Spin valve magnetoresistive thin film element, for a magnetic head, e.g. for reading hard disks, has a free magnetic layer of specified thickness comprising a nickel-iron alloy film and optionally a cobalt or cobalt alloy film

摘要

A spin valve magnetoresistive thin film element has a free magnetic layer (5) of specified thickness comprising a NiFe alloy film and optionally a Co or Co alloy film. A spin valve magnetoresistive thin film element comprises: an antiferromagnetic layer (2); a fixed magnetic layer (3) in contact with the antiferromagnetic layer and having its magnetization direction determined by an anisotropic exchange magnetic field between itself and the antiferromagnetic layer; a nonmagnetic electrically conductive layer (4) formed between a free magnetic layer (5) and the fixed magnetic layer; a pre-magnetization layer (6) for orienting the free magnetic layer magnetization in a direction intersecting the magnetization direction of the fixed magnetic layer; and an electrically conductive layer (9) for supplying a read current to the fixed magnetic layer (3), the nonmagnetic electrically conductive layer (4) and the free magnetic layer (5). The free magnetic layer (5) comprises a 30-100 Angstrom thick NiFe alloy film or a NiFe alloy film and a Co or Co alloy film of total thickness 30-100 Angstrom , the ratio of the Co or Co alloy film thickness to the free magnetic layer thickness being 0-0.5.