Characterization of the MgO(100) surface by electron stimulated desorption

Electron stimulated desorption from the MgO(100) surface has been studied over the energy range up to 500 eV. The observed threshold of the ESD O+ desorbed ion from the MgO(100) clean surface at 55 eV incident electron energy agrees well with the excitation energy of the Mg 2p core level. The kinetic energy distribution of the O+ desorbed ions presents a bi-modal structure with most probable kinetic energies of 6 and 9 eV. The result is possibly influenced by the presence of defects at the (100) surface. These results indicate that the desorption of the O+ ions follows the Feibelman-Knotek model for full valence metal oxides. Charging effects at the surface have been taken into account to determine absolute values of ion energy, particularly toward the higher energy range of incident electron energy. (C) 1997 Elsevier Science Ltd.