Morphologies in two-dimensional growth with attractive long-range interactions

A two-dimensional growth model is introduced in which the morphology of agg regates depends on long-range two-body attractive interactions with a poten tial of the kind U(r) = C/r(alpha). Its relation with continuum diffusive m odels is discussed. The morphology changes are studied for clusters of 2000 particles as a function of the potential parameters p = C/k(B)7 < 0 and al pha. The effect of anisotropy is taken into account by letting particles di ffuse and aggregate on a triangular lattice. Tip-splitting occurs for small \p\ and large alpha. The cluster scaling and symmetry properties are inves tigated in connection with the morphology transitions. (C) 1999 Elsevier Sc ience B.V. All rights reserved.