Abstract: A method is provided for inhibiting corrosion in a layer of Cu or other material in a GMR sensor, wherein the GMR sensor may be used in a magnetic data storage system such as a tape drive system to substantially improve read head sensitivity. The GMR sensor comprises stacked layers of ferromagnetic and non-magnetic materials. In one useful embodiment, a layer of Cu material is positioned between first and second layers of a specified ferromagnetic material, such as CoFe. Respective end surfaces of the Cu layer and first and second CoFe layers are initially located in substantially co-planar relationship with one another, in a common plane. The method further comprises etching the Cu layer to remove an amount of material therefrom. A new end surface is thus formed in the Cu layer, wherein the new end surface is selectively spaced apart from the common plane. A protective coating is then applied to the new end surface of the Cu layer, to inhibit corrosion of such layer.

Abstract: There is provided a practical magnetoresistance effect element which has an appropriate value of resistance, which can be sensitized and which has a small number of magnetic layers to be controlled, and a magnetic head and magnetic recording and/or reproducing system using the same. In a magnetoresistance effect element wherein a sense current is caused to flow in a direction perpendicular to the plane of the film, if a pinned layer and a free layer have a stacked construction of a magnetic layer and a non-magnetic layer or a stacked construction of a magnetic layer and a magnetic layer, it is possible to provide a practical magnetoresistance effect element which has an appropriate value of resistance, which can be sensitized and which has a small number of magnetic layers, while effectively utilizing the scattering effect depending on spin.

Abstract: A read sensor with a uniform longitudinal bias (LB) stack is proposed. The read sensor is a giant magnetoresistance (GMR) sensor used in a current-in-plane (CIP) or a current-perpendicular-to-plane (CPP) mode, or a tunneling magnetoresistance (TMR) sensor used in the CPP mode. The transverse pinning layer of the read sensor is made of an antiferromagnetic Pt—Mn, Ir—Mn or Ir—Mn—Cr film. In one embodiment of this invention, the uniform LB stack comprises a longitudinal pinning layer, preferable made of an antiferromagnetic Ir—Mn—Cr or Ir—Mn film, in direct contact with and exchange-coupled to sense layers of the read sensor. In another embodiment of the present invention, the uniform LB stack comprises the Ir—Mn—Cr or Ir—Mn longitudinal pinning layer exchange coupled to a ferromagnetic longitudinal pinned layer, and a nonmagnetic antiparallel-coupling spacer layer sandwiched between and the ferromagnetic longitudinal pinned layer and the sense layers.

Abstract: A method to fabricate a tunneling magnetoresistive (TMR) read transducer is disclosed. An insulative layer is deposited on a wafer substrate, and a bottom lead is deposited over the insulative layer. A laminated TMR layer, having a plurality of laminates, is deposited over the bottom lead. A TMR sensor having a stripe height is defined in the TMR layer, and a parallel resistor and first and second shunt resistors are also defined in the TMR layer. A top lead is deposited over the TMR sensor. The parallel resistor is electrically connected to the bottom lead and to the top lead. The first shunt resistor is electrically connected to the bottom lead and the wafer substrate, and the second shunt resistor is electrically connected to the top lead and the wafer substrate.

Abstract: An apparatus includes a magnetically biased multilayer structure having a reference layer and a free layer separated by a spacer layer; a DC current source connected to the multilayer structure; an AC current source connected to the multilayer structure; and a phase detector for measuring a phase difference between an AC current and a voltage across the multilayer structure. A method performed by the apparatus is also provided.

Abstract: Disclosed is a CPP type giant magnetoresistance device (10, 20, 50) capable of exhibiting a giant magnetoresistance effect by spin dependent current in a direction perpendicular to a film plane as well as magnetic components and units using the device. The CPP type giant magnetoresistance device has a multi-layered structure of an antiferromagnetic layer (9), a ferromagnetic fixed layer (11, 11A), a nonmagnetic conductive layer (12) and a ferromagnetic free layer (13, 13A) wherein the ferromagnetic free layer (13, 13A) has a first magnetic layer (14, 14A) and a second magnetic layer (16, 16A) magnetically coupled together antiparallel to each other via a magnetic coupler (15, 15A) and formed to have different magnitudes of magnetization (17, 17?; 18, 18A) from each other.

