Structural, Electronic and Optical Properties of Titanium Based Fluoro-Perovskites MTiF3 (M = Rb and Cs) via Density Functional Theory Computation.

Abstract

This study reports the theoretical investigations on the structural, electronic, and optical properties of titanium-based fluoro-perovskites MTiF3 (M = Cs and Rb) using density functional theory. The impact of on-site Coulomb interactions is considered, and calculations are performed in generalized gradient approximation with the Hubbard U term (GGA + U). The ground state parameters, such as lattice constants, bulk modulus, and pressure derivatives of bulk modulus, were found. These compounds are found stable in cubic perovskite structures having lattice constants of 4.30 and 4.38 Å for RbTiF3 and CsTiF3, respectively. Analysis of elastic properties shows that both of the compounds are ductile in nature. According to the band structure profile, the examined compounds have a half-metallic character, exhibiting conducting behavior in the spin-up configuration and nonconducting behavior in the spin-down configuration. The ferromagnetic nature is conformed from the study of its magnetic moments. The optical behaviors such as reflectivity, absorption, refraction, and conductivity of the cubic phase of MTiF3 (M = Rb and Cs) are studied in the energy range of 0-40 eV.