A spin valve sensor for setting the magnetization direction of the fixed layer and the free layer using the sensing current field

摘要

A self-biasing magnetoresistive (MR) spin valve sensor is provided that does not require an antiferromagnetic layer to set the magnetization direction. A nonmagnetic electrically conductive spacer layer is sandwiched between the ferromagnetic free layer and the pinned layer. The first and second leads are connected to the spin valve sensor to allow current flow therethrough. Due to the magnetic coupling between the free layer and the pinned layer, the free layer and the pinned layer, which are oriented in the first direction and parallel to each other when the sense current flows,_FC When the sensing current flows, from the fixed layer to the free layer,_DEMAG Since the first flux guide is magnetically coupled to the first edge of the layers in the ABS and the second flux guide is magnetically coupled to the second edge of the free layer away from the ABS,_DEMAGIs minimized or preferably zero. Due to the sensing current flowing through the spin valve sensor, the sense current field from the pinned layer is balanced with the ferromagnetic coupling on the free layer and the sense current field from the free layer is added to the ferromagnetic coupling on the pinned layer. Thus, the magnetic moment of the free layer rotates freely according to the influence of the field signal from the rotating magnetic disk, and the magnetic moment of the pinned layer is fixed in a predetermined direction perpendicular to the ABS.