The use of Auger photoelectron coincidence spectroscopy to deconvolute the M45N45N45 AES of Palladium

Abstract

Palladium (Pd) has a complex Auger spectrum. It is difficult to fully describe the M45N45N45 Auger spectra of its surface atoms because of the many possible cascade processes placing intensity in this energy region. Weightman et al. described this Auger peak from a multiplet-splitting point of view and we used this model as a starting point. The model was compared to Auger photoelectron coincidence spectroscopy (APECS) data of the same peak and intensity was found in the M4N45N45 APECS spectra that could not be accounted for by Weightman's model. Thus new model curves for each component of the Auger peak were created by applying the Cini-Sawatzky Theory to the convoluted one-electron density of states. Experimental APECS data was used to verify the model curves and the final composite picture was compared to a high resolution AES spectrum. There was a good fit between the final model, the APECS data and high resolution AES data. The model also provided evidence for an M4-M5N45-N45N45(N45) Coster-Kronig process.