AVS 45th International Symposium
    Surface Science Division Monday Sessions
       Session SS1-MoM

Paper SS1-MoM3
Auger Photoelectron Coincidence Spectroscopy of Ag and the Ag/Cu(100) Surface Alloy

Monday, November 2, 1998, 9:00 am, Room 308

Session: Issues in Surface Electronic Structure
Presenter: D.A. Arena, Rutgers, The State University of New Jersey
Authors: D.A. Arena, Rutgers, The State University of New Jersey
R.A. Bartynski, Rutgers, The State University of New Jersey
Q. Qian, New Jersey Institute of Technology
S.L. Hulbert, Brookhaven National Laboratory
Correspondent: Click to Email
The question of atomic versus band-like contributions to the core-valence-valence (CVV) Auger line shape in Ag remains a controversy. Theoretical predictions are ambiguous as the correlation energy, U, is comparable to the 4d valence band width, W. Using Auger-photoelectron coincidence spectroscopy (APECS), we measured the line shape of the Ag M@sub 4,5@VV and N@sub 2,3@VV Auger transitions from single crystal Ag. In addition to a dominant atomic-like component, both spectra show a significant contribution from band-like decays. However, the N@sub 2,3@VV spectrum cannot be accounted for within the Cini-Sawatzky theory, suggesting that dynamical effects of the very rapid 4p core hole decay influences the lineshape. Furthermore, the N@sub 2,3@VV transition exhibits a much larger low energy tail that may be of the same origin. We have also measured the Ag CVV Auger spectra for 0.1ML Ag/Cu(100) to investigate the electronic structure of this prototypical surface alloy. In contrast to theoretical predictions, the Auger lineshape suggests that the Ag d-band shifts towards the Fermi level.