Low energy ion beam scattering for surface analysis

The use of low energy ions for surface analysis is based on elastic scattering events. If rare gas ions are used neutralization effects favour single scattering events such that with a double differential spectroscopy (energy and scattering angle) surface composition analysis with extreme surface sensitivity is achieved. With alkali ions undergoing, in many cases, no appreciable neutralization the plural scattering events can be exploited for the analysis of the structure of single crystals. Here a triple differential spectroscopy is necessary which allows energy, scattering angle and crystal orientation to be determined. (author)