Kinetic roughening during electrodeposition was studied by grazing incidence small angle x-ray scattering for the case of Au(001) homoepitaxial growth in $\mathrm{Cl}{}^{-}$ containing electrolytes. The formation and coarsening of an isotropic mound distribution on unreconstructed Au(001) and of [110]-oriented anisotropic mounds on the “hex” reconstructed surface was observed. The lateral mound coarsening is described by a well-defined scaling law. On unreconstructed Au a transition in the coarsening exponent from $\approx 1/4$ to $\approx 1/3$ with increasing potential is found, which can be explained by the pronounced potential dependence of surface transport processes in an electrochemical environment.

• Received 23 November 2013

DOI:https://doi.org/10.1103/PhysRevLett.112.055503