Generalization of transient equations due to the growth of hemispheroids

Abstract

Abstract A generalized form of current-time transient, operative over the whole range of nucleation rates and applicable to both preferred and non-preferred site nucleation processes, is derived for the model of growth of hemispheroids. This generalized form is shown to reduce at high and low rates of nucleation to the forms derived for instantaneous and progressive nucleation of hemispheroids respectively. The flow of current is shown to reach a maximum before approaching a steady value. It is found that 89.5%–90.8% of the surface of the electrode is covered, depending on the rate of nucleation, by the time the current reaches a maximum value. Generalized forms of transients for the flow of charge and for the average thickness of the deposit are also derived. The transient behaviour of these quantities over all nucleation rates is characterized.