Low-Energy Electron Diffraction from Liquid Hg: Multiple Scattering, Scattering Factor, and Attenuation

Abstract

The elastic scattering of electrons from liquid Hg has been measured for energies between 100 and 500 eV and for scattering angles between 60° and 170°. The observed scattering is remarkably similar to that from Hg vapor; a model calculation shows that the differences between the liquid and vapor scattering are due to multiple scattering and inelastic processes. The analysis shows that (i) higher-order multiple scatterings are strongly attenuated by inelastic processes; (ii) approximately half the observed integrated intensity has been scattered only once; (iii) for back angles, the atomic scattering factor is essentially the same for the atoms in the liquid and the vapor; and (iv) attenuation coefficients for elastic electrons are of the order of several tenths of a reciprocal angstrom.