Room temperature ferromagnetism and thermoelectric behavior of calcium based spinel chalcogenides CaZ2S4 (Z = Ti, V, Cr, Fe) for spintronic applications

The electronic, magnetic, and thermoelectric properties of CaZ(2)S(4) (Z = Ti, V, Cr, Fe) are explored comprehensively. The stability in the ferromagnetic state (FM) has been ensured by energy released from optimized structures and enthalpy of formation (AH). The Heisenberg classical model has been used to calculate Curie temperature (Tc). The band structures (BS), as well as densities of states (DOS), are analyzed to explore half metallic ferromagnetism and 100% spin polarization. The Ax(pd) (exchange energy) overcome ACF (Crystal field energy) because of ferromagnetism prompted by strong hybridization. The negative Ax(pd) and exchange constant N0p reduced exchange energy that satisfies the double exchange model. The thermoelectric properties of the studied compounds are elaborated by estimating electrical conductivity, thermal conductivity, and the Seebeck coefficient. The increase in power factor with the CaFe2S4 has been noted while other spinels have very low power factor.