Theoretical investigation of the mechanical and thermodynamics properties of Nb3Ga superconductor under pressure

The mechanical and thermodynamics properties of Nb3Ga under pressure have been studied and analyzed using first-principles combined with quasi-harmonic Debye model. The calculated lattice parameter of the ground state is in well agreement with the experimental data. The pressure dependence of a/a(0) and V/V-0 are investigated, the bulk modulus B-0 and its pressure derivative B' are found to be 164.5 GPa and 3.936, respectively. The elastic constants under pressure are obtained and the polycrystalline elastic moduli of Nb3Ga are calculated derived from the single-crystal elastic constants. The results show that Nb3Ga is stable and behaves in a ductile manner up to 40 GPa. In addition, the elastic anisotropy, Vickers hardness as well as the melting temperature of Nb3Ga are investigated. Finally, the pressure and temperature dependence of the thermodynamic properties are also been obtained in the ranges of 0-40 GPa and 0-1000 K through the quasi-harmonic Debye model. (C) 2015 Elsevier B.V. All rights reserved.