LOW-ENERGY ELECTRON-SCATTERING FROM MOLECULES ON SURFACES

An elementary introduction on direct and resonant low-energy (0-20 eV) electron scattering from molecules condensed on surfaces is given with reference to concepts developed from gas-phase investigations. It is shown that while elastic scattering can be described in terms of band-structure parameters, inelastic processes are often governed by intramolecular mechanisms. Following a brief description of the experimental techniques, elastic scattering and resonant vibrational excitation of physisorbed and chemisorbed molecules are reviewed. The results of electron impact experiments leading to stable anion formation are also reviewed. Typical data are presented to illustrate the main characteristics of the processes involved in electron scattering from molecules condensed in submonolayer, single and multilayer coverages of various solid surfaces.