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

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.