Spin valve sensor having an antiparallel (AP) self-pinned layer structure comprising cobalt for high magnetostriction

A disk drive, comprising:

• a housing;
• a magnetic disk rotatably supported in the housing;
• a magnetic head assembly;
• a support mounted in the housing for supporting the magnetic head assembly so as to be in a transducing relationship with the magnetic disk;
• a spindle motor for rotating the magnetic disk;
• an actuator positioning means connected to the support for moving the magnetic head assembly to multiple positions with respect to said magnetic disk;
• a processor connected to the magnetic head assembly, to the spindle motor, and to the actuator for exchanging signals with the magnetic head assembly for controlling movement of the magnetic disk and for controlling the position of the magnetic head assembly;
• the magnetic head assembly including a read head;
• the read head including a spin valve sensor comprising:
• a free layer structure;
• an antiparallel (AP) self-pinned layer structure;
• a non-magnetic electrically conductive spacer layer in between the free layer structure and the AP self-pinned layer structure;
• the AP self-pinned layer structure being pinned by its magnetostriction and air bearing surface (ABS) stress without any antiferromagnetic (AFM) layer being utilized for pinning;
• the AP self-pinned layer structure including:
• a first AP pinned layer comprising a cobalt-iron layer;
• a second AP pinned layer comprising a cobalt layer and including no iron content;
• the second AP pinned layer being in closer proximity to the free layer structure than the first AP pinned layer;
• and
• an antiparallel coupling (APC) layer formed between the first and the second AP pinned layer.