Read head spin valve sensor with triple antiparallel coupled free layer structure

A magnetic head assembly comprising:

• a write head including:
• ferromagnetic first and second pole piece layers;
• each of the first and second pole piece layers having a yoke portion located between a pole tip portion and a back gap portion;
• a nonmagnetic write gap layer located between the pole tip portions of the first and second pole piece layers;
• an insulation stack with at least one coil layer embedded therein located between the yoke portions of the first and second pole piece layers;
• and
• the first and second pole piece layers being connected at their back gap portions;
• and
• a read head including:
• a dual spin valve sensor;
• nonmagnetic nonconductive first and second read gap layers;
• the dual spin valve sensor being located between the first and second read gap layers;
• a ferromagnetic first shield layer;
• and
• the first and second read gap layers being located between the first shield layer and the first pole piece layer;
• and
• the dual spin valve sensor including:
• first and second pinned layer structures wherein each pinned layer structure has a magnetic moment;
• antiferromagnetic first and second pinning layers exchange coupled to the first and second pinned layer structures respectively for pinning the magnetic moments of the first and second pinned layers respectively;
• an antiparallel (AP) coupled free layer structure located between the first and second pinned layer structures and having a net magnetic moment;
• a nonmagnetic conductive first spacer layer located between the first pinned layer structure and the AP coupled free layer structure and a nonmagnetic conductive second spacer layer located between the second pinned layer structure and the AP coupled free layer structure;
• the AP coupled free layer structure including:
• ferromagnetic first, second and third antiparallel (AP) coupled free layers;
• a nonmagnetic first antiparallel (AP) coupling layer located between the first and second AP coupled free layers and a nonmagnetic second antiparallel (AP) coupling layer located between the second and third AP coupled free layers.

A magnetic disk drive having at least one slider that has an air bearing surface (ABS), the slider supporting at least one magnetic head assembly that includes a read head and a write head, the disk drive comprising:

• the write head including:
• ferromagnetic first and second pole piece layers;
• each of the first and second pole piece layers having a yoke portion located between a pole tip portion and a back gap portion;
• a nonmagnetic write gap layer located between the pole tip portions of the first and second pole piece layers;
• an insulation stack with at least one coil layer embedded therein located between the yoke portions of the first and second pole piece layers;
• and
• the first and second pole piece layers being connected at their back gap portions;
• and
• the read head including:
• a dual spin valve sensor;
• nonmagnetic nonconductive first and second read gap layers;
• the dual spin valve sensor being located between the first and second read gap layers;
• a ferromagnetic first shield layer;
• and
• the first and second read gap layers being located between the first shield layer and the first pole piece layer;
• the dual spin valve sensor including:
• first and second pinned layer structures wherein each pinned layer structure has a magnetic moment;
• antiferromagnetic first and second pinning layers exchange coupled to the first and second pinned layer structures respectively for pinning the magnetic moments of the first and second pinned layers respectively;
• an antiparallel (AP) coupled free layer structure located between the first and second pinned layer structures and having a net magnetic moment;
• and
• a nonmagnetic conductive first spacer layer located between the first pinned layer structure and the AP coupled free layer structure and a nonmagnetic conductive second spacer layer located between the second pinned layer structure and the AP coupled free layer structure;
• the AP coupled free layer structure including:
• ferromagnetic first, second and third antiparallel (AP) coupled free layers;
• and
• a nonmagnetic first antiparallel (AP) coupling layer located between the first and second AP coupled free layers and a nonmagnetic second antiparallel (AP) coupling layer located between the second and third AP free layers;
• a housing;
• a magnetic disk rotatably supported in the housing;
• a support mounted in the housing for supporting the magnetic head assembly with its ABS facing the magnetic disk so that the magnetic head assembly is in a transducing relationship with the magnetic disk;
• a spindle motor for rotating the magnetic disk;
• an actuator connected to the support for moving the magnetic head assembly to multiple positions with respect to said magnetic disk;
• and
• 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 rotation of the magnetic disk and for controlling the position of the magnetic head assembly relative to the magnetic disk.