Investigating the structure of the Tin M 45N 45N 45 auger spectrum using auger photoelectron coincidence spectroscopy

Abstract

Auger photoelectron coincidence spectroscopy (APECS) data were collected for the M 45N 45N 45 Auger peak in coincidence with the 3p 3/2, 3d 3/2 and 3d 5/2 photoelectron lines of Tin. Model spectra were created to fit the APECS data from sets of Gaussian curves defined by Parry-Jones et al., J. Phys. C: Solid State Physics, 12 (1979) 1587. These models were then combined using information about the relative intensities of the peaks from the aforementioned paper to produce a model of the Auger peak which proved a good comparison to high resolution AES spectra. The APECS data revealed satelite structure in the M 5N 45N 45 peak in coincidence with the 3d 5/2 photoelectron line (M 5N 45N 45:3d 5/2) due to the Mg Kα 3 line of the X-ray source. There was evidence of a small Coster–Kronig component in the M 4N 45N 45:3d 3/2 data and the M 45N 45N 45:3p 3/2 data showed intensity in the M 4N 45N 45 and M 5N 45N 45 regions also arising from Coster–Kronig processes. The contribution of the M 4N 45N 45 plasmon was included in each of the APECS models and was reflected in the high resolution AES spectra. Slight oxidation of the surface of the sample during each 24-h period produced a 0.7 eV shift of the singles Auger peak to lower kinetic energies. The shift was not reflected in the coincidence peak which produced a spectrum of a clean surface due to the nature of the coincidence experiment.