Magnetic susceptibility of magnetic viscous-based colloids in shear flow

D. V. Gladkikh - Yu. I. Dikansky

Institute of Mathematics and Natural Sciences, North-Caucasus Federal University 355009 Stavropol, Russia

Abstract
Investigation results on the influence of shear flow on the magnetic susceptibility of magnetic viscous-based colloids are reported. Additional action of an external constant magnetic field has been found to cause a maximum in the dependence of magnetic susceptibility on shear rate, the position of which is determined by the magnitude and orientation of the external field. The obtained results are theoretically based on an assumption that the action of the external magnetic field initiates the formation of aggregates in an initially homogeneous magnetic colloid sample; the aggregates' size is determined by the external field magnitude and shear rate. A mean critical number of particles in an aggregate is defined which corresponds to the magnetic susceptibility maximum for different orientations of the external magnetic field. Figs 7, Refs 21.