Structure Or Manufacture Of Flux-sensitive Heads, [n: I.e. For Reproduction Only; Combination Of Such Heads With Means For Recording Or Erasing Only] ([n: Single Head Using Magnetic Domains For Scanning G9b/5.165; Multiple Head For Scanning G9b/5.16 And Subgroups]; General Details Therefor G9b/5.045 To G9b/5.067) {g11b 5/33} Patents (Class G9B/5.104)

  • Publication number: 20100033879
    Abstract: A perpendicular magnetic head for writing information on a magnetic recording medium comprises an ABS, a coil for generating a magnetic flux, a magnetic pole layer, a magnetic shield layer, and a gap layer disposed between the magnetic pole layer and the magnetic shield layer. Further the magnetic head has a non-magnetic region of a non-magnetic material. The non-magnetic region is disposed in the magnetic shield layer and positioned behind the ABS at a predetermined distance. The non-magnetic region is also disposed in the magnetic shield layer and has a predetermined width. With such a configuration, an undesirable concentration of the magnetic flux on the ABS is prevented.
    Type: Application
    Filed: August 8, 2008
    Publication date: February 11, 2010
    Applicant: TDK CORPORATION
    Inventors: Norikazu OTA, Tatsuhiro NOJIMA, Tsuyoshi UMEHARA
  • Publication number: 20100033880
    Abstract: A multi-bit spin torque magnetic element that has a ferromagnetic pinned layer having a pinned magnetization orientation, a non-magnetic layer, and a ferromagnetic free layer having a magnetization orientation switchable among at least four directions, the at least four directions being defined by a physical shape of the free layer. The magnetic element has at least four distinct resistance states. Magnetic elements with at least eight magnetization directions are also provided.
    Type: Application
    Filed: October 21, 2008
    Publication date: February 11, 2010
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Dimitar V. Dimitrov, Zheng Gao, Xiaobin Wang
  • Publication number: 20100027168
    Abstract: A thin film magnetic head comprise an MR laminated body composed of a first and second MR magnetic layers, first and second shield layers, and a bias magnetic field application layer provided on an opposite side of an air bearing surface (ABS) of the MR laminated body in order to apply a bias magnetic field orthogonal relative to the ABS. The first shield layer comprises a first exchange coupling magnetic field application layer, a first antimagnetic layer, a second exchange coupling magnetic field application layer, and a second antimagnetic layer. The first antimagnetic layer is provided in contact with the first exchange coupling magnetic field application layer on the rear face of the first exchange coupling magnetic field application layer and which is antimagnetically coupled with the first exchange coupling magnetic field application layer. The second shield layer has the same configuration as that of the first shield layer.
    Type: Application
    Filed: July 29, 2008
    Publication date: February 4, 2010
    Applicant: TDK CORPORATION
    Inventors: Tsutomu Chou, Yoshihiro Tsuchiya, Shinji Hara, Daisuke Miyauchi, Takahiko Machita
  • Publication number: 20100007988
    Abstract: A magnetic recording medium includes a nonmagnetic granular layer that has a granular structure in which a plurality of nonmagnetic grains made of a nonmagnetic material are separated from one another by a Cr oxide. The magnetic recording medium further includes a magnetic granular layer that is formed on the nonmagnetic granular layer and has a granular structure in which a plurality of magnetic grains made of a magnetic material are separated from one another by a nonmagnetic material.
    Type: Application
    Filed: July 6, 2009
    Publication date: January 14, 2010
    Applicant: SHOWA DENKO K.K.
    Inventors: Satoshi Igarashi, Tohru Horie, Ryo Kurita, Isatake Kaitsu, Akira Kikuchi, Shinya Sato
  • Publication number: 20100007996
    Abstract: It is made possible to reduce the write magnetic field generated from the main magnetic pole toward the spin torque oscillator, so as to reduce the variation in the oscillation characteristics of the spin torque oscillator, and reduce the current required for oscillation. The magnetic head assembly includes: a recording magnetic pole; a spin torque oscillator that has first and second magnetic layers, and an intermediate layer interposed between the first and second magnetic layers, the spin torque oscillator generating a high-frequency magnetic field by applying a current between the first and second magnetic layers; and a third magnetic layer that is placed adjacent to at least part of a side face of the second magnetic layer.
    Type: Application
    Filed: June 17, 2009
    Publication date: January 14, 2010
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Hitoshi Iwasaki, Kenichiro Yamada, Masayuki Takagishi, Tomomi Funayama, Masahiro Takashita, Mariko Shimizu, Soichi Oikawa, Katsuhiko Koui
  • Publication number: 20100002332
    Abstract: An optical path or waveguide for a laser-assisted transducing head is disclosed. The optical path extends between the poles of the transducing head to near the write gap. A solid-state laser is attached to or incorporated into the slider or head and is positioned to direct thermal energy through a waveguide and onto a track of a read/write surface to lower the coercivity of the recording medium to facilitate the write process.
