Many-body effect in the N23-VV Auger-photoelectron coincidence spectroscopy (APECS) spectra of Ag metal

The coincidence N23-VV Auger-electron spectroscopy (AES) spectra and N23 photoelectron spectroscopy (PES) spectra of Ag metal are analyzed. Here NX is the notation for atomic shell Nx (X = 2, 3). The band-like feature in the coincidence N23-VV AES spectra is much more intense than that in the coincidence M45-VV ones because the potential in the delocalized two-hole state is less attractive than that in the localized one. The partial N23-VV super Coster–Kronig (sCK) transition rate depends critically on both the final-state potential and the sCK-electron kinetic energy (KE) because the KE is low, whereas the partial M45-VV Auger-transition rate is fairly independent of them because the KE is very high. As a result, the partial sCK-transition rate to the band-like state is enhanced compared to that to the atomic-like localized state. The low KE tail in the coincidence N23-VV AES spectra which is likely due to the sCK transition involving more than two electrons, is more enhanced than that in the coincidence M45-VV ones. This is due to the enhancement of the partial sCK-transition rate by the presence of extra holes in the final state. The sharp peaks of small intensity on the lower KE side of the main line in the coincidence N2 PES spectrum are tentatively attributed to the shakeup satellites.