2-DIMENSIONAL TRUNCATED NUCLEATION IN THE ANODIC FILM FORMATION OF CALOMEL ON MERCURY

The anodic deposition of the first monolayer of calomel has been inves tigated by current-time and current-potential curves. A new theoretica l model for two-dimensional nucleation and growth has been developed t hat considers a stop in nucleation caused by a drop in monomer supersa turation, Growth was assumed to proceed via surface diffusion. This me chanism explains the experimental current-time transients well. We det ermined data for the critical nucleus formation, such as Gibbs free en ergies, line tensions and nucleation rates. These change with overpote ntial in a sensible way.