First-principles study on the lattice dynamics, electronic, mechanical, and thermoelectric properties of half-heusler compounds TiXSn (X = Ni, Pd, Pt)

Abstract

The rapid depletion of fossil fuels and their environmental impact can be mitigated through the exploration of efficient and sustainable materials capable of converting waste heat into electrical energy. Half-Heusler compounds are considered highly promising materials in the field of thermoelectric applications. In this study, utilizing semi-classical Boltzmann transport theory and deformation potential theory, we investigate the electronic structure, mechanical properties, and thermoelectric performance of TiXSn (X = Ni, Pd, Pt) compounds. Our results indicate that TiXSn (X = Ni, Pd, Pt) compounds are indirect bandgap semiconductors. All three compounds are ductile materials. p-type doping in TiXSn (X = Ni, Pd, Pt) compounds demonstrates better thermoelectric performance than n-type doping. At 300 K, the lattice thermal conductivity of TiPdSn is as low as 5.25 Wm−1K−1. Moreover, at 900 K, the maximum ZT values for p-type TiNiSn, TiPdSn, and TiPtSn are 0.56, 0.59, and 0.70, respectively, suggests that p-type TiXSn (X = Ni, Pd, Pt) compounds have promising thermoelectric applications.