Self-assembly of magnetic nanostructures

Abstract. We use Monte Carlo and quaternion molecular dynamics simulations to study the self-assembly of intriguing structures which form in colloidal suspensions of small magnetite particles. We show that the only stable isomers with few particles, a ring and a chain, can be efficiently interconverted using a magnetizable tip. We propose to use the oscillating dipole field of the tip to locally anneal the aggregates to either a ring in zero field or a chain in nonzero applied field. PACS: 75.50.Mm Given the present advanced stage of miniaturization, the most promising way to significantly reduce the dimension of devices involves a transition from micro-manufacturing to self-assembly of nanostructures [1]. Inspired by the richness of structures observed in aggregates of magnetic nanoparticle