Probing electron correlation, charge transfer, and Coster-Kronig transitions at the 3d and 4d thresholds of Nd by resonant inelastic scattering

Soft x-ray emission near the 3d-4f and 4d-4f thresholds of Nd2O3 is studied with monochromatic synchrotron radiation excitation. At:excitation energie s above the MN threshold, we observe Coster-Kronig enhanced fluorescence fr om the refill of the 3d hole via the 5p and 4f channel. Fluorescence occurs mainly due to transitions in which charge-transfer provides additional 4f electrons. Resonant inelastic scattering dominates the emission process and we observe two energy loss features at 2.3 and 21 eV, which are due to net transitions within the 4f shell (4f(3)-->4f(3)) and 5p(6)4f(3)-->5p(5)4f(4 ), respectively. The emission spectra resulting from excitations at various energies through the 3d and 4d thresholds were compared and a number of di fferences were found. Our atomic calculations are in excellent agreement wi th the experimental results indicating strong localization and a low degree of correlation of the 4f electrons. [S0163-1829(99)01707-5].