Resonant valence-to-core x-ray fluorescence spectroscopy on PrO2

The results of 4f --> 3d x-ray fluorescence measurements, performed with monochromatic-photon excitation at Pr M-4,M-5 absorption edges of PrO2, are presented and discussed in the framework of an Anderson impurity model. The dependence of the fluorescence structures on varying excitation energies is found to be in agreement with the localized, many-body description of the fluorescence process. Experimental spectra are reproduced by model calculations using values for the model parameters in the ground state of the system which are somewhat different from those obtained earlier in an analysis of core-level photoemission and absorption. Referring to this difference, the importance of resonant x-ray fluorescence data for the spectroscopic analysis of strongly correlated systems and for deriving a unique set of model parameters is stressed.