Ab-initio computations of CaV2S4 and CaMn2S4 spinels for spintronics and energy storage system applications

Abstract

Having ferromagnetism capabilities and energy storage capacity, CaV2S4 and CaMn2S4 spinels are interesting materials owing to their potential applications in spintronics applications. In the present study, the half-metallic ferromagnetic nature and the electronic transport properties of CaV2S4 and CaMn2S4 has been explored using density functional theory computations. The ground-state energies of these spinels have been computed through volume optimization of non-magnetic (NM), ferromagnetic (FM) and anti-ferromagnetic (AFM) phases, which show FM phase to be stable for both the studied spinels. In additions, the lattice parameters calculated for the FM phase show good comparison with existing theoretical data. For the investigation of the magnetic and electronic structure properties, we have used the modified Becke-Johnson (mBJ) potential functional. The density of state (DOS) plots and spin-polarized electronic band structures (BS) confirm half-metallic behavior of the studies spinels. Further, to reveal the magnetic nature of studied spinels, we have also calculated crystal field splitting and exchange energies. Occurrence of strong p-d hybridization arising from V/Mn 3dt2g-states and S p-states is confirmed which is also evident from the fact that total sum of magnetic moment proved to be lower than the estimated values. In addition, the influence of electron spin on transport properties of the CaV2S4 and CaMn2S4 has also been examined using the Boltzmann transport theory.