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Microscopic model of diffusion limited aggregation and electrodeposition in the presence of levelling molecules

G. J. Ackland·E. S. Tweedie
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Abstract

A microscopic model of the effect of unbinding in diffusion limited aggregation based on a cellular automata approach is presented. The geometry resembles electrochemical deposition - ``ions'' diffuse at random from the top of a container until encountering a cluster in contact with the bottom, to which they stick. The model exhibits dendritic (fractal) growth in the diffusion limited case. The addition of a field eliminates the fractal nature but the density remains low. The addition of molecules which unbind atoms from the aggregate transforms the deposit to a 100% dense one (in 3D). The molecules are remarkably adept at avoiding being trapped. This mimics the effect of so-called ``leveller'' molecules which are used in electrochemical deposition.

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G. J. Ackland, E. S. Tweedie. 2005-08-29. Microscopic model of diffusion limited aggregation and electrodeposition in the presence of levelling molecules. https://doi.org/10.1103/physreve.73.011606

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