Having Giant Magnetoresistive (gmr) Or Colossal Magnetoresistive (cmr) Sensor Formed Of Multiple Thin Films Patents (Class 360/324)
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Publication number: 20110235216Abstract: A read head having an improved longitudinal bias stack for stabilizing the sense layer structure of a CPP read sensor is proposed. The longitudinal bias stack is separated by an insulation layer from the CPP read sensor in each of two side regions, and is sandwiched together with the insulation layer and the CPP read sensor between lower and upper ferromagnetic shields in the read head. In a preferred embodiment of the invention, the longitudinal bias stack mainly comprises an Fe—Pt longitudinal bias layer without any seed layers, and thus the thickness of the insulation layer alone defines a spacing between the Fe—Pt longitudinal bias layer and the CPP read sensor. Since the Fe—Pt longitudinal bias layer without any seed layers exhibits good in-plane hard-magnetic properties after annealing and the spacing is narrow, the stabilization scheme is effective.Type: ApplicationFiled: March 26, 2010Publication date: September 29, 2011Inventor: Tsann Lin
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Patent number: 8027129Abstract: A sensor includes a sensor stack and a layer of high resistivity material having a precursor within the sensor stack. When a current is applied at the precursor, a current confining path is formed through the layer of high resistivity material at the precursor. The shape of the current confining path is adjustable by adjusting a thickness of the layer of high resistivity material.Type: GrantFiled: June 27, 2006Date of Patent: September 27, 2011Assignee: Seagate Technology LLCInventors: Janusz J. Nowak, Konstantin R. Nikolaev, Khuong T. Tran, Mark T. Kief
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Publication number: 20110228427Abstract: A magnetoresistive element includes a first ferromagnetic layer, a second ferromagnetic layer, a nonmagnetic layer, a first metal layer, a second metal layer, a first electrode, and a second electrode. The nonmagnetic layer is provided between the first ferromagnetic layer and the second ferromagnetic layer. The first metal layer includes Au and is provided so that the first ferromagnetic layer is sandwiched between the nonmagnetic layer and the first metal layer. The second metal layer includes a CuNi alloy, and is provided so that the first metal layer is sandwiched between the first ferromagnetic layer and the second metal layer. In addition, magnetization of either one of the first ferromagnetic layer and the second ferromagnetic layer is fixed in a direction. Magnetization of the other is variable in response to an external field. At least one of the first ferromagnetic layer and the second ferromagnetic layer includes a half metal.Type: ApplicationFiled: September 10, 2010Publication date: September 22, 2011Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Hiromi YUASA, Shuichi Murakami, Yoshihiko Fuji, Hideaki Fukuzawa
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Patent number: 8013407Abstract: There is provided a magnetic memory device stable in write characteristics. The magnetic memory device has a recording layer. The planar shape of the recording layer has the maximum length in the direction of the easy-axis over a primary straight line along the easy-axis, and is situated over a length smaller than the half of the maximum length in the direction perpendicular to the easy-axis, and on the one side and on the other side of the primary straight line respectively, the planar shape has a first part situated over a length in the direction perpendicular to the easy-axis, and a second part situated over a length smaller than the length in the direction perpendicular to the easy-axis. The outer edge of the first part includes only a smooth curve convex outwardly of the outer edge.Type: GrantFiled: March 6, 2009Date of Patent: September 6, 2011Assignee: Renesas Electronics CorporationInventors: Takashi Takenaga, Takeharu Kuroiwa, Hiroshi Takada, Shuichi Ueno, Kiyoshi Kawabata
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Patent number: 8012771Abstract: A method for manufacturing magnetic field detection devices comprises the operations of manufacturing a magneto-resistive element comprising regions with metallic conduction and regions with semi-conductive conduction. The method comprises the following operations: forming metallic nano-particles to obtain regions with metallic conduction; providing a semiconductor substrate; and applying metallic nano-particles to the porous semiconductor substrate to obtain a disordered mesoscopic structure. A magnetic device comprises a spin valve, which comprises a plurality of layers arranged in a stack which in turn comprises at least one free magnetic layer able to be associated to a temporary magnetisation (MT), a spacer layer and a permanent magnetic layer associated to a permanent magnetisation (MP). The spacer element is obtained by means of a mesoscopic structure of nanoparticles in a metallic matrix produced in accordance with the inventive method for manufacturing magneto-resistive elements.Type: GrantFiled: November 8, 2010Date of Patent: September 6, 2011Assignee: C.R.F. Societa Consortile per AzioniInventors: Daniele Pullini, Brunetto Martorana, Piero Perlo
