Detailed Planar Magnetic Anisotropy Evaluation from Flux Sensing Measurements

A method is described for accurate measurement of the variations of magnetic anisotropy energy with magnetization orientation in the plane of a magnetic thin film. The result, when properly chosen bias fields are applied, is shown to be identical in form to the torque curves obtained by mechanical means. The method is suitable for study of non-uniaxial as well as uniaxial anisotropies. For uniaxial films, values of Hk can be obtained with far greater sensitivity than is possible in conventional switching-type measurements. A major advantage of the technique is that it can be applied to small areas of large films, for local anisotropy variation studies.