Magnetic instabilities of microdrop aggregates in an AC magnetic field

V. I. Drozdova - G. V. Shargova

Abstract
We have studied the instabilities of microdrops induced in thin films of magnetic liquids or in thin capillaries by an ac magnetic field applied normal to the plane of the film or to the axis of the capillary. Characteristic feature of microdrops behaviour in ac field is that such instabilities as scissions and bending of microdrops can occur simultaneously. This differs from the microdrops behaviour in dc field where only one of these instabilities takes place simultaneously. Besides, an ac magnetic field applied normal to the axis of capillary can induce rotation of the microdrops edges with a frequency ≈ 1 Hz. Very Thin plane layers of magnetic liquid with agglomerate magnetic microdrops have a high sensitivity towards the field because multiple scissions of microdrops result in threshold changes of hexagonal lattice and in scattering pattern in both dc and ac magnetic fields normal to the film plane. Figs. 5, refs 7.