On the interpretation of ion scattering studies of ultrathin metallic films

Medium Energy Ion Scattering studies of the thin metallic film systems created by the deposition of Ag on AI(100), non AI(100) and Au on Fe(100) were conducted. Work was specifically focussed on expanding the arsenal of data analysis methods available to the researcher of such structures by the interpretation of the data obtainable from this, the most versatile, of the Rutherford backscattering based techniques. For the Ag on Al(100) system it has been shown that significant surface reconstruction occurs for a coverage of 1.05 ML. An investigation, by means of an original atom-by-atom simulation fitting approach was conducted, with the aim of examining the validity of a documented model of this reconstruction. The results suggested that the documented model is inadequate, but a more suitable model was not found. The 3.57 ML Ag coverage was studied extensively by means of quantitative comparison with simulations, including the use of a novel layer-by-Iayer compositional analysis technique. This study culminated in the production of a highly credible model based on the depth profiling of the first six atomic layers of a prospective, epitaxial, fcc structure. It was qualitatively argued that the 6.12 ML Ag film was fcc in nature with extremely limited intermixing between the substrate and the overlayer. [Continues.]