Crystal structure and high temperature thermoelectric properties of the Mo_3-xRu_xSb₇ compounds

International audienceZintl phases are currently focusing great attention for their thermoelectric potential typified by the discovery of a high ZT value in Yb14MnSb11 based compounds. Here, we report on the crystallographic characterization via neutron and X-ray diffraction experiments and on the thermoelectric properties measured in the 300-1000 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 improves substantially its thermoelectric properties resulting in a ZT value of ~ 0.45 at 1000 K for x = 0.8