Island Growth Kinetics Research Articles

Kinetics of island growth in models of physisorbed and chemisorbed systems

A brief review is given of recent computer simulation studies of the kinetics of island formation in submonolayers of physisorbed and chemisorbcd systems. Examples include models of O/W(112). O/W(110) and orientational ordering in N 2 on graphite.

A possible model for corrosion pitting and tunneling in noble-metal alloys

Abstract Electron microscope observations of the micromorphology of silver-gold and copper-gold alloys corroded in nitric acid and ferric chloride solutions demonstrate how the surfaces of these alloys become covered by a gold-rich layer following the selective dissolution of the less-noble component. The gold layer forms initially from island nuclei which grow and eventually merge to form a connected structure, enclosing channels and pits where the merger is incomplete. Observations on the kinetics of island growth suggest a model for this form of corrosion by which the surface of the alloy becomes disordered by selective dissolution and then reorders by surface diffusion of the residual gold atoms. Analysis of this model is used to discuss the morphology of islands and pits and the conditions under which the pits might transform into corrosion tunnels. Those results are discussed in relation to previous morphological studies of corrosion tunnelling. It is shown that the surface disordering-reordering model not only provides a satisfactory description of tunnel formation, but might also lead to a better quantitative understanding of this form of corrosion.