Science.gov

Sample records for antimony tellurides

  1. Diameter Dependence of the Transport Properties of Antimony Telluride Nanowires

    NASA Astrophysics Data System (ADS)

    Zuev, Yuri; Lee, Jin Sook; Park, Hongkun; Kim, Philip

    2010-03-01

    We report measurements of electronic, thermoelectric, and galvanometric properties of individual semimetallic single crystal antimony telluride (Sb2Te3) nanowires. Microfabricated heater and thermometer electrodes were used to probe the transport properties of the nanowires with diameters in the range of 22 - 95nm and temperatures in the range of 2 - 300K. Temperature dependent resistivity varies depending on nanowire diameter. Thermoelectric power (TEP) measurements indicate hole dominant diffusive thermoelectric generation, with an enhancement of the TEP for smaller diameter wires. The large surface-to-volume ratio of Sb2Te3 nanowires makes them an excellent platform to explore novel phenomena in this predicted topological insulator. We investigate mesoscopic magnetoresistance effects in magnetic fields both parallel and perpendicular to the nanowire axis.

  2. Seebeck and figure of merit enhancement in nanostructured antimony telluride by antisite defect suppression through sulfur doping.

    PubMed

    Mehta, Rutvik J; Zhang, Yanliang; Zhu, Hong; Parker, David S; Belley, Matthew; Singh, David J; Ramprasad, Ramamurthy; Borca-Tasciuc, Theodorian; Ramanath, Ganpati

    2012-09-12

    Antimony telluride has a low thermoelectric figure of merit (ZT < ∼0.3) because of a low Seebeck coefficient α arising from high degenerate hole concentrations generated by antimony antisite defects. Here, we mitigate this key problem by suppressing antisite defect formation using subatomic percent sulfur doping. The resultant 10-25% higher α in bulk nanocrystalline antimony telluride leads to ZT ∼ 0.95 at 423 K, which is superior to the best non-nanostructured antimony telluride alloys. Density functional theory calculations indicate that sulfur increases the antisite formation activation energy and presage further improvements leading to ZT ∼ 2 through optimized doping. Our findings are promising for designing novel thermoelectric materials for refrigeration, waste heat recovery, and solar thermal applications. PMID:22891784

  3. Solid solutions based on bismuth and antimony tellurides andbismuth selenides

    SciTech Connect

    Abrikosov, N.K.; Stasova, M.M.

    1986-05-01

    The phase diagrams of the systems Bi-Te, Bi-Se, and Sb-Te serve as a basis for constructing multiphase diagrams of ternary semiconductor systems. This paper studies layered structures with large unit-cell parameters in the regions of the solid solutions to explain the ordering processes in the solid solutions of semiconductor and intermetallic systems. The laws governing the formation and structral features of bismuth and antimony chalcogenides are studied to obtain thermoelectric materials and identification of minerals.

  4. Antimony as an amphoteric dopant in lead telluride

    SciTech Connect

    Jaworski, Christopher M.; Tobola, Janusz; Levin, E.M.; Schmidt-Rohr, Klaus; Heremans, Joseph P.

    2009-09-24

    We elucidate the amphoteric nature of antimony as a dopant in PbTe. Band-structure calculations show that Sb substituting for Pb is a donor and that Sb on the Te site is an acceptor giving rise to a large excess density of states (DOS). Experimentally, in Te-rich Pb{sub 1-x}Sb{sub x}Te samples, {sup 125}Te NMR spectroscopy shows that Sb substitutes for Pb and transport data reveal that it then acts as a simple donor. In Pb-rich PbSb{sub x}Te{sub 1-x} samples, {sup 125}Te NMR shows that little Sb substitutes for Te when samples are prepared above 770 K and then quenched; {sup 207}Pb NMR shows four types of charge carriers, but only a majority hole and a minority electron contribute to transport. Sb acts as an acceptor in PbSb{sub x}Te{sub 1-x}, but the large DOS calculated must correspond to a large concentration of localized holes and the Seebeck coefficient is not enhanced.

  5. Suppression of Grain Growth by Additive in Nanostructured P-type Bismuth Antimony Tellurides

    SciTech Connect

    Zhang, Qian; Zhang, Qinyong; Chen, S.; Liu, W S; Lukas, K; Yan, X; Wang, H; Wang, D.; Opeil, C; Chen, Gang; Ren, Z. F.

    2011-01-01

    Grain growth is a major issue in the preparation of nanostructured bismuth-antimony-tellurides during hot pressing the nanopowders into dense bulk samples. To prevent grain agglomeration during ball milling and growth during hot pressing, organic agent (Oleic Acid, OA) as additive was added into the materials at the beginning of the ball milling process. With different concentrations of OA (0.5, 1.0, 1.5, 2.0, and 2.5 wt%), grains with different sizes are obtained. Structural analysis clearly shows that it is the particle size of the nanopowders that determines the final grain size in the densely compacted bulk samples. A combination of small grains ~200–500 nm and nanopores leads to effective phonon scattering, which results in the decrease of lattice thermal conductivity, and ZT of ~1.3 at 373 K for the sample with 2.0 wt% OA.

  6. Antimony

    Integrated Risk Information System (IRIS)

    Antimony ; CASRN 7440 - 36 - 0 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Effects

  7. Nanoscale arrays of antimony telluride single crystals by selective chemical vapor deposition

    PubMed Central

    Huang, Ruomeng; Benjamin, Sophie L.; Gurnani, Chitra; Wang, Yudong; Hector, Andrew L.; Levason, William; Reid, Gillian; De Groot, C. H. (Kees)

    2016-01-01

    Arrays of individual single nanocrystals of Sb2Te3 have been formed using selective chemical vapor deposition (CVD) from a single source precursor. Crystals are self-assembled reproducibly in confined spaces of 100 nm diameter with pitch down to 500 nm. The distribution of crystallite sizes across the arrays is very narrow (standard deviation of 15%) and is affected by both the hole diameter and the array pitch. The preferred growth of the crystals in the <1 1 0> orientation along the diagonal of the square holes strongly indicates that the diffusion of adatoms results in a near thermodynamic equilibrium growth mechanism of the nuclei. A clear relationship between electrical resistivity and selectivity is established across a range of metal selenides and tellurides, showing that conductive materials result in more selective growth and suggesting that electron donation is of critical importance for selective deposition. PMID:27283116

  8. Nanoscale arrays of antimony telluride single crystals by selective chemical vapor deposition.

    PubMed

    Huang, Ruomeng; Benjamin, Sophie L; Gurnani, Chitra; Wang, Yudong; Hector, Andrew L; Levason, William; Reid, Gillian; De Groot, C H Kees

    2016-01-01

    Arrays of individual single nanocrystals of Sb2Te3 have been formed using selective chemical vapor deposition (CVD) from a single source precursor. Crystals are self-assembled reproducibly in confined spaces of 100 nm diameter with pitch down to 500 nm. The distribution of crystallite sizes across the arrays is very narrow (standard deviation of 15%) and is affected by both the hole diameter and the array pitch. The preferred growth of the crystals in the <1 1 0> orientation along the diagonal of the square holes strongly indicates that the diffusion of adatoms results in a near thermodynamic equilibrium growth mechanism of the nuclei. A clear relationship between electrical resistivity and selectivity is established across a range of metal selenides and tellurides, showing that conductive materials result in more selective growth and suggesting that electron donation is of critical importance for selective deposition. PMID:27283116

  9. Nanoscale arrays of antimony telluride single crystals by selective chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Huang, Ruomeng; Benjamin, Sophie L.; Gurnani, Chitra; Wang, Yudong; Hector, Andrew L.; Levason, William; Reid, Gillian; de Groot, C. H. (Kees)

    2016-06-01

    Arrays of individual single nanocrystals of Sb2Te3 have been formed using selective chemical vapor deposition (CVD) from a single source precursor. Crystals are self-assembled reproducibly in confined spaces of 100 nm diameter with pitch down to 500 nm. The distribution of crystallite sizes across the arrays is very narrow (standard deviation of 15%) and is affected by both the hole diameter and the array pitch. The preferred growth of the crystals in the <1 1 0> orientation along the diagonal of the square holes strongly indicates that the diffusion of adatoms results in a near thermodynamic equilibrium growth mechanism of the nuclei. A clear relationship between electrical resistivity and selectivity is established across a range of metal selenides and tellurides, showing that conductive materials result in more selective growth and suggesting that electron donation is of critical importance for selective deposition.

  10. Effects of chemical intermixing on electrical and thermal contact conductances at metallized bismuth and antimony telluride interfaces

    SciTech Connect

    Devender,; Mehta, Rutvik J.; Ramanath, Ganpati; Lofgreen, Kelly; Mahajan, Ravi; Yamaguchi, Masashi; Borca-Tasciuc, Theodorian

    2015-03-15

    Tailoring electrical and thermal contact conductivities (Σ{sub c} and Γ{sub c}) across metallized pnictogen chalcogenide interfaces is key for realizing efficient thermoelectric devices. The authors report that Cu, Ni, Ti, and Ta diffusion and interfacial telluride formation with n-Bi{sub 2}Te{sub 3} and p-Sb{sub 2}Te{sub 3} influence both Σ{sub c} and Γ{sub c}. Cu metallization yields the highest Γ{sub c} and the lowest Σ{sub c}, correlating with maximal metal diffusion and copper telluride formation. Ni diffuses less and yields the highest Σ{sub c} with Sb{sub 2}Te{sub 3} due to p-type nickel telluride formation, which diminishes Σ{sub c} improvement with n-Bi{sub 2}Te{sub 3} interfaces. Ta and Ti contacts yield the lowest properties similar to that in Ni-metallized structures. These correlations between interfacial diffusion and phase formation on electronic and thermal transport properties will be important for devising suitable metallization for thermoelectric devices.

  11. Enhanced Thermoelectric Properties of Antimony Telluride Thin Films with Preferred Orientation Prepared by Sputtering a Fan-Shaped Binary Composite Target

    NASA Astrophysics Data System (ADS)

    Zheng, Zhuang-hao; Fan, Ping; Luo, Jing-ting; Liang, Guang-xing; Zhang, Dong-ping

    2013-12-01

    p-Type antimony telluride (Sb2Te3) thermoelectric thin films were deposited on BK7 glass substrates by ion beam sputter deposition using a fan-shaped binary composite target. The deposition temperature was varied from 100°C to 300°C in increments of 50°C. The influence of the deposition temperature on the microstructure, surface morphology, and thermoelectric properties of the thin films was systematically investigated. x-Ray diffraction results show that various alloy composition phases of the Sb2Te3 materials are grown when the deposition temperature is lower than 200°C. Preferred c-axis orientation of the Sb2Te3 thin film became obvious when the deposition temperature was above 200°C, and thin film with single-phase Sb2Te3 was obtained when the deposition temperature was 250°C. Scanning electron microscopy reveals that the average grain size of the films increases with increasing deposition temperature and that the thin film deposited at 250°C shows rhombohedral shape corresponding to the original Sb2Te3 structure. The room-temperature Seebeck coefficient and electrical conductivity range from 101 μV K-1 to 161 μV K-1 and 0.81 × 103 S cm-1 to 3.91 × 103 S cm-1, respectively, as the deposition temperature is increased from 100°C to 300°C. An optimal power factor of 6.12 × 10-3 W m-1 K-2 is obtained for deposition temperature of 250°C. The thermoelectric properties of Sb2Te3 thin films have been found to be strongly enhanced when prepared using the fan-shaped binary composite target method with an appropriate substrate temperature.

  12. Mercury Telluride and Cadmium Telluride

    NASA Technical Reports Server (NTRS)

    2004-01-01

    A semiconductor's usefulness is determined by how atoms are ordered within the crystal's underlying three-dimensional structure. While this mercury telluride and cadmium telluride alloy sample mixes completely in Earth -based laboratories, convective flows prevent them from mixing uniformly.

  13. Mercury Telluride and Cadmium Telluride

    NASA Technical Reports Server (NTRS)

    2004-01-01

    A semiconductor's usefulness is determined by how atoms are ordered within the crystal's underlying three-dimensional structure. While this mercury telluride and cadmium telluride alloy sample mixes completely in Earth -based laboratories, convective flows prevent them from mixing uniformly. In space, the ingredients mix more homogenously, resulting in a superior product.

  14. Antimony Toxicity

    PubMed Central

    Sundar, Shyam; Chakravarty, Jaya

    2010-01-01

    Antimony toxicity occurs either due to occupational exposure or during therapy. Occupational exposure may cause respiratory irritation, pneumoconiosis, antimony spots on the skin and gastrointestinal symptoms. In addition antimony trioxide is possibly carcinogenic to humans. Improvements in working conditions have remarkably decreased the incidence of antimony toxicity in the workplace. As a therapeutic, antimony has been mostly used for the treatment of leishmaniasis and schistosomiasis. The major toxic side-effects of antimonials as a result of therapy are cardiotoxicity (~9% of patients) and pancreatitis, which is seen commonly in HIV and visceral leishmaniasis co-infections. Quality control of each batch of drugs produced and regular monitoring for toxicity is required when antimonials are used therapeutically. PMID:21318007

  15. Antimony trioxide

    Integrated Risk Information System (IRIS)

    Antimony trioxide ; CASRN 1309 - 64 - 4 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogeni

  16. Antimony: a flame fighter

    USGS Publications Warehouse

    Wintzer, Niki E.; Guberman, David E.

    2015-01-01

    In the 11th century, the word antimonium was used by medieval scholar Constantinus Africanus, but antimony metal was not isolated until the 16th century by Vannoccio Biringuccio, an Italian metallurgist. In the early 18th century, chemist Jons Jakob Berzelius chose the periodic symbol for antimony (Sb) based on stibium, which is the Latin name for stibnite.

  17. Chalcogenide Cobalt telluride nanotubes

    NASA Astrophysics Data System (ADS)

    Dahal, Bishnu; Dulal, Rajendra; Pegg, Ian L.; Philip, John

    Cobalt telluride nanotubes are grown using wet chemical and hydrothermal syntheses. Wet chemical synthesized nanotubes display nearly 1: 1 Co to Te ratio. On the other hand, CoTe nanotubes synthesized using hydrothermal method show excess Co content leading to the compound Co58Te42. Both CoTe and Co58Te42 display magnetic properties, but with totally different characteristics. The Curie temperature of CoTe is higher than 400 K. However, the Tc of Co58Te42 is below 50 K. Transport properties of cobalt telluride (CoTe) nanotube devices show that they exhibit p-type semiconducting behavior. The magnetoresistance measured at 10 K show a magnetoresistance of 54%. . National Science Foundation under ECCS-0845501 and NSF-MRI, DMR-0922997.

  18. Hafnium germanium telluride

    PubMed Central

    Jang, Gyung-Joo; Yun, Hoseop

    2008-01-01

    The title hafnium germanium telluride, HfGeTe4, has been synthesized by the use of a halide flux and structurally characterized by X-ray diffraction. HfGeTe4 is isostructural with stoichiometric ZrGeTe4 and the Hf site in this compound is also fully occupied. The crystal structure of HfGeTe4 adopts a two-dimensional layered structure, each layer being composed of two unique one-dimensional chains of face-sharing Hf-centered bicapped trigonal prisms and corner-sharing Ge-centered tetra­hedra. These layers stack on top of each other to complete the three-dimensional structure with undulating van der Waals gaps. PMID:21202163

  19. Oligosilanylated Antimony Compounds

    PubMed Central

    2015-01-01

    By reactions of magnesium oligosilanides with SbCl3, a number of oligosilanylated antimony compounds were obtained. When oligosilanyl dianions were used, either the expected cyclic disilylated halostibine was obtained or alternatively the formation of a distibine was observed. Deliberate formation of the distibine from the disilylated halostibine was achieved by reductive coupling with C8K. Computational studies of Sb–Sb bond energies, barriers of pyramidal inversion at Sb, and the conformational behavior of distibines provided insight for the understanding of the spectroscopic properties. PMID:25937691

  20. Thin film cadmium telluride solar cell

    SciTech Connect

    Mitchell, R.

    1987-03-17

    A photovoltaic cell is described comprising: (a) a substrate layer consisting of a transparent or semi-transparent material; (b) an n conductivity type layer of tin oxide contiguous to the substrate layer; (c) a rho conductivity type layer of polycrystalline cadmium telluride contiguous to the layer of tin oxide thereby forming a pn junction, the layer of cadmium telluride containing atoms of phosphorus; and (d) a layer of lead telluride contiguous to the layer of the cadmium telluride.

  1. Atomic layer deposition of metal tellurides and selenides using alkylsilyl compounds of tellurium and selenium.

    PubMed

    Pore, Viljami; Hatanpää, Timo; Ritala, Mikko; Leskelä, Markku

    2009-03-18

    Atomic layer deposition (ALD) of metal selenide and telluride thin films has been limited because of a lack of precursors that would at the same time be safe and exhibit high reactivity as required in ALD. Yet there are many important metal selenide and telluride thin film materials whose deposition by ALD might be beneficial, for example, CuInSe2 for solar cells and Ge2Sb2Te5 for phase-change random-access memories. Especially in the latter case highly conformal deposition offered by ALD is essential for high storage density. By now, ALD of germanium antimony telluride (GST) has been attempted only using plasma-assisted processes owing to the lack of appropriate tellurium precursors. In this paper we make a breakthrough in the development of new ALD precursors for tellurium and selenium. Compounds with a general formula (R3Si)2Te and (R3Si)2Se react with various metal halides forming the corresponding metal tellurides and selenides. As an example, we show that Sb2Te3, GeTe, and GST films can be deposited by ALD using (Et3Si)2Te, SbCl3, and GeCl2 x C4H8O2 compounds as precursors. All three precursors exhibit a typical saturative ALD growth behavior and GST films prepared at 90 degrees C show excellent conformality on a high aspect-ratio trench structure. PMID:19123860

  2. Thin film cadmium telluride solar cells

    SciTech Connect

    Chu, T.L.; Chu, S.S.; Xi, X.J.; Yang, Y.T.

    1983-05-01

    Cadmium telluride films have been deposited on coated graphite and mullite substrates by the direct combination of the vapors of the elements in a hydrogen atmosphere. The properties of nearly stoichiometric films on mullite substrates were measured by the van der Pauw technique in the temperature range of 25/sup 0/ - 150/sup 0/C. The deposition of n-type cadmium telluride by using hydrogen iodide as a dopant and the deposition of p-type cadmium telluride films by using arsine or phosphine as a dopant were studied. Schottky barrier solar cells were prepared from n-type cadmium telluride films and heterojunction cells from p-type cadmium telluride films.

  3. Cadmium telluride photovoltaic radiation detector

    DOEpatents

    Agouridis, D.C.; Fox, R.J.

    A dosimetry-type radiation detector is provided which employs a polycrystalline, chlorine-compensated cadmium telluride wafer fabricated to operate as a photovoltaic current generator used as the basic detecting element. A photovoltaic junction is formed in the wafer by painting one face of the cadmium telluride wafer with an n-type semi-conductive material. The opposite face of the wafer is painted with an electrically conductive material to serve as a current collector. The detector is mounted in a hermetically sealed vacuum containment. The detector is operated in a photovoltaic mode (zero bias) while DC coupled to a symmetrical differential current amplifier having a very low input impedance. The amplifier converts the current signal generated by radiation impinging upon the barrier surface face of the wafer to a voltage which is supplied to a voltmeter calibrated to read quantitatively the level of radiation incident upon the detecting wafer.

  4. Cadmium telluride photovoltaic radiation detector

    DOEpatents

    Agouridis, Dimitrios C.; Fox, Richard J.

    1981-01-01

    A dosimetry-type radiation detector is provided which employs a polycrystalline, chlorine-compensated cadmium telluride wafer fabricated to operate as a photovoltaic current generator used as the basic detecting element. A photovoltaic junction is formed in the wafer by painting one face of the cadmium telluride wafer with an n-type semiconductive material. The opposite face of the wafer is painted with an electrically conductive material to serve as a current collector. The detector is mounted in a hermetically sealed vacuum containment. The detector is operated in a photovoltaic mode (zero bias) while DC coupled to a symmetrical differential current amplifier having a very low input impedance. The amplifier converts the current signal generated by radiation impinging upon the barrier surface face of the wafer to a voltage which is supplied to a voltmeter calibrated to read quantitatively the level of radiation incident upon the detecting wafer.

  5. Extraction of antimony with tertiary amines.

    PubMed

    Alian, A; Sanad, W

    1967-06-01

    The extractability of antimony(III) and (V) with tridodecylamine from various aqueous solutions is reported. Extraction from nitric and hydrofluoric acid solutions is low, but extraction from sulphuric, hydrochloric and hydrobromic solutions is high. Antimony-(III) can be separated from antimony(V) in 7M nitric acid or 0.64M hydrobromic acid. The extraction of antimony from hydrochloric acid solutions in methanol, ethanol, and acetone-water mixtures is greater than from pure aqueous solutions of the same acidity. The elements from which antimony can be separated with tertiary amines are given. PMID:18960147

  6. Mineral Resource of the Month: Antimony

    USGS Publications Warehouse

    Guberman, David E.

    2015-01-01

    Antimony is a lustrous silvery-white semimetal or metalloid. Archaeological and historical studies indicate that antimony and its mineral sulfides have been used by humans for at least six millennia. The alchemist Basil Valentine is sometimes credited with “discovering” the element; he described the extraction of metallic antimony from stibnite in his treatise “The Triumphal Chariot of Antimony,” published sometime between 1350 and 1600. In the early 18th century, Jöns Jakob Berzelius chose the periodic symbol for antimony (Sb) based on stibium, which is the Latin name for stibnite.

  7. Phonon dynamics of americium telluride

    NASA Astrophysics Data System (ADS)

    Arya, B. S.; Aynyas, Mahendra; Ahirwar, Ashok K.; Sanyal, S. P.

    2013-06-01

    We report for the first time the complete phonon dispersion curves for Americium telluride (AmTe) using a breathing shell models (BSM) to establish their predominant ionic nature. The results obtained in the present study show the general features of the phonon spectrum. We could not compare our results with the experimental measurements as they are not available so far. We emphasize the need of neutron scattering measurements to compare our results. We also report, for the first time specific heat for this compound.

  8. Thin film cadmium telluride, zinc telluride, and mercury zinc telluride solar cells

    SciTech Connect

    Chu, T.L. )

    1992-04-01

    This report describes research to demonstrate (1) thin film cadmium telluride solar cells with a quantum efficiency of 75% or higher at 0. 44 {mu}m and a photovoltaic efficiency of 11.5% or greater, and (2) thin film zinc telluride and mercury zinc telluride solar cells with a transparency to sub-band-gap radiation of 65% and a photovoltaic conversion efficiency of 5% and 8%, respectively. Work was directed at (1) depositing transparent conducting semiconductor films by solution growth and metal-organic chemical vapor deposition (MOCVD) technique, (2) depositing CdTe films by close-spaced sublimation (CSS) and MOCVD techniques, (3) preparing and evaluating thin film CdTe solar cells, and (4) preparing and characterizing thin film ZnTe, CD{sub 1-x}Zn{sub 1-x}Te, and Hg{sub 1-x}Zn{sub x}Te solar cells. The deposition of CdS films from aqueous solutions was investigated in detail, and their crystallographic, optical, and electrical properties were characterized. CdTe films were deposited from DMCd and DIPTe at 400{degrees}C using TEGa and AsH{sub 3} as dopants. CdTe films deposited by CSS had significantly better microstructures than those deposited by MOCVD. Deep energy states in CdTe films deposited by CSS and MOCVD were investigated. Thin films of ZnTe, Cd{sub 1- x}Zn{sub x}Te, and Hg{sub 1-x}Zn{sub x}Te were deposited by MOCVD, and their crystallographic, optical, and electrical properties were characterized. 67 refs.

  9. 40 CFR 421.140 - Applicability: Description of the primary antimony subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... primary antimony subcategory. 421.140 Section 421.140 Protection of Environment ENVIRONMENTAL PROTECTION... CATEGORY Primary Antimony Subcategory § 421.140 Applicability: Description of the primary antimony... antimony at primary antimony facilities....

  10. 40 CFR 421.140 - Applicability: Description of the primary antimony subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... primary antimony subcategory. 421.140 Section 421.140 Protection of Environment ENVIRONMENTAL PROTECTION... CATEGORY Primary Antimony Subcategory § 421.140 Applicability: Description of the primary antimony... antimony at primary antimony facilities....

  11. 40 CFR 421.140 - Applicability: Description of the primary antimony subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... primary antimony subcategory. 421.140 Section 421.140 Protection of Environment ENVIRONMENTAL PROTECTION... CATEGORY Primary Antimony Subcategory § 421.140 Applicability: Description of the primary antimony... antimony at primary antimony facilities....

  12. Process for producing large grain cadmium telluride

    DOEpatents

    Hasoon, F.S.; Nelson, A.J.

    1996-01-16

    A process is described for producing a cadmium telluride polycrystalline film having grain sizes greater than about 20 {micro}m. The process comprises providing a substrate upon which cadmium telluride can be deposited and placing that substrate within a vacuum chamber containing a cadmium telluride effusion cell. A polycrystalline film is then deposited on the substrate through the steps of evacuating the vacuum chamber to a pressure of at least 10{sup {minus}6} torr.; heating the effusion cell to a temperature whereat the cell releases stoichiometric amounts of cadmium telluride usable as a molecular beam source for growth of grains on the substrate; heating the substrate to a temperature whereat a stoichiometric film of cadmium telluride can be deposited; and releasing cadmium telluride from the effusion cell for deposition as a film on the substrate. The substrate then is placed in a furnace having an inert gas atmosphere and heated for a sufficient period of time at an annealing temperature whereat cadmium telluride grains on the substrate grow to sizes greater than about 20 {micro}m.

  13. Process for producing large grain cadmium telluride

    DOEpatents

    Hasoon, Falah S.; Nelson, Art J.

    1996-01-01

    A process for producing a cadmium telluride polycrystalline film having grain sizes greater than about 20 .mu.m. The process comprises providing a substrate upon which cadmium telluride can be deposited and placing that substrate within a vacuum chamber containing a cadmium telluride effusion cell. A polycrystalline film is then deposited on the substrate through the steps of evacuating the vacuum chamber to a pressure of at least 10.sup.-6 torr.; heating the effusion cell to a temperature whereat the cell releases stoichiometric amounts of cadmium telluride usable as a molecular beam source for growth of grains on the substrate; heating the substrate to a temperature whereat a stoichiometric film of cadmium telluride can be deposited; and releasing cadmium telluride from the effusion cell for deposition as a film on the substrate. The substrate then is placed in a furnace having an inert gas atmosphere and heated for a sufficient period of time at an annealing temperature whereat cadmium telluride grains on the substrate grow to sizes greater than about 20 .mu.m.

  14. Observations on the measurement of total antimony and antimony species in algae, plant and animal tissues.

    PubMed

    Foster, S; Maher, W; Krikowa, F; Telford, K; Ellwood, M

    2005-12-01

    This paper describes our experiences with undertaking measurements of total antimony and antimony speciation in algae, plant and animal tissues. Digestion with nitric acid alone is suitable to release antimony from animal tissues. When organisms have high silica contents, e.g. some plants and algae, the addition of tetrafluorboric acid is required to dissolve silica as some antimony is retained by silica in extracts. Antimony in digested extracts is present as Sb5+ and hydride generation procedures can be used to determine total antimony concentrations, as total antimony in extracts will not be under estimated. Relatively non-aggressive solvents such as water, dilute nitric acid, sodium hydroxide and enzymes remove highly variable amounts of antimony (2-84%) from algae, plant and animal tissues. Addition of Sb3+ and Sb5+ to NIST CRM 1572 Citrus Leaves, pre- and post-extraction with water showed that Sb3+ is oxidised to Sb5+ while Sb5+ is redistributed amongst binding sites giving rise to artefacts. DOLT-2 and algae extracts indicated the presence of only inorganic antimony. A moss sample had inorganic antimony and a number of unknown antimony species in extracts. Future studies should explore the nature of the binding of antimony in tissues as solvents commonly used to extract metals and metalloids from algae, plant and animal tissues are not appropriate. PMID:16307074

  15. Research support for cadmium telluride crystal growth

    NASA Technical Reports Server (NTRS)

    Rosenberger, Franz; Banish, Michael

    1993-01-01

    Work performed during the period 11 Feb. 1992 to 10 Aug. 1993 on research support for cadmium telluride crystal growth is reported. Work on chemical impurity characterization and mass spectroscopy is described.

  16. Process for producing cadmium sulfide on a cadmium telluride surface

    DOEpatents

    Levi, Dean H.; Nelson, Art J.; Ahrenkiel, Richard K.

    1996-01-01

    A process for producing a layer of cadmium sulfide on a cadmium telluride surface to be employed in a photovoltaic device. The process comprises providing a cadmium telluride surface which is exposed to a hydrogen sulfide plasma at an exposure flow rate, an exposure time and an exposure temperature sufficient to permit reaction between the hydrogen sulfide and cadmium telluride to thereby form a cadmium sulfide layer on the cadmium telluride surface and accomplish passivation. In addition to passivation, a heterojunction at the interface of the cadmium sulfide and the cadmium telluride can be formed when the layer of cadmium sulfide formed on the cadmium telluride is of sufficient thickness.

  17. ANTIMONY REMOVAL TECHNOLOGY FOR MINING INDUSTRY WASTEWATERS

    EPA Science Inventory

    This report assessed the current state-of-the-art of antimony removal technology for mining industry wastewaters. Through literature review and personal interviews, it was found that most mines and mills reporting significant quantities of antimony in their raw wastewater had app...

  18. Mineral resource of the month: antimony

    USGS Publications Warehouse

    U.S. Geological Survey

    2008-01-01

    The article describes the characteristics and industrial uses of antimony. Antimony, which is produced as a byproduct of mining other metals such as gold, lead or silver, is used in everything from flame retardants, batteries, ceramics and glass. It is also used in glass for television picture tubes, computer monitors, pigments and catalysts.

  19. 21 CFR 862.3110 - Antimony test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Antimony test system. 862.3110 Section 862.3110....3110 Antimony test system. (a) Identification. An antimony test system is a device intended to measure antimony, a heavy metal, in urine, blood, vomitus, and stomach contents. Measurements obtained by...

  20. 21 CFR 862.3110 - Antimony test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Antimony test system. 862.3110 Section 862.3110....3110 Antimony test system. (a) Identification. An antimony test system is a device intended to measure antimony, a heavy metal, in urine, blood, vomitus, and stomach contents. Measurements obtained by...

  1. 21 CFR 862.3110 - Antimony test system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Antimony test system. 862.3110 Section 862.3110....3110 Antimony test system. (a) Identification. An antimony test system is a device intended to measure antimony, a heavy metal, in urine, blood, vomitus, and stomach contents. Measurements obtained by...

  2. 21 CFR 862.3110 - Antimony test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Antimony test system. 862.3110 Section 862.3110....3110 Antimony test system. (a) Identification. An antimony test system is a device intended to measure antimony, a heavy metal, in urine, blood, vomitus, and stomach contents. Measurements obtained by...

  3. 21 CFR 862.3110 - Antimony test system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Antimony test system. 862.3110 Section 862.3110....3110 Antimony test system. (a) Identification. An antimony test system is a device intended to measure antimony, a heavy metal, in urine, blood, vomitus, and stomach contents. Measurements obtained by...

