Abstract: A main magnetic pole includes a first part extending from a medium facing surface to a point at a predetermined distance from the medium facing surface, and a second part other than the first part. An accommodation part for accommodating the main magnetic pole includes: a first layer having a groove; a second layer lying between the first layer and the main magnetic pole in the first layer's groove; and a third layer interposed in part between the second layer and the main magnetic pole in the first layer's groove. The second layer is formed of a metal material different from a material used to form the first layer. The third layer is formed of an inorganic insulating material. The second and third layers lie between the first layer and the first part. The second layer lies between the bottom of the first layer's groove and the second part, but the third layer does not. The distance between the bottom of the first layer's groove and the second part is smaller than that between the bottom and the first part.

Abstract: The invention discloses a MAMR head that has the STO stack placed at the trailing side of the write element, with both STO and write element completely self-aligned in the cross track direction. A method for defining both the MP and the STO stack geometries in a single step is also described.

Abstract: A structure according to one embodiment includes a substrate having a media facing side; and a thin film stack formed on the substrate, the thin film stack including magnetic films and insulating films, wherein the thin film stack is recessed from a plane extending along the media facing side of the substrate, wherein the magnetic films are recessed more than the insulating films, wherein the magnetic films each have a substantially flat media facing surface, wherein the insulating films each have a substantially flat media facing surface.

Abstract: According to one embodiment, a magnetic head includes an upper magnetic shield, a lower magnetic shield,a magnetoresistive element having a magnetization-free layer formed therein formed between the shields, an upper magnetic shield restricting part formed on a medium facing surface side, a lower magnetic shield restricting part formed on the medium facing surface side, and a non-magnetic part formed between the upper and lower magnetic shield restricting parts on the medium facing surface side such that the magnetoresistive element is not exposed at the medium facing surface. The non-magnetic part is positioned such that a distance between the upper and lower magnetic shield restricting parts in a direction perpendicular to a plane of deposition is smaller than a distance between the upper and lower magnetic shields in the direction perpendicular to the plane of deposition near the medium facing surface. Other systems and heads are disclosed as well.

Abstract: A magnetoresistive (MR) sensor or read head for a magnetic recording disk drive has multiple independent current-perpendicular-to-the-plane (CPP) MR sensing elements. The sensing elements are spaced-apart in the cross-track direction and separated by an insulating separation region so as to be capable of reading data from multiple data tracks on the disk. The sensing elements have independent CPP sense currents, each of which is directed to independent data detection electronics, respectively. Each sensing element comprises a stack of layers formed on a common electrically conducting base layer, which may be a bottom magnetic shield layer formed of electrically conducting magnetically permeable material. Each sensing element has a top electrical lead layer. A top magnetic shield layer is located above the sensing elements in contact with the top lead layers.

Abstract: An MR element in a CPP structure includes an MR part configured with a nonmagnetic layer, a first ferromagnetic layer that functions as first free layer and a second ferromagnetic layer that functions as a second free layer, and first and second ferromagnetic layers are laminated to sandwich the nonmagnetic intermediate layer, and a sense current flows in a lamination direction of the MR part, an orthogonalizing bias function part, which influences a substantial orthogonalization function for magnetization directions of the first ferromagnetic layer and the second ferromagnetic layer, is formed on the rear side the MR part, side shield layers are disposed on both sides in the width direction of the MR part, the side shield layers are perpendicular magnetized layers with a magnetic shield function, and magnetization directions of the perpendicular magnetized layers are in an orthogonal direction that corresponds to the thickness direction.

Abstract: A perpendicular magnetic write head in which unintended erasure of information at the time of non-writing can be suppressed while keeping the capability of writing is provided. The perpendicular magnetic write head includes a magnetic pole tip portion, a first yoke portion connected to the magnetic pole tip portion, having a width larger than that of the magnetic pole tip portion, and having a recess portion in a center region thereof, and a second yoke portion embedded in the recess portion. The magnetic pole tip portion and the first yoke portion are integrally formed with a vapor deposition method, and the second yoke portion is formed with a plating method. Since the saturation flux density of the magnetic pole tip portion formed with the vapor deposition method becomes higher than that of the yoke portion, a magnetic flux intake capacity of the magnetic pole tip portion is ensured.

