Local correlation during Ostwald ripening of two-dimensional islands on Ag(111)

Using two-dimensional Ag adatom islands on Ag(111) as a model system, we study the importance of local correlations in diffusion-limited Ostwald ripening. For the coverages studied (0.08, 0.21, and 0.3ML), we find that the ripening can be surprisingly well described in a nearest neighbour model based on pairwise atom exchange between neighbouring islands. The results reveal the local nature of diffusion-limited Ostwald ripening and demonstrate the limits of the mean-field theories in describing experimental data.