  4. Temperature-dependent ordering phenomena in single crystals of germanium antimony tellurides

    SciTech Connect

    Urban, Philipp; Schneider, Matthias N.; Oeckler, Oliver

    2015-07-15

    The temperature-dependent behavior of quenched single-crystalline (GeTe){sub n}Sb{sub 2}Te{sub 3} (n~2.8, n~5 and n~11) was investigated by semiquantitative modeling of diffuse X-ray scattering. The structure at room temperature exhibits trigonal twin domains, each comprising a stacking-disordered sequence of distorted rocksalt-type slabs with variable thicknesses. Ge and Sb share the cation position and vacancies are partially ordered in defect layers (van der Waals gaps) between the slabs. The average structure determined with resonant diffraction data corresponds to a rocksalt-type structure whose cation position is split along the stacking direction. Upon heating, cation ordering leads to a metastable superstructure of the rocksalt type at ~400 °C, which transforms to a rocksalt-type high-temperature phase with randomly distributed cations and vacancies at ~500 °C; this structure was also refined using resonant diffraction. Cooling at high or intermediate rates does not yield the long-range ordered phase, but directly leads to the twinned disordered phase. - Graphical abstract: Development of the diffraction patterns of (GeTe){sub ~11}Sb{sub 2}Te{sub 3} upon heating; the insets symbolically sketch the real structure at the corresponding temperatures. - Highlights: • The structure of disordered (GeTe){sub n}Sb{sub 2}Te{sub 3} is described as a function of temperature. • Structural changes are tracked by modeling diffuse X-ray scattering. • Quenched crystals exhibit distorted NaCl-type slabs with different thicknesses. • Vacancy ordering upon heating leads to a metastable superstructure of the NaCl type. • Further heating leads to an undistorted disordered NaCl-type high-temperature phase.

  5. Novel superstructure of the rocksalt type and element distribution in germanium tin antimony tellurides

    SciTech Connect

    Rosenthal, Tobias; Welzmiller, Simon; Neudert, Lukas; Urban, Philipp; Fitch, Andy; Oeckler, Oliver

    2014-11-15

    A superstructure of the rocksalt-type observed in quenched CVT-grown single crystals of Ge{sub 3.25(7)}Sn{sub 1.10(3)}Sb{sub 1.10(3)}Te{sub 6} was elucidated by X-ray diffraction using fourfold twinned crystals (space group P3{sup ¯}m1, a=4.280(1) Å, c=20.966(3) Å). The structure is built up of distorted rocksalt-type building blocks typical for long-range ordered GST materials and substitution variants thereof. In contrast to those phases, an exclusive ABC-type cubic stacking sequence of the Te-atom layers is present. High-resolution electron microscopy reveals spheroidal domains with this structure (average diameter 25 nm) whose stacking direction is perpendicular to the 〈1 1 1〉 directions of the basic rocksalt-type structure. Additional slab-like domains with a lateral extension up to 1 µm occasionally result in a hierarchical structure motif. Due to the similar electron counts of the elements involved, resonant diffraction was used in order to elucidate the element distribution in rocksalt-type building blocks of the stable layered compound 39R-Ge{sub 3}SnSb{sub 2}Te{sub 7} (R3{sup ¯}m, a=4.24990(4) Å, c=73.4677(9) Å). Sb tends to occupy the atom site close to the van der Waals gaps while Ge concentrates in the center of the building blocks. - Graphical abstract: High-resolution transmission electron micrograph, SAED pattern and reciprocal lattice section of X-ray single crystal data of Ge{sub 3.25}Sn{sub 1.1}Sb{sub 1.1}Te{sub 6} with an 11P-type superstructure of the rocksalt type. - Highlights: • A novel superstructure of the rocksalt-type in the system Ge–Sn–Sb–Te is elucidated. • It combines the cubic stacking of the HT phase with building blocks of the RT phase. • It indicates the ordering mechanism during the phase transition of GST materials. • A hierarchical structure motif is promising with respect to the reduction of κ{sub L}. • Resonant diffraction reveals the element distribution in 39R-Ge{sub 3}SnSb{sub 2}Te{sub 7}.

  6. Layered germanium tin antimony tellurides: element distribution, nanostructures and thermoelectric properties.

    PubMed

    Welzmiller, Simon; Rosenthal, Tobias; Ganter, Pirmin; Neudert, Lukas; Fahrnbauer, Felix; Urban, Philipp; Stiewe, Christian; de Boor, Johannes; Oeckler, Oliver

    2014-07-21

    In the system Ge-Sn-Sb-Te, there is a complete solid solution series between GeSb2Te4 and SnSb2Te4. As Sn2Sb2Te5 does not exist, Sn can only partially replace Ge in Ge2Sb2Te5; samples with 75% or more Sn are not homogeneous. The joint refinement of high-resolution synchrotron data measured at the K-absorption edges of Sn, Sb and Te combined with data measured at off-edge wavelengths unambiguously yields the element distribution in 21R-Ge(0.6)Sn(0.4)Sb2Te4 and 9P-Ge(1.3)Sn(0.7)Sb2Te5. In both cases, Sb predominantly concentrates on the position near the van der Waals gaps between distorted rocksalt-type slabs whereas Ge prefers the position in the middle of the slabs. No significant antisite disorder is present. Comparable trends can be found in related compounds; they are due to the single-side coordination of the Te atoms at the van der Waals gap, which can be compensated more effectively by Sb(3+) due to its higher charge in comparison to Ge(2+). The structure model of 21R-Ge(0.6)Sn(0.4)Sb2Te4 was confirmed by high-resolution electron microscopy and electron diffraction. In contrast, electron diffraction patterns of 9P-Ge(1.3)Sn(0.7)Sb2Te5 reveal a significant extent of stacking disorder as evidenced by diffuse streaks along the stacking direction. The Seebeck coefficient is unaffected by the Sn substitution but the thermal conductivity drops by a factor of 2 which results in a thermoelectric figure of merit ZT = ~0.25 at 450 °C for both Ge(0.6)Sn(0.4)Sb2Te4 and Ge(1.3)Sn(0.7)Sb2Te5, which is higher than ~0.20 for unsubstituted stable layered Ge-Sb-Te compounds. PMID:24681809

  7. Decoupling electrical and thermal properties in antimony telluride based artificial multilayer for high thermoelectric performance

    NASA Astrophysics Data System (ADS)

    Zheng, Wenwen; Yang, Dongwang; Wei, Wei; Liu, Fengming; Tang, Xinfeng; Shi, Jing; Wang, Ziyu; Xiong, Rui

    2015-11-01

    In this work, Sb2Te3/Poly(3,4-ethylenedioxythiophene)/Sb2Te3 sandwich structure was artificially fabricated. This leads to a simultaneous increase of electrical conductivity and decrease of thermal conductivity by tailoring electric flow along the more-electrically conductive parallel path and thermal flow blocked across the less-thermally conductive perpendicular direction. The maximum of thermoelectric figure of merit was increased by 116%, reaching 1.3 at 523 K.

  8. Reaction Mechanism Underlying Atomic Layer Deposition of Antimony Telluride Thin Films.

    PubMed

    Han, Byeol; Kim, Yu-Jin; Park, Jae-Min; Yusup, Luchana L; Ishii, Hana; Lansalot-Matras, Clement; Lee, Won-Jun

    2016-05-01

    The mechanism underlying the deposition of SbTe films by alternating exposures to Sb(NMe2)3 and Te(GeMe3)2 was investigated. Sb(NMe2)3 and Te(GeMe3)2 were selected because they have very high vapor pressure and are free of Si, Cl, and O atoms in the molecules. The mechanism of deposition was proposed by density functional theory (DFT) calculation and was verified by in-situ quartz crystal microbalance (QCM) analysis. DFT calculation expected the ligand-exchange reactions between the Sb and Te precursors to form Me2NGeMe3 as the byproduct. QCM analysis indicated that a single -NMe2 group in Sb(NMe2)3 reacts with -TeGeMe3 on the surface to form an Sb2Te3 film, and that a small fraction of Sb is incorporated into the film by the thermal decomposition of Sb(NMe2)3. The Te(GeMe3)2 molecules were thermally stable up to 120 degrees C, while the Sb(NMe2)3 molecules decomposed at temperatures of 60 degrees C and higher. Sb-rich SbTe films with different Sb contents were prepared by controlling the partial decomposition of Sb(NMe2)3 molecules, which was enhanced by increasing the pulse time of the precursor. PMID:27483847

  9. Novel superstructure of the rocksalt type and element distribution in germanium tin antimony tellurides

    NASA Astrophysics Data System (ADS)

    Rosenthal, Tobias; Welzmiller, Simon; Neudert, Lukas; Urban, Philipp; Fitch, Andy; Oeckler, Oliver

    2014-11-01

    A superstructure of the rocksalt-type observed in quenched CVT-grown single crystals of Ge3.25(7)Sn1.10(3)Sb1.10(3)Te6 was elucidated by X-ray diffraction using fourfold twinned crystals (space group P3barm1, a=4.280(1) Å, c=20.966(3) Å). The structure is built up of distorted rocksalt-type building blocks typical for long-range ordered GST materials and substitution variants thereof. In contrast to those phases, an exclusive ABC-type cubic stacking sequence of the Te-atom layers is present. High-resolution electron microscopy reveals spheroidal domains with this structure (average diameter 25 nm) whose stacking direction is perpendicular to the <1 1 1> directions of the basic rocksalt-type structure. Additional slab-like domains with a lateral extension up to 1 μm occasionally result in a hierarchical structure motif. Due to the similar electron counts of the elements involved, resonant diffraction was used in order to elucidate the element distribution in rocksalt-type building blocks of the stable layered compound 39R-Ge3SnSb2Te7 (R3barm, a=4.24990(4) Å, c=73.4677(9) Å). Sb tends to occupy the atom site close to the van der Waals gaps while Ge concentrates in the center of the building blocks.

  10. Template synthesis of bismuth telluride nanowires. Interim report

    SciTech Connect

    Sapp, S.A.; Lakshmi, B.B.; Martin, C.R.

    1998-12-01

    The authors report the fabrication of thermoelectric bismuth telluride nanowires using the template synthesis method. A simple electrodeposition procedure was used to produce the nanowires within the pores of an alumina filtration membrane. The resulting bismuth telluride/alumina composite membranes constitute an array of thermoelectric nanowires surrounded by a thermally and electrically insulating matrix. The individual bismuth telluride nanowires can be isolated by removal of the template membrane. These nanowires were characterized and found to be composed of stoichiometric bismuth telluride.

  11. Antimony and silicon environments in antimony silicate glasses

    SciTech Connect

    Mee, M.; Davies, B.C.; Orman, R.G.; Thomas, M.F.; Holland, D.

    2010-09-15

    Antimony silicate glasses, of general formula xSb{sub 2}O{sub 3}.(1-x)SiO{sub 2} (0.1{<=}x{<=}0.78), have been prepared by melt-quenching and their structures studied using {sup 29}Si MAS NMR spectroscopy, {sup 121}Sb Moessbauer spectroscopy and Raman spectroscopy. Oxidation during melting gives rise to Sb{sup 5+} in concentrations, which increase linearly with x to give a value of {approx}10% when x=0.78. {sup 121}Sb Moessbauer spectra show Moessbauer shifts and quadrupole splittings consistent with Sb{sup 3+} in a [:SbO{sub 3}] trigonal pyramid, similar to that in crystalline Sb{sub 2}O{sub 3}. A broad band in the Raman spectrum at {approx}410 cm{sup -1} is due to the vibrations of such a unit. The dependence of the silicon Q{sup n} speciation on x can be interpreted by the formation of Sb-O-Sb links possibly to form rings of 4 [:SbO{sub 3}] units such as are found in valentinite. - Graphical abstract: Antimony silicate glasses have been shown to contain Sb{sup 3+} in [:SbO{sub 3}] trigonal pyramid units using {sup 121}Sb Moessbauer spectroscopy and Raman spectroscopy. {sup 29}Si magic-angle-spinning NMR has shown silicon Q{sup n} speciation which can be interpreted as formation of rings of 4 [:SbO{sub 3}] units such as are found in valentinite.

  12. Electrodeposition and Characterization of Bismuth Telluride Nanowires

    NASA Astrophysics Data System (ADS)

    Frantz, C.; Stein, N.; Gravier, L.; Granville, S.; Boulanger, C.

    2010-09-01

    In this work, we report thermoelectric measurements on electroplated bismuth telluride nanowires. Porous polycarbonate membranes, obtained by ion-track irradiation lithography, were chosen as electroplating templates. Bismuth telluride nanowires were achieved in acidic media under potentiostatic conditions at -100 mV versus saturated silver chloride electrode. The filling ratio of the pores was increased to 80% by adding dimethyl sulfoxide to the electrolyte. Whatever the experimental conditions, the nanowires were polycrystalline in the rhombohedral phase of Bi2Te3. Finally, the power output of arrays of bismuth telluride nanowires was analyzed as a function of load resistance. The results were strongly dependent on the internal resistance, which can be significantly reduced by the presence of dimethyl sulfoxide during electroplating.

  13. Floating zone melting of cadmium telluride

    NASA Technical Reports Server (NTRS)

    Chang, Wen-Ming; Regel, L. L.; Wilcox, W. R.

    1992-01-01

    To produce superior crystals of cadmium telluride, floating zone melting in space has been proposed. Techniques required for floating zone melting of cadmium telluride are being developed. We have successfully float-zoned cadmium telluride on earth using square rods. A resistance heater was constructed for forming the molten zone. Evaporation of the molten zone was controlled by adding excess cadmium to the growth ampoule combined with heating of the entire ampoule. An effective method to hold the feed rod was developed. Slow rotation of the growth ampoule was proven experimentally to be necessary to achieve a complete symmetric molten zone. Most of the resultant cylindrical rods were single crystals with twins. Still needed is a suitable automatic method to control the zone length. We tried a fiber optical technique to control the zone length, but experiments showed that application of this technique to automate zone length control is unlikely to be successful.

  14. Improvement of the Thermoelectric Figure-of-Merit of a Doped Telluride Nanocomposite by Combining Phonon Scattering with Grain Boundary-Modifying Zn-Containing Nanostructures

    NASA Astrophysics Data System (ADS)

    Rowe, Michael P.; Zhou, Li Qin; Banerjee, Debasish; Zhang, Minjuan

    2015-01-01

    Recovery of waste heat from internal combustion engines is one strategy for meeting the ever increasing demand for more fuel efficient-automobiles. Thermoelectric materials are capable of this, by solid-state conversion of thermal to electrical energy, but the efficiency of this energy conversion requires improvement. In this work the thermoelectric figure of merit ( ZT) was improved by combining phonon scattering with grain boundary modification in a bismuth antimony telluride nanocomposite material with zinc antimony grain boundaries and zinc oxide nanoparticle inclusions. The advantage of including these zinc nanostructures is discussed. By reducing thermal conductivity while increasing the power factor, ZT was been increased from 0.6 to 1.1.

  15. Antimony-doped graphene nanoplatelets

    PubMed Central

    Jeon, In-Yup; Choi, Min; Choi, Hyun-Jung; Jung, Sun-Min; Kim, Min-Jung; Seo, Jeong-Min; Bae, Seo-Yoon; Yoo, Seonyoung; Kim, Guntae; Jeong, Hu Young; Park, Noejung; Baek, Jong-Beom

    2015-01-01

    Heteroatom doping into the graphitic frameworks have been intensively studied for the development of metal-free electrocatalysts. However, the choice of heteroatoms is limited to non-metallic elements and heteroatom-doped graphitic materials do not satisfy commercial demands in terms of cost and stability. Here we realize doping semimetal antimony (Sb) at the edges of graphene nanoplatelets (GnPs) via a simple mechanochemical reaction between pristine graphite and solid Sb. The covalent bonding of the metalloid Sb with the graphitic carbon is visualized using atomic-resolution transmission electron microscopy. The Sb-doped GnPs display zero loss of electrocatalytic activity for oxygen reduction reaction even after 100,000 cycles. Density functional theory calculations indicate that the multiple oxidation states (Sb3+ and Sb5+) of Sb are responsible for the unusual electrochemical stability. Sb-doped GnPs may provide new insights and practical methods for designing stable carbon-based electrocatalysts. PMID:25997811

  16. Speciation of antimony in polyethylene terephthalate bottles

    SciTech Connect

    Martin, R.R.; Ablett, J.; Shotyk, W.S.; Naftel, S.; Northrup, P.

    2009-12-18

    Antimony contamination has been reported in drinking water from polyethylene terephthalate (PET) bottles. Micro-X-ray fluorescence (XRF) analysis has been used to identify the distribution and chemical form of residual antimony used as a catalyst in the manufacture of PET bottles. The results are consistent with clusters of Sb(III) having dimensions of the order of tens of micrometers, clearly showing the ability of synchrotron radiation analyses to both map elemental distribution and determine oxidation state.

  17. Process for producing cadmium sulfide on a cadmium telluride surface

    DOEpatents

    Levi, D.H.; Nelson, A.J.; Ahrenkiel, R.K.

    1996-07-30

    A process is described for producing a layer of cadmium sulfide on a cadmium telluride surface to be employed in a photovoltaic device. The process comprises providing a cadmium telluride surface which is exposed to a hydrogen sulfide plasma at an exposure flow rate, an exposure time and an exposure temperature sufficient to permit reaction between the hydrogen sulfide and cadmium telluride to thereby form a cadmium sulfide layer on the cadmium telluride surface and accomplish passivation. In addition to passivation, a heterojunction at the interface of the cadmium sulfide and the cadmium telluride can be formed when the layer of cadmium sulfide formed on the cadmium telluride is of sufficient thickness. 12 figs.

  18. 40 CFR 721.1930 - Butanoic acid, antimony (3=) salt.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Butanoic acid, antimony (3=) salt. 721... Substances § 721.1930 Butanoic acid, antimony (3=) salt. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as butanoic acid, antimony (3=) salt (PMN...

  19. 40 CFR 721.1930 - Butanoic acid, antimony (3=) salt.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Butanoic acid, antimony (3=) salt. 721... Substances § 721.1930 Butanoic acid, antimony (3=) salt. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as butanoic acid, antimony (3=) salt (PMN...

  20. 40 CFR 721.1930 - Butanoic acid, antimony (3=) salt.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Butanoic acid, antimony (3=) salt. 721... Substances § 721.1930 Butanoic acid, antimony (3=) salt. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as butanoic acid, antimony (3=) salt (PMN...

  1. 40 CFR 721.1930 - Butanoic acid, antimony (3=) salt.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Butanoic acid, antimony (3=) salt. 721... Substances § 721.1930 Butanoic acid, antimony (3=) salt. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as butanoic acid, antimony (3=) salt (PMN...

  2. 40 CFR 721.1930 - Butanoic acid, antimony (3=) salt.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Butanoic acid, antimony (3=) salt. 721... Substances § 721.1930 Butanoic acid, antimony (3=) salt. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as butanoic acid, antimony (3=) salt (PMN...

  3. 40 CFR 721.10713 - Antimony tris(dialkyldithiocarbamate) (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Antimony tris(dialkyldithiocarbamate... Specific Chemical Substances § 721.10713 Antimony tris(dialkyldithiocarbamate) (generic). (a) Chemical... as antimony tris(dialkyldithiocarbamate) (PMN P-13-259) is subject to reporting under this...

  4. 40 CFR 721.10712 - Antimony tris(dialkyldithiocarbamate) (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Antimony tris(dialkyldithiocarbamate... Specific Chemical Substances § 721.10712 Antimony tris(dialkyldithiocarbamate) (generic). (a) Chemical... as antimony tris(dialkyldithiocarbamate) (PMN P-13-217) is subject to reporting under this...

  5. 40 CFR 721.5547 - Antimony double oxide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Antimony double oxide. 721.5547... Substances § 721.5547 Antimony double oxide. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substances identified generically as antimony double oxide (PMNs P-95-677 and...

  6. 40 CFR 721.5547 - Antimony double oxide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Antimony double oxide. 721.5547... Substances § 721.5547 Antimony double oxide. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substances identified generically as antimony double oxide (PMNs P-95-677 and...

  7. 40 CFR 721.5547 - Antimony double oxide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Antimony double oxide. 721.5547... Substances § 721.5547 Antimony double oxide. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substances identified generically as antimony double oxide (PMNs P-95-677 and...

  8. 40 CFR 721.5547 - Antimony double oxide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Antimony double oxide. 721.5547... Substances § 721.5547 Antimony double oxide. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substances identified generically as antimony double oxide (PMNs P-95-677 and...

  9. 40 CFR 721.5547 - Antimony double oxide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Antimony double oxide. 721.5547... Substances § 721.5547 Antimony double oxide. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substances identified generically as antimony double oxide (PMNs P-95-677 and...

  10. Growth of lead tin telluride crystals in gels

    NASA Technical Reports Server (NTRS)

    Barber, Patrick G.

    1986-01-01

    Improved gels and several geometries were investigated for use in growing crystals. The use of lead sulfide test crystals proved workable, but it was impossible to obtain and maintain a sufficiently concentrated telluride ion solution to successfully grow lead telluride crystals. It appears that oxygen in the solution is capable of oxidizing the telluride ion up to tellurium metal. The method may still be successful, but only if precautions are taken to eliminate dissolved oxygen from the gels and aqueous solutions and to maintain a suitable concentration of telluride, Te(2)-(aq.).

  11. Cadmium telluride films on foreign substrates

    SciTech Connect

    Chu, T.L.; Chu, S.S.; Pauleau, Y.; Murthy, K.; Stokes, E.D.; Russell, P.E.

    1983-01-01

    Thin films of cadmium telluride have been deposited on mullite and tungsten-coated graphite substrates at 500--700 /sup 0/C by the direct combination of cadmium and tellurium in a hydrogen atmosphere. Their microstructure and crystallographic properties were studied. The importance of controlling the Cd/Te molar ratio in the reaction mixture to obtain nearly stoichiometric films was demonstrated. The electrical properties of nonstoichiometric and nearly stoichiometric films on mullite substrates were measured by the van der Pauw technique. Schottky barriers were used to measure the electrical properties of cadmium telluride films on W/graphite substrates. The effective intragrain minority carrier diffusion length in n-type films was measured by the scanned electron beam method using a Schottky barrier structure.

  12. Cadmium zinc telluride charged particle nuclear detectors

    SciTech Connect

    Toney, J.E. |; James, R.B.; Antolak, A.

    1997-02-01

    This report describes the improvements in understanding of transport phenomena in cadmium zinc telluride radiation sensors achieved through studies of alpha particle response and spatially resolved photoconductivity mapping. Alpha particle response waveforms and photocurrent profiles both indicate non-uniformities in the electric field which may have detrimental effects on detector performance. Identifying and eliminating the sources of these nonuniformities will ultimately lead to improved detector performance.

  13. Electron mobility in mercury cadmium telluride

    NASA Technical Reports Server (NTRS)

    Patterson, James D.

    1988-01-01

    A previously developed program, which includes all electronic interactions thought to be important, does not correctly predict the value of electron mobility in mercury cadmium telluride particularly near room temperature. Part of the reason for this discrepancy is thought to be the way screening is handled. It seems likely that there are a number of contributors to errors in the calculation. The objective is to survey the calculation, locate reasons for differences between experiment and calculation, and suggest improvements.

  14. The Membrane Electrowinning Separation of Antimony from a Stibnite Concentrate

    NASA Astrophysics Data System (ADS)

    Yang, Jian-Guang; Yang, Sheng-Hai; Tang, Chao-Bo

    2010-06-01

    The main purpose of this study was to characterize and to extract antimony from a stibnite concentrate through electrowinning. This article reports an account of a study conducted on the optimization of the process parameters for antimony pentachloride circular leaching, purification, and electrowinning of antimony from antimony trichloride solution. The effect of electrowinning parameters, such as antimony and sodium chloride concentration in the catholyte, temperature, current density, polar distance, etc., on the voltage requirement and the current efficiency (CE) of antimony electrodeposition was explored. A maximum CE of more than 97 pct was attained with a catholyte composition of 70-g/L antimony, 25-g/L NaCl, 4.5-mol/L hydrogen ion concentration, with an anolyte composition of 40-g/L antimony trichloride at a temperature of 328 K (55 °C), a 4-cm polar distance, and a cathode current density of 200 A/m2. Under the optimized conditions, the CE was more than 97 pct, and a 99.98 pct antimony plate was obtained on the cathode. The chemical content analysis of the resulting anolyte was indicated to be 97 pct antimony pentachloride and 3 pct antimony trichloride, which could be recycled to leaching tank as the leaching agent.

  15. Microbial antimony biogeochemistry: Enzymes, regulation, and related metabolic pathways

    USGS Publications Warehouse

    Li, Jingxin; Qian Wang; Oremland, Ronald S.; Kulp, Thomas R.; Rensing, Christopher; Wang, Gejiao

    2016-01-01

    Antimony (Sb) is a toxic metalloid that occurs widely at trace concentrations in soil, aquatic systems, and the atmosphere. Nowadays, with the development of its new industrial applications and the corresponding expansion of antimony mining activities, the phenomenon of antimony pollution has become an increasingly serious concern. In recent years, research interest in Sb has been growing and reflects a fundamental scientific concern regarding Sb in the environment. In this review, we summarize the recent research on bacterial antimony transformations, especially those regarding antimony uptake, efflux, antimonite oxidation, and antimonate reduction. We conclude that our current understanding of antimony biochemistry and biogeochemistry is roughly equivalent to where that of arsenic was some 20 years ago. This portends the possibility of future discoveries with regard to the ability of microorganisms to conserve energy for their growth from antimony redox reactions and the isolation of new species of “antimonotrophs.”

  16. Microbial Antimony Biogeochemistry: Enzymes, Regulation, and Related Metabolic Pathways.

    PubMed

    Li, Jingxin; Wang, Qian; Oremland, Ronald S; Kulp, Thomas R; Rensing, Christopher; Wang, Gejiao

    2016-09-15

    Antimony (Sb) is a toxic metalloid that occurs widely at trace concentrations in soil, aquatic systems, and the atmosphere. Nowadays, with the development of its new industrial applications and the corresponding expansion of antimony mining activities, the phenomenon of antimony pollution has become an increasingly serious concern. In recent years, research interest in Sb has been growing and reflects a fundamental scientific concern regarding Sb in the environment. In this review, we summarize the recent research on bacterial antimony transformations, especially those regarding antimony uptake, efflux, antimonite oxidation, and antimonate reduction. We conclude that our current understanding of antimony biochemistry and biogeochemistry is roughly equivalent to where that of arsenic was some 20 years ago. This portends the possibility of future discoveries with regard to the ability of microorganisms to conserve energy for their growth from antimony redox reactions and the isolation of new species of "antimonotrophs." PMID:27342551

  17. Vacuum Evaporation Technology for Treating Antimony-Rich Anode Slime

    NASA Astrophysics Data System (ADS)

    Qiu, Keqiang; Lin, Deqiang; Yang, Xuelin

    2012-11-01

    A vacuum evaporation technology for treating antimony-rich anode slime was developed in this work. Experiments were carried out at temperatures from 873 K to 1073 K and residual gas pressures from 50 Pa to 600 Pa. During vacuum evaporation, silver from the antimony-rich anode slime was left behind in the distilland in a silver alloy containing antimony and lead, and antimony trioxide was evaporated. The experimental results showed that 92% by weight of antimony can be removed, and the silver content in the alloy was up to 12.84%. The antimony trioxide content in the distillate was more than 99.7%, and the distillate can be used directly as zero-grade antimony trioxide (China standard).

  18. Thank God for Babel: Analysis, Articulation, Antimony.

    ERIC Educational Resources Information Center

    Nyberg, David

    1981-01-01

    Three approaches to philosophical inquiry (analysis, articulation, antimony) are explored in a commentary on "Philosophy and Education: Eightieth Yearbook of the National Society for the Study of Education." A discussion of the sometimes-contradictory school role in providing both educational excellence and socialization illustrates how these…

  19. Arsenic and Antimony Transporters in Eukaryotes

    PubMed Central

    Maciaszczyk-Dziubinska, Ewa; Wawrzycka, Donata; Wysocki, Robert

    2012-01-01

    Arsenic and antimony are toxic metalloids, naturally present in the environment and all organisms have developed pathways for their detoxification. The most effective metalloid tolerance systems in eukaryotes include downregulation of metalloid uptake, efflux out of the cell, and complexation with phytochelatin or glutathione followed by sequestration into the vacuole. Understanding of arsenic and antimony transport system is of high importance due to the increasing usage of arsenic-based drugs in the treatment of certain types of cancer and diseases caused by protozoan parasites as well as for the development of bio- and phytoremediation strategies for metalloid polluted areas. However, in contrast to prokaryotes, the knowledge about specific transporters of arsenic and antimony and the mechanisms of metalloid transport in eukaryotes has been very limited for a long time. Here, we review the recent advances in understanding of arsenic and antimony transport pathways in eukaryotes, including a dual role of aquaglyceroporins in uptake and efflux of metalloids, elucidation of arsenic transport mechanism by the yeast Acr3 transporter and its role in arsenic hyperaccumulation in ferns, identification of vacuolar transporters of arsenic-phytochelatin complexes in plants and forms of arsenic substrates recognized by mammalian ABC transporters. PMID:22489166

  20. Thermal conductivity of bulk nanostructured lead telluride

    SciTech Connect

    Hori, Takuma; Chen, Gang; Shiomi, Junichiro

    2014-01-13

    Thermal conductivity of lead telluride with embedded nanoinclusions was studied using Monte Carlo simulations with intrinsic phonon transport properties obtained from first-principles-based lattice dynamics. The nanoinclusion/matrix interfaces were set to completely reflect phonons to model the maximum interface-phonon-scattering scenario. The simulations with the geometrical cross section and volume fraction of the nanoinclusions matched to those of the experiment show that the experiment has already reached the theoretical limit of thermal conductivity. The frequency-dependent analysis further identifies that the thermal conductivity reduction is dominantly attributed to scattering of low frequency phonons and demonstrates mutual adaptability of nanostructuring and local disordering.

  1. High Temperature Interactions of Antimony with Nickel

    SciTech Connect

    Marina, Olga A.; Pederson, Larry R.

    2012-07-01

    In this chapter, the surface and bulk interactions of antimony with the Ni-based anodes in solid oxide fuel cells (SOFC) will be discussed. High fuel flexibility is a significant advantage of SOFCs, allowing the direct use of fossil and bio fuels without a hydrogen separation unit. Synthesis gas derived from coal and biomass consists of a mixture of hydrogen, carbon monoxide, carbon dioxide, and steam, but finite amounts of tars and trace impurities such as S, Se, P, As, Sb, Cd, Pb, Cl, etc, are also always present. While synthesis gas is commonly treated with a series of chemical processes and scrubbers to remove the impurities, complete purification is not economical. Antimony is widely distributed in coals. During coal gasification antimony is volatilized, such that contact with the SOFC anodes and other SOFC parts, e.g., interconnect, current collecting wires, fuel gas supplying tubing, is most likely. This chapter addresses the following topics: high temperature Ni - Sb interactions; alteration phase, Ni3Sb, Ni5Sb2, NiSb, formation; thermochemical modeling; impact of Sb on the electrocatalytic activity of Ni toward the fuel oxidation and the presence of other impurities (sulfur, in particular); converted anode structural instability during long-term SOFC operation; comparison with nickel heterogeneous catalysts.

