Properties of vector Preisach models

In this paper, we discuss rotational anisotropy and rotational accommodation of magnetic-particle tape; phenomena that affect performance during reading and writing in the recording process. We introduce the reduced vector Preisach model (RVPM) to simplify the selection rules and eliminate the rotational correction of the simplified vector Preisach model (SVPM). In order to make the model agree with our measurements, we introduce the RVPM, which eliminates the need for a rotational correction in the SVPM. Using this new model as a basis to characterize the medium, we have measured and computed the angle of magnetization for a magnetic-particle tape rotated in an applied field. Because rotational models must accurately compute the anisotropic characteristics of ellipsoidally magnetizable media, we use an ellipticity factor that accurately computes the two-dimensional magnetization trajectories for small applied fields, and that corrects the orientation error for both isotropic and anisotropic media. We report rotational magnetization measurements that demonstrate vector accommodation for ellipsoidally magnetizable media. The magnetization trajectories show that accommodation is achieved.