title: Hydrodynamic instabilities in ferronematics.
abstract: In the hydrodynamic description of ferronematics there are various dynamic magnetic-field effects, linear in the field strength, that are negligible in usual nematics, but can play a role in ferronematics. Here, we investigate theoretically the influence of these new terms on the thermal convection (Rayleigh-Bénard) and the viscous fingering (Saffman-Taylor) instability in ferronematics in the presence of a strong magnetic field. We find that the instabilities are qualitatively changed due to the occurrence of a finite vorticity component--a feature that is known from simple liquids in the case of a superimposed mechanical rotation. We suggest to use the additional effects (cross-flow within convection rolls, oblique rolls, rotating fingers) for measuring the phenomenological coefficients involved.
authors.affiliation: Max Planck Institute for Polymer Research, PO Box 3148, 55021 Mainz, Germany.
authors.forename: A B
authors.initials: AB
authors.lastname: Ryskin
authors.forename: H
authors.initials: H
authors.lastname: Pleiner
authors.forename: H W
authors.initials: HW
authors.lastname: Müller