Ab initio studies of adsorption and migration surface processes on an α-Al2O3 surface

Surface processes on α-Al2O3 (0001) have been investigated theoretically using density functional theory. Ion-surface interactions prior to collision were investigated by means of ab initio molecular dynamics simulations, showing an adsorbate trajectory towards a preferred adsorption site. Furthermore, the adsorption process at different surface sites was investigated, together with calculations of barriers for migration between these sites. Although the equilibrium (bulk) adsorption site was energetically favourable, the presence and magnitude of the migration barriers indicate that activation energy is necessary to form the equilibrium surface structure. These results are of importance for a fundamental understanding of ion-surface interactions.