Dual AP pinned spin valve sensor biased by opposite ferromagnetic coupling fields and opposite demagnetizing fields

摘要

A dual antiparallel (AP) pinned spin valve sensor has a free layer which is biased by opposite ferromagnetic coupling fields and opposite demagnetizing fields from first and second AP pinned layer structures. The opposite magnetic coupling fields are obtained by appropriately sizing first and second spacer layers of the sensor and the opposite demagnetizing fields are obtained by appropriately sizing first and second AP pinned layers of a first AP pinned layer structure and appropriately sizing third and fourth AP pinned layers of a second AP pinned layer structure.