Abstract: The invention relates to the identification of molecules using electromagnetic write-heads and magneto-resistive sensors. In one embodiment, an electromagnetic write-head magnetically excites a molecule with an alternating magnetic field. A magneto-resistive sensor measures the resonant response of the magnetically excited molecule. A processor compares the resonant response to a table of known responses of different molecules to identify the chemical composition of the molecule based in whole or in part on the comparison.

Abstract: Read elements and associated methods of fabrication are disclosed. During fabrication of the read element, and more particularly, the fabrication of the hard bias magnets, a non-magnetic sacrificial layer is deposited on top of the hard bias material. When a CMP process is subsequently performed, the sacrificial layer is polished instead of the hard bias material. The thicknesses of the hard bias magnets are not affected by the CMP process, but are rather defined by the deposition process of the hard bias material. As a result, the variations in the CMP process will not negatively affect the magnetic properties of the hard bias magnets so that they are able to provide substantially uniform effective magnetic fields to bias the free layer of the magnetoresistance (MR) sensor of the read element.

Abstract: A magnetoresistive sensor having a novel seed layer that allows a bias layer formed there over to have exceptional hard magnetic properties when deposited over a crystalline structure such as an AFM layer in a partial mill sensor design. The seed layer structure includes alternating layers of Ru and Si and a layer of CrMo formed thereover. The seed layer interrupts the epitaxial growth of an underlying crystalline structure, allowing a hard magnetic material formed over the seed layer to have a desired grain structure that is different from that of the underlying crystalline layer. The seed layer is also resistant to corrosion, providing improved sense current conduction to the sensor.

Abstract: A magnetic sensor includes a sensor stack having a sensing layer. A first biasing structure having a first magnetization vector is positioned adjacent to the sensor stack to produce a biasing field that biases the sensing layer. A second biasing structure having a second magnetization vector is positioned within the sensor stack relative to the sensing layer to counter the biasing field at a center of the sensing layer.

Abstract: A magneto-resistive sensor head and a method of manufacturing the magneto-resistive sensor head. The magneto-resistive sensor head includes a first lead and a second lead. A magneto-resistive layer and a biasing layer are disposed between the first lead and the second lead. A grating is disposed in the magneto-resistive layer. The topography of the biasing layer is unaffected by the presence of the grating.

Abstract: A magnetoresistive film is interposed between domain controlling films in a current-perpendicular-to-the-plane (CPP) structure magnetoresistive element. The domain controlling films are designed to establish a first biasing magnetic field of a first intensity across the magnetoresistive film along the front end of the magnetoresistive film and a second biasing magnetic field of a second intensity larger than the first intensity along the rear end of the magnetoresistive film. The second biasing magnetic field serves to establish a single domain property within the magnetoresistive film along the rear end. Although the first biasing magnetic field acts in the same direction as the current field at a position near the front end of the magnetoresistive film, the magnetization is allowed to reliably rotate near the front end. A sensing current having a larger current value can be supplied to the magnetoresistive film. The magnetoresistive film exhibits a sufficient sensitivity.

Abstract: It is necessary to stabilize the free layer of GMR or TMR devices by providing a longitudinal bias field. As read tracks become very narrow, this field can drastically reduce the strength of the output signal. This problem has been overcome by adding an additional bias layer. This layer, which may be located either above or below the conventional bias layer, is permanently magnetized in the opposite direction to that of the permanent magnets used to achieve longitudinal stability. Through control of the magnetization strength and location of this additional bias layer, cancellation of much of the field induced in the free layer by the conventional bias layers is achieved.

Abstract: A magnetoresistive effect (MR) element, a thin-film magnetic head having the MR element, a method for manufacturing the MR element, and a method for manufacturing the thin-film magnetic head are disclosed. The MR element, which uses electric current in a direction perpendicular to layer planes, includes a lower electrode layer, a MR multilayered structure formed on the lower electrode layer, a magnetic domain controlling bias layer that is disposed on both sides of the MR multilayered structure along the track-width direction and is made of a material at least partially including an hcp structure, a metal layer made of a material having a bcc structure formed on the magnetic domain controlling bias layer and the MR multilayered structure to cover the magnetic domain controlling bias layer and the MR multilayered structure, and an upper electrode layer formed on the metal layer.

Abstract: A combined stripe of a magnetoresistive (MR) film and domain control stripe layers can be formed below a photoresist film on the surface of a substratum. An insulating base layer is then formed to extend over the surface of the substratum. The insulating base layer is allowed to cover over the photoresist film, the magnetoresistive film and the domain control stripe layers on the substratum. When the photoresist film is removed, the insulating base layer remains on the substratum. The insulating base layer keeps contacting the side surface of the magnetoresistive film. The magnetoresistive film can be kept covered with the insulating base layer at the side surface during a subsequent etching process. Any chemical reaction can be avoided between the magnetoresistive film and the etching gas employed in the etching process. The resulting magnetoresistive head element is allowed to exhibit an ideal characteristic in the magnetoresistive effect.

