Electrochemical instability of Ag/Sb co-deposition coupled with a magnetohydrodynamic flow

Surface-element analysis of spatiotemporal stripe patterns formed by Ag and Sb coelectrodeposition

Various spatiotemporal patterns of light and dark stripes are formed in the Ag and Sb coelectrodeposition system. In this research, we report the results of the element analysis of three spatiotemporal stripe patterns using an electron probe (x-ray) microanalyzer. The results indicate that all the patterns have an O distribution reflecting the color configuration of the patterns, in addition to Ag and Sb distributions, which have been advocated as forming the patterns. It is suggested that O, as well as Ag and Sb, contributes to the formation of the patterns.

Macroscopically Uniform Nanoperiod Alloy Multilayers Formed by Coupling of Electrodeposition with Current Oscillations

The electrodeposition from an acidic solution containing Cu(2+), Sn(2+), and a cationic surfactant gave a negative differential resistance (NDR) and a current oscillation in a narrow potential region of about 20 mV lying slightly more negative than the onset potential for Sn-Cu alloy deposition. Scanning Auger microscopic inspection has indicated that alloy films deposited during the oscillation have a clear alternate multilayer structure composed of two alloy layers of different compositions. The multilayer had the period of thickness of 40-90 nm and was uniform over a macroscopically wide area of about 1 mm x 1 mm. Detailed investigations have revealed that the NDR arises from adsorption of a cationic surfactant (acting as an inhibitor for diffusion of metal ions) on the alloy surface, and the oscillation comes from coupling of the NDR with the ohmic drop in the electrolyte.