    Type: Application
    Filed: May 11, 2009
    Publication date: January 7, 2010
    Inventors: Matthew P. Dugas, Jeffrey A. Wallhoff
  • Publication number: 20100002337
    Abstract: According to one embodiment, a magnetic recording apparatus includes a current modulator and a recording head. The current modulator modulates current according to codes with run-length limitation in which a run-length is limited to a predetermined number. The recording head moves relative to the surface of a magnetic recording medium where the information is recorded based on directions of magnetizations and forms the magnetizations by the modulated current. The recording head includes a coil and a magnetic core. The coil generates a magnetic field corresponding to the modulated current. The magnetic core extends inside the coil with an end facing the magnetic recording medium. The magnetic core forms the magnetizations by guiding and applying the magnetic field from the end to the magnetic recording medium. The length of the end in the direction in which the magnetizations are aligned is not less than a length of the predetermined number.
    Type: Application
    Filed: September 14, 2009
    Publication date: January 7, 2010
    Applicant: FUJITSU LIMITED
    Inventor: Hiroshi Uno
  • Publication number: 20090323219
    Abstract: A method for the production of a magnetic recording medium (30) includes the steps of depositing a magnetic layer or Co-containing magnetic layer (3) on at least one side of a nonmagnetic substrate (1) and partially implanting atoms into the magnetic layer or Co-containing magnetic layer to partially unmagnetize the magnetic layer or Co-containing magnetic layer, thereby forming nonmagnetic parts (4) and a magnetic recording pattern magnetically separated by the nonmagnetic parts and, in the case of the Co-containing magnetic layer, lowering Co (002) or Co (110) peak strength of a relevant part of the Co-containing magnetic layer as determined by the X-ray diffraction to ½ or less.
    Type: Application
    Filed: February 6, 2007
    Publication date: December 31, 2009
    Applicant: SHOWA DENKO K.K.
    Inventors: Masato Fukushima, Akira Sakawaki, Yasumasa Sasaki
  • Publication number: 20090323229
    Abstract: In a read-write head, the shields can serve as magnetic flux conductors for external fields, so that they direct a certain amount of flux into the recording medium. This problem has been overcome by the addition to the shields of a pair of tabs located at the edges closest to the ABS. These tabs serve to prevent flux concentrating at the edges so that horizontal fields at these edges are significantly reduced. Said tabs need to have aspect ratios of at least 2 and may be either triangular or rectangular in shape. Alternatively, the tabs may be omitted and, instead, outer portions of the shield's lower edge may be shaped so as to slope upwards away from the ABS.
    Type: Application
    Filed: September 1, 2009
    Publication date: December 31, 2009
    Inventors: Lijie Guan, Moris Dovek
  • Publication number: 20090316308
    Abstract: A CPP giant magnetoresistive head includes lower and upper shield layers, and a giant magnetoresistive element disposed between the upper and lower shield layers and including a pinned magnetic layer, a free magnetic layer and a nonmagnetic layer disposed between the pinned magnetic layer and the free magnetic layer. In the CPP giant magnetoresistive head, the pinned magnetic layer extends to the rear of the nonmagnetic layer and the free magnetic layer in the height direction, and the dimension of the pinned magnetic layer in the height direction is larger than that in the track width direction. Also, the pinned magnetic layer comprises a magnetic material having a positive magnetostriction constant or a magnetic material having high coercive force, and the end of the pinned magnetic layer is exposed at a surface facing a recording medium.
    Type: Application
    Filed: August 27, 2009
    Publication date: December 24, 2009
    Inventors: Masamichi Saito, Yoshihiro Nishiyama, Yosuke Ide, Eiji Umetsu, Naoya Hasegawa, Yasuo Hayakawa
  • Publication number: 20090316292
    Abstract: A magnetoresistive head is provided with high reliability and produced at a high yield rate. The magnetoresistive head includes a lower magnetic shield layer, an upper magnetic shield layer, a magnetoresistive effect film, and means for causing a current to flow in the direction of the thickness of the magnetoresistive effect film. The magnetoresistive effect film is provided between the lower magnetic shield layer and the upper magnetic shield layer. The magnetoresistive effect film is composed of a fixed layer, a non-magnetic layer, an insulating barrier layer and a free layer. The four layers of the magnetoresistive effect film are formed in this order. The insulating barrier layer is an oxide layer containing at least one of titanium and nickel.
    Type: Application
    Filed: February 9, 2009
    Publication date: December 24, 2009
    Inventor: Tomio IWASAKI
  • Publication number: 20090303639
    Abstract: A device capable of exhibiting the extraordinary magnetoresistance (EMR) effect includes an elongate channel formed of silicon. A conductor comprising heavily doped silicon is connected to the channel along one side of the channel so as to provide a shunt. A gate arrangement including a gate electrode is provided on the channel. Applying a bias of appropriate polarity and sufficient magnitude to the gate electrode results in the formation of an inversion layer in the channel.
    Type: Application
    Filed: February 23, 2009
    Publication date: December 10, 2009
    Inventors: Susumu OGAWA, Andrew Troup, David Williams, Hiroshi Fukuda
  • Publication number: 20090303638
    Abstract: A magnetoresistance device has a channel extending between first and second ends in a first direction comprising non-ferromagnetic semiconducting material, such as silicon, a plurality of leads connected to and spaced apart along the channel, a gate structure for applying an electric field to the channel in a second direction which is substantially perpendicular to the first direction so as to form an inversion layer in the channel and a face which lies substantially in a plane defined by the first and second directions and which is configured such that an edge of the channel runs along the face.
