The self-diffusion processes of single adatoms on Ag(100) and Ag(111) surfaces were studied using simulations involving a many-body potential derived within the framework of the second-moment approximation to the tight-binding model. The results for the (100) surface indicated that, although the migration energy for hopping was lower than that of the exchange mechanism, the exchange diffusion was higher than hopping diffusion for temperatures above 600K. The migration energy for the hopping mechanism was in very good agreement with the experiment and the results of ab initio calculations. It was also found that, for the Ag(111) face, the predominant mechanism was the hopping, which exhibited an Arrhenius behaviour with two distinct temperature ranges; corresponding to two different migration energies. The diffusion in the high temperature region was mainly due to correlated jumps requiring an activation energy which was in excellent agreement with the experimental data. In addition the temperature dependence of the mean-square-displacements and the relaxations of both surface atoms and adatoms were presented and compared with previous studies.

Molecular Dynamics Description of Silver Adatom Diffusion on Ag(100) and Ag(111) Surfaces. Papanicolaou, N.I., Evangelakis, G.A., Kallinteris, G.C.:  Computational Materials Science, 1998, 10[1-4], 105-10