Magneto-induced stress enhancing effect in a colloidal suspension of paramagnetic and superparamagnetic particles dispersed in a ferrofluid medium.

The magneto-induced stress and relative microstructure in a colloidal suspension of paramagnetic and superparamagnetic particles dispersed in a ferrofluid medium is studied using particle-level dynamics simulation. It shows that the stress perpendicular to the direction of an external uniaxial magnetic field can be strongly enhanced by increasing the ratio of paramagnetic particles to approaching that of superparamagnetic particles. The magnetic field-induced net-like or embedded chain-like microstructures formed by paramagnetic and superparamagnetic particles contribute to this stress enhancing effect.