Abstract: A GMR read head is described. The device comprises a spin valve stack whose top layer is a first capping layer. On the first capping layer are two additional layers, a lead overlay layer and a second capping layer. These are divided into two opposing portions, separated from each other by a trench that is filled with a dielectric. A bias layer and a conductive lead layer contact the stack on its sidewalls.

Abstract: In the present invention, a thin film whose main component is a metal having a specific resistance of 4 ??·cm to 200 ??·cm is used as a nonmagnetic layer of a so-called CPP-GMR element. Therefore, even when an area of the element becomes limited, the element is not increased excessively in resistance. Thus, even when a magnetic gap is narrow, a large output can be obtained.

Abstract: A magnetic head for reproducing a signal recorded on a recording medium, includes a substrate, a magnetic head core provided on the substrate, having a magnetic gap, and a magnetoresistance device provided on the magnetic head core. The magnetic head core is provided in such a manner that a thickness direction of the magnetic head core around the magnetic gap is substantially the same as a track width direction of the recording medium.

Abstract: An improvement in the corrosion resistance of a magnetoresistive head is aimed for, and a high magnetoresistivity ratio is maintained. In a magnetoresistive head equipped with, as a magnetic sensor element for detecting magnetic signals while in contact with a magnetic recording medium, a spin-valve film, which has a structure where an anti-ferromagnetic layer, a pinned layer in which the direction of magnetization is pinned in a predetermined direction by an exchange-coupling magnetic field at work between itself and the anti-ferromagnetic layer, a free layer in which the direction of magnetization changes in accordance with an external magnetic field, and a non-magnetic layer for magnetically isolating the pinned layer and the free layer are layered, the corrosion potential of the spin-valve film relative to a standard hydrogen electrode measured while immersed in a NaCl solution of a concentration of 0.1 mol/L is specified at +0.4 [V vs. SHE] or above.

Abstract: A spin-valve thin-film magnetic element includes a laminate including a free magnetic layer and a pinned magnetic layer. A pair of hard bias layers is provided on both sides of the laminate to orient the magnetic moment of the free magnetic layer in one direction. A pair of insulating layers extend over the hard bias layers and both top ends of the laminate in the track width direction. A pair of lead layers is provided on the insulating layers. Each lead layer has an overlay section extending over the insulating layer and the laminate. The edge of the overlay section is in direct contact with the central portion of the laminate.

Abstract: Provided is a magnetoresistance device. The device includes a substrate, a lower layer formed on the substrate, and a magnetoresistance structure formed on the lower layer, and the lower layer is formed of amorphous ZrxAl1-x (0<x<1) or ZrxAl1-xOy (0<x<1, 0<y<1). In a tunneling magnetoresistance (TMR) device, a tunneling barrier layer is formed of at least one selected from the group consisting of ZrxAl1-xOy (0<x<1, 0<y<1), TixAl1-xOy (0<x<1, 0<y<1), and NbxAl1-xOy (0<x<1, 0<y<1).

Abstract: A magneto-resistive magnetic sensor has an overlay-type structure and includes a cap layer on a top surface of a magneto-resistive structure and a pair of electrodes provided on said cap layer with a separation from each other, wherein there is interposed an oxidation-resistant conductive film underneath each electrode, such that the oxidation-resistant conductive film is sandwiched between the cap film and the electrode.

Abstract: A positioner (20) for a disk drive (10) that includes a magnet assembly (52), a conductor assembly (54), and a control system (22) is provided herein. The magnet assembly (52) includes a pair of magnet arrays (56A) (56B) and a pair of spaced apart flux return plates (75A) (75B). The conductor assembly (54) includes a coil array (78). The coil array includes a first portion (84) and a second portion (86) that are positioned substantially perpendicular to a longitudinal axis (43) of an E-block (16). The control system (22) directs current to electrically excite the first and second portions (84) (86) to generate a first force F1 and a second force F2 which are (i) parallel to the longitudinal axis (43) of the E-block (16), and (ii) equal in magnitude and directionally opposite to better position a data transducer (50) on a target track (32) of a storage disk (28).

Abstract: In a magnetoresistive effect transducer including a pinning layer, a pinned layer, a free layer and a non-magnetic layer inserted between the pinned layer and the free layer, a longitudinal bias layer is connected directly to a part of the free layer to apply a bias magnetic field to the free layer, thus biasing a magnetization direction of the free layer so that the magnetization direction of the free layer coincides with that of the longitudinal bias layer.

