The deposition (at 500eV) and subsequent diffusion of Ag400 clusters on a stepped graphite surface were investigated via a combination of scanning electron microscopy experiments and computer simulations (molecular dynamics and Monte Carlo methods). It was found that the shape of the clusters was only partially deformed by the impact with the surface, moreover the clusters do not create surface defects upon landing, and so were able to diffuse freely over the surface. Many clusters were found to become trapped at surface steps, where their mobility was reduced by the higher binding energy. Exploring the 1D diffusion of clusters along the steps revealed the low mobility for larger islands, as well as the importance of defects on the step (for example kinks), which trap the mobile clusters.

Deposition and Diffusion of Size-Selected (Ag400+) Clusters on a Stepped Graphite Surface. Carroll, S.J., Palmer, R.E., Mulheran, P.A., Hobday, S., Smith, R.: Applied Physics A, 1998, 67[6], 613-9