THEORY OF THE 4D-]2P X-RAY-EMISSION SPECTROSCOPY IN CE2O3, PR2O3 AND DY2O3

The 4d-->2p X-ray emission spectra (XES) of Ce2O3, Pr2O3 and Dy2O3 have been calculated with an impurity Anderson model with the full multiplet couplings, following the Kramers-Heisenberg formula in the second order optical process. Experimental results have been well reproduced with this model by using a constant value for the 4d core hole lifetime damping Gamma (4d) in the case of Ce2O3 and Pr2O3, while in the case of Dy2O3 it is necessary to take into account the term dependence of Gamma (4d), which is consistent with the previous theoretical analyses of 4d X-ray photoemission spectra. It was also shown that both the spin-orbit couplings of the 4d core level in the final state and the 4flevel in the initial state are key factors to cause the branching ratio in the L(gamma) line larger than that in the L(beta) line. The phase matching of the wave functions between the intermediate and final states smears out the hybridization effect in the 4d-->2p XES in Ce2O3 and Pr2O3.