Magnetoresistance effect device, magnetic memory apparatus, personal digital assistance, and magnetic reproducing head, and magnetic information

Abstract

Magnetoresistance effect devices for attaining magnetically stability and for reducing a switching magnetic field. One of the ferromagnetic layers of the magnetoresistance effect device has a plane shape in which a width of an end portions is wider than a center portion sandwiched by two end portions. The end portions are not symmetrical with respect to an easy magnetization axis or longer axis of the plane shape of ferromagnetic material layer, but are substantially rotationally symmetrical with a center of the plane shape as a pivot. The plane shape may have an S-shape where its magnetic domain is stabilized and the switching magnetic field is reduced. The magnetoresistance effect devices may be used in a magnetic memory apparatus, such as a random access memory, a personal digital assistance, a magnetic reproducing head, and a magnetic information reproducing apparatus.