The magnetization process in RE-TM alloys studied using the extraordinary Hall effect (abstract)

The extraordinary Hall effect can be used to monitor the magnetization component perpendicular to the plane of a thin film.1 This technique has been used to monitor the time dependence of the magnetization of a series of RE-TM alloys. At room temperature these samples exhibit relatively square hysteresis loop, i.e., the demagnetization effects are minimal. The data are accumulated in the presence of applied magnetic fields approximately equal to the coercive field. The time dependence of the magnetization can be altered by tuning the applied field by only a few percent. Two simple models have been applied to the magnetization process in these films. The first considers the magnetization process in the films if disorder is dominate; then the relaxation of the magnetization would be quasilogrithmic in time. The second is if disorder does not dominate then one might expect an exponential time dependence to be observed. The data have been analyzed in terms of both of these simple models.