AN EXPERIMENTAL AND THEORETICAL-STUDY OF MULTIELECTRON EXCITATIONS AT THE L3 ABSORPTION-EDGE IN SOME RARE-EARTH ALLOYS AND THEIR HYDRIDES

In this work, an extensive X-ray absorption study at the L edges of the cubic Laves phase rare earth compounds: LaRu2, CeRu2 and CeFe2, and of some related hydrides is presented. The EXAFS spectra of these materials were measured as a function of the hydrogen concentration. The structural disorder induced by the hydridation process smears the EXAFS oscillatory signal, and in both L2 and L3 spectra a new structure at about 130 eV above the Ce and La edges is observed. This structure, absent in the L1 EXAFS spectra, is interpreted as an intra-atomic two-electron transition involving 2p and 4d electrons. © 1990.