CPP sensor with in-stack biased free layer

A magnetic head assembly, that has a head surface for facing a magnetic medium, comprising:

• a read head that includes a CPP sensor;
• the CPP sensor including:
• an antiparallel (AP) pinned layer structure;
• a ferromagnetic free layer having a magnetic moment that is free to rotate in response to a field signal;
• and
• a material spacer layer located between the free layer and the AP pinned layer structure;
• the antiparallel (AP) pinned layer structure including:
• ferromagnetic first and second antiparallel (AP) pinned layers;
• and
• an antiparallel (AP) coupling layer located between and interfacing the first and second AP pinned layers;
• an in-stack longitudinal biasing layer structure located within a track width of the sensor;
• the in-stack longitudinal biasing structure including:
• a ferromagnetic pinned layer having a magnetic moment;
• an antiferromagnetic (AFM) pinning layer exchange coupled to the pinned layer for pinning the magnetic moment of the pinned layer parallel to the head surface and parallel to major thin film planes of the layer of the sensor;
• a chrominum spacer layer located between the pinned layer and the free layer;
• and
• the pinned layer consisting of iron (Fe);
• and
• first and second leads connected to the sensor for conducting a current through the sensor perpendicular to major planes of the layers of the sensor.

A magnetic head assembly, that has a head surface for facing a magnetic medium, comprising:

• a read head that includes a CPP sensor;
• the CPP sensor including:
• an antiparallel (AP) pinned layer structure;
• a ferromagnetic free layer having a magnetic moment that is free to rotate in response to a field signal;
• and
• a material spacer layer located between the free layer and the AP pinned layer structure;
• the antiparallel (AP) pinned layer structure including:
• ferromagnetic first and second antiparallel (AP) pinned layers;
• and
• an antiparallel (AP) coupling layer located between and interfacing the first and second AP pinned layers;
• a first antiferromagnetic pinning layer exchange coupled to the first AP pinned layer for pinning the magnetic moment of the first AP pinned layer perpendicular to the head surface;
• an in-stack longitudinal biasing layer structure located within a track width of the sensor:
• the in-stack longitudinal biasing layer including:
• a ferromagnetic pinned layer having a magnetic moment;
• a second antiferromagnetic (AFM) pinning layer exchange coupled to the pinned layer for pinning the magnetic moment of the pinned layer parallel to the head surface and parallel to major thin film planes of the layer of the sensor;
• and
• a chromium spacer layer located between the pinned layer and the free layer;
• first and second leads connected to the sensor for conducting a current through the sensor perpendicular to major planes of the layers of the sensor.

A magnetic disk drive including at least one magnetic head assembly that has a head surface for facing a magnetic medium and that includes a write head and a read head, comprising:

• the write head including:
• ferromagnetic first and second pole piece layers that have 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;
• the read head including:
• ferromagnetic first and second shield layers;
• and
• a CPP sensor located between the first and second shield layers;
• the CPP sensor including:
• an antiparallel (AP) pinned layer structure;
• a ferromagnetic free layer having a magnetic moment that is free to rotate in response to a field signal;
• and
• a material spacer layer located between the free layer and the AP pinned layer structure;
• the antiparallel (AP) pinned layer structure including:
• ferromagnetic first and second antiparallel (AP) pinned layers;
• and
• an antiparallel (AP) coupling layer located between and interfacing the first and second AP pinned layers;
• an in-stack longitudinal biasing layer structure located within a track width of the sensor;
• the in-stack longitudinal biasing layer including:
• a ferromagnetic pinned layer having a magnetic moment;
• an antiferromagnetic (AFM) pinning layer exchange coupled to the pinned layer for pinning the magnetic moment of the pinned layer parallel to the head surface and parallel to major thin film planes of the layer of the sensor;
• and
• a chrominum spacer layer located between the pinned layer and the free layer;
• first and second leads connected to the sensor for conducting a current through the sensor perpendicular to major planes of the layers of the sensor.
• a housing;
• the magnetic medium being supported in the housing;
• a support mounted in the housing for supporting the magnetic head assembly with said head surface facing the magnetic medium so that the magnetic head assembly is in a transducing relationship with the magnetic medium;
• a motor for moving the magnetic medium;
• and
• a processor connected to the magnetic head assembly and to the motor for exchanging signals with the magnetic head assembly and for controlling movement of the magnetic medium.

