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Sample records for chalcopyrite

  1. Ternary chalcopyrite semiconductors

    CERN Document Server

    Shay, J L; Pamplin, B R

    2013-01-01

    Ternary Chalcopyrite Semiconductors: Growth, Electronic Properties, and Applications covers the developments of work in the I-III-VI2 and II-IV-V2 ternary chalcopyrite compounds. This book is composed of eight chapters that focus on the crystal growth, characterization, and applications of these compounds to optical communications systems. After briefly dealing with the status of ternary chalcopyrite compounds, this book goes on describing the crystal growth of II-IV-V2 and I-III-VI2 single crystals. Chapters 3 and 4 examine the energy band structure of these semiconductor compounds, illustrat

  2. Wide-Gap Chalcopyrites

    CERN Document Server

    Siebentritt, Susanne

    2006-01-01

    Chalcopyrites, in particular those with a wide band gap, are fascinating materials in terms of their technological potential in the next generation of thin-film solar cells and in terms of their basic material properties. They exhibit uniquely low defect formation energies, leading to unusual doping and phase behavior and to extremely benign grain boundaries. This book collects articles on a number of those basic material properties of wide-gap chalcopyrites, comparing them to their low-gap cousins. They explore the doping of the materials, the electronic structure and the transport through interfaces and grain boundaries, the formation of the electric field in a solar cell, the mechanisms and suppression of recombination, the role of inhomogeneities, and the technological role of wide-gap chalcopyrites.

  3. Bioleaching of two different types of chalcopyrite by Acidithiobacillus ferrooxidans

    Science.gov (United States)

    Dong, Ying-bo; Lin, Hai; Fu, Kai-bin; Xu, Xiao-fang; Zhou, Shan-shan

    2013-02-01

    Two different types of chalcopyrite (pyritic chalcopyrite and porphyry chalcopyrite) were bioleached with Acidithiobacillus ferrooxidans ATF6. The bioleaching of the pyritic chalcopyrite and porphyry chalcopyrite is quite different. The copper extraction reaches 46.96% for the pyritic chalcopyrite after 48-d leaching, but it is only 14.50% for the porphyry chalcopyrite. Proper amounts of initial ferrous ions can improve the efficiency of copper extraction for the two different types of chalcopyrite. The optimum dosage of ferrous ions for the pyritic chalcopyrite and porphyry chalcopyrite is different. The adsorption of ATF6 on the pyritic chalcopyrite and porphyry chalcopyrite was also studied in this paper. It is found that ATF6 is selectively adsorbed by the two different types of chalcopyrite; the higher adsorption onto the pyritic chalcopyrite than the porphyry chalcopyrite leads to the higher copper dissolution rate of the pyritic chalcopyrite. In addition, the zeta-potential of chalcopyrite before and after bioleaching further confirms that ATF6 is more easily adsorbed onto the pyritic chalcopyrite.

  4. Ball milling of chalcopyrite: Moessbauer spectroscopy and XRD studies

    International Nuclear Information System (INIS)

    The aim of this project is to study the behavior of chalcopyrite under ball milling for extended periods in order to determine how it's decompose or transform. Tests were done with chalcopyrite mixed with iron and zinc with and without surfactant. The use of surfactants has various effects such as avoiding oxidation and clustering of the fine particles. In all case magnetic chalcopyrite is transformed into a paramagnetic component showing a disordered structure, thus revealing that Cu atoms have replaced Fe atoms. In the case of ball milling in air, chalcopyrite is decomposed with the lost of iron, while in milling under surfactants, iron enters into the chalcopyrite structure. (author)

  5. Hybrid Chalcopyrite-Polymer Magnetoconducting Materials.

    Science.gov (United States)

    Zhang, Zhuolei; Xu, Beibei; Zhang, Lin; Ren, Shenqiang

    2016-05-11

    The search for emerging materials combining magnetic and semiconducting properties has attracted widespread interest in contemporary materials science. Chalcopyrite (CuFeS2), as an earth abundant and nontoxic chalcogenide compound in the I-III-VI2 family, is a promising class of such materials that exhibit unusual electrical, optical, and magnetic properties. However, its successful implementation largely depends on our ability to understand, control and manipulate their structural, transport and spin behavior. Here we show that solution processing monodispersed CuFeS2 quantum dots exhibit a strong coupling among optical, electronic, and magnetic degrees of freedom. The photoresponse and magnetoconductance of CuFeS2 quantum dots are realized under external stimuli. We further exploit a fast and efficient way to achieve an exceptionally large performance in a magneto-optoelectronic hybrid system consisting of magnetic semiconducting CuFeS2 and conducting polymer matrix. The results demonstrate a promising potential of magnetic semiconductor CuFeS2 in the field of spin electronics. PMID:27110834

  6. Mechanochemical leaching of chalcopyrite concentrate by sulfuric acid

    Institute of Scientific and Technical Information of China (English)

    Sina Hejazi; Jalil Vahdati khaki; Abolfazl Babakhani

    2016-01-01

    This study aimed to introduce a new cost-effective methodology for increasing the leaching efficiency of chalcopyrite concentrates at ambient temperature and pressure. Mechanical activation was employed during the leaching (mechanochemical leaching) of chalcopyrite concentrates in a sulfuric acid medium at room temperature and atmospheric pressure. High energy ball milling process was used during the leaching to provide the mechanochemical leaching condition, and atomic absorption spectroscopy and cyclic voltammetry were used to de-termine the leaching behavior of chalcopyrite. Moreover, X-ray diffraction and scanning electron microscopy were used to characterize the chalcopyrite powder before and after leaching. The results demonstrated that mechanochemical leaching was effective; the extraction of copper increased significantly and continuously. Although the leaching efficiency of chalcopyrite was very low at ambient temperature, the percentages of copper dissolved in the presence of hydrogen peroxide (H2O2) and ferric sulfate (Fe2(SO4)3) after 20 h of mechanochemical leaching reached 28%and 33%, respectively. Given the efficiency of the developed method and the facts that it does not require the use of an autoclave and can be conducted at room temperature and atmospheric pressure, it represents an economical and easy-to-use method for the leaching industry.

  7. Mechanochemical leaching of chalcopyrite concentrate by sulfuric acid

    Science.gov (United States)

    Mohammadabad, Farhad Khorramshahi; Hejazi, Sina; khaki, Jalil Vahdati; Babakhani, Abolfazl

    2016-04-01

    This study aimed to introduce a new cost-effective methodology for increasing the leaching efficiency of chalcopyrite concentrates at ambient temperature and pressure. Mechanical activation was employed during the leaching (mechanochemical leaching) of chalcopyrite concentrates in a sulfuric acid medium at room temperature and atmospheric pressure. High energy ball milling process was used during the leaching to provide the mechanochemical leaching condition, and atomic absorption spectroscopy and cyclic voltammetry were used to determine the leaching behavior of chalcopyrite. Moreover, X-ray diffraction and scanning electron microscopy were used to characterize the chalcopyrite powder before and after leaching. The results demonstrated that mechanochemical leaching was effective; the extraction of copper increased significantly and continuously. Although the leaching efficiency of chalcopyrite was very low at ambient temperature, the percentages of copper dissolved in the presence of hydrogen peroxide (H2O2) and ferric sulfate (Fe2(SO4)3) after 20 h of mechanochemical leaching reached 28% and 33%, respectively. Given the efficiency of the developed method and the facts that it does not require the use of an autoclave and can be conducted at room temperature and atmospheric pressure, it represents an economical and easy-to-use method for the leaching industry.

  8. Catalytic effect of light illumination on bioleaching of chalcopyrite.

    Science.gov (United States)

    Zhou, Shuang; Gan, Min; Zhu, Jianyu; Li, Qian; Jie, Shiqi; Yang, Baojun; Liu, Xueduan

    2015-04-01

    The influence of visible light exposure on chalcopyrite bioleaching was investigated using Acidithiobacillus ferrooxidans. The results indicated, in both shake-flasks and aerated reactors with 8500-lux light, the dissolved Cu was 91.80% and 23.71% higher, respectively, than that in the controls without light. The catalytic effect was found to increase bioleaching to a certain limit, then plateaued as the initial chalcopyrite concentration increased from 2% to 4.5%. Thus a balanced mineral concentration is highly amenable to bioleaching via offering increased available active sites for light adsorption while eschewing mineral aggregation and screening effects. Using semiconducting chalcopyrite, the light facilitated the reduction of Fe(3+) to Fe(2+) as metabolic substrates for A.ferrooxidans, leading to better biomass, lower pH and redox potential, which are conducive to chalcopyrite leaching. The light exposure on iron redox cycling was further confirmed by chemical leaching tests using Fe(3+), which exhibited higher Fe(2+) levels in the light-induced system. PMID:25722073

  9. Electrochemical dissolution of chalcopyrite studied by voltammetry of immobilized microparticles

    Czech Academy of Sciences Publication Activity Database

    Pikna, L.; Lux, L.; Grygar, Tomáš

    2006-01-01

    Roč. 60, č. 4 (2006), s. 293-296. ISSN 0366-6352 Grant ostatní: VEGA(SK) No1/1108/04; APVT(SK) No20-009404 Institutional research plan: CEZ:AV0Z40320502 Keywords : chalcopyrite * cyclic voltammetry Subject RIV: CA - Inorganic Chemistry Impact factor: 0.360, year: 2006

  10. Leaching of Bornite Produced from the Sulfurization of Chalcopyrite

    Science.gov (United States)

    Veloso, T. C.; Paiva, P. R. P.; Silva, C. A.; Leão, V. A.

    2016-06-01

    The pyrometallurgical route accounts for 80 pct of world metallic copper production, because chalcopyrite, the most abundant copper sulfide, is refractory to hydrometallurgical treatment. However, pyrometallurgical routes are quite restrictive as far as copper concentrates are concerned mainly owing to limits on the concentration of impurities, such as fluorine, chlorine, and arsenic that can be tolerated. Such concentrates require innovative processing solutions because their market value is greatly reduced. A potential alternative is the transformation of chalcopyrite to a sulfide amenable to leaching, such as chalcocite, covellite, or bornite, through treatment in either aqueous or gaseous environments. In this study, the sulfurization of a chalcopyrite concentrate containing 78 pct CuFeS2 in the presence of gaseous sulfur was investigated, with the goal of demonstrating its conversion to the leachable phases, i.e., bornite and covellite. The concentrate was reacted with elemental sulfur in a tubular furnace at temperatures ranging from 573 K to 723 K (300 °C to 450 °C), followed by atmospheric leaching in an Fe(III)-bearing solution. The mineral phases in the sample were quantified using the Rietveld method, and it was shown that at temperatures below 673 K (400 °C) chalcopyrite was converted to covellite (41 pct) and pyrite (34 pct), whereas at temperatures above these, the reaction products were bornite (45 pct) and pyrite (31 pct). Leaching tests [6 hours at 353 K (80 °C)] showed significantly higher copper extraction rates after sulfurization (90 pct) than those using the raw chalcopyrite concentrate (15 pct).

  11. Leaching of Bornite Produced from the Sulfurization of Chalcopyrite

    Science.gov (United States)

    Veloso, T. C.; Paiva, P. R. P.; Silva, C. A.; Leão, V. A.

    2016-02-01

    The pyrometallurgical route accounts for 80 pct of world metallic copper production, because chalcopyrite, the most abundant copper sulfide, is refractory to hydrometallurgical treatment. However, pyrometallurgical routes are quite restrictive as far as copper concentrates are concerned mainly owing to limits on the concentration of impurities, such as fluorine, chlorine, and arsenic that can be tolerated. Such concentrates require innovative processing solutions because their market value is greatly reduced. A potential alternative is the transformation of chalcopyrite to a sulfide amenable to leaching, such as chalcocite, covellite, or bornite, through treatment in either aqueous or gaseous environments. In this study, the sulfurization of a chalcopyrite concentrate containing 78 pct CuFeS2 in the presence of gaseous sulfur was investigated, with the goal of demonstrating its conversion to the leachable phases, i.e., bornite and covellite. The concentrate was reacted with elemental sulfur in a tubular furnace at temperatures ranging from 573 K to 723 K (300 °C to 450 °C), followed by atmospheric leaching in an Fe(III)-bearing solution. The mineral phases in the sample were quantified using the Rietveld method, and it was shown that at temperatures below 673 K (400 °C) chalcopyrite was converted to covellite (41 pct) and pyrite (34 pct), whereas at temperatures above these, the reaction products were bornite (45 pct) and pyrite (31 pct). Leaching tests [6 hours at 353 K (80 °C)] showed significantly higher copper extraction rates after sulfurization (90 pct) than those using the raw chalcopyrite concentrate (15 pct).

  12. EPS-contact-leaching mechanism of chalcopyrite concentrates by A. ferrooxidans

    Institute of Scientific and Technical Information of China (English)

    YU Run-lan; TAN Jian-xi; YANG Peng; SUN Jing; OU Yang; XIONG Jing; DAI Yun-jie

    2008-01-01

    The effect of extracelluar polymeric substances(EPS) on the bioleaching chalcopyrite concentrates in the presence of iron- and sulphur-oxidizing bacteria (A.ferrooxidans) was studied.The bacterial number,pH,redox potential,and the concentrations of Fe2+and Cu2+ ions were investigated.The leached residues were analyzed by the X-ray diffraction and FT-IR.The results indicate that the EPS makes the bacteria adhere to the chalcopyrite surface easily and it is helpful for bacteria in disadvantageous environment.At the same time,EPS film layer with Fe3+ deposits on the surface of chalcopyrite and becomes a barrier of oxygen transfer to chalcopyrite to passivate chalcopyrite,and creates the high redox potential space through concentrating Fe3+ ions to accelerate bioleaching pyrite in chalcopyrite concentrates.The results suggest that EPS formation promotes bioleaching pyrite and inhibits bioleaching chalcopyrite,especially under high potential condition.

  13. Kesterites and Chalcopyrites: A Comparison of Close Cousins; Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Repins, I.; Vora, N.; Beall, C.; Wei, S. H.; Yan, Y.; Romero, M.; Teeter, G.; Du, H.; To, B.; Young, M.; Noufi, R.

    2011-05-01

    Chalcopyrite solar cells based on CuInSe2 and associated alloys have demonstrated high efficiencies, with current annual shipments in the hundreds of megawatts (MW) range and increasing. Largely due to concern over possible indium (In) scarcity, a related set of materials, the kesterites, which comprise Cu2ZnSnS4 and associated alloys, has received increasing attention. Similarities and differences between kesterites and chalcopyrites are discussed as drawn from theory, depositions, and materials characterization. In particular, we discuss predictions from density functional theory, results from vacuum co-evaporation, and characterization via x-ray diffraction, scanning electron microscopy, electron beam-induced current, quantum efficiency, secondary ion mass spectroscopy, and luminescence.

  14. Bacterial leaching of chalcopyrite and bornite with native bioleaching microorganism

    Institute of Scientific and Technical Information of China (English)

    WANG Jun; QIN Wen-qing; ZHANG Yan-sheng; YANG Cong-ren; ZHANG Jian-wen; NAI Shao-shi; SHANG He; QIU Guan-zhou

    2008-01-01

    A native mesophilic iron-oxidizing bacterium,Acidithiobacillus ferrooxidans,has been isolated (30 ℃) from a typical,lead-zinc concentrate of Dachang Mine in the region of Liuzhou located in the southwest of China.Two typical copper sulfide minerals,chalcopyrite and bornite,were from Meizhou Copper Mine in the region of Guangdong Province,China.Variation of pH and cell growth on time and effects of some factors such as temperature,inoculation cell number,and pulp density on the bioleaching of chalcopyrite and bornite were investigated.The results obtained from the bioleaching experiments indicate that the efficiency of copper extraction depends on all of the mentioned variables,especially the pulp density has more effect than the other factors on the microorganism.In addition,the results show that the maximum copper recovery was achieved using a mesophilic culture.The copper dissolution reached 51.34% for the chalcopyrite while it was 72.35% for the bornite at pH 2.0,initial Fe(Ⅱ) concentration 9 g/L and pulp density 5%,after 30 d.

  15. Characterization of dolomite, pyrite and chalcopyrite mineral rocks of Pakistan

    International Nuclear Information System (INIS)

    We studied the dolomite CaMg(CO/sub 3/)/sub 2/, pyrite FeS/sub 2/ and the chalcopyrite CuFeS/sub 2/ mineral rocks of Pakistan, using electronic probe micro analyzer (EPMA) of scanning electron microscope (SEM) with energy dispersive X-ray spectrum (EDS) analyzer. We observed in dolomite two phases perhaps due to crystallization in the matrix, due to calcite CaCO/sub 3/ and quartz SiO/sub 2/. In pyrite phase transition occurs due to pyrrhotite Fe/sub 1-x/, S( x = 0 to 0.2) and Carbon in the matrix of pyrite. In chalcopyrite two different kind of phase transitions are observed due to carbon. quartz SiO/sub 2/ and pyrrhotite Fe/sub 1-x/S (x = 0 to 0.2) in the matrix of chalcopyrite. These phase transitions in respective mineral rocks show disperse crystal mineralization due to pressure and temperature changes for more than thousands of years. Phases are observed with EDS and MLA. (author)

  16. Effects of pyrite and bornite on bioleaching of two different types of chalcopyrite in the presence of Leptospirillum ferriphilum.

    Science.gov (United States)

    Zhao, Hongbo; Wang, Jun; Gan, Xiaowen; Zheng, Xihua; Tao, Lang; Hu, Minghao; Li, Yini; Qin, Wenqing; Qiu, Guanzhou

    2015-10-01

    The effects of pyrite and bornite on bioleaching of two different chalcopyrite samples by Leptospirillum ferriphilum were studied for the first time. Results showed that bioleaching behaviors of the two chalcopyrite samples were extremely different. Bornite decreased the redox potential (ORP) and maintained it at an appropriate range (380-480 mV vs. Ag/AgCl) to promote chalcopyrite (A) dissolution, but caused the redox potential out of the optimum range and inhibited chalcopyrite (B) dissolution. Large amount of pyrite decreased the redox potential and maintained it at an optimum range to promote chalcopyrite (A) dissolution, while increased the redox potential and kept it at appropriate range for a longer period of time to enhance the dissolution rate of chalcopyrite (B). Chalcopyrite (B) had significantly higher values of conductivity and oxidation-reduction rate when compared with those of chalcopyrite (A). The work is potentially useful in interpreting the inconsistence of the researches of chalcopyrite hydrometallurgy. PMID:26183922

  17. Kinetic process of oxidative leaching of chalcopyrite under low oxygen pressure and low temperature

    Institute of Scientific and Technical Information of China (English)

    QIU Ting-sheng; NIE Guang-hua; WANG Jun-feng; CUI Li-feng

    2007-01-01

    Kinetic process of oxidative leaching of chalcopyrite in chloride acid hydroxide medium under oxygen pressure and low temperature was investigated. The effect on leaching rate of chalcopyrite caused by these factors such as ore granularity, vitriol concentration, sodium chloride concentration, oxygen pressure and temperature was discussed. The results show that the leaching rate of chalcopyrite increases with decreasing the ore granularity. At the early stage of oxidative reaction, the copper leaching rate increases with increasing the oxygen pressure and dosage of vitriol concentration, while oxygen pressure affects leaching less at the later stage. At low temperature, the earlier oxidative leaching process of chalcopyrite is controlled by chemical reactions while the later one by diffusion. The chalcopyrite oxidative leaching rate has close relation with ion concentration in the leaching solution. The higher ion concentration is propitious for chalcopyrite leaching.

  18. Thin-film intermediate band chalcopyrite solar cells

    International Nuclear Information System (INIS)

    Chalcopyrite-based solar cells currently lead the efficiency tables of thin-film photovoltaic technologies. Further improvements are foreseen upon implementation of an intermediate band in the absorber layers. We present a theoretical analysis of the efficiency limit for this type of device as a function of factors such as the gap of the host, the relative position of the intermediate band with respect to the band edge and the level of light concentration used as illumination. We have also considered the impact of non-idealities on the performance of the device, particularly the effect of electronic losses related to non-radiative recombination

  19. Insights into the relation between adhesion force and chalcopyrite-bioleaching by Acidithiobacillus ferrooxidans.

    Science.gov (United States)

    Zhu, Jianyu; Wang, Qianfen; Zhou, Shuang; Li, Qian; Gan, Min; Jiang, Hao; Qin, Wenqing; Liu, Xueduan; Hu, Yuehua; Qiu, Guanzhou

    2015-02-01

    This paper presents a study on the relation between bacterial adhesion force and bioleaching rate of chalcopyrite, which sheds light on the influence of interfacial interaction on bioleaching behavior. In our research, Acidithiobacillus ferrooxidans (A. ferrooxidans) were adapted to grow with FeSO4 · 7H2O, element sulfur or chalcopyrite. Then, surface properties of Acidithiobacillus ferrooxidans and chalcopyrite were analyzed by contact angle, zeta potential and Fourier transform infrared spectroscopy (FTIR). Adhesion force between bacteria and chalcopyrite was measured by atomic force microscopy (AFM). Attachment and bioleaching behaviors were also monitored. The results showed that A. ferrooxidans adapted with chalcopyrite exhibited the strongest adhesion force to chalcopyrite and the highest bioleaching rate. Culture adapted with sulfur bacteria took second place and FeSO4 · 7H2O-adapted bacteria were the lowest. Bioleaching rate and bacterial attachment capacity were positively related to bacterial adhesion force, which is affected by the nature of energy source. According to this work, the attachment of bacteria to chalcopyrite surface is one of the most important aspects that influence the bioleaching process of chalcopyrite. PMID:25511439

  20. Comparative study on the selective chalcopyrite bioleaching of a molybdenite concentrate with mesophilic and thermophilic bacteria.

    Science.gov (United States)

    Romano, P; Blázquez, M L; Alguacil, F J; Muñoz, J A; Ballester, A; González, F

    2001-03-01

    This study evaluates different bioleaching treatments of a molybdenite concentrate using mesophilic and thermophilic bacterial cultures. Further studies on the chemical leaching and the electrochemical behavior of the MoS(2) concentrate were carried out. Bioleaching tests showed a progressive removal of chalcopyrite from the molybdenite concentrate with an increase in temperature. Chemical leaching tests support the idea of an indirect attack of the concentrate. Electrochemical tests indicate that chalcopyrite dissolution is favored when molybdenite is present. Therefore, this type of bioleaching treatment could be applied to purify molybdenite flotation concentrates by selectively dissolving chalcopyrite. PMID:11257551

  1. Optimization of the use of carbon paste electrodes (CPE for electrochemical study of the chalcopyrite

    Directory of Open Access Journals (Sweden)

    Daniela G. Horta

    2009-01-01

    Full Text Available The use of carbon paste electrodes (CPE of mineral sulfides can be useful for electrochemical studies to overcome problems by using massive ones. Using CPE-chalcopyrite some variables were electrochemically evaluated. These variables were: (i the atmosphere of preparation (air or argon of CPE and elapsed time till its use; (ii scan rate for voltammetric measurements and (iii chalcopyrite concentration in the CPE. Based on cyclic voltammetry, open-circuit potential and electrochemical impedance results the recommendations are: oxygen-free atmosphere to prepare and kept the CPE until around two ours, scan rates from 10 to 40 mV s-1, and chalcopyrite concentrations > 20%.

  2. Bioleaching of chalcopyrite and bornite by moderately thermophilic bacteria: an emphasis on their interactions

    Science.gov (United States)

    Zhao, Hong-bo; Wang, Jun; Gan, Xiao-wen; Qin, Wen-qing; Hu, Ming-hao; Qiu, Guan-zhou

    2015-08-01

    Interactions between chalcopyrite and bornite during bioleaching by moderately thermophilic bacteria were investigated mainly by X-ray diffraction, scanning electron microscopy, and electrochemical measurements performed in conjunction with bioleaching experiments. The results showed that a synergistic effect existed between chalcopyrite and bornite during bioleaching by both Acidithiobacillus caldus and Leptospirillum ferriphilum and that extremely high copper extraction could be achieved when chalcopyrite and bornite coexisted in a bioleaching system. Bornite dissolved preferentially because of its lower corrosion potential, and its dissolution was accelerated by the galvanic current during the initial stage of bioleaching. The galvanic current and optimum redox potential of 390-480 mV vs. Ag/AgCl promoted the reduction of chalcopyrite to chalcocite (Cu2S), thus accelerating its dissolution.

  3. Single-source precursors for ternary chalcopyrite materials, and methods of making and using the same

    Science.gov (United States)

    Banger, Kulbinder K. (Inventor); Hepp, Aloysius F. (Inventor); Harris, Jerry D. (Inventor); Jin, Michael Hyun-Chul (Inventor); Castro, Stephanie L. (Inventor)

    2006-01-01

    A single source precursor for depositing ternary I-III-VI.sub.2 chalcopyrite materials useful as semiconductors. The single source precursor has the I-III-VI.sub.2 stoichiometry built into a single precursor molecular structure which degrades on heating or pyrolysis to yield the desired I-III-VI.sub.2 ternary chalcopyrite. The single source precursors effectively degrade to yield the ternary chalcopyrite at low temperature, e.g. below 500.degree. C., and are useful to deposit thin film ternary chalcopyrite layers via a spray CVD technique. The ternary single source precursors according to the invention can be used to provide nanocrystallite structures useful as quantum dots. A method of making the ternary single source precursors is also provided.

  4. Presentation on mechanisms and applications of chalcopyrite and pyrite bioleaching in biohydrometallurgy – a presentation

    OpenAIRE

    Huang Tao; Li Dongwei

    2014-01-01

    This review outlines classic and current research, scientific documents and research achievements in bioleaching, particularly in respect of the bioleaching of chalcopyrite and pyrite. The diversity and commonality of the microbial leaching process can be easily studied through comparing the bioleaching mechanism and the application of these two metal sulfides. The crystal, electronic and surface structures of chalcopyrite and pyrite are summarized in detail in this paper. It determines the s...

  5. Electronic structure of epitaxial chalcopyrite surfaces and interfaces for photovoltaics

    International Nuclear Information System (INIS)

    This thesis constitutes a comprehensive study of the surface physics of epitaxial CuInSe2 films. It comprises analyses of the surface morphology and reconstruction, electronic band structure as well as hetero-junctions relevant to photovoltaic applications. Therefore, especially the aspect of stoichiometry variation from the CuInSe2 to the copper-deficient defect phases was considered. Preparation and analysis was completely performed under ultra-high vacuum conditions in order to ensure the investigation of well-defined samples free of contaminants. For some of the analysis techniques, single-crystalline samples are indispensable: They allow for the determination of surface periodicity by low-energy electron diffraction (LEED). In combination with concentration depth profiling by angle-resolved x-ray photoemission, to types of surface reconstructions could be distinguished for the near-stoichiometric CuInSe2(112) surface. In the copper-rich case, it is stabilized by CuIn anti-site defects and on the indium-rich side by 2 VCu defects, as predicted by surface total energy calculations by Jaffe and Zunger. Both configurations correspond to a c(4 x 2) reconstruction of the zinc blende type (111) surface. For the defect compound CuIn3Se5, a sphalerite order of the surface was found, which points at a weakening or absence of the chalcopyrite order in the bulk of the material. The unusual stability of the (112) surface could also be proven by comparison with the reconstruction and surface order of (001) and (220) surfaces. The results from surface analysis were used to measure the valence band structure of the epitaxial samples by synchrotron-based angle-resolved photoelectron spectroscopy. The CuInSe2(001) surface gives access to the high symmetry directions Γ-T and Γ-N of momentum space. By contrasting the data obtained for the stoichiometric surface with the copper-poor defect compound, a reduction of the valence band dispersion and a broadening of electron states

  6. Current scenario of chalcopyrite bioleaching: a review on the recent advances to its heap-leach technology.

    Science.gov (United States)

    Panda, Sandeep; Akcil, Ata; Pradhan, Nilotpala; Deveci, Haci

    2015-11-01

    Chalcopyrite is the primary copper mineral used for production of copper metal. Today, as a result of rapid industrialization, there has been enormous demand to profitably process the low grade chalcopyrite and "dirty" concentrates through bioleaching. In the current scenario, heap bioleaching is the most advanced and preferred eco-friendly technology for processing of low grade, uneconomic/difficult-to-enrich ores for copper extraction. This paper reviews the current status of chalcopyrite bioleaching. Advanced information with the attempts made for understanding the diversity of bioleaching microorganisms; role of OMICs based research for future applications to industrial sectors and chemical/microbial aspects of chalcopyrite bioleaching is discussed. Additionally, the current progress made to overcome the problems of passivation as seen in chalcopyrite bioleaching systems have been conversed. Furthermore, advances in the designing of heap bioleaching plant along with microbial and environmental factors of importance have been reviewed with conclusions into the future prospects of chalcopyrite bioleaching. PMID:26318845

  7. Electrochemical behavior of chalcopyrite in presence of Thiobacillus ferrooxidans

    Institute of Scientific and Technical Information of China (English)

    LI Hong-xu; QIU Guan-zhou; HU Yue-hua; CANG Da-qiang; WANG Dian-zuo

    2006-01-01

    The chalcopyrite anode dissolution behavior in the presence or absence of bacteria in 9 K media using bacteria modified powder microelectrode at 30 ℃ was studied. It is found that during the anode dissolution, many intermediate transient reactions occur accompanying with the production of chalcocite and covellite at potential between -0.075 V and -0.025 V (vs SCE). At low scanning potential between -0.1 and -0.250 V, the iron ion is released in ferrous form, but at the relative high potential up to 0.7 V, it is the ferric one. The presence of Thiobacillus ferrooxidans makes peak current increase and the initial peak potential negatively move, hinting the decomposed oxidation reaction easily occurred and especially the iron ion released and ferrous oxidation reaction enhanced. The characteristic at potential between -0.75 and -0.5 V demonstrates the Thiobacillus ferrooxidans also contributes to the element sulfur formed on the oxidation surface and removed during anode process. The added ferric in the cell could enhance the dissolution reaction, while the increased acid under pH=2 might slightly hamper the process. The anode dissolution kinetics studies show that the presence of bacteria could decease corrosion potential from 0.238 V to 0.184 V and increase the corrosion current density from 1.632 14×10-8 A/cm2 to 2.374 11×10-7A/cm2.

  8. Electrochemical and XPS analysis of chalcopyrite (CuFeS2) dissolution in sulfuric acid solution

    International Nuclear Information System (INIS)

    Highlights: ► The chalcopyrite electrode was shown to be passive for potentials up to 0.90 VSHE. ► Metal-deficient sulfide film passivates chalcopyrite. ► Transpassive dissolution is linked to oxidation of sulfide to elemental sulfur. ► No S0 or polysulfide species were detected for potentials below 0.90 VSHE. ► Potentiodynamic polarization cannot demonstrate chalcopyrite's electrodissolution. - Abstract: The influence of potential on the species and surface films formed during electrodissolution of chalcopyrite were investigated in 0.5 M sulfuric acid solution at 25 °C. Cyclic voltammetry, chronoamperometry, potentiostatic and potentiodynamic polarization methods were applied. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) were used to analyze the minerals and product layers on the surface before and after electrodissolution. The chalcopyrite electrode was shown to be passive for potentials up to 0.90 VSHE. Above this potential, transpassive dissolution occurs. Results of XPS studies have suggested that a metal-deficient sulfide film (Cu1−xFe1−yS2−z) consisting of cuprous sulfide (Cu–S) and iron sulfide (Fe–S) bonds, is the most plausible copper and iron containing sulfide phase which passivates the surface of chalcopyrite. It is demonstrated that the transpassive dissolution of chalcopyrite is significantly linked to oxidation of sulfur (from sulfide in the passive film to elemental sulfur and maybe sulfur species with higher oxidation states, e.g. thiosulfate). No elemental sulfur or polysulfide species were detected on the surface for potentials below 0.90 VSHE.

  9. Chalcopyrite semimagnetic semiconductors: From nanocomposite to homogeneous material

    Directory of Open Access Journals (Sweden)

    Kilanski L.

    2014-01-01

    Full Text Available Currently, complex ferromagnetic semiconductor systems are of significant interest due to their potential applicability in spintronics. A key feature in order to use semiconductor materials in spintronics is the presence of room temperature ferromagnetism. This feature was recently observed and is intensively studied in several Mn-alloyed II-IV-V2 group diluted magnetic semiconductor systems. The paper reviews the origin of room temperature ferromagnetism in II-IV-V2 compounds. In view of our recent reports the room temperature ferromagnetism in Mn-alloyed chalcopyrite semiconductors with more than 5 molar % of Mn is due to the presence of MnAs clusters. The solubility of magnetic impurities in bulk II-IV-V2 materials is of the order of a few percent, depending on the alloy composition. High values of the conducting hole - Mn ion exchange constant Jpd have significant value equal to 0.75 eV for Zn0.997Mn0.003GeAs2. The sample quality has significant effect on the magnetotransport of the alloy. The magnetoresistance of the alloy change main physical mechanism from spin-disorder scattering and weak localization for homogeneous samples to cluster-related geometrical effect observed for nanocomposite samples. The magnetoresistance of the II-IV-V2 alloys can be then tuned up to a few hundreds of percent via changes of the chemical composition of the alloy as well as a degree of disorder present in a material. [Projekat Ministarstva nauke Republike Srbije, br. III45003

  10. Chalcopyrite Thin Film Materials for Photoelectrochemical Hydrogen Evolution from Water under Sunlight

    Directory of Open Access Journals (Sweden)

    Hiroyuki Kaneko

    2015-07-01

    Full Text Available Copper chalcopyrite is a promising candidate for a photocathode material for photoelectrochemical (PEC water splitting because of its high half-cell solar-to-hydrogen conversion efficiency (HC-STH, relatively simple and low-cost preparation process, and chemical stability. This paper reviews recent advances in copper chalcopyrite photocathodes. The PEC properties of copper chalcopyrite photocathodes have improved fairly rapidly: HC-STH values of 0.25% and 8.5% in 2012 and 2015, respectively. On the other hand, the onset potential remains insufficient, owing to the shallow valence band maximum mainly consisting of Cu 3d orbitals. In order to improve the onset potential, we explored substituting Cu for Ag and investigate the PEC properties of silver gallium selenide (AGSe thin film photocathodes for varying compositions, film growth atmospheres, and surfaces. The modified AGSe photocathodes showed a higher onset potential than copper chalcopyrite photocathodes. It was demonstrated that element substitution of copper chalcopyrite can help to achieve more efficient PEC water splitting.

  11. Structural, microstructural, and thermal characterizations of a chalcopyrite concentrate from the Singhbhum shear zone, India

    Institute of Scientific and Technical Information of China (English)

    Ritayan Chatterjee; Shamik Chaudhuri; Saikat Kumar Kuila; Dinabandhu Ghosh

    2015-01-01

    The structural and morphological characterizations of a chalcopyrite concentrate, collected from the Indian Copper Complex, Ghatshila, India, were carried out by X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The con-centrate powder was composed mainly of free chalcopyrite and low quartz in about 3:1 weight ratio. The particle size was about 100 µm. Spectroscopic studies (FTIR, Raman, UV-visible) of the concentrate supported the XRD findings, and also revealed a marginal oxidation of the sulfide phase. The energy band gap of the sulfide was found to be 3.4 eV. Differential thermal analysis and thermogravimetry of the con-centrate showed a decomposition of chalcopyrite at 658 K with an activation energy of 208 kJ⋅mol−1, and two successive structural changes of silica at 848 K and 1145 K.

  12. Galvanic Interaction between Chalcopyrite and Pyrite with Low Alloy and High Carbon Chromium Steel Ball

    Directory of Open Access Journals (Sweden)

    Asghar Azizi

    2013-01-01

    Full Text Available This study was aimed to investigate the galvanic interaction between pyrite and chalcopyrite with two types of grinding media (low alloy and high carbon chromium steel ball in grinding of a porphyry copper sulphide ore. Results indicated that injection of different gases into mill altered the oxidation-reduction environment during grinding. High carbon chromium steel ball under nitrogen gas has the lowest galvanic current, and low alloy steel ball under oxygen gas had the highest galvanic current. Also, results showed that the media is anodic relative to pyrite and chalcopyrite, and therefore pyrite or chalcopyrite with a higher rest potential acted as the cathode, whilst the grinding media with a lower rest potential acted as the anode, when they are electrochemically contacted. It was also found that low alloy steel under oxygen produced the highest amount of EDTA extractable iron in the slurry, whilst high carbon chromium steel under nitrogen atmosphere led to the lowest amount.

  13. Structural characteristics of chalcopyrite from a Cu(Au) ore deposit in the Carajas Mineral Province, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Aparecida Ribeiro, Andreza; Quintao Lima, Diana; Anderson Duarte, Helio; Murad, Enver [ICEx, UFMG, Departamento de Quimica (Brazil); Pereira, Marcio Cesar, E-mail: mcpqui@yahoo.com.br [Universidade Federal dos Vales do Jequitinhonha e Mucuri, Instituto de Ciencia e Tecnologia (Brazil); Tadeu de Freitas Suita, Marcos [UFOP, Departamento de Geologia (Brazil); Ardisson, Jose Domingos [Centro de Desenvolvimento da Tecnologia Nuclear (Brazil); Fabris, Jose Domingos [Universidade Federal dos Vales do Jequitinhonha e Mucuri, UFVJM (Brazil)

    2011-11-15

    Moessbauer spectra and X-ray diffraction data show a chalcopyrite from the Cristalino Cu(Au) deposit in the Carajas Mineral Province in northern Brazil to consist of a single, tetragonal phase. This is in stark contrast to a previously described chalcopyrite from the Camaqua copper mine in southern Brazil, obviously reflecting differences in mineral (and thus ore deposit) genesis.

  14. The influence of mechanical activation of chalcopyrite on the selective leaching of copper by sulphuric acid

    Directory of Open Access Journals (Sweden)

    Achimovičová, M.

    2006-01-01

    Full Text Available In this paper chalcopyrite, CuFeS2, has been selective leached by H2SO4 as leaching agent (170 g/dm3 in procedure of hydrometallurgical production of copper. Mechanical activation of the chalcopyrite resulted in mechanochemical surface oxidation as well as in the mineral surface and bulk disordering. Furthermore, the formation of agglomerates during grinding was also occured. Surface changes of the samples using infrared spectroscopy and scanning electron microscopy methods were investigated before and after leaching. The leaching rate, specific surface area, structural disorder as well as copper extraction increased with the mechanical activation of mineral.

  15. Isolation of a strain of Acidithiobacillus caldus and its role in bioleaching of chalcopyrite

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Q.G.; Bo, F.; Bo, Z.H.; Xi, L.; Jian, G.; Fei, L.F.; Hua, C.X. [Central South University of Technology, Changsha (China)

    2007-09-15

    A moderately thermophilic and acidophilic sulfur-oxidizing bacterium named S-2, was isolated from coal heap drainage. The bacterium was motile, Gramnegative, rod-shaped, measured 0.4 to 0.6 by 1 to 2 gm, and grew optimally at 42-45{sup o}C and an initial pH of 2.5. The strain S-2 grew autotrophically by using elemental sulfur, sodium thiosulfate and potassium tetrathionate as energy sources. The strain did not use organic matter and inorganic minerals including ferrous sulfate, pyrite and chalcopyrite as energy sources. The morphological, biochemical, physiological characterization and analysis based on 16S rRNA gene sequence indicated that the strain S2 is most closely related to Acidithiobacillus caldus (> 99% similarity in gene sequence). The combination of the strain S-2 with Leptospirillum ferriphilum or Acidithiobacillus ferrooxidans in chalcopyrite bioleaching improved the copper-leaching efficiency. Scanning electron microscope (SEM) analysis revealed that the chalcopyrite surface in a mixed culture of Leptospirillum ferriphilum and Acidithiobacillus caldus was heavily etched. The energy dispersive X-ray (EDX) analysis indicated that Acidithiobacillus caldus has the potential role to enhance the recovery of copper from chalcopyrite by oxidizing the sulfur formed during the bioleaching progress.

  16. Facile one-pot synthesis of polytypic (wurtzite-chalcopyrite) CuGaS2

    Science.gov (United States)

    Vahidshad, Yaser; Mirkazemi, Seyed Mohammad; Tahir, Muhammad Nawaz; Zad, Azam Iraji; Ghasemzadeh, Reza; Tremel, Wolfgang

    2016-03-01

    In this investigation, monodisperse CuGaS2 nanoparticles intended for use as visible-light-absorbing materials were synthesized using a facile one-step heating method that involved dissolving the precursors copper chloride, gallium acetylacetonate, and thiourea in a solvent consisting of either oleylamine alone or a combination of oleylamine, oleic acid, and 1-octadecene. The shapes of the resulting nanoparticles were either elongated, polygonal, or a mixture of both, depending on whether the crystal structure of the nanoparticles was predominantly wurtzite, predominantly chalcopyrite, or a more balanced mixture of both wurtzite and chalcopyrite (i.e., the nanoparticles were polytypic: both wurtzite and chalcopyrite phases were present). The crystal structure of the synthesized nanoparticles was found to be influenced by the temperature and the solvent applied during synthesis. X-ray diffraction data for the nanoparticles indicated that applying a temperature of 270 °C or using oleylamine, oleic acid solvent, and 1-octadecene during synthesis tended to yield a chalcopyrite phase, whereas applying a somewhat lower temperature (210 °C) or using oleylamine alone during synthesis tended to result in a wurtzite phase. The chemical states of the compounds obtained at different temperatures and using various solvents, as well as their crystal structures, morphologies, and optical properties were characterized via X-ray photoelectron spectroscopy, X-ray diffraction, transmission electron microscopy, ultraviolet-visible spectroscopy, and photoluminescence.

  17. Laboratory chalcopyrite oxidation by Acidithiobacillus ferrooxidans: Oxygen and sulfur isotope fractionation

    Science.gov (United States)

    Thurston, R.S.; Mandernack, K.W.; Shanks, Wayne C., III

    2010-01-01

    Laboratory experiments were conducted to simulate chalcopyrite oxidation under anaerobic and aerobic conditions in the absence or presence of the bacterium Acidithiobacillus ferrooxidans. Experiments were carried out with 3 different oxygen isotope values of water (??18OH2O) so that approach to equilibrium or steady-state isotope fractionation for different starting conditions could be evaluated. The contribution of dissolved O2 and water-derived oxygen to dissolved sulfate formed by chalcopyrite oxidation was unambiguously resolved during the aerobic experiments. Aerobic oxidation of chalcopyrite showed 93 ?? 1% incorporation of water oxygen into the resulting sulfate during the biological experiments. Anaerobic experiments showed similar percentages of water oxygen incorporation into sulfate, but were more variable. The experiments also allowed determination of sulfate-water oxygen isotope fractionation, ??18OSO4-H2O, of ~ 3.8??? for the anaerobic experiments. Aerobic oxidation produced apparent ??SO4-H2O values (6.4???) higher than the anaerobic experiments, possibly due to additional incorporation of dissolved O2 into sulfate. ??34SSO4 values are ~ 4??? lower than the parent sulfide mineral during anaerobic oxidation of chalcopyrite, with no significant difference between abiotic and biological processes. For the aerobic experiments, a small depletion in ??34SSO4 of ~- 1.5 ?? 0.2??? was observed for the biological experiments. Fewer solids precipitated during oxidation under aerobic conditions than under anaerobic conditions, which may account for the observed differences in sulfur isotope fractionation under these contrasting conditions. ?? 2009 Elsevier B.V.

  18. Fabrication of chalcopyrite light-absorbing layers based on nanoparticle and nanowire networks

    Science.gov (United States)

    Ren, Yuhang; Luo, Paifeng; Gao, Bo; Cevher, Zehra; Sun, Chivin

    2013-03-01

    We report on a method of preparing chalcopyrite, CuInGaSe2 (CIGS) light-absorbing layers using low cost air stable ink based on semiconductor nanoparticle and nanowires. The nanoparticles and nanowires are prepared from metal salts such as metal chloride and acetate at room temperature without inert gas protection. A uniform and non-aggregation CIGS precursor layer is fabricated with the formation of nanoparticle and nanowire networks utilizing ultrasonic spaying technique. We obtain a high quality CIGS absorber by cleaning the residue salts and carbon agents at an increased temperature and through selenizing the pretreated CIGS precursors. Our results offer an opportunity for the low-cost deposition of chalcopyrite absorber materials at large scale with high throughput. This work was partially sponsored by Sun Harmonics Ltd. and by NYSTAR through the Photonics Center for Applied Technology at the City University of New York.

  19. Biofilm forming and leaching mechanism during bioleaching chalcopyrite by Thiobacillus ferrooxidans

    Institute of Scientific and Technical Information of China (English)

    傅建华; 胡岳华; 邱冠周; 柳建设; 徐竞

    2004-01-01

    The mechanism of attachment and leaching of thiobacillus ferrooxcidans (T. f. ) on chalcopyrite were studied. The shaking flasks with bacteria were observed by SEM. The process of T. f attached to the surface of the mineral sample and the biofilm forming were described. The promoting role of the biofilm for bioleaching was discussed. The existence of Fe2+ in the exopolysaccharide layer of T. f was demonstrated by EM(electronic microscope)cell-chemistry analysis. These results show that under the proper growth condition of bacteria, bioleaching of chalcopyrite results in the formation of complete biofilm after 2 - 3 weeks. There are iron ions in the outer layer polymer of T. f. , which provides the micro-environment for themselves, and can guaruntee the energy needed for the bacteria growth in the biofilm. At the same time, Fe3+ ions produced oxidize sulfide which brings about the increase of both growth rate of the bacterial and leaching rate of sulfide minerals.

  20. MODELLING CHALCOPYRITE LEACHING BY Fe+3 IONS WITH THE SHRINKING CORE MODEL

    Directory of Open Access Journals (Sweden)

    Rodrigo Rangel Porcaro

    2015-03-01

    Full Text Available Chalcopyrite leaching by ferric iron is considered a slow process with low copper recovery; a phenomenon ascribed to the passivation of the mineral surface during leaching. Thus, the current study investigated the leaching kinetics of a high purity chalcopyrite sample in the presence of ferric sulfate as oxidant. The effects of the stirring rate, temperature, Eh and Fe3+ concentration on copper extraction were assessed. The leaching data could be described by the shirking core model (SCM for particles of unchanging size and indicated diffusion in the ash layer as the rate-controlling step with a high activation energy (103.9±6.5kJ/mol; likely an outcome of neglecting the effect of particle size distribution (PSD on the kinetics equations. Both the application of the quasi-steady-state assumption to solid-liquid systems and the effect of the particle size distribution on the interpretation of kinetics data are also discussed.

  1. Microrespirometry as an effective technique for monitoring biomass growth and activity in chalcopyrite bioleaching processes

    OpenAIRE

    Benzal Montes, Eva; Morral Moltó, Eloi; Guimerà Villalba, Xavier; Gamisans Noguera, Javier; Solé Sardans, Maria Montserrat; Dorado Castaño, Antonio David

    2014-01-01

    Bioleaching is a technology that uses specific bacteria to extract valuable metals from minerals. The advantages of this technique over traditional methods (chemical leaching) include low cost, high efficiency and environment friendliness. Bioleaching allows to recovers metals from low grade ores at conditions where traditional techniques are not efficient and then, mining waste can be valorized and the impact on the environment is reduced. Chalcopyrite (CuFeS2) is the most abundant ...

  2. Biomining with bacteriophage: selectivity of displayed peptides for naturally occurring sphalerite and chalcopyrite.

    Science.gov (United States)

    Curtis, Susan B; Hewitt, Jeff; Macgillivray, Ross T A; Dunbar, W Scott

    2009-02-01

    During mineral processing, concentrates of sulfide minerals of economic interest are formed by froth flotation of fine ore particles. The method works well but recovery and selectivity can be poor for ores with complex mineralogy. There is considerable interest in methods that improve the selectivity of this process while avoiding the high costs of using flotation chemicals. Here we show the first application of phage biotechnology to the processing of economically important minerals in ore slurries. A random heptapeptide library was screened for peptide sequences that bind selectively to the minerals sphalerite (ZnS) and chalcopyrite (CuFeS2). After several rounds of enrichment, cloned phage containing the surface peptide loops KPLLMGS and QPKGPKQ bound specifically to sphalerite. Phage containing the peptide loop TPTTYKV bound to both sphalerite and chalcopyrite. By using an enzyme-linked immunosorbant assay (ELISA), the phage was characterized as strong binders compared to wild-type phage. Specificity of binding was confirmed by immunochemical visualization of phage bound to mineral particles but not to silica (a waste mineral) or pyrite. The current study focused primarily on the isolation of ZnS-specific phage that could be utilized in the separation of sphalerite from silica. At mining sites where sphalerite and chalcopyrite are not found together in natural ores, the separation of sphalerite from silica would be an appropriate enrichment step. At mining sites where sphalerite and chalcopyrite do occur together, more specific phage would be required. This bacteriophage has the potential to be used in a more selective method of mineral separation and to be the basis for advanced methods of mineral processing. PMID:18767194

  3. The kinetic flotation modelling of chalcopyrite from domestic ores using Software tools

    OpenAIRE

    Krstev, Aleksandar; Krstev, Boris; Zdravev, Zoran; Sala, Ferat; Zivanovic, Jordan; Gocev, Zivko

    2013-01-01

    To improve kinetic flotation models, many first-order flotation kinetics models with distributions of flotation rate constants were redefined so that they could all be represented by the same set of three model parameters. As a result, the width of the distribution become independent of its mean, and parameters of the model and the curve fitting errors, became virtually the same, independent of the chosen distribution function. In our case, investigations of the chalcopyrite ores are ...

  4. Printable, wide band-gap chalcopyrite thin films for power generating window applications

    OpenAIRE

    Sung Hwan Moon; Se Jin Park; Yun Jeong Hwang; Doh-Kwon Lee; Yunae Cho; Dong-Wook Kim; Byoung Koun Min

    2014-01-01

    Printable, wide band-gap chalcopyrite compound films (CuInGaS2, CIGS) were synthesized on transparent conducting oxide substrates. The wide band-gap and defective nature of the films reveal semi-transparent and bifacial properties that are beneficial for power generating window applications. Importantly, solar cell devices with these films demonstrate a synergistic effect for bifacial illumination resulting in a 5.4–16.3% increase of the apparent power conversion efficiency compared to the si...

  5. Passivation of chalcopyrite during the leaching with sulphuric acid solution in presence of sodium nitrate

    Directory of Open Access Journals (Sweden)

    Sokić Miroslav D.

    2010-01-01

    Full Text Available In this work, the process of the chalcopyrite leaching in sulphuric acid solution was investigated. Sodium nitrate was used as oxidant in the leaching process. Chemical reactions of leaching and their thermodynamic possibilities are predicted based on the calculated Gibbs energies and analysis of E−pH diagrams. The negative values of the Gibbs energy show that all chemical reactions are thermodynamically feasible at atmospheric pressure and in a temperature range 25-90°C. At high electrode potential and low pH values, Cu2+, Fe2+ and Fe3+ ions exist in water solutions. The increase of temperature reduces the probability of Fe3+ ion existence in the system. The chalcopyrite concentrate, enriched in the “Rudnik” flotation plant, with 27.08% Cu, 25.12% Fe, 4.15% Zn and 2.28% Pb was used in the work. XRD and DTA analysis of the concentrate reveals that the sample contains mainly the chalcopyrite with small amount of sphalerite. For the description of the reaction of leaching process the leach residuals, obtained at different conditions, were chosen for XRD, TG/DTA and SEM/EDX analyses. The elemental sulphur and chalcopyrite phases identified in leach residuals confirm our prediction that the elemental sulphur is formed during the leaching process. Accordingly, elemental sulphur is the main product of the reaction, while a minor amount of sulphide sulphur is oxidized to sulphate during the leaching. The sulphur formed during the reaction was precipitated at the particle surfaces, and slowed down the leaching rate in the final stage of leaching process. In the initial stage, the reaction rate was controlled by the surface reaction. The mechanism, latter has been changed into a diffusion controlled one.

  6. Study of the Dissolution of Chalcopyrite in Sulfuric Acid Solutions Containing Alcohols and Organic Acids

    International Nuclear Information System (INIS)

    Chalcopyrite dissolution under environmental conditions has been one of the major challenges facing researchers. The current processes for obtaining copper have pollution issues, which will severely limit their application as environmental controls become stricter. Faced with this problem, a number of eco-friendlier methods, such as GALVANOX and HydroCopper (Outokumpu), have been proposed, although they have not been industrialized, mainly due to their high operating costs. The authors previously proposed an alternative system to leach chalcopyrite, which is based on the use of aqueous polar organic solutions. In the process, copper extraction increases in mixtures of acetone or ethylene glycol with aqueous sulfuric acid solutions. The drawback is the large concentration of oxidizing agents needed to obtain high percentages of chalcopyrite dissolution, which can make the process lose viability. In this investigation, the effect of acetic acid, formic acid, methanol and ethanol, whose chemical characteristics are similar to those previously proposed, were evaluated by cyclic voltammetry. It was found that, in the presence of these organic solvents, higher electrochemical responses were obtained compared with those found with sulfuric acid alone, a similar behavior to that obtained with acetone. Leaching experiments results coincided with the corresponding findings of the electrochemical study and X-ray diffraction results provided evidence to support the proposed reactions

  7. Interface characterization of nanometer scale CdS buffer layer in chalcopyrite solar cell

    Science.gov (United States)

    Lin, Shih-Hung; Cheng, Tzu-Huan

    2016-06-01

    The buffer layer of a chalcopyrite solar cell plays an important role in optical responses of open circuit voltage (V oc) and short circuit current (J sc). A CdS buffer layer is applicable on the nanometer scale owing to its high carrier concentration and n-type semiconductor behavior in chalcopyrite solar cells. The thin buffer layer also contributes to the passivation of the absorber surface to reduce defect recombination loss. Non-destructive metrological parameters such as photoluminescence (PL) intensity, external quantum efficiency (EQE), and depth-resolved photovoltage are used to characterize the interface quality of CdS/chalcopyrite. The defects and dangling bonds at the absorber surface will cause interface recombination and reduce the cell performance in build-in voltage distribution. Post annealing can improve Cd ion diffusion from the buffer layer to the absorber surface and reduce the density of defects and dangling bonds. After thermal annealing, the EQE, PL intensity, and minority carrier lifetime are improved.

  8. Diffusion in copper sulphides. An experimental study of chalcocite, chalcopyrite and bornite

    International Nuclear Information System (INIS)

    Diffusion measurements on three copper-containing sulphides have been performed by an electrochemical potentiometric method. Chalcocite (Cu2S), Chalcopyrite (CuFeS2) and Bornite (Cu5FeS4) were synthesized and fully characterized by X-ray diffraction. The diffusivities were measured on compacted powders yielding both the chemical and the component diffusion coefficients in the temperature range 5-50 C. The chemical diffusion coefficients found were: for Chalcocite 38.7*exp (-5600/T), for Chalcopyrite 15.4*exp(-6000/T) and for Bornite 14.4*exp(-4900/T). The diffusion coefficient for Chalcocite is in good agreement with values found previously, and a reasonable agreement is also found for Chalcopyrite and Bornite when our data are compared with values acquired at much higher temperatures with a different technique. The activation energies (here on a Kelvin scale) are remarkably similar for the three sulfides, considering that their relative errors are of a 10% magnitude, which indicates that the bonding strengths and the diffusion mechanisms are similar. The chemical diffusion coefficients which enter the empirical Fick's diffusion laws that describe concentration changes, are of the order of exp(-8) to exp (-7) cm2/s at room temperature. Such values bring the ion mobilities near values found for solid state 'fast ion conductors', used as electrolytes at elevated temperatures. 17 refs, 8 figs, 5 tabs

  9. Magnetic exchange interactions in Mn doped ZnSnAs{sub 2} chalcopyrite

    Energy Technology Data Exchange (ETDEWEB)

    Bouhani-Benziane, H.; Sahnoun, O. [Laboratoire de Physique Quantique de la Matière et Modélisation Mathématique (LPQ3M), University of Mascara (Algeria); Sahnoun, M., E-mail: sahnoun_cum@yahoo.fr [Laboratoire de Physique Quantique de la Matière et Modélisation Mathématique (LPQ3M), University of Mascara (Algeria); Department of Chemistry, University of Fribourg (Switzerland); Driz, M. [Laboratoire de Sciences des Matériaux (LSM), University of Sidi Bel Abbes (Algeria); Daul, C. [Department of Chemistry, University of Fribourg (Switzerland)

    2015-12-15

    Accurate ab initio full-potential augmented plane wave (FP-LAPW) electronic calculations within generalized gradient approximation have been performed for Mn doped ZnSnAs{sub 2} chalcopyrites, focusing on their electronic and magnetic properties as a function of the geometry related to low Mn-impurity concentration and the spin magnetic alignment (i.e., ferromagnetic vs antiferromagnetic). As expected, Mn is found to be a source of holes and localized magnetic moments of about 4 µ{sub B} per Mn atom are calculated which are sufficiently large. The defect calculations are firstly performed by replacing a single cation (namely Zn and Sn) with a single Mn atom in the pure chalcopyrite ZnSnAs{sub 2} supercell, and their corresponding formation energies show that the substitution of a Sn atom (rather than Zn) by Mn is strongly favored. Thereafter, a comparison of total energy differences between ferromagnetic (FM) and antiferromagnetic (AFM) are given. Surprisingly, the exchange interaction between a Mn pairs is found to oscillate with the distance between them. Consequently, the AFM alignment is energetically favored in Mn-doped ZnSnAs{sub 2} compounds, except for low impurity concentration associated with lower distances between neighboring Mn impurities, in this case the stabilization of FM increases. Moreover, the ferromagnetic alignment in the Mn-doped ZnSnAs{sub 2} systems behaves half-metallic; the valence band for majority spin orientation is partially filled while there is a gap in the density of states for the minority spin orientation. This semiconducting gap of ~1 eV opened up in the minority channel and is due to the large bonding–antibonding splitting from the p–d hybridization. Our findings suggest that the Mn-doped ZnSnAs{sub 2} chalcopyrites could be a different class of ferromagnetic semiconductors. - Highlights: • ab initio calculations were performed on Mn doped ZnSnAs{sub 2} chalcopyrite. • Substitution of a Sn atom (rather than Zn) by Mn

  10. Structural and thermal properties of Cu1-xAgxInS2 chalcopyrite solid solutions

    International Nuclear Information System (INIS)

    The roentgenographic study on the concentration, and temperature dependences of the elementary cell parameters a and c and the thermal expansion coefficients along various directions in the CuInS2-AgInS2 system crystals with the chalcopyrite structure is carried out within the temperature range of 80-650 K. It is shown, that by replacement of copper ions by silver both parameters of the elementary cell a and c, its volume, bond length monotonously increase at all temperatures. It is established, that thermal expansion in the solid solutions under study is anisotropic one

  11. Electronic modification of Cu-based chalcopyrite semiconductors induced by lattice deformation and composition alchemy

    Science.gov (United States)

    Jiang, F. D.; Feng, J. Y.

    2008-02-01

    Using first principles calculation, we systematically investigate the electronic modification of Cu-based chalcopyrite semiconductors induced by lattice deformation and composition alchemy. It is shown that the optical band gap Eg is remarkably sensitive to the anion displacement μ, resulting from the opposite shifts of conduction band minimum and valence band maximum. Meanwhile, the dependence of structural parameters of alloyed compounds on alloy composition x is demonstrated for both cation and anion alloying. The d orbitals of group-III cations are found to be of great importance in the calculation. Abnormal changes in the optical band gap Eg induced by anion alloying are addressed.

  12. Electronic modification of Cu-based chalcopyrite semiconductors induced by lattice deformation and composition alchemy

    International Nuclear Information System (INIS)

    Using first principles calculation, we systematically investigate the electronic modification of Cu-based chalcopyrite semiconductors induced by lattice deformation and composition alchemy. It is shown that the optical band gap Eg is remarkably sensitive to the anion displacement μ, resulting from the opposite shifts of conduction band minimum and valence band maximum. Meanwhile, the dependence of structural parameters of alloyed compounds on alloy composition x is demonstrated for both cation and anion alloying. The d orbitals of group-III cations are found to be of great importance in the calculation. Abnormal changes in the optical band gap Eg induced by anion alloying are addressed

  13. Room-temperature ferromagnetism in novel Mn-doped ZnSiAs2 chalcopyrite

    International Nuclear Information System (INIS)

    Based on Mn-doped chalcopyrite ZnSiAs2 the new dilute magnetic semiconductor with p-type conductivity was produced. The Curie temperature behaviour of the produced semiconductor is distinctly dependent on the Mn concentration: 325 K for 1 wt.% and 337 K for 2 wt.% of Mn, consequently. Magnetization, electrical resistance, magnetic resistance and Hall effect of mentioned compositions were studied. Temperature dependence of magnetization M(T) have complicate behaviour. For T ≤ 15 K the M(T) dependence is characteristic for superparamagnetic and at T > 15 K magnetization is sum of magnetizations of ensemble of superparamagnetic clusters and ferromagnetic phase contained frustration regions.

  14. Room-temperature ferromagnetism in novel Mn-doped ZnSiAs{sub 2} chalcopyrite

    Energy Technology Data Exchange (ETDEWEB)

    Marenkin, S F; Novotortsev, V M; Fedorchenko, I V; Varnavskiy, S A [Institute of General and Inorganic Chemistry RAS, Leninskii str. 31, 119991 Moscow (Russian Federation); Koroleva, L I; Zashchirinskii, D M; Khapaeva, T M [M.V. Lomonosov Moscow State University, Vorobyevy Gory, 119992 Moscow (Russian Federation); Szymczak, R; Krzymanska, B; Dobrowolski, V; Kilanski, L, E-mail: koroleva@phys.msu.r [Institute of Physics PAS, Lotnicow al., Warsaw 02668 (Poland)

    2009-03-01

    Based on Mn-doped chalcopyrite ZnSiAs{sub 2} the new dilute magnetic semiconductor with p-type conductivity was produced. The Curie temperature behaviour of the produced semiconductor is distinctly dependent on the Mn concentration: 325 K for 1 wt.% and 337 K for 2 wt.% of Mn, consequently. Magnetization, electrical resistance, magnetic resistance and Hall effect of mentioned compositions were studied. Temperature dependence of magnetization M(T) have complicate behaviour. For T <= 15 K the M(T) dependence is characteristic for superparamagnetic and at T > 15 K magnetization is sum of magnetizations of ensemble of superparamagnetic clusters and ferromagnetic phase contained frustration regions.

  15. Fractal analysis to discriminate between biotic and abiotic attacks on chalcopyrite and pyrolusite.

    Science.gov (United States)

    Cardone, P; Ercole, C; Breccia, S; Lepidi, A

    1999-05-01

    In the present paper, a model describing release and mobility of copper and manganese in chalcopyrite and pyrolusite powders due to bacterial bioleaching, i.e. Thiobacillus ferrooxidans and Arthrobacter sp., is proposed. Sites where copper and manganese were released were examined by scanning electron microscopy (SEM). The resulting micrographs were scanned and submitted to a point by point fractal analysis to verify if a discrimination between biological and chemical attack could be established on the basis of the distribution of the fractional part of the fractal dimension over the whole surface. We demonstrate that such a method is able to discriminate among the different attacks. PMID:10353795

  16. Insights to the effects of free cells on community structure of attached cells and chalcopyrite bioleaching during different stages.

    Science.gov (United States)

    Feng, Shoushuai; Yang, Hailin; Wang, Wu

    2016-01-01

    The effects of free cells on community structure of attached cells and chalcopyrite bioleaching by Acidithiobacillus sp. during different stages were investigated. The attached cells of Acidithiobacillus thiooxidans owned the community advantage from 14thd to the end of bioprocess in the normal system. The community structure of attached cells was greatly influenced in the free cells-deficient systems. Compared to A. thiooxidans, the attached cells community of Acidithiobacillus ferrooxidans had a higher dependence on its free cells. Meanwhile, the analysis of key biochemical parameters revealed that the effects of free cells on chalcopyrite bioleaching in different stages were diverse, ranging from 32.8% to 64.3%. The bioleaching contribution of free cells of A. ferrooxidans in the stationary stage (8-14thd) was higher than those of A. thiooxidans, while the situation was gradually reversed in the jarosite passivation inhibited stage (26-40thd). These results may be useful in guiding chalcopyrite bioleaching. PMID:26492170

  17. Probing the whole ore chalcopyrite-bacteria interactions and jarosite biosynthesis by Raman and FTIR microspectroscopies.

    Science.gov (United States)

    Adamou, Anastasia; Manos, Giorgos; Messios, Nicholas; Georgiou, Lazaros; Xydas, Constantinos; Varotsis, Constantinos

    2016-08-01

    The whole ore chalcopyrite-bacteria interaction and the formation of the extracellular polymeric substances (EPS) during the bioleaching process by microorganisms found in the mine of Hellenic Copper Mines in Cyprus were investigated. Raman and FTIR microspectroscopies have been applied towards establishing a direct method for monitoring the formation of secondary minerals and the newly found vibrational marker bands were used to monitor the time evolution of the formation of covellite, and the K(+) and NH4(+)-jarosites from the chalcopyrite surfaces. The Raman data indicate that the formation of K(+)-jarosite is followed by the formation of NH4(+)-jarosite. The variation in color in the FTIR imaging data and the observation of the amide I vibration at 1637cm(-1) indicate that the microorganisms are attached on the mineral surface and the changes in the frequency/intensity of the biofilm marker bands in the 900-1140cm(-1) frequency range with time demonstrate the existence of biofilm conformations. PMID:27233839

  18. Electrochemical performance of the chalcopyrite CuFeS2 as cathode for lithium ion battery

    International Nuclear Information System (INIS)

    Chalcopyrite CuFeS2 was synthesized by solvothermal process. It was used as active species to prepare cathode of lithium ion batteries together with some conducting materials. Electrochemical performance of the assembled Li/CuFeS2 batteries was characterized by cyclic voltammetry and discharging test. Our results proved that CuFeS2 as a new cathode material showed room-temperature specific discharging capacity of 1100 mAh g−1 at a current density of 14 mA g−1, and that its specific discharging capacity was higher than 500 mAh g−1 at a current density of 350 mA g−1. Different from what reported by Eda et al., the discharging curves presented two apparent plateaus, which were related to different cathode reactions, in the whole measured temperature range. -- Highlights: ► Chalcopyrite CuFeS2 in the form of hexagonal plate was synthesized by solvothermal method. ► The prepared CuFeS2 was used as the cathode active species for lithium-ion batteries. ► The CuFeS2 showed specific discharging capacity of 1100 mAh g−1 at room temperature. ► The CuFeS2 presented two apparent discharging plateaus in the whole measured temperature range.

  19. Synchrotron PEEM and ToF-SIMS study of oxidized heterogeneous pentlandite, pyrrhotite and chalcopyrite.

    Science.gov (United States)

    Acres, Robert George; Harmer, Sarah Louise; Beattie, David Allan

    2010-09-01

    Synchrotron-based photoemission electron microscopy (PEEM; probing the surface region) and time-of-flight secondary ion mass spectrometry (ToF-SIMS; probing the uppermost surface layer) have been used to image naturally heterogeneous samples containing chalcopyrite (CuFeS(2)), pentlandite [(Ni,Fe)(9)S(8)] and monoclinic pyrrhotite (Fe(7)S(8)) both freshly polished and exposed to pH 9 KOH for 30 min. PEEM images constructed from the metal L(3) absorption edges were acquired for the freshly prepared and solution-exposed mineral samples. These images were also used to produce near-edge X-ray absorption fine-structure spectra from regions of the images, allowing the chemistry of the surface of each mineral to be interrogated, and the effect of solution exposure on the mineral surface chemistry to be determined. The PEEM results indicate that the iron in the monoclinic pyrrhotite oxidized preferentially and extensively, while the iron in the chalcopyrite and pentlandite underwent only mild oxidation. The ToF-SIMS data gave a clearer picture of the changes happening in the uppermost surface layer, with oxidation products being observed on all three minerals, and significant polysulfide formation and copper activation being detected for pyrrhotite. PMID:20724782

  20. Modelling of chalcopyrite oxidation reactions in the Outokumpu flash smelting process

    Energy Technology Data Exchange (ETDEWEB)

    Ahokainen, T.; Jokilaakso, A. [Helsinki Univ. of Technology, Otaniemi (Finland)

    1996-12-31

    A mathematical model for simulating oxidation reactions of chalcopyrite particles together with momentum, heat and mass transfer between particle and gas phase in a flash smelting furnace reaction shaft is presented. In simulation, the equations governing the gas flow are solved numerically with a commercial fluid flow package, Phoenics. The particle phase is introduced into the gas flow by a Particle Source In Cell (PSIC) - technique, where a number of discrete particles is tracked in a gas flow and the relevant source terms for momentum, mass, and heat transfer are added to the gas phase equations. The gas phase equations used are elliptic in nature and the fluid turbulence is described by the (k-{epsilon}) -model. Thermal gas phase radiation is simulated with a six-flux radiation model. The chemical reactions of concentrate particles are assumed to happen at two sharp interfaces, and a shrinking core model is applied to describe the mass transfer of chemical species through the reaction product layer. In a molten state, the oxygen consumption is controlled by a film penetration concept. The reacting concentrate particles are a mixture of chalcopyrite and silica. Also a certain amount of pure inert silica is fed to the process as flux. In the simulations the calculation domain includes the concentrate burner and a cylindrical reaction shaft of an industrial scale flash smelting furnace. Some examples about the simulations carried out by the combustion model are presented. (author)

  1. An insight into the mechanism of charge-transfer of hybrid polymer:ternary/quaternary chalcopyrite colloidal nanocrystals

    Directory of Open Access Journals (Sweden)

    Parul Chawla

    2014-08-01

    Full Text Available In this work, we have demonstrated the structural and optoelectronic properties of the surface of ternary/quaternary (CISe/CIGSe/CZTSe chalcopyrite nanocrystallites passivated by tri-n-octylphosphine-oxide (TOPO and tri-n-octylphosphine (TOP and compared their charge transfer characteristics in the respective polymer: chalcopyrite nanocomposites by dispersing them in poly(3-hexylthiophene polymer. It has been found that CZTSe nanocrystallites due to their high crystallinity and well-ordered 3-dimensional network in its pristine form exhibit a higher steric- and photo-stability, resistance against coagulation and homogeneity compared to the CISe and CIGSe counterparts. Moreover, CZTSe nanocrystallites display efficient photoluminescence quenching as evident from the high value of the Stern–Volmer quenching constant (KSV and eventually higher charge transfer efficiency in their respective polymer P3HT:CZTSe composites. We modelled the dependency of the charge transfer from the donor and the charge separation mechanism across the donor–acceptor interface from the extent of crystallinity of the chalcopyrite semiconductors (CISe/CIGSe/CZTSe. Quaternary CZTSe chalcopyrites with their high crystallinity and controlled morphology in conjunction with regioregular P3HT polymer is an attractive candidate for hybrid solar cells applications.

  2. An insight into the mechanism of charge-transfer of hybrid polymer:ternary/quaternary chalcopyrite colloidal nanocrystals.

    Science.gov (United States)

    Chawla, Parul; Singh, Son; Sharma, Shailesh Narain

    2014-01-01

    In this work, we have demonstrated the structural and optoelectronic properties of the surface of ternary/quaternary (CISe/CIGSe/CZTSe) chalcopyrite nanocrystallites passivated by tri-n-octylphosphine-oxide (TOPO) and tri-n-octylphosphine (TOP) and compared their charge transfer characteristics in the respective polymer: chalcopyrite nanocomposites by dispersing them in poly(3-hexylthiophene) polymer. It has been found that CZTSe nanocrystallites due to their high crystallinity and well-ordered 3-dimensional network in its pristine form exhibit a higher steric- and photo-stability, resistance against coagulation and homogeneity compared to the CISe and CIGSe counterparts. Moreover, CZTSe nanocrystallites display efficient photoluminescence quenching as evident from the high value of the Stern-Volmer quenching constant (K SV) and eventually higher charge transfer efficiency in their respective polymer P3HT:CZTSe composites. We modelled the dependency of the charge transfer from the donor and the charge separation mechanism across the donor-acceptor interface from the extent of crystallinity of the chalcopyrite semiconductors (CISe/CIGSe/CZTSe). Quaternary CZTSe chalcopyrites with their high crystallinity and controlled morphology in conjunction with regioregular P3HT polymer is an attractive candidate for hybrid solar cells applications. PMID:25161859

  3. Oxidation of sulphide minerals--I: determination of ferrous and ferric iron in samples of pyrrhotite, pyrite and chalcopyrite.

    Science.gov (United States)

    Steger, H F

    1977-04-01

    A method has been developed for determining small amounts of both ferrous and ferric iron in oxidized samples of pyrrhotite, pyrite and chalcopyrite. The oxidized iron is selectively dissolved in 10M phosphoric acid under reflux and can be determined with the accuracy generally accepted in chemical phase analysis. PMID:18962075

  4. Mechanism of electro-generating leaching of chalcopyrite-MnO2 in presence of Acidithiobacillus thiooxidans

    Institute of Scientific and Technical Information of China (English)

    XIAO Li; LIU Jian-she; FANG Zheng; QIU Guan-zhou

    2008-01-01

    A dual cell system with chalcopyrite anode and MnO2 cathode was used to study the relations between time and such data as the electric quantity and the dissolution rates of the two minerals in the electro-generating leaching(EGL) and the bio-electro-generating leaching(BEGL),respectively.The results showed that the dissolution rates for Cu2+ and Fe2+ in BEGL were almost 2 times faster than those in EGL,and nearly 3 times for Mn2+; the electric output increased nearly by 3 times.The oxidation residue of chalcopyrite was represented by TEM and XRD,whose pattern was similar to that of the raw ore in EGL.The mechanism for leaching of CuFeS2-MnO2 in the presence of Acidithiobacillus thiooxidans was proposed as a successive reaction of two independent sub-processes for the anode.The first stage,common to both processes,is dissolution of chalcopyrite to produce Cu2+,Fe2+ and sulfur.The second stage is subsequent oxidization of sulfur only in BEGL,which is the controlling step of the process.However,the dissolution of MnO2 lasts until the reaction of chalcopyrite stops or the ores exhaust in two types of leaching.

  5. Kinetics and Mechanisms of Chalcopyrite Dissolution at Controlled Redox Potential of 750 mV in Sulfuric Acid Solution

    Directory of Open Access Journals (Sweden)

    Yubiao Li

    2016-08-01

    Full Text Available To better understand chalcopyrite leach mechanisms and kinetics, for improved Cu extraction during hydrometallurgical processing, chalcopyrite leaching has been conducted at solution redox potential 750 mV, 35–75 °C, and pH 1.0 with and without aqueous iron addition, and pH 1.5 and 2.0 without aqueous iron addition. The activation energy (Ea values derived indicate chalcopyrite dissolution is initially surface chemical reaction controlled, which is associated with the activities of Fe3+ and H+ with reaction orders of 0.12 and −0.28, respectively. A surface diffusion controlled mechanism is proposed for the later leaching stage with correspondingly low Ea values. Surface analyses indicate surface products (predominantly Sn2− and S0 did not inhibit chalcopyrite dissolution, consistent with the increased surface area normalised leach rate during the later stage. The addition of aqueous iron plays an important role in accelerating Cu leaching rates, especially at lower temperature, primarily by reducing the length of time of the initial surface chemical reaction controlled stage.

  6. Characterization of products emanating from conventional and microwave energy roasting of chalcopyrite (CuFeS{sub 2}) concentrate

    Energy Technology Data Exchange (ETDEWEB)

    Mulaba-Bafubiandi, Antoine F., E-mail: Mulaba@twr.ac.za [University of Johannesburg, Extraction Metallurgy Department, Faculty of Engineering and the Built Environment (South Africa)

    2006-02-15

    Chalcopyrite concentrate (83% CuFeS{sub 2}, 3% FeS{sub 2} and 14% ZnS) which is a typical feed to the matte smelting process for copper extraction via pyro metallurgical route has been roasted with microwaves. Comparison of mineralogical phases obtained was made with the case of conventional roasting. Resulting calcines were characterised with Moessbauer spectroscopy and XRD. It was observed that complete oxidation (dead roasting) of the chalcopyrite was achieved after 10 min with microwaves while 20 min were required in the conventional route. The mineralogical phases found in the dead-roasted calcines produced from microwave roasting of this chalcopyrite concentrate were the hematite (Fe{sub 2}O{sub 3}), franklinite (ZnFe{sub 2}O{sub 4}), copper-rich ferrite (Cu{sub 1-x}Zn{sub x}Fe{sub 2}O{sub 4}, x {<=} 0.5), and copper ferrite (CuFe{sub 2}O{sub 4}). The findings of this work indicated that it was technologically feasible to oxidize the chalcopyrite with microwaves using a 2.45 GHz multimode applicator.

  7. Characterization of products emanating from conventional and microwave energy roasting of chalcopyrite (CuFeS2) concentrate

    International Nuclear Information System (INIS)

    Chalcopyrite concentrate (83% CuFeS2, 3% FeS2 and 14% ZnS) which is a typical feed to the matte smelting process for copper extraction via pyro metallurgical route has been roasted with microwaves. Comparison of mineralogical phases obtained was made with the case of conventional roasting. Resulting calcines were characterised with Moessbauer spectroscopy and XRD. It was observed that complete oxidation (dead roasting) of the chalcopyrite was achieved after 10 min with microwaves while 20 min were required in the conventional route. The mineralogical phases found in the dead-roasted calcines produced from microwave roasting of this chalcopyrite concentrate were the hematite (Fe2O3), franklinite (ZnFe2O4), copper-rich ferrite (Cu1-xZnxFe2O4, x ≤ 0.5), and copper ferrite (CuFe2O4). The findings of this work indicated that it was technologically feasible to oxidize the chalcopyrite with microwaves using a 2.45 GHz multimode applicator.

  8. Full potential calculations on the electron bandstructures of Sphalerite, Pyrite and Chalcopyrite

    Science.gov (United States)

    Edelbro, R.; Sandström, Å.; Paul, J.

    2003-02-01

    The bulk electronic structures of Sphalerite, Pyrite and Chalcopyrite have been calculated within an ab initio, full potential, density functional approach. The exchange term was approximated with the Dirac exchange functional, the Vosko-Wilk-Nusair parameterization of the Cepler-Alder free electron gas was used for correlation and linear combinations of Gaussian type orbitals were used as basis functions. The Sphalerite (zinc blende) band gap was calculated to be direct with a width of 2.23 eV. The Sphalerite valence band was 5.2 eV wide and composed of a mixture of sulfur and zinc orbitals. The band below the valence band located around -6.2 eV was mainly composed of Zn 3d orbitals. The S 3s orbitals gave rise to a band located around -12.3 eV. Pyrite was calculated to be a semiconductor with an indirect band gap of 0.51 eV, and a direct gap of 0.55 eV. The valence band was 1.25 eV wide and mainly composed of non-bonding Fe 3d orbitals. The band below the valence band was 4.9 eV wide and composed of a mixture of sulfur and iron orbitals. Due to the short inter-atomic distance between the sulfur dumbbells, the S 3s orbitals in Pyrite were split into a bonding and an anti-bonding range. Chalcopyrite was predicted to be a conductor, with no band-crossings at the Fermi level. The bands at -13.2 eV originate from the sulfur 3s orbitals and were quite similar to the sulfur 3s bands in Sphalerite, though somewhat shifted to lower energy. The top of the valence band consisted of a mixture of orbitals from all the atoms. The lower part of the same band showed metal character. Computational modeling as a tool for illuminating the flotation and leaching processes of Pyrite and Chalcopyrite, in connection with surface science experiments, is discussed.

  9. X-PEEM, XPS and ToF-SIMS characterisation of xanthate induced chalcopyrite flotation: Effect of pulp potential

    Science.gov (United States)

    Kalegowda, Yogesh; Chan, Yuet-Loy; Wei, Der-Hsin; Harmer, Sarah L.

    2015-05-01

    Synchrotron-based X-ray photoemission electron microscopy (X-PEEM), X-ray photo-electron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (ToF-SIMS) and ultraviolet visible spectroscopy were used to characterize the flotation behaviour of chalcopyrite with xanthate at different processing conditions. The flotation recovery of chalcopyrite decreased from 97% under oxidative conditions (Eh ~ 385 mV SHE, pH 4) to 41% at a reductive potential of - 100 mV SHE (at pH 9). X-PEEM images constructed from the metal L3 absorption edges were used to produce near-edge X-ray absorption fine structure (NEXAFS) spectra from regions of interest, allowing the variability in mineral surface chemistry of each mineral particle to be analysed, and the effect of pulp potential (Eh) on the flotation of chalcopyrite to be determined. XPS, ToF-SIMS and NEXAFS analyses of chalcopyrite particles at oxidative conditions show that the surface was mildly oxidised and covered with adsorbed molecular CuEX. The Cu 2p XPS and Cu L2,3 NEXAFS spectra were dominated by CuI species attributed to bulk chalcopyrite and adsorbed CuEX. At a reductive potential of - 100 mV SHE, an increase in concentration of CuI and FeIII oxides and hydroxides was observed. X-PEEM analysis was able to show the presence of a low percentage of CuII oxides (CuO or Cu(OH)2) with predominantly CuI oxide (Cu2O) which is not evident in Cu 2p XPS spectra.

