Deformation of a ferrovesicle in a uniform magnetic field

A sphere with a concentric spherical cavity is considered as a model for a magnetic vesicle: a bubble whose walls are made of a magnetiziable polymer or ferrogel. The material of the body is assumed to be homogeneous, linearly magnetizable, and linearly elastic. Using self-consistent finite element calculation we study the elongation of the sphere under the action of a uniform field and the change of the cavity volume which accompanies this deformation.