Browsing by Author "Huang, Jih-Chen"

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Synthesis and characterization of a new quaternary selenide Sr(3)GeSb(2)Se(8)
(2008-09-01)
Yu, Ching-Yi
;
Wang, Ming-Fang
;
Chung, Ming-Yang
;
Jang, Shyue-Ming
;
Huang, Jih-Chen
A new quaternary selenide Sr(3)GeSb(2)Se(8) has been synthesized at 750 degrees C from pure elements in a stoichiometric ratio under vacuum. The product as-synthesized is characterized by single-crystal X-ray diffraction, diffuse reflectance spectroscopy, and thermoanalysis. The title compound crystallizes in the orthorhombic space group Pnma with a = 12.633(4) angstrom, b = 4.301(1) angstrom, c = 28.693(7) angstrom, V = 1558.8(8) angstrom(3), Z = 4, R(1)/wR(2) = 0.0582/0.1221, and GOF = 1.077. The structure of Sr(3)GeSb(2)Se(8) features a new structural type that consists of one-dimensional chains of vertex-sharing tetrahedra (1)(infinity)[MSe(3)] (M = Ge/Sb) and fused double chains of edge-shared square pyramids (1)(infinity)[M(2)Se(5)], which are held together by Sr(2+) ions. A band gap of 0.75 eV for Sr(3)GeSb(2)Se(8) was derived from its diffuse reflectance spectrum. (C) 2007 Elsevier Masson SAS. All rights reserved.
Synthesis and characterization of quaternary chalcogenides InSn(2)Bi(3)Se(8) and In(0.2)Sn(6)Bi(1.8)Se(9)
(2009-06-01)
Wang, Ming-Fang
;
Jang, Shyue-Ming
;
Huang, Jih-Chen
;
Lee, Chi-Shen
;
應用化學系
Quaternary chalcogenides InSn(2)Bi(3)Se(8) and In(0.2)Sn(6)Bi(1.8)Se(9) were synthesized on direct combination of their elements in stoichiometric ratios at T>800 degrees C under vacuum. Their structures were determined with X-ray diffraction of single crystals. InSn(2)Bi(3)Se(8) crystallizes in monoclinic space group C2/m (No. 12) with a = 13.557(3) angstrom, b = 4.1299(8) angstrom, c = 15.252(3)angstrom, beta = 115.73(3)degrees, V = 769.3(3) angstrom(3), Z = 2, and R(1)/wR(2)/GOF = 0.0206/0.0497/1.092; In(0.2)Sn(6)Bi(1.8)Se(9) crystallizes in orthorhombic space group Cmc2(1) (No. 36) with a = 4.1810(8) angstrom, b = 13.799(3) angstrom, c = 31.953(6) angstrom, V=1843.4(6) angstrom(3), Z = 4, and R(1)/wR(2)/GOF = 0.0966/0.2327/1.12. InSn(2)Bi(3)Se(8) and In(0.2)Sn(6)Bi(1.8)Se(9) are isostructural with CuBi(5)S(8) and Bi(2)Pb(6)S(9) phases, respectively. The structures of InSn(2)Bi(3)Se(8) and In(0.2)Sn(6)Bi(1.8)Se(9) feature a three-dimensional framework containing slabs of NaCl-(311) type with varied thicknesses. Calculations of the electronic structure and measurements of electrical conductivity indicate that these materials are semiconductors with narrow band gaps. Both compounds show n-type semiconducting properties with Seebeck coefficients -270 and -230 mu V/K at 300 K for InSn(2)Bi(3)Se(8) and In(0.2)Sn(6)Bi(1.8)Se(9), respectively. (C) 2009 Elsevier Inc. All rights reserved.
Synthesis and characterization of quaternary chalcogenides InSn2Bi3Se8 and In0.2Sn6Bi1.8Se9
(2009-06-01)
Wang, Ming-Fang
;
Jang, Shyue-Ming
;
Huang, Jih-Chen
;
Lee, Chi-Shen
;
應用化學系
Quaternary chalcogenides InSn2Bi3Se8 and In0.2Sn6Bi1.8Se9 were synthesized on direct combination of their elements in stoichiometric ratios at T>800 degrees C under vacuum. Their structures were determined with X-ray diffraction of single crystals. InSn2Bi3Se8 crystallizes in monoclinic space group C2/m (No. 12) with a = 13.557(3) angstrom, b = 4.1299(8) angstrom, c = 15.252(3)angstrom, beta = 115.73(3)degrees, V = 769.3(3) angstrom(3), Z = 2, and R-1/wR(2)/GOF = 0.0206/0.0497/1.092; In0.2Sn6Bi1.8Se9 crystallizes in orthorhombic space group Cmc2(1) (No. 36) with a = 4.1810(8) angstrom, b = 13.799(3) angstrom, c = 31.953(6) angstrom, V=1843.4(6) angstrom(3), Z = 4, and R-1/wR(2)/GOF = 0.0966/0.2327/1.12. InSn2Bi3Se8 and In0.2Sn6Bi1.8Se9 are isostructural with CuBi5S8 and Bi2Pb6S9 phases, respectively. The structures of InSn2Bi3Se8 and In0.2Sn6Bi1.8Se9 feature a three-dimensional framework containing slabs of NaCl-(311) type with varied thicknesses. Calculations of the electronic structure and measurements of electrical conductivity indicate that these materials are semiconductors with narrow band gaps. Both compounds show n-type semiconducting properties with Seebeck coefficients -270 and -230 mu V/K at 300 K for InSn2Bi3Se8 and In0.2Sn6Bi1.8Se9, respectively. (C) 2009 Elsevier Inc. All rights reserved.