Abstract: A magnetic tunnel junction having a first electrode separated from a second electrode by a tunneling barrier is provided. The tunneling barrier is a ferromagnetic insulator that provides a spin dependent barrier energy for tunneling. The first electrode includes a ferromagnetic, electrically conductive layer. Electrons emitted from the first electrode toward the tunneling barrier are partially or completely spin-polarized according to the magnetization of the ferromagnetic electrode layer. The electrical resistance of the tunnel junction depends on the relative orientation of the electrode layer magnetization and the tunneling barrier magnetization. Such tunnel junctions are widely applicable to spintronic devices, such as spin valves, magnetic tunnel junctions, spin switches, spin valve transistors, spin filters, and to spintronic applications such as magnetic recording, magnetic random access memory, ultrasensitive magnetic field sensing (including magnetic biosensing), spin injection and spin detection.

Abstract: A perpendicular magnetic recording system has a write head having a main coil (the write coil) and main pole (the write pole) that directs write flux in a direction perpendicular to the recording layer in the magnetic recording medium, and a transverse auxiliary pole (TAP) that injects auxiliary magnetic flux into the write pole at an angle to the primary or perpendicular axis of the write pole. The additional flux from the TAP, which is injected non-parallel to the primary magnetization of the write pole, exerts a torque on the magnetization of the write pole, thereby facilitating magnetization reversal of the write pole. The TAP is coupled to the main coil but not electrically connected to it. A separate passive coil, not electrically connected to the main coil, may be wrapped as a loop around the main pole and the TAP. Alternatively, the TAP may be located near one of the electrically conductive turns of the main coil.

Abstract: In an MR element of the present invention, an effect of an extremely-high MR ratio is obtained since a crystal structure of a CoFe magnetic layer in the vicinity of an interface with a spacer layer is formed as a close packed structure, such as an hcp structure and an fcc structure, and a total existing ratio of these crystal structures is 25% or more by an area ratio.

Abstract: A thin film magnetic head includes first and second shield layers that are positioned on both sides of a magnetoresistive (MR) stack with respect to a film surface orthogonal direction; a first exchange-coupling layer that is positioned between the MR stack and the first shield layer and that generates an exchange-coupling between a first magnetoresistive (MR) magnetic layer and a first magnetic control layer of the first shield layer; a second exchange-coupling layer that is positioned between the MR stack and the second shield layer and that generates an exchange-coupling between a second magnetoresistive (MR) magnetic layer and a second magnetic control layer of the second shield layer; a bias magnetic field application layer that is disposed at an opposite surface of the MR stack from an air bearing surface (ABS) and that applies a bias magnetic field to the MR stack in a direction orthogonal to the ABS; and pair of side shield layers that are positioned at both sides of the MR stack with respect to a tra

Abstract: Perpendicular recording media with sublayers of dual oxide dopant magnetic materials are disclosed. The magnetic layer may comprise multiple sublayers of magnetic materials. In each sublayer, dual oxide dopants are incorporated. The compositions of the sublayers can be the same or different depending on the application. The magnetic layer may be deposited using a target comprising a mixture of CoPtCrB and dual oxides as dopants. The layer deposited with such targets can be the entire magnetic layer or a sublayer.

Abstract: A thin film magnetic disk overcoat for perpendicular magnetic recording media comprises three layers. The initial layer comprises a dense mixture of both SiCx and SiNy compounds. The intermediate layer is a relatively dense high energy carbon process and the outer layer is sputtered CNx. The overall thickness of the overcoat is less than about 35 ?. The overcoat has the desired lubricant interaction with the elements that comprise the magnetic layers adjacent to the overcoat. Adjusting the SiC/SiN ratio in the overcoat eliminates potential negative interaction with the magnetic layers of the disk.

