Blocking inhibitors in cathodic leveling .2. Experimental investigations

A model for cathodic leveling based on a diffusion-adsorption-reduction mechanism for the leveling agent was tested experimentally by electrodepositing nickel into a semicircular groove in the presence of coumarin. The inhibition of nickel by coumarin was measured on a rotating disk electrode, and kinetics for the reduction of coumarin and Langmuir adsorption coefficient were obtained from polarization data. Satisfactory agreement was found between experimentally measured and simulated leveling for groove depths on the order of the diffusion layer thickness or smaller.