%0 Journal Article
%@ 0295-5075      
%A Cafiero, Raffaele
%A Caldarelli, Guido
%D 2001
%F eprints:1144
%I IOPscience
%J EPL (Europhysics Letters)
%K PACS: 68.35.Ja Surface and interface dynamics and vibrations; 61.43.Hv Fractals; macroscopic aggregates (including diffusion-limited aggregates)  
%N 2
%P 187-193
%T Fractal growth from local instabilities
%U http://eprints.imtlucca.it/1144/
%V 54
%X We study, both with numerical simulations and theoretical methods, a cellular automata model for surface growth in the presence of a local instability, driven by an external flux of particles. The growing tip is selected with probability proportional to the local curvature. A probability p of developing overhangs through lateral growth is also introduced. For small external fluxes, we find a fractal regime of growth. The value of p determines the fractal dimension of the aggregate. Furthermore, for each value of p a crossover between two different fractal dimensions is observed. The roughness exponent χ of the aggregates, instead, does not depend on p (χ simeq 0.5). A Fixed Scale Transformation (FST) approach is applied to compute theoretically the fractal dimension for one of the branches of the structure.