    Type: Application
    Filed: February 23, 2009
    Publication date: December 10, 2009
    Inventors: Susumu OGAWA, Andrew Troup, David Williams, Hiroshi Fukuda
  • Publication number: 20090303640
    Abstract: A magneto resistance effect element includes a first magnetic layer, a second magnetic layer and a spacer layer interposed between the first and second magnetic layers. The magneto resistance effect element is configured to allow sense current to flow in a direction that is perpendicular to film planes of the first magnetic layer, the second magnetic layer and the spacer layer so that a relative angle between a magnetization direction of the first magnetic layer and a magnetization direction of the second magnetic layer varies depending on an external magnetic field. The present invention aims at providing a magneto resistance effect element which ensures high resistance to sense current, while limiting the influence of the current limiting layer on the magnetic layer, and which thereby achieves a high magneto resistance ratio.
    Type: Application
    Filed: April 25, 2008
    Publication date: December 10, 2009
    Applicant: TDK CORPORATION
    Inventors: Tomohito Mizuno, Koji Shimazawa, Yoshihiro Tsuchiya, Daisuke Miyauchi, Takahiko Machita, Shinji Hara, Tsutomu Chou, Hironobu Matsuzawa, Toshiyuki Ayukawa, Tsuyoshi Ichiki
  • Publication number: 20090296276
    Abstract: A magnetic recording medium A is provided on a non-magnetic substrate with at least a soft under layer a, an under film 5, an intermediate film 6 and a perpendicular magnetic recording film 7. The soft under layer a is a soft magnetic film having an amorphous structure. The under film 5 is formed of an Ni—W alloy. The intermediate film 6 is formed of an Ru alloy. In the Ni—W alloy, the Ni content is 80 atom % or more, and the W content is 20 atom % or less and preferably in the range of 1 atom % to 12 atom %. A magnetic recording and reproducing device 12 equipped with the magnetic recording medium A is excellent in productivity and capable of recording and reproducing information of high density.
    Type: Application
    Filed: November 2, 2006
    Publication date: December 3, 2009
    Applicant: SHOWA DENKO K.K
    Inventor: Kenji Shimizu
  • Publication number: 20090296258
    Abstract: An electromagnetic field detecting element 10 includes a lamination of three insulation layers 2, 3, and 4. The dielectric breakdown strength of the insulation layer 3 is greater than the dielectric breakdown strengths of insulation layers 2 and 4. The three insulation layers 2, 3, and 4 are disposed between a pair of electrodes 5 and 6. Boundaries 7 and 8 on both ends of an overlapping region of the opposing surfaces 5a and 6a in a Z direction are apart from the insulation layer 3 by thicknesses t1 and t3 of the insulation layers 2 and 4, respectively. Between the pair of electrodes 5 and 6, ballistic current paths interposing therebetween the insulation layer 3 are formed by applying, between the pair of electrodes 5 and 6, an electric field having a magnitude which causes dielectric breakdown in the insulation layers 2 and 4 while causing no dielectric breakdown in the insulation layer 3.
    Type: Application
    Filed: September 25, 2006
    Publication date: December 3, 2009
    Applicant: SHARP KABUSHIKI KAISHA
    Inventors: Shintaro Miyanishi, Yasushi Ogimoto, Yoshiteru Murakami, Kunio Kojima
  • Publication number: 20090296283
    Abstract: The invention provides a magnetoresistive device of the CPP (current perpendicular to plane) structure, comprising a magnetoresistive unit, and a first shield layer and a second shield layer which are located and formed such that the magnetoresistive unit is sandwiched between them with a sense current applied in a stacking direction. The magnetoresistive unit comprises a nonmagnetic intermediate layer, and a first ferromagnetic layer and a second ferromagnetic layer stacked and formed such that the nonmagnetic intermediate layer is sandwiched between them. The first shield layer and the second shield layer are each controlled by magnetization direction control means in terms of magnetization direction to create an antiparallel magnetization state where their magnetizations are in opposite directions.
    Type: Application
    Filed: May 28, 2008
    Publication date: December 3, 2009
    Applicant: TDK CORPORATION
    Inventors: Tomohito Mizuno, Koji Shimazawa, Yoshihiro Tsuchiya
  • Publication number: 20090290264
    Abstract: The invention provides a magnetoresistive device of the CPP (current perpendicular to plane) structure, comprising a magnetoresistive unit, and a first, substantially soft magnetic shield layer positioned below and a second, substantially soft magnetic shield layer positioned above, which are located and formed such that the magnetoresistive effect is sandwiched between them from above and below, with a sense current applied in the stacking direction. The magnetoresistive unit comprises a nonmagnetic intermediate layer, and a first ferromagnetic layer and a second ferromagnetic layer stacked and formed such that said nonmagnetic intermediate layer is sandwiched between them. At least one of the first shield layer positioned below and the second shield layer positioned above is configured in a framework form having a planar shape (X-Y plane) defined by the width and length directions of the device.
