Attenuation of Low-Energy Electrons by Solids: Results from X-Ray Photoelectron Spectroscopy

Abstract

The scattering half-thickness for electrons has been experimentally determined to be \ensuremath{\approx} 0.25 \ensuremath{\mu}g/${\mathrm{cm}}^{2}$ (\ensuremath{\approx} 13 \AA{} carbon) for 1169-eV electrons and \ensuremath{\approx} 0.21 \ensuremath{\mu}g/${\mathrm{cm}}^{2}$ (\ensuremath{\approx} 10 \AA{} carbon) for 920-eV electrons. The corresponding mass-scattering coefficients are 2.75 \ifmmode\pm\else\textpm\fi{} 0.19 and 3.32\ifmmode\pm\else\textpm\fi{}0.37 ${\mathrm{cm}}^{2}$/\ensuremath{\mu}g. Other useful and related attenuation parameters are defined and calculated. These results were obtained from measurements of the attenuation by thin carbon films (5-60 \AA{}) of monoenergetic photoelectrons originating from gold substrates irradiated with Mg ${K}_{\ensuremath{\alpha}}$ x rays, and also from measurements of the concomitant increase in carbon photoelectron intensity. Scattering of electrons in the energy range about 1 keV is greater than has generally been indicated.