Spin-resolved electronic, magnetic, and thermodynamic properties of perovskites XTiO3 (X = Rb, Cs) using GGA, TB-mBJ, and GGA + U potentials: a DFT approach

Abstract

Half-metallic ferromagnetism is reported in RbTiO3 and CsTiO3 compounds under the exchange-correlation functions GGA, TB-mBJ, and GGA + U using the full-potential linearized augmented plane wave method. Spin-resolved calculations were carried out and implemented within the framework of density functional theory. The compounds exhibit energy band gap in the spin-up direction using three functionals of PBE-GGA, TB-mBJ, and GGA + U. A larger band gap is predicted to occur in both the compounds with the use of TB-mBJ potential. A higher value of magnetic moment is evidenced for RbTiO3 and CsTiO3 using the PBE-GGA method as compared to the mBJ and GGA + U methods. The Curie temperature was determined for the compounds at equilibrium and reduced volumes. It is reported that the Curie temperature increases with the increase in hydrostatic pressure. With the help of second-order elastic constants, the Debye temperature and anisotropy factor were predicted for the compounds.