SOME STATISTICAL ASPECTS OF THE GROWTH OF CRYSTALS IN PASSIVATION, METAL-DEPOSITION AND ANODIC FILM FORMATION

The formation of solid crystalline phases is a common feature of many electrochemical reactions including corrosion, metal deposition, and anodic and cathodic film formations. Unfortunately the problem of modelling the crystal growth processes in an accurate and verifiable way has raised a number of serious theoretical difficulties which as yet have not been resolved. Among the many difficulties we address ourselves in the present paper to three important questions:o(a)What is the spatial distribution of growth centres, and how may this be statistically described?(b)How may the growth geometry of individual crystals be recovered from experimental data?(c)How do crystals of the emergent phase interact with each other and with the boundaries of the electrode? The statistics of a large number of potentiostatic experiments are theoretically described, and we indicate how the geometries and the spatial distribution of crystals may be investigated via an analysis of the moments of the experimental (i-t) responses. © 1979 Elsevier Sequoia S.A.