    Type: Application
    Filed: May 23, 2008
    Publication date: November 26, 2009
    Applicant: TDK CORPORATION
    Inventors: Toshiyuki Ayukawa, Takahiko Machita, Daisuke Miyauchi, Tsutomu Chou, Koji Shimazawa, Shinji Hara, Tomohito Mizuno, Yoshihiro Tsuchiya
  • Publication number: 20090290265
    Abstract: The magnetic head having shielding layers is capable of preventing fluctuation of output caused by magnetic domain structures of the shielding layers, stabilizing the output, restraining variation of products and improving production yield. The magnetic head comprises: shielding layers for magnetically shielding a magnetoresistance effect reproducing element; hard films being located on the both sides of the magnetoresistance effect reproducing element as seen from a facing surface which faces a recording medium; and soft magnetic layers being composed of a soft magnetic material, the soft magnetic layers being located on the both sides of the shielding layers as seen from the facing surface.
    Type: Application
    Filed: December 15, 2008
    Publication date: November 26, 2009
    Applicant: FUJITSU LIMITED
    Inventor: Junichi Kane
  • Publication number: 20090290256
    Abstract: A perpendicular magnetic recording system and medium has a multilayered recording layer that includes an exchange-spring structure and a ferromagnetic lateral coupling layer (LCL). The exchange-spring structure is made up of two ferromagnetically exchange-coupled magnetic layers (MAG1 and MAG2), each with perpendicular magnetic anisotropy. MAG1 and MAG2 may have a coupling layer (CL) located between them that permits ferromagnetic exchange coupling of MAG1 with MAG2. The LCL is located either above or below MAG1 and in direct contact with MAG1 and mediates an effective intergranular exchange coupling in MAG1. The ferromagnetic alloy in the LCL has significantly greater intergranular exchange coupling than the ferromagnetic alloy in MAG1, which typically will include segregants such as oxides. The LCL is preferably free of oxides or other non-metallic segregants, which would tend to reduce intergranular exchange coupling in the LCL.
    Type: Application
    Filed: August 3, 2009
    Publication date: November 26, 2009
    Applicant: HITACHI GLOBAL STORAGE TECHNOLOGIES NETHERLANDS B.V.
    Inventors: Andreas Klaus Berger, Eric E. Fullerton, Byron Hassberg Lengsfield, III, David Thomas Margulies
  • Publication number: 20090290267
    Abstract: A magnetic recording and reproducing apparatus with a thin-film magnetic head having microwave magnetic exciting function, includes a metal housing, a magnetic recording medium, arranged in the metal housing, having a magnetic recording layer, and a thin-film magnetic head, arranged in the metal housing, having a write magnetic field production unit and a resonance magnetic field production unit. The write magnetic field production unit produces, in response to a write signal, a write magnetic field to be applied into the magnetic recording layer, and the resonance magnetic field production unit produces, in response to a microwave excitation signal, a resonance magnetic field with a frequency equal to or in a range near a ferromagnetic resonance frequency FR of a the magnetic recording layer.
    Type: Application
    Filed: May 21, 2009
    Publication date: November 26, 2009
    Applicant: TDK CORPORATION
    Inventors: Hiroshi Ikeda, Saori Kajihara, Kiyoshi Noguchi, Isamu Sato
  • Publication number: 20090290255
    Abstract: A manufacturing method which is capable of easily and inexpensively manufacturing discrete track-type magnetic recording media is provided. A method of manufacturing magnetic recording media having a main surface on which magnetic tracks 4 are disposed in a substantially concentric arrangement and on which grooves 5 for magnetically separating radially adjoining magnetic tracks 4 from one another are formed is characterized by forming on a flat substrate 1 at least a magnetic recording layer 2 so as to fabricate a workpiece 1a, then pressing a stamper having protrusions corresponding to the grooves 5 against a main surface of the workpiece so as to transfer the shape of the protrusions to the workpiece and form grooves 5 between the magnetic tracks 4.
    Type: Application
    Filed: November 7, 2006
    Publication date: November 26, 2009
    Applicant: SHOWA DENKO K.K.
    Inventor: Akira Sakawaki
  • Publication number: 20090290266
    Abstract: 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: Application
    Filed: November 14, 2008
    Publication date: November 26, 2009
    Applicant: Cummissariat A L'Energie Atomique
    Inventors: Bernard Dieny, Bernard Rodmacq, Franck Ernult
  • Publication number: 20090273863
    Abstract: A perpendicular recording thin-film magnetic head comprises a main magnetic pole having a tip main magnetic pole part extending in a height direction from a medium-opposing surface and a base main magnetic pole part connected to the tip main magnetic pole part on a side opposite from the medium-opposing surface side and wider than the tip main magnetic pole part in a track width direction; a return yoke extending in the height direction from the medium-opposing surface and magnetically coupling with the base main magnetic pole part at a position distanced from the medium-opposing surface in the height direction, while opposing the tip main magnetic pole part through a write gap layer in a bit length direction in the medium-opposing surface; and a main magnetic pole adjacent magnetic shield layer extending along at least part of side faces of the main magnetic pole other than the medium-opposing surface as seen in a laminating direction, while holding a nonmagnetic layer between the main magnetic pole and the
    Type: Application
    Filed: December 13, 2007
    Publication date: November 5, 2009
    Applicants: TDK CORPORATION, SAE MAGNETICS (H.K.) LTD.