Abstract: A perpendicular recording magnetic media with a partially-oxidized cap layer combines a second oxide layer with a first cap layer to form the singular, partially-oxidized cap. The oxidized portion and the non-oxidized portion of the partially-oxidized layer are sputtered from a same target and have a same composition of metallic elements. The Ms of the oxidized portion is about twice as high as the non-oxidized portion. The oxidized portion has a thickness in the range of about 5 to 25 angstroms. The layer composition may comprise CoPtCrBTa, with a Cr at % of about 18-24%, Pt at about 13-20%, B at about 4-10%, and Ta at about 0-2%.

Abstract: A dual current-perpendicular-to-plane scissor sensor according to one embodiment includes a middle free layer; two outer free layers positioned on opposite sides of the middle free layer; spacer layers between the middle free layer and each of the outer free layers; and a hard bias layer positioned behind the free layers relative to a media-facing surface of the sensor, wherein the free layers are about magnetostatically balanced.

Abstract: A magnetic head according to one embodiment includes an array of sensor structures formed on a common substrate. Each sensor structure further comprises: a magnetic tunnel junction sensor spaced from a media-facing surface of the head; and a flux guide between the media-facing surface of the head and the sensor, the flux guide guiding magnetic flux from a magnetic medium adjacent the media-facing surface to the sensor. Additional systems and methods are also presented.

Abstract: A method and system for providing a magnetic transducer are disclosed. The method and system include providing a magnetic element that includes a free layer, a pinned layer, and a nonmagnetic spacer layer between the free layer and the pinned layer. The nonmagnetic spacer layer is a tunneling barrier layer. The free layer is configured to be biased in a first direction. The pinned layer has a pinned layer magnetization configured to be pinned in a second direction that is at a first angle from perpendicular to the ABS. The first angle is nonzero and different from ninety degrees. The second direction and the first direction form a second angle that is different from ninety degrees.

Abstract: An MR element in a CPP structure includes a spacer layer made of Cu, a magnetic pinned layer containing CoFe and a free layer containing CoFe that are laminated to sandwich the spacer layer. The free layer is located below the magnetic pinned layer. The free layer is oriented in a (001) crystal plane, the spacer layer is formed and oriented in a (001) crystal plane on the (001) crystal plane of the free layer. Therefore, in a low resistance area where an area resistivity (AR) of the MR element is, for example, lower than 0.3 ?·?m2, an MR element that has a large variation of a resistance is obtained.

Abstract: A magnetic sensor assembly including first and second shields, and a sensor stack between the first and second shields. The sensor stack includes a seed layer adjacent the first shield, a cap layer adjacent the second shield, and a magnetic sensor between the seed layer and the cap layer, wherein at least one of the seed layer and the cap layer has a synthetic antiferromagnetic structure.

Abstract: An MR element in a CPP-GMR structure includes a first ferromagnetic layer, a spacer layer that is epitaxially formed on the first ferromagnetic layer, a second ferromagnetic layer that is located on the spacer layer, and that is laminated with the first ferromagnetic layer to sandwich the spacer layer. A sense current flows along a lamination direction of the first and second ferromagnetic layers. Angle of magnetization directions of the first ferromagnetic layer and the second ferromagnetic layer relatively change due to an externally applied magnetic field.

Abstract: A magneto-resistive reader includes a first magnetic shield element, a second magnetic shield element and a magneto-resistive sensor stack separating the first magnetic shield element from the second magnetic shield element. The first shield element includes two ferromagnetic anisotropic layers separated by a grain growth suppression layer.

Abstract: A magnetic writer comprises a surface, a write pole, a trailing shield and a gap. The write pole has a write pole tip proximate the surface. The trailing shield is proximate the surface and space away from the write pole. The gap is proximate the surface and located between the write pole tip and the trailing shield. The gap has an effective thickness. The gap comprises a first write gap and a synthesized low magnetization shield. The synthesized low magnetization shield is configured such that a magnetization of the synthesized magnetization shield adjacent the surface has a perpendicular component in an opposite direction to the magnetization of the write pole tip during a write operation.

