Spatially confined copper dissolution by an STM tip: a new type of electrochemical reaction?

With the tip of an STM, Cu can be dissolved from an electrode at potentials at which Cu dissolution should normally not occur. The dissolution process takes place only underneath the tip allowing for a nanometer scale pattern ing of the Cu surface. The dissolution rate is shown to depend sensitively on the tip potential as well as on the electrode potential. The electrochem ical conditions are also given at which the tip influence is negligible and surfaces can be safely imaged. An explanation for the tip-induced metal di ssolution on the basis of a direct charge transfer to the tip is offered. ( C) 2000 Elsevier Science S.A. All rights reserved.