Pressure induced structural phase transition and influence of pressure on the electronic and mechanical properties of TiPdSn: an ab initio study

Structural, electronic, mechanical and optical properties of half-Heusler alloy TiPdSn were investigated from first-principles calculation as well as the structural phase transition under pressure.  The projected augmented wave (PAW) type of pseudopotential within the generalized gradient approximation (GGA) was used during the calculation. The obtained results revealed that TiPdSn is a semiconductor with an indirect band gap.  Also the results from the mechanical property showed that TiPdSn is ductile and mechanically stable. TiPdSn is seen to undergo structural phase transition from cubic to two different structures namely type1 and type2 which crystallize in  hexagonal structure and the transition pressures recorded were 4.53GPa for type 1 and 25.3 GPa for type 2. Optical properties revealed that TiPdSn has a static dielectric function of 21.47 and a refractive index of 4.63. The band gap of the alloy decreases and later increases as pressure increases.