Ab initio investigation of strain effects on the physical properties of PdVTe alloy

Abstract

The investigations of the strain effects on magnetism, elasticity, electronic, optical, and thermodynamic properties of PdVTe half-Heusler alloy are carried out using the most accurate methods to obtain electronic band structure (i.e., the full-potential linearized augmented plane wave plus a local orbital (FP-LAPW + lo) approach). The analysis of the band structures and the density of states reveals half-metallic behavior with a small indirect band gap Eg of 0.51 eV around the Fermi level for the minority spin channels. The study of magnetic properties led to the predicted value of total magnetic moment µtot = 3µB, which nicely follows the Slater–Pauling rule µtot = Zt – 18. Several optical properties are calculated for the first time and the predicted values are in line with the Penn model. It is shown from the imaginary part of the complex dielectric function that the investigated alloy is optically metallic. The variations of thermodynamic parameters calculated using the quasi-harmonic Debye model agree well with the results predicted by the Debye theory. Moreover, the dynamical stability of the investigated alloy is computed by means of the phonon dispersion curves, the density of states, and the formation energies. Finally, the analysis of the strain effects reveals that PdVTe alloy preserves its ferromagnetic half-metallic behavior, it remains mechanically stable, the ionic nature dominates the atomic bonding, and the thermodynamic and the optical properties keep the same features in a large interval of pressure.