Abstract: A magnetoresistive sensor having a self biased free layer. The free layer is constructed upon an underlayer that has been treated by a surface texturing process that configures the underlayer with an anisotropic roughness that induces a magnetic anisotropy in the free layer. The treated layer underlying the free layer can be a spacer layer sandwiched between the free layer and pinned layer or can be a separate underlayer formed opposite the spacer layer. Alternatively, the texturing of an underlayer can be used to induce a magnetic anisotropy in a bias layer that is separated from the free layer by an orthogonal coupling layer. This self biasing of the free layer induced by texturing can also be used in conjunction with biasing from a hard-bias structure.

Abstract: A magnetoresistance effect element comprises a magnetoresistance effect film including a magnetically pinned layer whose direction of magnetization is pinned substantially in one direction, a magnetically free layer whose direction of magnetization changes in response to an external magnetic field, and a nonmagnetic intermediate layer located between the pinned layer and the free layer; and a pair of electrodes electrically connected to said magnetoresistance effect film to supply a sense current perpendicularly to a film plane of said magnetoresistance effect film, The intermediate layer has a first layer including a first region whose resistance is relatively high and second regions whose resistance is relatively low. The sense current preferentially flows through the second regions when the current passes the first layer.

Abstract: A magnetic head is provided with a giant magnetoresistive element, barrier layer, and highly polarized spin injection layer. The barrier layer is inserted between the giant magnetoresistive element and the injection layer. By applying a sensing current to both the magnetoresistive element and the injection layer, an output of the magnetic head can be multiplied significantly. The output of the head is increased by increasing a resistance change rate of a magnetoresistive element used as a reading element. The increasing of the resistance change rate is due to that a band of s electrons in the Cu film grown in the highly polarized spin injection layer is placed in a highly polarized state near the Fermi level and the upward spin current only flows into the giant magnetoresistive element, which has multiplied the output.

Abstract: A spacer layer of an MR element includes: a nonmagnetic metal layer disposed on a pinned layer; a protection layer disposed on the nonmagnetic metal layer to prevent oxidation or nitriding of the nonmagnetic metal layer; an island-shaped insulating layer disposed on the protection layer; and a coating layer covering these layers. When seen in a direction perpendicular to the top surface of the pinned layer, there are formed in the spacer layer a region where the insulating layer is present and a region where the insulating layer is absent. A thickness of the protection layer taken in at least part of the region where the insulating layer is absent is zero or smaller than a thickness of the protection layer taken in the region where the insulating layer is present.

Abstract: A lead overlay design of a magnetic sensor is described with sensor and free layer dimensions such that the free layer is stabilized by the large demagnetization field due to the shape anisotropy. In one embodiment the giant magnetoresistive (GMR) effect under the leads is destroyed by removing the antiferromagnetic (AFM) and pinned layers above the free layer. The overlaid lead pads are deposited on the exposed spacer layer at the sides of the mask that defines the active region. In other embodiment a layer of electrically insulating material is deposited over the sensor to encapsulate it and thereby insulate it from contact with the hardbias structures. Various embodiments with self-aligned leads are also described. In a variation of the encapsulation embodiment, the insulating material is also deposited under the lead pads so the electrical current is channeled through the active region of the sensor and sidewall deposited lead pads.

Abstract: A method for fabricating a read head for a magnetic disk drive having a read head sensor and a hard bias layer, where the read head has a shaped junction between the read head sensor and the hard bias layer. The method includes providing a layered wafer stack to be shaped. A single- or multi-layered photoresist mask having no undercut is deposited upon the layered wafer stack to be shaped. The layered wafer stack is shaped by the output of a milling source, where the shaping includes partial milling to within a partial milling range to form a shaped junction. A hard bias layer is then deposited which is in contact with the shaped junction of the wafer stack.

