Spin valve magnetoresistive sensor using permanent magnet biased artificial antiferromagnet layer

摘要

A spin valve magnetoresistive sensor of the type used in a data storage system includes a free layer extending in a sensor plane. The free layer has a magnetization which changes in the presence of a magnetic field. An artificial antiferromagnet layer is used as a pinned layer. The artificial antiferromagnet layer includes a first ferromagnetic layer extending in the sensor plane which has a first ferromagnetic layer vector. A second ferromagnetic layer extends in the sensor plane and includes a second ferromagnetic layer vector. A spacer layer of non-magnetic material extends in the sensor plane and is positioned between the first and second ferromagnetic layers. The first and second magnetization vectors in the first and second ferromagnetic layers include vector components which are directed perpendicular to the air bearing surface which is parallel to the sensor plane due to a DC bias field provided by two permanent magnet poles.