Atomic layer growth on Al(111) by ion bombardment

Instead of the expected erosion morphology composed of craters, rare gas ion bombardment of the Al(111) surface is found to cause initial surface growth of several atomic layers. This phenomenon is observed for Ne+, Ar+, and Xe+ at all temperatures at which bombardment induces morphological surface changes and for ion energies down to a few hundred eV. The effect is interpreted on the basis of a thermal spike induced separation of damage into subsurface vacancy clusters and surface adatom clusters.