Abstract: Magnetic heads capable of recording and reading with high sensitivity and resolution are provided by minimizing the outflow of magnetic fluxes from a flux guide to magnetic shields while using a flux guide structure for an MR element. In the magnetic head, magnetic shields exposed on a surface opposite a magnetic recording medium (air bearing surface) and a flux guide exposed between the magnetic heads via a non-magnetic layer are provided, and magnetic fluxes are guided by the flux guide to a magnetoresistive (MR) element formed in a position not exposed on the air bearing surface. The height of the magnetic shields in direction perpendicular to the air bearing surface is less than the distance from the air bearing surface to the MR element.

Abstract: A thin film head comprising a GMR element formed of an antiferromagnetic layer, a pinning layer, a nonmagnetic conductive layer and a free magnetic layer; and a pair of the right and the left laminated longitudinal biasing layers, each of the layers containing a hard magnetic layer, a nonmagnetic layer and a soft magnetic layer provided on said free magnetic layer of GMR element. Said hard magnetic layer and said soft magnetic layer are antiferromagnetically exchange-coupled via said nonmagnetic layer, and said hard magnetic layer and said free magnetic layer locating next to said hard magnetic layer are ferromagnetically coupled. The present invention contains also a method for manufacturing the thin film head.

Abstract: Conventional liftoff processes used to define track width in magnetic read heads can produce an uneven etch-depth of dielectric materials around the sensor and cause shorting to the overlay top lead layer. This problem has been overcome by printing the images of track width and stripe height onto an intermediate layer to form a hard mask. Through this hard mask, the GMR stack can be selectively etched and then back-filled with a high-resistivity material by using newly developed electroless plating processes.

Abstract: Patterned, longitudinally and transversely antiferromagnetically exchange biased GMR sensors are provided which have narrow effective trackwidths and reduced side reading. The exchange biasing significantly reduces signals produced by the portion of the ferromagnetic free layer that is underneath the conducting leads while still providing a strong pinning field to maintain sensor stability. In the case of the transversely biased sensor, the magnetization of the free and biasing layers in the same direction as the pinned layer simplifies the fabrication process and permits the formation of thinner leads by eliminating the necessity for current shunting.

Abstract: A method and system for forming a microscopic transducer are described. The method and system include forming a plurality of adjoining sensor layers. The sensor layers include a first magnetically soft layer, a nonmagnetic layer on the first magnetically soft layer, and a second magnetically soft layer on the nonmagnetic layer. The method and system also include forming a sidewall over the second magnetically soft layer. The sidewall formation includes forming a base having a surface oriented substantially perpendicular to the sensor layers and depositing an electrically conductive material on the surface. The method and system also include removing a portion of the sensor layers not covered by the sidewall.

Abstract: The method of making a thin-film magnetic head in accordance with the present invention forms a cover layer on an insulating layer about a magnetoresistive film so as to eliminate a protrusion riding on the magnetoresistive film. Then, the protrusion can be eliminated by etching. The part of insulating layer clad with the cover layer is not etched. This can prevent short-circuit from occurring because of thinning the insulating layer.

Abstract: A method for manufacturing a magnetic recording medium, including the steps of applying a magnetic coating containing ferromagnetic powder and a binder onto a nonmagnetic band-shaped flexible base material to be transferred to form a magnetic layer, and grinding the magnetic layer continuously with a grinding wheel on the downstream side of transfer, wherein a cleaning device which cleans a grindstone of the grinding wheel is additionally provided in close proximity of the grinding wheel to clean the grindstone during the grinding operation.

Abstract: On a surface of a bottom pole, a write gap film and first magnetic material film having a high saturation magnetic flux density are formed, and the first magnetic material film is etched to remain a portion extending from an air bearing surface to a throat height zero reference position and a first non-magnetic film is formed in a removed portion. The first non-magnetic material film is polished to obtain a flat surface which is coplanar with a surface of the first magnetic material film. A second magnetic material film having a high saturation magnetic flux density is formed on the flat surface. The second magnetic material film, first magnetic material film, write gap film and bottom pole are partially removed by RIE using a mask formed on the flat surface.