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 magnetic head including a spin valve sensor having a sensor layer stack that includes a pinned magnetic layer, a spacer layer formed on the pinned magnetic layer, and a free magnetic layer formed on the spacer layer. In a preferred embodiment the spacer layer is comprised of CuOx. Plasma smoothing of the upper surface of the pinned magnetic layer is conducted prior to depositing the spacer layer, and a preferred plasma gas is a mixture of argon and oxygen.

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, a resistance regulating layer is provided in at least one of a pinned layer, a free layer and an non-magnetic intermediate layer. The resistance regulating layer contains, as a principal component, an oxide, a nitride, a fluoride, a carbide or a boride. The resistance regulating layer may be a continuous film or may have pin holes. Thus, 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 magnetoresistance effect element includes a first ferromagnetic layer, insulating layer overlying the first ferromagnetic layer, and second ferromagnetic layer overlying the insulating layer. The insulating layer has formed a through hole having an opening width not larger than 20 nm, and the first and second ferromagnetic layers are connected to each other via the through hole.

Abstract: A unit element of a magnetic device or a ferroelectric device and magnetic particles of a magnetic recording medium are provided. The outline of the unit element and the magnetic particles is arranged so as to have a portion topologically identical to one of a letter-C shape and a letter-S shape that correspond to the magnetization or polarization distribution immediately before the rotation of magnetization or polarization.

Abstract: This invention teaches a way for the shield to shield (S1-S2) distance of a magnetic read head to be reduced. The key feature is that the upper and lower dielectric layers D1 and D3, which are normally pure aluminum oxide, have each been replaced by a bilayer dielectric, which consists of aluminum oxide in contact with the shield layer followed by a layer of a high voltage breakdown material. For D1 this layer may be either tantalum oxide or tantalum nitride while for D3 our preferred material has been tantalum oxide. The addition of the two high breakdown layers allows the thickness of the upper and lower dielectric layers to be reduced without having to reduce the S2—S2 voltage difference.

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 magnetoresistive element includes a pair of ferromagnetic layers and a non-magnetic layer arranged between the ferromagnetic layers. At least one of the ferromagnetic layers has a composition expressed by (MxLy)100-zRz at the interface with the non-magnetic layer. The non-magnetic layer includes at least one element selected from the group consisting of B, C, N, O, and P. Here, M is FeaCobNic, L is at least one element selected from the group consisting of Pt, Pd, Ir, and Rh, R is an element that has a lower free energy to form a compound with the element of the non-magnetic layer that is at least one selected from the group consisting of B, C, N, O, and P than does any other element included in the composition as M or L, and a, b, c, x, y, and z satisfy a+b+c=100, a?30, x+y=100, 0<y?35, and 0.1?z?20. This element can provide a high MR ratio. A method for manufacturing a magnetoresistive element includes a first heat treatment process at 200° C. to 330° C.

Abstract: A magnetoresistance effect element includes a magnetization fixed layer in which the direction of magnetization is substantially fixed to one direction, a magnetization free layer in which the direction of magnetization varies in response to an external magnetic field, and a non-magnetic intermediate layer formed between the magnetization fixed layer and the magnetization free layer. The magnetoresistance effect element has 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, the resistance being detected when a sense current is applied to the film planes of the magnetization fixed layer, the non-magnetic intermediate layer, and the magnetization free layer in a direction substantially perpendicular thereto.

Abstract: A method of manufacturing a spin valve film, which produces a large read out signal. After a completion of a film making process for forming a previous film of two films to be formed successively, but before an initiation of a film making process forming a succeeding film of the two the films, a step of decreasing an anisotropic magnetic field of the spin valve film is introduced by interrupting a film making process. This step may be performed by keeping a substrate within a sputtering vacuum chamber. The interruption can be shortened by exposing the substrate to a plasma, transferring the substrate in a separate vacuum chamber whose degree of vacuum is lower or whose H2O or O2 concentration is higher than that in the sputtering vacuum chamber, conducting a surface treatment with a gas containing H2O or O2, or flowing a process gas.

Abstract: A method for forming a bottom spin valve sensor having a synthetic antiferromagnetic pinned (SyAP) layer, antiferromagnetically coupled to a pinning layer, in which one of the layers of the SyAP is formed as a three layer lamination that contains a specularly reflecting oxide layer of FeTaO. The sensor formed according to this method has an extremely high GMR ratio and exhibits good pinning strength.

Abstract: A spin valve sensor is provided with a negative ferromagnetic coupling field ?HFC for properly biasing a free layer and a spin filter layer is employed between the free layer and a capping layer for increasing the magnetoresistive coefficient dr/R of the spin valve sensor. A top portion of the free layer is oxidized for improving the negative ferromagnetic coupling field ?HFC when the spin filter layer is employed for increasing the magnetoresistive coefficient dr/R.

