, 2, 5 mm) and ten concentrations of metallic vapours (pure gas, 0.01%, 0.1%, 1%, 5%, 10%, 25%, 50%, 75% and pure metal vapours in mass proportions). The results are in good agreement with most of the works published on the subject for such mixtures. They highlight the influence of three parameters on the radiation of the plasma: the NEC is directly related to temperature and inversely related to plasma radius and is highly sensitive to the presence of metal vapours. Finally, numerical data are supplied in tables in order to develop accurate computational modelling of welding arc and to estimate both qualitatively and quantitatively the influence of each metallic vapour on the size and on the shape of the weld pool.

  17. High Critical Current Density of YBa2Cu3O7-x Superconducting Films Prepared through a DUV-assisted Solution Deposition Process.

    Science.gov (United States)

    Chen, Yuanqing; Bian, Weibai; Huang, Wenhuan; Tang, Xinni; Zhao, Gaoyang; Li, Lingwei; Li, Na; Huo, Wen; Jia, Jiqiang; You, Caiyin

    2016-12-01

    Although the solution deposition of YBa2Cu3O7-x (YBCO) superconducting films is cost effective and capable of large-scale production, further improvements in their superconductivity are necessary. In this study, a deep UV (DUV) irradiation technique combined with a low-fluorine solution process was developed to prepare YBCO films. An acrylic acidic group as the chelating agent was used in the precursor solution. The acrylic acidic group was highly sensitive to DUV light at 254 nm and significantly absorbed UV light. The coated gel films exposed to DUV light decomposed at 150 °C and copper aggregation was prevented. The UV irradiation promoted the removal of the carbon residue and other by-products in the films, increased the density and enhanced the crystallinity and superconductivity of the YBCO films. Using a solution with F/Ba = 2, YBCO films with thicknesses of 260 nm and enhanced critical current densities of nearly 8 MA/cm(2) were produced on the LaAlO3 (LAO) substrates.

  18. High Critical Current Density of YBa2Cu3O7‑x Superconducting Films Prepared through a DUV-assisted Solution Deposition Process

    Science.gov (United States)

    Chen, Yuanqing; Bian, Weibai; Huang, Wenhuan; Tang, Xinni; Zhao, Gaoyang; Li, Lingwei; Li, Na; Huo, Wen; Jia, Jiqiang; You, Caiyin

    2016-12-01

    Although the solution deposition of YBa2Cu3O7‑x (YBCO) superconducting films is cost effective and capable of large-scale production, further improvements in their superconductivity are necessary. In this study, a deep UV (DUV) irradiation technique combined with a low-fluorine solution process was developed to prepare YBCO films. An acrylic acidic group as the chelating agent was used in the precursor solution. The acrylic acidic group was highly sensitive to DUV light at 254 nm and significantly absorbed UV light. The coated gel films exposed to DUV light decomposed at 150 °C and copper aggregation was prevented. The UV irradiation promoted the removal of the carbon residue and other by-products in the films, increased the density and enhanced the crystallinity and superconductivity of the YBCO films. Using a solution with F/Ba = 2, YBCO films with thicknesses of 260 nm and enhanced critical current densities of nearly 8 MA/cm2 were produced on the LaAlO3 (LAO) substrates.

  19. Van Der Waals-Corrected Density Functional Theory Simulation of Adsorption Processes on Noble-Metal Surfaces: Xe on Ag(111), Au(111), and Cu(111)

    Science.gov (United States)

    Silvestrelli, Pier Luigi; Ambrosetti, Alberto

    2016-10-01

    The DFT/vdW-WF2s1 method based on the generation of localized Wannier functions, recently developed to include the van der Waals interactions in the density functional theory and describe adsorption processes on metal surfaces by taking metal-screening effects into account, is applied to the case of the interaction of Xe with noble-metal surfaces, namely Ag(111), Au(111), and Cu(111). The study is also repeated by adopting the DFT/vdW-QHO-WF variant relying on the quantum harmonic oscillator model which describes well many body effects. Comparison of the computed equilibrium binding energies and distances, and the C_3 coefficients characterizing the adatom-surface van der Waals interactions, with available experimental and theoretical reference data shows that the methods perform well and elucidates the importance of properly including screening effects. The results are also compared with those obtained by other vdW-corrected DFT schemes, including PBE-D, vdW-DF, vdW-DF2, rVV10, and by the simpler local density approximation and semi-local (PBE) generalized gradient approximation approaches.

  20. LoCuSS: The slow quenching of star formation in cluster galaxies and the need for pre-processing

    CERN Document Server

    Haines, C P; Smith, G P; Egami, E; Babul, A; Finoguenov, A; Ziparo, F; McGee, S L; Rawle, T D; Okabe, N; Moran, S M

    2015-01-01

    We present a study of the spatial distribution and kinematics of star-forming galaxies in 30 massive clusters at 0.15processed within galaxy groups. Despite the increasing f_SF-radius trend, the surface density of star-forming galaxies actually declines steadily with radius, falling ~15x from the core to 2r200. This requires star-formation to survive within recently accreted spirals for 2--3Gyr to build up the apparent over-density of star-forming galaxies within clusters...

  1. Effect of the burn-out step on the microstructure of the solution-processed Cu(In,Ga)Se{sub 2} solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Batuk, Maria, E-mail: Maria.Batuk@uantwerpen.be [Electron Microscopy for Materials Science (EMAT), University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp (Belgium); SIM vzw, Technologiepark 935, 9052 Zwijnaarde (Belgium); Buffière, Marie [Department of Electrical Engineering (ESAT), KU Leuven, Kasteelpark Arenberg 10, 3001 Heverlee (Belgium); imec—partner in Solliance, Kapeldreef 75, 3001 Heverlee (Belgium); SIM vzw, Technologiepark 935, 9052 Zwijnaarde (Belgium); Zaghi, Armin E.; Lenaers, Nick [imec—partner in Solliance, Kapeldreef 75, 3001 Heverlee (Belgium); Department of Materials Engineering (MTM), KU Leuven, Kasteelpark Arenberg 44, 3001 Heverlee (Belgium); SIM vzw, Technologiepark 935, 9052 Zwijnaarde (Belgium); Verbist, Christophe [Electron Microscopy for Materials Science (EMAT), University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp (Belgium); Khelifi, Samira [Electronics and Information Systems Department (ELIS), University of Gent, Sint-Pietersnieuwstraat 41, 9000 Gent (Belgium); SIM vzw, Technologiepark 935, 9052 Zwijnaarde (Belgium); Vleugels, Jef [Electronics and Information Systems Department (ELIS), University of Gent, Sint-Pietersnieuwstraat 41, 9000 Gent (Belgium); Meuris, Marc [imec division IMOMEC—partner of Solliance, Wetenschapspark 1, 3590 Diepenbeek (Belgium); Institute for Material Research (IMO), Hasselt University, Wetenschapspark 1, 3590 Diepenbeek (Belgium); Hadermann, Joke [Electron Microscopy for Materials Science (EMAT), University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp (Belgium)

    2015-05-29

    For the development of the photovoltaic industry cheap methods for the synthesis of Cu(In{sub ,}Ga)Se{sub 2} (CIGSe) based solar cells are required. In this work, CIGSe thin films were obtained by a solution-based method using oxygen-bearing derivatives. With the aim of improving the morphology of the printed CIGSe layers, we investigated two different annealing conditions of the precursor layer, consisting of (1) a direct selenization step (reference process), and (2) a pre-treatment thermal step prior to the selenization. We showed that the use of an Air/H{sub 2}S burn-out step prior to the selenization step increases the CIGSe grain size and reduces the carbon content. However, it leads to the reduction of the solar cell efficiency from 4.5% in the reference sample down to 0.5% in the annealed sample. Detailed transmission electron microscopy analysis, including high angle annular dark field scanning transmission electron microscopy and energy dispersive X-ray mapping, was applied to characterize the microstructure of the film and to determine the relationship between microstructure and the solar cell performance. We demonstrated that the relatively low efficiency of the reference solar cells is related not only to the nanosize of the CIGSe grains and presence of the pores in the CIGSe layer, but also to the high amount of secondary phases, namely, In/Ga oxide (or hydroxide) amorphous matter, residuals of organic matter (carbon), and copper sulfide that is formed at the CIGSe/MoSe{sub 2} interface. The annealing in H{sub 2}S during the burn-out step leads to the formation of the copper sulfide at all grain boundaries and surfaces in the CIGSe layer, which results in the noticeably efficiency drop. - Highlights: • Cu(Ga,In)Se{sub 2} solar cells were synthesized by a solution-based method. • The morphology of the CIGSe layer improves during the annealing. • The efficiency of the reference sample is 4.5% and of the annealed is 0.5%. • Upon the annealing

  2. 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).

  3. LoCuSS: THE SLOW QUENCHING OF STAR FORMATION IN CLUSTER GALAXIES AND THE NEED FOR PRE-PROCESSING

    Energy Technology Data Exchange (ETDEWEB)

    Haines, C. P. [Departamento de Astronomía, Universidad de Chile, Casilla 36-D, Correo Central, Santiago (Chile); Pereira, M. J.; Egami, E.; Rawle, T. D. [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Smith, G. P.; Ziparo, F.; McGee, S. L. [School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham, B15 2TT (United Kingdom); Babul, A. [Department of Physics and Astronomy, University of Victoria, 3800 Finnerty Road, Victoria, BC, V8P 1A1 (Canada); Finoguenov, A. [Department of Physics, University of Helsinki, Gustaf Hällströmin katu 2a, FI-0014 Helsinki (Finland); Okabe, N. [Academia Sinica Institute of Astronomy and Astrophysics (ASIAA), P.O. Box 23-141, Taipei 10617, Taiwan (China); Moran, S. M., E-mail: cphaines@das.uchile.cl [Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, MA 02138 (United States)

    2015-06-10

    We present a study of the spatial distribution and kinematics of star-forming galaxies in 30 massive clusters at 0.15 < z < 0.30, combining wide-field Spitzer 24 μm and GALEX near-ultraviolet imaging with highly complete spectroscopy of cluster members. The fraction (f{sub SF}) of star-forming cluster galaxies rises steadily with cluster-centric radius, increasing fivefold by 2r{sub 200}, but remains well below field values even at 3r{sub 200}. This suppression of star formation at large radii cannot be reproduced by models in which star formation is quenched in infalling field galaxies only once they pass within r{sub 200} of the cluster, but is consistent with some of them being first pre-processed within galaxy groups. Despite the increasing f{sub SF}-radius trend, the surface density of star-forming galaxies actually declines steadily with radius, falling ∼15× from the core to 2r{sub 200}. This requires star formation to survive within recently accreted spirals for 2–3 Gyr to build up the apparent over-density of star-forming galaxies within clusters. The velocity dispersion profile of the star-forming galaxy population shows a sharp peak of 1.44 σ{sub ν} at 0.3r{sub 500}, and is 10%–35% higher than that of the inactive cluster members at all cluster-centric radii, while their velocity distribution shows a flat, top-hat profile within r{sub 500}. All of these results are consistent with star-forming cluster galaxies being an infalling population, but one that must also survive ∼0.5–2 Gyr beyond passing within r{sub 200}. By comparing the observed distribution of star-forming galaxies in the stacked caustic diagram with predictions from the Millennium simulation, we obtain a best-fit model in which star formation rates decline exponentially on quenching timescales of 1.73 ± 0.25 Gyr upon accretion into the cluster.

  4. Kinetics of Corrosion Process in H2SO4 and HNO3 Aqueous Solutions of Lead Free Sn-Ag-Cu Solder Alloys

    OpenAIRE

    Guśpiel J.; Wierzbicka-Miernik A.; Reczyński W.

    2016-01-01

    This paper presents the results of the corrosion resistance of Sn-Ag-Cu alloys in air-saturated aqueous solutions containing NO3-, SO42- ions, whose concentration was equivalent to their contents in acid rains and in concentrations 10 - 100 times higher. The Ag, Cu and Sn concentrations in the corrosive media were determined using the Atomic Absorption Spectrometry. The specific dissolution rate and corrosion current were derived using the a rotating disc technique. The corrosion rate of Sn- ...

  5. Bond strength of W-Cu/CuCr integrated material

    Institute of Scientific and Technical Information of China (English)

    范志康; 梁淑华; 薛旭

    2001-01-01

    The bond strength of W-Cu/CuCr integrated material was investigated. The results show that the fracture of W-Cu/CuCr integrated material often takes place at W-Cu/CuCr interface. Some alloying elements enhance the bond of W and CuCr alloy, which results in the increase of the strength of the W-Cu/CuCr interface. And the fracture of the WCu/CuCr integrated material occurs in the CuCr alloy part, not at the W-Cu/CuCr interface. Chromium in CuCr alloy part of the integrated material can improve Cr diffusing from the CuCr alloy to W-Cu composite and can be alloyed (near the W-Cu/CuCr interface) in the W-Cu composite. Thus the strength of W-Cu/CuCr interface is also increased.

  6. Luminescence investigation of Cu(In,Ga)Se{sub 2}solar cells with different Ga-contents grown in a three-stage-process on glass substrate

    Energy Technology Data Exchange (ETDEWEB)

    Wendt, Kristin; Mueller, Mathias; Hempel, Thomas; Bertram, Frank; Christen, Juergen [Institute of Experimental Physics, Otto-von-Guericke-University Magdeburg (Germany); Abou-Ras, Daniel; Rissom, Thorsten; Unold, Thomas; Schock, Hans-Werner [Helmholtz-Zentrum Berlin for Materials and Energy (Germany)

    2011-07-01

    A fundamental advantage of Cu(In,Ga)Se{sub 2} (CIGS) alloys as absorber materials in thin-film solar cells is their direct band gap energies which can be varied between 1.04 eV (CuInSe{sub 2}) and 1.68 eV (CuGaSe{sub 2}). Photoluminescence (PL) spectra of complete CIGS solar cells with a systematic variation of the Ga-content in the absorber layer will be presented. The CIGS cells investigated were grown on a Mo back contact sputtered on soda lime glass and have a Ga-concentration ranging over the entire range from CuInSe{sub 2} to CuGaSe{sub 2}. Samples with Ga-contents between 100 % and 33 % show two broad luminescence bands. In contrast, CuInSe{sub 2} exhibits only one broad luminescence band. Each band is composed of two or three different transitions. Varying excitation density over four orders of magnitude results for samples with Ga-content of 0 % and 33 % in a blueshift of the main peak with increasing excitation density. For higher Ga-concentrations, first a blue- and then a redshift of the dominating peak with increasing excitation density is visible. The temperature dependence of the PL spectra is investigated going from 4 K to 300 K.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-11-30

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

  8. Cu metabolism in the liver.

    Science.gov (United States)

    McArdle, H J; Bingham, M J; Summer, K; Ong, T J

    1999-01-01

    This paper has, given some idea of our concepts of the processes involved in the transport of Cu across cell membranes in the liver, which we have summarised in Fig 1. Cu(II)His2 is reduced to Cu(I). This is transported across the membrane, re-oxidised, either before or after binding to glutathione (Freedman et al., 1989) or HAH1 (Klomp et al., 1997), binds to SAHH, and donates Cu(II) to the ATPase. It is very interesting that cells which are very diverse from an evolutionary point of view still use very similar methods to handle the metal. Whether regulation of transport is also the sam remains to be seen. We would guess that, although there will be strong similarities, there will also be very significant differences, reflecting the different environments seen by different tissues in mammalian cells and given the different requirements of the tissues.