Abstract: A method and structure for a spin valve transistor (SVT) comprises a magnetic field sensor, an insulating layer adjacent the magnetic field sensor, a bias layer adjacent the insulating layer, a non-magnetic layer adjacent the bias layer, and a ferromagnetic layer over the non-magnetic layer, wherein the insulating layer and the non-magnetic layer comprise antiferromagnetic materials. The magnetic field sensor comprises a base region, a collector region adjacent the base region, an emitter region adjacent the base region, and a barrier region located between the base region and the emitter region. The bias layer is between the insulating layer and the non-magnetic layer. The bias layer is magnetic and is at least three times the thickness of the magnetic materials in the base region.

Abstract: An exchange-coupled film includes a seed layer, an antiferromagnetic layer, and a ferromagnetic layer. The seed layer is formed at a thickness that is larger than the critical thickness, and the thickness of the seed layer is then decreased by etching so as to be smaller than or equal to the critical thickness. Thereby, a crystalline phase which extends through the seed layer from the upper surface to the lower surface can be formed, and/or the average size, in a direction parallel to the layer surface, of the crystal grains in the seed layer can be set to be larger than the thickness of the seed layer. Consequently, a large exchange coupling magnetic field Hex can be generated between the antiferromagnetic layer and the ferromagnetic layer.

Abstract: A CPP giant magnetoresistive head includes a lower shield layer; an upper shield layer; and a giant magnetoresistive element (GMR) between the lower shield layer and the upper shield layer. The GMR includes a nonmagnetic material layer; a pinned magnetic layer; and a free magnetic layer. The pinned layer and the free layer are laminated with the nonmagnetic layer provided therebetween. A current flows perpendicularly to a film plane of the GMR, the pinned magnetic layer extends in the height direction longer than in a track-width direction and includes a first portion in the GMR. The first portion is disposed above or below the nonmagnetic layer and the free layer. A second portion is behind the nonmagnetic layer and the free layer in the height direction. The first and second portions are in the same plane. The width of the pinned layer in the track-width direction in the first portion is greater than that in the second portion.

Abstract: A layer system, a method for forming the layer system, and devices utilizing the layer system are provided. In one embodiment, the method includes providing a bilayer system comprised of a first layer including a first ferromagnetic material doped with a dopant material selected from one of a 4d transition metal, 5d transition metal, and 4f rare earth metal. The dopant material may be predetermined to provide a magnetic damping in the bilayer which is greater than the magnetic damping in the first ferromagnetic material. The first layer may be very thin, e.g., less than or equal to two nanometers thick. The method also includes providing a second layer disposed on the first layer. The second layer includes a second ferromagnetic material and the second layer may be greater than or equal to two nanometers thick.

Abstract: A magnetic sensor is provided. The magnetic sensor includes a magnetoresistive multi-layered portion that has a first resistance region and a second resistance region. At least two contacts are coupled to the magnetoresistive multi-layered portion. A sensing current flows from a first contact of the at least two contacts to a second contact of the at least two contacts via the first resistance region and the second resistance region of the magnetoresistive multi-layered portion. The first resistance region promotes a primary flow of the sensing current in a first direction substantially perpendicular to surface planes of the layers of the magnetoresistive multi-layered portion, and the second resistance region promotes the primary flow of the sensing current in a second direction substantially in parallel to surface planes of the layers of the magnetoresistive multi-layered portion.

Abstract: The effectiveness of an IrMn pinning layer in a CPP GMR device at high switching fields has been improved by replacing the conventional single layer seed by a layer of tantalum and either ruthenium or copper. The tantalum serves to cancel out the crystallographic influence of underlying layers while the ruthenium or copper provide a suitable base on which to grow the IrMn layer.

