Dipolar-random-field Ising model: An application to garnet films

The dipolar-random-field Ising model (DRFIM) recently introduced [A. Magni, Phys. Rev. B 59, 985 (1999)] displays a behavior that can be connected to the magnetization of bidimensional magnetic media. Epitaxial magnetic garnet films seem to be the ideal test material for such a model. In this work the results of the measurements performed on garnet samples are presented, as well as the comparisons with simulation results obtained by the DRFIM. The results prove that a variety of hysteresis loops are well described by the DRFIM. This capability does not derive from the fine tuning of a great number of parameters, but by the interplay of exchange and dipolar interactions