Cd(13-x)In(y)Sb10 (x approximately 2.7, y approximately 1.5): an interstitial-free variant of thermoelectric beta-Zn4Sb3.

Cd(13-x)In(y)Sb10 (x approximately 2.7, y approximately 1.5) was synthesized in the form of mm-sized crystals from reaction mixtures containing excess cadmium. The intermetallic compound crystallizes in the rhombohedral space group R3m with a=12.9704(4), c=12.9443(5) A, V=1886.0(1) A3, Z=3 and is isostructural to thermoelectric beta-Zn4Sb3 and beta-Cd4Sb3. However, in contrast to these last two compounds Cd(13-x)In(y)Sb(10) is free from interstitial atoms and does not display any temperature polymorphism. The electrical resistivity of Cd(13-x)In(y)Sb10 is considerably higher than that of Zn4Sb3 and Cd4Sb3 although the temperature behavior remains that of a metal. The thermal conductivity of Cd(13-x)In(y)Sb10 is low, with room-temperature magnitudes around 0.8 W m(-1) K(-1), which is comparable to disordered or complex structured Cd4Sb3 and Zn4Sb3.