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Title of article :
Ab initio band structure calculations of the low-temperature phases of Ag2Se, Ag2Te and Ag3AuSe2 Original Research Article
Author/Authors :
C.M. Fang، نويسنده , , R.A. de Groot، نويسنده , , G.A. Wiegers، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2002
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Abstract :
Ab initio band structure calculations were performed for the low-temperature modifications of the silver chalcogenides β-Ag2Se, β-Ag2Te and the ternary compound β-Ag3AuSe2 by the local spherical wave (LSW) method. Coordinates of the atoms of β-Ag2Se and β-Ag3AuSe2 were obtained from refinements using X-ray powder data. The structures are characterized by three, four and five coordinations of silver by the chalcogen, a linear coordination of gold by Se, and by metal–metal distances only slightly larger than in the metals. The band structure calculations show that β-Ag3AuSe2 is a semiconductor, while β-Ag2Se and β-Ag2Te are semimetals with an overlap of about 0.1–0.2 eV. The Ag 4d and Au 5d states are strongly hybridized with the chalcogen p states all over the valence bands. β-Ag2Se and β-Ag2Te have a very low DOS in the energy range from about −0.1 to +0.5 eV. The calculated effective mass β-Ag2Se is about 0.1–0.3 me for electrons and 0.75 me for holes, respectively.
Keywords :
C. X-ray powder diffraction , D. Crystal structure , C. ab initio calculations , A. Chalcogenides , D. Electronic structure
Journal title :
Journal of Physics and Chemistry of Solids
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