Recoil broadening of the elastic peak in electron spectroscopy

Electrons scattered elastically by the atomic nuclei suffer Rutherford-type recoil losses. This results in the shift Δ E _em and width broadening Δ E _eR of the elastic peak. This paper deals with the recoil broadening Δ E _eR and the shape of the elastic peak, varying considerably for low Z (atomic number) elements and compounds. For the high Z region we assume, that Δ E _emAu and Δ E _eRAu can be neglected. Gold was used as the reference in our work. The E _p primary energy dependence (1-5 keV) of Δ E _eR was studied by spectrometers of high-energy resolution ESA 31 and DESA 100 on elemental Au, Ag, Pd, Ge, Ni, Cu, Si, C (graphite and glassy carbon powder) and on LiF. The elastic peak in the latter case is split to those due to Li and F. Several processes, possibly contributing to the recoil broadening (multiple elastic scattering, Doppler broadening, low-energy losses, e.g. phonons) are considered. The effects of recoil on the shape of the elastic peaks confirm that the peak areas should be used in determining the elastic yield ratios which are important for derivation of the inelastic mean-free path in solids.