Exchange coupling film and magnetoresistive element using the same
AssigneeAlps Electric Co., Ltd.
InventorsNaoya Hasegawa, Masamichi Saito
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Abstract
A PtMn alloy film known as an antiferromagnetic material having excellent corrosion resistance is used for an antiferromagnetic layer. However, an exchange coupling magnetic field is decreased depending upon the conditions of crystal grain boundaries. Therefore, in the present invention, the crystal grain boundaries formed in an antiferromagnetic layer (PtMn alloy film) and the crystal grain boundaries formed in a ferromagnetic layer are made discontinuous in at least a portion of the interface between both layers. As a result, the antiferromagnetic layer can be appropriately transformed to an ordered lattice by heat treatment to obtain a larger exchange coupling magnetic field than a conventional element.
Claims10
An exchange coupling film comprising an antiferromagnetic layer and a ferromagnetic layer, which are formed in contact with each other so that a magnetization direction of the ferromagnetic layer is pinned in a predetermined direction by an exchange coupling magnetic field produced at an interface between both layers, wherein the antiferromagnetic layer is made of an antiferromagnetic material comprising an element X (at least one element selected from Pt, Pd, Ir, Rh, Ru, and Os) and Mn;
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- in a section of the exchange coupling film in parallel with a thickness direction thereof, crystal grain boundaries formed in the antiferromagnetic layer and crystal grain boundaries formed in the ferromagnetic layer extend in a nonparallel direction with respect to an interface between the ferromagnetic layer and antiferromagnetic layer and are discontinuous in at least a portion of the interface.
Dependencies are inferred from the claim text.