Focusing of He+ ions on semichannel planes in the Pt{111} surface

Abstract

Focusing of scattered ions on semichannel planes has been observed for 4 keV He+ scattering from a Pt{111}-(1 × 1) surface. Atoms scattered on such semichannel planes are highly focused by the detailed structural features of the surface and subsurface layers, giving rise to intricate three-dimensional spatial patterns. These scattering patterns can be readily observed through the use of a time- and spatially-resolving microchannel plate detector using the technique of scattering and recoiling imaging spectrometry (SARIS). Such three-dimensional scattering features are not normally observed in conventional ion scattering experiments using small-area detectors. Classical ion trajectory simulations using the scattering and recoiling imaging code (SARIC) are used to simulate the scattering patterns and to provide an analysis of the surface and subsurface layers involved in the scattering, the focusing of incoming and outgoing atom trajectories, and the role of thermal vibrations on the scattering patterns. The high sensitivity of the SARIS images to the details of the surface and subsurface atomic arrangements advocate its potential as a surface structural analysis technique.