Abstract: A current perpendicular to plane dual giant magnetoresistive sensor (dual CPP GMR sensor) that prevents spin torque noise while having high dR/R performance. The sensor has a design that maximizes the GMR effect (dR/R) by providing a pinned layer structure that maximizes the positive GMR contribution of the AP2 layer (or magnetic layer closest to the spacer layer) while minimizing the negative GMR contribution of the AP1 layer (or layer furthest from the spacer layer). The pinned layer structure includes an AP1 layer that includes a thin CoFe layer that is exchange coupled with an IrMn or IrMnCr AFM layer and has two or more Co layers with a spin blocking layer sandwiched between them. The use of the Co layers and the spin blocking layer in the AP1 layer minimizes the negative contribution of the AP1 layer. The AP2 layer has a plurality of CoFe layers with nano-layers such as Cu sandwiched between the CoFe layers.

Abstract: The TTM sensor includes a semiconductor structure and a spin valve structure, where the semiconductor structure includes at least two layers. Two of the three leads of the TTM sensor are engaged to the semiconductor layers, where a semiconductor junction between the layers is disposed between the two leads. Generally, the junction may comprise a P-N junction between a P-type layer and an N-type layer and in an embodiment of the present invention the collector lead is engaged to the P-type semiconductor layer and the base lead is connected to the N-type semiconductor layer. The spin valve structure is fabricated upon the semiconductor structure and the emitter is engaged to the spin valve structure. In this configuration, a free magnetic layer of the spin valve structure is fabricated upon the semiconductor material, such that a schottky barrier is formed between the metallic free magnetic layer material and the semiconductor material.

Abstract: A method for fabricating a spin-valve GMR sensor having a reference layer with a magnetic moment that moves in an opposite direction to that of the free layer in the presence of external magnetic field transitions. The reference layer is a part of a three ferromagnetic layer structure, including pinned, intermediate and reference layers, that when the layers are taken pairwise and separated by spacer layers, includes a strongly exchange coupled synthetic ferrimagnetic pinned and intermediate layer pair and a weakly exchange coupled synthetic ferrimagnetic intermediate and reference layer pair. The reference layer, because of its weak coupling to the intermediate layer, has a magnetic moment that is free to move. During sensor operation, the reference layer and free layer move in opposite directions under the influence of external magnetic field transitions The novel three layer structure provides a sensor of increased sensitivity for a given track width.

Abstract: A spin injection magnetization reversal device is disclosed which inhibits an increase in resistance to enable multi-valued data recording. A ferromagnetic fixed layer and n groups each including a ferromagnetic free layer and an isolation layer are disclosed. The groups are disposed from the group including the first ferromagnetic free layer provided on the ferromagnetic fixed layer to the group including the n-th ferromagnetic free layer in the order. Each of the ferromagnetic free layers is preferably formed of one of a CoCrPt alloy, a CoCr alloy and a CoPt alloy with Pt or Cu concentration therein made monotonically decreased from the concentration in the first ferromagnetic free layer to that in the n-th ferromagnetic free layer.

Abstract: The magnetoresistive effect element comprises an electrode layer 12 of a crystalline material; a base layer 14 of a conductive amorphous material formed over the electrode layer 12, an antiferromagnetic layer 18 of a crystalline material formed over the base layer 14, a ferromagnetic layer 20 formed over the antiferromagnetic layer 18 and having the magnetization direction defined by the antiferromagnetic layer 18, a nonmagnetic intermediate layer 22 formed over the ferromagnetic layer 20, a ferromagnetic layer 24 formed over the nonmagnetic intermediate layer 22 and having the magnetization direction changed by an external magnetic field, and an electrode layer 28 formed over the ferromagnetic layer 24.

