Study on Magnetic Anisotropy for Fe Based Particulate Medium

The rotational hysteresis loss of MP tapes was analyzed in order to evaluate the magnitude of the magnetic anisotropy of metal particles and to clarify the effect of the degree of preferred particle orientation on their magnetic properties. Taking account of the magnetostatic interactions among particles, it is shown that the mean value of the magnetic anisotropy of metal particles is 7.7 kOe. Furthermore, it is thought that the mean value of the saturation magnetization inside the particles is about 1270 emu/cc. The ratio of Hk(2θ) to Hkptc is the key to evaluating the degree of the preferred particle orientation. Here Hk(2θ) is defined as the macroscopic anisotropy field, which is equivalent to the macroscopic uniaxial magnetic anisotropy in the tape plane. It was established that there are correlations between Hk(2θ)/Hkptc and the squareness of the magnetization curve, the coercive force, and the remanent coercive force.