MAGNETORESISTANCE EFFECT DEVICE, AND MAGNETORESISTANCE EFFECT MAGNETIC HEAD

摘要

A magnetoresistance effect device comprising a magnetoresistance effect device body (11) formed of a multilayer structure part comprising a free layer having rotating magnetization with respect to at least an external magnetic field, a fixed layer, an antiferromagnetic layer for fixing the magnetization of the fixed layer, and a spacer layer interposed between the free layer and the fixed layer which are provided between first and second magnetic shields (21 and 22) facing to each other and formed of a soft magnetic material, and a hard magnetic layer (12) for applying a bias magnetic field thereto, wherein the magnetoresistive effect device has a CPP configuration in which sensing current is made to flow in a direction perpendicular to the surface of a multilayer film and a detection magnetic field is introduced in the direction of the surface of the multilayer film. Stable single domain is achieved in the free layer by setting the direction of the bias magnetic field perpendicular to with the direction of the introduction of the detection magnetic field, applying the bias magnetic field along the film surface, and setting the front end on the introducing side of the detection magnetic field to be same as the direction of the substantial magnetic field at a rear end with the detection magnetic field not applied in the free layer.