Hysteresis of the magnetic properties of soft magnetic gels

We present results of an experimental and theoretical study of the magnetic properties of soft magnetic gels consisting of micron-sized magnetizable particles embedded in a polymer matrix. Experiments demonstrate hysteretic dependences of composite magnetization on an applied magnetic field and non-monotonic, with maximum, dependence of the sample susceptibilities on the field. We propose a theoretical approach which describes the main physical features of these experimental results.