  10. Bacterial consortium for copper extraction from sulphide ore consisting mainly of chalcopyrite

    Directory of Open Access Journals (Sweden)

    E. Romo

    2013-01-01

    Full Text Available The mining industry is looking forward for bacterial consortia for economic extraction of copper from low-grade ores. The main objective was to determine an optimal bacterial consortium from several bacterial strains to obtain copper from the leach of chalcopyrite. The major native bacterial species involved in the bioleaching of sulphide ore (Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans, Leptospirillum ferrooxidans and Leptospirillum ferriphilum were isolated and the assays were performed with individual bacteria and in combination with At. thiooxidans. In conclusion, it was found that the consortium integrated by At. ferrooxidans and At. thiooxidans removed 70% of copper in 35 days from the selected ore, showing significant differences with the other consortia, which removed only 35% of copper in 35 days. To validate the assays was done an escalation in columns, where the bacterial consortium achieved a higher percentage of copper extraction regarding to control.

  11. Simulation of Bioleaching Heat Effects for Enhancement of Copper Recovery from Sarcheshmeh Chalcopyrite

    Science.gov (United States)

    Mahmoudian, Ali Reza; Sadrnezhaad, S. K.; Manafi, Zahra

    2014-08-01

    A heat-transfer model was formulated to determine the distribution of temperature within a bioheap of chalcopyrite of Sarcheshmeh copper mine. Bioleaching employs mixed mesophilic and thermophilic microbes for Cu extraction. Thermophiles are better than mesophiles to dissolve CuFeS2. The solution irrigation and aeration rates were taken into account as the main operational factors. The model was validated by comparing the temperature profiles of test columns with those of bioheap. The model was used to find the optimal ratio of irrigation to aeration. It was found that when the solution was fed at a flow rate of 5 kg/m2 h and air was blown at a flow rate of 7.5 kg/m2 h, the transition from a mesophilic to thermophilic state inside the heap was possible. In this situation, the maximum temperature rise inside the heap was about 332 K (59 °C) after 60 days.

  12. Hydrometallurgical application for treating a Nigerian chalcopyrite ore in chloride medium: Part I. Dissolution kinetics assessment

    Science.gov (United States)

    Baba, Alafara A.; Ayinla, Kuranga I.; Adekola, Folahan A.; Bale, Rafiu B.; Ghosh, Malay K.; Alabi, Abdul G. F.; Sheik, Abdul R.; Folorunso, Ismael O.

    2013-11-01

    The dissolution kinetics of a Nigerian chalcopyrite ore in hydrochloric acid was studied in this article. Acid concentration, reaction temperature, and ore particle size were chosen as experimental parameters. The chemical and morphological studies of the ore before and after leaching at optimal conditions were carried out by X-ray diffraction (XRD) and scanning electron microscopy (SEM). It is revealed that increasing the acid concentration and system temperature and decreasing the ore particle size greatly enhances the dissolution rate. The dissolution kinetics was found to follow the shrinking core model for the diffusion control mechanism where the activation energy ( E a) of 32.92 kJ·mol-1 was obtained for the process and supported by morphological changes at a higher dissolution of 91.33%.

  13. Solution-processed In2S3 buffer layer for chalcopyrite thin film solar cells

    Science.gov (United States)

    Wang, Lan; Lin, Xianzhong; Ennaoui, Ahmed; Wolf, Christian; Lux-Steiner, Martha Ch.; Klenk, Reiner

    2016-02-01

    We report a route to deposit In2S3 thin films from air-stable, low-cost molecular precursor inks for Cd-free buffer layers in chalcopyrite-based thin film solar cells. Different precursor compositions and processing conditions were studied to define a reproducible and robust process. By adjusting the ink properties, this method can be applied in different printing and coating techniques. Here we report on two techniques, namely spin-coating and inkjet printing. Active area efficiencies of 12.8% and 12.2% have been achieved for In2S3-buffered solar cells respectively, matching the performance of CdS-buffered cells prepared with the same batch of absorbers.

  14. Solution-processed In2S3 buffer layer for chalcopyrite thin film solar cells

    Directory of Open Access Journals (Sweden)

    Wang Lan

    2016-01-01

    Full Text Available We report a route to deposit In2S3 thin films from air-stable, low-cost molecular precursor inks for Cd-free buffer layers in chalcopyrite-based thin film solar cells. Different precursor compositions and processing conditions were studied to define a reproducible and robust process. By adjusting the ink properties, this method can be applied in different printing and coating techniques. Here we report on two techniques, namely spin-coating and inkjet printing. Active area efficiencies of 12.8% and 12.2% have been achieved for In2S3-buffered solar cells respectively, matching the performance of CdS-buffered cells prepared with the same batch of absorbers.

  15. Printable, wide band-gap chalcopyrite thin films for power generating window applications

    Science.gov (United States)

    Moon, Sung Hwan; Park, Se Jin; Hwang, Yun Jeong; Lee, Doh-Kwon; Cho, Yunae; Kim, Dong-Wook; Min, Byoung Koun

    2014-03-01

    Printable, wide band-gap chalcopyrite compound films (CuInGaS2, CIGS) were synthesized on transparent conducting oxide substrates. The wide band-gap and defective nature of the films reveal semi-transparent and bifacial properties that are beneficial for power generating window applications. Importantly, solar cell devices with these films demonstrate a synergistic effect for bifacial illumination resulting in a 5.4-16.3% increase of the apparent power conversion efficiency compared to the simple sum of the efficiencies of the front and rear side illumination only. We also confirmed that this extra output power acquisition due to bifacial irradiation is apparently not influenced by the light intensity of the rear side illumination, which implies that weak light (e.g., indoor light) can be efficiently utilized to improve the overall solar cell efficiency of bifacial devices.

  16. Assessment of the flotability of chalcopyrite, molybdenite and pyrite using biosolids and their main components as collectors for greening the froth flotation of copper sulphide ores.

    OpenAIRE

    Sobarzo, Francisco; Herrera Urbina, Ronaldo; Higueras Higueras, Pablo Leon; SÁez Navarrete, CÉsar; Godoy FaÚndez, Alex; Reyes Bozo, Lorenzo; VÁsquez Bestagno, Jorge

    2014-01-01

    Biosolids and representative compounds of their main components ? humic acids, sugars, and proteins ? have been tested as possible environment-friendly collectors and frothers for the flotation of copper sulphide ores. The floatability of chalcopyrite and molybdenite ? both valuable sulphide minerals present in these ores ? as well as non-valuable pyrite was assessed through Hallimond tube flotation tests. Humic acids exhibit similar collector ability for chalcopyrite and molybdenite as that ...

  17. Effect of pH values on the extracellular polysaccharide secreted by Acidithiobacillus ferrooxidans during chalcopyrite bioleaching

    Science.gov (United States)

    Yu, Run-lan; Liu, Jing; Tan, Jian-xi; Zeng, Wei-min; Shi, Li-juan; Gu, Guo-hua; Qin, Wen-qing; Qiu, Guan-zhou

    2014-04-01

    The pH value plays an important role in the bioleaching of sulphide minerals. The effect of pH values on the extracellular polysaccharide secreted by Acidithiobacillus ferrooxidans was investigated in different phases of bacterial growth during chalcopyrite bioleaching. It is found that extracellular polysaccharide secretion from the cells attached to chalcopyrite is more efficiently than that of the free cells in the bioleaching solution. Three factors, pH values, the concentration of soluble metal ions, and the bacterial growth and metabolism, affect extracellular polysaccharide secretion in the free cells, and are related to the bacterial growth phase. Extracellular polysaccharide secretion from the attached cells is mainly dependent on the pH value of the bacterial culture.

  18. Cu and Fe chalcopyrite leach activation energies and the effect of added Fe 3+

    Science.gov (United States)

    Kaplun, K.; Li, J.; Kawashima, N.; Gerson, A. R.

    2011-10-01

    The leaching kinetics of chalcopyrite (CuFeS 2) concentrate in sulfuric acid leach media with and without the initial addition of Fe 3+ under carefully controlled solution conditions ( Eh 750 mV SHE, pH 1) at various temperatures from 55 to 85 °C were measured. Kinetic analyses by (i) apparent rate (not surface area normalised), and rate dependence using (ii) a shrinking core model and (iii) a shrinking core model in conjunction with Fe 3+ activity, were performed to estimate the activation energies ( Ea) for Cu and Fe dissolution. The Ea values determined for Cu and Fe leaching in the absence of added Fe 3+ are within experimental error, 80 ± 10 kJ mol -1 and 84 ± 10 kJ mol -1, respectively (type iii analyses Ea are quoted unless stated otherwise), and are indicative of a chemical reaction controlled process. On addition of Fe 3+ the initial Cu leach rate (up to 10 h) was increased and Cu was released to solution preferentially over Fe, with the Ea value of 21 ± 5 kJ mol -1 (type ii analysis) suggestive of a transport controlled rate determining process. However, the rate of leaching rapidly decreased until it was consistently slower than for the equivalent leaches where Fe 3+ was not added. The resulting Ea value for this leach regime of 83 ± 10 kJ mol -1 is within experimental error of that determined in the absence of added Fe 3+. In contrast to Cu release, Fe release to solution was consistent with a chemical reaction controlled leach rate throughout. The Fe release Ea of 76 ± 10 kJ mol -1 is also within experimental error of that determined in the absence of added Fe 3+. Where type (ii) and (iii) analyses were both successfully carried out (in all cases except for Cu leaching with added Fe 3+, 10 h), as compared to in the absence of added Fe 3+, returned a considerably smaller pre-exponential factors for both Cu and Fe leach analyses commensurate with the considerably slower leach rate, suggestive of a more applicable kinetic analysis. XPS examination

  19. Adsorption of biosolids and their main components on chalcopyrite, molybdenite and pyrite: Zeta potential and FTIR spectroscopy studies

    OpenAIRE

    Reyes Bozo, Lorenzo; Escudey, Mauricio; Vyhmeister, Eduardo; Higueras Higueras, Pablo Leon; Godoy FaÚndez, Alex; Salazar, José Luis; ValdÉs GonzÁlez, HÉctor; Wolf Sepúlveda, Germán; Herrera Urbina, Ronaldo

    2015-01-01

    Zeta potential measurements were used to assess the electrokinetic characteristics of chalcopyrite, molybdenite and pyrite in the presence of biosolids and their main components (humic acids, glucose and serum albumin) as well as a commercial collector (Aero 6697). Fourier transform infrared spectroscopy (FTIR) was then used to gain a deeper understanding of the interaction of these compounds with these sulfide minerals. It aims to achieve a better understanding of the surface che...

  20. The presentation of the selectivity indexes and techno-economical efficiences in selective flotation from domestic chalcopyrite and galenasphalerite ores

    OpenAIRE

    Gocev, Zivko; Krstev, Aleksandar; Krstev, Boris; Golomeova, Mirjana; Zendelska, Afrodita; Vuckovski, Zoran; Golomeov, Blagoj

    2013-01-01

    The presentation and comparative analysis and the tabular and figurative shown of the techno indicators of the concentration, techno efficiency and economic efficiency for the treated ores in mineral processing technologies for copper-chalcopyrite ores in Bucim mine and lead/zinc-galena/sphalerite ores in Sasa mine in the Republic of Macedonia, their correlation and other characteristics using descriptive statistics of experimental/industrial results with Microsoft Excel 2010. The pr...

  1. Dependence of Ionicity and Thermal Expansion Coefficient on Valence Electron Density in AIIBIVC2V Chalcopyrite Semiconductors

    Directory of Open Access Journals (Sweden)

    Amar BAHADUR

    2013-06-01

    Full Text Available A striking correlation has been found to exist between the free electron density parameter, average bond length, homoplar energy gap, heteropolar energy gap, ionicity and thermal expansion coefficient for AIIBIVC2V chalcopyrite semiconductors. The estimated values of these parameters are in good agreement with the available experimental values and theoretical findings. The electron density parameter data is the only one input data to estimate all above properties.

  2. Surface characterization by X-ray photoelectron spectroscopy and cyclic voltammetry of products formed during the potentiostatic reduction of chalcopyrite

    Energy Technology Data Exchange (ETDEWEB)

    Nava, Dora [Universidad Autonoma Metropolitana - Iztapalapa, Departamento de Quimica, Area de Electroquimica, A.P. 55-534, C.P. 09340, Mexico, D.F. (Mexico); Gonzalez, Ignacio [Universidad Autonoma Metropolitana - Iztapalapa, Departamento de Quimica, Area de Electroquimica, A.P. 55-534, C.P. 09340, Mexico, D.F. (Mexico)], E-mail: igm@xanum.uam.mx; Leinen, Dietmar; Ramos-Barrado, Jose R. [Departamento de Fisica Aplicada, Laboratorio de Materiales y Superficie, Unidad asociada al CSIC, Universidad de Malaga, Campus Teatinos, Malaga, C.P. 29071 (Spain)

    2008-05-30

    Surface characterization of the transient products that precede chalcocite formation during chalcopyrite reduction was carried out. The experimental strategy employed in the present work consisted of the application of different potential pulses (fixed energetic conditions) on the surface of chalcopyrite electrodes in 1.7 M H{sub 2}SO{sub 4}. The chemical products formed at different potential pulses were characterized by cyclic voltammetry (CV) and XPS. Each electrogenerated species presented a specific voltammetric behavior and an XPS spectrum, in which the values of principal photoelectronic peak bond energies for Cu 2p{sub 3/2}, Fe 2p{sub 3/2} and S 2p{sub 3/2} and the atomic concentrations were considered. Several potential intervals could be identified: in 0.115 {>=} E{sub cat} {>=} -0.085 V vs. SHE, an intermediate copper sulfide is formed whose composition is between those of chalcopyrite and bornite, such as talnakhite. The reduction of this product occurs slowly, giving bornite at potentials less than -0.085 V. In the applied potential region -0.085 {>=} E{sub cat} > -0.185 V, the bornite gradually decomposes causing the incomplete conversion to chalcocite. In the potential interval -0.185 > E{sub cat} {>=} -0.285 V, energetic conditions are large enough to allow the immediate decomposition of bornite, forming chalcocite in a more quantitative manner.

  3. Synthesis, structural and magnetic properties of self-organized single-crystalline nanobricks of chalcopyrite CuFeS2

    International Nuclear Information System (INIS)

    A thermal pyrolysis method has been developed to synthesize the tetragonal phase of chalcopyrite magnetic semiconductor CuFeS2 nanoparticles. All nanoparticles have the same anisotropic brick-like shape, and the “bricks” are self-organized in a certain orientation, creating well-ordered nanocomposites. High-resolution transmission electron microscopy and electron diffraction data show that every nanobrick is a single crystal with a layered atomic structure and characteristic dimensions of about 5 nm × 20 nm in plane. Magnetic measurements support the antiferromagnetic spin structure and reveal the appearance of a small ferromagnetic component below 60 K. Magnetic anomalies observed in the zero-field cooled magnetization curves at low temperatures may be related to an appearance of magnetic moment at the Cu ion site. The Mössbauer spectra show that only about 50% of Fe atoms are in the magnetically ordered α-phase of chalcopyrite. The remaining Fe is non-magnetic and may be located either in the γ-phase of chalcopyrite or in isocubanite

  4. Fe and Cu isotope fractionation between chalcopyrite and dissolved metal species during hydrothermal recrystallization: An experimental study at 350°C and 500 bars

    Science.gov (United States)

    Syverson, D. D.; Luhmann, A. J.; Tan, C.; Borrok, D. M.; Ding, K.; Seyfried, W. E., Jr.

    2015-12-01

    The equilibrium Fe and Cu isotope fractionation factor between chalcopyrite and dissolved metal species was determined under hydrothermal conditions at 350°C and 500 bars. The experiments took advantage of gold-cell reaction technology, allowing time-series sampling of solution during the hydrothermal recrystallization of chalcopyrite over 3000 hours. One of the recrystallization experiments utilized an anomalous 57Fe spike in solution to quantify the degree and rate of isotopic exchange towards equilibrium between mineral and fluid reservoirs. The time-series 57Fe spike data suggests that chalcopyrite exchanges rapidly with dissolved Fe and Cu in solution and the isotopic fractionation between each metal-bearing reservoir throughout reaction progress, upon dissolution and recrystallization, represents close to equilibrium conditions. The isotope data indicate that the equilibrium fractionation between chalcopyrite and dissolved Fe and Cu at 350°C, Δ56FeCpy-Fe(aq), is 0.129±0.171‰ and Δ65CuCpy-Fe(aq), is -0.201±0.341‰ (2σ), and are in good agreement with recent theoretical equilibrium predictions. Comparison of the experimental data from this study with conjugate chalcopyrite and dissolved Fe and Cu pairs from a variety of hydrothermal systems along the mid-ocean ridge system indicates that chalcopyrite precipitates and recrystallizes at isotopic equilibrium with the fluid during cooling upon ascent to the seafloor. The rapid exchange between the mineral and fluid metal-reservoirs suggests that chalcopyrite effectively records the isotopic composition of the coexisting hydrothermal fluid during the evolution of hydrothermal systems. In addition, the pyrite-chalcopyrite equilibrium Fe isotope fractionation, Δ56FePyr-Cpy, at 350°C is quantified by combination of pyrite-Fe2+(aq) equilibrium fractionation data from Syverson et al., [2013] with chalcopyrite-Fe2+(aq) from this study, resulting in a fractionation of 0.861±0.337‰ (2σ). The empirical

  5. A stochastic model of solid state thin film deposition: Application to chalcopyrite growth

    Science.gov (United States)

    Lovelett, Robert J.; Pang, Xueqi; Roberts, Tyler M.; Shafarman, William N.; Birkmire, Robert W.; Ogunnaike, Babatunde A.

    2016-04-01

    Developing high fidelity quantitative models of solid state reaction systems can be challenging, especially in deposition systems where, in addition to the multiple competing processes occurring simultaneously, the solid interacts with its atmosphere. In this work, we develop a model for the growth of a thin solid film where species from the atmosphere adsorb, diffuse, and react with the film. The model is mesoscale and describes an entire film with thickness on the order of microns. Because it is stochastic, the model allows us to examine inhomogeneities and agglomerations that would be impossible to characterize with deterministic methods. We demonstrate the modeling approach with the example of chalcopyrite Cu(InGa)(SeS)2 thin film growth via precursor reaction, which is a common industrial method for fabricating thin film photovoltaic modules. The model is used to understand how and why through-film variation in the composition of Cu(InGa)(SeS)2 thin films arises and persists. We believe that the model will be valuable as an effective quantitative description of many other materials systems used in semiconductors, energy storage, and other fast-growing industries.

  6. Copper solvent extraction from chalcopyrite concentrate acid leach solutions by LIX 984

    Directory of Open Access Journals (Sweden)

    Elamari K.

    2006-01-01

    Full Text Available Copper production from ores or sulphide concentrates is classically realized by pyrometallurgical route. In this study, hydrometallurgical treatment of a copper sulphide concentrate, provided by Hajar Mine (ONA-Group, Morocco, was tested by using a mixture of nitric and hexafluorosilicic acids. Copper is present in the solid product as chalcopyrite and its amount is 28.1 % by weight. Leaching stage allows to dissolve more than 90% of copper witch is accompanied, in the same averages, by Zn and Fe. The leach solution obtained has pH = 0.6 and Eh = 580 mV/ENH and contains 19.3 g/L Cu, 18.1 g/L Fe, 4.5 g/L Zn and 0.03 g/L Pb. The recovery of copper from this leach solution was curried out by solvent extraction using Lix 984, diluted in Escaid 110. McCabe - Thiele distribution isotherms showed that at pH 1.7 total and selective copper extraction can be realized with Øo:Øa =1.5:1 in 3 extraction stages. Stripping of the loaded copper by treating the organic phases was easily obtained by a sulphuric acid solution.

  7. Investigation of thermodynamics properties of chalcopyrite compound CdGeAs2

    Science.gov (United States)

    Huang, Wei; Zhao, Beijun; Zhu, Shifu; He, Zhiyu; Chen, Baojun; Zhen, Zhen; Pu, Yunxiao; Liu, Weijia

    2016-06-01

    Chalcopyrite of CdGeAs2 single crystal was grown by a modified vertical Bridgman method with sufficient size and quality, and its optical, electrical and thermodynamic properties are characterized. The transmission is recorded in the 2.3-18 μm range, and the band-gap at room temperature is at 0.56 eV. Non-ideal transparency near 5.5 μm which limited its application severely exists in the front of the crystal. The crystal is p type at room temperature with hole concentrations varying from 1014 to 1016 cm-3. From the results of X-ray diffraction measurements carried out over the range 25-450 °C and thermal dilatometer tests, the thermal expansion coefficients are evaluated. And on this basis the Grüneisen parameters at different temperatures are evaluated and also exhibit anisotropic behavior (γa>γc). It is found that γa, γc, and γV have some difference between these two kinds of test methods. Using these Grüneisen parameters, lattice thermal conductivities have been deduced by two correction formulas. Meanwhile, specific heat capacity and thermal conductivity of [204] have been obtained as a function of temperature by experiment.

  8. Improved chalcopyrite bioleaching by Acidithiobacillus sp. via direct step-wise regulation of microbial community structure.

    Science.gov (United States)

    Feng, Shoushuai; Yang, Hailin; Wang, Wu

    2015-09-01

    A direct step-wise regulation strategy of microbial community structure was developed for improving chalcopyrite bioleaching by Acidithiobacillus sp. Specially, the initial microbial proportion between Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans was controlled at 3:1 with additional 2 g/L Fe(2+) for faster initiating iron metabolism. A. thiooxidans biomass was fed via a step-wise strategy (8-12th d) with the microbial proportion 1:1 for balancing community structure and promoting sulfur metabolism in the stationary phase. A. thiooxidans proportion was further improved via another step-wise feeding strategy (14-18th d) with the microbial proportion 1:2 for enhancing sulfur metabolism and weakening jarosite passivation in the later phase. With the community structure-shift control strategy, biochemical reaction was directly regulated for creating a better balance in different phases. Moreover, the final copper ion was increased from 57.1 to 93.2 mg/L, with the productivity 2.33 mg/(Ld). The novel strategy may be valuable in optimization of similar bioleaching process. PMID:26011694

  9. Influence of doping and solid solution formation on the thermoelectric properties of chalcopyrite semiconductors

    International Nuclear Information System (INIS)

    Highlights: • Zinc substituting on the cation site in CuInTe2 and CuGaTe2 is a p-type dopant. • Thermoelectric power factor optimized by 1% zinc doping. • CuInTe2–CuGaTe2 solid solution formation reduces the lattice thermal conductivity. • Optimized samples have dimensionless thermoelectric figure of merit in excess of unity over a wide temperature range. - Abstract: We have investigated the influence of zinc doping on the thermoelectric properties of CuInTe2–CuGaTe2 solid solution alloys. Undoped end-member compounds display typical p-type semiconducting behavior, with a negative temperature coefficient of resistivity and large Seebeck coefficient. With zinc substituting for indium or gallium, the hole concentration is increased and the electrical transport behavior evolves into that of a degenerate semiconductor, with both electrical resistivity and Seebeck coefficient increasing with temperature up to the highest temperature measured. For undoped samples the thermoelectric power factor is maximized close to 750 K, while in doped specimens the maximum occurs at much lower temperature. Substitution of gallium for indium induces significant phonon scattering and thermal conductivity reduction below 500 K. The dimensionless figure of merit rises to above unity over a range of compositions in these chalcopyrite compounds, with optimized samples reaching a figure of merit of 1.3

  10. Influence of doping and solid solution formation on the thermoelectric properties of chalcopyrite semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Carr, Winston D. [Department of Physics & Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Morelli, Donald T. [Department of Physics & Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Department of Chemical Engineering & Materials Science, Michigan State University, East Lansing, MI 48824 (United States)

    2015-05-05

    Highlights: • Zinc substituting on the cation site in CuInTe{sub 2} and CuGaTe{sub 2} is a p-type dopant. • Thermoelectric power factor optimized by 1% zinc doping. • CuInTe{sub 2}–CuGaTe{sub 2} solid solution formation reduces the lattice thermal conductivity. • Optimized samples have dimensionless thermoelectric figure of merit in excess of unity over a wide temperature range. - Abstract: We have investigated the influence of zinc doping on the thermoelectric properties of CuInTe{sub 2}–CuGaTe{sub 2} solid solution alloys. Undoped end-member compounds display typical p-type semiconducting behavior, with a negative temperature coefficient of resistivity and large Seebeck coefficient. With zinc substituting for indium or gallium, the hole concentration is increased and the electrical transport behavior evolves into that of a degenerate semiconductor, with both electrical resistivity and Seebeck coefficient increasing with temperature up to the highest temperature measured. For undoped samples the thermoelectric power factor is maximized close to 750 K, while in doped specimens the maximum occurs at much lower temperature. Substitution of gallium for indium induces significant phonon scattering and thermal conductivity reduction below 500 K. The dimensionless figure of merit rises to above unity over a range of compositions in these chalcopyrite compounds, with optimized samples reaching a figure of merit of 1.3.

  11. A stochastic model of solid state thin film deposition: Application to chalcopyrite growth

    Directory of Open Access Journals (Sweden)

    Robert J. Lovelett

    2016-04-01

    Full Text Available Developing high fidelity quantitative models of solid state reaction systems can be challenging, especially in deposition systems where, in addition to the multiple competing processes occurring simultaneously, the solid interacts with its atmosphere. In this work, we develop a model for the growth of a thin solid film where species from the atmosphere adsorb, diffuse, and react with the film. The model is mesoscale and describes an entire film with thickness on the order of microns. Because it is stochastic, the model allows us to examine inhomogeneities and agglomerations that would be impossible to characterize with deterministic methods. We demonstrate the modeling approach with the example of chalcopyrite Cu(InGa(SeS2 thin film growth via precursor reaction, which is a common industrial method for fabricating thin film photovoltaic modules. The model is used to understand how and why through-film variation in the composition of Cu(InGa(SeS2 thin films arises and persists. We believe that the model will be valuable as an effective quantitative description of many other materials systems used in semiconductors, energy storage, and other fast-growing industries.

  12. Raman spectroscopy for quality control and process optimization of chalcopyrite thin films and devices

    International Nuclear Information System (INIS)

    We will demonstrate in this paper that Raman scattering of visible light is a versatile tool both for research and industrial process monitoring of thin chalcopyrite films for solar cells. Thin films of Cu(In, Ga)(S,Se)2 (CIGSSe) are produced by rapid thermal processing of stacked elemental Cu-In-Ga-Se layers. The Raman investigations are accompanied by grazing incidence X-ray diffraction (GI-XRD) and X-ray florescence (XRF) measurements. GI-XRD measurements confirm that the films show a two-fold elemental gradient: a sulfur gradient from the top and a Ga gradient from the CIGSSe/Mo interface. By Rietveld refinement of the GI-XRD spectra of the surface-near (∼ 100nm) ratio of sulfur to selenium can be obtained which corresponds well to the intensity ratio of the two Raman A1 modes of CuInS2 and CuInSe2. The asymmetric line shape of both XRD diffractograms and Raman spectra is attributed to the sulfur gradient. In addition we show that the intensity ratio of the satellite Raman B and E modes shows a correlation with the Cu to In + Ga ratio obtained by XRF

  13. Development of a composite collector scheme for flotation of chalcopyrite ore

    International Nuclear Information System (INIS)

    Xanthate-type collectors reported for the upgradation of Chalcopyrite ore of North Waziristan area were studied and a new technique was developed, in which -two collectors were used (composite collectors) in the bulk-stage process of froth-flotation to achieve metallurgical grade with maximum recovery. The collectors studied were thiol-type surfactants, such as sodium ethyl xanthate (NaEX), sodium propyl xanthate (NaPX), sodium butyl xanthate (NaBX) and sodium Amyl xanthate (NaAX). Mixed collectors examined were in the varying dosage ratio of (0-100:100-0) through the combination of(i) sodium ethyl xanthate with sodium propyl xanthate, sodium ethyl xanthate with sodium butyl xanthate, sodium ethyl xanthate with sodium amyl xanthate, (ii) sodium propyl xanthate with sodium butyl xanthate, sodium propyl xanthate with sodium amyl xanthate and (iii) sodium butyl xanthate with sodium amyl xanthate. All the remaining flotation parameters were kept constant during the various flotation tests. The results were compared and the conclusions were drawn that the optimum grade in the concentrate was obtained with a mixture having a ratio of 4: 1 with sodium ethyl xanthate and sodium butyl xanthate. Recovery of copper content in the concentrate was achieved with ratio of 2:3 with sodium butyl xanthate and sodium amyl xanthate. (author)

  14. An optimized In–CuGa metallic precursors for chalcopyrite thin films

    Energy Technology Data Exchange (ETDEWEB)

    Han, Jun-feng, E-mail: junfeng.han@cnrs-imn.fr [Institut des Matériaux Jean Rouxel (IMN), Université de Nantes, UMR CNRS 6502, 2 rue de la Houssinière, BP 32229, 44322 Nantes Cedex 3 (France); Department of Physics, Peking University, Beijing 100871 (China); Liao, Cheng [Department of Physics, Peking University, Beijing 100871 (China); Chengdu Green Energy and Green Manufacturing Technology R and D Center, Chengdu, Sichuan Province 601207 (China); Jiang, Tao; Xie, Hua-mu; Zhao, Kui [Department of Physics, Peking University, Beijing 100871 (China); Besland, M.-P. [Institut des Matériaux Jean Rouxel (IMN), Université de Nantes, UMR CNRS 6502, 2 rue de la Houssinière, BP 32229, 44322 Nantes Cedex 3 (France)

    2013-10-31

    We report a study of CuGa–In metallic precursors for chalcopyrite thin film. CuGa and In thin films were prepared by DC sputtering at room temperature. Due to low melting point of indium, the sputtering power on indium target was optimized. Then, CuGa and In multilayers were annealed at low temperature. At 120 °C, the annealing treatment could enhance diffusion and alloying of CuGa and In layers; however, at 160 °C, it caused a cohesion and crystalline of indium from the alloy which consequently formed irregular nodules on the film surface. The precursors were selenized to form copper indium gallium selenide (CIGS) thin films. The morphological and structural properties were investigated by scanning electron microscopy, X-ray diffraction and Raman spectra. The relationships between metallic precursors and CIGS films were discussed in the paper. A smooth precursor layer was the key factor to obtain a homogeneous and compact CIGS film. - Highlights: • An optimized sputtered indium film • An optimized alloying process of metallic precursor • An observation of nodules forming on the indium film and precursor surface • An observation of cauliflower structure in copper indium gallium selenide film • The relationship between precursor and CIGS film surface morphology.

  15. Photoelectrochemical hydrogen-evolution over p-type chalcopyrite CuInSe2

    International Nuclear Information System (INIS)

    Photocatalytic H2-production has been realized over active CuInSe2, synthesized by the fusion technique. The material crystallizes in the chalcopyrite structure and exhibits p-type conductivity ascribed to copper deficiency. An optical gap of 0.95 eV was determined from the reflectance diffuse spectrum. The electrical conductivity follows an Arrhenius-type law with activation energy of 23 meV in conformity with polaron hopping. The slope and the intercept of the Mott-Schottky plot gave a holes density NA of 5.9 x 1018 cm-3 and a flat band potential of -0.36VSCE, in perfect agreement with the photo-onset potential Von (-0.35VSCE). Hence, the conduction band, located at -1.29VSCE, allows a spontaneous H2 liberation upon visible light. In aqueous solutions, the material is stabilized by hole consumption involving X2- species (=S2- and SO32-). H2 formation would become thermodynamically easy in alkaline media and the best photoactivity was obtained in thiosulfate electrolyte (10-2 M S2O32-, 0.5 M KOH) with an evolution rate of 0.009 ml mg-1 h-1. The light induced electron transfer through the interface involves two steps mechanism where S2O32- is oxidized to SO32- and SO42- by successive reactions. Such results are corroborated by the semi logarithmic plots and photocurrent-photopotential characteristics. The influence of pH was studied with S2O32- The tendency towards saturation for prolonged irradiation is attributed to competitive reductions of the end products Sn2- and S2O62- with water and to the yellow color of polysulfide Sn2-.

  16. Electronic structure of semiconductor thin films (chalcopyrites) as absorbermaterials for thin film solar cells

    International Nuclear Information System (INIS)

    The objective of this work was to determine for the first time the band structure of CuInS2. For this purpose a new GSMBE process with TBDS as sulphur precursor was established to prevent the use of elemental sulphur in an UHV system. Additionally to the deposited films a cleave surface was prepared. The samples were characterized in situ by XPS/UPS and LEED. XRD and SEM were used for further ex situ investigations. The band structure was determined by ARUPS using synchrotron light. CuInS(001) and CuInS2(112) were deposited on Si and GaAs. The deposition of CuInS2 on GaAs showed a strong dependence on the existing surface reconstruction. A 2 x 1 reconstruction of GaAs(001) yielded CuInS2(001) films featuring terraces. A deposition on 2 x 2 reconstructed GaAs(111)A surfaces led to a facetted CuInS2 surface. On sulphur-passivated non-reconstructed GaAs(111)B a deposition of chalcopyrite ordered CuInS2 free of facets was possible. On the surface of Cu-rich CuInS2 films CuS crystallites formed. This yields ARUPS spectra showing the electronic stucture of CuInS2 superimposed by non-dispergative states of the polycrystalline CuS segregations. The effective hole masses were derived from the k verticalstrokeverticalstroke measurements. Finally the results of this work showed that the use of a (111) substrate leads to domain formation of the deposited CuInS2(112) films. Thus ARUPS spectra of such films show a superposition of the band structures along different directions. (orig.)

  17. Effect of pH and Fe(III) ions on chalcopyrite bioleaching by an adapted consortium from biogas sweetening

    OpenAIRE

    Dorado Castaño, Antonio David; Solé Sardans, Maria Montserrat; Lao Luque, Concepción; Alfonso Abella, María Pura; Gamisans Noguera, Javier

    2012-01-01

    Particle size, pH and Fe(III) ions affect the process of bioleaching of copper from chalcopyrite ores. In the study presented herein a copper sulfide ore was subjected to bioleaching process using a mixed microbial consortium obtained from a biotrickling filter treating high loads of H2S at different mineral particle size, distinct medium pH and various additional Fe(III) ion concentrations as leaching agent. After 1300 h of operation, the total copper recovery achieved a value of 50% in the ...

  18. Mathematical model of the chemistry of the dump leaching of chalcopyrite

    Energy Technology Data Exchange (ETDEWEB)

    Liddell, K.C.

    1980-03-01

    In a leach dump, chalcopyrite is dissolved by Fe/sup 3 +/ and by O/sub 2/ and H/sup +/. Neither reaction is at equilibrium under operational conditions. The solution contains Fe(III), Fe(II) and Cu(II) in an aqueous sulfate medium with a pH of about 2. The equilibrium concentrations of H/sup +/, OH/sup -/, SO/sub 4//sup 2 -/, HSO/sub 4//sup -/, Fe/sup 3 +/, FeOH/sup 2 +/, Fe(OH)/sub 2//sup +/, Fe/sub 2/(OH)/sub 2//sup 4 +/, FeSO/sub 4//sup +/, Fe(SO/sub 4/)/sub 2//sup -/, FeHSO/sub 4//sup 2 +/, Fe/sup 2 +/, FeSO/sub 4//sup 0/, FeHSO/sub 4//sup +/, Cu/sup 2 +/ and CuSO/sub 4//sup 0/ were calculated for different Fe/sub 2/(SO/sub 4/)/sub 3/, FeSO/sub 4/, CuSO/sub 4/ and H/sub 2/SO/sub 4/ analytical concentrations using both ideal solution and high ionic strength apparent equilibrium constants. Conditions under which Fe/sup 3 +/ precipitates have been investigated by including K/sub Sp/ values as constraints in the computer program. Jarosite, KFe/sub 3/(SO/sub 4/)/sub 2/(OH)/sub 6/, precipitates except when the K/sup +/ concentration is very small. Formation of goethite, ..cap alpha..-FeOOH, occurs through aging of amorphous Fe(OH)/sub 3/; ferric hydroxide precipitation is favored by high Fe/sup 3 +/ concentrations and high pH. With both dissolution reactions occurring, it was found that the H/sup +/ consumed was partially restored by dissociation of HSO/sub 4//sup -/, FEHSO/sub 4//sup 2 +/ and FeHSO/sub 4//sup +/. With no O/sub 2/ reacting, there were only slight changes in the H/sup +/ and HSO/sub 4//sup -/ concentrations and FeHSO/sub 4//sup +/ was a product. The maximum copper concentration was obtained with high starting Fe/sub 2/(SO/sub 4/)/sub 3/ concentrations and little or no O/sub 2/ consumption. Too large an amount of O/sub 2/ reacting led to pH increases that caused precipitation of Fe(OH)/sub 3/.

  19. Spray Chemical Vapor Deposition of Single-Source Precursors for Chalcopyrite I-III-VI2 Thin-Film Materials

    Science.gov (United States)

    Hepp, Aloysius F.; Banger, Kulbinder K.; Jin, Michael H.-C.; Harris, Jerry D.; McNatt, Jeremiah S.; Dickman, John E.

    2008-01-01

    Thin-film solar cells on flexible, lightweight, space-qualified substrates provide an attractive approach to fabricating solar arrays with high mass-specific power. A polycrystalline chalcopyrite absorber layer is among the new generation of photovoltaic device technologies for thin film solar cells. At NASA Glenn Research Center we have focused on the development of new single-source precursors (SSPs) for deposition of semiconducting chalcopyrite materials onto lightweight, flexible substrates. We describe the syntheses and thermal modulation of SSPs via molecular engineering. Copper indium disulfide and related thin-film materials were deposited via aerosol-assisted chemical vapor deposition using SSPs. Processing and post-processing parameters were varied in order to modify morphology, stoichiometry, crystallography, electrical properties, and optical properties to optimize device quality. Growth at atmospheric pressure in a horizontal hotwall reactor at 395 C yielded the best device films. Placing the susceptor closer to the evaporation zone and flowing a more precursor-rich carrier gas through the reactor yielded shinier-, smoother-, and denser-looking films. Growth of (112)-oriented films yielded more Cu-rich films with fewer secondary phases than growth of (204)/(220)-oriented films. Post-deposition sulfur-vapor annealing enhanced stoichiometry and crystallinity of the films. Photoluminescence studies revealed four major emission bands and a broad band associated with deep defects. The highest device efficiency for an aerosol-assisted chemical vapor deposited cell was one percent.

  20. Comparison of microbial communities in three different mine drainages and their bioleaching efficiencies to low grade of chalcopyrite

    Institute of Scientific and Technical Information of China (English)

    YIN Hua-qun; QIU Guan-zhou; WANG Dian-zuo; CAO Lin-hui; DAI Zhi-min; WANG Jie-wei; LIU Xue-duan

    2007-01-01

    Microbial community diversities in the drainage from three mines (Dexing Copper Mine, Qibaoshan Copper Mine and Yaogangxian Tungsten Mine, China) were analyzed using 16S rDNA PCR-RFLP approach. The efficiencies of chalcopyrite bioleaching were compared using enrichment of the three cultures. Phylogenetic analysis indicates that the dominant microorganisms are clustered with the Proteobacteria, the remaining is affiliated with Nitrospira, Acidobacteria and Actinobacteria.At the genus level, Acidithiobacillus is the dominant group in both YTW and QBS samples, while Spingomonas is dominant in YGX sample. Moreover, the principal component analysis (PCA) reveals that QBS and YTW have similar geochemical character and microbial communities. The results also show that pH value and tungsten concentration play a key role in microbial community distribution and relative abundance. The bioleaching efficiency of the enrichment cultures from YTW and QBS is similar. After 15 d,the bioleaching rates of low grade chalcopyrite (0.99%) are both up to 99.5% when using 10 g/L pulp density due to the similar microbial composition of YTW and QBS. Moreover, the leaching efficiencies of enrichment cultures containing multiple bioleaching microorganisms are higher than that of pure culture Acidithiobacillus ferrooxidans.

  1. Structural and electronic properties of chalcopyrite semiconductors AgXY{sub 2} (X=In,Ga; Y=S,Se,Te) under pressure

    Energy Technology Data Exchange (ETDEWEB)

    Chahed, A.; Benhelal, O.; Rozale, H.; Laksari, S.; Abbouni, N. [Computational Materials Science Laboratory, Physics Department, University of Sidi-Bel-Abbes, 22000 Sidi-Bel-Abbes (Algeria)

    2007-02-15

    Results are presented of a first-principles calculation of the direct band-gap pressure coefficient a{sub g} for a series of Al, Ga and In chalcopyrite semiconductor compounds AgXY{sub 2} (X=Ga,In; Y=S,Se,Te) and the corresponding zinc-blende structure. Good agreement was found between the calculated and experimental pressure coefficients. It was found that a{sub g} in chalcopyrites are dramatically reduced relative to zinc-blende compounds, and that the Al{yields}Ga{yields}In substitution lowers a{sub g} in chalcopyrites more than in zinc-blende compounds. As a result, the empirical rule suggested for zinc-blende compounds, stating that for a given transition (e.g. {gamma}{sub 15v}{yields}{gamma}{sub 1c}) a{sub g} does not depend on substitutions, has to be modified for chalcopyrites. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  2. Low-temperature heat capacity and entropy of chalcopyrite (CuFeS2): estimates of the standard molar enthalpy and Gibbs free energy of formation of chalcopyrite and bornite (Cu5FeS4)

    Science.gov (United States)

    Robie, R.A.; Wiggins, L.B.; Barton, P.B., Jr.; Hemingway, B.S.

    1985-01-01

    The heat capacity of CuFeS2 (chalcopyrite) was measured between 6.3 and 303.5 K. At 298.15 K, Cp,mo and Smo(T) are (95.67??0.14) J??K-1??mol-1 and (124.9??0.2) J??K-1??mol-1, respectively. From a consideration of the results of two sets of equilibrium measurements we conclude that ??fHmo(CuFeS2, cr, 298.15 K) = -(193.6??1.6) kJ??mol-1 and that the recent bomb-calorimetric determination by Johnson and Steele (J. Chem. Thermodynamics 1981, 13, 991) is in error. The standard molar Gibbs free energy of formation of bornite (Cu5FeS4) is -(444.9??2.1) kJ??mol-1 at 748 K. ?? 1985.

  3. Terahertz electro-optic detection using a ⟨012⟩-cut chalcopyrite ZnGeP2 crystal

    Science.gov (United States)

    Carnio, B. N.; Greig, S. R.; Firby, C. J.; Zawilski, K. T.; Schunemann, P. G.; Elezzabi, A. Y.

    2016-06-01

    The electro-optic detection capabilities of a -cut chalcopyrite ZnGeP2 (ZGP) crystal is investigated in the terahertz (THz) frequency regime. Our experiments attest that ZGP exhibits low THz losses and dispersion, and that phonon-polariton effects are too weak to perturb the THz pulse. Additionally, ZGP is shown to have excellent phase matching between an optical probe pulse and a THz pulse. For a 1080 μm thick ZGP crystal, this phase matching yields a detection bandwidth 1.3 times greater than ZnTe and 4.8 times greater than ZnSe and GaP. Thus, ZGP has promising applications in THz time-domain spectroscopy.

  4. Defect formation energies and homogeneity ranges of rock salt-, pyrite-, chalcopyrite- and molybdenite-type compound semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Fiechter, S. [Hahn-Meitner-Institut, Glienicker Strasse 100, Berlin D-14109 (Germany)

    2004-07-01

    Employing the generalisation of Van Vechten's cavity model, formation energies of neutral point defects in pyrites (FeS{sub 2}, RuS{sub 2}), chalcopyrites (II-IV-V{sub 2} and I-III-VI{sub 2}) as well as molybdenites (MoS{sub 2}, WS{sub 2}) have been estimated. As input parameters the fundamental band gaps, work functions, electron affinities, surface energies, coordination numbers, covalent or ionic radii and unit cell parameters were used. The values calculated for tetrahedrally and octahedrally coordinated compounds agreed well with measured values. The data obtained can be used to calculate point defect concentrations and homogeneity ranges as a function of partial pressure and temperature. Introducing charged vacancies, the conductivity type can be predicted.

  5. First and second harmonic generation of the XAl2Se4 (X=Zn,Cd,Hg) defect chalcopyrite compounds

    International Nuclear Information System (INIS)

    The chemical bonding of the ZnAl2Se4, CdAl2Se4 and HgAl2Se4 defect chalcopyrites has been studied in the framework of the quantum theory of atoms in molecules (AIM). The GW quasi-particle approximation is used to correct the DFT-underestimation of energy gap, and as a consequence the linear and nonlinear optical properties are significantly enhanced. The second harmonic generation (SHG) displays certain dependence with the ionicity degree decrease through the dependency of the SHG on the band gap. The occurrence of the AIM saddle point is characterized and some clarifying features in relationship with the density topology are exposed, which enable to understand the relation with the second harmonic generation effect.

  6. Vibrational and thermal properties of ternary semiconductors and their isotopic dependence: chalcopyrite CuGaS{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Kremer, Reinhard K.; Cardona, Manuel; Lauck, Rudolf [MPI fuer Festkoerperforschung, Stuttgart (Germany); Romero, Aldo H. [CINVESTAV, Unidad Queretaro, Queretaro (Mexico); Munoz, Alfonso [MALTA Consolider Team, Dept. de Fisica, Universidad de La Laguna, La Laguna, Tenerife (Spain)

    2011-07-01

    The availability of ab initio electronic calculations and the concomitant techniques for deriving the corresponding lattice dynamics have been profusely used in the past decade for calculating thermodynamic and vibrational properties of semiconductors, as well as their dependence on isotopic masses. The latter have been compared with experimental data for elemental and binary semiconductors with different isotopic compositions. Here we present experimental and theoretical data for several vibronic and thermodynamic properties of a canonical ternary semiconductor of the chalcopyrite family: CuGaS{sub 2}. Among these properties are the lattice parameters, the phonon dispersion relations and densities of states (projected on the Cu, Ga, and S constituents), the specific heat and the volume expansion coefficient. The calculations were performed with the ABINIT and VASP codes within the LDA approximation for exchange and correlation.

  7. Structural and elastic properties of defect chalcopyrite HgGa{sub 2}S{sub 4} under high pressure

    Energy Technology Data Exchange (ETDEWEB)

    Gomis, O., E-mail: osgohi@fis.upv.es [Centro de Tecnologías Físicas: Acústica, Materiales y Astrofísica, MALTA Consolider Team, Universitat Politècnica de València, 46022 València (Spain); Santamaría-Pérez, D. [Departamento de Física Aplicada-ICMUV, MALTA Consolider Team, Universitat de València, Edificio de Investigación, C/Dr. Moliner 50, Burjassot, 46100 València (Spain); Departamento de Química Física I, Universidad Complutense de Madrid, MALTA Consolider Team, Avenida Complutense s/n, 28040 Madrid (Spain); Vilaplana, R.; Luna, R. [Centro de Tecnologías Físicas: Acústica, Materiales y Astrofísica, MALTA Consolider Team, Universitat Politècnica de València, 46022 València (Spain); Sans, J.A.; Manjón, F.J. [Instituto de Diseño para la Fabricación y Producción Automatizada, MALTA Consolider Team, Universitat Politècnica de València, 46022 València (Spain); Errandonea, D. [Departamento de Física Aplicada-ICMUV, MALTA Consolider Team, Universitat de València, Edificio de Investigación, C/Dr. Moliner 50, Burjassot, 46100 València (Spain); and others

    2014-01-15

    Highlights: • Single crystals of HgGa{sub 2}S{sub 4} with defect-chalcopyrite (DC) structure were synthesized. • High-pressure X-ray diffraction in DC-HgGa{sub 2}S{sub 4} was performed. • Equation of state of DC-HgGa{sub 2}S{sub 4} determined (bulk modulus of 48.4 GPa). • Calculated elastic constants of DC-HgGa{sub 2}S{sub 4} reported at different pressures. • DC-HgGa{sub 2}S{sub 4} becomes mechanically unstable above 13.8 GPa. -- Abstract: In this work, we focus on the study of the structural and elastic properties of mercury digallium sulfide (HgGa{sub 2}S{sub 4}) at high pressures. This compound belongs to the family of AB{sub 2}X{sub 4} ordered-vacancy compounds and exhibits a tetragonal defect chalcopyrite structure. X-ray diffraction measurements at room temperature have been performed under compression up to 15.1 GPa in a diamond anvil cell. Our measurements have been complemented and compared with ab initio total energy calculations. The axial compressibility and the equation of state of the low-pressure phase of HgGa{sub 2}S{sub 4} have been experimentally and theoretically determined and compared to other related ordered-vacancy compounds. The pressure dependence of the theoretical cation–anion and vacancy-anion distances and compressibilities in HgGa{sub 2}S{sub 4} are reported and discussed in comparison to other related ordered-vacancy compounds. Finally, the pressure dependence of the theoretical elastic constants and elastic moduli of HgGa{sub 2}S{sub 4} has been studied. Our calculations indicate that the low-pressure phase of HgGa{sub 2}S{sub 4} becomes mechanically unstable above 13.8 GPa.

  8. Microwave heating synthesis and formation mechanism of chalcopyrite structured CuInS{sub 2} nanorods in deep eutectic solvent

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jianjun, E-mail: zhangjianjun7110@163.com; Chen, Jun; Li, Qiang

    2015-03-15

    Graphical abstract: Chalcopyrite structured CuInS{sub 2} nanorods were synthesized by an environmentally friendly microwave heating method in deep eutectic solvent. Results show that microwave heating time plays an important role in the formation of CuInS{sub 2} nanostructure phase. The SEM results indicated that the obtained CuInS{sub 2} nanostructures display rod-like morphology with diameters of about 40 nm and lengths of about 400 nm. The UV–vis spectrum results indicated that the CuInS{sub 2} nanorods exhibit strong absorption from the entire visible light region to the near-infrared region beyond 1100 nm. The possible growth mechanism of CuInS{sub 2} nanorods was discussed. - Abstract: Chalcopyrite structured CuInS{sub 2} nanorods were synthesized by an environmentally friendly microwave heating method in deep eutectic solvent. The as-synthesized CuInS{sub 2} nanorods were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS), respectively. The results indicated that the obtained CuInS{sub 2} nanostructures display rod-like morphology with diameters of about 40 nm and lengths of about 400 nm. The influences of microwave heating time on the formation of CuInS{sub 2} phase were discussed. Ultraviolet–visible (UV–vis) and photoluminescence (PL) spectra were utilized to investigate the optical properties of CuInS{sub 2} nanorods. The results showed that the as-synthesized CuInS{sub 2} nanorods exhibit strong absorption from the entire visible light region to the near-infrared region beyond 1100 nm. PL spectrum of the as-synthesized CuInS{sub 2} nanorods displays an emission peak centered at 580 nm under excitation wavelength of 366 nm at room temperature. The possible growth mechanism of CuInS{sub 2} nanorods was discussed.

  9. Microwave heating synthesis and formation mechanism of chalcopyrite structured CuInS2 nanorods in deep eutectic solvent

    International Nuclear Information System (INIS)

    Graphical abstract: Chalcopyrite structured CuInS2 nanorods were synthesized by an environmentally friendly microwave heating method in deep eutectic solvent. Results show that microwave heating time plays an important role in the formation of CuInS2 nanostructure phase. The SEM results indicated that the obtained CuInS2 nanostructures display rod-like morphology with diameters of about 40 nm and lengths of about 400 nm. The UV–vis spectrum results indicated that the CuInS2 nanorods exhibit strong absorption from the entire visible light region to the near-infrared region beyond 1100 nm. The possible growth mechanism of CuInS2 nanorods was discussed. - Abstract: Chalcopyrite structured CuInS2 nanorods were synthesized by an environmentally friendly microwave heating method in deep eutectic solvent. The as-synthesized CuInS2 nanorods were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS), respectively. The results indicated that the obtained CuInS2 nanostructures display rod-like morphology with diameters of about 40 nm and lengths of about 400 nm. The influences of microwave heating time on the formation of CuInS2 phase were discussed. Ultraviolet–visible (UV–vis) and photoluminescence (PL) spectra were utilized to investigate the optical properties of CuInS2 nanorods. The results showed that the as-synthesized CuInS2 nanorods exhibit strong absorption from the entire visible light region to the near-infrared region beyond 1100 nm. PL spectrum of the as-synthesized CuInS2 nanorods displays an emission peak centered at 580 nm under excitation wavelength of 366 nm at room temperature. The possible growth mechanism of CuInS2 nanorods was discussed

  10. Evidence for the existence of two electronic states in the chalcopyrite-type alloys CuFe(S1-zSez)2

    International Nuclear Information System (INIS)

    Results of Moessbauer spectroscopy for the chalcopyrite-type of alloys CuFe(S1-zSez)2 in the range of composition 0 ≤ z ≤ 0.45 are presented. Room temperature spectra show two contributions: one is a magnetic spectrum (six lines) with a value of the hyperfine field near to that of chalcopyrite (z = 0, in which an antiferromagnetic order occurs below T = 823 K), the other having only one line. The relative area of the single-line contribution increases as z increases. For z = 0.2, we also made Moessbauer measurements as a function of temperature. The ratio of the two contributions evolves according to a Boltzmann law, in which the single line corresponds to the excited state at 81 K above the antiferromagnetic ground state. (orig.)

  11. Defect chalcopyrite Cu(In{sub 1-x}Ga{sub x}){sub 3}Se{sub 5} (0

    Energy Technology Data Exchange (ETDEWEB)

    Contreras, M.A.; Wiesner, H.; Niles, D.; Ramanathan, K.; Matson, R. [National Renewable Energy Lab., Golden, CO (United States)] [and others

    1996-05-01

    Crystallographic, optical, and electrical properties of defect chalcopyrite Cu(In{sub 1{minus}x}Ga{sub x}){sub 3}Se{sub 5} (0chalcopyrite CuIn{sub 1 {minus}x}Ga{sub x}Se{sub 2} absorber materials is presented. Considering the chalcopyrite/defect chalcopyrite junction model, the authors postulate that the traditionally poor device performance of uniform high-Ga-content absorbers (x>0.3) is due to a relatively inferior character - both structural and electrical - at the very chalcopyrite/defect chalcopyrite interface. They demonstrate that this situation can be circumvented (for absorbers with x>0.3) by properly engineering such an interface by reducing Ga content in the region near the surface of the absorber.

  12. Electronic structure of epitaxial chalcopyrite surfaces and interfaces for photovoltaics; Elektronische Struktur epitaktischer Chalkopyrite und deren Heterokontakte fuer die Photovoltaik

    Energy Technology Data Exchange (ETDEWEB)

    Hofmann, Andreas

    2012-02-14

    This thesis constitutes a comprehensive study of the surface physics of epitaxial CuInSe{sub 2} films. It comprises analyses of the surface morphology and reconstruction, electronic band structure as well as hetero-junctions relevant to photovoltaic applications. Therefore, especially the aspect of stoichiometry variation from the CuInSe{sub 2} to the copper-deficient defect phases was considered. Preparation and analysis was completely performed under ultra-high vacuum conditions in order to ensure the investigation of well-defined samples free of contaminants. For some of the analysis techniques, single-crystalline samples are indispensable: They allow for the determination of surface periodicity by low-energy electron diffraction (LEED). In combination with concentration depth profiling by angle-resolved x-ray photoemission, to types of surface reconstructions could be distinguished for the near-stoichiometric CuInSe{sub 2}(112) surface. In the copper-rich case, it is stabilized by Cu{sub In} anti-site defects and on the indium-rich side by 2 V{sub Cu} defects, as predicted by surface total energy calculations by Jaffe and Zunger. Both configurations correspond to a c(4 x 2) reconstruction of the zinc blende type (111) surface. For the defect compound CuIn{sub 3}Se{sub 5}, a sphalerite order of the surface was found, which points at a weakening or absence of the chalcopyrite order in the bulk of the material. The unusual stability of the (112) surface could also be proven by comparison with the reconstruction and surface order of (001) and (220) surfaces. The results from surface analysis were used to measure the valence band structure of the epitaxial samples by synchrotron-based angle-resolved photoelectron spectroscopy. The CuInSe{sub 2}(001) surface gives access to the high symmetry directions {Gamma}-T and {Gamma}-N of momentum space. By contrasting the data obtained for the stoichiometric surface with the copper-poor defect compound, a reduction of the

  13. Synthesis and Characterization of the First Liquid Single Source Precursors for the Deposition of Ternary Chalcopyrite (CuInS2) Thin Film Materials

    Science.gov (United States)

    Banger, Kulbinder K.; Cowen, Jonathan; Hepp, Aloysius

    2002-01-01

    Molecular engineering of ternary single source precursors based on the [{PBu3}2Cu(SR')2In(SR')2] architecture have afforded the first liquid CIS ternary single source precursors (when R = Et, n-Pr), which are suitable for low temperature deposition (liquid phase and reduced stability. X-ray diffraction studies, energy dispersive analyzer (EDS), and scanning electron microscopy (SEM) support the formation of the single-phase chalcopyrite CuInS2 at low temperatures.

  14. Scientific communications: Re-Os sulfide (bornite, chalcopyrite, and pyrite) systematics of the carbonate-hosted copper deposits at ruby creek, southern brooks range, Alaska

    Science.gov (United States)

    Selby, D.; Kelley, K.D.; Hitzman, M.W.; Zieg, J.

    2009-01-01

    New Re-Os data for chalcopyrite, bornite, and pyrite from the carbonate-hosted Cu deposit at Ruby Creek (Bornite), Alaska, show extremely high Re abundances (hundreds of ppb, low ppm) and contain essentially no common Os. The Re-Os data provide the first absolute ages of ore formation for the carbonate-hosted Ruby Creek Cu-(Co) deposit and demonstrate that the Re-Os systematics of pyrite, chalcopyrite, and bornite are unaffected by greenschist metamorphism. The Re-Os data show that the main phase of Cu mineralization pre dominantly occurred at 384 ?? 4.2 Ma, with an earlier phase possibly at ???400 Ma. The Re-Os data are consistent with the observed paragenetic sequence and coincide with zircon U-Pb ages from igneous rocks within the Ambler metallogenic belt, some of which are spatially and genetically associated with regional volcanogenic massive sulfide deposits. The latter may suggest a temporal link between regional magmatism and hydrothermal mineralization in the Ambler district. The utility of bornite and chalcopyrite, in addition to pyrite, contributes to a new understanding of Re-Os geochronology and permits a refinement of the genetic model for the Ruby Creek deposit. ?? 2009 Society of Economices Geologists, Inc.

  15. Attachment of Acidithiobacillus ferrooxidans and Leptospirillum ferriphilum cultured under varying conditions to pyrite, chalcopyrite, low-grade ore and quartz in a packed column reactor.

    Science.gov (United States)

    Africa, Cindy-Jade; van Hille, Robert P; Harrison, Susan T L

    2013-02-01

    The attachment of Acidithiobacillus ferrooxidans and Leptospirillum ferriphilum spp. grown on ferrous medium or adapted to a pyrite mineral concentrate to four mineral substrata, namely, chalcopyrite and pyrite concentrates, a low-grade chalcopyrite ore (0.5 wt%) and quartzite, was investigated. The quartzite represented a typical gangue mineral and served as a control. The attachment studies were carried out in a novel particle-coated column reactor. The saturated reactor containing glass beads, which were coated with fine mineral concentrates, provided a quantifiable surface area of mineral concentrate and maintained good fluid flow. A. ferrooxidans and Leptospirillum spp. had similar attachment characteristics. Enhanced attachment efficiency occurred with bacteria grown on sulphide minerals relative to those grown on ferrous sulphate in an ore-free environment. Selective attachment to sulphide minerals relative to gangue materials occurred, with mineral adapted cultures attaching to the minerals more efficiently than ferrous grown cultures. Mineral-adapted cultures showed highest levels of attachment to pyrite (74% and 79% attachment for A. ferrooxidans and L. ferriphilum, respectively). This was followed by attachment of mineral-adapted cultures to chalcopyrite (63% and 58% for A. ferrooxidans and L. ferriphilum, respectively). A. ferrooxidans and L. ferriphilum exhibited lower levels of attachment to low-grade ore and quartz relative to the sulphide minerals. PMID:22410741

  16. Effect of Nanostructuring and High-Pressure Torsion Process on Thermal Conductivity of Carrier-Doped Chalcopyrite

    Science.gov (United States)

    Tsujii, Naohito; Meng, Fanqiang; Tsuchiya, Koich; Maruyama, Satofumi; Mori, Takao

    2016-03-01

    Carrier-doped chalcopyrite (CuFeS2) has been shown to exhibit a high power factor exceeding 1 mW/K2-m at room temperature. However, it has a relatively high thermal conductivity of 6 W/K-m in this temperature range. To reduce the thermal conductivity, nanostructuring by a ball-milling process and the high-pressure torsion (HPT) method have been applied to Zn0.03Cu0.97FeS2. While ball milling yielded a fine powder specimen with crystal grain size of about 20 nm, a subsequent synthesis process using spark plasma sintering at 720 K for 2 min caused crystal grain regrowth. The thermal conductivity of the ball-milled and spark-plasma-sintered sample was similar to that of a bulk sample above room temperature. The HPT-treated sample showed a significant drop in thermal conductivity over the entire temperature range. However, the electrical resistivity increased, resulting in a degradation of the overall thermoelectric performance. Annealing at 520 K after HPT was partly effective in recovering the electrical conductivity while retaining low thermal conductivity.

  17. Spectroscopic ellipsometry studies of In2S3 top window and Mo back contacts in chalcopyrite photovoltaics technology

    International Nuclear Information System (INIS)

    Spectroscopic ellipsometry (SE) was used to characterize the conventional back contact layer (Mo) as well as a novel top window layer (In2S3) for use in chalcopyrite photovoltaics technology. For the Mo back contact, in-situ SE measurements of thin films magnetron sputtered onto glass enabled determination of ε at different thicknesses during growth. The observed strong variations could be understood on the basis of a Drude relaxation time that varies with the Mo film thickness. For the In2S3 window layer, ex-situ SE measurements showed critical point structures at 2.77±0.08 eV, 4.92±0.005 eV, and 5.64±0.005 eV, as well as an absorption tail with an onset near 1.9 eV. A comparison of the solar cell performance in simulations using either In2S3 or conventional CdS revealed similar quantum efficiencies irrespective of the selected window layer. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  18. 黄铜矿硫化焙烧及氧压酸浸研究%Research on Oxygen Pressure Acid Leaching of Sulfidized Chalcopyrite

    Institute of Scientific and Technical Information of China (English)

    叶钟林; 施哲; 史谊峰; 张邦琪; 代红坤

    2014-01-01

    The special crystal structure of chalcopyrite makes it difficult to be leached in sulfuric acid system. Sulfidation roast process is studied in the present paper which transforms the chemical composition and structure of chalcopyrite into simple sulfides,which are more amenable to leaching.Both of the chalcopyrite and its sulfi-dation products are then leached for the extraction of copper in an appropriate leaching system.The results show that only covellite and pyrite could be found in the sulfidation product after being roasted for 60 min at 350 ℃which suggests nearly complete conversion of chalcopyrite.The leaching rate of copper from chalcopyrite and its sulfidation product,with leaching temperature of 150 ℃,time 120 min,oxygen partial pressure 0.5 MPa,stir-ring speed 700 r/min,and sulfuric acid 0.1 M,is 45% and 98%,respectively.The dissolve performance of chalcopyrite can be greatly improved by sulfidation roast.The results will provide theoretical instruction and tech-nological supports for industrializing application of chalcopyrite hydrometallurgy.%黄铜矿因其特殊的晶体结构在硫酸体系中较难溶解,采用硫化焙烧法使黄铜矿(CuFeS2)由复杂矿物组成及结构转变为易酸溶的简单硫化物(CuS,FeS2),并对黄铜矿及其硫化焙烧产物进行氧压酸浸对比实验研究.研究结果表明:350℃下黄铜矿与硫磺硫化焙烧60 min后,硫化焙烧反应进行的比较完全,焙烧产物中只有铜蓝CuS 和黄铁矿FeS2;当浸出温度为150℃、时间为120 min、氧分压为0.5 MPa、搅拌转速为700 r/min、木质磺酸钠为5 g/kg,液固比为7∶1,硫酸浓度为0.1 mol/L时,黄铜矿及硫化焙烧产物中铜的浸出率分别为45%和98%,经硫化焙烧后可显著改善黄铜矿在氧压酸浸过程中的溶解性能,为黄铜矿湿法冶炼工艺的工业化生产提供理论指导和技术支撑.

  19. Structural, elastic, electronic, bonding, and optical properties of BeAZ2 (A = Si, Ge, Sn; Z = P, As) chalcopyrites

    International Nuclear Information System (INIS)

    A first principles density functional theory (DFT) technique is used to study the structural, chemical bonding, electronic and optical properties of BeAZ2 (A = Si, Ge, Sn; Z = P, As) chalcopyrite materials. The calculated parameters are in good agreement with the available experimental results. The lattice constants and the equilibrium volume increased as we moved from Si to Ge to Sn, whereas the c/a and internal parameters u decreased by shifting the cation from P to As. These compounds are elastically stable. An investigation of the band gap using the WC-GGA, EV-GGA, PBE-GGA and mBJ-metaGGA potentials suggested that BeSiP2 and BeSiAs2 are direct band gap compounds, whereas BeGeP2, BeGeAs2, BeSnP2, BeSnAs2 are indirect band gap compounds. The energy band gaps decreased by changing B from Si to Sn and increased by changing the anion C from P to As. The bonding among the cations and anions is primarily ionic. In the optical properties, the real and imaginary parts of the dielectric functions, reflectivity and optical conductivity have been studied over a wide energy range. - Highlights: • The compounds are studied by FP-LAPW method within mBJ approximation. • All of the studied materials show isotropic behaviour. • All the compounds show direct band gap nature. • Bonding nature is mostly covalent among the studied compounds. • High absorption peaks and reflectivity ensures there utility in optoelectronic devices

  20. A Study of the Effect of Djurliete, Bornite and Chalcopyrite during the Dissolution of Gold with a Solution of Ammonia-Cyanide

    Directory of Open Access Journals (Sweden)

    Mike Fulton

    2012-11-01

    Full Text Available The high solubility of copper sulphide minerals is an issue in the cyanidation of gold ores. The objective of this study was to quantify the effect of individual copper sulphide minerals on the Hunt process, which showed advantages over cyanidation. High purity djurleite, bornite and chalcopyrite, with a P70 of 70–74 microns, were mixed with fine quartz and gold powder (3–8 micron to obtain a copper concentration of 0.3%. The ammonia-cyanide leaching of slurry with djurleite proved to be more effective than cyanidation; producing comparable extraction of gold (99%, while reducing the cyanide consumption from 5.8 to 1.2 kg/t NaCN. Lead nitrate improved the Hunt leaching. The lower cyanide consumption is associated to a significant reduction of copper dissolved. XPS surface analysis of djurleite showed that lead nitrate favored the formation of Cu(OH2 species. Lead was also detected on the surface (oxide or hydroxide. Sulphide and copper compounds (cyanide and sulphide were reaction products responsible for inhibiting the dissolution of gold. Lead nitrate added in the Hunt leaching of bornite produced 99% gold extraction. Surface reaction products were similar to djurleite. The cyanide consumption (~4.4 kg/t NaCN was not reduced by the addition of ammonia. Cyanidation of chalcopyrite showed a lower consumption of cyanide 0.33 kg/t NaCN compared to 0.21 kg/t NaCN for Hunt. No significant interferences were observed in gold leaching with a slurry containing chalcopyrite.

  1. Computational materials design of negative effective U system in hole-doped chalcopyrite CuFeS2

    International Nuclear Information System (INIS)

    A general rule of negative effective U(Ueff) system caused by (i) exchange correlation and (ii) charge excitation mechanisms is proposed. Based on the general rule, we perform ab initio electronic structure calculations by generalized gradient approximation (GGA) + U method for hole-doped chalcopyrite CuFeS2 [Cu+(d10)Fe3+(d5)S2−(s2p6)2]. It is found from our calculations that the hole-doped CuFeS2 has the negative Ueff = −0.44 eV, where Ueff ≡ E(N + 1) + E(N − 1) − 2E(N) 2. The negative Ueff is caused by the charge-excitation in the hole-doped Cu2+(d9) and S−(s2p5), and also caused by the exchange-correlation in the hole-doped Fe4+(d4). The strong attractive electron–electron interaction (Ueff = −0.44 eV ∼ −5000 K) originates from the purely electronic mechanism. The closed shell of the d10 electronic configuration is more stable than the d9 electronic configuration, since the first excited state with the d9s1 electronic configuration and the ground state with the d10 electronic configuration are very close, then these two states repel very strongly through the second order perturbation. Therefore, the spin-polarized total energy curve for the hole-doped CuFeS2 shows the strong upward convexity with N − 1, N and N + 1 electronic configurations leading to the negative Ueff. The hole-doped paramagnetic and metallic CuFeS2 with the negative Ueff may cause a possible high-Tc superconductor (Tc ∼ 1000 K, if 2Δ/kBTc ≈ 10 by assuming a strong coupling regime) because of the strong attractive electron–electron interactions (superconducting gap Δ ≈ |Ueff| ∼ 5000 K). Finally, we propose a new computational materials design methodology to design ultra high-Tc superconductors by using three steps starting from the atomic number only. (paper)

  2. Expression of Critical Sulfur- and Iron-Oxidation Genes and the Community Dynamics During Bioleaching of Chalcopyrite Concentrate by Moderate Thermophiles.

    Science.gov (United States)

    Zhou, Dan; Peng, Tangjian; Zhou, Hongbo; Liu, Xueduan; Gu, Guohua; Chen, Miao; Qiu, Guanzhou; Zeng, Weimin

    2015-07-01

    Sulfate adenylyltransferase gene and 4Fe-4S ferredoxin gene are the key genes related to sulfur and iron oxidations during bioleaching system, respectively. In order to better understand the bioleaching and microorganism synergistic mechanism in chalcopyrite bioleaching by mixed culture of moderate thermophiles, expressions of the two energy metabolism genes and community dynamics of free and attached microorganisms were investigated. Specific primers were designed for real-time quantitative PCR to study the expression of these genes. Real-time PCR results showed that sulfate adenylyltransferase gene was more highly expressed in Sulfobacillus thermosulfidooxidans than that in Acidithiobacillus caldus, and expression of 4Fe-4S ferredoxin gene was higher in Ferroplasma thermophilum than that in S. thermosulfidooxidans and Leptospirillum ferriphilum. The results indicated that in the bioleaching system of chalcopyrite concentrate, sulfur and iron oxidations were mainly performed by S. thermosulfidooxidans and F. thermophilum, respectively. The community dynamics results revealed that S. thermosulfidooxidans took up the largest proportion during the whole period, followed by F. thermophilum, A. caldus, and L. ferriphilum. The CCA analysis showed that 4Fe-4S ferredoxin gene expression was mainly affected (positively correlated) by high pH and elevated concentration of ferrous ion, while no factor was observed to prominently influence the expression of sulfate adenylyltransferase gene. PMID:25941022

  3. Manganese-doped CdGeAs2, ZnGeAs2 and ZnSiAs2 chalcopyrites: A new materials for spintronics

    International Nuclear Information System (INIS)

    Based on Mn-doped chalcopyrites CdGeAs2, ZnGeAs2 and ZnSiAs2 the new dilute magnetic semiconductors with p-type conductivity were produced. Magnetization, electrical resistivity, magnetoresistance and Hall effect of mentioned compositions were studied. Their curves of temperature dependence of magnetization have the similar form in spite of complicated character, for which the concentration and mobility of the charge carriers are responsible. Thus, for T15 K for a frustrated ferromagnetics. In compounds with Zn these two states dilute by spinglass-like state. This specific feature is assigned to an attraction of Mn ions occupying neighboring sites and to the competition between the carrier-mediated exchange and superexchange interactions. Curie temperatures of these compounds are above room temperature. These are the highest Curie temperatures in the AIIBIVCV2:Mn systems. - Highlights: → We received and studied a new spintronics materials those are manganese-doped CdGeAs2, ZnGeAs2 and ZnSiAs2 chalcopyrites. → Their Curie points are higher than room temperature. → These new spintronics materials are nonhomogeneous magnetics.

  4. Optimization of staged bioleaching of low-grade chalcopyrite ore in the presence and absence of chloride in the irrigating lixiviant: ANFIS simulation.

    Science.gov (United States)

    Vakylabad, Ali Behrad; Schaffie, Mahin; Naseri, Ali; Ranjbar, Mohammad; Manafi, Zahra

    2016-07-01

    In this investigation, copper was bioleached from a low-grade chalcopyrite ore using a chloride-containing lixiviant. In this regard, firstly, the composition of the bacterial culture media was designed to control the cost in commercial application. The bacterial culture used in this process was acclimated to the presence of chloride in the lixiviant. Practically speaking, the modified culture helped the bio-heap-leaching system operate in the chloridic media. Compared to the copper recovery from the low-grade chalcopyrite by bioleaching in the absence of chloride, bioleaching in the presence of chloride resulted in improved copper recovery. The composition of the lixiviant used in this study was a modification with respect to the basal salts in 9 K medium to optimize the leaching process. When leaching the ore in columns, 76.81 % Cu (based on solid residues of bioleaching operation) was recovered by staged leaching with lixiviant containing 34.22 mM NaCl. The quantitative findings were supported by SEM/EDS observations, X-ray elemental mapping, and mineralogical analysis of the ore before and after leaching. Finally, Adaptive neuro-fuzzy inference system (ANFIS) was used to simulate the operational parameters affecting the bioleaching operation in chloride-sulfate system. PMID:27000968

  5. In situ monitoring the growth of thin-film ZnS/Zn (S,O) bilayer on Cu-chalcopyrite for high performance thin film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Saez-Araoz, R.; Abou-Ras, D. [Helmholtz-Zentrum Berlin fuer Materialien und Energie GmbH, Solar Energy Division, Glienicker Strasse 100, 14109 Berlin (Germany); Niesen, T.P. [AVANCIS GmbH and Co KG Otto-Hahn-Ring 6, 81739 Munich (Germany); Neisser, A.; Wilchelmi, K. [SULFURCELL Solartechnik GmbH Barbara-McClintock-Strasse 11, 12489 Berlin (Germany); Lux-Steiner, M.Ch. [Helmholtz-Zentrum Berlin fuer Materialien und Energie GmbH, Solar Energy Division, Glienicker Strasse 100, 14109 Berlin (Germany); Ennaoui, A. [Helmholtz-Zentrum Berlin fuer Materialien und Energie GmbH, Solar Energy Division, Glienicker Strasse 100, 14109 Berlin (Germany)], E-mail: ennaoui@helmholtz-berlin.de

    2009-02-02

    This paper highlights the crucial role that the control of the chemical bath deposition (CBD) process plays for buffer production of Cu-chalcopyrite solar-cell devices. ZnS/Zn (S,O) bilayer was deposited on CuInS{sub 2} (CIS) and Cu(In,Ga)(SSe){sub 2} (CIGSSe) and monitored using turbidity measurements of the solution. The results were correlated to the X-ray photoemission spectra of the samples obtained by interruption of the process at sequential stages. Two different feature regimes were distinguished: In the first stage, a heterogeneous reaction takes place on the absorber resulting in the formation of pure ZnS. The second stage of the process is homogeneous, and the in-situ turbidity measurement shows a loss in the transmission of light through the CBD solution. The measured ZnL3M45M45 Auger-peaks, during this second stage of the process, show a shift of the kinetic energy from pure ZnS to a solid-solution ZnS/ZnO ('Zn (S,O)') with decreasing amount of sulfur. These results are supported by the observations from Energy-filtered transmission electron microscopy. This paper also demonstrates that monitoring of the CBD process combined with the basic understanding using surface and interface analysis have contributed to improve the reproducibility and to enhance the photovoltaic performance of Cu-chalcopyrite thin-film solar modules.

  6. In situ monitoring the growth of thin-film ZnS/Zn (S,O) bilayer on Cu-chalcopyrite for high performance thin film solar cells

    International Nuclear Information System (INIS)

    This paper highlights the crucial role that the control of the chemical bath deposition (CBD) process plays for buffer production of Cu-chalcopyrite solar-cell devices. ZnS/Zn (S,O) bilayer was deposited on CuInS2 (CIS) and Cu(In,Ga)(SSe)2 (CIGSSe) and monitored using turbidity measurements of the solution. The results were correlated to the X-ray photoemission spectra of the samples obtained by interruption of the process at sequential stages. Two different feature regimes were distinguished: In the first stage, a heterogeneous reaction takes place on the absorber resulting in the formation of pure ZnS. The second stage of the process is homogeneous, and the in-situ turbidity measurement shows a loss in the transmission of light through the CBD solution. The measured ZnL3M45M45 Auger-peaks, during this second stage of the process, show a shift of the kinetic energy from pure ZnS to a solid-solution ZnS/ZnO ('Zn (S,O)') with decreasing amount of sulfur. These results are supported by the observations from Energy-filtered transmission electron microscopy. This paper also demonstrates that monitoring of the CBD process combined with the basic understanding using surface and interface analysis have contributed to improve the reproducibility and to enhance the photovoltaic performance of Cu-chalcopyrite thin-film solar modules

  7. Re-Os sulfide (chalcopyrite, pyrite and molybdenite) systematics and fluid inclusion study of the Duobaoshan porphyry Cu (Mo) deposit, Heilongjiang Province, China

    Science.gov (United States)

    Liu, Jun; Wu, Guang; Li, Yuan; Zhu, Mingtian; Zhong, Wei

    2012-04-01

    The Duobaoshan porphyry deposit, located in the northwestern part of the Lesser Hinggan Range, is one of the biggest porphyry Cu (Mo) deposits in the Central Asian orogenic belt in China. The Duobaoshan porphyry deposit occurs in granodiorite and volcanic rocks of the Middle Ordovician Duobaoshan Formation. Six types of veins have been identified in three ore-forming stages as follows: a quartz-potassic feldspar vein in the early ore-forming stage, an early stage quartz-molybdenite vein, late stage quartz-molybdenite and quartz-chalcopyrite-pyrite veins in the middle ore-forming stage, and quartz-pyrite and calcite-quartz veins in the late ore-forming stage. The following four types of fluid inclusions are distinguished from various quartz veins: two-phase aqueous, pure gas phase, CO2-bearing and daughter mineral-bearing inclusions. The ore-forming fluid for the early ore-forming stage belongs to the H2O-CO2-NaCl system, which is characterized by high temperatures (>550 °C), intermediate salinities (16.2-18.1 wt% NaCl eqv.) and high CO2 content. The ore-forming fluid from the middle ore-forming stage evolved to the H2O-CO2-NaCl system, which is characterized by intermediate to high temperatures (230-450 °C) and high/low salinities (0.8 to >65.3 wt% NaCl eqv.) and is also rich in CO2 and metals. The ore-forming fluid finally reached cool temperatures (110-200 °C), low salinities (3.9-8.4 wt% NaCl eqv.) and was CO2-poor. Intensive fluid immiscibility or boiling occurred when the ore-forming fluid with temperatures of 230-450 °C and pressures of 10-41 MPa ascended to 4.1 km, inducing the escape of CO2, depressing the solubility of fluid, and depositing abundant metal sulfides. The total Re and Os concentrations of chalcopyrite and pyrite range from 0.15 to 2.95 μg/g and 0.74 to 15.01 ng/g, respectively. Analyses of seven chalcopyrite and pyrite samples yielded isochron ages of 482-486 Ma, and the model age of one molybdenite sample is 485.6 ± 3.7 Ma. The

  8. First and second harmonic generation of the XAl{sub 2}Se{sub 4} (X=Zn,Cd,Hg) defect chalcopyrite compounds

    Energy Technology Data Exchange (ETDEWEB)

    Ouahrani, Tarik, E-mail: tarik_ouahrani@yahoo.fr [Laboratoire de Physique Theorique, Universite de Tlemcen, B.P.230,13000 Tlemcen (Algeria); Ecole Preparatoire en Sciences et Techniques, Depertement de Physique EPST-T, Tlemcen 13000 (Algeria); Khenata, R. [Laboratoire de Physique Quantique et de Modelisation Mathematique (LPQ3M), Universite de Mascara, 29000 Mascara (Algeria); Lasri, B. [Laboratoire de Physique Theorique, Universite de Tlemcen, B.P.230,13000 Tlemcen (Algeria); Universite Dr Tahar Moulay de Saida, B.P. 138, Cite el Nasr, Saida 20000 (Algeria); Reshak, Ali H. [School of Complex systems, FFPW- South Bohemia University, Nove Hrady 37333 (Czech Republic); School of Material Engineering, Malaysia University of Perlis, P.O Box 77, d/a Pejabat Pos Besar, 01007 Kangar, Perlis (Malaysia); Bouhemadou, A. [Department of Physics, Faculty of Sciences, University of Setif, 19000 Setif (Algeria); Bin-Omran, S. [Department of Physics and Astronomy, Faculty of Science, King Saud University, P.O. Box 2455, Riyadh 11451 (Saudi Arabia)

    2012-09-15

    The chemical bonding of the ZnAl{sub 2}Se{sub 4}, CdAl{sub 2}Se{sub 4} and HgAl{sub 2}Se{sub 4} defect chalcopyrites has been studied in the framework of the quantum theory of atoms in molecules (AIM). The GW quasi-particle approximation is used to correct the DFT-underestimation of energy gap, and as a consequence the linear and nonlinear optical properties are significantly enhanced. The second harmonic generation (SHG) displays certain dependence with the ionicity degree decrease through the dependency of the SHG on the band gap. The occurrence of the AIM saddle point is characterized and some clarifying features in relationship with the density topology are exposed, which enable to understand the relation with the second harmonic generation effect.

