Kinetics of Two-Phase Electrocrystallization Processes IV. CTTs Associated with the Growth of Dissimilar Geometric Shapes

In this paper, current-time transient (CTT) forms associated with the two remaining models of two-phase growth are identified. The first model represents a scenario in which growth centers associated with the phase with the higher outward growth rate are conically shaped, while the shape of the remaining growth centers associated with the other phase are hemispheroidal. In the second model, we assume hemispheroidally shaped nuclei to possess a higher rate of outward growth, while, in this model, the conically shaped nuclei are assumed to have a lower outward growth rate. It is also shown that the model which previously was associated with the simultaneous growth of two phases, one formed instantaneously and the other progressively, is an appropriate representation of the electrocrystallization, in which nuclei of one phase are formed instantaneously at a prepulse potential of large magnitude and short duration, while at a much lower potential, applied immediately following the prepulse, nuclei of a second phase are progressively being formed.