Abstract: A seed layer structure for improved crystallographic orientation of grains in a hard magnetic material is disclosed. The seed layer structure is comprised of alternating layers of a metal and a dielectric. Hard magnetic materials deposited on the seed layer structure have superior properties and performance in providing hard bias to a ferromagnetic layer in a magnetic sensor. The seed layer structure also accommodates a relatively large total thickness, which is preferable in magnetic sensors with an ultra contiguous junction arrangement.

Abstract: A magnetic recording transducer, useful in a magnetic data storage device, having a read element with improved magnetic stability and a narrow track width is described. An MR stripe according to the invention has a magnetic-stability inducing (MSI) shape selected from an essentially trapezoidal shape, an essentially hexagonal shape, an essentially race-track shape, and an essentially half race track shape. These MSI shapes are oriented in a plane perpendicular to the air-bearing surface (ABS). The MSI shapes are used to encourage the formation of a single magnetic domain state with magnetization direction parallel to the ABS in the absence of a magnetic bias. In one embodiment according to the invention the sensor structure is overlaid on the sides of the top surface with layers of electrically conductive material (overlaid leads) to define an approximately rectangular active region of the larger MSI shape.

Abstract: A magnetic sensor is provided, having two bias layers separated by a decoupling layer to eliminate exchange coupling between the bias layers. The two bias layers may have differing coercivities, such that the biases provided by the bias layers to the free layer are independently adjustable. The grain structures of the two bias layers may be substantially decorrelated by the decoupling layer.

Abstract: A magnetoresistance sensor structure includes a magnetoresistance sensor having a sensor surface plane and having a free layer. An upper antiferromagnetic layer overlies at least a portion of the free layer, and an upper ferromagnetic layer overlies and contacts at least a portion of the upper antiferromagnetic layer on a contact face lying parallel to the sensor surface plane, so that the upper antiferromagnetic layer lies between the upper ferromagnetic layer and the free layer. The magnetoresistance sensor may be a giant magnetoresistance sensor or a tunnel magnetoresistance sensor.

Abstract: There are provided a magnetoresistive sensor of the type of flowing a signal sensing current perpendicular to the plane to improve resolution at reproducing a signal, a magnetic head using the magnetoresistive sensor, and a magnetic disk apparatus.

Abstract: A magnetoresistive sensor of the type of flowing a signal sensing current perpendicular to the plane to improve resolution at reproducing a signal, a magnetic head using the magnetoresistive sensor, and a magnetic disk apparatus. A magnetoresistive sensor comprising a substrate, a pair of magnetic shield layers consisting of a lower magnetic shield layer and an upper magnetic shield layer, a magnetoresistive sensor layer, disposed between the pair of magnetic shield layers, an electrode terminal for flowing a signal current perpendicular to the plane of the magnetoresistive sensor layer, and magnetic domain control layers for controlling Barkhausen noise of the magnetoresistive sensor layer, wherein the magnetic domain control layers disposed in contact with opposite ends of the magnetoresistive sensor layer consist of a material having high electric resistivity and with a specific resistance not less than 10 m?cm so as to give the magnetoresistive sensor having excellent reproducing resolution.

Abstract: There are provided a magnetoresistive sensor of the type of flowing a signal sensing current perpendicular to the plane to improve resolution at reproducing a signal, a magnetic head using the magnetoresistive sensor, and a magnetic disk apparatus.

Abstract: Within a method for forming a magnetoresistive (MR) sensor element there is first provided a substrate. There is then formed over the substrate a first magnetoresistive (MR) layer having formed contacting the first magnetoresistive (MR) layer a magnetically biased first magnetic bias layer biased in a first magnetic bias direction with a first magnetic bias field strength. There is also formed separated from the first magnetoresistive (MR) layer by a spacer layer a second magnetoresistive (MR) layer having formed contacting the second magnetoresistive (MR) layer a magnetically un-biased second magnetic bias layer.

Abstract: Multi-channel magnetic head having a high channel density, provided with a head face (1) which extends in a first direction (I) in which a record carrier is relatively movable with respect to said magnetic head, and in a second direction (II) transverse to the first direction. The magnetic head has a structure of layers which, viewed in the first direction, are situated one on top of the other and extend substantially in the second direction and in a third direction (III) transverse to the first and the second direction. Viewed in the second direction, adjacent magnetoresistive sensors (S1, S2, S3) are distinguishable in the structure, each comprising a magnetoresistive measuring element (5), a first magnetic element (7) and a second magnetic element (9).

