Theoretical analysis of ferromagnetism and electronic transport aspects of CaM2S4 (M = Ti, Cr) spinels for the application of spintronic and energy storage system

摘要

By using the density functional theory (DFT), we explored ferromagnetic and electronic transport aspects of CaM2S4 (M = Ti, Cr) spinels. For both spinels, we used PBEsol generalized gradient approximation (GGA) to investigate structural parameters and noted that studied spinels are good compared with the existing parameters. A novel exchange correlation potential, modified Becke and Johnson (mBJ), was utilized for the investigation of electronic, magnetic and transport aspects because we assure our predicting results of electronic bandgap to be consistent to the experiments. The energy difference between ferromagnetic and nonmagnetic states is calculated to check the structural stability of ferromagnetic state. Further, the calculations of band structures and density of state have been explored to check ferromagnetic nature of semiconductor spinels that was further confirmed on the basis of exchange splitting energy and magnetic parameters. In addition, exchange constants (N-0 alpha and N-0 beta) and crystal field energy (E-cry = E-t2g - E-eg) along with magnetic moments were also calculated. Our calculated results of magnetic parameters indicate that these spinels are considered as suitable candidate for spintronic applications. Furthermore, to check the reliability of these spinels in energy storage systems, the electronic transport aspects were calculated in detail.