  2. Spin dynamics of complex oxides, bismuth-antimony alloys, and bismuth chalcogenides

    NASA Astrophysics Data System (ADS)

    Sahin, Cuneyt

    V, suggesting the potential for doping or voltage tuned spin Hall current. We have also calculated intrinsic spin Hall conductivities of bismuth selenide and bismuth telluride topological insulators from an effective tight-binding Hamiltonian including two nearest-neighbor interactions. We showed that both materials exhibit giant spin Hall conductivities calculated from the Kubo formula in linear response theory and the clean static limit. We conclude that bismuth-antimony alloys and bismuth chalcogenides are primary candidates for efficiently generating spin currents through the spin Hall effect.

  3. New Layered Ternary Transition-Metal Tellurides

    NASA Astrophysics Data System (ADS)

    Mar, Arthur

    Several new ternary transition-metal tellurides, a class of compounds hitherto largely unexplored, have been synthesized and characterized. These are layered materials whose structures have been determined by single -crystal X-ray diffraction methods. The successful preparation of the compound TaPtTe_5 was crucial in developing an understanding of the MM'Te_5 (M = Nb, Ta; M' = Ni, Pd, Pt) series of compounds, which adopt either of two possible closely-related layered structures. Interestingly, the compound TaPdTe _5 remains unknown. Instead, the compound Ta_4Pd_3Te _{16} has been prepared. Its structure is closely related to that of the previously prepared compound Ta_3Pd _3Te_{14}. The physical properties of these compounds have been measured and correlated with the metal substitutions and interlayer separations. A new series of compounds, MM'Te _4 (M = Nb, Ta; M' = Ru, Os, Rh, Ir), has been discovered. The structure of NbIrTe_4 serves as a prototype: it is an ordered variant of the binary telluride WTe_2. Electronic band-structure calculations have been performed in order to rationalize the trends in metal-metal and tellurium -tellurium bonding observed in WTe_2 and the MM'Te_4 phases. Extension of these studies to include main-group metals has resulted in the synthesis of the new layered ternary germanium tellurides TiGeTe_6, ZrGeTe_4 , and HfGeTe_4. Because germanium can behave ambiguously in its role as a metalloid element, it serves as an anion by capping the metal-centered trigonal prisms and also as a cation in being coordinated in turn by other tellurium atoms in a trigonal pyramidal fashion. Structural relationships among these compounds are illustrated through the use of bicapped trigonal prisms and trigonal pyramids as the basic structural building blocks. The electrical and magnetic properties of these compounds have been measured. Insight into the unusual bonding and physical properties of these germanium-containing compounds has been gained through

  4. A new occurrence of telluride minerals in South Carolina.

    USGS Publications Warehouse

    Bell, H.; Larson, R.R.

    1984-01-01

    A study of drill cores from the Haile gold mine, Lancaster County, South Carolina, has revealed grains containing large amounts of Te with various combinations of Pb, Ag and Au in pyrite. These telluride minerals have so far not been identified. The nearby Brewer mine, on the basis of chemical evidence, also contains tellurides. The probable telluride localities in South Carolina are now expanded to three, significantly increasing the few reports of Te minerals from the Au deposits of the southeastern Piedmont, many of which are now considered to be volcanogenic. The occurrence of telluride minerals in gold ore from the Haile-Brewer area may help to explain the divergence in Au/Ag ratios reported in chemical analyses of drill core, ore samples and production records. Te, in addition, may be useful in geochemical exploration programmes in the SE Piedmont, including programmes using heavy mineral concentrates derived from stream alluvium. -R.S.M.

  5. Polycrystalline Thin-Film Research: Cadmium Telluride (Fact Sheet)

    SciTech Connect

    Not Available

    2011-06-01

    Capabilities fact sheet that includes scope, core competencies and capabilities, and contact/web information for Polycrystalline Thin-Film Research: Cadmium Telluride at the National Center for Photovoltaics.

  6. Polycrystalline Thin-Film Research: Cadmium Telluride (Fact Sheet)

    SciTech Connect

    Not Available

    2013-06-01

    This National Center for Photovoltaics sheet describes the capabilities of its polycrystalline thin-film research in the area of cadmium telluride. The scope and core competencies and capabilities are discussed.

  7. Electron transfer in silver telluride melt

    SciTech Connect

    Glazov, V.M.; Burkhanov, A.S.

    1987-06-01

    Electron transfer in silver telluride melt was studied experimentally at different temperatures. The method used to study electron transfer and thermodiffusion is based on Onsager's theory and consists of measuring the electrodiffusion potential which varies as a function of time in the system formed by the liquid semiconductor and the neutral metallic electrodes. The effective charges and the average coefficients of diffusion of silver ions were calculated and the ionic component of the total electrical conductivity of Ag/sub 2/Te melt was evaluated. It was observed that the indicated characteristics vary systematically in the series of silver chalcogenides with anionic substitution. The negative temperature coefficient of electrical conductivity in silver sulfide and silver selenide melts was explained.

  8. The exposure to and health effects of antimony

    PubMed Central

    Cooper, Ross G.; Harrison, Adrian P.

    2009-01-01

    Context: This minireview describes the health effects of antimony exposure in the workplace and the environment. Aim: To collate information on the consequences of occupational and environmental exposure to antimony on physiological function and well-being. Methods: The criteria used in the current minireview for selecting articles were adopted from proposed criteria in The International Classification of Functioning, Disability and Health. Articles were classified from an acute and chronic exposure and toxicity thrust. Results: The proportion of utilised and non-utilised articles was tabulated. Antimony toxicity is dependent on the exposure dose, duration, route (breathing, eating, drinking, or skin contact), other chemical exposures, age, sex, nutritional status, family traits, life style, and state of health. Chronic exposure to antimony in the air at levels of 9 mg/m3 may exacerbate irritation of the eyes, skin, and lungs. Long-term inhalation of antimony can potentiate pneumoconiosis, altered electrocardiograms, stomach pain, diarrhea, vomiting, and stomach ulcers, results which were confirmed in laboratory animals. Although there were investigations of the effect of antimony in sudden infant death syndrome, current findings suggest no link. Antimony trioxide exposure is predominant in smelters. Mining and exposure via glass working, soldering, and brazing are also important. Conclusion: Antimony has some useful but undoubtedly harmful effects on health and well-being and measures need to be taken to prevent hazardous exposure of the like. Its biological monitoring in the workplace is essential. PMID:20165605

  9. Undercooling and crystallization behaviour of antimony droplets

    NASA Technical Reports Server (NTRS)

    Graves, J. A.; Perepezko, J. H.

    1986-01-01

    The droplet emulsion technique is presently used to examine the undercooling and crystallization behavior of pure antimony. Control of droplet size and applied cooling rate allowed maximum undercooling to be extended from 0.08 to 0.23 T(m). A droplet coating was produced by means of emulsification which appears to furnish a favorable crystallographic matching for effective nucleation catalysis of a metastable simple cubic structure. Thermal analysis shows the melting temperature of the single cubic phase to be about 625 C.

  10. Study of the Electrochemical System of Antimony-Tellurium in Dimethyl Sulfoxide for Growth of Nanowire Arrays, and an Innovative Method for Single Nanowire Measurements

    NASA Astrophysics Data System (ADS)

    Kalisman, Philip Taubman

    There is a strong interest in thermoelectric materials for energy production and savings. The properties which are integral to thermoelectric performance are typically linked, typically changing one of these properties for the better will change another for the worse. The intertwined nature of these properties has limited bulk thermoelectrics to low efficiencies, which has curbed their use to only niche applications. There has been theoretical and experimental work which has shown that limiting these materials in one or more dimensions will result in deconvolution of properties. Nanowires of well established thermoelectrics should show impressively high performance. Tellurium is attractive in many fields, including thermoelectrics. Nanowires of tellurium have been grown, but with limited success and with out the ability to dope the tellurium. Working on previous work with other systems, tellurium was studied in dimethyl sulfoxide (DMSO). The electrochemical system of tellurium was found to be quite dierent from its aqueous analog, but through comprehensive cyclic voltammetric study, all events were identified and explained. The binary antimony-tellurium system was also studied, as doping of tellurium is integral for many applications. Cyclic voltammograms of this system were studied, and the insight from these studies was used to grow nanowire arrays. Arrays of tellurium were grown and analysis showed that by using DMSO, antimony doped tellurium nanowire arrays could be grown. Furthermore, analysis showed that the antimony doped tellurium interstitially, resulting in a n-type material. Measurements were also performed on arrays and individual wires. Arrays of 1.15% antimony showed ZT of 0.092, with the low ZT attributed to poor contact methods. Although contacting was an obstacle towards measuring whole arrays, single wire measurements were also performed. Single wire measurements were done by a novel method which allows for easy, reproducible measurements of wire

  11. Off-stoichiometric silver antimony telluride: An experimental study of transport properties with intrinsic and extrinsic doping

    SciTech Connect

    Nielsen, Michele D.; Jaworski, Christopher M.; Heremans, Joseph P.

    2015-05-15

    AgSbTe{sub 2} is a thermoelectric semiconductor with an intrinsically low thermal conductivity and a valence band structure that is favorable to obtaining a high thermoelectric figure of merit zT. It also has a very small energy gap Eg ∼ 7.6 ± 3 meV. As this gap is less than the thermal excitation energy at room temperature, near-intrinsic AgSbTe{sub 2} is a two carrier system having both holes (concentration p) and electrons (n). Good thermoelectric performance requires heavy p-type doping (p > > n). This can be achieved with native defects or with extrinsic doping, e.g. with transition metal element. The use of defect doping is complicated by the fact that many of the ternary Ag-Sb-Te and pseudo-binary Sb{sub 2}Te{sub 3}-Ag{sub 2}Te phase diagrams are contradictory. This paper determines the compositional region most favorable to creating a single phase material. Through a combination of intrinsic and extrinsic doping, values of zT > 1 are achieved, though not on single-phased material. Additionally, we show that thermal conductivity is not affected by defects, further demonstrating that the low lattice thermal conductivity of I-V-VI{sub 2} materials is due to an intrinsic mechanism, insensitive to changes in defect structure.

  12. Antimony ore in the Fairbanks district, Alaska

    USGS Publications Warehouse

    Killeen, Pemberton Lewis; Mertie, John B., Jr.

    1951-01-01

    Antimony-bearing ores in the Fairbanks district, Alaska, are found principally in two areas, the extremities of which are at points 10 miles west and 23 miles northeast of Fairbanks; and one of two minor areas lies along this same trend 30 miles farther to the northeast. These areas are probably only local manifestations of mineralization that affected a much broader area and formed antimony-bearing deposits in neighboring districts, the closest of which is 50 miles away. The ores were exposed largely as a result of lode gold mining, but at two periods in the past, high prices for antimony ore warranted an independent production and about 2500 tons of stibnite ore was shipped. The sulfide deposits occupy the same fractures along which a gold-quartz mineralization of greater economic importance occurred; and both are probably genetically related to igneous rocks which intrude the schistose country rock. The sulfide is in part contemporaneous with some late-stage quartz in which it occurs as disseminated crystals; and in part the latest filling in the mineralized zones where it forms kidney-shaped masses of essentially solid sulfide. One extremely long mass must have contained nearly 100 tons of ore, but the average of the larger kidneys is closer to several tons. Much of the ore is stibnite, with quartz as a minor impurity, and assays show the tenor to vary from 40 to 65 percent antimony. Sulphantimonites are less abundant but likewise occur as disseminated crystals and as kidney-shaped bodies. Antimony oxides appear on the weathered surface and along fractures within the sulfide ore. Deposits containing either stibnite or sulphantimonite are known at more than 50 localities, but only eighteen have produced ore and the bulk of this came from the mines. The geology of the deposit, and the nature, extent, and period of the workings are covered in the detailed descriptions of individual occurrences. Several geologic and economic factors, which greatly affect

  13. Charge carrier effective mass and concentration derived from combination of Seebeck coefficient and Te125 NMR measurements in complex tellurides

    DOE PAGESBeta

    Levin, E. M.

    2016-06-27

    Thermoelectric materials utilize the Seebeck effect to convert heat to electrical energy. The Seebeck coefficient (thermopower), S, depends on the free (mobile) carrier concentration, n, and effective mass, m*, as S ~ m*/n2/3. The carrier concentration in tellurides can be derived from 125Te nuclear magnetic resonance (NMR) spin-lattice relaxation measurements. The NMR spin-lattice relaxation rate, 1/T1, depends on both n and m* as 1/T1~(m*)3/2n (within classical Maxwell-Boltzmann statistics) or as 1/T1~(m*)2n2/3 (within quantum Fermi-Dirac statistics), which challenges the correct determination of the carrier concentration in some materials by NMR. Here it is shown that the combination of the Seebeck coefficientmore » and 125Te NMR spin-lattice relaxation measurements in complex tellurides provides a unique opportunity to derive the carrier effective mass and then to calculate the carrier concentration. This approach was used to study AgxSbxGe50–2xTe50, well-known GeTe-based high-efficiency tellurium-antimony-germanium-silver thermoelectric materials, where the replacement of Ge by [Ag+Sb] results in significant enhancement of the Seebeck coefficient. Thus, values of both m* and n derived using this combination show that the enhancement of thermopower can be attributed primarily to an increase of the carrier effective mass and partially to a decrease of the carrier concentration when the [Ag+Sb] content increases.« less

  14. Ion beam sputter deposited zinc telluride films

    NASA Technical Reports Server (NTRS)

    Gulino, D. A.

    1985-01-01

    Zinc telluride is of interest as a potential electronic device material, particularly as one component in an amorphous superlattice, which is a new class of interesting and potentially useful materials. Some structural and electronic properties of ZnTe films deposited by argon ion beam sputter depoairion are described. Films (up to 3000 angstroms thick) were deposited from a ZnTe target. A beam energy of 1000 eV and a current density of 4 mA/sq. cm. resulted in deposition rates of approximately 70 angstroms/min. The optical band gap was found to be approximately 1.1 eV, indicating an amorphous structure, as compared to a literature value of 2.26 eV for crystalline material. Intrinsic stress measurements showed a thickness dependence, varying from tensile for thicknesses below 850 angstroms to compressive for larger thicknesses. Room temperature conductivity measurement also showed a thickness dependence, with values ranging from 1.86 x to to the -6/ohm. cm. for 300 angstrom film to 2.56 x 10 to the -1/ohm. cm. for a 2600 angstrom film. Measurement of the temperature dependence of the conductivity for these films showed complicated behavior which was thickness dependent. Thinner films showed at least two distinct temperature dependent conductivity mechanisms, as described by a Mott-type model. Thicker films showed only one principal conductivity mechanism, similar to what might be expected for a material with more crystalline character.

  15. Ion beam sputter deposited zinc telluride films

    NASA Technical Reports Server (NTRS)

    Gulino, D. A.

    1986-01-01

    Zinc telluride is of interest as a potential electronic device material, particularly as one component in an amorphous superlattice, which is a new class of interesting and potentially useful materials. Some structural and electronic properties of ZnTe films deposited by argon ion beam sputter deposition are described. Films (up to 3000 angstroms thick) were deposited from a ZnTe target. A beam energy of 1000 eV and a current density of 4 mA/sq cm resulted in deposition rates of approximately 70 angstroms/min. The optical band gap was found to be approximately 1.1 eV, indicating an amorphous structure, as compared to a literature value of 2.26 eV for crystalline material. Intrinsic stress measurements showed a thickness dependence, varying from tensile for thicknesses below 850 angstroms to compressive for larger thicknesses. Room temperature conductivity measurement also showed a thickness dependence, with values ranging from 1.86 x 10 to the -6th/ohm cm for 300 angstrom film to 2.56 x 10 to the -1/ohm cm for a 2600 angstrom film. Measurement of the temperature dependence of the conductivity for these films showed complicated behavior which was thickness dependent. Thinner films showed at least two distinct temperature dependent conductivity mechanisms, as described by a Mott-type model. Thicker films showed only one principal conductivity mechanism, similar to what might be expected for a material with more crystalline character.

  16. Thin-film cadmium telluride solar cells

    NASA Astrophysics Data System (ADS)

    Chu, T. L.

    1987-10-01

    Cadmium telluride, with a room-temperature band-gap energy of 1.5 eV, is a promising thin-film photovoltaic material. The major objective of this research has been to demonstrate thin-film CdTe heterojunction solar cells with a total area greater than 1 sq cm and photovoltaic efficiencies of 13 percent or more. Thin-film p-CdTe/CdS/SnO2:F/glass solar cells with an AM1.5 efficiency of 10.5 percent have been reported previously. This report contains results of work done on: (1) the deposition, resistivity control, and characterization of p-CdTe films by the close-spaced sublimation process; (2) the deposition of large-band-gap window materials; (3) the electrical properties of CdS/CdTe heterojunctions; (4) the formation of stable, reproducible, ohmic contacts (such as p-HgTe) to p-CdTe; and (5) the preparation and evaluation of heterojunction solar cells.

  17. Thin-film cadmium telluride solar cells

    NASA Astrophysics Data System (ADS)

    1986-09-01

    This is the final technical progress report of a research program entitled Thin-Film Cadmium Telluride Solar Cells. The major objective was to demonstrate chemical vapor deposition (CVD)-grown CdTe devices with a photovoltaic efficiency of at least 10%. The work included: (1) CVD and characterization of p-CdTe films of controlled resistivity; (2) deposition and characterization of heterojunction partners; (3) surface passivation of CdTe; and (4) preparation and characterization of thin-film solar cells. The CVD of p-CdTe was optimized with emphasis on resistivity control through nonstoichiometry and extrinsic doping. Both carbon and oxygen were identified as acceptors. The use of thermal oxidation for surface passivation of CdTe was investigated using capacitance-voltage measurement. Device-quality thermal oxide can be prepared by hydrogen annealing of CdTe before oxidation. Deposition and characterization of CdS, CdO, and ZnO:In were also carried out. The best thin-film cell to date had a conversion efficiency near 9%.

  18. Selective determination of antimony(III) and antimony(V) with ammonium pyrrolidinedithiocarbamate, sodium diethyldithiocarbamate and dithizone by atomic-absorption spectrometry with a carbon-tube atomizer.

    PubMed

    Kamada, T; Yamamoto, Y

    1977-05-01

    The extraction behaviour of antimony(III) and antimony(V) with ammonium pyrrolidinedithiocarbamate, sodium diethyldithiocarbamate and dithizone in organic solvents has been investigated by means of frameless atomic-absorption spectrophotometry with a carbon-tube atomizer. The selective extraction of antimony(III) and differential determination of antimony(III) and antimony(V) have been developed. With ammonium pyrrolidinedithiocarbamate and methyl isobutyl ketone, when the aqueous phase/solvent volume ratio is 50 ml/10 ml and the injection volume in the carbon tube is 20 mul, the sensitivity for antimony is 0.2 ng/ml for 1% absorption. The relative standard deviations are ca. 2%. Interferences by many metal ions can be prevented by masking with EDTA. The proposed methods have been applied satisfactorily to determination of antimony(III) and antimony(V) in various types of water. PMID:18962096

  19. Determination of the Origin of Crystal Orientation for Nanocrystalline Bismuth Telluride-Based Thin Films Prepared by Use of the Flash Evaporation Method

    NASA Astrophysics Data System (ADS)

    Takashiri, M.; Tanaka, S.; Miyazaki, K.

    2014-06-01

    We have investigated the origin of crystal orientation for nanocrystalline bismuth telluride-based thin films. Thin films of p-type bismuth telluride antimony (Bi-Te-Sb) and n-type bismuth telluride selenide (Bi-Te-Se) were fabricated by a flash evaporation method, with exactly the same deposition conditions except for the elemental composition of the starting powders. For p-type Bi-Te-Sb thin films the main x-ray diffraction (XRD) peaks were from the c-axis (Σ{00l}/Σ{ hkl} = 0.88) whereas n-type Bi-Te-Se thin films were randomly oriented (Σ{00l}/Σ{ hkl} = 0.40). Crystal orientation, crystallinity, and crystallite size were improved for both types of thin film by sintering. For p-type Bi-Te-Sb thin films, especially, high-quality structures were obtained compared with those of n-type Bi-Te-Se thin films. We also estimated the thermoelectric properties of the as-grown and sintered thin films. The power factor was enhanced by sintering; maximum values were 34.9 μW/cm K2 for p-type Bi-Te-Sb thin films at a sintering temperature of 300°C and 23.9 μW/cm K2 for n-type Bi-Te-Se thin films at a sintering temperature of 350°C. The exact mechanisms of film growth are not yet clear but we deduce the crystal orientation originates from the size of nano-clusters generated on the tungsten boat during flash evaporation.

  20. Disposition of antimony in rhesus monkeys infected with Leishmania braziliensis and treated with meglumine antimoniate.

    PubMed

    Friedrich, Karen; Vieira, Flávia A; Porrozzi, Renato; Marchevsky, Renato S; Miekeley, Norbert; Grimaldi, Gabriel; Paumgartten, Francisco J R

    2012-01-01

    Antimony (Sb) disposition and toxicity was evaluated in Leishmania braziliensis-infected monkeys (Macaca mulatta) treated with a 21-d course of low (LOW) or standard (STD) meglumine antimoniate (MA) dosage regimens (5 or 20 mg Sb(V)/kg body weight/d im). Antimony levels in biological matrices were determined by inductively coupled plasma mass spectrometry (ICPMS), while on-line ion chromatography coupled to ICPMS was used to separate and quantify Sb species in plasma. Nadir Sb levels rose steadily from 19.6 ± 4 and 65.1 ± 17.4 ng/g, 24 h after the first injection, up to 27.4 ± 5.8 and 95.7 ± 6.6 ng/g, 24 h after the 21st dose in LOW and SDT groups, respectively. Subsequently, Sb plasma levels gradually declined with a terminal elimination phase half-life of 35.8 d. Antimony speciation in plasma on posttreatment days 1-9 indicated that as total Sb levels declined, proportion of Sb(V) remained nearly constant (11-20%), while proportion of Sb(III) rose from 5% (d 1) to 50% (d 9). Plasma [Sb]/erythrocyte [Sb] ratio was >1 until 12 h after dosing and reversed thereafter. Tissue Sb concentrations (posttreatment days 55 and 95) were as follows: >1000 ng/g in thyroid, nails, liver, gall bladder and spleen; >200 and <1000 ng/g in lymph nodes, kidneys, adrenals, bones, skeletal muscles, heart and skin; and <200 ng/g in various brain structures, thymus, stomach, colon, pancreas. and teeth. Results from this study are therefore consistent with view that Sb(V) is reduced to Sb(III), the active form, within cells from where it is slowly eliminated. Localization of Sb active forms in the thyroid gland and liver and the pathophysiological consequences of marked Sb accumulation in these tissues warrant further studies. PMID:22129235

  1. Tissue distribution of residual antimony in rats treated with multiple doses of meglumine antimoniate

    PubMed Central

    Coelho, Deise Riba; Miranda, Elaine Silva; Saint’Pierre, Tatiana Dillenburg; Paumgartten, Francisco José Roma

    2014-01-01

    Meglumine antimoniate (MA) and sodium stibogluconate are pentavalent antimony (SbV) drugs used since the mid-1940s. Notwithstanding the fact that they are first-choice drugs for the treatment of leishmaniases, there are gaps in our knowledge of their toxicological profile, mode of action and kinetics. Little is known about the distribution of antimony in tissues after SbV administration. In this study, we evaluated the Sb content of tissues from male rats 24 h and three weeks after a 21-day course of treatment with MA (300 mg SbV/kg body wt/d, subcutaneous). Sb concentrations in the blood and organs were determined by inductively coupled plasma-mass spectrometry. In rats, as with in humans, the Sb blood levels after MA dosing can be described by a two-compartment model with a fast (t1/2 = 0.6 h) and a slow (t1/2 >> 24 h) elimination phase. The spleen was the organ that accumulated the highest amount of Sb, while bone and thyroid ranked second in descending order of tissues according to Sb levels (spleen >> bone, thyroid, kidneys > liver, epididymis, lungs, adrenals > prostate > thymus, pancreas, heart, small intestines > skeletal muscle, testes, stomach > brain). The pathophysiological consequences of Sb accumulation in the thyroid and Sb speciation in the liver, thyroid, spleen and bone warrant further studies. PMID:25075781

  2. Electronic structure of intrinsic defects in crystalline germanium telluride.

    SciTech Connect

    Thompson, Aidan Patrick; Pineda, Andrew C.; Umrigar, Cyrus J.; Hjalmarson, Harold Paul; Schultz, Peter Andrew; Edwards, Arthur H.; Martin, Marcus Gary

    2005-05-01

    Germanium telluride undergoes rapid transition between polycrystalline and amorphous states under either optical or electrical excitation. While the crystalline phases are predicted to be semiconductors, polycrystalline germanium telluride always exhibits p-type metallic conductivity. We present a study of the electronic structure and formation energies of the vacancy and antisite defects in both known crystalline phases. We show that these intrinsic defects determine the nature of free-carrier transport in crystalline germanium telluride. Germanium vacancies require roughly one-third the energy of the other three defects to form, making this by far the most favorable intrinsic defect. While the tellurium antisite and vacancy induce gap states, the germanium counterparts do not. A simple counting argument, reinforced by integration over the density of states, predicts that the germanium vacancy leads to empty states at the top of the valence band, thus giving a complete explanation of the observed p-type metallic conduction.

  3. Unconventional temperature enhanced magnetism in iron telluride

    SciTech Connect

    Zalinznyak, I.; Xu, Zhijun; Tranquada, John M.; Gu, G. D.; Tsvelik, A.; Stone, Matthew B

    2011-01-01

    Discoveries of copper and iron-based high-temperature superconductors (HTSC)1-2 have challenged our views of superconductivity and magnetism. Contrary to the pre-existing view that magnetism, which typically involves localized electrons, and superconductivity, which requires freely-propagating itinerant electrons, are mutually exclusive, antiferromagnetic phases were found in all HTSC parent materials3,4. Moreover, highly energetic magnetic fluctuations, discovered in HTSC by inelastic neutron scattering (INS) 5,6, are now widely believed to be vital for the superconductivity 7-10. In two competing scenarios, they either originate from local atomic spins11, or are a property of cooperative spin-density-wave (SDW) behavior of conduction electrons 12,13. Both assume clear partition into localized electrons, giving rise to local spins, and itinerant ones, occupying well-defined, rigid conduction bands. Here, by performing an INS study of spin dynamics in iron telluride, a parent material of one of the iron-based HTSC families, we have discovered that this very assumption fails, and that conduction and localized electrons are fundamentally entangled. In the temperature range relevant for the superconductivity we observe a remarkable redistribution of magnetism between the two groups of electrons. The effective spin per Fe at T 10 K, in the2 antiferromagnetic phase, corresponds to S 1, consistent with the recent analyses that emphasize importance of Hund s intra-atomic exchange15-16. However, it grows to S 3/2 in the disordered phase, a result that profoundly challenges the picture of rigid bands, broadly accepted for HTSC.

  4. The electronic structure of the antimony chalcogenide series: Prospects for optoelectronic applications

    SciTech Connect

    Carey, John J.; Allen, Jeremy P.; Scanlon, David O.; Watson, Graeme W.

    2014-05-01

    In this study, density functional theory is used to evaluate the electronic structure of the antimony chalcogenide series. Analysis of the electronic density of states and charge density shows that asymmetric density, or ‘lone pairs’, forms on the Sb{sup III} cations in the distorted oxide, sulphide and selenide materials. The asymmetric density progressively weakens down the series, due to the increase in energy of valence p states from O to Te, and is absent for Sb{sub 2}Te{sub 3}. The fundamental and optical band gaps were calculated and Sb{sub 2}O{sub 3}, Sb{sub 2}S{sub 3} and Sb{sub 2}Se{sub 3} have indirect band gaps, while Sb{sub 2}Te{sub 3} was calculated to have a direct band gap at Γ. The band gaps are also seen to reduce from Sb{sub 2}O{sub 3} to Sb{sub 2}Te{sub 3}. The optical band gap for Sb{sub 2}O{sub 3} makes it a candidate as a transparent conducting oxide, while Sb{sub 2}S{sub 3} and Sb{sub 2}Se{sub 3} have suitable band gaps for thin film solar cell absorbers. - Graphical abstract: A schematic illustrating the interaction between the Sb{sup III} cations and the chalcogenide anions and the change in their respective energy levels down the series. - Highlights: • The electronic structure of the antimony chalcogenide series is modelled using DFT. • Asymmetric density is present on distorted systems and absent on the symmetric telluride system. • Asymmetric density is formed from the mixing of Sb 5s and anion p states, where the anti-bonding combination is stabilised by the Sb 5p states. • The asymmetric density weakens down the series due to the increase in energy of chalcogenide p states. • The increase in energy of the anion p states reduces the fundamental and optical band gaps.

  5. Reduced Antimony Accumulation in ARM58-Overexpressing Leishmania infantum

    PubMed Central

    Schäfer, Carola; Tejera Nevado, Paloma; Zander, Dorothea

    2014-01-01

    Antimony-based drugs are still the mainstay of chemotherapy against Leishmania infections in many countries where the parasites are endemic. The efficacy of antimonials has been compromised by increasing numbers of resistant infections, the basis of which is not fully understood and likely involves multiple factors. By using a functional cloning strategy, we recently identified a novel antimony resistance marker, ARM58, from the parasite Leishmania braziliensis that protects the parasites against antimony-based antileishmanial compounds. Here we show that the Leishmania infantum homologue also confers resistance against antimony but not against other antileishmanial drugs and that its function depends critically on one of four conserved domains of unknown function. This critical domain requires at least two hydrophobic amino acids and is predicted to form a transmembrane structure. Overexpression of ARM58 in antimony-exposed parasites reduces the intracellular Sb accumulation by over 70%, indicating a role for ARM58 in Sb extrusion pathways, but without involvement of energy-dependent transporter proteins. PMID:24366738

  6. Cloud point extraction combined with electrothermal atomic absorption spectrometry for the speciation of antimony(III) and antimony(V) in food packaging materials.

    PubMed

    Jiang, Xiuming; Wen, Shengping; Xiang, Guoqiang

    2010-03-15

    A simple, sensitive method for the speciation of inorganic antimony by cloud point extraction combined with electrothermal atomic absorption spectrometry (ETAAS) is presented and evaluated. The method based on the fact that formation of a hydrophobic complex of antimony(III) with ammonium pyrrolidine dithiocarbamate (APDC) at pH 5.0 and subsequently the hydrophobic complex enter into surfactant-rich phase, whereas antimony(V) remained in aqueous solutions. Antimony(III) in surfactant-rich phase was analyzed by ETAAS after dilution by 0.2 mL nitric acid in methanol (0.1M), and antimony(V) was calculated by subtracting antimony(III) from the total antimony after reducing antimony(V) to antimony(III) by l-cysteine. The main factors affecting the cloud point extraction, such as pH, concentration of APDC and Triton X-114, equilibrium temperature and incubation time, sample volume were investigated in detail. Under the optimum conditions, the detection limit (3 sigma) of the proposed method was 0.02 ng mL(-1) for antimony(III), and the relative standard deviation was 7.8% (c=1.0 ng mL(-1), n=7). The proposed method was successfully applied to speciation of inorganic antimony in the leaching solutions of different food packaging materials with satisfactory results. PMID:19853991

  7. Ultrasonication of Bismuth Telluride Nanocrystals Fabricated by Solvothermal Method

    NASA Technical Reports Server (NTRS)

    Chu, Sang-Hyon; Choi, Sang H.; Kim, Jae-Woo; King, Glen C.; Elliott, James R.

