Robust Half-Metallicity and Magnetic Properties of Cubic Perovskite CaFeO₃

Theoretical studies of the cubic perovskite CaFeO₃ are performed using the full potential linearized augmented plane-wave method with GGA+U. The calculated structural parameters are consistent with the experimental results. The tolerance factor reveals the cubic phase of the compound. The spin polarized electronic band structures and densities of states as well as the integer value of the magnetic moment of the unit cell (4μ_B) demonstrate that CaFeO₃ is half metal. Ferromagnetism in CaFeO₃ is due to Fe⁺4–O²–Fe⁺4 superexchange interaction. The robust properties of the compound show that with their compression up to a certain critical lattice constant, known as the robust transition lattice constant, an abrupt change in the electronic and magnetic properties occurs; the compounds lose their integer magnetic moment and become metallic.