    Inventors: Hidetaka Kawano, Hiromichi Umehara, Takamitsu Sakamoto, Koichi Otani, Noriaki Kasahara, Naoto Matono
  • Publication number: 20090262466
    Abstract: Soft magnetic material elements are provided on both sides of each of magneto-resistance effect elements with a spacing therebetween. As a result, an external magnetic field generated from a magnet can be pulled to above a substrate on which the magneto-resistance effect element is provided, thereby making it possible to amplify the external magnetic field to be applied to the magneto-resistance effect element to more than in the related art. Since a bias magnetic field is applied to a free magnetic layer, a magnetic sensor is resistant to a disturbance magnetic field. Moreover, since the external magnetic field applied to the magneto-resistance effect element can be amplified, even if the bias magnetic field is applied to the free magnetic layer, the magnetic detection sensitivity can be apparently improved to more than in the related art, thereby increasing the output.
    Type: Application
    Filed: June 12, 2009
    Publication date: October 22, 2009
    Applicant: ALPS ELECTRIC CO., LTD.
    Inventors: Koji KURATA, Ichiro TOKUNAGA
  • Publication number: 20090257151
    Abstract: A spin valve structure for a spintronic device is disclosed and includes a composite seed layer made of at least Ta and a metal layer having a fcc(111) or hcp(001) texture to enhance perpendicular magnetic anisotropy (PMA) in an overlying (Co/Ni)x multilayer. The (Co/Ni)x multilayer is deposited by a low power and high Ar pressure process to avoid damaging Co/Ni interfaces and thereby preserving PMA. As a result, only a thin seed layer is required. PMA is maintained even after annealing at 220° C. for 10 hours. Examples of GMR and TMR spin valves are described and may be incorporated in spin transfer oscillators and spin transfer MRAMs. The free layer is preferably made of a FeCo alloy including at least one of Al, Ge, Si, Ga, B, C, Se, Sn, or a Heusler alloy, or a half Heusler alloy to provide high spin polarization and a low magnetic damping coefficient.
    Type: Application
    Filed: June 19, 2009
    Publication date: October 15, 2009
    Inventors: Kunliang Zhang, Min Li, Yuchen Zhou, Soichi Oikawa, Kenichiro Yamada, Katsuhiko Koui
  • Publication number: 20090257152
    Abstract: A magnetoresistive sensor having an antiparallel coupled pinned layer structure including an AP1 layer and an AP2 layer. The AP2 layer includes two ferromagnetic layers AP2(a) and AP2(b), and a separation layer sandwiched therebetween. The AP2(a) layer is significantly larger than the AP2(b) layer, which results in strong pinning, while the separation layer provides increased TMR and reduced RA.
    Type: Application
    Filed: December 30, 2008
    Publication date: October 15, 2009
    Inventors: Wen-yaung Lee, Chang Man Park, Brian R. York, Alexander M. Zeltser
  • Publication number: 20090251830
    Abstract: Magnetoresistive elements each have a layered structure including a pinned magnetic layer having a magnetization direction pinned in one direction, a free magnetic layer with magnetization being variable by an external magnetic field, and a nonmagnetic material layer arranged therebetween. Assuming that a center distance between a N-pole and a S-pole of a permanent magnet is ?, the magnetoresistive elements connected in series are arranged in a direction parallel to a relative movement direction with a center distance ? arranged therebetween. Interfaces in the layers of the layered structure of each of the magnetoresistive elements are orthogonal to a facing surface of the permanent magnet, and are in the relative movement direction. The pinned magnetic layers of the magnetoresistive elements have magnetization directions, all the magnetization directions are orthogonal to the relative movement direction in a plane parallel to the interfaces.
    Type: Application
    Filed: June 15, 2009
    Publication date: October 8, 2009
    Applicant: ALPS ELECTRIC CO., LTD.
    Inventors: Koji Kurata, Ichiro Tokunaga
  • Publication number: 20090251820
    Abstract: A magnetic storage system according to one embodiment includes magnetic media containing magnetic domain tracks; and at least one head for reading from the magnetic media, each head having: a first Extraordinary Magentoresistive (EMR) device for detecting magnetic fields of a first magnetic domain track; a second EMR device for detecting magnetic fields of a second magnetic domain track. The system further includes a slider for supporting the head; and a control unit coupled to the head for controlling operation of the head. A system according to another embodiment includes a first Extraordinary Magnetoresistive (EMR) device for detecting magnetic fields of a magnetic domain of interest. A system according to yet another embodiment includes an Extraordinary Magnetoresistive (EMR) device for deriving servoing information.
    Type: Application
    Filed: June 18, 2009
    Publication date: October 8, 2009
    Inventors: Bruce Alvin Gurney, Ernesto E. Marinero
  • Publication number: 20090244792
    Abstract: A magnetoresistance effect element includes: a first ferromagnetic layer having invariable magnetization perpendicular to a film plane; a second ferromagnetic layer having variable magnetization perpendicular to the film plane; a first nonmagnetic layer interposed between the first ferromagnetic layer and the second ferromagnetic layer; a third ferromagnetic layer provided on an opposite side of the second ferromagnetic layer from the first nonmagnetic layer, and having variable magnetization parallel to the film plane; and a second nonmagnetic layer interposed between the second and third ferromagnetic layers.
