Rotational dynamics of a uniaxial ferroparticle in a liquid

The behavior of a spherical ferromagnetic particle having magnetic anisotro py of the "light axis" type was studied in a volume of liquid rotating as a n entity in a vortex flow under the effect of a weak (compared to the field of the magnetic anisotropy of the particle) magnetic field normal to the r otation axis (the whirl). Depending on the rotation frequency, this problem has two known stationary solutions for the orientation of the light axis f or a rigid dipole. At frequencies below some critical value, the light axis is in the plane perpendicular to the vortex, and the particle is retained by the field in the quiescent state. In the supercritical stationary state, the weak axis is in the plane perpendicular to the field, approaching some specific direction of the rotation axis with an increase in frequency; the particle rotates around the light axis with a permanent velocity. It was f ound that if the supercritical stationary state of the rigid dipole is neut ral, and it is supplemented by the uncountable quantity of periodic motions of the light axis, the infinitesimally small freedom that is allowed for t he magnetic moment tends to stabilize the particle in this state. Experimen ts supported the fact that the uniaxial particle is characterized by the pr esence of a high-frequency attractor.