Abstract: In current synthetically pinned CPP SV designs, AP2 always makes a negative contribution to the device's GMR since its magnetization direction must be anti-parallel to the pinned layer (AP1). This effect has been reduced by replacing the conventional single layer AP2, that forms part of the synthetic pinned layer, with a multilayer structure into which has been inserted at least one layer of a material such as tantalum that serves to depolarize the spin of electrons that traverse its interfaces. The result is a reduction of said negative contribution by AP2, leading to a significant increase in the GMR ratio.

Abstract: A specular layer and a nonmagnetic layer are provided on a central portion of a free magnetic layer, and ferromagnetic layers and second antiferromagnetic layers are provided on both end portions of the free magnetic layer. In the present invention, the total thickness of the specular layer and the nonmagnetic layer can be decreased, and thus ion milling for removing the layers from both end portions of the free magnetic layer can be performed with low energy. Therefore, both end portions of the free magnetic layer are less damaged by ion milling, and ferromagnetic coupling produced between both end portions of the free magnetic layer and the ferromagnetic layers can be increased, thereby permitting appropriate control of magnetization of the free magnetic layer.

Abstract: A magnetic field sensor has a pair of magnetic shields serving as a negative electrode and a positive electrode, respectively, a magnetoresistive element arranged between the pair of magnetic shields, a nonmagnetic conductive layer for the negative electrode arranged between the magnetic shield for the negative electrode and the magnetoresistive element and including a first metal layer formed in contact with the magnetoresistive element and a second metal layer formed in contact with the first metal layer, and a nonmagnetic conductive layer for the positive electrode arranged between the magnetic shield for the positive electrode and the magnetoresistive element and formed of a first metal layer, the first metal layer containing at least one metal selected from the group consisting of Ta, Ti, Cr, V, Mo and W.

Abstract: The invention is a magnetic device, i.e., a magnetoresistive sensor or a magnetic tunnel junction device, that has a ferromagnetic structure of two ferromagnetic layers antiferromagnetically coupling together with an improved antiferromagnetically coupling (AFC) film. The AFC film is an alloy of Ru100-xFex where x is between approximately 10 and 60 atomic percent. This AFC film increases the exchange coupling by up to a factor or two and has an hcp crystalline structure making it compatible with Co alloy ferromagnetic layers.

Abstract: A method of making provides a smooth surface of a pinned or free layer interfacing a barrier layer in a tunnel junction sensor wherein the smooth surface is an oxidized monolayer of the pinned or free layer. After sputter depositing the pinned or free layer the layer is subjected to an oxygen (O2) atmosphere which is extremely low for a very short duration. In a preferred embodiment of the invention a partial thickness of the barrier layer is provided with a smooth surface by the same process after which a remainder thickness of the barrier layer is deposited and the barrier layer is exposed to oxygen (O2) to form an oxide of the deposited metal.

Abstract: In a thin film magnetic head device including a reading giant magneto-resistive thin film magnetic head element whose electric equivalent circuit is expressed by a series circuit of an equivalent voltage source and a series resistor RH and a parallel capacitor C connected in parallel with said series circuit, inductor L is connected in series with said series resistor RH and a parallel resistor R is connected in series with said parallel capacitor C. The coil L and parallel capacitor C are set such that an angular frequency ?0=1/(LC)1/2, an angular frequency ?1=1/CR and an angular frequency ?H=1/CRH satisfy conditions of ?0>?1 and ?0>?H, preferably ?0>>?1 and ?0>>?H to extend a frequency characteristic toward a high frequency range.

Abstract: A method and system for providing a magnetoresistive sensor and a read head that includes the magnetoresistive sensor is disclosed. The method and system include providing a pinned layer, a nonmagnetic spacer layer and a composite sensor layer. The pinned layer has a first magnetization that is pinned in a particular direction. The nonmagnetic spacer layer resides between the composite sensor layer and the pinned layer. The composite sensor layer includes a CoFe layer and a composite layer adjacent to the CoFe layer. The composite layer includes CoFe and at least one of Ta, Hf, Ti, Nb, Zr, Au, Ag, Cu, B, C, O2, H2 and N2.

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

Abstract: Disclosed is a method of making a SVGMR sensor element. In the first embodiment a buffer layer is formed between a seed layer and a ferromagnetic (FM) free layer, the buffer layer being composed of alpha-Fe2O3 having a crystal lattice constant that is close to the FM free layer's crystal constant and has the same crystal structure. The metal oxide buffer layer enhances the specular scattering. In the second embodiment, a high conductivity layer (HCL) is formed over the buffer layer to create a spin filter-SVGMR. The HCL layer enhances the GMR ratio of the spin filter SVGMR. The third embodiment include a pinned FM layer comprising a three layer structure of a lower AP layer, a space layer (e.g., Ru) and an upper AP layer.

