Interaction of Xenon at Surface Steps

The adsorption of Xe on Pt(111) has been investigated using scanning tunneling microscopy. At low coverage Xe preferentially adsorbs on the upper edge of the preexisting Pt steps resulting in the formation of one-dimensional chains of Xe atoms. With increasing coverage the adsorption proceeds with the growth of compact 2D Xe islands nucleated on the Pt terraces and at the lower Pt step edges, but not adjacent to the Xe chains on the upper terraces. This is indicative of a repulsive interaction between the Xe chains and Xe atoms on the upper Pt terrace.