Abstract: In magnetic read heads based on bottom spin valves the preferred structure is for the longitudinal bias layer to be in direct contact with the free layer. Such a structure is very difficult to manufacture. The present invention overcomes this problem by introducing an extra layer between the bias electrodes and the free layer. This layer protects the free layer during processing but is thin enough to not interrupt exchange between the bias electrodes and the free layer. In one embodiment this is a layer of copper about 5 ? thick and parallel exchange is operative. In other embodiments ruthenium is used to provide antiparallel exchange between the bias electrode and the free layer. A process for manufacturing the structure is also described.

Abstract: A pinned magnetic layer 20 and a free magnetic layer 26 include a magnetic portion 17 and a magnetic sublayer 22, respectively, each comprising a half-metallic ferromagnetic alloy. Since each of the magnetic portion 17 and magnetic sublayer 22 comprising the half-metallic alloy layer has a larger value ? and a larger resistivity ? compared to the conventional CoFe alloy or the like, the change in resistance (?R) can be increased, and the rate of change in resistance (?R/R) can be appropriately improved.

Abstract: A TMR sensor, a CPP GMR sensor and a CCP CPP GMR sensor all include a tri-layered free layer that is of the form CoFe/CoFeB/NiFe, where the atom percentage of Fe can vary between 5% and 90% and the atom percentage of B can vary between 5% and 30%. The sensors also include SyAP pinned layers which, in the case of the GMR sensors include at least one layer of CoFe laminated onto a thin layer of Cu. In the CCP CPP sensor, a layer of oxidized aluminum containing segregated particles of copper is formed between the spacer layer and the free layer. All three configurations exhibit extremely good values of coercivity, areal resistance, GMR ratio and magnetostriction.

Abstract: A magnetoresistive sensor having a substrate that has been treated with nitrogen (nitrogenated). The nitrogenated substrate includes an alumina base layer and a thin top layer of crystalline alumina that has had a very small amount of nitrogen deposited on top. The amount of nitrogen deposited on top of the alumina is less than or equal to two monolayer, and is preferably less than on monolayer. The amount of nitrogen deposited on top of the alumina substrate is not enough to constitute a layer of nitrogen, but affects the structure of the alumina to cause the alumina to have a desired crystalline structure and an extremely smooth surface.

Abstract: A CPP giant magnetoresistive (GMR) head includes lower and upper shield layers; and a GMR element disposed between the upper and lower shield layers and comprising a pinned magnetic layer, a free magnetic layer, and a nonmagnetic layer disposed between the pinned magnetic layer and the free magnetic layer. Nonmagnetic metal films are provided directly above the lower shield layer and below the upper shield layer making direct contact with and having larger areas than the pinned magnetic layer and the free magnetic layer, respectively. An antiferromagnetic layer is provided in the rear of the GMR element in the height direction, for pinning the magnetization direction of the pinned magnetic layer. Alternatively, the dimension of the pinned magnetic layer in the height direction is larger than the dimension in the track width direction so that the magnetization direction of the pinned magnetic layer is stabilized without using an antiferromagnetic layer.

Abstract: Two embodiments of a GMR sensor of the bottom spin valve (BSV) spin filter spin valve (SFSV) type are provided together with methods for their fabrication. In each embodiment the sensor includes an in-situ naturally oxidized specularly reflecting layer (NOL) which is a more uniform and dense layer than such layers formed by high temperature annealing or reactive-ion etching. In one embodiment, the sensor has an ultra thin composite free layer and a high-conductance layer (HCL), providing high output and low coercivity. In a second embodiment, along with the same NOL, the sensor has a laminated free layer which includes a non-magnetic conductive layer, which also provides high output and low coercivity. The sensors are capable of reading densities exceeding 60 Gb/in2.

Abstract: A magnetoresistive sensor having a trackwidth defined by AFM biasing layers disposed beneath a free layer of the sensor. The present invention provides a current in plane magnetoresistive sensor that includes a non-magnetic, electrically conductive layer in a trackwidth region. The non-magnetic, electrically conductive layer can be for example Ta, but could be some other material. This non-magnetic, electrically conductive layer has first and second laterally opposed sides and a planar upper surface. First and second insulating layers are formed at each of the sides of the non-magnetic, electrically conductive layer, and bias layers extend laterally outward from the insulation layers. The bias layers can be constructed of either an antiferromagnetic (AFM) material or could be constructed of a hard magnetic material such as CoPtCr. The bias layers have planar upper surfaces that are coplanar with the upper surface of the non-magnetic, electrically conductive layer.

