Evidence of Coulomb correction and spin–orbit coupling in rare-earth dioxides CeO2, PrO2 and TbO2: An ab initio study

Abstract

The current study investigates the structural, elastic, electronic and optical properties of CeO2, PrO2 and TbO2 using the full potential (linearized) augmented plane wave plus local orbital method within the Wu–Cohen generalized gradient approximation (GGA) with Hubbard (U) correction and spin–orbit coupling (SOC). The GGA+U implementation lead us to describe correctly the relativistic effect on 4f electrons for CeO2. We clarify that the inclusion of the Hubbard U parameter and the spin–orbit coupling are responsible for the ferromagnetic insulating of PrO2 and TbO2. The magnetic description is achieved by the spin-density contours and magnetic moment calculations, where we show the polarization of oxygen atoms from the rare earth atoms. The mechanical stability is shown via the elastic constants calculations. The optical properties, namely the dielectric function and the reflectivity are calculated for radiation up to 12eV, giving interesting optoelectronic properties to these dioxides.