Characteristic features of the x-ray L/sub III/ absorption spectra of tetravalent lanthanides in chemical compounds

The L/sub III/ adsorption spectra of tetravalent cerium, praseodymium, and terbium, present in chemical compounds, contain additional absorption maxima in the short-wave part of the principal edge. It is suggested that they are related to the process of relaxation of the electronic system, perturbed by a vacancy in the inner 2p level. To verify this hypothesis, the x-ray electron spectra of the 3d levels of cerium, praseodymium, and neodymium in the trifluorides have been obtained and discussed