  9. Effect of copper content and sulfurization process on optical, structural and electrical properties of ultrasonic spray pyrolysed Cu{sub 2}ZnSnS{sub 4} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Kermadi, S., E-mail: kermadisalim@yahoo.fr [CRTSE- Division DDCS 02, Bd Dr Frantz Fanon BP: 140, Les 07 Merveilles, 16038, Algiers (Algeria); Sali, S.; Ait Ameur, F.; Zougar, L.; Boumaour, M. [CRTSE- Division DDCS 02, Bd Dr Frantz Fanon BP: 140, Les 07 Merveilles, 16038, Algiers (Algeria); Toumiat, A. [Ceramics Laboratory, Physics Department, Constantine University 1, 25017, Constantine (Algeria); Melnik, N.N. [Lebedev Physical Institute, Russian Academy of Sciences, Leninskii pr. 53, Moscow, 119991 (Russian Federation); Hewak, D.W. [Optoelectronics Research Centre, University of Southampton, Southampton, SO17 1BJ (United Kingdom); Duta, Anca [Transilvania University of Brasov, Department of Renewable Energy Systems and Recycling, Eroilor 29, 500036, Brasov (Romania)

    2016-02-01

    This paper reports the effect of copper content and of the sulfurization process (using elemental sulfur vapor) on the growth, structure, elemental composition, and on the optical and electrical properties of Cu{sub 2}ZnSnS{sub 4} (CZTS) thin films deposited on glass substrates using ultrasonic Spray Pyrolysis. For this purpose, a series of aqueous solutions consisting of copper (II) and tin (IV) chlorides, zinc (II) acetate and thiourea with different copper concentrations (x = Cu/(Zn + Sn) = 0.8, 1, 1.2 and 1.4 while Zn/Sn = 1) were prepared. X-ray diffraction, raman spectroscopy, scanning electronic microscopy, atomic force microscopy, energy dispersive X-ray spectroscopy, ultraviolet–visible–near infrared absorbance spectroscopy and sheet resistance analyses were used to follow the evolution of the investigated properties. The results outlined a Kesterite type CZTS phase and a secondary copper sulfide (Cu{sub 2-x}S) phase, and their ratio strongly depends on the copper salt concentration and heat-treatment atmosphere. No traces of secondary phases of zinc or tin sulfides are found while high purity CZTS was obtained with the post-sulfurized film at x = 1.2. It was found that the application of additional sulfurization enhances the grain growth to reach 300 nm in size and induces significant improvement of both CZTS crystallinity and electrical conductivity. The optical band gap ranges between 1.44 and 1.57 eV depending on the composition and the sulfur deficiency is strongly reduced leading to Cu-poorer and Zn-richer compounds, as compared to those annealed in nitrogen atmosphere. This study shows promising results, as a first step in developing photovoltaic applications, using sprayed CZTS as absorber. - Highlights: • Cu{sub 2}ZnSnS{sub 4} (CZTS) thin films were obtained by ultrasonic Spray Pyrolysis. • The copper content and sulfurization process affect the Cu{sub 2}S/CZTS ratio. • Cu/(Zn + Sn) = 1.2 found to be optimum composition

  10. Excitation functions and isomeric cross section ratios of the 63Cu(n,α)60Com,g, 65Cu(n,α)62Com,g, and 60Ni(n,p)60Com,g processes from 6 to 15 MeV

    Science.gov (United States)

    Cserpák, F.; Sudár, S.; Csikai, J.; Qaim, S. M.

    1994-03-01

    Excitation functions were measured for the 63Cu(n,α)60Com, 65Cu(n,α)62Com, and 65Cu(n,α)62Cog reactions over the neutron energy range of 6.3 to 14.8 MeV. Use was made of the activation technique in combination with high resolution γ-ray spectroscopy. The nuetrons were produced via the 2H(d,n)3He reaction using a deuterium gas target at a variable energy compact cyclotron (En=6.3-11.9 MeV) and via the 3H(d,n)4He reaction using a solid Ti-T target at a neutron generator (En=13.7-14.8 MeV). From the available experimental data isomeric cross section ratios were determined for the isomeric pair 60Com,g in 63Cu(n,α) and 60Ni(n,p) reactions, and for the pair 62Com,g in the 65Cu(n,α) reaction. Statistical model calculations taking into account precompound effects were performed for the formation of both the isomeric and ground states of the products. The calculational results on the total (n,p) and (n,α) cross sections agree well with the experimental data; in the case of isomeric states, however, some deviations occur. The experimental isomeric cross section ratios are reproduced only approximately by the calculation; at 15 MeV the spin distribution of the level density has a significant effect on the calculation. For low-lying levels the isomeric cross section ratio depends strongly on the spins of the levels involved and not on their excitation energies. At a given neutron energy the population of the higher spin isomer appears to be higher in the (n,α) process than in the (n,p) reaction.

  11. Enhanced electrical properties of pulsed laser-deposited CuIn{sub 0.7}Ga{sub 0.3}Se{sub 2} thin films via processing control

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Yeon Hwa; Mohanty, Bhaskar Chandra; Cho, Yong Soo [Department of Materials Science and Engineering, Yonsei University, Seoul (Korea, Republic of)

    2010-12-15

    Polycrystalline CuIn{sub 0.7}Ga{sub 0.3}Se{sub 2} thin films were prepared on soda-lime glass substrates using pulsed laser deposition (PLD) with various process parameters such as laser energy, repetition rate and substrate temperature. It was confirmed that there existed a limited laser energy, i.e. less than 300 mJ, to get phase pure CIGS thin films at room temperature. Particularly, even at room temperature, distinct crystalline CIGS phase was observed in the films. Crystallinity of the films improved with increasing substrate temperature as evidenced by the decrease of FWHM from 0.65 degto 0.54 deg. Slightly Cu-rich surface with Cu{sub 2-x}Se phase was confirmed to exist by Raman spectra, depending on substrate temperature. Improved electrical properties, i.e., carrier concentration of {proportional_to}10{sup 18} cm{sup -3} and resistivity of 10{sup -1}{omega} cm at higher substrate temperature for the optimal CIGS films are assumed to be induced by the potential contributions from highly crystallized thin films, existence of Cu{sub 2-x}Se phase and diffusion of Na from substrates to films. (author)

  12. Effects of processing parameters on the morphology, structure, and magnetic properties of Cu{sub 1−x}Fe{sub x}Cr{sub 2}Se{sub 4} nanoparticles synthesized with chemical methods

    Energy Technology Data Exchange (ETDEWEB)

    Ivantsov, R.D. [Kirensky Institute of Physics, Russian Academy of Sciences, Krasnoyarsk, 660036 (Russian Federation); Edelman, I.S., E-mail: ise@iph.krasn.ru [Kirensky Institute of Physics, Russian Academy of Sciences, Krasnoyarsk, 660036 (Russian Federation); Zharkov, S.M.; Velikanov, D.A. [Kirensky Institute of Physics, Russian Academy of Sciences, Krasnoyarsk, 660036 (Russian Federation); Siberian Federal University, Krasnoyarsk, 660041 (Russian Federation); Petrov, D.A. [Kirensky Institute of Physics, Russian Academy of Sciences, Krasnoyarsk, 660036 (Russian Federation); Ovchinnikov, S.G. [Kirensky Institute of Physics, Russian Academy of Sciences, Krasnoyarsk, 660036 (Russian Federation); Siberian Federal University, Krasnoyarsk, 660041 (Russian Federation); Lin, Chun-Rong [National Pingtung University, Pingtung City, Pingtung County, 90003, Taiwan (China); Li, Oksana [Siberian Federal University, Krasnoyarsk, 660041 (Russian Federation); National Pingtung University, Pingtung City, Pingtung County, 90003, Taiwan (China); Tseng, Yaw-Teng [National Pingtung University, Pingtung City, Pingtung County, 90003, Taiwan (China)

    2015-11-25

    Cu{sub 1−x}Fe{sub x}Cr{sub 2}Se{sub 4} nanoparticles with x = 0, 0.2, and 0.4 were synthesized via thermal decomposition of metal nitrate or chloride salts and selenium powder using different precursor compositions and processing details. Single crystalline nano-belts or nano-rods coexist in the synthesized powder samples with hexagon-shaped plates in dependence on the precursor composition. The belts gathered into conglomerates forming “hierarchical” particles. Visible magnetic circular dichroism (MCD) of Cu{sub 1−x}Fe{sub x}Cr{sub 2}Se{sub 4} nanoparticles embedded into a transparent matrix was investigated for the first time. The similarity of the MCD spectra of all samples showed the similarity of the nanoparticles electronic structure independent of their morphology. Basing on the MCD spectral maxima characteristics, electron transitions from the ground to the excited states were identified with the help of the conventional band theory and the multi-electron approach. - Highlights: • Single crystalline Cu{sub 1−x}Fe{sub x}Cr{sub 2}Se{sub 4} nanoparticles with x = 0, 0.2, 0.4 were synthesized. • Correlation between synthesis conditions and nanoparticles morphology were obtained. • The nanoparticles magnetization behavior was studied. • Visible MCD of the Cu{sub 1−x}Fe{sub x}Cr{sub 2}Se{sub 4} nanoparticles were studied for the first time.

  13. Cu-TDPAT, an rht -type dual-functional metal-organic framework offering significant potential for use in H 2 and natural gas purification processes operating at high pressures

    KAUST Repository

    Wu, Haohan

    2012-08-09

    The separations of CO 2/CO/CH 4/H 2, CO 2/H 2, CH 4/H 2, and CO 2/CH 4 mixtures at pressures ranging to 7 MPa are important in a variety of contexts, including H 2 production, natural gas purification, and fuel-gas processing. The primary objective of this study is to demonstrate the selective adsorption potential of an rht-type metal-organic framework [Cu 3(TDPAT)(H 2O) 3]·10H 2O·5DMA (Cu-TDPAT), possessing a high density of both open metal sites and Lewis basic sites. Experimental high pressure pure component isotherm data for CO 2, CO, CH 4, and H 2 are combined with the Ideal Adsorbed Solution Theory (IAST) for estimation of mixture adsorption equilibrium. The separation performance of Cu-TDPAT is compared with four other microporous materials, specifically chosen in order to span a wide range of physicochemical characteristics: MgMOF-74, MIL-101, LTA-5A, and NaX. For all mixtures investigated, the capacity of Cu-TDPAT to produce the desired product, H 2 or CH 4, satisfying stringent purity requirements, in a fixed bed operating at pressures exceeding about 4 MPa, is either comparable to, or exceeds, that of other materials. © 2012 American Chemical Society.

  14. Study on Mechanics Performance of Cu-Al-Ni Shape Memory Alloys Prepared by Ohno Continuous Casting Process%热型连铸制备Cu-Al-Ni形状记忆合力学性能研究

    Institute of Scientific and Technical Information of China (English)

    杨少锋; 曹玉梅; 许广济; 张穗萌

    2007-01-01

    在自制的水平热型连铸设备(OCC)上,采用一定的工艺参数,制备出表面呈镜面,内部组织沿轴向定向排列的柱状组织Cu-Al-Ni形状记忆合金.其与金属型、定向凝固生产的样品相比,屈服强度、伸长率有一定的提高,伸长率可达12.8%.

  15. Solution processing of CuSe quantum dots: Photocatalytic activity under RhB for UV and visible-light solar irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Kaviyarasu, K., E-mail: kaviyarasuloyolacollege@gmail.com [UNESCO-UNISA Africa Chair in Nanosciences/Nanotechnology Laboratories, College of Graduate Studies, University of South Africa (UNISA), Muckleneuk Ridge, P O Box 392, Pretoria (South Africa); Nanosciences African Network (NANOAFNET), Materials Research Department (MSD), iThemba LABS-National Research Foundation - NRF, 1 Old Faure Road, 7129, P O Box 722, Somerset West, Western Cape Province (South Africa); Ayeshamariam, A. [Department of Physics, Khadir Mohideen College, Adirampattinam, Tamil Nadu (India); Research and Development Centre, Bharathiyar University, Coimbatore, Tamil Nadu (India); Manikandan, E. [UNESCO-UNISA Africa Chair in Nanosciences/Nanotechnology Laboratories, College of Graduate Studies, University of South Africa (UNISA), Muckleneuk Ridge, P O Box 392, Pretoria (South Africa); Central Research Laboratory, Sree Balaji Medical College & Hospital, Bharath University, Chrompet, Chennai, Tamil Nadu 600044 (India); Kennedy, J. [UNESCO-UNISA Africa Chair in Nanosciences/Nanotechnology Laboratories, College of Graduate Studies, University of South Africa (UNISA), Muckleneuk Ridge, P O Box 392, Pretoria (South Africa); National Isotope Centre, GNS Science, PO Box 31312, Lower Hutt 5010 (New Zealand); Ladchumananandasivam, R. [Department of Textile Engineering & Post Graduate Programme in Mechanical Engineering, Centre of Technology, Federal University of the State of Rio Grande do Norte, Campus Universitario, 59078-970 Natal, RN (Brazil); Umbelino Gomes, Uilame [Graduate Program in Materials Science and Engineering, Departamento de Fisica, Universidade Federal do Rio Grande do Norte, 59.072 Natal, RN (Brazil); Jayachandran, M. [Electrochemical Materials Science Division, CSIR-Central Electrochemical Research Institute, Council of Scientific & Industrial Research New Delhi, Karaikudi, 630 006 Tamil Nadu (India); and others

    2016-08-15

    Highlights: • Reflex method generates highly crystalline products with high purity. • Photocatalytic activities are closely related with their surface area. • The average lattice constants are a = 3.96 Å & c = 17.23 Å. • Atomic percentage of Cu and Se elements sample is 54.65 and 45.35. • Stoichiometric atomic percentage of Cu is 33.33% and Se is 66.67%. - Graphical Abstract: - Abstract: Exploit of photodegradation and photocatalytic activity of large scale synthesis of (CuSe) copper selenide semiconductor quantum dots was reported. The obtained nanocrystals were characterized by X-ray diffraction (XRD), UV-visible absorption spectroscopy (UV-vis) photoluminescence (PL) and high resolution transmission electron microscopy (HRTEM). The crystalline, nearly monodisperse with uniform size were synthesized by the reflux condensation method. This method promises a range of possibilities for the preparation of CuSe materials with enhanced properties. Experimental investigation shows the nanoscale photocatalysts with high surface area, small particle size and high crystallinity is of current interest in nanophase materials. The chemical composition of the CuSe samples and the valence states of elements were determined by X-ray photoelectron spectroscopy (XPS). We present our investigations to the shape and size of the quantum dots and are good agreement with experimental results.

  16. Effect of Joint Scale and Processing on the Fracture of Sn-3Ag-0.5Cu Solder Joints: Application to Micro-bumps in 3D Packages

    Science.gov (United States)

    Talebanpour, B.; Huang, Z.; Chen, Z.; Dutta, I.

    2016-01-01

    In 3-dimensional (3D) packages, a stack of dies is vertically connected to each other using through-silicon vias and very thin solder micro-bumps. The thinness of the micro-bumps results in joints with a very high volumetric proportion of intermetallic compounds (IMCs), rendering them much more brittle compared to conventional joints. Because of this, the reliability of micro-bumps, and the dependence thereof on the proportion of IMC in the joint, is of substantial concern. In this paper, the growth kinetics of IMCs in thin Sn-3Ag-0.5Cu joints attached to Cu substrates were analyzed, and empirical kinetic laws for the growth of Cu6Sn5 and Cu3Sn in thin joints were obtained. Modified compact mixed mode fracture mechanics samples, with adhesive solder joints between massive Cu substrates, having similar thickness and IMC content as actual micro-bumps, were produced. The effects of IMC proportion and strain rate on fracture toughness and mechanisms were investigated. It was found that the fracture toughness G C decreased with decreasing joint thickness ( h Joint). In addition, the fracture toughness decreased with increasing strain rate. Aging also promoted alternation of the crack path between the two joint-substrate interfaces, possibly proffering a mechanism to enhance fracture toughness.

