Electronic structure and magnetic properties of rare-earth perovskite gallates from first principles

The density functional calculation is performed for centrosymmetric (La-Pm) GaO₃ rare earth gallates, using a full potential linear augmented plane wave method with the LSDA and LSDA+U exchange correlation to treat highly correlated electrons due to the very localized 4f orbitals of rare earth elements, and explore the influence of U=0.478 Ry on the magnetic phase stability and the densities of states. LSDA+U calculation shows that the ferromagnetic (FM) state of RGaO₃ is energetically more favorable than the anti-ferromagnetic (AFM) one, except for LaGaO₃ where the NM state is the lowest in energy. The energy band gaps of RGaO₃ are found to be in the range of 3.8-4.0 eV, indicating the semiconductor character with a large gap.