First Principle Study of Electronic and Optical Properties of DyF3 Compound

The electronic and optical properties of DyF3 compound are studied using full potential linearized augmented plane wave (FPLAPW) method. To account better for on-site f –electron correlation, we adopted the Coulomb corrected local spin density approximation (LSDA + U) to the exchange correlation functional in the calculations. We find that the standard LSDA approach is incapable of correctly describing the electronic properties of such materials since it positions the f-bands incorrectly resulting in an incorrect metallic ground state. On the other hand, LSDA + U approximation, known for treating the highly correlated 4f electrons properly, is able to reproduce the correct insulating ground state. Interestingly, however, we do not find any significant differences in the optical properties calculated using LSDA and LSDA + U suggesting that the 4f electrons do not play a decisive role in the optical properties of DyF3 compound. The reflectivity for DyF3 compound stays low around 7 eV which is consistent with their large energy gaps. The calculated energy gaps and calculated reflectivity spectra are in good agreement with experiments.