Abstract: At two sides of a multilayer film including a free magnetic layer, a first non-magnetic material layer, and a fixed magnetic layer, extension portions extending from the fixed magnetic layer are formed. At lower sides of the extension portions, a pair of first antiferromagnetic layers is formed with a space therebetween in a track width direction, and in addition, at upper sides of the extension portions, a pair of second antiferromagnetic layers is formed with a space therebetween in the track width direction.

Abstract: A magnetic head has less variations in the resistance of a magneto-resistive device before and after the magnetic head is left in a high temperature environment so as to have higher stability of the characteristics of the magnetic head against a high temperature environment. A TMR device includes a tunnel barrier layer made of an oxide layer. A DLC film serving as a protection film and an underlying layer therefor are formed on an end face of the TMR device on an air bearing surface side. A layer made of an oxide of a metal or an oxide of a semiconductor is formed between the underlying layer and the end face of the tunnel barrier layer on the air bearing surface side to be in contact with the end face of the tunnel barrier layer.

Abstract: A magnetoresistive sensor having hard bias layers constructed of CoPtCrB, which high coercivity when deposited over crystalline materials such as an AFM layer or other sensor material. The bias layer material exhibits high coercivity and high moment even when deposited over a crystalline structure such as that of an underlying sensor material by not assuming the crystalline structure of the underlying crystalline layer. The bias layer material is especially beneficial for use in a partial mill sensor design wherein a portion of the sensor layers extends beyond the active area of the sensor and the bias layer must be deposited on the extended portion of sensor material.

Abstract: A magnetic head has less variations in the resistance of a magneto-resistive device before and after the magnetic head is left in a high temperature environment so as to have higher stability of the characteristics of the magnetic head against a high temperature environment. A TMR device includes a tunnel barrier layer made of an oxide layer. A DLC film serving as a protection film and an underlying layer therefor are formed on an end face of the TMR device on an air bearing surface side. A layer made of an oxide of a metal or an oxide of a semiconductor is formed between the underlying layer and the end face of the tunnel barrier layer on the air bearing surface side to be in contact with the end face of the tunnel barrier layer.

Abstract: A magnetic head in one embodiment includes first and second ferromagnetic shield layers, first and second nonmagnetic read-gap layers positioned between the first and second ferromagnetic shield layers, a sensor used in a current-in-plane (CIP) mode, first and second longitudinal bias layers electrically coupled with the sensor, and first and second conducting layers electrically coupled with the first and second longitudinal bias layers, respectively.

Abstract: A magnetoresistance device includes an elongate channel formed of silicon. A conductor comprising titanium silicide is connected to the channel along one side of the channel and leads are connected to and spaced along the channel on the opposite side.

Abstract: A magnetoresistive element includes a first magnetic layer a magnetization direction of which is substantially pinned, a second magnetic layer a magnetization direction of which varies depending on an external field, a magnetic spacer layer provided between the first magnetic layer and the second magnetic layer, and electrodes which supply a current perpendicularly to a plane of a stacked film including the first magnetic layer, the magnetic spacer layer and the second magnetic layer. In this element, the magnetization directions of the first and the second magnetic layers are substantially orthogonal at zero external field.

Abstract: A method and system for providing a spin filter is disclosed. The method and system include providing a pinned layer, a free layer, and a conductive nonmagnetic spacer layer between the pinned layer and the free layer. The method and system also include providing a spin filter layer and a capping layer on the spin filter layer. The spin filter layer is adjacent to the free layer. The spin filter layer is on an opposite side of the free layer as the nonmagnetic spacer layer and includes at least Pt and/or Rh. The capping layer has a specular reflection layer therein. In one aspect, the specular reflection layer allows specular reflection of current carriers traveling from the spin filter layer to the specular reflection layer. In another aspect, the specular reflection layer includes at least Ta, Ti, Zr, Hf, Nb, Al, Mo, W, Si, Cr, V, Ni, Co, and Fe.

