Self-assembly of magnetic spheres in two dimensions: The relevance of onion-like structures
1 Laboratoire de Chimie et Physique - Approche Multi-Echelle des Milieux Complexes (LCP - A2MC), Institut de Chimie, Physique et Matériaux (ICPM), Université de Lorraine - 1 Bd. Arago, 57070 Metz, France
2 Scientific Computing Laboratory, Institute of Physics Belgrade, University of Belgrade - 11080 Belgrade, Serbia
Received: 27 February 2015
Accepted: 23 May 2015
The self-assembly in two dimensions of spherical magnets is addressed theoretically. Minimal energy structures are obtained by optimization procedures as well as Monte Carlo computer simulations. For a small number of constitutive magnets , ring-like structures are found to be stable. In the regime of larger , the magnets form touching concentric rings that are reminiscent of the onion-like structures. At sufficiently large N, the (edgy) shells are hexagonal where dipole moments tend to align to the edge direction. All these relevant predicted shapes are experimentally reproduced by manipulating millimetric magnets.
PACS: 64.75.Yz – Self-assembly / 41.20.Gz – Magnetostatics; magnetic shielding, magnetic induction, boundary-value problems / 05.65.+b – Self-organized systems
© EPLA, 2015