The Changes of Auger Electron Appearance Potential Spectra of Fe by CO Adsorption

Abstract

It was shown that AEAPS (Auger Electron Appearance Potential Spectroscopy) is useful for the observation of the change of unfilled density of states on solid surfaces. The changes of Fe-L₃ spectra after CO exposure and heat treatments were observed. The Fe (L₃ dip/L₃ peak) is a good indicator of the change. The changes correspond to the splitting of 3d and 4s band densities. It is considered that the oxide layer on the iron surfaces may be formed at more than 100L CO exposure. The unfilled density of states calculated from clean Fe spectrum shows good agreement with the results obtained by X-ray isochromat spectroscopy.