First principles calculations of structural, elastic, electronic properties of Ir3Zr with L12 structure under high pressure

Abstract

The effects of pressure on the structural, elastic and electronic properties of Ir3Zr are investigated by means of the first-principles calculations based on the density functional theory with generalized gradient approximation and local density approximation methods. The calculated lattice parameters and elastic modulus of Ir3Zr at zero pressure are in good agreement with available experimental and theoretical results. The values of elastic constants (C11, C12, C44), bulk modulus (B), shear modulus (G), Young modulus (E), Poisson's ratio (υ), anisotropy index (A) and Debye temperature (TD) present the linearly increasing dependences on the external pressure. Additionally, the B/G values exhibit an upward trend with increasing pressure, which means that higher pressure can improve its ductility. Ir3Zr exhibits a brittle characteristic at zero pressure. When the pressure reaches 10 GPa, the Cauchy pressure and B/G value show ductile feature. In addition, the pressure-dependence behavior of density of states, Mulliken charge and bond length are analyzed.