Experiment and numerical simulation of interactions among magnetic dipoles induced in feeble magnetic substances under high magnetic fields

Using a two-dimensional closed vessel filled with an aqueous solution, we present triangle-lattice alignments with some spacing formed by interactions among magnetic dipoles induced in feeble magnetic substances under high magnetic fields. We conducted an experiment and a numerical simulation using Au particles with a 1 mm diameter dispersed in a MnCl2 aqueous solution and compared their configurations quantitatively using a three-body distribution function. We confirmed that the numerical simulation demonstrates the formation of triangle-lattice alignments in a two-dimensional plane as obtained in the experiment and also verified that the interaction among induced magnetic dipoles is a significant force that governs the structure formed by feeble magnetic substances under high magnetic fields. On the basis of the results obtained in the experiment and the numerical simulation, it is clear that the distance among particles and the interaction force depend on the number of particle at a steady state and they are closely correlative with each other. The distance among particles can be estimated from the correlative relation. (C) 2005 Elsevier B.V. All rights reserved.