Abstract: A magnetoresistive sensor having a trilayer sensor stack with two ferromagnetic freelayers separated by a nonmagnetic spacer layer is disclosed. The sensor is biased with a back biasing magnet adjacent a back of the trilayer sensor. The back biasing magnet, the trilayer sensor stack, or both have substantially trapezoidal shapes to enhance the biasing field and to minimize noise. In some embodiments, the trilayer sensor or back bias magnet have a shape designed to stabilize a micromagnetic “C” shape or concentrate magnetic flux in the trilayer sensor stack.

Abstract: Apparatus and associated method for writing data to a non-volatile memory cell, such as spin-torque transfer random access memory (STRAM). In accordance with some embodiments, a resistive sense element (RSE) has a heat assist region, magnetic tunneling junction (MTJ), and pinned region. When a first logical state is written to the MTJ with a spin polarized current, the pinned and heat assist regions each have a substantially zero net magnetic moment. When a second logical state is written to the MTJ with a static magnetic field, the pinned region has a substantially zero net magnetic moment and the heat assist region has a non-zero net magnetic moment.

Abstract: According to one embodiment, a perpendicular magnetic recording head includes a main magnetic pole having a trailing side and two lateral sides, a magnetic shield near the trailing side and both lateral sides of the main magnetic pole, the magnetic shield comprising: a first soft magnetic film with a relatively high saturation flux density positioned facing depthwise from a floating surface side thereof, a second soft magnetic film with a relatively low saturation flux density, and a first non-magnetic film. The head also includes a non-magnetic film interposed between the magnetic shield and the main magnetic pole, a first magnetic film magnetically coupled to the magnetic shield and the main magnetic pole on a side opposite a floating surface side thereof, and a coil surrounding a magnetic circuit, the magnetic circuit comprising the main magnetic pole and the first magnetic film. Other systems and methods are also described.

Abstract: A spin torque oscillation magnetoresistive sensor for measuring a magnetic field. The sensor uses a change in precessional oscillation frequency of a magnetization of a magnetic layer to determine the magnitude of a magnetic field. The sensor can include a magnetic free layer, a magnetic pinned layer and a non-magnetic layer sandwiched therebetween. Circuitry is connected with these layers to induce an electrical current through the layers. Spin polarization of electrons traveling through the device causes a spin torque induced precession of the magnetization of one or more of the layers. The frequency of this oscillation modulates in response to a magnetic field. The modulation of the oscillation frequency can be measured to detect the presence of the magnetic field, and determine its magnitude.

Abstract: A magnetic writer includes a write pole, a first partial shield and a second partial shield. The write pole has a leading edge, a trailing edge, a first side and a second side. The first partial side shield is located on the first side of the write pole, and the second partial side shield is located on the second side of the write pole. The first partial side shield and the second partial side shield extend along side of the write pole from the trailing edge to a location intermediate that trailing edge and the leading edge so that the first partial side shield and the second partial side shield do not shield the leading edge.

Abstract: A perpendicular magnetic write head capable of suppressing damage and corrosion of a magnetic pole to secure a stable writing performance is provided. A non-magnetic protruding layer protruding from a main magnetic pole layer (tip portion) toward an air bearing surface side is formed on both sides of the tip portion in a writing track width direction. The non-magnetic protruding layer is located closer to a recording medium than the tip portion during writing operation, and more likely to be in contact with the writing medium instead of the tip portion. Since the portion of the protective film covering the tip portion hardly peels off while the portion of the protective film covering the non-magnetic protruding layer is easy to peel off, the tip portion is hardly damaged or corroded. Since the tip portion is protected physically and chemically by the non-magnetic protruding layer, the deterioration of the soft magnetic characteristics of the tip portion is suppressed.

