Structure analysis of the KBr(100) surface An investigation with a new method for surface analysis of insulators

The surface structure of highly insulating KBr(100) was investigated by a new technique, impact collision atom scattering spectroscopy with detection of neutrals (NICASS). By using neutral atoms in the scattering experiment as projectiles [different from conventional ion scattering (ISS)], uncertainties in the experimental data due to surface charging effects are avoided. As a result, a surface structure model for KBr(100) is presented. By comparing the experimental scattering information with computer simulated data, an inward relaxation in the first layer has been deduced. The relaxation is different for the two components K and Br: K is shifted by 0.5 Å and Br by 0.3 Å, resulting in a surface rumpling of 0.2 Å.