2-DIMENSIONAL MONTE-CARLO SIMULATIONS TO CAPTURE THICK CHAIN-LIKE CLUSTERS OF FERROMAGNETIC PARTICLES IN COLLOIDAL DISPERSIONS

The present study theoretically investigates the aggregate structures of thick chainlike clusters arising in ferromagnetic colloidal dispers ions by means of the cluster-moving Monte Carlo method, Pair correlati on functions are also evaluated to clarify the internal structures the mselves of such clusters, The following aggregation image of thick cha inlike clusters has been obtained from the Monte Carlo simulations for a two-dimensional model system, Particles aggregate to form chainlike clusters when magnetic attractions between particles become strong ov er a certain value, Such thin chainlike clusters prefer nearly linear formation along a magnetic field direction, if the strength of magneti c field is sufficiently large. In this situation, attractive forces co me to act between these nearly linear chainlike clusters, and these fo rces increase with the lengths of the clusters, Such attractions betwe en the clusters lead to the formation of thick chainlike clusters. (C) 1996 Academic Press, Inc.