Line shape analysis and relaxation energies in the MVV Auger spectra of zinc and zinc oxide

The oxidation of polycrystalline zinc has been studied by recording the evolution of the line shape of the corresponding Auger spectra. The fine structure of the surface-sensitive low energy M₁ VV and M₂₃VV (V = 4s ? 3d valence band) lines in pure zinc has been analyzed and a new feature involving the 4s band tentatively identified. In the course of oxidation the main peaks broaden and shift to lower energies. This behaviour is explained in terms of increase of the 3d band width and decrease in the extraatomic relaxation energies. The extraatomic relaxation is found to decrease in the oxide by ~3.8 eV. A derivation of Auger intra and Extraatomic energies involving basically experimental data is presented. These values are compared to theoretical evaluations and their connection with photoemission dynamical relaxation data is discussed.