A synchrotron powder X-ray diffraction study of the skutterudite-related phases AB1.5Te1.5 (A = Co, Rh, Ir; B = Ge, Sn).
X-Ray resonant scattering has been exploited to investigate the crystal structure of the AB(1.5)Te(1.5) phases (A = Co, Rh, Ir; B = Ge, Sn). Analysis of the diffraction data reveals that CoGe(1.5)Te(1.5) and ASn(1.5)Te(1.5) adopt a rhombohedral skutterudite-related structure, containing diamond-shape B(2)Te(2) rings, in which the B and Te atoms are ordered and trans to each other. Anion ordering is however incomplete, and with increasing the size of both cations and anions, the degree of anion ordering decreases. By contrast, the diffraction data of IrGe(1.5)Te(1.5) are consistent with an almost statistical distribution of the anions over the available sites, although some ordered domains may be present. The thermoelectric properties of these materials are discussed in light of these results.
Vaqueiro
Paz
P
Department of Chemistry, Heriot-Watt University, Edinburgh, UK EH14 4AS. chepv@hw.ac.uk
Sobany
Gerard G
GG
Powell
Anthony V
AV