The Mn K ß fluorescence emission in MnO after photoionization and in "Fe 2 O 3 after radioactive electron
capture decay from the K shell have been measured using a crystal array spectrometer with an instrumental
energy bandwidth of 0.7 eV (full width at half maximum). Both compounds have a 3d 5 valence electron
configuration in the ionic approximation. It is found that the spectral features after K capture in 55 Fe 2 O 3 are
shifted in emission energy and are sharper, compared to the spectra following photoionization in MnO, i.e., the
spectra exhibit a dependence on the mode of excitation. Crystal-field multiplet calculations including ligand-to-
metal charge transfer have been carried out for the 1s intermediate states as well as for the 3p to 1s (K ß)
radiative transition. The populated 1s intermediate states after photoionization are found to be spread over
several eV. In comparison, only the lowest-lying 1s intermediate states split by the weak (1s,3d) exchange
interaction are populated after K capture. It is proposed that the differences in population of the 1s intermediate
states together with a term-dependent final-state lifetime broadening can account for the changes in the spectral
shapes due to the different modes of excitation