Abstract: A thin film magnetic head that includes an improved P2 pole tip/yoke interface. The process for forming the P2 pole tip/yoke interface includes a CMP polishing step that is performed on the surface of the wafer subsequent to the plating of the P2 pole tip. This CMP step utilizes a relatively soft polishing pad and an acidic polishing slurry which preferentially attacks the P2 pole tip material, such that the CMP step results in the recession of the upper surface of the P2 pole tip relative to the dielectric layer surrounding it, as well as the significant rounding of the upper edges of the dielectric trench in which the P2 pole tip is formed. Thereafter, when the yoke is plated onto the P2 pole tip the rounded upper edges of the dielectric trench result in a concave curved interface between the yoke and the P2 pole tip.

Abstract: A non-magnetic material layer which is formed with a taper region of which the film thickness is gradually reduced over the top surface and the side of an upper core layer and the side of the gap layer is formed by cutting the gap layer and the upper core layer on a lower core layer with a track width and the lower periphery of the taper region is contacted with the top surface of the lower core layer. On the top surface of the lower core layer extending from the lower periphery of the taper region to the both sides, the slopes inclined in the direction apart from the upper core layer are formed and a protrusion having a track width is formed on the lower core layer. The material layer having the same material as the lower core layer adhered to the outside of the non-magnetic material layer is removed.

Abstract: A method of manufacturing a thin film magnetic head. The method includes forming, near a pole portion: a first magnetic layer supported by a base substrate; a first insulating layer on the first magnetic layer with an end edge which forms a reference position for an air bearing surface; a gap layer on the pole portion of the first magnetic layer and the first insulation layer; a second magnetic layer that extends to a region beyond the pole portion; a thin film coil isolated by a second insulation layer located above the first insulation layer; a third magnetic layer on the second insulation layer. The air bearing surface is formed by grinding in part an end face of the pole portion of the first magnetic layer and an end face of the pole portion of the second magnetic layer and the gap layer placed therebetween.

Abstract: A GMR bottom spin valve sensor longitudinally exchange biased with a zero net magnetic moment biasing multi-layer is provided, together with a method of forming said sensor. The sensor may be additionally biased with a hard biasing layer formed against an abutted junction. The exchange biasing provides the advantages of a highly sensitive free layer in the bottom spin valve sensor element, while producing very strong exchange pinning of the lateral ends of the free layer. The zero net magnetic moment assures stability in the lateral edge and central region of the free layer.

Abstract: A method and materials to fabricate a trailing shield write pole that resolve the problems of controlling the write gap and preventing damages to the write gap or pole during fabrication of the subsequent structure. This process also introduces a CMP assisted lift-off process to remove re-deposition and fencing (increase yields) and a method to create dishing in the top of the write pole. Moreover, also included in this disclosure are suitable materials that can function as an ion mill transfer layer, CMP layer, and RIEable layer.

Abstract: A method of manufacturing a magnetic head device includes forming a thin film magnetic head element over a substrate, the thin film magnetic head element including a magnetoresistance (MR) element. The substrate is cut such that the MR element is exposed on a side surface of the substrate. The side surface is then polished. Afterward, a magnetically degenerated layer is removed from the thin film magnetic head element along the side surface. It is emphasized that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

Abstract: In a method of fabricating a giant magnetoresistive (GMR) device a plurality of magnetoresistive device layers is deposited on a first silicon nitride layer formed on a silicon oxide layer. An etch stop is formed on the magnetoresistive device layers, and a second layer of silicon nitride is formed on the etch stop. The magnetoresistive device layers are patterned to define a plurality of magnetic bits having sidewalls. The second silicon nitride layer is patterned to define electrical contact portions on the etch stop in each magnetic bit. The sidewalls of the magnetic bits are covered with a photoresist layer. A reactive ion etch (RIE) process is used to etch into the first silicon nitride and silicon oxide layers to expose electrical contacts. The photoresist layer and silicon nitride layers protect the magnetoresistive layers from exposure to oxygen during the etching into the silicon oxide layer.