  9. Effects of post-heat treatment on the characteristics of chalcopyrite CuInSe2 film deposited by successive ionic layer absorption and reaction method

    International Nuclear Information System (INIS)

    The influence of annealing effects in CuInSe2 ternary films prepared by successive ionic layer absorption and reaction method has been investigated. The films have firstly been deposited on glass substrates at room temperature and then heat-treated under Ar atmosphere at various annealing temperatures. CuInSe2 films were characterized using X-ray diffraction (XRD), scanning electron microscopy, X-ray photoelectron spectra, optical absorption spectrum and Hall system. XRD results showed that the proper post-annealing process can lead to a complete formation of chalcopyrite structure CuInSe2 with high degree of preferred orientation towards (112) reflection. After annealing process, the composition of annealed films was close to the standard stoichiometry and O, Cl impurities decreased. The direct band gap increased from 0.94 to 0.98 eV and resistivity showed a big decrease with the increase of annealing temperature

  10. Lattice dynamics of chalcopyrite semiconductors LiAlTe{sub 2},LiGaTe{sub 2} and LiInTe{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Kosobutsky, A.V.; Basalaev, Yu.M.; Poplavnoi, A.S. [Physics Faculty, Kemerovo State University (Russian Federation)

    2009-02-15

    Within density functional perturbation theory using norm-conserving pseudopotentials and a plane-wave basis set calculations of phonon dispersion relations and densities of states of LiAlTe{sub 2}, LiGaTe{sub 2} and LiInTe{sub 2} compounds being crystallized into the tetragonal chalcopyrite structure have been performed. Theoretical values of phonon mode frequencies in LiGaTe{sub 2} and LiInTe{sub 2} are in good agreement with the experimental data available for these crystals obtained by the methods of Raman and infrared spectroscopies. The similarity of the physical and chemical properties of the crystals concerned manifests itself in the similarity of their phonon spectra that are especially close to each other in low- and high-frequency ranges. Phonon modes of the upper phonon band are predominantly caused by the lithium sublattice vibrations and have an upper bound of 350-370 cm{sup -1}. In a mid-frequency range a significant downshift of the vibrational frequencies is observed on going from LiAlTe{sub 2} to LiGaTe{sub 2} and LiInTe{sub 2} that is a consequence of the third group cation mass reduction. From calculated electron density maps it follows that Li-containing chalcopyrites are characterized by a less pronounced bond between the first group cation and anion as compared with the Cu- and Ag-based analogs due to the absence of pd-hybridization. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  11. Synthesis of AgInSnS4 thin films by adding tin (Sn) into the chalcopyrite structure of AgInS2 using spray pyrolysis

    International Nuclear Information System (INIS)

    AgInSnS4 thin films were prepared by adding a tin salt to the starting solution used for preparing chalcopyrite AgInS2 thin films by spray pyrolysis The AgInSnS4 films were grown at substrate temperatures in the 300-400 oC range, using an alcoholic solution comprised of silver acetate, indium chloride, tin chloride and thiourea. The tin chloride content in the starting solution was gradually varied in terms of the molar ratio x = [Sn]/([S] + [Ag]) from 0 to 0.5 to obtain Sn-doped chalcopyrite AgInS2 (x 4 (x = 0.2-0.4). X-ray diffraction studies indicated that AgInSnS4 has a cubic spinel-like structure with lattice parameter of 10.77 A. All AgInSnS4 thin films exhibited p-type conduction, and their room temperature conductivity ranged from 10-1 to 10-2 S/cm. The conductivity versus 1/T plots for this material showed an Arrhenius-like behavior, from which two activation energies of Ea1 = 0.23-0.40 eV and Ea2 = 0.07-0.20 eV were determined. These results suggest that the grain boundary scattering and the ionization of shallow acceptors dominate the charge carrier transport in the sprayed AgInSnS4 thin films. The AgInSnS4 absorption spectrum revealed an energy gap around Eg = 1.89 eV, which was associated to direct-allowed transitions. To our knowledge, the quaternary compound has been prepared for the first time using spray pyrolysis.

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

    International Nuclear Information System (INIS)

    The X-ray Diffraction (XRD) technique is applied to study five samples of Cu-Ni orebodies, and it is shown that they contain chalcopyrite CuFeS2 as the source of Cu, pentlandite (Fe,Ni)9S8 as the source of Ni and pyrrhotite Fe1-xS as a dominant compound. There are also other less dominant compounds such as bunsenite NiO, chalcocite Cu2S, penrosite (Ni, Cu)Se2 and magnetite Fe3O4. Using the obtained XRD data, we obtain the lattice parameters for tetragonal chalcopyrite as a=b=5.3069A and c=10.3836A, cubic pentlandite as a=b=c=10.0487A, and hexagonal pyrrhotite as a=b=6.8820A and c=22.8037A. (author)

  13. Re-Os molybdenite, pyrite and chalcopyrite geochronology, Lupa Goldfield, SW Tanzania: Implications for metallogenic time scales and shear zone reactivation

    Science.gov (United States)

    Lawley, Christopher; Selby, David; Imber, Jonathan

    2013-04-01

    Fault zone reactivation is a well-documented deformation processes that is related, in part, to long-term fault weakening induced by fluid-rock interaction. However, the dearth of suitable geochronometers means very little data has been available to constrain the absolute timing of fault reactivation. Thus the time scales of fault processes remain unclear for most ancient fault networks. Gold occurrences in the western portion of the Lupa goldfield, SW Tanzania are associated with pyrite ± chalcopyrite ± molybdenite bearing quartz veins and a brittle-ductile shear zone network at the Tanzanian cratonic margin. The laminated appearance of auriferous quartz veins records evidence for a complex hydrothermal history which, coupled with complex relative-timing relationships between brittle and ductile deformation mechanisms within the mylonitic shear zones, suggests that these gold occurrences are best interpreted within a progressive deformation context characterized by repeated shear zone reactivation events. As a result, Au occurrences from the western Lupa goldfield are typical of the orogenic gold deposit type and represent an ideal natural laboratory to investigate the time scale of metallogenesis and shear zone processes operating at mid-crustal levels. Re-Os molybdenite, pyrite and chalcopyrite ages from five gold occurrences record a protracted hydrothermal history (1.95-1.87 Ga) comprising at least three temporally distinct sulphidation events (ca. 1.95, 1.94 and 1.88 Ga), which are each represented in detail by a complex vein history that occurred at a time scale less than the resolution of the Re-Os method. Together these Re-Os ages provide the first constraints on the absolute age of mineralization for gold occurrences in the western Lupa goldfield and also record a broad period of deformation and mineralization spanning ca. 70 Myr. This time period is also concurrent with felsic-mafic magmatic activity (1.96-1.88 Ga) and suggests mineralization

  14. Room temperature synthesis of nanostructured mixed-ordered-vacancy compounds (OVCs) and chalcopyrite CuInSe{sub 2} (CIS) thin films in alkaline chemical bath

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Ramphal [Thin Film and Nanotechnology Laboratory, Department of Physics, Dr Babasaheb Ambedkar Marathwada University, Aurangabad 431004 (India); Mane, Rajaram S; Ghule, Gangri Cai Anil; Ham, Duk-Ho; Min, Sun-Ki; Lee, Seung-Eon; Han, Sung-Hwan, E-mail: rps.phy@gmail.co, E-mail: shhan@hanyang.ac.k [Inorganic-Nanomaterials Laboratory, Department of Chemistry, Hanyang University, Sungdong-Ku, Haengdang-dong 17, Seoul 133-791 (Korea, Republic of)

    2009-03-07

    Room temperature synthesis of ordered-vacancy-compounds (OVCs) and copper indium diselenide (CuInSe{sub 2}, CIS) by cation and anion exchange reactions of solid CdS thin films with CIS ionic solution in an alkaline chemical bath is reported. The growth parameters such as pH, deposition time and concentration of the solutions were optimized to achieve uniform thin films. Nanostructured CdS thin films (150 nm thick) prepared by chemical bath deposition are used for the deposition of OVC and CIS thin films. The ion exchange reaction between the CdS thin film and the CIS ionic solutions transforms the yellow colour CdS film into faint black, indicating the formation of OVC and CIS film. The resultant films were annealed in air at 200 deg. C for 1 h and further subjected to characterization using the x-ray diffraction, transmission electron microscopy, energy dispersive x-ray analysis, x-ray photoelectron spectroscopy, scanning electron microscopy, atomic force microscopy, optical absorption and electrical measurement techniques. The OVC and CuIn{sub 3}Se{sub 5} nanodomains are observed in chalcopyrite CIS thin films and these films have nanostructured morphology onto amorphous/nanocrystalline phase of CdS. The OVC-CIS films are p-type with a band gap energy of 1.453 eV.

  15. The dry and damp heat stability of chalcopyrite solar cells prepared with an indium sulfide buffer deposited by the spray-ILGAR technique

    International Nuclear Information System (INIS)

    Cadmium free chalcopyrite solar cells based upon industrial Cu(In,Ga)(S,Se)2 absorber films with indium sulfide buffer layers deposited by the Spray-ILGAR technique have recently achieved certified efficiencies of 14.7%. Here we report for the first time on the stability of these cells. The cells were subjected to dry and damp heat conditions of 85 deg. C and 85% humidity for 100 h without encapsulation. The resulting cell parameters are measured and compared to cells prepared using a standard cadmium sulfide layer deposited by chemical bath deposition. Two different zinc oxide window processes were used for both buffers and the effect of changing the zinc oxide process is discussed. Before the damp heat tests, using an rf-sputtered zinc oxide process the indium sulfide buffers have an efficiency equal to the cadmium sulfide buffered cells and when using a second rf/dc-sputtered zinc oxide process a superior efficiency is obtained with the indium sulfide. The biggest loss in efficiency after damp heat testing is shown to arise from shunt paths at the scribe lines. The indium sulfide buffered cells degrade by only 11% under damp heat conditions when measured after rescribing. A difference between the cell efficiencies using two different zinc oxide windows highlights the interdependence of the process steps

  16. Electronic structure of semiconductor thin films (chalcopyrites) as absorbermaterials for thin film solar cells; Elektronische Struktur duenner Halbleiterfilme (Chalkopyrite) als Absorbermaterialien fuer Duennschichtsolarzellen

    Energy Technology Data Exchange (ETDEWEB)

    Lehmann, Carsten

    2007-12-11

    The objective of this work was to determine for the first time the band structure of CuInS{sub 2}. For this purpose a new GSMBE process with TBDS as sulphur precursor was established to prevent the use of elemental sulphur in an UHV system. Additionally to the deposited films a cleave surface was prepared. The samples were characterized in situ by XPS/UPS and LEED. XRD and SEM were used for further ex situ investigations. The band structure was determined by ARUPS using synchrotron light. CuInS(001) and CuInS{sub 2}(112) were deposited on Si and GaAs. The deposition of CuInS{sub 2} on GaAs showed a strong dependence on the existing surface reconstruction. A 2 x 1 reconstruction of GaAs(001) yielded CuInS{sub 2}(001) films featuring terraces. A deposition on 2 x 2 reconstructed GaAs(111)A surfaces led to a facetted CuInS{sub 2} surface. On sulphur-passivated non-reconstructed GaAs(111)B a deposition of chalcopyrite ordered CuInS{sub 2} free of facets was possible. On the surface of Cu-rich CuInS{sub 2} films CuS crystallites formed. This yields ARUPS spectra showing the electronic stucture of CuInS{sub 2} superimposed by non-dispergative states of the polycrystalline CuS segregations. The effective hole masses were derived from the k {sub vertical} {sub stroke} {sub vertical} {sub stroke} measurements. Finally the results of this work showed that the use of a (111) substrate leads to domain formation of the deposited CuInS{sub 2}(112) films. Thus ARUPS spectra of such films show a superposition of the band structures along different directions. (orig.)

  17. Structural, elastic, electronic, bonding, and optical properties of BeAZ{sub 2} (A = Si, Ge, Sn; Z = P, As) chalcopyrites

    Energy Technology Data Exchange (ETDEWEB)

    Fahad, Shah [Department of Physics, Hazara University Mansehra, KPK, Mansehra (Pakistan); Murtaza, G., E-mail: murtaza@icp.edu.pk [Materials Modeling Laboratory, Department of Physics, Islamia College University, Peshawar (Pakistan); Ouahrani, T. [Laboratoire de Physique Théorique, B.P. 230, Université de Tlemcen, Tlemcen 13000 (Algeria); Ecole Préparatoire en Sciences et Techniques, BP 165 R.P., 13000 Tlemcen (Algeria); Khenata, R., E-mail: khenata_rabah@yahoo.fr [Laboratoire de Physique Quantique et de Modélisation Mathématique, Université de Mascara, 29000 (Algeria); Yousaf, Masood [Center for Multidimensional Carbon Materials, Institute for Basic Science, Department of Physics, Ulsan National Institute of Science and Technology, Ulsan 689-798 (Korea, Republic of); Omran, S.Bin [Department of Physics and Astronomy, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451 (Saudi Arabia); Mohammad, Saleh [Department of Physics, Hazara University Mansehra, KPK, Mansehra (Pakistan)

    2015-10-15

    A first principles density functional theory (DFT) technique is used to study the structural, chemical bonding, electronic and optical properties of BeAZ{sub 2} (A = Si, Ge, Sn; Z = P, As) chalcopyrite materials. The calculated parameters are in good agreement with the available experimental results. The lattice constants and the equilibrium volume increased as we moved from Si to Ge to Sn, whereas the c/a and internal parameters u decreased by shifting the cation from P to As. These compounds are elastically stable. An investigation of the band gap using the WC-GGA, EV-GGA, PBE-GGA and mBJ-metaGGA potentials suggested that BeSiP{sub 2} and BeSiAs{sub 2} are direct band gap compounds, whereas BeGeP{sub 2,} BeGeAs{sub 2,} BeSnP{sub 2,} BeSnAs{sub 2} are indirect band gap compounds. The energy band gaps decreased by changing B from Si to Sn and increased by changing the anion C from P to As. The bonding among the cations and anions is primarily ionic. In the optical properties, the real and imaginary parts of the dielectric functions, reflectivity and optical conductivity have been studied over a wide energy range. - Highlights: • The compounds are studied by FP-LAPW method within mBJ approximation. • All of the studied materials show isotropic behaviour. • All the compounds show direct band gap nature. • Bonding nature is mostly covalent among the studied compounds. • High absorption peaks and reflectivity ensures there utility in optoelectronic devices.

  18. Effect of p–d hybridization, structural distortion and cation electronegativity on electronic properties of ZnSnX{sub 2} (X=P, As, Sb) chalcopyrite semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, S. [National Institute of Technology, Rourkela 769008, Odisha (India); Ganguli, B., E-mail: biplabg@nitrkl.ac.in [National Institute of Technology, Rourkela 769008, Odisha (India)

    2013-04-15

    Significant effects of p–d hybridization, structural distortion and cation-electro-negativity are found on band gap in ZnSnX{sub 2} (X=P, As, Sb). Our study suggests these compounds to be direct band gap semiconductors with band gaps of 1.23, 0.68 and 0.19 eV respectively. Lattice constants, tetragonal distortion (η), anion displacement, bond lengths and bulk moduli are calculated by Density Functional Theory based on Tight binding Linear Muffin-Tin orbital method. Our result of structural properties is in good agreement with the available experimental and other theoretical results. Calculated band gaps also agree well with the experimental works within LDA limitation. Unlike other semiconductors in the group II–IV–V{sub 2}, there is a reduction in the band gap of 0.22, 0.20 and 0.24 eV respectively in ZnSnX{sub 2} (X=P, As, Sb) due to p–d hybridization. Structural distortion decreases band gap by 0.20, 0.12 and 0.10 eV respectively. We find that cation electronegativity effect is responsible for increasing the band gap relative to their binary analogs GaInP{sub 2}, InGaAs{sub 2} and GaInSb{sub 2} respectively and increment are 0.13, 0.04 and 0.13 eV respectively. - Graphical abstract: One unit cell of ZnSnX{sub 2} (X=P, As, Sb) chalcopyrite semiconductor. Semiconductors ZnSnX{sub 2} (X=P, As, Sb) are found to be direct band gap semiconductors with band gaps 1.23, 0.68 and 0.19 eV respectively. The quantitative estimate of effects of p–d hybridization, structural distortion and cation electronegativity shows band gaps change significantly due to these effects. Highlights: ► ZnSnX{sub 2} (X=P, As, Sb) are direct band gap semiconductors. ► These have band gaps of 1.23 eV, 0.68 eV and 0.19 eV respectively. ► The band gap reduction due to p–d hybridization is 13.41%, 18.51% and 40% respectively. ► Band gap reduction due to structural distortion is 12.12%, 11.11% and 16.66% respectively. ► Band gap increases 8.38%, 3.70% and 21.31% respectively

  19. 天然黄铜矿矿物晶体的表面弛豫信息与理论分析%Theory analysis and vestigial information of surface relaxation of natural chalcopyrite mineral crystal

    Institute of Scientific and Technical Information of China (English)

    文书明; 邓久帅; 先永骏; 刘丹

    2013-01-01

    X-ray diffraction was used to measure the unit cell parameters of chalcopyrite crystal.The results showed that the chalcopyrite crystal is perfect,and the arrangement of its atoms is regular.A qualitative analysis of molecular mechanics showed that surface relaxation causes the chalcopyrite surface to be sulfur enriched.Atomic force microscope (AFM) was used to obtain both a microscopic three-dimensional topological map of chalcopyrite surface and a two-dimensional topological map of its electron cloud.The AFM results revealed that the horizontal and longitudinal arrangements of atoms on the chalcopyrite surface change dramatically compared with those in the interior of the crystal.Longitudinal shifts occur among the copper,iron and sulfur atoms relative to their original positions,namely,surface relaxation occurs,causing sulfur atoms to appear on the outermost surface.Horizontally,AFM spectrum showed that the interatomic distance is irregular and that a reconstruction occurs on the surface.One result of this reconstruction is that two or more atoms can be positioned sufficiently close so as to form atomic aggregates.The lattice properties of these models were calculated based on DFT theory and compared with the experimental results and those of previous theoretical works.On analyzing the results,the atomic arrangement on the (001) surface of chalcopyrite is observed to become irregular,S atoms move outward along the Z-axis,and the lengths of Cu-S and Fe-S bonds are enlarged after geometry optimization because of the surface relaxation and reconstruction.The sulfur-rich surface and irregular atomic aggregates caused by the surface relaxation and reconstruction greatly influence the bulk flotation properties of chalcopyrite.%通过XRD测定黄铜矿晶体的晶胞参数,表明黄铜矿结晶完整,内部原子排列规则.通过分子力学定性分析,指出黄铜矿表面弛豫出现表面富硫现象.采用AFM获得黄铜矿表面的三维微观结构拓扑图

  20. Enrichment of ferric iron on mineral surface during bioleaching of chalcopyrite%黄铜矿生物浸出过程中三价铁在矿物表面的富集

    Institute of Scientific and Technical Information of China (English)

    彭堂见; 周丹; 刘学端; 余润兰; 姜涛; 顾帼华; 陈淼; 邱冠周; 曾伟民

    2016-01-01

    In order to investigate the enrichment of ferric iron bound by extracellular polymeric substance (EPS) on the mineral surface during bioleaching of chalcopyrite, several methods including sonication, heating and vortexing were used and sonication at 48 °C was shown as a good way to extract ferric iron. Scanning electron microscope (SEM) and energy dispersive X-ray spectrometer (EDX) analysis showed that lots of cracks and pits can be found on the chalcopyrite surface after bioleaching and that iron oxide was filled in these cracks and pits. The variations of contents of ferric iron and EPS on the chalcopyrite surface were investigated. The results indicated that the content of EPS increased rapidly in the first 10 d and then maintained at a stable level, while ferric iron content increased all the time, especially in the later stage of bioleaching.%为探究黄铜矿生物浸出过程中与胞外多聚物结合的三价铁在矿物表面的富集,采用超声、加热和涡旋振荡提取矿物表面的三价铁。结果表明,在48°C条件下超声是一种有效的方法。扫描电镜和能量色散X射线能谱(EDX)分析表明,浸出后黄铜矿表面存在大量裂缝和凹陷,并且铁氧化物填充于这些裂缝和凹陷中。研究浸出过程黄铜矿表面三价铁和胞外多聚物的含量变化。结果表明,胞外多聚物的含量在浸出前10 d迅速上升,之后维持在一个稳定的水平,而三价铁含量随浸出时间的延长而增加,尤其是在浸出后期。

  1. Characterizations of Some Semi magnetic Chalcopyrite Compounds

    International Nuclear Information System (INIS)

    Cd1-xZnxSe (x=0, 0.5 and 1) and Cd0.5Zn0.5X0.02Se (X= Mn, Fe and Co) semiconductor and semi magnetic semiconductor compounds were prepared in the bulk form by melt quenching technique in ice water. Thin films of thickness 300 nm have been deposited on ultra cleaned soda lime glass substrates, at room temperature by thermal evaporation technique. The structural, optical and electrical properties of Cd1-xZnxSe (x=0, 0.5 and 1) and Cd0.5Zn0.5X0.02Se (X= Mn, Fe and Co) thin film samples have been studied. ESR and magnetic properties of Cd0.5Zn0.5X0.02Se (X= Mn, Fe and Co) powder samples also have been studied. The structural properties of Cd1-xZnxSe (x=0, 0.5 and 1) and Cd0.5Zn0.5X0.02Se (X= Mn, Fe and Co) thin film and powder samples have been investigated by using X-ray diffraction (XRD) technique. The crystal structure, lattice parameters, grain size, micro strain and dislocation density were determined from the X- ray diffraction patterns of the investigated samples. The optical properties of the investigated thin film samples were studied. Transmittance and reflectance were measured in wavelength range from 400 nm to 2500 nm and used to calculate the optical constants like absorption coefficient, refractive index and optical band gap. The obtained values of the optical band gap illustrated that the films exhibit direct band gap. The analysis of the obtained values of the refractive index yielded the high frequency dielectric constant and other optical dispersion parameters. The photon energy dependence of the relaxation time, dissipation factor and optical conductivity of the investigated thin film samples were studied also. The temperature dependence of dc conductivity for the investigated thin films was studied in temperature range from 300 K to 420 K. The obtained results showed that there are two different conduction mechanisms with two different values of activation energy in the defined temperature range. The temperature dependence of Hall coefficient RH for the thin film samples was studied in temperature range from 300 K to 420 K and in constant applied magnetic field (3.2 kG). The Hall coefficient of all thin film samples decreases with the temperature in opposite to that of the dc conductivity except for Cd0.5Zn0.5Co0.02Se; RH increases in high temperature. All of semiconductor thin films were n-type semiconductors. The Hall mobility increases with increase the temperature this means that the charge carrier mobility within the grains increases with the increase of temperature. The transverse magnetoresistance TMR of the investigated thin film samples was investigated in magnetic field range (0-3.2 k G) and in temperature range (300-420 K). It has been observed from the obtained results that the TMR for all films are negative at high temperatures and positive at lower temperatures. Also TMR magnitude increases with increasing the magnetic field and temperature but it is irregular. The ac conductivity as a function of temperature at different frequencies in temperature range from 300 K to 420 K and frequency range from 80 Hz to 5 MHz for the investigated thin films was studied. It is clear from the obtained results that σac(ω) is slightly temperature and frequency dependant. The temperature dependence decreases as ω increases, while increases at higher temperatures and lower frequencies. AC conductivity increases linearly with frequency according to the power relation . The obtained values of s as a function of temperature for the investigated thin films can be explained on the basis of the CBH model between centers forming IVAP'S proposed by Elliott. The dielectric constant and dielectric loss increase with the temperature and decrease with the frequency. The maximum barrier height was calculated according to Guintini equation at different temperatures. The relaxation time, resistance and σ ac ω = Aω capacitance were calculated from the Nyquist diagram. The behavior can be modeled by an equivalent parallel RC circuit for all investigated thin film samples. The ESR spectra of the Cd0.5Zn0.5X0.02Se (X= Mn, Fe and Co) powder samples were studied at room temperature. The obtained results showed that all samples were paramagnetic materials at the room temperature. The g-factor and concentration of paramagnetic defects were determined. The magnetic properties (hysteresis loops and ZFC/FC curves) were studied in temperature range from 5 K to 200 K. The obtained results indicated the ferromagnetic exchange interaction between the magnetic ions in case of Cd0.5Zn0.5Fe0.02Se and Cd0.5Zn0.5Co0.02Se but did not indicate conventional ferromagnetism, samples exhibit spin-glass behavior and also indicated antiferromagnetic interaction between Mn2+ ions in case of Cd0.5Zn0.5Mn0.02Se sample.

  2. Chalcopyrite Nanoparticles as a Sustainable Thermoelectric Material

    Directory of Open Access Journals (Sweden)

    Maninder Singh

    2015-10-01

    Full Text Available In this report, copper iron sulfide nanoparticles with various composition were synthesized by a thermolysis based wet chemical method. These inherently sustainable nanoparticles were then fully characterized in terms of composition, structure, and morphology, as well as for suitability as a thermoelectric material. The merits of the material preparation include a straightforward bulk material formation where particles do not require any specialized treatment, such as spark plasma sintering or thermal heating. The Seebeck coefficient of the materials reveals P-type conductivity with a maximum value of 203 µV/K. The results give insight into how to design and create a new class of sustainable nanoparticle material for thermoelectric applications.

  3. 电感耦合等离子体光谱法测定黄铁矿和黄铜矿中的铁铜硫%Determination of Fe, Cu and S in Pyrite and Chalcopyrite Samples by Inductively Coupled Plasma-Atomic Emission Spectrometry

    Institute of Scientific and Technical Information of China (English)

    马新荣; 王蕾; 温宏利; 巩爱华

    2011-01-01

    The methods of water bath dissolution by aqua regia to open dissolution by acid mixing HC1-HNO3 -HF-HC104 and determine Fe, Cu and S in pyrite and chalcopyrite by Inductively Coupled Plasma-Atomic Emission Spectrometry ( ICP-AES ) are discussed in this paper. By applying a weighting method to prepare standard solutions, the error caused by scale reading can be greatly reduced during the dilution step. The advantages of using the water bath dissolution by aqua regia method include reduced digestion time, reduced amount of reagent addition and simple analytical processing. When Fe combines with Si in sulfide ore, it cannot be dissolved by aqua regia, yet it can when using open dissolution by acid mixing. The optimal spectrum lines were selected to determine high concentration of Fe, Cu and S ( x%-xx% ) with dilution factor of 1000. Both sample preparation methods are simple to operate and attain good accuracy and precision. The method was validated by the national standard materials of GBW 07267 ( pyrite ) and GBW 07268 ( chalcopyrite ). The accuracy ( RE ) and precision ( RSD, n =5 ) of Fe and Cu were less than 2%. However, accuracy and precision for S was lower when using the method of open dissolution by acid mixing, yielding a RE and RSD of -9.48% and - 18% , respectively. The short period stability of GBW 07267 and GBW 07268 was tested by 10 continuous determinations using the method of water bath dissolution with aqua regia; the RSD being less than 2.%样品用王水水浴和HCl-HNO3-HF-HClO4敞开酸溶两种溶矿方式分解,电感耦合等离子体发射光谱法(ICP-AES)测定黄铜矿和黄铁矿中铁、铜、硫.应用称重法配制标准溶液,明显地降低了在标准溶液在逐级稀释过程中由于体积读数等原因产生的误差.样品用王水水浴分解,消解时间短,试剂加入量少,分析步骤简单;由于硫化矿石中Fe的一部分可能与Si结合,王水无法将其全部溶解,对于Fe的测定采用混合酸敞开酸溶.

  4. Bacterial leaching kinetics for copper dissolution from a lowgrade Indian chalcopyrite ore Cinética de lixiviação por bactéria para a dissolução de cobre de um minério de calcopirita de baixo teor encontrado na Índia

    Directory of Open Access Journals (Sweden)

    Abhilash

    2013-06-01

    Full Text Available Bio-leaching of copper (0.3% from a low grade Indian chalcopyrite ore of Malanjkhand copper mines, using a native mesophilic isolate predominantly Acidithiobacillus ferrooxidans (A.ferrooxidans, is reported. A bio-recovery of 72% Cu was recorded in the presence of this culture (not adapted, which increased to 75% with an ore adapted culture after 35 days at 35ºC and pH 2.0 with Biolixiviação de cobre (0,3% de um minério de calcopirita de baixo teor, extraído em minas de Malanjkhand, usando um isolador mesofílico nativo, predominante Acidithiobacillus ferrooxidans (A.ferrooxidans, é apresentada. Uma biorrecuperação de 72% Cu foi registrada na presença dessa cultura (não adaptada, que aumentou para 75% com a cultura do minério adaptado e cultivado por 35 dias ao 35ºC e pH 2,0, com <50um partículas. Os dados cinemáticos mostraram mais adequados para o modelo básico de encolhimento controlado por difusão, exibindo lotes lineares de [1- 2/3X- (1-X2/3] vs temp (X - fração lixiviada. Parece que o papel da bactéria, no processo, é o de converter o íon ferroso para o estado férrico, que oxida a calcopirita para poder dissolver o cobre, mantendo o alto potencial redoxante. O valor da energia de ativação (E foi calculado em 96 e 108 kJ/mol, para as culturas sem e com adaptação, respectivamente, com temperaturas entre 25-35ºC. Esse mecanismo de lixiviação foi corroborado por identificação fásica XR D e em estudos da resídua da lixiviação.

  5. Desulfurization of chalcopyrite and molybdenite by atomic hydrogen

    International Nuclear Information System (INIS)

    Molybdenite (MoS2) desulfurization by monatomic hydrogen in 625-800 K range was studied using helium as diluent gas. Desulfurization degree at 680 K equals 9%. Temperature growth elevates sulfur content in molybdenite. The effect of initial molybdenite enrichment with temperature growth up to 800 K is probably caused by removal of reduced molybdenum capable to form oxide in the presence of traces of oxygen contained in inert diluent gas

  6. Structural trends in off stoichiometric chalcopyrite type compound semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Stephan, Christiane

    2011-03-15

    Energy supply is one of the most controversial topics that are currently discussed in our global community. Most of the energy delivered to the customer today has its origin in fossil and nuclear power plants. Indefinable risks and the radioactive waste repository problem of the latter as well as the global scarcity of fossil resources cause the renewable energies to grow more and more important for achieving sustainability. The main renewable energy sources are wind power, hydroelectric power and solar energy. On the photovoltaic (PV) market different materials are competing as part of different kinds of technologies, with the largest contribution still coming from wafer based crystalline silicon solar cells (95 %). Until now thin film solar cells only contribute a small portion to the whole PV market, but large capacities are under construction. Thin film photovoltaic shows a number of advantages in comparison to wafer based crystalline silicon PV. Among these material usage and production cost reduction are two prominent examples. The type of PV materials, which are analyzed in this work, are high potential compounds that are widely used as absorber layer in thin film solar cells. These are compound semiconductors of the type CuB{sup III}C{sup VI}{sub 2} (B{sup III} = In, Ga and C{sup VI} = Se, S). Several years of research have already gone into understanding the efficiency limiting factors for solar cell devices fabricated from this compound. Most of the studies concerning electronic defects are done by spectroscopic methods mostly performed using thin films from different kinds of synthesis, without any real knowledge regarding the structural origin of these defects. This work shows a systematic fundamental structural study of intrinsic point defects that are present within the material at various compositions in CuB{sup III}C{sup VI}{sub 2} compound semiconductors. The study is done on reference powder samples with well determined chemical composition and using advanced diffraction techniques, such as neutron and synchrotron X-ray diffraction. The results show that the main existing defects are found to be copper vacancies and B{sup III}{sub Cu} anti-site defects. Type and concentrations vary with the composition. It is demonstrated that, when assuming spontaneous formation of electrically neutral defect complexes made of these isolated point defects, the density of cationic point defects is reduced by an order of magnitude. This explains why the existence of native cationic point defects may not be the main efficiency limiting factor in thin film solar cells built with a CuB{sup III}C{sup VI}{sub 2} absorber. This pinpoints why the mere presence of native cationic point defects does probably not suffice as main efficiency limiting factor in thin film solar cells based on CuB{sup III}C{sup VI}{sub 2}-type absorbers.

  7. Chalcopyrite semimagnetic semiconductors: From nanocomposite to homogeneous material

    OpenAIRE

    Kilanski L.; Dobrowolski W.; Szymczak R.; Dynowska E.; Wójcik M.; Romčević M.; Romčević N.; Fedorchenko I.V.; Marenkin S.F.

    2014-01-01

    Currently, complex ferromagnetic semiconductor systems are of significant interest due to their potential applicability in spintronics. A key feature in order to use semiconductor materials in spintronics is the presence of room temperature ferromagnetism. This feature was recently observed and is intensively studied in several Mn-alloyed II-IV-V2 group diluted magnetic semiconductor systems. The paper reviews the origin of room temperature ferromagnetism i...

  8. Structural trends in off stoichiometric chalcopyrite type compound semiconductors

    International Nuclear Information System (INIS)

    Energy supply is one of the most controversial topics that are currently discussed in our global community. Most of the energy delivered to the customer today has its origin in fossil and nuclear power plants. Indefinable risks and the radioactive waste repository problem of the latter as well as the global scarcity of fossil resources cause the renewable energies to grow more and more important for achieving sustainability. The main renewable energy sources are wind power, hydroelectric power and solar energy. On the photovoltaic (PV) market different materials are competing as part of different kinds of technologies, with the largest contribution still coming from wafer based crystalline silicon solar cells (95 %). Until now thin film solar cells only contribute a small portion to the whole PV market, but large capacities are under construction. Thin film photovoltaic shows a number of advantages in comparison to wafer based crystalline silicon PV. Among these material usage and production cost reduction are two prominent examples. The type of PV materials, which are analyzed in this work, are high potential compounds that are widely used as absorber layer in thin film solar cells. These are compound semiconductors of the type CuBIIICVI2 (BIII = In, Ga and CVI = Se, S). Several years of research have already gone into understanding the efficiency limiting factors for solar cell devices fabricated from this compound. Most of the studies concerning electronic defects are done by spectroscopic methods mostly performed using thin films from different kinds of synthesis, without any real knowledge regarding the structural origin of these defects. This work shows a systematic fundamental structural study of intrinsic point defects that are present within the material at various compositions in CuBIIICVI2 compound semiconductors. The study is done on reference powder samples with well determined chemical composition and using advanced diffraction techniques, such as neutron and synchrotron X-ray diffraction. The results show that the main existing defects are found to be copper vacancies and BIIICu anti-site defects. Type and concentrations vary with the composition. It is demonstrated that, when assuming spontaneous formation of electrically neutral defect complexes made of these isolated point defects, the density of cationic point defects is reduced by an order of magnitude. This explains why the existence of native cationic point defects may not be the main efficiency limiting factor in thin film solar cells built with a CuBIIICVI2 absorber. This pinpoints why the mere presence of native cationic point defects does probably not suffice as main efficiency limiting factor in thin film solar cells based on CuBIIICVI2-type absorbers.

  9. Photoluminescence spectra of some ternary and quaternary chalcopyrite semiconductors

    International Nuclear Information System (INIS)

    Photoluminescence (PL) emission spectra of single crystals and thin films of CuGa/sub x/In1√/sub x/Se2 compounds have been investigated at various measuring temperatures, and compared with the emission from CuGaSe2 and CuInSe2. The observed PL spectra consisted of two groups of emission lines: the near-band-gap group (A) and the lower energy group (B). It was found that the type of emission obtained is determined by the amount of stoichiometry and molecularity deviations. The PL data also showed a correspondence between the defect related transitions from the CuGa/sub x/In1√/sub x/Se2 solid solution and CuGaSe2 for x2 and CuGaSe2, the predominant defect states transitions in the solid solution are defined for the m0. Interpretation of the PL spectra of Se-deficient compounds with m>1 are rather complicated, and much work remains to be done before the defect chemistry of CuGa/sub x/In1√/sub x/Se2 could be fully understood

  10. Chemical and biological sensors based on optically confined birefringent chalcopyrite heterostructures

    International Nuclear Information System (INIS)

    This paper introduces and discusses the design and application(s) of a new and unique integrated solid-state molecular sensor (SSMS) system. The SSMS is based on optically confined birefringent heterostructure technology, which has the capability of recognizing target chemicals and biological molecules in an ambient environment. The SSMS technology is applicable for miniaturized sensor devices that can be used for quick, remote screening and recognition of chemical hazards in the environment. For example, trace impurities related to air/water pollution can be continuously monitored. Just as important, however, the SSMS technology will have a worldwide impact--economically as well as technologically--when used in the detection of chemical and biological agents, as well as for a variety of medical sensing applications, such as to identify and monitor complex biological structures, test for allergic reactions and screen for common diseases. Moreover, it could hasten the time of development and introduction into the marketplace of critically needed new drugs by the monitoring of biochemical and molecular cellular responses to the candidate drugs. Materials selection criteria, growth parameters and device architecture requirements are given and discussed. In addition, the results of a recent phase matching calculation, substantiating the feasibility of the SSMS, are given and discussed

  11. Theoretical modelling of intermediate band solar cell materials based on metal-doped chalcopyrite compounds

    International Nuclear Information System (INIS)

    Electronic structure calculations are carried out for CuGaS2 partially substituted with Ti, V, Cr or Mn to ascertain if some of these systems could provide an intermediate band material able to give a high efficiency photovoltaic cell. Trends in electronic level positions are analyzed and more accurate advanced theory levels (exact exchange or Hubbard-type methods) are used in some cases. The Ti-substituted system seems more likely to yield an intermediate band material with the desired properties, and furthermore seems realizable from the thermodynamic point of view, while those with Cr and Mn might give half-metal structures with applications in spintronics

  12. A Numerical Evaluation on the Viability of Heap Thermophilic Bioleaching of Chalcopyrite

    Science.gov (United States)

    Vilcaez, J.; Suto, K.; Inoue, C.

    2007-03-01

    The present numerical evaluation explores into the interactions among the many variables governing the mass and heat transport processes that take place in a heap thermophilic bioleaching system. The necessity of using mesophiles together with thermophiles is proved by tracing the activity of both microorganisms individually at each point throughout the heap. The role of key variables such as the fraction of FeS2 per CuFeS2 leached was quantified and its importance highlighted. In this evaluation, the heat transfer process plays the main role because of the heat accumulation required to maintain the heap temperature within the range of 60 °C to 80 °C where thermophilic microorganisms are capable of completing the unfinished dissolution of copper started by mesophilic microorganisms at 30 °C. The evaluation was done taking into consideration: biological activity as function of the temperature in the heap, heat loss due to conduction and advection from the top and bottom of the heap, and mass transfer between the gas and liquid phases as a function of temperature. The exothermic nature of the leaching reactions of CuFeS2 and FeS2 makes the system auto-thermal.

  13. Microbial community succession mechanism coupling with adaptive evolution of adsorption performance in chalcopyrite bioleaching.

    Science.gov (United States)

    Feng, Shoushuai; Yang, Hailin; Wang, Wu

    2015-09-01

    The community succession mechanism of Acidithiobacillus sp. coupling with adaptive evolution of adsorption performance were systematically investigated. Specifically, the μmax of attached and free cells was increased and peak time was moved ahead, indicating both cell growth of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans was promoted. In the mixed strains system, the domination courses of A. thiooxidans was dramatically shortened from 22th day to 15th day, although community structure finally approached to the normal system. Compared to A. ferrooxidans, more positive effects of adaptive evolution on cell growth of A. thiooxidans were shown in either single or mixed strains system. Moreover, higher concentrations of sulfate and ferric ions indicated that both sulfur and iron metabolism was enhanced, especially of A. thiooxidans. Consistently, copper ion production was improved from 65.5 to 88.5 mg/L. This new adaptive evolution and community succession mechanism may be useful for guiding similar bioleaching processes. PMID:25978855

  14. Acidithiobacillus thiooxidans secretome containing a newly described lipoprotein Licanantase enhances chalcopyrite bioleaching rate

    OpenAIRE

    Bobadilla Fazzini, Roberto A.; Levican, Gloria; Parada, Pilar

    2010-01-01

    The nature of the mineral–bacteria interphase where electron and mass transfer processes occur is a key element of the bioleaching processes of sulfide minerals. This interphase is composed of proteins, metabolites, and other compounds embedded in extracellular polymeric substances mainly consisting of sugars and lipids (Gehrke et al., Appl Environ Microbiol 64(7):2743–2747, 1998). On this respect, despite Acidithiobacilli—a ubiquitous bacterial genera in bioleaching processes (Rawlings, Micr...

  15. Impact of Molecular Hydrogen on Chalcopyrite Bioleaching by the Extremely Thermoacidophilic Archaeon Metallosphaera sedula▿

    OpenAIRE

    Auernik, Kathryne S.; Kelly, Robert M.

    2010-01-01

    Hydrogen served as a competitive inorganic energy source, impacting the CuFeS2 bioleaching efficiency of the extremely thermoacidophilic archaeon Metallosphaera sedula. Open reading frames encoding key terminal oxidase and electron transport chain components were triggered by CuFeS2. Evidence of heterotrophic metabolism was noted after extended periods of bioleaching, presumably related to cell lysis.

  16. Kelvin probe force microscopy for the nano scale characterization of chalcopyrite solar cell materials and devices

    International Nuclear Information System (INIS)

    Kelvin probe force microscopy allows to determine not only the surface topography as does atomic force microscopy, but in addition also delivers images of the surface work function on a nanometer scale. Operation in ultrahigh vacuum improves the lateral and energy resolution and allows to obtain absolute work function values. In this paper we will introduce the method and give examples for the application to solar cell materials and devices. We review examples where the surface of an oriented CuGaSe2 film showed distinct work function values for differently oriented facets of single grains, with differences as high as 250 meV, possibly affecting the power conversion efficiency of a solar cell. A cross-sectional study of a complete solar cell device based on the CuGaSe2 absorber material revealed the formation of an additional MoSex layer between the Mo back contact and the absorber. We will present results of measurements at individual grain boundaries of the absorber material. Furthermore, band bending effects at these grain boundaries are discussed and compared to results from transport studies

  17. Scanning tunneling spectroscopy on the chalcopyrite solar cell absorber material Cu(In,Ga)Se2

    International Nuclear Information System (INIS)

    Cu(In,Ga)Se2-based thin film solar cells have reached efficiencies close to 20%. Nevertheless, little is known about electronic transport and carrier recombination in this material on a microscopic scale. Especially grain boundaries in these polycrystalline materials are considered to play an important role in the performance of these solar cells. We applied scanning tunneling microscopy and spectroscopy to gain more insight in the electronic microstructure of the material. Our results point to lateral electronic inhomogeneities on the absorber surface and to an enhanced density of states at grain boundaries. The influence of charging effects is discussed

  18. Characterizing the effects of silver alloying in chalcopyrite CIGS solar cells with junction capacitance methods

    Energy Technology Data Exchange (ETDEWEB)

    Erslev, Peter T.; Hanket, Gregory M.; Shafarman, William N.; Cohen, J. David

    2009-04-01

    A variety of junction capacitance-based characterization methods were used to investigate alloys of Ag into Cu(In1-xGax)Se2 photovoltaic solar cells over a broad range of compositions. These alloys show encouraging trends of increasing VOC with increasing Ag content, opening the possibility of wide-gap cells for use in tandem device applications. Drive level capacitance profiling (DLCP) has shown very low free carrier concentrations for all Ag-alloyed devices, in some cases less than 1014 cm-3, which is roughly an order of magnitude lower than that of CIGS devices. Transient photocapacitance spectroscopy has revealed very steep Urbach edges, with energies between 10 meV and 20 meV, in the Ag-alloyed samples. This is in general lower than the Urbach edges measured for standard CIGS samples and suggests a significantly lower degree of structural disorder.

  19. Theoretical modelling of intermediate band solar cell materials based on metal-doped chalcopyrite compounds

    Energy Technology Data Exchange (ETDEWEB)

    Palacios, P. [Instituto de Energia Solar and Dpt. de Tecnologias Especiales, ETSI de Telecomunicacion, UPM, Ciudad Universitaria s/n, 28040 Madrid (Spain)]. E-mail: pablop@etsit.upm.es; Sanchez, K. [Instituto de Energia Solar and Dpt. de Tecnologias Especiales, ETSI de Telecomunicacion, UPM, Ciudad Universitaria s/n, 28040 Madrid (Spain); Conesa, J.C. [Instituto de Catalisis y Petroleoquimica, CSIC, Marie Curie 2, Cantoblanco, 28049 Madrid (Spain); Fernandez, J.J. [Dpt. de Fisica Fundamental, Universidad Nacional de Educacion a Distancia, 28080, Madrid (Spain); Wahnon, P. [Instituto de Energia Solar and Dpt. de Tecnologias Especiales, ETSI de Telecomunicacion, UPM, Ciudad Universitaria s/n, 28040 Madrid (Spain)

    2007-05-31

    Electronic structure calculations are carried out for CuGaS{sub 2} partially substituted with Ti, V, Cr or Mn to ascertain if some of these systems could provide an intermediate band material able to give a high efficiency photovoltaic cell. Trends in electronic level positions are analyzed and more accurate advanced theory levels (exact exchange or Hubbard-type methods) are used in some cases. The Ti-substituted system seems more likely to yield an intermediate band material with the desired properties, and furthermore seems realizable from the thermodynamic point of view, while those with Cr and Mn might give half-metal structures with applications in spintronics.

  20. Structural phase transition, elastic properties and electronic properties of chalcopyrite CuAlX{sub 2} (X = S, Se, Te)

    Energy Technology Data Exchange (ETDEWEB)

    Abdellaoui, A., E-mail: aekabdellaoui@yahoo.f [Laboratoire Materiaux (LABMAT) ENSET d' Oran, BP 1523 Oran Mnaouar, Oran (Algeria); Ghaffour, M.; Bouslama, M. [Laboratoire Materiaux (LABMAT) ENSET d' Oran, BP 1523 Oran Mnaouar, Oran (Algeria); Benalia, S. [Laboratoire des Materiaux Magnetiques, Departement de Physique, Faculte des Sciences, Universite Djillali LIABES, Sidi-Bel-Abbes 22000 (Algeria); Ouerdane, A. [Laboratoire Materiaux (LABMAT) ENSET d' Oran, BP 1523 Oran Mnaouar, Oran (Algeria); Abidri, B. [Laboratoire des Materiaux Magnetiques, Departement de Physique, Faculte des Sciences, Universite Djillali LIABES, Sidi-Bel-Abbes 22000 (Algeria); Monteil, Y. [Laboratoire des Multimateriaux et Interfaces, Universite Claude Bernard Lyon 1, 43 Bd du 11 Novembre 1918, Villeurbanne 69622 (France)

    2009-11-13

    The density functional theory calculations of structural phase transition, elastic constants and electronic structure of the CuAlX{sub 2} (X = S, Se, Te) have been reported using the full potential linear muffin-tin orbital (FP-LMTO). In this approach, the local density approximation is used for the exchange-correlation potential. Results are given for lattice constant, bulk modulus, and its pressure derivative, band structure, density of states and pressure dependence of energy gaps. We note that these compounds are semiconductors with direct energy gaps. The valence-band maximum and conduction-band minimum are located at {Gamma}. Our results are compared with previous theoretical calculations and experimental data. The elastic constants at equilibrium in BCT structure are also determined.

  1. Local versus global electronic properties of chalcopyrite alloys: X-ray absorption spectroscopy and ab initio calculations

    International Nuclear Information System (INIS)

    Element-specific unoccupied electronic states of Cu(In, Ga)S2 were studied as a function of the In/Ga ratio by combining X-ray absorption spectroscopy with density functional theory calculations. The S absorption edge shifts with changing In/Ga ratio as expected from the variation of the band gap. In contrast, the cation edge positions are largely independent of composition despite the changing band gap. This unexpected behavior is well reproduced by our calculations and originates from the dependence of the electronic states on the local atomic environment. The changing band gap arises from a changing spatial average of these localized states with changing alloy composition

  2. Methods for synthesizing semiconductor quality chalcopyrite crystals for nonlinear optical and radiation detection applications and the like

    Science.gov (United States)

    Stowe, Ashley; Burger, Arnold

    2016-05-10

    A method for synthesizing I-III-VI.sub.2 compounds, including: melting a Group III element; adding a Group I element to the melted Group III element at a rate that allows the Group I and Group III elements to react thereby providing a single phase I-III compound; and adding a Group VI element to the single phase I-III compound under heat, with mixing, and/or via vapor transport. The Group III element is melted at a temperature of between about 200 degrees C. and about 700 degrees C. Preferably, the Group I element consists of a neutron absorber and the group III element consists of In or Ga. The Group VI element and the single phase I-III compound are heated to a temperature of between about 700 degrees C. and about 1000 degrees C. Preferably, the Group VI element consists of S, Se, or Te. Optionally, the method also includes doping with a Group IV element activator.

  3. Scanning tunneling spectroscopy on the chalcopyrite solar cell absorber material Cu(In,Ga)Se{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Moenig, Harry; Saez-Araoz, Rodrigo; Lux-Steiner, Martha [Freie Universitaet Berlin (Germany); Sadewasser, Sascha; Ennaoui, Ahmed; Kaufmann, Christian; Kropp, Timo; Lauermann, Iver; Muenchenberg, Tim; Schock, Hans-Werner; Streicher, Ferdinand [Hahn- Meitner-Institut Berlin (Germany)

    2007-07-01

    Cu(In,Ga)Se{sub 2}-based thin film solar cells have reached efficiencies close to 20%. Nevertheless, little is known about electronic transport and carrier recombination in this material on a microscopic scale. Especially grain boundaries in these polycrystalline materials are considered to play an important role in the performance of these solar cells. We applied scanning tunneling microscopy and spectroscopy to gain more insight in the electronic microstructure of the material. Our results point to lateral electronic inhomogeneities on the absorber surface and to an enhanced density of states at grain boundaries. The influence of charging effects is discussed.

  4. Occurrence and speciation of copper in slags obtained during the pyrometallurgical processing of chalcopyrite concentrates at the Huelva smelter (Spain

    Directory of Open Access Journals (Sweden)

    Fernández-Caliani J.C.

    2012-01-01

    Full Text Available Slags involved in smelting-converting-refining operations to produce blister copper at the Atlantic Copper smelter, in Huelva (Spain, have been investigated by quantitative electron microprobe analysis, X-ray diffraction and digital imaging techniques. The results showed that mechanically entrapped matte particles are the dominant copper losses in the slags. The largest proportion of Cubearing particles (2.0-3.5 vol % is present in the magnetite-rich converter slags, due to the negative effect of viscosity on coalescence and precipitation of copper matte during conversion. They consist of high-grade matte particles with a core of copper metal rimmed by a copper sulfide phase (Cu2S. The mechanical entrainment of copper matte by slags from both the flash and electric furnaces resulted in copper losses accounting for less than 1.5 vol %, mostly occurring as tiny particles with a stoichiometric composition close to that of bornite (Cu5FeS4. Copper was not found to be enriched in fayalite and magnetite as solid solution.

  5. Dispersion of the second harmonic generation from CdGa2X4 (X = S, Se) defect chalcopyrite: DFT calculations

    International Nuclear Information System (INIS)

    Highlights: • Nonlinear optical properties of CdGa2X4 (X = S, Se) were investigated. • The compounds have large uniaxial anisotropy and large negative birefringence. • The second order susceptibility and the first hyperpolarizability were calculated. • CdGa2Se4 posses huge second harmonic generation. - Abstract: All electron full potential linear augmented plane wave method was used for calculating the nonlinear optical susceptibilities of CdGa2X4 (X = S, Se) within the framework of density functional theory. The exchange correlation potential was solved by recently developed modified Becke and Johnson (mBJ) approximation. The crystal structure of CdGa2S4 and CdGa2Se4 reveals a large uniaxial dielectric anisotropy ensuing the birefringence of −0.036 and −0.066 which make it suitable for second harmonic generation. The second order susceptibility |χijk(2)(ω)| and microscopic first hyperpolarizability βijk(ω) were calculated. The calculated |χ123(2)(ω)| and |χ312(2)(ω)| static values for the dominant components found to be 18.36 pm/V and 22.23 pm/V for CdGa2S4 and CdGa2Se4. Both values shifted to be 60.12 pm/V and 108.86 pm/V at λ = 1064 nm. The calculated values of β123(ω) is 6.47 × 10−30 esu at static limit and 12.42 × 10−30 esu at λ = 1064 nm for CdGa2S4, whereas it is 8.82 × 10−30 esu at static limit and 20.51 × 10−30 esu at λ = 1064 nm for CdGa2Se4. The evaluation of second order susceptibilities and first hyperpolarizabilties suggest that CdGa2X4 possess huge second harmonic generation

  6. The effect of copper vacancies on the optical bowing of chalcopyrite Cu(In,Ga)Se2 alloys

    International Nuclear Information System (INIS)

    This paper reports that the optical bowling behavior of polycrystalline thin film CuIn1-yGaySe2 alloys is dependent upon the Cu stoichiometry. The variation in optical band gap, Eg, for alloys in which Cu is near stoichiometric (25 at. %) is parabolic and follows the relationship: Eg(y) = 1.011 + 0.421 y + 0.244 y2 (eV), where y is the alloy parameter, [at.% Ga]/[at.%Ga + at.%In]. Contrary to this, films with Cu-poor stoichiometries (∼19 at.% Cu) exhibit little alloy bowing: Eg(y) = 1.01 + 0.733 y - 0.046 y2 (eV). The increase in Eg with Cu deficiency appears to be the result of both a structural effect associated with tetragonal lattice shrinkage, ΔV = Vstoichiometric - VCu-poor (resulting from the presence of Cu vacancies) and a chemical effect, possibly associated with a counterbalance between p-d repulsion and anion displacement effects

  7. Photoluminescence and solar cell studies of chalcopyrites - comparison of Cu-rich vs. Cu-poor and polycrystalline vs. epitaxial material

    OpenAIRE

    Regesch, David

    2014-01-01

    The quasi-Fermi level splitting (qFls) in a solar cell absorber limits the maximum achievable open circuit voltage of the final device. A calibrated photoluminescence set-up allows the determination of the qFls at room temperature under conditions equivalent to the illumination from the sun. In this work the qFls is used as an indicator for the quality of epitaxial and polycrystalline thin CuInSe2 films with different compositions. It is shown, that the epitaxial material exhibits improve...

  8. Hybrid particles and associated methods

    Science.gov (United States)

    Fox, Robert V; Rodriguez, Rene; Pak, Joshua J; Sun, Chivin

    2015-02-10

    Hybrid particles that comprise a coating surrounding a chalcopyrite material, the coating comprising a metal, a semiconductive material, or a polymer; a core comprising a chalcopyrite material and a shell comprising a functionalized chalcopyrite material, the shell enveloping the core; or a reaction product of a chalcopyrite material and at least one of a reagent, heat, and radiation. Methods of forming the hybrid particles are also disclosed.

  9. Screened-exchange density functional theory description of the electronic structure and phase stability of the chalcopyrite materials AgInSe2 and AuInSe2

    Science.gov (United States)

    Kim, Namhoon; Martin, Pamela Peña; Rockett, Angus A.; Ertekin, Elif

    2016-04-01

    We present a systematic assessment of the structural properties, the electronic density of states, the charge densities, and the phase stabilities of AgInSe2 and AuInSe2 using screened-exchange hybrid density functional theory, and compare their properties to those of CuInSe2. For AgInSe2, hybrid density functional theory properly captures several experimentally measured properties, including the increase in the band gap and the change in the direction of the lattice distortion parameter u in comparison to CuInSe2. While the electronic properties of AuInSe2 have not yet been experimentally characterized, we predict it to be a small gap (≈0.15 eV) semiconductor. We also present the phase stability of AgInSe2 and AuInSe2 according to screened-exchange density functional theory, and compare the results to predictions from conventional density functional theory, results tabulated from several online materials data repositories, and experiment (when available). In comparison to conventional density functional theory, the hybrid functional predicts phase stabilities of AgInSe2 in better agreement with experiment: discrepancies in the calculated formation enthalpies are reduced by approximately a factor of 3, from ≈0.20 eV/atom to ≈0.07 eV/atom, similar to the improvement observed for CuInSe2. We further predict that AuInSe2 is not a stable phase, and can only be present under nonequilibrium conditions.

  10. Identifying the Electronic Properties Relevant to Improving the Performance of High Band-Gap Copper Based I-III-VI2 Chalcopyrite Thin Film Photovoltaic Devices: Final Subcontract Report, 27 April 2004-15 September 2007

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, J. D.

    2008-08-01

    This report summarizes the development and evaluation of higher-bandgap absorbers in the CIS alloy system. The major effort focused on exploring suitable absorbers with significant sulfur alloying in collaboration with Shafarman's group at the Institute of Energy Conversion. Three series of samples were examined; first, a series of quaternary CuIn(SeS)2-based devices without Ga; second, a series of devices with pentenary Cu(InGa)(SeS)2 absorbers in which the Se-to-S and In-to-Ga ratios were chosen to keep the bandgap nearly constant, near 1.52 eV. Third, based on the most-promising samples in those two series, we examined a series of devices with pentenary Cu(InGa)(SeS)2 absorbers with roughly 25 at.% S/(Se+S) ratios and varying Ga fractions. We also characterized electronic properties of several wide-bandgap CuGaSe2 devices from both IEC and NREL. The electronic properties of these absorbers were examined using admittance spectroscopy, drive-level capacitance profiling, transient photocapacitance, and transient photocurrent optical spectroscopies. The sample devices whose absorbers had Ga fraction below 40 at.% and S fractions above 20 at.% but below 40% exhibited the best electronic properties and device performance.

  11. Use of different Zn precursors for the deposition of Zn(S,O) buffer layers by chemical bath for chalcopyrite based Cd-free thin-film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Saez-Araoz, R.; Lux-Steiner, M.C. [Hahn Meitner Institut, Berlin (Germany); Freie Universitaet Berlin, Berlin (Germany); Ennaoui, A.; Kropp, T.; Veryaeva, E. [Hahn Meitner Institut, Berlin (Germany); Niesen, T.P. [AVANCIS GmbH and Co. KG, Munich (Germany)

    2008-10-15

    Progress in fabricating Cu(In,Ga)(S,Se){sub 2} (CIGSSe) solar cells with Zn(S,O) buffer layers prepared by chemical bath deposition (CBD) is discussed. The effect of different Zn salt precursors on solar cell device performance is investigated using production scale CIGSSe absorbers provided by AVANCIS GmbH and Co. KG. The CBD process has been developed at the Hahn-Meitner-Institut (HMI) using zinc nitrate, zinc sulphate or zinc chloride as zinc precursor. An average efficiency of 14.2{+-}0.8% is obtained by using one-layer CBD Zn(S,O) The dominant recombination path for well performing solar cells is discussed based on the results obtained from temperature dependent J(V) analysis. The structure and morphology of buffer layers deposited using zinc nitrate and zinc sulphate has been studied by means of transmission electron micrographs of glass/Mo/CIGSSe/Zn(S,O) structures. Results show a conformal coverage of the absorber by a Zn(S,O) layer of 15-25 nm consisting of nanocrystals with radii of {proportional_to}5 nm. XAES analysis of the buffer layer reveals a similar surface composition for buffer layers deposited with zinc nitrate and zinc sulphate. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  12. Comparative study on the passivation layers of copper sulphide minerals during bioleaching

    Science.gov (United States)

    Fu, Kai-bin; Lin, Hai; Mo, Xiao-lan; Wang, Han; Wen, Hong-wei; Wen, Zi-long

    2012-10-01

    The bioleaching of copper sulphide minerals was investigated by using A. ferrooxidans ATF6. The result shows the preferential order of the minerals bioleaching as djurleite>bornite>pyritic chalcopyrite>covellite>porphyry chalcopyrite. The residues were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). It is indicated that jarosite may not be responsible for hindered dissolution. The elemental sulfur layer on the surface of pyritic chalcopyrite residues is cracked. The compact surface layer of porphyry chalcopyrite may strongly hinder copper extraction. X-ray photoelectron spectroscopy (XPS) further confirms that the passivation layers of covellite, pyritic chalcopyrite, and porphyry chalcopyrite are copper-depleted sulphide Cu4S11, S8, and copper-rich iron-deficient polysulphide Cu4Fe2S9, respectively. The ability of these passivation layers was found as Cu4Fe2S9>Cu4S11>S8>jarosite.

  13. Cu(In,Ga)Se2 and Related Solar Cells

    Science.gov (United States)

    Rau, Uwe; Schock, Hans W.

    2015-10-01

    The following sections are included: * Introduction * Material properties * Cell and module technology * Device physics * Wide-gap chalcopyrites * Kesterite (CZTS) solar cells * Conclusions * References

  14. Recovery of Copper from Cyanidation Tailing by Flotation

    Science.gov (United States)

    Qiu, Tingsheng; Huang, Xiong; Yang, Xiuli

    2016-02-01

    In this work, sodium hypochlorite, hydrogen peroxide, sodium metabisulfite and copper sulfate as activators were investigated to lessen the depression effect of cyanide for deep-depressing chalcopyrite. The experimental results indicate that the copper recovery exceeded 94%, 84% and 97% at the dosage: sodium hypochlorite 3 mL/L, hydrogen peroxide 2 mL/L, sodium metabisulfite 2 × 10-3 mol/L and copper sulfate 1.67 × 10-4 mol/L, respectively. According to the results of zeta potential and Fourier transform infrared spectrum, it is suggested that chalcopyrite was depressed because of the chemical adsorption of cyanide on the chalcopyrite surfaces. Sodium hypochlorite, hydrogen peroxide and sodium metabisulfite can destroy Cu-C bond on the deep-depressing chalcopyrite surface by chemical reaction. Copper sulfate can activate deep-depressing chalcopyrite by copper ion adsorption.

  15. Effect of ultrasound on flotation kinetics in the reactor-separator

    International Nuclear Information System (INIS)

    Effect of the ultrasound on flotation kinetics in reactor-separator has been studied for chalcopyrite/quartz mix mineral system. Under ultrasound treatment, recovery of chalcopyrite into bulk concentrate is higher than that at reagent-only treatment. It can be explained by increased of flotation rate for slow fraction as defined by Kelsall model. The slow fraction flotation rate increase multiplied by 6 vs. ultrasound treatment. Additional effect of the ultrasound treatment has been noticed under conditions when gangue minerals detachment from bubbles can be controlled. Reactor-separator has advantages over other types of flotation cells for this purpose providing a special zone for the ultrasound treatment that can be easily designed in this impeller less machine. The ultrasound influence on particles collision probability is able to explain of chalcopyrite recovery increase in the concentrate and activation chalcopyrite particles flotation.

  16. Effect of ultrasound on flotation kinetics in the reactor-separator

    Science.gov (United States)

    Filippov, L. O.; Matinin, A. S.; Samiguin, V. D.; Filippova, I. V.

    2013-03-01

    Effect of the ultrasound on flotation kinetics in reactor-separator has been studied for chalcopyrite/quartz mix mineral system. Under ultrasound treatment, recovery of chalcopyrite into bulk concentrate is higher than that at reagent-only treatment. It can be explained by increased of flotation rate for slow fraction as defined by Kelsall model. The slow fraction flotation rate increase multiplied by 6 vs. ultrasound treatment. Additional effect of the ultrasound treatment has been noticed under conditions when gangue minerals detachment from bubbles can be controlled. Reactor-separator has advantages over other types of flotation cells for this purpose providing a special zone for the ultrasound treatment that can be easily designed in this impeller less machine. The ultrasound influence on particles collision probability is able to explain of chalcopyrite recovery increase in the concentrate and activation chalcopyrite particles flotation.

  17. Magnetic transitions observed in sulfide minerals at elevated pressures and their geophysical significance.

    Science.gov (United States)

    Vaughan, D J; Tossell, J A

    1973-01-26

    The magnetic behavior of iron in chalcopyrite (CuFeS(2)) and pyrrhotite (Fe(7)S(8)) in the pressure range from 1 atmosphere to 20 kilobars has been studied by Mössbauer spectroscopy. Both chalcopyrite and pyrrhotite exhibit transitions from magnetically ordered to disordered states over the range from 5 to 16 kilobars. Both transitions, particularly the loss of ferrimagnetism in pyrrhotite, have geophysical consequences. PMID:17843765

  18. Effect of pH on Pulp Potential and Sulphide Mineral Flotation

    OpenAIRE

    GÖKTEPE, Ferihan

    2002-01-01

    Control of pH is one of the most widely applied methods for the modulation of mineral flotation. In this study the effect of pH on potential in solution and sulphur minerals flotation is discussed with various electrodes. The electrodes were platinum, gold, chalcopyrite, pyrite and galena. In solution, potentials were linearly dependent on pH with a different slope for each electrode. Chalcopyrite, pyrite, sphalerite and galena minerals flotation tests were performed in a microflot...

  19. <報文>中国金川産含銅ニッケル硫化鉱の浮選(第1報) : パルプ温度, pHおよびヘキサメタ燐酸ナトリウムの効果について

    OpenAIRE

    山本, 泰二; 呉, 振東; 張, 礼強

    1988-01-01

    Copper-nickel sulphide ores from Jinchuan mine in China contain mainly pentlandite, chalcopyrite, pyrrhotite and gangue minerals consisting of serpentine, olivine and pyroxyne. In the flotation of pentlandite and chalcopyrite, these gangue minerals, containing particularly serpentine, lead to poor separation. At present, the bulk concentrates of nickel-copper are low grade due to the high content of magnesium. In the smelting, both higher grade of nickel-copper and lower grade of magnesium in...

  20. Moessbauer study on microwave synthesized (Cu,Fe) sulfide composites and correlation with natural mineral-cubanite

    International Nuclear Information System (INIS)

    In nature, the mineral 'Cubanite' with composition CuFe2S3 occurs in orthorhombic structure in the matrix of chalcopyrite and pyrrhotite. Synthesis of this mineral in the laboratory conditions has not been reported yet. An attempt to synthesize the orthorhombic Cu-Fe-Sulfide (cubanite) by resistive as well as microwave heating technique is reported. MW-heated sample shows the presence of orthorhombic component along with isocubanite and pyrrhotite. The synthesized samples were studied in details through XRD and Moessbauer spectroscopy. The synthesis process, responsible for different proportions of the minerals, may indicate the conditions of their genesis in nature. Formation of isocubanite (cubic cubanite) seems unavoidable under the conditions of synthesis. The striking indistinguishable character of cubanite and chalcopyrite could be challenged through Moessbauer hyperfine parameter-the hyperfine field of chalcopyrite (∼37 T) being quite different from that of cubanite (∼33 T).

  1. Moessbauer study on microwave synthesized (Cu,Fe) sulfide composites and correlation with natural mineral-cubanite

    Energy Technology Data Exchange (ETDEWEB)

    Pareek, Sarita [University of Rajasthan, High-Pressure Physics Laboratory, Department of Physics (India); Rais, Anwar [Geological Survey of India (India); Tripathi, Amita [J. N. V. University, Moessbauer Lab., Department of Physics (India); Chandra, Usha, E-mail: ushac_jp1@sancharnet.in [University of Rajasthan, High-Pressure Physics Laboratory, Department of Physics (India)

    2008-09-15

    In nature, the mineral 'Cubanite' with composition CuFe{sub 2}S{sub 3} occurs in orthorhombic structure in the matrix of chalcopyrite and pyrrhotite. Synthesis of this mineral in the laboratory conditions has not been reported yet. An attempt to synthesize the orthorhombic Cu-Fe-Sulfide (cubanite) by resistive as well as microwave heating technique is reported. MW-heated sample shows the presence of orthorhombic component along with isocubanite and pyrrhotite. The synthesized samples were studied in details through XRD and Moessbauer spectroscopy. The synthesis process, responsible for different proportions of the minerals, may indicate the conditions of their genesis in nature. Formation of isocubanite (cubic cubanite) seems unavoidable under the conditions of synthesis. The striking indistinguishable character of cubanite and chalcopyrite could be challenged through Moessbauer hyperfine parameter-the hyperfine field of chalcopyrite ({approx}37 T) being quite different from that of cubanite ({approx}33 T).

  2. Terahertz generation by optical rectification in uniaxial birefringent crystals

    CERN Document Server

    Rowley, J D; Zawilski, K T; Schunemann, P G; Giles, N C; Bristow, A D

    2012-01-01

    The angular dependence of terahertz (THz) emission from birefringent crystals can differ significantly from that of cubic crystals. Here we consider optical rectification in uniaxial birefringent materials, such as chalcopyrite crystals. The analysis is verified in a (110)-cut ZnGeP2 and compared to (zincblende) GaP. Although the structures share the same nonzero second-order tensor elements, birefringence causes the pump pulse polarization to evolve as it propagates through the crystal, resulting in a drastically different angular dependence in chalcopyrite crystals. The analysis is extended to predict the response from {012}- and (114)-cut chalcopyrite crystals, revealing an increase in the maximum emission in comparison to (110)-cut crystals.

  3. Methods for forming particles

    Energy Technology Data Exchange (ETDEWEB)

    Fox, Robert V.; Zhang, Fengyan; Rodriguez, Rene G.; Pak, Joshua J.; Sun, Chivin

    2016-06-21

    Single source precursors or pre-copolymers of single source precursors are subjected to microwave radiation to form particles of a I-III-VI.sub.2 material. Such particles may be formed in a wurtzite phase and may be converted to a chalcopyrite phase by, for example, exposure to heat. The particles in the wurtzite phase may have a substantially hexagonal shape that enables stacking into ordered layers. The particles in the wurtzite phase may be mixed with particles in the chalcopyrite phase (i.e., chalcopyrite nanoparticles) that may fill voids within the ordered layers of the particles in the wurtzite phase thus produce films with good coverage. In some embodiments, the methods are used to form layers of semiconductor materials comprising a I-III-VI.sub.2 material. Devices such as, for example, thin-film solar cells may be fabricated using such methods.

  4. Electronic structure and optical properties of CuGaS{sub 2} and CuInS{sub 2} solar cell materials

    Energy Technology Data Exchange (ETDEWEB)

    Soni, Amit [Department of Electrical Eng., Global Institute of Technology, Jaipur 302 022, Rajasthan (India); Gupta, Vikas; Arora, C.M. [Department of Electrical Eng., Malaviya National Institute of Technology, Jaipur 302 017, Rajasthan (India); Dashora, Alpa; Ahuja, B.L. [Department of Physics, M L Sukhadia University, Udaipur 313 001, Rajasthan (India)

    2010-08-15

    We report energy bands, density of states and optical properties of CuGaS{sub 2} and CuInS{sub 2} chalcopyrites. The electronic structure has been computed using linear combination of atomic orbitals (LCAO) scheme within density functional theory (DFT) and full-potential linearised augmented plane wave method. The energy bands, density of states, components of dielectric tensors and absorption coefficients are compared with the available data. It is seen that the present LCAO-DFT calculations reproduce the electronic properties of both the chalcopyrites in a reasonable way. The optical properties show more absorption of solar radiations for CuGaS{sub 2} chalcopyrite, depicting its more usefulness in the solar cells. (author)

  5. Effect of Flotation Reagents on the Cake Moisture of Copper Concentrate

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The effect of reagents used in separating chalcopyrite from pyrite on the cake moisture of the copper concentrate at Daye Iron Mine Mineral Processing Plant was investigated. The results showed that the dosage of lime used for depressing pyrite was the main factor that increased the filter cake moisture of copper concentrate. With increasing the dosage of lime, the cake moisture of copper concentrate increased sharply. The cause was concluded to be the addition of lime to the pulp, which resulted in the formation of floc and a high pH value. The collector Z-200#, used for collecting chalcopyrite, had, as well, an adverse effect on the cake moisture of copper concentrate, but its effect was inferior in respect to that of lime. The cake moisture of copper concentrate can be decreased by changing the method with which lime is added and the pH value of pulp is regulated. The experiment results showed that the sulfuric acid was the best regulator. When the clarified liquor of lime was used as a depressant and the pH value of the pulp was regulated to 6.5€?7.0 by adding sulfuric acid, the cake moisture of copper concentrate was reduced from 15.49% to 13.13%. The examination of chalcopyrite surface by using ESCA (Electron Spectroscopy for Chemical Analysis) showed that calcium sulfate and iron hydroxide had formed on the surface of chalcopyrite when lime was added to the pulp. The formation of calcium sulfate and iron hydroxide on its surface increased the hydrophilicity of chalcopyrite so that its cake moisture increased. The addition of sulfuric acid to the pulp not only removed the calcium sulfate, but also reduced the concentration of iron hydroxide on the surface of chalcopyrite so that the cake moisture of copper concentrate was decreased.

  6. Les minéralisations Cu_(Ni_Bi_U_Au_Ag) d'Ifri (district du Haut Seksaoua, Maroc) : apport de l'étude texturale au débat syngenèse versus épigenèseThe Cu_(Ni_Bi_U_Au_Ag) mineralization of Ifri ('Haut Seksaoua' district, Morocco): contribution of a textural study to the discussion syngenetic versus epigenetic

    Science.gov (United States)

    Barbanson, Luc; Chauvet, Alain; Gaouzi, Aziz; Badra, Lakhifi; Mechiche, Mohamed; Touray, Jean Claude; Oukarou, Saı̈d

    2003-11-01

    The Cu ore of Ifri is a chalcopyrite stockwork hosted by Cambrian formations and was until now interpreted as a syngenetic massive sulphide deposit. Textural studies highlight two generations of pyrite early (Py I) and late (Py II) with respect to the regional deformation. The chalcopyrite stockwork overprinted Py II, outlining the epigenetic nature of the Cu mineralization. Regarding the origin of Cu-depositing fluids, the presence in the stockwork paragenesis of an U, W, Sn association and preliminary Pb/Pb dating of a brannerite belonging to this association suggest a contribution of the Tichka granite. To cite this article: L. Barbanson et al., C. R. Geoscience 335 (2003).

  7. Phenocrysts in obsidian glasses

    International Nuclear Information System (INIS)

    Minerals mainly of Carpathian obsidian glasses were mapped by nuclear microprobe based on the particle induced X-ray emission (PIXE) providing analytical data on them for the first time. Some samples from Armenia, Greece are also involved to make a comparison with the Carpathian specimens. The following minerals are identified and analyzed: pyrrhotite, chalcopyrite, pyrite, zircon, pyroxene, biotite, plagioclase feldspar, and anhydrite. On the basis of rock-forming silicate minerals, some petrologic processes are outlined. With the identification of accessory minerals (anhydrite, pyrrhotite, chalcopyrite, pyrite), some geological conclusions are also drawn. (author)

  8. The Lattice Compatibility Theory: Arguments for Recorded I-III-O2 Ternary Oxide Ceramics Instability at Low Temperatures beside Ternary Telluride and Sulphide Ceramics

    Directory of Open Access Journals (Sweden)

    K. Boubaker

    2013-01-01

    Full Text Available Some recorded behaviours differences between chalcopyrite ternary oxide ceramics and telluride and sulphides are investigated in the framework of the recently proposed Lattice Compatibility Theory (LCT. Alterations have been evaluated in terms of Urbach tailing and atomic valence shell electrons orbital eigenvalues, which were calculated through several approximations. The aim of the study was mainly an attempt to explain the intriguing problem of difficulties of elaborating chalcopyrite ternary oxide ceramics (I-III-O2 at relatively low temperatures under conditions which allowed crystallization of ternary telluride and sulphides.

  9. Characterization of a Copper mineral from Rio Grande do Sul (RS, Brazil) by Moessbauer spectroscopy and chemical analysis

    International Nuclear Information System (INIS)

    A sample from a copper-based mineral is analysed by Moessbauer spectroscopy. The results are compared with those form X-ray diffraction and microscopic analyses. A graphic correlation between the areas in the chalcopyrite spectra and the copper contents determined by chemical analysis is also made. (C.L.B.)

  10. Electron-density distribution in CuFeS2 as determined by 63,65Cu NMR in an internal magnetic field

    Science.gov (United States)

    Pogoreltsev, A. I.; Gavrilenko, A. N.; Matukhin, V. L.; Korzun, B. V.; Schmidt, E. V.

    2013-07-01

    NMR spectra of 63,65Cu in an internal magnetic field were studied experimentally. The electric field gradient (EFG) at Cu nuclei in chalcopyrite CuFeS2 was evaluated ab initio by using a cluster approach. Calculations were carried out in the framework of the self-consistent field restricted open-shell Hartree-Fock method (SCF-LCAO-ROHF). The largest cluster for which calculations were carried out had the formula Cu9Fe10S28 n ( R ~ 6 Å, 47 atoms), where n is the cluster charge. The best agreement of the quadrupole parameters (quadrupole frequency νQ and EFG tensor asymmetry parameter η) that were determined experimentally (νQ = 1.29 MHz, η = 0.34) and were calculated (νQ = 1.40 MHz, η = 0.50) was obtained for the cluster Cu9Fe10S28 -4. Maps of electron-density distribution in the neighborhood of the Cu quadrupolar nucleus were built for the cluster Cu9Fe10S28 -4. It was suggested based on an analysis of the obtained electron-density distribution that the bond in chalcopyrite is not covalent. The energy-level diagram that was calculated in the ROHF high-spin approximation defined rather well chalcopyrite as a semiconductor with a very narrow LUMO-HOMO gap and was consistent with the notion of chalcopyrite as a gapless semiconductor.

  11. Cu isotope geochemistry of volcanogenic massive sulphide deposits of the eastern Pontides, Turkey

    International Nuclear Information System (INIS)

    A large number of volcanogenic massive sulfide (VMS) deposits are associated with Late Cretaceous to Eocene arc-like volcanic rocks in the eastern Pontides of NE Turkey. Cu isotope studies on thirteen VMS and two vein deposits were undertaken to examine the nature of copper isotope variations and to compare these with other VMS and black smoker deposits. φ65Cu of chalcopyrite from these deposits range between +0.34 and -0.62 per mille . Chalcopyrite from the VMS deposits of the eastern Pontides have a mean φ65Cu = -0.13 per mille . φ65Cu of chalcopyrite is generally heavier than that of corresponding bornite. The range of φ65Cu for chalcopyrite from VMS deposits in the eastern Pontides is larger than that observed from Alexandrinka, a Devonian VMS deposit in the southern Urals, but is significantly smaller than the up to 3 per mille variations observed from individual modern sea-floor hydrothermal fields along modern mid-ocean ridges. The range of Cu isotope variation in VMS deposits from the eastern Pontides is interpreted to result from processes related to both oxidation and leaching of previously deposited copper by seawater and to its subsequent deposition elsewhere in the hydrothermal system

  12. Cu isotope geochemistry of volcanogenic massive sulphide deposits of the eastern Pontides, Turkey

    Energy Technology Data Exchange (ETDEWEB)

    Housh, T B [Department of Geological Sciences, University of Texas at Austin, 1 University Station C1100, Austin, TX 78712 (United States); Ciftci, E [Department of Geological Engineering, Nigde University, 51245 Nigde (Turkey)], E-mail: housh@mail.utexas.edu

    2008-07-01

    A large number of volcanogenic massive sulfide (VMS) deposits are associated with Late Cretaceous to Eocene arc-like volcanic rocks in the eastern Pontides of NE Turkey. Cu isotope studies on thirteen VMS and two vein deposits were undertaken to examine the nature of copper isotope variations and to compare these with other VMS and black smoker deposits. {phi}{sup 65}Cu of chalcopyrite from these deposits range between +0.34 and -0.62 per mille . Chalcopyrite from the VMS deposits of the eastern Pontides have a mean {phi}{sup 65}Cu = -0.13 per mille . {phi}{sup 65}Cu of chalcopyrite is generally heavier than that of corresponding bornite. The range of {phi}{sup 65}Cu for chalcopyrite from VMS deposits in the eastern Pontides is larger than that observed from Alexandrinka, a Devonian VMS deposit in the southern Urals, but is significantly smaller than the up to 3 per mille variations observed from individual modern sea-floor hydrothermal fields along modern mid-ocean ridges. The range of Cu isotope variation in VMS deposits from the eastern Pontides is interpreted to result from processes related to both oxidation and leaching of previously deposited copper by seawater and to its subsequent deposition elsewhere in the hydrothermal system.

