Calculations of electron inelastic mean free paths for carbides

Knowledge of the values of inelastic mean free paths (IMFPs) for low-energy electrons in solids is important for quantitative surface analysis by AES and XPS as well as for determining the surface sensitivity of other electron-spectroscopic methods of surface characterization. In previous papers, we have described the Penn algorithm for calculations of electron inelastic mean free paths in solids, and used this algorithm for calculations of IMFPs for 50 – 2000 eV electrons in a group of 27 elements, a group of 15 inorganic compounds, and a group of 14 organic compounds. We fitted the calculated IMFPs for the groups of elements and organic compounds to a modified form of the Bethe equation4 for inelastic electron scattering in matter and found that the four parameters in this equation could be related empirically to several material parameters. The resulting general formula TPP-2M for IMFPs in solids could be used to estimate IMFPs for other materials.