Justification of crystal stability and origin of transport properties in ternary half-Heusler ScPtBi

Abstract

In this study, the mechanical stability, machinability, flexibility, ductility, hardness and crystal stability have been analysed for the justification of suitability of ScPtBi for practical applications and device fabrication. We observed that ScPtBi satisfies the Born stability criterion nicely as well as possessing a negative value of formation enthalpy which suggests that ScPtBi is a mechanically stable compound and can be synthesized by chemical synthesis techniques. We have investigated the nature of the bonding in ScPtBi via Mulliken bond population analysis and charge density mapping which suggest that both ionic and covalent bonding exist in the ScPtBi with bonding and anti-bonding features. We have correlated band structure (BS), density of states (DOS), Fermi surface (FS) and charge density mapping to explain the origin of transport properties in ScPtBi by exploring the electronic behavior in detail with the help of first principles calculation. We have observed an octahedral hole like sheet due to a heavy hole pocket at the Γ point whose flat surfaces enhance transport properties in the direction parallel to the edges. The electron and hole like multi sheets achieved in the same topology are favorable for skipping of carriers and Fermi surface nesting. We have also calculated the electronic specific heat coefficient successfully using the density of states at the Fermi level.