Abstract: A major problem in Lead Overlay design for GMR structures is that the magnetic read track width is wider than the physical read track width. This is due to high interfacial resistance between the leads and the GMR layer which is an unavoidable side effect of prior art methods. The present invention uses electroplating preceded by a wet etch to fabricate the leads. This approach requires only a thin protection layer over the GMR layer to ensure that interface resistance is minimal. Using wet surface cleaning avoids sputtering defects and plating is compatible with this so the cleaned surface is preserved Only a single lithography step is needed to define the track since there is no re-deposition involved.

Abstract: Methods are provided for forming current perpendicular to the plane thin film read heads. In one embodiment, the method comprises the steps of forming a lower sensor lead, forming a lower sensor lead cladding of a low sputter yield material on the lower sensor lead, forming a sensor element on the lower sensor lead cladding, and forming an upper sensor lead coupled to the sensor element. The low sputter yield material helps to reduce redeposition of the lower sensor lead material onto side walls of the sensor element as the sensor element is being formed.

Abstract: A method for improving hard bias properties of layers of a magnetoresistance sensor is disclosed. Properties of the hard bias layer are improved using a seedlayer structure that includes at least a first layer of silicon and a second layer comprising chromium or chromium molybdenum. Further, benefits are achieved when the seedlayer structure includes a layer of tantalum.

Abstract: A method for manufacturing a magnetic recording head includes the steps of forming a first lifting layer and a second lifting layer on a bottom core layer, forming an inorganic insulating layer in a gap between the first lifting layer and the second lifting layer, forming a groove in the inorganic insulating layer to form a coil layer, and forming the coil layer in the groove and over the groove by plating.

Abstract: A first and a second longitudinal bias-applying films are formed via a first mask at both sides of a magnetoresistive effective element film so that the difference in surface level between the magnetoresistive effective element film and the first and the second longitudinal bias-applying films is set within ±20 nm. Then, a first and a second electrode films are formed so as to cover edge portions of the magnetoresistive effective element film and the first and the second longitudinal bias-applying films.

Abstract: A magnetoresistive thin film head comprises a magnetoresistive element including an antiferromagnetic layer, a pinned layer, a nonmagnetic conductive layer and a free magnetic layer, and a pair of the right and the left laminated transverse biasing layers, each including a nonmagnetic layer, a ferromagnetic layer and an antiferromagnetic layer, provided on the free magnetic layer constituting said magnetoresistive element. The layer thickness of said nonmagnetic layer has been established to a certain specific value so that magnetizing direction in said free magnetic layer opposing to the ferromagnetic layer via said nonmagnetic layer assumes a direction that is opposite to that of said ferromagnetic layer.

Abstract: A magnetic tunnel junction (MTJ) sensor in which the free layer longitudinal biasing elements are coupled, without insulation, to the free layer outside of the MTJ stack to provide reliable non-shunting MTJ free layer stabilization without extremely thin dielectric layers. In one embodiment, hard magnetic (HM) layers are disposed in contact with the free layer outside of and separated from the MTJ stack active region by a thick dielectric layer. In another embodiment, antiferromagnetic (AFM) bias layers are disposed in contact with the free layer outside of and separated from the MTJ stack active region by a thick dielectric layer. In other embodiments, nonconductive HM layers are disposed either in contact with the free layer outside of the MTJ stack active region and/or in abutting contact with the MTJ stack active region.

Abstract: A method for producing a magnetic head, including the steps of forming a magnetic body on a substrate, the magnetic body including a principal plane facing the substrate and a rear plane opposite to the principal plane; applying a beam to the rear plane of the magnetic body and forming a portion defining a hole extending from the rear plane to the principal plane; forming a magnetic gap in the hole; and separating the magnetic body and the magnetic gap from the substrate and forming medium facing surface substantially coplanar with the principal plane.

