Recent Insights Into Electronic Performance, Magnetism and Exchange Splittings in the Cr-substituted CaO

Abstract

The first-principles computations of density functional theory are employed to characterize the structural properties, electronic structures, and ferromagnetism induced by Cr impurities in Ca 1-x Cr x O compounds at concentrations x = 0. 25, 0.5, and 0.75. The dynamic stability is performed by the phonon spectra calculations. The structural parameters are computed by using Wu-Cohen generalized gradient approximation, while the electronic and magnetic properties are determined by the accurate Tran-Blaha-modified Becke-Johnson exchange potential. The crystal field, direct and indirect exchange splittings were investigated to determine the origin and stability of ferromagnetic state configuration. The Ca 1-x Cr x O systems have right half-metallicities, which are verified by the spin polarization of 100% and the integer values of total magnetic moments. The Ca 0.75 Cr 0.25 O, Ca 0.5 Cr 0.5 O, and Ca 0.25 Cr 0.75 O are half-metallic ferromagnetic with flip-gaps of 1.495, 0.888, and 0.218 eV, respectively. Therefore, the Ca 1-x Cr x O materials are suitable candidates for possible applications of spin-injection in future semiconductors spintronics.