Core-hole induced charge transfer and Coster-Kronig enhanced fluorescence at the 3d threshold of lanthanum studied by resonant inelastic scattering

Soft x-ray emission near the 3d threshold of La is studied with synchrotron radiation. At excitation energies above the M-IV edge we observe Coster-Kr onig enhanced fluorescence that refills the 3d hole via 5p and 4f electrons . We find a new delayed onset of the fluorescence as the 7.5-eV inelastic s cattering evolves into 3d-4f emission about 8 eV above the absorption thres hold, which we attribute to the energy required to produce a charge-transfe r hole. The 16.3-eV Raman-scattering loss is due to a net transition of a 5 p electron into a 4f orbit. The results are compared with our calculations. [S0163-1829(98)50148-8].