Syntheses and Characterization of Quaternary Indium Selenides

• Main Authors: Chi-wen Tsai, 蔡智文
• Other Authors: Kuei-fang Hsu
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/33114461749532754807

碩士 === 國立成功大學 === 化學系碩博士班 === 95 === Two new quaternary compounds of Ba4AgInSe6 and Ba4Cu3In3Se10 have been synthesized by the flux-growth methods at 800℃. The compound of Ba4AgInSe6 crystallizes in triclinic, P-1, a = 4.509 Å, b = 9.19480(10) Å, c = 17.8841(2) Å, α = 89.9980(10)°, β= 90.0010(10)°, γ= 90.0020(10)°, z = 4 and V = 741.447(12) Å3. The structure is composed of [MSe4] (M = Ag and In) tetrahedra to form one-dimensional chains by corner-sharing. The bond distances of M-Se are between 2.6140(9) Å and 2.6655(9) Å, which values correspond to the average distances as the metal sites occupied by both indium and silver ions. The barium ions are located between these chains and surrounded by seven selenium anions with the Ba-Se distances distributed between 3.2118(8) Å and 3.4812(8) Å. The measure band-gap of the compound is 1.81eV .The compound of Ba4Cu3In3Se10 crystallizes in monoclinic, P21/c, a = 4.0839(8) Å, b = 27.148(5) Å, c = 21.599(4) Å, α = 90°, β= 90.05(3)°, γ= 90°, z = 8 and V = 2394.7(8) Å3. The structure is composed of [CuSe5] square pyramids and [CuSe6] octahedra to form two-dimensional slabs by edge-sharing where [InSe4] tetrahedra surround the periphery of slabs by corner-sharing. Interestingly, the copper polyhedra are arranged as the antifluorite-like connectivity in the slabs. The barium ions are located between these slabs and surrounded by eight selenium anions.