Static and dynamic Monte Carlo simulations of Br electrodeposition on Ag(100)

SURFACE SCIENCE

卷:471

Article

Mitchell, SJ ; Brown, G ; Rikvold, PA

关键词: bromine;    adsorption kinetics;    Monte Carlo simulations;    non-equilibrium thermodynamics and statistical mechanics;   

DOI  :  10.1016/S0039-6028(00)00892-X

来源: Elsevier

【 摘 要 】

We study the static and dynamic properties of bromine electrosorption onto single-crystal silver (1 0 0) electrodes by Monte Carlo (MC) simulation. At room temperature the system displays a second-order phase transition between a low-coverage disordered phase at more negative electrode potentials and a c(2 x 2) ordered phase with bromine coverage 1/2 at more positive potentials. We explore the phase diagram and demonstrate that the broad shoulder observed in room-temperature cyclic voltammograms is due to local fluctuations resembling ordered phases with coverage 1/4, which exist in the model at much lower temperatures. We construct a dynamic MC algorithm using a thermally activated stochastic barrier-hopping model for the microscopic dynamics. We use this algorithm to study the phase ordering and disordering processes following sudden potential steps between the disordered phase and the c(2 x 2) phase, and to study the sweep-rate dependence in simulated cyclic-voltammetry experiments. (C) 2001 Elsevier Science B.V. All rights reserved.

【 授权许可】

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