    2006-01-01

    The objective of this study is to evaluate the effect of ultrasonication on bismuth telluride nanocrystals prepared by solvothermal method. In this study, a low dimensional nanocrystal of bismuth telluride (Bi2Te3) was synthesized by a solvothermal process in an autoclave at 180 C and 200 psi. During the solvothermal reaction, organic surfactants effectively prevented unwanted aggregation of nanocrystals in a selected solvent while controlling the shape of the nanocrystal. The atomic ratio of bismuth and tellurium was determined by energy dispersive spectroscopy (EDS). The cavitational energy created by the ultrasonic probe was varied by the ultrasonication process time, while power amplitude remained constant. The nanocrystal size and its size distribution were measured by field emission scanning electron microscopy (FESEM) and a dynamic light scattering system. When the ultrasonication time increased, the average size of bismuth telluride nanocrystal gradually increased due to the direct collision of nanocrystals. The polydispersity of the nanocrystals showed a minimum when the ultrasonication was applied for 5 min. Keywords: bismuth telluride, nanocrystal, low-dimensional, ultrasonication, solvothermal

  8. Photoemission Spectroscopic Study of Cesium Telluride Thin Film Photocathode

    SciTech Connect

    Sugiyama, Harue; Ogawa, Koji; Azuma, Junpei; Takahashi, Kazutoshi; Kamada, Masao

    2009-08-04

    The photoemission spectroscopy using synchrotron radiation has been carried out to study the high quantum efficiency and long working lifetime of cesium telluride (Cs{sub x}Te{sub y}) thin film photocathode. The electron affinity derived from the observed energy-distribution curves provides an important hint for long persistency of the photocathode.

  9. VIEW, LOOKING SOUTHEAST, OF TELLURIDE IRON WORKS RETORT USED FOR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW, LOOKING SOUTHEAST, OF TELLURIDE IRON WORKS RETORT USED FOR FLASHING MERCURY OFF OF GOLD TO CREATE SOFT INGOTS CALLED "SPONGES." AT RIGHT ARE SAFES FOR STORING 22-POUND SPONGES WORTH OVER $60,000 EACH, CA. 1985. - Shenandoah-Dives Mill, 135 County Road 2, Silverton, San Juan County, CO

  10. Understanding the Meaning of the Entrance Image: The Telluride Process.

    ERIC Educational Resources Information Center

    Garnham, Harry L.; Garnham, Penny

    1989-01-01

    Describes a project to define the images of Telluride (Colorado) held by its residents and tourists and contributing to sense of place. Discusses the design of the town's entry points and efforts to maintain their visual environments in harmony with the town's defined character during ongoing community development. (SV)

  11. Antimony distribution and environmental mobility at an historic antimony smelter site, New Zealand.

    PubMed

    Wilson, N J; Craw, D; Hunter, K

    2004-05-01

    A historic antimony smelter site at Endeavour Inlet, New Zealand has smelter residues with up to 17 wt.% antimony. Residues include coarse tailings (cm scale particles, poorly sorted), sand tailings (well sorted) and smelter slag (blocks up to 30 cm across). All of this material has oxidised to some degree over the ca. 100 years since the site was abandoned. Oxidation has resulted in acidification of the residues down to pH 2-5. Smelter slag contains pyrrhotite (FeS) and metallic antimony, and oxidation is restricted to surfaces only. The coarse tailings are the most oxidised, and few sulfide grains persist. Unoxidised sand tailings contain 10-20 vol.% stibnite (Sb2S3) containing up to 5% As, with subordinate arsenopyrite (FeAsS), and minor pyrite (FeS2). The sand tailings are variably oxidised on a scale of 2-10 cm, but original depositional layering is preserved during oxidation and formation of senarmontite (Sb2O3). Oxidation of sand tailings has resulted in localised mobility of both Sb and As on the cm scale, resulting in redistribution of these metalloids with iron oxyhydroxide around sand grain boundaries. Experiments demonstrate that Sb mobility decreases with time on a scale of days. Attenuation of both As and Sb occurs due to adsorption on to iron oxyhydroxides which are formed during oxidation of the smelter residues. There is no detectable loss of Sb or As from the smelter site into the adjacent river, <50 m away, which has elevated Sb (ca. 20 microg/l) and As (ca. 7 microg/l) from mineralised rocks upstream. Despite the high concentrations of Sb and As in the smelter residues, these metalloids are not being released into the environment. PMID:14987811

  12. 40 CFR 421.140 - Applicability: Description of the primary antimony subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... primary antimony subcategory. 421.140 Section 421.140 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS NONFERROUS METALS MANUFACTURING POINT SOURCE CATEGORY Primary Antimony Subcategory § 421.140 Applicability: Description of the primary...

  13. 40 CFR 421.140 - Applicability: Description of the primary antimony subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... primary antimony subcategory. 421.140 Section 421.140 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS NONFERROUS METALS MANUFACTURING POINT SOURCE CATEGORY Primary Antimony Subcategory § 421.140 Applicability: Description of the primary...

  14. pH-dependent release characteristics of antimony and arsenic from typical antimony-bearing ores.

    PubMed

    Hu, Xingyun; Guo, Xuejun; He, Mengchang; Li, Sisi

    2016-06-01

    The pH-dependent leaching of antimony (Sb) and arsenic (As) from three typical Sb-bearing ores (Banxi, Muli and Tongkeng Antimony Mine) in China was assessed using a pH-static leaching experiment. The pH changes of the leached solutions and pH-dependent leaching of Sb and As occurred in different ways. For the Banxi and Muli Sb ores, alkaline conditions were more favorable for the release of Sb compared to neutral and acidic conditions, but the reverse was true for the pH-dependent release of As. For the Tongkeng Sb ore, unlike the previous two Sb-bearing ores, acidic conditions were more favorable for Sb release than neutral and alkaline conditions. The ores with lower Sb and As contents released higher percentages of their Sb and As after 16day leaching, suggesting that they are the largest potential sources of pollution. This work may provide key information on the geochemistry of Sb and As in the weathering zone. PMID:27266313

  15. 40 CFR 440.90 - Applicability; description of the antimony ore subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... antimony ore subcategory. 440.90 Section 440.90 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) ORE MINING AND DRESSING POINT SOURCE CATEGORY Antimony Ore Subcategory § 440.90 Applicability; description of the antimony ore subcategory....

  16. 40 CFR 440.90 - Applicability; description of the antimony ore subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... antimony ore subcategory. 440.90 Section 440.90 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) ORE MINING AND DRESSING POINT SOURCE CATEGORY Antimony Ore Subcategory § 440.90 Applicability; description of the antimony ore subcategory....

  17. 40 CFR 440.90 - Applicability; description of the antimony ore subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... antimony ore subcategory. 440.90 Section 440.90 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORE MINING AND DRESSING POINT SOURCE CATEGORY Antimony Ore Subcategory § 440.90 Applicability; description of the antimony ore subcategory. The provisions of...

  18. 40 CFR 440.90 - Applicability; description of the antimony ore subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... antimony ore subcategory. 440.90 Section 440.90 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORE MINING AND DRESSING POINT SOURCE CATEGORY Antimony Ore Subcategory § 440.90 Applicability; description of the antimony ore subcategory. The provisions of...

  19. 40 CFR 440.90 - Applicability; description of the antimony ore subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... antimony ore subcategory. 440.90 Section 440.90 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) ORE MINING AND DRESSING POINT SOURCE CATEGORY Antimony Ore Subcategory § 440.90 Applicability; description of the antimony ore subcategory....

  20. Thin films and solar cells of cadmium telluride and cadmium zinc telluride

    NASA Astrophysics Data System (ADS)

    Ferekides, Christos Savva

    The objectives of this dissertation are to investigate (1) the metalorganic chemical vapor deposition (MOCVD) and properties of cadmium telluride (CdTe) and cadmium zinc telluride (Cd(1-x)Zn(z)Te) films and junctions, and their potential application to solar cells, and (2) the fabrication and characterization of CdTe solar cells by the close spaced sublimation (CSS) technique. CdTe and Cd(1-x)Zn(x)Te films have been deposited by MOCVD on a variety of substrates at 300-400 C. The effect of the deposition parameters and post deposition heat treatments on the electrical, optical, and structural properties have been investigated. Heterojunctions of the configuration CdTe/transparent conducting semiconductor (TCS) and Cd(1-x)Zn(x)Te/TCS have been prepared and characterized. CdTe(MOCVD)/CdS and Cd(1-x)Zn(x)Te(E sub g = 1.65eV)/Cd(1-x)Zn(x)S solar cells with efficiencies of 9.9 percent and 2.4 percent, respectively have been fabricated. The as-deposited CdTe(MOCVD)/CdS junctions exhibited high dark current densities due to deflects at the interface associated with small grain size. Their characteristics of the Cd(1-x)Zn(x)Te junctions degraded with increasing Zn concentration due to the crystalline quality and very small grain size (0.3 microns) in films with high ZnTe contents (greater than 25 percent). No effective post-deposition heat treatment has been developed. CdTe/CdS solar cells have also been fabricated by the close spaced sublimation (CSS). Significant improvements in material and processing have been made, and in collaboration with fellow researchers an AM1.5 conversion efficiency of 13.4 percent has been demonstrated, the highest efficiency ever measured for such devices. The highest conversion efficiency for the CdTe(CSS)/CdS solar cell was achieved by reaching high open-circuit voltages and fill factors, while the short-circuit current densities were moderate. These results indicate that further improvements to increase the short-circuit current densities

  1. Possible Links between Sickle Cell Crisis and Pentavalent Antimony

    PubMed Central

    Garcerant, Daniel; Rubiano, Luisa; Blanco, Victor; Martinez, Javier; Baker, Nancy C.; Craft, Noah

    2012-01-01

    For over 60 years, pentavalent antimony (Sbv) has been the first-line treatment of leishmaniasis. Sickle cell anemia is a disease caused by a defect in red blood cells, which among other things can cause vasooclusive crisis. We report the case of a 6-year-old child with leishmaniasis who during treatment with meglumine antimoniate developed a sickle cell crisis (SCC). No previous reports describing the relationship between antimonial drugs and sickle cell disease were found. Reviews of both the pathophysiology of SCC and the mechanism of action of Sbv revealed that a common pathway (glutathione) may have resulted in the SCC. ChemoText, a novel database created to predict chemical-protein-disease interactions, was used to perform a more expansive and systematic review that was able to support the association between glutathione, Sbv, and SCC. Although suggestive evidence to support the hypothesis, additional research at the bench would be needed to prove Sbv caused the SCC. PMID:22665619

  2. Technetium-99m antimony colloid for bone-marrow imaging

    SciTech Connect

    Martindale, A.A.; Papadimitriou, J.M.; Turner, J.H.

    1980-11-01

    Technetium-99m antimony colloid was prepared in our laboratory for bone-marrow imaging. Optimal production of colloid particles of size range 1 to 13 nm was achieved by the use of polyvinylpyrrolidone of mol. wt. 44,000. Electron microscopy was used to size the particles. Studies in rabbits showed exclusive concentration in the subendothelial dendritic phagocytes of the bone marrow. Pseudopods from these cells were found to traverse interendothelial junctions and concentrate colloid from the sinusoids. Imaging studies of bone marrow in rabbits showed the superiority of the Tc-99m antimony colloid over the much larger colloidal particle of Tc-99m sulfur colloid. Tissue distribution studies in the rat confirmed that bone-marrow uptake of Tc-99m antimony colloid was greater than that of Tc-99m sulfur colloid, although blood clearance was much slower.

  3. Antimony Based III-V Thermophotovoltaic Devices

    SciTech Connect

    CA Wang

    2004-06-09

    Antimony-based III-V thermophotovoltaic (TPV) cells are attractive converters for systems with low radiator temperature around 1100 to 1700 K, since these cells potentially can be spectrally matched to the thermal source. Cells under development include GaSb and the lattice-matched GaInAsSb/GaSb and InPAsSb/InAs quaternary systems. GaSb cell technology is the most mature, owing in part to the relative ease in preparation of the binary alloy compared to quaternary GaInAsSb and InPAsSb alloys. Device performance of 0.7-eV GaSb cells exceeds 90% of the practical limit. GaInAsSb TPV cells have been the primary focus of recent research, and cells with energy gap E{sub g} ranging from {approx}0.6 to 0.49 eV have been demonstrated. Quantum efficiency and fill factor approach theoretical limits. Open-circuit voltage factor is as high as 87% of the practical limit for the higher-E{sub g} cells, but degrades to below 80% with decreasing E{sub g} of the alloy, which might be due to Auger recombination. InPAsSb cells are the least studied, and a cell with E{sub g} = 0.45-eV has extended spectral response out to 4.3 {micro}m. This paper briefly reviews the main contributions that have been made for antimonide-based TPV cells, and suggests additional studies for further performance enhancements.

  4. Lattice dynamics of femtosecond laser-excited antimony

    NASA Astrophysics Data System (ADS)

    Abdel-Fattah, Mahmoud Hanafy; Bugayev, Aleksey; Elsayed-Ali, Hani E.

    2016-07-01

    Ultrafast electron diffraction is used to probe the lattice dynamics of femtosecond laser-excited antimony thin film. The temporal hierarchies of the intensity and position of diffraction orders are monitored. The femtosecond laser excitation of antimony film was found to lead to initial compression after the laser pulse, which gives way to tension vibrating at new equilibrium displacement. A damped harmonic oscillator model, in which the hot electron-blast force contributes to the driving force of oscillations in lattice spacing, is used to interpret the data. The electron-phonon energy-exchange rate and the electronic Grüneisen parameter were obtained.

  5. Barium and antimony distributions on the hands of nonshooters.

    PubMed

    Havakost, D G; Peters, C A; Koons, R D

    1990-09-01

    Barium and antimony levels from selected areas of the left and right hands of 269 nonshooters provide a database for interpretation of gunshot residue swab analysis results. The database represents a variety of activities of individuals sampled by collectors throughout the United States. Nonshooting exposure to barium and antimony can generally be distinguished from firearms-associated exposure by considering the relative levels of the elements, location on the hands, and condition of the swabs. Consistent definition of sampling procedures and accurate analytical results make this database applicable for interpretation of data generated by most gunshot residue swab examiners. PMID:2230685

  6. Reductive precipitation of metals photosensitized by tin and antimony porphyrins

    DOEpatents

    Shelnutt, John A.; Gong, Weiliang; Abdelouas, Abdesselam; Lutze, Werner

    2003-09-30

    A method for reducing metals using a tin or antimony porphyrin by forming an aqueous solution of a tin or antimony porphyrin, an electron donor, such as ethylenediaminetetraaceticacid, triethylamine, triethanolamine, and sodium nitrite, and at least one metal compound selected from a uranium-containing compound, a mercury-containing compound, a copper-containing compound, a lead-containing compound, a gold-containing compound, a silver-containing compound, and a platinum-containing compound through irradiating the aqueous solution with light.

  7. Antimony recycling in the United States in 2000

    USGS Publications Warehouse

    Carlin, James F.

    2006-01-01

    The importance of recycling has become more obvious as concerns about the environment and import dependence have grown in recent years. When materials are recycled, fewer natural resources are consumed, and less waste products go to landfills or pollute the water and air. This study, one of a series of reports on metals recycling in 2000, discusses the flow of antimony from mining through its uses and disposal with emphasis on recycling. In 2000, the recycling efficiency for antimony was estimated to be 89 percent, and the recycling rate was about 20 percent.

  8. Brain SPECT thallium using cadmium zinc telluride: a first experience.

    PubMed

    Farid, Karim; Queneau, Mathieu; Guernou, Mohamed; Lussato, David; Petras, Slavomir; Songy, Bernard

    2011-11-01

    A 70-year-old man underwent a thallium-201 brain SPECT in the work-up and characterization of a frontotemporal mass. SPECT images were performed on cadmium zinc telluride system during only 5 minutes and after the injection of only 2 mCi. Images demonstrated high thallium uptake in frontotemporal areas considered as a potential malignant tumor. Surgical removal confirmed the diagnosis of malignant glioblastoma. The thallium SPECT fast acquisition imaging on cadmium zinc telluride systems is feasible with reduced injected dose. This method allows a significantly decrease of patient radiation exposure without compromising the image quality. This initial experience needs to be confirmed and optimized in larger clinical studies. PMID:21975418

  9. Thin film cadmium telluride, zinc telluride, and mercury zinc telluride solar cells. Final subcontract report, 1 July 1988--31 December 1991

    SciTech Connect

    Chu, T.L.

    1992-04-01

    This report describes research to demonstrate (1) thin film cadmium telluride solar cells with a quantum efficiency of 75% or higher at 0. 44 {mu}m and a photovoltaic efficiency of 11.5% or greater, and (2) thin film zinc telluride and mercury zinc telluride solar cells with a transparency to sub-band-gap radiation of 65% and a photovoltaic conversion efficiency of 5% and 8%, respectively. Work was directed at (1) depositing transparent conducting semiconductor films by solution growth and metal-organic chemical vapor deposition (MOCVD) technique, (2) depositing CdTe films by close-spaced sublimation (CSS) and MOCVD techniques, (3) preparing and evaluating thin film CdTe solar cells, and (4) preparing and characterizing thin film ZnTe, CD{sub 1-x}Zn{sub 1-x}Te, and Hg{sub 1-x}Zn{sub x}Te solar cells. The deposition of CdS films from aqueous solutions was investigated in detail, and their crystallographic, optical, and electrical properties were characterized. CdTe films were deposited from DMCd and DIPTe at 400{degrees}C using TEGa and AsH{sub 3} as dopants. CdTe films deposited by CSS had significantly better microstructures than those deposited by MOCVD. Deep energy states in CdTe films deposited by CSS and MOCVD were investigated. Thin films of ZnTe, Cd{sub 1- x}Zn{sub x}Te, and Hg{sub 1-x}Zn{sub x}Te were deposited by MOCVD, and their crystallographic, optical, and electrical properties were characterized. 67 refs.

  10. Modeling insights on the melt growth of cadmium zinc telluride

    NASA Astrophysics Data System (ADS)

    Derby, Jeffrey J.; Zhang, Nan; Yeckel, Andrew

    2013-09-01

    Computational modeling has provided the understanding needed to unravel many of the unusual characteristics of the melt growth of cadmium zinc telluride. Results are presented that clarify the origin and benefit of horizontal Bridgman shelf growth employed for infrared substrate material. Another example provides insight on how a non-classical approach may provide improved outcomes using multiple-zone, gradient-freeze furnaces for the vertical Bridgman growth of bulk material for gamma radiation detectors.

  11. Gamma-ray peak shapes from cadmium zinc telluride detectors

    SciTech Connect

    Namboodiri, M.N.; Lavietes, A.D.; McQuaid, J.H.

    1996-09-01

    We report the results of a study of the peak shapes in the gamma spectra measured using several 5 x 5 x 5 mm{sup 3} cadmium zinc telluride (CZT) detectors. A simple parameterization involving a Gaussian and an exponential low energy tail describes the peak shapes sell. We present the variation of the parameters with gamma energy. This type of information is very useful in the analysis of complex gamma spectra consisting of many peaks.

  12. Transient Response of Cadmium Telluride Modules to Light Exposure: Preprint

    SciTech Connect

    Deline, C.; del Cueto, J.; Albin, D. S.; Petersen, C.; Tyler, L.; TamizhMani, G.

    2011-07-01

    Commercial cadmium telluride (CdTe) photovoltaic (PV) modules from three different manufacturers were monitored for performance changes during indoor and outdoor light-exposure. Short-term transients in Voc were recorded on some modules, with characteristic times of ~1.1 hours. Outdoor performance data shows a similar drop in Voc after early morning light exposure. Preliminary analysis of FF changes show light-induced changes on multiple time scales, including a long time scale.

  13. Synthesis and characterization of bismuth telluride based nanostructured thermoelectric composite materials

    NASA Astrophysics Data System (ADS)

    Keshavarz Khorasgani, Mohsen

    Thermoelectric (TE) materials and devices are attractive in solid-state energy conversion applications such as waste heat recovery, air-conditioning, and refrigeration. Since the 1950's lots of unremitting efforts have been made to enhance the efficiency of energy conversion in TE materials (i. e. improving the figure of merit (ZT)), however, most of commercial bulk TE materials still suffer from low efficiency with ZTs around unity. To enhance the performance of bismuth telluride based TE alloys, we have developed composite TE materials, based on the idea that introducing more engineered interfaces in the bulk TE materials may lead to thermal conductivity reduction due to increased phonon scattering by these interfaces. In this approach it is expected that the electronic transport properties of the material are not effectively affected. Consequently, ZT enhancement can be achieved. In this dissertation we will discuss synthesis and characterization of two types of bismuth telluride based bulk composite TE materials. The first type is engineered to contain the presence of coherent interfaces between phases in the material resulting from different mixtures of totally miscible compounds with similar composition. The second type includes the nanocomposites with embedded foreign nano-particles in which the matrix and the particles are delimited by incoherent interfaces. The synthesis procedure, micro- and nano-structures as well as thermoelectric properties of these composites will be presented. In our study on the composites with coherent interfaces, we produced a series of different composites of p-type bismuth antimony telluride alloys and studied their microstructure and thermoelectric properties. Each composite consists of two phases that were obtained in powder form by mechanical alloying. Mixed powders in various proportions of the two different phases were consolidated by hot extrusion to obtain each bulk composite. The minimum grain size of bulk composites as

  14. Density functional study of silver defects in telluride thermoelectric materials

    NASA Astrophysics Data System (ADS)

    Ryu, Byungki; Oh, Min-Wook; Park, Su-Dong

    2015-03-01

    Silver impurity in telluride thermoelectric materials forms various defect and impurity structures, such as AgSb rich nanoregion in Ag-Sb-Pb-Te, Ag2Te and metallic silver in PbTe. To understand the atomic, electronic, energetic, and diffusion properties of silver impurities in telluride systems, we have performed the density functional theory and density functional perturbation theory calculations of silver doped PbTe. Under Te and Ag rich condition, silver telluride impurity phase or Ag-dimer defects are expected to be easily formed. Under Te poor condition, silver point defects are calculated to be easily formed and they are more stable than native point defects of PbTe, implying that silver point defect might be the major dopant responsible for the carrier generation in PbTe. We also calculated the diffusion coefficient and diffusion length of silver point defect in PbTe. Based on the results, we discussed the electrical and thermoelectric properties of silver doped PbTe. This work was supported by the National Institute of Supercomputing and Network/Korea Institute of Science and Technology Information with supercomputing resources including technical support (KSC-2014-C1-022).

  15. Discovery of palladium, antimony, tellurium, iodine, and xenon isotopes

    SciTech Connect

    Kathawa, J.; Fry, C.; Thoennessen, M.

    2013-01-15

    Currently, thirty-eight palladium, thirty-eight antimony, thirty-nine tellurium, thirty-eight iodine, and forty xenon isotopes have been observed and the discovery of these isotopes is described here. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.

  16. Antimony to Cure Visceral Leishmaniasis Unresponsive to Liposomal Amphotericin B.

    PubMed

    Morizot, Gloria; Jouffroy, Romain; Faye, Albert; Chabert, Paul; Belhouari, Katia; Calin, Ruxandra; Charlier, Caroline; Miailhes, Patrick; Siriez, Jean-Yves; Mouri, Oussama; Yera, Hélène; Gilquin, Jacques; Tubiana, Roland; Lanternier, Fanny; Mamzer, Marie-France; Legendre, Christophe; Peyramond, Dominique; Caumes, Eric; Lortholary, Olivier; Buffet, Pierre

    2016-01-01

    We report on 4 patients (1 immunocompetent, 3 immunosuppressed) in whom visceral leishmaniasis had become unresponsive to (or had relapsed after) treatment with appropriate doses of liposomal amphotericin B. Under close follow-up, full courses of pentavalent antimony were administered without life-threatening adverse events and resulted in rapid and sustained clinical and parasitological cure. PMID:26735920

  17. Acid-base properties of titanium-antimony oxides catalysts

    SciTech Connect

    Zenkovets, G.A.; Paukshtis, E.A.; Tarasova, D.V.; Yurchenko, E.N.

    1982-06-01

    The acid-base properties of titanium-antimony oxide catalysts were studied by the methods of back titration and ir spectroscopy. The interrelationship between the acid-base and catalytic properties in the oxidative ammonolysis of propylene was discussed. 3 figures, 1 table.

  18. Antimony tartrate corrosion inhibitive composition for coolant systems

    SciTech Connect

    Payerle, N.E.

    1987-08-11

    An automobile coolant concentrate is described comprising (a) a liquid polyhydric alcohol chosen from the group consisting of ethylene glycol, propylene glycol, diethylene glycol and mixtures thereof, and (b) corrosion inhibitors in a corrosion inhibitory amount with respect to corrosion of lead-containing solders, the corrosion inhibitors comprising (i) an alkali metal antimony tartrate, and (ii) an azole compound.

  19. Antimony to Cure Visceral Leishmaniasis Unresponsive to Liposomal Amphotericin B

    PubMed Central

    Morizot, Gloria; Jouffroy, Romain; Faye, Albert; Chabert, Paul; Belhouari, Katia; Calin, Ruxandra; Charlier, Caroline; Miailhes, Patrick; Siriez, Jean-Yves; Mouri, Oussama; Yera, Hélène; Gilquin, Jacques; Tubiana, Roland; Lanternier, Fanny; Mamzer, Marie-France; Legendre, Christophe; Peyramond, Dominique; Caumes, Eric; Lortholary, Olivier; Buffet, Pierre

    2016-01-01

    We report on 4 patients (1 immunocompetent, 3 immunosuppressed) in whom visceral leishmaniasis had become unresponsive to (or had relapsed after) treatment with appropriate doses of liposomal amphotericin B. Under close follow-up, full courses of pentavalent antimony were administered without life-threatening adverse events and resulted in rapid and sustained clinical and parasitological cure. PMID:26735920

  20. Solvothermal synthesis and study of nonlinear optical properties of nanocrystalline thallium doped bismuth telluride

    SciTech Connect

    Molli, Muralikrishna; Parola, Sowmendran; Avinash Chunduri, L.A.; Aditha, Saikiran; Sai Muthukumar, V; Mimani Rattan, Tanu; Kamisetti, Venkataramaniah

    2012-05-15

    Nanocrystalline Bismuth telluride and thallium (4 mol %) doped Bismuth telluride were synthesized through hydrothermal method. The as-prepared products were characterized using Powder X-ray Diffraction, High Resolution Transmission Electron Microscopy, Energy Dispersive X-Ray Spectroscopy, UV-Visible spectroscopy and Fourier Transform Infrared Spectroscopy. Powder XRD results revealed the crystalline nature of the obtained phases. HRTEM showed the particle-like morphology of the products. The decrease in the absorption coefficient due to thallium doping was observed in FTIR spectra. The intensity dependent nonlinear optical properties of nanocrystalline bismuth telluride and thallium doped bismuth telluride were studied using the Z-scan technique in open-aperture configuration. Bismuth telluride doped with thallium showed enhanced nonlinear optical response compared to pristine bismuth telluride and hence could be used as a potential candidate for optical power limiting applications. - Graphical Abstract: Nonlinear transmission (Z-scan) curves of nanocrystalline bismuth telluride ({Delta}) and thallium doped bismuth telluride ({open_square}). Thallium doped bismuth telluride showed enhanced nonlinear absorption compared to bismuth telluride. Inset: TEM micrograph of bismuth telluride nanocrystallites. Highlights: Black-Right-Pointing-Pointer Synthesis of Nanocrystalline Bi{sub 2}Te{sub 3} and Thallium doped Bi{sub 2}Te{sub 3} through solvothermal method. Black-Right-Pointing-Pointer Reduced absorption coefficient due to thallium doping found from IR spectroscopy. Black-Right-Pointing-Pointer Open-aperture Z-scan technique for nonlinear optical studies. Black-Right-Pointing-Pointer Two photon absorption based model for theoretical fitting of Z-scan data. Black-Right-Pointing-Pointer Enhanced nonlinear absorption in Thallium doped Bi{sub 2}Te{sub 3} - potential candidate for optical power limiting applications.

  1. Charge carrier effective mass and concentration derived from combination of Seebeck coefficient and 125Te NMR measurements in complex tellurides

    NASA Astrophysics Data System (ADS)

    Levin, E. M.

    2016-06-01

    Thermoelectric materials utilize the Seebeck effect to convert heat to electrical energy. The Seebeck coefficient (thermopower), S , depends on the free (mobile) carrier concentration, n , and effective mass, m*, as S ˜m*/n2 /3 . The carrier concentration in tellurides can be derived from 125Te nuclear magnetic resonance (NMR) spin-lattice relaxation measurements. The NMR spin-lattice relaxation rate, 1 /T1 , depends on both n and m* as 1 /T1˜(m*)3/2n (within classical Maxwell-Boltzmann statistics) or as 1 /T1˜(m*)2n2 /3 (within quantum Fermi-Dirac statistics), which challenges the correct determination of the carrier concentration in some materials by NMR. Here it is shown that the combination of the Seebeck coefficient and 125Te NMR spin-lattice relaxation measurements in complex tellurides provides a unique opportunity to derive the carrier effective mass and then to calculate the carrier concentration. This approach was used to study A gxS bxG e50-2xT e50 , well-known GeTe-based high-efficiency tellurium-antimony-germanium-silver thermoelectric materials, where the replacement of Ge by [Ag+Sb] results in significant enhancement of the Seebeck coefficient. Values of both m* and n derived using this combination show that the enhancement of thermopower can be attributed primarily to an increase of the carrier effective mass and partially to a decrease of the carrier concentration when the [Ag+Sb] content increases.

  2. Antimony and arsenic biogeochemistry in the East China Sea

    NASA Astrophysics Data System (ADS)

    Ren, Jing-Ling; Zhang, Xu-Zhou; Sun, You-Xu; Liu, Su-Mei; Huang, Daji; Zhang, Jing

    2016-02-01

    The biogeochemical cycles of the metalloid elements arsenic and antimony in the East China Sea (ECS), one of the most important marginal seas for western Pacific, were examined in May 2011. Dissolved inorganic arsenic (As(V) and As(III)) and antimony (Sb(V) and Sb(III)) species were determined by selective hydride generation-atomic fluorescence spectrometry (HG-AFS). Results show that total dissolved inorganic arsenic (TDIAs; [TDIAs]=[As(V)]+[As(III)]) were moderately depleted in the surface water and enriched in the deep water. Arsenite (As(III)) showed different vertical profiles with that of TDIAs, with significant surface enrichment in the middle shelf region where the concentrations of phosphate were extremely low. Speciation of dissolved arsenic was subtly controlled by the stoichiometric molar ratio of arsenate (As(V)) to phosphate. The average As(V)/P ratio for the ECS in spring 2011 was 10.8×10-3, which is higher than previous results and indicates the arsenate stress. The concentrations of total dissolved inorganic antimony (TDISb; [TDISb]=[Sb(V)]+[Sb(III)]) were high near the Changjiang Estuary and the coastal area of Hangzhou Bay and decreased moderately off the coast. TDISb displayed moderate conservative behavior in the ECS that confirms by the correlations with salinity and dissolved aluminum. Different with that of As(III), antimonite (Sb(III)) concentrations were extremely lower in the ECS, with relative higher concentration appeared at the bottom layer which indicates the contribution from sediment-water interface. A preliminary box model was established to estimate the water-mass balance and antimony budgets for the ECS. Compared with other areas in the world, the concentrations of dissolved inorganic arsenic and antimony in the ECS remain at natural levels.

