We have measured the M4,5 edge in Ag, Pd, and Rh by means of reflection electron-energy-loss spectroscopy (REELS) and compare the results with x-ray-absorption spectra and theoretical calculations. It is not possible to interpret the results obtained by REELS on the basis of dipole selection rules. We explain this behavior as a combined effect of the non-negligible momentum transfer during the excitation process and the high density of the dipole-forbidden final states. We conclude that the interpretation of REELS excited-core-level spectra is more complicated than for the corresponding x-ray-absorption data and requires, in general, a joint experimental and theoretical effort.
M-4,5 ABSORPTION-EDGE OF AG, PD, AND RH BY REFLECTION ELECTRON-ENERGY-LOSS SPECTROSCOPY - ROLE OF NONDIPOLE TRANSITIONS
AGOSTINO, Raffaele Giuseppe
1991-01-01
Abstract
We have measured the M4,5 edge in Ag, Pd, and Rh by means of reflection electron-energy-loss spectroscopy (REELS) and compare the results with x-ray-absorption spectra and theoretical calculations. It is not possible to interpret the results obtained by REELS on the basis of dipole selection rules. We explain this behavior as a combined effect of the non-negligible momentum transfer during the excitation process and the high density of the dipole-forbidden final states. We conclude that the interpretation of REELS excited-core-level spectra is more complicated than for the corresponding x-ray-absorption data and requires, in general, a joint experimental and theoretical effort.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