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Patent number: 8000062Abstract: 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.Type: GrantFiled: December 30, 2008Date of Patent: August 16, 2011Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Thomas Dudley Boone, Jr., Bruce Alvin Gurney, Ernesto E. Marinero
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Patent number: 7990660Abstract: An improved CPP magnetic read device whose oxide barrier comprises at least two separate CCP layers is disclosed. These two CCP layers differ in the PIT and IAO treatments that they received relative to the PIT/IAO treatment that would be used when only a single CCP layer is formed.Type: GrantFiled: January 14, 2011Date of Patent: August 2, 2011Assignee: Headway Technologies, Inc.Inventors: Kunliang Zhang, Min Li, Yu-Hsia Chen
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Patent number: 7985599Abstract: Arrays of spin-valve elements that can be selectively activated to trap, hold, manipulate and release magnetically tagged biological and chemical particles, including molecules and polymers. The spin-valve elements that can be selectively activated and deactivated by applying a momentary applied magnetic field thereto. The spin valve element array can be used for selectively sorting and transporting magnetic particles one particle at a time within the array. As the magnetically tagged particles are held by the spin-valve elements, application of an auxiliary magnetic field can be used to apply tension or torsion to the held particles or to move, e.g. rotate, the trapped particles. The arrays of spin-valve elements can be used in a variety of applications including drug screening, nucleic acid sequencing, structural control and analysis of RNA/DNA and proteins, medical diagnosis, and magnetic particle susceptibility and size homogenization for other medical applications.Type: GrantFiled: February 13, 2007Date of Patent: July 26, 2011Assignee: The United States of America as represented by the Secretary of Commerce, The National Institute of Standards and TechnologyInventors: John Moreland, Elizabeth Mirowski, Stephen E. Russek
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Patent number: 7981696Abstract: Arrays of spin-valve elements that can be selectively activated to trap, hold, manipulate and release magnetically tagged biological and chemical particles, including molecules and polymers. The spin-valve elements that can be selectively activated and deactivated by applying a momentary applied magnetic field thereto. The spin valve element array can be used for selectively sorting and transporting magnetic particles one particle at a time within the array. As the magnetically tagged particles are held by the spin-valve elements, application of an auxiliary magnetic field can be used to apply tension or torsion to the held particles or to move, e.g. rotate, the trapped particles. The arrays of spin-valve elements can be used in a variety of applications including drug screening, nucleic acid sequencing, structural control and analysis of RNA/DNA and protiens, medical diagnosis, and magnetic particle susceptibility and size homogenization for other medical applications.Type: GrantFiled: February 18, 2005Date of Patent: July 19, 2011Assignee: The United States of America, as represented by the Secretary of Commerce, The National Institute of Standards and TechnologyInventors: John Moreland, Elizabeth Mirowski, Stephen E. Russek
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Patent number: 7982986Abstract: A magnetic head, includes a magnetic oscillation element, the oscillation frequency of which is modulated by a medium magnetic field, and a reproducing device configured to detect a phase difference between the adjacent oscillation signals derived from the magnetic oscillation element and output a phase difference signal as a reproduced signal.Type: GrantFiled: September 24, 2010Date of Patent: July 19, 2011Assignee: Kabushiki Kaisha ToshibaInventors: Rie Sato, Koichi Mizushima
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Patent number: 7969692Abstract: A magnetic head includes a pair of ferromagnetic electrodes, namely, a first ferromagnetic electrode layer which is in contact with a portion of a first electrode layer with a first insulating barrier layer interposed in between; and a second ferromagnetic electrode layer which is in contact with another portion of the first electrode layer with a second insulating barrier layer interposed in between. The first electrode layer and the first ferromagnetic layer collectively constitute part of a current-supplying circuit. Moreover, the first electrode layer and the second ferromagnetic layer which are in contact with the first electrode layer with the second insulating barrier layer interposed in between in a region where the two layers are not in contact with the first insulating barrier layer, collectively constitute part of a voltage-measurement circuit.Type: GrantFiled: April 26, 2007Date of Patent: June 28, 2011Assignee: Hitachi, Ltd.Inventor: Hiromasa Takahashi
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Patent number: 7968833Abstract: The uppermost metallic wiring layer in light-blocking layers constituted by multilevel metallic wiring that prevents light from impinging on areas other than the light-receiving area of a photodiode in each picture cell is used as a measurement electrode to be directly contacted with a specimen to measure electrical signals. Furthermore, in each picture cell including a circuit for reading out electrical signals collected through the measurement electrode, another circuit for reading out electrical signals generated by the photodiode is provided in an independent or shared form. This configuration enables the photodiode for optical measurements and the measurement electrode for electrical measurements to be provided in every picture cell.Type: GrantFiled: April 12, 2007Date of Patent: June 28, 2011Assignee: National University Corporation Nara Institute of Science and TechnologyInventors: Takashi Tokuda, Jun Ohta
