Morphology of cluster formation in magnetic fluids

Dynamic Monte Carlo simulations are used to study the evolution of clusters in magnetic fluids subjected to a rectangular magnetic pulse. The number o f clusters and their perimeter provide quantitative estimations of the morp hology of cluster structures. For large values of the dipolar interaction e nergy with respect to thermal energy, break up of existing clusters, follow ed by their elongation, predominate. For small values of the dipolar intera ction energy, the process of cluster formation is enhanced in the presence of the external magnetic field. (C) 1999 Elsevier Science B.V. All rights r eserved.