  17. Kinetics of Corrosion Process in H2SO4 and HNO3 Aqueous Solutions of Lead Free Sn-Ag-Cu Solder Alloys

    Directory of Open Access Journals (Sweden)

    Guśpiel J.

    2016-06-01

    Full Text Available This paper presents the results of the corrosion resistance of Sn-Ag-Cu alloys in air-saturated aqueous solutions containing NO3-, SO42- ions, whose concentration was equivalent to their contents in acid rains and in concentrations 10 - 100 times higher. The Ag, Cu and Sn concentrations in the corrosive media were determined using the Atomic Absorption Spectrometry. The specific dissolution rate and corrosion current were derived using the a rotating disc technique. The corrosion rate of Sn- Ag-Cu alloys depends on pH of the examined solutions and on the concentration of oxygen near the phase boundary. In the whole range of concentrations of the applied H2SO4 + HNO3 mixtures of acids, the pure Sn was more corrosion resistant than eutectic alloy as well as the near eutectic one, following the sequence: Sn>Sn3.66Ag0.91Cu>3.8Ag0.7Cu.

  18. Iotron development of Cu67 radioisotope

    Energy Technology Data Exchange (ETDEWEB)

    Ehst, David A. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-10-31

    The collaboration has developed a method of producing the Cu-67 medical isotope for beta therapy of cancers such as non-Hodgkins melanoma. In particular we have used electron linac production of intense gamma ray beams to convert Zn-68 into Cu-67 in metal targets. The targets are subsequently processed by separating the Cu isotope from the Zn metal using sublimation, with ceramic components to avoid contamination of the final product.

  19. Cu{sub 2}ZnSnSe{sub 4} absorbers processed from solution deposited metal salt precursors under different selenization conditions

    Energy Technology Data Exchange (ETDEWEB)

    Fella, Carolin M.; Uhl, Alexander R.; Romanyuk, Yaroslav E.; Tiwari, Ayodhya N. [Empa, Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Thin Films and Photovoltaics, Duebendorf (Switzerland)

    2012-06-15

    Cu{sub 2}ZnSnSe{sub 4} (CZTSe) thin film solar cells are fabricated by a simple, non-vacuum deposition of metal salts dissolved in non-hazardous solvents followed by selenization in Se atmosphere. Despite a residual carbon-rich layer between the back contact and the CZTSe absorber layer, solar cells with up to 4.28% conversion efficiency are obtained for Cu-poor and Zn-rich CZTSe absorbers. A frequently reported problem, the loss of tin, is investigated with respect to the influence of the selenization conditions such as substrate temperature and selenium partial pressure. EDX point measurements directly confirm that the remaining decomposed layer consists of a mixture of binary ZnSe and Cu{sub 2-x}Se phases if the substrate temperature is too high and not sufficient Se is supplied. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  20. Atom probe study of Cu-poor to Cu-rich transition during Cu(In,Ga)Se{sub 2} growth

    Energy Technology Data Exchange (ETDEWEB)

    Couzinie-Devy, F.; Cadel, E.; Pareige, P. [Groupe de Physique des Materiaux (GPM), UMR 6634 CNRS, Universite et INSA de Rouen, Avenue de l' Universite BP 12, 76801 Saint Etienne du Rouvray (France); Barreau, N.; Arzel, L. [Institut des Materiaux Jean Rouxel (IMN), UMR 6502 CNRS, 2 rue de la Houssiniere BP 32229, 44322 Nantes cedex 3 (France)

    2011-12-05

    Atomic scale chemistry of polycrystalline Cu(In,Ga)Se{sub 2} (CIGSe) thin film has been characterized at key points of the 3-stage process using atom probe tomography. 3D atom distributions have been reconstructed when the layer is Cu-poor ([Cu]/([Ga] + [In]) < 1), Cu-rich ([Cu]/([Ga] + [In]) > 1), and at the end of the process. Particular attention has been devoted to grain boundary composition and Na atomic distribution within the CIGSe layer. Significant variation of composition is highlighted during the growing process, providing fundamental information helping the understanding of high efficiency CIGSe formation.

  1. Role of Sulfur Vapor on PGE-Fractionation Processes in Cu-Ni Deposits: Experimental Study by ICP-MS Laser Ablation

    Science.gov (United States)

    Peregoedova, A.; Barnes, S.; Baker, D. R.

    2004-05-01

    We have investigated the transport of platinum-group elements (PGE) and base-metals (BM) by S-vapor in the systems Fe-S-PGE and Fe-Ni-Cu-PGE-S at 1 atm pressure, 1000° C and 1100° C. Open-system, with respect to the gas-phase, conditions were set up using the tube-in-tube technique. A S-rich donor, (Fe,Ni,Cu)1-xS of variable BM ratio, was doped with 2000 ppm of each PGE. A S-poor pyrrhotite (Po) was used as the PGE receiver. The metal/S ratio of the system was varied by changing the donor/receiver ratio to assess whether the metals were transported as S-species or metals. In the system Fe-S-PGE the run products were receiver Po and donor Po containing exsolutions of individual PGE phases (PGM). In the system Fe-Cu-Ni-S-PGE the run products were receiver Po and a donor association composed of monosulfide solid-solution ± Cu-rich sulfide melt ± PGM. The final compositions of both PGE receivers and donors were determined by electron microprobe at McGill University for the major PGE, BM and S, and by ICP-MS-LA at the University of Quebec in Chicoutimi for trace PGE. The detection limit for all PGE is in the 10 to 30 ppb range. The receiver Po contained significant quantities of transported Pt and Pd (PPGE), Os and Au, but little Ir, Ru and Rh (IPGE). In addition, a much higher quantity of Ni was transported trough the vapor-phase (700 ppm to 11300 ppm) compared to Cu (1000 ppm). There is a dependence of the amount of Ni and PPGE transported on the metal/S ratio of the system. This suggests that Ni and the PPGE were transported as BM sulfide species whereas Cu and the IPGE were transported as metals. In experiments where no Cu-rich sulfide liquid formed, Pt (12-38 ppm) was slightly better transported than Pd (7-27 ppm), while in the presence of a sulfide liquid Pd (48-69 ppm) appears to be more effectively transported than Pt (31-44 ppm). In most natural examples where mobilization of PGE has been suggested, the remobilized material is enriched in Cu, Pd and to a

  2. Study of Cu-Inhibitor State for Post-Chemical Mechanical Polishing Cleaning

    Science.gov (United States)

    Harada, Ken; Ito, Atsushi; Kawase, Yasuhiro; Suzuki, Toshiyuki; Hara, Makoto; Sakae, Rina; Kimura, Chiharu; Aoki, Hidemitsu

    2011-05-01

    In order to reduce corrosion on the Cu surface in post-chemical mechanical polishing (CMP) cleaning, controlling the state of inhibitor layers is indispensable. In this study, to investigate the behavior of inhibitor layers in the cleaning process, Cu-benzotriazole (BTA) layers on CuOX were analyzed by electrochemical measurements and surface analysis. Electrochemical measurements revealed that Cu(I)-BTA can prevent corrosion more efficiently than Cu(II)-BTA, and surface analysis revealed that the Cu(I)-BTA layer is thin, whereas the Cu(II)-BTA layer is bulky. The Cu(I)-BTA layer is effective in preventing corrosion of the Cu surface.

  3. Mechanical and Memory Performance of CuAlNi Shape Memory Alloy Wires Cast by Ohno Continuous Casting Process%热型连铸CuAlNi形状记忆合金丝的性能研究

    Institute of Scientific and Technical Information of China (English)

    尹占华; 黎沃光; 余业球

    2004-01-01

    用热型连铸法制取φ1.5mm的柱晶CuAlNi合金丝,具有轴向排列的柱晶组织.经过900℃固溶处理,拉伸曲线与单晶的相似,具有两个阶段的马氏体转变,抗拉强度可达633MPa,延伸率14.95%.在4%的固定应变下,反复拉伸疲劳断裂次数高达38560次,形状回复率为100%.反复拉伸后在晶界上形成一种新相,有效地松弛了晶界上的应力集中,可能是疲劳寿命大幅度提高的原因.

  4. Domino One-Pot Process for the Synthesis of Isobenzofuran-1(3H)-ones via [Cu]-Catalysis Using Water as the Green Solvent.

    Science.gov (United States)

    Mahendar, Lodi; Satyanarayana, Gedu

    2015-07-17

    An efficient domino one-pot strategy via [Cu]-catalyzed intermolecular "cyanation" of o-bromobenzyl alcohols → in situ intramolecular "nucleophilic attack" → "hydrolysis" is presented, for the synthesis of isobenzofuran-1(3H)-ones. Significantly, the reaction is successfully carried out under environmentally benign conditions, using water as sole green solvent.

  5. Effects of Different Copper Sources on Preparation and Optical Property of La2CuO4 Crystallites Synthesized by Sol-Gel Process%铜源对溶胶-凝胶法制备La2CuO4晶体及光学性能的影响

    Institute of Scientific and Technical Information of China (English)

    李意峰; 黄剑锋; 曹丽云; 吴建鹏

    2012-01-01

    以硝酸镧为镧源,柠檬酸为络合剂,水为溶剂,分别以硫酸铜,氯化铜和硝酸铜为铜源,采用溶胶-凝胶法制备了La2CuO4纳米晶.通过热重-示差扫描量热(TG-DSC),X射线衍射(XRD),红外光谱(IR),透射电子显微镜(TEM)和紫外-可见-近红外光谱(UV-Vis-NIR)等方法对La2CuO4粉体进行了测试和表征;研究了不同铜源对前驱体及La2CuO4粉体的热性能、相组成、官能团、显微结构及光学性能的影响.结果表明:以硫酸铜和氯化铜为铜源,600℃煅烧保温2h,产物均含有杂质相,而以硝酸铜为铜源时,可获得单一的正交晶型的La2CuO4物相,晶粒尺寸80~100 nm.根据UV-Vis-NIR分析,La2CuO4的光学带隙依次为1.193 eV,1.258 eV,1.380 eV.%La2CuO4 crystallites were prepared via a sol-gel process using lanthanum nitrate as lanthanum source, citric acid as complexing agent, distilled water as solvent agent, and copper sulfate, copper chloride and copper nitrate as copper source respectively. The influences of different copper sources on thermal property, phase composition, functional group, microstructure and optical property of the as-prepared La2CuO4 crystallites were investigated by thermogravimetric-differential scanning calorimetry, X-ray diffraction, infrared spectrum, transmission electron microscope and UV-Vis-NIR spectrophotometer. The results show that impurity phases will be introduced when copper sulfate or copper, chloride is used as copper source. Pure La2CuO4 crystallites can be obtained after calcining at 600 ℃ for 2 h when the copper source is copper nitrate, and the crystallites exhibit an orthogonal structure with grain size of 80~100 nm. By UV-Vis-NIR spectral analysis, the corresponding optical band gap of La2CuO4 crystallites is about 1.193 eV, 1.258 eV and 1.380 eV, when the copper source is copper sulfate, copper chloride and copper nitrate, respectively.

  6. 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.

  7. Processing of CuInSe{sub 2}-based solar cells: Characterization of deposition processes in terms of chemical reaction analyses. Phase 2 Annual Report, 6 May 1996--5 May 1997

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, T.

    1999-10-20

    This report describes research performed by the University of Florida during Phase 2 of this subcontract. First, to study CIGS, researchers adapted a contactless, nondestructive technique previously developed for measuring photogenerated excess carrier lifetimes in SOI wafers. This dual-beam optical modulation (DBOM) technique was used to investigate the differences between three alternative methods of depositing CdS (conventional chemical-bath deposition [CBD], metal-organic chemical vapor deposition [MOCVD], and sputtering). Second, a critical assessment of the Cu-In-Se thermochemical and phase diagram data using standard CALPHAD procedures is being performed. The outcome of this research will produce useful information on equilibrium vapor compositions (required annealing ambients, Sex fluxes from effusion cells), phase diagrams (conditions for melt-assisted growth), chemical potentials (driving forces for diffusion and chemical reactions), and consistent solution models (extents of solid solutions and extending phase diagrams). Third, an integrated facility to fabricate CIS PV devices was established that includes migration-enhanced epitaxy (MEE) for deposition of CIS, a rapid thermal processing furnace for absorber film formation, sputtering of ZnO, CBD or MOCVD of CdS, metallization, and pattern definition.

  8. Overlay Accuracy in 0.18 μm Copper-Dual-Damascene Process%0.18μm铜金属双重镶嵌工艺中空间成像套刻精度分析

    Institute of Scientific and Technical Information of China (English)

    Bernd Schulz; Harry J. Levinson; Rolf Seltmann; Joel Seligson; Pavel Izikson; Anat Ronen

    2005-01-01

    由于空间成像套刻(Overlay)技术的预算随集成电路(IC)设计规范的紧缩而吃紧,因此,Overlay测量技术准确度的重要意义也随之提高.通过对后开发(After Develop DI)阶段和后蚀刻(After Etch FI)阶段的Overlay测量结果进行比较,研究了0.18 μm设计规范下的铜金属双重镶嵌工艺过程中的Overlay准确度.在确保对同一个晶圆进行后开发(DI)阶段和后蚀刻(FI)阶段测试的条件下,我们对成品晶圆的5个工艺层进行了比较.此外,还利用CD-SEM(线宽-扫描电子显微镜)测量了某个工艺层(Poly Gate)上的芯片内Overlay,并与采用分割线方法的光学Overlay测量结果进行了比较.发现对芯片内overlay的校准存在着严重的局限性,即在应用CD-SEM时缺乏合适的结构进行Overlay测量.我们还将继续为大家提供定量的比较结果,同时也会向大家推荐组合的CD-SEM测量结构,使其能够被应用到今后的光刻设计中.

  9. Bubbfil electrospinning of PA66/Cu nanofibers

    Directory of Open Access Journals (Sweden)

    Li Ya

    2016-01-01

    Full Text Available Different PA66/Cu nanofibers were prepared under various electrospinning parameters through bubbfil electrospinning. The process parameters were determined. Cuprum particles with different size were added to PA66 solution to produce PA6/66-Cu composite nanofibers. The influence of cuprum nanoparticle size on the PA66 nanofibers was analyzed.

  10. 新型耐磨锡青铜合金包套挤压工艺及组织性能%Microstructure and properties of wear-resisting Cu-Sn-Pb-Ni alloy prepared by canning extrusion process

    Institute of Scientific and Technical Information of China (English)

    赵培峰; 周延军; 宋克兴; 张彦敏

    2012-01-01

    Directing to the difficulties in the densification of Cu-Sn-Pb-Ni alloy containing 8%~12% tin by conventional plastic forming,the plastic deformation of Cu-Sn-Pb-Ni alloy was carried out by the canning extrusion process.The microstructure and properties of as-cast alloy and as-extruded alloy were analyzed.The as-extruded alloy with the density of 8.98g/cm3 and strength of 345MPa was obtained.The results reveal that the properties of the Cu-Sn-Pb-Ni alloy can be improved via the canning extrusion process.%针对锡含量为8%~12%的锡青铜合金脆性大,难以通过塑性变形实现较高致密度的问题,采用包套挤压工艺制备新型耐磨Cu-Sn-Pb-Ni合金,分析其铸态及包套挤压态的微观组织及性能.包套挤压的密度和硬度分别达到8.98g/cm3和HB135.7;挤压后合金抗拉强度和伸长率分别为345.366MPa和11.4%.结果表明,合金在外加包套作用下塑性有所提高.

