Viscosity of a finely divided suspension of particles with cubic crystal symmetry in a magnetic field

A. O. Tsebers

Institute of Physics, Latvian Academy of Sciences, Salaspils-1, LV-2169, Latvia

Abstract
The effective viscosity has been calculated for a ferroliquid consisting of particles of cubic symmetry; the calculation is for strong magnetic fields much greater than the internal anisotropy field. The distribution of the orientation of the cubic axes is described by a Fokker-Planck equation, and this is used to calculate the antisymmetric part of the viscous stress tensor. The equation is solved by expansion in the small parameters τω and k_aV/kT, where T is the Brownian rotational diffusion time and ω is the angular velocity of rotation of the liquid, while K_a is the magnetic anisotropy constant. An expression is derived for the effective viscosity. It is shown that the magnetoviscous effect for a nickel suspension is weaker than that for a suspension containing iron.