Electronic Structure of the Half-Heusler ScAuSn, LuAuSn and their Superlattice: A Comparative GGA, mBJ and GGA+SOC Study

A detailed analysis of electronic band structure of the ScAuSn, LuAuSn and their Superlattice have been performed using the full potential linearized augmented plane waves (FP-LAPW). The exchange-correlation between the electrons was treated with three schemes, generalized gradient approximation (GGA), Trans and Blaha modified Becke-Johnson potential (TB-mBJ) and Spin-Orbit Coupling (SOC) incorporated with GGA. The GGA method reveals an indirect spin-gapless semiconducting nature for LuAuSn, an indirect band gap semiconducting nature for ScAuSn and direct semiconducting nature for their superlattice whereas under mBJ scheme, the band gap values are found to be enhanced. The inclusion of Spin-Orbit Coupling effects in GGA predicts the materials to be semi-metallic. The density of states is mainly dominated by the Sc and Lu atom near the vicinity of Fermi energy level and in the conduction region in ScAuSn and LuAuSn alloys, respectively whereas in superlattice the density of states is mainly dominated by Sc atom with significant contribution from Sn atoms.

Keywords: Half-metal, Spin-gapless semiconductor, Semi-metal, Superlattice.