Micro-MHD effect on electrodeposition in the vertical magnetic field

R. Aogaki

Department of Product Design, Polytechnic University, 4-1-1, Hashimotodai, Sagamihara, 229-1196, Japan }

Abstract
The mechanism of electrodeposition in a vertical magnetic field was theoretically examined, so that it was clarified that two kinds of fluid motion are essentially required; one is macroscopic large-scale rotations resulting from asymmetrical fluctuations, and another microscopic vortices induced by symmetrical fluctuations. The former fluctuations arise from the local breaks of the electrostatic equilibrium in the electric double layer, and the latter are attributed to the thermal motion in the diffusion layer. The degree of the surface irregularity for the deposit, which was theoretically derived, predicted partial suppression of the nucleation by the magnetic field. A resultant honeycomb-like pattern called ``micro-mystery circles'' were experimentally ascertained in copper electrodeposition. Tables 2, Figs 5, Refs 8.