    Type: Application
    Filed: March 3, 2009
    Publication date: October 1, 2009
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Masahiko NAKAYAMA, Tadashi KAI, Sumio IKEGAWA, Hiroaki YODA, Tatsuya KISHI
  • Publication number: 20090237844
    Abstract: A magnetic sensor device (300) for sensing magnetic particles (15), the magnetic sensor device (300) comprising a magnetic field generator unit (12) adapted for generating a magnetic field, an excitation signal source (302) adapted for supplying the magnetic field generator unit (12) with a static electric excitation signal, an excitation switch unit (303) adapted for switching between different modes of electrically coupling the excitation signal source (302) to the magnetic field generator unit (12), and a sensing unit (11) adapted for sensing a signal indicative of the presence of the magnetic particles (15) in the generated magnetic field.
    Type: Application
    Filed: April 27, 2007
    Publication date: September 24, 2009
    Applicant: KONINKLIJKE PHILIPS ELECTRONICS N.V.
    Inventors: Haris Duric, Josephus Arnoldud Henricus Maria Kahlman, Jeroen Jacob Arnold Tol
  • Publication number: 20090231755
    Abstract: The invention provides a magnetic recording medium, and a magnetic recording and reproducing apparatus. The magnetic recording medium includes a substrate 11, an under layer 12 formed on the substrate 11, a magnetic recording layer 13 formed on the under layer 12, and a protective layer 14 formed on the magnetic recording layer 13. The magnetic recording layer 13 is composed of a primary recording layer 14 and a secondary recording layer 15 which are mutually exchange-coupled. The primary recording layer 14 has magnetic grains and a nonmagnetic material that surrounds the magnetic grains, and has a perpendicular magnetic anisotropy. The secondary recording layer 15 is made of a material having a negative crystal magnetic anisotropy and its easy plane of the magnetization is a plane of the medium.
    Type: Application
    Filed: June 9, 2006
    Publication date: September 17, 2009
    Inventors: Migaku Takahashi, Masahiro Oka, Akira Kikitsu
  • Publication number: 20090225465
    Abstract: A magnetic recording head includes a main magnetic pole, and a laminated body. The laminated body includes a first magnetic layer, a second magnetic layer, a first intermediate layer provided between the first magnetic layer and the second magnetic layer, and a third magnetic layer laminated with the first and second magnetic layers and the first intermediate layer. The third magnetic layer exerts a magnetic field on at least any of the first magnetic layer and the second magnetic layer. The third magnetic layer has larger saturation magnetization than at least any of the first magnetic layer and the second magnetic layer.
    Type: Application
    Filed: September 9, 2008
    Publication date: September 10, 2009
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Hitoshi Iwasaki, Kenichiro Yamada, Junichi Akiyama, Masayuki Takagishi, Tomomi Funayama, Masahiro Takashita, Mariko Shimizu
  • Publication number: 20090225477
    Abstract: A magnetoresistance effect element comprises a magnetoresistance effect film and a pair of electrode. The magnetoresistance effect film having a first magnetic layer whose direction of magnetization is substantially pinned in one direction; a second magnetic layer whose direction of magnetization changes in response to an external magnetic field; a nonmagnetic intermediate layer located between the first and second magnetic layers; and a film provided in the first magnetic layer, in the second magnetic layer, at a interface between the first magnetic layer and the nonmagnetic intermediate layer, and/or at a interface between the second magnetic layer and the nonmagnetic intermediate layer, the film having a thickness not larger than 3 nanometers, and the film has as least one selected from the group consisting of oxide, nitride, oxinitride, phosphide, and fluoride.
    Type: Application
    Filed: May 19, 2009
    Publication date: September 10, 2009
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Hideaki FUKUZAWA, Hiromi Yuasa, Hiromi Fuke, Hitoshi Iwasaki, Masashi Sahashi
  • Publication number: 20090213501
    Abstract: A composite thin-film magnetic head includes a substrate; a first insulation layer laminated on the substrate; an MR read head element formed on the first insulation layer and provided with a lower shield layer, an upper shield layer and an MR layer in which a sense current flows in a direction perpendicular to a surface of the MR layer through the upper shield layer and the lower shield layer; a second insulation layer laminated on the MR read head element; an inductive write head element formed on the second insulation layer and provided with a lower magnetic pole layer, a recording gap layer, an upper magnetic pole layer whose end portion is opposed to an end portion of the lower magnetic pole layer through the recording gap layer and a write coil; and a nonmagnetic conductive layer electrically conducted with the lower shield layer and opposed to the substrate in order to increase substantially countered area between the lower shield layer and the substrate.
    Type: Application
    Filed: April 21, 2009
    Publication date: August 27, 2009
    Applicant: TDK Corporation
    Inventors: Takeo Kagami, Noriaki Kasahara, Tetsuya Kuwshima
  • Publication number: 20090207532
    Abstract: A magneto resistance effect device includes a fixed magnetization portion including a ferromagnetic material, in which the magnetization direction can be fixed, and a tunnel barrier layer including high band gap metal oxide and low band gap metal oxide, and arranged on the fixed magnetization portion. The device includes a free magnetization portion including a ferromagnetic material, arranged on the tunnel barrier layer, in which the magnetization can be changed.
