Auger-type electron emission from the (001) surface by incident rare-gas ions exhibited two intense peaks in the energy spectra. These strong electron emissions in the high and low energy regions were due to auto-detachment and Auger de-excitation, respectively. From the energy of these peaks, the transition distances of the electrons from the surface to the excited atoms were estimated by means of an image potential effect for the emitted electrons. The results revealed a size effect of incident ions upon the electron transition between the surface and the metastable atoms.

Size Effects of Incident Ions on Electron Transition between LaB6(001) Surface and Metastable Atoms. Asari, E., Otani, S., Aizawa, T., Kawanowa, H., Ahn, J., Souda, R.: Surface Science, 1999, 426[3], 269-76