| abstract |
An Anti-Parallel (AP)-pinned spin valve (SV) sensor having a free layer disposed between an AP-pinned layer and a pinned layer. The free layer being separated from the AP-pinned layer by a first conducting spacer and separated from the pinned layer by a second conducting spacer layer. The AP-pinned layer includes a first, second and third AP-pinned layers where the first and second AP-pinned layers are separated from the third AP-pinned layer by an anti-parallel coupling layer. The first AP-pinned layer is formed over and in contact with an antiferromagnetic (AFM) layer. The AFM layer is used to pin the AP-pinned layer magnetizations directions. The presence of both an AP-pinned layer and a pinned layer dramatically improves the symmetry of the signal read by the SV sensor; the presence of the second spacer layer made of GMR promoting material increases the GMR coefficient; and the addition of the first AP-pinned layer eliminates the interdiffusion at the interface between the AFM and the AP-pinned layer resulting in larger GMR coefficient, well controlled net moment, and a highly stable sensor. |