Abstract: In a magnetic tunnel junction (MTJ) device having a pinned layer and upper and lower antiparallel-coupled free sublayers, to avoid loss in tunnel magnetoresistance, etching or milling of the free sublayer layer materials is stopped in the lower free sublayer. The total thickness of the free sublayers may be large to ease manufacture because the effective magnetic thickness of the free layer combination may be as small as desired by appropriately establishing a small difference between the thicknesses of the AP-coupled free sublayers. A contiguous hard bias material is centered on the free sublayers for stabilization.

Abstract: A differential giant magnetoresistive sensor for sensing a magnetic signal. The differential sensor has a structure configured to minimize spin torque noise. The differential magnetoresistive sensor includes first and second magnetoresistive sensor elements and a three lead structure including an inner lead sandwiched between the first and second sensor elements and first and second outer leads. each of the sensor elements includes an antiparallel coupled free layer structure with the free layer of each of the sensor elements preferably being positioned near the inner lead. The three lead structure allows sense current to be supplied to the sensor such that electrons travel first through the free layer of each sensor element and then through the pinned layer structure.

Abstract: A current in plane giant magnetoresistive (GMR) sensor having a hard bias layer that extends along the back edge (strip height) of the sensor rather than from the sides of the sensor. The hard bias layer preferably extends beyond the track width of the sensor. Electrically conductive leads, which may be a highly conductive material such as Cu, Rh or Au, or may be an electrically conductive magnetic material extend from the sides of the sensor stack. The bias layer is separated from the sensor stack and from the leads by thin layer of electrically conductive material, thereby preventing current shunting through the hard bias layer.

Abstract: In one illustrative example, a spin valve (SV) sensor of the self-pinned type includes a free layer; an antiparallel (AP) self-pinned layer structure; and a non-magnetic electrically conductive spacer layer in between the free layer and the AP self-pinned layer structure. The AP self-pinned layer structure includes a first AP pinned layer having a first thickness; a second AP pinned layer having a second thickness; and an antiparallel coupling (APC) layer formed between the first and the second AP pinned layers. The first thickness is slightly greater than the second thickness. Configured as such, the AP pinned layer structure provides for a net magnetic moment that is in the same direction as a magnetic field produced by the sense current flow, which reduces the likelihood of amplitude flip in the SV sensor.

Abstract: A magnetoresistive sensor having a trilayer structure for improved pinning. The pinned layer is exchange coupled with a IrMnCr AFM layer, and has a three ferromagnetic layer, the center one comprising Co50Fe50 and V.

Abstract: A magnetic structure for use in a perpendicular magnetic write head that prevents magnetic domain formation and reduces magnetic remanence in the structure. The magnetic structure includes magnetic layers sandwiched between thin non-magnetic layers. Each of the magnetic layers includes a relatively thicker layer of CoFe sandwiched between relatively thinner layers of NiFe.

Abstract: A dual current perpendicular to plane (CPP) sensor having an in stack bias structure disposed between first and second free layers. The hard bias structure includes a plurality of magnetic layers antiparallel coupled with one another. At least one of the magnetic layers of the in stack bias structure includes a layer of Ni sandwiched between first and second layer of NiFe. The Ni provides a strong negative magnetostriction that sets the moment of the magnetic layer in a desired direction parallel with the ABS while the NiFe layers at either side of the Ni provide good antiparallel coupling properties, allowing the magnetic layer to be antiparallel coupled with adjacent magnetic layers of the in stack bias structure.

Abstract: Improved sensitivity GMR sensors useful for thin film magnetic read heads are disclosed. Spin transfer induced destabilization of the magnetic free layer is suppressed through the application of Tb containing alloys in the free layer. Sense currents can be increased by a factor of five in comparison to prior art designs without an increase in spin transfer induced noise.

Abstract: A current perpendicular to plane (CPP) sensor having FeN in their free and pinned layers. A tunnel junction sensor (TMR) according to the present invention can have a MgO barrier layer, and a CPP GMR sensor according to the present invention can have a Cr spacer layer.

Abstract: A magnetic tunnel transistor (MTT) having a pinned layer that has no antiferromagnetic material in an active area of the sensor. The MTT can include a layer of antiferromagnetic material that is exchange coupled with the pinned layer in an area outside of the active area of me sensor, such as outside the track-width, beyond the stripe height, or both outside the track-width and beyond the stripe height. The pinned layer can also be pinned without any exchange coupling at all. In that case, pinning can be assisted by shape enhanced magnetic anisotropy, by extending the pinned layer beyond the stripe height.

Abstract: A current perpendicular to plane (CPP) magnetoresistive sensor having an in-stack bias structure that is pinned by an AFM layer located behind the back edge (stripe height) of the sensor stack. A magnetic coupling layer is exchange coupled to the in-stack bias structure and extends beyond the back edge of the sensor stack where it is pinned by the AFM layer. The magnetic coupling layer may be either directly exchange coupled with the AFM layer or exchange coupled with an intermediate magnetic layer that is itself exchange coupled with the AFM layer. The AFM layer is located entirely beyond the stripe height of the sensor stack and between top and bottom elevations as defined by the top and bottom of the sensor stack. In this way, the AFM can pin the biasing structure without consuming any gap budget.