  13. First-principles analysis of the spectroscopic limited maximum efficiency of photovoltaic absorber layers for CuAu-like chalcogenides and silicon.

    Science.gov (United States)

    Bercx, Marnik; Sarmadian, Nasrin; Saniz, Rolando; Partoens, Bart; Lamoen, Dirk

    2016-07-27

    Chalcopyrite semiconductors are of considerable interest for application as absorber layers in thin-film photovoltaic cells. When growing films of these compounds, however, they are often found to contain CuAu-like domains, a metastable phase of chalcopyrite. It has been reported that for CuInS2, the presence of the CuAu-like phase improves the short circuit current of the chalcopyrite-based photovoltaic cell. We investigate the thermodynamic stability of both phases for a selected list of I-III-VI2 materials using a first-principles density functional theory approach. For the CuIn-VI2 compounds, the difference in formation energy between the chalcopyrite and CuAu-like phase is found to be close to 2 meV per atom, indicating a high likelihood of the presence of CuAu-like domains. Next, we calculate the spectroscopic limited maximum efficiency (SLME) of the CuAu-like phase and compare the results with those of the corresponding chalcopyrite phase. We identify several candidates with a high efficiency, such as CuAu-like CuInS2, for which we obtain an SLME of 29% at a thickness of 500 nm. We observe that the SLME can have values above the Shockley-Queisser (SQ) limit, and show that this can occur because the SQ limit assumes the absorptivity to be a step function, thus overestimating the radiative recombination in the detailed balance approach. This means that it is possible to find higher theoretical efficiencies within this framework simply by calculating the J-V characteristic with an absorption spectrum. Finally, we expand our SLME analysis to indirect band gap absorbers by studying silicon, and find that the SLME quickly overestimates the reverse saturation current of indirect band gap materials, drastically lowering their calculated efficiency. PMID:27405243

  14. Geology, petrography, geochemistry, and genesis of sulfide-rich pods in the Lac des Iles palladium deposits, western Ontario, Canada

    Science.gov (United States)

    Duran, Charley J.; Barnes, Sarah-Jane; Corkery, John T.

    2016-04-01

    The Lac des Iles Pd deposits are known for their Pd-rich sulfide-poor mineralization. However, previously undocumented sulfide-rich pods also occur within the intrusion that hosts the deposits. Given the complex magmatic and hydrothermal history of the mineralization at Lac des Iles, the sulfide-rich pods could have crystallized from magmatic sulfide liquids or precipitated from hydrothermal fluids. Sulfide-rich pods occur throughout the stratigraphy, in all rock types, and along comagmatic shear zones, and contain net-textured to massive sulfides. They can be divided into four main groups based on the variation in mineral assemblages: (1) pyrrhotite-pentlandite ± pyrite-chalcopyrite-magnetite-ilmenite; (2) chalcopyrite ± pyrrhotite-pentlandite-pyrite-magnetite-ilmenite; (3) pyrite ± pentlandite-chalcopyrite-pyrrhotite-magnetite-ilmenite; and (4) magnetite ± ilmenite-pyrrhotite-pentlandite-pyrite-chalcopyrite. Whole rock metal contents and S isotopic compositions do not change with the amount of pyrite present, except for slight enrichments in As and Bi. The presence of an essentially magmatic sulfide mineral assemblage (pyrrhotite-pentlandite ± chalcopyrite) with pentlandite exsolution flames in pyrrhotite in some pods suggests that the pods crystallized from magmatic sulfide liquids. The very low Cu contents of the pods suggests that they are mainly cumulates of monosulfide solid solution (MSS). We propose a model whereby sulfide liquids were concentrated into dilation zones prior to crystallizing cumulus MSS. Intermediate solid solution crystallized from the fractionated liquids at the edges of some pods leaving residual liquids enriched in Pt, Pd, Au, As, Bi, Sb, and Te. These residual liquids are no longer associated with the pods. During subsequent alteration, pyrite replaced MSS/pyrrhotite, but this did not affect the platinum-group element contents of the pods.

  15. Copper isotope fractionation in acid mine drainage

    Science.gov (United States)

    Kimball, B.E.; Mathur, R.; Dohnalkova, A.C.; Wall, A.J.; Runkel, R.L.; Brantley, S.L.

    2009-01-01

    We measured the Cu isotopic composition of primary minerals and stream water affected by acid mine drainage in a mineralized watershed (Colorado, USA). The ??65Cu values (based on 65Cu/63Cu) of enargite (??65Cu = -0.01 ?? 0.10???; 2??) and chalcopyrite (??65Cu = 0.16 ?? 0.10???) are within the range of reported values for terrestrial primary Cu sulfides (-1??? fractionation (??aq-min = ??65Cuaq - ??65Cumin, where the latter is measured on mineral samples from the field system), equals 1.43 ?? 0.14??? and 1.60 ?? 0.14??? for chalcopyrite and enargite, respectively. To interpret this field survey, we leached chalcopyrite and enargite in batch experiments and found that, as in the field, the leachate is enriched in 65Cu relative to chalcopyrite (1.37 ?? 0.14???) and enargite (0.98 ?? 0.14???) when microorganisms are absent. Leaching of minerals in the presence of Acidithiobacillus ferrooxidans results in smaller average fractionation in the opposite direction for chalcopyrite (??aq-mino = - 0.57 ?? 0.14 ???, where mino refers to the starting mineral) and no apparent fractionation for enargite (??aq-mino = 0.14 ?? 0.14 ???). Abiotic fractionation is attributed to preferential oxidation of 65Cu+ at the interface of the isotopically homogeneous mineral and the surface oxidized layer, followed by solubilization. When microorganisms are present, the abiotic fractionation is most likely not seen due to preferential association of 65Cuaq with A. ferrooxidans cells and related precipitates. In the biotic experiments, Cu was observed under TEM to occur in precipitates around bacteria and in intracellular polyphosphate granules. Thus, the values of ??65Cu in the field and laboratory systems are presumably determined by the balance of Cu released abiotically and Cu that interacts with cells and related precipitates. Such isotopic signatures resulting from Cu sulfide dissolution should be useful for acid mine drainage remediation and ore prospecting purposes. ?? 2008 Elsevier Ltd.

  16. Influence of annealing temperature on properties of Cu(In,Ga)(Se,S)2 thin films prepared by co-sputtering from quaternary alloy and In2S3 targets

    International Nuclear Information System (INIS)

    Pentanary Cu(In,Ga)(Se,S)2 (CIGSS) thin films were deposited on soda-lime glass substrate by co-sputtering quaternary alloy, and In2S3 targets. In this study, we investigated the influence of post-annealing temperature on structural, compositional, electrical, and optical properties of CIGSS films. Our experimental results show that the CIGS quaternary target had chalcopyrite characteristics. All CIGSS films annealed above 733 K exhibited a polycrystalline tetragonal chalcopyrite structure, with (1 1 2) preferred orientation. The carrier concentration and resistivity of the resultant CIGSS layer annealed above 763 K was 4.86x1016 cm-3 and 32 Ω cm, respectively, and the optical band-gap of the CIGSS absorber layer was 1.18 eV. Raman spectral analysis demonstrated the existence of many different phases, including CuInSe2, CuGaSe2, and CuInS2. This may be because the vibration frequencies of In-Se, In-S bonds are similar to the Ga-Se and Ga-S bonds, causing their absorption bands overlap. -- Research Highlights: → We report a chalcopyrite Cu(In,Ga)(Se,S)2 (CIGSS) thin films on soda lime glass substrate by co-sputtering quaternary single-phase chalcopyrite CIGS alloy, and In2S3 targets. → By incorporating sulfur into partly selenized CIGS films, researchers fabricated a chalcopyrite CIGSS layer with double-graded band-gap structure. → The CIGS quaternary target and Raman spectra were analyzed for investigating the CIGSS structure and quality.

  17. Global transcriptional responses of Acidithiobacillus ferrooxidans Wenelen under different sulfide minerals.

    Science.gov (United States)

    Latorre, Mauricio; Ehrenfeld, Nicole; Cortés, María Paz; Travisany, Dante; Budinich, Marko; Aravena, Andrés; González, Mauricio; Bobadilla-Fazzini, Roberto A; Parada, Pilar; Maass, Alejandro

    2016-01-01

    In order to provide new information about the adaptation of Acidithiobacillus ferrooxidans during the bioleaching process, the current analysis presents the first report of the global transcriptional response of the native copper mine strain Wenelen (DSM 16786) oxidized under different sulfide minerals. Microarrays were used to measure the response of At. ferrooxidans Wenelen to shifts from iron supplemented liquid cultures (reference state) to the addition of solid substrates enriched in pyrite or chalcopyrite. Genes encoding for energy metabolism showed a similar transcriptional profile for the two sulfide minerals. Interestingly, four operons related to sulfur metabolism were over-expressed during growth on a reduced sulfur source. Genes associated with metal tolerance (RND and ATPases type P) were up-regulated in the presence of pyrite or chalcopyrite. These results suggest that At. ferrooxidans Wenelen presents an efficient transcriptional system developed to respond to environmental conditions, namely the ability to withstand high copper concentrations. PMID:26476161

  18. The (CuGaSe{sub 2}){sub 1-x}(MgSe){sub x} alloy system (0{<=}x{<=}0.5): X-ray diffraction, energy dispersive spectrometry and differential thermal analysis

    Energy Technology Data Exchange (ETDEWEB)

    Grima Gallardo, P.; Munoz, M.; Ruiz, J. [Centro de Estudios en Semiconductores (C.E.S.), Dpto. Fisica, Fac. Ciencias, La Hechicera, Merida (Venezuela); Delgado, G.E. [Laboratorio de Cristalografia, Dpto. Quimica, Fac. Ciencias, Universidad de Los Andes, Merida 5101 (Venezuela); Briceno, J.M. [Laboratorio de Analisis Quimico y Estructural (LAQUEM), Dpto. Fisica, Fac. Ciencias, La Hechicera, Merida (Venezuela)

    2004-07-01

    The (CuGaSe{sub 2}){sub 1-x}(MgSe){sub x} alloy system (0=}0.15. All the alloys showed the chalcopyrite structure and the lattice parameters of the unit cell do not follow a linear behavior but showed a soft local maximum at x {proportional_to} 0.15. In the single-phase field, the increasing behavior of the lattice parameters can be reproduced using an extension for quaternary alloys of Jaffe and Zunger's model for chalcopyrites. (copyright 2004 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  19. Synthesis of CulnS_2 nanocrystals and their structural transformation triggered by lisand exchange

    Institute of Scientific and Technical Information of China (English)

    KATSUHIRO Nose; YUKI Soma; TAKAHISA Omata; SHINYA Otsuka-Yao-Matsuo

    2009-01-01

    Chalcopyrite-type CulnS_2 NCs was synthesized by the hot-soap method.Mixed solutions,Cul and InCI_3 dissolved in the mixture of the tri-octylphosphite and 1-octadecene and the sulfur dissolved in tri-phenylphosphite,were used as source solutions;the hexadecylamine was additionally mixed as a surfactant before the reaction.It was observed that the product CulnS_2 NCs structurally transformed from the chalcopyrite(CP)-or zincblende(ZB)-to the wurtzite(WZ)-type depending on the amount of the surfactant and a storage time after the surfactant addition.Very weak photoluminescence in the nearinfrared region was observed for the CP-or ZB-type NCs.This band was attributable to the electronhole recombination via defect levels.No photoluminescence was detected for the wurtzite-type NCs.

  20. Mineralogy and paragenetic study of uranium mineralisation in Rabau Hulu sector west Kalimantan

    International Nuclear Information System (INIS)

    Mineralogy and paragenetic study of uranium mineralization in Rabau Hulu sector west Kalimantan. Uranium mineralisation in Rabau Hulu was found in favourable bed of metasiltstone. Genetically the mineralization seems to be hydrothermal type, and occured at temperatures 2000C -5000C and deposited in tectonic traps. Uranium mineral found in this sector is uraninite and the associates are pyrrhotite, molybdenite pyrite, sphalterite, chalcopyrite, lollingite, bornite, tourmaline and quartz. The paragenetic can be devided into 3 paragenetic stages: 1st stage characterized by ilmenite magnetite, pyrrhotite, pyrite, rutil, and tourmaline; 2nd stage characterized by veins of uraninite, pyrrhotite, molybdenite, pyrite, spalerite, chalcopyrite, lollingite, bornite, tourmaline, and quartz; and 3rd stage contains pyrite, calcite and gypsum. (author). 7 refs.; 8 figs

  1. Improved Single-Source Precursors for Solar-Cell Absorbers

    Science.gov (United States)

    Banger, Kulbinder K.; Harris, Jerry; Hepp, Aloysius

    2007-01-01

    Improved single-source precursor compounds have been invented for use in spray chemical vapor deposition (spray CVD) of chalcopyrite semiconductor absorber layers of thin-film cells. A "single-source precursor compound" is a single molecular compound that contains all the required elements, which when used under the spray CVD conditions, thermally decomposes to form CuIn(x)Ga(1-x)S(y)Se(2-y).

  2. Reliable wet-chemical cleaning of natively oxidized high-efficiency Cu(In,Ga)Se2 thin-film solar cell absorbers

    International Nuclear Information System (INIS)

    Currently, Cu-containing chalcopyrite-based solar cells provide the highest conversion efficiencies among all thin-film photovoltaic (PV) technologies. They have reached efficiency values above 20%, the same performance level as multi-crystalline silicon-wafer technology that dominates the commercial PV market. Chalcopyrite thin-film heterostructures consist of a layer stack with a variety of interfaces between different materials. It is the chalcopyrite/buffer region (forming the p-n junction), which is of crucial importance and therefore frequently investigated using surface and interface science tools, such as photoelectron spectroscopy and scanning probe microscopy. To ensure comparability and validity of the results, a general preparation guide for “realistic” surfaces of polycrystalline chalcopyrite thin films is highly desirable. We present results on wet-chemical cleaning procedures of polycrystalline Cu(In1-xGax)Se2 thin films with an average x = [Ga]/([In] + [Ga]) = 0.29, which were exposed to ambient conditions for different times. The hence natively oxidized sample surfaces were etched in KCN- or NH3-based aqueous solutions. By x-ray photoelectron spectroscopy, we find that the KCN treatment results in a chemical surface structure which is – apart from a slight change in surface composition – identical to a pristine as-received sample surface. Additionally, we discover a different oxidation behavior of In and Ga, in agreement with thermodynamic reference data, and we find indications for the segregation and removal of copper selenide surface phases from the polycrystalline material

  3. Photosensitivity of In-p-CuIn[sub x]Ga[sub 1-x]Se[sub 2] thin film structures

    Energy Technology Data Exchange (ETDEWEB)

    Gremenok, V.F. (Inst. of Physics of Solids and Semiconductors, Academy of Sciences of Belarus, Minsk (Belarus)); Zaretskaya, E.P. (Inst. of Physics of Solids and Semiconductors, Academy of Sciences of Belarus, Minsk (Belarus)); Bodnar, I.V. (Minsk Radioengineering Inst., Minsk (Belarus)); Rud' , Yu.V. (Minsk Radioengineering Inst., Minsk (Belarus)); Magomedov, M.A. (Minsk Radioengineering Inst., Minsk (Belarus))

    1993-09-10

    Thin film polycrystalline layers of the quaternary compounds CuIn[sub x]Ga[sub 1-x]Se[sub 2] with 0 [<=] x [<=] 1 of chalcopyrite structure have been prepared by laser-assisted evaporation. Schottky barriers have been formed on the deposited films using indium. By illuminating the samples through the semitransparent indium contact, the spectral dependence of the photocurrent on the atomic composition has been investigated. The analysis of some preliminary data on the structures examined is presented. (orig.)

  4. Chemical bath composition effect on the properties of electrodeposited CuInSe2 thin films

    International Nuclear Information System (INIS)

    Highlights: • CIS thin films were grown by electrodeposition technique. • For [Se]/[Cu + In] molar ratio less than 1.3 CIS films have single phase chalcopyrite structure. • For [Se]/[Cu + In] = 1.3 CuSe secondary phase is present. • The optical absorption is due to an allowed direct transition with band gap range between 1.04 and 1.2 eV. -- Abstract: Polycrystalline chalcopyrite CuInSe2 (CIS) thin films were deposited by electrodeposition technique onto ITO coated glass substrates. The used bath solution is formed by dissolution of CuCl2, InCl3, and SeO2 salts in de-ionized water, where the [Se]/[Cu + In] molar ratio is ranged from 0.4 to 1.3. The deposited films have been annealed at 300 °C for 30 min in argon atmosphere. The films structure and surface morphology characterizations were carried out respectively by means of X-ray diffraction method (XRD) and scanning electron microscope (SEM). XRD results indicate that CIS films having single phase chalcopyrite are obtained when the [Se]/[Cu + In] molar ratio is less than 1.3. While, for [Se]/[Cu + In] = 1.3, CuSe secondary phase is present together with CIS chalcopyrite phase. The crystallites were found to have a preferred orientation along (1 1 2) direction. The UV–visible optical transmittance measurements show that films absorption is due to allowed direct transition with a band gap ranged from 1.04 to 1.2 eV

  5. Structural and optical properties of electrodeposited culnSe2 thin films for photovoltaic solar cells

    International Nuclear Information System (INIS)

    Optical an structural properties of electrodeposited copper indium diselenide, CulnSe2, thin films were studied for its application in photovoltaic devices. X-ray diffraction patterns showed that thin films were grown in chalcopyrite phase after suitable treatments. Values of Eg for the CulnSe2 thin films showed a dependence on the deposition potential as determined by optical measurements. (Author) 47 refs

  6. The distribution, character, and rhenium content of molybdenite in the Aitik Cu-Au-Ag-(Mo) deposit and its southern extension in the northern Norrbotten ore district, northern Sweden.

    OpenAIRE

    Christina Wanhainen; Wondowossen Nigatu; David Selby; Claire L. McLeod; Roger Nordin; Nils-Johan Bolin

    2014-01-01

    Molybdenite in the Aitik deposit and its southern extension was studied through mineralogical/chemical analysis and laboratory flotation tests. It is demonstrated that molybdenite varies considerably in grain size, ranging from coarse (>20 μm) to very fine (<2 μm) and occurs predominantly as single grains in the groundmass of the rocks, as grain aggregates, and intergrown with chalcopyrite and pyrite. The dominating molybdenite-bearing rocks are the mica schists, the quartz-monzodiori...

  7. The study of molybdenite types related to the ore processing plant of the Sar Cheshmeh mine

    OpenAIRE

    Balandeh Aminzadeh; Jamshid Shahabpour; Mortaza Asadipour

    2010-01-01

    Molybdenite occurs in five forms in the Sar Cheshmeh porphyry copper deposit, namely, (1)-veinlets with quartz-molybdenite, (2)-veinlets with quartz-molydenite that were filled with pyrite, (3)-veinlets with quartz-molybdenite-pyrite–chalcopyrite, (4)-Molybdenite veinlets with very low quartz and (5)-disseminated molybdenite grains. Because of their large size, the veinlet-related molybdenite grains are easily liberated from the gangue minerals, provided the grinding is properly conducted (74...

  8. Relationship between bioleaching performance, bacterial community structure and mineralogy in the bioleaching of a copper concentrate in stirred-tank reactors

    OpenAIRE

    Spolaore, Pauline; Joulian, Catherine; Gouin, Jérôme; Morin, Dominique; d'Hugues, Patrick

    2011-01-01

    During the Bioshale European project, a technoeconomic study of the bioleaching of a copper concentrate originating from a black shale ore was carried out. This concentrate is a multi-mineral resource in which the copper sulphides are mainly chalcocite, covellite, bornite and chalcopyrite. The experiments undertaken to produce the techno-economic data were also an opportunity to carry out more fundamental research. The objective of this work was to combine the results of the bioleaching exper...

  9. Metal Resistance and Lithoautotrophy in the Extreme Thermoacidophile Metallosphaera sedula

    OpenAIRE

    Maezato, Yukari; Johnson, Tyler; McCarthy, Samuel; Dana, Karl; Blum, Paul

    2012-01-01

    Archaea such as Metallosphaera sedula are thermophilic lithoautotrophs that occupy unusually acidic and metal-rich environments. These traits are thought to underlie their industrial importance for bioleaching of base and precious metals. In this study, a genetic approach was taken to investigate the specific relationship between metal resistance and lithoautotrophy during biotransformation of the primary copper ore, chalcopyrite (CuFeS2). In this study, a genetic system was developed for M. ...

  10. The principles and examples of leaching and bioleaching of copper ores

    OpenAIRE

    Krstev, Boris; Krstev, Aleksandar; Danovska, Milena

    2015-01-01

    The refractory or low grade copper chalcopyrite ores are investigated by conventional copper flotation and selective flotation for galena/sphalerite. In the meantime, investigations are directed to the new possibilities of leaching by microorganisms – bioleaching. The paper is result of these technologies and investigations carried out for recovery of in the mentioned ores. Using Simplex EVOP and computer programme Multisimplex the tabular and especially graphic performances are most acceptab...

  11. THE SEARCH OF CHEMICAL OXIDATION STAGE OF TWO STAGE PYRITE AND COPPER CONCENTRATE BIOLEACHING TECHNOLOGY

    OpenAIRE

    Scornyacov, A.; Petukhova, N.; Meftakhov, R.; Zorin, V.

    2011-01-01

    The bioleaching stage of two-stage biochemical leaching technology of pyrite and copper concentrate consisted of bornite, chalcopyrite and chalcocite, by moderate thermophiles consortium was searched. It has been shown that at 45 oC the bioleaching of copper concentrate pre-treated by biogenic leaching solution seems to be near 1.7 times faster than the non-treated one. Though the similar chemical pre-treatment of pyrite doesnt show any significant increase of its bioleaching rate.

  12. The performance of leaching and bio-leaching from sulphide ores usiing SEVOP

    OpenAIRE

    Krstev, Boris; Krstev, Aleksandar; Golomeov, Blagoj; Golomeova, Mirjana; Sala, Ferat; Gocev, Zivko; Zivanovic, Jordan; Krstev, Dejan

    2013-01-01

    The refractory or low grade copper chalcopyrite ores or galena/sphalerite domestic ores in Republic of Macedonia are investigated by conventional copper flotation and selective flotation for galena/sphalerite. In the meantime, investigations are directed to the new possibilities of leaching by microorganisms – bioleaching. The paper is result of these technologies and investigations carried out for recovery of in the mentioned ores. Using Simplex EVOP and computer programme. Multisimple...

  13. Structural and optical properties of electrodeposited culnSe{sub 2} thin films for photovoltaic solar cells; Propiedades estructurales y opticas de laminas delgadas de CulnSe2 electrodepositadas para su aplicacion en celulas solares fotovoltaicas

    Energy Technology Data Exchange (ETDEWEB)

    Guillen, C.; Herrero, J.; Galiano, F.

    1990-07-01

    Optical an structural properties of electrodeposited copper indium diselenide, CulnSe2, thin films were studied for its application in photovoltaic devices. X-ray diffraction patterns showed that thin films were grown in chalcopyrite phase after suitable treatments. Values of Eg for the CulnSe2 thin films showed a dependence on the deposition potential as determined by optical measurements. (Author) 47 refs.

  14. El proyecto de El Berrocal: síntesis preliminar

    OpenAIRE

    Pardillo, J.; Pelayo, M.; García, M.; Marín, C.; Hernández, A.; Tunero, M.; G??mez, P.; De La Cruz, B.; Pérez del Villar, L.; Rivas, P

    1993-01-01

    El Berrocal is an international research project on the natural radionuclide migration in a fissured granitic environment. This project is being carried out in the El Berrocal zone, north of the village of Nombela (Toledo). The gelogical formation studied is a granitic pluton with an epithermal vein-type mineralization comprising quartz, sphalerite, pyrite and chalcopyrite; and pitchblende, pyrite, carbonates and barite. The activities of the project are focused on the structural, lithol...

  15. New materials for intermediate band photovoltaic cells. A theoretical and experimental approach

    OpenAIRE

    Wahnón Benarroch, Perla; Palacios Clemente, Pablo; Aguilera Bonet, Irene; Seminóvski Pérez, Yohanna; Conesa, Jose Carlos; Lucena, Raquel

    2010-01-01

    Density functional theory calculations of certain transition-metal doped semiconductors show a partially occupied relatively narrow band located between valence band and conduction band. These novel systems, containing the metallic band, are called intermediate-band materials. They have enhanced optoelectronic properties which allow an increase in solar energy conversion efficiency of conventional solar cells. We previously proposed III-V, chalcopyrite and sulfide derived compounds show...

  16. A fundamental investigation into the microwave assisted leaching of sulphide minerals

    OpenAIRE

    Al-Harahsheh, Mohammad

    2005-01-01

    Microwave assisted leaching has been investigated in an attempt to improve both the yield of extracted metal and reduce processing time. This is especially pertinent in view of the increased demands for metal and more environmentally friendly processes. This work reports a fundamental study on the influence of microwave energy on the dissolution of sulphide minerals. Chalcopyrite and sphalerite were chosen as model materials due to their economic importance and the diversity of their hea...

  17. The Nussir copper deposit: petrology, mineralogy, geochemistry and distribution of ore mineralization

    OpenAIRE

    Mun, Yulia

    2013-01-01

    The geology, petrography, mineralogy and geochemistry of the Nussir copper deposit in Finnmark, Northern Norway were studied during writing this thesis. The Nussir deposit of copper is a sedimentary-hosted hydrothermal deposit affected by low grade methamorphism and ductile deformation. The copper mineralization includes chalcopyrite, chalcocite, bornite, covellite, and digenite. The deposit contains also economically interesting trace elements, such as silver, gold, and PGE. The deposit show...

  18. Magnetic Separation of Weakly Magnatic Copper Minerals

    OpenAIRE

    Agricola, J. N.M.; Top, J. L.; Fort, A. F.

    1989-01-01

    High Gradient Magnetic Separation of small (5-38 µm) weakly magnetic copper mineral particles from a copper concentrate and ore has been performed. In previous work coarser fractions of these minerals, bornite and chalcopyrite, were separated successfully. The recovery of the smaller particles in the magnetic fraction decreases but their grade increases compared to the results obtained on the larger particles. At a magnetic background field of 1.3 T the concentrate was upgraded from 72% borni...

  19. Petrography, mineral chemistry, fluid inclusion microthermometry and Re–Os geochronology of the Küre volcanogenic massive sulfide deposit (Central Pontides, Northern Turkey).

    OpenAIRE

    Akbulut, M; Oyman, T.; Çiçek, M.; Selby, D.; Özgenç, İ.; Tokçaer, M.

    2016-01-01

    The Re–Os isotopic system is applied for the first time to the sulfide ores and the overlying black-shales at the Küre volcanogenic massive sulfide deposit of the Central Pontides, Northern Turkey. The ore samples collected include predominantly pyrite, accompanied by chalcopyrite, sphalerite and other species. Massive ore is almost free of gangues, whereas the stockwork ore includes quartz and calcite gangue. The composition of sphalerite is similar to ancient and modern massive sulfide mine...

  20. The kinetic modelling from domestic ores using software tools

    OpenAIRE

    Krstev, Aleksandar; Krstev, Boris; Gocev, Zivko; Golomeov, Blagoj; Golomeova, Mirjana; Zendelska, Afrodita

    2013-01-01

    To improve kinetic models, many first - order flotation kinetics models with distributions of flotation rate constants were redefined so that they could all be represented by the same set of three model parameters. As a result, the width of the distribution become independent of its mean, and parameters of the model and the curve fitting errors, became virtually the same, independent of the chosen distribution function. In our case, investigations of the chalcopyrite ores are carried out usin...

  1. The models of optimization for increasing of copper and gold recoveries in Bucim Mine

    OpenAIRE

    Gocev, Zivko; Krstev, Aleksandar; Krstev, Boris; Golomeova, Mirjana; Zendelska, Afrodita

    2015-01-01

    The increasing in the chalcopyrite copper Bucim mine are gone forward to renewed reagent regime, including and involving new reagents for increased recovery of copper and gold. The optimization and mathematical linear are good example for improvement of industrial recoveries in flotation circuit. Nevertheless, the choice between flotation and new leaching or bioleaching method are challenge for future. The optimization techniques, for matting the mathematical model and adequate...

  2. The optimization and mathematical modelling – The precondition for increasing of recoveries from domestic mines

    OpenAIRE

    Krstev, Boris; Krstev, Aleksandar; Golomeova, Mirjana; Zendelska, Afrodita; Gocev, Zivko

    2013-01-01

    The increasing in the chalcopyrite copper Bucim mine are gone forward to renewed reagent regime, including and involving new reagents for increase d recovery of copper and gold. The optimization and mathematical linear are good example for improvement of industrial recoveries in flotation circuit. Nevertheless, the choice between flotation and new leaching or bioleaching method are challenge for future. The optimization techniques, formatting the mathematical model and adequate model for c...

  3. The mineralized veins and the impact of old mine workings on the environment at Segura, central Portugal

    OpenAIRE

    Antunes, I. M. H. R.; Neiva, A. M. R.; Silva, M. M. V. G.

    2002-01-01

    At Segura, granitic pegmatite veins with cassiterite and lepidolite, hydrothermal Sn-W quartz veins and Ba-Pb-Zn quartz veins intruded the Cambrian schist-metagraywacke complex and Hercynian granites. Cassiterite from Sn-W quartz veins is richer in Ti and poorer in Nb and Nb+Ta than cassiterite from granitic pegmatite. Wolframite from Sn-W quartz veins is enriched in ferberite component. The Sn-W quartz veins contain pyrrhotite, arsenopyrite, sphalerite, chalcopyrite, stannite, matildite and ...

  4. The Aguablanca Cu–Ni ore deposit (Extremadura, Spain), a case of synorogenic orthomagmatic mineralization: age and isotope composition of magmas (Sr, Nd) and ore (S)

    OpenAIRE

    Casquet, César; Galindo Francisco, Mª del Carmen; Tornos Arroyo, Fernando; Velasco Roldán, Francisco; Canales Gallarosa, Ángel

    2001-01-01

    The Aguablanca Cu–Ni orthomagmatic ore deposit is hosted by mafic and ultramafic rocks of the Aguablanca stock, which is part of the larger, high-K calc-alkaline Santa Olalla plutonic complex. This intrusive complex, ca. 338 Ma in age, is located in the Ossa-Morena Zone (OMZ) of the Iberian Variscan Belt. Mineralization consists mainly of pyrrhotite, pentlandite and chalcopyrite resulting from the crystallization of an immiscible sulphide-rich liquid. Isotope work on the host igne...

  5. Metabolomic study of Chilean biomining bacteria Acidithiobacillus ferrooxidans strain Wenelen and Acidithiobacillus thiooxidans strain Licanantay

    OpenAIRE

    Martínez, Patricio; Gálvez, Sebastián; Ohtsuka, Norimasa; Budinich, Marko; Cortés, María Paz; Serpell, Cristián; Nakahigashi, Kenji; Hirayama, Akiyoshi; Tomita, Masaru; Soga, Tomoyoshi; Martínez, Servet; Maass, Alejandro; Parada, Pilar

    2012-01-01

    In this study, we present the first metabolic profiles for two bioleaching bacteria using capillary electrophoresis coupled with mass spectrometry. The bacteria, Acidithiobacillus ferrooxidans strain Wenelen (DSM 16786) and Acidithiobacillus thiooxidans strain Licanantay (DSM 17318), were sampled at different growth phases and on different substrates: the former was grown with iron and sulfur, and the latter with sulfur and chalcopyrite. Metabolic profiles were scored from planktonic and sess...

  6. High and intermediate sulphidation environment in the same hydrothermal deposit: the example of Au-Cu Palai???Islica deposit, Carboneras (Almer??a)

    OpenAIRE

    Carrillo-Ros??a, Javier; Morales-Ruano, Salvador; Boyce, Adrian J.; Fallick, Anthony E.

    2003-01-01

    Two epithermal environments have been identified in the Miocene Palai???Islica Au???Cu deposit: A) Intermediate sulphidation, hosted mainly in quartz veins, comprises pyrite, chalcopyrite, sphalerite and galena as the major sulphides, which are accompanied by a variety of Ag-bearing accessory minerals. Au???Ag alloys are the only gold-bearing phase. The veins are enclosed by sericitic and chloritic alteration. Fluid inclusions in quartz, sphalerite and calcite give Th between 118???453 ??C, a...

  7. Mode de genèse et valorisation des minerais de type black shales : cas du Kupferschiefer (Pologne) et des schistes noirs de Talvivaara (Finlande)

    OpenAIRE

    Gouin, Jérôme

    2008-01-01

    This thesis was carried out in the frame of an EU-FP6 project (Bioshale) and has, as main objective a better understanding of metal concentration processes in black shale ores and their beneficiation by hydro-and biotechnologies. The low mature organic matter (OM) of the Lubin ore (Kupferschiefer) played a role during syn-, dia- and epigenetic metal enrichment processes. The ore contains 7% of Cu as well as Ag, Co, Ni, Pb, Zn, as sulphides (chalcocite, covellite, bornite, chalcopyrite...). Th...

  8. Investigation of impact materials around Barringer Meteor Crater by SEM-EDX and micro-PIXE techniques

    Energy Technology Data Exchange (ETDEWEB)

    Uzonyi, I. [Institute of Nuclear Research of the Hungarian Academy of Sciences (ATOMKI), Department of Electrostatic Accelerators, H-4026 Debrecen, Bem ter 18/C (Hungary)], E-mail: uzonyi@atomki.hu; Szoeor, Gy.; Rozsa, P. [Department of Mineralogy and Geology, University of Debrecen, H-4010 Debrecen, Egyetem ter 1 (Hungary); Pelicon, P.; Simcic, J. [Jozef Stefan Institute, Microanalytical Center, Jamova 39, P.P. 3000, SI-1001 Ljubljana (Slovenia); Cserhati, C.; Daroczi, L. [Department of Solid State Physics, University of Debrecen, H-4032 Debrecen, Bem ter 18/b (Hungary); Kiss, A.Z. [Institute of Nuclear Research of the Hungarian Academy of Sciences (ATOMKI), Department of Electrostatic Accelerators, H-4026 Debrecen, Bem ter 18/C (Hungary)

    2009-06-15

    Impact materials collected at the Barringer Meteor Crater have been characterized by SEM-EDX and micro-PIXE techniques. Fine textural and true elemental images were created. As a main feature silica-bearing shell and an S-Fe-Ni-Cu core could be distinguished. Three different types of S-Fe-Ni-Cu systems were identified such as chalcopyrite, pentlandite and pyrrhotite.

  9. Doped semiconductors and other solar energy materials

    International Nuclear Information System (INIS)

    A review is presented of recent applications of Moessbauer spectroscopy that focus on determining the fate of doped impurities in semiconductors, primarily GaAs, Ga1-xAlxAs and Si. Other solar energy materials and processes which are discussed include amorphous Si:H-based alloys, chalcopyrites, transparent conducting oxides, photochemical processing via semiconductor powders in electrolytes, mirror making, and plant photosynthesis. (orig.)

  10. Molecular solution processing of metal chalcogenide thin film solar cells

    OpenAIRE

    Yang, Wenbing

    2013-01-01

    The barrier to utilize solar generated electricity mainly comes from their higher cost relative to fossil fuels. However, innovations with new materials and processing techniques can potentially make cost effective photovoltaics. One such strategy is to develop solution processed photovoltaics which avoid the expensive vacuum processing required by traditional solar cells. The dissertation is mainly focused on two absorber material system for thin film solar cells: chalcopyrite CuIn(S,Se)2 (C...

  11. Selective Conversion of Biorefinery Lignin into Dicarboxylic Acids

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Ruoshui; Guo, Mond; Zhang, Xiao

    2014-02-01

    The emerging biomass-to-biofuel conversion industry has created an urgent need for identifying new applications for biorefinery lignin. This paper demonstrates a new route to producing dicarboxylic acids from biorefinery lignin through chalcopyrite-catalyzed oxidation in a highly selective process. Up to 95 % selectivity towards stable dicarboxylic acids was obtained for several types of biorefinery lignin and model compounds under mild, environmentally friendly reaction conditions. The findings from this study paved a new avenue to biorefinery lignin conversions and applications.

  12. Environmental geochemistry of the polymetallic ore deposits: Case studies from the Rude and the Sv. Jakob historical mining sites, NW Croatia

    OpenAIRE

    Strmić Palinkaš, Sabina; A. Palinkaš, Ladislav; Kuzmanović, Maja; Martinić, Maša; Kampić, Štefica; Dogančić, Dragana; Obhođaš, Jasmina

    2013-01-01

    This paper presents the results of the sampling surveys carried out in order to evaluate the environmental impact of the Rude and the Sv. Jakob historical mining sites, NW Croatia. The studied polymetallic ore deposits are differing in the mineralogical and geochemical features as well as in the host rock lithology. The Rude Fe-Cu-Pb-Zn-Ba deposit is hosted by Permian siliciclastic sediments. Siderite, hematite, galena, sphalerite, chalcopyrite, pyrite, barite and gypsum are the major ore mi...

  13. Information technologies and using of the software tools for the copper kinetic flotation modelling

    OpenAIRE

    Krstev, Aleksandar; Krstev, Boris; Zdravev, Zoran; Krstev, Dejan; Gocev, Zivko; Zivanovic, Jordan

    2013-01-01

    To improve kinetic flotation models, many first-order flotation kinetics models with distributions of flotation rate constants were redefined so that they could all be represented by the same set of three model parameters. As a result, the width of the distribution become independent of its mean, and parameters of the model and the curve fitting errors, became virtually the same, independent of the chosen distribution function. In our case, investigations of the chalcopyrite ores are carried ...

  14. The evolutionary planning of the flotation concentration from the copper ore

    OpenAIRE

    Krstev, Boris; Dimovski, Simeon; Blazev, Sande

    1994-01-01

    In this paper will be shown practical application of the simulation in flotation process by means of simulation programmes SIMPROC & EVOP using chalcopyrite concentration from Buвim-Macedoni-amine. In fact, the operation conditions of the flotation process are planned for determined period, and on the bassis of the obtained results once more will, be planned following conditions of the same process. Simulation by computer programmes SIMPROC & EVOP is the good possibility for optimisation of t...

  15. Banded sulfide-magnetite ores of Mauk copper massive sulfide deposit, Central Urals: Composition and genesis

    Science.gov (United States)

    Safina, N. P.; Maslennikov, V. V.; Maslennikova, S. P.; Kotlyarov, V. A.; Danyushevsky, L. V.; Large, R. R.; Blinov, I. A.

    2015-05-01

    The results of investigation of metamorphosed sulfide-magnetite ores from the Mauk deposit located within the Main Ural Fault at the junction of Tagil and Magnitogorsk massive sulfide zones are discussed. The ore-hosting sequence comprises metamorphic rocks formed from basalt, carbonaceous and carbonaceous-cherty siltstone, and lenticular serpentinized ultramafic bodies. The ores of the deposit are represented by banded varieties and less frequent breccia. The clastic origin of the banded ore is indicated by load casts at the bottom of sulfide beds, alternation of sulfide and barren beds, and the truncation of the growth zones of pyrite crystals. Pyrite, pyrrhotite, chalcopyrite, sphalerite, and magnetite are the major minerals of the banded ores. The internal structure of the listed minerals testifies to the deep metamorphic recrystallization of primary hydrothermal-sedimentary ores accompanied with deformation. Cubanite, pyrrhotite, mackinawite, greigite, and gold are enclosed in metacrysts of pyrite, magnetite, and chalcopyrite. The accessory minerals of the Pb-Bi-Te, Bi-Te, and Ag-Te systems as well as uraninite have been found at the Mauk deposit for the first time. Magnetite predominantly replaces pyrite and less frequently chalcopyrite, pyrrhotite, and gangue minerals. It was established that the major carriers of As and Co are crystals of metamorphic pyrite. Chalcopyrite is the major carrier of Zn, Sn, Te, Pb, Bi, and Ag. Admixture of Fe and Cu is typical of sphalerite, and Se and Ni are characteristic of pyrrhotite. Ti, V, Mn, Sb, As, Ba, and U are concentrated in magnetite. The banded ores of the Mauk deposit are suggested as having been transformed in several stages: diagenesis, anadiagenesis, epidiagenesis ( t 500°C).

  16. Air pollution in surrounding environment of Sasa tailing dam – ambient air, plant dust and ceiling dust

    OpenAIRE

    Krstev, Boris; Krstev, Aleksandar; Golomeov, Blagoj; Golomeova, Mirjana; Zendelska, Afrodita; Danevski, Tome; Fidancev, Boris

    2013-01-01

    The current and recent activities in the lead-zinc Sasa mine or copper Bucim mine and flotation of galena and sphalerite or chalcopyrite, producing metals for market, are reason for possible troubles from tailing dam-pond and surrounding river, ambient air and plant or ceiling dust. This appearance is significant for the surrounding environment, but legislative and ecological law directive limited the quantity of these. In this paper will be present results of investigations from plant ...

  17. Assessment of heavy metals pollution in sulphide mine affected-soils of madrid, central spain

    OpenAIRE

    Torres, M.; Recio Vázquez, Lorena; Carral, Pilar; Álvarez, Ana María

    2011-01-01

    The uncontrolled extraction of mineral resources is considered one of the major anthropogenic sources of soil pollution. In Spain, exploitation of metallic mineral deposits and its subsequent abandonment in last decades has lead to significant environmental hazard for natural systems. In this research, potentially contaminated soils surrounding an old chalcopyrite mine district in Madrid (Central Spain) have been studied. The focus is to assess the degree of pollution by heavy metals and othe...

  18. <報文>中国金川産含銅ニッケル硫化鉱の浮選(第2報) : 捕収剤, 抑制剤および再摩鉱の効果について

    OpenAIRE

    山本, 泰二; 呉, 振東; 張, 礼強

    1988-01-01

    The effects of the collectors such as xanthate, aerofloat, aerophine (3418A), aeropromoter (4037) and sodium mercaptobenzothiazole, the depressants such as meyprofloc, jaguar (CP-B and CMHP), tannic acid and carboxymethylcellulose, and the regrinding were investigated with respect to the flotation of coppernickel sulphide ores front the Jinchuan mine. The results obtained are as follows ; (1) The floatabilities of pentlandite and chalcopyrite with sodium mercaptobenzothiazole are similar to t...

  19. Revealing the optoelectronic and thermoelectric properties of the Zintl quaternary arsenides ACdGeAs{sub 2} (A = K, Rb)

    Energy Technology Data Exchange (ETDEWEB)

    Azam, Sikander; Khan, Saleem Ayaz [New Technologies—Research Center, University of West Bohemia, Univerzitni 8, 306 14 Pilsen (Czech Republic); Goumri-Said, Souraya, E-mail: Souraya.Goumri-Said@chemistry.gatech.edu [School of Chemistry and Biochemistry and Center for Organic Photonics and Electronics, Georgia Institute of Technology, Atlanta, GA 30332-0400 (United States)

    2015-10-15

    Highlights: • Zintl tetragonal phase ACdGeAs{sub 2} (A = K, Rb) are chalcopyrite and semiconductors. • Their direct band gap is suitable for PV, optolectronic and thermoelectric applications. • Combination of DFT and Boltzmann transport theory is employed. • The present arsenides are found to be covalent materials. - Abstract: Chalcopyrite semiconductors have attracted much attention due to their potential implications in photovoltaic and thermoelectric applications. First principle calculations were performed to investigate the electronic, optical and thermoelectric properties of the Zintl tetragonal phase ACdGeAs{sub 2} (A = K, Rb) using the full potential linear augmented plane wave method and the Engle–Vosko GGA (EV–GGA) approximation. The present compounds are found semiconductors with direct band gap and covalent bonding character. The optical transitions are investigated via the dielectric function (real and imaginary parts) along with other related optical constants including refractive index, reflectivity and energy-loss spectrum. Combining results from DFT and Boltzmann transport theory, we reported the thermoelectric properties such as the Seebeck’s coefficient, electrical and thermal conductivity, figure of merit and power factor as function of temperatures. The present chalcopyrite Zintl quaternary arsenides deserve to be explored for their potential applications as thermoelectric materials and for photovoltaic devices.

  20. The complicated substrates enhance the microbial diversity and zinc leaching efficiency in sphalerite bioleaching system.

    Science.gov (United States)

    Xiao, Yunhua; Xu, YongDong; Dong, Weiling; Liang, Yili; Fan, Fenliang; Zhang, Xiaoxia; Zhang, Xian; Niu, Jiaojiao; Ma, Liyuan; She, Siyuan; He, Zhili; Liu, Xueduan; Yin, Huaqun

    2015-12-01

    This study used an artificial enrichment microbial consortium to examine the effects of different substrate conditions on microbial diversity, composition, and function (e.g., zinc leaching efficiency) through adding pyrite (SP group), chalcopyrite (SC group), or both (SPC group) in sphalerite bioleaching systems. 16S rRNA gene sequencing analysis showed that microbial community structures and compositions dramatically changed with additions of pyrite or chalcopyrite during the sphalerite bioleaching process. Shannon diversity index showed a significantly increase in the SP (1.460), SC (1.476), and SPC (1.341) groups compared with control (sphalerite group, 0.624) on day 30, meanwhile, zinc leaching efficiencies were enhanced by about 13.4, 2.9, and 13.2%, respectively. Also, additions of pyrite or chalcopyrite could increase electric potential (ORP) and the concentrations of Fe3+ and H+, which were the main factors shaping microbial community structures by Mantel test analysis. Linear regression analysis showed that ORP, Fe3+ concentration, and pH were significantly correlated to zinc leaching efficiency and microbial diversity. In addition, we found that leaching efficiency showed a positive and significant relationship with microbial diversity. In conclusion, our results showed that the complicated substrates could significantly enhance microbial diversity and activity of function. PMID:26266752

  1. Nuclear chemical mining of primary copper sulfides

    International Nuclear Information System (INIS)

    A contained nuclear explosion is proposed to produce a chimney of broken ore well below the water table. After the chimney is filled with water and reaches hydrostatic equilibrium, O, under pressure, is introduced near the bottom of the mass of broken rock. The increase in solubility of O at high hydrostatic pressure is sufficient to initiate the oxidation of the primary sulphides, chalcopyrite and pyrite. The oxidation and dissolution of these sulphides produces enough heat to increase the temperature of the ore and water in the chimney as much as 100 to 1500C. The rate of dissolution of chalcopyrite exposed to O-saturated solutions becomes so rapid under these conditions that the rate of Cu extraction becomes limited to the accessibility of chalcopyrite to the solutions. Means of solution control and distribution of O in the chimney have been examined in some detail. A calculational model utilizing experimentally determined solubility rates is utilized to estimate the temperature rise in the chimney and the rate of Cu recovery as a function of initial temperature, sulphide content of ore and size of ore particles. It is concluded that the high pressure and high temperature obtainable in a large ore mass broken by nuclear explosives promise the rapid and economic recovery of minerals not considered soluble by conventional in situ leaching methods. The method should be broadly applicable to the kinds of deep deposits that must be depended on for future production and with minimum disruption of the environment. (U.S.)

  2. Revealing the optoelectronic and thermoelectric properties of the Zintl quaternary arsenides ACdGeAs2 (A = K, Rb)

    International Nuclear Information System (INIS)

    Highlights: • Zintl tetragonal phase ACdGeAs2 (A = K, Rb) are chalcopyrite and semiconductors. • Their direct band gap is suitable for PV, optolectronic and thermoelectric applications. • Combination of DFT and Boltzmann transport theory is employed. • The present arsenides are found to be covalent materials. - Abstract: Chalcopyrite semiconductors have attracted much attention due to their potential implications in photovoltaic and thermoelectric applications. First principle calculations were performed to investigate the electronic, optical and thermoelectric properties of the Zintl tetragonal phase ACdGeAs2 (A = K, Rb) using the full potential linear augmented plane wave method and the Engle–Vosko GGA (EV–GGA) approximation. The present compounds are found semiconductors with direct band gap and covalent bonding character. The optical transitions are investigated via the dielectric function (real and imaginary parts) along with other related optical constants including refractive index, reflectivity and energy-loss spectrum. Combining results from DFT and Boltzmann transport theory, we reported the thermoelectric properties such as the Seebeck’s coefficient, electrical and thermal conductivity, figure of merit and power factor as function of temperatures. The present chalcopyrite Zintl quaternary arsenides deserve to be explored for their potential applications as thermoelectric materials and for photovoltaic devices

  3. Electrodeposition of Mg doped ZnO thin film for the window layer of CIGS solar cell

    Science.gov (United States)

    Wang, Mang; Yi, Jie; Yang, Sui; Cao, Zhou; Huang, Xiaopan; Li, Yuanhong; Li, Hongxing; Zhong, Jianxin

    2016-09-01

    Mg doped ZnO (ZMO) film with the tunable bandgap can adjust the conduction band offset of the window/chalcopyrite absorber heterointerface to positive to reduce the interface recombination and resulting in an increasement of chalcopyrite based solar cell efficiency. A systematic study of the effect of the electrodeposition potential on morphology, crystalline structure, crystallographic orientation and optical properties of ZMO films was investigated. It is interestingly found that the prepared doped samples undergo a significant morphological change induced by the deposition potential. With negative shift of deposition potential, an obvious morphology evolution from nanorod structrue to particle covered films was observed. A possible growth mechanism for explaining the morphological change is proposed and briefly discussed. The combined optical techniques including absorption, transmission and photoluminescence were used to study the obtained ZMO films deposited at different potential. The sample deposited at -0.9 V with the hexagonal nanorods morphology shows the highest optical transparency of 92%. The photoluminescence spectra reveal that the crystallization of the hexagonal nanorod ZMO thin film deoposited at -0.9 V is much better than the particles covered ZMO thin film. Combining the structural and optical properties analysis, the obtained normal hexagonal nanorod ZMO thin film could potentially be useful in nanostructured chalcopyrite solar cells to improve the device performance.

  4. Solvent effect in the synthesis of Cu–In–S and Cu–In–Se nanocrystals with tunable structure and composition

    International Nuclear Information System (INIS)

    The role of the solvent in the preparation of ternary CuInX2 (X = S or Se) nanocrystals was investigated. It was found that the use of oleylamine as a solvent with copper(II) oleate, indium(III) acetate diphenyl diselenide as precursors yields copper-rich, wurtzite-type Cu2.0In1.0Se2.5 (2Cu2Se–In2Se3) nanocrystals which after size sorting exhibit the quantum confinement effect. Changing oleylamine for 1-octadecene, while keeping the same set of precursors and reaction conditions, results in the formation of indium-rich chalcopyrite nanocrystals Cu1.0In1.8Se3.2 (Cu2Se-1.8 In2Se3). The differences in the stoichiometry can be rationalized on the basis of stronger reducing properties of oleylamine which more effectively reduces Cu(II) to Cu(I) in the reaction medium. Stoichiometric chalcopyrite CuInSe2 nanocrystals can be obtained in the same conditions by exchanging diphenyl diselenide for the Woollins' reagent, never previously applied to the preparation of Cu–In–Se nanocrystals. In the case of Cu–In–S nanocrystals the chemical composition is governed not by the type of the solvent but by the reducing properties of 1-dodecanethiol, the precursor of sulfur. Independently of the solvent copper-rich nanocrystals are obtained of either wurtzite-type Cu1.6In1.0S2.3 (1.6 Cu2S–In2S3) in 1-octadecene or chalcopyrite-type Cu1.8In1.0S2.4 (1.8 Cu2S–In2S3) in oleylamine. - Graphical abstract: Display Omitted - Highlights: • The role of the solvent in the preparation of ternary nanocrystals was investigated. • OLA yields wurtzite-type Cu2.0In1.0Se2.5 and chalcopyrite-type Cu1.8In1.0S2.4. • ODE yields chalcopyrite-type Cu1.0In1.8Se3.2 and wurtzite-type Cu1.6In1.0S2.3

  5. Adaptación de una cepa compatible con Acidithiobacillus ferrooxidans sobre concentrados de calcopirita (CuFeS2, esfalerita (ZnS y galena (PbS

    Directory of Open Access Journals (Sweden)

    E Mejía

    2011-08-01

    Full Text Available Adaptation of a strain Acidithiobacillus ferrooxidans compatible on concentrates of chalcopyrite (CuFeS2, sphalerite (ZnS and galena (PbSRESUMENEn este estudio se evaluó la adaptación de una cepa compatible con Acidithiobacillus ferrooxidans a altas densidades de pulpa de calcopirita, esfalerita y galena, con dos distribuciones de tamaño de partícula, -200 y -325 serie Tyler de tamices. Los microorganismos fueron adaptados por la disminución gradual de la fuente principal de energía, sulfato ferroso, y el aumento en el contenido de mineral, para finalmente realizar un subcultivo sin la adición de fuente de energía externa. La realización de subcultivos en serie resultó ser una estrategia eficaz para la adaptación a altas densidades de pulpa de esfalerita, calcopirita y galena indicando que el protocolo empleado es adecuado. Los resultados muestran que la cepa compatible con Acidithiobacillus ferrooxidans es más resistente a altas concentraciones de esfalerita, seguido por calcopirita y finalmente por galena. El tamaño de partícula juega un papel fundamental en la adaptación de los microorganismos al mineral. Palabras clave: esfalerita, calcopirita, galena, adaptación, Acidithiobacillus ferrooxidans, biolixiviación. ABSTRACTIn this study the adaptation of Acidithiobacillus ferrooxidans-like to high concentrations of chalcopyrite, sphalerite and galena were evaluated with two mineral-particle sizes: 200 and 325 Tyler mesh. The strain was adapted using two simultaneous processes. The first one consisted in a gradual decreasing of the main energy source, ferrous sulphate. The second one consisted in a gradual increasing of the mineral content. Finally, a test was made without ferrous sulphate. The serial subculturing was found to be an efficient strategy to adapt Acidithiobacillus ferrooxidans-like to higher concentrations of chalcopyrite, sphalerite and galena. This indicates that a suitable protocol was employed. The results

  6. Platinum-group element concentrations in pyrite from the Main Sulfide Zone of the Great Dyke of Zimbabwe

    Science.gov (United States)

    Piña, R.; Gervilla, F.; Barnes, S.-J.; Oberthür, T.; Lunar, R.

    2016-02-01

    The Main Sulfide Zone (MSZ) of the Great Dyke of Zimbabwe hosts the world's second largest resource of platinum-group elements (PGE) after the Bushveld Complex in South Africa. The sulfide assemblage of the MSZ comprises pyrrhotite, pentlandite, chalcopyrite, and minor pyrite. Recently, several studies have observed in a number of Ni-Cu-PGE ore deposits that pyrite may host significant amounts of PGE, particularly Pt and Rh. In this study, we have determined PGE and other trace element contents in pyrite from the Hartley, Ngezi, Unki, and Mimosa mines of the Great Dyke by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Based on the textures and PGE contents, two types of pyrite can be differentiated. Py1 occurs as individual euhedral or subhedral grains or clusters of crystals mostly within chalcopyrite and pentlandite, in some cases in the form of symplectitic intergrowths, and is PGE rich (up to 99 ppm Pt and 61 ppm Rh; 1.7 to 47.1 ppm Ru, 0.1 to 7.8 ppm Os, and 1.2 to 20.2 ppm Ir). Py2 occurs as small individual euhedral or subhedral crystals within pyrrhotite, pentlandite, and less frequently within chalcopyrite and silicates and has low PGE contents (<0.11 ppm Pt, <0.34 ppm Rh, <2.5 ppm Ru, <0.37 ppm Ir, and <0.40 ppm Os). Py1 contains higher Os, Ir, Ru, Rh, and Pt contents than the associated pyrrhotite, pentlandite, and chalcopyrite, whereas Py2 has similar PGE contents as coexisting pyrrhotite and pentlandite. Based on the textural relationships, two different origins are attributed for each pyrite type. Py1 intergrowth with pentlandite and chalcopyrite is inferred to have formed by late, low temperature (<300 °C) decomposition of residual Ni-rich monosulfide solid solution, whereas Py2 is suggested to have formed by replacement of pyrrhotite and pentlandite caused by late magmatic/hydrothermal fluids.

  7. Petrography, sulfide mineral chemistry, and sulfur isotope evidence for a hydrothermal imprint on Musina copper deposits, Limpopo Province, South Africa: Evidence for a breccia pipe origin?

    Science.gov (United States)

    Chaumba, Jeff B.; Mundalamo, Humbulani R.; Ogola, Jason S.; Cox, J. A.; Fleisher, C. J.

    2016-08-01

    The Musina copper deposits are located in the Central Zone of the Limpopo orogenic belt in Limpopo Province, South Africa. We carried out a petrographic, sulfide composition, and δ34S study on samples from Artonvilla and Campbell copper deposits and a country rock granitic gneiss to Artonvilla Mine to place some constrains on the origin of these deposits. The assemblages at both Artonvilla and Campbell Mines of brecciated quartz, potassium feldspar, muscovite, chlorite, calcite, and amphibole are consistent with sericitic alteration. Quartz, amphibole, feldspars, and micas often display angular textures which are consistent with breccias. Sulfur concentrations in pyrite from Artonvilla Mine plot in a narrow range, from 50.2 wt. % to 55.7 wt. %. With the exception of a positive correlation between Fe and Cu, no well defined correlations are shown by data from the Musina copper deposits. The occurrence of sulfides both as inclusions in, or as interstitial phases in silicates, suggests that hydrothermal alteration that affected these deposits most likely helped concentrate the mineralization at the Musina copper deposits. Sulfur concentrations in chalcopyrite samples investigated vary widely whereas the copper concentrations in chalcopyrite are not unusually higher compared to those from chalcopyrite from other tectonic settings, probably indicating that either the Cu in the Musina copper deposits occurs in native form, and/or that it is hosted by other phases. This observation lends support to the Cu having been concentrated during a later hydrothermal event. One sample from Artonvilla Mine (AtCal01) yielded pyrite δ34S values of 3.1and 3.6‰ and chalcopyrite from the same sample yielded a value of 3.9‰. A country rock granitic gneiss to Artonvilla Mine yielded a δ34Spyrite value of 8.2‰. For Campbell Mine samples, one quartz vein sample has a δ34Spyrite value of 0.5‰ whereas chalcopyrite samples drilled from different areas within the same sample

  8. Proton microprobe study of tin-polymetallic deposits

    Energy Technology Data Exchange (ETDEWEB)

    Murao, S. [Geological Survey of Japan, Tsukuba, Ibaraki (Japan); Sie, S.H.; Suter, G.F. [Commonwealth Scientific and Industrial Research Organisation (CSIRO), North Ryde, NSW (Australia). Div. of Exploration Geoscience

    1996-12-31

    Tin-polymetallic vein type deposits are a complex mixture of cassiterite and sulfides and they are the main source of technologically important rare metals such as indium and bismuth. Constituent minerals are usually fine grained having wide range of chemical composition and often the elements of interest occur as trace elements not amenable to electron microprobe analysis. PIXE with a proton microprobe can be an effective tool to study such deposits by delineating the distribution of trace elements among carrier minerals. Two representative indium-bearing deposits of tin- polymetallic type, Tosham of India (Cu-ln-Bi-Sn-W-Ag), and Mount Pleasant of Canada (Zn-Cu-In-Bi-Sn-W), were studied to delineate the distribution of medical/high-tech rare metals and to examine the effectiveness of the proton probe analysis of such ore. One of the results of the study indicated that indium and bismuth are present in chalcopyrite in the deposits. In addition to these important rare metals, zinc, copper, arsenic, antimony, selenium, and tin are common in chalcopyrite and pyrite. Arsenopyrite contains nickel, copper, zinc, silver, tin, antimony and bismuth. In chalcopyrite and pyrite, zinc, arsenic, indium, bismuth and lead are richer in Mount Pleasant ore, but silver is higher at Tosham. Also thallium and gold were found only in Tosham pyrite. The Tosham deposit is related to S-type granite, while Mount Pleasant to A-type. It appears that petrographic character of the source magma is one of the factors to determine the trace element distribution in tin-polymetallic deposit. 6 refs., 2 figs.

  9. Exploration of gold occurrences in alteration zones at Dungash district, Southeastern Desert of Egypt using ASTER data and geochemical analyses

    Science.gov (United States)

    Salem, S. M.; El Sharkawi, M.; El-Alfy, Z.; Soliman, N. M.; Ahmed, S. E.

    2016-05-01

    The present study aims at exploration of new gold occurrences in the alteration zones at Dungash district. Processed ASTER images band ratios 7/6 × 4/6 and (7 + 9/8), field geology and mineralogical and geochemical data help characterize three types of alterations in three areas 1 to 3 that may be targeted for Au exploration. Area1 confined to the metavolcanics located in the SE of Dungash gold mine and revealed silicified and sericitized type alterations, composed of quartz, epidote, chlorite, biotite and opaque minerals mainly pyrite and chalcopyrite. Area2 occurs in the gabbro-diorite rocks at Abu Meraiwa area NE of Dungash gold mine, which are rich in kaolinite, illite, sericite, pyrite, arsenopyrite and chalcopyrite that record kaolinitized alteration. Area3 is hosted in carbonaceous listwaenized serpentinite thus indicating the role of listwaenitization type alteration in ore genesis. It is composed of calcite, chromite, pyrite, arsenopyrite, chalcopyrite and Ni-bearing sulphides. Au contents in area 1 range between 0.12 and 14.91 ppm, and between 6.1 and 16.3 ppm in area 2, while gold values in area 3 vary from <0.01 to 0.03 ppm. Dungash district is comprised of Pan-African assemblages of ophiolitic ultramafics thrusted over the island arc metavolcanics of dacitic- andesite composition. Gabbro-diorite rocks are intruded in the ultramafics and the acidic metavolcanics as well as diorite-quartz diorite suite intruded in the intermediate metavolcanics. Several acidic dykes, granitic dykes and quartz veins cut through the different rocks types.

  10. Control of gallium incorporation in sol–gel derived CuIn{sub (1−x)}Ga{sub x}S{sub 2} thin films for photovoltaic applications

    Energy Technology Data Exchange (ETDEWEB)

    Bourlier, Yoan [Institut de Recherche sur les Composants logiciels et matériels pour l’Information et la Communication Avancée (IRCICA), CNRS USR 3380, Université Lille 1, 50 avenue Halley, 59655 Villeneuve d’Ascq CEDEX (France); Cristini Robbe, Odile [Institut de Recherche sur les Composants logiciels et matériels pour l’Information et la Communication Avancée (IRCICA), CNRS USR 3380, Université Lille 1, 50 avenue Halley, 59655 Villeneuve d’Ascq CEDEX (France); Laboratoire de Physique des Lasers, Atomes et Molécules (PhLAM), CNRS UMR 8523, Université Lille, 59655 Villeneuve d’Ascq CEDEX (France); Lethien, Christophe [Institut de Recherche sur les Composants logiciels et matériels pour l’Information et la Communication Avancée (IRCICA), CNRS USR 3380, Université Lille 1, 50 avenue Halley, 59655 Villeneuve d’Ascq CEDEX (France); Laboratoire de Physique des Lasers, Atomes et Molécules (PhLAM), CNRS UMR 8523, Université Lille, 59655 Villeneuve d’Ascq CEDEX (France); Institut d’Electronique, de Microélectronique et de Nanotechnologie (IEMN), CNRS UMR 8520, Avenue Poincaré, 59652 Villeneuve d’Ascq CEDEX (France); and others

    2015-10-15

    Highlights: • CuIn{sub (1−x)}Ga{sub x}S{sub 2} thin films were prepared by sol–gel process. • Evolution of lattice parameters is characteristic of a solid solution. • Optical band gap was found to be linearly dependent on the gallium rate. - Abstract: In this paper, we report the elaboration of Cu(In,Ga)S{sub 2} chalcopyrite thin films via a sol–gel process. To reach this aim, solutions containing copper, indium and gallium complexes were prepared. These solutions were thereafter spin-coated onto the soda lime glass substrates and calcined, leading to metallic oxides thin films. Expected chalcopyrite films were finally obtained by sulfurization of oxides layers using a sulfur atmosphere at 500 °C. The rate of gallium incorporation was studied both at the solutions synthesis step and at the thin films sulfurization process. Elemental and X-ray diffraction (XRD) analyses have shown the efficiency of monoethanolamine used as a complexing agent for the preparation of CuIn{sub (1−x)}Ga{sub x}S{sub 2} thin layers. Moreover, the replacement of diethanolamine by monoethanolamine has permitted the substitution of indium by isovalent gallium from x = 0 to x = 0.4 and prevented the precipitation of copper derivatives. XRD analyses of sulfurized thin films CuIn{sub (1−x)}Ga{sub x}S{sub 2,} clearly indicated that the increasing rate of gallium induced a shift of XRD peaks, revealing an evolution of the lattice parameter in the chalcopyrite structure. These results were confirmed by Raman analyses. Moreover, the optical band gap was also found to be linearly dependent upon the gallium rate incorporated within the thin films: it varies from 1.47 eV for x = 0 to 1.63 eV for x = 0.4.

  11. Gene identification and substrate regulation provide insights into sulfur accumulation during bioleaching with the psychrotolerant acidophile Acidithiobacillus ferrivorans.

    Science.gov (United States)

    Liljeqvist, Maria; Rzhepishevska, Olena I; Dopson, Mark

    2013-02-01

    The psychrotolerant acidophile Acidithiobacillus ferrivorans has been identified from cold environments and has been shown to use ferrous iron and inorganic sulfur compounds as its energy sources. A bioinformatic evaluation presented in this study suggested that Acidithiobacillus ferrivorans utilized a ferrous iron oxidation pathway similar to that of the related species Acidithiobacillus ferrooxidans. However, the inorganic sulfur oxidation pathway was less clear, since the Acidithiobacillus ferrivorans genome contained genes from both Acidithiobacillus ferrooxidans and Acidithiobacillus caldus encoding enzymes whose assigned functions are redundant. Transcriptional analysis revealed that the petA1 and petB1 genes (implicated in ferrous iron oxidation) were downregulated upon growth on the inorganic sulfur compound tetrathionate but were on average 10.5-fold upregulated in the presence of ferrous iron. In contrast, expression of cyoB1 (involved in inorganic sulfur compound oxidation) was decreased 6.6-fold upon growth on ferrous iron alone. Competition assays between ferrous iron and tetrathionate with Acidithiobacillus ferrivorans SS3 precultured on chalcopyrite mineral showed a preference for ferrous iron oxidation over tetrathionate oxidation. Also, pure and mixed cultures of psychrotolerant acidophiles were utilized for the bioleaching of metal sulfide minerals in stirred tank reactors at 5 and 25°C in order to investigate the fate of ferrous iron and inorganic sulfur compounds. Solid sulfur accumulated in bioleaching cultures growing on a chalcopyrite concentrate. Sulfur accumulation halted mineral solubilization, but sulfur was oxidized after metal release had ceased. The data indicated that ferrous iron was preferentially oxidized during growth on chalcopyrite, a finding with important implications for biomining in cold environments. PMID:23183980

  12. Potential distribution of Cu(In,Ga)(S,Se)2-solar cell cross-sections measured by Kelvin probe force microscopy

    International Nuclear Information System (INIS)

    Current high-efficiency chalcopyrite thin-film solar cells contain multilayer structures consisting of an absorber, a buffer and a window layer. The modeling and optimization of the structures have been hampered by the lack of characterization methods to assess the electrical potential and conduction band alignment in actual devices. In this work, Kelvin probe force microscopy (KPFM) under ultrahigh vacuum (UHV) conditions is used to directly image the electronic structure of a complete thin film solar cell based on Cu(In,Ga)(S,Se)2 absorber material. The potential distribution along different solar cells is directly measured by KPFM on polished and UHV-cleaned cross-sections. Due to the high-energy sensitivity together with a lateral resolution in the nanometer range, detailed information about the various interfaces within the heterostructure is obtained. In combination with simulations of the tip-sample interaction, the work function of the different layers and the built-in voltage of the heterostructure are deduced. In our previous work, we have demonstrated that the use of a Zn1-xMg xO alloy instead of the i-ZnO layer influences the conduction band offset between chalcopyrite absorber and window layer. This substitution enabled us to improve the solar cell performance from no. etano. =6.3% for the CdS-free solar cell with pure i-ZnO to no. etano. =12.5% for the cell with Zn1-xMg xO, which is comparable to that of the reference cells with a CdS buffer (no. etano. =13.2%). We present KPFM studies of comparable devices to illustrate the possibilities of our novel characterization method. The studies demonstrate that KPFM is an excellent tool for the characterization of heterostructures on a nanometer length scale. In chalcopyrite solar cells, the KPFM technique can lead to a direct correlation between the electronic structure and the solar cell performance

  13. The use of autoradiography to accurately enumerate viable iron oxidizing leaching bacteria

    International Nuclear Information System (INIS)

    A method using 14CO2 fixation and autoradiography has been developed. The method relies on viable leaching bacteria being able to oxidize iron, fix 14CO2 and form colonies on membrane filters. After drying, the membranes are placed on X-ray film and colonies containing radioactive carbon expose the film. Colonies were visualized as black spots on the X-ray film. The autoradiograph method was used to measure viable iron oxidizing leaching bacteria in a variety of leachates. A direct relationship was found between total cell count (T. ferrooxidans batch culture) and viable cells using the autoradiographic method (r2 = 0.96). The results suggested that one in four cells counted by phase contrast microscopy were viable by the autoradiographic method. The autoradiographic method and agarose gel plating were used to determine the number of viable leaching bacteria in leachates from a variety of sulfides. The number of viable leaching bacteria using autoradiography was well correlated to metal release from Mt Lyell and Mr Isa chalcopyrite. Lead release from galena (PbS) was correlated to viable cell number using autoradiography was well correlated to metal release from Mt Lyell and Mr Isa chalcopyrite. Lead release from galena (PbS) was correlated to viable cell number using autoradiography (r2 = 0.98). Good correlations between metal ion release and viability using the autoradiographic technique suggests that the technique is enumerating organisms involved in biodegradation of sulfides. Viable cell numbers using agarose gel plating were much lower (6--25 times) and showed no correlations to metal ion release from Mt Lyell and Mt Isa chalcopyrites and galena (PbS). Viable cell numbers from marmatite (ZnS) did not correlate with zinc release

  14. Control of gallium incorporation in sol–gel derived CuIn(1−x)GaxS2 thin films for photovoltaic applications

    International Nuclear Information System (INIS)

    Highlights: • CuIn(1−x)GaxS2 thin films were prepared by sol–gel process. • Evolution of lattice parameters is characteristic of a solid solution. • Optical band gap was found to be linearly dependent on the gallium rate. - Abstract: In this paper, we report the elaboration of Cu(In,Ga)S2 chalcopyrite thin films via a sol–gel process. To reach this aim, solutions containing copper, indium and gallium complexes were prepared. These solutions were thereafter spin-coated onto the soda lime glass substrates and calcined, leading to metallic oxides thin films. Expected chalcopyrite films were finally obtained by sulfurization of oxides layers using a sulfur atmosphere at 500 °C. The rate of gallium incorporation was studied both at the solutions synthesis step and at the thin films sulfurization process. Elemental and X-ray diffraction (XRD) analyses have shown the efficiency of monoethanolamine used as a complexing agent for the preparation of CuIn(1−x)GaxS2 thin layers. Moreover, the replacement of diethanolamine by monoethanolamine has permitted the substitution of indium by isovalent gallium from x = 0 to x = 0.4 and prevented the precipitation of copper derivatives. XRD analyses of sulfurized thin films CuIn(1−x)GaxS2, clearly indicated that the increasing rate of gallium induced a shift of XRD peaks, revealing an evolution of the lattice parameter in the chalcopyrite structure. These results were confirmed by Raman analyses. Moreover, the optical band gap was also found to be linearly dependent upon the gallium rate incorporated within the thin films: it varies from 1.47 eV for x = 0 to 1.63 eV for x = 0.4

  15. Fluid inclusion and sulfur isotope thermometry of the Inkaya (Simav-Kütahya) Cu-Pb-Zn-(Ag) mineralization, NW TURKEY

    Science.gov (United States)

    Özen, Yeşim; Arik, Fetullah

    2013-09-01

    The Inkaya Cu-Pb-Zn-(Ag) mineralization, located about 20 km west of the Simav (Kütahya-Turkey), is situated in the northern part of the Menderes Massif Metamorphics. The mineralization is located along an E-W trending fault in the Cambrian Simav metamorphics consisting of quartz-muscovite schist, quartz-biotite schist, muscovite schist, biotite schist and the Arıkayası formation composed of marbles. Mineralized veins are 30-35 cm in width. The primary mineralization is represented by abundant galena, sphalerite, chalcopyrite, pyrite, fahlore and minor amounts of cerussite, anglesite, digenite, enargite, chalcocite, covellite, bornite, limonite, hematite and goethite with gangue quartz. Fluid inclusion studies on the quartz samples collected from the mineralized veins indicate that the temperature range of the fluids is 235°C to 340°C and the salinities are 0.7 to 4.49 wt. % NaCl equivalent. The wide range of homogenization temperatures indicates that two different fluid generations were trapped in quartz. Sulfur isotope studies of the sulfide minerals showed that all of the δ 34S values are between -2.1 and 2.6 per mil. These values are a typical range for hydrothermal sulfide minerals that have sulfur derived from a magmatic source. Pyrite-galena and pyrite-chalcopyrite sulfur isotope fractionation is consistent with an approach to isotopic equilibrium, and calculated temperatures are 254.6 and 277.4°C for pyrite-galena and 274.7°C for pyrite-chalcopyrite. The microthermometric data and sulfur isotope thermometry indicate the existence of a hydrothermal fluid that circulated along the fault crossing the Simav metamorphics and Arıkayası formation. Fluid inclusion and sulfur isotope thermometry can be used in combination with ore petrographical and geological information to provide site-specific targets for meso-hypothermal metal concentrations.

  16. Proton microprobe study of tin-polymetallic deposits

    International Nuclear Information System (INIS)

    Tin-polymetallic vein type deposits are a complex mixture of cassiterite and sulfides and they are the main source of technologically important rare metals such as indium and bismuth. Constituent minerals are usually fine grained having wide range of chemical composition and often the elements of interest occur as trace elements not amenable to electron microprobe analysis. PIXE with a proton microprobe can be an effective tool to study such deposits by delineating the distribution of trace elements among carrier minerals. Two representative indium-bearing deposits of tin- polymetallic type, Tosham of India (Cu-ln-Bi-Sn-W-Ag), and Mount Pleasant of Canada (Zn-Cu-In-Bi-Sn-W), were studied to delineate the distribution of medical/high-tech rare metals and to examine the effectiveness of the proton probe analysis of such ore. One of the results of the study indicated that indium and bismuth are present in chalcopyrite in the deposits. In addition to these important rare metals, zinc, copper, arsenic, antimony, selenium, and tin are common in chalcopyrite and pyrite. Arsenopyrite contains nickel, copper, zinc, silver, tin, antimony and bismuth. In chalcopyrite and pyrite, zinc, arsenic, indium, bismuth and lead are richer in Mount Pleasant ore, but silver is higher at Tosham. Also thallium and gold were found only in Tosham pyrite. The Tosham deposit is related to S-type granite, while Mount Pleasant to A-type. It appears that petrographic character of the source magma is one of the factors to determine the trace element distribution in tin-polymetallic deposit. 6 refs., 2 figs

  17. 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.

  18. High intensity polarized electron sources

    International Nuclear Information System (INIS)

    The status of the polarized electron source development program at SLAC will be reviewed. Emission currents of 60 A, corresponding to a space charge limited current density of 180 A/cm2, have been obtained from GaAs photocathodes. Electron beam polarization 20% greater than that obtainable from GaAs cathodes has been observed from multilayer GaAs-GaAlAs structures. Work in progress to produce high beam polarization from II-IV-V2 chalcopyrite photocathodes will also be described

  19. A density functional study of the high-pressure chemistry of MSiN2(M = Be, Mg, Ca): prediction of high-pressure phases and examination of pressure-induced decomposition

    Science.gov (United States)

    Rebecca Römer, S.; Kroll, Peter; Schnick, Wolfgang

    2009-07-01

    Normal pressure modifications and tentative high-pressure phases of the nitridosilicates MSiN2 with M = Be, Mg, or Ca have been thoroughly studied by density functional methods. At ambient pressure, BeSiN2 and MgSiN2 exhibit an ordered wurtzite variant derived from idealized filled β-cristobalite by a C1-type distortion. At ambient pressure, the structure of CaSiN2 can also be derived from idealized filled β-cristobalite by a different type of distortion (D1-type). Energy-volume calculations for all three compounds reveal transition into an NaCl superstructure under pressure, affording sixfold coordination for Si. At 76 GPa BeSiN2 forms an LiFeO2-type structure, corresponding to the stable ambient-pressure modification of LiFeO2, while MgSiN2 and CaSiN2 adopt an LiFeO2-type structure, corresponding to a metastable modification (24 and 60 GPa, respectively). For both BeSiN2 and CaSiN2 intermediate phases appear (for BeSiN2 a chalcopyrite-type structure and for CaSiN2 a CaGeN2-type structure). These two tetragonal intermediate structures are closely related, differing mainly in their c/a ratio. As a consequence, chalcopyrite-type structures exhibit tetrahedral coordination for both cations (M and Si), whereas in CaGeN2-type structures one cation is tetrahedrally (Si) and one bisdisphenoidally (M) coordinated. Both structure types, chalcopyrite and CaGeN2, can also be derived from idealized filled β-cristobalite through a B1-type distortion. The group-subgroup relation of the BeSiN2/MgSiN2, the CaSiN2, the chalcopyrite, the CaGeN2 and the idealized filled β-cristobalite structure is discussed and the displacive phase transformation pathways are illustrated. The zero-pressure bulk moduli were calculated for all phases and have been found to be comparable to compounds such as α- Si3N4, CaIrO3 and Al4C3. Furthermore, the thermodynamic stability of BeSiN2, MgSiN2 and CaSiN2 against phase agglomerates of the binary nitrides M3N2 and Si3N4 under pressure are examined.

  20. CuGaTe2-CuAlTe2 system

    International Nuclear Information System (INIS)

    The results of studies on the chemical interaction in the CuGaTe2-CuAlTe2 as well as on the thermal and optical properties of the formed solid solutions are presented. It is shown, that continuous number of solid solutions are formed in the CuGaTe2-CuAlTe2 system, which crystallize in the chalcopyrite structure. The diagram of state of this system is plotted. The thermal expansion of these materials is studied through the dilatometric method. The linear dependence of the thermal expansion coefficient on the composition is established. The concentration dependences of the forbidden zone width diverge from the linearity

  1. Fabrication and properties of AgInTe2 thin films

    International Nuclear Information System (INIS)

    The results of studying the structure, composition and optical properties of thin films of the AgInTe2 ternary system, obtained through the method of pulsed laser evaporation, are presented for the first time. It is established, that the above films are characterized by chalcopyrite structure and their composition corresponds to the composition of crystals, used as a target. The interzone transition energies and values of crystalline and spin-orbital fission are calculated. The optical characteristics were determined from the equations for reflection and transmission in the air/film/glass substrate/air system

  2. Growth and characterisation of (CuInTe{sub x}){sub 1-x} (2 ZnTe){sub x} solid solution single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Bodnar, I.V. [Belorusskij Gosudarstvennyj Univ., Minsk (Belarus). Khimicheskij Fakul' tet; Eifler, A.; Riede, V. [Belorusskij Gosudarstvennyj Univ., Minsk (Belarus). Khimicheskij Fakul' tet; Leipzig Univ. (Germany). Arbeitsgruppe Duennschichttechnik; Doering, Th.; Schmitz, W.; Bente, K. [Belorusskij Gosudarstvennyj Univ., Minsk (Belarus). Khimicheskij Fakul' tet; Inst. fuer Mineralogie, Kristallographie und Materialwissenschaft, Univ. Leipzig (Germany); Gremenok, V.F.; Victorov, I.A. [Belorusskij Gosudarstvennyj Univ., Minsk (Belarus). Khimicheskij Fakul' tet; Inst. of Physics of Solids and Semiconductors, National Academy of Sciences, Minsk (Belarus)

    2000-07-01

    The crystal structure as well as the optical properties in the band gap region of (CuInTe{sub 2}){sub 1-x} (2 ZnTe){sub x} solid solution single crystals grown by directional freezing have been studied. The lattice constants exhibit a linear dependence on crystal composition. The chalcopyrite-sphalerite phase transition was observed between x = 0.3 and x = 0.4. The variation of the band gap with respect to crystal composition can be described by a quadratic expression. (orig.)

  3. The formation of CuInSe{sub 2}-based thin-film solar cell absorbers from alternative low-cost precursors

    Energy Technology Data Exchange (ETDEWEB)

    Jost, S.