  3. Method of Creating Micro-scale Silver Telluride Grains Covered with Bismuth Nanoparticles

    NASA Technical Reports Server (NTRS)

    Kim, Hyun-Jung (Inventor); Choi, Sang Hyouk (Inventor); King, Glen C. (Inventor); Park, Yeonjoon (Inventor); Lee, Kunik (Inventor)

    2014-01-01

    Provided is a method of enhancing thermoelectric performance by surrounding crystalline semiconductors with nanoparticles by contacting a bismuth telluride material with a silver salt under a substantially inert atmosphere and a temperature approximately near the silver salt decomposition temperature; and recovering a metallic bismuth decorated material comprising silver telluride crystal grains.

  4. Metal telluride clusters composed of niobocene carbonyl, telluride, and cobalt carbonyl units: syntheses, structures, and reactivity

    PubMed

    Brunner; Lucas; Monzon; Mugnier; Nuber; Stubenhofer; Stuckl; Wachter; Wanninger; Zabel

    2000-02-01

    Abstract: The reaction of [Cp#2NbTe2H] (1#; Cp# = Cp* (C5Me5) or Cp(x) (C5Me4Et)) with two equivalents of [Co2(CO)8] gives a series of cobalt carbonyl telluride clusters that contain different types of niobocene carbonyl fragments. At 0 degrees C, [Cp#2NbTe2CO3(CO)7] (2#) and [Co4Te2(CO)10] (3) are formed which disappear at higher temperatures: in boiling toluene a mixture of [cat2][Co9Te6(CO)8] (5#) (cat= [Cp#2Nb(CO)2]+) and [cat2][Co11Te7(CO)10] (6#) is formed along with [cat][Co(CO)4] (4#). Complexes 6# transform into [cat][Co11Te7(CO)10] (7#) upon interaction with HPF6 or wet SiO2. The molecular structures of 2(Cp(x)), 4(Cp(x)), 5(Cp*), 6(Cp*) and 7(Cp*) have been determined by X-ray crystallography. The structure of the neutral 2(Cp(x)) consists of a [Co3(CO)6Te2] bipyramid which is connected to a [(C5Me4Et)2Nb(CO)] fragment through a mu4-Te bridge. The ionic structures of 4(Cp(x)), 5(Cp*), 6(Cp*) and 7(Cp*) each contain one (4, 7) or two (5, 6) [Cp#2Nb(CO)2]+ cations. Apart from 4, the anionic counterparts each contain an interstitial Co atom and are hexacapped cubic cluster anions [Co9Te6(CO)8]2- (5) or heptacapped pentagonal prismatic cluster anions [Co11Te7(CO)10]n- (n=2: [6]2- , n=1: [7]-), respectively. Electrochemical studies established a reversible electron transfer between the anionic clusters [Co11,Te7(CO)10]- and [Co11Te7(CO)10]2in 6# and 7# and provided evidence for the existence of species containing [Co11Te7(CO),0] and [Co11Te7(CO)0]3-. The electronic structures of the new clusters and their relative stabilities are examined by means of DFT calculations. PMID:10747416

  5. BioGeochemistry of antimony, Sources, Transfers, Impacts and Assessment

    NASA Astrophysics Data System (ADS)

    Le Roux, Gael; Pinelli, Eric; Hedde, Mickael; Guiresse, Maritxu; De Vleeschouwer, François; Silvestre, Jérôme; Enrico, Maxime; Gandois, Laure; Monna, Fabrice; Gers, Charles; Probst, Anne

    2013-04-01

    BioGeoSTIB is a project funded by ADEME (French Environmental Protection Agency). Its aim is to provide a better understanding of biogeochemical cycle disturbances of antimony by man. Specifically, it is focused on the atmosphere-soil-organism interfaces. Based on a multi-scale approach, the impact of antimony on organisms and organism communities and the factors of Sb dispersion in the environment aim to better characterized. This report gives the main results of 2 and 1 -2 years of research. Using peat bogs as environmental archives, we show that Sb contamination in soils date back to the beginning of the metallurgy. Atmospheric deposition of Sb largely increased by 100 times during the Industrial Revolution compared to natural levels (~0,001-0,01 mg m-2 an-1) estimated in the deepest peat layers. This disturbance in the antimony geochemical cycle modified its concentrations in soils. One main source of present Sb contamination is automotive traffic due to Sb in braking lines. This emerging contamination was characterized close to a roundabout. This additional source of Sb does not seem to impact soil fauna but Sb concentrations in soil solutions exceed 1 μg L-1. Genotoxicity tests have been performed on the model plant Vicia faba and show that antimony is genotoxic at its lowest concentrations and that there is a synergistic effect lead, a trace metal frequently found in association with antimony in the environment. It is a main issue to determine Sb critical loads in the environment but main identified lacks are thermodynamic data, which are not available yet, to model the behavior of Sb in soil solutions and the fact the antimony is always associated with other anthropogenic trace metals like lead. Critical thresholds of Sb have been determined for the first time based on genotoxicity experiment. Simulations show that these thresholds can be exceeded in the future, whereas present limits for invertebrates (US-EPA) are and will not be reached. However

  6. Photoreflectance Study of Boron Ion-Implanted (100) Cadmium Telluride

    NASA Technical Reports Server (NTRS)

    Amirtharaj, P. M.; Odell, M. S.; Bowman, R. C., Jr.; Alt, R. L.

    1988-01-01

    Ion implanted (100) cadmium telluride was studied using the contactless technique of photoreflectance. The implantations were performed using 50- to 400-keV boron ions to a maximum dosage of 1.5 x 10(16)/sq cm, and the annealing was accomplished at 500 C under vacuum. The spectral measurements were made at 77 K near the E(0) and E(1) critical points; all the spectra were computer-fitted to Aspnes' theory. The spectral line shapes from the ion damaged, partially recovered and undamaged, or fully recovered regions could be identified, and the respective volume fraction of each phase was estimated.

  7. Cadmium zinc telluride detector system for nuclear material assay

    SciTech Connect

    Lavietes, A.D.; McQuaid, J.H.; Paulus, T.J.

    1997-07-15

    Three tools were developed towards design of an ambient temperature radiometric instrument, namely the CZT Probe--a cadmium zinc telluride based gamma and x ray detector probe, the MicroNOMAD--a low power, portable multichannel analyzed, and CZTU--spectral analysis software that provides uranium enrichment analysis. The combination of these three tools with an optimal sodium iodide (NaI) detector provides the ability to search for and then analyze uranium as well as other radionuclides in the field. Several national and international organizations including the International Atomic Energy Agency, the European Communities Safeguards Directorate, US Customs, and US DOE have expressed interest and are currently evaluating these systems.

  8. Ultrafast carrier dynamics in polycrystalline bismuth telluride nanofilm

    SciTech Connect

    Jia, Lin; Ma, Weigang; Zhang, Xing

    2014-06-16

    In this study, the dynamics of energy carriers in polycrystalline bismuth telluride nanofilm are investigated by the ultrafast pump-probe method. The energy relaxation processes are quantitatively analyzed by using the numerical fitting models. The extracted hot carrier relaxation times of photon excitation, thermalization, and diffusion are around sub-picosecond. The initial reflectivity recovery is found to be dominantly determined by the carrier diffusion, electron-phonon coupling, and photo-generated carriers trapping processes. High-frequency and low-frequency oscillations are both observed and attributed to coherent optical phonons and coherent acoustic phonons, respectively.

  9. The photocorrosion of n-cadmium telluride and its suppression

    NASA Astrophysics Data System (ADS)

    Curran, J. S.

    1980-09-01

    The photoelectrochemical properties of n-type cadmium telluride were studied in water and five other organic solvents, with a view to suppression of the photocorrosion reaction which prevents this and other n-type small bandgap semiconductors from being used in a practical semiconductor-electrolyte junction solar cell. Only the low donicity organic solvents propylene carbonate and methyl nitrate reduce the corrosion rate significantly. A stable photocurrent can be obtained using a solution of ferrocene in these two solvents but analysis of photoelectrolyzed solutions revealed a slow photocorrosion. The dependence of the flatband potential and of the practical significance with respect to solar cell applications considered.

  10. Thermodynamics of defect subsystem in zinc telluride crystals

    NASA Astrophysics Data System (ADS)

    Horichok, I. V.; Nykyruy, L. I.; Parashchuk, T. O.; Bardashevska, S. D.; Pylyponuk, M. P.

    2016-06-01

    Using method on the base of minimizing of thermodynamic potential in “crystal-vapor” system as a function of defect concentration the equilibrium concentration of point defects and free charge carriers in zinc telluride (ZnTe) crystals have been calculated depending on the technological factors of two-temperature annealing (annealing temperature T and vapor pressure PZn of zinc or PTe of tellurium). It is shown that the dominant defects are zinc vacancies the charge state of which depends on the technological conditions of annealing.

  11. Thermoelectric and structural characterizations of individual electrodeposited bismuth telluride nanowires

    NASA Astrophysics Data System (ADS)

    Mavrokefalos, Anastassios; Moore, Arden L.; Pettes, Michael T.; Shi, Li; Wang, Wei; Li, Xiaoguang

    2009-05-01

    The thermoelectric properties and crystal structure of individual electrodeposited bismuth telluride nanowires (NWs) were characterized using a microfabricated measurement device and transmission electron microscopy. Annealing in hydrogen was used to obtain electrical contact between the NW and the supporting Pt electrodes. By fitting the measured Seebeck coefficient with a two-band model, the NW samples were determined to be highly n-type doped. Higher thermal conductivity and electrical conductivity were observed in a 52 nm diameter monocrystalline NW than a 55 nm diameter polycrystalline NW. The electron mobility of the monocrystalline NW was found to be about 19% lower than that of bulk crystal at a similar carrier concentration and about 2.5 times higher than that of the polycrystalline NW. The specularity parameter for electron scattering by the NW surface was determined to be about 0.7 and partially specular and partially diffuse, leading to a reduction in the electron mean-free path from 61 nm in the bulk to about 40 nm in the 52 nm NW. Because of the already short phonon mean-free path of about 3 nm in bulk bismuth telluride, diffuse phonon-surface scattering is expected to reduce the lattice thermal conductivity of the 52-55 nm diameter NWs by only about 20%, which is smaller than the uncertainty in the extracted lattice thermal conductivity based on the measured total thermal conductivity and calculated electron thermal conductivity. Although the lattice thermal conductivity of the polycrystalline NW is likely lower than the bulk values, the lower thermal conductivity observed in this polycrystalline sample is mainly caused by the lower electron concentration and mobility. For both samples, the thermoelectric figure of merit (ZT) increases with temperature and is about 0.1 at a temperature of 400 K. The low ZT compared to that of bulk crystals is mainly caused by a high doping level, suggesting the need for better control of the chemical composition in

  12. High pressure phase transition and elastic properties of americium telluride

    NASA Astrophysics Data System (ADS)

    Aynyas, Mahendra; Rukmangad, Aditi; Arya, B. S.; Sanyal, S. P.

    2013-06-01

    The structural and elastic properties of Americium Telluride (AmTe) have been investigated by using a modified inter-ionic potential theory (MIPT). This theory is capable of explaining first order phase transition with a crystallographic change NaCl to CsCl structure for this compound. The values of optimized lattice constant, phase transition pressure, zero pressure bulk modulus and second order elastic constants (C11, C44) agree well with their corresponding experimental data. Debye temperature (θD) is also calculated for this compound for the first time.

  13. An evaluation of cadmium telluride detectors for computer assisted tomography.

    PubMed

    Chu, D; Kaufman, L; Hosier, K; Hoenninger, J

    1978-11-01

    Cadmium telluride (CdTe) presents a set of extremely attractive features as an X-ray detector for computer assisted tomography (CAT). It is stable and easily handled; has a high detection efficiency and very efficient conversion of energy to charge; and permits a high element density in a compact configuration. Unfortunately, effects due to "polarization," "tailing," high and variable leakage currents, and long "memory" are incompatible with the needs of CAT instrumentation. Pulse-processing techniques have allowed us to eliminate these problems in positive-sensitive detectors, thus opening the way for utilization of CdTe in CAT. PMID:711945

  14. High efficiency thin film cadmium telluride solar cells

    NASA Astrophysics Data System (ADS)

    Chu, T. L.; Chu, S. S.; Ang, S. T.; Han, K. D.; Liu, Y. Z.

    Thin films of cadmium telluride deposited by the close-spaced sublimation (CSS) technique have been characterized and used for the preparation of CdS/CdTe heterojunction solar cells. The current-voltage and capacitance-voltage relations of CdS/CdTe heterojunctions indicate that the cleanliness of the interface is an important factor affecting the characteristics of the solar cells. The best cell has an area of about 1.2 sq cm and an AM1.5 (global) efficiency of 10.5 percent.

  15. Determination of fluorine in antimony catalysts for the liquid-phase production of freons

    SciTech Connect

    Shchavelev, V.B.

    1986-08-01

    In order to reduce the solubility of lanthanum fluoride and to improve the precision of fluorine determination, (ILLEGIBLE) recommend (ILLEGIBLE) organic solvents (ethanol, acetone, etc.) to the titrated solution. It is shown that fluoride can be determined in the presence of antimony without preparation only when all antimony is present in the tervalent state. The results obtained in the determination of fluoride ion in synthetic mixtures at a fluorine:antimony molar ratio of 2, which approximates the composition of the antimony catalyst, are shown in tables. It can be seen that hydrobromic acid is the only suitable of the agents tested, whereby its concentration in the analyzed sample must not be less than 7.6. The relatively high reproducibility of the proposed procedure allows the authors to recommend it for the determination of fluorine in antimony catalysts or other analogous compositions when fluorine and pentavalent antimony are present simultaneously.

  16. Antimony-assisted carbonization of Si(111) with solid source molecular beam epitaxy

    SciTech Connect

    Hackley, Justin; Richardson, Christopher J. K.; Sarney, Wendy L.

    2013-11-15

    The carbonization of an antimony-terminated Si (111) surface in a solid source molecular beam epitaxy system is presented. Reflection high-energy electron diffraction, atomic force microscopy, x-ray photoelectron spectroscopy, and cross-sectional transmission electron microscopy are used to characterize samples grown with and without antimony termination. It is shown that the antimony-terminated surface promotes the formation of thin, smooth and continuous SiC films at a relatively low temperature of 800 °C.

  17. States of antimony and tin atoms in lead chalcogenides

    SciTech Connect

    Bordovsky, G. A.; Nemov, S. A.; Marchenko, A. V.; Zaiceva, A. V.; Kozhokar, M. Yu.; Seregin, P. P.

    2011-04-15

    It is shown by Moessbauer spectroscopy of the {sup 119}Sb({sup 119m}Sn) isotope that impurity antimony atoms in PbS, PbSe, and PbTe lattices are distributed between cation and anion sublattices. In n-type samples, the greatest part of antimony is located in the anion sublattice; in hole ones, in the cation sublattice. The tin atoms formed as a result of radioactive decay of {sup 119}Sb (antisite state) are electrically inactive in the anion sub-lattice of PbS and PbSe, while, in the cation sublattice, they form donor U{sup -} centers. Electron exchange between the neutral and doubly ionized tin U{sup -} centers via the allowed band states is observed. The tin atoms formed after radioactive decay of {sup 119}Sb are electrically inactive in the anion and cation sublattices of PbTe.

  18. Transmission Potential of Antimony-Resistant Leishmania Field Isolates

    PubMed Central

    Seblova, Veronika; Oury, Bruno; Eddaikra, Naouel; Aït-Oudhia, Khatima; Pratlong, Francine; Gazanion, Elodie; Maia, Carla; Volf, Petr

    2014-01-01

    We studied the development of antimony-resistant Leishmania infantum in natural vectors Lutzomyia longipalpis and Phlebotomus perniciosus to ascertain the risk of parasite transmission by sand flies. All three resistant strains produced fully mature late-stage infections in sand flies; moreover, the resistant phenotype was maintained after the passage through the vector. These results highlight the risk of circulation of resistant Leishmania strains and question the use of human drugs for treatment of dogs as Leishmania reservoirs. PMID:25049256

  19. Transmission potential of antimony-resistant leishmania field isolates.

    PubMed

    Seblova, Veronika; Oury, Bruno; Eddaikra, Naouel; Aït-Oudhia, Khatima; Pratlong, Francine; Gazanion, Elodie; Maia, Carla; Volf, Petr; Sereno, Denis

    2014-10-01

    We studied the development of antimony-resistant Leishmania infantum in natural vectors Lutzomyia longipalpis and Phlebotomus perniciosus to ascertain the risk of parasite transmission by sand flies. All three resistant strains produced fully mature late-stage infections in sand flies; moreover, the resistant phenotype was maintained after the passage through the vector. These results highlight the risk of circulation of resistant Leishmania strains and question the use of human drugs for treatment of dogs as Leishmania reservoirs. PMID:25049256

  20. [Successful treatment of cutaneous leishmaniasis with amphotericin B; a case of unresponsive to pentavalent antimony therapy].

    PubMed

    Yeşilova, Yavuz; Turan, Enver; Sürücü, Hacer Altın; Aksoy, Mustafa; Özbilgin, Ahmet

    2015-03-01

    Cutaneous Leishmaniasis (CL) is a skin infection caused by various species of Leishmania parasites, which is transmitted by infected Phlebotomus sandfly bites. Pentavalent antimonials (meglumine antimoniate and sodium stibogluconate) are used for the treatment of adult CL patients as an effective and safe method. Liposomal amphotericin B is an alternative for the treatment of choice in cutaneous leishmaniasis cases which pentavalan antimony contraindicated or unresponsive to pentavalent antimony therapy. In this study, successful treatment with systemic liposomal amphotericin B of a cutaneous leishmaniasis case developing local side effects related both systemic and intralesional meglumine antimonate treatment was presented. PMID:25917587

  1. Correlation of CsK{sub 2}Sb photocathode lifetime with antimony thickness

    SciTech Connect

    Mamun, M. A. Elmustafa, A. A.; Hernandez-Garcia, C.; Poelker, M.

    2015-06-01

    CsK{sub 2}Sb photocathodes with quantum efficiency on the order of 10% at 532 nm, and lifetime greater than 90 days at low voltage, were successfully manufactured via co-deposition of alkali species emanating from an effusion source. Photocathodes were characterized as a function of antimony layer thickness and alkali consumption, inside a vacuum chamber that was initially baked, but frequently vented without re-baking. Photocathode lifetime measured at low voltage is correlated with the antimony layer thickness. Photocathodes manufactured with comparatively thick antimony layers exhibited the best lifetime. We speculate that the antimony layer serves as a reservoir, or sponge, for the alkali.

  2. Correlation of CsK2Sb photocathode lifetime with antimony thickness

    SciTech Connect

    Mamun, M. A.; Hernandez-Garcia, C.; Poelker, M.; Elmustafa, A. A.

    2015-06-01

    CsK2Sb photocathodes with quantum efficiency on the order of 10% at 532 nm, and lifetime greater than 90 days at low voltage, were successfully manufactured via co-deposition of alkali species emanating from an effusion source. Photocathodes were characterized as a function of antimony layer thickness and alkali consumption, inside a vacuum chamber that was initially baked, but frequently vented without re-baking. Photocathode lifetime measured at low voltage is correlated with the antimony layer thickness. Photocathodes manufactured with comparatively thick antimony layers exhibited the best lifetime. We speculate that the antimony layer serves as a reservoir, or sponge, for the alkali.

  3. Possible links between sickle cell crisis and pentavalent antimony.

    PubMed

    Garcerant, Daniel; Rubiano, Luisa; Blanco, Victor; Martinez, Javier; Baker, Nancy C; Craft, Noah

    2012-06-01

    For over 60 years, pentavalent antimony (Sb(v)) has been the first-line treatment of leishmaniasis. Sickle cell anemia is a disease caused by a defect in red blood cells, which among other things can cause vasooclusive crisis. We report the case of a 6-year-old child with leishmaniasis who during treatment with meglumine antimoniate developed a sickle cell crisis (SCC). No previous reports describing the relationship between antimonial drugs and sickle cell disease were found. Reviews of both the pathophysiology of SCC and the mechanism of action of Sb(v) revealed that a common pathway (glutathione) may have resulted in the SCC. ChemoText, a novel database created to predict chemical-protein-disease interactions, was used to perform a more expansive and systematic review that was able to support the association between glutathione, Sb(v), and SCC. Although suggestive evidence to support the hypothesis, additional research at the bench would be needed to prove Sb(v) caused the SCC. PMID:22665619

  4. Ore petrology and geochemistry of Tertiary gold telluride deposits of the Colorado mineral belt

    SciTech Connect

    Saunders, J.A.; Romberger, S.B.

    1985-01-01

    Epithermal gold telluride deposits from the Colorado mineral belt share a number of similarities: relationship to alkalic stocks; high fluorine and CO/sub 2/ content; and similar paragenesis. Petrography of deposits in the Jamestown, Cripple Creek, and La Plata districts has resulted in a composite paragenesis: early Fe-Cu-Pb-Zn sulfides + hematite; tetrahedrite; high Te tellurides; low Te tellurides; late native gold. Fluid inclusion studies suggest telluride deposition occurred below 200/sup 0/C from low salinity. Gangue and alteration mineralogy indicates the ore fluids were near neutral pH during telluride deposition. The presence of hematite and locally barite suggest relatively oxidizing conditions. Evaluation of thermodynamic stabilities of tellurides and aqueous tellurium species indicates that progressive oxidation is consistent with the observed ore mineral paragenesis. Available data on gold bisulfide and chloride complexes suggest neither were important in the transport of gold in these systems. Thermodynamic data suggest the ditelluride ion (Te/sub 2//sup 2 -/) predominates in the range of inferred physiochemical conditions for the transport and deposition of gold in these systems. Inferred complexes such as AuTe/sub 2//sup -/ could account for the gold transport, and oxidation would be the most effective mechanism of precipitation of gold telluride or native gold. Published data suggest the associated alkalic stocks may be the ultimate source of the metals, since they are enriched in Au, Ag, Te, As, and Bi.

  5. TOP as ligand and solvent to synthesize silver telluride nanosheets

    SciTech Connect

    Chen, Shutang; Lee, Soonil

    2015-11-15

    Highlights: • Silver telluride nanosheets were prepared through one-pot synthetic strategy. • TOP as both ligand and solvent favors silver telluride nanosheets growth. • The I–V curve of an Ag{sub 2}Te-nanosheet film indicates that as-prepared Ag{sub 2}Te nanosheets have good electric conductivity. - Abstract: Ag{sub 2}Te nanosheets are synthesized by a simple one-pot route using trioctylphosphine (TOP) as both solvent and stabilizer. Various controlling parameters were examined, such as molar ratios of AgNO{sub 3} to tellurium powder, reaction temperature and time, and precursor concentration. The morphology and composition of the products were characterized by X-ray diffraction, field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, and transmission electron microscopy. On the basis of a series of synthesis and characterizations, the formation mechanism of the Ag{sub 2}Te nanosheets are discussed. The I–V curve of an Ag{sub 2}Te-nan osheet film indicates that as-prepared Ag{sub 2}Te nanosheets have good electric conductivity.

  6. Superconductivity in oxygen doped iron telluride by molecular beam epitaxy

    NASA Astrophysics Data System (ADS)

    Zheng, Mao

    Iron base superconductor have gained much attention in the research community. They offer great potentials to improve our understanding of the subject of superconductivity by having another family of high temperature superconductors to compare and contrast to the cuprates. Practically, the iron based superconductors seems to be even better candidates for applications in power generation and power transmission. Iron telluride is regarded as the parent compound of the "11" family, the family of iron chalcogenide that has the simplest structure. Iron telluride itself is not a superconductor, by can become one when doped with oxygen. In this investigation, we developed the growth recipe of thin film iron telluride by Molecular Beam Epitaxy (MBE). We found the growth to be self-regulated, similar to that of GaAs. The initial layers of growth seem to experience a spontaneous crystallization, as the film quickly go from the initial polycrystalline phase to highly crystalline in just a few unit cells. We studied oxygen doping to the iron telluride thin films and the resultant superconductivity. We characterized the sample with AFM, XRD, transport, and STEM-EELS, and we found that interfacial strain is not an essential ingredient of superconductivity in this particular case. We investigated the doping conditions for two candidate oxygen doping modes: substitution and interstitial. We found that substitution occurs when the film grown in oxygen, while interstitial oxygen is primarily incorporated during annealing after growth. The substitutional oxygen are concentrated in small local regions where substitution is around 100%, but does not contribute to superconductivity. We estimated substitutional oxygen to be about 5%, and is the proximate cause of superconductivity. Hall experiment on our sample showed a shift of dominant carrier type from holes to electrons around 35 K, but the transition was set in motion as early as the structural phase transition around 70 K. We

  7. Recent advances on antimony(III/V) compounds with potential activity against tumor cells.

    PubMed

    Hadjikakou, S K; Ozturk, I I; Banti, C N; Kourkoumelis, N; Hadjiliadis, N

    2015-12-01

    Antimony one of the heavier pnictogens, has been in medical use against microbes and parasites as well. Antimony-based drugs have been prescribed against leishmaniasis since the parasitic transmission of the tropical disease was understood in the beginning of the 20th century. The activity of arsenic against visceral leishmaniasis led to the synthesis of an array of arsenic-containing parasitic agents, among them the less toxic pentavalent antimonials: Stibosan, Neostibosan, and Ureastibamine. Other antimony drugs followed: sodium stibogluconate (Pentostam) and melglumine antimoniate (Glucantim or Glucantime); both continue to be in use today despite their toxic side effects and increasing loss in potency due to the growing resistance of the parasite against antimony. Antimony compounds and their therapeutic potentials are under consideration from many research groups, while a number of early reviews recording advances of antimony biomedical applications are also available. However, there are only few reports on the screening for antitumor potential of antimony compounds. This review focuses upon results obtained on the anti-proliferative activity of antimony compounds in the past years. This survey shows that antimony(III/V) complexes containing various types of ligands such as thiones, thiosemicarbazones, dithiocarbamates, carboxylic acids, or ketones, nitrogen donor ligands, exhibit selectivity against a variety of cancer cells. The role of the ligand type of the complex is elucidated within this review. The complexes and their biological activity are already reported elsewhere. However quantitative structure-activity relationship (QSAR) modeling studies have been carried out and they are reported for the first time here. PMID:26092367

  8. Corrosion of low-antimony lead-cadmium alloys in conditions of long-term polarization

    NASA Astrophysics Data System (ADS)

    Nuzhny, Alex

    Nowadays, lead-acid battery grids are manufactured mostly from low-antimony and lead-calcium alloys. A variable corrosion resistance of battery grids is caused by either battery operation conditions, purity of used alloy components, an alloy makeup, and the castings quality. Such compositions as usual lead-antimony alloy, low-antimony lead-arsenious alloy and lead-calcium alloy with moderate content of tin today may be regarded as the most studied ones. A significant share of published works has been devoted to low-antimony lead-tin alloys. In the present article, results of corrosion tests of the samples made with application of cadmium as the second component of low-antimony alloy, has been represented. Several samples were extra-alloyed by selenium and silver. Samples of lead-calcium and usual antimony alloys as well as pure lead samples were being tested simultaneously. Upon termination of polarization, weight of anodic films referred to a unit of the sample surface has been determined. Thus, the film covering lead-antimony alloy sample has the maximal weight, whereas the oxidation products on the pure lead surface have the lowest one. Among low-antimony alloys, the highest corrosion resistance has been found out with the samples alloyed by a low amount of silver. The microstructure of the castings surface has been analysed. Process of corrosion has been considered in connection with size of grains.

  9. Oxidation and mobilization of metallic antimony in aqueous systems with simulated groundwater

    NASA Astrophysics Data System (ADS)

    Ilgen, A. G.; Majs, F.; Barker, A. J.; Douglas, T. A.; Trainor, T. P.

    2014-05-01

    Antimony (Sb) is a contaminant of concern that can be present in elevated concentrations in shooting range soils due to mobilization from spent lead/antimony bullets. Antimony in shooting range soils has been observed as either metallic Sb(0) or as Sb(V) immobilized by iron (hydr)oxides. The absence of Sb(III) in soils is indicative of rapid Sb(III) oxidation to Sb(V) under surface soil conditions. However, the major controls on antimony oxidation and mobility are poorly understood. To better understand these controls we performed multiple batch experiments under oxic conditions to quantify the oxidation and dissolution of antimony in systems where Sb(0) is oxidized to Sb(III) and further to Sb(V). We also tested how variations in the aqueous matrix composition and the presence of metallic lead (Pb) affect the dissolution, solid phase speciation, and oxidation of antimony. We monitored changes in the aqueous antimony speciation using liquid chromatography inductively coupled plasma mass spectrometry (LC-ICP-MS). To test which solid phases form as a result of Sb(0) oxidation, and therefore potentially limit the mobility of antimony in our studied systems, we characterized the partially oxidized Sb(0) powders by means of extended X-ray absorption fine structure (EXAFS) spectroscopy and powder X-ray diffraction (XRD).

  10. 78 FR 59679 - Antimony Trioxide TSCA Chemical Risk Assessment; Notice of Public Meetings and Opportunity To...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-27

    ... AGENCY Antimony Trioxide TSCA Chemical Risk Assessment; Notice of Public Meetings and Opportunity To... review of EPA's draft Toxic Substances Control Act (TSCA) chemical risk assessment, ``TSCA Workplan Chemical Risk Assessment for Antimony Trioxide.'' EPA will hold three peer review meetings by web...

  11. A preliminary study on the use of cadmium telluride detectors in the scintigraphy of thyroid gland

    NASA Astrophysics Data System (ADS)

    Mancini, A. M.; Quirini, A.; Vasanelli, L.; Bacci, C.; Bernabei, R.; Pani, R.; Rispoli, B.; Ballesio, P. L.; Furetta, C.

    1981-10-01

    A cadmium telluride gamma detector has been used for monitoring the activity of a radioactive tracer in a thyroid gland. Preliminary measurements are reported in comparison with those obtained with a standard NaI(Tl) scintillator.

  12. Tunable split-ring resonators using germanium telluride

    NASA Astrophysics Data System (ADS)

    Kodama, C. H.; Coutu, R. A.

    2016-06-01

    We demonstrate terahertz (THz) split-ring resonator (SRR) designs with incorporated germanium telluride (GeTe) thin films. GeTe is a chalcogenide that undergoes a nonvolatile phase change from the amorphous to crystalline state at approximately 200 °C, depending on the film thickness and stoichiometry. The phase change also causes a drop in the material's resistivity by six orders of magnitude. In this study, two GeTe-incorporated SRR designs were investigated. The first was an SRR made entirely out of GeTe and the second was a gold SRR structure with a GeTe film incorporated into the gap region of the split ring. These devices were characterized using THz time-domain spectroscopy and were heated in-situ to determine the change in the design operation with varying temperatures.

