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Abstract: The as-grown arsenic-doped HgCdTe typically exhibits compensated n-type conductivity. Based on first-principles calculations, we identify Hg vacancies (V Hg) as a dominant defect species involved in the compensation. Arsenic donor (AsHg) and V Hg acceptor no doubt tend to combine into complex defects but little has been recognized about the features of the complex defects in precious studies. These features outlined in this work enable us to provide a consistent explanation for arsenic activation mechanism proposed by Zandian et al. [] and Berding et al. []. [Copyright &y& Elsevier]

Abstract: The Mg-doped Li3V2− x Mg x (PO4)3 (x =0.00, 0.01, 0.02, 0.05, 0.10, 0.20, 0.30, 0.33, 0.50, 1.00 and 1.33) compounds have been prepared by a sol–gel method in reducing atmosphere (70%Ar+30%H2) using citric acid as a chelating agent and a carbon source coated on the samples. The Mg-doped effects on the structural and electrochemical performance of Li3V2(PO4)3 are investigated by X-ray diffraction, galvanostatic, charge/discharge and four-point probe measurement method. The Li3V2− x Mg x (PO4)3 solid solution phase can exist stable in the composition range between x =0.00 and 0.27. The simple improve mechanism of the electrochemical performance for Mg-doped Li3V2− x Mg x (PO4)3 system is discussed too. In the Mg-doped Li3V2− x Mg x (PO4)3 system, at a lower charge/discharge rate (0.1C), the cycle performance has no much improvement with the increasing Mg doping content. However, at higher rates, there has an excited improvement in both cycle performance and rate capability due to the increase of electrical conductivity (more than one order of magnitude). At 5C charge/discharge rate, for the Li3V1.95Mg0.05(PO4)3 sample, the discharge capacities for the 1st and 100th cycle were 138.9 and 123.3mAhg−1. The discharge capacity retention reached to 89% (more than 51% for undoped Li3V2(PO4)3 system). More important is that, except for the first 15 cycles, the discharge capacities kept almost a constant. Based on the excellent electrochemical performance, Li3V1.95Mg0.05(PO4)3 will be a promising cathode material for rechargeable lithium-ion batteries. [Copyright &y& Elsevier]

Abstract: Using first-principles method we studied the compensation mechanism of As donor in Hg1− x Cd x Te based on the model Berding et al. (1998, 1999) of pair. We show that the binding of AsHg and results from donor-acceptor coupling, and the compensation of As donor can be clearly explained in terms of electronic deactivation by . The pairing physics derived from this study confirm the available theoretical and experimental results. [ABSTRACT FROM AUTHOR]

Abstract: Lithium iron phosphate (LiFePO4) cathode material has been synthesized by a solid-state reaction. The XRD patterns of the samples show that the single-phase LiFePO4 compounds can be obtained in our experimental conditions. According to Popa theory, using the result from Rietveld refinement, the shape and the size of crystallite can be obtained. The result shows that the use of carbon gel in precursors do not change the structure of the crystal, but it can inhibit the particle growth and restrain the anisotropy growth of the grain at a lower temperature. At a higher temperature, carbon-coated LiFePO4 shows an anisotropy growth, i.e. growth rate along (100) crystal plane is more rapid than that of (111) crystal plane. In our experimental conditions, a spherical carbon-coated LiFePO4 can be synthesized successfully at 650°C. The electrochemical testing indicated that the spherical carbon-coated LiFePO4 had the excellent performance. Its initial specific capacities were 156.7mAhg−1 under the rate of C/10. At the 50th cycle, the reversible specific capacities were found to approach 151.2mAhg−1 (the ratio of 96.5% of initial capacity). [Copyright &y& Elsevier]

Abstract: Phase equilibria in the ternary Li2O–FeO–B2O3 system were studied by means of X-ray powder diffraction. The Li2O–FeO–B2O3 system can be characterized by the existence of 17 three-phase regions. For the two ternary compounds found in this system, the compound A with molar ratio of Li2O, FeO and B2O3 in 2:1:1 had not been reported previously. The nearly unchanged d values for the X-ray diffraction peaks of the samples around the new compounds A indicate the existence of the new compound A in the ternary Li2O–FeO–B2O3 system. Other new information includes the electrochemical properties of LiFeBO3 compound, where the electrochemical test indicated that the discharge plateau potential of LiFeBO3 compound is around 2.3V and initial discharge-specific capacities can reach to 91.8mAhg−1. Our results show that LiFeBO3 samples have better capacity retention except for the first two cycles. [Copyright &y& Elsevier]

Abstract: LiFeBO3 cathode material has been synthesized successfully by solid-state reaction using Li2CO3, H3BO3 and FeC2O4·2H2O as starting materials. The crystal structure has been determined by the X-ray diffraction. Electrochemical tests show that an initial discharge capacity of about 125.8mAh/g can be obtained at the discharge current density of 5mA/g. When the discharge current density is increased to 50mA/g, the specific capacity of 88.6mAh/g can still be held. In order to further improve the electrochemical properties, the carbon-coated LiFeBO3, C-LiFeBO3, are also prepared. The amount of carbon coated on LiFeBO3 particles was determined to be around 5% by TG analysis. In comparison with the pure LiFeBO3, a higher discharge capacity, 158.3mAh/g at 5mA/g and 122.9mAh/g at 50mA/g, was obtained for C-LiFeBO3. Based on its low cost and reasonable electrochemical properties obtained in this work, LiFeBO3 may be an attractive cathode for lithium-ion batteries. [Copyright &y& Elsevier]

Abstract: The electrodeposition of iron disulfide pyrite (FeS2) thin films on indium–tin oxide (ITO) substrate in aqueous solution containing Na2S2O3·5H2O, FeCl2·4H2O reagents was investigated. The deposited material is successively annealed in sulfur atmosphere. In this way, we successfully obtained pyrite thin films with good quality. The structure, optical and electrical property analysis for the resulted films was carried out and some special results have been concluded. [Copyright &y& Elsevier]

Pyrite FeS2 powder was initially synthesized using sol–gel hydrothermal method by the reaction of S and the colloid precursor formed from FeSO4·7H2O and thiourea fluxes. We present some results on the influence of reactants, reaction temperature and time, and the quantity of S on the formation of single-phase pyrite FeS2 powder. Then EPD technique was applied to the deposited as-prepared pyrite powder. Crystal structure, optical and electrical property measurements for the pyrite films prepared in this way were carried out and some special results have been obtained. [Copyright &y& Elsevier]