The master-equation formalism was used to calculate the center-of-mass diffusion coefficient analytically for small 2-dimensional islands on face-centered cubic (100) metal surfaces. The case of up to 9 Cu atoms on Cu(100) was considered, with the energetics being obtained from semi-empirical interaction potentials. In the case where only single-particle processes were taken into account, the analytical results agreed well with previous Monte Carlo simulation data. However, when many-particle processes were included, the diffusion coefficients increased by an order of magnitude at room temperature in some cases. The oscillatory behavior of diffusion, as a function of island size, was not qualitatively affected by the many-particle processes.

Role of Concerted Atomic Movements on the Diffusion of Small Islands on FCC (100) Metal Surfaces. P.Salo, J.Hirvonen, I.T.Koponen, O.S.Trushin, J.Heinonen, T.Ala-Nissila: Physical Review B, 2001, 64[16], 161405(R) (4pp)