Controlled alignments of feeble magnetic particles utilizing induced magnetic dipole interactions

Some ordered alignments of feeble magnetic particles were obtained utilizing magnetic dipole interactions. The interactions among feeble magnetic substances under magnetic fields, that is, interactions among magnetic dipoles induced in feeble magnetic substances have been believed too small to be observed. However, by controlling experimental conditions carefully, we confirmed that such interactions can be observed visually even in feeble magnetic substances. Furthermore, by applying the interactions to many-particle systems, ordered alignments were obtained such as chain-like alignments parallel to and triangle-lattice alignments perpendicular to magnetic fields. These results suggest that structures of feeble magnetic substances can be controlled by magnetic fields, and such application would be of use in materials processing.