Experimental and theoretical characterization of the optical properties of CeO2, SrCeO3, and Sr2CeO4 containina Ce4+ (f0) ions

In an effort to find new UV absorbers, the optical properties of CeO2, SrCeO3, and Sr2CeO4 were examined by UV-visible diffuse reflectance measurements and electron energy-loss spectroscopy (EELS), and their electronic structures were investigated on the basis of first-principles density functional theory (DFT) calculations. The extinction coefficient k and the refractive index n determined from the loss function Im(- 1/epsilon) by EELS were compared with the corresponding quantities calculated from DFT calculations. The U-V absorption thresholds of these materials were determined by the electron excitation from the O 2p anionic band to the empty Ce 4f orbitals. The calculated and measured refractive indices were in satisfactory agreement. The applicability of CeO2, SrCeO3, and Sr2CeO4 as potential T-TV absorbers was assessed.