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High-frequency oscillation element, magnetic information recording head, and magnetic storage device
Patent number: 7961439Abstract: A high-frequency oscillation element has a ferromagnetic material which exhibits thermal fluctuation of magnetization and generates spin fluctuations in conduction electrons, a nonmagnetic conductive material which is laminated on the first magnetic material and transfers the conduction electrons, a magnetic material which is laminated on the nonmagnetic conductive material, generates magnetic resonance upon injection of the conduction electrons, and imparts magnetic dipole interaction to magnetization of a neighboring magnetic area by means of magnetic vibration stemming from the magnetic resonance, a first electrode electrically coupled with the first magnetic material, and a second electrode electrically coupled with the second magnetic material.Type: GrantFiled: June 29, 2004Date of Patent: June 14, 2011Assignee: Kabushiki Kaisha ToshibaInventors: Rie Sato, Koichi Mizushima -
Patent number: 7948717Abstract: A magneto-resistance effect element includes a first magnetic layer of which a magnetization direction is fixed; a second magnetic layer of which a magnetization direction is fixed; an intermediate layer which is provided between the first magnetic layer and the second magnetic layer; and a pair of electrodes for flowing a current perpendicular to a film surface of the resultant laminated body comprised of the first magnetic layer, the second magnetic layer and the intermediate layer. The intermediate layer includes insulating portions and metallic portions containing at least one selected from the group consisting of Fe, Co, Ni, Cr and the metallic portions are contacted with the first magnetic layer and the second magnetic layer.Type: GrantFiled: September 7, 2007Date of Patent: May 24, 2011Assignee: Kabushiki Kaisha ToshibaInventors: Hiromi Yuasa, Hideaki Fukuzawa, Yoshihiko Fuji
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Patent number: 7944650Abstract: An MR element includes an MR stack including a first ferromagnetic layer, a second ferromagnetic layer, and a spacer layer disposed between the first and the second ferromagnetic layer. The MR stack has an outer surface, and the spacer layer has a periphery located in the outer surface of the MR stack. The magnetoresistive element further includes a layered film that touches the periphery of the spacer layer. The spacer layer includes a semiconductor layer formed using an oxide semiconductor as a material. The layered film includes a first layer, a second layer, and a third layer stacked in this order. The first layer is formed of the same material as the semiconductor layer, and touches the periphery of the spacer layer. The second layer is a metal layer that forms a Schottky barrier at the interface between the first layer and the second layer. The third layer is an insulating layer.Type: GrantFiled: September 11, 2007Date of Patent: May 17, 2011Assignee: TDK CorporationInventors: Yoshihiro Tsuchiya, Koji Shimazawa, Tomohito Mizuno, Shinji Hara, Daisuke Miyauchi, Takahiko Machita
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Patent number: 7940042Abstract: A method for testing an MR element includes a step of obtaining a ferromagnetic resonance frequency f0 of the MR element to be tested by applying an external magnetic field in a track-width direction to the MR element, a step of calculating a stiffness magnetic field Hstiff from the obtained ferromagnetic resonance frequency f0 using a predetermined formula, a step of obtaining a relationship of a stiffness magnetic field Hstiff with respect to an external magnetic field applied in the track-width direction from the applied external magnetic field and the calculated stiffness magnetic field Hstiff, a step of obtaining a uniaxial anisotropic magnetic field Hk of a free layer of the MR element from the obtained relationship of the stiffness magnetic field Hstiff with respect to the external magnetic field applied, and a step of judging whether the MR element is good product or not by comparing the obtained uniaxial anisotropic magnetic field Hk with a predetermined threshold.Type: GrantFiled: January 7, 2009Date of Patent: May 10, 2011Assignee: TDK CorporationInventor: Takumi Yanagisawa
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Patent number: 7918013Abstract: A system and method for the production level screening of low flying magnetic heads in the manufacture of disk drive head disk assemblies (HDAs) is disclosed. A test disk is provided and has a plurality of bumps extending from at least one surface thereof to a predetermined height between 2 and 12 nanometers. The test disk is rotated to fly a head of a head gimbal assembly selected from the group adjacent the surface of the test disk. An interaction of the head with one or more of the plurality of bumps may be sensed and the head gimbal assembly may be screened out from the group in response to the sensing of the interaction.Type: GrantFiled: March 11, 2008Date of Patent: April 5, 2011Assignee: Western Digital (Fremont), LLCInventors: Victor K. F. Dunn, Ciuter Chang
