Strain effect on topological and thermoelectric properties of half Heusler compoundsXPtS (X=Sr, Ba)

In this article, we report theoretical investigations of topological and thermoelectric (TE) properties of non-centrosymmetric half Heusler compoundsXPtS (X= Sr, Ba) using first principles calculations. In addition, we also investigated the effect of static strain (up to 10%) on its topological and TE properties. Our detailed investigations show that the XPtS compounds are topological insulators (TIs) and continue as TIs up to a strain of 10%. However, the band gap becomes a maximum of 0.213 eV under a strain of 3% for SrPtS and 0.164 eV at a strain of 5% for BaPtS. TE investigations show that the figure of merit (a measure of TE performance) ZT becomes maximum (0.222) at room temperature for BaPtS under a strain of 1%. The detailed theoretical investigations ofXPtS with and without strain provide a theoretical platform for experiments and its possible applications in spintronics and thermoelectricity.