A comparison between Auger and photoelectron emission detection in an X-ray standing-wave analysis of adsorbates

We studied the contribution of secondary electrons emission to the Auger intensity when the adsorption edge is low compared to the photon energy. We performed a normal incidence X-ray standing-wave (XSW) experiment comparing photoemission K 2s and Auger K-LVV yields of Ni(1 1 1)-p(2 × 2)K system. The analysis of both profiles permits us to estimate that 5% of the total secondary electrons contributes to the K-L23 VV excitation strongly modifying the line-shape of the potassium Auger profile. In this case, the use of the Auger peak intensity profile as a monitor during an XSW experiment for surface structural studies gives completely unreliable results. © 2004 Elsevier B.V. All rights reserved.

We studied the contribution of secondary electrons emission to the Auger intensity when the adsorption edge is low compared to the photon energy. We performed a normal incidence X-ray standing-wave (XSW) experiment comparing photoemission K 2s and Auger K-LVV yields of Ni(1 1 1)-p(2 x 2)K system. The analysis of both profiles permits us to estimate that 5% of the total secondary electrons contributes to the K-L23VV excitation strongly modifying the line-shape of the potassium Auger profile. In this case, the use of the Auger peak intensity profile as a monitor during an XSW experiment for surface structural studies gives completely unreliable results. (C) 2004 Elsevier B.V. All rights reserved.