  11. Preparation of Polycrystalline Cu(In,Ga)Se2 Thin Film with Nano-metal Oxide:the Chemical Reaction Process and Its Properties%纳米金属氧化物制备多晶Cu(In,Ga)Se2薄膜反应过程及其性能研究

    Institute of Scientific and Technical Information of China (English)

    郑春满; 韦永滔; 谢凯; 韩喻

    2013-01-01

    以铜铟镓纳米金属氧化物为起始原料,采用化学还原+固体硒源后硒化的方法在不锈钢表面制备出多晶Cu(In,Ga)Se2(CIGS)薄膜.采用场发射扫描电镜、高分辨透射电镜、能谱分析和X射线衍射等方法对制备过程中材料组成和结构的演变进行了研究,采用霍尔效应测试仪和吸收光谱分析等对多晶CIGS薄膜的性能进行了表征.研究结果表明,纳米金属氧化物主要含CuO、In2O3、Ga2O3和铜-铟、铜-镓二元合金氧化物等成分,在还原反应中逐渐转变成Cu11In9、Cu9In4等产物,同时薄膜中形成大量孔隙;硒化过程中,硒蒸气沿孔隙通道进入还原产物的晶格,反应生成CIS和CGS,从而形成具有黄铜矿结构的多晶CIGS薄膜;多晶CIGS薄膜表面晶粒排列紧密,属于p型半导体,其载流子浓度为2.3×1015 cm-3,迁移率为217 cm2/(V.s),电阻率为36Ω·cm,带隙宽度约为1.15 eV.%Polycrystalline Cu(In,Ga)Se2(CIGS)thin film was prepared by non-vacuum method with nano-metal oxide as starting materials.The evolution of the composition and structure during the preparation process was investigated by field emission scanning electron microscope,high resolution transmission electron microscope,energy dispersive analysis and X-ray diffraction.The properties of CIGS film was characterized using Hall Effect tester and absorption spectroscopic analysis.The results show that the nano-metal oxide is consist of CuO,In2O3,Ga2O3 and copper-indium,copper-gallium binary alloy oxides.The metal oxides gradually transform into Cu11In9 and Cu9In4 during the reduction reaction.Moreover,it forms a large number of pores,which is benefit for the selenide reaction.The selenium vapors enter the film along the pore,react with the reduction product and form CIS and CGS in the selenide process.Then,the polycrystalline CIGS film with the chalcopyrite structure forms.The carrier concentration,mobility and the resistivity of CIGS film are about 2.3×1015

  12. Atom probe study of Cu-poor to Cu-rich transition during Cu(In,Ga)Se2 growth

    Science.gov (United States)

    Couzinie-Devy, F.; Cadel, E.; Barreau, N.; Arzel, L.; Pareige, P.

    2011-12-01

    Atomic scale chemistry of polycrystalline Cu(In,Ga)Se2 (CIGSe) thin film has been characterized at key points of the 3-stage process using atom probe tomography. 3D atom distributions have been reconstructed when the layer is Cu-poor ([Cu]/([Ga] + [In]) 1), and at the end of the process. Particular attention has been devoted to grain boundary composition and Na atomic distribution within the CIGSe layer. Significant variation of composition is highlighted during the growing process, providing fundamental information helping the understanding of high efficiency CIGSe formation.

  13. DISTRIBUTION OF CU AND ITS EFFECT ON MICROSTRUCTURE OF CU-BEARING STEEL

    Institute of Scientific and Technical Information of China (English)

    CHEN Xinhua; DONG Junhua; HAN Enhou; KE Wei

    2006-01-01

    In order to investigate the distribution of Cu and its effect on the microstructure of Cu-bearing steel, a series of mild steels containing different contents of Cu are developed by vacuum electric arc furnace. These steels are annealed at 1 260 ℃, 1 100 ℃ and 1 000 ℃ respectively for one hour and followed by furnace cooling to room temperature to simulate the heat treatment before the rolling process. The results show that Cu did not obviously segregate in annealed steels. The scanning electron microscope (SEM) observation show that the main microstructures in Cu-bearing steel are ferrite and pearlite; The volume fraction of pearlite in steel increase with increasing Cu content. The grain size reduces with the decrease of annealing temperature. The results of energy dispersive X-ray analysis (EDXA) suggest that the Cu content in pearlite is higher than that in ferrite, which means that the microstructure-segregation of Cu exists. However, the cast specimens show that Cu content in MnS and S-rich phase is very high, and Cu changed the distribution of MnS in steel. In addition, the optimal Cu content in steel between 0.2%~0.4% and the optimal annealing temperature between 1100~1 200 ℃ are determined by the economical and practical principles.

  14. Acidification Process in the Area of the Abandoned Ľubietová - Podlipa Cu-Deposit, Slovakia / Proces Acidifikácie V Oblasti Opusteného Cu-Ložiska Ľubietová - Podlipa, Slovensko

    Directory of Open Access Journals (Sweden)

    Dirner Vojtech

    2012-09-01

    Full Text Available Acidita v okolí opusteného Cu-ložiska Ľubietová - Podlipa závisí predovšetkým od geochemického správania sa (zvetrávania niektorých minerálov (hlavne pyritu. V článku sú prezentované výsledky meraní základných fyzikálno-chemických parametrov - pH a Eh v technogénnych sedimentoch a v povrchovej a drenážnej vode haldového poľa. Haldový materiál síce stále vykazuje značné množstvo mobilizovateľných kovov a teda aj istý potenciál tvoriť kyslosť, podľa výsledkov výpočtu rizika, k masívnejšej tvorbe AMD nebude v budúcnosti pravdepodobne dochádzať.

  15. Study on thermit welding process of corrosion resistance rail U68CuCr%耐蚀钢轨U68CuCr铝热焊工艺试验

    Institute of Scientific and Technical Information of China (English)

    朱敏; 吉玉; 郑建国; 任安超; 费俊杰

    2015-01-01

    耐蚀钢轨U68CuCr是新研发的钢轨品种,通过对铝热焊接工艺试验,制定出耐蚀钢轨铝热焊接工艺.试验结果表明,采用国产焊剂,轨头预热7 min,预热温度达到880℃,预留轨缝27 mm条件下进行铝热焊,焊接后焊缝组织为珠光体十铁素体,焊缝处抗拉强度Rm为815 MPa,断后伸长率为2.3%,钢轨熔合区冲击功Aku为7.1J,焊缝布氏硬度为285 HB,软化区宽度不大于20 mn,静弯和实物疲劳性能合格,焊头各项性能满足TB/T 1632-2005《钢轨焊接》的要求.采用闪光焊工艺焊接的这种钢轨,已在京广铁路上使用.

  16. Simple one step spray process for CuInS2 / In2S3 heterojunctions on flexible substrates for photovoltaic applications

    Science.gov (United States)

    Thomas, Titu; Kumar, K. Rajeev; Kartha, C. Sudha; Vijayakumar, K. P.

    2015-09-01

    Flexible semiconducting devices such as solar cells and displays have been a recent attraction. Unlike heavy, brittle glass substrates, plastics and metallic foils have advantage of flexibility. They also have added advantages like good thermal stability and high melting point. In this paper we present a very simple method for the growth of Copper Indium Sulphide (CIS) films by depositing merely Indium Sulphide (InS) directly over the Cu foil using simple and economical chemical spray pyrolysis technique. The effects of volume of precursor solution on structural and morphological properties of the films were studied. Finally trials on heterojunctions with a structure of Cu foil/CIS/InS/Ag were also employed. Further improvement on heterojunction is expected by optimizing the morphological and structural properties of the film.

  17. To Enhance Performance of Light Soaking Process on ZnS/CuIn1-xGaxSe2 Solar Cell

    Directory of Open Access Journals (Sweden)

    Yu-Jen Hsiao

    2013-01-01

    Full Text Available The ZnS/CuInGaSe2 heterojunction solar cell fabricated on Mo coated glass is studied. The crystallinity of the CIGS absorber layer is prepared by coevaporated method and the ZnS buffer layer with a band gap of 3.21 eV. The MoS2 phase was also found in the CuInGaSe2/Mo system form HRTEM. The light soaking effect of photoactive film for 10 min results in an increase in F.F. from 55.8 to 64%, but series resistivity from 7.4 to 3.8 Ω. The efficiency of the devices improved from 8.12 to 9.50%.

  18. Chalcophile element (Ni, Cu, PGE, and Au) variations in the Tamarack magmatic sulfide deposit in the Midcontinent Rift System: implications for dynamic ore-forming processes

    Science.gov (United States)

    Taranovic, Valentina; Ripley, Edward M.; Li, Chusi; Rossell, Dean

    2016-10-01

    The Tamarack magmatic sulfide deposit is hosted by the Tamarack Intrusive Complex (1105.6 ± 1.2 Ma) in the Midcontinent Rift System. The most important sulfide mineralization in the Complex occurs in the northern part, which consists of two separate intrusive units: an early funnel-shaped layered peridotite body containing relatively fine-grained olivine (referred to as the FGO Intrusion) at the top, and a late gabbro-troctolite-peridotite dike-like body containing relatively coarse-grained olivine (referred to as the CGO Intrusion) at the bottom. Disseminated, net-textured, and massive sulfides occur in the base of the FGO Intrusion as well as in the upper part of the CGO Intrusion. The widest part of the CGO Intrusion also hosts a large semi-massive (net-textured) sulfide ore body locally surrounded by disseminated sulfide mineralization. Small massive sulfide veins occur in the footwall of the FGO Intrusion and in the wall rocks of the CGO dike. The sulfide mineralization is predominantly composed of pyrrhotite, pentlandite, and chalcopyrite, plus minor magnetite. Pyrrhotite containing the highest Ni and Co contents occurs in the FGO disseminated sulfides and in the CGO semi-massive sulfide ores, respectively. The most important platinum-group minerals associated with the base metal sulfides are sperrylite (PtAs2), sudburyite (PdSb), and michenerite (PdBiTe). Nickel shows a strong positive correlation with S in all types of sulfide mineralization, and Cu shows a strong positive correlation with S in the disseminated sulfide mineralization. At a given S content, the concentrations of Pt, Pd, and Au in the CGO disseminated sulfides are significantly higher than those in the FGO disseminated sulfides. The semi-massive sulfide ores are characterized by significantly higher IPGE (Ir, Os, Ru, and Rh) concentrations than most of the massive sulfide ores. With few exceptions, all of the various textural types of sulfide mineralization collectively show a good positive

  19. Vacancy behavior in Cu(In{sub 1−x}Ga{sub x})Se{sub 2} layers grown by a three-stage coevaporation process probed by monoenergetic positron beams

    Energy Technology Data Exchange (ETDEWEB)

    Uedono, Akira; Islam, Muhammad M.; Sakurai, Takeaki [Division of Applied Physics, Faculty of Pure and Applied Science, University of Tsukuba, Tsukuba, Ibaraki 305-8573 (Japan); Hugenschmidt, Christoph [Physics Department E21 and Heinz Maier-Leibnitz Zentrum (MLZ), Technische Universität München, 85748 Garching (Germany); Egger, Werner [Universität der Bundeswehr München, Institut für Angewandte Physik und Messtechnik, 85577 Neubiberg (Germany); Scheer, Roland; Krause-Rehberg, Reinhard [Department of Physics, Martin Luther University Halle, 06099 Halle (Germany); Akimoto, Katsuhiro [Division of Applied Physics, Faculty of Pure and Applied Science, University of Tsukuba, Tsukuba, Ibaraki 305-8573 (Japan)

    2016-03-31

    Vacancy-type defects in Cu(In{sub 1−x}Ga{sub x})Se{sub 2} (x ≅ 0.45 and 1) grown by a three-stage coevaporation process were probed using monoenergetic positron beams. Measurements of Doppler broadening spectra of the annihilation radiation and positron lifetime spectra showed that two different defect species coexist in the Cu(In{sub 1−x}Ga{sub x})Se{sub 2} layers, and these were identified as mono/divacancy-type defects and vacancy clusters, respectively. The vacancy clusters were mainly introduced during the third growth stage, and were located in the subsurface region. The concentration of the defects affected the short-circuit current density and the conversion efficiency of the solar cells. The defect concentration and their depth distributions varied depending on Se beam equivalent pressure, growth time, and post-growth annealing time. The behavior of the vacancy-type defects is discussed also with respect to results obtained using an electron probe micro-analyzer. - Highlights: • We applied positron annihilation to characterize Cu(In{sub 1−x}Ga{sub x})Se{sub 2}. • Defect species were identified as mono/divacancy-type defects and vacancy clusters. • The conversion efficiency increased with a decreasing vacancy concentration.

  20. Crystallization process and soft magnetic properties of nanocrystalline (Fe0.5 Co0.5 ) 86 Hf7 B6 Cu1 alloy used in elevated temperature applications

    Institute of Scientific and Technical Information of China (English)

    LIANG Xiu-bing; J.Ferenc; T.Kulik; XU Bin-shi

    2004-01-01

    Nanocrystalline (Fe0.5 Co0.5 )86 Hf7 B6 Cu1 HITPERM alloy was investigated as the candidate of soft magnetic material for high temperature applications, compared with Fe86 Hf7B6 Cu1 NANOPERM alloy. Amorphous alloy ribbons were prepared by single-roller melt-spinning technology. Crystallization process of as-quenched ribbon was investigated using differential scanning calorimeter at different heating rates. The coercivity was determined from quasi-static hysteresis loop measured at room temperature using a computerized hysteresis loop tracer. X-ray diffraction with Cu Kα radiation was used to determine the structure. The vibrating sample magnetometer was usedto measure the magnetization as a function of temperature of the nanocrystllized alloys. That Co substitution for Fein alloy enhances the Curie temperature of amorphous alloy and the magnetization of nanocrystalline alloy at hightemperature. After annealing amorphous precursor, the optimum nanocrystalline alloy obtained shows the local minimum coercivity. The coercivity increases with the increasing annealing temperature corresponding to the formation of ferromagnetic phase in the secondary crystallization.

  1. The preparation of high-J c Gd0.5Y0.5Ba2Cu3O7-δ thin films by the MOCVD process

    Science.gov (United States)

    Zhao, R. P.; Zhang, F.; Liu, Q.; Xia, Y. D.; Lu, Y. M.; Cai, C. B.; Tao, B. W.; Li, Y. R.

