Method for testing hard and easy magnetization direction of exchange bias film

Abstract

The invention relates to a magnetic measurement method, in particular to a method for testing a hard and easy magnetization direction of a magnetic film material with exchange bias. The method comprises the following steps of: arranging a sample film to be tested in an external direct current magnetic field, so that a plane of the sample film to be tested is parallel to the direction of the external magnetic field; rotating the sample film to be tested around an axis vertical to the plane; during test, optionally applying a given external magnetic field, keeping the magnetic field invariable, and recording an initial position of the sample and magnetization at the moment; rotating the sample film to be tested at an angle, and measuring a corresponding projection value M of spontaneous magnetization MS of the film to be tested in the direction of the external magnetic field at the angle theta0 so as to obtain a function of the sample film to be tested at different rotating angles theta0 and corresponding M values; and determining an easy magnetization axis or a hard magnetization axis of the exchange bias film according to a measured M-theta0 curve.

Description

technical field [0001] The invention relates to a magnetic measurement method, specifically a method for measuring the direction of difficult and easy magnetization of magnetic film materials with exchange bias. Background technique [0002] The exchange bias effect, especially the ferromagnetic / antiferromagnetic bilayer system, has been widely studied due to its application in the field of magnetic storage technology. For the ferromagnetic / antiferromagnetic double-layer film system, the hard and easy magnetization directions have been obtained mainly in two ways so far: one is to heat the prepared magnetic film to above the Neel temperature of the antiferromagnetic layer in vacuum , and then add a given external magnetic field to cool down, and finally obtain a bilayer film with an exchange bias; the other is to apply an external magnetic field on both sides of the substrate during the preparation process, and under the induction of the external magnetic field, obtain a Ex...

AI Technical Summary

Problems solved by technology

However, for exchange-biased thin film samples, in the case where the hard-to-easy magnetization direction is unknown, such as when the uniaxial anisotropy field from the ferromagnetic layer is coupled with the unidirectional anisotropy field from the interface coupling (exchange bias field) is not collinear, that is, the two anisotropic fields have a certain angle; in the case of no external magnetic field, the exchange bias occurs after the ferromagnetic layer is prepared first, and the antiferromagnetic layer is prepared. The previous method Can not meet the actual needs

How to obtain the hard and easy magnetization direction of the exchange bias thin film sample has become a key factor in the study of the magnetic properties of this type of sample, but there is no introduction of this technology at this stage

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