6533b852fe1ef96bd12aac15

RESEARCH PRODUCT

Rotating-field-driven ensembles of magnetic particles.

M. BricsAndrejs CēbersM. Belovs

subject

PhysicsField (physics)Dynamics (mechanics)Angular velocityMechanicsRotation01 natural sciences010305 fluids & plasmasVortexDipole0103 physical sciencesLubricationMagnetic nanoparticles010306 general physics

description

Vortex patterns in ensembles of magnetic particles driven by a rotating field are studied. The driving arises due to the lubrication forces between the rotating particles acting in the direction perpendicular to the radius vector between the particles. Since the lubrication forces cannot be equilibrated by the radial forces due to the dipolar attraction and steric repulsion, the ensemble is in a nonequilibrium state. Different regimes are found for the dynamics of the driven ensembles---solid-body rotation at low frequency of the rotating field and stick-slip motion of the external layers of the aggregate with respect to the internal structure as the frequency is increased. The relation obtained for describing the angular velocity of the solid-body rotation is in good agreement with existing experimental data.

10.1103/physreve.99.042605https://pubmed.ncbi.nlm.nih.gov/31108629