Step edge diffusion and step atom detachment in surface evolution: ion erosion of Pt(111)

The temperature dependent morphological evolution of Pt(111) under 1 keV Xe+ normal incidence ion bombardment has been investigated up to 600 monolayers removed. Coarsening of the surface structures during erosion and a qualitative change in roughness evolution between 650 and 700 K are found to be caused by different atomic processes: the former by diffusion of atoms along steps, the latter by the onset of step atom detachment.