    2008-01-18

    This work deals with real-time investigations concerning the crystallisation process of CuInSe{sub 2}-based thin-film solar cell absorbers while annealing differently produced and composed ''low-cost'' precursors. Various types of precursors have been investigated concerning their crystallisation behaviour. Three groups of experiments have been performed: (i) Investigations concerning the crystallisation process of the quaternary chalcopyrite Cu(In,Al)Se{sub 2} and Cu(In,Al)S{sub 2}, (ii) investigations concerning the formation process of the compound semiconductor CuInSe{sub 2} from electroplated precursors, and (iii) investigations concerning the crystallisation of Cu(In,Ga)Se{sub 2} using precursors with thermally evaporated indium. A specific sample surrounding has been constructed, which enables to perform time-resolved angle-dispersive X-ray powder diffraction experiments during the annealing process of precursor samples. A thorough analysis of subsequently recorded diffraction patterns using the Rietveld method provides a detailed knowledge about the semiconductor crystallisation process while annealing. Based on these fundamental investigations, conclusions have been drawn concerning an adaptation of the precursor deposition process in order to optimise the final solar cell results. The investigations have shown, that one class of electroplated precursors shows a crystallisation behaviour identical to the one known for vacuum-deposited precursors. The investigations concerning the crystallisation process of the quaternary chalcopyrite Cu(In,Al)Se{sub 2} revealed, that the chalcopyrite forms from the ternary selenide (Al,In){sub 2}Se{sub 3} and Cu{sub 2}Se at elevated process temperatures. This result is used to explain the separation of the absorber layer into an aluminum-rich and an indium-rich chalcopyrite phase, which has been observed at processed Cu(In,Al)Se{sub 2} absorbers from several research groups. In addition, differences

  4. Growth and characterization of CuIn{sub x}Ga{sub 1-x}Te{sub 2} used for photovoltaic conversion

    Energy Technology Data Exchange (ETDEWEB)

    Benabdeslem, M.; Bechiri, L.; Benslim, N.; Mahdjoubi, L.; Hannech, E.B.; Zouiti, M. [Laboratoire des Surfaces et Interfaces (LSIMS), Universite d' Annaba (Algerie) (France); Nouet, G. [CRISMAT-ISMRA, Universite, 6-Boulevard du Marechal Juin, 14050 Caen (France)

    2006-02-15

    Bulk and thin films of CuIn{sub 0.75}Ga{sub 0.25}Te{sub 2} have been grown using respectively the sealed quartz ampoule and the flash evaporation techniques. X-ray diffraction results showed that the semiconductor has the chalcopyrite structure. The gaps of the materials were determined from optical measurements and found to be 0.99 and 1.14eV, respectively for bulk and annealed films. Photoluminescence data showed a broad emission localised at 1.05eV. (author)

  5. STUDY ON OCCURENCE FORM OF PLATINUM IN XINJIE Cu—Pt DEPOSIT BY NAA AND SCANNING PROTON MICROPROBE

    Institute of Scientific and Technical Information of China (English)

    李晓林; 童纯菡; 等

    1995-01-01

    A combination of NAA and micro-PIXE was used to study concentrations and distributions of platinum group elements (PGE) in ores from Xinjie Cu-Pt deposit.The NAA results of the bulk indicate that the ores belong to the enriched Pt-Pd type.The element concentration maps of scanning micro-PIXE for the ores show that the occurence form of Pt is independent arsenide minerals.No PGE were detected in chalcopyrite of Xinjie Cu-Pt deposit.These information are economically beneficial to the mineral smelting process.

  6. The study of molybdenite types related to the ore processing plant of the Sar Cheshmeh mine

    Directory of Open Access Journals (Sweden)

    Balandeh Aminzadeh

    2010-11-01

    Full Text Available Molybdenite occurs in five forms in the Sar Cheshmeh porphyry copper deposit, namely, (1-veinlets with quartz-molybdenite, (2-veinlets with quartz-molydenite that were filled with pyrite, (3-veinlets with quartz-molybdenite-pyrite–chalcopyrite, (4-Molybdenite veinlets with very low quartz and (5-disseminated molybdenite grains. Because of their large size, the veinlet-related molybdenite grains are easily liberated from the gangue minerals, provided the grinding is properly conducted (74 micron. Because of their fine-grain size, the disseminated molybdenite grains are not liberated from the gangue and enter the tailings during the flotation process.

  7. Phonon Scattering through a Local Anisotropic Structural Disorder in the Thermoelectric Solid Solution Cu_2Zn_(1−x)Fe_xGeSe_4

    OpenAIRE

    Zeier, Wolfgang G.; Pei, Yanzhong; Pomrehn, Gregory; Day, Tristan; Heinz, Nicholas; Heinrich, Christophe P.; Snyder, G. Jeffrey; Tremel, Wolfgang

    2013-01-01

    Inspired by the promising thermoelectric properties of chalcopyrite-like quaternary chalcogenides, here we describe the synthesis and characterization of the solid solution Cu_2Zn_(1–x)Fe_xGeSe_4. Upon substitution of Zn with the isoelectronic Fe, no charge carriers are introduced in these intrinsic semiconductors. However, a change in lattice parameters, expressed in an elongation of the c/a lattice parameter ratio with minimal change in unit cell volume, reveals the existence of a three-sta...

  8. Mineralogical data on angelaite, Cu2AgPbBiS4, from the Los Manantiales District, Chubut, Argentina

    DEFF Research Database (Denmark)

    Topa, D.; Paar, W.H.; Putz, H.;

    2010-01-01

    Angelaite, ideally Cu2AgPbBiS4, occurs as a hypogene mineral in polymetallic ores at the Ángela groups of veins in the mining district of Los Manantiales, in the province of Chubut, Argentina. The new mineral species is predominantly associated with pyrite, sphalerite, chalcopyrite, hematite......, native gold and galena; less common associates are aikinite, wittichenite, miharaite and cervelleite. Angelaite forms subhedral, commonly oriented inclusions in galena; these may attain a size of up to 200 3 50 mm. The mineral is grey in color with a brownish tint, opaque, and lacks internal reflections...

  9. Mineralogy and fluid inclusion studies in kalchoye Copper- gold deposit, East of Esfahan

    Directory of Open Access Journals (Sweden)

    Rezvan Mehvary

    2009-09-01

    Full Text Available Kalchoye Copper-gold deposit is located about 110 kilometers east of Esfahan province and within the Eocene volcano sedimentary rocks. Sandy tuff and andesite lava are important members of this complex.The form of mineralization in area is vein and veinlet and quartz as the main gangue phase. The main ore minerals are chalcopyrite, chalcocite, galena and weathered minerals such as goethite, iron oxides, malachite and azurite. Studies in area indicate that ore mineralization Kalchoye is low sulfide, quartz type of hydrothermal ore deposits and results of thermometry studies on quartz minerals low- medium fluid with low potential mineralization is responsible for mineralization in this area.

  10. The Chahe Copper Deposit—Its Age and Genesis

    Institute of Scientific and Technical Information of China (English)

    张玉学; 邵树勋; 等

    1995-01-01

    The Chahe copper deposit occurs in the Early Proterozoic metamorphic series in the area of Chahe and its chalcopyrite yielded a Pb-Pb isochron age of 951±36 Ma ,providing evidence for copper mineralization at the early stage of the Jinning movement. The ore -forming material came from terrestrial clastic sediments and marine volcamic eruption and the ores were deposited in a relatively open beach environment. The Jinning movement led to folding and metamorphism of country strata, as well as to the rebomilization and transport of copper ,resulting in ore deposition in structurally weak locations. This deposit is a volcano-sedimentary metamorphic deposit.

  11. Laser annealing and defect study of chalcogenide photovoltaic materials

    Science.gov (United States)

    Bhatia, Ashish

    Cu(In,Ga)Se2 (CIGSe), CuZnSn(S,Se)4(CZTSSe), etc., are the potential chalcogenide semiconductors being investigated for next-generation thin film photovoltaics (TFPV). While the champion cell efficiency of CIGSe has exceeded 20%, CZTSSe has crossed the 10% mark. This work investigates the effect of laser annealing on CISe films, and compares the electrical characteristics of CIGSe (chalcopyrite) and CZTSe (kesterite) solar cells. Chapter 1 through 3 provide a background on semiconductors and TFPV, properties of chalcopyrite and kesterite materials, and their characterization using deep level transient spectroscopy (DLTS) and thermal admittance spectroscopy (TAS). Chapter 4 investigates electrochemical deposition (nonvacuum synthesis) of CISe followed by continuous wave laser annealing (CWLA) using a 1064 nm laser. It is found that CWLA at ≈ 50 W/cm2 results in structural changes without melting and dewetting of the films. While Cu-poor samples show about 40% reduction in the full width at half maximum of the respective x-ray diffraction peaks, identically treated Cu-rich samples register more than 80% reduction. This study demonstrates that an entirely solid-phase laser annealing path exists for chalcopyrite phase formation and crystallization. Chapter 5 investigates the changes in defect populations after pulse laser annealing in submelting regime of electrochemically deposited and furnace annealed CISe films. DLTS on Schottky diodes reveal that the ionization energy of the dominant majority carrier defect state changes nonmonotonically from 215+/-10 meV for the reference sample, to 330+/-10 meV for samples irradiated at 20 and 30 mJ/cm2, and then back to 215+/-10 meV for samples irradiated at 40 mJ/cm2. A hypothesis involving competing processes of diffusion of Cu and laser-induced generation of In vacancies may explain this behavior. Chapter 6 compares the electrical characteristics of chalcopyrite and kesterite materials. Experiments reveal CZTSe cell has an

  12. Ab-Initio Study of Magnetic Properties of Mn-doped MgSiN

    Science.gov (United States)

    Rufinus, Jeffrey

    2010-03-01

    The current interest in the field of semiconductor spintronics is mostly focused on transition metal-doped binary materials. Recently, however, the explorations of transition metal-dopd ternary semiconductors have gained attention, duel to experimental confirmations of possible high Curie temperature in chalcopyrite compounds. A density functional theory study was performed on Mn-doped ternary material MgSiN2. Our results show Mn-doped MgSiN2 to be antiferromagnetic for MnMg (Mn substitutes Mg site) and ferromagnetic for MnSi (Mn substitutes Si site).

  13. Liquid phase synthesis of copper indium diselenide nanoparticles

    International Nuclear Information System (INIS)

    Nanoparticles of Copper Indium diselenide (CuInSe2), belongs to I-III-VI2 family has been synthesized via liquid phase route using ethylenediamine as a solvent. Characterization of as-grown particles is done by XRD, HRTEM, DLS, optical microscopy and UV-Vis spectroscopy. X-ray diffraction pattern confirmed that the CuInSe2 nanoparticles obtained reveals chalcopyrite structure. Particle size evaluated from dynamic light scattering of as grown particle possessing radius of 90 nm. The bandgap of 1.05eV is obtained from UV-Vis spectrum which will applicable to the solar cell devices

  14. Preparation and characterization of Zn Se thin films

    CERN Document Server

    Ganchev, M; Stratieva, N; Gremenok, V; Zaretskaya, E; Goncharova, O

    2003-01-01

    Chemical bath deposition technique for preparation of ZnSe thin films is presented. The influence of bath temperature and duration of deposition on film growth and quality has been studied. The effect of post-deposition annealing in different ambient is also discussed. It has been determined that heat treatment removes the oxygen-containing phase from the as-deposited films and improves crystallinity. The optical and electric properties of the deposits show their potential for an alternative buffer layer in chalcopyrite-based solar cells.

  15. The geology and mineralogy of the uranium occurrence at Hoehensteinweg near Poppenreuth (NE Bavaria) - a model of its mode of formation

    International Nuclear Information System (INIS)

    The uranium mineralization consists of U oxides, U titanates, U silicates and secondary U minerals, arranged roughly in order of crystallization. These ores are associated with muscovite, chlorite and smectite. The non-uranium mineralization consists of scheelite, arsenopyrite, native gold, pyrite/chalcopyrite, Bi/Pb-selenides, sulphides and iron sulphides. Scheelite only occurs in the outermost part of the granite (e.g. at Tirschenreuth). Isotope disequilibria show that further redeposition of uranium minerals probably took place in joints and alteration zones in recent or sub-recent times. The uranium mineralization is, on the basis of its geological setting, comparable with the Spanish deposits of Iberian type. (orig./HP)

  16. In situ sulfur isotope analysis by laser ablation MC-ICPMS

    International Nuclear Information System (INIS)

    A new method for in situ S isotopic analysis was tested using a laser ablation system together with a multi-collector (MC)-ICPMS. The method was tested for the analysis of pyrite, pyrrhotite, chalcopyrite and pentlandite using a large pyrite crystal as an in-house standard. Repeated measurements of Py, Pn, Po and Cpy provide an average internal precision of less than 0.1 per mille (2σ). The method was also applied to a pyrite-bearing orogenic Au deposit to display the ability of the method to resolve minor variations in δ 34S across growth zoning in pyrite

  17. Oxidation of sulphide minerals-VI Ferrous and ferric iron in the water-soluble oxidation products of iron sulphide minerals.

    Science.gov (United States)

    Steger, H F

    1979-06-01

    A pseudo-kinetic method has been developed for determining the ferrous and ferric iron in the water-soluble oxidation products of pyrrhotite, pyrite and chalcopyrite, and ores and concentrates containing them. Two determinations are required for each material. In one, the total iron is determined with 1,10-phenanthroline after reduction to Fe(II). In the other, the reduction of Fe(III) is retarded by complexation with fluoride. The difference in the amount of ferrous phenanthranoline complex produced in these two determinations is a function of the original FE(III) concentration and of time. PMID:18962467

  18. The clayey fissural fillings associated with N100º-110ºE fractures at the El Berrocal uranium mine (Sierra de Gredos, Spain): characterization, genesis and retention capacity of radioactive and other elements

    OpenAIRE

    Pérez del Villar, L.; De La Cruz, B.; Cózar, J. S.; Pardillo, J.; Gómez, P.; Turrero, M. J.; Rivas, P.; Reyes, E.; Delgado, A; Caballero, E.

    1993-01-01

    The clayey fissural fillings (< 60 ¼m and < 2 μm fractions) associated with the N100-110 ºE fractures, at the El Berrocal U mine, have been studied in relation to the natural radionuclide migration/retention processes in a fissured granitic environment. The fracture filled with pyrite, chalcopyrite, sphalerite, galena-bearing quartz, later mineralized by pyrite, pitchblende, carbonate and barite also belongs to that fracture seto According to the data obtained by X-ray diffraction, thermal ...

  19. Studies on Environmentally Friendly Leaching Processes in China

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The newly developed green leaching processes for chromium, lead and gold extraction from ores or concentrates are described. The chromium is extracted from the iron chromite ore with fused sodium hydroxide at 500-550°C as sodium chromate. The galena in lead sulfide concentrate is converted into lead carbonate in ammonium or sodium carbonate solution at 50-80°C followed by the separation of lead carbonate formed from the unconverted sulfide ores by flotation. Gold associated with sulfide ore (such as pyrite and chalcopyrite) can be extracted into sodium thiosulfate solution without any pretreatment such as roasting, high pressure aqueous oxidation or bacteria pre-leaching.

  20. SELENIUM and arsenic concentrations in platinum group minerals of placer origin from Borneo and Sierra Leone

    Science.gov (United States)

    Hattori, K. H.; Johanson, B.; Cabri, L. J.

    2003-04-01

    Laurite grains were examined from the type locality, Pontijn River, Tanah Laur, Borneo and from South Tambanio River, S.E. Borneo, and erlichmanite grains from Sierra Leone. The Borneo samples are associated with ophiolite (Alpine-type) ultramafic rocks and the Sierra Leone samples with the layered Freetown Igneous Complex. Laurite grains from Borneo are sub-rounded to spherical with pits and show conchoidal fractures. They contain rare inclusions of an exsolved chalcopyrite+ bornite+ pentlandite mixture. On the other hand, the erlichmanite grains from Sierra Leone are euhedral with minor smooth edges and contain abundant rounded inclusions of exsolved sulphides;(chalcopyrite +bornite) and (chalcopyrite+ pentlandite+ pyrrhotite). All grains examined are solid solutions of Ru and Os with minor to moderate Ir and Rh (mostly less than 1wt percent, and rarely over 5 wt percent). Arsenic contents vary from 0.4 to 1.3 wt percent and Se from 40 to 620 ppm and the two are correlated. Grains with less Se contain greater amounts of As; [As] = -55 x [Se]+ 16,000 (ppm). The evidence supports their presence at the S site, but the huge departure from 1:1 correlation is not understood. The laurite grains from Borneo are relatively homogeneous, showing rare zoning of Ru and Os. Ratios of S/Se show a narrow spread from 1600 to 2400, which are in the range for sulphides from the shallow, sub-arc mantle (Hattori et al., 2002). The data support their formation in the mantle and subsequent erosion after the obduction of the host ultramafic rocks. The laurite-erlichmanite from Sierra Leone show complicated internal zoning of Ru and Os, as shown pictorially previously (Hattori et al., 1991). The contents of Se and As systematically vary with Ru and Os. The Ru-rich parts (close to laurite composition) are enriched in Se and depleted in As. Furthermore; chalcopyrite inclusions contain even higher Se and lower As than the host laurite/erlichmanite. They show a narrow spread from 1650 to

  1. Emilite,  Cu10.72Pb10.72Bi21.28S48, the last missing link of the bismuthinite-aikinite series?

    DEFF Research Database (Denmark)

    Topa, Dan; H. Paar, Werner; Balic Zunic, Tonci

    2006-01-01

    and a greyish black streak. In refl ected light, it has a greyish white color with a distinct anisotropy and perceptible birefl ectance in air and oil, without internal refl ections. The measured values of refl ectance in air are: 39.4-46.95 (470 nm), 39.21-48.25 (546 nm), 38.98-48.35 (589 nm), 38...... 0.1 mm in diameter. The associated minerals are: bismuthinite derivatives in the range krupkaite-hammarite, Ag-bearing lillianite, makovickyite, pavonite, cosalite, galenobismutite, cannizzarite, tetradymite, native bismuth, chalcopyrite, pyrite and quartz. Emilite is opaque, with a metallic luster...

  2. Studies on genesis of chromite and PGE in Naein ophiolite melange

    Directory of Open Access Journals (Sweden)

    Reza Shamsipour Dehkordi

    2011-10-01

    Full Text Available Nain ophiolite melange is located 140 Km east of Isfahan. Based on the geological studies, this area belongs to Mesozoic ophiolite of Urumieh – Dokhtar zone, west of central Iran. Country rocks are pridotite and serpentinized pridotite. The pridotite rocks are composed of Harzburgite, Lherzolite and replacement Dunite which is belong to spinel pridotite facies. Paragenesis of ore minerals are Chromite, Irarsite, Magnetite, Hematite, Pentlandite, Millerite, Chalcopyrite, Pyrite, and Covelline. Geochemical surveys of host rock and chromite show tholeiite series of magma and alpine type chromite. PGE (Ir, Pt, Pd, and Os are enriched in chromite. REE spider diagram pattern show the processes of boninitic magma and partial melting.

  3. Methods for forming particles from single source precursors

    Science.gov (United States)

    Fox, Robert V.; Rodriguez, Rene G.; Pak, Joshua

    2011-08-23

    Single source precursors are subjected to carbon dioxide to form particles of material. The carbon dioxide may be in a supercritical state. Single source precursors also may be subjected to supercritical fluids other than supercritical carbon dioxide to form particles of material. The methods may be used to form nanoparticles. In some embodiments, the methods are used to form chalcopyrite materials. Devices such as, for example, semiconductor devices may be fabricated that include such particles. Methods of forming semiconductor devices include subjecting single source precursors to carbon dioxide to form particles of semiconductor material, and establishing electrical contact between the particles and an electrode.

  4. Proton non-Rutherford backscattering study of oxidation kinetics in Cu and Fe sulphides

    Energy Technology Data Exchange (ETDEWEB)

    Chiari, M. [Padua Univ. (Italy). Dipt. di Fisica]|[INFN - Laboratori Nazionali di Legnaro, via Romea 4, 35020 Legnaro (Padova) (Italy); Giuntini, L. [INFN - Firenze, Largo Fermi 2, 50125 Firenze (Italy); Pratesi, G. [Museo di Mineralogia e Litologia, Universita di Firenze, via La Pira 4, 50121 Firenze (Italy); Santo, A.P. [Dipartimento di Scienze della Terra, Universita di Firenze, via La Pira 4, 50121 Firenze (Italy)

    1998-04-01

    Non-Rutherford backscattering spectrometry (NBS) with 2.4 MeV protons was performed for depth profiling of oxygen in three species of copper and iron sulphides - pyrite, chalcopyrite and bornite - on both altered and fresh surfaces. The tarnished surfaces were obtained by bathing samples in H{sub 2}O{sub 2} (35% vol.) for 100 and 1000 s. The spectra collected were compared to simulations to extract quantitative data on oxygen depth distributions for the different bathing times. The measurements have shown that the kinetics of oxidation has completely different patterns in the three investigated minerals. (orig.) 11 refs.

  5. Low-Temperature Studies of CuFe2 S3 and CuFeS2 by ^{63,65} Cu NMR in the Internal Magnetic Field

    Science.gov (United States)

    Gavrilenko, Andrey Nikolaevich; Pogoreltsev, Aleksandr Iliich; Matukhin, Vadim Leonidovich; Korzun, Barys Vasilyevich; Schmidt, Ekaterina Vadimovna; Sevastianov, Iliya Germanovich

    2016-02-01

    The resonance ^{63,65} Cu NMR spectra in the internal magnetic field in cubanite CuFe2 S3 and chalcopyrite CuFeS2 were studied experimentally at 77 K. Using a cluster approach, ab initio evaluation of the electric field gradient (EFG) at the nuclei of copper in both compounds was performed. The calculations were carried out by the self-consistent restricted method of Hartree-Fock with open shells (SCF-LCAO-ROHF). The largest clusters for which calculations were made had a formula of Cu7 Fe_{14} S_{29}^n for cubanite and Cu9 Fe_{10} S_{28}^n for chalcopyrite, where n is the cluster charge. The best-fit values of the quadrupole parameters (quadrupole frequency ν _Q and the asymmetry parameter of the EFG tensor η )—determined experimentally (ν _Q ≈ 7.30 MHz and η ≈ 0.82) and by calculation (ν _Q ≈ 7.38 MHz and η ≈ 0.87)—were obtained for a cluster Cu7 Fe_{14} S_{29}^{10} for cubanite. Similarly, the best-fit values of the quadrupole parameters—determined experimentally (ν _Q ≈ 1.29 MHz and η ≈ 0.34) and by calculation (ν _Q ≈ 1.40 MHz and η ≈ 0.50)—were obtained for a cluster Cu9 Fe_{10} S_{28}^{-4} for chalcopyrite. For these clusters, maps of the electron density distribution in the neighborhood of quadrupole nucleus of copper were built. Based on the analysis of the resulting electron density distribution, it is supposed that the bond in these compounds is not quite covalent. Evaluations of the hyperfine interaction constants were made and maps of the spin density distribution in the neighborhood of quadrupole nucleus of copper were built. The energy level diagram calculated in the high-spin ROHF approximation defined chalcopyrite as a compound with a very narrow LUMO-HOMO gap rather well and is consistent with the notion of this compound as a semiconductor.

  6. Chemical extraction of copper from copper sulphide ores of Pakistan by roast leach method

    International Nuclear Information System (INIS)

    Copper ores, containing both complex sulphide minerals and those containing chalcopyrite mineral, were studied for the extraction of copper by leaching after roasting. Roasting at 650 deg. C for 30 min rendered the ore leachable in dilute sulphuric acid of 2.5% concentration. The process of metal extraction would be of hydro metallurgical importance for low to high grade sulphide and polymetallic complex sulphide ores occurring in Pakistan. The kinetic models of roasting reaction fit phase boundary as well as diffusion reaction mechanism. (author)

  7. Reclamation of copper mine tailings using sewage sludge

    OpenAIRE

    Stjernman Forsberg, Lovisa

    2008-01-01

    Tailings are the fine-grained fraction of waste produced during mining operations. This work was carried out on tailings from the Aitik copper mine in northern Sweden. Establishment of vegetation on the Aitik mine tailings deposit is planned to take place at closure of the mine, using sewage sludge as fertiliser. However, the tailings contain traces of metal sulphides, e.g. pyrite, FeS2, and chalcopyrite, CuFeS2. When the sulphides are oxidised, they start to weather and release metals and st...

  8. Thin Film CuInS2 Prepared by Spray Pyrolysis with Single-Source Precursors

    Science.gov (United States)

    Jin, Michael H.; Banger, Kulinder K.; Harris, Jerry D.; Cowen, Jonathan E.; Hepp, Aloysius F.; Lyons, Valerie (Technical Monitor)

    2002-01-01

    Both horizontal hot-wall and vertical cold-wall atmospheric chemical spray pyrolysis processes deposited near single-phase stoichiometric CuInS2 thin films. Single-source precursors developed for ternary chalcopyrite materials were used for this study, and a new liquid phase single-source precursor was tested with a vertical cold-wall reactor. The depositions were carried out under an argon atmosphere, and the substrate temperature was kept at 400 C. Columnar grain structure was obtained with vapor deposition, and the granular structure was obtained with (liquid) droplet deposition. Conductive films were deposited with planar electrical resistivities ranging from 1 to 30 Omega x cm.

  9. Properties of CuInS2 thin films prepared by spray pyrolysis

    International Nuclear Information System (INIS)

    CuInS2 thin films of about 1 μm are prepared by spray pyrolysis. The X-ray analysis shows that the film sprayed at 1:1:3 ratio in the spraying mixture present single phase CuInS2 with chalcopyrite structure, and oriented preferentially in the (112) direction. The optical band gap at room temperature is around 1.45 eV. The composition of the thin films can be controlled by varying the sulphur content in the spray solution as shown by electron probe micro-analysis. The electrical properties are studied by varying the Cu:In ratio. (orig.)

  10. Flotation separation of arsenopyrite from several sulphide minerals with organic depressants

    Institute of Scientific and Technical Information of China (English)

    Wang Fuliang; Wang Ligang; Sun Chuanyao

    2008-01-01

    In this paper,the separation of arsenopyrite from chalcopyrite,pyrite,galena with organic depressants (guergum and sodium humic)was discussed,and the functioning mechanism of those organic depressants was dis-cussed.The experimental results of monomineral flotation indicated that both guergum and sodium humic have depress-ing effect on arsenopyrite in the presence of ethyl xanthate.Guergum and sodium humic showed different depressing a-bility to pyrite,chalcopyrite and galena,and the higher the pH value in pulp,the stronger the depressing ability.Ultra-violet-Visible Spectrophotometric study showed that the adsorption layer of xanthate on surface of minerals had been de-sorbed by the two organic depressants,and the selective desorption of the collector layer was found from different miner-als.The xanthate cover on minerals surface was set free when dosage of the organic depressants was high enough.For artificially-mixed minerals,the separation of arsenopyrite from other sulphides was successfully realized by controlling dosage of the organic depressants.And sodium humic had been used successfully to decrease arsenic content in sulphide concentr ates in a commercial Lead-Zinc concentrator.

  11. Temperature dependence of thermal expansion coefficient of (CuInTe{sub 2}){sub 1-x}(2ZnTe){sub x} solid solutions

    Energy Technology Data Exchange (ETDEWEB)

    Bodnar, I.V.; Chibusova, L.V. [Belarus State Univ. of Information Science and Radio Electronics, Minsk (Belarus); Korzun, B.V. [Inst. of Physics of Solids and Semiconductors, Minsk (Belarus)

    2000-06-16

    Investigations have been made for the first time of the thermal expansion of the (CuInTe{sub 2}){sub 1-x}(2ZnTe){sub x} solid solutions. It has been demonstrated that the thermal expansion coefficient {alpha}{sub L} grows considerably in the temperature range from 77 to 300 K whereas the temperature dependence above 300 K is rather weak. For the solid solutions with 0chalcopyrite structure into sphalerite one takes place. Such anomaly in {alpha}{sub L}(T) has not been observed for x{<=}0.4. The isotherms of the composition dependence of {alpha}{sub L} for 77, 293 and 500 K were constructed. They are linear within one-phase ranges with the chalcopyrite structure (0 < x {<=} 0.3) or sphalerite structure (x {>=} 0.4). The Debye temperatures {theta}{sub D} and the average quadratic dynamic displacements u{sup 2} were calculated. (orig.)

  12. Leaching of complex sulphide concentrate in acidic cupric chloride solutions

    Institute of Scientific and Technical Information of China (English)

    M. TCHOUMOU; M. ROYNETTE

    2007-01-01

    The chemical analysis of a complex sulphide concentrate by emission spectrometry and X-ray diffraction shows that it contains essentially copper, lead, zinc and iron in the form of chalcopyrite, sphalerite and galena. A small amount of pyrite is also present in the ore but does not be detected with X-ray diffraction. The cupric chloride leaching of the sulphide concentrate at various durations and solid/liquid ratios at 100 ℃ shows that the rate of dissolution of the ore is the fastest in the first several hours, and after 12 h it does not evolve significantly. If oxygen is excluded from the aqueous cupric chloride solution during the leaching experiment at 100 ℃, the pyrite in the ore will not be leached. The determination of principal dissolved metals in the leaching liquor by flame atomic absorption spectrometry, and the chemical analysis of solid residues by emission spectrometry and X-ray diffraction allow to conclude that the rate of dissolution of the minerals contained in the complex sulphide concentrate are in the order of galena>sphalerite>chalcopyrite.

  13. Structural, electronic and optical properties of AgXY{sub 2}(X = Al, Ga, In and Y = S, Se, Te)

    Energy Technology Data Exchange (ETDEWEB)

    Ullah, Saeed; Din, Haleem Ud [Materials Modeling Lab, Department of Physics, Islamia College University, Peshawar (Pakistan); Murtaza, G., E-mail: murtaza@icp.edu.pk [Materials Modeling Lab, Department of Physics, Islamia College University, Peshawar (Pakistan); Ouahrani, T. [Laboratoire de Physique Théorique, B.P. 119, Université de Tlemcen, Tlemcen 13000 (Algeria); Khenata, R., E-mail: khenata_rabah@yahoo.fr [Laboratoire de Physique Quantique et de Modélisation Mathématique, Université de Mascara, Mascara 29000 (Algeria); Naeemullah [Department of Physics, G.D.C. Darra Adam Khel, F.R. Kohat, KPK (Pakistan); Bin Omran, S. [Department of Physics and Astronomy, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451 (Saudi Arabia)

    2014-12-25

    Highlights: • The compounds are studied by FP-LAPW method within mBJ approximation. • All of the studied materials show isotropic behavior. • All the compounds show direct band gap nature. • Bonding nature is mostly covalent among the studied compounds. • High absorption peaks and reflectivity ensures there utility in optoelectronic devices. - Abstract: The structural, electronic and optical properties of the ternary semiconducting compounds AgXY{sub 2} (X = Al, Ga, In and Y = S, Se, Te) in Heusler and chalcopyrite crystal phases have been investigated using the density functional theory (DFT) based on the full potential linear augmented plane wave (FP-LAPW) method. The calculated lattice constant and band gap values for AgXY{sub 2} in chalcopyrite phase are in good agreement with the available experimental data. Band structure calculations are performed using modified Becke–Johnson (mBJ) method which match closely with experimental data and yield better band gaps rather than those obtained by using generalized gradient approximation (GGA) and Engel–Vosko generalized gradient approximation (EV–GGA). Decrease in band gap is observed by changing cations X and Y from the top to bottom of periodic table. Chemical bonding trends are predicted through charge density plots and quantified by Bader’s analysis. Optical properties reveal that these compounds are suitable candidates for optoelectronic devices in the visible and ultraviolet (UV) regions.

  14. Thermoelectric properties of zinc based pnictide semiconductors

    Science.gov (United States)

    Sreeparvathy, P. C.; Kanchana, V.; Vaitheeswaran, G.

    2016-02-01

    We report a detailed first principles density functional calculations to understand the electronic structure and transport properties of Zn-based pnictides ZnXPn2 (X: Si, Ge, and Sn; Pn: P and As) and ZnSiSb2. The electronic properties calculated using Tran-Blaha modified Becke-Johnson functional reveals the semi-conducting nature, and the resulting band gaps are in good agreement with experimental and other theoretical reports. We find a mixture of heavy and light bands in the band structure which is an advantage for good thermoelectric (TE) properties. The calculated transport properties unveils the favour p-type conduction in ZnXP2 (X: Si, Ge, and Sn) and n-type conduction in ZnGeP2 and ZnSiAs2. Comparison of transport properties of Zn-based pnictides with the prototype chalcopyrite thermoelectric materials implies that the thermopower values of the investigated compounds to be higher when compared with the prototype chalcopyrite thermoelectric materials, together with the comparable values for electrical conductivity scaled by relaxation time. In addition to this, Zn-based pnictides are found to possess higher thermopower than well known traditional TE materials at room temperature and above which motivates further research in these compounds.

  15. Preparation and characterization of (CuInSe{sub 2}){sub 1-x}(CoSe){sub x} alloys in the composition range 0{<=}x{<=}2/3

    Energy Technology Data Exchange (ETDEWEB)

    Grima-Gallardo, P.; Munoz, M.; Ruiz, J.; Power, C.; Gonzalez, J. [Centro de Estudios en Semiconductores (C.E.S.), Dpto. Fisica, Fac. Ciencias, Universidad de Los Andes, La Hechicera, Merida (Venezuela); LeGodec, Y.; Munsch, P.; Itie, J.P. [Laboratoire de Physique des Milieux Condenses, Universite Pierre et Marie Curie, Paris VI, Paris (France); Briceno, V. [Facultad Experimental de Ciencias y Tecnologia (FACYT), Dpto. Fisica, Universidad de Carabobo, Valencia (Venezuela); Briceno, J.M. [Laboratorio de Analisis Quimico y Estructural (LAQUEM), Dpto. Fisica, Fac. Ciencias, La Hechicera, Merida (Venezuela)

    2004-07-01

    Polycrystalline samples of (CuInSe{sub 2}){sub 1-x}(CoSe){sub x} alloys were prepared by the normal melt and anneal technique in the composition range 0chalcopyrite structure exists in a narrow interval 0chalcopyrite-like phase ({alpha}{sup ''}) was observed together with traces of the {gamma} phase. The sequence of phase transformations in the studied composition range seems to be {alpha} {yields} {alpha}' {yields} {alpha}'+{gamma} {yields} {alpha}{sup ''}+{gamma}. (copyright 2004 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  16. Trace Metal and Sulfur Dynamics in the First Meter of Buoyant Hydrothermal Vent Plumes

    Science.gov (United States)

    Findlay, A.; Gartman, A.; Shaw, T. J.; Luther, G. W., III

    2014-12-01

    The speciation and reactivity of metals and metal sulfides within the buoyant plume is critical to determining the ultimate fate of metals emitted from hydrothermal vents. The concentration, size fractionation, and partitioning of trace metals (Fe, Mn, Cu, Co, Zn, Cd, Pb) were determined within the first meter of the rising plume at three vent fields (TAG, Snakepit, and Rainbow) along the Mid-Atlantic Ridge. At Rainbow, total Fe concentrations exceed total sulfide concentrations by an order of magnitude, whereas at the other two sites, total Fe and total sulfide concentrations are nearly equal. At all three sites, Mn and Fe are primarily in the filtered (zinc is correlated with unfiltered cadmium and lead. At Rainbow, unfiltered zinc, cadmium and lead are correlated, but unfiltered copper and cobalt are not, indicating precipitation dynamics at Rainbow are different than those at TAG and Snakepit due to bulk geochemical differences, including a higher iron to sulfide ratio. A sequential HCl/HNO3 leaching method was used to distinguish metals present in pyrite and chalcopyrite in both unfiltered and filtered samples. Significant portions of unfiltered Cu and Co were extracted in HNO3, whereas unfiltered Zn, Cd, and Pb were extracted in HCl. Up to 95 % of filtered Cu, Co, and Zn, up to 80% Cd, and up to 60 % Pb are only extractable in HNO3, indicating that a significant portion of metals < 0.2 μm are incorporated into a recalcitrant fraction such as nanoparticulate pyrite or chalcopyrite.

  17. Chemically deposited In2S3–Ag2S layers to obtain AgInS2 thin films by thermal annealing

    International Nuclear Information System (INIS)

    Highlights: ► We obtained polycrystalline silver indium sulfide thin films through the annealing of chemically deposited In2S3–Ag2S films. ► According to XRD chalcopyrite structure of AgInS2 was obtained. ► AgInS2 thin film has a band gap of 1.86 eV and a conductivity value of 1.2 × 10−3 (Ω cm)−1. - Abstract: AgInS2 thin films were obtained by the annealing of chemical bath deposited In2S3–Ag2S layers at 400 °C in N2 for 1 h. According to the XRD and EDX results the chalcopyrite structure of AgInS2 has been obtained. These films have an optical band gap, Eg, of 1.86 eV and an electrical conductivity value of 1.2 × 10−3 (Ω cm)−1.

  18. Structural, electronic and optical properties of AgXY2(X = Al, Ga, In and Y = S, Se, Te)

    International Nuclear Information System (INIS)

    Highlights: • The compounds are studied by FP-LAPW method within mBJ approximation. • All of the studied materials show isotropic behavior. • All the compounds show direct band gap nature. • Bonding nature is mostly covalent among the studied compounds. • High absorption peaks and reflectivity ensures there utility in optoelectronic devices. - Abstract: The structural, electronic and optical properties of the ternary semiconducting compounds AgXY2 (X = Al, Ga, In and Y = S, Se, Te) in Heusler and chalcopyrite crystal phases have been investigated using the density functional theory (DFT) based on the full potential linear augmented plane wave (FP-LAPW) method. The calculated lattice constant and band gap values for AgXY2 in chalcopyrite phase are in good agreement with the available experimental data. Band structure calculations are performed using modified Becke–Johnson (mBJ) method which match closely with experimental data and yield better band gaps rather than those obtained by using generalized gradient approximation (GGA) and Engel–Vosko generalized gradient approximation (EV–GGA). Decrease in band gap is observed by changing cations X and Y from the top to bottom of periodic table. Chemical bonding trends are predicted through charge density plots and quantified by Bader’s analysis. Optical properties reveal that these compounds are suitable candidates for optoelectronic devices in the visible and ultraviolet (UV) regions

  19. Isolation of Leptospirillum ferriphilum by single-layered solid medium

    Institute of Scientific and Technical Information of China (English)

    LIU Jian-she; XIE Xue-hui; XIAO Sheng-mu; WANG Xiu-mei; ZHAO Wen-jie; TIAN Zhuo-li

    2007-01-01

    According to physiological and biochemical characteristics of Leptospirillum ferriphilum, a strain of object bacteria was isolated successfully. Bacteria were enriched by selective liquid medium and plated on designed single-layered agar solid medium.Colony was cultured and bacteria were collected. The morphologies of the object bacteria were observed using crystal violet staining,scanning electron microscope(SEM) and transmission electron microscope (TEM). The result of 16S rDNA identification shows that this bacterium belongs to Leptospirillum ferriphilum and it is named as Leptospirillum ferriphilum strain D1. These results indicate that this new single-layered agar solid medium is efficient and simple for isolation of Leptospirillum ferriphilum. Additionally,physiological-biochemical characteristics show that the optimum initial pH value and its growth temperature are 1.68 and 40 ℃,respectively. The culture of it is used to leach a complex concentrate chalcopyrite, the leaching efficiencies of copper and iron are 1.93% and 13.74%, respectively, and it is more effective than the A.ferrooxidans culture in the leaching of the complex concentrate chalcopyrite.

  20. The setting of mineralization in a portion of the Eersteling goldfield, Pietersburg granite-greenstone terrane, South Africa

    International Nuclear Information System (INIS)

    Eersteling goldfield is situated in the Pietersburg granite-greenstone terrane within greenstones of the Archaean Eersteling Formation (Pietersburg Group). In the vicinity of the Eersteling Gold Mine, gold occurs in quartz-carbonate vein systems within coupled shear zones. This mineralization occurs within two settings: in east-west-trending shear zones located at lithological contacts or within discrete units (the Pienaar, Doreen, and Girlie reefs); and in Riedal shear zones between east-west trending zones (the Maltz, Dog, and unnamed reefs). In both cases, gold grades are highest within steeply plunging, structurally controlled pay shoots or boudins. Pay shoots in the Pienaar, Maltz, Dog, and an unnamed reef are characterized by the presence of pyrrhotite, chalcopyrite, and pyrite; arsenopyrite is absent or present in extremely minor amounts. Secondary calcite occurs as large crystals in extension fractures and as a finegrained infilling around clasts. Pay shoots in the Doreen and Girlie reefs are characterized by the presence of arsenopyrite and pyrite while pyrrhotite and chalcopyrite characterize low-grade zones. 28 refs., 8 figs., 4 tabs

  1. Light-stimulated carrier dynamics of CuInS2/CdS heterotetrapod nanocrystals

    Science.gov (United States)

    Sakamoto, Masanori; Inoue, Koki; Okano, Makoto; Saruyama, Masaki; Kim, Sungwon; So, Yeong-Gi; Kimoto, Koji; Kanemitsu, Yoshihiko; Teranishi, Toshiharu

    2016-05-01

    We synthesized a heterotetrapod composed of a chalcopyrite(ch)-CuInS2 core and wurtzite(w)-CdS arms and elucidated its optical properties and light-stimulated carrier dynamics using fs-laser flash photolysis. The CuInS2/CdS heterotetrapod possessed quasi-type II band alignment, which caused much longer-lived charge separation than that in the isolated CuInS2 nanocrystal.We synthesized a heterotetrapod composed of a chalcopyrite(ch)-CuInS2 core and wurtzite(w)-CdS arms and elucidated its optical properties and light-stimulated carrier dynamics using fs-laser flash photolysis. The CuInS2/CdS heterotetrapod possessed quasi-type II band alignment, which caused much longer-lived charge separation than that in the isolated CuInS2 nanocrystal. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr01097k

  2. Effects of pulsed laser annealing on deep level defects in electrochemically-deposited and furnace annealed CuInSe2 thin films

    International Nuclear Information System (INIS)

    CuInSe2 (CISe) is a prototype material for the I–III–VI chalcopyrites such as Cu(In,Ga)(S,Se)2 used as absorber layers in thin film photovoltaic cells. Carefully-controlled pulsed-laser annealing (PLA) is a unique annealing process that has been demonstrated to improve the device performance of chalcopyrite solar cells. Here, we investigate the changes in defect populations after PLA of electrochemically-deposited CISe thin films previously furnace annealed in selenium vapor. The films were irradiated in the sub-melting regime at fluences inducing temperatures up to 840 ± 100 K. Deep-level transient spectroscopy on Schottky diodes reveals that the activation energy of the dominant majority carrier trap changes non-monotonically from 215 ± 10 meV for the reference sample, to 330 ± 10 meV for samples irradiated at 20 and 30 mJ/cm2, and then back to 215 ± 10 meV for samples irradiated at 40 mJ/cm2. A hypothesis involving competing processes of diffusion of Cu and laser-induced generation of In vacancies may explain this behavior. - Highlights: ► Pulsed laser annealing (PLA) effects studied on CuInSe2 films ► PLA improves crystalline order parameter. ► PLA induces changes in majority carrier defect levels

  3. Bioflotation of sulfide minerals with Acidithiobacillus ferrooxidans in relation to copper activation and surface oxidation.

    Science.gov (United States)

    Pecina-Treviño, E T; Ramos-Escobedo, G T; Gallegos-Acevedo, P M; López-Saucedo, F J; Orrantia-Borunda, E

    2012-08-24

    Surface oxidation of sulfides and copper (Cu) activation are 2 of the main processes that determine the efficiency of flotation. The present study was developed with the intention to ascertain the role of the phenomena in the biomodification of sulfides by Acidithiobacillus ferrooxidans culture (cells and growth media) and their impact in bioflotation. Surface characteristics of chalcopyrite, sphalerite, and pyrrhotite, alone and in mixtures, after interaction with A. ferrooxidans were evaluated. Chalcopyrite floatability was increased substantially by biomodification, while bacteria depressed pyrrhotite floatability, favoring separation. The results showed that elemental sulfur concentration increased because of the oxidation generated by bacterial cells, the effect is intensified by the Fe(III) left in the culture and by galvanic contact. Acidithiobacillus ferrooxidans culture affects the Cu activation of sphalerite. The implications of elemental sulfur concentration and Cu activation of sphalerite are key factors that must be considered for the future development of sulfide bioflotation processes, since the depressive effect of cells could be counteracted by elemental sulfur generation. PMID:22920540

  4. Bacterial oxidation of sulfide minerals in column leaching experiments at suboptimal temperatures.

    Science.gov (United States)

    Ahonen, L; Tuovinen, O H

    1992-02-01

    The purpose of the work was to quantitatively characterize temperature effects on the bacterial leaching of sulfide ore material containing several sulfide minerals. The leaching was tested at eight different temperatures in the range of 4 to 37 degrees C. The experimental technique was based on column leaching of a coarsely ground (particle diameter, 0.59 to 5 mm) ore sample. The experimental data were used for kinetic analysis of chalcopyrite, sphalerite, and pyrrhotite oxidation. Chalcopyrite yielded the highest (73 kJ/mol) and pyrrhotite yielded the lowest (25 kJ/mol) activation energies. Especially with pyrrhotite, diffusion contributed to rate limitation. Arrhenius plots were also linear for the reciprocals of lag periods and for increases of redox potentials (dmV/dt). Mass balance analysis based on total S in leach residue was in agreement with the highest rate of leaching at 37 and 28 degrees C. The presence of elemental S in leach residues was attributed to pyrrhotite oxidation. PMID:16348648

  5. Temperature effects on bacterial leaching of sulfide minerals in shake flask experiments.

    Science.gov (United States)

    Ahonen, L; Tuovinen, O H

    1991-01-01

    The microbiological leaching of a sulfide ore sample was investigated in shake flask experiments. The ore sample contained pyrite, pyrrhotite, pentlandite, sphalerite, and chalcopyrite as the main sulfide minerals. The tests were performed at eight different temperatures in the range of 4 to 37 degrees C. The primary data were used for rate constant calculations, based on kinetic equations underlying two simplified models of leaching, i.e., a shrinking particle model and a shrinking core model. The rate constants thus derived were further used for the calculation of activation energy values for some of the sulfide minerals present in the ore sample. The chalcopyrite leaching rates were strongly influenced by the interaction of temperature, pH, and redox potential. Sphalerite leaching could be explained with the shrinking particle model. The data on pyrrhotite leaching displayed good fit with the shrinking core model. Pyrite leaching was found to agree with the shrinking particle model. Activation energies calculated from the rate of constants suggested that the rate-limiting steps were different for the sulfide minerals examined; they could be attributed to a chemical or biochemical reaction rather than to diffusion control. PMID:16348389

  6. Invisible gold in Colombian auriferous soils

    International Nuclear Information System (INIS)

    Optic microscopy, X-ray diffraction (XRD), Moessbauer spectroscopy (MS), Electron microprobe analysis (EPMA) and secondary ions mass spectroscopy (SIMS) were used to study Colombian auriferous soils. The auriferous samples, collected from El Diamante mine, located in Guachavez-Narino (Colombia), were prepared by means of polished thin sections and polished sections for EPMA and SIMS. Petrography analysis was made using an optical microscope with a vision camera, registering the presence, in different percentages, of the following phases: pyrite, quartz, arsenopyrite, sphalerite, chalcopyrite and galena. By XRD analysis, the same phases were detected and their respective cell parameters calculated. By MS, the presence of two types of pyrite was detected and the hyperfine parameters are: δ1 = 0.280 ± 0.01 mm/s and ΔQ1 = 0.642 ± 0.01 mm/s, δ2 = 0.379 ± 0.01 mm/s and ΔQ2 = 0.613 ± 0.01 mm/s. For two of the samples MS detected also the arsenopyrite and chalcopyrite presence. The mean composition of the detected gold regions, established by EPMA, indicated 73% Au and 27% Ag (electrum type). Multiple regions of approximately 200 x 200 μm of area in each mineral sample were analyzed by SIMS registering the presence of 'invisible gold' associated mainly with the pyrite and occasionally with the arsenopyrite.

  7. Hysteresis effects on I-V relations in a single crystal of the Cu-In-Te system with two mobile ions

    International Nuclear Information System (INIS)

    Three slices of the same In-rich chalcopyrite single crystal ingot of the Cu-In-Te system with different compositions and stoichiometric deviations are studied by means of electrical measurements. The slices are mixed electronic and ionic conductors, and under a constant applied voltage and under dark conditions, variations of the current intensity with time are observed due to ionic motion. The measuring time was 25, or 300 s, in measurements carried out subsequently two months later. Symmetric electrodes formed by graphite paint are used on both sides of the samples. The electrode/semiconductor/electrode solid-state device does not block the electrons, while it blocks the ions at the semiconductor/electrode interface. Nonlinear I-V relations and different hysteresis effects are obtained, relating the different ionic mobilities to the measuring time. To understand the different I-V relations and hysteresis cycles, a two-mobile-ion framework is applied. The effect of ion motion in the electronic current and the voltage drop at the semiconductor/electrode interface, due to ionic accumulation, are studied. The different results in each sample can only be explained by taking into account the motion of two different ions, and the different compositions and stoichiometric deviations of the slices. The understanding and, above all, the control of the ionic motion in In-rich chalcopyrites could be the key to improve the reproducibility of solar cell efficiency.

  8. Compound semiconductor alloys: From atomic-scale structure to bandgap bowing

    International Nuclear Information System (INIS)

    Compound semiconductor alloys such as InxGa1−xAs, GaAsxP1−x, or CuInxGa1−xSe2 are increasingly employed in numerous electronic, optoelectronic, and photonic devices due to the possibility of tuning their properties over a wide parameter range simply by adjusting the alloy composition. Interestingly, the material properties are also determined by the atomic-scale structure of the alloys on the subnanometer scale. These local atomic arrangements exhibit a striking deviation from the average crystallographic structure featuring different element-specific bond lengths, pronounced bond angle relaxation and severe atomic displacements. The latter, in particular, have a strong influence on the bandgap energy and give rise to a significant contribution to the experimentally observed bandgap bowing. This article therefore reviews experimental and theoretical studies of the atomic-scale structure of III-V and II-VI zincblende alloys and I-III-VI2 chalcopyrite alloys and explains the characteristic findings in terms of bond length and bond angle relaxation. Different approaches to describe and predict the bandgap bowing are presented and the correlation with local structural parameters is discussed in detail. The article further highlights both similarities and differences between the cubic zincblende alloys and the more complex chalcopyrite alloys and demonstrates that similar effects can also be expected for other tetrahedrally coordinated semiconductors of the adamantine structural family

  9. Determination of molybdenum in flotation concentrates by atomic absorption spectrophotometry

    International Nuclear Information System (INIS)

    Molybdenum was determined by atomic absorption spectrophotometry in 0.05 N ammoniacal solution after the decomposition of the concentrate with aqua regia. Negros ore from Philippines was used as a flotation feed, which contained chalcopyrites and calcium-magnesium minerals. Among the metals tested copper, iron and the alkaline earths interfered. Less than 50 ppm of copper yielded lower results for molybdenum. Higher results came out with more than 50 ppm of copper. In the presence of iron and citric acid (0.4 g/100 ml) which is a suppressor for hydroxide formation, a lower estimation resulted for molybdenum. Calcium interfered, lower results by 2 and >10% being obtained with respective 2.5 and 20 ppm of calcium. More than 20 ppm of magnesium behaved similarly. Sodium sulfate (0.5 g/100 ml) served as the suppressor for copper, iron and citric acid; 100 ppm each of copper and iron did not interfere in this way. Interferences due to calcium and magnesium (less than 60 ppm) was able to be masked by the addition of sodium silicate (200 ppm as silica). The analysis of flotation products and synthetic samples consisting of molybdenite, chalcopyrite, calcium chloride and magnesium sulfate revealed that the atomic absorption method can be applied to the analysis of the concentrates for molybdenum with an error of about 2%. (auth.)

  10. Copper isotope fractionation in acid mine drainage

    Energy Technology Data Exchange (ETDEWEB)

    Kimball, Bryn E; Mathur, Ryan; Dohnalkova, Alice; Wall, A J; Runkel, R L; Brantley, Susan L

    2009-03-01

    We surveyed the Cu isotopic composition of primary minerals and stream water affected by acid mine drainage in a mineralized watershed located in southwestern Colorado, USA. The δ65Cu values (based on 65Cu/63Cu) of local enargite (δ65Cu = -0.01 ± 0.10‰; 2σ) and chalcopyrite65Cu = 0.16 ± 0.10‰) are within the general range of previously reported values for terrestrial primary Cu sulfides (-1‰ < δ65Cu < 1). These mineral samples show lower δ65Cu values than stream waters (δ65Cu = 1.36 - 1.74 ± 0.10‰), with an average isotopic fractionation (quantified as Δaq-mino = δ65Cuaq – δ65Cu min, where Cuaq is leached Cu and Cu mino is the original mineral) of 1.60 ± 0.14‰ and 1.43 ± 0.14‰ for enargite and chalcopyrite, respectively.

  11. Oklo as a natural analogue. Reconstruction of ancient fluid circulations using trace-element geochemistry from near to far field

    International Nuclear Information System (INIS)

    The natural nuclear reactors located in the Oklo uranium ore deposit (Gabon) represent one of the best analogy of what could be the interaction of a site of radioactive wastes storage with geological medium. It is under this view of natural analogue that reaction zones and uranium ore deposit are studied in part of european program coordinated by C.E.A. The aim of the thesis is to characterize the ancient fluid circulation which have induced some elementary redistributions from near field to far field. Tracing fluid phase geochemistry have been made by study of several mineral populations (apatite, zircon, pyrite chalcopyrite). Fluids escaping from reaction zones during their critically have been identified by isotopic and elementary compositions of apatites located in 'argiles de pile'. Geochemical feature of those fluids have not been founded in the bearing sandstones. Although, mineralogical observations, chemical analysis on whole rocks and analysis of trace elements of zircons and apatites allowed to characterize an early hydrothermal stage which predates criticality in reaction zones. At the scale of uranium ore deposit, study of sulfur allowed to identify several hydrothermal stages. All those stages are later with respect to criticality in reaction zones. The principal fluid circulation stage, present both in pyrites and galena is interpreted as a resulting from mixing between a locally induced fluid and a regional circulation. A second stage is certainly later and correspond to a reworking of lead in galena and precipitation of pyrites and chalcopyrites. (author)

  12. Mineralogical considerations in leaching of primary copper sulfides at elevated temperatures and pressures

    International Nuclear Information System (INIS)

    The leaching characteristics of four different ores in sulfuric acid systems pressurized with oxygen are described. The variations in the leaching characteristics between different ores can be largely attributed to differences in mineralogy. Certain gangue mineral alteration phases produced during leaching may trap copper from solution, as well as reduce the porosity of the ore. In addition, the formation of secondary copper sulfides, digenite, and covellite may limit the extraction of copper if the supply of oxygen is restricted to chalcopyrite. Apparently, the key consideration for successful leaching is maximizing the rate of oxidation of the sulfides and, at the same time, minimizing the rate of gangue mineral alteration. This can be accomplished at high oxygen pressures and moderate temperatures (70 to 900C) and low pH (less than or equal to 2.0). The ideal ore mineralogy is one that is low in carbonates and easily altered Fe-Mg minerals such as biotite and hornblende, and one that has acceptable pyrite/chalcopyrite ratios. (auth)

  13. Influence of post-treatment on properties of Cu(In,Ga)Se2 thin films deposited by RF magnetron sputtering using a quaternary single target for photovoltaic devices

    International Nuclear Information System (INIS)

    The deposition of Cu(In,Ga)Se2 (CIGS) thin films has been performed by one-step RF sputtering using a single quaternary target and followed by sulfurization to incorporate S into CIGS films. The effect of sulfurization temperature and time on the properties of the films was studied. The sulfurized Cu(In,Ga)(Se,S)2 (CIGSeS) films show that the chalcopyrite peaks shifted to high diffraction angles and the CuS and InS second phases could be formed at low sulfurization temperature. These indicate possible incorporation of S into the films. The formation and disappearance of these second phases depended on the sulfurization temperature and time. The band gap increased with increasing sulfurization temperature and time because of the shift of the absorption edge due to the increase of S/(S + Se) ratio. It was revealed that the resistivity of the as-deposited CIGS film increased after sulfurization while the carrier concentration and mobility decreased. It is believed that the sulfurization process of CIGS films can be utilized as a method to control the properties of the films. - Highlights: • Development of sputtering process of CIGS thin films using single quaternary target • Effect of sulfurization temperature and time on the properties of CIGS films • Application of sulfurization process to improve the properties of CIGS films • Successful transformation of CIGS films to chalcopyrite structure through post-sulfirization

  14. Microstructure characterization of the soda-lime-glass/copper-indium-gallium-selenium interface in Cu-poor Cu(In,Ga)Se2 thin films

    International Nuclear Information System (INIS)

    The microstructure characteristics of the soda-lime-glass/Cu(In,Ga)Se2 (SLG/CIGS) interface in Cu-poor CIGS films are investigated by transmission electron microscopy and selected area electronic diffraction (SAED). The SAED patterns show very sharp and strong spots, indicating the main structure of CIGS chalcopyrite. Small dispersed crystals with size distribution from 2 to 5 nm seem to be embedded in amorphous matrix, and additional spots indicate the presence of an ordered vacancy compound (OVC). This observation is consistent with the Raman results, and the OVC phase with the nanoclusters exists in the CIGS matrix, instead of layer structure. Lattice distortion results in local changes in contrast. Some pseudo-disordered structure is observed, however, the structure is actually the chalcopyrite CIGS structure. 180° rotation twins are also observed at the SLG/CIGS interface. Lattice distortion is widely observed at the interface of the Cu-poor CIGS films, and the extra spots could be caused by different lattice orientations. - Highlights: • Cu(In,Ga)Se2 (CIGS) were prepared on bare soda-lime-glass (SLG) substrates. • Microstructure of the SLG/CIGS interface was investigated. • An ordered vacancy compound (OVC) phase was observed. • The OVC phase with nanoclusters exists in the CIGS matrix, instead of layer structure. • 180° rotation twins were observed at the SLG/CIGS interface

  15. The Effect of Ga2Se3 Doping Ratios on Structure, Composition, and Electrical Properties of CuIn0.5Ga0.5Se2 Absorber Formed by Thermal Sintering

    Directory of Open Access Journals (Sweden)

    Chung Ping Liu

    2013-01-01

    Full Text Available Chalcopyrite compounds of copper indium gallium diselenide (CIGS absorber were fabricated by using binary-particle (Cu2Se, In2Se3, and Ga2Se3 precursors with thermal sintering method. The binary-particle ink was firstly prepared by milling technology and then printed onto a soda lime glass substrate, which was baked at a low temperature to remove solvents and form a dry precursor. Following milling, the average particle size of agglomerated CIGS powder is smaller than 1.1 μm. Crystallographic, stoichiometric, and electrical properties of precursor CIGS films with various doping amounts of Ga2Se3 had been widely investigated by using thermal sintering in a nonvacuum environment without selenization. Analytical results reveal that the CIGS absorption layer prepared with a Ga2Se3 doping ratio of 3 has a chalcopyrite structure and favorable composition. The mole ratio of Cu : In : Ga : Se of this sample was 1.03 : 0.49 : 0.54 : 1.94, and related ratios of Ga/(In + Ga and Cu/(In + Ga were 0.52 and 0.99, respectively. The resistivity and carrier concentration were 3.77 ohm-cm and 1.15 E  +  18 cm-3.

  16. Microstructure characterization of the soda-lime-glass/copper-indium-gallium-selenium interface in Cu-poor Cu(In,Ga)Se{sub 2} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jian, E-mail: wangjustb@gmail.com; Qiao, Yi; Zhu, Jie, E-mail: jiezhu@ustb.edu.cn

    2015-05-29

    The microstructure characteristics of the soda-lime-glass/Cu(In,Ga)Se{sub 2} (SLG/CIGS) interface in Cu-poor CIGS films are investigated by transmission electron microscopy and selected area electronic diffraction (SAED). The SAED patterns show very sharp and strong spots, indicating the main structure of CIGS chalcopyrite. Small dispersed crystals with size distribution from 2 to 5 nm seem to be embedded in amorphous matrix, and additional spots indicate the presence of an ordered vacancy compound (OVC). This observation is consistent with the Raman results, and the OVC phase with the nanoclusters exists in the CIGS matrix, instead of layer structure. Lattice distortion results in local changes in contrast. Some pseudo-disordered structure is observed, however, the structure is actually the chalcopyrite CIGS structure. 180° rotation twins are also observed at the SLG/CIGS interface. Lattice distortion is widely observed at the interface of the Cu-poor CIGS films, and the extra spots could be caused by different lattice orientations. - Highlights: • Cu(In,Ga)Se{sub 2} (CIGS) were prepared on bare soda-lime-glass (SLG) substrates. • Microstructure of the SLG/CIGS interface was investigated. • An ordered vacancy compound (OVC) phase was observed. • The OVC phase with nanoclusters exists in the CIGS matrix, instead of layer structure. • 180° rotation twins were observed at the SLG/CIGS interface.

  17. Hydrometallurgical Extraction of Zinc and Copper - A {sup 57}Fe-Moessbauer and XRD Approach

    Energy Technology Data Exchange (ETDEWEB)

    Mulaba-Bafubiandi, A. F., E-mail: antoinemulaba@hotmail.com [Technikon Witwatersrand, Extraction Metallurgy Department, Faculty of Engineering (South Africa); Waanders, F. B., E-mail: chifbw@puk.ac.za [North-West University (Potchefstroom campus), School of Chemical and Minerals Engineering (South Africa)

    2005-02-15

    The most commonly used route in the hydrometallurgical extraction of zinc and copper from a sulphide ore is the concentrate-roast-leach-electro winning process. In the present investigation a zinc-copper ore from the Maranda mine, located in the Murchison Greenstone Belt, South Africa, containing sphalerite (ZnS) and chalcopyrite (CuFeS{sub 2}), was studied. The {sup 57}Fe-Moessbauer spectrum of the concentrate yielded pyrite, chalcopyrite and clinochlore, consistent with XRD data. Optimal roasting conditions were found to be 900{sup o}C for 3 h and the calcine produced contained according to X-ray diffractometry equal amounts of franklinite (ZnFe{sub 2}O{sub 4}) and zinc oxide (ZnO) and half the amount of willemite (Zn{sub 2}SiO{sub 4}). The Moessbauer spectrum showed predominantly franklinite (59%), hematite (6%) and other Zn- or Cu-depleted ferrites (35%). The latter could not be detected by XRD analyses as peak overlapping with other species occurred. Leaching was done with HCl, H{sub 2}SO{sub 4} and HNO{sub 3}, to determine which process would result in maximum recovery of Zn and Cu. More than 80% of both were recovered by using either one of the three techniques. From the residue of the leaching, the Fe-compounds were precipitated and <1% of the Zn and Cu was not recovered.

  18. Hydrometallurgical Extraction of Zinc and Copper - A 57Fe-Moessbauer and XRD Approach

    International Nuclear Information System (INIS)

    The most commonly used route in the hydrometallurgical extraction of zinc and copper from a sulphide ore is the concentrate-roast-leach-electro winning process. In the present investigation a zinc-copper ore from the Maranda mine, located in the Murchison Greenstone Belt, South Africa, containing sphalerite (ZnS) and chalcopyrite (CuFeS2), was studied. The 57Fe-Moessbauer spectrum of the concentrate yielded pyrite, chalcopyrite and clinochlore, consistent with XRD data. Optimal roasting conditions were found to be 900oC for 3 h and the calcine produced contained according to X-ray diffractometry equal amounts of franklinite (ZnFe2O4) and zinc oxide (ZnO) and half the amount of willemite (Zn2SiO4). The Moessbauer spectrum showed predominantly franklinite (59%), hematite (6%) and other Zn- or Cu-depleted ferrites (35%). The latter could not be detected by XRD analyses as peak overlapping with other species occurred. Leaching was done with HCl, H2SO4 and HNO3, to determine which process would result in maximum recovery of Zn and Cu. More than 80% of both were recovered by using either one of the three techniques. From the residue of the leaching, the Fe-compounds were precipitated and <1% of the Zn and Cu was not recovered.

  19. Application of Raman Spectroscopy to the Biooxidation Analysis of Sulfide Minerals

    Directory of Open Access Journals (Sweden)

    J. V. García-Meza

    2012-01-01

    Full Text Available We report the application of confocal laser scanning microscopy CLSM and Raman spectroscopy on the (biochemical oxidation of pyrite and chalcopyrite, in order to understand how surface sulfur species (S2−/S0 affects biofilm evolution during mineral colonization by Acidithiobacillus thiooxidans. We found that cells attachment occurs as cells clusters and monolayered biofilms within the first 12 h. Longer times resulted in the formation of micro- and macrocolonies with variable cell density and higher epifluorescence signal of the extracellular polymeric substances (EPS, indicating double dynamic activity of A. thiooxidans: sulfur biooxidation and biofilm formation. Raman spectra indicated S2−/S0 consumption modification during biofilm evolution. Hence, cell density increase was primarily associated with the presence of S0; the presence of refractory sulfur species on the mineral surfaces does not to affect biofilm evolution. The EPS of the biofilms was mainly composed of extracellular hydrophobic compounds (vr. gr. lipids and a minor content of hydrophilic exopolysaccharides, suggesting a hydrophobic interaction between attached cells and the altered pyrite and chalcopyrite.

  20. Effect of sodium addition on Cu-deficient CuIn{sub 1-x}Ga{sub x}S{sub 2} thin film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Vasekar, Parag S.; Dhere, Neelkanth G. [Florida Solar Energy Center, University of Central Florida, 1679 Clearlake Road, Cocoa, FL 32922 (United States)

    2009-01-15

    Chalcopyrites are important contenders among solar-cell materials due to direct band gap and very high-absorption coefficients. Copper-indium-gallium disulfide (CIGS2) is a chalcopyrite material with a near-optimum band gap of 1.5 eV for terrestrial as well as space applications. At FSEC PV Materials Laboratory, record efficiency of 11.99% has been achieved on a 2.7 {mu}m CIGS2 thin film prepared by sulfurization. There are reports of influence of sodium on copper-indium-gallium selenide (CIGS) as well as copper-indium disulfide (CIS2) solar cells. However, this is the first of its kind approach to study the effect of sodium on CIGS2 solar cells and resulting in encouraging efficiencies. Copper-deficient CIGS2 thin films were prepared with and without the addition of sodium fluoride (NaF). Effects of addition of NaF on the microstructure and device electrical properties are presented in this work. (author)

  1. Photovoltaic characterization of Copper-Indium-Gallium Sulfide (CIGS2) solar cells for lower absorber thicknesses

    Energy Technology Data Exchange (ETDEWEB)

    Vasekar, Parag S., E-mail: psvasekar@yahoo.co [Florida Solar Energy Center, 1679 Clearlake Rd., Cocoa FL, 32922 (United States); Jahagirdar, Anant H.; Dhere, Neelkanth G. [Florida Solar Energy Center, 1679 Clearlake Rd., Cocoa FL, 32922 (United States)

    2010-01-31

    Chalcopyrites are important contenders among thin-film solar cells due to their direct band gap and higher absorption coefficient. Copper-Indium-Gallium Sulfide (CIGS2) is a chalcopyrite material with a near-optimum band gap of {approx} 1.5 eV. Record efficiency of 11.99% has been achieved on a 2.7 {mu}m CIGS2 film prepared by sulfurization at the Florida Solar Energy Center (FSEC) PV Materials Lab. In this work, photovoltaic performance analysis has been carried out for a 1.5 {mu}m absorber prepared under similar conditions as that of a 2.7 {mu}m thick absorber sample. It was observed that there is an increase in diode factor and reverse saturation current density when the absorber thickness was decreased. The diode factor increased from 1.69 to 2.18 and reverse saturation current density increased from 1.04 x 10{sup -10} mA/cm{sup 2} to 1.78 x 10{sup -8} mA/cm{sup 2}. This can be attributed to a decrease in the grain size when the absorber thickness is decreased. It was also observed that there is an improvement in the shunt resistance. Improvement in shunt resistance can be attributed to optimized value of i:ZnO for lower absorber thickness and less shunting paths due to a smoother absorber.

  2. Photovoltaic characterization of Copper-Indium-Gallium Sulfide (CIGS2) solar cells for lower absorber thicknesses

    International Nuclear Information System (INIS)

    Chalcopyrites are important contenders among thin-film solar cells due to their direct band gap and higher absorption coefficient. Copper-Indium-Gallium Sulfide (CIGS2) is a chalcopyrite material with a near-optimum band gap of ∼ 1.5 eV. Record efficiency of 11.99% has been achieved on a 2.7 μm CIGS2 film prepared by sulfurization at the Florida Solar Energy Center (FSEC) PV Materials Lab. In this work, photovoltaic performance analysis has been carried out for a 1.5 μm absorber prepared under similar conditions as that of a 2.7 μm thick absorber sample. It was observed that there is an increase in diode factor and reverse saturation current density when the absorber thickness was decreased. The diode factor increased from 1.69 to 2.18 and reverse saturation current density increased from 1.04 x 10-10 mA/cm2 to 1.78 x 10-8 mA/cm2. This can be attributed to a decrease in the grain size when the absorber thickness is decreased. It was also observed that there is an improvement in the shunt resistance. Improvement in shunt resistance can be attributed to optimized value of i:ZnO for lower absorber thickness and less shunting paths due to a smoother absorber.

  3. Hydrothermal Evolution of the Giant Cenozoic Kadjaran porphyry Cu-Mo deposit, Tethyan metallogenic belt, Armenia, Lesser Caucasus: mineral paragenetic, cathodoluminescence and fluid inclusion constraints

    Science.gov (United States)

    Hovakimyan, Samvel; Moritz, Robert; Tayan, Rodrik; Rezeau, Hervé

    2016-04-01

    The Lesser Caucasus belongs to the Central segment of the Tethyan metallogenic belt and it is a key area to understand the metallogenic evolution between the Western & Central parts of the Tethyan belt and its extension into Iran. Zangezur is the most important mineral district in the southernmost Lesser Caucasus. It is a component of the South Armenian block, and it was generated during the convergence and collision of the southern margin of the Eurasian plate and the northern margin of the Arabian plate, and terranes of Gondwana origin (Moritz et al., in press). The Zangezur ore district consists of the Tertiary Meghri-Ordubad composite pluton, which is characterized by a long-lasting Eocene to Pliocene magmatic, tectonic and metallogenic evolution. It hosts major porphyries Cu-Mo and epithermal Au - polymetallic deposits and occurrences, including the giant world class Kadjaran porphyry Cu-Mo deposit (2244 Mt reserves, 0.3% Cu, 0.05% Mo and 0.02 g/t Au). The Kadjaran deposit is hosted by a monzonite intrusion (31.83±0.02Ma; Moritz et al., in press). Detailed field studies of the porphyry stockwork and veins of the different mineralization stages, their crosscutting and displacement relationships and the age relationship between different paragenetic mineral associations were the criteria for distinction of the main stages of porphyry mineralization at the Kadjaran deposit. The economic stages being: quartz- molybdenite, quartz-molybdenite-chalcopyrite, and quartz-chalcopyrite. The main paragenetic association of the Kadjaran porphyry deposit includes pyrite, molybdenite, chalcopyrite, bornite, chalcocite, pyrrhotite, covellite, sphalerite, and galena. Recent field observations in the Kadjaran open pit revealed the presence of epithermal veins with late vuggy silica and advanced argillic alteration in the north-eastern and eastern parts of the deposit. They are distributed as separate veins and have also been recognized in re-opened porphyry veins and in

  4. Geologic setting, sedimentary architecture, and paragenesis of the Mesoproterozoic sediment-hosted Sheep Creek Cu-Co-Ag deposit, Helena embayment, Montana

    Science.gov (United States)

    Graham, Garth; Hitzman, Murray W.; Zieg, Jerry

    2012-01-01

    The northern margin of the Helena Embayment contains extensive syngenetic to diagenetic massive pyrite horizons that extend over 25 km along the Volcano Valley-Buttress fault zone and extend up to 8 km basinward (south) within the Mesoproterozoic Newland Formation. The Sheep Creek Cu-Co deposit occurs within a structural block along a bend in the fault system, where replacement-style chalcopyrite mineralization is spatially associated mostly with the two stratigraphically lowest massive pyrite zones. These mineralized pyritic horizons are intercalated with debris flows derived from synsedimentary movement along the Volcano Valley-Buttress fault zone. Cominco American Inc. delineated a geologic resource of 4.5 Mt at 2.5% Cu and 0.1% Co in the upper sulfide zone and 4 Mt at 4% Cu within the lower sulfide zone. More recently, Tintina Resources Inc. has delineated an inferred resource of 8.48 Mt at 2.96% Cu, 0.12% Co, and 16.4 g/t Ag in the upper sulfide zone. The more intact upper sulfide zone displays significant thickness variations along strike thought to represent formation in at least three separate subbasins. The largest accumulation of mineralized sulfide in the upper zone occurs as an N-S–trending body that thickens southward from the generally E trending Volcano Valley Fault and probably occupies a paleograben controlled by normal faults in the hanging wall of the Volcano Valley Fault. Early microcrystalline to framboidal pyrite was accompanied by abundant and local barite deposition in the upper and lower sulfide zones, respectively. The sulfide bodies underwent intense (lower sulfide zone) to localized (upper sulfide zone) recrystallization and overprinting by coarser-grained pyrite and minor marcasite that is intergrown with and replaces dolomite. Silicification and paragenetically late chalcopyrite, along with minor tennantite in the upper sulfide zone, replaces fine-grained pyrite, barite, and carbonate. The restriction of chalcopyrite to inferred

  5. Preparation and characterization of CuInSe{sub 2} nanoparticles elaborated by novel solvothermal protocol using DMF as a solvent

    Energy Technology Data Exchange (ETDEWEB)

    Ben Marai, A., E-mail: Achraf.Benmarai@promes.cnrs.fr [Laboratoire Procédés, Matériaux et Energie Solaire, PROMES-CNRS, Tecnosud, Rambla de la thermodynamique, 66100 Perpignan (France); Laboratoire de Physique des Matériaux et des Nanomatériaux appliquée à l' Environnement, LaPhyMNE, Université de Gabès, Faculté des Sciences de Gabès, Cité Erriadh Manara Zrig, 6072 Gabès (Tunisia); Djessas, K. [Laboratoire Procédés, Matériaux et Energie Solaire, PROMES-CNRS, Tecnosud, Rambla de la thermodynamique, 66100 Perpignan (France); Université de Perpignan, Via Domitia, 52 Avenue Paul Alduy, 68860, Perpignan Cedex9 (France); Ben Ayadi, Z.; Alaya, S. [Laboratoire de Physique des Matériaux et des Nanomatériaux appliquée à l' Environnement, LaPhyMNE, Université de Gabès, Faculté des Sciences de Gabès, Cité Erriadh Manara Zrig, 6072 Gabès (Tunisia)

    2015-11-05

    In this study, high purity and near stoichiometric CuInSe{sub 2} (CIS) nanoparticles have been successfully synthesized using solvothermal route. The goal of this paper is to improve the crystal quality while reducing production cost and limiting the toxicity of solvothermal reaction, as compared to processes including selenization step. Therefore, the starting solution solvothermal is constituted by the following precursors (CuSO{sub 4}.5H{sub 2}O, InCl{sub 3}.xH{sub 2}O and Se powder) which were dissolved in N, N Dimethylformamide (DMF) as solvent. A reasonable possible mechanism for the growth of CIS nanoparticles is proposed. The effect of process parameters on the synthesis and characterization of CIS nanoparticles were examined including reaction temperature (165–240 °C), process time (12–24 h) and the drying route. The as-obtained CIS nanoparticles are analyzed using diverse techniques such as x-ray diffraction (XRD), energy dispersive spectrometer (EDS), transmission electron microscopy (TEM), Raman spectroscopy and UV–vis-IR spectrophotometer. All results demonstrate that the optimal conditions for preparing a single-phase CIS obtained at 220 °C for 24 h and followed by annealing at 400 °C for 30 min under a nitrogen atmosphere. In addition, XRD results showed that the CIS nanoparticles crystallize in the chalcopyrite structure, with grain size in the order of 25 nm, which is also confirmed by TEM images. Raman spectra show the intense peak at 171 cm{sup −1}, which correspond to the chalcopyrite structure, no signature of secondary phases. Optical measurements revealed strong absorption in the entire visible light to near-infrared region and band gap (≈1.04 eV) is very close to those of absorbent materials in thin film solar cells. - Highlights: • Highly dispersed chalcopyrite CuInSe{sub 2} nanoparticles were successfully synthesized. • The DMF solvent act as both the solvent and the complexing agent. • Band gap was calculated to be 1

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-05-01

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

  7. First-principles study of electronic structure of CuSbS2 and CuSbSe2 photovoltaic semiconductors

    International Nuclear Information System (INIS)

    We studied the features of CuSbS2 (CAS) and CuSbSe2 (CASe), two proposed photovoltaic compounds, and clarified their electronic structures by first-principles calculations and compared them to the chalcopyrite-type CuInSe2 results. For both CAS and CASe, the calculated enthalpies of formation of the chalcostibite phases were considerably lower than those of the chalcopyrite phases. Therefore, we considered that the chalcostibite phase is more stable for CAS and CASe. In their band structure calculated with the HSE06 hybrid functional, the valence band maxima of CAS and CASe were located at the Γ-point, and the conduction band minima were located at the R-point. Their second lowest conduction band was located at the Γ-point, whose energy level nearly equaled the R-point. For CAS (CASe), the partial density of the states shows the character of the Cu 3d and S 3p (Se 4p) orbitals at the top of the valence bands and the Sb 5p and S 3p (Se 4p) orbitals at the bottom of the conduction bands. The conduction bands of CAS and CASe have a p-orbital character (Sb 5p) that differs from the s-orbital character (In 5s) of CuInSe2. It is for the reason that CAS and CASe do not have a chalcopyrite structure but a chalcostibite-type structure. The calculated absorption coefficient of CuSbS2 (104-105 cm−1) is comparable to that of CuInSe2. - Highlights: • We studied the features of CuSbS2 and CuSbSe2, newly proposed photovoltaic compounds. • Chalcostibite phase is more stable in CuSbS2 and CuSbSe2. • Band structures of CuSbS2 and CuSbS2 were calculated with HSE06 hybrid functional. • Absorption coefficient of chalcostibite-type CuSbS2 is comparable to that of CuInSe2

  8. SIP response for volume content of sulfide mineral in artificial specimen

    Science.gov (United States)

    Park, Mi Kyung; Park, Samgyu; Jong Yi, Myeong; Kim, Jung Ho

    2014-05-01

    Spectral Induced Polarization (SIP) method has recently been introduced to enhance mineral resource exploration techniques in metal ore deposit, South Korea. Because the valuable mineral ore contains various sulfide minerals such as pyrite (FeS), chalcopyrite (CuFeS2), and galena (PbS), which show IP (Induced Polarization) effect. The conventional IP method was not adequate to find these various sulfide minerals because of certain restrictions, including limited frequency. In order to solve this problem, the SIP (Spectral Induced Polarization) method was introduced, which measures responses like as amplitude (or resistivity) and phase for a wide frequency band. The application of the SIP method has been increasing as an exploration technology for mineral resources, because it can be used to acquire and analyze high quality IP data according to the spectral frequency. SIP responses are strong in the presence of the sulfide minerals; however, sufficient study on the characteristics of the SIP response for the various sulfide minerals is not available so far. In this study, in order to identify the SIP response characteristics of sulfide minerals, the SIP method was used in the laboratory; on artificial specimens filled with glass beads and sulfide minerals. The experiment was controlled by the changing volume content, and grain size, of three kinds of sulfide minerals (i.e., chalcopyrite, pyrite, and galena). The grain sizes of the sulfide minerals were varied in five steps: under 0.5 mm, 0.5 - 1.0 mm, 1.0 - 2.0 mm, 2.0 - 2.85 mm, and 2.85 - 4.0 mm, while the grain size of the glass beads was in the range of 0.75 - 1.0 mm. Variation of the volume content of the sulfide mineral was divided into eight grades. The sulfide minerals occupied 0.5, 1, 2, 3, 5, 7, 10, and 20 percent of the total volume 250 ml specimens. The volume content was converted from the weight using the density of a standard volume of 100 ml for each grain size. The results show that phase response

  9. Preparation and characterization of CuInSe2 nanoparticles elaborated by novel solvothermal protocol using DMF as a solvent

    International Nuclear Information System (INIS)

    In this study, high purity and near stoichiometric CuInSe2 (CIS) nanoparticles have been successfully synthesized using solvothermal route. The goal of this paper is to improve the crystal quality while reducing production cost and limiting the toxicity of solvothermal reaction, as compared to processes including selenization step. Therefore, the starting solution solvothermal is constituted by the following precursors (CuSO4.5H2O, InCl3.xH2O and Se powder) which were dissolved in N, N Dimethylformamide (DMF) as solvent. A reasonable possible mechanism for the growth of CIS nanoparticles is proposed. The effect of process parameters on the synthesis and characterization of CIS nanoparticles were examined including reaction temperature (165–240 °C), process time (12–24 h) and the drying route. The as-obtained CIS nanoparticles are analyzed using diverse techniques such as x-ray diffraction (XRD), energy dispersive spectrometer (EDS), transmission electron microscopy (TEM), Raman spectroscopy and UV–vis-IR spectrophotometer. All results demonstrate that the optimal conditions for preparing a single-phase CIS obtained at 220 °C for 24 h and followed by annealing at 400 °C for 30 min under a nitrogen atmosphere. In addition, XRD results showed that the CIS nanoparticles crystallize in the chalcopyrite structure, with grain size in the order of 25 nm, which is also confirmed by TEM images. Raman spectra show the intense peak at 171 cm−1, which correspond to the chalcopyrite structure, no signature of secondary phases. Optical measurements revealed strong absorption in the entire visible light to near-infrared region and band gap (≈1.04 eV) is very close to those of absorbent materials in thin film solar cells. - Highlights: • Highly dispersed chalcopyrite CuInSe2 nanoparticles were successfully synthesized. • The DMF solvent act as both the solvent and the complexing agent. • Band gap was calculated to be 1.04 eV according to the UV–vis absorption

  10. Orogenic-type copper-gold-arsenic-(bismuth) mineralization at Flatschach (Eastern Alps), Austria

    Science.gov (United States)

    Raith, Johann G.; Leitner, Thomas; Paar, Werner H.

