NUCLEATION ON ACTIVE-SITES .5. THE THEORY OF NUCLEATION RATE DISPERSION

The recently discovered phenomenon of nucleation rate dispersion is not fully understood. In the present work we propose a theory of its origin that is both physically plausible and consistent with the known facts. The theory is based on the hypothesis that a distribution of surface energies exists at the interface between an electrode and a set of crystal nuclei. This hypothesis is attractive because it explains, in a natural way, how different nucleation rates can manifest at different locations on the same electrode surface: the highly non-linear dependence of the nucleation rate on the surface energy causes small spatial inhomogeneities in surface energy to be "amplified" into large spatial inhomogeneities in nucleation rate. Numerical data illustrating this effect are presented. © 1990.