Theoretical investigation of structural, topological, mechanical and thermal behavior of SrPtS and BaPtS Heusler alloys

Abstract

Topological Insulators (TIs) have become new potential materials because of their super surface conduction and bulk insulation. Their technological importance motivated us to explore the topological nature of SrPtS and BaPtS Heusler alloys using full potential linearized augmented plane wave (FP-LAPW) method as implemented in Wien2k. Structural stability is checked using three different Wyckoff positions and further investigations were carried out to find the dynamic stability with phonon dispersion curves. The electronic band structure of both materials show metallic nature when generalized gradient approximation with Perdew–Burke–Ernzerhof (GGA + PBE) exchange and correlation functional is used but there appears a band gap when spin–orbit coupling (SOC) was implemented. The band inversion strength has also been tested by applying the external pressure. Further, both alloys have been found mechanically stable and ductile in nature by determining the elastic parameters. Thermal and electrical conductances were also determined and discussed. The findings show that these materials being topological insulators are suitable for technological applications.