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Publication number: 20110069413Abstract: 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.Type: ApplicationFiled: September 23, 2009Publication date: March 24, 2011Applicant: HITACHI GLOBAL STORAGE TECHNOLOGIES NETHERLANDS B.V.Inventors: Stefan Maat, James Terrence Olson, Hal J. Rosen
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Publication number: 20110050211Abstract: A magnetic sensor comprises a sensor stack and magnetic bias elements positioned adjacent each side of the sensor stack. The sensor stack and bias elements have substantially trapezoidal shapes.Type: ApplicationFiled: August 26, 2009Publication date: March 3, 2011Applicant: Seagate Technology LLCInventors: Kaizhong Gao, Jiaoming Qiu, Lei Wang, Yonghua Chen
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Publication number: 20110051295Abstract: 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.Type: ApplicationFiled: August 31, 2009Publication date: March 3, 2011Applicant: TDK CORPORATIONInventors: Shinji Hara, Tsutomu Chou, Yoshihiro Tsuchiya, Hironobu Matsuzawa
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Patent number: 7898774Abstract: A spin valve type magnetoresistive effect element for vertical electric conduction includes a magnetoresistive effect film in which a resistance adjustment layer made of a material containing conductive carriers not more than 1022/cm3 is inserted. Thus the resistance value of a portion in change of spin-relied conduction is raised to an adequate value, thereby to increase the resistance variable amount.Type: GrantFiled: October 31, 2007Date of Patent: March 1, 2011Assignee: Kabushiki Kaisha ToshibaInventors: Hiromi Yuasa, Masatoshi Yoshikawa, Katsuhiko Koui, Hitoshi Iwasaki, Masashi Sahashi
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Patent number: 7888755Abstract: A storage element 3 has an arrangement in which magnetization fixed layers 31 and 32 are provided above and below a storage layer 17 for storing information based on the magnetization state of a magnetic material through intermediate layers 16 and 18, directions of magnetizations M15 and M19 of ferromagnetic layers 15 and 19 closest to the storage layer 17 of the magnetization fixed layers 31 and 32 above and below the storage layer 17 are opposite to each other, the two intermediate layers 16 and 18 above and below the storage layer 17 have a significant difference between sheet resistivity values thereof and in which the direction of a magnetization M1 of the storage layer 17 is changed with application of an electric current to the lamination layer direction to record information on the storage layer 17.Type: GrantFiled: September 26, 2005Date of Patent: February 15, 2011Assignee: Sony CorporationInventors: Masanori Hosomi, Kazuhiro Ohba, Hiroshi Kano, Yiming Huai, Zhitao Diao, Mahendra Pakala
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Patent number: 7880999Abstract: A magnetic storage system includes a magnetic storage medium and a transducer positioned adjacent the magnetic storage medium. The transducer has a reader positioned adjacent writer and a reader bias coil located on the transducer. Transducer circuitry is configured to apply a bias signal to the reader bias coil during a read-write operation. The reader bias coil generates a reader bias field proximate the reader.Type: GrantFiled: September 5, 2008Date of Patent: February 1, 2011Assignee: Seagate Technology LLCInventors: Mourad Benakli, Michael L. Mallary
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Patent number: 7881021Abstract: A magnetoresistive device with CPP structure, comprising a nonmagnetic intermediate layer, and a first ferromagnetic layer and a second ferromagnetic layer stacked and formed with said nonmagnetic intermediate layer interposed between them, wherein each of said first and second ferromagnetic layers comprises a sensor area joining to the nonmagnetic intermediate layer and a magnetization direction control area that extends further rearward from the position of the rear end of said nonmagnetic intermediate layer; a magnetization direction control multilayer arrangement is interposed at an area where the magnetization direction control area for said first ferromagnetic layer is opposite to the magnetization direction control area for said second ferromagnetic layer to produce magnetizations of the said first and second ferromagnetic layers which are antiparallel with each other; and said sensor area is provided at both width direction ends with biasing layers working such that the mutually antiparallel magnetizaType: GrantFiled: January 30, 2008Date of Patent: February 1, 2011Assignee: TDK CorporationInventors: Tsutomu Chou, Yoshihiro Tsuchiya, Daisuke Miyauchi, Takahiko Machita, Shinji Hara, Tomohito Mizuno, Hironobu Matsuzawa, Toshiyuki Ayukawa, Koji Shimazawa, Kiyoshi Noguchi
