First-principles study of structural, mechanical, electronic properties and Debye temperature of NbCo2 Laves phases under pressure

Abstract

The structural, mechanical, electronic properties and Debye temperature of NbCo2 Laves phases are investigated by density functional theory. The formation enthalpy and elastic constants of NbCo2 Laves phases show that they are thermodynamically and mechanically stable structures. The mechanical properties such as bulk modulus, shear modulus are evaluated by Voigt–Reuss–Hill approximation. The calculated value of B/G and Poisson's ratio ν of NbCo2 Laves phases reveal their ductility and plasticity properties. The anisotropic properties of sound velocities for NbCo2 Laves phases are studied. Debye temperature can be used to characterize the strength of covalent bonds. The density of states agree well with the formation enthalpy and the Debye temperature results.