Dft Investigation of Half-Metallic Ferromagnetic Mgho2x4 (X = S, Se) Spinels for Spintronic Applications

Abstract

Half-metallic ferromagnetism, mechanical as well as thermoelectric properties for spinels MgHo2Z4 (Z = S, Se) were investigated using density functional theory (DFT). Structural optimization is done with PBEsol-generalized gradient approximation (GGA) to calculate the lattice constant of both spinels comparable to experimental data. In addition, Born stability criteria and negative (-ve) formation-energy show that our studied spinels are also structurally and dynamically stable in the cubic phase. For ferromagnetic (FM) state stability, we also calculate the energy differences among FM, anti-ferromagnetic (AFM), and non-magnetic (NM) states. Additionally, Curie temperatures of ferromagnetic phases were also estimated. We use Trans-Bhala improved Becke-Johnson (TB-mBJ) potential functional for electronics as well as magnetic characteristics, which lead to the consistent explanation of half-metallic ferromagnetism, representing the whole band-occupancy in material with exact detail of density of states (DOS). The stable FM state is examined in spinels due to the exchange splitting of Ho cation consisting of p-d hybridizations that are compatible with to result achieved for electronics band structure and DOS. The exchange splitting of the band may be clarified by spin-magnetic-moment among anion, cation, and sharing charge. The calculations associated with thermoelectric characteristics were used to help define the material's potentials for energy wastage regaining systems and various other novel applications.

Keywords: Ho-based spinels, DFT simulations, Mechanical parameters, Electronic properties, HM ferro-magnetism, Figure of merit