    2016-06-01

    A home-designed metal organic chemical vapor deposition (MOCVD) system has been employed to prepare high critical current density (J c) Gd0.5Y0.5Ba2Cu3O7-δ (GdYBCO) thin films on LaMnO3/epitaxial MgO/ion beam assisted deposition (IBAD)-MgO/solution deposition planarization (SDP)-Y2O3-buffered Hastelloy tapes; the thin films were directly heated by the Joule effect after applying an heating current (I h ) through the Hastelloy tapes. The effect of the mole ratio of the metal organic sources has been systematically investigated. X-ray diffraction (XRD) and scanning electron microscope (SEM) analyses indicated that the GdYBCO films crystallized better and became denser with the increasing of the Cu/Ba ratio from 1.0 to 1.1, yielding a J c at 77 K and 0 T of 200 nm GdYBCO film increasing from 2.5 MA cm-2 to 7 MA cm-2. In addition, SEM and energy dispersive spectrometer (EDS) characterizations revealed that more and more outgrowths appeared and the density of the film was reduced with an increase in the Cu/Ba ratio from 1.1 to 1.2. When the I h was 26.8 A and the mole ratio of Gd(tmhd)3, Y(tmhd)3, Ba(tmhd)2 and Cu(tmhd)2 in the precursor was 0.55:0.55:2:2.2, the critical current (I c) of the deposited 200 nm-thick GdYBCO film reached a 140 A cm-1 width (77 K, 0 T), corresponding to the J c 7 MA cm-2 (77 K, 0 T).

  2. An unusual coordination polymer containing Cu(+) ions and featuring possible Cu...Cu `cuprophilic' interactions: poly[di-μ-chlorido-(μ4-3,5-diaminobenzoato-κ(4)O:O':N:N')tricopper(I)(3 Cu-Cu)].

    Science.gov (United States)

    Khosa, Muhammad Kaleem; Wood, Paul T; Humphrey, Simon M; Harrison, William T A

    2016-01-01

    Compounds containing copper(I) are of interest for their role in biological processes. The nature of short (coordination polymer, [Cu3(C7H7N2O2)Cl2]n, was formed from the in situ reduction of CuCl2 in the presence of 3,5-diaminobenzoic acid and KOH under hydrothermal conditions. Its complex crystal structure contains ten distinct Cu(I) atoms, two of which lie on crystallographic inversion centres. The copper coordination geometries include near-linear CuOCl and CuN2, T-shaped CuOCl2 and distorted tetrahedral CuOCl3 groups. Each Cu(I) atom is also associated with two adjacent metal atoms, with Cu...Cu distances varying from 2.7350 (14) to 3.2142 (13) Å; if all these are regarded as `cuprophilic' interactions, then infinite [-101] zigzag chains of Cu(I) atoms occur in the crystal. The structure is consolidated by N-H...Cl hydrogen bonds.

  3. Morphology, structure, and properties of Cu-poor and Cu-rich Cu(In,Ga)Se2 films partially selenized using H2Se gas

    Science.gov (United States)

    Han, Anjun; Huang, Yongliang; Liu, Xiaohui; Xian, Wang; Meng, Fanying; Liu, Zhengxin

    2016-11-01

    Cu-poor and Cu-rich metallic precursors were prepared by cosputtering from In and Cu-Ga alloy targets and then partially selenized using H2Se gas. The properties of Cu(In,Ga)Se2 (CIGS) films are comparatively studied and the phase transition process is analyzed. The cosputtered metallic precursor has a rough morphology mostly covered by large In-rich nodules. After selenization, a large number of crumblike InSe grains were formed from the nodules on the surface of the Cu-rich film, whereas the Cu-poor film shows a dense surface. The selenized films comprise CIGS, Cu9(In,Ga)4 intermetallic, and the InSe phases. The proportion of the Cu9(In,Ga)4 phase in the Cu-rich film is more than that in the Cu-poor film. After annealing, the residual Cu9(In,Ga)4 of the Cu-poor film is eliminated. A negligible effect of Cu/(In+Ga) on the grain size can be observed. The CIGS solar cell with an efficiency of 15.1% was prepared by this method.

  4. Investigation of selenization process of electrodeposited Cu–Zn–Sn precursor for Cu{sub 2}ZnSnSe{sub 4} thin-film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Kondrotas, R., E-mail: rokas.kondrotas@ftmc.lt [State Research Institute Centre for Physical Sciences and Technology, Chemistry Institute, Savanoriu ave. 231, Vilnius (Lithuania); Juškėnas, R.; Naujokaitis, A.; Niaura, G.; Mockus, Z.; Kanapeckaitė, S. [State Research Institute Centre for Physical Sciences and Technology, Chemistry Institute, Savanoriu ave. 231, Vilnius (Lithuania); Čechavičius, B. [State Research Institute Centre for Physical Sciences and Technology, Semiconductor Physics Institute, Savanoriu ave. 231, Vilnius Lithuania (Lithuania); Juškevičius, K. [State Research Institute Centre for Physical Sciences and Technology, Physics Institute, Savanoriu ave. 231, Vilnius (Lithuania); Saucedo, E.; Sánchez, Y. [Catalonia Institute for Energy Research (IREC), Jardins de les dones de negre 1, Sant Adrià de Besòs, Barcelona (Spain)

    2015-08-31

    In this study we present the investigation of Cu{sub 2}ZnSnSe{sub 4} (CZTSe) absorber layers formed using electrochemical co-deposition in the stirred citrate solution. Two different Mo back contacts were tested to evaluate the formation of MoSe{sub 2} during selenization of electrodeposited Cu–Zn–Sn (CZT) precursor. Cleaved and focused ion beam made cross-sections of CZT/Mo and CZTSe/MoSe{sub 2}/Mo layers and surface morphology of CZTSe were studied by scanning microscopy. The chemical composition was determined by x-ray energy dispersive and fluorescence spectroscopy, whereas phase composition was examined by x-ray diffraction and Raman spectroscopy. The formation of MoSe{sub 2} strongly depended on the microstructure of Mo and annealing conditions. Possible reasons for different selenization of Mo back contacts used were discussed. Photoluminescence (PL) measurements revealed that characteristics of CZTSe main PL peak were compositional dependent. The highest CZTSe solar cell efficiency obtained was 2.64%. - Highlights: • The thickness of MoSe{sub 2} of home-made Mo substrate was constant. • Center of photoluminescence peak was dependent on Cu{sub 2}ZnSnSe{sub 4} composition. • Poor quality of Mo/Cu{sub 2}ZnSnSe{sub 4} interface resulted in low shunt resistance.

  5. Intergrain ordering processes of YBa{sub 2}Cu{sub 4}O{sub 8} and related complex ceramic systems

    Energy Technology Data Exchange (ETDEWEB)

    Hagiwara, M., E-mail: hag@kit.ac.j [Kyoto Institute of Technology, Sakyo-ku, Kyoto 606-8585 (Japan); Shima, T.; Kitada, R. [Kyoto Institute of Technology, Sakyo-ku, Kyoto 606-8585 (Japan); Deguchi, H. [Kyushu Institute of Technology, Kitakyusyu 804-8550 (Japan); Koyama, K. [University of Tokushima, Tokushima 770-8502 (Japan)

    2010-11-01

    Intergrain ordering phenomena of frustrated ceramic YBa{sub 2}Cu{sub 4}O{sub 8} (Y124) and dual phase mixed ceramic containing CuO are studied by both magnetic and resistivity observations. Magnetically estimated intergrain ordering temperature T{sub c2} and zero-resistivity attainment temperature T{sub z} are both decreased with CuO content. However, it is also revealed that mutual location of T{sub c2} and T{sub z} is changed. For the mixed ceramic with torn intergrain network structure, T{sub z} stays above T{sub c2}, indicating local dissolution of frustration by cluster structure. On the other side, remaining resistivity tails blow T{sub c2}, indicating intrinsic fluctuation effect on the resistivity caused by frustration in the ordered state. It is known then that, superconductive ceramic samples which is free from structural phase inhomogeneity is essential in order to clarify the frustration effect.

  6. Solidification pathways of ternary Cu62.5Fe27.5Sn10 alloy modulated through liquid undercooling and containerless processing

    Science.gov (United States)

    Xia, Z. C.; Wang, W. L.; Wu, Y. H.; Luo, S. B.; Wei, B.

    2016-11-01

    The active control of microstructure evolution is still a challenging factor for the development of advanced immiscible alloys. Here, we make an attempt to modulate the solidification pathways of undercooled Cu62.5Fe27.5Sn10 alloy by glass fluxing and drop tube techniques. Through regulating the liquid undercooling, three types of microstructures, dendrite, dispersive structure and macrosegregation pattern, were formed under the normal gravity condition. Below the first critical undercooling of 15 K, the alloy melt displayed the normal peritectic solidification. At moderate undercoolings above 15 K, the metastable liquid phase separation took place and the solidified microstructure appeared as homogeneously dispersed structure. If undercooling further overtook the second threshold of 107 K, macrosegregation occurred and the bulk alloy separated into an Fe-rich zone and a Cu-rich zone. Under the free fall condition, the alloy droplets with the droplet diameter beyond 805 μm showed the equilibrium peritectic solidification. If the droplet diameter decreased below 805 μm, the metastable liquid phase separation was induced and the microstructural morphology of Cu62.5Fe27.5Sn10 alloy droplet evolved from dendrite into dispersive structure. Furthermore, experimental and simulated results revealed that the temperature gradient had great influence on the size distribution of Fe-rich globules.

  7. Record critical current densities in IG processed bulk YBa{sub 2}Cu{sub 3}O{sub y} fabricated using ball-milled Y{sub 2}Ba{sub 1}Cu{sub 1}O{sub 5} phase

    Energy Technology Data Exchange (ETDEWEB)

    Muralidhar, Miryala; Kenta, Nakazato; Murakami, Masato [Department of Materials Science and Engineering, Superconducting Materials Laboratory, Shibaura Institute of Technology, Tokyo (Japan); Zeng, XianLin; Koblischka, Michael R. [Institute of Experimental Physics, Saarland University, Saarbruecken (Germany); Diko, Pavel [Institute of Experimental Physics, Material Physics Laboratory, Slovak Academy of Sciences, Kosice (Slovakia)

    2016-02-15

    The infiltration-growth (IG) technique enables the uniform and controllable Y{sub 2}BaCuO{sub 5} (Y211) secondary phase particles formation within the YBa{sub 2}Cu{sub 3}O{sub y} (Y123) matrix. Recent results clarified that the flux pinning performance of the Y123 material was dramatically improved by optimizing the processing conditions during the IG process. In this paper, we adapted the IG technique and produced several samples with addition of nanometer-sized Y211 secondary phase particles, which were produced by a ball milling technique. We found that the performance of the IG processed Y123 material dramatically improved in the low field region for a ball milling time of 12 h as compared to the samples without a ball milling step. Magnetization measurements showed a sharp superconducting transition with an onset T{sub c} at around 92 K. The critical current density (J{sub c}) at 77 K and zero field was determined to be 224 022 Acm{sup -2}, which is higher than the not ball-milled sample. Furthermore, microstructural observations exhibited a uniform microstructure with homogenous distribution of nanosized Y-211 inclusions within the Y-123 matrix. The improved performance of the Y-123 material can be understood in terms of fine distribution of the secondary phases. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  8. Controlling Solid-Gas Reactions at Nanoscale for Enhanced Thin Film Morphologies and Device Performances in Solution-Processed Cu2ZnSn(S,Se)4 Solar Cells.

    Science.gov (United States)

    Jiang, Chengyang; Hsieh, Yao-Tsung; Zhao, Hongxiang; Zhou, Huanping; Yang, Yang

    2015-09-02

    Using Cu2ZnSn(S,Se)4 (CZTSSe) as a model system, we demonstrate the kinetic control of solid-gas reactions at nanoscale by manipulating the surface chemistry of both sol-gel nanoparticles (NPs) and colloidal nanocrystals (NCs). Specifically, we first identify that thiourea (commonly used as sulfur source in sol-gel processes for metal sulfides) can transform into melamine upon film formation, which serves as surface ligands for as-formed Cu2ZnSnS4 (CZTS) NPs. We further reveal that the presence of these surface ligands can significantly affect the outcome of the solid-gas reactions, which enables us to effectively control the selenization process during the fabrication of CZTSSe solar cells and achieve optimal film morphologies (continuous large grains) by fine-tuning the amount of surface ligands used. Such enhancement leads to better light absorption and allows us to achieve 6.5% efficiency from CZTSSe solar cells processed via a sol-gel process using nontoxic, low boiling point mixed solvents. We believe our discovery that the ligand of particulate precursors can significantly affect solid-gas reactions is universal to solid-state chemistry and will boost further research in both understanding the fundamentals of solid-state reactions at nanoscale and taking advantage of these reactions to fabricate crystalline thin film semiconductors with better morphologies and performances.

  9. In silico and in vitro studies to elucidate the role of Cu2+ and galanthamine as the limiting step in the amyloid beta (1-42) fibrillation process.

    Science.gov (United States)

    Hernández-Rodríguez, Maricarmen; Correa-Basurto, José; Benitez-Cardoza, Claudia G; Resendiz-Albor, Aldo Arturo; Rosales-Hernández, Martha C

    2013-10-01

    The formation of fibrils and oligomers of amyloid beta (Aβ) with 42 amino acid residues (Aβ 1-42 ) is the most important pathophysiological event associated with Alzheimer's disease (AD). The formation of Aβ fibrils and oligomers requires a conformational change from an α-helix to a β-sheet conformation, which is encouraged by the formation of a salt bridge between Asp 23 or Glu 22 and Lys 28. Recently, Cu(2+) and various drugs used for AD treatment, such as galanthamine (Reminyl(®) ), have been reported to inhibit the formation of Aβ fibrils. However, the mechanism of this inhibition remains unclear. Therefore, the aim of this work was to explore how Cu(2+) and galanthamine prevent the formation of Aβ1-42 fibrils using molecular dynamics (MD) simulations (20 ns) and in vitro studies using fluorescence and circular dichroism (CD) spectroscopies. The MD simulations revealed that Aβ1-42 acquires a characteristic U-shape before the α-helix to β-sheet conformational change. The formation of a salt bridge between Asp 23 and Lys 28 was also observed beginning at 5 ns. However, the MD simulations of Aβ 1-42 in the presence of Cu(2+) or galanthamine demonstrated that both ligands prevent the formation of the salt bridge by either binding to Glu 22 and Asp 23 (Cu(2+) ) or to Lys 28 (galanthamine), which prevents Aβ 1-42 from adopting the U-characteristic conformation that allows the amino acids to transition to a β-sheet conformation. The docking results revealed that the conformation obtained by the MD simulation of a monomer from the 1Z0Q structure can form similar interactions to those obtained from the 2BGE structure in the oligomers. The in vitro studies demonstrated that Aβ remains in an unfolded conformation when Cu(2+) and galanthamine are used. Then, ligands that bind Asp 23 or Glu 22 and Lys 28 could therefore be used to prevent β turn formation and, consequently, the formation of Aβ fibrils.

  10. Significance of the direct relaxation process in the low-energy spin dynamics of a one-dimensional ferrimagnet NiCu(C 7H 6N 2O 6)(H 2O) 3·2H 2O

    Science.gov (United States)

    Yamamoto, S.

    2000-11-01

    In response to recent nuclear magnetic resonance measurements on a ferrimagnetic chain compound NiCu(C 7H 6N 2O 6)(H 2O) 3·2H 2O [Solid State Commun. 113 (2000) 433], we calculate the nuclear spin-lattice relaxation rate 1/ T1 in terms of a modified spin-wave theory. Emphasizing that the dominant relaxation mechanism arises from the direct (single-magnon) process rather than the Raman (two-magnon) one, we explain the observed temperature and applied-field dependences of 1/ T1. Ferrimagnetic relaxation phenomena are generally discussed and novel ferrimagnets with extremely slow dynamics are predicted.

