Determination of phase stability, half metallicity, mechanical and thermal behavior of Fe based quaternary Heusler alloys

Abstract

Structural, magnetic, mechanical, and thermal characteristics of equiatomic quaternary Heusler alloys (EQHA) FeTiVZ (Z = Ga, In) and FeZrVZ (Z = Ga, In) were examined by employing full potential – linearized augmented plane wave (FP-LAPW) scheme. The calculations for structural optimization were performed for three different types of structures based on atomic positions named as Type I (TI), Type II (TII) and Type III (TIII). Geometry optimization results confirmed that TI is the most optimized structure as compared to other two types. The phase stability calculations confirmed the ferromagnetic (FM) nature of these Heusler alloys (HA). The magnetic characteristics have shown that the findings of band structures are agreed to the density of states (DOS). All these Fe-based HA have clear band gap (Eg) in spin down (S↓) channel which confirmed their half metallic (HM) nature and 100% spin polarization (SP). The S↓Eg of FeTiVGa, FeTiVIn, FeZrVGa, and FeZrVIn is 0.33eV, 0.35eV, 0.90eV, and 0.84eV respectively. The elastic constants and other calculated mechanical parameters verify the mechanical stability of compounds except FeTiVIn which needs further investigation. Based on elastic constants, the calculated Debye temperature (θD), and melting temperature (Tm) proves the thermodynamic stability of FeZrVZ (Z = Ga, In) and FeTiVGa. The obtained results have predicted that these alloys may be utilized in spintronic applications.