Abstract: Ultrafast solid state amplifiers of electrical current, including power amplification devices, use injection of spin-polarized electrons from a magnetic region into another magnetic region through a semiconductor control region and electron spin precession inside the control region induced by a magnetic field resulting from a current flowing through a conductive nanowire. The amplifiers may include magnet-semiconductor-magnet heterostructures and are able to operate on electric currents and electromagnetic waves having frequencies up to 100 GHz or more.

Abstract: A memory device includes a plurality of memory elements each having: an antiferromagnetic layer, a first pinned layer coupled to the antiferromagnetic layer, a nonmagnetic spacer layer coupled to the first pinned layer, a second pinned layer coupled to the spacer, and a free layer coupled to the second pinned layer. A plurality of single wiring circuits are provided, each wiring circuit being coupled to a memory element. An addressing mechanism applies current pulses to the memory elements via the single wiring circuits for writing to the memory elements. The addressing mechanism also applies a sense current to the memory elements via the single wiring circuits for reading the memory elements.

Abstract: A metal manganese oxide buffer layer is used to seed a barrier layer in a magnetic tunnel junction memory element having pinned and free magnetic layers. An alumina tunnel barrier layer is formed on the oxidized metal manganese layer with the barrier layer and oxidized metal manganese layer being between the pinned or free ferromagnetic layers.

Abstract: A semiconductor slider including an integral spin valve transistor (SVT) having a read width of 250 nm or less disposed on a monolithic semiconductor substrate, useful in magnetic data storage applications. The monolithic slider may also include other magnetic and semiconductor transistor structures and is fabricated in a single process using standard thin-film processing steps. The SVT includes a sensor stack having a top surface and including a first ferromagnetic (FM) layer in contact with and forming a Schottky barrier at the monolithic semiconductor substrate, a FM shield layer disposed over the sensor stack and in electrical contact with the top surface thereof, a SVT emitter terminal coupled to the FM shield, a SVT collector terminal coupled to the substrate and a SVT base terminal coupled to the first FM layer. The sensor stack may include a spin valve (SV) stack or a tunnel valve (TV) stack, for example.

Abstract: A pinned/pinning layer configuration of the form: AP1/coupling bilayer/AP2/AFM, suitable for use in a CIP or CPP GMR sensor, a TMR sensor or an MRAM element, is found to have improved magnetic stability, yield good values of dR/R and have high values of saturation magnetization that can be adjusted to meet the requirements of magnetic field annealing. The coupling bilayer is a layer of Ru/Rh or their alloys, which provides a wide range of coupling strengths by varying either the thickness of the Ru layer or the Rh layer.

Abstract: In a spin valve, an underlayer is made of oxygen-rich nickel oxide to enhance the giant magnetoresistive ratio (?R/R). The oxygen-rich nickel oxide film is made using reactive sputtering of a nickel target in an oxygen-rich sputtering atmosphere consisting substantially of pure oxygen and argon gases. The total pressure of the oxygen-rich atmosphere is reduced during the oxygen-rich nickel oxide film formation to additionally enhance the ?R/R value. A spin valve including two adjacent oxygen-rich nickel oxide underlayers provides a higher ?R/R ratio at a given pinning strength Hua than does a spin valve having only one oxygen-rich nickel oxide underlayer.

Abstract: A spin valve sensor in a read head has a spacer layer which is located between a self-pinned AP pinned layer structure and a free layer structure. The free layer structure is longitudinally stabilized by first and second hard bias layers which abut first and second side surfaces of the spin valve sensor. The AP pinned layer structure has an antiparallel coupling layer (APC) which is located between first and second AP pinned layers (AP1) and (AP2). The invention employs a preferential setting of the magnetic moments of the AP pinned layers by applying a field at an acute angle to the head surface in a plane parallel to the major planes of the layers of the sensor. The preferential setting sets a proper polarity of each AP pinned layer, which polarity conforms to processing circuitry employed with the spin valve sensor.

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

Abstract: There are provided a magnetoresistance effect element, a magnetic head, a magnetic head assembly and a magnetic recording system, which have high sensitivity and high reliability. The magnetoresistance effect element has two ferromagnetic layers, a non-magnetic layer provided between the ferromagnetic layers, and a layer containing an oxide or nitride as a principal component, wherein the layer containing the oxide or nitride as the principal component contains a magnetic transition metal element which does not bond to oxygen and nitrogen and which is at least one of Co, Fe and Ni.

