First principles study on electronic properties and mechanical stability of HfRhZ (Z = As and Sb) half Heusler alloys

Abstract

The structural, electronic, elastic and mechanical properties of half-Heusler HfRhZ (Z = As and Sb) alloys are investigated using first principles calculations. The optimized lattice constants, bulk modulus and its pressure derivatives within LDA and GGA approaches are reported. The calculated results of band structure and density of states using GGA and TB-mBJ confirm that HfRhSb is an indirect band gap semiconductor while HfRhAs is a direct band gap semiconductor. The elastic and mechanical properties of HfRhZ (Z = As and Sb) alloys within LDA and GGA approaches are also investigated. The alloys are elastically stable as their elastic constants such as C11,C12 and C44 satisfy the mechanical stability condition. The mechanical properties such as Young’s modulus (E), bulk modulus (B), shear modulus (GH), Poisson’s ratio (σ), the Pugh’s ratio (B/GH), anisotropic factor (A) and Cauchy’s pressure (Cp) are calculated. The studied alloys are ductile in nature, elastically anisotropic and HfRhSb has more stiffness than HfRhAs.