Computer simulation of electrochemical nanostructuring induced by supersaturation conditions

First steps are taken towards computer simulation of the atomistic mechanism taking place during the supersaturation induced local metal deposition method, as developed by Schindler and coworkers [D. Hofmann, W. Schindler, J. Kirchner, Appl. Phys. Lett. 73 (1998) 3279]. Using a combination of stochastic Langevin dynamics (LD) and deterministic atom dynamics (AD), different results are observed depending on the model systems considered. For instance, when a profile of neutral diffusing species is used, atom dispersion over the whole electrode was found, whereas when charged species are introduced to the model system, a clear definite nucleation area was observed underneath the tip. The present computer simulations suggest that in the early stages of the process of cluster generation, the strong ion–ion repulsion may play an important role if the nanostructuring process is achieved in the nanosecond range. At the same time, a fast Co/Au surface mixing was observed in the top layer of the substrate in these short simulation times.