First-principles study of the structural, elastic, and mechanical properties of Ni3Ga compound under pressure

Abstract

There was employed the density functional theory plane-wave pseudopotential method with local density approximation and generalized gradient approximation to investigate the structural, elastic and mechanical properties of the intermetallic compound Ni3Ga. The calculated equilibrium lattice constant and bulk modulus are in good agreement with the experimental values. The elastic constants were determined from a linear fit of the calculated stress-strain function according to Hooke's law. From the elastic constants, the bulk modulus B, anisotropy factor A, shear modulus G, Young's modulus E and Poisson's ratio v for Ni3Ga compound are obtained. Our results for the bulk modulus B, anisotropy factor A, shear modulus G, Young's modulus E and Poisson's ratio v are consistent with the experimental values. The sound velocities and the Debye temperature are also predicted from elastic constants. The dependences of the elastic and mechanical properties of Ni3Ga compound on pressure were investigated for the first time. It was found that the cubic Ni3Ga compound is mechanically stable according to the elastic stability criteria and it is not elastically isotropic. By analyzing the ratio B=G, it was concluded that Ni3Ga compound is ductile in nature.