Local Electronic and Atomic Structure of Ce³⁺-Containing Fluoride/Oxide Determined by TEM-EELS and First-Principles Calculations

We investigated the local atomic and electronic structure around Ce in CeF3 and Ce2O3 by the combination analysis of F- and O-K shell electron energy loss near edge structures (ELNES) and first-principles calculations. The energy width of the main edge structure depended on the interaction between Ce5d orbitals and the neighboring F/O atoms. Not only ELNES but also the reported emission and excitation spectra were qualitatively consistent with the electronic structures of density functional theory (DFT) calculations with Hubbard U for the Ce4f energy correction. Main factors determining the emission wavelength of the fluoride and Ce-doped oxides were discussed.