Line shape of the Ag N23W Auger spectrum measured by Auger-photoelectron coincidence spectroscopy

Abstract

We present Ag N3VV and N2VV Auger spectra obtained in coincidence with 4p 3/2 and 4p 1/2 core photoelectrons, respectively. We have also obtained the 4p 3/2 and 4p 1/2 core level spectra in coincidence with N3VV and N 2 VV Auger electrons. As the on-site Coulomb correlation energy of Ag, U, is comparable to the 4d band width, W, the coincidence Auger spectra exhibit aspects of both atomic-like and band-like components. We find a surprisingly large - 30% of the spectral weight of 2-hole decays is in the band-like region. Furthermore, the Auger spectra have large low energy tails that are attributed to nonradiative decays involving more than two electrons. In the coincidence core level spectra, the large (> 5 eV) lifetime broadening is eliminated, leaving a width of 2.5 eV associated with the Auger lifetime. This sharp peak in the coincidence photoemission spectrum resides on a broader feature owing to the properties of the Auger transitions.