Abstract: A magneto-resistance effect element comprises a stacked body which comprises a pinned layer having a fixed magnetization direction, a free layer having a magnetization direction that varies according to an external magnetic field, and a nonmagnetic spacer layer which is interposed between the pinned layer and the free layer. The stacked body having a constricted shape in which at least one part of the spacer layer is constricted when viewed from at least one direction perpendicular to a stacked direction of the stacked body.

Abstract: A GMR sensor having improved longitudinal biasing is provided as is a method of forming it. The improved biasing is provided by longitudinal biasing structures in which a soft magnetic layer is interposed between a hard magnetic biasing layer and the lateral edge of the GMR sensor element. The soft magnetic layer eliminates the need for a seed layer directly between the hard magnetic layer and the GMR element and provides improved coupling to the free layer of the GMR element and a substantial reduction in random domain variations.

Abstract: A magnetoresistance effect element comprises a magnetoresistance effect film and a pair of electrode. The magnetoresistance effect film having a first magnetic layer whose direction of magnetization is substantially pinned in one direction; a second magnetic layer whose direction of magnetization changes in response to an external magnetic field; a nonmagnetic intermediate layer located between the first and second magnetic layers; and a film provided in the first magnetic layer, in the second magnetic layer, at a interface between the first magnetic layer and the nonmagnetic intermediate layer, and/or at a interface between the second magnetic layer and the nonmagnetic intermediate layer, the film having a thickness not larger than 3 nanometers, and the film has as least one selected from the group consisting of oxide, nitride, oxinitride, phosphide, and fluoride.

Abstract: A magnetoresistance effect element a stacked film including a magnetization fixed layer in which the direction of magnetization is substantially fixed to one direction, and a magnetization free layer in which the direction of magnetization varies in response to an external magnetic field, an electrode connected to a part of a principal plane of the stacked film, the magnetoresistance effect element having a resistance varying in response to a relative angle between the direction of magnetization in the magnetization fixed layer and the direction of magnetization in the magnetization free layer, a sense current detecting the variation of the resistance being applied to the film planes of the magnetization fixed layer and the magnetization free layer via the electrode in a direction substantially perpendicular to the magnetization fixed layer and the magnetization free layer.

Abstract: In a magnetic sensing element, the amounts of spin-dependent bulk scattering in the upstream part of a multilayer film and in the downstream part of the multilayer film are controlled to be asymmetric. Thus, a value ?R×A, which represents the variation in magnetoresistance×element area, for the upstream part of the multilayer film is controlled so as to be smaller than the value ?R×A for the downstream part of the multilayer film.

Abstract: A method is provided for preserving the transverse biasing of a GMR (or MR) read head during back-end processing. In a first preferred embodiment, the method comprises magnetizing the longitudinal biasing layers of the read head in a transverse direction, so that the resulting field at the position of the transverse biasing layer places it in a minimum of potential energy which stabilizes its direction. The field of the longitudinal biasing layer is then reset to the longitudinal direction in a manner which maintains the transverse biasing direction. In a second embodiment, a novel fixture for mounting the read head during processing includes a magnetic portion which stabilizes the transverse bias of the read head. The two methods may be used singly or in combination.

