Dipolar interactions in hard-soft nanocomposites

We report on the hysteretic behavior of nanocomposite samples formed by Fe and Ba hexaferrite particles. Our most interesting result corresponds to the observation of a loop displacement (in the sense of the negative fields) which depended in a complex way on the composition of the samples. That result was supported by the observation of measurable differences between the high field values of the isothermal and demagnetization remanences. We discuss our experimental data in terms of the characteristics of the dipolar field created into the Fe regions by the hard Ba hexaferrite particles.