First-principles Calculation of Elastic and Electronic Structure Properties of Hexagonal Antiperovskite-type Carbides XCCr3 (X=Al, Ga or Zn) Materials

Abstract

Hexagonal chromium based Antiperovskite materials have been attracting a lot of research interest lately as a result of their superconducting properties. In this study the elastic and electronic structure properties of XCCr3 (X= Al, Ga or Zn) were investigated using first principles density functional theory within the generalized gradient approximations using Quantum Espresso code. Shear Modulus (G), Young’s Modulus (E), Bulk modulus (B), Poisson ratios (υ) and Zener anisotropy factor (A) values are calculated and evaluated in calculations of elastic properties. Mechanical stability and stiffness of these materials are determined and XCCr3 (X= Al, Ga or Zn) compounds are found to be mechanically stable at zero pressure. The Fermi level locates at the vicinity of density of states (DOS) peak, which leads large DOS at the Fermi level N(EF) with values of 4.89, 5.72 and 4.32 states/eV for AlCCr3, GaCCr3 and ZnCCr3 respectively. The band structures are similar to that of superconducting Antiperovskite MgCNi3.