Abstract: A magnetic recording transducer, useful in a magnetic data storage device, having a read element with improved magnetic stability and a narrow track width is described. An MR stripe according to the invention has a magnetic-stability inducing (MSI) shape selected from an essentially trapezoidal shape, an essentially hexagonal shape, an essentially race-track shape, and an essentially half race track shape. These MSI shapes are oriented in a plane perpendicular to the air-bearing surface (ABS). The MSI shapes are used to encourage the formation of a single magnetic domain state with magnetization direction parallel to the ABS in the absence of a magnetic bias. In one embodiment according to the invention the sensor structure is overlaid on the sides of the top surface with layers of electrically conductive material (overlaid leads) to define an approximately rectangular active region of the larger MSI shape.

Abstract: A fixed magnetic recording device which can suppress dispersions appearing, upon manufacturing, on an effective track width and a longitudinal bias magnetic field of a magnetic head using a hard bias system. A magnetic recording device, which includes a magnetic head using a hard bias system, the head having a hard magnetic film (3) for adding a magnetic field in a longitudinal bias direction to a magnetic resistance film (1) and for controlling a magnetic domain, is characterized in that the hard magnetic film (3) includes a solenoid (4) for adjusting a magnetic field running in a longitudinal bias direction. Thus, it is possible to make fine adjustments on a magnetic field in a longitudinal bias direction and to maintain an optimum value. Consequently, it is possible to improve the linear response of a reproducing output of the magnetic head and to adjust an effective track width of the magnetic head.

Abstract: There are provided a magnetoresistive sensor of the type of flowing a signal sensing current perpendicular to the plane to improve resolution at reproducing a signal, a magnetic head using the magnetoresistive sensor, and a magnetic disk apparatus.

Abstract: A spin valve sensor is disclosed that comprises a first layer of ferromagnetic material and a second layer of ferromagnetic material. A first layer of non-ferromagnetic material is positioned between the first and second layers of ferromagnetic material. A pinning layer is positioned adjacent to the first layer of ferromagnetic material such that the pinning layer is in contact with the first layer of ferromagnetic material. The spin valve includes synthetic antiferromagnetic bias means extending over passive end regions of the second layer of ferromagnetic material for producing a longitudinal bias in the passive end regions of a level sufficient to maintain the passive end regions in a single domain state. A method for forming a spin valve sensor with exchange tabs is also disclosed.

Abstract: A magnetoresistive transducer includes a magnetoresistive (MR) film interposed between domain control layers along the surface of a lower non-magnetic gap layer. Lead layers are formed on the domain control layers. An upper non-magnetic gap layer and an upper shield layer are sequentially formed to extend over the MR film and the lead layers. The upper shield layer is opposed to the surfaces of the MR element and the lead layers at a flat boundary or interface. The residual magnetization is supposed to exist in the upper shield layer in the direction of the magnetization established in the domain control layers after the upper shield layer has been subjected to the applied magnetic field for the magnetization of the domain control layers. The residual magnetization can be kept continuous along the flat interface of the upper shield layer. Any magnetic poles are hardly generated along the interface of the upper shield layer.

Abstract: A magnetoresistive element is formed by laminating a soft magnetic bias gap layer, a soft magnetic bias layer, a magnetic separation layer, a magnetoresistive layer and a magnetoresistive gap layer, so as to define a sliding surface on which a tape-shaped magnetic recording medium is slid. An upper shield layer and a lower shield layer vertically sandwich the magnetoresistive element therebetween. A vertically stepped portion is provided on each of the upper or the lower shield layer and the respective layers forming the magnetoresistive element, so as to extend horizontally in a track width direction of the sliding surface.

Abstract: A combined stripe of a magnetoresistive (MR) film and domain control stripe layers can be formed below a photoresist film on the surface of a substratum. An insulating base layer is then formed to extend over the surface of the substratum. The insulating base layer is allowed to cover over the photoresist film, the magnetoresistive film and the domain control stripe layers on the substratum. When the photoresist film is removed, the insulating base layer remains on the substratum. The insulating base layer keeps contacting the side surface of the magnetoresistive film. The magnetoresistive film can be kept covered with the insulating base layer at the side surface during a subsequent etching process. Any chemical reaction can be avoided between the magnetoresistive film and the etching gas employed in the etching process. The resulting magnetoresistive head element is allowed to exhibit an ideal characteristic in the magnetoresistive effect.

Abstract: A magnetoresistive film through which a sense current for detecting a resistance change due to a magnetic field to be detected flows in a longitudinal direction, and a lateral bias film which is magnetized in a fixed direction by a constant magnitude such that a lateral bias is applied to said magnetoresistive film in a lateral direction intersecting said longitudinal direction are arranged to be opposed to each other via a magnetic isolation film. By conducting said sense current by means of a pair of lead conductive films coupled electrically to both edges of said magnetoresistive film, a magnetization recorded on a magnetic record medium can be detected. Since the lateral bias is applied to the magnetoresistive film such that the lateral bias is not affected by the sense current and external magnetic fields, the magnetization of the magnetic record medium can be stably detected without being influenced by the sense current and external magnetic fields.

