Structural and Half-Metallic Stabilities of the Half-Heusler Alloys KNaAs, KRbAs and NaRbAs: First Principles Method

The full-potential linearized augmented plane waves (FP-LAPW) method, within the density functional theory (DFT), has been used to investigate the structural and elastic properties of KRbAs, KNaAs and NaRbAs. The obtained results, utilizing the generalized gradient approximation (GGA), revealed that all compounds prefer their type-I structure ferromagnetic (FM) phase. However, only two among them, KRbAs and KNaAs, exhibit a mechanical stability thus the electronic and magnetic properties have been calculated for both compounds. In the electronic properties, we found that both compounds show a half-metallic character with direct gaps of 1.114[Formula: see text]eV and 1.514[Formula: see text]eV, in the spin-up channel, for KNaAs and KRbAs, respectively. Thus, they may be potential candidates for spin injection in the field of spintronic applications. Moreover, their integer calculated total magnetic moment of [Formula: see text] agrees with the Slater–Pauling rule.