Nucleus size and Zeldovich factor in two-dimensional nucleation at the Kossel crystal (0Â 0Â 1) surface

A Monte Carlo simulation method to determine the growth probability of two-dimensional clusters on the Kossel (0 0 1) surface is described. From this growth probability the nucleus size and the Zeldovich factor for two-dimensional nucleation were obtained. For low supersaturations the Gibbs-Thomson equation describes the supersaturation dependency of the nucleus size very well. At higher supersaturations a deviation from the predicted nucleus sizes is observed. This is mainly due to the size dependence of the apparent specific step free energy and/or the shape factor of the nucleus. A small systematic deviation between the theoretical and actual growth probability is observed and explained.