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Publication number: 20110013321Abstract: A hard bias (HB) structure for longitudinally biasing a free layer in a MR sensor is disclosed that is based on HB easy axis growth perpendicular to an underlying seed layer which is formed above a substrate and along two sidewalls of the sensor. In one embodiment, a conformal soft magnetic layer that may be a top shield contacts the HB layer to provide direct exchange coupling that compensates HB surface charges. Optionally, a thin capping layer on the HB layer enables magneto-static shield-HB coupling. After HB initialization, HB regions along the sensor sidewalls have magnetizations that are perpendicular to the sidewalls as a result of surface charges near the seed layer. Sidewalls may be extended into the substrate (bottom shield) to give enhanced protection against side reading. The top surface of the seed layer may be amorphous or crystalline to promote HB easy axis perpendicular growth.Type: ApplicationFiled: September 24, 2010Publication date: January 20, 2011Inventors: Yuchen Zhou, Kenichi Takano, Kunliang Zhang
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Publication number: 20110007421Abstract: 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.Type: ApplicationFiled: July 10, 2009Publication date: January 13, 2011Applicant: TDK CORPORATIONInventors: Shinji Hara, Tsutomu Chou, Yoshihiro Tsuchiya, Hironobu Matsuzawa
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Patent number: 7842334Abstract: A magnetic sensor includes a single substrate, a conventional GMR element formed of a spin-valve film including a single-layer-pinned fixed magnetization layer, and a SAF element formed of a synthetic spin-valve film including a plural-layer-pinned fixed magnetization layer. When the spin-valve film intended to act as the conventional GMR element and the synthetic spin-valve film intended to act as the SAF element are subjected to the application of a magnetic field oriented in a single direction at a high temperature, they become giant magnetoresistive elements whose magnetic-field-detecting directions are antiparallel to each other. Since films intended to act as the conventional GMR element and the SAF element can be disposed close to each other, the magnetic sensor which has giant magnetoresistive elements whose magnetic-field-detecting directions are antiparallel to each other can be small.Type: GrantFiled: February 6, 2008Date of Patent: November 30, 2010Assignee: Yamaha CorporationInventors: Yukio Wakui, Masayoshi Omura
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Patent number: 7830640Abstract: Magnetoresistive device comprising a spin valve formed from a stack of layers including at least two magnetic layers for which a relative orientation of their magnetisation directions are capable varying under influence of a magnetic field; at least one discontinuous dielectric or semiconducting layer with electrically conducting bridges at least partially passing through a thickness of the dielectric or semiconducting layer, the bridges configured to locally concentrate current that passes transversely through the stack; and means for circulating a current in the spin valve transverse to the plane of the layers, characterised in that the dielectric or semiconducting layer with electrically conducting bridges is arranged inside one of the magnetic layers.Type: GrantFiled: November 14, 2008Date of Patent: November 9, 2010Assignee: Commissariat A L'Energie AtomiqueInventors: Bernard Dieny, Bernard Rodmacq, Franck Ernult
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Patent number: 7829962Abstract: A method for manufacturing magnetic field detection devices comprises the operations of manufacturing a magneto-resistive element comprising regions with metallic conduction and regions with semi-conductive conduction. The method comprises the following operations: forming metallic nano-particles to obtain regions with metallic conduction; providing a semiconductor substrate; and applying metallic nano-particles to the porous semiconductor substrate to obtain a disordered mesoscopic structure. A magnetic device comprises a spin valve, which comprises a plurality of layers arranged in a stack which in turn comprises at least one free magnetic layer able to be associated to a temporary magnetisation (MT), a spacer layer and a permanent magnetic layer associated to a permanent magnetisation (MP). The spacer element is obtained by means of a mesoscopic structure of nanoparticles in a metallic matrix produced in accordance with the inventive method for manufacturing magneto-resistive elements.Type: GrantFiled: July 30, 2004Date of Patent: November 9, 2010Assignee: C.R.F. Società Consortile per AzioniInventors: Daniele Pullini, Brunetto Martorana, Piero Perlo
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Patent number: 7826160Abstract: A magnetic head, includes a magnetic oscillation element, the oscillation frequency of which is modulated by a medium magnetic field, and a reproducing device configured to detect a phase difference between the adjacent oscillation signals derived from the magnetic oscillation element and output a phase difference signal as a reproduced signal.Type: GrantFiled: September 19, 2008Date of Patent: November 2, 2010Assignee: Kabushiki Kaisha ToshibaInventors: Rie Sato, Koichi Mizushima
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Patent number: 7810227Abstract: Using a beam of xenon ions together with a suitable mask, a GMR stack is ion milled until a part of it, no more than about 0.1 microns thick, has been removed so that a pedestal, having sidewalls comprising a vertical section that includes all of the free layer, has been formed. This is followed by formation of the dielectric and conductive lead layers in the usual way. Using xenon as the sputtering gas enables the point at which milling is terminated to be more precisely controlled.Type: GrantFiled: October 18, 2007Date of Patent: October 12, 2010Assignees: Headway Technologies, Inc., TDK CorporationInventors: Stuart Kao, Chunping Luo, Chaopeng Chen, Takahiko Machita, Daisuke Miyauchi, Jeiwei Chang