A method of making a magnetic head assembly, that has a head surface for facing a magnetic medium, comprising the steps of:

• forming a read head that includes a CPP sensor;
• a making of the CPP sensor including the steps of:
• forming an antiparallel (AP) pinned layer structure;
• forming a ferromagnetic free layer having a magnetic moment that is free to rotate in response to a field signal;
• and
• forming a material spacer layer between the free layer and the AP pinned layer structure;
• a making of the antiparallel (AP) pinned layer structure including the steps of:
• forming ferromagnetic first and second antiparallel (AP) pinned layers;
• and
• forming an antiparallel (AP) coupling layer between and interfacing the
• first and second AP pinned layers;
• forming an in-stack longitudinal biasing layer structure within a track width of the sensor;
• a making of the in-stack longitudinal biasing layer including the steps of:
• forming a ferromagnetic pinned layer having a magnetic moment;
• forming an antiferromagnetic (AFM) pinning layer exchange coupled to the pinned layer for pinning the magnetic moment of the pinned layer parallel to the head surface and parallel to major thin film planes of the layer of the sensor;
• and
• forming a chrominum spacer layer located between the pinned layer and the free layer;
• connecting first and second leads to the sensor for conducting a current through the sensor perpendicular to major planes of the layers of the sensor.

A method of making a magnetic head assembly, that has a head surface for facing a magnetic medium, comprising the steps of:

• forming a read head that includes a CPP sensor;
• a making of the CPP sensor including the steps of:
• forming an antiparallel (AP) pinned layer structure;
• forming a ferromagnetic free layer having a magnetic moment that is free to rotate in response to a field signal;
• and
• forming a material spacer layer between the free layer and the AP pinned layer structure;
• a making of the antiparallel (AP) pinned layer structure including the steps of:
• forming ferromagnetic first and second antiparallel (AP) pinned layers;
• and
• forming an antiparallel (AP) coupling layer between and interfacing the first and second AP pinned layers;
• forming an in-stack longitudinal biasing layer structure within a track width of the sensor;
• a making of the in-stack longitudinal biasing layer including the steps of:
• forming a ferromagnetic pinned layer having a magnetic moment;
• forming an antiferromagnetic (AFM) pinning layer exchange coupled to the pinned layer for pinning the magnetic moment of the pinned layer parallel to the head surface and parallel to major thin film planes of the layer of the sensor;
• forming a chrominum spacer layer located between the pinned layer and the free layer;
• and
• forming the pinned layer of only iron (Fe);
• and
• connecting first and second leads to the sensor for conducting a current through the sensor perpendicular to major planes of the layers of the sensor.

A method of making a magnetic head assembly, that has a head surface for facing a magnetic medium, comprising the steps of:

• forming a read head that includes a CPP sensor;
• a making of the CPP sensor including the steps of:
• forming an antiparallel (AP) pinned layer structure;
• forming a ferromagnetic free layer having a magnetic moment that is free to rotate in response to a field signal;
• and
• forming a material spacer layer between the free layer and the AP pinned layer structure;
• a making of the antiparallel (AP) pinned layer structure including the steps of:
• forming ferromagnetic first and second antiparallel (AP) pinned layers;
• and
• forming an antiparallel (AP) coupling layer between the first and second AP pinned layers;
• forming a first antiferromagnetic pinning layer exchange coupled to the first AP pinned layer for pinning the magnetic moment of the first AP pinned layer perpendicular to the head surface;
• forming an in-stack longitudinal biasing layer structure within a track width of the sensor;
• a making of the in-stack longitudinal biasing layer including the steps of:
• forming a ferromagnetic pinned layer with a magnetic moment;
• forming a second antiferromagnetic (AFM) pinning layer exchange coupled to the pinned layer for pinning the magnetic moment of the pinned layer parallel to the head surface and parallel to major thin film planes of the layer of the sensor;
• and
• forming a chromium spacer layer between the pinned layer and the free layer;
• and
• connecting first and second leads to the sensor for conducting a current through the sensor perpendicular to major planes of the layers of the sensor.