Abstract: A perpendicular magnetic recording system and medium has a multilayered recording layer that includes an exchange-spring structure and a ferromagnetic lateral coupling layer (LCL). The exchange-spring structure is made up of two ferromagnetically exchange-coupled magnetic layers (MAG1 and MAG2), each with perpendicular magnetic anisotropy. MAG1 and MAG2 may have a coupling layer (CL) located between them that permits ferromagnetic exchange coupling of MAG1 with MAG2. The LCL is located either above or below MAG1 and in direct contact with MAG1 and mediates an effective intergranular exchange coupling in MAG1. The ferromagnetic alloy in the LCL has significantly greater intergranular exchange coupling than the ferromagnetic alloy in MAG1, which typically will include segregants such as oxides. The LCL is preferably free of oxides or other non-metallic segregants, which would tend to reduce intergranular exchange coupling in the LCL.

Abstract: A magnetic sensor for identifying small magnetic particles bound to a substrate includes a regular, planar orthogonal array of MTJ cells formed within or beneath that substrate. Each MTJ cell has a high aspect ratio and positions of stable magnetic equilibrium along an easy magnetic axis and positions of unstable magnetic equilibrium along a hard magnetic axis. By initializing the magnetizations of each MTJ cell in its unstable hard-axis position, the presence of even a small magnetic particle can exert a sufficient perturbative strayfield to tip the magnetization to its stable position. The magnetization change in an MTJ cell can be measured after each of two successive opposite polarity magnetizations of a bound particle and the presence of the particle thereby detected.

Abstract: Magnetoresistive structures, devices, memories, and methods for forming the same are presented. For example, a magnetoresistive structure includes a first ferromagnetic layer, a first nonmagnetic spacer layer proximate to the first ferromagnetic layer, a second ferromagnetic layer proximate to the first nonmagnetic spacer layer, and a first antiferromagnetic layer proximate to the second ferromagnetic layer. For example, the first ferromagnetic layer may comprise a first pinned ferromagnetic layer, the second ferromagnetic layer may comprise a free ferromagnetic layer, and the first antiferromagnetic layer may comprise a free antiferromagnetic layer.

Abstract: A spin accumulation sensor having a three terminal design that allows the free layer to be located at the air bearing surface. A non-magnetic conductive spin transport layer extends from a free layer structure (located at the ABS) to a reference layer structure removed from the ABS. The sensor includes a current or voltage source for applying a current across a reference layer structure. The current or voltage source has a lead that is connected with the non-magnetic spin transport layer and also to electric ground. Circuitry for measuring a signal voltage measures a voltage between a shield that is electrically connected with the free layer structure and the ground. The free layer structure can include a spin diffusion layer that ensures that all spin current is completely dissipated before reaching the lead to the voltage source, thereby preventing shunting of the spin current to the voltage source.

Abstract: An aspect of the present invention relates to a magnetic recording medium comprising a magnetic layer comprising a ferromagnetic powder and a binder on a nonmagnetic support. A height of protrusions with a protrusion density of 0.002 protrusion/?m2 or lower on a surface of the magnetic layer as measured by AFM is 40 nm or lower; a density of protrusions that are 15 nm or higher in height on the surface of the magnetic layer as measured by AFM ranges from 0.01 to 0.18 protrusion/?m2; and the protrusions that are 15 nm or higher in height include protrusions formed of carbon black and protrusions formed of a substance with a Mohs' hardness exceeding 7, and an average height of the protrusions formed of carbon black is greater than an average height of the protrusions formed of the substance with a Mohs' hardness exceeding 7.

Abstract: An apparatus, system, and method comprise a magnetoresistive head configured to respond to magnetization states of patterned cells formed on a patterned medium. The magnetoresistive head detects the magnetization states of at least two patterned cells formed on a patterned medium. The magnetoresistive head generates a readback signal based on the magnetization state of the at least two patterned cells. A detector circuit coupled to the head determines a bit pattern corresponding to the readback signal. A processor circuit coupled to the detector circuit determines positional information associated with the magnetoresistive head relative to the at least two patterned cells based on the bit pattern. The system further comprises a patterned medium.