    Type: Application
    Filed: February 13, 2009
    Publication date: August 20, 2009
    Applicant: FUJITSU LIMITED
    Inventors: Atsushi Furuya, Yuji Uehara, Kenji Noma
  • Publication number: 20090207531
    Abstract: A magnetic recording read head is provided capable of achieving high reproduction output, resolution, and SNR, even at a high linear density. There is also provided a magnetic recording and reproducing device capable of achieving sufficient error bit rate. The magnetic recording read head includes a differential read head and a write head. The differential read head has a multilayer structure formed by laminating a first magnetoresistive sensor having a first free layer, a differential gap layer, and a second magnetoresistive sensor having a second free layer. Outside the multilayer structure, a pair of electrodes and a pair of magnetic shields are provided respectively. A ratio (Gl/bl) of an inside distance (Gl) between the first and second free layers to a bit length (bl) is set to 0.6 or more and 1.6 or less.
    Type: Application
    Filed: February 4, 2009
    Publication date: August 20, 2009
    Inventors: Masato SHIIMOTO, Takeshi Nakagawa, Hiroyuki Katada, Naoto Ito, Kenichi Meguro
  • Publication number: 20090201614
    Abstract: It is made possible to to provide a spin-torque oscillator that has a high Q value and a high output. A spin-torque oscillator includes: an oscillating field generating unit configured to generate an oscillating field; and a magnetoresistive element including a magnetoresistive effect film including a first magnetization pinned layer of which a magnetization direction is pinned, a first magnetization free layer of which a magnetization direction oscillates with the oscillating field, and a first spacer layer interposed between the first magnetization pinned layer and the first magnetization free layer.
    Type: Application
    Filed: September 29, 2008
    Publication date: August 13, 2009
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Kiwamu Kudo, Tazumi Nagasawa, Koichi Mizushima, Rie Sato
  • Publication number: 20090195940
    Abstract: In the magnetic head, terminal sections for mutually electrically connecting layers in the multilayer structure can be formed without forming raising layers. The magnetic head having a multilayer structure comprises: an upper shielding layer; a lower shielding layer; a magnetoresistance effect element section provided between the shielding layers; a magnetic pole; terminal sections mutually electrically connecting layers of the multilayer structure; and a first low-thermal expansion material layer composed of an insulating material, and each of the terminal sections has a multilayer structure comprising: a second low-thermal expansion material layer composed of a material which is the same as that of the first low-thermal expansion material layer; and a plurality of electrically conductive layers.
    Type: Application
    Filed: October 3, 2008
    Publication date: August 6, 2009
    Applicant: FUJITSU LIMITED
    Inventors: Junji Sato, Takashi Ito
  • Publication number: 20090174969
    Abstract: The present invention relates to a magnetic recording medium comprising a magnetic layer comprising a ferromagnetic powder and a binder on a nonmagnetic support, wherein the magnetic layer has a thickness ? ranging from 10 to 80 nm, a product, Mr?, of a residual magnetization Mr of the magnetic layer and the thickness ? of the magnetic layer is equal to or greater than 1 mA but less than 5 mA, a ratio, Sdc/Sac, of an average area Sdc of magnetic clusters in a DC demagnetized state to an average area Sac of magnetic clusters in an AC demagnetized state as measured by a magnetic force microscope, MFM, ranges from 0.8 to 2.0.
    Type: Application
    Filed: March 30, 2007
    Publication date: July 9, 2009
    Applicant: Fujifilm Corporation
    Inventors: Toshio Tada, Takeshi Harasawa
  • Publication number: 20090174970
    Abstract: The present invention relates to a magnetic recording medium comprising a nonmagnetic layer comprising a nonmagnetic powder and a binder and a magnetic layer comprising a ferromagnetic powder and a binder in this order on a nonmagnetic support. The magnetic layer has a thickness ranging from 30 to 130 nm, and a glossiness of the magnetic layer surface ranges from 155 to 270 percent.
    Type: Application
    Filed: March 30, 2007
    Publication date: July 9, 2009
    Inventors: Kenichiro Inoue, Takeshi Harasawa, Satoshi Matsubaguchi
  • Publication number: 20090168265
    Abstract: The present invention relates to a magnetic recording medium comprising a magnetic layer comprising a hexagonal ferrite powder and a binder on one surface of a nonmagnetic support and a backcoat layer on the other surface of the nonmagnetic support. A power spectrum density at a pitch of 10 micrometers ranges from 800 to 10,000 nm3 on the magnetic layer surface, a power spectrum density at a pitch of 10 micrometers ranges from 20,000 to 80,000 nm3 on the backcoat layer surface, the magnetic layer has a center surface average surface roughness Ra, as measured by an atomic force microscope, ranging from 0.5 to 2.5 nm, and the hexagonal ferrite powder has an average plate diameter ranging from 10 to 40 nm.
    Type: Application
    Filed: March 30, 2007
    Publication date: July 2, 2009
    Applicant: FUJIFILM Corporation
    Inventors: Takeshi Harasawa, Masahito Oyanagi
  • Publication number: 20090168270
    Abstract: In comparison with conventional exchange-coupled elements, the exchange-coupled element of the present invention has greater unidirectional magnetization anisotropy. The exchange-coupled element comprises: an ordered antiferromagnetic layer; and a pinned magnetic layer being exchange-coupled with the ordered antiferromagnetic layer, the pinned magnetic layer having unidirectional magnetization anisotropy. The pinned magnetic layer is constituted by a first pinned magnetic layer having a composition, which can have a face-centered cubic lattice structure, and a second pinned magnetic layer having a composition, which can have a body-centered cubic lattice structure.
