TEMPERATURE AND DISEQUILIBRIUM DEPENDENCE OF CLUSTER GROWTH

A growth model, in which the morphology of the clusters grown depends on temperature and disequilibrium, is presented. The model is a modifi ed version of Kadanoff's pedestrian model. Sticking, rearrangement and evaporation compete with rates appropriate to the inverse temperature betaJ and to the disequilibrium beta DELTAmu. The relation between th e simulations and the continuum thermal model is discussed, and the de pendence of growth morphologies on the anisotropy epsilon is stressed. As temperature and disequilibrium increase the clusters become more a nd more branched. The same occurs to a lesser extent, for given temper ature and disequilibrium, as time goes by. For 4 < betaJ < 5 a fairly well defined tip-splitting transition takes place from a dendritic to a dense branching morphology. The model correctly describes the behavi our of the growth velocity upsilon of a dendrite as a function of time . After a transient decrease, upsilon tends to a constant value. The m odel may be relevant for understanding domain growth in a lipid monola yer.