Abstract: A method of making a magnetic head includes imbedding a coil layer in an insulation stack. The coil layer is formed with a filament that extends about a central axis. The central axis is perpendicular to a planar head surface and a coil plane. First and second pole pieces are formed with the insulation stack sandwiched between the first and second pole pieces. A first shield layer having first and second major planar thin film surfaces is joined by a third edge with the first major planar thin film surface of the first shield layer forming a portion of the planar head surface. A magnetoresistive (MR) sensor and first and second gap layers are formed with the MR sensor sandwiched between the first and second gap layers and the first and second gap layers located between the third edge and the first horizontal component and with the MR sensor and the first and second gap layers forming portions of the planar head surface.

Abstract: A beveled writing pole includes a top portion, a beveled portion, and a throat portion. The top portion has an end that defines a writing pole tip. The beveled portion adjoins the top portion and has a bevel that extends from the writing pole tip and increases a thickness of the writing pole proximate the pole tip. The throat portion is formed of the top and beveled portions and has tapered sides that extend from the writing pole tip and increase a width of the writing pole proximate the writing pole tip. A method of forming the beveled writing pole is also presented.

Abstract: A problem associated with current bottom spin valve designs is that it is difficult to avoid magnetic charge accumulation at the edge of the sensor area, making a coherent spin rotation during sensing difficult to achieve. This problem has been eliminated by introducing an exchange coupling layer between the free layer and the ferromagnetic layer that is used to achieve longitudinal bias for stabilization and by extending the free layer well beyond the sensor area. After all layers have been deposited, the read gap is formed by etching down as far as this layer. Since it is not critical exactly how much of the biasing layers (antiferromagnetic as well as ferromagnetic) are removed, the etching requirements are greatly relaxed. Whatever material remains in the gap is then oxidized thereby providing a capping layer as well as a good interface for specular reflection in the sensor region.

Abstract: The object of the invention is to provide a thin film magnetic head and a method of manufacturing the same, which allow the magnetic pole width to be precisely controlled and a sufficient overwrite performance to be attained even in a case where the magnetic pole width is microfabricated. The coupling position where the intermediate portion and the tip of the top pole are coupled each other is located closer to the air bearing surface than the throat height 0 position (TH0 position) which is the reference point for determining the throat height TH. The tip of the top pole defines the write track width on a recording medium. At least the portion of the intermediate portion from the TH0 position to the rear edge portion of the tip has a width wider than that of the tip. The intermediate portion suppresses saturation of the magnetic flux before flowing into the tip of the top pole.

Abstract: There is provided a magnetoresistive head which can realize high sensitivity and low noise even when the reading track is being reduced. Longitudinal biasing is performed to a ferromagnetic free layer whose magnetization is rotated according to an external magnetic field by providing unidirectional magnetic anisotropy by exchange coupling to an antiferromagnetic layer. A hard magnetic film is arranged at the edge of a magnetoresistive film to reduce an effective reading track width.

Abstract: Currently, the shield-to-shield separation of a spin valve head cannot be below about 800 ?, mainly due to sensor-to-lead shorting problems. This problem has now been overcome by a manufacturing method that includes inserting a high permeability, high resistivity, thin film shield on the top or bottom (or both) sides of the spin valve sensor. A permeability greater than about 500 is required together with a resistivity about 5 times greater than that of the free layer and an MrT value for the thin film shield that is 4 times greater than that of the free layer.

Abstract: A method of fabricating a thin film magnetic recording head including a perpendicular recording head having an auxiliary pole, a main pole and a shield against an external magnetic field. The shield against the external magnetic field is formed so that an edge of the shield against the external magnetic field is disposed at a position recessed at least from an edge of the main pole relative to a surface against a medium.

