A new approach was proposed for the determination of the activation energy and attempt frequency for the diffusion of a single adatom on a surface. It was demonstrated with regard to the diffusion of Pt adatoms on Pt(111). The method was based upon a combination of low-temperature scanning tunnelling microscopy and kinetic Monte Carlo simulations. The method required the making of only a minimum number of assumptions, and was independent of classical nucleation theory. It was found that the measurement of the mean square displacement of individual adatoms was affected by the scanning tunnelling microscope tip.

M.Bott, M.Hohage, M.Morgenstern, T.Michely, G.Comsa: Physical Review Letters, 1996, 76[8], 1304-7