Surface analysis of crystals by surface channeling

In surface channeling, fast ions are incident at a grazing angle upon a crystal surface along a low index surface direction. Surface channeled ions are used as versatile probes for surface analysis. The atomic structure of crystal surfaces, especially surface reconstructions and positions of adsorbed atoms, can be analyzed by ions channeled at the crystal surface in combination with appropriate detection reactions. We review the application of ion surface channeling to surface structure analysis. The principles of surface channeling are outlined. Several detection reactions, such as backscattering, nuclear reactions, X-ray emission, Auger electron emission, forwardscattering, light emission and secondary electron emission, are discussed with respect to surface channeling. Finally, some recent experiments are given as examples: (2×1)-O/Ni(110), steps on Ni0.6Fe0.4(110) and (2×2)-In/Si(100).