Abstract: In a CPP magnetic head a free magnetic layer and a magnetic biasing layer are disposed within a central layer stack. To pin the magnetization of the bias layer, an antiferromagnetic (AFM) layer is fabricated on the sides of the central stack. The AFM layer may be comprised of an electrically non-conductive AFM material such as NiO, or, where the AFM material is electrically conductive, such as PtMn or IrMn, a layer of electrical insulation is deposited to prevent the sense current from flowing through the outwardly disposed AFM layer. Portions of the bias layer are deposited upon the outwardly disposed AFM layer, such that the magnetization of the outwardly disposed portions of the bias layer are pinned by the AFM layer, which creates an effective pinning of the central portions of the bias layer. This then provides an effective biasing of the magnetization of the free magnetic layer.

Abstract: A magnetoresistive sensor having an in stack bias structure for biasing the magnetic moment of the free layer. The in stack bias structure includes a magnetic bias layer that may include a layer of NiFe and a layer of CoFe. A layer of antiferromagnetic material (AFM layer) is exchange coupled with the bias layer. Preferably, the NiFe layer of the bias layer is located adjacent to the AFM layer. A non-magnetic spacer layer is sandwiched between the free layer and the bias layer. The spacer layer comprises NiFeCr and is of such a thickness that magnetostatic coupling between the free layer and the bias layer across the spacer layer biases the magnetic moment of the free layer in a direction antiparallel to the magnetic moment of the bias layer. The NiFeCr promotes a desired crystalline growth in the bias layer that causes excellent exchange coupling between the bias layer and the AFM layer.

Abstract: A magnetic head having an in-stack bias structure and a free layer structure. The in-stack bias structure includes an antiferromagnetic layer, and first through fourth antiparallel (AP) pinned bias layers separated by three AP coupling layers. A first spacer layer is positioned above the fourth bias layer of the bias structure. A free layer is positioned above the first spacer layer. The fourth bias layer magnetostatically stabilizes the free layer.

Abstract: A magnetic head includes first and second shield layers and a read sensor formed between and in electrical contact with the first and second shield layers. The read sensor includes a free layer structure; an antiparallel (AP) self-pinned structure which includes a first AP self-pinned layer, a second AP self-pinned layer, and an AP coupling layer formed between the first and the second AP self-pinned layers; and a non-magnetic spacer layer formed between the free layer structure and the AP self-pinned structure. The first AP self-pinned layer is formed in both a central region of the read sensor and in side regions adjacent the central region. Since thermal stability of the first AP self-pinned layer is proportional to its volume, extending the first AP self-pinned layer in the side regions improves the thermal stability to reduce the likelihood of amplitude flip in the self-pinned sensor.

Abstract: A spin valve sensor in a read head has a spacer layer which is located between a self-pinned AP pinned layer structure and a free layer structure. The free layer structure is longitudinally stabilized by first and second hard bias layers which abut first and second side surfaces of the spin valve sensor. The AP pinned layer structure has an antiparallel coupling layer (APC) which is located between first and second AP pinned layers (AP1) and (AP2). The invention employs a resetting process for setting of the magnetic moments of the AP pinned layers by applying a field at an acute angle to the head surface in a plane parallel to the major planes of the layers of the sensor. The resetting process sets a proper polarity of each AP pinned layer, which polarity conforms to processing circuitry employed with the spin valve sensor.

Abstract: A magnetic tunnel transistor (MTT) having a pinned layer that is extended in a stripe height direction and is exchange coupled with an antiferromagnetic (AFM) layer in the extended portion outside of the active area of the sensor. Exchange coupling only the extended portion of the pinned layer with the AFM results in strong, robust pinning of the pinned layer while eliminating the AFM layer from the active portion of the sensor. The presence of an AFM layer within the active area of the sensor would result in an extreme loss of hot electrons resulting in a prohibitively large loss of performance. Therefore, eliminating the AFM layer from the active area provides a very large performance enhancement while maintaining robust pinning.

Abstract: A current perpendicular to plane magnetorestive sensor having an improved in stack biasing. An amorphous layer breaks the structure allowing a desire crystolographic structure in an in stack bias layer that provides greatly increased coercivity (Hc) in the bias layer.

Abstract: A current in plane giant magnetoresistive (GMR) sensor having a hard bias layer that extends along the back edge (strip height) of the sensor rather than from the sides of the sensor. The hard bias layer preferably extends beyond the track width of the sensor. Electrically conductive leads, which may be a highly conductive material such as Cu, Rh or Au, or may be an electrically conductive magnetic material extend from the sides of the sensor stack. The bias layer is separated from the sensor stack and from the leads by thin layer of electrically conductive material, thereby preventing current shunting through the hard bias layer.

Abstract: A spin valve sensor with an antiparallel coupled lead/sensor overlap region is provided comprising a ferromagnetic bias layer antiparallel coupled to a free layer in first and second passive regions where first and second lead layers overlap the spin valve sensor layers. The ferromagnetic material of the bias layer in a track width region defined by a space between the first and second lead layers is converted to a nonmagnetic oxide layer allowing the free layer in the track width region to rotate in response to signal fields from a magnetic disk.