Abstract: A magnetoresistive element has a first end face for detecting an external magnetic field and a second end face which is opposed to the first end face. A pair of vertical bias layers sandwich the magnetoresistive element so as to expose the first and second end faces, to apply a bias magnetic field to the magnetoresistive element. Each of the vertical bias layers includes a face, which is continuous and flush with the second end face, having a length of 1.5 &mgr;m or greater. Alternatively, each of the vertical bias layers includes a face which is continuous with the second end face, and inclined by 0 to 45 degrees with respect to the second end face.

Abstract: There are provided a magnetoresistive sensor of the type of flowing a signal sensing current perpendicular to the plane to improve resolution at reproducing a signal, a magnetic head using the magnetoresistive sensor, and a magnetic disk apparatus.

Abstract: A method for forming a longitudinally magnetically biased dual stripe magnetoresistive (DSMR) sensor element comprises forming a first patterned magnetoresistive (MR) layer. Contact the opposite ends of the patterned magnetoresistive (MR) layer with a first pair of stacks defining a track width of the first magnetoresistive (MR) layer, each of the stacks including a first Anti-Ferro-Magnetic (AFM) layer and a first lead layer. Then anneal the device in the presence of a longitudinal external magnetic field. Next, form a second patterned magnetoresistive (MR) layer above the previous structure. Contact the opposite ends of the second patterned magnetoresistive (MR) layer with a second pair of stacks defining a second track width of the second patterned magnetoresistive (MR) layer. Each of the second pair of stacks includes spacer layer composed of a metal, a Ferro-Magnetic (FM) layer, a second Anti-Ferro-Magnetic (AFM) layer and a second lead layer.

Abstract: A longitudinal bias structure to be placed adjacent a ferromagnetic free layer or a sense layer which is responsive to an external magnetic field and belongs to a magnetic sensor, for example a magnetic readback sensor such as an anisotropic magnetoresistive (AMR) sensor, giant magnetoresistive (GMR) sensor such as GMR spin valve sensor or GMR multilayer sensor or in tunnel valve sensor. The longitudinal bias structure is built up of a top ferromagnetic bias layer of first thickness t1 having a first magnetic moment M1, a bottom ferromagnetic bias layer of second thickness t2 having a second magnetic moment M2 which is anti-parallel to first magnetic moment M1 of the top ferromagnetic bias layer, and an exchange-coupling layer disposed between the top and bottom bias layers.

Abstract: A magnetic structure, such as a magnetoresistive sensor, having a continuous multi-region magnetic layer in which the magnetic and electrical characteristics of each region is locally defined. In the preferred embodiment, the continuous multi-region magnetic layer has high coercivity end regions separated by a low coercivity central region.

Abstract: Bias layers for a magnetoresistive (MR) sensor have an in-plane easy axis of magnetization for providing a longitudinal bias to MR layers. The bias layers include cobalt (Co), and are formed on various underlayers having crystalline structures that encourage an in-plane alignment of the C-axis of that Co. Preferred underlayers include nickel aluminum (NiAl) and magnesium oxide (MgO), and an interlayer containing chromium (Cr) may be interposed between a bias layer and an underlayer.

Abstract: The back end of an MR sensor and a flux guide are joined by a contiguous self-aligned junction so that a predictable overlap of the flux guide on the back end of the MR sensor can be achieved for optimizing signal flux density in the MR sensor. Lead/longitudinal bias layers for the MR sensor are also joined by a contiguous self-aligned junction to the flux guide for stabilizing the flux guide. By employing a single lift off resist mask the MR sensor and the lead/longitudinal bias layers can be patterned followed by deposition of the flux guide. The flux guide is a bilayer of an insulation material layer and a flux guide material layer. The insulation material layer is sandwiched between the MR sensor and the flux guide material layer and between the lead/longitudinal bias layers and the flux guide material layer. A heat guide or combined flux guide and heat guide may be substituted for the aforementioned flux guide.

Abstract: A magnetoresistive head in which Barkhausen noise is substantially suppressed and a variation in reproduction is minimized, and a magnetic disk apparatus using the same magnetic head have been provided. The feature of the magnetic head and the magnetic disk apparatus of the invention resides in the provision of the longitudinal bias layer which comprises a hard magnetic thin film formed on an underlayer made of either of a ferromagnetic thin film having a body-centered cubic lattice crystal structure formed of body-centered cells, an amorphous ferromagnetic thin film or antiferromagnetic thin film having a body-centered cubic lattice crystal structure formed of body-centered cells.