Abstract: A current-perpendicular-to-the-plane spin-valve (CPP-SV) magnetoresistive sensor has an improved antiparallel (AP) pinned structure. The AP-pinned structure has two ferromagnetic layers separated by a nonmagnetic antiparallel coupling (APC) layer and with their magnetization directions oriented antiparallel. One of the ferromagnetic layers in the AP-pinned structure is the reference layer in contact with the CPP-SV sensor's nonmagnetic electrically conducting spacer layer. In the improved AP-pinned structure each of the ferromagnetic layers has a thickness greater than 30 ?, preferably greater than approximately 50 ?, and the APC layer is either Ru or Ir with a thickness less than 7 ?, preferably about 5 ? or less. The ultrathin APC layer, especially if formed of iridium (Ir), provides significant coupling strength to allow the thick ferromagnetic layers to retain their magnetization directions in a stable antiparallel orientation.

Abstract: Magnetoresistive (MR) sensors are disclosed having mechanisms for reducing edge effects such as Barkhausen noise. The sensors include a pinned layer and a free layer with an exchange coupling layer adjoining the free layer, and a ferromagnetic layer having a fixed magnetic moment adjoining the exchange coupling layer. The exchange coupling layer and ferromagnetic layer form a synthetic antiferromagnetic structure with part of the free layer, providing bias that reduces magnetic instabilities at edges of the free layer. Such synthetic antiferromagnetic structures can provide a stronger bias than conventional antiferromagnetic layers, as well as a more exactly defined track width than conventional hard magnetic bias layers. The synthetic antiferromagnetic structures can also provide protection for the free layer during processing, in contrast with the trimming of conventional antiferromagnetic layers that exposes if not removes part of the free layer.

Abstract: A thin dual magnetic tunnel junction head having a free layer and first and second antiparallel (AP) pinned layer structures positioned on opposite sides of the free layer, each of the AP pinned layer structures including at least two pinned layers having magnetic moments that are self-pinned antiparallel to each other, the pinned layers of each AP pinned layer structure being separated by an AP coupling layer. A first barrier layer is positioned between the first AP pinned layer structure and the free layer. A second barrier layer is positioned between the second AP pinned layer structure and the free layer. The head does not have any antiferromagnetic layers, and so is much thinner than dual magnetic tunnel junction sensors heretofore known. As such, dual magnetic tunnel junction heads can be fabricated at a thickness of less than about 500 ?.

Abstract: A magnetic head having a spin valve sensor that is fabricated utilizing an Al2O3, NiMnO, NiFeCr seed layer upon which a typical PtMn spin valve sensor layer structure is subsequently fabricated. The preferred embodiment fabrication process of the NiFeCr layer includes the overdeposition of the layer to a first thickness of from 15 ? to 45 ? followed by the etching back of the seed layer of approximately 5 ? to approximately 15 ? to its desired final thickness of approximately 10 ? to 40 ?. The Cr at. % composition in the NiFeCr layer is preferably from approximately 35 at. % to approximately 46 at. %. The crystal structure of the surface of the etched back NiFeCr layer results in an improved crystal structure to the subsequently fabricated spin valve sensor layers, such that the fabricated spin valve exhibits increased ?R/R and reduced coercivity.

Abstract: A magnetoresistance effect element has a lamination structure comprising a free layer including two ferromagnetic layers, a pinned layer including two ferromagnetic layers, and at least one nano-contact portion composed of a single ferromagnetic layer and disposed at least one portion between the free layer and the pinned layer. A distance between the free layer and the pinned layer, i.e., thickness of the nano-contact portion in the lamination direction, is not more than Fermi length, preferably less than 100 nm.

Abstract: Provided is a magnetic head having a magnetoresistive device which has high output and is best suited to high-recording-density magnetic recording/reading. A magnetic sensor having large output can be realized by providing a magnetic sensor which comprises: a first ferromagnetic film; a conductor which intersects the first ferromagnetic film via a first intermediate layer; a current circuit structure which is connected so as to cause a current to flow from the first ferromagnetic layer to the conductor; a second ferromagnetic film which is formed on the conductor in an intersecting manner via a second intermediate layer and which generates a signal of voltage changing according to a change in an external magnetic field; a voltage change amplifier film which contains materials whose resistance changes nonlinearly due to voltage; and an electrode which is connected to the voltage change amplifier film.