Potential-Controlled Crossover from Step Flow to 3D Step Decoration:Ni Electrodeposition on Ag(lll)

摘要

A novel growth effect,the potential-controlled transition from 2D step-flow growth (-0.69 V_(Ag/AgCl)) to (i) selective growth of 3D admetal islands at substrate steps (-0.73 V) and (ii) 3D island growth on steps and substrate terraces (-0.85 V),is demonstrated for Ni electro-deposition on Ag(111).The nucleation and growth process apparently proceeds via direct deposition from the solution at step sites and can be rationalized by a kinetically controlled multiplayer growth process,where the higher layer nucleation rate increases more with over-potential than does the 2D growth rate.This effect affords new possibilities for the controlled nanostructuring of metal electrodes.