Crystal Structure and High-Temperature Thermoelectric Properties of the Mo3−xRuxSb7 Compounds

Zintl phases are currently receiving great attention for their thermoelectric potential typified by the discovery of a high ZT value in Yb14MnSb11-based compounds. Herein, we report on the crystallographic characterization via neutron and x-ray diffraction experiments, and on the thermoelectric properties measured in the 300 K to 1000 K temperature range, of Mo3Sb7 and its isostructural compounds Mo3−xRuxSb7. Even though Mo3Sb7 displays rather high ZT values given its metallic character, the partial substitution of Mo by Ru substantially improves its thermoelectric properties, resulting in a ZT value of ∼0.45 at 1000 K for x = 0.8.