Patent ID: 6639762
Filing Date: 2003-10-28
Classification: B82Y,G01R,G11B,H01F,Y10T

Abstract:
A spin valve thin-film magnetic device comprising:a free magnetic layer; a pair of nonmagnetic conductive layers formed on both sides of the free magnetic layer in the thickness direction thereof; a pair of fixed magnetic layers formed on the pair nonconductive layers; a pair of antiferromagnetic layers formed on the pair of fixed magnetic layers; a pair of conductive layers imparting a sensing current to the free magnetic layer, the pair of nonmagnetic conductive layers, and the pair of fixed magnetic layers; and a pair of bias layers for aligning a magnetization direction of the free magnetic layer; wherein the free magnetic layer is a laminate composed of at least 2L ferromagnetic layers with a nonmagnetic interlayer provided therebetween, the L being an integer of 1 or more, in which magnetization directions of the ferromagnetic layers adjacent to each other are antiparallel, one of the pair of fixed magnetic layers is a laminate composed of at least 2M ferromagnetic layers with a nonmagnetic layer provided therebetween, the M being an integer of 1 or more, in which magnetization directions of the ferromagnetic layers adjacent to each other are antiparallel, and a second direction of a second magnetic moment of the entire fixed magnetic layer by an exchange coupling magnetic field formed by the one of the pair of fixed magnetic layers and the one of the pair of antiferromagnetic layers adjacent thereto, is fixed in a direction crossing a first direction of a first magnetic moment of the entire free magnetic layer, the other fixed magnetic layer is a laminate composed of at least 2N ferromagnetic layers with a nonmagnetic layer provided therebetween, the N being an integer of 1 or more, in which magnetization directions of the ferromagnetic layers adjacent to each other are antiparallel, and a third direction of a third magnetic moment of the entire other fixed magnetic layer by an exchange coupling magnetic field formed by the other fixed magnetic layer and the other antiferromagnetic layer adjacent thereto, is fixed in a direction parallel to the second direction of the entire fixed magnetic layer, and a magnetization direction of a ferromagnetic layer, which is closest to the free magnetic layer among the ferromagnetic layers forming the fixed magnetic layer, and a magnetization direction of a ferromagnetic layer, which is closest to the free magnetic layer among the ferromagnetic layers forming the other fixed magnetic layer, are antiparallel to each other.