Inelastic scattering of electrons in solids from a generalized oscillator strength model using optical and photoelectric data

Inelastic scattering of electrons in solids is computed from a generalized oscillator strength model based on optical and photoelectric data. The optical oscillator strength is extended into the non-zero momentum transfer region by using free-electron gas dispersion for the weakly bound electrons. The applicability of this method to non-conduction valence electrons and to inner shells is discussed. A different extension method, which reproduces ionization thresholds, is used for inner-shell ionization. The calculations are simplified by using a two-modes model for the Lindhard theory of the free-electron gas. Exchange effects are accounted for by means of a modified Ochkur approximation. Inelastic mean free paths and stopping powers obtained from this optical-data model for four materials (Al, Si, Cu and Au) and for electrons with energies from 10 eV to 10 keV are presented.