CONVECTION AND TURBULENCE EFFECTS IN STRONGLY DRIVEN ELECTROCHEMICAL DEPOSITION

We study fast electrodeposition of zinc in a narrow channel using high magnification video microscopy to visualize the activities near the g rowth tips. We find that streamline and turbulent convection occur for different growth morphologies. In the regime of dendritic growth, we observed space charge fluctuations and the eruption of plumes. We prob e the dynamics of such convective dendritic growth by applying an ac v oltage on top of the dc deposition voltage. The ac current response sh ows a broad-band nonlinear behavior, in sharp contrast to the narrow-b and linear behavior of diffusion-limited dendritic growth.