Abstract: A manufacturing method of an MR sensor including a step of stacking an anti-ferromagnetic layer made of an electrically conductive anti-ferromagnetic material, a step of stacking a pinned layer on the anti-ferromagnetic layer, a step of stacking a nonmagnetic spacer layer on the pinned layer, a step of exposing at least once a surface of the nonmagnetic spacer layer to an oxygen-contained atmosphere, a step of stacking a free layer on the nonmagnetic spacer layer, a magnetization direction of the free layer being free depending upon a magnetic filed applied thereto, and a step of providing the pinned layer a magnetization direction fixed by an exchange coupling between the anti-ferromagnetic layer and the pinned layer.

Abstract: A magnetoresisive device comprises: an MR element having two surfaces that face toward opposite directions and two side portions that face toward opposite directions; two bias field applying layers that are located adjacent to the side portions of the MR element and apply a longitudinal bias magnetic field to the MR element; and two electrode layers that are located adjacent to one of the surfaces of each of the bias field applying layers and feed a sense current to the MR element. The electrode layers overlap the one of the surfaces of the MR element. The magnetoresistive device further comprises two nonconductive layers that are located between the one of the surfaces of the MR element and the two electrode layers and located in two regions that include ends of the MR element near the side portions thereof, the two regions being parts of the region in which the electrode layers face toward the one of the surfaces of the MR element.

Abstract: Currently, the shield-to-shield separation of a spin valve head cannot be below about 800 ?, mainly due to sensor-to-lead shorting problems. This problem has now been overcome by inserting a high permeability, high resistivity, thin film shield on the top or bottom (or both) sides of the spin valve sensor. A permeability greater than about 500 is required together with a resistivity about 5 times greater than that of the free layer and an MrT value for the thin film shield that is 4 times greater than that of the free layer. Five embodiments of the invention are described.

Abstract: A thin-film magnetic head comprises a top pole layer incorporating a throat height defining layer, an intermediate layer, and a yoke portion layer. The yoke portion layer includes a track width defining portion for defining the track width. Each of the throat height defining layer, the intermediate layer, and the track width defining portion has a width equal to the track width. The length of the intermediate layer is greater than the length of the throat height defining layer, and the length of the yoke portion layer is greater than the length of the intermediate layer, each of the lengths being taken in the direction orthogonal to the air bearing surface.

Abstract: One illustrative method of fabricating magnetic write heads includes the acts of forming a pole tip structure at least partially over a magnetic shaping layer; forming non-magnetic materials around and over the pole tip structure; etching side shield voids within the non-magnetic materials adjacent the pole tip structure while leaving non-magnetic materials around the pole tip structure; electroplating side shield materials within the side shield voids; and forming, over the non-magnetic materials above the pole tip structure, trailing shield materials which connect with the side shield materials adjacent the pole tip structure. Preferably, the non-magnetic materials are etched with use of a reactive ion etching (RIE) process.

Abstract: A first magnetic film is formed in a primary pattern which is larger than its definitive pattern and of which edges are located within frames to be used in a frame-plating method for the second magnetic film after forming the first pole portion and the gap film. Then, the second magnetic film is formed by the frame-plating method, and the first magnetic film is etched into the definitive pattern through the second magnetic film as a mask.

Abstract: In a method of manufacturing a thin-film magnetic head, a bottom pole layer is formed and a thin-film coil is formed on the bottom pole layer. A recording gap layer is then formed on the pole portion of the bottom pole layer. Next, the recording gap layer and a portion of the bottom pole layer are selectively etched through the use of a mask so as to form an end portion of the recording gap layer for defining the throat height. Next, a nonmagnetic layer is formed to fill the etched portions of the recording gap layer and the bottom pole layer while the mask is left unremoved. Next, the mask is removed, and the top surfaces of the recording gap layer and the nonmagnetic layer are flattened by polishing. A top pole layer is formed on the flattened top surfaces of the recording gap layer and the nonmagnetic layer.

