Dynamic phases in non-equilibrium magnetic colloids at liquid interfaces under in-plane magnetic field driving
ORAL
Abstract
Ensembles of interacting colloidal particles subject to an external periodic forcing often develop nontrivial collective behavior. We study emergent phenomena in magnetic colloidal ensembles suspended at a liquid-air interface and driven out of equilibrium by alternating magnetic fields. We use ferromagnetic colloidal micro-particles (so the magnetic moment is fixed in each particle and interactions between colloids is highly anisotropic and directional) suspended over a water-air interface and energized by alternating magnetic fields applied in-pane of the interface. Experiments reveal new types of dynamic self-assembled phases (in particular, ``wires,'' ``rotators'') emerging in such systems in a certain range of excitation parameters. Transition between different self-assembled phases with parameters of external driving magnetic field is observed. Molecular dynamic simulations captures some of the non-equilibrium self-assembled phases in our system.
*The research was supported by the U.S. DOE, Office of Basic Energy Sciences, Division of Materials Science and Engineering, under the Contract No. DE AC02-06CH11357
–