  13. Comparison of Germanium Telluride (GeTe) Crystals

    NASA Technical Reports Server (NTRS)

    2004-01-01

    Comparison of Germanium Telluride (GeTe) Crystals grown on Earth (left) and in space (right) during the Skylab SL-3 mission. These crystals were grown using a vapor transport crystal growth method in the Multipurpose Electric Furnace System (MEFS). Crystals grown on earth are needles and platelettes with distorted surfaces and hollow growth habits. The length of the ground-based needle is approximately 2 mm and the average lenth of the platelets is 1 mm. The dull appearance of the Skylab crystals resulted from condensation of the transport agent during the long cooling period dictated by the Skylab furnace. In a dedicated process, this would be prevented by removing the ampoule from the furnace and quenching the vapor source.

  14. Study on thermal annealing of cadmium zinc telluride (CZT) crystals

    SciTech Connect

    Yang, G.; Bolotnikov, A.E.; Fochuk, P.M.; Camarda, G.S.; Cui, Y.; Hossain, A.; Kim, K.; Horace, J.; McCall, B.; Gul, R.; Xu, L.; Kopach, O.V.; and James, R.B.

    2010-08-01

    Cadmium Zinc Telluride (CZT) has attracted increasing interest with its promising potential as a room-temperature nuclear-radiation-detector material. However, different defects in CZT crystals, especially Te inclusions and dislocations, can degrade the performance of CZT detectors. Post-growth annealing is a good approach potentially to eliminate the deleterious influence of these defects. At Brookhaven National Laboratory (BNL), we built up different facilities for investigating post-growth annealing of CZT. Here, we report our latest experimental results. Cd-vapor annealing reduces the density of Te inclusions, while large temperature gradient promotes the migration of small-size Te inclusions. Simultaneously, the annealing lowers the density of dislocations. However, only-Cd-vapor annealing decreases the resistivity, possibly reflecting the introduction of extra Cd in the lattice. Subsequent Te-vapor annealing is needed to ensure the recovery of the resistivity after removing the Te inclusions.

  15. Towards understanding junction degradation in cadmium telluride solar cells

    SciTech Connect

    Nardone, Marco

    2014-06-21

    A degradation mechanism in cadmium telluride (CdTe/CdS) solar cells is investigated using time-dependent numerical modeling to simulate various temperature, bias, and illumination stress conditions. The physical mechanism is based on defect generation rates that are proportional to nonequilibrium charge carrier concentrations. It is found that a commonly observed degradation mode for CdTe/CdS solar cells can be reproduced only if defects are allowed to form in a narrow region of the absorber layer close to the CdTe/CdS junction. A key aspect of this junction degradation is that both mid-gap donor and shallow acceptor-type defects must be generated simultaneously in response to photo-excitation or applied bias. The numerical approach employed here can be extended to study other mechanisms for any photovoltaic technology.

  16. Ion implantation of erbium into polycrystalline cadmium telluride

    SciTech Connect

    Ushakov, V. V. Klevkov, Yu. V.; Dravin, V. A.

    2015-05-15

    The specific features of the ion implantation of polycrystalline cadmium telluride with grains 20–1000 μm in dimensions are studied. The choice of erbium is motivated by the possibility of using rare-earth elements as luminescent “probes” in studies of the defect and impurity composition of materials and modification of the composition by various technological treatments. From the microphotoluminescence data, it is found that, with decreasing crystal-grain dimensions, the degree of radiation stability of the material is increased. Microphotoluminescence topography of the samples shows the efficiency of the rare-earth probe in detecting regions with higher impurity and defect concentrations, including regions of intergrain boundaries.

  17. Electric Field Distribution of Cadmium Zinc Telluride (CZT)

    SciTech Connect

    Yang,G.; Bolotnikov, A.; Camarda, G.S.; Cui, Y.; Hossain, A.; Kim, K.; James, R.B.

    2009-08-02

    Cadmium Zinc Telluride (CZT) is attracting increasing interest with its promise as a room-temperature nuclear-radiation-detector material. The distribution of the electric field in CZT detectors substantially affects their detection performance. At Brookhaven National Laboratory (BNL), we employed a synchrotron X-Ray mapping technique and a Pockels-effect measurement system to investigate this distribution in different detectors. Here, we report our latest experimental results with three detectors of different width/height ratios. A decrease in this ratio aggravates the non-uniform distribution of electric field, and focuses it on the central volume. Raising the bias voltage effectively can minimize such non-uniformity of the electric field distribution. The position of the maximum electric field is independent of the bias voltage; the difference between its maximum- and minimum-intensity of electric field increases with the applied bias voltage.

  18. Cadmium Telluride Solar Cells with PEDOT:PSS Back Contact

    NASA Astrophysics Data System (ADS)

    Mount, Michael; Duarte, Fernanda; Paudel, Naba; Yan, Yanfa; Wang, Weining

    Cadmium Telluride (CdTe) solar cell is one of the most promising thin film solar cells and its highest efficiency has reached 21%. To keep improving the efficiency of CdTe solar cells, a few issues need to be addressed, one of which is the back contact. The back contact of CdTe solar cells are mostly Cu-base, and the problem with Cu-based back contact is that Cu diffuses into the grain boundary and into the CdS/CdTe junction, causing degradation problem at high temperature and under illumination. To continue improving the efficiency of CdTe/CdS solar cells, a good ohmic back contact with high work function and long term stability is needed. In this work, we report our studies on the potential of conducting polymer being used as the back contact of CdTe/CdS solar cells. Conducting polymers are good candidates because they have high work functions and high conductivities, are easy to process, and cost less, meeting all the requirements of a good ohmic back contact for CdTe. In our studies, we used poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) with different conductivities and compared them with traditional Cu-based back contact. It was observed that the CdTe solar cell performance improves as the conductivity of the PEDOT:PSS increase, and the efficiency (9.1%) is approaching those with traditional Cu/Au back contact (12.5%). Cadmium Telluride Solar Cells with PEDOT:PSS Back Contact.

  19. Interfacial structure in Telluride-based thermoelectric materials.

    SciTech Connect

    Medlin, Douglas L.

    2010-06-01

    Chalcogenide compounds based on the rocksalt and tetradymite structures possess good thermoelectric properties and are widely used in a variety of thermoelectric devices. Examples include PbTe and AgSbTe2, which have the rocksalt structure, and Bi2Te3, Bi2Se3, and Sb2Te3, which fall within the broad tetradymite-class of structures. These materials are also of interest for thermoelectric nanocomposites, where the aim is to improve thermoelectric energy conversion efficiency by harnessing interfacial scattering processes (e.g., reducing the thermal conductivity by phonon scattering or enhancing the Seebeck coefficient by energy filtering). Understanding the phase stability and microstructural evolution within such materials is key to designing processing approaches for optimal thermoelectric performance and to predicting the long-term nanostructural stability of the materials. In this presentation, we discuss our work investigating relationships between interfacial structure and formation mechanisms in several telluride-based thermoelectric materials. We begin with a discussion of interfacial coherency and its special aspects at interfaces in telluride compounds based on the rocksalt and tetradymite structures. We compare perfectly coherent interfaces, such as the Bi2Te3 (0001) twin, with semi-coherent, misfitting interfaces. We next discuss the formal crystallographic analysis of interfacial defects in these systems and then apply this methodology to high resolution transmission electron microscopy (HRTEM) observations of interfaces in the AgSbTe2/Sb2Te3 and PbTe/Sb2Te3 systems, focusing on interfaces vicinal to {l_brace}111{r_brace}/{l_brace}0001{r_brace}. Through this analysis, we identify a defect that can accomplish the rocksalt-to-tetradymite phase transformation through diffusive-glide motion along the interface.

  20. Testing of antimony selective media for treatment of liquid radwaste

    SciTech Connect

    Yarnell, P.A.

    2007-07-01

    Nuclear power plants have sought radiation source term reduction and reduced discharge of radioactive constituents for many years. In the case of pressurized water reactors (PWRs), the latter efforts have been directed toward capture and immobilization of recalcitrant (ubiquitous radionuclides with long half-lives) species such as Cs-134 and Cs-137 and Co-58 and Co-60. As these plants resolved, or at least mitigated, the problems with radiocesium and radio-cobalt, antimony radionuclides (Sb-122, Sb-124, and Sb-125) have become a primary concern in liquid liquid radwaste systems Graver Technologies developed a granular composite metal oxide media with good selectivity for radio-antimony. Initial laboratory data were collected using non-radioactive salts of antimony, cesium, and cobalt to judge efficacy of selective removal of antimony. Based on success of those trials, the media, designated Gravex GX187, was tested in partnership with Energy Solutions (nee Duratek) using actual liquid liquid radwaste in two PWR plants. One of these plants performed extensive slip-stream trials comparing the GX187 with strong base anion resins. With more than 2500 bed volumes of throughput, the GX187 outperformed the other competitors by reducing both Sb-124 and Sb-125 radionuclides below minimum detectable activity (MDA) with average decontamination factors (DF's) of 170, even when subjected to high levels of borate. Based on these favorable results, Energy Solutions installed the GX187 in a layered bed in their ALPS liquid radwaste processing system at this plant in August 2005. After one year of intermittent, batchwise operation including an outage, the GX187 processed more than 2.25 million liters (>600,000 gallons) of liquid liquid radwaste while reducing the Sb-125 activity to 2.9 E-08 Bq/L (DF=111) on average. This evaluation is ongoing and will continue at least until the fall 2006 outage at this plant. Concurrently, Graver developed a second generation antimony selective

  1. New antimony substituted Mg-Al layered double hydroxides.

    PubMed

    Kim, Jin A; Hwang, Seong-Ju; Choy, Jin-Ho

    2008-10-01

    No antimony hydroxide has been previously reported not only in solid state but also in aqueous solution, surely due to the fact that the formation of antimony oxide, Sb2O3, is thermodynamically more favorable than that of the hydroxide phase, Sb(OH)3. According to the pH dependent solubility diagram of Sb2O3, antimony (III) hydroxide may not exist as a definite compound but be proposed as a hydrated monomeric molecular species, Sb(OH)3(aq), which is in equilibrium with Sb2O3, under a condition of very small ionic strength. This is probably the reason why no Sb(3+)-containing layered double hydroxide, LDH, has been reported as yet. In the present study, an attempt has been made to prepare new Sb(3+)-LDH by substituting the Al3+ in octahedral site partially with Sb3+ up to approximately 10%. From the X-ray diffraction analysis, we found that the lattice constants (a = 3.075 angstroms, c = 23.788 angstroms) of the pristine, Mg-Al LDH, increased gradually upto those (a = 3.087 angstroms, c = 24.167 angstroms) of Sb-LDH (8%-substituted). Beyond 10%, the Sb substitution does not lead to any further increases of lattice constants but the impurity Sb2O3 phase is formed. It is, therefore, concluded that the solubility limit of Sb3+ in LDH would be around 10%. In addition, we were able to determine the chemical formula of Sb-substituted LDHs as follows, Mg4Al(1-x)Sb(x)OH10(CO3)(1/2) x H2O (x = 0 approximately 0.08) on the basis of energy dispersive X-ray spectroscopy. PMID:19198414

  2. The Hydrothermal Chemistry of Gold, Arsenic, Antimony, Mercury and Silver

    SciTech Connect

    Bessinger, Brad; Apps, John A.

    2003-03-23

    A comprehensive thermodynamic database based on the Helgeson-Kirkham-Flowers (HKF) equation of state was developed for metal complexes in hydrothermal systems. Because this equation of state has been shown to accurately predict standard partial molal thermodynamic properties of aqueous species at elevated temperatures and pressures, this study provides the necessary foundation for future exploration into transport and depositional processes in polymetallic ore deposits. The HKF equation of state parameters for gold, arsenic, antimony, mercury, and silver sulfide and hydroxide complexes were derived from experimental equilibrium constants using nonlinear regression calculations. In order to ensure that the resulting parameters were internally consistent, those experiments utilizing incompatible thermodynamic data were re-speciated prior to regression. Because new experimental studies were used to revise the HKF parameters for H2S0 and HS-1, those metal complexes for which HKF parameters had been previously derived were also updated. It was found that predicted thermodynamic properties of metal complexes are consistent with linear correlations between standard partial molal thermodynamic properties. This result allowed assessment of several complexes for which experimental data necessary to perform regression calculations was limited. Oxygen fugacity-temperature diagrams were calculated to illustrate how thermodynamic data improves our understanding of depositional processes. Predicted thermodynamic properties were used to investigate metal transport in Carlin-type gold deposits. Assuming a linear relationship between temperature and pressure, metals are predicted to predominantly be transported as sulfide complexes at a total aqueous sulfur concentration of 0.05 m. Also, the presence of arsenic and antimony mineral phases in the deposits are shown to restrict mineralization within a limited range of chemical conditions. Finally, at a lesser aqueous sulfur

  3. Growth and Characterization of Bismuth and Antimony Thin Films

    NASA Astrophysics Data System (ADS)

    Martinez, A.; Berrios, A. R.; Collazo, R.; Garcia, J. L.; Ducoudray, G. O.

    1996-03-01

    We have grown thin films of bismuth and antimony using hot wall epitaxy. The polycrystalline films were grown onto (111)-silicon substrates. The chemical integrity of the films was established using Auger electron spectroscopy. The crystallographical properties of the films were assessed using x-ray diffraction techniques. We will report on the results of these characterization efforts, as well as, on the growth apparatus and process. Work supported in part by NSWC-CRADA 93-01 and EPSCoR-NSF Grant EHR-9108775

  4. Powder processing and mechanical properties of Silver0.86Lead19Antimony telluride20 (LAST) and Lead0.95Tin0.05Tellurium - Lead sulfide 8% (Lead telluride -Lead sulfide) thermoelectric materials

    NASA Astrophysics Data System (ADS)

    Ni, Jennifer Elisabeth

    Thermoelectric (TE) materials convert between thermal and electrical energy and when used with existing processes will increase the efficiency via waste heat recovery. Ag0.86Pb19SbTe20 (LAST) and Pb0.95Sn0.05Te - PbS 8% (PbTe-PbS) materials exhibit good thermoelectric (TE) properties and have potential applications as thermoelectric generators in waste heat recovery. However, to fully characterize the thermo-mechanical behavior of LAST and PbTe-PbS materials under in-service conditions, knowledge is needed of the mechanical and thermal properties at room and high temperature. As fracture strength is inversely proportional to the square root of grain size, cast ingots were powder processed to reduce powder particle size. Three different powder processing methods were used (1) dry milling only, (2) wet milling only, or (3) dry milling and wet milling The specimens were fabricated using hot pressing or pulsed electric current sintering (PECS) from planetary ball milled powders. In this study, elastic moduli, including Young's modulus, shear modulus, and Poisson's ratio, were measured dynamically using resonant ultrasound spectroscopy (RUS) at room temperature and as a function of temperature up to 663 K. The room temperature porosity dependence for Young's modulus followed the empirical exponential relationships common for brittle materials, with a material dependent constant bPE of 3.5 and 1.3 for LAST and PbTe-PbS, respectively. The room temperature Young's modulus for a theoretically dense specimen was 58.4 +/- 0.6 GPa and 56.2 +/- 0.4 GPa for for LAST and PbTe-PbS, respectively. For hot pressed PbTe-PbS specimens, the Vickers indentations mean hardness and fracture toughness was 1.18 + 0.09 GPa and 0.35 +/- 0.04 MPa·m 1/2. The coefficient of thermal expansion is important for understanding the mechanical response of a material to a thermal gradient or a thermal transient. For PbTe-PbS the coefficient of thermal expansion measured using dilatometry and high temperature x-ray diffraction was 21.5 x 10-6 K -1. Bloating during post-densification annealing was measured indirectly using resonant ultrasound spectroscopy and dilatometry and directly using scanning electron microscopy. Dry milled only PECS-processed PbTe-PbS specimens did not bloat during post-densification anneals up to 936 K. Hot pressed and PECS-processed specimens processed from wet milled and dry and wet milled powder bloated during densification anneals at temperatures over 603 K.

  5. Antimony contamination and its effect on Trifolium plants

    NASA Astrophysics Data System (ADS)

    Corrales, Isabel; Barceló, Juan; Bech, Jaume; Poschenrieder, Charlotte

    2014-05-01

    Antimony is not an essential element and soil Sb contents usually are low.However, soil contamination by Sb has increased in the last years due to the human activities (combustion of fossil fuels, mining, waste incineration, smelting, shooting and road traffic). The main objective of this work was to study the effect of different concentrations of antimony (KSb(OH)6) in order to evaluate the effect on growth and Sb uptake on Trifolium pratense cv. Milvus and Trifolium repens. Our results show that Sb accumulated both in roots and shoots of clover without any negative effect on root growth, cellular viability and lipid peroxidation. This absence of toxicity sympthoms in clover plants could be very dangerous because Sb can be inadvertedly incorporated into the trophic chain causing toxic effects both in animals and humans. The absence of toxic effects on plants does not seem to be due to detoxification by phytochelatins because the use of the gamma-glutamylcysteine synthetase inhibitor, L-buthionine-[S,R]-sulphoximine (BSO) did not enhance Sb toxicity to plants. (Supported by the Spanish MICINN project BFU2010-14873)

  6. Electronic band structure calculations of bismuth-antimony nanowires

    NASA Astrophysics Data System (ADS)

    Levin, Andrei; Dresselhaus, Mildred

    2012-02-01

    Alloys of bismuth and antimony received initial interest due to their unmatched low-temperature thermoelectric performance, and have drawn more recent attention as the first 3D topological insulators. One-dimensional bismuth-antimony (BiSb) nanowires display interesting quantum confinement effects, and are expected to exhibit even better thermoelectric properties than bulk BiSb. Due to the small, anisotropic carrier effective masses, the electronic properties of BiSb nanowires show great sensitivity to nanowire diameter, crystalline orientation, and alloy composition. We develop a theoretical model for calculating the band structure of BiSb nanowires. For a given crystalline orientation, BiSb nanowires can be in the semimetallic, direct semiconducting, or indirect semiconducting phase, depending on nanowire diameter and alloy composition. These ``phase diagrams'' turn out to be remarkably similar among the different orientations, which is surprising in light of the anisotropy of the bulk BiSb Fermi surface. We predict a novel direct semiconducting phase for nanowires with diameter less than ˜15 nm, over a narrow composition range. We also find that, in contrast to the bulk and thin film BiSb cases, a gapless state with Dirac dispersion cannot be realized in BiSb nanowires.

  7. Antimony sulphide, an absorber layer for solar cell application

    NASA Astrophysics Data System (ADS)

    Ali, N.; Hussain, Arshad; Ahmed, R.; Shamsuri, W. N. Wan; Shaari, A.; Ahmad, N.; Abbas, S. M.

    2016-01-01

    Replacement of the toxic, expensive and scarce materials with nontoxic, cheap and earth-abundant one, in solar cell absorber layer, is immensely needed to realize the vision of green and sustainable energy. Two-micrometre-thin antimony sulphide film is considered to be adequate as an absorbing layer in solar cell applications. In this paper, we synthesize antimony sulphide thin films on glass substrate by physical vapour deposition technique, and the obtained films were then annealed at different temperatures (150-250 °C). The as-deposited and annealed samples were investigated for structural and optoelectronic properties using different characterization techniques. The X-ray diffraction analysis showed that the annealed samples were polycrystalline with Sb2S3 phase, while the as-deposited sample was amorphous in nature. The optical properties are measured via optical ellipsometric techniques. The measured absorbance of the film is adequately high, and every photon is found to be absorbed in visible and NIR range. The conductivity type of the films measured by hot-point probe technique is determined to be p-type. The optical band gap of the resulted samples was in the range (2.4-1.3 eV) for the as-deposited and annealed films.

  8. Alkali oxide-tantalum, niobium and antimony oxide ionic conductors

    NASA Technical Reports Server (NTRS)

    Roth, R. S.; Brower, W. S.; Parker, H. S.; Minor, D. B.; Waring, J. L.

    1975-01-01

    The phase equilibrium relations of four systems were investigated in detail. These consisted of sodium and potassium antimonates with antimony oxide and tantalum and niobium oxide with rubidium oxide as far as the ratio 4Rb2O:llB2O5 (B=Nb, Ta). The ternary system NaSbO3-Sb2O4-NaF was investigated extensively to determine the actual composition of the body centered cubic sodium antimonate. Various other binary and ternary oxide systems involving alkali oxides were examined in lesser detail. The phases synthesized were screened by ion exchange methods to determine mobility of the mobility of the alkali ion within the niobium, tantalum or antimony oxide (fluoride) structural framework. Five structure types warranted further investigation; these structure types are (1) hexagonal tungsten bronze (HTB), (2) pyrochlore, (3) the hybrid HTB-pyrochlore hexagonal ordered phases, (4) body centered cubic antimonates and (5) 2K2O:3Nb2O5. Although all of these phases exhibit good ion exchange properties only the pyrochlore was prepared with Na(+) ions as an equilibrium phase and as a low porosity ceramic. Sb(+3) in the channel interferes with ionic conductivity in this case, although relatively good ionic conductivity was found for the metastable Na(+) ion exchanged analogs of RbTa2O5F and KTaWO6 pyrochlore phases.

  9. Periodic macroporous nanocrystalline antimony-doped tin oxide electrode.

    PubMed

    Arsenault, Eric; Soheilnia, Navid; Ozin, Geoffrey A

    2011-04-26

    Optically transparent and electrically conductive electrodes are ubiquitous in the myriad world of devices. They are an indispensable component of solar and photoelectrochemical cells, organic and polymer light emitting diodes, lasers, displays, electrochromic windows, photodetectors, and chemical sensors. The majority of the electrodes in such devices are made of large electronic band-gap doped metal oxides fashioned as a dense low-surface-area film deposited on a glass substrate. Typical transparent conducting oxide materials include indium-, fluorine-, or antimony-doped tin oxides. Herein we introduce for the first time a transparent conductive periodic macroporous electrode that has been self-assembled from 6 nm nanocrystalline antimony-doped tin oxide with high thermal stability, optimized electrical conductivity, and high quality photonic crystal properties, and present an electrochemically actuated optical light switch built from this electrode, whose operation is predicated on its unique combination of electrical, optical, and photonic properties. The ability of this macroporous electrode to host active functional materials like dyes, polymers, nanocrystals, and nanowires provides new opportunities to create devices with improved performance enabled by the large area, spatially accessible and electroactive internal surface. PMID:21391718

  10. Exploring antimony isotope ratio variations for provenancing purposes

    NASA Astrophysics Data System (ADS)

    Lobo, L.; Degryse, P.; Vanhaecke, F.

    2012-04-01

    Production sites and trade routes of Roman glass have received much attention over the past decade. It is assumed that raw glass was produced in primary workshops near the raw material sources used, to be transported to secondary glass houses. Colourless glass was a particularly prestigious material in this process, difficult to make. It has been looked at from the perspective of the provenance of its sand and flux, but rarely from the perspective of the origin of the decolourizing material. In effect, for the production of early Roman colourless glass, antimony was used, deliberately added under the form of Sb-bearing minerals. Isotopic analysis of Sb ores could help identify the origin of the decolorizing agent present in Roman glasses and, consequently, to reconstruct how such material was traded and transported, and how this can be integrated in the network of primary and secondary glass producers. In this work, variations in the isotopic composition of Sb in different ore sources (stibnites) are explored using multi-collector ICP - mass spectrometry. A new method is proposed, where Sb is directly analysed for its isotopic composition using MC-ICP-MS after chromatographic isolation of the target element from a sample digest. The isotopic composition of the selected materials shows variations up to 6 ?-units relative to an antimony standard solution. Indium was used as internal standard for correction for instrumental mass discrimination and an external precision for the 123Sb/121Sb ratio of 0.01% RSD was obtained

  11. Immobilization of antimony waste slag by applying geopolymerization and stabilization/solidification technologies.

    PubMed

    Salihoglu, Güray

    2014-11-01

    During the processing of antimony ore by pyrometallurgical methods, a considerable amount of slag is formed. This antimony waste slag is listed by the European Union as absolutely hazardous waste with a European Waste Catalogue code of 10 08 08. Since the levels of antimony and arsenic in the leachate of the antimony waste slag are generally higher than the landfilling limits, it is necessary to treat the slag before landfilling. In this study, stabilization/solidification and geopolymerization technologies were both applied in order to limit the leaching potential of antimony and arsenic. Different combinations ofpastes by using Portland cement, fly ash, clay, gypsum, and blast furnace slag were prepared as stabilization/solidification or geopoljymer matrixes. Sodium silicate-sodium hydroxide solution and sodium hydroxide solution at 8 M were used as activators for geopolymer samples. Efficiencies of the combinations were evaluated in terms of leaching and unconfined compressive strength. None of the geopolymer samples prepared with the activators yielded arsenic and antimony leaching below the regulatory limit at the same time, although they yielded high unconfined compressive strength levels. On the other hand, the stabilization/solidification samples prepared by using water showed low leaching results meeting the landfilling criteria. Use of gypsum as an additive was found to be successful in immobilizing the arsenic and antimony. PMID:25509550

  12. Antimony in the environment: A review focused on natural waters. III. Microbiota relevant interactions

    NASA Astrophysics Data System (ADS)

    Filella, Montserrat; Belzile, Nelson; Lett, Marie-Claire

    2007-02-01

    Antimony is ubiquitously present in the environment as a result of natural processes and human activities. Antimony is not considered to be an essential element for plants or animals. In this third review paper on the occurrence of antimony in natural waters, the interactions of antimony with microbiota are discussed in relation to its fate in natural waters. This paper covers the following aspects: occurrence in microbiota, uptake transport mechanisms, pathways of Sb(III) removal from cells involved in antimony tolerance, oxidation and reduction of antimony by living organisms, phytochelatin induction and biomethylation. This review is based on a careful and systematic examination of a comprehensive collection of papers on the above mentioned aspects of the subject. All data are quoted from the original sources. Relatively little existing information falls within the strict scope of this review and, when relevant, discussion on the interactions of antimony with reference microorganisms, such as Escherichia coli, Saccharomyces cerevisiae and different protozoan parasites of the genus Leishmania, has been included.

  13. Removal of arsenic and antimony from anode slime by vacuum dynamic flash reduction.

    PubMed

    Lin, Deqiang; Qiu, Keqiang

    2011-04-15

    Anode slime is an important material of recycling precious metals. Up to now, treating the arsenic- and antimony-rich anode slime by conventional processes has the following problems: its economic and environmental effect is less than satisfactory, and the removal effect of arsenic and antimony from anode slime in present processes is not all that could be desired. Therefore, vacuum dynamic flash reduction, a new process for treating arsenic- and antimony-rich anode slime, was investigated in this work. During vacuum dynamic flash reduction, silver from the arsenic- and antimony-rich anode slime was left behind in the distilland as the silver alloy, and trivalent oxides of arsenic and antimony were evaporated in the distillate. The experimental results showed that the evaporation percent of the arsenic- and antimony-rich anode slime was 65.6%. Namely, 98.92% by weight of arsenic and 93.67% by weight of antimony can be removed under the following experimental conditions: temperature of 1083 K, vacuum evaporation time of 60 min, and air flow rate of 400 mL/min corresponding to the residual gas pressure of 250 Pa. Moreover, vacuum treatment eliminates much of the air pollution and material losses associated with other conventional treatment methods. PMID:21446728

  14. Structural and optical characterization of thermally evaporated bismuth and antimony films for photovoltaic applications

    NASA Astrophysics Data System (ADS)

    Srimathy, N.; Ruban Kumar, A.

    2016-05-01

    In this present study, the thin film of bismuth and antimony is coated by thermal evaporation system equipped with the inbuilt ultra high vacuum system. XRD analysis confirmed the rhombohedral structure of Bismuth and Antimony on the prepared film. The surface roughness and physical appearance is analyzed by Atomic force microscopy. The results of Raman Spectroscopy show the wave functions and the spectrum of electrons. The preparation technique and conditions strongly influence the crystalline structure and the phase composition of bismuth and antimony thin films. The electrical and optical properties for the prepared film are analyzed. The results show a great interest and promising applications in Photovoltaic devices.

  15. Coordination- and Redox-Noninnocent Behavior of Ambiphilic Ligands Containing Antimony.

    PubMed

    Jones, J Stuart; Gabbaï, François P

    2016-05-17

    Stimulated by applications in catalysis, the chemistry of ambiphilic ligands featuring both donor and acceptor functionalities has experienced substantial growth in the past several years. The unique opportunities in catalysis offered by ambiphilic ligands stem from the ability of their acceptor functionalities to play key roles via metal-ligand cooperation or modulation of the reactivity of the metal center. Ligands featuring group 13 centers, most notably boranes, as their acceptor functionalities have undoubtedly spearheaded these developments, with remarkable results having been achieved in catalytic hydrogenation and hydrosilylation. Motivated by these developments as well as by our fundamental interest in the chemistry of heavy group 15 elements, we became fascinated by the possibility of employing antimony centers as Lewis acids within ambiphilic ligands. The chemistry of antimony-based ligands, most often encountered as trivalent stibines, has historically been considered to mirror that of their lighter phosphorus-based congeners. There is growing evidence, however, that antimony-based ligands may display unique coordination behavior and reactivity. Additionally, despite the diverse Lewis acid and redox chemistry that antimony exhibits, there have been only limited efforts to explore this chemistry within the coordination sphere of a transition metal. By incorporation of antimony into the framework of polydentate ligands in order to enforce the main group metal-transition metal interaction, the effect of redox and coordination events at the antimony center on the structure, electronics, and reactivity of the metal complex may be investigated. This Account describes our group's continuing efforts to probe the coordination behavior, reactivity, and application of ambiphilic ligands incorporating antimony centers. Structural and theoretical studies have established that both Sb(III) and Sb(V) centers in polydentate ligands may act as Z-type ligands toward late

  16. Induced Positron Annihiliation Investigation of Cadmium Zinc Telluride Crystal Microstructures

    SciTech Connect

    D. W. Akers

    2005-06-01

    Cadmium-Zinc-Telluride (CZT) crystals are used in semiconductor radiation detectors for the detection of x-ray and gamma radiation. However, production of detector grade crystals is difficult as small variations in compositional uniformity and primarily the zinc content can significantly affect the ability of the CZT crystal to function as a radiation detector. Currently there are no known nondestructive methods that can be used to identify detector grade crystals. The current test method is to fabricate and test the detector to determine if the crystal is sufficiently uniform and of the correct composition to be considered a detector grade crystal. Consequently, nondestructive detection methods are needed to identify detector grade crystals prior to the fabrication process. The purpose of this feasibility study was to perform a preliminary assessment of the ability of several new, nondestructive technologies based on Induced Positron Annihilation (IPA) to determine if detector grade CZT crystals can be identified. Results of measurements performed on specimens from Fisk University and EV Products, Inc. indicate that both the near surface Distributed Source Positron Annihilation (up to 3 mm penetration) and the volumetric Photon Induced Positron Annihilation methods may be suitable for determining CZT crystal quality. Further work on CZT crystals with a broader range of compositions and detector characteristics is needed to provide a well defined, calibrated, method for assessing CZT crystal quality.

  17. Preliminary uranium enrichment analysis results using cadmium zinc telluride detectors

    SciTech Connect

    Lavietes, A.D.; McQuaid, J.H.; Paulus, T.J.

