Energy and material dependence of the inelastic mean free path of low-energy electrons in solids

Abstract

Calculations have been made of the inelastic mean free paths (IMFP’s) of 100–2000-eV electrons in C, Mg, Al, Al2O3, Cu, Ag, Au, and Bi. These calculations have been based on experimental optical data and on theory. The optical data gives the dependence of the differential inelastic scattering cross section at zero momentum transfer on electron energy loss; the data used here satisfy optical sum rules closely. Theory is needed to specify the dependence of the differential inelastic scattering cross section on momentum transfer; results for free-electron-like solids were assumed to be applicable to the present materials. The calculated IMFP’s show significant deviations from the dependencies on electron energy and material expected from the formulas of Seah and Dench, Szajman et al., and Ashley.