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Patent number: 7807218Abstract: A magnetic tunneling element is constructed from a MgO or Mg—ZnO tunnel barrier and an amorphous magnetic layer in proximity with the tunnel barrier. The amorphous magnetic layer includes Co and at least one additional element selected to make the layer amorphous. Magnetic tunnel junctions formed from the amorphous magnetic layer, the tunnel barrier, and an additional ferromagnetic layer have tunneling magnetoresistance values of up to 200% or more.Type: GrantFiled: July 26, 2007Date of Patent: October 5, 2010Assignee: International Business Machines CorporationInventor: Stuart Stephen Papworth Parkin
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Publication number: 20100246073Abstract: 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.Type: ApplicationFiled: March 29, 2010Publication date: September 30, 2010Applicant: FUJIFILM CorporationInventor: Kazutoshi Katayama
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Publication number: 20100232073Abstract: A thin film magnetic head includes a magnetoresistive effect (MR) laminated body that has the following structure: first and second magnetic layers in which the magnetization direction of at least one of the magnetic layers changes according to an external magnetic field; the first magnetic layer is provided at a lower side of a laminated direction; the second magnetic layer is provided at an upper side of the laminated direction; a non-magnetic intermediate layer made of ZnO sandwiched between the first and the second magnetic layers; a first intermediate interface layer is provided at the interface between the first magnetic layer and the non-magnetic intermediate layer; and a second intermediate interface layer is provided at the interface between the non-magnetic intermediate layer and the second magnetic layer. At least the first intermediate interface layer contains Ag and Zn, or Au and Zn.Type: ApplicationFiled: March 10, 2009Publication date: September 16, 2010Applicant: TDK CORPORATIONInventors: Tsutomu Chou, Shinji Hara, Yoshihiro Tsuchiya, Hironobu Matsuzawa
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Patent number: 7795696Abstract: A magnetoresistive memory element has a read module with a first pinned layer that has a magnetoresistance that is readable by a read current received from an external circuit. The element has a write module that receives a write current from the external circuit. A coupling module adjacent both the write module and the read module has a free layer that functions as a shared storage layer for both the read module and the write module. The shared storage layer receives spin torque from both the read module and the write module and has a magnetization that is rotatable by the write current.Type: GrantFiled: January 4, 2008Date of Patent: September 14, 2010Assignee: Seagate Technology LLCInventors: Oleg N. Mryasov, Thomas F. Ambrose, Werner Scholz
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Publication number: 20100220415Abstract: 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.Type: ApplicationFiled: May 14, 2010Publication date: September 2, 2010Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Kenichiro Yamada, Hitoshi Iwasaki, Junichi Akiyama, Masayuki Takagishi, Tomomi Funayama, Masahiro Takashita, Mariko Shimizu, Shuichi Murakami, Tadashi Kai
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Patent number: 7784170Abstract: A resist pattern for lift-off is formed on a first film composed of one or more layers deposited on a substrate. The first film is patterned by dry-etching using the resist pattern as a mask. Subsequently, a second film is deposited with presence of the resist pattern on the first film. Then, the resist pattern for lift-off is removed for conducting lift-off. Subsequently, the resulting substrate is etched. In the etching, the substrate is dry-etched using etching particles which are oriented at an incident angle set in a range of 60 ° to 90 ° relative to the normal direction of the substrate.Type: GrantFiled: May 11, 2007Date of Patent: August 31, 2010Assignee: TDK CorporationInventors: Takeo Kagami, Kazuki Sato
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Patent number: 7782577Abstract: A magnetic random access memory structure comprising an anti-ferromagnetic layer structure, a crystalline ferromagnetic structure physically coupled to the anti-ferromagnetic layer structure and a ferromagnetic free layer structure physically coupled to the crystalline ferromagnetic structure.Type: GrantFiled: June 6, 2006Date of Patent: August 24, 2010Assignees: Infineon Technologies AG, ALTIS Semiconductor, SNCInventors: Wolfgang Raberg, Ulrich Klostermann
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Publication number: 20100188782Abstract: A magnetoresistive element includes: a detection surface that receives a magnetic field to be detected; a free layer made of a ferromagnetic material, having an end face located in the detection surface, and exhibiting a change in magnetization direction in response to the magnetic field to be detected; a pinned layer made of a ferromagnetic material, disposed away from the detection surface, and having a fixed magnetization direction; and a coupling portion made of a nonmagnetic material and coupling the free layer to the pinned layer. The coupling portion includes a nonmagnetic conductive layer that allows electrons to be conducted while conserving their spins.Type: ApplicationFiled: January 28, 2009Publication date: July 29, 2010Applicant: TDK CORPORATIONInventor: Hiroshi Yamazaki
