Metastable Fractal Aggregates as a Result of Competition Between Diffusion-Limited Aggregation and Dissociation

The cellular automaton model is used to simulate diffusion and aggregation with dissociation of point particles in 2D. A continuous phase transition is found that separates creation of compact aggregates and fractal ones. The transition is the function of pair-interaction energy ($E_b$), type of neighborhood and temperature $T$. Manifestations of the transition in real physical systems are discussed.