Formation of hollow atoms at metal- and insulator surfaces

The interaction of multiply charged ions with various surfaces gives rise to the formation of so-called hollow atoms via multiple electron capture into excited orbitals. The potential energy of the ions is partly converted into photons and kinetic energy of emitted electrons during subsequent decay of these hollow atoms. Also it might give rise to localized surface structure modifications. We have used Auger electron spectroscopy to investigate the various electronic processes which take place at metal- and LiF insulator surfaces as well as a LiF-covered Au(111) surface. The surface sensitivity of these processes is demonstrated by the fact that after a monolayer coverage, the spectra closely resemble those of a pure LiF target.