Dissolution kinetics at edge dislocation site of (1Â 1Â 1) surface of copper crystals

For the study of the dissolution kinetics at dislocation site of crystal surface, copper crystals were anodically dissolved under several different conditions of potentiostatic electrolysis by using an electrolytic cell. The overpotential and temperature dependences of the dissolution rates at dislocation-free and edge dislocation sites of (1 1 1) surface were investigated. The experimental results were electrochemically analyzed, and quantitatively discussed by a nucleation model of two-dimensional pit. The critical free energy change for the formation of a two-dimensional pit at edge dislocation site as well as the activation energy at separation of an atom from the active site were estimated. It is concluded that the present estimation of the critical free energy change seems to reasonably consist with the evaluation of the precedent study and also that its value changes in different manners respectively with overpotential and temperature.