Anisotropic magneto-optical hysteresis of permalloy slanted columnar thin films determined by vector magneto-optical generalized ellipsometry

We present magneto-optical dielectric function tensor data of permalloy slanted columnar thin films obtained by vector magneto-optical generalized ellipsometry. Room-temperature hysteresis magnetization measurements were performed in transverse, longitudinal, and polar configurations, and at three different sample in plane azimuth orientations. We observe strongly anisotropic hysteresis behaviors, which depend on the nanocolumn and magnetizing field orientations. We present a model dielectric function approach by implementing vectorial magneto-optical magnetization hysteresis functions with major axes coincident with the major optical polarizability axes of the nanocolumns. Our approach provides excellent match with experimental data and reveals strongly anisotropic coercive field and ferromagnetic model parameters for the permalloy slanted columnar thin films. Ferromagnetic coupling is strongest parallel to the nanocolumn direction and substantially weaker perpendicular to the nanocolumns.