Thin film magnetic head having a pair of magnetic layers whose magnetization is controlled by shield layer including amorphous layer

摘要

A thin film magnetic head includes a magnetoresistance (MR) layered body that has first and second magnetic layers whose magnetization direction are changed according to an external magnetic field, a nonmagnetic middle layer and where the first magnetic layer, the nonmagnetic middle layer and the second magnetic layer are disposed in a manner of facing each other in respective order, first and second shield layers that are disposed in a manner of sandwiching the MR-stack in the film surface orthogonal direction of the MR-stack facing the first magnetic layer and the second magnetic layer, respectively, and that also serve as an electrode for applying a sense current to the film surface orthogonal direction of the MR-stack; and a bias magnetic field application means that is disposed on an opposite surface of an air bearing surface (ABS) of the MR-stack, and that applies a bias magnetic field to the MR-stack in the direction orthogonal to the ABS. The first shield layer has a first exchange coupling magnetic field (ECMF) application layer that is disposed in a manner of facing the first magnetic layer, and that transmits to the first magnetic layer an exchange coupling magnetic field in the direction in parallel with the ABS, and that includes an amorphous layer, and has a first antiferromagnetic layer that is disposed on a rear surface of the first ECMF application layer viewed from the first magnetic layer in a manner of facing the first ECMF application layer, and that is exchange-coupled with the first ECMF application layer. The second shield layer has a second exchange coupling magnetic field (ECMF) application layer that is disposed in a manner of facing the second magnetic layer, and that transmits to the second magnetic layer the exchange coupling magnetic field in a direction in parallel with the ABS; and a second antiferromagnetic layer that is disposed on a rear surface of the second ECMF application layer viewed from the second magnetic layer, and that is exchange-coupled with the second ECMF application layer.