    2015-10-01

    Structurally controlled Cu-Au mineralization in the historic Flatschach mining district (Styria, Austria) occurs in a NE-SW to NNE-WSW oriented vein system as multiple steep-dipping calcite-(dolomite)-quartz veins in amphibolite facies metamorphic rocks (banded gneisses/amphibolites, orthogneisses, metagranitoids) of the poly-metamorphosed Austroalpine Silvretta-Seckau nappe. Vein formation postdated ductile deformation events and Eoalpine (Late Cretaceous) peak metamorphism but predated Early to Middle Miocene sediment deposition in the Fohnsdorf pull-apart basin; coal-bearing sediments cover the metamorphic basement plus the mineralized veins at the northern edge of the basin. Three gold-bearing ore stages consist of a stage 1 primary hydrothermal (mesothermal?) ore assemblage dominated by chalcopyrite, pyrite and arsenopyrite. Associated minor minerals include alloclasite, enargite, bornite, sphalerite, galena, bismuth and matildite. Gold in this stage is spatially associated with chalcopyrite occurring as inclusions, along re-healed micro-fractures or along grain boundaries of chalcopyrite with pyrite or arsenopyrite. Sericite-carbonate alteration is developed around the veins. Stage 2 ore minerals formed by the replacement of stage 1 sulfides and include digenite, anilite, "blue-remaining covellite" (spionkopite, yarrowite), bismuth, and the rare copper arsenides domeykite and koutekite. Gold in stage 2 is angular to rounded in shape and occurs primarily in the carbonate (calcite, Fe-dolomite) gangue and less commonly together with digenite, domeykite/koutekite and bismuth. Stage 3 is a strongly oxidized assemblage that includes hematite, cuprite, and various secondary Cu- and Fe-hydroxides and -carbonates. It formed during supergene weathering. Stage 1 and 2 gold consists mostly of electrum (gold fineness 640-860; mean = 725; n = 46), and rare near pure gold (fineness 930-940; n = 6). Gold in stage 3 is Ag-rich electrum (fineness 350-490, n = 12), and has a

  11. Source of ore-forming fluids of the Tianbaoshan Pb-Zn deposit, Southwest China: constrains from C-O, S, and He-Ar isotopes

    Science.gov (United States)

    Wang, Jian; Zhang, Jun; Zhong, Wenbin

    2016-04-01

    The Sichuan-Yunnan-Guizhou (SYG) metallogenic province is one of the most important areas for Pb-Zn resources in China. The metallogenic sources of these Pb-Zn deposits have long been debated. In this study, we provide integrated C-O-S-He-Ar isotopic data of the typical Tianbaoshan Pb-Zn deposit, with an aim to constrain the sources of ore-forming fluids. The Tianbaoshan deposit a large-sized Pb-Zn deposit in SYG metallogenic province, Southwest China. The proven resources include 2.6 Mt metals of Zn+Pb with average grades of 10.09% Zn and 1.50% Pb. The orebodies are hosted within the carbonates of the Ediacaran Dengying Formation. Ore minerals consist mainly of sphalerite, galena, chalcopyrite, and pyrite. Gangue minerals are dominated by calcite and dolomite. The calcite samples from the Tianbaoshan deposit yield homogeneous δ13CV ‑PDBvalues of -1.70‰ to -1.60‰ (average -1.63), with δ18OV ‑SMOW values ranging from 12.9‰ to 15.2‰ (average 14.4). The C-O isotopic data suggest the hydrothermal fluids may be originated from a mixed source involving both mantle and carbonate wall rocks. The δ34S values of the sphalerite, galena and chalcopyrite samples vary from 3.32‰ to 5.71‰ -0.36‰ to 1.31‰ and 4.5‰ to 4.7‰ respectively, indicating a magmatic source for sulfur. The 3He/4He ratios of chalcopyrite samples range from 0.01 to 0.32 Ra which is slightly higher than the crustal ratios (0.05 Ra), but obviously lower than that of mantle fluids (6 to 9 Ra). The 40Ar/36Ar ratios range from 345.0 to 669.1, which are slightly higher than that of air (298.5). The He-Ar isotopic compositions suggest that the ore-forming fluids are dominantly derived from the crust, with litter contamination from mantle-derived fluids. In combination with the C-O, S, and He-Ar isotopic data, we propose the ore-forming fluids of the Tianbaoshan deposit were derived by mixing of crustal and mantle fluids. And the metallogenic process may be genetically related to the

  12. Chemical and mineralogical data of the metalliferous mineralization from S. Carlo mine (Peloritani mts, Ne Sicily, Italy

    Directory of Open Access Journals (Sweden)

    Pisacane, G

    2006-05-01

    Full Text Available The mineralization processes in the Peloritani Belt (Southern Sector of the Calabria- Peloritani Arc prevalently developed during the Variscan orogenesis producing Pb, Zn, Fe, As, Sb, Cu, Ag, W, etc. polymetalliferous ore-bearing horizons. This paper focuses on the polymetalliferous mineralization recognised in the ancient S. Carlo Mine, which has already been subject of some studies and is part of an important discordant vein deposits system that are widespread in the Mandanici Unit (MaU. This Unit is characterized by a Variscan low-P, polyphasic and plurifacial metamorphic basement, exhibiting a prograde zoning, from chlorite zone of greenschist facies to oligoclase-almandine zone of amphibolite facies. The Variscan main foliation (Fv2 is irregularly cut by mineralized veins of decimetric to metric width. They are also perpendicular to the Alpine mylonitic shear zones of metric thickness developing along the sub-horizontal tectonic contacts between the tectono-stratigraphic units. These vein deposits formed along late-Alpine systems of fractures and faults, after Peloritani nappe emplacement. Minerographic study reveals a metalliferous mineral association mainly composed of tetrahedrite associated with, in order of decreasing abundance, chalcopyrite, bournonite, pentlandite, stromeyerite, arsenopyrite, scheelite, galena, sphalerite, pyrite, bismuthinite, boulangerite, jamesonite, covellite, bornite and argentite. Quartz, siderite and ankerite among non-metalliferous minerals are predominant. This work has been supported by mineralogical studies and chemical analyses carried out by Atomic Absorption and Inductively Coupled Plasma-Mass Spectrometry on powdered and separated samples of minerals. Geochemical data (major and trace elements have allowed a detailed characterization of the minerals. They have revealed that the most significant minerals with Au contents around 1 ppm are tetrahedrite, sphalerite, chalcopyrite and bournonite. The

  13. Ab initio calculation of ZnSiAs2 and CdSiAs2 semiconductor compounds

    International Nuclear Information System (INIS)

    In order to get a good overall description of the structural, electronic and optical properties of ternary chalcopyrite semiconductors especially for ZnSiAs2 and CdSiAs2, they have been calculated self consistently using the full potential augmented plane wave plus local orbital method (FPAPW+lo). The calculations are presented within the local density approximation (LDA), where we clarify the electronic and optical properties for both compounds. Since, we prove the existence of the direct band gap and also the efficiency of the method to give more details about the optical properties. We found that the most important features of the band gap is pseudo-direct for ZnSiAs2, and direct for CdSiAs2; then the contribution of the different transitions peaks are analyzed from the imaginary part of the dielectric function and the reflectivity spectra.

  14. First-principles calculations of magnetic properties for CdCrO{sub 2} under pressure

    Energy Technology Data Exchange (ETDEWEB)

    Amari, S., E-mail: siham_amari@yahoo.fr [Laboratoire de Modelisation et de Simulation en Sciences des Materiaux, Departement de Physique Universite Djillali Liabes, Faculte des sciences, Universite Djillali Liabes, BP 89 Sidi Bel Abbes 22000 (Algeria); Mecabih, S.; Abbar, B.; Bouhafs, B. [Laboratoire de Modelisation et de Simulation en Sciences des Materiaux, Departement de Physique Universite Djillali Liabes, Faculte des sciences, Universite Djillali Liabes, BP 89 Sidi Bel Abbes 22000 (Algeria)

    2013-02-15

    By employing the first-principles method of the full potential linear augmented plane waves plus the local orbitals (FP-L/APW+lo) within the generalized gradient approximation for the exchange and correlation potential, the structural, electronic, and magnetic properties of chalcopyrite compound CdCrO{sub 2} are investigated. In order to take into account the strong on-site Coulomb interaction, we also performed the generalized gradient approximation plus the Hubbard correlation terms. We systematically study how the exchange interactions and magnetic moments of CdCrO{sub 2} are affected by the different choice of U as well as the exchange correlation potential. We have also carried out the pressure effect on the magnetic properties. - Highlights: Black-Right-Pointing-Pointer The calculation of the exchange constants. Black-Right-Pointing-Pointer The pressure dependence of the magnetic properties. Black-Right-Pointing-Pointer The exchange correlation potential effect on the magnetic properties.

  15. Ab initio calculation of ZnSiAs{sub 2} and CdSiAs{sub 2} semiconductor compounds

    Energy Technology Data Exchange (ETDEWEB)

    Boukabrine, F., E-mail: bk_fouzia@yahoo.f [Applied Materials Laboratory, Electronics Department, Djillali Liabes University of Sidi Bel-Abbes (Algeria); Physics Department, Djillali Liabes University Of Sidi Bel-Abbes (Algeria); Chiker, F. [Physics Department, Djillali Liabes University Of Sidi Bel-Abbes (Algeria); Khachai, H., E-mail: h_khachai@yahoo.f [Applied Materials Laboratory, Electronics Department, Djillali Liabes University of Sidi Bel-Abbes (Algeria); Physics Department, Djillali Liabes University Of Sidi Bel-Abbes (Algeria); Haddou, A. [Applied Materials Laboratory, Electronics Department, Djillali Liabes University of Sidi Bel-Abbes (Algeria); Physics Department, Djillali Liabes University Of Sidi Bel-Abbes (Algeria); Baki, N. [Physics Department, Djillali Liabes University Of Sidi Bel-Abbes (Algeria); Khenata, R. [Department of Physics and Astronomy, College of Science, King Saud University, P.O Box 2455, Riyadh 11451 (Saudi Arabia); Laboratoire de Physique Quantique et de Modelisation Mathematique (LPQ3M), Departement de Technologie, Universite de Mascara, 29000 (Algeria); Abbar, B. [Laboratoire de Modelisation et de Simulation en Sciences des Materiaux, Physics Department, Djillali Liabes University of Sidi Bel-Abbes (Algeria); Khalfi, A [Laboratory of Catalysis and Reactive Systems, Djillali Liabes University of Sidi Bel-Abbes (Algeria)

    2011-01-15

    In order to get a good overall description of the structural, electronic and optical properties of ternary chalcopyrite semiconductors especially for ZnSiAs{sub 2} and CdSiAs{sub 2}, they have been calculated self consistently using the full potential augmented plane wave plus local orbital method (FPAPW+lo). The calculations are presented within the local density approximation (LDA), where we clarify the electronic and optical properties for both compounds. Since, we prove the existence of the direct band gap and also the efficiency of the method to give more details about the optical properties. We found that the most important features of the band gap is pseudo-direct for ZnSiAs{sub 2}, and direct for CdSiAs{sub 2}; then the contribution of the different transitions peaks are analyzed from the imaginary part of the dielectric function and the reflectivity spectra.

  16. Thermal expansion of CuInSe2 in the 11-1,073 K range: an X-ray diffraction study

    International Nuclear Information System (INIS)

    Structural and elastic properties of chalcopyrite-type CuInSe2 are determined in almost full stability range of temperature from 11 to 1,073 K, by in situ X-ray diffraction, employing a synchrotron-radiation source. The studied polycrystalline sample was prepared from a stoichiometric single crystal. Phase analysis reveals the formation of a trace amount of indium oxide impurity phase at the highest temperatures studied. From the obtained smooth lattice-parameter dependencies on temperature, the temperature dependencies of thermal expansion coefficients are derived. These coefficients are found to follow the trends previously reported for narrow temperature intervals. The present results provide a clear experimental evidence that the linear expansion coefficient is slightly negative below 47 K in both, a and c, directions; this temperature limit is in between the previously reported theoretical value (35 K) and the experimental ones (60 and 80 K) of such limit. (orig.)

  17. Effect of Annealing Temperature on Crystal Size for the Cu(In,GaSe2 Powder

    Directory of Open Access Journals (Sweden)

    Harith I. Jaafer

    2015-07-01

    Full Text Available The effect of annealing temperatures on CIGS powder were investigated. The effect of different temperature (200°C, 450°C, 500°C, and 525°C on structural properties of CIGS using X-ray diffraction (XRD. The obtained polycrystalline CIGS powder showed the chalcopyrite structure with predominant growth in the plane (112 direction. It is found that increasing of the heat treatment from 500 to 525°C causes increasing the intensity of the first major plane (112 with some shift of the values (2Theta=28.74 degree with shift equal to 1.9, the d-Spacing equal to 3.103 A°, FWHM equal to 0.203 degree, and the crystal size was equal to 42.21nm.

  18. Growth and properties of CuAlSe{sub 2} single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Bodnar, I.V. [Belarussian State Univ., Minsk (Belarus)

    1994-09-01

    The compound CuAlSe{sub 2} is one of the A{sup I}B{sup III}C{sup VI}{sub 2} ternary compounds that crystallize in the chalcopyrite structure (sp. gr. D{sup 12}{sub 2d} - I{bar 4}2m). Given that CuAlSe{sub 2} exhibits birefringence and an optical isotropy point (the intersection point of the dispersion curves for ordinary n{sub o} and extraordinary n{sub e} indices), it is considered as a promising material for producing electro-optic choppers and narrow-band visible/near-IR filters. Up to now, there have been no reports on growth of high-quality CuAlSe{sub 2} single crystals by the Bridgman technique. Therefore, the purpose of this work was to grow high-quality crystals of CuAlSe{sub 2} and to study their properties.

  19. Transmittance spectra of the CuGa3Se5 ternary compound near the fundamental absorption edge

    International Nuclear Information System (INIS)

    The CuGa3Se5 ternary compound films are produced by laser deposition at the substrate temperatures 480 and 580 K. The composition and structure of the films are studied. It is shown that, similarly to the corresponding crystals, the CuGa3Se5 films crystallize into the imperfect chalcopyrite structure. The transmittance spectra near the fundamental absorption edge are used to establish the energies and nature of optical transitions. The energies of crystal-field splitting (Δcr) and spin-orbit splitting (ΔSO of the valence band of the CuGa3Se5 ternary compound are calculated in the context of the Hopfield quasi-cubic model.

  20. Transmittance spectra of the CuGa{sub 3}Se{sub 5} ternary compound near the fundamental absorption edge

    Energy Technology Data Exchange (ETDEWEB)

    Bodnar, I. V., E-mail: chemzav@bsuir.by [Belarusian State University of Information and Radio Electronics (Belarus)

    2011-04-15

    The CuGa{sub 3}Se{sub 5} ternary compound films are produced by laser deposition at the substrate temperatures 480 and 580 K. The composition and structure of the films are studied. It is shown that, similarly to the corresponding crystals, the CuGa{sub 3}Se{sub 5} films crystallize into the imperfect chalcopyrite structure. The transmittance spectra near the fundamental absorption edge are used to establish the energies and nature of optical transitions. The energies of crystal-field splitting ({Delta}{sub cr}) and spin-orbit splitting ({Delta}{sub SO} of the valence band of the CuGa{sub 3}Se{sub 5} ternary compound are calculated in the context of the Hopfield quasi-cubic model.

  1. Thermoelectric properties of CuAlCh2 (Ch = S, Se and Te)

    International Nuclear Information System (INIS)

    Electronic and thermoelectric properties of ternary chalcopyrite-type CuAlCh2 (S, Se and Te) were studied using the first principles density functional calculations implemented in the full potential linear augmented plane wave (FP-LAPW) method. The thermoelectric properties are calculated by solving the Boltzmann transport equation within the constant relaxation time approximation. The calculated band gap using the Tran-Blaha modified Becke-Johnson potential (TB-mBJ), of all the compounds are in good agreement with the available experiment and other theoretical reports. Thermoelectric properties like thermopower, electrical conductivity scaled by relaxation time are calculated as a function of carrier concentrations at different temperatures. The calculated thermoelectric properties are compared with the available experiment and other theoretical calculations of similar materials

  2. Cu isotope variability in Bavariás largest Cu-Zn deposit in Kupferberg (NE Bavaria, Germany)

    Science.gov (United States)

    Höhn, Stefan; Frimmel, Hartwig E.; Debaille, Vinciane; Debouge, Wendy

    2016-04-01

    Kupferberg, a small town c. 15 km northeast of Kulmbach, owns its existence to Bavaria's largest Cu-Zn deposit, which was mined intermittently from the 13th to the 19th century. The deposit is located in the Saxothuringian Zone of the Variscan basement in northeastern Bavaria. It is positioned between the allochthonous Münchberg metamorphic complex in the east and a major northwest-southeast tending regional fault zone, the "Franconian Lineament", in the west. The deposit is hosted by an Early Palaeozoic volcano-sedimentary succession of the Randschiefer Formation (RF) and consists of a northwest-southeast directed string of several stratiform, sulfide-rich ore lenses. These lenses show a remarkably simple mineralogy dominated by quartz, carbonate, pyrite and chalcopyrite with minor amounts of sphalerite and chlorite. The genesis of the Cu-Zn mineralization has remained speculative. A purely syngenetic model, supported by the generally laminated appearance of the ore, has to be questioned because of the ore lenses occurring in different tectonic units. Urban & Vaché (1972) proposed supergene enrichment between the Cretaceous and the Tertiary as most critical. To test such a supergene versus hypogene Cu-mineralization, we investigated the Cu isotopic composition of primary and secondary Cu phases as well as the trace element distribution in three pyrite generations. The pyrite generation that is coeval with the principal Cu-mineralization in the form of chalcopyrite has Co/Ni ratios (on average 35) typical of hydrothermal, possibly metamorphic, formation. Chalcopyrite, present at highly variable modal proportions, yielded a narrow range in δ65Cu from -0.26 to 0.36 ‰Ḃoth the absolute values and the narrow range are similar to the δ65Cu range known for hydrothermal chalcopyrite in crustal rocks (Markl et al. 2006). Metamorphism has been shown to further restrict the range in δ65Cu (Ikehata et al. 2011) - an effect that might be applicable to Kupferberg. In

  3. Granite-hosted molybdenite mineralization from Archean Bundelkhand craton-molybdenite characterization, host rock mineralogy, petrology, and fluid inclusion characteristics of Mo-bearing quartz

    Science.gov (United States)

    Pati, J. K.; Panigrahi, M. K.; Chakarborty, M.

    2014-06-01

    The dominantly high-K, moderate to high SiO2 containing, variably fractionated, volcanic-arc granitoids (± sheared) from parts of Bundelkhand craton, northcentral India are observed to contain molybdenite (Mo) in widely separated 23 locations in the form of specks, pockets, clots and stringers along with quartz ± pyrite ± arsenopyrite ± chalcopyrite ± bornite ± covellite ± galena ± sphalerite and in invisible form as well. The molybdenite mineralization is predominantly associated with Bundelkhand Tectonic Zone, Raksa Shear Zone, and localized shear zones. The incidence of molybdenite is also observed within sheared quartz and tonalite-trondhjemite-granodiorite (TTG) gneisses. The fluid inclusion data show the presence of bi-phase (H2O-CO2), hypersaline and moderate temperature (100°-300°C) primary stretched fluid inclusions suggesting a possible hydrothermal origin for the Mo-bearing quartz occurring within variably deformed different granitoids variants of Archean Bundelkhand craton.

  4. The bioleaching of different sulfide concentrates using thermophilic bacteria

    Science.gov (United States)

    Torres, F.; Blázquez, M. L.; González, F.; Ballester, A.; Mier, J. L.

    1995-05-01

    The bioleaching of different mineral sulfide concentrates with thermophilic bacteria (genus Sulfolobus @#@) was studied. Since the use of this type of bacteria in leaching systems involves stirring and the control of temperature, the influence of the type of stirring and the pulp density on dissolution rates was studied in order to ascertain the optimum conditions for metal recovery. At low pulp densities, the dissolution kinetic was favored by pneumatic stirring, but for higher pulp densities, orbital stirring produced the best results. A comparative study of three differential concentrates, one mixed concentrate, and one global concentrate was made. Copper and iron extraction is directly influenced by bacterial activity, while zinc dissolution is basically due to an indirect mechanism that is activated in the presence of copper ions. Galvanic interactions between the different sulfides favors the selective bioleaching of some phases (sphalerite and chalcopyrite) and leads to high metal recovery rates. However, the formation of galvanic couples depends on the type of concentrate.

  5. Growth and properties of crystalline CuInSe2 thin films by SPD technique

    Science.gov (United States)

    Shrotriya, Vipin; Rajaram, P.

    2016-05-01

    CuInSe2 thin films were grown on glass substrates using the chemical spray pyrolysis technique. The CuInSe2 films were co-deposited from aqueous solutions containing CuCl2, InCl3, and SeO2 used as Cu, In and Se precursors respectively. EDC was used as a complexing agent and films were grown at the constant temperature of 270°C. The films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Energy dispersive analysis of X-rays (EDAX) and the results indicate that the films are single phase, p-type in conductivity and have the chalcopyrite structure. Optical study shows that the optical band gap value is 1.03 eV. From the XRD study it is clear that the average crystallite size of the films is in the range 50 to 70 nm.

  6. Structural controls and evolution of gold-, silver-, and REE-bearing copper-cobalt ore deposits, Blackbird district, east-central Idaho: Epigenetic origins

    Science.gov (United States)

    Lund, K.; Tysdal, R.G.; Evans, K.V.; Kunk, M.J.; Pillers, R.M.

    2011-01-01

    The Cu-Co ± Au (± Ag ± Ni ± REE) ore deposits of the Blackbird district, east-central Idaho, have previously been classified as Besshi-type VMS, sedex, and IOCG deposits within an intact stratigraphic section. New studies indicate that, across the district, mineralization was introduced into the country rocks as a series of structurally controlled vein and alteration systems. Quartz-rich and biotite-rich veins (and alteration zones) and minor albite and siderite veinlets maintain consistent order and sulfide mineral associations across the district. Both early and late quartz veins contain chalcopyrite and pyrite, whereas intermediate-stage tourmaline-biotite veins host the cobaltite. Barren early and late albite and late carbonate (generally siderite) form veins or are included in the quartz veins. REE minerals, principally monazite, allanite, and xenotime, are associated with both tourmaline-biotite and late quartz veins. The veins are in mineralized intervals along axial planar cleavage, intrafolial foliation, and shears.

  7. Electrodeposition and Characterization of CulnSe2 Thin Films for Solar Cells

    Institute of Scientific and Technical Information of China (English)

    LI Jianzhuang; ZHAO Xiujian; XIA Donglin

    2007-01-01

    CuInSe2 (CIS) thin films were prepared by electrodeposition from the de-ionized water solution consisting of CuCl2, InCl3, H2SeO3 and Na-citrate onto Mo/soda-lime glass (SLG) substrates. A thermal processing in Se atmosphere at 450 ℃ was carried out for the electrodepositied films to improve the stoichiometry. The composition and morphology of selenized CIS thin films were studied using energy dispersive spectroscopy (EDS) and scanning electron microscopy (SEM), respectively. X-ray diffraction(XRD) studies show that the annealing in Se atmosphere at 450 ℃ promotes the structural formation of CIS chalcopyrite structure.

  8. Zn(O, S) layers for chalcoyprite solar cells sputtered from a single target

    Science.gov (United States)

    Grimm, A.; Kieven, D.; Lauermann, I.; Lux-Steiner, M. Ch.; Hergert, F.; Schwieger, R.; Klenk, R.

    2012-09-01

    A simplified Cu(In, Ga)(S, Se)2/Zn(O, S)/ZnO:Al stack for chalcopyrite thin-film solar cells is proposed. In this stack the Zn(O, S) layer combines the roles of the traditional CdS buffer and undoped ZnO layers. It will be shown that Zn(O, S) films can be sputtered in argon atmosphere from a single mixed target without substrate heating. The photovoltaic performance of the simplified stack matches that of the conventional approach. Replacing the ZnO target with a ZnO/ZnS target may therefore be sufficient to omit the CdS buffer layer and avoid the associated complexity, safety and recycling issues, and to lower production cost.

  9. Progress report - Physical and Environmental Sciences - Physics Division, 1996 January 1 to December 31

    Energy Technology Data Exchange (ETDEWEB)

    Powell, B.M. (ed.)

    1997-04-01

    This document is the last Progress Report for the Neutron and Condensed Matter Science Branch, at Chalk River Labs of Atomic Energy of Canada Limited. The materials science program continued to include measurements of stress as a major component, but the determination of phase diagrams for specific alloys was also a prominent activity. Studies were made of two types of unusual magnetic materials. The magnetic properties of several oxide pyrochlore were investigated and spin waves were measured in the magnetic semiconductor, chalcopyrite. The crystal structures of the deuterated anti fluorite were determined and the reorientation of the ammonium ion was refined in detail. Differential scanning calorimetry measurements were used to investigate whether spontaneous phase separation into chiral domains occurs for mixtures of DPPC of opposite chirality. A new Neutron Velocity Selector was commissioned.

  10. Searching for new thermoelectric materials: some examples among oxides, sulfides and selenides

    International Nuclear Information System (INIS)

    Different families of thermoelectric materials have been investigated since the discovery of thermoelectric effects in the mid-19th century, materials mostly belonging to the family of degenerate semi-conductors. In the last 20 years, new thermoelectric materials have been investigated following different theoretical proposals, showing that nanostructuration, electronic correlations and complex crystallographic structures (low dimensional structures, large number of atoms per lattice, presence of ‘rattlers’…) could enhance the thermoelectric properties by enhancing the Seebeck coefficient and/or reducing the thermal conductivity. In this review, the different strategies used to optimize the thermoelectric properties of oxides and chalcogenides will be presented, starting with a review on thermoelectric oxides. The thermoelectric properties of sulfides and selenides will then be discussed, focusing on layered materials and low dimensional structures (TiS2 and pseudo-hollandites). Some sulfides with promising ZT values will also be presented (tetrahedrites and chalcopyrites). (topical review)

  11. Identification Of Chemical Compound Content On Sand Using Electron Microscope And Optical Microscope

    International Nuclear Information System (INIS)

    ln this research, two kinds of sands were used as a sample, i.e. Cilacap sand and Aceh sand. The sand was milled until the grain was fine, and then it was pressed so that 20 mm diameter of pellet was resulted. The pressure was about 7 tons. The sample of pellet then to be sintered at 1100oC during 2 hours. The sintered pellet was polished gradually using SiC paper, then using diamond paste 6μm and I μlm, and then it was etched using Nital solution. The result of analysis using optical microscope and SEM/ WDX was indicated that mineral contents of Cilacap sand and Aceh sand were almost the same, i.e. mineral of magnetite, hematite, ilmenite, marcasite. chalcopyrite. cuprite. uvarovite and TiO2 compound. Despite the fact that SiO2 compound was only identified in Aceh sand

  12. Phonon scattering through a local anisotropic structural disorder in the thermoelectric solid solution Cu2Zn(1-x)Fe(x)GeSe4.

    Science.gov (United States)

    Zeier, Wolfgang G; Pei, Yanzhong; Pomrehn, Gregory; Day, Tristan; Heinz, Nicholas; Heinrich, Christophe P; Snyder, G Jeffrey; Tremel, Wolfgang

    2013-01-16

    Inspired by the promising thermoelectric properties of chalcopyrite-like quaternary chalcogenides, here we describe the synthesis and characterization of the solid solution Cu(2)Zn(1-x)Fe(x)GeSe(4). Upon substitution of Zn with the isoelectronic Fe, no charge carriers are introduced in these intrinsic semiconductors. However, a change in lattice parameters, expressed in an elongation of the c/a lattice parameter ratio with minimal change in unit cell volume, reveals the existence of a three-stage cation restructuring process of Cu, Zn, and Fe. The resulting local anisotropic structural disorder leads to phonon scattering not normally observed, resulting in an effective approach to reduce the lattice thermal conductivity in this class of materials. PMID:23256607

  13. Granite-hosted molybdenite mineralization from Archean Bundelkhand cratonmolybdenite characterization, host rock mineralogy, petrology, and fluid inclusion characteristics of Mo-bearing quartz

    Indian Academy of Sciences (India)

    J K Pati; M K Panigrahi; M Chakarborty

    2014-07-01

    The dominantly high-K, moderate to high SiO2 containing, variably fractionated, volcanic-arc granitoids (± sheared) from parts of Bundelkhand craton, northcentral India are observed to contain molybdenite (Mo) in widely separated 23 locations in the form of specks, pockets, clots and stringers along with quartz ± pyrite ± arsenopyrite ± chalcopyrite ± bornite ± covellite ± galena ± sphalerite and in invisible form as well. The molybdenite mineralization is predominantly associated with Bundelkhand Tectonic Zone, Raksa Shear Zone, and localized shear zones. The incidence of molybdenite is also observed within sheared quartz and tonalite–trondhjemite–granodiorite (TTG) gneisses. The fluid inclusion data show the presence of bi-phase (H2O–CO2), hypersaline and moderate temperature (100°–300°C) primary stretched fluid inclusions suggesting a possible hydrothermal origin for the Mo-bearing quartz occurring within variably deformed different granitoids variants of Archean Bundelkhand craton.

  14. Zn incorporation in CuInSe2: Particle size and strain effects on microstructural and electrical properties

    Indian Academy of Sciences (India)

    M Benabdeslem; A Bouasla; N Benslim; L Bechiri; S Mehdaoui; O Aissaoui; A Djekoun; M Fromm; X Portier

    2014-05-01

    Incorporation of the doping element Zn in the temperature range (550–700 °C) and the impact on structural and electrical properties of CuInSe2 material are investigated. X-ray diffraction patterns showed the chalcopyrite nature of the pure and doped CuInSe2 and revealed that diffusion temperature governs particle size as well as tensile strain. The calculated lattice parameters and cell volumes revealed that Zn diffuses in CuInSe2 by substitution on Cu sites. Electrical properties of the material have been investigated using a contact-less technique based on high frequency microwave (HF). It is found that Zn atoms influence the defect equilibrium resulting in the conversion of the conduction type. The conductivity of the samples has been found increasing as the diffusion temperature increases.

  15. Complex electric conductivity of rocks

    International Nuclear Information System (INIS)

    Laboratory measurements of complex conductivity were made on 28 drill-core samples from area MM1-Prospect 1 of the Carajas Mining District. The objective of this research was to help interpret field geophysical survey of the area using Induced Polarization and AFMAG methods. A petrographic study of the samples was done, using thin sections, polished sections and X-ray diffraction. Copper content, in the form of sulfides, was determined using atomic absorption. As a result of the petrographic study, the samples were classified in five distinct groups: granite, biotite schist, amphibolite and magnetite quartzite-iron formation. The grade of Cu was variable in the five groups, ranging from 50 ppm to 6000 ppm. In conclusion, these measurements show that the field Induced Polarization and AFMAG anomalies near these three drill holes (F1, F2 and F3) are due primarily to the magnetic iron formation, and secondarily due to associated low-grade chalcopyrite mineralization. (author)

  16. Optical and electrical properties of p-type AgInSn xS2-x (x = 0-0.04) thin films prepared by spray pyrolysis

    International Nuclear Information System (INIS)

    AgInSn xS2-x (x = 0-0.2) polycrystalline thin films were prepared by the spray pyrolysis technique. The samples were deposited on glass substrates at temperatures of 375 and 400 deg. C from alcoholic solutions comprising silver acetate, indium chloride, thiourea and tin chloride. All deposited films crystallized in the chalcopyrite structure of AgInS2. A p-type conductivity was detected in the Sn-doped samples deposited at 375 deg. C, otherwise they are n-type. The optical properties of AgInSn xS2-x (x 2. Low-temperature PL measurements revealed that Sn occupying an S-site could be the responsible defect for the p-type conductivity observed in AgInSn xS2-x (x < 2) thin films

  17. Solar thermal extraction of copper from sulfides

    Energy Technology Data Exchange (ETDEWEB)

    Winkel, L.; Guesdon, C.; Sturzenegger, M.

    2003-03-01

    With the aim to develop a solar-driven process for the extraction of copper from sulfide concentrates re-search on the decomposition of copper sulfides under inert atmospheres has been initiated. Thermogravimetric measurements on chalcocite (Cu{sub 2}S) revealed that copper is formed already at 1823 K. Chalcopyrite (CuFeS{sub 2}) also disintegrates at this temperature, although at a lower rate. Copper and iron have been identified in the solid residue. The results confirm the feasibility of copper extraction by direct decomposition of sulfides under atmospheric pressure. The decomposition under inert atmosphere prevents generation of SO{sub 2}, and is beneficial to the removal of volatile impurities. Chemical equilibrium calculations for CuFeS{sub 2} contaminated with enargite (Cu{sub 3}AsS{sub 4}) have shown that the absence of an oxidic slag allows for a complete evaporation of arsenic and subsequent separation. (author)

  18. Assessment of the geoavailability of trace elements from minerals in mine wastes: analytical techniques and assessment of selected copper minerals

    Science.gov (United States)

    Driscoll, Rhonda; Hageman, Phillip L.; Benzel, William M.; Diehl, Sharon F.; Adams, David T.; Morman, Suzette; Choate, LaDonna M.

    2012-01-01

    In this study, four randomly selected copper-bearing minerals were examined—azurite, malachite, bornite, and chalcopyrite. The objectives were to examine and enumerate the crystalline and chemical properties of each of the minerals, to determine which, if any, of the Cu-bearing minerals might adversely affect systems biota, and to provide a multi-procedure reference. Laboratory work included use of computational software for quantifying crystalline and amorphous material and optical and electron imaging instruments to model and project crystalline structures. Chemical weathering, human fluid, and enzyme simulation studies were also conducted. The analyses were conducted systematically: X-ray diffraction and microanalytical studies followed by a series of chemical, bio-leaching, and toxicity experiments.

  19. Lateral inhomogeneities in CuInS2-thin film absorbers by confocal optical and spectroscopic analyses with μm-lateral resolution

    International Nuclear Information System (INIS)

    CuInS2-absorbers from runs for thin film pv-module production have been analyzed by confocal spectrally resolved photoluminescence (PL) and focused spectral white light transmission. We observe in 300 K-experiments substantial lateral variations in PL-yield, spectral shapes, and white light spectral transmission, potentially originating from the grainy structure, which we interpret in terms of lateral variations in element composition, defect densities and according lateral fluctuations of the splitting of quasi-Fermi levels (EFn-EFp). In histograms we show the distribution of fluctuations of (EFn-EFp) and extract half widths and higher order momenta. The comparison with CIS-absorbers of lab cells prepared under differing conditions and with data from selenide chalcopyrites, such as Cu(In,Ga)Se2 show weaker fluctuation of the latter ones

  20. Searching for new thermoelectric materials: some examples among oxides, sulfides and selenides

    Science.gov (United States)

    Hébert, S.; Berthebaud, D.; Daou, R.; Bréard, Y.; Pelloquin, D.; Guilmeau, E.; Gascoin, F.; Lebedev, O.; Maignan, A.

    2016-01-01

    Different families of thermoelectric materials have been investigated since the discovery of thermoelectric effects in the mid-19th century, materials mostly belonging to the family of degenerate semi-conductors. In the last 20 years, new thermoelectric materials have been investigated following different theoretical proposals, showing that nanostructuration, electronic correlations and complex crystallographic structures (low dimensional structures, large number of atoms per lattice, presence of ‘rattlers’…) could enhance the thermoelectric properties by enhancing the Seebeck coefficient and/or reducing the thermal conductivity. In this review, the different strategies used to optimize the thermoelectric properties of oxides and chalcogenides will be presented, starting with a review on thermoelectric oxides. The thermoelectric properties of sulfides and selenides will then be discussed, focusing on layered materials and low dimensional structures (TiS2 and pseudo-hollandites). Some sulfides with promising ZT values will also be presented (tetrahedrites and chalcopyrites).

  1. Zn(O, S layers for chalcoyprite solar cells sputtered from a single target

    Directory of Open Access Journals (Sweden)

    Schwieger R.

    2012-09-01

    Full Text Available A simplified Cu(In, Ga(S, Se2/Zn(O, S/ZnO:Al stack for chalcopyrite thin-film solar cells is proposed. In this stack the Zn(O, S layer combines the roles of the traditional CdS buffer and undoped ZnO layers. It will be shown that Zn(O, S films can be sputtered in argon atmosphere from a single mixed target without substrate heating. The photovoltaic performance of the simplified stack matches that of the conventional approach. Replacing the ZnO target with a ZnO/ZnS target may therefore be sufficient to omit the CdS buffer layer and avoid the associated complexity, safety and recycling issues, and to lower production cost.

  2. Colloidal-chemistry based synthesis of quantized CuInS2/Se2 nanoparticles

    Directory of Open Access Journals (Sweden)

    Abazović Nadica D.

    2012-01-01

    Full Text Available Ternary chalcogenide nanoparticles, CuInS2 and CuInSe2, were synthesized in high- temperature boiling organic non-polar solvent. The X-ray diffraction analysis revealed that both materials have tetragonal (chalcopyrite crystal structure. Morphology of the obtained materials was revealed by using transmission electron microscopy. Agglomerated spherical CuInS2 nanoparticles with broad size distribution in the range from 2 to 20 nm were obtained. In the case of CuInSe2, isolated particles with spherical or prismatic shape in the size range from 10 to 25 nm were obtained, as well as agglomerates consisting of much smaller particles with diameter of about 2-5 nm. The particles with the smallest diameters of both materials exhibit quantum size effect.

  3. CuInSe2 formation through Cu2Se-In3Se2 multilayer structures prepared by thermal evaporation technique

    Science.gov (United States)

    Mohan, A.; Rajesh, S.; Srikesh, G.

    2016-05-01

    The current study investigates the Cu2Se/In3Se2 multilayer structure deposited by thermal evaporation technique for CIS solar cells with different number of layers. The X-ray diffraction pattern reveals that the layer thickness improves the crystallinity and the formation of CIS for the 30 layer films through photoluminescence (PL) emission. The optical band gap values are found to be 2.87 eV and 2.79 eV for 5 and 10 period films respectively. The splitted band gap ranging 1.30 and 2.25 eV for 15 periods and decrease in the band gap values are due to large grains. This splitting is due to quantum size effect and CIS composite formation. The vibration frequency at 174.54 cm-1 is evident for formation of CuInSe2 Chalcopyrite phase.

  4. Grain size enlargement of Cu(InGa)Se2 thin films by Hot Filament Melting process

    International Nuclear Information System (INIS)

    Hot Filament Melting (HFM) process has been newly proposed to enlarge the grain size of Cu(In1-xGax)Se2 (CIGS) films grown by a mechanochemical process (MCP). When the substrate temperature was 500 C and 600 C and the current through the hot filament was 15A, we confirmed encouraging the sintering of CIGS grains. Additionally, when the substrate temperature was 700 C, the melt of the CIGS grains at the surface was observed. The crystal structure of CIGS films after the process were analyzed by X-ray diffraction and Raman spectroscopy, and it was found that the CIGS films kept the chalcopyrite structure and that the formation of hetero-phase was not observed. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  5. Thermal expansion of CuInSe{sub 2} in the 11-1,073 K range: an X-ray diffraction study

    Energy Technology Data Exchange (ETDEWEB)

    Paszkowicz, W.; Minikayev, R.; Wojciechowski, T. [Institute of Physics PAS, Warsaw (Poland); Piszora, P. [A. Mickiewicz University, Faculty of Chemistry, Poznan (Poland); Trots, D. [Universitaet Bayreuth, Bayerisches Geoinstitut, Bayreuth (Germany); Knapp, M. [Institute for Applied Materials-Energy Storage Systems, Karlsruhe Institute of Technology, Karlsruhe (Germany); Bacewicz, R. [Warsaw University of Technology, Faculty of Physics, Warsaw (Poland)

    2014-08-15

    Structural and elastic properties of chalcopyrite-type CuInSe{sub 2} are determined in almost full stability range of temperature from 11 to 1,073 K, by in situ X-ray diffraction, employing a synchrotron-radiation source. The studied polycrystalline sample was prepared from a stoichiometric single crystal. Phase analysis reveals the formation of a trace amount of indium oxide impurity phase at the highest temperatures studied. From the obtained smooth lattice-parameter dependencies on temperature, the temperature dependencies of thermal expansion coefficients are derived. These coefficients are found to follow the trends previously reported for narrow temperature intervals. The present results provide a clear experimental evidence that the linear expansion coefficient is slightly negative below 47 K in both, a and c, directions; this temperature limit is in between the previously reported theoretical value (35 K) and the experimental ones (60 and 80 K) of such limit. (orig.)

  6. Ab-Initio Calculation of the Basic Magnetic Properties of (Mn, Cr, V)-doped MgSiN2

    International Nuclear Information System (INIS)

    The current interest in the emerging field of semiconductor spintronics is mostly focused on transition metal-doped binary materials, e.g. Mn-doped GaAs, GaN, etc. Recently, however, the explorations of transition metal-doped ternary semiconductors have intensified, due to some experimental confirmations of high Curie temperature in chalcopyrite compounds. A density functional theory within generalized gradient approximation study was performed on (Mn, Cr, V)-doped ternary material MgSiN2. Our results show Mn-doped MgSiN2 to be antiferromagnetic for MnMg (Mn substitutes Mg site) and ferromagnetic for MnSi (Mn substitutes Si site). On the other hand, (Cr, V)-doped MgSiN2 was found to be ferromagnetic, independent of the substitution sites.

  7. The magnetic properties of (Cr, V)-doped ZnGeN2

    International Nuclear Information System (INIS)

    The current interest in the emerging field of semiconductor spintronics is mostly focused on transition metal-doped binary materials, e.g. Mn-doped GaAs, GaN, etc. Recently, however, the explorations of transition metal-doped ternary semiconductors have intensified, due to some experimental confirmations of high Curie temperature in chalcopyrite compounds. A density functional theory within generalized gradient approximation study was performed on (Cr, V)-doped ternary material ZnGeN2. Our results show that both Cr- and V-doped ZnGeN2 to be ferromagnetic, independent of the substitution sites. Formation of half-metallic ferromagnetism is also possible in this type of material.

  8. Genesis of the Xinqiao Gold-Sulfide Orefield, Anhui Province, China

    Institute of Scientific and Technical Information of China (English)

    ZANG Wenshuan; WU Ganguo; ZHANG Da; LI Jinwen; ZHANG Xiangxin; LIU Aihua; ZHANG Zhongyi

    2004-01-01

    The Xinqiao S-Fe-Cu-Au orefield is located in the Tongling ore cluster in the middle and lower reaches of the Yangtze River in East China. There have been many researches regarding the genesis of the Xinqiao orefield in recent years, showing that it belongs to various types, such as sedimentary-reformed type, stratabound-skarn type, sedimentary submarine rocks-hosted exhalative type. We propose that it was formed in two periods of mineralization base on systematic field observation and Pb and S isotopic analyses in nearly ten years. The first period was formed during a syngenetic sedimentary process, whereas the massive sulphide orebodies are mainly related to the Yanshanian granitic magmatism. Sulfide metallic mineral associations show zoning around a granite intrusion, i.e. magnetite and pyrite →pyrite, chalcopyrite and native gold→ pyrite, sphalerite and galena. Gold orebodies occur outside the contact zone of the granite intrusion.

  9. Nature and origin of multicomponent aerial emissions of the copper-nickel smelter complex.

    Science.gov (United States)

    Barcan, Valery

    2002-12-01

    The Severonickel Smelter Complex as well as other big nickel-copper smelter plants are the source of metallurgical dust emissions, enriched with toxic elements Ni, Cu, Pb, Zn and As. The phase composition of typical metallurgy dust is described as pentlandite (Ni,Fe)9S8, pyrrhotite Fe7S8(Ni(x)), chalcopyrite CuFeS2, chalcosite Cu2S, covellite CuS, cuprite Cu2O, tenorite CuO, and metal copper and nickel. The fine dust fractions are enriched by lead, zinc and arsenic oxides. The obtained data can be turned to account when conducting the investigations of heavy metal behaviour in nature media, in particular soils. PMID:12503910

  10. Microscopic studies of uranium mineralization at Mentawa Area, Central Kalimantan

    International Nuclear Information System (INIS)

    In Mentawa areas there are indications that the U mineralization associated with tourmaline, quartz, sulfide minerals that fill the fracture aperture, on the rocks meta silt, and fill it with the direction of WNW - ESE, the thickness milli metric - centi metric with radioactivity 500-15000 c/s SPP 2 NF. The purpose of this study is to know the characters. para geneses and the process of formation of uranium minerals. The method used by microscopic observation of several examples of thin sections and polished sections of the previous research results. The study shows that uranium minerals are uraninite, associated with molybdenite, magnetite, rutile, ilmenite, pyrite, pyrrhotite, tourmaline, garnet, quartz and mineral pitchblende associated with arsenopyrite, hematite, chalcopyrite, pyrite, pyrrhotite, tourmaline, quartz till in cracks in rocks biotite and biotite schist. Mineral associations indicate that the process of formation of uranium mineralization occurs in three phases: pegmatites pneumatolitic, and hydrothermal alteration. (author)

  11. CIGS nanostructure: preparation and study using liquid phase method

    Science.gov (United States)

    Jakhmola, P.; Jha, P. K.; Bhatnagar, S. P.

    2016-06-01

    Present study is motivated by interesting attainment obtained for copper indium gallium diselenide compound as a light absorbing material for thin-film solar cell. Formation of copper indium gallium diselenide nanostructures via solvothermal method using starting precursors of copper, indium, gallium salts, and selenium powder is represented. Preparation is done by varying x (0.1 and 0.3) in CuIn1- x Ga x Se2 compound at a constant temperature and using ethanolamine as a solvent. Characterization of nanostructures is done using powder X-ray diffraction, scanning electron microscopy, dynamic light scattering, Fourier transform infrared spectroscopy, and UV-Vis spectroscopy. It is found that grown chalcopyrite structure at different x, possess agglomeration in nanostructures. Results indicate that presence of 10 % gallium in copper indium gallium diselenide compound leads to the single-phase growth, prepare at the temperature of 190 °C for 19 h.

  12. Point defects and p-type conductivity in Zn1–xMnxGeAs2

    International Nuclear Information System (INIS)

    Positron annihilation spectroscopy is used to study point defects in Zn1–xMnxGeAs2 crystals with low Mn content 0≤x≤0.042 with disordered zincblende and chalcopyrite structure. The role of negatively charged vacancies and non-open-volume defects is discussed with respect to the high p-type conductivity with carrier concentration 1019≤p≤1021cm−3 in our samples. Neutral As vacancies, together with negatively charged Zn vacancies and non-open-volume defects with concentrations around 1016−1018cm−3, are observed to increase with increasing Mn content in the alloy. The observed concentrations of defects are not sufficient to be responsible for the strong p-type conductivity of our crystals. Therefore, we suggest that other types of defects, such as extended defects, have a strong influence on the conductivity of Zn1–xMnxGeAs2 crystals.

  13. Evaluation of the exploration drilling result of TML-3, TML-4, TML-5, TML-6 at Tanah Merah sector West Kalimantan

    International Nuclear Information System (INIS)

    Previous researcher obvioused that the uranium favourable zone at Tanah Merah has been existed, it is oriented NW-SE. In those zones have been discovered uranium mineralizations of NW-SE orientation and sub vertical dipping. This research intend to get knowledge about the uranium geology, character and geometry of the sub surface mineralization using exploration drilling. The result shows that lithologically the area dominated by biotite quartzite which is intruded by granitic rocks and lamprophyres. The mineralization consist of uraninite/ pitchblende associated by pyrite, chalcopyrite, pyrhotite, ilmenite, molybdenite, quartz, feldsphart and biotite. It seems to be granitic related mineralization as a vein type. Surface mineralization could be correlable to those of sub surface with in the lensoid or tabular shape favourable zones. Geological reserve of those mineralization is about 157 ton U3O8

  14. Geochemistry of mine tailings and behavior of arsenic at Kombat, northeastern Namibia.

    Science.gov (United States)

    Sracek, O; Mihaljevič, M; Kříbek, B; Majer, V; Filip, J; Vaněk, A; Penížek, V; Ettler, V; Mapani, B

    2014-08-01

    The mine tailings at Kombat, in semiarid northeastern Namibia, were investigated by the combination of solid-phase analyses, mineralogical methods, leaching tests, and speciation modeling. Dissolution of the most abundant primary sulfides, chalcopyrite and galena, released copper and lead which were adsorbed onto ferric oxyhydroxides or precipitated in the form of malachite, Cu2CO3(OH)2, and cerussite, PbCO3, respectively. Arsenic released from arsenopyrite was incorporated into ferric oxyhydroxides. Based on sequential extraction and (57)Fe Mössbauer spectroscopy, a large amount of ferric iron is present as low solubility hematite and goethite formed rapidly (carbonate minerals represent a more serious environmental risk. Immobilization of As in hematite has implications for other mining sites in regions with similar climatic conditions because this process results in long-term immobilization of As. PMID:24691736

  15. Laser synthesis and modification of composite nanoparticles in liquids

    International Nuclear Information System (INIS)

    The works devoted to the formation and modification of nanoparticles using laser ablation of solid targets in liquids are reviewed. Several approaches to implement laser ablation in liquids, aimed at synthesising nanoparticles of complex composition, are considered: direct laser ablation of a target of corresponding composition, laser ablation of a combined target composed of two different metals, laser irradiation of a mixture of two or more colloidal solutions, and laser ablation in reactive liquids. The properties of two-component bimetallic systems (Ag - Cu, Ag - Au), semiconductor nanocrystals (ZnO, CdSe), chalcopyrite nanoparticles, and doped oxide nanoparticles (ZnO:Ag, Gd2O2:Tb3+) formed as a result of single- and double-pulse laser ablation in different liquids (water, ethanol, acetone, solutions of polysaccharides) are discussed. (photonics and nanotechnology)

  16. Collective sulphide flotation of the polymetallic molybdenic ore

    International Nuclear Information System (INIS)

    Results of investigations on polymetallic molybdenic ore are presented. The useful minerals of this ore are as follows: molybdenite, sphalerite, galena and chalcopyrite whereas quartz, feldspars, chlorite and sericite are barren rocks. The flotation process parameters are established i.e. the consumption of flotation reagents, the flotation time and the most advantageous grain composition of the ore submitted to flotation. Taking into consideration the established parameters, a collective sulphide flotation of ore and a control flotation of wastes were carried out. The obtained concentrate was submitted to a single cleaning flotation whereby a concentrate was obtained containing: 4,65% Mo, 2,51% Cu, 0,9% Zn, 0,69% Pb, and 1,4% Bi. (author)

  17. Zoned Cr, Fe-spinel from the La Perouse layered gabbro, Fairweather Range, Alaska

    Science.gov (United States)

    Czamanske, G.K.; Himmelberg, G.R.; Goff, F.E.

    1976-01-01

    Zoned spinel of unusual composition and morphology has been found in massive pyrrhotite-chalcopyrite-pent-landite ore from the La Perouse layered gabbro intrusion in the Fairweather Range, southeastern Alaska. The spinel grains show continuous zoning from cores with up to 53 wt.% Cr2O3 to rims with less than 11 wt.% Cr2O3. Their composition is exceptional because they contain less than 0.32 wt.% MgO and less than 0.10 wt.% Al2O3 and TiO2. Also notable are the concentrations of MnO and V2O3, which reach 4.73 and 4.50 wt.%, respectively, in the cores. The spinel is thought to have crystallized at low oxygen fugacity and at temperatures above 900??C, directly from a sulfide melt that separated by immiscibility from the gabbroic parental magma. ?? 1976.

  18. A hybrid-exchange density functional study of the bonding and electronic structure in bulk CuFeS2

    Science.gov (United States)

    Martínez-Casado, Ruth; Chen, Vincent H.-Y.; Mallia, Giuseppe; Harrison, Nicholas M.

    2016-05-01

    The geometric, electronic, and magnetic properties of bulk chalcopyrite CuFeS2 have been investigated using hybrid-exchange density functional theory calculations. The results are compared with available theoretical and experimental data. The theoretical description of the bonding and electronic structure in CuFeS2 is analyzed in detail and compared to those computed for chalcocite (CuS2) and greigite (Fe3S4). In particular, the behavior of the 3d electrons of Fe3+ is discussed in terms of the Hubbard-Anderson model in the strongly correlated regime and found to be similarly described in both materials by an on-site Coulomb repulsion (U) of ˜8.9 eV and a transfer integral (t) of ˜0.3 eV.

  19. Progress report - Physical and Environmental Sciences - Physics Division, 1996 January 1 to December 31

    International Nuclear Information System (INIS)

    This document is the last Progress Report for the Neutron and Condensed Matter Science Branch, at Chalk River Labs of Atomic Energy of Canada Limited. The materials science program continued to include measurements of stress as a major component, but the determination of phase diagrams for specific alloys was also a prominent activity. Studies were made of two types of unusual magnetic materials. The magnetic properties of several oxide pyrochlore were investigated and spin waves were measured in the magnetic semiconductor, chalcopyrite. The crystal structures of the deuterated anti fluorite were determined and the reorientation of the ammonium ion was refined in detail. Differential scanning calorimetry measurements were used to investigate whether spontaneous phase separation into chiral domains occurs for mixtures of DPPC of opposite chirality. A new Neutron Velocity Selector was commissioned

  20. Chemical mining of primary copper ores by use of nuclear technology

    International Nuclear Information System (INIS)

    Chemical mining of primary copper ores, with nuclear explosives to break the ore and in-situ hydrostatic pressure to accelerate dissolution of primary ore minerals, may be feasible. A contained nuclear explosion well below the water table would be used to provide a mass of broken ore in a flooded 'chimney'. The hydrostatic pressure in the chimney should increase the solubility of oxygen in a water-sulfuric acid system enough to allow primary copper minerals such as chalcopyrite and bornite to be dissolved in an acceptably short time. Circulation and collection would be accomplished through drill holes. This method should be especially applicable to the deep portions of porphyry copper deposits that are not economical to mine by present techniques. (author)

  1. Control over the preferred orientation of CIGS films deposited by magnetron sputtering using a wetting layer

    Science.gov (United States)

    Yan, Yong; Jiang, Fan; Liu, Lian; Yu, Zhou; Zhang, Yong; Zhao, Yong

    2016-01-01

    A growth method is presented to control the preferred orientation in chalcopyrite CuIn x Ga1- x Se2 (CIGS) thin films grown by magnetron sputtering. Films with (220/204) and (112) preferred orientation as well as randomly oriented films were prepared. The effects of an In2Se3 wetting layer and the working pressure on the texture transition phenomena were examined. A large-grained CIGS film with (220/204) texture was formed at 400°C with the inclusion of a thin (80 nm) In2Se3 layer and liquid phase (excess copper selenide phase) formation, and the reaction mechanism is proposed. The device deposited at 2.0 Pa on an In2Se3 layer exhibited the optimal electrical properties. [Figure not available: see fulltext.

  2. Characteristics of Fluid Inclusions of Relin Cu-Mo Deposit in Northwestern Yunnan Province%滇西北热林Cu-Mo矿床流体包裹体特征

    Institute of Scientific and Technical Information of China (English)

    万多; 王可勇; 李文昌; 尹光侯; 余海军; 薛顺荣; 韦烈民

    2012-01-01

    热林Cu-Mo矿床为滇西北地区有代表性的燕山期斑岩型矿床.它产于似斑状二长花岗岩-二长花岗斑岩复式侵入体内,成矿作用经历了黄铁矿±黄铜矿-石英脉(Ⅰ)、黄铁矿-黄铜矿±辉钼矿-石英脉(Ⅱ)、辉钼矿±黄铜矿-石英脉(Ⅲ)及黄铜矿-石英-方解石脉(Ⅳ)4个阶段.流体包裹体岩相学、显微测温及碳、氢、氧同位素综合研究表明:Ⅰ-Ⅲ成矿阶段石英中均发育含NaC1子矿物三相、气液两相、富气相及含CO2三相4种类型的原生流体包裹体,与含矿的二长花岗斑岩斑晶石英中发育的包裹体类型及组合特征相似,表明成矿流体为中高温、高盐度NaCl-CO2-H2O体系热液,且主要来源于容矿的燕山期岩浆侵入体;Ⅳ阶段主要发育气液两相原生流体包裹体,成矿流体为中低温、低盐度NaCl-H2O体系热液,为岩浆来源NaCl-CO2-H2O体系热液演化晚期与大气降水混合流体.%The Relin Cu-Mo deposit located in northwest Yunnan province is a typical porphyry deposit formed in Yanshanian period.It occurs in porphyritic monzonitic granite-monzogranite porphyry intrusive complex and experienced four stages,pyrite ± chalcopyrite-quartz (Ⅰ),pyrite-chalcopyrite ± molybdenite-quartz (Ⅱ),molybdenite ± chalcopyrite-quartz(Ⅲ) and chalcopyrite-quartz-calcite (Ⅳ),respectively.Comprehensive studies of petrography,microthermometry as well as hydrogen,oxygen and carbon isotopes of fluid inclusions show that there develop four types of fluid inclusions in quartz grains formed from Ⅰ to Ⅲ mineralization stages,halite daughter mineral-bearing three-phase,aqueous two-phase,vapor-rich two-phase as well as carbon dioxide-bearing three-phase fluid inclusions.The fact that both type and assemblage of fluid inclusions in hydrothermal-origin quartz are similar to those in phenocryst quartz of ore-hosting monzo-granite porphyry indicates that the ore-forming NaCl-CO2-H2O hydrothermal fluid with medium to

  3. A versatile interaction chamber for laser-based spectroscopic applications, with the emphasis on Laser-Induced Breakdown Spectroscopy

    International Nuclear Information System (INIS)

    The technical note describes the interaction chamber developed particularly for the laser spectroscopy technique applications, such as Laser-Induced Breakdown Spectroscopy (LIBS), Raman Spectroscopy and Laser-Induced Fluorescence. The chamber was designed in order to provide advanced possibilities for the research in mentioned fields and to facilitate routine research procedures. Parameters and the main benefits of the chamber are described, such as the built-in module for automatic 2D chemical mapping and the possibility to set different ambient gas conditions (pressure value and gas type). Together with the chamber description, selected LIBS application examples benefiting from chamber properties are described. - Highlights: • Development of the interaction chamber for LIBS applications • Example of automated chemical mapping of lead in a chalcopyrite sample • Example of LIBS measurement of fluorine in underpressure • Overview of chamber benefits

  4. Find of U and Pb-Zn-Cu ore mineralization in the Cista massif

    International Nuclear Information System (INIS)

    In late 1982, during the survey of the development of the Hurky fault in the northeastern part of the Cista granitoid massif and its influence on the ore mineralization using the H-25 borehole a new type of ore mineralization was found in form of a separate vein of uraninite occurring in the vein of aplitic igneous rock in the Cista granodiorite. There is a separate galenite-sphalerite-chalcopyrite ore mineralization bound to the carbonate gangue. This gangue cements the crushed hydrothermally altered zone in the vicinity of the uraninite mineralization, also in the granodiorite. In view of the existence, in the close vicinity of the northern boundary of the Hurky-center fault, of the richest molybdenite mineralization of phenites, the possible genetic relation of Mo ore mineralization of phenites as well as the significance of radial disturbances for the ore bearing character are assumed of the massif. (B.S.)

  5. Thermoelectric properties of CuAlCh2 (Ch = S, Se and Te)

    Science.gov (United States)

    Gudelli, Vijay Kumar; Vaitheeswaran, G.; Kanchana, V.

    2015-06-01

    Electronic and thermoelectric properties of ternary chalcopyrite-type CuAlCh2 (S, Se and Te) were studied using the first principles density functional calculations implemented in the full potential linear augmented plane wave (FP-LAPW) method. The thermoelectric properties are calculated by solving the Boltzmann transport equation within the constant relaxation time approximation. The calculated band gap using the Tran-Blaha modified Becke-Johnson potential (TB-mBJ), of all the compounds are in good agreement with the available experiment and other theoretical reports. Thermoelectric properties like thermopower, electrical conductivity scaled by relaxation time are calculated as a function of carrier concentrations at different temperatures. The calculated thermoelectric properties are compared with the available experiment and other theoretical calculations of similar materials.

  6. Absorption Spectra of CuGaSe 2 and CuInSe 2 Semiconducting Nanoclusters

    KAUST Repository

    Mokkath, Junais Habeeb

    2015-10-01

    The structural and optical properties of the chalcopyrite CunGanSe2n and CunInnSe2n nanoclusters (n = 2, 4, 6, and 8) are investigated as a function of the size using a combination of basin-hopping global optimization and time-dependent density functional theory. Although the lowest energy structures are found to show almost random geometries, the band gaps and absorption spectra still are subject to systematic blue shifts for decreasing cluster size in the case of CunGanSe2n, indicating strong electron confinement. The applicability of the nanoclusters in photovoltaics is discussed. © 2015 American Chemical Society.

  7. Iron sulphides in mining ores

    International Nuclear Information System (INIS)

    Full text: Mineral samples were obtained from different stages of a mineral processing circuit used to extract the copper and gold rich mineralogical phases. The aim of this work is to characterise the quality of the samples at different stages of processing. The samples were taken of the initial head grade, tailings, initial cyclone concentration and the final concentrate. Characterisation of the samples was carried out using Cu Kα x-ray powder diffraction and 57Fe Moessbauer spectroscopy. These measurements will be presented and discussed in terms of the enrichment of the ore, showing the removal of magnetite and quartz through the processing, the final concentrate being rich in chalcopyrite, bornite and pyrite

  8. Structural, optical, and electrical properties of pulsed laser deposition CIGSS thin films

    Science.gov (United States)

    Xu, Yan-Bin; Kang, Y. Zhen-Feng; Fan, Yue; Xiao, Ling-ling; Bo, Qing-Rui; Ding, Tie-Zhu

    2015-12-01

    High-quality CuIn0.75Ga0.25(Se0.75S0.25)2 (CIGSS) thin films were synthesized on the soda-lime glass (SLG) substrates by pulsed laser deposition. The structural and optical properties of CIGSS thin films were studied by experiments and theoretical calculations. XRD result reveals that the films are of chalcopyrite structure. The experiments and theory show that CIGSS is a semiconductor with a direct band gap. The direct band gap energy of the deposited CIGSS thin films are in the solar energy range. The band structure and density of states of the CIGSS crystals were studied by the first principles density functional theory. The experimental data and theoretical data have demonstrated good agreement.

  9. Effects of the CuS phase on the growth and properties of CuInS2 thin films

    Science.gov (United States)

    Liu, Xiaohui; Han, Anjun; Liu, Zhengxin; Sugiyama, Mutsumi

    2016-01-01

    CuInS2 thin films were prepared by sulfurization using a less hazardous liquid, metal-organic ditertiarybutylsulfide, on soda-lime glass substrates. Single-phase chalcopyrite CuInS2 films were obtained after 15 min at 515 °C. The obtained CuInS2 films were repeatedly sulfurized under different sulfurization conditions. The characteristics of these CuInS2 films were determined by X-ray diffraction (XRD) and photoluminescence (PL) spectra analyses. The secondary impurity phase such as CuS was confirmed from XRD patterns. The growth mechanism of intrinsic defects related to the secondary phase is discussed in this paper.

  10. Electronic structure of the Zn(O,S)/Cu(In,Ga)Se2 thin-film solar cell interface

    Energy Technology Data Exchange (ETDEWEB)

    Mezher, Michelle [Department of Chemistry and Biochemistry, University of Nevada, Las Vegas (UNLV), Las Vegas NV 89154 USA; Garris, Rebekah [National Renewable Energy Laboratory (NREL), Golden CO 80401 USA; Mansfield, Lorelle M. [National Renewable Energy Laboratory (NREL), Golden CO 80401 USA; Horsley, Kimberly [Department of Chemistry and Biochemistry, University of Nevada, Las Vegas (UNLV), Las Vegas NV 89154 USA; Weinhardt, Lothar [Department of Chemistry and Biochemistry, University of Nevada, Las Vegas (UNLV), Las Vegas NV 89154 USA; Institute for Photon Science and Synchrotron Radiation (IPS), Karlsruhe Institute of Technology (KIT), 76344 Eggenstein-Leopoldshafen Germany; ANKA Synchrotron Radiation Facility, Karlsruhe Institute of Technology (KIT), 76344 Eggenstein-Leopoldshafen Germany; Institute for Chemical Technology and Polymer Chemistry (ITCP), Karlsruhe Institute of Technology (KIT), 76128 Karlsruhe Germany; Duncan, Douglas A. [Department of Chemistry and Biochemistry, University of Nevada, Las Vegas (UNLV), Las Vegas NV 89154 USA; Blum, Monika [Department of Chemistry and Biochemistry, University of Nevada, Las Vegas (UNLV), Las Vegas NV 89154 USA; Rosenberg, Samantha G. [Department of Chemistry and Biochemistry, University of Nevada, Las Vegas (UNLV), Las Vegas NV 89154 USA; Bär, Marcus [Department of Chemistry and Biochemistry, University of Nevada, Las Vegas (UNLV), Las Vegas NV 89154 USA; Renewable Energy, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, 14109 Berlin Germany; Institut für Physik und Chemie, Brandenburgische Technische Universität Cottbus-Senftenberg, 03046 Cottbus Germany; Ramanathan, Kannan [National Renewable Energy Laboratory (NREL), Golden CO 80401 USA; Heske, Clemens [Department of Chemistry and Biochemistry, University of Nevada, Las Vegas (UNLV), Las Vegas NV 89154 USA; Institute for Photon Science and Synchrotron Radiation (IPS), Karlsruhe Institute of Technology (KIT), 76344 Eggenstein-Leopoldshafen Germany; ANKA Synchrotron Radiation Facility, Karlsruhe Institute of Technology (KIT), 76344 Eggenstein-Leopoldshafen Germany; Institute for Chemical Technology and Polymer Chemistry (ITCP), Karlsruhe Institute of Technology (KIT), 76128 Karlsruhe Germany

    2016-03-10

    The electronic band alignment of the Zn(O,S)/Cu(In,Ga)Se2 interface in high-efficiency thin-film solar cells was derived using X-ray photoelectron spectroscopy, ultra-violet photoelectron spectroscopy, and inverse photoemission spectroscopy. Similar to the CdS/Cu(In,Ga)Se2 system, we find an essentially flat (small-spike) conduction band alignment (here: a conduction band offset of (0.09 +/- 0.20) eV), allowing for largely unimpeded electron transfer and forming a likely basis for the success of high-efficiency Zn(O,S)-based chalcopyrite devices. Furthermore, we find evidence for multiple bonding environments of Zn and O in the Zn(O,S) film, including ZnO, ZnS, Zn(OH)2, and possibly ZnSe.

  11. Synthesis of CuInSe2 thin films from electrodeposited Cu11In9 precursors by two-step annealing

    Directory of Open Access Journals (Sweden)

    TSUNG-WEI CHANG

    2014-02-01

    Full Text Available In this study, copper indium selenide (CIS films were synthesized from electrodeposited Cu-In-Se precursors by two-step annealing. The agglomeration phenomenon of the electrodeposited In layer usually occurred on the Cu surface. A thermal process was adopted to turn Cu-In precursors into uniform Cu11In9 binary compounds. After deposition of the Se layer, annealing was employed to form chalcopyrite CIS. However, synthesis of CIS from Cu11In9 requires sufficient thermal energy. Annealing temperature and time were investigated to grow high quality CIS film. Various electrodeposition conditions were investigated to achieve the proper atomic ratio of CIS. The properties of the CIS films were characterized by scanning electron microscopy (SEM, X-ray Diffraction (XRD, and Raman spectra.

  12. Pressure effect on the structural and electronic properties of CuInS2

    Science.gov (United States)

    Adetunji, B. I.

    2016-05-01

    The pressure dependence of the bond length and energy gap in chalcopyrite CuInS2 between 0 and 40 GPa has been investigated using pseudopotentials plane-wave method within the generalized gradient approximation for the exchange-correlation potential. We found that the bond length decreases as the pressure increases. Also, the energy gap of CuInS2 expands as the pressure increases with a rate of 10.693 meV/GPa. The linear pressure coefficient calculated is approximately half the reported experimental value of 23 meV/GPA. Our calculated bulk modulus of 68.7 GPa is in good agreement with the available experimental and theoretical values. The present calculations show that the d-electrons of Cu ions are one of the important factors that dominate the contributions to the I-VI bonds and the energy gap in CuInS2.

  13. Direct synthesis of CuIn(Sex, S1-x)2 films from elemental In, Cu, Se, S particle precursor films and its dependence on energy

    International Nuclear Information System (INIS)

    CuIn(Sex, S1-x)2 films were prepared by means of non-vacuum, instantaneous, direct synthesis from elemental In, Cu, Se and S particle precursor films by passing an electrical current with precise control through the metal substrate. For a constant reaction period of 1 s, unreacted elemental particles remained in the films for powers below 1 kV A, whereas the reaction to CuIn(Sex, S1-x)2 (x = 1) appeared to be complete at higher power. Chalcopyrite structure was observed in the range from 1.08 kV A to 1.24 kV A, the sphalerite structure appeared over 1.35 kV A. X-ray diffraction shows single (112) peaks of CuIn(Sex, S1-x)2 and the peak position agreed with the nominal composition of the precursors.

  14. Determination of copper isotope ratios by LA-MC-ICP-MS

    International Nuclear Information System (INIS)

    Full text: The stable isotope ratios of metals commonly found in sulphide ore deposits (e.g., Cu, Zn. Fe, Sb, Ag) may be fractionated significantly during ore-forming processes (redox reactions, etc.) and thus provide important information on the source, transport and depositional mechanisms of these metals. However, little work has been done on these isotopic systems because of past analytical difficulties in making precise measurements. Recently developed laser ablation (LA)-multi-collector (MC)-ICP-MS technology now allows routine rapid, in situ determination of the isotope ratios of these metals. This study reports on: (a) the development of an analytical protocol for the measurement of the 65Cu/63Cu ratio of chalcopyrite, (b) preliminary data for samples from a wide range of copper-bearing mineral deposits, and (c) a preliminary study of the spatial distribution of Cu isotope ratios within the Cadia Hill porphyry Cu-Au deposit. The instrumentation used in this study was a Merchantek LUV266 laser sampler operated with either Ar or He as the sample carrier gas. The ablated material was transported into a Plasma MC-ICP-MS for isotopic determination. Instrumental mass bias was corrected using the measured 66Zn/64Zn ratio of a Zn-bearing aerosol added continuously to the ablated sample carrier gas flow via a T-junction. The isotopes of copper (and other metals) are fractionated significantly by volatilisation and condensation processes operative during the laser sampling/transport processes, both of which favour depletion of 65Cu relative to 63Cu in the transported material. This fractionation may be reduced by using high laser pulse energies, low repetition rates and, most significantly, by ablation in He, which reduces dramatically the condensation blanket of sulphidic material around the ablation site. Using these conditions, relatively stable Cu isotope ratios may be maintained over a long ablation period (up to 4 minutes). However, absolute ratios are still

  15. CuInS2 thin films obtained by spray pyrolysis for photovoltaic applications

    International Nuclear Information System (INIS)

    Copper indium disulphide, CuInS2, is a promising absorber material for thin film photovoltaic which has recently attracted considerable attention due to its suitability to reach high efficiency solar cells by using low-cost techniques. In this work CuInS2 thin films have been deposited by chemical spray pyrolysis onto glass substrates at ambient atmosphere, using different composition solutions at various substrate temperatures. Structural, chemical composition and optical properties of CIS films were analysed by X-ray diffraction, energy dispersive X-ray spectroscopy and optical spectroscopy. Sprayed CIS films are polycrystalline with a chalcopyrite structure with a preferential orientation along the direction and no remains of oxides were found after spraying in suitable conditions. X-ray microanalysis shows that a chemical composition near to stochiometry can be obtained. An optical gap of about 1.51 eV was found for sprayed CIS thin films

  16. Comparative study of structural and morphological properties of CuIn{sub 3}S{sub 5} and CuIn{sub 7}S{sub 11} materials

    Energy Technology Data Exchange (ETDEWEB)

    Khemiri, N., E-mail: naoufel_khemiri@yahoo.f [Laboratoire de Photovoltaique et Materiaux Semi-conducteurs, ENIT BP 37, Le belvedere 1002-Tunis (Tunisia); Kanzari, M. [Laboratoire de Photovoltaique et Materiaux Semi-conducteurs, ENIT BP 37, Le belvedere 1002-Tunis (Tunisia)

    2010-02-15

    CuIn{sub 3}S{sub 5} and CuIn{sub 7}S{sub 11} powders were prepared by solid-state reaction method using high-purity elemental copper, indium and sulphur. The films prepared from CuIn{sub 3}S{sub 5} and CuIn{sub 7}S{sub 11} powders were grown by thermal evaporation under vacuum (10{sup -6} Torr) on glass substrates at different substrate temperature Ts varying from room temperature to 200 deg. C. The powders and thin films were characterized for their structural properties by using X-ray diffraction (XRD) and energy dispersive X-ray (EDX). Both powders were polycrystalline with chalcopyrite and spinel structure, respectively. From the XRD data, we calculated the lattice parameters of the structure for the compounds. For CuIn{sub 3}S{sub 5} powder, we also calculated the cation-anion bond lengths. The effect of substrate temperature Ts on the structural properties of the films, such as crystal phase, preferred orientation and crystallinity was investigated. Indeed, X-ray diffraction analysis revealed that the films deposited at a room temperature (30 deg. C) are amorphous in nature while those deposited on heated were polycrystalline with a preferred orientation along (1 1 2) of the chalcopyrite phase and (3 1 1) of the spinel phase for CuIn{sub 3}S{sub 5} and CuIn{sub 7}S{sub 11} films prepared from powders, respectively. The morphology of the films was determined by atomic force microscopy AFM. The surface roughness and the grain size of the films increase on increasing the substrate temperature.

  17. Genesis of Pb-Zn-Cu-Ag Deposits within Permian Carboniferous-Carbonate Rocks in Madina Regency, North Sumatra

    Directory of Open Access Journals (Sweden)

    Bhakti Hamonangan Harahap

    2015-11-01

    Full Text Available Strong mineralized carbonate rock-bearing Pb-Zn-Cu-Ag-(Au ores are well exposed on the Latong River area, Madina Regency, North Sumatra Province. The ore deposit is hosted within the carbonate rocks of the Permian to Carboniferous Tapanuli Group. It is mainly accumulated in hollows replacing limestone in the forms of lensoidal, colloform, veins, veinlets, cavity filling, breccia, and dissemination. The ores dominantly consist of galena (126 000 ppm Pb and sphalerite (2347 ppm Zn. The other minerals are silver, azurite, covellite, pyrite, marcasite, and chalcopyrite. This deposit was formed by at least three phases of mineralization, i.e. pyrite and then galena replaced pyrite, sphalerite replaced galena, and pyrite. The last phase is the deposition of chalcopyrite that replaced sphalerite. The Latong sulfide ore deposits posses Pb isotope ratio of 206Pb/204Pb = 19.16 - 20.72, 207Pb/204Pb = 16.16 - 17.29, and 208Pb/204Pb = 42.92 - 40.78. The characteristic feature of the deposit indicates that it is formed by a sedimentary process rather than an igneous activity in origin. This leads to an interpretation that the Latong deposit belongs to the Sedimentary Hosted Massive Sulfide (SHMS of Mississippi Valley-Type (MVT. The presence of SHMS in the island arc such as Sumatra has become controversial. For a long time, ore deposits in the Indonesian Island Arc are always identical with the porphyry and hydrothermal processes related to arc magmatism. This paper is dealing with the geology of Latong and its base metal deposits. This work is also to interpret their genesis as well as general relationship to the regional geology and tectonic setting of Sumatra.

  18. Gold and uranium metallogenesis in the framework of Neo-proterozoic crust growth and differentiation: example of the Mayo-Kebbi Massif (Chad) in the Central Africa Orogenic belt

    International Nuclear Information System (INIS)

    The Mayo Kebbi massif located in southwestern Chad between the Congo craton in the South, the West African craton in the west and the Sahara meta-craton to the east exposes a segment of Neo-proterozoic juvenile crust accreted in the Central African orogenic belt during the Pan African orogeny. It consists of two greenstone belts (Zalbi and Goueygoudoum) separated by the May Kebbi calc-alkaline batholith complexes and intruded by calc-alkaline high-K granitic plutons. The whole is covered by Phanerozoic sedimentary formations. The greenstone belts contain sulphide zones hosted mainly by meta-plutonic rocks (granodiorites) and meta-basalts and meta-volcaniclastics. The mineralization comprises pyrite, pyrrhotite, arsenopyrite, chalcopyrite, pentlandite, pentlandite silver, pentlandite cobaltiferous, sphalerite, cobaltite. These sulphides are disseminated, aggregated in form of layers or are filling veins and cracks. The greenstones also contain quartz veins with calcite and chlorite comprising a mineralization made of pyrite, chalcopyrite, galena and gold. Gold is present both as native crystals and as electrum. The high-K calc-alkaline Zabili granitic pluton hosts uranium mineralization related to a superposition of: (1) ductile deformation and metasomatic alteration implying the interaction between magmatic minerals with a Na-rich fluid, of potential magmatic origin, coeval to the main deposition of uranium oxides, followed by (2) brittle deformation and deposition of secondary hydrated uranium silicates involving a Na-Ca-rich fluid. We propose that these uranium mineralizations represent the extreme expression of crustal differentiation as a result of Pan-African reworking of a Neo-proterozoic juvenile crustal segment. (author)

  19. Lead and neodymium isotopic results from metabasalts of the Haveri Formation, southern Finland: evidence for Palaeoproterozoic enriched mantle

    Directory of Open Access Journals (Sweden)

    Vaasjoki, M.

    1999-06-01

    Full Text Available Tholeiitic metabasalts and coexisting sulphides have been analysed for their Pb and Nd isotopic compositions from the Proterozoic Haveri Formation, which forms the basal unit of the Tampere Schist Belt in southern Finland. Ten whole rock samples analysed for Pb isotopes form a sublinear array which yields rather uncertain age estimates in the 1900-2000 Ma range and lies on the 207Pb/204Pb vs. 206Pb/204Pb diagram well below the average global lead evolution curve. The initial lead isotopic composition inferred from the whole rock data and measured on chalcopyrite is the least radiogenic obtained from the Svecofennian domain, and precludes involvement of old upper crustal material in basalt genesis. This together with the geochemical composition and initial eNd (1900 of +0.5±0.6 suggest that the Haveri mafic metavolcanic rocks were not derived from convective MORB-type mantle. The source was rather a mantle, which had been enriched in LREE for a considerable time period. Some chalcopyrite trace leads plot close to the whole rock array while others lie above it. This is interpreted as indicating two distinct mineralisation processes. The primary and major process involved lead which was cogenetic with the basalts, while the second mineralising fluid introduced radiogenic (high 207Pb upper crustal lead scavenged from the adjacent sedimentary rocks. The least radiogenic leads at Haveri and in the Outokumpu ophiolite complex some 300 km NE are similar and the two occurrences can be coeval. The preservation of original mantle material at Haveri may be interpreted as suggesting that continental crust had formed in the Tampere area 1900-2000 Ma ago.

  20. Influencia de la temperatura en la fijación y penetración de la plata durante la lixiviación de calcopirita con microorganismos termófilos moderados

    Directory of Open Access Journals (Sweden)

    Cancho, L.

