On the semi-empirical elemental sensitivity factors for AES: ionization cross-section and electron mean free path

Two important parameters in semi-empirical theories of elemental sensitivity in Auger electron spectroscopy are the electron-impact ionization cross-section and the electron mean free path. This paper compares the Gryziński, Lotz, and Casnati et al. theories of ionization cross-section, as well as the Seah and Bench empirical theory and the Szajman et al. dielectric theory of electron mean free path, by matching the elemental sensitivity factors calculated with these parameters to experimental AES elemental sensitivities. Electron mean free paths, calculated with the dielectric theory, are presented, for the Auger electron energies of interest, for most elements in the periodic table. The best match between the semi-empirical and experimental sensitivities (with a standard deviation of 56%) was for the combination of the Casnati et al. ionization cross-section and the dielectric theory electron mean free path.