Thin film magnetic head with side layers under compression stress

A thin film magnetic head, comprising:

• a spin valve film that includes
• a magnetization free layer of which a magnetization direction changes according to an external magnetic field,
• a magnetization pinned layer that has a positive saturation magnetostriction constant and of which a magnetization direction with respect to the external magnetic field is oriented to a direction perpendicular to an air bearing surface, and
• a non-magnetic spacer layer that is disposed between the magnetization free aye and the magnetization pinned layer;
• and
• a pair of side layers that are disposed at both sides of the spin valve film in a track width direction and at least in the vicinity of the magnetization free layer and the magnetization pinned layer, wherein
• each of the side layers has
• a bias magnetic field application layer that includes a soft magnetic layer and applies a bias magnetic field in the track width direction to the magnetization free layer, and
• a gap layer that is positioned between the spin valve film and the bias magnetic field application laver, and
• the side layers have compression stresses at least in the vicinity of the magnetization pinned layer, wherein
• the bias magnetic field application layer includes a base material made of one of Co, Fe, and Ni, or a combination of two or more of them, and an additional material that is added to the base material and changes the base material to an amorphous or a microcrystal.

A thin film magnetic head, comprising:

• a spin valve film that includes
• a magnetization free layer of which a magnetization direction changes according to an external magnetic field,
• a magnetization pinned layer that has a positive saturation magnetostriction constant and of which a magnetization direction with respect to the external magnetic field is oriented to a direction perpendicular to an air bearing surface, and
• a non-magnetic spacer layer that is disposed between the magnetization free layer and the magnetization pinned layer;
• and
• a pair of side layers that are disposed at both sides of the spin valve film in a track width direction and at least in the vicinity of the magnetization free layer and the magnetization pinned layer, wherein
• each of the side layers has
• a bias magnetic field application layer that includes a soft magnetic layer and applies a bias magnetic field in the track width direction to the magnetization free layer, and
• a gap layer that is positioned between the spin valve film and the bias magnetic field application laver, and
• the side layers have compression stresses at least in the vicinity of the magnetization pinned layer, wherein
• the soft magnetic layer is made of a material of one, two or more of Co, Fe, and Ni,
• the bias magnetic field application layer includes at least one insert layer that is inserted to the soft magnetic layer, and
• the insert layer is able to become an amorphous or a microcrystal when the insert layer is formed as a single layer.

A thin film magnetic head, comprising:

• a spin valve film that includes
• a magnetization free layer of which a magnetization direction changes according to an external magnetic field,
• a magnetization pinned layer that has a positive saturation magnetostriction constant and of which a magnetization direction with respect to the external magnetic field is oriented to a direction perpendicular o an air bearing surface, and
• a non-magnetic spacer that is disposed between the magnetization free layer and the magnetization pinned layer;
• and
• a pair of side layers that are disposed at both sides of the spin valve film in a track width direction and at least in the vicinity of the magnetization free layer and the magnetization pinned layer, wherein
• each of the side lavers has
• a bias magnetic field application layer that includes a soft magnetic layer and applies a bias magnetic field in the track width direction o the magnetization free layer, and
• a gap layer that is positioned between the spin valve film and the bias magnetic field application layer, and
• the side layers have compression stresses at least in the vicinity of the magnetization pinned layer, wherein
• the soft magnetic layer is made of a material of one or two or more of Co, Fe, and Ni,
• the bias magnetic field application layer includes at least one insert layer inserted to the soft magnetic layer, and
• an interatomic spacing of the insert layer differs by 2.5% or more with respect to an interatomic spacing of the soft magnetic layer.

A thin film magnetic head, comprising:

• a spin valve fill that includes
• a magnetization free layer of which a magnetization direction changes according to an external magnetic field,
• a magnetization pinned layer that has a positive saturation magnetostriction constant and of which a magnetization direction with respect to the external magnetic field is oriented to a direction perpendicular to an air bearing surface, and
• a non-magnetic spacer layer that is disposed between the magnetization free layer and the magnetization pinned layer;
• and
• a pair of side layers that are disposed at both sides of the spin valve film in a track width direction and at least in the vicinity of the magnetization free layer and the magnetization pinned layer, wherein
• each of the side layers has
• a bias magnetic field application layer that includes a soft magnetic layer and applies a bias magnetic field in the track width direction to the magnetization free layer, and
• a gap layer that is positioned between the spin valve film and the bias magnetic field application layer, and
• the side layers have compression stresses at least in the vicinity of the magnetization pinned layer, further comprising:
• a shield layer that covers the pair of side layers and the spin valve film and is magnetized in the track width direction, wherein
• the soft magnetic layer magnetically connects to the shield layer and is magnetized in parallel or antiparallel to the shield layer.

A hard disk device, comprising:

• a thin film magnetic head slider that includes
• a substrate;
• and
• a thin fill magnetic head formed on the substrate, the thin film magnetic head includes
• a spin valve fill that includes
• a magnetization free layer of which a magnetization direction changes according to an external magnetic field,
• a magnetization pinned layer that has a positive saturation magnetostriction constant and of which a magnetization direction with respect to the external magnetic field is oriented to a direction perpendicular to an air bearing surface, and
• a non-magnetic spacer layer that is disposed between the magnetization aver and the magnetization pinned layer;
• and
• a pair of side layers that are disposed at both sides of the spin valve film in a track width direction and at least in the vicinity of the magnetization free layer and the magnetization pinned layer, wherein
• each of the side layers has
• a bias magnetic field application layer that includes a soft magnetic layer and applies a bias magnetic field in the track width direction to the magnetization free layer, and
• a gap layer that is positioned between the spin valve film and the bias magnetic field application layer, wherein the gap layer is made with a MgO layer, and
• the side layers have compression stresses at least in the vicinity of the magnetization pinned layer,
• wherein
• the side layer includes either one of a Ta film and a Ru film or both of the Ta film and the Ru film, being positioned between the gap layer and the bias magnetic field application layer;
• a recording medium that is positioned facing the thin film magnetic head slider;
• a spindle motor that rotatably drives the recording medium;
• and
• a positioning device that supports the thin film magnetic head slider and positions the thin film magnetic head slider with respect to the magnetic recording medium.

A thin film magnetic head slider, comprising:

• a substrate;
• and
• the thin film magnetic head formed on the substrate, the thin film magnetic head includes
• a spin valve film that includes
• a magnetization free layer of which a magnetization direction changes according to an external magnetic field,
• a magnetization pinned layer that has a positive saturation magnetostriction constant and of which a magnetization direction with respect to the external magnetic field is oriented to a direction perpendicular to an air bearing surface, and
• a non-magnetic spacer layer that is disposed between the magnetization free layer and the magnetization pinned layer;
• and
• a pair of side layers that are disposed at both sides of the spin valve film in a track width direction and at least in the vicinity of the magnetization free layer and the magnetization pinned layer, wherein
• each of the side layers has
• a bias magnetic field application layer that includes a soft magnetic layer and applies a bias magnetic field in the track width direction to the magnetization free layer, and
• a gap layer that is positioned between the spin valve film and the bias magnetic field application layer, and
• the side layers have compression stresses at least in the vicinity of the magnetization pinned layer, further comprising:
• a shield layer that covers the pair of side layers and the spin valve film and is magnetized in the track width direction, wherein
• the soft magnetic layer magnetically connects to the shield layer and is magnetized in parallel or antiparallel to the shield layer.