Electron emission during collisions of low-energy ions with MgO( [formula omitted])

Electron spectra arising in collisions between low-energy He + and Ne + ions and bulk MgO(1 1 0) are reported. For both ions the measured spectra are virtually the same and consist of very-low-energy electrons with energies of up to only about 6 eV. Electron emission originating in Auger neutralization of the primary ions close to the MgO surface is considered. The strong Coulomb interaction between primary ions and O 2− cores may significantly reduce the ionization potentials and thereby the final electron energies. Contributions from other neutralization channels can presently not be excluded.