First-principles study of structural, elastic, electronic, magnetic and thermoproperties of Ni_2Zr_X (X = Sn, Sb) Heusler alloys under pressure

摘要

The elastic stabilities, electronic, magnetic and thermodynamic properties of Ni_2Zr_X (X = Sn and Sb) alloy under pressure are extensively investigated by using the first-principle calculations and quasi-harmonic Debye model. Through a series of researches, for instance Gibbs free energy as a function of pressure, P-V equation of states and elastic stabilities, the optimized lattice constants, Bulk, Shear and Young's moduli, Anisotropy, ductility, Density of State (DOS) and Poisson's ratio of Ni_2Zr_X alloy are obtained. The effects of temperature (T) and pressure (P) on heat capacity are opposite, and the effect of T is larger than P, which are consistent with a compression rate of volume. The results of thermal expansion coefficient (a) show the effect of T and P on a is small. The magnetic studies indicate that Ni_2Zr_X has little magnetism due to different atomic position in the generalized Heusler alloy structure. The DOS of Sn p and Sb p electrons form double-peak.