Slow relaxation in structure-forming ferrofluids.
We study the behavior of colloidal magnetic fluids at low density for various dipolar interaction strengths by performing extensive Langevin dynamics simulations with model parameters that mimic cobalt-based ferrofluids used in experiments. Our study mainly focuses on the structural and dynamical properties of dipolar fluids and the influence of structural changes on their dynamics. Drastic changes from chainlike to networklike structures in the absence of an external magnetic field are observed. This crossover plays an important role in the slowing down of dynamics that is reflected in various dynamical properties including the tracer diffusion and the viscosity and also in the structural relaxation.
Polymer Physics, Department of Materials, ETH Zürich, Wolfgang-Pauli Strasse 10, CH-8093 Zürich, Switzerland.
Aparna
A
Sreekumari
Patrick
P
Ilg