Simultaneous energy and angle resolved ion scattering spectroscopy; first results

Low-energy ion scattering can give detailed information on the composition and structure of the outermost atomic layers. The EARISS (energy and angle resolved ion scattering spectrometer) makes a very efficient use of the scattered ions by measuring simultaneously the energy and azimuthal distributions of the scattered ions, using both a special analyzer and two-dimensional detection system. This reduces the required ion dose, and thus the damage to the surface will be orders of magnitude smaller. In order to obtain the azimuthal distribution of the scattered ions it was necessary to correct for the apparatus profile. First results showing both energy and azimuthal dependent scattering from Ni(110) are presented. Comparison of these results with ion trajectory simulations, confirms the location of the Ni atoms in the outermost layers.