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

    Science.gov (United States)

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

    2016-11-01

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

  12. Evaluation of Cu Ion Concentration Effects on Cu Etching Rate in Chemical-Mechanical Polishing Slurry

    Science.gov (United States)

    Nishizawa, Hideaki; Sugiura, Osamu; Matsumura, Yoshiyuki; Kinoshita, Masaharu

    2007-04-01

    The effects of Cu ion concentration of the different solutions on Cu etching rate were investigated. From the dipping experiment of Cu substrates in different solutions of malic acid, hydrogen peroxide (H2O2), benzotriazole (BTA), and Cu ions, it was revealed that Cu etching rate is increased if the concentration of Cu(II) ions added in the solution is high. This is considered to be caused by the effect of Cu(II) ions on H2O2 molecules. In the solution of pH 7, the Cu etching rate increased markedly between 1.7× 10-4 and 3.4× 10-4 M Cu(II) ion concentrations. The maximum increase in the etching rate was from 990 to 2200 nm/min at a H2O2 concentration of 2 wt %. In the solution of pH 3, a marked change in the etching rate was not observed. Our results show that the concentration of Cu ions on the polishing pad in chemical-mechanical polishing (CMP) process is very important.

  13. Steps Towards Industrialization of Cu-III-VI2Thin-Film Solar Cells:Linking Materials/Device Designs to Process Design For Non-stoichiometric Photovoltaic Materials.

    Science.gov (United States)

    Hwang, Huey-Liang; Chang, Hsueh-Hsin; Sharma, Poonam; Letha, Arya Jagadhamma; Shao, Lexi; Zhang, Yafei; Tseng, Bae-Heng

    2016-10-01

    The concept of in-line sputtering and selenization become industrial standard for Cu-III-VI2 solar cell fabrication, but still it's very difficult to control and predict the optical and electrical parameters, which are closely related to the chemical composition distribution of the thin film. The present review article addresses onto the material design, device design and process design using parameters closely related to the chemical compositions. Its variation leads to change in the Poisson equation, current equation, and continuity equation governing the device design. To make the device design much realistic and meaningful, we need to build a model that relates the opto-electrical properties to the chemical composition. The material parameters as well as device structural parameters are loaded into the process simulation to give a complete set of process control parameters. The neutral defect concentrations of non-stoichiometric CuMSe2 (M = In and Ga) have been calculated under the specific atomic chemical potential conditions using this methodology. The optical and electrical properties have also been investigated for the development of a full-function analytical solar cell simulator. The future prospects regarding the development of copper-indium-gallium-selenide thin film solar cells have also been discussed.

  14. Effects of diethanolamine on sol–gel–processed Cu{sub 2}ZnSnS{sub 4} photovoltaic absorber thin films

    Energy Technology Data Exchange (ETDEWEB)

    Kahraman, S., E-mail: suleymanmku@gmail.com; Çetinkaya, S.; Çetinkara, H.A.; Güder, H.S.

    2014-02-01

    Highlights: • DEA content significantly affected the crystal structure and the phase purity. • The films’ crystallite sizes increased with increasing DEA content. • Two different impurity levels were found for each film via R-T characteristics. • Under different illuminations, the n-Si/CZTS exhibited good photo-response. • The light on/off current ratios confirmed the photo-sensitivity of the junction. - Abstract: As a promising solar absorber, the Cu{sub 2}ZnSnS{sub 4} compound has been popular recently for the production of green and economical thin-film solar cells owing to the abundancy and non-toxicity of all the constituents. In this study, we have produced Cu{sub 2}ZnSnS{sub 4} films via the sol–gel technique. As a stabilizer, the effects of the diethanolamine on the properties of the films were investigated. The amount of diethanolamine significantly affected the crystal structure, crystallite sizes and phase purity of the films. X-ray diffraction and Raman spectroscopy analyses confirmed the formation of phase-pure CZTS films. It was found that the film produced by using 2 ml of diethanolamine in sol exhibited pure CZTS phase, compact and dense morphology and enhanced photo-sensitivity. Light on/off current ratio of the n-Si/Cu{sub 2}ZnSnS{sub 4} junction was found to be 47 under 100 mW/cm{sup 2} of illumination. Electrical activation energies of the films were investigated and the variations were attributed to delocalized phonon states generating from the presence of other phases and lattice defects.

  15. Cu(In,Ga)Se2 absorber thinning and the homo-interface model: Influence of Mo back contact and 3-stage process on device characteristics

    OpenAIRE

    Leonard, E.; Arzel, L.; Tomassini, M.; Zabierowski, P.; Fuertes Marrón, David; Barreau, Nicolas

    2014-01-01

    Thinning the absorber layer is one of the possibilities envisaged to further decrease the production costs of Cu(In,Ga)Se2 (CIGSe) thin films solar cell technology. In the present study, the electronic transport in submicron CIGSe-based devices has been investigated and compared to that of standard devices. It is observed that when the absorber is around 0.5 μm-thick, tunnelling enhanced interface recombination dominates, which harms cells energy conversion efficiency. It is also shown that b...

  16. Use of multivariate statistical tool for data processing in the analysis of Cu, Cr, Fe, Pb, Mo and Mg in lubricating oil by LIBS

    Energy Technology Data Exchange (ETDEWEB)

    Alves, Luana F.N.; Sarkis, Jorge E.S.; Bordon, Isabela C.A.C., E-mail: ludemar1@hotmail.com, E-mail: jesarkis@ipen.br, E-mail: isabella.bordon@gmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    Analysis of industrial lubricants is widely used for monitoring and predicting maintenance requirements in a broad range of mechanical systems. Laser induced breakdown spectroscopy has been used to evaluate the potentiality of the technique for the determination of metals in lubricating oils. Prior to quantitative analysis, the LIBS system was calibrated using standard samples containing the elements investigated (Cu, Cr, Fe, Pb, Mo and Mg). This study presents the usefulness of multivariate statistical techniques for evaluation and interpretation of large complex data sets in order to get more information about concentration of metals in oils lubricants is related to engine wear. (author)

  17. Response surface methodological approach for the optimization of adsorption process in the removal of Cr(VI) ions by Cu{sub 2}(OH){sub 2}CO{sub 3} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, Varsha, E-mail: varsha.srivastava@lut.fi [Laboratory of Green Chemistry, Faculty of Technology, Lappeenranta University of Technology, Sammonkatu 12, FI-50130 Mikkeli (Finland); Sharma, Y.C. [Department of Chemistry, Indian Institute of Technology, Banaras Hindu University, Varanasi 221005 (India); Sillanpää, Mika [Laboratory of Green Chemistry, Faculty of Technology, Lappeenranta University of Technology, Sammonkatu 12, FI-50130 Mikkeli (Finland)

    2015-01-30

    Graphical abstract: - Highlights: • Nanoparticles of Cu{sub 2}(OH){sub 2}CO{sub 3} were synthesized for the treatment of wastewater from printing press. • Central composite design was employed for the optimization of important adsorption parameters. • The ANOVA study demonstrated that the regression model was highly significant. • Experimental data followed pseudo-second-order kinetic models. • Synthesized nanoparticles had high adsorptive capacity for Cr(VI) and could be used effectively for Cr(VI) removal. - Abstract: Cu{sub 2}(OH){sub 2}CO{sub 3} nanoparticles were synthesized and characterized by XRD, TEM, SEM and ATR-FTIR. SEM suggested the porous nature of nanoparticles. BET surface area of nanoparticles was measured to be 87 m{sup 2} g{sup −1}. Cu{sub 2}(OH){sub 2}CO{sub 3} nanoparticles were used as adsorbent for the removal of Cr(VI) ions from aqueous solutions and wastewater of the printing press. The central composite design (CCD) of the response surface methodology was employed to optimize important adsorption parameters viz. initial Cr(VI) concentration, pH and dose. Analysis of variance (ANOVA) of the quadratic model suggested that experimental data were excellently fitted to the quadratic model. Optimum conditions for approximately 99% removal of Cr(VI) from synthetic wastewater were determined to be pH 6.5, initial concentration of 550 mg/L, adsorbent dose 0.69 g. The kinetic data for Cr(VI) adsorption were best fitted to the pseudo second order model. The Langmuir adsorption capacity of the adsorbent was determined as 87.72 mg/g. Thermodynamic analysis revealed that the adsorption process was spontaneous and endothermic. Desorption study confirms its reusability up to four adsorption–desorption cycles. Cu{sub 2}(OH){sub 2}CO{sub 3} nanoparticles also showed efficient removal in presence of anions like SO{sub 4}{sup 2−}, PO{sub 4}{sup 3−}, NO{sub 3}{sup 2−} and Cl{sup −}. Findings of the present study suggest that Cu{sub 2}(OH

  18. Research on the Agglomeration Collision and Fragmentation Process in a Fluidized Bed of ZnO and CuO Composite Nanoparticles Added with FCC Coarse Particles%ZnO和CuO混合纳米颗粒在添加FCC粗颗粒的流态化及聚团碰撞与破碎过程研究

    Institute of Scientific and Technical Information of China (English)

    徐宝; 周涛; 罗传宝; 张金霞; 范百林

    2016-01-01

    研究混合纳米ZnO和CuO颗粒添加3种不同粒径FCC粗颗粒(催化裂化催化剂)的流化行为,用高速摄像机观察流化现象并对聚团碰撞与破碎过程、聚团成分进行分析。结果表明,添加FCC粗颗粒可显著改善纳米颗粒的流化性能,FCC3对纳米颗粒流化性能的改善效果比FCC1或FCC2更明显;且随着FCC粗颗粒添加量的增加,纳米颗粒流化行为的改善效果越好,体系的混合均匀程度是影响混合纳米ZnO和CuO流化性能的重要因素。%A research has been conducted on the fluidization behaviors of ZnO and CuO composite nanoparticles, added with FCC coarse particles of three different particle sizes (catalytic cracking catalysts). An observation of the whole fluidization process, with the aid of a high-speed camera, has been made for a detailed analysis of the agglomeration collision and fragmentation, and agglomeration components as well. The results show that the fluidization performance of the composite nanoparticles can be improved significantly with the addition of FCC coarse particles. Moreover, compared with the other two kinds of coarse particles FCC2 or FCC1, a more significant effect can be achieved with the addition of FCC3 in the process. With the increase of the addition amount of FCC coarse particles, the improvement of the fluidization performance of the composite nanoparticles becomes more obvious. Thus, it can be concluded that the mixing uniformity of nanoparticles is an important factor that influence the fluidization performance of ZnO and CuO composite nanoparticles.

  19. Ti-Cu-W体系Pillow飞片加载铋熔化再凝固过程计算分析%Calculation Analysis of the Impact Melting and Resolidification Process for the Bismuth Using the Ti-Cu-W Pillow Flyer

    Institute of Scientific and Technical Information of China (English)

    柏劲松; 张联盟; 于继东; 戴诚达; 王宇; 刘坤; 罗国强; 沈强; 谭华; 吴强

    2015-01-01

    采用数值计算设计了Ti-Cu-W材料体系 Pillow飞片,实现金属铋样品的冲击加载和准等熵加载,并通过实验研究铋的冲击熔化再凝固这一复杂的物理过程,实验获得的速度波剖面结果与数值模拟结果基本一致。还建立了金属铋的包含5个固相和1个液相的完全物态方程,计算相图的三相点以及高压区的 Hugoniot线与实验数据吻合较好,计算还获得了冲击加载再凝固实验中的温度信息和相变信息。通过计算分析和对实验数据的解读,认为Ti-Cu-W材料体系Pillow飞片加载可以用于铋的冲击熔化再凝固复杂物理过程研究,为实验探索研究建立了适用的研究方法和有效的技术手段。%Numerical simulations are carried out to design the Pillow flyer of Ti-Cu-W system,and the impact loading and quasi-isentropic loading of the bismuth sample are also carried out.We experimentally investigate the intricate physical process of impact melting and resolidification.Experiment results of wave profiles are similar with numerical ones.The complete equation of state of bismuth including five solid phases and one liquid phase is established.Triple points in phase diagram and the Hugoniot curve in high pressure area agree well with the experiment data.The temperature and phase transition information in impact loading and resolidification experiment are also obtained.According to the calculation analysis and interpretation of the experiment data,the loading experiment based on Ti-Cu-W flyer is available to study the physical process of impact melting and resolidification of bismuth,and an appropriate research method and effective technique means for experiment exploration is established.

  20. Effect of reducing agents in the conversion of Cu2O nanocolloid to Cu nanocolloid

    Directory of Open Access Journals (Sweden)

    V. Andal

    2017-02-01

    Full Text Available Current work reports the conversion of copper (I oxide, nano-colloid to stable copper nanocolloid. Different reduction conditions were attempted to control the stability and size of the Cu nanoparticles. Hydrazine hydrate, ascorbic acid and glucose are found to be good reductants. In our work stable copper nanoparticles are obtained by reducing Cu2O without any special protections like inert gas atmosphere etc. Ascorbic acid, a natural vitamin C not only reduces cuprous oxide but protects the new born copper due to its antioxidant properties. A red shift is observed when Cu2O nanospheres get converted to Cu. UV, XRD, FTIR and TEM were used to characterize the prepared Cu nanoparticles. The mechanism for the growth process of Cu nanomaterials are discussed.

  1. Formation of Ag-Cu nanoparticles in SiO{sub 2} films by sol-gel process and their effect on the film properties

    Energy Technology Data Exchange (ETDEWEB)

    Diaz-Flores, L.L. [Universidad Juarez Autonoma de Tabasco, 86000 Villahermosa, Tabasco (Mexico); Garnica-Romo, M.G. [Universidad Michoacana de San Nicolas de Hidalgo, 58000 Morelia, Michoacan (Mexico); Gonzalez-Hernandez, J. [CIMAV, 31109 Chihuahua (Mexico); Yanez-Limon, J.M.; Vorobiev, Y.V. [CINVESTAV, Unidad Queretaro, 76230 Queretaro, QRO. (Mexico); Vorobiev, P. [Universidad Autonoma de Queretaro, 76001 Queretaro, QRO. (Mexico)

    2007-07-01

    Sol-gel thin films and microcrystalline powders of SiO{sub 2} doped with Ag and Cu were obtained under environmental conditions of pressure and temperature. The precursor material was a mixture of water, tetraethyl-orthosilicate, ethanol and aqueous solutions of Ag and Cu salts, the components were taken in ratios known to provide SiO{sub 2} matrix material with good structure. The annealing was performed in oxidizing and reducing atmosphere, the temperature varied in the range of 100-800 C. Formation of metal particles of 100 nm order of magnitude was confirmed by X-ray, optical and SEM analysis. In presence of metal particles, the SiO{sub 2} matrix was crystallized in {alpha}-cristobalite at annealing temperature as low as 500 C, and in quartz form at 800 C. A simple model treating the metal-induced low-temperature crystallization is presented. The material obtained is promising for the use as optical filter, gas sensing element and antibacterial agent. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  2. Cu2+ ions as a paramagnetic probe to study the surface chemical modification process of layered double hydroxides and hydroxide salts with nitrate and carboxylate anions.

