AUGER-TYPE ELECTRON-EMISSION FROM ENERGETIC HE+ IONS INTERACTING WITHTHE LAB6(001) SURFACE

Low-energy (10eV-500eV) He+ ions are scattered from the LaB6(001) surf ace and the ejected electrons are detected. Two characteristic peaks a re discernible in the electron energy spectra; one is assignable to th e surface state of the LaB,(001) surface resulting from Auger deexcita tion of He(S-3) descended from He+, and the other is due to autodetac hment of temporary He- ions. These two peaks are very little broadened with increase of the velocity perpendicular to the surface, indicatin g that the electron emission occurs rather distant from the surface. O n the other hand, marked energy broadening depending on the target spe cies has been reported to occur if the electron is ejected via the Aug er neutralization process. This is because Auger neutralization takes place even in a closer encounter with the individual surface atoms.