Island dynamics on silver electrodes: a kinetic Monte Carlo simulation

WOLFGANG SCHMICKLER; KAY POETTING; PAOLA QUAINO; HARALD IBACH

Alemania

Congreso; Gesellschaft Deutscher Chemiker (GDCh), Wissenschaftsforum Chemie 2007; 2007

GDCh

The dynamic of low dimensional structures often depends exponentially on the electrode potential, being this effect associated to the interaction of local dipole moments with the electric field of the double layer [1].To clarify the mechanism involved, the step fluctuations of silver islands on Ag(100) electrodes were studied through the evaluation of the stiffness coefficients in the following temperature range: 300K-500K in the presence of the electric field of the double layer (5.109 < Eef / V/m < 1.1010).The investigation was performed by a combination of DFT calculations and Kinetic Monte Carlo simulations (KMC). For this purpose, the diffusion rates of the elementary processes were the basis for the Monte Carlo simulations, and they were calculated by a combination of embedded atom potentials and the dipole moments for the most important processes calculated by DFT.Our results show that the interaction of the electric field of the double layer with the surface dipole moments leads to an increase of the step fluctuations and, consequently, to a decrease in the stiffness coeffcients.[1] M. Giesen, G. Beltramo, S. Dieluweit, J. Müller, H. Ibach, W. Schmickler, Surf. Sci, 595 (2005) 12