Abstract: A magnetic sensor includes a freelayer, a reference layer and a front shield. The freelayer has a magnetization direction substantially perpendicular to the planar orientation of the layer and extends to the media confronting surface. The reference layer has a magnetization direction substantially in the plane of the layer and substantially perpendicular to the magnetization direction of the freelayer. The reference layer is recessed from the media confronting surface and a front shield is positioned between the reference layer and the media confronting surface thereby reducing the shield-to-shield spacing and increasing the areal density of the reader.

Abstract: A magnetoresistive effect element is structured in the manner that the antiferromagnetic layer interposed between the upper and lower shields is eliminated and the antiferromagnetic layer is positioned in a so-called shield layer. Therefore, it is realized to solve a pin reversal problem and to allow narrower tracks and narrower read gaps.

Abstract: A magnetic recording head includes: a main magnetic pole; a laminated body; and a pair of electrodes. The laminated body includes a first magnetic layer having a coercivity lower than magnetic field applied by the main magnetic pole, a second magnetic layer having a coercivity lower than the magnetic field applied by the main magnetic pole, and an intermediate layer provided between the first magnetic layer and the second magnetic layer. The pair of electrodes are operable to pass a current through the laminated body.

Abstract: An MR element according to the present invention has the superior effects that further improve an MR ratio because a structure of a spacer layer 40 is configured of a certain three-layer structure with certain materials, and at least one of a first ferromagnetic layer 30 and a second ferromagnetic layer 50 contains a certain amount of an element selected from the group of nitrogen (N), carbon (C), and oxygen (O).

Abstract: A magnetic head according to one embodiment includes a first magnetic shield; a first insulation layer disposed above said first magnetic shield; a plurality of sensor layers disposed above said first insulation layer; two electrical leads overlying a majority of a surface of the sensor layers, the electrical leads being formed of a magnetic material and serving as a second magnetic shield; and a read width insulation member disposed above said sensor layers and between said two electrically conductive members, the read width insulation members lying in a common plane with the electrically conductive members, the common plane being oriented parallel to a plane of deposition of the read width insulation member. Other systems and methods are also presented.

Abstract: A shield for a read element of a magnetic recording head includes a first domain with boundaries remote from the read element and stabilized with a patterned bias element. The patterned bias element comprises a topographical pattern of grooves formed on the shield substrate.

Abstract: The present disclosure provides a magnetic recording head for a data storage system having improved write field characteristics. In one example, an apparatus having magnetic properties is provided. The apparatus includes a pole, a shield, and a multilayer block positioned between the pole and the shield. The multilayer block includes a plurality of layers wherein at least one of the plurality of layers comprises a magnetic material. In one embodiment, the multilayer block provides an antiferromagnetic coupling between the pole and the shield such that a magnetization of the pole is in a first direction and a magnetization of the shield in a second direction that is substantially anti-parallel to the first direction.

Abstract: A method includes: fabricating a wafer having a plurality of layers, each including a feature of interest and a lapping guide positioned at a known location relative to the feature of interest, wherein the feature of interest and the lapping guide cross a common plane; lapping the wafer to the common plane to expose portions of the lapping guides; and measuring dimensions of the lapping guides and an offset of the lapping guides with respect to each other. An apparatus constructed using the method is also included.

Abstract: In a magnetic disk device including a magnetic disk coated with a lubricant, a face of a magnetic head slider, at a trailing side of the slider, is constructed so that all or part of an outer region adjoining other faces is made less wettable than other regions present at the trailing side face. For example, the trailing side face 13 of the magnetic head slider 8 has a protrusion 12 at both upper and lower ends of the face 13. Surface wettability of a face 12a forming the top of one of the protrusions 12 is reduced below surface wettability of other regions (a face 12c orthogonal to the face 12a, and a region 11). In addition, the other regions each have surface wettability that allows any sticking droplets of the lubricant to provide a sufficient wetting spread, but to such an extent that the droplets do not fall. This prevents a wetting spread of the lubricant to an air bearing surface, and hence, a fall of the lubricant from the magnetic head slider. Reliability is therefore enhanced.

