Chiral surface formation in magnetoelectrolysis on micro-electrodes

I. Mogi¹ - R. Aogaki² - K. Takahashi¹

¹ Institute for Materials Research, Tohoku University, Katahira, Sendai 980-8577, Japan
² Polytechnic University, Sagamihara, Kanagawa 252-5196, Japan

Abstract
Chiral surface formation in magnetoelectrolysis arises from micro-MHD vortices under vertical MHD flows. Here we report the chiral behaviors of Cu films prepared by magnetoelectrodeposition (MED) and magnetoelectrochemical etching (MEE) on micro-electrodes, where the strong influence of the vertical MHD flow on the micro MHD vortices is expected. The MED and MEE of Cu films were conducted on a Pt disc electrode with diameters of 10-100 μm and 3 mm at constant currents in a magnetic field of 5 T. The chiral sign of the MED films at the 3-mm-electrodes depended on the polarity of the magnetic field. On the contrary, the MED films at the 100-μm-electrodes exhibited chiral symmetry breaking for the polarity of the magnetic field. Chiral behavior disappeared in the films at the 10-μm electrodes, suggesting the suppression of the micro-MHD vortices. Similar results were obtained in the MEE processes. Figs 5, Refs 10.