    1995-09-08

    Lawrence Livermore National Laboratory (LLNL) and EG&G ORTEC have jointly developed a portable ambient-temperature detection system that can be used in a number of application scenarios. The detection system uses a planar cadmium zinc telluride (CZT) detector with custom-designed detector support electronics developed at LLNL and is based on the recently released MicroNOMAD multichannel analyzer (MCA) produced by ORTEC. Spectral analysis is performed using software developed at LLNL that was originally designed for use with high-purity germanium (HPGe) detector systems. In one application, the CZT detection system determines uranium enrichments ranging from less than 3% to over 75% to within accuracies of 20%. The analysis was performed using sample sizes of 200 g or larger and acquisition times of 30 min. The authors have demonstrated the capabilities of this system by analyzing the spectra gathered by the CZT detection system from uranium sources of several enrichments. These experiments demonstrate that current CZT detectors can, in some cases, approach performance criteria that were previously the exclusive domain of larger HPGe detector systems.

  18. Bismuth telluride nanostructures: preparation, thermoelectric properties and topological insulating effect

    NASA Astrophysics Data System (ADS)

    Ashalley, Eric; Chen, Haiyuan; Tong, Xin; Li, Handong; Wang, Zhiming M.

    2015-05-01

    Bismuth telluride is known to wield unique properties for a wide range of device applications. However, as devices migrate to the nanometer scale, significant amount of studies are being conducted to keep up with the rapidly growing nanotechnological field. Bi2Te3 possesses distinctive properties at the nanometer level from its bulk material. Therefore, varying synthesis and characterization techniques are being employed for the realization of various Bi2Te3 nanostructures in the past years. A considerable number of these works have aimed at improving the thermoelectric (TE) figure-of-merit (ZT) of the Bi2Te3 nanostructures and drawing from their topological insulating properties. This paper reviews the various Bi2Te3 and Bi2Te3-based nanostructures realized via theoretical and experimental procedures. The study probes the preparation techniques, TE properties and the topological insulating effects of 0D, 1D, 2D and Bi2Te3 nanocomposites. With several applications as a topological insulator (TI), the topological insulating effect of the Bi2Te3 is reviewed in detail with the time reversal symmetry (TRS) and surface state spins which characterize TIs. Schematics and preparation methods for the various nanostructural dimensions are accordingly categorized.

  19. Quasiparticle electronic structure of bismuth telluride in the GW approximation

    NASA Astrophysics Data System (ADS)

    Kioupakis, Emmanouil; Tiago, Murilo L.; Louie, Steven G.

    2010-12-01

    The quasiparticle band structure of bismuth telluride (Bi2Te3) , an important thermoelectric material that exhibits topologically insulating surface states, is calculated from first principles in the GW approximation. The quasiparticle energies are evaluated in fine detail in the first Brillouin zone using a Wannier-function interpolation method, allowing the accurate determination of the location of the band extrema (which is in the mirror plane) as well as the values of the quasiparticle band gap (0.17 eV) and effective-mass tensors. Spin-orbit interaction effects were included. The valence band exhibits two distinct maxima in the mirror plane that differ by just 1 meV, giving rise to one direct and one indirect band gap of very similar magnitude. The effective-mass tensors are in reasonable agreement with experiment. The Wannier interpolation coefficients can be used for the tight-binding parametrization of the band structure. Our work elucidates the electronic structure of Bi2Te3 and sheds light on its exceptional thermoelectric and topologically insulating properties.

  20. Quasiparticle electronic structure of bismuth telluride in the GW approximation

    SciTech Connect

    Kioupakis, Emmanouil; Tiago, Murilo L; Louie, Steven G.

    2010-01-01

    The quasiparticle band structure of bismuth telluride Bi2Te3 , an important thermoelectric material that exhibits topologically insulating surface states, is calculated from first principles in the GW approximation. The quasiparticle energies are evaluated in fine detail in the first Brillouin zone using a Wannier-function interpo- lation method, allowing the accurate determination of the location of the band extrema which is in the mirror plane as well as the values of the quasiparticle band gap 0.17 eV and effective-mass tensors. Spin-orbit interaction effects were included. The valence band exhibits two distinct maxima in the mirror plane that differ by just 1 meV, giving rise to one direct and one indirect band gap of very similar magnitude. The effective- mass tensors are in reasonable agreement with experiment. The Wannier interpolation coefficients can be used for the tight-binding parametrization of the band structure. Our work elucidates the electronic structure of Bi2Te3 and sheds light on its exceptional thermoelectric and topologically insulating properties.

  1. A cadmium-zinc-telluride crystal array spectrometer

    SciTech Connect

    H. R. McHugh; W. Quam; T. DeVore; R. Vogle; J. Weslowski

    2003-09-01

    This paper describes a gamma detector employing an array of eight cadmium-zinc-telluride (CZT) crystals configured as a high resolution gamma ray spectrometer. This detector is part of a more complex instrument that identifies the isotope,displays this information, and records the gamma spectrum. Various alarms and other operator features are incorporated in this battery operated rugged instrument. The CZT detector is the key component of this instrument and will be described in detail in this paper. We have made extensive spectral measurements of the usual laboratory gamma sources, common medical isotopes, and various Special Nuclear Materials (SNM) with this detector. Some of these data will be presented as spectra. We will also present energy resolution and detection efficiency for the basic 8-crystal array. Additional data will also be presented for a 32-crystal array. The basic 8-crystal array development was completed two years ago, and the system electronic design has been imp roved recently. This has resulted in significantly improved noise performance. We expect to have a much smaller detector package, using 8 crystals, in a few months. This package will use flip-chip packaging to reduce the electronics physical size by a factor of 5.

  2. Development of a cadmium telluride pixel detector for astrophysical applications

    NASA Astrophysics Data System (ADS)

    Miyasaka, Hiromasa; Harrison, Fiona A.; Cook, Walter R.; Mao, Peter H.; Rana, Vikram R.; Ishikawa, Shin-Nosuke; Ushio, Masayoshi; Aono, Hiroyuki; Watanabe, Shin; Sato, Goro; Kokubun, Motohide; Takahashi, Tadayuki

    2009-08-01

    We are developing imaging Cadmium Telluride (CdTe) pixel detectors optimized for astrophysical hard X-ray applications. Our hybrid detector consist of a CdTe crystal 1mm thick and 2cm × 2cm in area with segmented anode contacts directly bonded to a custom low-noise application specific integrated circuit (ASIC). The CdTe sensor, fabricated by ACRORAD (Okinawa, Japan), has Schottky blocking contacts on a 605 micron pitch in a 32 × 32 array, providing low leakage current and enabling readout of the anode side. The detector is bonded using epoxy-gold stud interconnects to a custom low noise, low power ASIC circuit developed by Caltech's Space Radiation Laboratory. We have achieved very good energy resolution over a wide energy range (0.62keV FWHM @ 60keV, 10.8keV FWHM @ 662keV). We observe polarization effects at room temperature, but they are suppressed if we operate the detector at or below 0°C degree. These detectors have potential application for future missions such as the International X-ray Observatory (IXO).

  3. Frustrated square lattice Heisenberg model and magnetism in Iron Telluride

    NASA Astrophysics Data System (ADS)

    Zaliznyak, Igor; Xu, Zhijun; Gu, Genda; Tranquada, John; Stone, Matthew

    2011-03-01

    We have measured spin excitations in iron telluride Fe1.1Te, the parent material of (1,1) family of iron-based superconductors. It has been recognized that J1-J2-J3 frustrated Heisenberg model on a square lattice might be relevant for the unusual magnetism and, perhaps, the superconductivity in cuprates [1,2]. Recent neutron scattering measurements show that similar frustrated model might also provide reasonable account for magnetic excitations in iron pnictide materials. We find that it also describes general features of spin excitations in FeTe parent compound observed in our recent neutron measurements, as well as in those by other groups. Results imply proximity of magnetic system to the limit of extreme frustration. Selection of spin ground state under such conditions could be driven by weak extrinsic interactions, such as lattice distortion, or strain. Consequently, different nonuniversal types of magnetic order could arise, both commensurate and incommensurate. These are not necessarily intrinsic to an ideal J1-J2-J3 model, but might result from lifting of its near degeneracy by weak extrinsic perturbations.

  4. Compensation mechanism of bromine dopants in cadmium telluride single crystals

    DOE PAGESBeta

    Bolotnikov, A. E.; Fochuk, P. M.; Verzhak, Ye. V.; Parashchuk, T. O.; Freik, D. M.; Panchuk, O. E.; James, R. B.; Gorichok, I. V.

    2015-01-02

    We grew single crystals of cadmium telluride, doped with bromine by the Bridgman method, annealed them under a cadmium overpressure (PCd = 10² - 10⁵ Pa) at 800-1100 K, and investigated their electrical properties at high- and low-temperature. The influence of impurities on the crystals' electrical properties were analyzed using the defect subsystem model; the model includes the possibility of the formation of point intrinsic defects (V²⁻Cd, Cd²⁺i, V²⁺Te, Te²⁻i), and substitutional ones (Br⁰Te, Br⁺Te), as well as complexes of point defects, i.e., (Br⁺Te V²⁻Cd)⁻ and (2Br⁺Te V²⁻Cd)⁰. We established the concentration dependence between free charge carriers and themore » parameters of the annealing process. Here, n(T) and n(PCd) are determined by two dominant defects – Br⁺Te and (2Br⁺Te V²⁻Cd)⁰. Their content varies with the annealing temperature and the vapor pressure of the component; the concentration of other defects is much smaller and almost does not affect the electron density.« less

  5. Growth and electrical properties of mercury indium telluride single crystals

    SciTech Connect

    Wang Linghang Dong Yangchun; Jie Wanqi

    2007-11-06

    A novel photoelectronic single crystal, mercury indium telluride (MIT), has been successfully grown by using vertical Bridgman method (VB). The crystallinity, thermal and electrical properties of the MIT crystal were investigated. The results of X-ray rocking curve show that the as-grown MIT crystal has good crystal quality with the FWHM on (3 1 1) face of about 173 in. DSC measurement reveals that the Hg element is easy to solely evaporate from the compound when the temperature is higher than 387.9 deg. C in the open system. Hall measurements at room temperature show that the resistivity, carrier density and mobility of the MIT crystal were 4.79 x 10{sup 2} {omega} cm, 2.83 x 10{sup 13} cm{sup -3} and 4.60 x 10{sup 2} cm{sup 2} V{sup -1} s{sup -1}, respectively. The reduction of carrier mobility and the increase of the resistivity are related to the adding of In{sub 2}Te{sub 3} into HgTe, which changes the energy band structure of the crystal.

  6. Brief review of cadmium telluride-based photovoltaic technologies

    NASA Astrophysics Data System (ADS)

    Başol, Bülent M.; McCandless, Brian

    2014-01-01

    Cadmium telluride (CdTe) is the most commercially successful thin-film photovoltaic technology. Development of CdTe as a solar cell material dates back to the early 1980s when ˜10% efficient devices were demonstrated. Implementation of better quality glass, more transparent conductive oxides, introduction of a high-resistivity transparent film under the CdS junction-partner, higher deposition temperatures, and improved Cl-treatment, doping, and contacting approaches yielded >16% efficient cells in the early 2000s. Around the same time period, use of a photoresist plug monolithic integration process facilitated the demonstration of the first 11% efficient module. The most dramatic advancements in CdTe device efficiencies were made during the 2013 to 2014 time frame when small-area cell conversion efficiency was raised to 20% range and a champion module efficiency of 17% was reported. CdTe technology is attractive in terms of its limited life-cycle greenhouse gas and heavy metal emissions, small carbon footprint, and short energy payback times. Limited Te availability is a challenge for the growth of this technology unless Te utilization rates are greatly enhanced along with device efficiencies.

  7. Thin tungsten telluride layer preparation by thermal annealing.

    PubMed

    Lu, Wei; Zhang, Yudao; Zhu, Zusong; Lai, Jiawei; Zhao, Chuan; Liu, Xuefeng; Liu, Jing; Sun, Dong

    2016-10-14

    We report a simple method to prepare a thin Tungsten Telluride (WTe2) flake with accurate thickness control, which allows preparing and studying this two dimensional material conveniently. First, the WTe2 flake, which is relatively thick due to its strong interlayer van der Waals forces, is obtained by a conventional mechanical exfoliation method. Then, the exfoliated flake is annealed at 600 °C under a constant Ar protecting flow. Raman and atomic force spectroscopy characterizations demonstrate that thermal annealing can effectively thin down the WTe2 flake and retain its original lattice structure, though its surface smoothness is slightly deteriorated. Additionally, systematical study indicates that the thinning process strongly depends on the initial thickness of the WTe2 flake before annealing: the thinning rate increases from 0.12 nm min(-1) to 0.36 nm min(-1) as the initial thickness increases from 10 nm to 45 nm, while the roughness of the final product also increases with the increase of its initial thickness. However, the method fails when it is applied to WTe2 flakes thicker than 100 nm, resulting in uneven or burnt surface, which is possibly caused by big cavities formed by a large amount of defects gathered at the top surface. PMID:27608057

  8. Ambient temperature cadmium zinc telluride radiation detector and amplifier circuit

    DOEpatents

    McQuaid, James H.; Lavietes, Anthony D.

    1998-05-29

    A low noise, low power consumption, compact, ambient temperature signal amplifier for a Cadmium Zinc Telluride (CZT) radiation detector. The amplifier can be used within a larger system (e.g., including a multi-channel analyzer) to allow isotopic analysis of radionuclides in the field. In one embodiment, the circuit stages of the low power, low noise amplifier are constructed using integrated circuit (IC) amplifiers , rather than discrete components, and include a very low noise, high gain, high bandwidth dual part preamplification stage, an amplification stage, and an filter stage. The low noise, low power consumption, compact, ambient temperature amplifier enables the CZT detector to achieve both the efficiency required to determine the presence of radio nuclides and the resolution necessary to perform isotopic analysis to perform nuclear material identification. The present low noise, low power, compact, ambient temperature amplifier enables a CZT detector to achieve resolution of less than 3% full width at half maximum at 122 keV for a Cobalt-57 isotope source. By using IC circuits and using only a single 12 volt supply and ground, the novel amplifier provides significant power savings and is well suited for prolonged portable in-field use and does not require heavy, bulky power supply components.

  9. Ambient temperature cadmium zinc telluride radiation detector and amplifier circuit

    DOEpatents

    McQuaid, J.H.; Lavietes, A.D.

    1998-05-26

    A low noise, low power consumption, compact, ambient temperature signal amplifier for a Cadmium Zinc Telluride (CZT) radiation detector is disclosed. The amplifier can be used within a larger system (e.g., including a multi-channel analyzer) to allow isotopic analysis of radionuclides in the field. In one embodiment, the circuit stages of the low power, low noise amplifier are constructed using integrated circuit (IC) amplifiers , rather than discrete components, and include a very low noise, high gain, high bandwidth dual part preamplification stage, an amplification stage, and an filter stage. The low noise, low power consumption, compact, ambient temperature amplifier enables the CZT detector to achieve both the efficiency required to determine the presence of radionuclides and the resolution necessary to perform isotopic analysis to perform nuclear material identification. The present low noise, low power, compact, ambient temperature amplifier enables a CZT detector to achieve resolution of less than 3% full width at half maximum at 122 keV for a Cobalt-57 isotope source. By using IC circuits and using only a single 12 volt supply and ground, the novel amplifier provides significant power savings and is well suited for prolonged portable in-field use and does not require heavy, bulky power supply components. 9 figs.

  10. Thickness-induced structural phase transformation of layered gallium telluride.

    PubMed

    Zhao, Q; Wang, T; Miao, Y; Ma, F; Xie, Y; Ma, X; Gu, Y; Li, J; He, J; Chen, B; Xi, S; Xu, L; Zhen, H; Yin, Z; Li, J; Ren, J; Jie, W

    2016-07-28

    The thickness-dependent electronic states and physical properties of two-dimensional materials suggest great potential applications in electronic and optoelectronic devices. However, the enhanced surface effect in ultra-thin materials might significantly influence the structural stability, as well as the device reliability. Here, we report a spontaneous phase transformation of gallium telluride (GaTe) that occurred when the bulk was exfoliated to a few layers. Transmission electron microscopy (TEM) results indicate a structural variation from a monoclinic to a hexagonal structure. Raman spectra suggest a critical thickness for the structural transformation. First-principle calculations and thermodynamic analysis show that the surface energy and the interlayer interaction compete to dominate structural stability in the thinning process. A two-stage transformation process from monoclinic (m) to tetragonal (T) and then from tetragonal to hexagonal (h) is proposed to understand the phase transformation. The results demonstrate the crucial role of interlayer interactions in the structural stability, which provides a phase engineering strategy for device applications. PMID:27198938

  11. Using atomistic simulations to model cadmium telluride thin film growth.

    PubMed

    Yu, Miao; Kenny, Steven D

    2016-03-16

    Cadmium telluride (CdTe) is an excellent material for low-cost, high efficiency thin film solar cells. It is important to conduct research on how defects are formed during the growth process, since defects lower the efficiency of solar cells. In this work we use computer simulation to predict the growth of a sputter deposited CdTe thin film. On-the-fly kinetic Monte Carlo technique is used to simulate the CdTe thin film growth on the (1 1 1) surfaces. The results show that on the (1 1 1) surfaces the growth mechanisms on surfaces which are terminated by Cd or Te are quite different, regardless of the deposition energy (0.1~10 eV). On the Te-terminated (1 1 1) surface the deposited clusters first form a single mixed species layer, then the Te atoms in the mixed layer moved up to form a new layer. Whilst on the Cd-terminated (1 1 1) surface the new Cd and Te layers are formed at the same time. Such differences are probably caused by stronger bonding between ad-atoms and surface atoms on the Te layer than on the Cd layer. PMID:26881827

  12. Using atomistic simulations to model cadmium telluride thin film growth

    NASA Astrophysics Data System (ADS)

    Yu, Miao; Kenny, Steven D.

    2016-03-01

    Cadmium telluride (CdTe) is an excellent material for low-cost, high efficiency thin film solar cells. It is important to conduct research on how defects are formed during the growth process, since defects lower the efficiency of solar cells. In this work we use computer simulation to predict the growth of a sputter deposited CdTe thin film. On-the-fly kinetic Monte Carlo technique is used to simulate the CdTe thin film growth on the (1 1 1) surfaces. The results show that on the (1 1 1) surfaces the growth mechanisms on surfaces which are terminated by Cd or Te are quite different, regardless of the deposition energy (0.1∼ 10 eV). On the Te-terminated (1 1 1) surface the deposited clusters first form a single mixed species layer, then the Te atoms in the mixed layer moved up to form a new layer. Whilst on the Cd-terminated (1 1 1) surface the new Cd and Te layers are formed at the same time. Such differences are probably caused by stronger bonding between ad-atoms and surface atoms on the Te layer than on the Cd layer.

  13. Vapor crystal growth technology development: Application to cadmium telluride

    NASA Technical Reports Server (NTRS)

    Rosenberger, Franz; Banish, Michael; Duval, Walter M. B.

    1991-01-01

    Growth of bulk crystals by physical vapor transport was developed and applied to cadmium telluride. The technology makes use of effusive ampoules, in which part of the vapor contents escapes to a vacuum shroud through defined leaks during the growth process. This approach has the advantage over traditional sealed ampoule techniques that impurity vapors and excess vapor constituents are continuously removed from the vicinity of the growing crystal. Thus, growth rates are obtained routinely at magnitudes that are rather difficult to achieve in closed ampoules. Other advantages of this effusive ampoule physical vapor transport (EAPVT) technique include the predetermination of transport rates based on simple fluid dynamics and engineering considerations, and the growth of the crystal from close to congruent vapors, which largely alleviates the compositional nonuniformities resulting from buoyancy driven convective transport. After concisely reviewing earlier work on improving transport rates, nucleation control, and minimization of crystal wall interactions in vapor crystal growth, a detail account is given of the largely computer controlled EAPVT experimentation.

  14. Compensation mechanism of bromine dopants in cadmium telluride single crystals

    SciTech Connect

    Bolotnikov, A. E.; Fochuk, P. M.; Verzhak, Ye. V.; Parashchuk, T. O.; Freik, D. M.; Panchuk, O. E.; James, R. B.; Gorichok, I. V.

    2015-01-02

    We grew single crystals of cadmium telluride, doped with bromine by the Bridgman method, annealed them under a cadmium overpressure (PCd = 10² - 10⁵ Pa) at 800-1100 K, and investigated their electrical properties at high- and low-temperature. The influence of impurities on the crystals' electrical properties were analyzed using the defect subsystem model; the model includes the possibility of the formation of point intrinsic defects (V²⁻Cd, Cd²⁺i, V²⁺Te, Te²⁻i), and substitutional ones (Br⁰Te, Br⁺Te), as well as complexes of point defects, i.e., (Br⁺Te V²⁻Cd)⁻ and (2Br⁺Te V²⁻Cd)⁰. We established the concentration dependence between free charge carriers and the parameters of the annealing process. Here, n(T) and n(PCd) are determined by two dominant defects – Br⁺Te and (2Br⁺Te V²⁻Cd)⁰. Their content varies with the annealing temperature and the vapor pressure of the component; the concentration of other defects is much smaller and almost does not affect the electron density.

  15. Copper, lead, zinc, antimony, and arsenic in Pakistan

    USGS Publications Warehouse

    White, Max Gregg

    1975-01-01

    Copper localities that merit geological investigation are found in the western Chasai District, in North Waziristan Agency, and in the Salt Range in Mianwali and Sargodha Districts. No high-grade deposits have been .reported from these ,areas and if deposits are developed they will likely be low-grade, high-tonnage, disseminated deposits. Those localities reported from Chitral State are too remote and inaccessible to be of interest now. All lead localities found to date are of minor importance; there has been small production at one .locality in Chasai District and in the southern part of the Hazara District. Zinc, antimony, and arsenic are sparse in Pakistan and no important localities of these metals are reported.

  16. Magnesium-Antimony Liquid Metal Battery for Stationary Energy Storage

    SciTech Connect

    Bradwell, DJ; Kim, H; Sirk, AHC; Sadoway, DR

    2012-02-01

    Batteries are an attractive option for grid: scale energy storage applications because of their small footprint and flexible siting. A high-temperature (700 degrees C) magnesium antimony (MgllSb) liquid metal battery comprising a negative electrode of Mg, a molten salt electrolyte (MgCL2-KCl-NaCl), and a positive electrode of Sb is proposed and characterized. Because of the immiscibility of the contiguous salt and metal phases, they stratify by density into three distinct layers. Cells were cycled at rates ranging from 50 to 200 mA/cm(2) and demonstrated up to 69% DC-DC energy efficiency. The self-segregating nature of the battery components and the use Of low-cost materials results in a promising technology for stationary energy storage applications.

  17. Atomistic mechanisms governing structural stability change of zinc antimony thermoelectrics

    SciTech Connect

    Yang, Xiaolong; Lin, Jianping; Qiao, Guanjun; Wang, Zhao

    2015-01-05

    The structural stability of thermoelectric materials is a subject of growing importance for their energy harvesting applications. Here, we study the microscopic mechanisms governing the structural stability change of zinc antimony at its working temperature, using molecular dynamics combined with experimental measurements of the electrical and thermal conductivity. Our results show that the temperature-dependence of the thermal and electrical transport coefficients is strongly correlated with a structural transition. This is found to be associated with a relaxation process, in which a group of Zn atoms migrates between interstitial sites. This atom migration gradually leads to a stabilizing structural transition of the entire crystal framework, and then results in a more stable crystal structure of β–Zn{sub 4}Sb{sub 3} at high temperature.

  18. Calcium metal as a scavenger for antimony from aluminum alloys

    SciTech Connect

    Bonsignore, P.V.; Daniels, E.J.; Wu, C.T.

    1994-10-04

    Previous work has shown that trace amounts of antimony (Sb) can affect the mechanical properties of strontium (Sr) modified aluminum castings. ANL has been investigating technology to remove or neutralize Sb to reduce its negative effect on the physical properties of those alloys. Review of past work on processing and recovery of scrap aluminum inferred that calcium (Ca) is an effective scavenger of Sb, bismuth, lead and cadmium. Following up on that lead, we have found that Ca is, indeed, effective for removing Sb from molten aluminum alloys although its effectiveness can be compromised by a wide range of processing conditions. A minimum ratio of about four to one, by weight, of Ca to Sb appears necessary to insure an effective scavenging of contained Sb.in 356 aluminum alloys.

  19. Antimony toxicity in the lichen Xanthoria parietina (L.) Th. Fr.

    PubMed

    Paoli, L; Fiorini, E; Munzi, S; Sorbo, S; Basile, A; Loppi, S

    2013-11-01

    In this paper we tested if treating the lichen Xanthoria parietina with Sb-containing solutions causes Sb bioaccumulation as well as physiological and ultrastructural changes. Total and intracellular antimony content in Sb-treated samples increased progressively with increasing concentration in the treatment solutions. Incubation of X. parietina thalli with Sb at concentrations as low as 0.1mM caused a decrease in sample viability, measured as intensity of respiratory activity, and damage to cell membranes, expressed in terms of membrane lipid peroxidation, as well as ultrastructural changes such as plasmolysis, impairment of the thylakoid system of the alga and cytoplasmic lipid droplets. The photosynthetic system hardly responded, at least under the tested experimental conditions. PMID:24001672

  20. Silicon quantum dots with counted antimony donor implants

    NASA Astrophysics Data System (ADS)

    Singh, Meenakshi; Pacheco, Jose; Perry, Daniel; Wendt, Joel; Manginell, Ronald; Dominguez, Jason; Pluym, Tammy; Luhman, Dwight; Bielejec, Edward; Lilly, Michael; Carroll, Malcolm

    Antimony donor implants next to silicon quantum dots have been detected with integrated solid-state diode detectors with single ion precision. Devices with counted number of donors have been fabricated and low temperature transport measurements have been performed. Charge offsets, indicative of donor ionization and coupling to the quantum dot, have been detected in these devices. The number of offsets corresponds to 10-50% of the number of donors counted. We will report on tunneling time measurements and spin readout measurements on the donor offsets. This work was performed, in part, at the Center for Integrated Nanotechnologies, a U.S. DOE Office of Basic Energy Sciences user facility. The work was supported by Sandia National Laboratories Directed Research and Development Program. Sandia National Laboratories is a multi-program laboratory operated by Sandia Corporation, a Lockheed-Martin Company, for the U. S. Department of Energy under Contract No. DE-AC04-94AL85000.

  1. Geochemistries of arsenic, antimony, mercury, and related elements in sediments of puget sound

    USGS Publications Warehouse

    Crecelius, E.A.; Bothner, Michael H.; Carpenter, R.

    1975-01-01

    The natural distributions of arsenic, antimony mercury, chromium, cobalt, iron, aluminum, and carbon in the surface sediments of Puget Sound are perturbed by two major anthropogenic sources of trace metals: a copper smelter near Tacoma, Wash., that discharges large amounts of arsenic and antimony, and a chlor-alkali plant in Bellingham, Wash., which, in the recent past, discharged significant amounts of mercury. Arsenic and antimony inputs from the smelter over the past 80 years are evident in sediment cores whose accumulation rates have been determined by the lead-210 technique. An arsenic budget for Puget Sound reveals the importance of atmospheric input resulting from smokestack emissions of the smelter. Chemical extraction studies of sediments showed that more than 82% of the mercury was associated with easily oxidizable organic matter, whereas about 50% of both arsenic and antimony was associated with extractable iron and aluminum compounds.

  2. Concentrations of arsenic, antimony, and boron in steam and steam condensate at The Geysers, California

    USGS Publications Warehouse

    Smith, C.L.; Ficklin, W.H.; Thompson, J.M.

    1987-01-01

    Studies at The Geysers Geothermal Field, California indicate that under some circumstances elements that are transported in the vapor phase can become enriched in the liquid phase. Waters from two condensate traps (steam traps) on steam lines at The Geysers are enriched with arsenic, antimony, and boron compared to the concentrations of these elements in coexisting steam. Concentrations of boron in condensate-trap waters were as high as 160 mg/L, arsenic as high as 35 mg/L, and antimony as high as 200 ??g/L. Enrichment of arsenic, antimony, and boron is at least partially controlled by the partitioning of these elements into the liquid phase, according to their vapor-liquid distribution coefficients, after they are transported in steam. Several of the elements that are most soluble in steam, including arsenic and antimony, are part of the trace-element suite that characterizes precious-metal epithermal ore deposits. ?? 1987.

  3. One-step synthesis and flame retardancy of sheaf-like microcrystal antimony oxychloride.

    PubMed

    Zhou, Jing; Zhao, Hewei; Li, Lidong; Tian, Ming; Han, Jibing; Zhang, Liqun; Guo, Lin

    2011-10-01

    A mild and facile solution route has been developed for large-scale synthesis of sheaf-like antimony oxychloride Sb8O11CI2 (H2O)6 microcrystal at room temperature. The morphologies and structures of the as-prepared products were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). A mechanism for the formation of the sheaf-like microstructure was tentatively proposed. The shape regulation was attributed to the capping mode of the PVP-directed antimony oxychloride crystal. The thermogravimetric and differential thermal analysis (TG/DTA) were employed to investigate thermal decomposition mechanism and temperature-dependent phase transition of antimony oxychloride Sb8O11CI2 (H2O)6 in the air. The flammable property determined by the cone calorimeter showed excellent flame retardancy when applied this antimony oxychloride in poly (vinyl chloride) (PVC) polymer. PMID:22400215

  4. New low-antimony alloy for straps and cycling service in lead-acid batteries

    NASA Astrophysics Data System (ADS)

    Prengaman, R. David

    Lead-antimony alloys used for the positive grids in lead-acid batteries for cycling service have generally used antimony contents of 4.5 wt.% and above. Tubular batteries for cycling service that impart high compression of the active material to the grid surface via gauntlet use alloys with antimony contents as low as 1.5 wt.%. These batteries are generally employed in less-severe cycling service. Value-regulated lead-acid (VRLA) batteries can give good cycling service without lead-antimony in the positive grid, but require a high tin content and high compression. The change in automotive battery positive grid alloys to lead-calcium-tin and the tin contents of VRLA positive grids and straps have dramatically increased the tin content of the recycled grid and strap lead in the USA, Europe, and Australia. The higher tin contents can contaminate the lead used for lead-antimony battery grids and generally must be removed to low levels to meet the specifications. This study describes a low-antimony alloy that contains a substantial amount of tin. The high tin content reduces the rate of corrosion of low-antimony positive grid alloys, improves conductivity, increases the bond between the grid and the active material, and cycles as well as the traditional 5-6 wt.% antimony alloys employed in conventional flat-plate batteries. The alloy is also used as a corrosion-resistant cast-on strap alloy for automotive batteries for high temperature service, as well as for posts, bushings, and connectors for all wet batteries.