    Science.gov (United States)

    Arizaga, Gregorio Guadalupe Carbajal; Mangrich, Antonio Salvio; Wypych, Fernando

    2008-04-01

    A layered zinc hydroxide nitrate (Zn5(OH)8(NO3)2.2H2O) and a layered double hydroxide (Zn/Al-NO3) were synthesized by coprecipitation and doped with different amounts of Cu2+ (0.2, 1, and 10 mol%), as paramagnetic probe. Although the literature reports that the nitrate ion is free (with D3h symmetry) between the layers of these two structures, the FTIR spectra of two zinc hydroxide nitrate samples show the C2v symmetry for the nitrate ion, whereas the g ||/A || value in the EPR spectra of Cu2+ is high. This fact suggests bonding of some nitrate ions to the layers of the zinc hydroxide nitrate. The zinc hydroxide nitrate was used as matrix in the intercalation reaction with benzoate, o-chlorobenzoate, and o-iodobenzoate ions. FTIR spectra confirm the ionic exchange reaction and the EPR spectroscopy reveals bonding of the organic ions to the inorganic layers of the zinc hydroxide nitrate, while the layered double hydroxides show only exchange reactions.

  3. Degradation process analysis of the azo dyes by catalytic wet air oxidation with catalyst CuO/γ-Al2O3.

    Science.gov (United States)

    Hua, Li; Ma, Hongrui; Zhang, Lei

    2013-01-01

    Three azo dyes (Methyl Orange, Direct Brown and Direct Green) were treated by catalytic wet air oxidation (CWAO) with the catalysts CuO/γ-Al(2)O(3) prepared by consecutive impregnation. The relationship of decolorization extent, chemical oxygen demand (COD) removal extent and total organic carbon (TOC) in dye solution were investigated. The results indicated that the CuO/γ-Al(2)O(3) catalyst had excellent catalytic activity in treating azo dyes. Almost 99% of color and 70% of TOC were removed in 2h. The high removal extent of color and TOC indicated that the CWAO obtained perfect decomposition for pollutants. The degradation pathway of azo dyes was analyzed by UV-Vis, FTIR and MS. According to the examined results, the hydroxyl ((·)OH) radicals induced strong oxidizing effects in the target solution and destroyed the chromophoric groups of azo-benzene conjugated of the molecular structure. Considering characteristics of the dye structure, the azo bond (-N=N-) would first be attacked by the hydroxyl radical and other free radicals. With the continuous oxidization and the long reaction time at high temperature, these intermediates could be oxidized to the final oxidation products, such as water and carbon dioxide.

  4. One-Pot Synthesis of Cu2O/Cu Self-Assembled Hollow Nanospheres with Enhanced Photocatalytic Performance

    Directory of Open Access Journals (Sweden)

    Bo Zhou

    2014-01-01

    Full Text Available Cu2O/Cu hollow spheres are prepared using one-pot template-free solvent-thermal synthesis route with (CH3COO2Cu·H2O as a precursor. With the reaction time increasing gradually from 2 h to 20 h, the morphology of the Cu2O/Cu evolves from nanoparticle to hollow nanosphere. The hollow structure is obtained when the cooling rate falls down to 0.7°C/min. And the content of Cu in the hollow spheres also can be easily controlled by adjusting the solvent-thermal synthesis time. Using photocatalytic degradation of phenol as the probe molecules under visible-light illumination, we have investigated the influence of hollow structure on the photocatalytic activity of Cu2O/Cu. The prepared hollow sphere Cu2O/Cu particles exhibited a higher photodegradation capability than nanoparticles and solid spheres. When the content of Cu lies in the range of 11–86 wt%, the samples exhibit higher photocatalytic performance, indicating that the Cu2O/Cu particles with hollow structure are promising candidates for the processing of pollutants.

  5. One-dimensional simulation of sequentially processed Cu(In{sub 1−x}Ga{sub x})(Se{sub 1−y}S{sub y}){sub 2} heterojunction solar cells with vertically graded absorber composition

    Energy Technology Data Exchange (ETDEWEB)

    Riedel, Ingo, E-mail: ingo.riedel@uni-oldenburg.de [Energy and Semiconductor Research Laboratory, Laboratory for Chalcogenide Photovoltaics (LCP), Department of Physics, University of Oldenburg, Carl-von-Ossietzky Strasse 9–11, 26129 Oldenburg (Germany); Keller, Jan; Parisi, Jürgen [Energy and Semiconductor Research Laboratory, Laboratory for Chalcogenide Photovoltaics (LCP), Department of Physics, University of Oldenburg, Carl-von-Ossietzky Strasse 9–11, 26129 Oldenburg (Germany); Dalibor, Thomas; Avellán, Alejandro [AVANCIS GmbH, Otto-Hahn-Ring 6, 81739 München (Germany)

    2014-04-15

    The successful definition and verification of a one-dimensional device simulation baseline for sequentially processed Mo/Cu(In{sub 1−x}Ga{sub x})(Se{sub 1−y}S{sub y}){sub 2}/CdS/i-ZnO/ZnO:Al thin film solar cells is presented. The appropriate modeling of the layer sequence requires experimental assessment of the relevant material properties of each film within the layer sequence of the device. The properties of the CdS/i-ZnO/ZnO:Al window layer stack and of the molybdenum back electrode have been approximated by their bulk properties obtained from experiment and from the literature, respectively. This approach is, however, not meaningful for the sequentially processed Cu(In{sub 1−x}Ga{sub x})(Se{sub 1−y}S{sub y}){sub 2} (CIGSSe) thin films due to characteristic segregation/grading of the chemical composition and the presence of structural inhomogeneities. This work shows that a suitable modeling of the CIGSSe film can be achieved by definition of effective medium properties. With this approach a 1D device simulation baseline for the studied system was established, which accurately reproduces the experimental characteristics of the studied CdS/CIGSSe heterojunction solar cells.

  6. Co-evaporation process study of Cu{sub 2}ZnSnSe{sub 4} thin films by in situ light scattering and in situ X-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Hartnauer, Stefan; Waegele, Leonard A.; Kaune, Gunar; Scheer, Roland [Photovoltaics Group, Martin-Luther-University Halle-Wittenberg, Halle (Saale) (Germany); Syrowatka, Frank [Martin-Luther-University Halle-Wittenberg, IZM/Nanotechnikum Weinberg, Halle (Saale) (Germany)

    2015-02-01

    Multi-stage co-evaporation processes for the growth of Cu{sub 2}ZnSnSe{sub 4} (CZTSe) thin films are investigated with time-resolved in situ angle-dispersive X-ray diffraction (in situ XRD). Different preparation protocols were applied and controlled by in situ laser light scattering (in situ LLS). The composition of the deposited layers was adjusted by making use of a stoichiometric transitions in the LLS signal at the point where the Cu content equals the [Zn + Sn]. The ability of in situ XRD to distinguish between CZTSe and ZnSe is used to develop new processes that minimize the formation of ZnSe as a secondary phase. At high temperatures, an initially grown ZnSe layer forms at the Mo interface, which may not be incorporated into the CZTSe due to Zn-rich preparation conditions. By using lower temperatures at the beginning, CZTSe growth starts directly and a heating step restores the high temperature of the substrate. Thus, the formation of secondary phases is diminished without losing the benefits of higher preparation temperature. The ZnSe growth is reduced and the formation of a continuous layer is not observed. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  7. In-situ X-ray diffraction analysis of the recrystallization process in Cu{sub 2}ZnSnS{sub 4} nanoparticles synthesised by hot-injection

    Energy Technology Data Exchange (ETDEWEB)

    Brandl, Marco [Chair for Crystallography and Structural Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Staudtstr. 3, 91058 Erlangen (Germany); Ahmad, Rameez; Distaso, Monica [Institute of Particle Technology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Cauerstr. 4, 91058 Erlangen (Germany); Azimi, Hamed; Hou, Yi [Institute of Materials for Electronics and Energy Technology (I-MEET), Friedrich-Alexander-Universität Erlangen-Nürnberg, Martensstr. 7, 91058 Erlangen (Germany); Peukert, Wolfgang [Institute of Particle Technology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Cauerstr. 4, 91058 Erlangen (Germany); Brabec, Christoph J. [Institute of Materials for Electronics and Energy Technology (I-MEET), Friedrich-Alexander-Universität Erlangen-Nürnberg, Martensstr. 7, 91058 Erlangen (Germany); Hock, Rainer [Chair for Crystallography and Structural Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Staudtstr. 3, 91058 Erlangen (Germany)

    2015-05-01

    Kesterite Cu{sub 2}ZnSnS{sub 4} (CZTS) is a promising material for thin film solar cell applications. The biggest advantages of this compound lie in the abundance and non-toxicity of the contained elements. Low temperature hot injection synthesis can provide an economic way to produce CZTS nanoparticles for application in solution processed solar cells. Powder X-ray diffraction (PXRD) measurements on the as-synthesised particles suggest that the crystal structure is cubic and can be best described as sphalerite-like. This means that the cations in the CZTS are statistically distributed on the cation sites of the crystal lattice rather than well-ordered like in the tetragonal kesterite structure. An in-situ PXRD measurement while annealing the particles up to 550 °C revealed a recrystallization process that transforms the structure from cubic to tetragonal meaning an ordering of the cations. - Highlights: • Cu{sub 2}ZnSnS{sub 4} (CZTS) nanoparticles crystallise in an apparent cubic structure. • In-situ X-ray diffraction reveals a phase transition to the tetragonal crystal system. • Post annealing measurements show a well ordered tetragonal CZTS.

  8. Wafer bonding using Cu-Sn intermetallic bonding layers

    NARCIS (Netherlands)

    Flötgen, C.; Pawlak, M.; Pabo, E.; Wiel, H.J. van de; Hayes, G.R.; Dragoi, V.

    2014-01-01

    Wafer-level Cu-Sn intermetallic bonding is an interesting process for advanced applications in the area of MEMS and 3D interconnects. The existence of two intermetallic phases for Cu-Sn system makes the wafer bonding process challenging. The impact of process parameters on final bonding layer

  9. Nanoporous CuS with excellent photocatalytic property

    Science.gov (United States)

    Xu, Wence; Zhu, Shengli; Liang, Yanqin; Li, Zhaoyang; Cui, Zhenduo; Yang, Xianjin; Inoue, Akihisa

    2015-12-01

    We present the rational synthesis of nanoporous CuS for the first time by chemical dealloying method. The morphologies of the CuS catalysts are controlled by the composition of the original amorphous alloys. Nanoporous Cu2S is firstly formed during the chemical dealloying process, and then the Cu2S transforms into CuS. The nanoporous CuS exhibits excellent photocatalytic activity for the degradation of the methylene blue (MB), methyl orange (MO) and rhodamine B (RhB). The excellent photocatalytic activity of the nanoporous CuS is mainly attributed to the large specific surface area, high adsorbing capacity of dyes and low recombination of the photo generated electrons and holes. In the photo degradation process, both chemical and photo generated hydroxyl radicals are generated. The hydroxyl radicals are favor in the oxidation of the dye molecules. The present modified dealloying method may be extended for the preparation of other porous metal sulfide nanostructures.

  10. Cu2O/Bi2O3光催化降解罗丹明B的工艺条件研究%Process Conditions of the Degradation of Rhodamine B by Cu2O/Bi2O3 Photocatalytic

    Institute of Scientific and Technical Information of China (English)

    梁光远; 孙伟

    2013-01-01

    This paper used supported catalyst Cu2O/Bi2O3 to study the degradation of soluble dye rhodamine B, and surveyed the impact of degradation conditions on catalytic degradation process of Rhodamine B. The results show that it has better degradation effect, degradation of 5mg/L Rhodamine B solution nearly to 100% for 5 minutes, under the optimum conditions its pH is 3-5, the catalyst is 1g/L, and the amount of hydrogen peroxide is 1.0% (volume ratio).%  本文采用负载型催化剂 Cu2O/Bi2O3,研究了对可溶性染料罗丹明 B 的降解情况。考察了降解条件对罗丹明 B 催化降解过程的影响。结果表明,对罗丹明 B 有较好的降解效果,5分钟使5mg/L 的罗丹明 B 溶液降解近100%,最佳工艺条件下 pH 为3-5,催化剂为1g/L,双氧水加入量为1.0%(体积比)。

  11. Binuclear Cu(A) Formation in Biosynthetic Models of Cu(A) in Azurin Proceeds via a Novel Cu(Cys)2His Mononuclear Copper Intermediate.

    Science.gov (United States)

    Chakraborty, Saumen; Polen, Michael J; Chacón, Kelly N; Wilson, Tiffany D; Yu, Yang; Reed, Julian; Nilges, Mark J; Blackburn, Ninian J; Lu, Yi

    2015-10-06

    Cu(A) is a binuclear electron transfer (ET) center found in cytochrome c oxidases (CcOs), nitrous oxide reductases (N₂ORs), and nitric oxide reductase (NOR). In these proteins, the Cu(A) centers facilitate efficient ET (kET > 10⁴s⁻¹) under low thermodynamic driving forces (10-90 mV). While the structure and functional properties of Cu(A) are well understood, a detailed mechanism of the incorporation of copper into the protein and the identity of the intermediates formed during the Cu(A) maturation process are still lacking. Previous studies of the Cu(A) assembly mechanism in vitro using a biosynthetic model Cu(A) center in azurin (Cu(A)Az) identified a novel intermediate X (Ix) during reconstitution of the binuclear site. However, because of the instability of Ix and the coexistence of other Cu centers, such as Cu(A)' and type 1 copper centers, the identity of this intermediate could not be established. Here, we report the mechanism of Cu(A) assembly using variants of Glu114XCuAAz (X = Gly, Ala, Leu, or Gln), the backbone carbonyl of which acts as a ligand to the Cu(A) site, with a major focus on characterization of the novel intermediate Ix. We show that Cu(A) assembly in these variants proceeds through several types of Cu centers, such as mononuclear red type 2 Cu, the novel intermediate Ix, and blue type 1 Cu. Our results show that the backbone flexibility of the Glu114 residue is an important factor in determining the rates of T2Cu → Ix formation, suggesting that Cu(A) formation is facilitated by swinging of the ligand loop, which internalizes the T2Cu capture complex to the protein interior. The kinetic data further suggest that the nature of the Glu114 side chain influences the time scales on which these intermediates are formed, the wavelengths of the absorption peaks, and how cleanly one intermediate is converted to another. Through careful understanding of these mechanisms and optimization of the conditions, we have obtained Ix in ∼80

  12. A trapped field of 17.6 T in melt-processed, bulk Gd-Ba-Cu-O reinforced with shrink-fit steel

    Science.gov (United States)

    Durrell, J. H.; Dennis, A. R.; Jaroszynski, J.; Ainslie, M. D.; Palmer, K. G. B.; Shi, Y.-H.; Campbell, A. M.; Hull, J.; Strasik, M.; Hellstrom, E. E.; Cardwell, D. A.

    2014-08-01

    The ability of large-grain (RE)Ba2Cu3O7-δ ((RE)BCO; RE = rare earth) bulk superconductors to trap magnetic fields is determined by their critical current. With high trapped fields, however, bulk samples are subject to a relatively large Lorentz force, and their performance is limited primarily by their tensile strength. Consequently, sample reinforcement is the key to performance improvement in these technologically important materials. In this work, we report a trapped field of 17.6 T, the largest reported to date, in a stack of two silver-doped GdBCO superconducting bulk samples, each 25 mm in diameter, fabricated by top-seeded melt growth and reinforced with shrink-fit stainless steel. This sample preparation technique has the advantage of being relatively straightforward and inexpensive to implement, and offers the prospect of easy access to portable, high magnetic fields without any requirement for a sustaining current source.

