Eur. Phys. J. E (2016) 39: 69
https://doi.org/10.1140/epje/i2016-16069-6

Regular Article

Non-equilibrium dynamics of magnetically anisotropic particles under oscillating fields

¹ Institute of Physics, Technische Universität Chemnitz, 09107, Chemnitz, Germany
² Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstrasse 400, 01328, Dresden, Germany

^* e-mail: gabi.steinbach.de@gmail.com

Received: 23 March 2016
Revised: 31 May 2016
Accepted: 2 June 2016
Published online: 14 July 2016

Abstract

In this article, we demonstrate how magnetic anisotropy of colloidal particles can give rise to unusual dynamics and controllable rearrangements under time-dependent fields. As an example, we study spherical particles with a radially off-centered net magnetic moment in an oscillating field. Based on complementary data from a numerical simulation of spheres with shifted dipole and experimental observations from particles with hemispherical ferromagnetic coating, it is explained on a two particle basis how this magnetic anisotropy causes nontrivial rotational motion and magnetic reorientation. We further present the behavior of larger ensembles of coated particles. It illustrates the potential for controlled reconfiguration based on the presented two-particle dynamics.