Abstract: The invention is devised to provide a magnetoresistive element that is hardly susceptible to harmful influence of unnecessary magnetic fields and noise of heat even when reduction in size is achieved to be adaptable to higher recording density, and therefore that is excellent in operational reliability. The magnetoresistive element includes a stacked structure including, in order: a magnetically pinned layer whose magnetization direction is fixed in a given direction; a non-magnetic layer; a magnetically free layer whose magnetization direction changes according to an external magnetic field; and an antiferromagnetic bias layer exchange-coupled with the magnetically free layer. The exchange-coupling magnetic field between the magnetically free layer and the antiferromagnetic bias layer is smaller than a saturation magnetic field of the magnetically free layer.

Abstract: According to one embodiment, a magnetic head of a disk apparatus includes a main magnetic pole, a recording coil, a return magnetic pole, and a side shield provided on both sides of the main magnetic pole in the width direction, apart magnetically away from the main magnetic pole. The side shield includes on each side of the main magnetic pole a first shield edge which extends from a leading side end face of the return magnetic pole toward the main magnetic pole and opposes the main magnetic pole in at least a part with a gap smaller than the write gap, and a second shield edge which extends from the first shield edge in a direction opposite to the leading side end face of the return magnetic pole and opposes the main magnetic pole with a gap larger than the write gap.

Abstract: A data storage medium that includes a multiferroic thin film and ferromagnetic storage domains formed in the multiferroic thin film. The multiferroic thin film may be formed of at least one of BiFeO3, or any other ferroelectric and antiferromagnetic material. The ferromagnetic storage domains may be formed in the multiferroic thin film by an ion implantation process. A data storage system that incorporates the data storage medium is also provided.

Abstract: An apparatus includes a current perpendicular to the plane sensing element, a DC current source connected to the sensing element, a microwave AC current source connected to supply AC current to the sensing element, and a detector for measuring a voltage representative of phase difference between the AC current and AC voltage across the multilayer structure when the sensing element is subjected to a magnetic field. A method for sensing a magnetic field is also provided.

Abstract: A composite free layer having a FL1/insertion/FL2 configuration is disclosed for achieving high dR/R, low RA, and low ? in TMR or GMR sensors. Ferromagnetic FL1 and FL2 layers have (+) ? and (?) ? values, respectively. FL1 may be CoFe, CoFeB, or alloys thereof with Ni, Ta, Mn, Ti, W, Zr, Hf, Tb, or Nb. FL2 may be CoFe, NiFe, or alloys thereof with Ni, Ta, Mn, Ti, W, Zr, Hf, Tb, Nb, or B. The thin insertion layer includes at least one magnetic element such as Co, Fe, and Ni, and at least one non-magnetic element selected from Ta, Ti, W, Zr, Hf, Nb, Mo, V, Cr, or B. In a TMR stack with a MgO tunnel barrier, dR/R>60%, ?˜1×10?6, and RA=1.2 ohm-um2 when FL1 is CoFe/CoFeB/CoFe, FL2 is CoFe/NiFe/CoFe, and the insertion layer is CoTa or CoFeBTa.

Abstract: A Lorentz magnetoresistive sensor that employs a gating voltage to control the momentum of charge carriers in a quantum well structure. A gate electrode can be formed at the top of the sensor structure to apply a gate voltage. The application of the gate voltage reduces the momentum of the charge carriers, which makes their movement more easily altered by the presence of a magnetic field, thereby increasing the sensitivity of the sensor.

Abstract: Various embodiments of the present invention provide systems and methods for reducing head distortion. For example, various embodiments of the present invention provide storage devices that include a storage medium, a read/write head assembly, and an adaptive distortion modification circuit. The storage medium includes information that may be sensed by the read/write head assembly that is disposed in relation to the storage medium. The adaptive distortion modification circuit receives the information sensed by the read/write head assembly and adaptively estimates and implements a distortion compensation factor in the analog domain. In some instances of the aforementioned embodiments, the read/write head assembly includes a magneto resistive head. In such instances, the distortion compensation factor is designed to compensate for non-linear distortion introduced by the magneto resistive head.