    2004-06-01

    Full Text Available Bioleaching of chalcopyrite using mesophilic microorganisms considerably improves in the presence of silver. However, the studies carried out with moderate thermophilic microorganisms do not show a significant improvement with regard to the use of mesophilic bacteria. The main objective of the present work has been to study the silver fixation on chalcopyrite at 35 and 45 °C and its influence on the microbiological attack. Different observations using SEM, EDS microanalysis and concentration profiles using electron microprobe have been carried out. The study of the different samples showed that silver fixation was more favourable at 35 °C than at 45 °C. In addition, bacterial action improved silver penetration through attack cracks.

    La biolixiviación de la calcopirita con microorganismos mesófilos mejora considerablemente cuando se utiliza plata en el medio de reacción. Sin embargo, los estudios realizados con microorganismos termófilos moderados no muestran una mejora significativa con respecto a la utilización de bacterias mesófilas. El objetivo del presente trabajo ha sido el estudio de la fijación de plata sobre calcopirita a 35 y 45 °C y su influencia en el ataque microbiológico. Se han realizado observaciones con SEM, microanálisis por EDS y perfiles de concentración con microsonda electrónica. El estudio de las distintas muestras reveló que la fijación de la plata fue más favorable a 35 que a 45 °C y que la acción bacteriana favoreció la penetración de la plata a través de las grietas de ataque.

  1. Effect of electromagnetic radiation on the physico-chemical properties of minerals

    International Nuclear Information System (INIS)

    The electromagnetic radiation effect represented by gamma rays was investigated through; chemical analysis, X-ray diffraction (XRD), scanning electron microscopy (Sem) and magnetization when applied at a dose of 0.5704 Gy (0.5704 J/ kg) at a feed relation of 18.40 ± 1.13 mGy/ h., in different minerals; in order to characterize the impact of the same from 137Cs in the physicochemical properties of these minerals. All the irradiated samples showed chemical stability at this stage undetectable other both in the XRD study and in the images analysis obtained by Sem; and at present almost the same chemical composition as the non-irradiated samples. So the same patterns of X-ray diffraction thereof, show a tendency to slightly lower the intensity of the most representative peaks of each mineral phase, which may be due to a decrease in crystallinity or preferential crystallographic orientation in crystals. In the micrographs analysis obtained by Sem on the irradiated samples, some holes (open pores) present in the particles were observed, mainly chalcopyrite and sphalerite lesser extent, seen this fact may be due to Compton Effect, in the radiation process. In relation to the magnetization property, a variation is obtained in the saturation magnetization (Ms) for the irradiated samples containing iron and more significantly in the chalcopyrite case. Therefore, with the radiation level used; slight changes occurring in the physical properties of minerals, whereas they remained stable chemically. These small changes may represent a signal that electromagnetic radiation applied at higher doses, is a viable option for improving the mineral processing. (author)

  2. Selenium content of sulfide ores related to ophiolites of Greece.

    Science.gov (United States)

    Economou-Eliopoulos, M; Eliopoulos, D G

    1998-01-01

    Several deposits of sulfide mineralization have been described in the ophiolites of Greece. Based on their mineralogical and chemical composition and the host rocks, two types can be distinguished: (1) the Fe-Cu-Ni-Co type consisting of pyrrhotite, chalcopyrite, Co-pentlandite, pyrite, magnetite + arsenides, +/- chromite, hosted in serpentinites, gabbros or diabases, which have variable geochemical characteristics, and (2) sulfide mineralization of the Cyprus type containing variable proportions of pyrite, chalcopyrite, bornite, and sphalerite. The spatial association with shear zones and fault systems, which is a common feature in both types of mineralization, provided the necessary permeability for the circulation of the responsible mineralized hydrothermal fluids. The selenium (Se) content in representative samples of both types of mineralization from the ophiolites of Pindos (Kondro, Perivoli, and Neropriona), Othrys (Eretria and A. Theodoroi), Veria (Trilofon), and Argolis (Ermioni) shows a wide variation. The highest values of Se (130 to 1900 ppm) were found in massive Fe-Cu sulfide ores from Kondro, in particular the Cu-rich portions (average 1300 ppm Se). The average values of Se for the Othrys sulfides are low (< 40 ppm Se). The Se content in a diabase breccia pipe (50 x 200 m) with disseminated pyrite mineralization (Neropriona) ranges from < 1 to 35 ppm Se. The highest values were noted in strongly altered samples that also exhibited a significant enrichment in platinum (1 ppm Pt). Sulfide mineralization (irregular to lens-like masses and stringers) associated with magnetite, hosted in gabbros exposed in the Perivoli area (Tsouma hill), shows a content ranging from 40 to 350 ppm Se. The distribution of Se in the studied type of the sulfide mineralization may be of genetic significance, indicating that the Se level, which often is much higher than in typical magmatic sulfides related to mafic-ultramafic rocks (average 90-100 ppm Se), may positively affect

  3. The Archean komatiite-hosted, PGE-bearing Ni-Cu sulfide deposit at Vaara, eastern Finland: evidence for assimilation of external sulfur and post-depositional desulfurization

    Science.gov (United States)

    Konnunaho, J. P.; Hanski, E. J.; Bekker, A.; Halkoaho, T. A. A.; Hiebert, R. S.; Wing, B. A.

    2013-12-01

    Archean komatiites host important resources of Ni, Cu, Co, and PGE, particularly in Western Australia and Canada. In Finland, several small, low-grade sulfide deposits have been found in komatiites, including the ca. 2.8 Ga Vaara deposit in the Archean Suomussalmi greenstone belt. It occurs in the central part of the serpentinized olivine cumulate zone of a komatiitic extrusive body and is composed of disseminated interstitial sulfides consisting of pyrite, pentlandite, millerite, violarite, and chalcopyrite accompanied by abundant magnetite. Although currently subeconomic, the mineralization is interesting due to the very high chalcophile element contents of the sulfide fraction (38 wt% Ni, 3.4 wt% Cu, 0.7 wt% Co, 22.4 ppm Pd, and 9.5 ppm Pt). The sulfides occur in relatively Cr-poor olivine cumulates suggesting involvement of a chromite-undersaturated magma. The parental magma was an Al-undepleted komatiite with an estimated MgO content of at least 24 wt%. In contrast to the common komatiite types in the eastern Finland greenstone belts, the Vaara rocks are moderately enriched in LREE relative to MREE, suggesting that crustal contamination played an important role in the genesis of the Vaara deposit. Multiple sulfur isotope data reveal considerable mass-independent sulfur isotope fractionation both in country rock sedimentary sulfides (Δ33S ranges from -0.50 to +2.37 ‰) and in the Vaara mineralization (Δ33S ranges from +0.53 to +0.66 ‰), which provides strong evidence for incorporation of crustal sulfur. Extensive replacement of interstitial sulfides by magnetite and the presence of millerite- and violarite-bearing, pyrrhotite-free sulfide assemblages indicate significant post-magmatic, low-temperature hydrothermal oxidation of the primary magmatic pyrrhotite-pentlandite-chalcopyrite assemblages and associated sulfur loss that led to a significant upgrading of the original metal tenors of the Vaara deposit.

  4. Synthesis and characteristics of spray deposited CuInS{sub 2} nanocrystals thin films for photovoltaic applications

    Energy Technology Data Exchange (ETDEWEB)

    Majeed Khan, M.A., E-mail: majeed_phys@rediffmail.com [King Abdullah Institute for Nanotechnology, King Saud University, Riyadh 11451 (Saudi Arabia); Kumar, Sushil [Materials Science Lab., Department of Physics, Chaudhary Devi Lal University, Sirsa 125055 (India); AlSalhi, Mohamad S. [King Abdullah Institute for Nanotechnology, King Saud University, Riyadh 11451 (Saudi Arabia); Physics and Astronomy Department, College of Science, King Saud University, P.O. Box 2455, Riyadh 114 51 (Saudi Arabia)

    2013-10-15

    Graphical abstract: - Highlights: • CuInS{sub 2} nanocrystals thin films were synthesized by spray pyrolysis technique. • They are polycrystalline and have chalcopyrite (tetragonal) structure. • They have high absorption coefficient ∼10{sup 4} cm{sup −1} and optimum band gap of 1.55 eV. • They showed excellent opto-electronic properties employable in photovoltaics. - Abstract: Nanocrystalline thin films of CuInS{sub 2}, an attractive absorber material for highly efficient and terrestrial photovoltaic devices, were deposited on ultraclean glass substrates using spray pyrolysis technique. The prepared films were characterized by FESEM, FETEM, HRTEM, AFM, XRD, optical absorption spectroscopy, photoluminescence and current–voltage characteristics. The films exhibit almost smooth, dense and uniform topography; and have nano-sized particles 40–60 nm of CuInS{sub 2}. XRD data show that the films are polycrystalline and have chalcopyrite (tetragonal) structure with crystallite size 45–60 nm. Optical absorption studies show that the band gap of spray deposited CuInS{sub 2} films is 1.55 eV, while absorption coefficient is of ∼10{sup 5} cm{sup −1}. PL spectra have only one peak at 1.43 eV which may be attributed to the excitonic recombination through donor–acceptor impurity levels in the sample. Furthermore, CdS/CuInS{sub 2} heterojunction was also produced onto ITO coated glass substrate to evaluate solar cell parameters such as short circuit current density, open circuit voltage, fill factor and conversion efficiency.

  5. The influence of stoichiometry and annealing temperature on the properties of CuIn0.7Ga0.3Se2 and CuIn0.7Ga0.3Te2 thin films

    International Nuclear Information System (INIS)

    CuIn0.7Ga0.3Se2 and CuIn0.7Ga0.3Te2 thin films have been prepared by the electron beam evaporation technique and annealed at various temperatures (450 °C, 475 °C, 500 °C, 525 °C and 600 °C). Optical transmittance measurements have been carried out in the wavelength range 300–1200 nm. The films show high absorption in the solar radiation spectral range, and their optical band gaps range from 1.33 eV to 1.22 eV for CuIn0.7Ga0.3Se2 and from 1.13 eV to 1.06 eV for CuIn0.7Ga0.3Te2, depending on the annealing temperature. X-ray diffraction (XRD) indicates the films are crystallized in a single phase with the chalcopyrite structure and a preferred orientation along the (112) plane. The dependence of the lattice parameters on the composition of the films is investigated. Surface morphology has been determined by atomic force microscopy (AFM) and scanning electron microscopy (SEM). These results are correlated with the XRD microstructural analysis. - Highlights: • Chalcopyrite CIGSe and CIGTe thin films have been grown by e-beam evaporation. • The samples have been annealed at 4 different temperatures up to 600 °C. • Annealing effects on the optical properties, morphology and structure were analyzed. • Annealing improves crystallinity and increases grain size. • Energy band gap reduces with annealing temperature and Se replacement by Te

  6. Generalized stacking fault energies, cleavage energies, ionicity and brittleness of Cu(Al/Ga/In)Se2 and CuGa(S/Se/Te)2

    International Nuclear Information System (INIS)

    We calculate the generalized stacking fault (GSF) energies and cleavage energies γcl of the chalcopyrite compounds CuAlSe2, CuGaSe2, CuInSe2, CuGaS2 and CuGaTe2 using first principles. From the GSF energies, we obtain the unstable stacking fault energies γus and intrinsic stacking fault energies γisf. By analyzing γus and γisf, we find that the 〈 1-bar 1 0〉 (1 1 2) direction is the easiest slip direction for these five compounds. Also, for CuInSe2, it is most possible to undergo a dislocation-nucleation-induced plastic deformation along the 〈 1-bar 1 0〉 (1 1 2) slip direction. We show that the (1 1 2) plane is the preferable plane for fracture in the five compounds by comparing γcl of the (0 0 1) and (1 1 2) planes. It is also found that both γus and γcl decrease as the cationic or anionic radius increases in these chalcopyrites, i.e. along the sequences CuAlSe2 → CuGaSe2 → CuInSe2 and CuGaS2 → CuGaSe2 → CuGaTe2. Based on the values of the ratio γcl/γus, we discuss the brittle–ductile properties of these compounds. All of the compounds can be considered as brittle materials. In addition, a strong relationship between γcl/γus and the total proportion of ionic bonding in these compounds is found. (paper)

  7. Paragenesis and conditions of formation of ore minerals from metalliferous breccia pipes, N. Arizona

    International Nuclear Information System (INIS)

    Ore deposits within N. Arizona breccia pipes are currently being exploited for U, but at various times during the past century Cu, Pb, Zn, and Ag were mined. These pipes formed as solution-collapses within the Mississippian Redwall Ls and stopped upward through overlying strata. The principal ore minerals are: uraninite, chalcopyrite, chalcocite, tennantite-tetrahedrite, galena, sphalerite, millerite, gersdorffite, siegenite, and molybdenite. Common gangue minerals are marcasite, pyrite, barite, dolomite, calcite and quartz. Marcasite and pyrite appear to have formed prior to the ore minerals, followed closely by chalcopyrite. The Ni and Co phases also appear to be early: gersdorffite crystals are rimmed by later galena. Tennantite-tetrahedrite formed later than both galena and sphalerite; uraninite, the latest ore mineral, consisting fills interstices. Primary fluid inclusions in dolomite, quartz, and sphalerite show filling temperatures from 80 to 145 degree C and high salinities, averaging 15 wt% NaCl (eq). Secondary inclusions in sphalerite have consistently higher filling temperatures from 105 to 173 degree C, but similar salinities. Rock-Eval pyrolysis of pyrobitumen yields little or no volatile hydrocarbons (S1=0-0.2 mg/gm), but large amounts of pyrolytic hydrocarbons (S2=105-216 mg/gm). Temperatures of maximum pyrolytic yield are relatively low (424-430 degree C), suggesting temperatures did not exceed 150 degree C following pyrobitumen emplacement. Except for uraninite, the breccia pipes are similar to Mississippi Valley-type (MVT) deposits in mineralogy, fluid-inclusion filling temperatures and salinities, and associated organic material. Because MVT deposits do not host U minerals, a possible two-stage mineralization history of the pipes is suggested, the first by a MVT brine and perhaps a second forming the uraninite

  8. Effect of electromagnetic radiation on the physico-chemical properties of minerals; Efecto de la radiacion electromagnetica en las propiedades fisicoquimicas de los minerales

    Energy Technology Data Exchange (ETDEWEB)

    Lopez M, A.; Delgadillo G, J. A. [Universidad Autonoma de San Luis Potosi, Instituto de Metalurgia, Doctorado Institucional de Ingenieria y Ciencia de Materiales, Av. Sierra Leona 550, 78210 San Luis Potosi (Mexico); Vega C, H. R., E-mail: alopezm6@yahoo.com.mx [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

    2014-08-15

    The electromagnetic radiation effect represented by gamma rays was investigated through; chemical analysis, X-ray diffraction (XRD), scanning electron microscopy (Sem) and magnetization when applied at a dose of 0.5704 Gy (0.5704 J/ kg) at a feed relation of 18.40 ± 1.13 mGy/ h., in different minerals; in order to characterize the impact of the same from {sup 137}Cs in the physicochemical properties of these minerals. All the irradiated samples showed chemical stability at this stage undetectable other both in the XRD study and in the images analysis obtained by Sem; and at present almost the same chemical composition as the non-irradiated samples. So the same patterns of X-ray diffraction thereof, show a tendency to slightly lower the intensity of the most representative peaks of each mineral phase, which may be due to a decrease in crystallinity or preferential crystallographic orientation in crystals. In the micrographs analysis obtained by Sem on the irradiated samples, some holes (open pores) present in the particles were observed, mainly chalcopyrite and sphalerite lesser extent, seen this fact may be due to Compton Effect, in the radiation process. In relation to the magnetization property, a variation is obtained in the saturation magnetization (Ms) for the irradiated samples containing iron and more significantly in the chalcopyrite case. Therefore, with the radiation level used; slight changes occurring in the physical properties of minerals, whereas they remained stable chemically. These small changes may represent a signal that electromagnetic radiation applied at higher doses, is a viable option for improving the mineral processing. (author)

  9. Alteration and petrology of Intrusive Rocks associated with Gold Mineralization at Kuh-E-Zar Gold Deposit, Torbat-e-Heydaryeh

    Directory of Open Access Journals (Sweden)

    Alireza Mazloumi Bajestani

    2009-09-01

    Full Text Available Kuh- e -Zar gold deposit located 35 km west of Torbat-e-Heydaryeh, (Khorassan e- Razavi province, East of Iran. This deposit is a specularite-rich Iron oxide type (IOCG. This mine is situated within Khaf-Bardascan volcanic plutonic belt. Based on recent exploration along this belt, several IOCG type system plus Kuh-e-Zar deposit are discovered. In the study area, several type of tuff and lava having acid to intermediate composition are identified (upper Eocene. Oligo-Miocene granite, granodiorite, synogranite and monzonite intruded upper Eocene andesite-dacite-rhyolite. Intrusive rocks are meta-aluminous, medium to high-K series I-type. Based on spider diagram, intrusive rocks show enrichment in LILE = K, Th, Rb and depletion in HFSE = Nb, Sr, Ti. Based geochemistry of igneous rock, they formed in continental margin subduction zone. Propylitic (chlorite alteration is dominated and covers large area. Silicification is restricted only to mineralized zones. Argillic and albitization is found in certain location and cover small areas. The style of mineralization was controlled by the type and geometry of fault zones. Mineralization is found as vein, stockwork and breccias. Hypogene mineral Paragenesis include: specularite-quartz-gold-chlorite ± chalcopyrite ± pyrite ± galena ± barite. Secondary minerals formed due to oxidation are: goethite, limonite, lepidocrucite, Malachite, Azurite, Covelite, Cerucite, hydrocerucite, Pyrolusite and Smitsonite. In a few localities, chalcopyrite and minor pyrite and galena are found. Based on SEM analysis gold is present as electrum. Mineralization appeared in different type such as vein, stockwork and Hydrothermal breccia in strike sleep fault zone which are hidden inside volcano plutonic rocks. The average gold grade is between 3.02 ppm and ore reserve is estimated more than 3 million tons (cut off grade = 0.7 ppm.

  10. Deposition and characterization of graded Cu(In1-xGax)Se2 thin films by spray pyrolysis

    International Nuclear Information System (INIS)

    Cu(In1-xGax)Se2 (CIGS) thin films and their graded (x = 1 to 0) layer were grown on soda lime glass substrates using chemical spray pyrolysis (CSP) at different substrate temperatures (Ts). After optimization of Ts, depositions were carried out at different gallium composition (x) at optimized temperature of 350 °C. All the films deposited at Ts ≥ 350 °C were polycrystalline chalcopyrite structure, with a preferential orientation of (112), including the graded layer. With increase in x, lattice parameters a and c were observed to decrease. Line scan of the CIGS layer showed intersection of gallium and indium concentrations, revealing the graded nature of the film. Composition dependence of Raman peak for CuInSe2 (CIS) deposited by CSP was analyzed. Optical transmittance at a wavelength of 800 nm of the film with x = 0 (CIS) (30%) was found lower than that of the film grown with x = 0.82 (CIGS) (50%). Cusp-shape of the resistivity was observed with an increase of x leading to steep rise in resistivity of the films (1.61–71.68 Ω-cm) till x = 0.42 and then decreased to 4.78 Ω-cm at x = 0.82. Carrier concentrations of the films were evaluated in the order of 1016–1019 cm−3 with p-type conductivity. These results indicate that graded CIGS thin films with modulated gallium composition can be prepared by CSP. - Graphical abstract: Display Omitted - Highlights: • Optimization of the spray deposition system for device grade chalcopyrite CIGS films. • Optimized substrate temperature to obtain single-phase CIGS by spray deposition. • Detailed report on compositional dependence of CuInSe2 (CIS) thin films. • Systematic analysis of the influence of Ga in CIS by spray deposition. • Bowing parameter is extracted from the experiment values

  11. Structural studies of mechano-chemically synthesized CuIn1-xGaxSe2 nanoparticles

    International Nuclear Information System (INIS)

    CuInGaSe2 is a I-III-VI2 semiconducting material of tetragonal chalcopyrite structure. It is a very prominent absorber layer for photovoltaic devices. Particle-based coating process for CIGS is considered to be promising technique with relatively simple procedures and low initial investment. In the present work CIGS nanoparticle precursors suitable for screen-printing ink has been prepared by ball milling. High purity elemental copper granules, selenium and indium powders and fine chips of gallium were used as starting materials. First the ball milling was carried out for CuIn1-xGaxSe2 (x = 0.5) with (i) 10 ml of ethyl alcohol (ii) 5 ml of tetra ethylene glycol (wet) and (iii) 1 ml of ethylene diamine (semi-dry) for a milling time of 3 h and the results are not stoichiometric. In order to obtain an improved stoichiometric composition dry ball milling of elemental sources for three different compositions of CuIn1-xGaxSe2 (x = 0.25, 0.5 and 0.75) has been carried out. X-ray diffraction analysis revealed the presence of (1 1 2), (2 2 0)/(2 0 4), (3 1 2)/(1 1 6), (4 0 0) and (3 3 2) reflections for all the milled powders. These reflections correspond to chalcopyrite structure of CIGS. Shift in peaks towards higher value of 2θ is observed with the increase in Ga composition. Average grain size calculated by Scherrer's formula is found to be around 13 nm for the dry samples milled for 1.5 h and 7-8 nm for the samples wet milled for 3 h. Lattice constants 'a' and 'c' are found to decrease with the increase in concentration of Gallium. FESEM analysis revealed a strong agglomeration of the particles and the particle size varied from 11 to 30 nm for the dry-milled samples. Composition of milled powders has been studied by energy dispersive X-ray analysis. TEM analysis revealed the presence of nanocrystalline particles and SAED pattern corresponds to (1 1 2), (2 2 0)/(2 0 4), (5 1 2)/(4 1 7) and (6 2 0)/(6 0 4) diffraction peaks of CIGS. From the HRTEM analysis the d

  12. Optics of the CuGaSe{sub 2} solar cell for highly efficient tandem concepts; Optik der CuGaSe{sub 2}-Solarzelle fuer hocheffiziente Tandemkonzepte

    Energy Technology Data Exchange (ETDEWEB)

    Schmid, Martina

    2010-01-25

    A principle aim of solar cell research lies in optimizing the exploitation of the incident solar light. Yet, for single junction solar cells there exists an efficiency limit as described by Shockley and Queisser. The only concept realized so far to overcome this threshold is - apart from concentration - the multijunction solar cell. However, any kind of multijunction design poses new challenges: The upper wide-gap solar cell (top cell) needs to show efficient light absorption in the short-wavelength region. At the same time sufficient transmission for long-wavelength light is required which then needs to be absorbed effectively by the low-gap bottom cell. In tandem solar cells a proper light management in top and bottom solar cell is of great importance. This work focuses on chalcopyrite-based tandem solar cells. For the wide-bandgap IR-transparent ZnO:Al/i-ZnO/CdS/CuGaSe{sub 2}/SnO{sub 2}:F/glass solar cell an optical model has been established. Starting from modeling each of the individual layers building the stack the optical behavior of the complete thin film system of the top cell could be described. Carefully selected layer combinations and comparison of experimental and calculated data allowed for the attribution of transmission losses to the distinct material properties. Defects in the absorber are of crucial importance but also free carrier absorption in the window and in the transparent back contact contribute significantly to optical losses. The quantification of the losses was achieved by calculating the effects of reduced top cell transmission on the photo current of a simplified bottom cell. An extension of the optical model allowed to calculate the effective absorption in the individual layers and to determine reflection losses at the interfaces. From these results an optimized top cell stack was derived which is characterized by A) simulation of the monolithic integration, B) reduced layer thicknesses wherever possible from the electrical point of

  13. Geochemistry of the Patricia Zn-Pb-Ag Deposit (paguanta, NE Chile)

    Science.gov (United States)

    Chinchilla Benavides, D.; Merinero Palomares, R.; Piña García, R.; Ortega Menor, L.; Lunar Hernández, R.

    2013-12-01

    The Patricia Zn-Pb-Ag ore deposit is located within the Paguanta mining project, situated at the northern end of the Andean Oligocene Porphyry Copper Belt of Chile. The sulfide mineralization occurs as W-E oriented veins hosted in volcanic rocks, mainly andesite (pyroclastic, ash and lavas), of Upper Cretaceous to Middle Tertiary age. The ore mineralogy (obtained by EMPA analyses) comprises in order of abundance, pyrite, sphalerite (5.5 - 10.89 wt % Fe, 9.8-19 % molar FeS and 0.52 wt % Cd), galena, arsenopyrite, chalcopyrite and Ag-bearing sulfosalts. The veins show a zoned and banded internal structure with pyrite at the edges and sphalerite in the center. The Ag occurs mostly as Ag-Cu-Sb sulfosalts, in order of abundance: series freibergite - argentotennantite -polybasite and stephanite. Other minor Ag phases such as argentite, pyrargirite and diaphorite were also identified. These Ag phases are typically associated with the base-metal sulfides. Freibergite occurs filling voids within sphalerite, chalcopyrite and at the contact between sphalerite and galena. Polybasite, stephanite, pyrargirite and argentite are mostly in close association with freibergite. In the case of diaphorite, it commonly occurs filling voids between galena crystals or as inclusions within galena. Some minor Ag-bearing sulfosalts are also identified between pyrite crystals. The alteration minerals are dominated by chlorite, illite and kaolinite. The gangue minerals consist of quartz and carbonates identified by XRD as kutnahorite. We obtained linear correlation statistically significant only for Ag, As Au, Cd, Cu, Pb, Sb and Zn and therefore we generated an enhanced scatter plot matrix of these elements. Bulk rock analyses (ICP/MS and XRF) of drill cores show that Ag is strongly and positively correlated with Pb and As, moderately with Cd, Sb, Au and Zn and weakly with Cu, while Au is moderately and positively correlated with Ag, As, Cd, Sb and Zn and weakly with Cu and Pb. These results

  14. Mineralogy of the Panulcillo skarn copper deposit, Coquimbo Region, Chile

    Directory of Open Access Journals (Sweden)

    Asahiko Sugaki

    2000-12-01

    Full Text Available The Panulcillo skarn copper deposit developed in an Early Cretaceous (Valanginian volcano-sedimentary sequence intruded by a Cretaceous diorite. The exoskarn zone of the deposit is composed of garnet skarn comprising grandite garnet (Ad12.9-47.4 and phlogopite with lesser amounts of diopside (Di89.6-91.6, clintonite, pargasitic hornblende, actinolite, pumpellyite, chlorite, quartz and calcite, exhibiting characteristic Mg-Al-rich assemblages. The principal ores consist of chalcopyrite, monoclinic pyrrhotite, sphalerite, pyrite, and magnetite with small amounts of galena, and locally secondary marcasite, hematite and covellite, generally filling interstices of the garnet skarn. Chalcopyrite shows characteristic polysynthetic twinning, normally including fine star-like crystals of sphalerite as exsolution products. Sphalerite contains 14.4 - 22.5 mol% FeS and 1.6 - 9.2 mol% MnS, and is associated intimately with chalcopyrite. It is highly likely that such Fe-rich sphalerite has coexisted primarily with hexagonal pyrrhotite under low-sulfidation conditions at higher temperatures than 275 - 254°C, below which monoclinic pyrrhotite is stableMineralogía del yacimiento cuprífero tipo skarn de Panulcillo, Región de Coquimbo, Chile. El yacimiento tipo skarn de cobre de Panulcillo se desarrolló en una secuencia volcano-sedimentaria de edad cretácica inferior (Valanginiana, la que es intruida por un cuerpo cretácico de composición diorítica. La zona del exoskarn característicamente presenta una asociación mineralógica rica en Mg y Al, y corresponde a un skarn de granate compuesto por granate tipo ugrandita (Ad12.9-47.4 y flogopita con candidades menores de diópsido (Di89.6-91.6, clintonita, hornblenda pargasítica, actinolita, pumpellita, clorita, cuarzo y calcita. Los minerales metálicos consisten mayoritariamente en calcopirita, pirrotina monoclínica, esfalerita, pirita, y magnetita con menos galena, localmente marcasita, hematita y

  15. Leaching of S, Cu, and Fe from disseminated Ni-(Fe)-(Cu) sulphide ore during serpentinization of dunite host rocks at Mount Keith, Agnew-Wiluna belt, Western Australia

    Science.gov (United States)

    Gole, Martin J.

    2014-10-01

    Komatiite-hosted disseminated Ni sulphide deposits in the Agnew-Wiluna greenstone belt occur both above and below the olivine isograd that was imposed on the greenstone sequence during the M2 metamorphic/deformation event. Deposits in the northern and central part of the belt and that are located below the isograd (Mount Keith, Honeymoon Well and West Jordan) have complex sulphide mineralogy and strongly zoned sulphide assemblages. These range from least-altered assemblages of pentlandite-pyrrhotite-chalcopyrite±pyrite to altered assemblages of pentlandite±chalcopyrite, pentlandite-heazlewoodite (or millerite), heazlewoodite (or millerite), and rarely to heazlewoodite-native Ni. Deposits to the south and that are above of the olivine isograd (Six Mile, Goliath North) are dominated by less complex magmatic assemblages with a lower proportion of weakly altered pentlandite±chalcopyrite assemblages. More altered assemblages are uncommon in these deposits and occur as isolated patches around the periphery of the deposits. The sulphide zonation is reflected by whole-rock reductions in S, Cu, Fe and Zn, whereas Ni, Pt and Pd and, with some exceptions, Co are conservative. The leaching of S, Cu, Fe and Zn from sulphide assemblages and the whole rock was initiated by highly reduced conditions that were produced during low fluid/rock ratio serpentinization. Consumption of H2O resulted in Cl, a component of the fluid, being concentrated sufficiently to stabilise iowaite as part of lizardite-rich assemblages. Once the rate of olivine hydration reactions declined and during and after expansion and associated fracturing of the ultramafic sequence allowed higher fluid access, a more fluid-dominated environment formed and new carbonate-bearing fluid gained access to varying extents to the ultramafic rock sequence. This drove Cl from iowaite (to form pyroaurite) and caused the sulphide assemblages to be altered from the original magmatic assemblages and compositions to those

  16. Fabrication of Cu(In,Ga)Se2 thin films by sputtering and selenization using diethylselenide

    International Nuclear Information System (INIS)

    Full text : Chalcopyrite structure CuIn1-xGaxSe2 (CIGS) alloys are used as light-absorbing medium in high conversion efficiency, low cost, lightweight, and radiation-resistant solar cells. The ideal band gap energy for solar cells is known to be 1.4 eV, which corresponds to the band gap of CuIn0.4Ga0.6Se2. However, growing CuIn0.4Ga0.6Se2 alloys or CIGS solid solutions of high CuGaSe2 (CGS) molar faction is difficult because of unwanted compositional separation caused by the difference in reaction rates of the two end-point compounds. The morphology and crystal structure of the CIGS thin films strongly depend on the heating profile and the time of each step during the selenization process. However, few experimental results have been reported. In this presentation, it will be introduced the fabrication of CIGS thin films by selenization using diethylselenide [(C2H5)2Se: DESe] as a selenization source. Cu-In-Ga precursors were deposited on Mo by RF magnetron sputtering. The precursors were selenized using DESe under atmospheric pressure. The selenization process was performed by two sequential stages. First, the precursors were selenized at 300 degrees Celsium for 20 min (first step). Then, the precursors were heated to 515 degrees Celsium and selenized for 60 min (second step). The precursor consisted of Cu11In9 alloy before selenization. The film selenized at 300 degrees Celsium for 10 min had binary compounds such as Cu-Se, In-Se, Cu-In except CIGS. After the first step selenization at 300 degrees Celsium for 20 min, the Cu-Se alloy was not observed. The film selenized at 515 degrees Celsium for 60 min had only a CIGS chalcopyrite phase without an extra phase. These results indicate that the films selenized at 300 degrees Celsium are due to insufficient of CIGS growth, and phase transformation occurred during the selenization process when using H2Se or elemental Se as a selenization source.

  17. Study of the growth of CuAlS{sub 2} thin films on oriented silicon (111)

    Energy Technology Data Exchange (ETDEWEB)

    Brini, R. [Laboratoire de Photovoltaique et Materiaux Semiconducteurs.(LPMS), Ecole Nationale d' ingenieurs de Tunis (ENIT), BP 37 le Belvedere 1002 Tunis (Tunisia)], E-mail: Brini_rawdha@yahoo.fr; Schmerber, G. [Institut de Physique et Chimie des Materiaux de Strasbourg (IPCMS) UMR7504 CNRS-ULP, 23 rue du Loess, BP 43, 67034 Strasbourg Cedex 2 (France); Kanzari, M. [Laboratoire de Photovoltaique et Materiaux Semiconducteurs.(LPMS), Ecole Nationale d' ingenieurs de Tunis (ENIT), BP 37 le Belvedere 1002 Tunis (Tunisia); Werckmann, J. [Institut de Physique et Chimie des Materiaux de Strasbourg (IPCMS) UMR7504 CNRS-ULP, 23 rue du Loess, BP 43, 67034 Strasbourg Cedex 2 (France); Rezig, B. [Laboratoire de Photovoltaique et Materiaux Semiconducteurs.(LPMS), Ecole Nationale d' ingenieurs de Tunis (ENIT), BP 37 le Belvedere 1002 Tunis (Tunisia)

    2009-02-02

    Within the chalcopyrite family the sulphur based compounds CuMS{sub 2} (M = In, Ga, Al) have attracted much interest in recent years because they show a direct wide band-gap covering from E{sub gap} = 1.53 eV (CuInS{sub 2}) over E{sub gap} = 2.43 eV (CuGaS{sub 2}) to E{sub gap} = 3.49 eV (CuAlS{sub 2}). Therefore they are particularly suitable for optoelectronic as well as photovoltaic applications. The CuAlS{sub 2} semiconductor is one of these compounds and has good luminescent properties and a wide direct gap of 3.5 eV making it suitable for the use as material for light-emitting devices in the blue region of the spectrum. To dig up fully its potential a better understanding of the fundamental properties of the CuAlS{sub 2} film itself is essential, which could be achieved from high-quality single-crystalline materials. So, the aim of this work has been to study the growth of multilayer CuAlS{sub 2} thin films on Si(111) substrates at a substrate temperature of 723 K. One, two and three layers with 60, 120 and 180 nm thicknesses, respectively, were deposited on Si(111) substrate. The effect of the CuAlS{sub 2} layer numbers on the structure, morphology and optical properties of the samples was investigated. The X-ray diffraction studies revealed that all the samples are polycrystalline in nature, single CuAlS{sub 2} phase and exhibiting chalcopyrite structure with a preferred orientation along the (112) direction. However, the sample with three CuAlS{sub 2} layers exhibit the highly oriented (112) plane with grain sizes of 80 nm. So we show that this experimental process affects significantly the structural properties of the CuAlS{sub 2} films. Raman spectroscopic measurements indicated five prominent peaks at 193, 205, 325, 335 and 370 cm{sup -1}. The possible origin of the 370 cm{sup -1} peak was investigated and was found to be some local vibration in the structure. The peaks at 193-205 and 335 cm{sup -1} were ascribed to A{sub 1} and B{sub 2} modes

  18. Simulation of acid mine drainage generation around Küre VMS Deposits, Northern Turkey

    Science.gov (United States)

    Demirel, Cansu; Kurt, Mehmet Ali; Çelik Balci, Nurgül

    2015-04-01

    This study investigated comparative leaching characteristics of acidophilic bacterial strains under shifting environmental conditions at proposed two stages as formation stage or post acidic mine drainage (AMD) generation. At the first stage, initial reactions associated with AMD generation was simulated in shaking flasks containing massive pyritic chalcopyrite ore by using a pure strain Acidithiobacillus ferrooxidans and a mixed culture of Acidithiobacillus sp. mostly dominated by A. ferrooxidans and A. thiooxidans at 26oC. At the second stage, long term bioleaching experiments were carried out with the same strains at 26oC and 40oC to investigate the leaching characteristics of pyritic chalcopyrite ore under elevated heavy metal and temperature conditions. During the experiments, physicochemical characteristics (e.i. Eh, pH, EC) metal (Fe, Co, Cu, Zn) and sulfate concentration of the experimental solution were monitored during 180 days. Significant acid generation and sulfate release were determined during bioleaching of the ore by mixed acidophilic cultures containing both iron and sulfur oxidizers. In the early stage of the experiments, heavy metal release from the ore was caused by generation of acid due to accelerated bacterial oxidation of the ore. Generally high concentrations of Co and Cu were released into the solution from the experiments conducted by pure cultures of Acidithiobacillus ferrooxidans whereas high Zn and Fe was released into the solution from the mixed culture experiments. In the later stage of AMD generation and post AMD, chemical oxidation is accelerated causing excessive amounts of contamination, even exceeding the amounts resulted from bacterial oxidation by mixed cultures. Acidithibacillus ferrooxidans was found to be more effective in leaching Cu, Fe and Co at higher temperatures in contrary to mixed acidophiles that are more prone to operate at optimal moderate conditions. Moreover, decreasing Fe values are noted in bioleaching

  19. W-Au skarns in the Neo-Proterozoic Seridó Mobile Belt, Borborema Province in northeastern Brazil: an overview with emphasis on the Bonfim deposit

    Science.gov (United States)

    Souza Neto, João Adauto; Legrand, Jean Michel; Volfinger, Marcel; Pascal, Marie-Lola; Sonnet, Philippe

    2008-02-01

    The Seridó Mobile Belt (SMB) is located in the Borborema Province in northeastern Brazil and consists of a gneiss basement (Archean to Paleo-Proterozoic), a metasedimentary sequence (marble, quartzites, and schists), and the Brasiliano igneous suite (both of Neo-Proterozoic age). In this region, skarns occur within marble and at the marble-schist contact in the metasedimentary sequence. Most of the skarn deposits have been discovered in the early 1940s, and since then, they have been exploited for tungsten and locally gold. Recently, the discovery of gold in the Bonfim tungsten skarn has resulted in a better understanding of the skarn mineralization in this region. The main characteristics of the SMB skarns are that they are dominantly oxidized tungsten skarns, with the exception of the Itajubatiba and Bonfim gold-bearing skarns, which are reduced based on pyrrhotite as the dominant sulfide, garnet with high almandine and spessartine component, and elevated gold contents. In the Bonfim deposit, pressure estimates indicate that the skarns formed at 10- to 15-km depth. The mineralized skarns present the prograde stage with almandine, diopside, anorthite, and actinolite-magnesio-hornblende, and titanite, apatite, allanite, zircon, and monazite as accessory minerals. The retrograde stage is characterized by alkali feldspar, clinozoisite-zoisite-sericite, calcite, and quartz. Scheelite occurs in four ore-shoots distributed within the marble and at the marble-schist contact. The main ore body is 5-120 cm wide and contains an average of 4.8-wt.% WO3, which occurs in the basal marble-schist contact. Fold hinges appear to control the location of high-grade scheelite. The late-stage gold mineralization contains bismite (Bi2O3), fluorine-bearing bismite, native bismuth, bismuthinite (Bi2S3), and joseite [Bi4(Te,S)3], and also chlorite, epidote, prehnite, chalcopyrite, and sphalerite. This gold-bismuth-tellurium mineralization exhibits a typical late character and occurs as a

  20. Stable isotope systematics and fluid inclusion studies in the Cu-Au Visconde deposit, Carajás Mineral Province, Brazil: implications for fluid source generation

    Science.gov (United States)

    da Costa Silva, Antonia Railine; Villas, Raimundo Netuno Nobre; Lafon, Jean-Michel; Craveiro, Gustavo Souza; Ferreira, Valderez Pinto

    2015-06-01

    The Cu-Au Visconde deposit is located in the Carajás Mineral Province (CMP), northern Brazil, near the contact between the ca. 2.76 Ga metavolcano-sedimentary rocks of the Itacaiunas Supergroup rocks and the ~3.0 Ga granitic-gneissic basement. It is hosted by mylonitized Archean rocks, mainly metadacites, the Serra Dourada granite, and gabbros/diorites, which have been successively altered by sodic, sodic-calcic-magnesian, potassic, and calcic-magnesian hydrothermal processes, producing diverse mineralogical associations (albite-scapolite; albite-actinolite-scapolite-epidote; K-feldspar-biotite; chlorite-actinolite-epidote-calcite, etc.). Chalcopyrite is the dominant ore mineral and occurs principally in breccias and veins/veinlets. The aqueous fluids responsible for the alteration/mineralization were initially hot (>460 °C) and very saline (up to 58 wt.% equivalent (equiv.) NaCl), but as the system evolved, they experienced successive dilution processes. Mineral oxygen and hydrogen isotope data show that 18O-rich ( to +9.4 ‰) fluids prevailed in the earlier alteration (including magnetitites) and reached temperatures as high as 410-355 °C. Metamorphic/formation waters, most likely derived from the Carajás Basin rocks, appear to have contributed a major component to the fluid composition, although some magmatic input cannot be discounted. In turn, the later alterations and the mineralization involved cooler (<230 °C), 18O-depleted ( to +3.7 ‰) and less saline (7-30 wt.% equiv. NaCl) fluids, indicating the influx of meteoric water. Fluid dilution and cooling might have caused abundant precipitation of sulfides, especially as breccia cement. Ore δ 34 S values (+0.5 to +3.4 ‰) suggest a magmatic source for sulfur (from sulfide dissolution in pre-existing igneous rocks). The chalcopyrite Pb-Pb ages (2.73 ± 0.15 and 2.74 ± 0.10 Ga) indicate that the Visconde mineralization is Neoarchean, rather than Paleoproterozoic as previously considered. If so, the

  1. Static and dynamical properties of II-VI and III-V group binary solids

    International Nuclear Information System (INIS)

    In this paper, we extend to II-VI and III-V group binary solids of zinc blende (ZB) structure with conduction d-electrons the calculation of static and dynamical properties such as bulk modulus (B) and cohesive energy or total energy (Ecoh) using the plasma oscillation theory of solids formalism already employed for ternary chalcopyrite semiconductors. The present method is not limited to tetrahedrally coordinated semiconductors and ternary chalcopyrites, but can be used for all semiconducting compounds. We have applied an extended formula on ZB structured binary semiconductors and found better agreement with the experimental data as compared to the values evaluated by previous researchers. The bulk modulus and cohesive energy of ZB-type structure compounds exhibit a linear relationship when plotted on a log-log scale against the plasmon energy ℎωp (in eV), but fall on a straight line. The results for bulk modulus differ from experimental values by the following amounts: ZnS 0.36%, ZnSe 10%, ZnTe 0.62%, CdS 1.8%, CdSe 7.4% and CdTe 1.6%, AlP 2.6%, AlAs 5.3%, AlSb 4.0%, GaP 0%, AlAs 0%, AlS 4.4%, InP 0%, InAs 0% and InSb 2.1%; and the results for cohesive energy differ from experimental values by the following amounts: ZnS 0.16%, ZnSe 0.73%, ZnTe 0.6%, CdS 7.6%, CdSe 3.5%, CdTe 2.5%, AlP 2.0%, AlAs 3.0%, AlSb 11.1%, GaP 14.6%, AlAs 17.0%, AlSb 8.7%, InP 4.3%, InAs 5.5% and InSb 0.6%.

  2. Deposition and characterization of graded Cu(In{sub 1-x}Ga{sub x})Se{sub 2} thin films by spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Babu, B.J. [Department of Electrical Engineering-SEES, CINVESTAV-IPN, Avenida IPN 2508, San Pedro Zacatenco, D.F. C.P 07360 (Mexico); Institute of Molecules and Materials, UMR-CNRS 6283, Université du Maine, Avenue O. Messiaen, F-72085 Le Mans (France); Velumani, S., E-mail: velu@cinvestav.mx [Department of Electrical Engineering-SEES, CINVESTAV-IPN, Avenida IPN 2508, San Pedro Zacatenco, D.F. C.P 07360 (Mexico); College of Information and Communication Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Kassiba, A. [Institute of Molecules and Materials, UMR-CNRS 6283, Université du Maine, Avenue O. Messiaen, F-72085 Le Mans (France); Asomoza, R. [Department of Electrical Engineering-SEES, CINVESTAV-IPN, Avenida IPN 2508, San Pedro Zacatenco, D.F. C.P 07360 (Mexico); Chavez-Carvayar, J.A. [Instituto Investigaciones en Materiales-UNAM, Ciudad Universitario, D.F.Mexico (Mexico); Yi, Junsin, E-mail: yi@yurim.skku.ac.kr [College of Information and Communication Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of)

    2015-07-15

    Cu(In{sub 1-x}Ga{sub x})Se{sub 2} (CIGS) thin films and their graded (x = 1 to 0) layer were grown on soda lime glass substrates using chemical spray pyrolysis (CSP) at different substrate temperatures (T{sub s}). After optimization of T{sub s}, depositions were carried out at different gallium composition (x) at optimized temperature of 350 °C. All the films deposited at T{sub s} ≥ 350 °C were polycrystalline chalcopyrite structure, with a preferential orientation of (112), including the graded layer. With increase in x, lattice parameters a and c were observed to decrease. Line scan of the CIGS layer showed intersection of gallium and indium concentrations, revealing the graded nature of the film. Composition dependence of Raman peak for CuInSe{sub 2} (CIS) deposited by CSP was analyzed. Optical transmittance at a wavelength of 800 nm of the film with x = 0 (CIS) (30%) was found lower than that of the film grown with x = 0.82 (CIGS) (50%). Cusp-shape of the resistivity was observed with an increase of x leading to steep rise in resistivity of the films (1.61–71.68 Ω-cm) till x = 0.42 and then decreased to 4.78 Ω-cm at x = 0.82. Carrier concentrations of the films were evaluated in the order of 10{sup 16}–10{sup 19} cm{sup −3} with p-type conductivity. These results indicate that graded CIGS thin films with modulated gallium composition can be prepared by CSP. - Graphical abstract: Display Omitted - Highlights: • Optimization of the spray deposition system for device grade chalcopyrite CIGS films. • Optimized substrate temperature to obtain single-phase CIGS by spray deposition. • Detailed report on compositional dependence of CuInSe{sub 2} (CIS) thin films. • Systematic analysis of the influence of Ga in CIS by spray deposition. • Bowing parameter is extracted from the experiment values.

  3. Mineralizing conditions and source fluid composition of base metal sulfides in the Lon District, southeastern Iceland

    Science.gov (United States)

    Kremer, C. H.; Thomas, D.; García del Real, P.; Zierenberg, R. A.; Bird, D. K.

    2014-12-01

    Hydrothermal base metal mineralization is rare in Iceland due to the scarcity of evolved magma bodies that discharge metal-rich aqueous fluids into bedrock. One exception is the Lon District of southeastern Iceland, where explosively emplaced rhyolitic breccias host base metal sulfide minerals. We performed petrographic, fluid inclusion, and stable isotope analyses on samples collected in Lon to constrain the conditions of sulfide mineral formation. Based on outcrop and hand sample observations, hot, early-stage hydrothermal fluids precipitated sulfide minerals, quartz, and epidote in rhyolitic breccia and basalt flows. Cooler late-stage fluids precipitated carbonates and quartz in rhyolitic breccia and basalt flows. The order of precipitation of the sulfides was: galena, sphalerite, then chalcopyrite. Homogenization temperatures of liquid-dominated multi-phase fluid inclusions in hydrothermal early-stage quartz coeval with chalcopyrite cluster around 303 °C and 330 °C, indicating precipitation of metallic sulfides in two main hydrothermal fluid pulses early in the period of hydrothermal activity in the Lon District. Freezing point depression analyses of fluid inclusions in quartz show that the sulfide minerals precipitated from a solution that was 4 wt. % NaCl. The 𝛿34S values of sulfides indicate that early-stage hydrothermal sulfur was derived from igneous rocks, either through leaching by non-magmatic hydrothermal fluids or by exsolution of magmatic waters. Early stage epidote 𝛿D values were on average -65.96 per mil, about 14 per mil higher than reported values in epidotes from elsewhere in southeastern Iceland. The 𝛿13C and 𝛿18O values of late-stage carbonates indicate that late stage hydrothermal fluids were meteoric in origin. Collectively, fluid inclusion and stable isotope analyses suggest that early-stage aqueous fluids derived from a mixture of magmatic waters exsolved from the proximal Geitafell intrusion and meteoric

  4. Theoretical Electron Density Distributions for Fe- and Cu-Sulfide Earth Materials: A Connection between Bond Length, Bond Critical Point Properties, Local Energy Densities, and Bonded Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Gibbs, Gerald V.; Cox, David F.; Rosso, Kevin M.; Ross, Nancy L.; Downs, R. T.; Spackman, M. A.

    2007-03-01

    Bond critical point and local energy density properties together with net atomic charges were calculated for theoretical electron density distributions, F(r), generated for a variety of Fe and Cu metal-sulfide materials with high- and low-spin Fe atoms in octahedral coordination and high-spin Fe atoms in tetrahedral coordination. The electron density, F(rc), the Laplacian, 32F(rc), the local kinetic energy, G(rc), and the oxidation state of Fe increase as the local potential energy density, V(rc), the Fe-S bond lengths, and the coordination numbers of the Fe atoms decrease. The properties of the bonded interactions for the octahedrally coordinated low-spin Fe atoms for pyrite and marcasite are distinct from those for high-spin Fe atoms for troilite, smythite, and greigite. The Fe-S bond lengths are shorter and the values of F(rc) and 32F(rc) are larger for pyrite and marcasite, indicating that the accumulation and local concentration of F(r) in the internuclear region are greater than those involving the longer, high-spin Fe-S bonded interactions. The net atomic charges and the bonded radii calculated for the Fe and S atoms in pyrite and marcasite are also smaller than those for sulfides with high-spin octahedrally coordinated Fe atoms. Collectively, the Fe-S interactions are indicated to be intermediate in character with the low-spin Fe-S interactions having greater shared character than the highspin interactions. The bond lengths observed for chalcopyrite together with the calculated bond critical point properties are consistent with the formula Cu+Fe3+S2. The bond length is shorter and the F(rc) value is larger for the FeS4 tetrahedron displayed by metastable greigite than those displayed by chalcopyrite and cubanite, consistent with a proposal that the Fe atom in greigite is tetravalent. S-S bond paths exist between each of the surface S atoms of adjacent slabs of FeS6 octahedra comprising the layer sulfide smythite, suggesting that the neutral Fe3S4 slabs are

  5. Theoretical electron density distributions for Fe- and Cu-sulfide earth materials: a connection between bond length, bond critical point properties, local energy densities, and bonded interactions.

    Science.gov (United States)

    Gibbs, G V; Cox, D F; Rosso, K M; Ross, N L; Downs, R T; Spackman, M A

    2007-03-01

    Bond critical point and local energy density properties together with net atomic charges were calculated for theoretical electron density distributions, rho(r), generated for a variety of Fe and Cu metal-sulfide materials with high- and low-spin Fe atoms in octahedral coordination and high-spin Fe atoms in tetrahedral coordination. The electron density, rho(rc), the Laplacian, triangle down2rho(rc), the local kinetic energy, G(rc), and the oxidation state of Fe increase as the local potential energy density, V(rc), the Fe-S bond lengths, and the coordination numbers of the Fe atoms decrease. The properties of the bonded interactions for the octahedrally coordinated low-spin Fe atoms for pyrite and marcasite are distinct from those for high-spin Fe atoms for troilite, smythite, and greigite. The Fe-S bond lengths are shorter and the values of rho(rc) and triangle down2rho(rc) are larger for pyrite and marcasite, indicating that the accumulation and local concentration of rho(r) in the internuclear region are greater than those involving the longer, high-spin Fe-S bonded interactions. The net atomic charges and the bonded radii calculated for the Fe and S atoms in pyrite and marcasite are also smaller than those for sulfides with high-spin octahedrally coordinated Fe atoms. Collectively, the Fe-S interactions are indicated to be intermediate in character with the low-spin Fe-S interactions having greater shared character than the high-spin interactions. The bond lengths observed for chalcopyrite together with the calculated bond critical point properties are consistent with the formula Cu+Fe3+S2. The bond length is shorter and the rho(rc) value is larger for the FeS4 tetrahedron displayed by metastable greigite than those displayed by chalcopyrite and cubanite, consistent with a proposal that the Fe atom in greigite is tetravalent. S-S bond paths exist between each of the surface S atoms of adjacent slabs of FeS6 octahedra comprising the layer sulfide smythite

  6. Understanding Cu release into environment from Kure massive sulfide ore deposits, Kastamonu, NW Turkey

    Science.gov (United States)

    Demirel, Cansu; Sonmez, Seref; Balci, Nurgul

    2014-05-01

    Covering a wide range on the earth's crust, oxidation of metal sulfide minerals have vital environmental impacts on the aquatic environment, causing one of the major environmental problems known as acid mine drainage (AMD). Located in the Kastamonu province of the Western Black Sea region, Kure district is one of the major copper mining sites in Turkey. Mining activities in the area heads back to ancient times, such that operation is thought to be started with the Roman Empire. Currently, only the underground mining tunnels of Bakibaba and Asikoy are being operated. Thus, mining heaps and ores of those pyritic deposits have been exposed to the oxidative conditions for so long. As a result of weathering processes of past and recent heaps of the Kure volcanic massive sulfide deposits in addition to the main ore mineral (chalcopyrite), significant amount of metals, especially Cu, are being released into the environment creating undesirable environmental conditions. In order to elucidate Cu release mechanisms from Kure pyritic ore deposits and mining wastes, field and laboratory approaches were used. Surface water and sediment samples from the streams around the mining and waste sites were collected. Groundwater samples from the active underground mining site were also collected. Physical parameters (pH, Eh, T°C, and EC) of water samples were determined in situ and in the laboratory using probes (WTW pH 3110, WTW Multi 9310 and CRISON CM 35). Metal and ion concentrations of the water samples were analysed using ICP-MS and DR 2800 spectrophotometer, respectively. High Cu, Co, Zn and Fe concentrations were determined in the water samples with pH values ranging from 2.9- 4. Cu concentrions ranges from 345 ppm to 36 ppm in the water samples. Consistent with the water samples, high Cu, Fe, Zn and Co were also determined in the sediment samples. Laboratory chalcopyrite oxidation experiments under the conditions representing the field site were set up as biological and

  7. Mineralogy and geochemistry of trace and Rare Earth Element from the Manaila massive sulphide deposit (Eastern Carpathians, Romania)

    Science.gov (United States)

    Moldoveanu, S.; Iancu, O. G.; Kasper, H. U.

    2012-04-01

    Keywords: Eastern Carpathians, Mănăila deposit, REE, trace elements, pyrite The present paper deal with the mineralogy and trace elements geochemistry of sulphide deposits from Mănăila mine field located in NE area of Eastern Carpathians Mountains (Romania). The mineralization occurs within metamorphic rocks of Tulgheş terrane, part of Crystalline-Mezozoic zone of the Eastern Carpathians. The metamorphic rocks in Mănăila area consist of felsic metavolcanics rocks with quartzites and quartz-feldspathic rocks as prevailing types. The P-T metamorphic conditions are typical of greenschis facies with biotite and garnet (Mn-Grt) in mineral assemblage. The mineralogical study was performed using reflected light microscope and Scanning Electron Microscopy (SEM) methods. Thus, the both methods show that the main sulphides minerals are represented by pyrite and chalcopyrite, being followed by sphalerite, galena and little amount of Cu sulphosalts (tetrahedrite and bournonite) and also by gangue minerals (quartz and carbonates). Pyrite occurs as large euhedral to subhedral grains in quartz and small rounded inclusion in chalcopyrite. The trace elements analysis was achieved on whole-rock samples and involved the determination of REE, LIL (Rb, Ba, Sr) and HFS (Y, Zr, Hf, U, Th, Nb, Ta) by ICP-MS method. The concentration of LIL and HFS trace elements in mineralized rocks decrease as follows: Ba > Bi > As > Sb > Co > Ga > Ni > Cd. Even if the barium contents in Mănăila ore is high, baritina (BaSO4) was not identified throught the mineralogical analyses carried out so far. The total rare earth element content (REE) of the samples from Mănăila range from 26.84 to 246.46 ppm. Chondrite - normalized REE patterns of the mineralized rocks show that the LREE are enriched in relation to the HREE. Also a positive Ce anomalies and negative Eu anomalies are present. Y/Ho and Zr/Hf ratios are close to the chondritic ratios indicating Charge-and-Radius-Controlled (CHARAC

  8. Chemical and sulphur isotope compositions of pyrite in the Jaduguda U (–Cu–Fe) deposit, Singhbhum shear zone, eastern India: Implications for sulphide mineralization

    Indian Academy of Sciences (India)

    Dipak C Pal; Surajit Sarkar; Biswajit Mishra; A K Sarangi

    2011-06-01

    The Jaduguda U (–Cu–Fe) deposit in the Singhbhum shear zone has been the most productive uranium deposit in India. Pyrite occurs as disseminated grains or in sulphide stringers and veins in the ore zone. Veins, both concordant and discordant to the pervasive foliation, are mineralogically either simple comprising pyrite ± chalcopyrite or complex comprising pyrite + chalcopyrite + pentlandite + millerite. Nickel-sulphide minerals, though fairly common in concordant veins, are very rare in the discordant veins. Pyrite in Ni-sulphide association is commonly replaced by pentlandite at the grain boundary or along micro-cracks. Based on concentrations of Co and Ni, pyrite is classified as: type-A — high Co (up to 30800 ppm), no/low Ni; type-B — moderate Co (up to 16500 ppm) and moderate to high Ni (up to 32700 ppm); type-C — no/low Co and high Ni (up to 43000 ppm); type-D — neither Co nor Ni. Textural and compositional data of pyrites suggest that the hydrothermal fluid responsible for pre-/early-shearing mineralization evolved from Co-rich to Ni-rich and the late-/post-shearing fluid was largely depleted in minor elements. Sulphur isotope compositions of pyrite mostly furnish positive values ranging between -0.33 and 12.06%. Composite samples of pyrites with only type-A compositions and mixed samples of type-A and type-B are consistently positive. However, pyrite with mixed type-A and type-C and pyrite with type-D compositions have negative values but close to 0. By integrating minor element and sulphur isotope compositions of pyrite in conjunction with other published data on the Jaduguda deposit, it is proposed that reduced sulphur for the precipitation of most pyrites (type-A, type-B) was likely derived from isotopically heavy modified seawater. However, some later sulphur might be magmatic in origin remobilized from existing sulphides in the mafic volcanic rocks in the shear zone.

  9. Microbial and Mineral Descriptions of the Interior Habitable Zones of Active Hydrothermal Chimneys from the Endeavour Segment, Juan de Fuca Ridge

    Science.gov (United States)

    Holden, J. F.; Lin, T.; Ver Eecke, H. C.; Breves, E.; Dyar, M. D.; Jamieson, J. W.; Hannington, M. D.; Butterfield, D. A.; Bishop, J. L.; Lane, M. D.

    2013-12-01

    Actively venting hydrothermal chimneys and their associated hydrothermal fluids were collected from the Endeavour Segment, Juan de Fuca Ridge to determine the mineralogy, chemistry and microbial community composition of their interiors. To characterize the mineralogy, Mössbauer, FTIR, VNIR and thermal emission spectroscopies were used for the first time on this type of sample in addition to thin-section petrography, x-ray diffraction and elemental analyses. A chimney from the Bastille edifice was Fe-sulfide rich and composed primarily of chalcopyrite, marcasite-sphalerite, and pyrrhotite while chimneys from the Dante and Hot Harold edifices were Fe-sulfide poor and composed primarily of anhydrite. The bulk emissivity and reflectance spectroscopies corroborated well with the petrography and XRD analyses. The microbial community in the interior of Bastille was most closely related to mesophilic-to-thermophilic anaerobes of the deltaproteobacteria and hyperthermophilic archaea while those in the interiors of Dante and Hot Harold were most closely related to mesophilic-to-thermophilic aerobes of the beta-, gamma- and epsilonproteobacteria. The fluid temperatures (282-321°C) and chemistries of the three chimneys were very similar suggesting that differences in mineralogy and microbial community compositions were more dependent on fluid flow characteristics and paragenesis within the chimney. Thin-section petrography of the interior of another hydrothermal chimney collected from the Dante edifice (emitting 336°C fluid) shows a thin coat of Fe3+ oxide associated with amorphous silica on the exposed outer surfaces of pyrrhotite, sphalerite and chalcopyrite in pore spaces, along with anhydrite precipitation in the pores that is indicative of seawater ingress. The Fe-sulfide minerals were likely oxidized to ferrihydrite with increasing pH and Eh due to cooling and seawater exposure, providing reactants for bioreduction. Culture-based most-probable-number estimates of

  10. Methane origin and oxygen-fugacity evolution of the Baogutu reduced porphyry Cu deposit in the West Junggar terrain, China

    Science.gov (United States)

    Shen, Ping; Pan, HongDi

    2015-12-01

    Most porphyry copper deposits worldwide contain magnetite, hematite, and anhydrite in equilibrium with hypogene copper-iron sulfides (chalcopyrite, bornite) and have fluid inclusions with CO2 >> CH4 that are indicative of high fO2. In contrast, the Baogutu porphyry Cu deposit in the West Junggar terrain (Xinjiang, China) lacks hematite and anhydrite, contains abundant pyrrhotite and ilmenite in equilibrium with copper-iron sulfides (chalcopyrite), and has fluid inclusions with CH4 >> CO2 that are indicative of low fO2. The mineralized intrusive phases at Baogutu include the main-stage diorite stock and minor late-stage diorite porphyry dikes. The main-stage stock underwent fractional crystallization and country-rock assimilation-contamination, and consists of dominant diorite and minor gabbro and tonalite porphyry. The country rocks contain organic carbons (0.21-0.79 wt.%). The δ13CvPDB values of the whole rocks (-23.1 to -25.8 ‰) in the wall rocks suggest a sedimentary organic carbon source. The δ13CvPDB values of CH4 (-28.2 to -36.0 ‰) and CO2 (-6.8 to -20.0 ‰) in fluid inclusions require an organic source of external carbon and equilibration of their Δ13CCO2-CH4 values (8.2-25.0 ‰) at elevated temperatures (294-830 °C) suggesting a significant contribution of thermogenic CH4. Mineral composition data on the main-stage intrusions, such as clinopyroxene, hornblende, biotite, magnetite, ilmenite, sphene, apatite, and pyrrhotite, suggest that the primary magma at Baogutu was oxidized and became reduced after emplacement by contamination with country rocks. Mineral compositions and fluid inclusion gas compositions suggest that the redox state of the system evolved from log fO2 > FMQ + 1 in the magma stage, to log fO2 rocks assimilation-contamination, to log fO2 > FMQ in the hydrothermal stage. Though oxidized magma was emplaced initially, assimilation-contamination of carbonaceous country rocks decreased its fO2 such that exsolved fluids contained

  11. Molecular solution processing of metal chalcogenide thin film solar cells

    Science.gov (United States)

    Yang, Wenbing

    The barrier to utilize solar generated electricity mainly comes from their higher cost relative to fossil fuels. However, innovations with new materials and processing techniques can potentially make cost effective photovoltaics. One such strategy is to develop solution processed photovoltaics which avoid the expensive vacuum processing required by traditional solar cells. The dissertation is mainly focused on two absorber material system for thin film solar cells: chalcopyrite CuIn(S,Se)2 (CISS) and kesterite Cu2ZnSn(S,Se) 4 organized in chronological order. Chalcopyrite CISS is a very promising material. It has been demonstrated to achieve the highest efficiency among thin film solar cells. Scaled-up industry production at present has reached the giga-watt per year level. The process however mainly relies on vacuum systems which account for a significant percentage of the manufacturing cost. In the first section of this dissertation, hydrazine based solution processed CISS has been explored. The focus of the research involves the procedures to fabricate devices from solution. The topics covered in Chapter 2 include: precursor solution synthesis with a focus on understanding the solution chemistry, CISS absorber formation from precursor, properties modification toward favorable device performance, and device structure innovation toward tandem device. For photovoltaics to have a significant impact toward meeting energy demands, the annual production capability needs to be on TW-level. On such a level, raw materials supply of rare elements (indium for CIS or tellurium for CdTe) will be the bottleneck limiting the scalability. Replacing indium with zinc and tin, earth abundant kesterite CZTS exhibits great potential to reach the goal of TW-level with no limitations on raw material availability. Chapter 3 shows pioneering work towards solution processing of CZTS film at low temperature. The solution processed devices show performances which rival vacuum

  12. Non-injection synthesis of monodisperse Cu-Fe-S nanocrystals and their size dependent properties.

    Science.gov (United States)

    Gabka, Grzegorz; Bujak, Piotr; Żukrowski, Jan; Zabost, Damian; Kotwica, Kamil; Malinowska, Karolina; Ostrowski, Andrzej; Wielgus, Ireneusz; Lisowski, Wojciech; Sobczak, Janusz W; Przybylski, Marek; Pron, Adam

    2016-06-01

    It is demonstrated that ternary Cu-Fe-S nanocrystals differing in composition (from Cu-rich to Fe-rich), structure (chalcopyrite or high bornite) and size can be obtained from a mixture of CuCl, FeCl3, thiourea and oleic acid (OA) in oleylamine (OLA) using the heating up procedure. This new preparation method yields the smallest Cu-Fe-S nanocrystals ever reported to date (1.5 nm for the high bornite structure and 2.7 nm for the chalcopyrite structure). A comparative study of nanocrystals of the same composition (Cu1.6Fe1.0S2.0) but different in size (2.7 nm and 9.3 nm) revealed a pronounced quantum confinement effect, confirmed by three different techniques: UV-vis spectroscopy, cyclic voltammetry and Mössbauer spectroscopy. The optical band gap increased from 0.60 eV in the bulk material to 0.69 eV in the nanocrystals of 9.3 nm size and to 1.39 eV in nanocrystals of 2.7 nm size. The same trend was observed in the electrochemical band gaps, derived from cyclic voltammetry studies (band gaps of 0.74 eV and 1.54 eV). The quantum effect was also manifested in Mössbauer spectroscopy by an abrupt change in the spectrum from a quadrupole doublet to a Zeeman sextet below 10 K, which could be interpreted in terms of the well defined energy states in these nanoparticles, resulting from quantum confinement. The Mössbauer spectroscopic data confirmed, in addition to the results of XPS spectroscopy, the co-existence of Fe(iii) and Fe(ii) in the synthesized nanocrystals. The organic shell composition was investigated by NMR (after dissolution of the inorganic core) and IR spectroscopy. Both methods identified oleylamine (OLA) and 1-octadecene (ODE) as surfacial ligands, the latter being formed in situ via an elimination-hydrogenation reaction occurring between OLA and the nanocrystal surface. PMID:27197089

  13. Correlation of surface contour, optoelectronic and spectroscopic properties of Cu(In,Ga)Se2 by SNOM and AFM

    International Nuclear Information System (INIS)

    Chalcopyrite absorbers exhibit local fluctuations of structural, optical and optoelectronic properties. We study the correlation of the surface contour and the local properties such as the integrated photoluminescence (PL) yield and the splitting of the quasi-Fermi levels in a Cu(In,Ga)Se2-based thin-film system at room temperature by AFM and spatially resolved PL measurements at the identical position with a scanning near-field optical microscope (SNOM). The Cu(In,Ga)Se2 layer is deposited on glass, etched with bromine-methanol to smooth the surface for a more homogeneous incoupling of laser light, and passivated with cadmium sulfide. Our measurements reveal a high structural correlation between surface contour, integrated PL yield and quasi-Fermi level splitting. Additionally, we observe trenches in the surface contour which correspond to a dip or to a peak in the splitting of the quasi-Fermi levels and integrated PL yield. Furthermore some trenches show spectral variation of the PL compared to their direct environment. We discuss these observations with respect to the optoelectronic property and the composition of the absorber.

  14. Uniform deposition of ternary chalcogenide nanoparticles onto mesoporous TiO2 film using liquid carbon dioxide-based coating

    International Nuclear Information System (INIS)

    We report the simultaneous deposition of two different metal precursors dissolved in liquid carbon dioxide (l-CO2), aiming to the synthesis of ternary chalcopyrite (e.g. CuInS2) nanoparticles on a mesoporous TiO2 film. The l-CO2-based deposition of Cu and In precursors and subsequent reaction with a dilute H2S gas resulted in CuxInySz nanoparticles uniformly deposited across the entire thickness of a mesoporous TiO2 film. Further heat treatment (air annealing and sulfurization) led to the formation of more stoichiometric CuInS2 nanoparticles. The formation of CuInS2 on TiO2 was confirmed by scanning electron microscopy, high resolution transmission electron microscopy, X-ray diffraction, and Raman spectroscopy. The crystal growth of CuInS2 was also found to be controllable by adjusting the number of coating cycles of the l-CO2-based deposition. - Highlights: • Simultaneous deposition of two different metal precursors dissolved in l-CO2. • Uniform deposition of CuInS2 nanoparticles across mesoporous TiO2 film. • Highly crystalline CuInS2 formed on mesoporous TiO2 film. • Nearly stoichiometric ratio of Cu:In:S was obtained

  15. Xanthate-Functional Temperature-Responsive Polymers: Effect on Lower Critical Solution Temperature Behavior and Affinity toward Sulfide Surfaces.

    Science.gov (United States)

    Ng, Wei Sung; Forbes, Elizaveta; Franks, George V; Connal, Luke A

    2016-08-01

    Xanthate-functional polymers represent an exciting opportunity to provide temperature-responsive materials with the ability to selectively attach to specific metals, while also modifying the lower critical solution temperature (LCST) behavior. To investigate this, random copolymers of poly(N-isopropylacrylamide) (PNIPAM) with xanthate incorporations ranging from 2 to 32% were prepared via free radical polymerization. Functionalization with 2% xanthate increased the LCST by 5 °C relative to the same polymer without xanthate. With increasing xanthate composition, the transition temperature increased and the transition range broadened until a critical composition of the hydrophilic xanthate groups (≥18%) where the transition disappeared completely. The adsorption of the polymers at room temperature onto chalcopyrite (CuFeS2) surfaces increased with xanthate composition, while adsorption onto quartz (SiO2) was negligible. These findings demonstrate the affinity of these functional smart polymers toward copper iron sulfide relative to quartz surfaces, presumably due to the interactions between xanthate and specific metal centers. PMID:27434760

  16. First-principles calculations of the structural, electronic and optical properties of AgGaS2 and AgGaSe2

    International Nuclear Information System (INIS)

    The structural, electronic and optical properties of two chalcopyrite crystals, AgGaS2 and AgGaSe2, are studied using the full potential linearized augmented plane waves method within the local density approximation. Geometrical optimization of the unit cell (equilibrium volume, c/a ratio, internal parameter u, and bulk modulus) is in good agreement with experimental data. The energy gap is found to be direct for both materials and the nature of the gap crucially depends on the manner in which the Ga 3d, and Ag 4d electrons are treated as core or valence states. Results on band structures, density of states, and charge-density distributions are presented. We report also our results on optical properties like the complex dielectric functions and the refractive index n of the AgGaS2 and AgGaSe2 crystals. We analyze in detail the structures of the dielectric function observed in the studied energy region

  17. The spin effect in zinc-blende Cd{sub 0.5}Mn{sub 0.5}Te and Zn{sub 0.5}Mn{sub 0.5}Te diluted magnetic semiconductors: FP-LAPW study

    Energy Technology Data Exchange (ETDEWEB)

    Touat, S.A. [Modelling and Simulation in Materials Science Laboratory, Physics Department, University of Sidi Bel-Abbes, 22000 Sidi Bel-Abbes (Algeria); Litimein, F., E-mail: flitimein@yahoo.f [Laboratoire des Materiaux Magnetiques, Departement de Physique, Faculte des Sciences, Universite Djillali Liabes de Sidi Bel Abbes, Sidi Bel Abbes -22000 (Algeria); Tadjer, A.; Bouhafs, B. [Modelling and Simulation in Materials Science Laboratory, Physics Department, University of Sidi Bel-Abbes, 22000 Sidi Bel-Abbes (Algeria)

    2010-01-15

    In this work we use the full potential linearized augmented plane wave (FPLAPW) method within the local spin density approximation. Our goal is to study the structural, electronic and magnetic properties of the ferromagnetic CdMnTe and ZnMnTe semiconductors alloys in its ordered chalcopyrite phases (50% of Mn). We have investigated the lattice parameters, bulk moduli, band structures, total and partial densities of states. The determined exchange constants N{sub 0}alpha (conduction band) and N{sub 0}beta (valence band) somewhat agree with a typical magneto-optical experiment. In these systems the s(p)-d exchange interaction between free electrons (holes) and localized magnetic moments plays an important role for their characteristic properties. Our results show that the localization of the Mn spin-majority states are positioned near the top of the valence band and strongly hybridized with it. Furthermore, calculations predict that the p-d hybridization reduces the local magnetic moment of Mn from its free space of 5-4.32mu{sub B} for Cd{sub 0.5}Mn{sub 0.5}Te and 4.23mu{sub B} for Zn{sub 0.5}Mn{sub 0.5}Te.

  18. The spin effect in zinc-blende Cd0.5Mn0.5Te and Zn0.5Mn0.5Te diluted magnetic semiconductors: FP-LAPW study

    International Nuclear Information System (INIS)

    In this work we use the full potential linearized augmented plane wave (FPLAPW) method within the local spin density approximation. Our goal is to study the structural, electronic and magnetic properties of the ferromagnetic CdMnTe and ZnMnTe semiconductors alloys in its ordered chalcopyrite phases (50% of Mn). We have investigated the lattice parameters, bulk moduli, band structures, total and partial densities of states. The determined exchange constants N0α (conduction band) and N0β (valence band) somewhat agree with a typical magneto-optical experiment. In these systems the s(p)-d exchange interaction between free electrons (holes) and localized magnetic moments plays an important role for their characteristic properties. Our results show that the localization of the Mn spin-majority states are positioned near the top of the valence band and strongly hybridized with it. Furthermore, calculations predict that the p-d hybridization reduces the local magnetic moment of Mn from its free space of 5-4.32μB for Cd0.5Mn0.5Te and 4.23μB for Zn0.5Mn0.5Te.

  19. Effect of electrodeposition potential on composition and morphology of CIGS absorber thin film

    Indian Academy of Sciences (India)

    N D Sang; P H Quang; L T Tu; D T B Hop

    2013-08-01

    CuInGaSe (CIGS) thin films were deposited on Mo/soda-lime glass substrates by electrodeposition at different potentials ranging from −0.3 to −1.1 V vs Ag/AgCl. Cyclic voltammetry (CV) studies of unitary Cu, Ga, In and Se systems, binary Cu–Se, Ga–Se and In–Se systems and quaternary Cu–In–Ga–Se were carried out to understand the mechanism of deposition of each constituent. Concentration of the films was determined by energy dispersive spectroscopy. Structure and morphology of the films were characterized by X-ray diffraction and scanning electron microscope. The underpotential deposition mechanism of Cu–Se and In–Se phases was observed in voltammograms of binary and quaternary systems. Variation in composition with applied potentials was explained by cyclic voltammetry (CV) data. A suitable potential range from −0.8 to −1.0 V was found for obtaining films with desired and stable stoichiometry. In the post-annealing films, chalcopyrite structure starts forming in the samples deposited at −0.5 V and grows on varying the applied potential towards negative direction. By adjusting the composition of electrolyte, we obtained the desired stoichiometry of Cu(In0.7Ga0.3)Se2.

  20. PGE distribution in the Chromite bearing mafic-ultramafic Kondapalli Layered Complex, Krishna district, Andhra Pradesh, India

    Directory of Open Access Journals (Sweden)

    Meshram Tushar M.

    2015-09-01

    Full Text Available The Kondapalli Layered Complex (KLC is a dismembered mafic-ultramafic layered intrusion, mainly composed of gabbroic and anorthositic rocks with subordinate ultramafics and chromitite. Chromitite occurs as lenses, pods, bands and disseminations. Platinum group of minerals (PGMs occur as inclusions within chromite and silicates. The study indicates an inhomogeneous distribution of PGMs and distinct dominance of IPGEs over the PPGEs. The average ΣPGE content of chromite of KLC varies from 64 ppb to 576 ppb with Pt ranging from 5 to 495 ppb, Pd 5 to 191 ppb, Ir 3 to 106 ppb, Ru 3 to 376 ppb and Rh 3 to 135 ppb. The PGMs identified in the KLC indicate primary deposition of the IPGE, preceding chromite, indicating its orthomagmatic nature. Most of the PGM grains are usually below 10 μm. The identified PGMs are Laurite (RuS2, irarsite (Ir, As, S, iridosmine (Os, Ir, undetermined Os-Ir sulphide and Ru-Os-Ir-Zn alloys. Chromite also contains inclusions of pentlandite, millerite, chalcopyrite and pyrite. Study indicating that the KLC have orthomagmatic origin for PGE which are dominated by IPGE group and formed under surpa-subduction zone peridotite setting.

  1. Raman scattering and structural analysis of electrodeposited CuInSe{sub 2} and S-rich quaternary CuIn(S,Se){sub 2} semiconductors for solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Izquierdo-Roca, Victor; Fontane, Xavier; Morante, Joan Ramon [Departament d' Electronica, Universitat de Barcelona (Spain); Saucedo, Edgardo; Ruiz, Carmen M.; Grand, Pierre-Philippe; Jaime-Ferrer, Jesus Salvador; Bermudez, Veronica [Institut de Recherche et Developement sur l' Energie Photovoltaique (IRDEP), Chatou (France); Calvo-Barrio, Lorenzo [Departament d' Electronica, Universitat de Barcelona (Spain); Lab. Analisis de Superficies, SCT, Universitat de Barcelona (Spain); Alvarez-Garcia, Jacobo [Centre de Recerca i Investigacio de Catalunya (CRIC), Barcelona (Spain); Perez-Rodriguez, Alejandro

    2009-05-15

    This work reports the Raman scattering characterisation of CuInSe{sub 2} precursors grown by single step electrodeposition and the corresponding layers recrystallised under sulphurising conditions for solar cell devices. The analysis of the spectra measured on the as-grown precursors has allowed identifying the main secondary phases in these layers with elemental Se, Cu-Se phases and chalcopyrite Cu-poor ordered vacancy domains. To deepen in the identification of the Cu-Se phases, these measurements have been correlated with the analysis of binary Cu-Se layers. The experimental data indicate that formation of both Se and Cu-Se phases is likely controlled by the Se content in the layers. For values of stoichiometry below 1.15, excess Cu in the layers is accommodated in a phase with very low Raman efficiency (as Cu{sub 2}Se). Increasing the content of Se leads to an increase in the spectral contribution from both Se and Cu{sub 2-x}Se, being the formation of these phases likely favoured under high excess Se conditions. The characterisation of the corresponding recrystallised layers has allowed analysing the impact of the presence of the secondary phases in the as-grown absorbers on the performance of the final solar cells. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  2. Effect of antimony incorporation on structural properties of CuInS{sub 2} crystals

    Energy Technology Data Exchange (ETDEWEB)

    Ben Rabeh, M., E-mail: mohamedbenrabeh@yahoo.f [Laboratoire de Photovoltaique et Materiaux Semi-Conducteurs - ENIT BP 37, Le belvedere, 1002 Tunis (Tunisia); Chaglabou, N., E-mail: nadia_chaglabou@yahoo.f [Laboratoire de Photovoltaique et Materiaux Semi-Conducteurs - ENIT BP 37, Le belvedere, 1002 Tunis (Tunisia); Kanzari, M., E-mail: Mounir.Kanzari@ipeit.rnu.t [Laboratoire de Photovoltaique et Materiaux Semi-Conducteurs - ENIT BP 37, Le belvedere, 1002 Tunis (Tunisia)

    2010-02-15

    CuInS{sub 2} (CIS) single crystals doped with 1, 2, 3 and 4 atomic percent (at.%) of antimony (Sb) were grown by the horizontal Bridgman method. The effect of Sb doping on the structural properties of CIS crystal was studied by means of X-ray diffraction (XRD), energy dispersive X-ray analysis (EDAX), scanning electron microscopy (SEM) and PL measurements. X-ray diffraction data suggests that the doping of Sb in the CIS single crystals does not affect the tetragonal (chalcopyrite) crystal structure and exhibited a (1 1 2) preferred orientation. In addition, with increasing Sb concentration, the X-ray diffraction analysis show that Sb doped CIS crystals are more crystallized and the diffraction peaks of the CuInS{sub 2} phase were more pronounced in particular the (1 1 2) plane. EDAX study revealed that Sb atoms can occupy the indium site and/or occupying the sulfur site to make an acceptor. PL spectra of undoped and Sb doped CIS crystals show two emission peaks at 1.52 and 1.62 eV, respectively which decreased with increasing atomic percent antimony. Sb doped CIS crystals show p-type conductivity.