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Patent number: 7764471Abstract: A magnetoresistance effect element (MR element) for use in a thin-film magnetic head has a buffer layer, an antiferromagnetic layer, a pinned layer, a spacer layer, a free layer, and a cap layer that are successively stacked. A sense current flows in a direction perpendicular to layer surfaces via a lower shield layer and an upper shield layer. The pinned layer comprises an outer layer having a fixed magnetization direction, a nonmagnetic intermediate layer, and an inner layer in the form of a ferromagnetic layer. The spacer layer comprises a first nonmagnetic metal layer, a semiconductor layer made of ZnO, and a second nonmagnetic metal layer. The inner layer or the outer layer includes a diffusion blocking layer made of an oxide of an element whose electronegativity is equal to or smaller than Zn, e.g., ZnO, TaO, ZrO, MgO, TiO, or HfO, or made of RuO.Type: GrantFiled: March 12, 2007Date of Patent: July 27, 2010Assignee: TDK CorporationInventors: Tomohito Mizuno, Takahiko Machita, Kei Hirata, Yoshihiro Tsuchiya, Shinji Hara
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Patent number: 7764470Abstract: A magneto-resistance effect element used for a thin film magnetic head is configured by a buffer layer, an anti-ferromagnetic layer, a pinned layer, a spacer layer, a free layer, and a cap layer, which are laminated in this order, and a sense current flows through the element in a direction orthogonal to the layer surface, via a lower shield layer and a upper shield layer. The pinned layer comprises an outer layer in which a magnetization direction is fixed, a non-magnetic intermediate layer, and an inner layer which is a ferromagnetic layer. The spacer layer comprises a first and second non-magnetic metal layer, and a semiconductor layer. The first and second non-magnetic metal layer and comprise CuPt films having a thickness of more than 0 nm but no more than 2.0 nm, and the Pt content ranges from a minimum of 5 to a maximum of 25 at %.Type: GrantFiled: March 6, 2007Date of Patent: July 27, 2010Assignee: TDK CorporationInventors: Tomohito Mizuno, Kei Hirata, Yoshihiro Tsuchiya, Koji Shimazawa
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Patent number: 7760472Abstract: A magnetic sensor includes a magnetic oscillation element whose oscillation frequency changes depending on the magnitude of an external magnetic field, and an oscillation element provided in the vicinity of the magnetic oscillation element and oscillating at an oscillation frequency close to that of the magnetic oscillation element. The magnetic oscillation element includes a first fixed magnetization layer whose magnetization is fixed, a first magnetization oscillation layer, a first non-magnetic layer provided between the first fixed magnetization layer and the first magnetization oscillation layer, and a pair of electrodes for passing current perpendicularly to the film surfaces of the first fixed magnetization layer, the first magnetization oscillation layer, and the first non-magnetic layer. These two elements are used in combination with the passed current to acquire a high frequency oscillation signal generated from the magnetic oscillation element and the oscillation element.Type: GrantFiled: June 22, 2007Date of Patent: July 20, 2010Assignee: Kabushiki Kaisha ToshibaInventors: Rie Sato, Koichi Mizushima, Kiwamu Kudo
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Patent number: 7760475Abstract: A magnetoresistance effect element includes a pinned layer having a fixed magnetization direction, a free layer having a magnetization direction variable depending on an external magnetic field, and a nonmagnetic spacer layer disposed between the pinned layer and the free layer. The free layer includes a Heusler alloy layer and a magnetostriction reduction layer made of a 4th group element, a 5th group element, or a 6th group element.Type: GrantFiled: March 12, 2007Date of Patent: July 20, 2010Assignee: TDK CorporationInventors: Tomohito Mizuno, Yoshihiro Tsuchiya, Kei Hirata
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Patent number: 7755929Abstract: First and second tunnel junctions having a common electrode composed of a nonmagnetic conductor and each of which has a counterelectrode composed of a ferromagnet are spaced apart from each other by a distance that is shorter than a spin diffusion length of the nonmagnetic conductor. The first tunnel junction injects spin from the ferromagnet into the nonmagnetic conductor and the second tunnel junction detects, between the ferromagnetic metal and the nonmagnetic conductor, a voltage that accompanies spin injection of the first tunnel junction. The nonmagnetic conductor may be a semiconductor or semimetal that is lower in carrier density than a metal. The common electrode alternatively may be composed of a superconductor. A spin injection device thus provided can exhibit a large signal voltage with a low current and under low magnetic field and can be miniaturized in device size.Type: GrantFiled: November 20, 2003Date of Patent: July 13, 2010Assignee: Japan Science and Technology AgencyInventors: Kouichiro Inomata, Sadamichi Maekawa, Saburo Takahashi
