DIFFUSION-LIMITED AGGREGATION IN 3 DIMENSIONS - RESULTS FROM A NEW CLUSTER CLUSTER AGGREGATION MODEL

Diffusion-limited aggregation has been investigated using three-dimensional lattice models in which both particles and clusters can move and stick together. The final state consists of a single cluster or network of occupied lattice sites with a fractal dimensionality of about 1. 75. Two versions of the model have been investigated. In Model 1, the cluster diffusion coefficient is independent of cluster size, and in Model 2, only the smallest clusters are allowed to 'diffuse. ' Both models give final states which are identical within the accuracy of the simulations. The results of the simulations are in good agreement with measurements of the fractal dimensionality of metal particle aggregates.