Physica A 308 (2002) 313–324 www.elsevier.com/locate/physa A simple model for roughening in the instantaneous electrodeposition process M. Santos, W. Cavalcanti, A.A. Pasa, W. Figueiredo ∗ Departamento de Ciencias Naturais, Universidade Federal de Santa Catarina, 88040-900, Florian opolis, SC, Brazil Received 14 September 2001; received in revised form 30 November 2001 Abstract We introduce a very simple model for the instantaneous electrodeposition process that takes into account the kinetic roughening during the lm growth. The main ingredients of the model are the characteristic time for the cation particles to attain their steady-state velocity and the choice of a velocity-dependent probability for the particles to relax on the substrate. The model is capable of reproducing the experimental results for the density current as a function of time for a xed value of the external potential during the electrodeposition experiment, as well as typical voltammograms. The model was investigated through a suitable continuous Monte Carlo algorithm where the number of particles to be deposited in a Monte Carlo step (MCs) changes with time. For small values of the particle velocities the deposition is essentially described by a pure random deposition model, while for high values of velocity a dominant local relaxation process is assumed. At each MC we compute the surface width in order to determine the roughness of the surface. From the plots of the surface width versus time we found the growing (), dynamic (z) and roughness () exponents for this model. c  2002 Elsevier Science B.V. All rights reserved. PACS: 05.40.-a; 64.60.Ht; 82.20.Mg; 81.15.Pq 1. Introduction Much attention has been devoted in recent years to the understanding of the structure of deposits formed by electrochemical deposition [1–3]. The phenomenon of electro- chemical deposition is very complex, being typically a nonequilibrium growth process, ∗ Corresponding author. Fax: +55-48-2319946. E-mail address: wagner@sica.ufsc.br (W. Figueiredo). 0378-4371/02/$-see front matter c  2002 Elsevier Science B.V. All rights reserved. PII:S0378-4371(02)00573-3