Ostwald ripening of two-dimensional islands on Si(001)

We have used low-energy electron microscopy to study two-dimensional island ripening on Si(001). By studying the behavior of individual islands compared to their surroundings, we are able to quantify the step-edge attachment and terrace diffusion processes that are responsible for the ripening. By comparing the time dependence of specific configurations of islands to simulations, we find correlations in the rate of change of an island's area with the sizes of neighboring islands, implying that the chemical potential of the adatom sea is not uniform as classical theories of Ostwald ripening assume. From measurements of the time dependence of each island, we chart out these nonuniformities and relate them to adatom diffusion coefficients. \textcopyright{} 1996 The American Physical Society.