Structural, elastic, thermodynamic and thermoelectric properties of Fe2TiSn Heusler alloy: High pressure study

Abstract

The effect of high pressure on the structural, electronic, mechanical, thermal and transport properties of Fe2TiSn Heusler alloy are investigated by means of ab-initio calculations adopting modified Becke-Johnson exchange potential. Fe2TiSn alloy crystallise in Fm-3 m structure with the lattice constant of 6.02 Å. The band structure divulges that Fe2TiSn is an indirect band gap semiconductor with a band gap of 0.6 eV. Elastic parameters confirm the stability of the material with ductile nature. Fe2TiSn displays high Debye and melting temperature at normal pressures. Increasing the pressure significantly reduces the band gap of the material, beyond 30GPa Fe2TiSn becomes metallic. Thermodynamic properties have also been calculated by varying the pressure from 0 to 25 GPa. The effect of varying chemical potential on the Seebeck coefficient and power factor were also studied. Fe2TiSn Heusler alloy presents decent Seebeck coefficient and power factor, thus the alloy can be a better candidate for thermoelectric applications. Keywords: Power factor, Seebeck coefficient, Grüneisen parameter, Specific heat