Abstract: Currently, the shield-to-shield separation of a spin valve head cannot be below about 800 ?, mainly due to sensor-to-lead shorting problems. This problem has now been overcome by inserting a high permeability, high resistivity, thin film shield on the top or bottom (or both) sides of the spin valve sensor. A permeability greater than about 500 is required together with a resistivity about 5 times greater than that of the free layer and an MrT value for the thin film shield that is 4 times greater than that of the free layer. Five embodiments of the invention are described.

Abstract: Longitudinal biasing of a free layer in a current perpendicular to the planes of the layers (CPP) type of sensor in a read head is implemented by pinning magnetic moments of first and second side portions of the free layer beyond the track width of the read head with first and second insulating antiferromagnetic (AFM) layers which are exchange coupled thereto. The pinning of the magnetic moments of the first and second side portions of the free layer pin and longitudinally bias the central active portion of the free layer within the track width so that the central portion of the free layer is magnetically stable.

Abstract: A magnetic sensing element with improved magnetic detection output and a method for making the same are provided. In the magnetic sensing element, the length of an upper pinned magnetic layer an upper antiferromagnetic layer in a track width direction is larger than the length of a free magnetic layer in the track width direction. In making the magnetic sensing element, there is no need to remove side portions of the upper pinned magnetic layer and the upper antiferromagnetic layer. The materials of the upper pinned magnetic layer and the upper antiferromagnetic layer are thus prevented from redepositing on two side faces of the free magnetic layer during milling.

Abstract: Present processes used for planarizing a cavity filled with a coil and hard baked photoresist require that a significant amount of the thickness of the coils be removed. This increases the DC resistance of the coil. In the present invention, cavity and coil are overfilled with photoresist which is then hard baked. A layer of alumina is then deposited onto the surface of the excess photoresist, following which CMP is initiated. The presence of the alumina serves to stabilize the photoresist so that it does not delaminate. CMP is terminated as soon as the coils are exposed, allowing their full thickness to be retained and resulting in minimum DC resistance.

Abstract: A current-perpendicular-to the-plane (CPP) magnetoresistive device, such as a magnetic tunnel junction (MTJ), is formed by patterning a capping layer (e.g., using resist) in the shape of a central region of an underlying free ferromagnetic layer that in turn resides over additional layers of the MTJ. Side regions of the capping layer are removed by ion milling or etching down into the free ferromagnetic layer. Unmasked side regions of the ferromagnetic layer are then oxidized to render them locally non-ferromagnetic and electrically insulating.

Abstract: A method of fabricating a current-perpendicular-to-plane (CPP) giant magnetoresistive (GMR) sensor stack, wherein the parasitic resistance of the high-resistance antiferromagnetic (AFM) pinning layer is effectively reduced by enlarging its surface area and forming between it and the remainder of the sensor stack an equal area, contiguous, thin, highly conductive ferromagnetic layer, the current channeling (CCL) layer. The magnetic properties and increased current carrying capacity of the CCL allows the AFM pinning layer to effectively couple to the pinned layer while eliminating the effect of its high resistance on the sensor sensitivity as measured by the GMR ratio, ?R/R.

Abstract: A magnetoresistive sensor for use in a data storage device has a recessed sensing element (magnetic tunnel junction, CPP spin valve, etc.) with an exchange biased sensing ferromagnetic (free) layer, and a flux guide that magnetically connects the sensing element to a sensing surface of the sensor. The free layer is selectively exchange biased by a layer of exchange bias material placed under non-active regions of the free layer that lie outside the sensing element and flux guide track widths. The flux guide is provided by extending the free layer from a forward edge of the sensing element to the sensor surface. Advantageously, the sensing element and the flux guide have equal track width so that magnetic flux directed from the flux guide into the sensing element is not diluted with consequent loss of sensitivity.

