Effects of long jumps, reversible aggregation, and Meyer-Neldel rule on submonolayer epitaxial growth.

We demonstrate, using kinetic Monte Carlo simulations of submonolayer epitaxial growth, that long jumps and reversible aggregation have a major impact on the evolution of island morphologies. Long jumps are responsible for a supra-Arrhenius behavior of the effective diffusion coefficient as the attachment and detachment kinetics give rise to a bimodal island size distribution that depends on temperature and long jump extent limits. As the islands density increases with temperature, the average size of stable islands reaches a maximum before decreasing. We have also observed that the diffusion coefficient cannot be used alone to predict the evolution of island sizes and morphologies, the relative rate of each process having a major importance. Our theoretical developments are of direct relevance for materials systems such as Au, Pd, Ag, Cu, Ni, H/Si , H/W(110), Co/Ru , and Co/Ru(S), that are known for exhibiting a compensation effect that cannot be contained within experimental uncertainties.