Ab-initio Study of Structural, Electronic and Elastic Properties of ErCu

Abstract

First principles density functional calculations were performed to study the structural, electronic, elastic and mechanical properties of erbium copper intermetallic compound (ErCu). The calculations are carried out within the generalized gradient approximation (GGA) for the exchange and correlation potential. The total energy as a function of volume is obtained by performing spin-polarized calculation. Magnetically the ErCu compound is stable in ferromagnetic (FM) state and its crystal structure is CsCl-type. Ground state properties such as lattice constant (a₀), bulk modulus (B), its pressure derivative (B?) and magnetic moment (?_B) are calculated. The density of states at the Fermi level, N(E_F) and specific heat coefficient are also estimated in majority and minority spin channels. The electronic properties such as band structure and density of states (DOS) reveal that no band gap lead to metallic character of ErCu. The elastic constants (C₁₁, C₁₂ and C₄₄) and mechanical properties such as Poisson’s ratio (? ), Young’s modulus (E), shear modulus (G_H), anisotropic factor (A) are also calculated .  Ductility for these compounds is further analyzed by calculating  the ratio of (B/G_H )  and Cauchy pressure (C₁₂ - C₄₄).

Keywords: Density functional theory, Band structure, Density of states, Lattice constant, Bulk Modulus, Specific heat