Estimation of some physical properties of new RuCrSb half-Heusler compound using first-principles formalism

In this study, we have predicted the ground-state properties of the half-Heusler RuCrSb compound using the plane-wave pseudopotential method. The structural optimization signifies that the material is energetically favoured in the ferrimagnetic state in a-phase with optimized lattice parameter 6.025 A . The positive cohesive energy as well as elastic constants indicate that the compound is thermodynamically and mechanically stable. The absence of a negative phonon dispersion curve also confirms that the sample material is dynamically durable. In order to explore the nature of bonding forces and determine the mechanical strength of the system, the elastic properties have been computed. Moreover, using the quasi-harmonic Debye model, it has been possible to determine the thermodynamical properties with regard to temperature for various pressures. For the strongly correlated d-transition electrons of the studied compound, we incorporated on-site Coulomb repulsion term (U) on GGA scheme during electronic and magnetic calculations. The studied compound reveals half-metallic performance, i.e., it conveys 100% spin polarization at the Fermi energy level (EF ) under both GGA and GGA + U approximations. The total magnetic moments (Mt ) of the sample material is 1 μ_g, which is in good agreement with the 18 Slater-Pauling rule; i.e., Mt = Zt - 18. The magnetism source is predominantly from the Cr atom in the studied compound. Moreover, the electronic properties are also supported by the Fermi surface, charge density distribution and the Bader charge method. As the Curie temperature (T_C) of the studied material is observed to be higher than room temperature; the material is suitable for spintronic applications. (author)