AP-tab spin valve with controlled magnetostriction of the biasing layer

A magnetic read/write head comprising:

• a write head including:
• at least one coil layer and an insulation stack, the coil layer being embedded in the insulation stack;
• first and second pole piece layers connected at a back gap and having pole tips with edges forming a portion of an air bearing surface (ABS);
• the insulation stack being sandwiched between the first and second pole piece layers;
• and
• a write gap layer sandwiched between the pole tips of the first and second pole piece layers and forming a portion of the ABS;
• a read head including:
• a spin valve (SV) sensor, the SV sensor being sandwiched between first and second read gap layers, the SV sensor having first and second passive regions
• and a central track width region transversely disposed between said first and second
• passive regions, said SV sensor comprising:
• a pinned layer;
• a ferromagnetic free layer;
• a spacer layer sandwiched between said pinned layer and said free layer;
• a bias layer in said first and second passive regions, said bias layer having a high uniaxial anisotropy caused by stressing said bias layer;
• and
• an antiparallel coupled layer sandwiched between said free layer and said bias layer for providing strong antiparallel coupling between said bias layer and said free layer in the first and second passive regions;
• and
• an insulation layer disposed between the second read gap layer of the read head and the first pole piece layer of the write head.

A disk drive system comprising:

• a magnetic recording disk;
• a magnetic read/write head for magnetically recording data on the magnetic recording disk and for sensing magnetically recorded data on the magnetic recording disk, said magnetic read/write head comprising:
• a write head including:
• at least one coil layer and an insulation stack, the coil layer being embedded in the insulation stack;
• first and second pole piece layers connected at a back gap and having pole tips with edges forming a portion of an air bearing surface (ABS);
• the insulation stack being sandwiched between the first and second pole piece layers;
• and
• a write gap layer sandwiched between the pole tips of the first and second pole piece layers and forming a portion of the ABS;
• a read head including:
• a spin valve (SV) sensor, the SV sensor being sandwiched between first and second read gap layers, the SV sensor having first and second passive regions and a central track width region transversely disposed between said first and second passive regions, said SV sensor comprising:
• a pinned layer;
• a ferromagnetic free layer;
• spacer layer sandwiched between said pinned layer and said free layer;
• a bias layer in said first and second passive regions, said bias layer having a high uniaxial anisotropy caused by stressing said bias layer;
• and
• an antiparallel coupled layer sandwiched between said free layer and said ferromagnetic bias layer for providing strong antiparallel coupling between said bias layer and said free layer in the first and second passive regions;
• an antiferromagnetic (AFM) layer adjacent to said ferromagnetic bias layer, said AFM layer exchange coupled to the ferromagnetic bias layer to provide a pinning field to the bias layer;
• and
• an insulation layer disposed between the second read gap layer of the read head and the first pole piece layer of the write head;
• and
• an actuator for moving said magnetic read/write head across the magnetic disk so that the read/write head may access different regions of the magnetic recording disk;
• and
• a recording channel coupled electrically to the write head for magnetically recording data on the magnetic recording disk and to the SV sensor of the read head for detecting changes in resistance of the SV sensor in response to magnetic fields from the magnetically recorded data.