IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Electrochemistry and Fluid-Solid Interfaces Monday Sessions
       Session EC-MoA

Paper EC-MoA3
In-situ STM Study of the Formation of Metal Nanostructures of Co on Ag(111)

Monday, October 29, 2001, 2:40 pm, Room 111

Session: Electrochemical Control of Surface Structure: Growth and Dissolution
Presenter: S. Morin, York University, Canada
Authors: D. Marcu, York University, Canada
N. Hall, York University, Canada
S. Morin, York University, Canada
Correspondent: Click to Email
Recently, there has been a growing interest in the study of the formation of thin metal films and multilayer films of Ni, Co and their alloys due to their interesting magnetic properties. To optimise these materials, we must understand the nucleation and growth processes that are involved in the formation of individual layers. This includes monitoring surface alloying and intermixing processes taking place at the early stages of growth as well as the effect of varying the electrode potential on the formation of these metal films. During this presentation, the electrodeposition of Co and Ni@footnote 1@] on the Ag(111) surface will be compared in terms of their nucleation and growth behaviour in similar electrolytes. Similar to Ni, Co electrodeposition proceeds via preferred nucleation and growth at the substrate step edges at high overpotential. At low overpotential values, the electrodeposition is very slow, with only a few islands nucleating at the step edges. Independently of island nucleation and growth, an adsorbed layer forms on the Ag terraces. This layer appears to be further reduced with time; possible explanations for the origin of this layer will be given. At high overpotential, there is strong evidence of Ag atom mobility, and the resulting substrate changes are only partially removed during Co dissolution. These results will be discussed in the view of possible surface alloying and intermixing between the Co and Ag substrate. These results contrast with previous studies concerning the electrodeposition of Co on Au(111),@footnote 2@ in which no 2D island growth was reported. @FootnoteText@@footnote 1@S. Morin, A. Lachenwitzer, O.M. Magnussen, R.J. Behm, Phys. Rev. Lett., 83 (1999) 5066. @footnote 2@L. Cagnon, A. Gundel, T. Devolder, A. Morrone, C. Chappert, J.E. Schmidt, P. Allongue, Appl. Surf. Sci., 164 (2000) 22.