Abstract: In a yoke type reproducing magnetic head, a magnetoresistance effect film can be arranged in the vicinity of a medium facing surface, so that sensitivity is improved. The yoke type reproducing magnetic head comprises: a pair of magnetic yokes which face each other via a magnetic gap, at least one of the pair of magnetic yokes extending from a medium facing surface to a position retracted from the medium facing surface; a magnetoresistance effect film which has a curved portion protruding toward the medium facing surface in the magnetic gap and which is magnetically connected to the magnetic yokes; and an electrode which is electrically connected to the magnetoresistance effect film.

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 using a liftoff technique to form, on the free layer, a buffer layer having a trapezoidal cross-section, sloping sidewalls, and a central area of uniform thickness, whose width defines the read track. A suitable bias layer and leads are then deposited on this buffer layer.

Abstract: A magneto-resistive device has a magneto-resistive layer laminated between electrodes. The magneto-resistive layer has a non-magnetic layer, a pinned layer and a free layer sandwiching the non-magnetic layer, and a pin layer formed on the pinned layer on the opposite side to the free layer. The pin layer is formed in a region which substantially overlaps with an effective region in a film plane direction in which a current flows in a direction substantially perpendicular to the film plane between the electrodes in a predetermined thickness, and is formed in a region which does not substantially overlap with the effective region substantially in the same thickness as the predetermined thickness or in a thickness smaller than the predetermined thickness, continuous from the region which substantially overlaps with the effective region.

Abstract: At both end portions of at least a soft magnetic layer of a magneto-resistive effect film, a pair of bias magnetic field applying layers are disposed for applying a longitudinal bias magnetic field to the soft magnetic layer via magnetic underlayers. Further, mutual lattice point-to-point distances in the plane where each magnetic underlayer and the corresponding bias magnetic field applying layer are mated, are substantially equalized to each other. Therefore, a coercive force Hc in an in-plane direction (direction parallel to a film surface) of each bias magnetic field applying layer can be maintained at a high level so that even when further gap narrowing or track narrowing is aimed, the bias magnetic field applying layers can act to apply an effective bias magnetic field, i.e. can act to suppress occurrence of the Barkhausen noise.

Abstract: A magnetoresistive sensor has bias magnets with substantially vertical end walls. The offset between the bias magnets and the free layer is optimized by adjusting the thickness of a spacer layer. A disk drive has a read element including a magnetoresistive sensor with optimized bias magnets having substantially vertical end walls.

Abstract: In a magnetoresistive effect element using a ferromagnetic tunnel junction having a tunnel barrier layer sandwiched between at least a pair of ferromagnetic layers, a magnetization free layer comprising one of the ferromagnetic layers is composed of a single layer of a material having an amorphous or microcrystal structure or a material layer the main portion of which has an amorphous or microcrystal structure. The magnetoresistive effect element can produce excellent magnetic-resistance characteristics, and a magnetic memory element and a magnetic memory device using the magnetoresistive effect element as a memory element thereof can improve both of write and read characteristics at the same time.

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.

Abstract: A spin valve head configured to operate in a Current-In-Plane (CIP) mode is provided. The spin valve head has an air bearing surface (ABS) and a top and a bottom shield separated by a central region proximate the ABS. A sensor, positioned in the central region, has a proximal end and a distal end, with the proximal end forming a portion of the ABS. A permanent magnet is positioned in the central region and proximate the distal end of the sensor. The permanent magnet being separated from the sensor by a gap layer. The top shield, the bottom shield and the permanent magnet are electrically coupled together to allow for electrical testing of the spin valve head.

Abstract: A spin valve magnetic head, providing on a substrate, a laminated structure that has an antiferromagnetic layer, fixation layer, non-magnetic layer and unconstraint layer, and having a first underlayer of Ta, a second underlayer of NiFeCr and a third underlayer of NiFe, which underlayers are interposed between the substrate and the laminated structure.

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: The invention relates to a magnetoresistive device with a spin valve (1) formed from a stack of layers including at least two magnetic layers (2, 3) for which the relative orientation of their magnetisation directions can vary under the influence of a magnetic field, and comprising means (6a, 6b) of circulating a current in the spin valve transverse to the plane of the layers. The spin valve (1) comprises at least one discontinuous dielectric or semiconducting layer (4) in the stack, with electrically conducting bridges (5) passing through the thickness of the dielectric or semiconducting layer, these bridges (5) being designed to locally concentrate the current that passes transversely through the stack.