  5. Neutron-activation analysis by standard addition and solvent extraction Determination of traces of antimony.

    PubMed

    Alian, A; Shabana, R; Sanad, W; Allam, B; Khalifa, K

    1968-02-01

    The application of neutron activation analysis by standard addition and solvent extraction to the determination of traces of antimony in aluminium and rocks is reported. Three simple extraction procedures, using isopropyl ether, hexone, and tributyl phosphate, are described for the selective separation of radioantimony from interfering radionuclides. Antimony concentration is measured by counting the activities of the (122)Sb and (124)Sb photopeaks at 0.564 and 0.603 MeV. PMID:18960289

  6. A comprehensive global inventory of atmospheric Antimony emissions from anthropogenic activities, 1995-2010.

    PubMed

    Tian, Hezhong; Zhou, JunRui; Zhu, Chuanyong; Zhao, Dan; Gao, Jiajia; Hao, Jiming; He, Mengchang; Liu, Kaiyun; Wang, Kun; Hua, Shenbing

    2014-09-01

    Antimony (Sb) and its compounds are considered as global pollutants due to their health risks and long-range transport characteristics. A comprehensive global inventory of atmospheric antimony emissions from anthropogenic activities during the period of 1995-2010 has been developed with specific estimation methods based on the relevant data available for different continents and countries. Our results indicate that the global antimony emissions have increased to a peak at about 2232 t (t) in 2005 and then declined gradually. Global antimony emissions in 2010 are estimated at about 1904 t (uncertainty of a 95% confidence interval (CI): -30% ∼ 67%), with fuel combustion as the major source category. Asia and Europe account for about 57% and 24%, respectively, of the global total emissions, and China, the United States, and Japan rank as the top three emitting countries. Furthermore, global antimony emissions are distributed into gridded cells with a resolution of 1° × 1°. Regions with high Sb emissions are generally concentrated in the Southeastern Asia and Western Europe, while South Africa, economically developed regions in the eastern U.S., and Mexico are also responsible for the high antimony emission intensity. PMID:25110938

  7. Urinary antimony and leukocyte telomere length: An analysis of NHANES 1999-2002.

    PubMed

    Scinicariello, Franco; Buser, Melanie C

    2016-10-01

    Telomeres are repetitive DNA sequences (TTAGGG) at the end of chromosomes. Cells with critically short telomeres enter replicative senescence and apoptosis. Several in vitro studies report that antimony causes cell apoptosis in human leukocyte cell lines. The goal of this analysis was to investigate whether there is an association between antimony exposure and leukocyte telomere length (LTL) among US adults aged 20 and older based on the National Health and Nutrition Examination Survey (NHANES) 1999-2002. We used multivariate linear regression to analyze the association of urinary antimony with LTL. LTL was log-natural transformed and the results were re-transformed and presented as percent differences. After adjustment for potential confounders, individuals in the 3rd and 4th quartiles of urinary antimony had statistically significantly shorter LTL (-4.78%, 95% CI: -8.42,-0.90; and -6.11%, 95% CI: -11.04,-1.00, respectively) compared to the lowest referent quartile, with evidence of a dose-response relationship (p-value for trend =0.03). Shorter LTL with antimony was driven by middle aged (40-59 years) and older (60-85 years) adult groups. The association may be biologically plausible because of reported oxidative stress and apoptosis effects of antimony on blood cells, effects known to shorten telomere length. PMID:27423705

  8. Nano-titania-crosslinked chitosan composite as a superior sorbent for antimony (III) and (V).

    PubMed

    Nishad, Padala Abdul; Bhaskarapillai, Anupkumar; Velmurugan, Sankaralingam

    2014-08-01

    Removal of radioactive antimony, especially at low levels, is a difficult problem faced by nuclear power plants all over the world. Further, antimony is classified as a pollutant of priority importance by the United States and the European environmental protection agencies. Chitosan, a biopolymer well known for its sorption properties, can also serve as a stable matrix for inorganic sorbents such as titania on crosslinking. A robust high performing sorbent for antimony, in the form of stable beads, has been prepared using nano-TiO2 and chitosan. Raman spectra of the beads confirmed the incorporation of nano-TiO2 in the chitosan matrix. The sorbent exhibited complete sorption of antimony from aqueous solutions with antimony concentrations ranging from as low as 150 ppb to as high as 120 ppm. The sorption dependence on equilibrium pH has been investigated. The beads have been shown to be effective sorbent of antimony in both +3 and +5 oxidation states. The sorption properties of the beads were attributed to the TiO2 component present in the beads, while the crosslinked chitosan provided strong matrix and influenced the formation of much needed stable spherical beads suitable for real life large scale applications. The beads exhibited high sorption efficiency in the column mode, and were found to be physically stable at a flow rate of one bed volume per minute. PMID:24751261

  9. Antimony: an unlikely confounder in the relationship between well water arsenic and health outcomes in Bangladesh.

    PubMed Central

    McCarty, Kathleen M; Senn, David B; Kile, Molly L; Quamruzzaman, Quazi; Rahman, Mahmuder; Mahiuddin, Golam; Christiani, David C

    2004-01-01

    Recent in vitro studies have suggested a potential role for antimony as a confounder in human health studies related to arsenic in drinking water. We measured tube-well water concentrations of antimony and arsenic in the Pabna region of Bangladesh, where arsenic concentrations are known to be elevated and the concentrations of antimony have not yet been thoroughly documented. Two hundred forty-five tube-well water samples were collected from various regions in Pabna, Bangladesh, as part of an ongoing case-control study. Water samples were analyzed for arsenic and antimony concentrations by inductively coupled plasma-mass spectrometry using U.S. Environmental Protection Agency method 200.8. The arsenic concentrations in the tube-well water samples ranged from < 1 microg/L to 747 microg/L. All 245 water samples had antimony concentrations < 1 microg/L. Based on consideration of the concentrations used the in vitro studies compared with field-observed concentrations, our results do not support the hypothesis that antimony would be a significant confounder in observed relationships between arsenic exposure through drinking water and potential health outcomes in Pabna, Bangladesh. PMID:15175164

  10. Fabrication of Nanovoid-Imbedded Bismuth Telluride with Low Dimensional System

    NASA Technical Reports Server (NTRS)

    Chu, Sang-Hyon (Inventor); Choi, Sang H. (Inventor); Kim, Jae-Woo (Inventor); Park, Yeonjoon (Inventor); Elliott, James R. (Inventor); King, Glen C. (Inventor); Stoakley, Diane M. (Inventor)

    2013-01-01

    A new fabrication method for nanovoids-imbedded bismuth telluride (Bi--Te) material with low dimensional (quantum-dots, quantum-wires, or quantum-wells) structure was conceived during the development of advanced thermoelectric (TE) materials. Bismuth telluride is currently the best-known candidate material for solid-state TE cooling devices because it possesses the highest TE figure of merit at room temperature. The innovative process described here allows nanometer-scale voids to be incorporated in Bi--Te material. The final nanovoid structure such as void size, size distribution, void location, etc. can be also controlled under various process conditions.

  11. Directional Solidification of Mercury Cadmium Telluride in Microgravity

    NASA Technical Reports Server (NTRS)

    Lechoczhy, Sandor L.; Gillies, Donald C.; Szofran, Frank R.; Watring, Dale A.

    1998-01-01

    Mercury cadmium telluride (MCT) has been directionally solidified for ten days in the Advanced Automated Directional Solidification Furnace (AADSF) on the second United States Microgravity Payload Mission (USMP-2). A second growth experiment is planned for the USMP-4 mission in November 1997. Results from USMP-2 demonstrated significant changes between microgravity and ground-based experiments, particularly in the compositional homogeneity. Changes were also observed during the microgravity mission which were dependent on the attitude of the space shuttle and the relative magnitudes of axial and transverse residual accelerations with respect to the growth axis of the crystal. Issues of shuttle operation, especially those concerned with safety and navigation, and the science needs of other payloads dictated the need for changes in attitude. One consequence for solidification of MCT in the USMP4 mission is the desire for a shorter growth time to complete the experiment without subjecting the sample to shuttle maneuvers. By using a seeded technique and a pre-processed boule of MCT with an established diffusion layer quenched into the solid, equilibrium steady state growth can be established within 24 hours, rather than the three days needed in USMP-2. The growth of MCT in AADSF during the USMP-4 mission has been planned to take less than 72 hours with 48 hours of actual growth time. A review of the USMP-2 results will be presented, and the rationale for the USMP-4 explained. Pre-mission ground based tests for the USN4P-4 mission will be presented, as will any available preliminary flight results from the mission.

  12. Equilibrium composition in II?VI telluride MOCVD systems

    NASA Astrophysics Data System (ADS)

    Ben-Dor, L.; Greenberg, J. H.

    1999-03-01

    Thermodynamic calculations, or computer simulation of the equilibrium composition, offer an excellent possibility to reduce drastically the elaborate trial-and-error experimental efforts of finding the optimal preparation conditions for MOCVD processes (temperature T, pressure P, initial composition of the vapors X), to limit them only to the P- T- X field of existence of the solid to be prepared and an acceptable yield of the product. In this communication equilibrium composition was investigated for MOCVD processes of CdTe, ZnTe, HgTe and solid solutions Cd xZn 1- xTe and Hg xCd 1- xTe. A number of volatile organometallic compounds have been used as precursors for MOCVD growth. These are dimethylcadmium (CH 3) 2Cd, DMCd; diethylzinc (C 2H 5) 2Zn, DEZn; diisopropylzinc [CH(CH 3) 2] 2Zn, DiPZn; diethyltellurium (C 2H 5) 2Te, DETe; diisopropyltellurium [CH(CH 3) 2] 2Te, DiPTe; methylallyltellurium CH 3TeCH 2CHCH 2, MATe. A choice of the particular combination of the precursors largely depends on the desired composition of the film to be prepared, especially in cases of solid solutions Cd xZn 1- xTe and Hg xCd 1- xTe where the vapor pressure of the precursors is instrumental for the composition of the vapor in the reaction zone and, ultimately, for the composition x of the solid solution. Equilibrium composition for II-VI telluride MOCVD systems was investigated at temperatures up to 873 K in hydrogen and inert gas atmospheres at pressures up to 1 atm. P- T- X regions of existence were outlined for each of the five materials.

  13. Cadmium zinc telluride detector for low photon energy applications

    NASA Astrophysics Data System (ADS)

    Shin, Kyung-Wook; Wang, Kai; Reznic, Alla; Karim, Karim S.

    2010-04-01

    Cadmium Zinc Telluride (CdZnTe or CZT) is a polycrystalline radiation detector that has been investigated over the years for a variety of applications including Constellation X-ray space mission [1] and direct-conversion medical imaging such as digital mammography [2]. Due to its high conversion gain and low electron-hole pair creation energy (~4.43 eV) [3], it has found use in high end, photon counting medical imaging applications including positron emission tomography (PET), computed tomography (CT) and single photon emission computed tomography (SPECT). However, its potential in low photon energy applications has not been fully explored. In this work, we explore the capacity of the CZT material to count low photon energies (6 keV - 20 keV). These energies are of direct relevance to applications in gamma ray breast brachytheraphy and mammography, X-ray protein crystallography, X-ray mammography and mammography tomosynthesis. We also present a design that integrates the CZT direct conversion detector with an inhouse fabricated amorphous silicon (a-Si:H) thin film transistor (TFT) passive pixel sensor (PPS) array. A CZT photoconductor (2 cm x 2 cm size, 5-mm-thick) prepared by the traveling heat method (THM) from RedlenTM is characterized. The current-voltage characteristics reveal a resistivity of 3.3 x 1011 Ω•cm and a steady state dark current in the range of nA. Photocurrent transients under different biases and illumination pulses are studied to investigate photogeneration and the charge trapping process. It is found that charge trapping plays a more significant role in transient behavior at low biases and low frequency.

  14. Simulation of antimony adsorption on nano-zero valent iron and kaolinite and analyzing the influencing parameters.

    PubMed

    Saeidnia, Setareh; Asadollahfardi, Gholamreza; Darban, Ahmad Khodadadi; Mohseni, Mehdi

    2016-01-01

    Antimony is one of the most toxic pollutants in industrial and mineral wastewaters threatening the life of humans and other creatures. We simulated the adsorption of antimony in the presence of nano-zero valent iron (nZVI) adsorbent, on kaolinite and in the presence of nZVI coated on kaolinite from mineral wastewater using VISUAL MINTEQ 3.1 software. Our aim was to determine the factors affecting the adsorption of antimony by applying simulation. The simulation was performed using an adsorption model of a diffuse layer model. The results of the simulation indicated that the nZVI concentration, initial concentrations of antimony and pH factor are effective on the adsorption of antimony. In the conducted stimulation, the optimum pH was 2-5 and the highest adsorption occurred in an acidic state. With increasing initial concentrations of antimony in the simulation, we concluded that nZVI had absorbed various concentrations above 90% and, by increasing the concentration of nZVI, antimony adsorption rate increased. The increased surface area of nZVI and the expansion of more interchangeable surfaces available for reaction with antimony ions causes more antimony ions to be adsorbed. In all cases, the coefficient of determination between the laboratory results and the model predictions that was obtained was more than 0.9. PMID:27191572

  15. New Antimony Lanthanide Disulfide Dibromides LnSbS

    SciTech Connect

    Gout, D.; Jobic, S.; Evain, M.; Brec, R.

    2001-05-01

    CeSbS{sub 2}Br{sub 2} (I), Ce{sub 1/2}La{sub 1/2}SbS{sub 2}Br{sub 2} (II), and LaSbS{sub 2}Br{sub 2} (III) have been synthesized at 700 C from a mixture of LnBr{sub 3}, Ln{sub 2}S{sub 3}, Sb, and S and characterized by single-crystal X-ray diffraction. The three phases are isostructural (space group P2{sub 1}/c, Z=4) and crystallize in a novel, dense, bidimensional structure with cell parameters a=8.709(3) {angstrom}, b=9.187(2) {angstrom}, c=17.397(5) {angstrom} {beta}=104.26(3) for I, a=8.739(7) {angstrom}, b=9.219(7) {angstrom}, c=17.41(2) {angstrom}, =104.3(1) for II, and a=8.785(1) {angstrom}, b=9.236(2) {angstrom}, c=17.372(3) {angstrom}, {beta}=104.09(2) for III. In these compounds, [Ln S{sub 5}Br{sub 4}] and [Ln S{sub 3}Br{sub 6}] (Ln=Ce, La) distorted tricapped trigonal prisms define infinite {sub {infinity}}{sup 2}[LnS{sub 2}Br{sub 2}] layers counterbalanced and capped by antimony cations. In good accordance with the structural features, the charge balance in these materials is to be written Ln{sup III}Sb{sup III}S{sup -II}{sub 2}Br{sup -I}{sub 2}. These compounds exhibit a yellow hue with a measured absorption threshold of 2.42(1), 2.55(1), and 2.72(1) eV for I, II, and III, respectively. In the two cerium containing bromothioantimonates I and II, the origin of the color is assigned to a Ce-4f{yields}Ce-5d electronic transition, which shifts to higher energy from I to II due either to a matrix effect (increase of the mean Ln-S distances under the substitution of Ce for La) or to an atomic ordering between Ce and La cations on the Ln(1) and Ln(2) crystallographic sites. In contrast, the electronic transition at play in III involves a charge transfer from the bromine and sulfur ions to the antimony ions, the latter contributing substantially to the lowermost levels of the conduction band.

  16. MAPK1 of Leishmania donovani Modulates Antimony Susceptibility by Downregulating P-Glycoprotein Efflux Pumps

    PubMed Central

    Garg, Mansi

    2015-01-01

    Emergence of resistance to pentavalent antimonials has become a severe obstacle in the treatment of visceral leishmaniasis (VL) in the Indian subcontinent. Mitogen-activated protein kinases (MAPKs) are well-known mediators of signal transduction of eukaryotes, regulating important processes, like proliferation, differentiation, stress response, and apoptosis. In Leishmania, MAPK1 has been shown to be consistently downregulated in antimony-resistant field isolates, suggesting that it has a role in antimony resistance. The present work investigates the molecular mechanism of MAPK1 in antimony resistance in Leishmania donovani. The L. donovani MAPK1 (LdMAPK1) single-allele replacement mutants exhibited increased resistance to Sb(III) (5.57-fold) compared to wild-type promastigotes, while overexpressing parasites became much more susceptible to antimony. The LdMAPK1-mediated drug sensitivity was directly related to antimony-induced apoptotic death of the parasite, as was evidenced by a 4- to 5-fold decrease in cell death parameters in deletion mutants and a 2- to 3-fold increase in MAPK1-overexpressing cells. LdMAPK1-underexpressing parasites also exhibited increased P-glycoprotein (P-gp)-mediated efflux pump activity, while a significant decrease in pump activity was observed in overexpressing cells. This change in efflux pump activity was directly related to expression levels of P-gp in all cell lines. However, episomal complementation of the gene restored normal growth, drug sensitivity, P-gp expression, and efflux pump activity. The data indicate that LdMAPK1 negatively regulates the expression of P-glycoprotein-type efflux pumps in the parasite. The decrease in efflux pump activity with an increase in LdMAPK1 expression may result in increased antimony accumulation in the parasite, making it more vulnerable to the drug. PMID:25870075

  17. The MRP1-mediated effluxes of arsenic and antimony do not require arsenic-glutathione and antimony-glutathione complex formation.

    PubMed

    Salerno, Milena; Petroutsa, Maria; Garnier-Suillerot, Arlette

    2002-04-01

    Arsenic trioxide is an effective treatment for acute promyelocytic leukemia, but resistance to metalloid salts is found in humans. Using atomic absorption spectroscopy, we have measured the rate of uptake of arsenic trioxide and of antimony tartrate in GLC4 and GLC4/ADR cells overexpressing MRP1 and the rate of their MRP1-mediated effluxes as a function of the intracellular GSH concentration. In sensitive cells, after 1 h, a pseudosteady state is reached where intra- and extracellular concentrations of metalloid are the same. This precludes the formation, at short term, of complexes between arsenic or antimony with GSH. In resistant cells reduced intracellular accumulation of arsenic (or antimony), reflecting an increased rate of arsenic (or antimony) efflux from the cells, is observed. No efflux of the metalloid is observed in GSH depleted cells. The two metalloids and GSH are pumped out by MRP1 with the same efficiency. Moreover for the three compounds 50% of the efflux is inhibited by 2 microM MK571. This led us to suggest that As- and Sb-containing species could be cotransported with GSH. PMID:12018890

  18. Terrestrial growth of lead-tin-telluride by techniques related to low G growth

    NASA Technical Reports Server (NTRS)

    Jesser, W. A.

    1982-01-01

    A modified Bridgman-Stockbarger furnace was constructed for a study of the solidification of silver, germanium and lead-tin-telluride. The melt-solid interface position with respect to the furnace and its temperature profile was determined by measuring the discontinuity in the slope of temperature as a function of position in the melt and in the solid. The results show that the interface position of the semiconductors germanium and lead-tin-telluride was essentially constant with respect to the furnace and hence the growth rate was constant and equal to the sample translation rate of 0.046 cm/min and 0.178 cm/min in each case. The metal, silver, on the other hand showed a continuous interface migration toward the hot zone of the furnace and always exhibited a growth rate which was higher than the ampoule translation rate. The K sub L/K sub S ratio of lead-tin-telluride was determined to be 2.33 + or - 0.06 where K sub L,S denotes the thermal conductivity of the liquid, solid respectively. The value of K sub L was calculated to be about 0.054 Watt 0.1 cm 0.1 K. The diffusion boundary layer thickness was calculated for lead-tin-telluride to be about 0.05 cm using a liquid diffusivity of .00007 sq cm/sec.

  19. INSTRUMENTS AND METHODS OF INVESTIGATION: Cadmium mercury telluride and the new generation of photoelectronic devices

    NASA Astrophysics Data System (ADS)

    Ponomarenko, Vladimir P.

    2003-06-01

    This paper is a 1969-2002 progress report on the development of solid semiconductor solutions of cadmium-mercury tellurides (single crystals and epitaxial layers) as well as of infrared photodetectors based on them (photoresistors and photodiodes, including the array variety).

  20. Study of Photo-Conductivity in Nano-Crystalline Cadmium Telluride Thin Films

    SciTech Connect

    Mahesha, M. G.; Bangera, Kasturi V.; Shivakumar, G. K.

    2011-07-15

    Nano crystallite thin films of Cadmium Telluride have been grown on glass substrates by thermal evaporation under vacuum. The growth conditions to get stoichiometric films of the compound have been optimized. The effect of substrate temperature and annealing on photosensitivity has been investigated. Also the effect of deposition parameters and post deposition annealing on rise time and decay time have been studied in detail.

  1. FRONT ELEVATION OF TELLURIDE IRON WORKS 2.5 BY 4FOOT RETORT, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    FRONT ELEVATION OF TELLURIDE IRON WORKS 2.5 BY 4-FOOT RETORT, USED TO FLASH MERCURY FROM GOLD. MERCURY VAPOR THEN CONDENSED ON INSIDE OF HOOD AND WAS COLLECTED FOR REUSE. - Shenandoah-Dives Mill, 135 County Road 2, Silverton, San Juan County, CO

  2. Growth of Cadmium-Zinc Telluride Crystals by Controlled Seeding Contactless Physical Vapor Transport

    NASA Technical Reports Server (NTRS)

    Palosz, W.; Grasza, K.; Gillies, D.; Jerman, G.

    1996-01-01

    Bulk crystals of cadmium-zinc telluride, 23 mm in diameter and up to 45 grams in weight were grown. Controlled seed formation procedure was used to limit the number of grains in the crystal. Most uniform distribution of ZnTe in the crystals was obtained using excess (Cd + Zn) pressure in the ampoule.

  3. Method and making group IIB metal - telluride films and solar cells

    DOEpatents

    Basol, Bulent M.; Kapur, Vijay K.

    1990-08-21

    A technique is disclosed forming thin films (13) of group IIB metal-telluride, such as Cd.sub.x Zn.sub.1-x Te (0.ltoreq.x.ltoreq.1), on a substrate (10) which comprises depositing Te (18) and at least one of the elements (19) of Cd, Zn, and Hg onto a substrate and then heating the elements to form the telluride. A technique is also provided for doping this material by chemically forming a thin layer of a dopant on the surface of the unreacted elements and then heating the elements along with the layer of dopant. A method is disclosed of fabricating a thin film photovoltaic cell which comprises depositing Te and at least one of the elements of Cd, Zn, and Hg onto a substrate which contains on its surface a semiconductor film (12) and then heating the elements in the presence of a halide of the Group IIB metals, causing the formation of solar cell grade Group IIB metal-telluride film and also causing the formation of a rectifying junction, in situ, between the semiconductor film on the substrate and the Group IIB metal-telluride layer which has been formed.

  4. Cadmium telluride in tellurium—cadmium films consisting of ultradispersed particles

    NASA Astrophysics Data System (ADS)

    Tuleushev, Yu. Zh.; Volodin, V. N.; Migunova, A. A.; Lisitsyn, V. N.

    2015-08-01

    Solid solutions of tellurium in cadmium, cadmium in tellurium, and cadmium in cadmium telluride synthesized during sputtering are formed for the first time by ion-plasma sputtering and the codeposition of ultradispersed Te and Cd particle fluxes onto substrates moving with respect to the fluxes. This fact supports thermofluctuation melting and coalescence of small particles. The lattice parameter of cadmium telluride, which coexists with an amorphous solid solution of tellurium in cadmium in a coating, is smaller than the tabulated value and reaches it when the cadmium concentration in a coating increases to 70 at %. The lattice parameter of the fcc lattice of cadmium telluride increases with the cadmium concentration in a coating according to the linear relation a = 0.0002CCd + 0.6346 nm (where CCd is the cadmium concentration in the coating, at %), which is likely to indicate a certain broadening of the homogeneity area. The estimation of the particle size shows that the cadmium telluride grain size is 10-15 nm, which implies that the coatings are nanocrystalline. The absorption and transmission spectra of the tellurium—cadmium films at the fundamental absorption edge demonstrate that their energy gaps are larger than that of stoichiometric CdTe, which can be explained by the experimental conditions of crystal structure formation.

  5. The Electrodeposition of Lead Telluride Nanowires for Thermoelectric Applications

    NASA Astrophysics Data System (ADS)

    Hillman, Peter

    The electrodeposition of PbTe nanowires for thermoelectric applications is presented in this thesis. The Pb-Te electrochemical system was investigated to determine the optimal conditions for deposition. It was found that citric acid complexed tellurium in solution shifting its reduction potential cathodically. The shift in reduction potential led to the deposition of pure PbTe without any observable excess tellurium. Nanowires of PbTe were doped p-type and n-type through the addition of thallium and indium to the plating solution. Indium-doped nanowire arrays showed a linear relation between lattice parameter and atomic percent indium confirming successful incorporation. The lattice parameter trend in thallium-doped nanowire arrays was linear only after annealing. In the case of thallium doping, thallium tellurides were formed, which upon annealing formed a solid solution with PbTe. The results of the thallium doping study led to the investigation of the Tl-Te electrochemical system. Cyclic voltammagrams were used to determine the deposition mechanism of TlTe and Tl5Te3. Thin films and nanowire arrays of these compounds were deposited. This was the first study of the electrochemical Tl-Te system and the first report of the electrodeposition of TlTe and Tl5Te3. Thermoelectric measurements were conducted on thin films and nanowire arrays of PbTe. The Seebeck coefficient and resistivity of PbTe thin film were measured. Results from thin films were complicated by the Pt substrate on which PbTe was deposited. Subtracting the effects of the Pt layer suggested PbTe thin films could have a large zT, however further work is needed to confirm this result. Resistivity measurements on nanowire arrays were also conducted. Despite efforts to minimize the oxidation of PbTe nanowires, good electrical contacts could not be created. The resistivity of nanowire arrays were orders of magnitude higher than expected. As a result of their low conductivity, the thermoelectric efficiency

  6. Simultaneous lead and antimony immobilization in shooting range soil by a combined application of hydroxyapatite and ferrihydrite.

    PubMed

    Ogawa, Shouhei; Katoh, Masahiko; Sato, Takeshi

    2015-01-01

    This study investigated whether a combined application of hydroxyapatite and ferrihydrite could immobilize lead and antimony in shooting range soil in which the level of lead contamination is markedly higher than that of antimony. In addition, we evaluated the stability of lead and antimony immobilized by the combined application with varying soil pH. The levels of water-soluble lead and antimony for the combined application were lower than those of single applications of hydroxyapatite or ferrihydrite, indicating that the combined application could suppress the levels of water-soluble lead and antimony by 99.9% and 95.5%, respectively, as compared with the levels in shooting range soil without immobilization material. The amounts of residual lead and amorphous Fe/Al oxide-bound antimony fractions in sequential extraction increased with a decrease in the exchangeable and carbonate lead fractions as well as in non-specifically bound and specifically bound antimony fractions. The alteration of lead and antimony phases to chemically more stable ones as a result of the combined application would result in the suppression of their mobility. The stability of immobilized lead and antimony in the combined application was equal to that of lead with a single application of hydroxyapatite and that of antimony with a single application of ferrihydrite within neutral to alkaline pH conditions, respectively. Therefore, this study suggests that the combined application of hydroxyapatite and ferrihydrite can simultaneously immobilize lead and antimony in shooting range soil with neutral to alkaline pH. PMID:25894550

  7. Antimony-Based III-V Thermophotovoltaic Materials and Devices

    NASA Astrophysics Data System (ADS)

    Wang, C. A.

    2004-11-01

    Antimony-based III-V thermophotovoltaic (TPV) cells are attractive converters for systems with low radiator temperature of around 1100 to 1700 K, since these cells can be spectrally matched to the thermal source. Cells under development include GaSb and lattice-matched GaInAsSb/GaSb and InPAsSb/InAs. GaSb cell technology is the most mature, owing in part to the relative ease in preparation of the binary alloy compared to the quaternary alloys. Cell performance of 0.7-eV GaSb devices is at ˜90% of the practical limit. GaInAsSb cells with energy gap Eg ranging from ˜0.6 to 0.49 eV have been demonstrated with quantum efficiency and fill factor approaching practical limits. InPAsSb cells are the least studied, and a 0.45-eV cell has spectral response out to 4.3 μm. This paper briefly reviews the main efforts in Sb-based TPV cells.

  8. Calcium-Antimony Alloys as Electrodes for Liquid Metal Batteries

    SciTech Connect

    Ouchi, T; Kim, H; Ning, XH; Sadoway, DR

    2014-08-08

    The performance of a calcium-antimony (Ca-Sb) alloy serving as the positive electrode in a Ca vertical bar vertical bar Sb liquid metal battery was investigated in an electrochemical cell, Ca(in Bi) vertical bar LiCl-NaCl-CaCl2 vertical bar Ca(in Sb). The equilibrium potential of the Ca-Sb electrode was found to lie on the interval, 1.2-0.95 V versus Ca, in good agreement with electromotive force (emf) measurements in the literature. During both alloying and dealloying of Ca at the Sb electrode, the charge transfer and mass transport at the interface are facile enough that the electrode potential varies linearly from 0.95 to 0.75 V vs Ca(s) as current density varies from 50 to 500 mA cm(-2). The discharge capacity of the Ca vertical bar vertical bar Sb cells increases as the operating temperature increases due to the higher solubility and diffusivity of Ca in Sb. The cell was successfully cycled with high coulombic efficiency (similar to 100%) and small fade rate (<0.01% cycle(-1)). These data combined with the favorable costs of these metals and salts make the Ca vertical bar vertical bar Sb liquid metal battery attractive for grid-scale energy storage. (C) The Author(s) 2014. Published by ECS. All rights reserved.

  9. Single-layer crystalline phases of antimony: Antimonenes

    NASA Astrophysics Data System (ADS)

    Aktürk, O. Üzengi; Ã-zçelik, V. Ongun; Ciraci, S.

    2015-06-01

    The pseudolayered character of 3D bulk crystals of antimony has led us to predict its 2D single-layer crystalline phase named antimonene in a buckled honeycomb structure like silicene. Sb atoms also form an asymmetric washboard structure like black phospherene. Based on an extensive analysis comprising ab initio phonon and finite-temperature molecular dynamics calculations, we show that these two single-layer phases are robust and can remain stable at high temperatures. They are nonmagnetic semiconductors with band gaps ranging from 0.3 eV to 1.5 eV, and are suitable for 2D electronic applications. The washboard antimonene displays strongly directional mechanical properties, which may give rise to a strong influence of strain on the electronic properties. Single-layer antimonene phases form bilayer and trilayer structures with wide interlayer spacings. In multilayers, this spacing is reduced and eventually the structure changes to 3D pseudolayered bulk crystals. The zigzag and armchair nanoribbons of the antimonene phases have fundamental band gaps derived from reconstructed edge states and display a diversity of magnetic and electronic properties depending on their width and edge geometry. Their band gaps are tunable with the widths of the nanoribbons. When grown on substrates, such as germanene or Ge(111), the buckled antimonene attains a significant influence of substrates.

  10. Yb3+/Ho3+-codoped antimony-silicate optical fiber

    NASA Astrophysics Data System (ADS)

    Żmojda, Jacek; Dorosz, Dominik; Kochanowicz, Marcin; Miluski, Piotr; Dorosz, Jan

    The emission properties of Yb3+/Ho3+-codoped antimony-silicate optical fiber has been investigated. Luminescence at 2.1 μm corresponding to 5I7--> 5I8 transition in holmium was obtained by energy transfer between Yb3+ and Ho3+ ions. According to the Dexter-Miyakawa model, the parameters of energy migration CDD of the 2F5/2 (Yb3+) <--> 2F5/2 (Yb3+) transition and direct energy transfer CDA of the 2F5/2 (Yb3+) --> 5I6 (Ho3+) transition was calculated. The optimization of the activator content and the concentration ratio were conducted with the purpose of maximizing the efficiency of energy transfer. It made possible to select best-suited glass which was used to manufacture double-clad optical fiber. Strong and narrow bands of spontaneous emission which formed as a result of energy transfer between ytterbium and holmium ions were observed in the fiber under exciting with radiation at 978 nm wavelength.