Island dynamics on charged silver electrodes: Kinetic Monte-Carlo simulations

KAY POETTING; NOELIA LUQUE; PAOLA QUAINO; HARALD IBACH; WOLFGANG SCHMICKLER

Erlangen

Simposio; 5th Kurt Schwabe Symposium from corrosion to semiconductors; 2009

The fluctuations of steps and the shapes of islands on metal surfaces generallydepend strongly on the electrode potential, an effect that has been attributed tothe interaction of local surface dipole moments with the double-layer field. In orderto understand the details of this effect, we have calculated the relevant energiesand dipole moments for the diffusion processes that govern the fluctuations of stepsand island shapes on Ag(100). The corresponding rates have been used in kineticMonte Carlo simulations to explore the dynamics of these structures. Due to thefield-dipole interactions the mobility of the surface becomes larger with increasingelectrode potential. Fourier analysis allows us to determine the step stiffness andthe kink energy, and from the shape of the islands we have obtained the line tension.All three quantities decrease with increasing double-layer field.