Temperature and composition insensitivity of thermoelectric properties of high-entropy half-heusler compounds

• DOI: 10.1016/j.actamat.2024.119761
• Publication Date: 2024-02-15T07:29:08Z
• Authors: Suwei Li; Kan Chen; Yichen Wang; Theo Saunders; Ruizhi Zhang; Jan-Willem G. Bos; Michael J. Reece
• Keywords: Valence electron; High-Entropy Alloys

Composition modification by doping and solid solution is a well-studied strategy in thermoelectric (TE) materials to optimise their properties. Recently, the concept of entropy stabilization has offered possibility forming random solutions that have properties go beyond rule mixture. In this study, we prepared series high-entropy half-Heusler (HEHHs) with varying valence electron counts (VEC), (Ti0.33Zr0.33Hf0.33)1-x(V0.33Nb0.33Ta0.33)xCoSb (x = 0.5 0.75). Compared medium- low-entropy counterparts, TE HEHHs are less sensitive temperature composition variation (charge carrier concentration efficiency ∼10%). An ultra-low lattice thermal conductivity for 1.19 W·m−1·K−1 was achieved.