Topological instability of magnetic fluids

A finite volume of a magnetic fluid resting on a solid base in an external homogeneous magnetic field is considered. An approach to the theory of topological instability is proposed and the instability criterion is derived. The shape hysteresis (first order phase transition) for fluids with high magnetic susceptibility is predicted On a etudie le comportement d'un volume limite de fluide magnetique reposant sur une base solide et place dans un champ magnetique exterieur homogene. On a obtenu un critere d'instabilite topologique. L'existence de l'hysteresis des formes (transition de phase du 1er ordre) a ete predite