  3. Influence of Ce doping on structural and photoelectric properties of CuInS{sub 2} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Jun, E-mail: jiulye@126.com; Xiao, Lingling; Ding, Tiezhu; Wang, Yanlai; Fan, Yue [School of Physical Science and Technology, Inner Mongolia University, Key Laboratory of Semiconductor Photovoltaic Technology at Universities of Inner Mongolia Autonomous Region, Hohhot 010021 (China)

    2015-09-21

    Cerium doped CuInS{sub 2} thin films were successfully fabricated by a powder metallurgy method. X-ray diffraction and scanning electron microscope measurements showed that the as-prepared CuIn{sub 1−x}Ce{sub x}S{sub 2} samples are of good crystallinity and crystallize with chalcopyrite structure when sintering at 550 °C. The presence of Ce{sup 3+} in host material was conformed by X-ray photoelectron spectroscopy. Two subband photon absorption peaks were observed at 1710 nm (0.73 eV) and 1955 nm (0.63 eV) in the UV–Vis–NIR absorption spectrum. This behavior could suggest that an intermediate band forms in the forbidden band of CuInS{sub 2} semiconductor due to cerium incorporation. The optical bandgap of CuIn{sub 1−x}Ce{sub x}S{sub 2} films was tuned in the range of 1.38 eV to 1.23 eV with increasing cerium content. And the electrical conductivity could be improved if doped moderate cerium content, especially x = 0.1.

  4. 4-Amino-1,2,4-triazole: Playing a key role in the chemical deposition of Cu-In-Ga metal layers for photovoltaic applications

    International Nuclear Information System (INIS)

    Liquid film processing of Cu(In,Ga)Se2 absorber layers has the potential to lower the cell production costs significantly namely because of the absence of vacuum steps and high material utilization. In this work an ink system based on metal carboxylates in a mixture of a nitrogen-containing base and an alcohol is investigated. After the coating step on a suitable substrate followed by the drying of the alcohol, the metal ions are reduced to the respective metals with a simple heat treatment. However, depending on the conditions, the resulting metal layers are either highly porous or dewetting above 160 °C due to the high surface tension of the intermediate liquid indium. Adding 4-amino-1,2,4-triazole to the ink leads to a homogeneous metal layer, which is crucial for the formation of dense chalcopyrite layers. We propose a stabilization mechanism based on a temporary polymeric complex of Cu2+ and the additive 4-amino-1,2,4-triazole which is decomposing completely at selenization conditions. - Highlights: • Influence of 4-amino-1,2,4-triazole on the film formation has been investigated. • Two polymers identified forming an organic matrix during the layer processing • This matrix allows processing of dense and crack free metallic layers. • The polymers decompose completely under selenization conditions

  5. Evaluation of the effect of conventionally prepared swarna makshika bhasma on different bio-chemical parameters in experimental animals

    Directory of Open Access Journals (Sweden)

    Sudhaldev Mohapatra

    2011-01-01

    Full Text Available Swarna makshika (chalcopyrite bhasma (SMB has been used for different therapeutic purposes since long in Ayurveda. The present study is conducted to evaluate the effect of conventionally prepared SMB on different bio-chemical parameters in experimental animals, for providing scientific data base for its logical use in clinical practice. The genuine SMB was prepared by following classical techniques of shodhana and marana most commonly used by different Ayurvedic drug manufacturers. Shodhana was done by roasting raw swarna makshika with lemon juice for three days and marana was performed by 11 putas . The experimental animals (rats were divided into two groups. SMB mixed with diluted honey was administered orally in therapeutic dose to Group SMB and diluted honey only was administered to vehicle control Group, for 30 days. The blood samples were collected twice, after 15 days and after 30 days of drug administration and different biochemical investigations were done. Biochemical parameters were chosen based on references from Ayurvedic classics and contemporary medicine. It was observed that Hb% was found significantly increased and LDL and VLDL were found significantly decreased in Group SMB when compared with vehicle control group. This experimental data will help the clinician for the logical use of SMB in different disease conditions with findings like low Hb% and high LDL, VLDL levels.

  6. Comparative study of uranium mineralised and non-mineralised dolostone of Vempalle formation, Cuddapah supergroup, Andhra Pradesh and its implication on role of algae and phosphate in uranium mineralisation

    International Nuclear Information System (INIS)

    Petromineralogical and geochemical study of both uraniferous phosphatic siliceous dolostone (PSD) and associated non uraniferous dolostone of Vempalle Formation has brought out significant mineralogical and chemical variations in these lithounits. The U-mineralisation is stratabound with exclusively impure PSD as host rock, which is sandwiched between lower massive dolostone and upper shale/cherty dolostone in the Vempalle Formation. Biogeochemical control is reflected by presence of specific types of algal stromatolites within the uraniferous PSD along with sulphur reducing bacteria, which have controlled the precipitation of biogenic pyrite, collophane (Ca phosphate) and high-Mg calcite. Geochemically, PSD compared to the associated dolostone is characterised by high U, P2O5, V, Mo, Pb, Cu and Sr which are expressed mineralogically in the form of pitchblende, coffinite, U-Ti complex, collophane, pyrite, molybdenite, galena, chalcopyrite, bornite, digenite and covellite with relatively higher Mo and V in the southern parts of the mineralised belt and higher Cu in the northern part. The organic matter and Ca phosphate have helped in initial fixing of uranium in them as indicated by the presence of pitchblende with collophane and adsorbed uranium in organic matter. Further diagenesis within a reducing environment provided by organic matter has resulted in localization of primary uranium mineralization along major diagenetic and sedimentary weak zones like carbonate-phosphate contact, clast boundaries, microstylolites, fibrous dolomite rich cavities and dolomicritic pelloids. (author)

  7. Optical absorption and photoluminescence spectra of the ordered defect compound CuIn{sub 3}Te{sub 5}

    Energy Technology Data Exchange (ETDEWEB)

    Rincon, C [Centro de Estudios de Semiconductores, Departamento de Fisica Facultad de Ciencias, Universidad de Los Andes, Apartado, Postal No 1, La Hechicera Merida 5101 (Venezuela); Wasim, S M [Centro de Estudios de Semiconductores, Departamento de Fisica Facultad de Ciencias, Universidad de Los Andes, Apartado, Postal No 1, La Hechicera Merida 5101 (Venezuela); Marin, G [Centro de Estudios de Semiconductores, Departamento de Fisica Facultad de Ciencias, Universidad de Los Andes, Apartado, Postal No 1, La Hechicera Merida 5101 (Venezuela); Delgado, J M [Centro Nacional de Difraccion de Rayos-X, Facultad de Ciencias, Universidad de Los Andes, Apartado, Postal No 40, La Hechicera, Merida 5101 (Venezuela); Petroff, P M [Materials Department, University of California, Santa Barbara, CA 93106 (United States)

    2003-05-21

    The optical properties of the ordered defect compound CuIn{sub 3}Te{sub 5} which crystallizes in a chalcopyrite-related structure have been studied by absorption and photoluminescence (PL) techniques. Optical absorption measurements show that the band gap energy E{sub G} varies from 1.078 to 1.040 eV between 10 and 300 K. It is found that the variation of E{sub G} with temperature is mainly due to the contribution of optical phonons with a characteristic energy of about 16 meV. The PL measurements, carried out between 4 and 100 K with laser excitation intensities in the range from 1 to 400 mW, reveal that the main PL band is due to a donor-acceptor recombination between donor and acceptor defect levels that have activation energies of 60 and 30 meV, respectively. These donor and acceptor states are tentatively assigned as originating from indium atoms on copper sites and copper vacancies, respectively.

  8. X-ray powder diffraction, phase transitions and optical characterization of the Cu(In1-xGa x)3Te5 semiconducting system

    International Nuclear Information System (INIS)

    Ingots of several compositions of the Cu(In1-xGa x)3Te5 semiconducting system were prepared by the Vertical Bridgman technique. X-ray powder diffraction, differential thermal analysis and optical absorption studies were used to characterize the fundamental structural aspects and phase transitions and determine the energy band gap E G of this alloy system. It is found that a solid solution with a tetragonal chalcopyrite-related structure is formed over the entire range of composition for temperatures below 620 deg. C. The parameters a and c at room temperature of the tetragonal unit cell were found to vary linearly with composition x from 6.1639(4) and 12.346(6) A for x = 0, to 5.93231(8) and 11.825(4) A for x = 1. A phase transition to a cubic phase in the whole range of composition was observed above 620 deg. C. The energy band gap has been determined to be direct and varies linearly with composition x

  9. X-ray powder diffraction, phase transitions and optical characterization of the Cu(In{sub 1-x}Ga {sub x}){sub 3}Te{sub 5} semiconducting system

    Energy Technology Data Exchange (ETDEWEB)

    Guevara, R. [Laboratorio Nacional de Difraccion de Rayos-X, Facultad de Ciencias, Universidad de Los Andes, Merida 5101 (Venezuela); Marin, G. [Centro de Estudios de Semiconductores, Facultad de Ciencias, Universidad de Los Andes, Merida 5101 (Venezuela); Delgado, J.M. [Laboratorio Nacional de Difraccion de Rayos-X, Facultad de Ciencias, Universidad de Los Andes, Merida 5101 (Venezuela)]. E-mail: migueld@ula.ve; Wasim, S.M. [Centro de Estudios de Semiconductores, Facultad de Ciencias, Universidad de Los Andes, Merida 5101 (Venezuela); Rincon, C. [Centro de Estudios de Semiconductores, Facultad de Ciencias, Universidad de Los Andes, Merida 5101 (Venezuela); Perez, G. Sanchez [Centro de Estudios de Semiconductores, Facultad de Ciencias, Universidad de Los Andes, Merida 5101 (Venezuela)

    2005-05-03

    Ingots of several compositions of the Cu(In{sub 1-x}Ga {sub x}){sub 3}Te{sub 5} semiconducting system were prepared by the Vertical Bridgman technique. X-ray powder diffraction, differential thermal analysis and optical absorption studies were used to characterize the fundamental structural aspects and phase transitions and determine the energy band gap E {sub G} of this alloy system. It is found that a solid solution with a tetragonal chalcopyrite-related structure is formed over the entire range of composition for temperatures below 620 deg. C. The parameters a and c at room temperature of the tetragonal unit cell were found to vary linearly with composition x from 6.1639(4) and 12.346(6) A for x = 0, to 5.93231(8) and 11.825(4) A for x = 1. A phase transition to a cubic phase in the whole range of composition was observed above 620 deg. C. The energy band gap has been determined to be direct and varies linearly with composition x.

  10. Thermal expansion of ternary semiconductor compounds AgB3C26

    International Nuclear Information System (INIS)

    Temperature dependences of elementary cell parameters, molar volume, main and mean coefficients of thermal expansion for crystals are determined, melting temperatures are improved characteristic Debay temperatures and some thermodynamic properties of AgGaSr, AgInS2, AgGaSe2, AgInSe2, AgGaTe2, AgInTe2 compounds are calculated, effect of anion (S-Se-Te) and cation substitutions on the change of these parameters is considered, using X-ray diffraction technique. It is shown, that within 80-650 K temperature range for AgB3C26 (B-Ga, In; C-S, Se, Te) with chalcopyrite tetragonal structure the thermal expansion coefficients along the direction, parallel to tetragonal axis, are negative, while along the perpendicular direction-positive ones. With temperature increase both main coefficients of expansion increase by absolute value, coefficients, characterizing thermal expansion anisotropy, grorespectively. AgGaSe2 compound has the largest anisotropy of thermal expansion, while AgInTe2 compound has the smalest anisotropy of thermal expansion, while AgInTe2 compound has the smalest anisotropy among the considered group of A1B3C26 ternary compounds

  11. Photosensitive structures based on CuIn5Te8 single crystals: Development and properties

    International Nuclear Information System (INIS)

    A new ternary compound is synthesized for the first time, and bulk CuIn5Te8 single crystals are grown by directed crystallization of near-stoichiometric melt. It is established from X-ray diffraction patterns of grown crystals that they exhibit the structure of imperfect chalcopyrite with parameters of the unit cell of CuIn5Te8, which were close to those known for the CuInTe2 ternary compound with the composition index n = 0. First, photosensitive structures are fabricated based on CuIn5Te8 crystals, and photosensitivity spectra are obtained for them; it is shown that it is possible to achieve broadband photosensitivity under illumination of the barrier side of these crystals. From the analysis of photosensitivity spectra, the character of band-to-band transitions and corresponding energies of these transitions in CuIn5Te8 are determined. This opens up prospects to use this new semiconductor in photoconverters of solar radiation.

  12. Thermal expansion in CuAlTe2 compounds

    International Nuclear Information System (INIS)

    The lattice parameters a and c as well as the axial thermal expansion coefficients α perpendicular and α parallel in CuAlTe2 chalcopyrite-type compounds are determined as a function of temperature in the range from 80 to 650 K by a X-ray diffractometry technique. The data obtained are used to evaluate the axial ratio c/a, the tetragonal distortion δ = 2 - c/a, the interatomic distances for Cu-Te and Al-Te bonds and their temperature coefficients. It is found that the thermal expansion behaviour of CuAlTe2 is similar to that of other CuBIIIC2VI compounds in having a relatively small expansivity along the c-axis and a large one in the perpendicular direction. When comparing the results for a series of the CuBIIIC2VI compounds (B-Al, Ga, In; C-S, Se, Te) it is shown that the correlations between the thermal expansion coefficients αperpendicular, αparallel, αm, dδ/dT and the tetragonal distortion δ, as well as the molar mass of the compound take place. (author)

  13. Compressibility and phase transformations of AgInSe{sub 2} from high-pressure X-ray diffraction studies

    Energy Technology Data Exchange (ETDEWEB)

    Orlova, N.S.; Turtsevich, G.A.; Bodnar, I.V. [Institute of Solid State and Semiconductor Physics, Minsk (Belarus)

    1994-06-01

    The compound AgInSe{sub 2} is one of the A{sup I}B{sup III}C{sup VI}{sub 2} ternary semiconductors, which exhibit unique optical properties and are highly promising materials for use in nonlinear optics and semiconductor engineering. Their elastic properties are of great importance and yet, unlike other characteristics, remain inadequately studied. In particular, the elastic constants were determined only for AgGaS{sub 2} and AgGaSe{sub 2}. The compressibilities were measured for a number of CuB{sup III}C{sup VI}{sub 2} compounds and for three Ag compounds AgGaS{sub 2}, AgGaSe{sub 2}, and AgGaTe{sub 2}. No data on the compressiblity of AgInC{sup VI}{sub 2} compounds is available in the literature. The compressibilities along the major directions of AgInS{sub 2} crystals with the chalcopyrite structure were reported. In this work, we studied the compressibility of AgInSe{sub 2} using high-pressure X-ray diffraction analysis.

  14. Photosensitive structures based on CuIn{sub 5}Te{sub 8} single crystals: Development and properties

    Energy Technology Data Exchange (ETDEWEB)

    Bodnar, I. V. [Belarussian State University of Information Science and Radioelectronics (Belarus); Rud, V. Yu. [St. Petersburg State Polytechnical University (Russian Federation); Rud, Yu. V., E-mail: Yuryrud@mail.ioffe.ru; Terukov, E. I. [Russian Academy of Sciences, Ioffe Physical Technical Institute (Russian Federation); Kovalchuk, A. M. [Belarussian State University of Information Science and Radioelectronics (Belarus)

    2011-05-15

    A new ternary compound is synthesized for the first time, and bulk CuIn{sub 5}Te{sub 8} single crystals are grown by directed crystallization of near-stoichiometric melt. It is established from X-ray diffraction patterns of grown crystals that they exhibit the structure of imperfect chalcopyrite with parameters of the unit cell of CuIn{sub 5}Te{sub 8}, which were close to those known for the CuInTe{sub 2} ternary compound with the composition index n = 0. First, photosensitive structures are fabricated based on CuIn{sub 5}Te{sub 8} crystals, and photosensitivity spectra are obtained for them; it is shown that it is possible to achieve broadband photosensitivity under illumination of the barrier side of these crystals. From the analysis of photosensitivity spectra, the character of band-to-band transitions and corresponding energies of these transitions in CuIn{sub 5}Te{sub 8} are determined. This opens up prospects to use this new semiconductor in photoconverters of solar radiation.

  15. Electrochemical preparation and characterization of CuInSe2 thin films for photovoltaic applications

    International Nuclear Information System (INIS)

    The objective of this work has been to investigate the electrodeposition as a low-cost, large-area fabrication process to obtain CuInSe2 this films for efficient photovoltaic devices. this objective entails the elucidation of thin film deposition mechanism, the study of the fundamental properties of electrodeposited material, and also the modification of their physical and chemical parameters for photovoltaic applications. CuInSe2 thin films have been successfully electrodeposited from a citric was characterized by compositional, structural, electrical, optical and electrochemical measurements, relating their properties with the preparation parameters and also studying the effect of various thermal and chemical treatments. The results showed post-deposition treatment are needed for optimizing these films for solar cells fabrication: first, an annealing in inert atmosphere at temperatures above 400 degrees celsius to obtain a high recrystallization in the chalcopyrite structure, and after a chemical etching in KCN solution to remove secondary phases of CuxSe and Se which are frequently electrodeposited with the CuInSe2. The treated samples showed appropriate photovoltaic activity in a semiconductor-electrolite liquid junction. (author) 193 ref

  16. Quality, quantity and geometric determination on uranium deposit at East Upper Rabau, West Kalimantan using drilling method

    International Nuclear Information System (INIS)

    Uranium mineralization has been discovered at western and middle part of Upper Rabau within favorable bed of meta silt stone E-W orientation dipping to north. The radiometric value of Eastern part of Rabau more than 15,00 c/s SPP2NF, according to the geology, litho logy, and mineral orientation similar to those at the western and middle part. The aim of this study is to obtain the information about mineralization pattern, dimension, lateral and vertical distribution and the quality and quality. The method has been applied in the study is geology mapping, core drilling identification, rock sampling, and mineralogical and geochemical laboratory analysis. Result of the data evaluation and it interpretation shown that some centimentric-decimetric mineralized vein lets with radiometric value range 700 - 2000 c/s SPP2NF at 72-92-20 m depth. U mineralization zones consist of pyrite, chalcopyrite, sphalerite, uraninite, and magnetite. It has been found 60 - 95 m That mineralized zone is correlated to TR 136 and TR 138. Total volume of mineralized rock 13,000 M3 with the density is about 2.7. So, the total resources will be 117,3 tons with the ore grade in between of 619.50 - 9,462.00 ppm

  17. Enumeration of thiobacilli within pH-neutral and acidic mine tailings and their role in the development of secondary mineral soil

    Energy Technology Data Exchange (ETDEWEB)

    Southam, G.; Beveridge, T.J. (Univ. of Guelph, Ontario (Canada))

    1992-06-01

    The Lemoine tailings of Chibougamau, Quebec, Canada, were deposited as a pH-neutral mineral conglomerate consisting of aluminum-silicates, iron-aluminum-silicate, pyrite, chalcopyrite, and sphalerite. These tailings are colonized by an active population of Thiobacillus ferrooxidans which is localized to an acid zone occupying 40% of the tailings' surface. This population peaked at 7 [times] 10[sup 8] most probable number per gram of tailings during July and August 1990 and extended to a depth of 40 cm from the surface. Examination of samples over this depth profile by transmission electron microscopy and electron dispersive spectroscopy revealed a microbially mediated mineral transition from sulfides to chlorides and phosphates. Silicate minerals were unaltered by microbial action. Transmission electron microscopy showed a tight association between Thiobacillus species and the sulfide minerals, which helps account for their prominence in tailings environments. Accurate enumeration of T. ferrooxidans from tailings required the disruption of their bonding to the mineral interface. Vortexing of a 10% aqueous suspension of the tailings materials prior to most-probable-number analysis best facilitated this release. Even though heavy metals were highly mobile under acidic conditions at the Lemoine tailings, it was evident by transmission electron microscopy containing iron, copper, chlorine, phosphorus, and oxygen on bacterial surfaces and exopolymers. This biomineralization increased with increasing bacterial numbers and was most evident in the upper 3 cm of the acidic zone.

  18. Partitioning of actinides, rare earth elements, and other trace elements in titanium-rich veins from Adamello, Italy

    International Nuclear Information System (INIS)

    Extensive mineralogical and chemical studies have been carried out on the Ti-rich hydrothermal veins emplaced within the contact aureole of the Adamello batholith. In addition to other actinide and rare earth element host phases, the veins contain both zirconolite and betafite and provide information relevant to ceramic wasteforms designed for the disposal of actinide-rich nuclear wastes. In this paper, we describe the results of element partitioning studies based on dissolution experiments using 9M HCl. Generally, the acid-resistant minerals include allanite, baddeleyite, betafite, chalcopyrite, geikielite, titanite, spinel, and zirconolite. We also found that the major silicate minerals forsterite, phlogopite, and titanian clinohumite and the sulfide mineral pyrrhotite are partially dissolved by the acid treatment, whereas calcite and apatite are highly soluble (as expected). In particular, the distributions of Th and U between the acid-resistant and acid-soluble fractions indicate that they partition mainly between zirconolite, titanite, betafite, and apatite. However, there is a considerable increase in the amounts of Zr, Nb, Th, and U released in certain actinide-rich samples that may result from enhanced dissolution following radiation damage. Copyright (2001) Material Research Society

  19. XPS characteristics of sulfur of bio-oxidized arsenic-bearing gold concentrate and changes of surface nature of bio-oxidation residue

    Institute of Scientific and Technical Information of China (English)

    杨洪英; 巩恩普; 杨立; 陈刚; 范有静; 张玉山; 吕久吉

    2004-01-01

    During bio-oxidation of sulfides, the chemical state change of sulfur is a complex and key factor. It is not only an indicator of the extent and intensity of the bio-oxidation, but also controls the property of bio-leaching medium and the period of oxidation. The chemical state of sulfur in sulfides oxidized by leaching bacteria was studied with XPS. Sulfide minerals in the arsenic-hearing gold concentrate consist of pyrite, arsenopyrite, chalcopyrite, galena, sphalerite and so on. In order to probe the pattern of the chemical state change of sulfur in the bio-oxidation residue of arsenic-bearing gold concentrate, the structure of the grains, and the surface nature of the residue, XPS test was carried out through different sputtering duration. The study of XPS clearly shows that: sulfides is progressively oxidized from the surface of minerals to the core by leaching bacteria; the chemical valence of sulfur changes from S2- or [S2]2- to [SO4]2-; sulfur in the core is in a reduction state, S2- or [S2]2- , but exists in an oxidation state S6+ on the surface; due to the chemical state change of sulfur, mineral phase of the bio-oxidation residue is also changed(sulfides inside, while sulfates outside); the layered structure is found in the grains of the bio-oxidation residue.

  20. Geochemical Characteristics of Jinwozi Gold Deposit,Xinjiang

    Institute of Scientific and Technical Information of China (English)

    章振根; 陈南生

    1991-01-01

    The Jinwozi gold deposit consists of gold-bearing quartz veins in a biotite granodiorite of Hercynian age (Zircon U-Pb age≈335.7Ma).Ore mineralogy is simple .In addition to native gold,there are only small amounts of sulfides,meinly pyrite and minor sphalerite,chalcopyrite and galena.δ34S val-ues average 6.69‰,and δ18O13.99‰.Abundant CO2 is contained in fluid inclusions from quartz.Homogenization temperatures of fluid inclusions are between 186 and 262°.REE distribution pat-terns indicate that the igneous mass may have been derived from a common initial material of calcareous-argillaceous sediments and alkali basalts as the country rocks.In other words,the Jinwozi granodiorite is of remelting origin from crustal material.Isotopic evidence of S,O and Pb shows that the ore-forming material is genetically related to magmatic hydrothermal activity.

  1. 黄铁矿和黄铜矿中铁铜钴镍的纸层析及定量测定

    Institute of Scientific and Technical Information of China (English)

    中国科学院贵阳地球化学研究所中心分析室

    1973-01-01

    The method of paper chromatography for the separation and quantitative determination of iron, copper, cobalt and nickel in pyrite and chalcopyrite is described.The three systems of ehromtograpbie solvents for the separation of iron, copper, cobalt and nickel on the 8×25 or 15×26 cm Whatman No. 3, involving acetone-hydrochloric acid-water, butanone-hydrochloric acid-water and acetone-acetylacetone-hydrochloric acid-water have been tested. As a developing system for the separation of this four elements in samples, the mixture of aoetone-acetylacetone-hydroehlorio acid-water is considered to be the best. After developing in a 30×40 cm glass dryer, the paper is dried in air and rendered the zone visible by treatment with 0.1% (W/V) rubeanic acid solution. The R1 values, colour reactions with this spray reagent and the eolour are given. A good paper chromatography of elements has been obtained. The elements are determined by colorimetrie method, with 1-nitroso-2-naphthol for cobalt,1-(2-pyridylozo)-2-naphthol for nickel, oxalic acid bis-cyelohexylidene hydrozide for copper, and sulfosalicylic acid for iron. In addition, iron and copper can also be determined by titration with potassium dichromate solution and iodimetry respectively.

  2. Bio-processing of copper from combined smelter dust and flotation concentrate: a comparative study on the stirred tank and airlift reactors.

    Science.gov (United States)

    Vakylabad, Ali Behrad; Schaffie, Mahin; Ranjbar, Mohammad; Manafi, Zahra; Darezereshki, Esmaeel

    2012-11-30

    To scrutinize the influence of the design and type of the bioreactors on the bioleaching efficiency, the bioleaching were evaluated in a batch airlift and a batch stirred tank bioreactors with mixed mesophilic and mixed moderately thermophilic bacteria. According to the results, maximum copper recoveries were achieved using the cultures in the stirred tank bioreactors. It is worth noting that the main phase of the flotation concentrate was chalcopyrite (as a primary sulphide), but the smelter dust mainly contained secondary copper sulphides such as Cu(2)S, CuS, and Cu(5)FeS(4).Under optimum conditions, copper dissolution from the combined flotation concentrate and smelter dust (as an environmental hazard) reached 94.50% in the STR, and 88.02% in the airlift reactor with moderately thermophilic, after 23 days. Also, copper extractions calculated for the bioleaching using mesophilic bacteria were 48.73% and 37.19% in the STR (stirred tank reactor) and the airlift bioreactor, respectively. In addition, the SEM/EDS, XRD, chemical, and mineralogical analyses and studies confirmed the above results. PMID:23046698

  3. The mineral composition and the ore types of the uranium-vanadium deposit Srednaya Padma (Onega region, Russian Federation)

    International Nuclear Information System (INIS)

    The deposit Srednaya Padma is the largest and best prospected of the uranium-vanadium deposits of the Onega region. There are abnormally high concentrations of gold, palladium, platinum, copper and molybdenum in the ores. The ore mineralization is located in the albite-mica-carbonate metasomatites upon the proterozoic aleorolites and schists. The ores are generally composed of albite, dolomite and micas. The main vanadium mineral is vanadian flogopite, the main uranium mineral is pitchblende. The proportions of the ore and ore-forming minerals are determined. The noble metal mineralization (which associates with selenides of lead, silver and bismuth) and the copper-molybdenum mineralization (represented by chalcopyrite and molybdenite) are spread extremely irregularly in the orebodies. The ores can be classified as carbonaceous by their compositions. Four mineral ore types, with regard to the mineralization composition of the ore, are determined: pitchblende-flogopite, noble metal-pitchblende-flogopite, sulphide-flogopite and hypergene. The ores are classified in three technological ore types (uranium-vanadium; uranium-vanadium with Au, Pd, Pt; vanadium with Cu, Mo) and two technological ore sorts (by the acid inventory in processing). The correlation between the composition of the ore and the technological processing parameters are determined. The specifics of the various ore types distribution in the orebodies are discovered. A comparison with the other U-V deposits of the Onega region is made. (author). 4 refs, 3 figs, 2 tabs

  4. Geology and uranium mineralization, Nyaan Sector, Upper Mahakam, East Kalimantan

    International Nuclear Information System (INIS)

    Nyaan Sector covered 0.5 km2 area. The aim of research is to understand the geological setting, mineralization and potency of uranium in Nyaan Sector. The research activities involved topography measurement, soil radioactivity measurement by grid of 20 x 20 m2, stratigraphic and detailed geological structure observation, the making of peels at any anomaly area and radioactivity anomaly area. There are 3 (three) significant radiometric anomaly locations at Nyaan Sector. They are anomaly Sungai Marta, Marta Hulu and Aloha with radiometric value ranges from 8000 c/s to > 15000 c/s with background value of 100 c/s. In these areas, the making of peels, trench and test pit were conducted by sampling mineralization using systematic channel sampling system by the sum of 15 channels sampling and 8 chips sampling. The petrography and mineralogy analysis exhibited that mineralization of pitchblende, monazite, autunite were associated with bornite, chalcocite, chalcopyrite, lolingite, pyrite, sphalerite, ilmenite, limonite, magnetite, marchasite, rutile, malnicovite, hematite and iron oxide. Results of geochemical analysis for total uranium content in the rocks ranged between 345 to 11.425 ppm of uranium. (author)

  5. Study geology and uranium mineralization of ririt-amir engkala - tiga dara sector West Kalimantan

    International Nuclear Information System (INIS)

    The results of previous research from Ririt, Amir Engkala, Tiga Dara sector which consist of geology, geophysics and drilling data show that all of the areas has similar in geology and Uranium mineralization. The purpose of this study is to know the relationship between geological condition and Uranium mineralization in Ririt, Amir Engkala and Tiga Dara sector. In general the geology of Ririt and Amir Engkala is similar with Tiga Dara sector. Those areas consist of tourmaline quartzite, muscovite quartzite, meta ignimbrite, biotite quartz schist, muscovite quartz schist, and micro diorite. The direction of the stratification is NE - SW and dipping to SE and the direction of the stochasticity is W - E and dipping to N. The dextral faults have WNW-ESE and NNE - SSW trends, while the sinistral one is WSW - ENE direction. There are also a thrust fault and a normal fault with WSW-ESE and NW-SE striking respectively. Uranium mineralization as a uraninite fill in the stochasticity and fracture N2600-30° E37°-59° in orientation which associated with magnetite, chalcopyrite, pyrite, arsenopyrite,. rutile, ilmenite, tourmaline and quartz. Radiometric value of Uranium mineralization is in the range of 500-15.000 c/s. The mineral association and the present of calcite, gypsum and quartz veins suggest that Uranium mineralization was resulted by hydrothermal magmatic processes. (author)

  6. Geology and uranium mineralization in Sarana sector, Kalan, West Kalimantan based on drilling data

    International Nuclear Information System (INIS)

    Favourable zone of uranium mineralization in Sarana sector with NE-SW direction are contained in metapelite rock and some in muscovite quartzite. Mineralization of uranium is occurred fill in the fields of parallel fractures with stochasticity by ENE-WSW direction, and moderate to strong inclination to the north. Three points drilling with the depth of 126.6, 174.50, and 150.90 meter has been conducted. This study is aimed to obtain the knowledge of geology, and geometry of sub-surface uranium mineralization. Geologically, research area are consists of metapelite, muscovite quartzite and biotite quartzite with milli metric - centi metric thicknesses. Uranium mineralization are in forms of veins or tabular as uraninite and pitchblende associated with pyrite, chalcopyrite, pyrrhotite, ilmenite and molybdenite. Uranium Mineralization on the surface could be correlated with sub-surface from bore-hole data, with the result that zone of uranium mineralization in lenses or tabular form with sub-vertical dip may be identified. (author)

  7. Geology and uranium occurrences in Paluq Sector, Upper Mahakam, East Kalimantan

    International Nuclear Information System (INIS)

    Systematic prospecting stage was conducted with area covered Paluq Sector (0.8 km2). The aims of activities are to get geological setting, mineralization and potency of uranium in Nyaan and Paluq Sector. The activities in this stage involved topographic measurement, soil radioactivity measurement, stratigraphic and detailed geological structure observation, making of peels at anomaly area and radioactivity anomaly area. At Paluq Sector there are 5 (five) significant radiometric anomaly locations which are Putra River, Roos, Upper Paluq, Mahakam and Siweg with radiometric value 500 - 10.000 c/s, with a background value of 100 c/s furthermore making peels, trance and test pit were conducted by sampling mineralization using systematic channel sampling method. The petrography and mineralogy analysis exhibited that mineralization of pitchblende, monazite, autunite were associated with bornite, chalcocite, chalcopyrite, lolingite, pyrite, sfalerite, ilmenite, limonite, magnetite, marcasite, rutile, malnicovite, hematite and iron oxide. Result of geochemical analysis for total uranium content in the rocks ranged between 35 to 4.600 ppm of uranium. (author)

  8. Orbital-frustration-induced ordering in semiconductor alloys

    Science.gov (United States)

    Liu, Kai; Yin, Wanjian; Chen, Shiyou; Gong, X. G.; Wei, S.-H.; Xiang, H. J.

    2016-05-01

    It is well known that ternary zinc-blende semiconductors are always more stable in the chalcopyrite (CH) structure than the Cu-Au (CA) structure because the CH structure has a large Coulomb interaction and a reduced strain energy. Surprisingly, an experimental study showed that the ZnFeS e2 alloy takes the CA order as the ground-state structure, which is consistent with our density functional theory calculations showing that the CA order has lower energy than the CH order for ZnFeS e2 . We reveal that the orbital degree of freedom of a high-spin F e2 + ion (d6) in the tetrahedral crystal field plays a key role in stabilizing the CA order. First, the spin-minority d electron of the F e2 + ion tends to occupy the dx2-y2-like orbital instead of the d3 z2-r2-like orbital because of its large negative Coulomb energy. Second, for a nearest-neighboring F e2 + pair, two spin-minority d electrons with occupied dx2-y2-like orbitals on the plane containing the Fe-Fe bond have lower electronic kinetic energies. Both conditions can be satisfied in the CA ordered ZnFeS e2 alloy, whereas there is an orbital frustration in the CH structure. Our results suggest that the orbital degree of freedom provides a new way to manipulate the structure and properties of alloys.

  9. Organometallic chemical vapor deposition and characterization of ZnGeP2/GaP multiple heterostructures on GaP substrates

    Science.gov (United States)

    Xing, G. C.; Bachmann, Klaus J.

    1993-01-01

    The growth of ZnGeP2/GaP double and multiple heterostructures on GaP substrates by organometallic chemical vapor deposition is reported. These epitaxial films were deposited at a temperature of 580 C using dimethylzinc, trimethylgallium, germane, and phosphine as source gases. With appropriate deposition conditions, mirror smooth epitaxial GaP/ZnGeP2 multiple heterostructures were obtained on (001) GaP substrates. Transmission electron microscopy (TEM) and secondary ion mass spectroscopy (SIMS) studies of the films showed that the interfaces are sharp and smooth. Etching study of the films showed dislocation density on the order of 5x10(exp 4)cm(sup -2). The growth rates of the GaP layers depend linearly on the flow rates of trimethylgallium. While the GaP layers crystallize in zinc-blende structure, the ZnGeP2 layers crystallize in the chalcopyrite structure as determined by (010) electron diffraction pattern. This is the first time that multiple heterostructures combining these two crystal structures were made.

  10. Geological and geochemical characteristics of the Aksug porphyry Cu-Mo system, Altay-Sayan region, Russia%俄罗斯阿尔泰-Sayan地区Aksug斑岩Cu-Mo体系的地质与地球化学特征

    Institute of Scientific and Technical Information of China (English)

    Berzina AN; Berzina AP

    2008-01-01

    The Aksug deposit, located in Ahay-Sayan region of Russia, is one of the largest porphyry Cu-Mo deposits in Southern Siberia. The ore-bearing porphyries of the Aksug porphyry Cu-Mo system were formed in post-collisional environment. Geochemically they belong to calk-alkaline and high K-calk-alkaline series. Rocks are characterized by enrichment of LILE and depletion of HSFE and HREE, showing the importance of subduction-related components in magma generation. Large plutonic intrusions that host porphyry systems have been formed during collision. The origin of porphyritic rocks is dominantly the mantle with lower crustal contribution. The mainly economically important Cu-Mo mineralization is closely related to a porphyry series in time and space, being emplaced towards the end of magmatic activity. Though the emplacement of plutonic and ore-bearing porphyry complexes took place in different geodynamic environments, both complexes are characterized by certain similarity in geochemical composition, alkalinity, trace element content, Sr isotopic composition. This fact evidently indicates a common deep-seated magmatic source (at the lower crust-upper mantle level), Low initial 87Sr/86Sr, sulfur isotopic characteristics and presence of PGE-Co-Ni mineralization in associated pyrite-chalcopyrite ores suggest that mantle source of chalcophile elements was of high importance in porphyry Cu-Mo mineralization of the Aksug deposit.

  11. Preparation and characterization of CuInS2 absorber layers by sol-gel method for solar cell applications

    Science.gov (United States)

    Amerioun, M. H.; Ghazi, M. E.; Izadifard, M.; Bahramian, B.

    2016-04-01

    CuInSe2 , CuInS2 ( CIS2 and CuInGaS2 alloys and their compounds with band gaps between 1.05 and 1.7eV are absorbance materials based on chalcopyrite, in which, because of their suitable direct band gap, high absorbance coefficient and short carrier diffusion are used as absorbance layers in solar cells. In this work, the effects of decrease in p H and thickness variation on characteristics of the CIS2 absorber layers, grown by spin coating on glass substrates, are investigated. Furthermore by using thiourea as a sulphur source in solvent, the sulfurization of layers was done easier than other sulfurization methods. Due to the difficulty in dissolving thiourea in the considered solvent that leads to a fast deposition during the dissolving process, precise conditions are employed in order to prepare the solution. In fact, this procedure can facilitate the sulfurization process of CuIn layers. The results obtained from this investigation indicate reductions in absorbance and band gap in the visible region of the spectrum as a result of decrease in p H. Finally, conductivity of layers is studied by the current vs. voltage curve that represents reduction of electrical resistance with decrease and increase in p H and thickness, respectively.

  12. The Distribution, Character, and Rhenium Content of Molybdenite in the Aitik Cu-Au-Ag-(Mo Deposit and Its Southern Extension in the Northern Norrbotten Ore District, Northern Sweden

    Directory of Open Access Journals (Sweden)

    Christina Wanhainen

    2014-12-01

    Full Text Available Molybdenite in the Aitik deposit and its southern extension was studied through mineralogical/chemical analysis and laboratory flotation tests. It is demonstrated that molybdenite varies considerably in grain size, ranging from coarse (>20 μm to very fine (<2 μm and occurs predominantly as single grains in the groundmass of the rocks, as grain aggregates, and intergrown with chalcopyrite and pyrite. The dominating molybdenite-bearing rocks are the mica schists, the quartz-monzodiorite, and the Salmijärvi biotite-amphibole gneiss, the latter containing mostly medium-coarsegrained molybdenite. Later geological features, such as garnet-magnetite-anhydrite-K feldspar alteration and pegmatite dikes appear to be responsible for a significant part of the distribution pattern of molybdenite. Molybdenite grains contain up to 1587 ppm Re, with an average of 211 ± 10 ppm in Aitik molybdenite and 452 ± 33 ppm in Salmijärvi molybdenite. The higher Re concentrations are found in molybdenite associated with sericite- and quartz-amphibole-magnetite altered rocks, whereas low Re values occur in rocks in which potassic alteration is prominent. Molybdenite recovery is influenced by the mineralogy of the host rock and the alteration grade; hence both of these factors will have an impact on potential recoveries. The recovery of molybdenite was lower from flotation feeds with significant amounts of Mg-bearing clay-micas.

  13. Late Carboniferous porphyry copper mineralization at La Voluntad, Neuquén, Argentina: Constraints from Re-Os molybdenite dating

    Science.gov (United States)

    Garrido, Mirta; Barra, Fernando; Domínguez, Eduardo; Ruiz, Joaquin; Valencia, Victor A.

    2008-07-01

    The La Voluntad porphyry Cu-Mo deposit in Neuquén, Argentina, is one of several poorly known porphyry-type deposits of Paleozoic to Early Jurassic age in the central and southern Andes. Mineralization at La Voluntad is related to a tonalite porphyry from the Chachil Plutonic Complex that intruded metasedimentary units of the Piedra Santa Complex. Five new Re-Os molybdenite ages from four samples representing three different vein types (i.e., quartz-molybdenite, quartz-sericite-molybdenite and quartz-sericite-molybdenite ± chalcopyrite-pyrite) are identical within error and were formed between ~312 to ~316 Ma. Rhenium and Os concentrations range between 34 to 183 ppm and 112 to 599 ppb, respectively. The new Re-Os ages indicate that the main mineralization event at La Voluntad, associated to sericitic alteration, was emplaced during a time span of 1.7 ± 3.2 Ma and that the deposit is Carboniferous in age, not Permian as previously thought. La Voluntad is the oldest porphyry copper deposit so far recognized in the Andes and indicates the presence of an active magmatic arc, with associated porphyry style mineralization, at the proto-Pacific margin of Gondwana during the Early Pennsylvanian.

  14. Zircon U-Pb and molybdenite Re-Os geochronology, and whole-rock geochemistry of the Hashitu molybdenum deposit and host granitoids, Inner Mongolia, NE China

    Science.gov (United States)

    Zhai, Degao; Liu, Jiajun; Wang, Jianping; Yang, Yongqiang; Zhang, Hongyu; Wang, Xilong; Zhang, Qibin; Wang, Gongwen; Liu, Zhenjiang

    2014-01-01

    The Hashitu deposit is a newly-discovered Mo deposit in the southern part of the Great Hinggan Range, NE China. Molybdenum mineralization occurs as quartz-sulfide veins within the Hashitu granite-porphyry composite pluton. The sulfide assemblage in the veins is dominated by molybdenite, with minor amounts of galena, sphalerite, chalcopyrite, pyrite and marcasite. The associated gangue minerals are quartz, fluorite, calcite, sericite, chlorite and epidote. Whole-rock chemical compositions show that the Hashitu granites belong to the A2-type. The U-Pb ages of zircons from the Hashitu granite and porphyry units are 147 ± 1 Ma and 143 ± 2 Ma, respectively. The Re-Os isochron age of molybdenites from the deposit is 150 ± 4 Ma. The molybdenite Re-Os model ages vary from 144 to 150 Ma, with a weighted mean of 147 ± 1 Ma. The results show that the ages of zircon crystallization and Mo mineralization are similar, mostly within analytical uncertainties, and that the host granite pluton is one of many late-Jurassic plutons in the Great Hinggan Range. The formation of the late-Jurassic granitic plutons in this region coincides with the subduction of the Pacific plate beneath the North China block which took place ˜2000 km to the east at the time. The occurrence of abundant late-Jurassic granitoids with compositions similar to the Hashitu pluton in the Great Hinggan Range is a positive sign for more discoveries of Mo deposits in this region.

  15. Bio-processing of copper from combined smelter dust and flotation concentrate: A comparative study on the stirred tank and airlift reactors

    International Nuclear Information System (INIS)

    Highlights: ► Flotation concentrate and smelter dust were sampled and combined. ► Copper bioleaching from the combined was investigated. ► Two bio-reactors were investigated and optimized: stirred and airlift. ► STRs had better technical conditions and situations for bacterial leaching. - Abstract: To scrutinize the influence of the design and type of the bioreactors on the bioleaching efficiency, the bioleaching were evaluated in a batch airlift and a batch stirred tank bioreactors with mixed mesophilic and mixed moderately thermophilic bacteria. According to the results, maximum copper recoveries were achieved using the cultures in the stirred tank bioreactors. It is worth noting that the main phase of the flotation concentrate was chalcopyrite (as a primary sulphide), but the smelter dust mainly contained secondary copper sulphides such as Cu2S, CuS, and Cu5FeS4.Under optimum conditions, copper dissolution from the combined flotation concentrate and smelter dust (as an environmental hazard) reached 94.50% in the STR, and 88.02% in the airlift reactor with moderately thermophilic, after 23 days. Also, copper extractions calculated for the bioleaching using mesophilic bacteria were 48.73% and 37.19% in the STR (stirred tank reactor) and the airlift bioreactor, respectively. In addition, the SEM/EDS, XRD, chemical, and mineralogical analyses and studies confirmed the above results.

  16. Molecular Characterization of Copper and Cadmium Resistance Determinants in the Biomining Thermoacidophilic Archaeon Sulfolobus metallicus

    Directory of Open Access Journals (Sweden)

    Alvaro Orell

    2013-01-01

    Full Text Available Sulfolobus metallicus is a thermoacidophilic crenarchaeon used in high-temperature bioleaching processes that is able to grow under stressing conditions such as high concentrations of heavy metals. Nevertheless, the genetic and biochemical mechanisms responsible for heavy metal resistance in S. metallicus remain uncharacterized. Proteomic analysis of S. metallicus cells exposed to 100 mM Cu revealed that 18 out of 30 upregulated proteins are related to the production and conversion of energy, amino acids biosynthesis, and stress responses. Ten of these last proteins were also up-regulated in S. metallicus treated in the presence of 1 mM Cd suggesting that at least in part, a common general response to these two heavy metals. The S. metallicus genome contained two complete cop gene clusters, each encoding a metallochaperone (CopM, a Cu-exporting ATPase (CopA, and a transcriptional regulator (CopT. Transcriptional expression analysis revealed that copM and copA from each cop gene cluster were cotranscribed and their transcript levels increased when S. metallicus was grown either in the presence of Cu or using chalcopyrite (CuFeS2 as oxidizable substrate. This study shows for the first time the presence of a duplicated version of the cop gene cluster in Archaea and characterizes some of the Cu and Cd resistance determinants in a thermophilic archaeon employed for industrial biomining.

  17. Influence of process variables on biooxidation of ferrous sulfate by an indigenous Acidithiobacillus ferrooxidans. Part I: Flask experiments

    Energy Technology Data Exchange (ETDEWEB)

    S.M. Mousavi; S. Yaghmaei; F. Salimi; A. Jafari [Sharif University of Technology, Tehran (Iran). Department of Chemical and Petroleum Engineering

    2006-12-15

    Biological oxidation of ferrous sulfate by Acidithiobacillus ferrooxidans has proved to be a significant step in the bioleaching of sulfide minerals and the treatment of acid mine drainage. The same bioreaction also has beneficial applications in the desulphurization of coal and removal of hydrogen sulfide from gaseous effluents. In this research, the effects of some process variables such as pH, temperature, elemental sulfur, amount of initial ferrous and magnesium ions on oxidation of ferrous sulfate by a native A. ferrooxidans, which was isolated from a chalcopyrite concentrate, were investigated. All experiments carried out in shake flasks at 33{sup o}C that was obtained as optimum temperature for the specific bacterial growth rate. The optimum range of pH for the maximum growth of the cells and effective biooxidation of ferrous sulfate varied from 2 to 2.3. The maximum biooxidation rate was achieved 1.2 g/L h in a culture initially containing 20.2 g/L Fe{sup 2+}. Mg{sup 2+} from 20 mg/L to 120 mg/L did not have any effect on the efficiency of the process, while the presence of elemental sulfur had negative effect on the biooxidation. 16 refs., 8 figs.

  18. A New Heterotrophic Strain for Bioleaching of Low Grade Complex Copper Ore

    Directory of Open Access Journals (Sweden)

    Kaijian Hu

    2016-02-01

    Full Text Available A new heterotrophic strain, named Providencia sp. JAT-1, was isolated and used in bioleaching of low-grade complex copper ore. The strain uses sodium citrate as a carbon source and urea as a nitrogen source to produce ammonia. The optimal growth condition of the strain is 30 C, initial pH 8, sodium citrate 10 g/L and urea 20 g/L, under which the cell density and ammonia concentration in the medium reached a maximum of 4.83 × 108 cells/mL and 14 g/L, respectively. Ammonia produced by the strain is used as the main lixiviant in bioleaching. Bioleaching results revealed that higher strain growth led to a higher copper recovery, while higher pulp density will cause a greater inhibitory effect on strain growth and ammonia production. The copper extraction reached the highest value of 54.5% at the pulp density of 1%. Malachite, chrysocolla and chalcocite are easy to leach out in this bioleaching system while chalcopyrite is difficult. Results of comparative leaching experiments show that bioleaching using JAT-1 is superior to ammonia leaching at the same condition. The metabolites produced by the strain other than ammonia are also involved in bioleaching.

  19. Characteristics of Cu(In,Ga)Se{sub 2} (CIGS) thin films deposited by a direct solution coating process

    Energy Technology Data Exchange (ETDEWEB)

    Park, Myoung Guk [Photovoltaic Center, Korea Institute of Energy Research, 71-2 JangDong, YuseongGu, DaeJeon 305-343 (Korea, Republic of); Ahn, Se Jin, E-mail: swisstel@kier.re.kr [Photovoltaic Center, Korea Institute of Energy Research, 71-2 JangDong, YuseongGu, DaeJeon 305-343 (Korea, Republic of); Yun, Jae Ho; Gwak, Jihye; Cho, Ara; Ahn, Seoung Kyu; Shin, Keeshik [Photovoltaic Center, Korea Institute of Energy Research, 71-2 JangDong, YuseongGu, DaeJeon 305-343 (Korea, Republic of); Nam, Dahyun; Cheong, Hyeonsik [Department of Physics, Sogang University, Seoul 121-742 (Korea, Republic of); Yoon, Kyunghoon [Photovoltaic Center, Korea Institute of Energy Research, 71-2 JangDong, YuseongGu, DaeJeon 305-343 (Korea, Republic of)

    2012-02-05

    Highlights: Black-Right-Pointing-Pointer Double layered CIGS/carbon films prepared by a direct solution coating. Black-Right-Pointing-Pointer Controllability of compositions of the CIGS layer. Black-Right-Pointing-Pointer Effects of Cu and Ga contents on properties of the CIGS layer. Black-Right-Pointing-Pointer Structure of the bottom carbon layer. - Abstract: Cu(In,Ga)Se{sub 2} (CIGS) thin films were formed by a direct non-vacuum coating and a subsequent selenization of low cost precursor solutions, and their compositional, structural and optical properties were characterized. Selenized films showed a double-layered structure with an upper layer of chalcopyrite CIGS and an amorphous bottom layer mainly composed of carbon. For the upper CIGS layer, good compositional controllability for Cu and Ga was confirmed by linear relationship between metal ratios of the precursor solution and those of the selenized films. Effects of Cu and Ga contents on structural and optical properties of the films were also characterized by X-ray diffraction (XRD), Raman and photoluminescence (PL) analyses, and the results were interpreted by defect supercluster formation (V{sub Cu}-In{sub Cu}) in Cu-deficient films and mass and size difference between In and Ga, respectively. Further, the bottom layer was found to be mostly composed of conductive amorphous carbon, which is the main current flow path in the completed solar cells.

  20. Uniform deposition of ternary chalcogenide nanoparticles onto mesoporous TiO{sub 2} film using liquid carbon dioxide-based coating

    Energy Technology Data Exchange (ETDEWEB)

    Nursanto, Eduardus Budi [Clean Energy Research Center, Korea Institute of Science and Technology, Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136–791 (Korea, Republic of); Department of Clean Energy and Chemical Engineering, Korea University of Science and Technology,217, Gajeong-ro, Yuseong-gu, Daejeon 305–333 (Korea, Republic of); Park, Se Jin [Clean Energy Research Center, Korea Institute of Science and Technology, Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136–791 (Korea, Republic of); Jeon, Hyo Sang; Hwang, Yun Jeong [Clean Energy Research Center, Korea Institute of Science and Technology, Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136–791 (Korea, Republic of); Department of Clean Energy and Chemical Engineering, Korea University of Science and Technology,217, Gajeong-ro, Yuseong-gu, Daejeon 305–333 (Korea, Republic of); Kim, Jaehoon, E-mail: jaehoonkim@skku.edu [School of Mechanical Engineering, Sungkyunkwan University, 2066, Seobu-Ro, Jangan-Gu, Suwon, GyeongGi-Do 440–746 (Korea, Republic of); SKKU Advanced Institute of Nano Technology (SAINT), 2066, Seobu-Ro, Jangan-Gu, Suwon, GyeongGi-Do 440–746 (Korea, Republic of); Min, Byoung Koun, E-mail: bkmin@kist.re.kr [Clean Energy Research Center, Korea Institute of Science and Technology, Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136–791 (Korea, Republic of); Department of Clean Energy and Chemical Engineering, Korea University of Science and Technology,217, Gajeong-ro, Yuseong-gu, Daejeon 305–333 (Korea, Republic of); Green School, Korea University, 145,Anam-ro, Seongbuk-gu, Seoul 136–713 (Korea, Republic of)

    2014-08-28

    We report the simultaneous deposition of two different metal precursors dissolved in liquid carbon dioxide (l-CO{sub 2}), aiming to the synthesis of ternary chalcopyrite (e.g. CuInS{sub 2}) nanoparticles on a mesoporous TiO{sub 2} film. The l-CO{sub 2}-based deposition of Cu and In precursors and subsequent reaction with a dilute H{sub 2}S gas resulted in Cu{sub x}In{sub y}S{sub z} nanoparticles uniformly deposited across the entire thickness of a mesoporous TiO{sub 2} film. Further heat treatment (air annealing and sulfurization) led to the formation of more stoichiometric CuInS{sub 2} nanoparticles. The formation of CuInS{sub 2} on TiO{sub 2} was confirmed by scanning electron microscopy, high resolution transmission electron microscopy, X-ray diffraction, and Raman spectroscopy. The crystal growth of CuInS{sub 2} was also found to be controllable by adjusting the number of coating cycles of the l-CO{sub 2}-based deposition. - Highlights: • Simultaneous deposition of two different metal precursors dissolved in l-CO{sub 2}. • Uniform deposition of CuInS{sub 2} nanoparticles across mesoporous TiO{sub 2} film. • Highly crystalline CuInS{sub 2} formed on mesoporous TiO{sub 2} film. • Nearly stoichiometric ratio of Cu:In:S was obtained.

  1. The role of magmatic and meteoric water mixing in mineralization of Shurab poly metal ore deposit South of Ferdowsi: isotope geochemistry and microthermometry evidences

    International Nuclear Information System (INIS)

    Shurab poly metal ore deposit is located in 77 Km south of Ferdows in north of Lut structural zone. Geology of the area includes a Jurassic sedimentary rocks, comprises shale and sandstone of Shemshak Formation, Badamo limestone, and andesite, dacite, rhyodacite and rhyolite volcanic and sub volcanic-calc-alkaline Tertiary rocks as a hydrothermal mineralization host rock. In these rocks, mineralization occurs as both series of NW-SE and E-W trending fault and fracturing. Galena, sphalerite, stibnite, chalcopyrite and pyrite are present as major sulfide ore mineral and frequently shows open-space filling, vein-type and crustified textures. The mineralization is subdivided into two stages, base metal-bearing assemblage (Pb>Zn>Cu) accompanied by first generation pyrite and second stage, stibnite-bearing minerals (stibnite, chalcostibnite, tetrahedrite and bournonite) with subordinate arsenopyrite and late generation pyrite sulfide minerals. Microtermometric measurement of fluid inclusions in co genetic quartz and sphalerite shows homogenization temperatures (Thtotal) between 114degreeC and 275degreeC and salinities between 4.2 to 17.2 wt.% NaCl equiv. Geochemistry of oxygen isotope (relative to SMOW) indicate ranging between +12.5% to +14.8% (mean 13.6%) which assume that mineralizing solutions in the area were a mixture of meteoric and magmatic waters. This study indicated that, mixing, cooling and fluid-rock interactions were the main controlling factors in formation of the Shurab poly metal ore deposit.

  2. Mineralogical, textural, structural and geochemical aspects of Nakhlak lead mine, Isfahan

    Directory of Open Access Journals (Sweden)

    Mohammad Ali Jazi

    2010-11-01

    Full Text Available Nakhlak lead mine is located at the Nakhlak mountain 55 km NE of Anarak town in Isfahan province. The mineralogy is simple; galena and barite are the main primary minerals and cerussite is the main secondary mineral. Sphalerite, pyrite, chalcopyrite, tetrahedrite-tennantite and acanthite occur as minor and trace mineral inclusions in galena. Secondary minerals are anglesite, plattnerite, wulfenite and malachite. The host rock has undergone a pre-mineralization dolomitization process. Four types of dolomite have been identified which saddle dolomite is the most distinguished. Open space filling textures occur in the form of breccia, cockade, crustification and colloform. Analysis of the galena samples indicates presence of many trace elements in galena among which silver is the most important. Element pairs such as Ag-As, Zn-Cd, As-Cu and As-Sb are highly correlated. This correlation may be explained by the presence of inclusions. Ag-Sb-Bi ternary diagram indicates that galena samples from Nakhlak are rich in Ag and Sb and poor in Bi. Sb/Bi (3773 ratio in galena is suggestive of a low temperature of formation for the deposit. The Upper Cretaceous carbonate host rocks and their dolomitization, the stratabound and epigenetic mineralization, the absence of igneous activity, the open space filling texture, the simple mineralogy and geochemistry all point to a Mississippi valley type model for the Nakhlak Pb deposit.

  3. Structural, photoelectrical characterization of Cu(InAl)Se2 thin films and the fabrication of Cu(InAl)Se2 based solar cells

    Science.gov (United States)

    Kavitha, B.; Dhanam, M.

    2013-01-01

    Films of Cu(InAl)Se2 were deposited onto glass substrates by SILAR (successive ionic layer adsorption and reaction) method. All the deposited films were found to be polycrystalline in nature exhibiting the chalcopyrite structure with the crystallite orientation along (112), (220/204) and (116/312) directions. The photocurrent was found to increase with increase in film thickness and also with increase of light intensity. Photocurrent spectra showed a peak related to the band-to-band transition. The spectral response of Cu(InAl)Se2 thin films was studied by allowing the radiation to pass through a series of interference filters in the wavelength range 300 to 1200 nm. Films of higher thickness exhibited higher photosensitivity while lower thickness films exhibited moderate photosensitivity. Cu(InAl)Se2-based solar cells with different types of buffer layers such as CdS, CdS:Cu, CdS:In were fabricated. The current and voltage were measured using an optical power meter and an electrometer and the fabricated solar cells were illuminated using 100 mW/cm2 white light under AM1 conditions.

  4. Late-stage sulfides and sulfarsenides in Lower Cambrian black shale (stone coal) from the Huangjiawan mine, Guizhou Province, People's Republic of China

    Science.gov (United States)

    Belkin, H.E.; Luo, K.

    2008-01-01

    The Ni-Mo Huangjiawan mine, Guizhou Province, People's Republic of China, occurs in Lower Cambrian black shale (stone coal) in an area where other mines have recently extracted ore from the same horizon. Detailed electron microprobe (EMPA) and scanning electron microscope (SEM) analyses of representative thin sections have revealed a complex assemblage of sulfides and sulfarsenides. Early sulfidic and phosphatic nodules and host matrix have been lithified, somewhat fractured, and then mineralized with later-stage sulfides and sulfarsenides. Gersdorffite, millerite, polydymite, pyrite, sphalerite, chalcopyrite, galena, and clausthalite have been recognized. EMPA data are given for the major phases. Pyrite trace-element distributions and coeval Ni-, As-sulfides indicate that in the main ore layer, the last sulfide deposition was Ni-As-Co-rich. Mo and V deposition were early in the petrogenesis of these rocks. The assemblages gersdorffite-millerite-polydymite (pyrite) and millerite-gersdorffite (pyrite) and the composition of gersdorffite indicate a formation temperature of between 200?? and 300??C suggesting that the last solutions to infiltrate and mineralize the samples were related to hydrothermal processes. Environmentally sensitive elements such as As, Cd, and Se are hosted by sulfides and sulfarsenides and are the main source of these elements to residual soil. Crops grown on them are enriched in these elements, and they may be hazardous for animal and human consumption. ?? Springer-Verlag 2007.

  5. Genetic relationship between L granite body and 3701 uranium deposit

    International Nuclear Information System (INIS)

    The ore deposit occurs in carbonate rocks situated in the exocontact zone (0 - 120 m) with the L granite body. The mineralization is hosted by argillaceous limestone of the middle Devonian Yingtang Formation. The ore bodies are in lenticular or stratifed form. The ores are fine vein-type and disseminated type. Four stages of mineralization in the deposit are recognized. Industrial mineral is pitchblende which occurs as micro-impregnation and micro-vein in the calcite, and fills or replaces its associated minerals. Gangue minerals are chiefly calcite, pyrite, galena, sphalerite, chalcopyrite and tennantite etc. The host rocks of the ore-veins show weak hydrothermal alterations with plane and linear distribution. The L granite body with an area of 238 km2 is a single-stage intrusive batholith which mainly consists of coarse-medium grained biotite granites. Because the urnium mineralization age (65.0 - 30.7 Ma) is much younger than that of the L granite (318 -202 Ma), it may be considered that the deposit is genetically not related to activity of the L granitic magma. However, the granitic rocks may play an important role in the formation of the 3701 uranium deposit in following hands: providing a large number of uranium and lead; providing minor amounts of surfur, carbon and trace elements; forming impermeable basement to promote the accumulation of uranium-bearing solution; providing an additional heat source for heating ore-bearing solution and its convective circulation

  6. Heat transfer law in leaching dump

    Institute of Scientific and Technical Information of China (English)

    WU Ai-xiang; WANG Hong-jiang; XI Yong; YANG Bao-hua; LI Jian-feng; YIN Sheng-hua; ZHA Ke-bing

    2005-01-01

    Based on the law of temperature changes in the leaching dump and the forming process of heat flux, the basic balance equation of heat flow in dump was established, the dissipated heat flow from dump to the atmosphere was analyzed to estimate the surface temperature of the ore particle in dump and discover the law of forced heat convection of heat flow transfer in dump. And the lixiviate flow formula taking a certain heat flow out of dump was deduced by using the inversion method. Through theoretic analysis, combining Dexing copper mine heap leaching production practice, the results show that the heat flow of chalcopyrite leaching emitted is not so great, but the heat flow of pyrite leaching and sulphur oxidation produced take up a higher proportion of total heat flow; the dissipated heat flow takes up a lower proportion, and most of heat flow is absorbed by itself, thus the inside temperature rises gradually; and the saturation flow form for leaching is adopted, which makes the lixiviate seepage in the transitional flow or even in the turbulent flow, so as to accelerate the heat flow diffusing and keep the leaching dump temperature suitable for bacteria living.

  7. Physics of Quantum Structures in Photovoltaic Devices

    Science.gov (United States)

    Raffaelle, Ryne P.; Andersen, John D.

    2005-01-01

    There has been considerable activity recently regarding the possibilities of using various nanostructures and nanomaterials to improve photovoltaic conversion of solar energy. Recent theoretical results indicate that dramatic improvements in device efficiency may be attainable through the use of three-dimensional arrays of zero-dimensional conductors (i.e., quantum dots) in an ordinary p-i-n solar cell structure. Quantum dots and other nanostructured materials may also prove to have some benefits in terms of temperature coefficients and radiation degradation associated with space solar cells. Two-dimensional semiconductor superlattices have already demonstrated some advantages in this regard. It has also recently been demonstrated that semiconducting quantum dots can also be used to improve conversion efficiencies in polymeric thin film solar cells. Improvement in thin film cells utilizing conjugated polymers has also be achieved through the use of one-dimensional quantum structures such as carbon nanotubes. It is believed that carbon nanotubes may contribute to both the disassociation as well as the carrier transport in the conjugated polymers used in certain thin film photovoltaic cells. In this paper we will review the underlying physics governing some of the new photovoltaic nanostructures being pursued, as well as the the current methods being employed to produce III-V, II-VI, and even chalcopyrite-based nanomaterials and nanostructures for solar cells.

  8. Oxygen, carbon and sulphur isotope studies in the Keban Pb-Zn deposits, eastern Turkey: An approach on the origin of hydrothermal fluids

    Science.gov (United States)

    Kalender, Leyla

    2011-03-01

    Pb-Zn deposits are widespread and common in various parts of the Taurus Belt. Most of the deposits are of pyrometasomatic and hydrothermal origin. The Keban Pb-Zn deposits are located along the intrusive contact between the Paleozoic - Lower Triassic Keban Metamorphic Formation and the syenite porphyry of the Upper Cretaceous Keban igneous rocks. Various studies have already been carried out; using fluid inclusion studies on fluorite, calcite and quartz on the pyrite-chalcopyrite bearing Keban ore deposits. This study focuses on the interpretation of stable isotope compositions in connexion with fluid inclusion data. Sulphur isotope values (δ 34S) of pyrite are within the range of -0.59 to +0.17‰ V-CDT ( n = 10). Thus, the source of sulphur is considered to be magmatic, as evidenced by associated igneous rocks and δ 34S values around zero"0". Oxygen isotope values δ 18O of quartz vary between +10.5 and +19.9‰ (SMOW). However, δ 18O and δ 13C values of calcite related to re-crystallized limestone (Keban Metamorphic Formation) reach up to +27.3‰ (SMOW) and +1.6‰ (PDB), respectively. The δ 34S, δ 13C and δ 18O values demonstrate that skarn-type Pb-Zn deposits formed within syeno-monzonitic rocks and calc-schist contacts could have developed at low temperatures, by mixing metamorphic and meteoric waters in the final stages of magmatism.

  9. CuAlTe{sub 2}: A promising bulk thermoelectric material

    Energy Technology Data Exchange (ETDEWEB)

    Gudelli, Vijay Kumar [Department of Physics, Indian Institute of Technology Hyderabad, Ordnance Factory Estate, Yeddumailaram 502 205, Telangana (India); Kanchana, V., E-mail: kanchana@iith.ac.in [Department of Physics, Indian Institute of Technology Hyderabad, Ordnance Factory Estate, Yeddumailaram 502 205, Telangana (India); Vaitheeswaran, G. [Advanced Centre of Research in High Energy Materials (ACRHEM), University of Hyderabad, Prof. C. R. Rao Road, Gachibowli, Hyderabad 500 046, Telangana (India)

    2015-11-05

    Transport properties of Cu-based chalcopyrite materials are presented using the full potential linear augmented plane wave method and Boltzmann Semi-classical theory. All the studied compounds appear to be direct band gap semiconductors evaluated based on the Tran-Blaha modified Becke-Johnson potential. The heavy and light band combination found near the valence band maximum (VBM) drive these materials to possess good thermoelectric properties. Among the studied compounds, CuAlTe{sub 2} is found to be more promising, in comparison with CuGaTe{sub 2}, which is reported to be an efficient thermoelectric material with appreciable figure of merit. Another interesting fact about CuAlTe{sub 2} is the comparable thermoelectric properties possessed by both n- type and p-type carriers, which might attract good device applications and are explained in detail using the electronic structure calculations. - Highlights: • Band structure calculation of Cu(Al,Ga)Ch{sub 2} compounds with the TB-mBJ functional. • Mixed heavy-light bands near Fermi level might favour good thermoelectric properties. • Among the investigated compounds CuAlTe{sub 2} appears to be more promising. • Thermoelectric properties of CuAlTe{sub 2} are almost comparable with CuGaTe{sub 2}. • Both n,p-type thermoelectric properties of CuAlTe{sub 2} can attract device applications.

  10. Solution-based colloidal synthesis of hybrid P3HT: Ternary CuInSe2 nanocomposites using a novel combination of capping agents for low-cost photovoltaics

    Science.gov (United States)

    Sharma, Shailesh Narain; Chawla, Parul; Akanksha; Srivastava, A. K.

    2016-06-01

    In this work, ternary CuInSe2 (CISe) chalcopyrite nanocrystallites efficiently passivated by a novel combination of capping agents viz: aniline and 1-octadecene during chemical route synthesis were dispersed in conducting polymer matrix poly(3-hexylthiophene) (P3HT). By varying the composition and concentration of the ligands, the properties of the resulting CISe nanocrystallites and its corresponding polymer nanocomposites thus could be tailored. The structural, morphological and optical studies accomplished by various complimentary techniques viz. Transmission Electron Microscopy (TEM), Contact angle, Photoluminescence (PL) and Raman have enabled us to compare the different hybrid organic (polymer)-inorganic nanocomposites. On the basis of aniline-octadecene equilibrium phase diagram, the polydispersity of the CISe nanocrystals could be tuned by using controlled variations in the reaction conditions of nucleation and growth such as composition of the solvent and temperature. To the best of author's knowledge, the beneficial effects of both the capping agents; aniline and octadecene contributing well in tandem in the development of large-sized (100-125 nm) high quality, sterically- and photo-oxidative stable polycrystalline CISe and its corresponding polymer (P3HT):CISe composites with enhanced charge transfer efficiency has been reported for the first time. The low-cost synthesis and ease of preparation renders this method of great potential for its possible application in low-cost hybrid organic-inorganic photovoltaics. The figure shows the Temperature vs Mole fraction graph of two different phases (aniline and 1-octadecene) in equilibrium.

  11. Re-Os geochronology on sulfides from the Tudun Cu-Ni sulfide deposit, Eastern Tianshan, and its geological significance

    Science.gov (United States)

    Wang, Minfang; Wang, Wei; Gutzmer, Jens; Liu, Kun; Li, Chao; Michałak, Przemysław P.; Xia, Qinlin; Guo, Xiaonan

    2015-11-01

    The Tudun deposit is a medium-sized Cu-Ni sulfide deposit, located at the westernmost edge of the Huangshan-Jing'erquan Belt in the northern part of Eastern Tianshan, NW China. Sulfide separates including pentlandite, pyrrhotite and chalcopyrite from the Tudun deposit, contain Re, common Os and 187Os ranging from 40.46 to 201.2, 0.8048 to 6.246 and 0.1709 to 0.9977 ppb, respectively. They have very low 187Os/188Os ratios of 1.224-2.352. The sulfides yield a Re-Os isochron age of 270.0 ± 7.5 Ma (MSWD = 1.3), consistent within uncertainty with the SHRIMP zircon U-Pb age for the Tudun mafic intrusion (gabbro) of 280.0 ± 3.0 Ma. The calculated initial 187Os/188Os ratio is 0.533 ± 0.022, and γOs values range from 283 to 307, with a mean of 297, indicating significant crustal contamination of the parent melt prior to sulfide saturation. The Tudun deposit shares the same age and Re-Os isotopic compositions with other orthomagmatic Cu-Ni sulfide deposits in Huangshan-Jing'erquan Belt, suggesting that they have formed in Early Permian.

  12. Temperature dependence of band gaps in semiconductors: electron-phonon interaction

    Energy Technology Data Exchange (ETDEWEB)

    Kremer, Reinhard K.; Cardona, M.; Lauck, R. [MPI for Solid State Research, Stuttgart (Germany); Bhosale, J.; Ramdas, A.K. [Physics Dept., Purdue University, West Lafayette, IN (United States); Burger, A. [Fisk University, Dept. of Life and Physical Sciences, Nashville, TN (United States); Munoz, A. [MALTA Consolider Team, Dept. de Fisica Fundamental II, Universidad de La Laguna, Tenerife (Spain); Instituto de Materiales y Nanotecnologia, Universidad de La Laguna, Tenerife (Spain); Romero, A.H. [CINVESTAV, Dept. de Materiales, Unidad Queretaro, Mexico (Mexico); MPI fuer Mikrostrukturphysik, Halle an der Saale (Germany)

    2013-07-01

    We investigate the temperature dependence of the energy gap of several semiconductors with chalcopyrite structure and re-examine literature data and analyze own high-resolution reflectivity spectra in view of our new ab initio calculations of their phonon properties. This analysis leads us to distinguish between materials with d-electrons in the valence band (e.g. CuGaS{sub 2}, AgGaS{sub 2}) and those without d-electrons (e.g. ZnSnAs{sub 2}). The former exhibit a rather peculiar non-monotonic temperature dependence of the energy gap which, so far, has resisted cogent theoretical description. We demonstrate it can well be fitted by including two Bose-Einstein oscillators with weights of opposite sign leading to an increase at low-T and a decrease at higher T's. We find that the energy of the former correlates well with characteristic peaks in the phonon density of states associated with low-energy vibrations of the d-electron constituents.

  13. SEM - EDS mineralogical study of the Cuaro Sill Tacuarembo dept. (Uruguay)

    International Nuclear Information System (INIS)

    The Mesozoic magmatism exposed in the Norte basin of Uruguay is related with the tectono-magmatic events of the South Atlantic Ocean opening and, regionally is part of the Parana Magmatic Province (PMP). It is represented by basaltic flows correspondent to the Arapey Formation and by the associated intrusive rocks of the Cuaro Formation. The aim of this work is the mineralogical characterization of the Cuaro Sill (Department of Tacuarembo, NE Uruguay), using conventional petrographic techniques (polarized transmitted and reflected microscopy) and scanning electron microscopy (SEM-EDS). Based on the petrographic features observed, the dolerites of the Cuaro Sill are composed by: plagioclase (labradorite), pyroxenes (augite and pigeonite), Fe-Ti oxides (magnetite and ilmenite), relicts of olivine and apatite. It presents frequent glomero-porphyritic textures, with plagioclase/clinopyroxene phenocrysts, with lack of cumulate textures. Anomalous concentrations of guide exploration elements have not been observed despite the presence of traces of Mn and Cr within the ilmenites or the presence of sulfides (chalcopyrite). Therefore, a greater potential of these elements at deeper levels of the intrusion is not rule out

  14. CGS based solar cells with In2S3 buffer layer deposited by CBD and coevaporation

    International Nuclear Information System (INIS)

    In this paper we investigated In2S3 as substitute for CdS, which is conventionally used as buffer layer in chalcopyrite based solar cells. In2S3 thin films were deposited by CBD and co-evaporation methods and these were employed as buffer layer in CuGaSe2 based solar cells. Previous to the device fabrication, comparative study was carried out on In2S3 thin films properties deposited from chemical bath containing thioacetamide, Indium Chloride, and sodium citrate, and In2S3 thin films prepared by co-evaporation from its constituents elements. The influence of synthesis conditions on the growth rate, optical, structural and morphological properties of the as-grown In2S3 thin films have been carried out with Spectrophotometry, X-ray diffraction and AFM microscopy techniques. Suitable conditions were found for reproducible and good quality In2S3 thin films synthesis. By depositing In2S3 thin films as buffer layers in CuGaSe2 configuration, a maximum solar cell efficiency of 6% was achieved, whilst the reference solar cell with CdS/CuGaSe2 on similar absorber exhibited 7% efficiency. (author)

  15. Environmental geochemistry of a Kuroko-type massive sulfide deposit at the abandoned Valzinco mine, Virginia, USA

    International Nuclear Information System (INIS)

    The abandoned Valzinco mine, which worked a steeply dipping Kuroko-type massive sulfide deposit in the Virginia Au-pyrite belt, contributed significant metal-laden acid-mine drainage to the Knight's Branch watershed. The host rocks were dominated by metamorphosed felsic volcanic rocks, which offered limited acid-neutralizing potential. The ores were dominated by pyrite, sphalerite, galena, and chalcopyrite, which represented significant acid-generating potential. Acid-base accounting and leaching studies of flotation tailings - the dominant mine waste at the site - indicated that they were acid generating and therefore, should have liberated significant quantities of metals to solution. Field studies of mine drainage from the site confirmed that mine drainage and the impacted stream waters had pH values from 1.1 to 6.4 and exceeded aquatic ecosystem toxicity limits for Fe, Al, Cd, Cu, Pb and Zn. Stable isotope studies of water, dissolved SO42-, and primary and secondary sulfate and sulfide minerals indicated that two distinct sulfide oxidation pathways were operative at the site: one dominated by Fe(III) as the oxidant, and another by molecular O2 as the oxidant. Reaction-path modeling suggested that geochemical interactions between tailings and waters approached a steady state within about a year. Both leaching studies and geochemical reaction-path modeling provided reasonable predictions of the mine-drainage chemistry

  16. Catalytic effect of activated carbon on bioleaching of low-grade primary copper sulfide ores

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The catalytic effect of activated carbon on the bioleaching of low-grade primary copper sulfide ores using mixture of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans was investigated. The results show that the addition of activated carbon can greatly accelerate the rate and efficiency of copper dissolution from low-grade primary copper sulfide ores. The solution with the concentration of 3.0 g/L activated carbon is most beneficial to the dissolution of copper. The resting time of the mixture of activated carbon and ores has an impact on the bioleaching of low-grade primary copper sulfide ores. The 2 d resting time is most favorable to the dissolution of copper. The enhanced dissolution rate and efficiency of copper can be attributed to the galvanic interaction between activated carbon and chalcopyrite. The addition of activated carbon obviously depresses the dissolution of iron and the bacterial oxidation of ferrous ions in solution. The lower redox potentials are more favorable to the copper dissolution than the higher potentials for low-grade primary copper sulfide ores in the presence of activated carbon.

  17. Comparison of the mineralogy of the Boss-Bixby, Missouri copper-iron deposit, and the Olympic Dam copper-uranium-gold deposit, South Australia

    International Nuclear Information System (INIS)

    An ore microscopic examination of 80 polished sections prepared from selected drill core specimens from the Boss-Bixby, Missouri copper-iron deposit has shown that its mineral assemblage is similar to that of the Olympic Dam (Roxby Downs) copper-uranium-gold deposit in South Australia. A comparison with the mineralogy reported for Olympic Dam shows that both deposits contain: 1) the principal minerals, magnetite, hematite, chalcopyrite, and bornite, 2) the cobalt-bearing phases, carrollite and cobaltian pyrite, 3) the titanium oxides, rutile and anatase, 4) smaller amounts of martite, covellite, and electrum, 5) fluorite and carbonates, and 6) some alteration minerals. The deposits also are similar with regard to the sequence of mineral deposition: 1) early oxides, 2) then sulfide minerals, and 3) a final oxide generation. The deposits, however, are dissimilar with regard to their host rock lithologies and structural settings. The Boss-Bixby ores occupy breccia zones within a hydrothermally altered basic intrusive and intruded silicic volcanics, whereas the Olympic Dam ores are contained in sedimentary breccias in a graben or trough. Also, some minerals have been found thus far to occur at only one of the deposits. The similarity of mineralogy in these deposits suggests that they were formed from ore fluids that had some similarities in character and that the St. Francois terrane of Missouri is an important region for further exploration for deposits with this mineral assemblage

  18. Tetrahedrite-Group Minerals in the Jinjitai Gold Deposit, Western Sichuan

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    There are quite a few tetrahedrite-group minerals in the Jinjitai gold deposit, western Sichuan, which occur in an interstratified fractured zone of Middle Devonian carbonate rock series. The gold ore consists of pyrite, chalcopyrite, tetrahedrite-group minerals, galena, sphalerite and gold-silver series minerals, with an element association of Au-Cu-Ag-Pb-As-Sb-Bi. Electron microprobe analyses of the tetrahedrite-group minerals gave the following results: copper 40.04 to 42.27% (average 40.04%), iron 1.24 to 7.78% (average 4.13%), zinc 0.39 to 7.06% (average 3.58%), arsenic 5.41 to 17.40% (average 8.84%), antimony 2.70 to 20.46% (average 15.87%), and silver 0.02 to 0.73% (average 0.28%). The mineral varieties include zinc-antimony-tetrahedrite, iron-antimony-tetrahedrite, iron-tennatite and zincotennatite. These data show that there is a complete isomorphous series between Sb and As. From above downwards tetrahedrite varies from zinc- and antimony-rich to iron- and arsenic-rich compositions. Their occurrence and zonal features are very important for exploration of the same type of gold deposits in western Sichuan.

  19. Mechanical properties and Raman scattering investigation under indentation of CdGa2S4 and CdGa2Se4

    Science.gov (United States)

    Shikimaka, O.; Burlacu, A.; Grabco, D.; Parvan, V.; Pyrtsac, C.; Ursaki, V.

    2016-05-01

    The behavior of CdGa2S4 and CdGa2Se4 single crystalline semiconductors under Berkovich indentation of the (1 1 2) face in the load range of 10–700 mN has been investigated. Values of hardness and Young’s modulus have been determined for this load range. A comparative analysis of crack development under indentation was performed for these two compounds. The observed indentation size effect was analyzed from the point of view of energy consumed for the formation of the residual imprint, fracture and relaxation processes. It was found that crack development affects the energy-load and hardness-load dependences, which show specific features for each compound. The effect of indentation on eventual phase transitions was investigated by comparing the micro-Raman spectra from a non-indented site with those measured in the indentation. Evidence of a phase transition under indentation from the initial defect chalcopyrite structure to a disordered zincblende phase is found.

  20. Effect of annealing on the properties of nanocrystalline CuInSSe thin films deposited by spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Shrotriya, Vipin, E-mail: vipinshrotriya@gmail.com; Rajaram, P. [School of Studies in Physics, Jiwaji University, Gwalior (MP), India-474011 (India)

    2015-08-28

    The effect of annealing CuInSSe thin films, which were grown on glass substrates using the spray pyrolysis technique from spray solutions having S/Se ionic ratio 0.6, were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), and optical transmission measurements. The CuInSSe films were co-deposited from an aqueous solution containing CuCl{sub 2}, InCl{sub 3}, thiourea and SeO{sub 2}. EDC was used as a complexing agent and films were deposited at the constant temperature 300°C. Post annealing (at 350°C) was used to improve the structural, morphological and optical properties of CuInSSe thin films. From the results, it is found that the films are single phase, p-type in conductivity having the chalcopyrite structure. From the Scherrer formula the average size of the films was found to be in the range (15-28) nm. Optical studies show that the optical band gap value increases slightly from 1.35 eV to 1.37 eV with annealing for films grown from spray solutions having S/Se ionic ratio 0.6.