Abstract: A method and apparatus for providing precise control of magnetic coupling field in NiMn top spin valve heads and amplitude enhancement is disclosed. The magnetic coupling between free and pinned layers in NiMn top spin valve heads is precisely controlled by employing the surface oxidation of Cu seed layer or/and Cu spacer layer that improve both the interfacial quality and the crystalline texture. According to the present invention the magnitude of coupling field can be precisely controlled without affecting resistance, and the amplitude of giant magneto-resistive(GMR) heads is improved by 15% at the same coupling field without affecting asymmetry performance. Thus, the present invention improves not only the interfacial roughness, but also improves the magnetic layer texture. The oxidation of Cu seed layer in the NiMn top spin valve structure provides more robust process with good control in coupling field that affects asymmetry of a GMR head.

Abstract: A method of manufacturing a thin-film magnetic head may include forming a first magnetic layer, a thin-film coil, an insulating layer, a gap layer, and a second magnetic layer. The first magnetic layer may be formed to include a first pole portion and a first yoke portion. The second magnetic layer may be formed to include a second pole portion and a second yoke portion. At least part of the thin-film coil may be located on a side of the first pole portion and between the gap layer and the first yoke portion, and may be covered with the gap layer. A surface of the first pole portion that faces toward the gap layer and a surface of the insulating layer that faces toward the gap layer may together form one flat surface. An interface region between the second pole portion and the second yoke portion may be formed to face toward the one flat surface.

Abstract: The method of manufacturing a magnetic head is capable of correctly setting a raw bar, which includes small sliders, on to a supporting jig, machining the raw bars precisely and improving yield of manufacturing sliders. The method comprises the steps of forming a magnetizable layer, on a surface of a substrate whose thickness is greater than a length of said slider; and cutting said wafer into a raw bar after forming the layers.

Abstract: An antiferromagnetic stabilization scheme is employed in a magnetic head for magnetically stabilizing a free layer of a spin valve. This is accomplished by utilizing an antiferromagnetic oxide film below a spin valve sensor in a read region and first and second lead layers in end regions and a ferromagnetic film in each of the lead layers that exchange couples to the antiferromagnetic oxide film in the end regions. The ferromagnetic films are pinned with their magnetic moments oriented parallel to an air bearing surface (ABS) of the magnetic head. The ferromagnetic film magnetostatically couples to the free layer which causes the free layer to be in a single magnetic domain state. Accordingly, when the free layer is subjected to magnetic incursions from a rotating disk in a disk drive, the free layer maintains a stable magnetic condition so that resistance changes of the free layer are not altered by differing magnetic conditions of the free layer.

Abstract: Although it is known that exchange bias can be utilized in abutted junctions for longitudinal stabilization, a relatively large moment is needed to pin down the sensor edges effectively. Due to the inverse dependence of the exchange bias on the magnetic layer thickness, a large exchange bias has been difficult to achieve by the prior art. This problem has been solved by introducing a structure in which the magnetic moment of the bias layer has been approximately doubled by pinning it from both above and below through exchange with antiferromagnetic layers. Additionally, since the antiferromagnetic layer is in direct abutted contact with the free layer, it acts directly to help stabilize the sensor edge, which is an advantage over the traditional magnetostatic pinning that had been used.

Abstract: A patterned, synthetic, longitudinally exchange biased GMR sensor is provided which has a narrow effective trackwidth and reduced side reading. The advantageous properties of the sensor are obtained by satisfying a novel relationship between the magnetizations (M) of the ferromagnetic free layer (F1) and the ferromagnetic biasing layer (F2) which enables the optimal thicknesses of those layers to be determined for a wide range of ferromagnetic materials and exchange coupling materials. The relationship to be satisfied is MF2/MF1=(Js+Jex)/Js, where Js is the synthetic coupling energy between F1 and F2 and Jex is the exchange energy between F2 and an overlaying antiferromagnetic pinning layer. An alternative embodiment omits the overlaying antiferromagnetic pinning layer which causes the relationship to become MF2/MF1=1.