Shape of Magnetization Curves

The shape of magnetoresistivity curves is discussed with reference to the rotation model of magnetization. The magnetoresistivity curve exhibits a dip when the magnetic field deviates from the direction of hard magnetization. Deviation of the direction of electric current from the easy axis direction causes an irreversibility in the magnetoresistivity curve. These results indicate that the fact that the dip and/or irreversibility is independent of the Barkhausen effect should be taken into account in explanations of experimentally observed curves. An asymmetric magnetoresistivity curve sometimes observed for 82Ni-Fe permalloy films is explained by the model, with the assumption of magnetic inhomogeneity. The shape of magnetoresistivity curves observed for Co/Au multilayer films with perpendicular magnetic anisotropy is also explained by the model.