Internal magnetostatic potentials of magnetization-graded ferromagnetic materials

Abstract

The authors investigated the internal magnetic field induced by a spatially varying magnetization in a compositionally graded ferromagnet. The authors discuss results on a hexagonal ferrite sample, with a variation in saturation magnetization of 30emu∕g over a sample thickness of 2.5mm. The direct current magnetization shows a small anisotropy depending on the direction of the external magnetic field relative to the grading direction. This contribution from a grading induced magnetic field is more pronounced in alternating current susceptibility measurements. The authors find a shift in magnetic properties corresponding to an internal magnetic field of 30Oe, which is significantly lower than the predicted value of approximately 1900Oe. The authors discuss reasons for this discrepancy.