Abstract: A method for fabricating a sensor having anti-parallel tab regions. The method includes forming a free layer having tab areas on opposite sides of an active area, forming a first layer of a carbon composition above the active area of the free layer, the first layer of carbon being substantially absent from tab areas of the free area, forming spacer layers above the tab areas of the free layer, the spacer layers being operable to make magnetic moments of ferromagnetic layers on opposite sides thereof antiparallel, forming bias layers above the spacer layers, the bias layers being operative to substantially pin magnetic moments of the tab areas of the free layer, forming second layers of carbon composition above the tab areas of the free layer, and removing the layers of carbon composition and any portions of the layers overlying the layers of carbon composition.

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 method and apparatus for providing a magnetic read sensor having a thin pinning layer and improved magnetoresistive coefficient ?R/R is disclosed. A thin IrMn alloy pinning layer is disposed adjacent a composite pinned layer, wherein the percentage of iron in the pinned layer adjacent the thin IrMn alloy pinning layer in the range of 20-40% to provide maximum pinning.

Abstract: A method for providing a self-pinned differential GMR sensor and self-pinned differential GMR sensor. The differential GMR head includes two self-pinned GMR sensors separated by a gap layer. The gap layer may act as a bias structure to provide antiparallel magnetizations for the first and second free layers without using an antiferromagnetic layer. The gap layer may include four NiFe ferromagnetic layers separated with three interlayers. The gap may also be formed to include a structure defined by Ta/Al2O3/NiFeCr/CuOx. One of the pinned layer may include three ferromagnetic layers so that the top ferromagnetic layer of the bottom pinned layer and the bottom ferromagnetic layer of the bottom pinned layer have a magnetization 180° out of phase. The self-pinned GMR sensors may include synthetic free layers that includes a first free sublayer, an interlayer and a second free sublayer that are biased 180° out of phase.

Abstract: A method for manufacturing a magnetoresistive sensor having improved free layer biasing and track width control. The method includes forming a ferromagnetic pinned layer, and depositing a ferromagnetic film thereover. A layer of Ta is deposited over the ferromagnetic film and a mask is formed over an active sensor area. A reactive ion etch process is performed to remove selected portions of said Ta layer. An etch is then performed to remove selected portions of the ferromagnetic film in unmasked areas and a ferromagnetic refill material is deposited.

Abstract: Magnetoresistive (MR) elements having flux guides defined by the free layer are disclosed. The MR element includes a free layer, a spacer/barrier layer, a pinned layer, and a pinning layer. A back edge of the free layer (opposite the sensing surface of the MR element) extends past a back edge of the spacer/barrier layer. The portion of the free layer extending past the back edge of the spacer/barrier layer defines a continuous flux guide. The flux guide is processed to reduce the conductive characteristics of the flux guide, thereby reducing current shunt loss in the flux guide.

Abstract: Dual-type tunneling magnetoresistance (TMR) elements and associated methods of fabrication are disclosed that allow for higher bias voltages. In one embodiment, the dual-type TMR element includes a lower pinned layer structure, a lower tunnel barrier layer, a ferromagnetic free layer structure, an upper tunnel barrier layer, and an upper pinned layer structure. The lower pinned layer structure has a first Fermi level, while the upper pinned layer structure has a second Fermi level that is different than the first Fermi level of the lower pinned layer structure. By having different Fermi levels, the bias voltage induced in the TMR element may advantageously be increased without a significant reduction in TMR.

Abstract: A current perpendicular to plane (CPP) magnetoresistive sensor having a front edge that is recessed from the air bearing surface (ABS). The sensor includes a pinned layer structure a free layer structure and a spacer layer sandwiched between the free layer and the pinned layer. The free layer is an AP coupled structure that includes a first magnetic layer F1 a second magnetic layer F2 and a coupling layer sandwiched between F1 and F2. The first magnetic layer F1 extends to the ABS while the other sensor layers terminate at the recessed front edge. In this way, the F1 layer acts as a flux guide that reacts to a magnetic field from a magnetic medium. The AP coupled structure of the free layer allows each magnetic layer F1 and F2 to be thicker than would be possible in a conventional single layer free layer, which increases the GMR effect of the sensor and increases the effectiveness of the flux guide (F2).

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: A method and apparatus for using a specular scattering layer in a free layer of a magnetic sensor while stabilizing the free layer by direct coupling with an antiferromagnetic layer is disclosed. A specular scattering layer is formed in a free layer of a magnetic sensor while stabilizing the free layer by direct coupling with an antiferromagnetic layer. An antiferromagnetic layer is formed abutting the free layer to provide direct exchange coupling with the free layer. The specular layer in the free layer removes any ?R degradation caused by placement of an antiferromagnetic layer over the free 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: Apparatus and method for providing a magnetic head that includes a magnetoresistive read sensor disposed between first and second magnetic shields. The shields are configured to reduce protrusion of the shields from a polished flat air bearing surface of the magnetic head upon increases in temperature. This configuration for the shields therefore at least reduces differences in thermal expansion of the shields relative to other parts of the magnetic head forming the air bearing surface. These shields according to some embodiments include one or more ferromagnetic layers exchange coupled with an antiferromagnetic layer. Further, in a particular embodiment, all the ferromagnetic layers within each of the shields can have a combined thickness per shield of less than 500 angstroms.

Abstract: A method and apparatus for providing improved pinning structure for tunneling magnetoresistive sensor is disclosed. A three layer pinned structure is used, wherein the second pinned layer is designed to balance the effects of the first and third pinned layers.

Abstract: In a magnetic tunnel junction (MTJ) device having a pinned layer and upper and lower free sublayers, to avoid loss in tunnel magnetoresistance, etching or milling of the free sublayer materials is stopped in the lower free sublayer. The upper free sublayer may be softer and thicker than the lower free sublayer to promote this, and may be doped to reduce its magnetization while maintaining physical thickness. The lower free sublayer can be made of CoFe and the upper free sublayer can made of NiFe and a dopant such as Mo or Rh.

Abstract: A magnetic tunnel transistor (MTT) for a disk drive read head includes a barrier of TiO disposed between a ferromagnetic collector and a ferromagnetic base for preferentially selecting only “hot” electrons for propagation to the collector.

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: Magnetoresistive (MR) elements having pinning layers formed from a permanent magnetic material are disclosed. An MR element of the invention includes a first pinning layer, a first pinned layer, a first spacer/barrier layer, a free layer, a second spacer/barrier layer, a second pinned layer, and a second pinning layer. One of the first pinning layer or the second pinning layer is formed from a permanent magnetic material, such as CoPt or CoPtCr. The other of the first pinning layer or the second pinning layer is formed from an antiferromagnetic (AFM) material, such as IrMn or PtMn.

Abstract: Magnetoresistive (MR) elements are disclosed that include pinned layers having canted magnetic moments. An MR element of the invention includes a first pinning layer, a first pinned layer, a first spacer/barrier layer, a free layer, a second spacer/barrier layer, a second pinned layer, and a second pinning layer. The first pinned layer has a canted magnetic moment. By having a canted magnetic moment, the first pinned layer acts as a bias layer to bias the free layer, and acts as a reference layer to enhance the MR signal in the MR element.

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 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.