Ferrofluid aggregation in chains under the influence of a magnetic field.

Magnetic fluids (ferrofluids, ferrocolloids ) are suspensions of magnetic nanosized particles (Fe oxides, Co, Ni, etc.) covered by a solvent layer. The magnetic particles generally are approximately 10 nm in diameter. The ferro- or ferrimagnetic particles of such a size are single domain. So, each particle has its own magnetic moment m, the value of which is proportional to the magnetic core volume and depends upon the saturation magnetization of the material. So, particles are not only involved in Brownian motion, but also interact with each other forming different aggregates. The rheological, hydrodynamic, diffusional, magnetic, and optical properties of a ferrofluid change by a hundred times under an applied magnetic field of moderate strength. So, such material is a challenging subject for scientific research as