Magnetoresistive sensor and head

摘要

PtMn films are used as antiferromagnetic layers of a dual spin-valve type magnetoresistive sensor. An exchange anisotropic magnetic field is achieved regardless of whether the PtMn film is formed over or under the pinned magnetic layer. Also, an effective exchange anisotropic magnetic field is produced even with heat treatment at a relatively low temperature. Alternatively, a PtMn film is used as an antiferromagnetic layer of a spin-valve film laminate. The use of a PtMn film enables a sufficient exchange anisotropic magnetic field to be produced even with a relatively low heat treatment temperature and a relatively small film thickness. Therefore, the number of total layers of the spin-valve film laminate can be increased to increase a magnetoresistance ratio, and a total thickness of the spin-valve film laminate can be made relatively small.