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Publication number: 20100165518Abstract: 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.Type: ApplicationFiled: December 30, 2008Publication date: July 1, 2010Inventors: Thomas Dudley Boone, JR., Bruce Alvin Gurney, Ernesto E. Marinero
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Publication number: 20100128400Abstract: A current-perpendicular-to-plane (CPP) tunneling magnetoresistance (TMR) or giant magnetoresistance (GMR) read sensor with ferromagnetic amorphous buffer and polycrystalline seed layers is disclosed for reducing a read gap, in order to perform magnetic recording at higher linear densities. The ferromagnetic amorphous buffer and polycrystalline seed layers couples to a ferromagnetic lower shield, thus acting as part of the ferromagnetic lower shield and defining the upper surface of the ferromagnetic polycrystalline seed layer as the lower bound of the read gap. In addition, a CPP TMR or GMR read sensor with nonmagnetic and ferromagnetic cap layers is also disclosed for reducing the read gap, in order to perform magnetic recording at even higher linear densities. The ferromagnetic cap layer couples to a ferromagnetic upper shield, thus acting as part of the ferromagnetic upper shield and defining the lower surface of the ferromagnetic cap layer as the upper bound of the read gap.Type: ApplicationFiled: November 21, 2008Publication date: May 27, 2010Inventor: Tsann Lin
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Patent number: 7719800Abstract: An example magnetoresistive effect element includes a magnetoresistive effect film including a magnetization pinned layer, a magnetization free layer, and an intermediate layer interposed therebetween and having a magnetic region and a nonmagnetic region whose electrical resistance is higher than the magnetic region. A sense current is passed to the magnetoresistive effect film in a direction substantially perpendicular to the film plane thereof. The magnetic region of the intermediate layer penetrates the nonmagnetic region locally and extends in the direction substantially perpendicular to the film plane. The nonmagnetic region contains a nonmagnetic metallic element having a larger surface energy than a magnetic metallic element contained in the magnetic region.Type: GrantFiled: December 26, 2006Date of Patent: May 18, 2010Assignees: Kabuhsiki Kaisha Toshiba, TDK CorporationInventors: Susumu Hashimoto, Hiromi Fuke, Hitoshi Iwasaki, Masaaki Doi, Kousaku Miyake, Masashi Sahashi
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Publication number: 20100110592Abstract: A spin torque oscillator includes a first magnetic layer, a second magnetic layer and a first nonmagnetic layer. The first magnetic layer includes a magnetic film of a magnetic material with a body-centered cubic (bcc) structure and an oriented {110} plane of the body-centered cubic structure, the oriented {110} plane being oriented substantially parallel to a principal plane of the magnetic film. The first nonmagnetic layer is disposed between the first magnetic layer and the second magnetic layer. In addition, a magnetic moment in the magnetic film precesses around an axis substantially parallel to the principal plane. Furthermore, a magnetic field is applied in a direction substantially perpendicular to the principal plane, and a current is passed perpendicularly to the principal plane.Type: ApplicationFiled: November 5, 2009Publication date: May 6, 2010Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Katsuhiko Koui, Mariko Shimizu, Kenichiro Yamada
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Publication number: 20100097722Abstract: The semiconductor oxide layer that forms a part of the spacer layer in the inventive giant magnetoresistive device (CPP-GMR device) is composed of zinc oxide of wurtzite structure that is doped with a dopant given by at least one metal element selected from the group consisting of Zn, Ge, V, and Cr in a content of 0.05 to 0.90 at %: there is the advantage obtained that ever higher MR ratios are achievable while holding back an increase in the area resistivity AR.Type: ApplicationFiled: October 21, 2008Publication date: April 22, 2010Applicant: TDK CORPORATIONInventors: Tsutomu Chou, Tomohito Mizuno, Koji Shimazawa, Yoshihiro Tsuchiya, Shinji Hara, Hironobu Matsuzawa
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Publication number: 20100097729Abstract: A magnetoresistive sensor having a scissor free layer design and no pinned layer. The sensor includes first and second free layers that have magnetizations that are oriented at 90 degrees to one another and has a third magnetic layer with a magnetization that is antiparallel coupled with one of the free layers. The antiparallel coupling of the third magnetic layer with one of the free layers, allows the sensor to be used in a tunnel valve design, having an electrically insulating barrier layer between the free layers. The tunnel valve design reduces spin torque noise in the sensor, and the presence of the third magnetic layer allows the free layers to remain bias at 90 degrees to one another in spite of interfacial coupling through the very thin barrier layer.Type: ApplicationFiled: October 20, 2008Publication date: April 22, 2010Inventors: Hardayal Singh Gill, Chang-Man Park