Abstract
The skutterudite (CoSb3) related crystal structure of Ir2Sn3Se3 = IrSn1.5Se1.5 is determined from single crystal data for the first time. High temperature solid state and flux reactions were applied to prepare powder and single crystals samples. Its crystal structure was refined from data of a fourfold twin crystal in space group R (3) over bar (no. 148). It contains 24 formula units per unit ...
Abstract
The skutterudite (CoSb3) related crystal structure of Ir2Sn3Se3 = IrSn1.5Se1.5 is determined from single crystal data for the first time. High temperature solid state and flux reactions were applied to prepare powder and single crystals samples. Its crystal structure was refined from data of a fourfold twin crystal in space group R (3) over bar (no. 148). It contains 24 formula units per unit cell [a = 12.6510(3) angstrom, c = 15.5236(6) angstrom, V = 2151.67(8) angstrom(3)] and represents the first single crystal determination of a colored skutterudite Ir(2)A(3)X(3) = Ir(A, X)(3) with heteroatomic [Sn2Se2] units and [Sn3Se3] coordination for Ir sites. The distorted Sn2Se2 rings show short and long Sn-Se distances. The obtained structure is isotypic to Ir2Sn3Te3 but differs from the cubic model estimated earlier for Ir2Sn3S3 (homoatomic Sn-4 and S-4 units). According to electronic band structure calculations Ir2Sn3Se3 is a low gap semiconductor (E = 0.4 eV).