Cd_13−xIn_ySb₁₀ (x≈2.7, y≈1.5): An Interstitial‐Free Variant of Thermoelectric β‐Zn₄Sb₃

Abstract

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.

Electron-poor antimonides: complex framework structures with narrow band gaps and low thermal conductivity

“…According to Slack, the probability of Umklapp scattering scales linearly with the lattice parameter, 29 and a simple explanation for the low lattice thermal conductivity of a-Cd 4 Sb 3 would be its large, 276 atom unit cell crystal structure. 11 The thermal conductivity of a-Cd 4 Sb 3 is somewhat larger than for disordered b-Zn 4 Sb 3 , but lower than for ordered a-and a¢-Zn 4 Sb 3 in the temperature range between 50 and 250 K.…”

Zn5Sb4In2−δ — a Ternary Derivative of Thermoelectric Zinc Antimonides

“…Especially, in both systems the occurrence of disordered, interstitial atoms that are susceptible to temperature dependent ordering is a characteristic feature. Furthermore, we found a ternary derivative, Cd 13− x In y Sb 10 , where trivalent indium appears to replace a considerable concentration of divalent cadmium . This results in an interstitial-free framework structure, where the electron concentration is essentially maintained with respect to Cd 4 Sb 3 but properties are radically changed.…”

Phase relations and structural properties of the ternary narrow gap semiconductors Zn5Sb4In2−δ (δ=0.15) and Zn9Sb6In2

“…Reactions with indium, however, provide an interesting possibility to modify the electron poor framework structures of zinc and cadmium antimonides while maintaining a weak polarity in the ternary compounds. Recently we reported on a ternary derivative of Cd 4 Sb 3 , Cd 13 À x In y Sb 10 , where trivalent indium appears to replace a considerable concentration of divalent cadmium [10]. This results in a framework structure which in contrast with Cd 4 Sb 3 does not contain interstitial Cd atoms [5].…”