  13. Influence of selenium evaporation temperature on the structure of Cu2ZnSnSe4 thin film deposited by a co-evaporation process

    Science.gov (United States)

    Ding, Sun; Shengzhi, Xu; Li, Zhang; Ze, Chen; Yang, Ge; Ning, Wang; Xuejiao, Liang; Changchun, Wei; Ying, Zhao; Xiaodan, Zhang

    2015-04-01

    Cu2ZnSnSe4 (CZTSe) thin film solar cells have been fabricated using a one-step co-evaporation technique. The structural properties of polycrystalline CZTSe films deposited at different selenium evaporation temperatures (TSe) have been investigated using X-ray diffraction spectra, scanning electron microscopy, and atomic force microscopy. A relationship between TSe and the secondary phases deposited in the initial stage is established to explain the experimental observations. The Se flux is not necessarily increased too much to reduce Sn loss and the consumption of Se during fabrication could also be reduced. The best solar cell, with an efficiency of 2.32%, was obtained at a medium TSe of 230 °C (active area 0.34 cm2). Project supported by the Specialized Research Fund for the PhD Program of Higher Education (No. 20120031110039).

  14. Effect of heat treatments and window layer processing on the characteristics of CuInGaSe{sub 2} thin film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Ramanathan, K.; Contreras, M.A.; Tuttle, J.R. [National Renewable Energy Lab., Golden, CO (United States)] [and others

    1996-05-01

    Interaction between chemical bath deposited CdS and ZnO window layers are a focus of this paper. Low temperature anneals were used to follow the changes at the interface. Optical absorption spectra show that CdS and ZnO intermix upon annealing. When applied to ZnO/CdS/CuInGaSe{sub 2} thin film solar cells, changes in the short and long wavelength response were observed. The latter is attributed to an increase in the energy gap of the absorber by diffusion of S. The interdiffusion is shown to increase the short wavelength collection, and hence the current density of the devices. Photoluminescence data provides some indication of the quality of the interface.

  15. Factors affecting the superconductivity in the process of depositing Nd1.85Ce0.15CuO4-δ by the pulsed electron deposition technique

    Institute of Scientific and Technical Information of China (English)

    GUO; YanFeng

    2007-01-01

    On SrTiO3 single crystal substrate, by using the pulsed electron deposition technique, the high-quality electron doped Nd1.85Ce0.15CuO4-δsuperconducting film was successfully fabricated. After careful study on the R-T curves of the obtained samples deposited with different substrate temperatures, thicknesses, annealing methods and pulse frequencies, the effects of them on the superconductivity of the films were found, and the reasons were also analyzed. Additionally, by using the same model of the pulsed laser deposition technique, the relation between the target-to-substrate distance and the deposition pressure was drawn out as a quantitative one.  ……

  16. The stored energy in processed Cu-0.4 wt.%Cr-0.12 wt.%Zr-0.02 wt.%Si-0.05 wt.%Mg

    Energy Technology Data Exchange (ETDEWEB)

    Li, X.F. [Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China); Dong, A.P.; Wang, L.T.; Yu, Z. [China Railway Electrification Bureau Group Co., Ltd., Beijing 100036 (China); Meng, L., E-mail: mengliang@zju.edu.cn [Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China)

    2011-04-07

    Research highlights: > The crystal orientation in processed Cu-0.4 wt.%Cr-0.12 wt.%Zr-0.02 wt.%Si-0.05 wt.%Mg is deviating from the as-cast specimens and microstrain of the alloy is gradually increasing as the draw ratio rising before {eta} {<=} 6.7. > The dynamic recovery has taken place as 6.7 < {eta} {<=} 7.4, which is confirmed by the change of the crystal orientation, microstrain, stored energy, flow stress and dislocation density. > The release of stored energy is primarily due to the decrease of dislocation density and the main strengthening effect of Cu-0.4 wt.%Cr-0.12 wt.%Zr-0.02 wt.%Si-0.05 wt.%Mg is attributed to dislocation mechanism. - Abstract: Cold drawing was conducted at room temperature to impose high strain on Cu-0.4 wt.%Cr-0.12 wt.%Zr-0.02 wt.%Si-0.05 wt.%Mg. The microstructure was studied by X-ray diffraction and transmission electron microscope. The thermal analysis was carried out for the alloy at different draw ratios and then the stored energy was calculated to estimate the dislocation density and the flow stress. Results indicate that the microstrain gradually increases and the <1 1 1> texture is formed with the draw ratio rising. Meanwhile, the stored energy also increases with the draw ratio rising and a peak is reached with draw ratio of 6.7. The release of stored energy is primarily due to the decrease of dislocation density. The flow stress estimated from the stored energy has a similar variation trend with the measured data with a stress difference {approx}20 to 120 MPa. The main strengthening effect is attributed to dislocation mechanism.

  17. 熔盐电解法制备钨铜合金粉%Preparation of W-Cu Alloy Powder with Molten Salt Electrolysis Process

    Institute of Scientific and Technical Information of China (English)

    肖志华; 廖春发; 王旭

    2013-01-01

    在NaCl-KCl-Na2WO4-CuO体系中采用熔盐电解法直接制取钨铜合金粉,并对产物进行了XRD、SEM及EDS分析.结果表明,在780~800℃电解、阴极电流密度106~133mA/cm2、电解时间3~4 h、电压2.2~3.2 V的条件下,可以得到纯度99%以上、平均粒度0.91 μm的钨铜合金粉末,各项指标基本达到了工业上烧结钨铜合金的要求.%Tungsten copper alloy powder was directly prepared in NaCl-KCl-Na2 WO4-CuO system with molten salt electrolysis.The cathode electrolysis products were analyzed by XRD, SEM and EDS.The results show that copper tungsten alloy powder with purity of above 99% and average particle size of 0.91 μm is obtained under the reaction conditions including electrolytic temperature of 740~820℃, cathode current density of 106~133 mA/cm2, electrolysis time of 1.5~3.5 h, cell voltage of 2.2~3.2 V.The product reaches the manufacture requirement of sintering tungsten copper alloy in industry.

  18. Barrier/Cu contact resistivity

    Energy Technology Data Exchange (ETDEWEB)

    Reid, J.S.; Nicolet, M.A. [California Inst. of Tech., Pasadena, CA (United States); Angyal, M.S.; Lilienfeld, D.; Shacham-Diamand, Y. [Cornell Univ., Ithaca, NY (United States); Smith, P.M. [Sandia National Labs., Albuquerque, NM (United States)

    1995-10-17

    The specific contact resistivity of Cu with ({alpha} + {beta})-Ta, TiN, {alpha}-W, and amorphous-Ta{sub 36}Si{sub 14}N{sub 50} barrier films is measured using a novel four-point-probe approach. Geometrically, the test structures consist of colinear sets of W-plugs to act as current and voltage probes that contact the bottom of a planar Cu/barrier/Cu stack. Underlying Al interconnects link the plugs to the current source and voltmeter. The center-to-center distance of the probes ranges from 3 to 200 {micro}m. Using a relation developed by Vu et al., a contact resistivity of roughly 7 {times} 10{sup {minus}9} {Omega} cm{sup 2} is obtained for all tested barrier/Cu combinations. By reflective-mode small-angle X-ray scattering, the similarity in contact resistivity among the barrier films may be related to interfacial impurities absorbed from the deposition process.

  19. 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.

  20. Influence of Solution and Aging Treatment Conditions on the Formation of Ultrafine-Grained Structure of CuFe2 Alloy Processed by Rolling with Cyclic Movement of Rolls

    Directory of Open Access Journals (Sweden)

    Urbańczyk-Gucwa A.

    2016-06-01

    Full Text Available The effect of second phase particles on grain refinement in CuFe2 alloy has been investigated by using rolling with the cyclic movement of rolls (RCMR method. Two different population of second phase particles of Fe: coherent, about 10 nm in diameter and about 100 nm in size were obtained by applying aging treatment followed at 500°C for 2 h and at 700°C for 24 h respectively. In addition, solution treated samples were deformed by RCMR method at the same parameters. The microstructures of the CuFe2 alloy were analyzed using light microscope (LM, electron backscattered diffraction (EBSD microscope technique and scanning transmission electron microscope (STEM. The presence of high-density of coherent Fe particles in the matrix inhibits recovery process and in the result obtained grain/subgrain boundaries have diffused character and are weakly visible. The largest particles which are not coherent with the matrix act as an effective barrier against the boundary motion.

  1. Statistical Approach to Optimize the Process Parameters of HAZ of Tool Steel EN X32CrMoV12-28 after Die-Sinking EDM with SF-Cu Electrode

    Directory of Open Access Journals (Sweden)

    L’uboslav Straka

    2017-01-01

    Full Text Available The paper describes the results of the experimental research of the heat affected zone (HAZ of an eroded surface after die-sinking electrical discharge machining (EDM. The research was carried out on chrome-molybdenum-vanadium alloyed tool steel EN X32CrMoV12-28 (W.-Nr. 1.2365 after die-sinking EDM with a SF-Cu electrode. The aim of the experimental measurements was to contribute to the database of knowledge that characterizes the significant impact of the main technological and process parameters on the eroded surface properties during die-sinking EDM. The quality of the eroded surface was assessed from the viewpoint of surface roughness, microhardness variation, and the total HAZ depth of the thin sub-surface layer adjacent to the eroded surface. On the basis of measurement results, mathematical models were established by statistical methods. These models can be applied for computer simulation and prediction of the resultant quality of the machined surface after die-sinking EDM. The results achieved by simulation were compared with the results of experimental measurements and high correlation indexes between the predicted and real values were achieved. Suggested mathematical models can be also applied for the determination of the optimal combination of significant technological parameters in order to minimize microhardness and total HAZ depth variations of tool steel EN X32CrMoV12-28 after die-sinking EDM with a SF-Cu electrode.

  2. Magnetic and microwave absorption properties of BaFe{sub 12-} {sub x} (Mn{sub 0.5}Cu{sub 0.5}Zr) {sub x} {sub /2}O{sub 19} synthesized by sol-gel processing

    Energy Technology Data Exchange (ETDEWEB)

    Ghasemi, Ali [Materials Engineering Department, Malek Ashtar University of Technology, Shahen Shahr (Iran, Islamic Republic of) and Electroceramics Research Center, Malek Ashtar University of Technology, Shahin Shahr (Iran, Islamic Republic of)]. E-mail: ali13912001@yahoo.com; Liu, Xiaoxi [Department of Information Engineering, Shinshu University, Nagano (Japan); Morisako, Akimitsu [Department of Information Engineering, Shinshu University, Nagano (Japan)

    2007-09-15

    BaFe{sub 12-} {sub x} (Mn{sub 0.5}Cu{sub 0.5}Zr) {sub x} {sub /2}O{sub 19} hexaferrites with x=1, 2 and 3 were prepared by sol-gel process. The ferrite powders possess hexagonal shape and are well separated from one another. The powders of these ferrites were mixed with polyvinylchloride (PVC) plasticizer to be converted into a microwave absorbing composite ferrite with a thickness of 1.8 mm. X-ray diffractometer (XRD), scanning electron microscope (SEM), ac susceptometer, vibrating sample magnetometer and vector network analyzer were used to analyze its structure, electromagnetic and microwave absorption properties. The results showed that magnetoplumbite structures for all samples were formed. The sample with higher magnetic susceptibility and coercivity exhibits a larger microwave absorbing ability. Also the present investigation demonstrates that a microwave absorber using BaFe{sub 12-} {sub x} (Mn{sub 0.5}Cu{sub 0.5}Zr) {sub x} {sub /2}O{sub 19} (x=2 and 3)/PVC with a matching thickness of 1.8 mm can be fabricated for applications over 15 GHz, with reflection loss more than -25 dB for specific frequencies, by controlling the molar ratio of the substituted ions.

  3. Miniaturization of BaHfO3 nanoparticles in YBa2Cu3O y -coated conductors using a two-step heating process in the TFA-MOD method

    Science.gov (United States)

    Horita, H.; Teranishi, R.; Yamada, Kazuhiro; Kaneko, K.; Sato, Y.; Otaguro, K.; Nishiyama, T.; Izumi, T.; Awaji, S.

    2017-02-01

    The critical current density (J c) of YBa2Cu3Oy (YBCO)-coated conductors in a magnetic field can be enhanced by the doping of flux-pinning centers in a metal organic deposition (MOD) process with trifluoroacetates (TFA). The size of these flux-pinning centers should be less than 10 nm to achieve commercial use due to the coherence length of YBCO at 77 K. In this paper, BaHfO3 (BHO) nanoparticles were introduced into YBCO films using the TFA-MOD method. Microstructures and the J c properties of the films prepared using a two-step heating process at crystallization were compared with film prepared using a conventional one-step heating process. The two-step heating process produced 15 nm average-sized BHO nanoparticles in the film compared to 19 nm nanoparticles in a film prepared using a one-step process. It was revealed that the size of nanoparticles in the films could be miniaturized by improving the heating processes in the MOD method, and the miniaturized nanoparticles could contribute to increased J c in magnetic fields. The mechanism of miniaturization is also discussed based on microstructure observations of quenched films.

  4. Cu-67 Photonuclear Production

    Science.gov (United States)

    Starovoitova, Valeriia; Foote, Davy; Harris, Jason; Makarashvili, Vakhtang; Segebade, Christian R.; Sinha, Vaibhav; Wells, Douglas P.

    2011-06-01

    Cu-67 is considered as one of the most promising radioisotopes for cancer therapy with monoclonal antibodies. Current production schemes using high-flux reactors and cyclotrons do not meet potential market need. In this paper we discuss Cu-67 photonuclear production through the reaction Zn-68(γ,p)Cu-67. Computer simulations were done together with experiments to study and optimize Cu-67 yield in natural Zn target. The data confirms that the photonuclear method has potential to produce large quantities of the isotope with sufficient purity to be used in medical field.

  5. Spectrographic determination of impurities in ammonium bifluoride. III. Study of the processes of vaporization, transport and excitation of the elements Al, B, Cu and Cr; Determinacion espectrografico de impurezas en bifluoruro amonico. III. Estudio de los procesos de volatilizacion, transporte y excitacion de los elementos Al, B, Cu, Cr

    Energy Technology Data Exchange (ETDEWEB)

    Alduan, F. A.; Roca, M.; Capdevila, C.

    1979-07-01

    The influences of the processes of vaporization, transport and excitation on the shape of the volatilization-excitation curves and on the values of the spectral-line intensities have been investigated in a method for the spectrographic determination of Al, B, Cu and Cr In ammonium bifluoride samples by direct current are excitation in Scribner type electrodes, with addition of different matrices (graphite, 63203, GeO{sub 2}, MgO and Zn0). The reaction products in the electrode cavity have been identified by X-ray powder diffraction analysis and the percentages of vaporized and diffused element evaluated through analysis by total-burning spectrographic methods. In addition, the values of both the number of particles entering the discharge column and the transport efficiencies have been calculated. Thus, the origin of most observed differences has been explained. (Author) 11 refs.

  6. Fe/Cu体-CAST工艺处理草甘膦废水的研究及改造方案%Fe/Cu System - CAST Process for Treatment of Glyphosate Wastewater and Transformation Scheme

    Institute of Scientific and Technical Information of China (English)

    陈恒宝; 王申

    2011-01-01

    The pesticide glyphosate wastewater is difficult to be treated with high concentration of TP and refractory biodegradable COD. A study has been made which applies Fe/Cu system-CAST process to treat the wastewater from anaerobic removing phosphorus tank. The study indicates that the average removal rates of COD, refractory biodegradable COD, TP and PO34- are 88.4%, 70.4%, 83.3% and 96.6%, respectively. Using Fe/Cu system-CAST process enhanced by microaeration to modify glyphosate original wastewater treatment p