Electronic structure and optical properties of rare earth sesquioxides (R₂ O₃, R=La, Pr, and Nd)

The electronic structure and optical properties of the rare earth sesquioxides (R2 O3, R=La, Pr, and Nd) have been studied using the full potential linearized augmented plane wave method within local spin density approximation (LSDA) and Coulomb corrected local density approximation (LSDA+U) as implemented in the WIEN2K code. Our calculations show that the LSDA+U results give a better representation of the band structure compared to LSDA. Our calculated reflectivity and optical conductivity spectra are compared with the experimental data. The peaks in the optical conductivity can be explained as arising out of the transitions from R-p and O-p to R-d states. We have also calculated the dielectric function and the coefficient of refraction for these rare earth sesquioxides. We do not find any significant differences in the optical properties calculated using LSDA and LSDA+U.