Role of concerted atomic movements on the diffusion of small islands on fcc(100) metal surfaces - art. no. 161405

The master equation formalism is used to analytically calculate the center- of-mass diffusion coefficient for small two-dimensional islands on fcc(100) metal surfaces. We consider the case of Cu on Cu(100) containing up to nin e atoms, with energetics obtained from semiempirical interaction potentials . In the case where only single-particle processes are taken into account, the analytic results agree well with previous Monte Carlo simulation data. However, when recently proposed many-particle processes are included, in so me cases the diffusion coefficients increase by an order of magnitude at ro om temperatures. Qualitatively, the oscillatory behavior of diffusion as a function of the island size is not affected by the many-particle processes.