    Type: Application
    Filed: December 23, 2008
    Publication date: July 2, 2009
    Applicants: FUJITSU LIMITED, TOHOKU UNIVERSITY
    Inventors: Migaku Takahashi, Masakiyo Tsunoda, Koujiro Komagaki, Yuji Uehara
  • Publication number: 20090168261
    Abstract: A magnetoresistive element is located between a lower shielding layer and an upper shielding layer. The magnetoresistive element receives an electric current through the lower shielding layer and the upper shielding layer. A non-magnetic conductive layer is embedded in the insulating film between the slider body and the lower shielding layer. An air layer is formed between the head slider and a storage medium. Capacitive coupling is established between the head slider and the storage medium. The capacitive coupling allows transmission of the noise from the storage medium to the slider body. The noise affects capacitance established between the lower shielding layer and the slider body. The non-magnetic conductive layer serves to prevent variation in a potential difference resulting from transmission of the noise between the lower shielding layer and the upper shielding layer.
    Type: Application
    Filed: September 3, 2008
    Publication date: July 2, 2009
    Applicant: FUJITSU LIMITED
    Inventors: Sachiko Furuya, Tetsuyuki Kubota, Junichi Hashimoto, Tomoka Aoki
  • Publication number: 20090161261
    Abstract: A magnetic sensor having at least a first and at least a second structure of soft-magnetic material that are spatially separated and define a first gap therebetween. The first and second structure of soft-magnetic material are adapted to form a gap magnetic field pointing in a direction substantially perpendicular to the elongation of the first gap in the vicinity of the first gap in response to an external magnetic field. Additionally, the magnetic sensor comprises at least a first magnetoresistive layered structure that is positioned in the vicinity of the first gap including inside the first gap and that is sensitive to the gap magnetic field.
    Type: Application
    Filed: July 9, 2008
    Publication date: June 25, 2009
    Inventors: Hubert Grimm, Jan Marien, Rolf Schaefer
  • Publication number: 20090161267
    Abstract: According to an aspect of an embodiment, a ferromagnetic tunnel junction device includes: a first pinned magnetic member including a ferromagnetic material having a boron atom; a second pinned magnetic member including a ferromagnetic material on the first pinned magnetic member, the content of the boron atom in the second pinned member being smaller than that in the first pinned member; and a first free magnetic member superposed with respect to the second pinned layer, including a ferromagnetic material. The ferromagnetic tunnel junction device further includes: an insulating layer between the second pinned magnetic layer and the first free magnetic layer; and a second free magnetic member including a ferromagnetic material having a boron atom on the first free magnetic member, the content of the boron atom in the second free member being smaller than that in the first free member.
    Type: Application
    Filed: December 19, 2008
    Publication date: June 25, 2009
    Applicant: FUJITSU LIMITED
    Inventors: Kenichi KAWAI, Yasushi Nishioka, Yusuke Hamada
  • Publication number: 20090161266
    Abstract: A high performance TMR element is fabricated by inserting an oxygen surfactant layer (OSL) between a pinned layer and AlOx tunnel barrier layer in a bottom spin valve configuration. The pinned layer preferably has a SyAP configuration with an outer pinned layer, a Ru coupling layer, and an inner pinned layer comprised of CoFeXBY/CoFeZ wherein x=0 to 70 atomic %, y=0 to 30 atomic %, and z=0 to 100 atomic %. The OSL is formed by treating the CoFeZ layer with oxygen plasma. The AlOx tunnel barrier has improved uniformity of about 2% across a 6 inch wafer and can be formed from an Al layer as thin as 5 Angstroms. As a result, the Hin value can be decreased by ? to about 32 Oe. A dR/R of 25% and a RA of 3 ohm-cm2 have been achieved for TMR read head applications.
    Type: Application
    Filed: January 27, 2009
    Publication date: June 25, 2009
    Inventors: Hui-Chuan Wang, Tong Zhao, Min Li, Kunliang Zhang
  • Publication number: 20090161264
    Abstract: The present invention relates to a sensor, preferably for magnetic rotary or linear sensor systems which include a scale arranged at a given distance from the sensor, with at least one magnetic field-sensitive GMR sensor element which is arranged in a housing, wherein the housing additionally includes one magnetic field source each associated to the at least one GMR sensor element, wherein the at least one GMR sensor element is firmly cast into an associated slot in the housing, wherein on at least one side of the slot a projection protrudes into the interior of the housing flush with this side wall of the slot, which also includes mounting recesses for accommodating the magnetic field source.
    Type: Application
    Filed: October 10, 2008
    Publication date: June 25, 2009
    Applicant: Woelke Magnetbandtechnik GmbH & Co. KG
    Inventor: Stefan Meyersweissflog
  • Publication number: 20090154029
    Abstract: A magnetic reproduction head includes a lower magnetic shield layer, an upper magnetic shield layer, a magnetoresistive film formed between the lower and the upper magnetic shield layers, a refill film in an element height direction disposed in contact with a surface opposite a floating surface of the magnetoresistive film, and a refill film in a track width direction disposed on a side wall surface of the magnetoresistive film. The magnetoresistive film is a tunneling magnetoresistive film including a free layer, an insulating barrier layer, and a fixed layer. The insulating barrier layer is one of a magnesium oxide film, an aluminum oxide film, and a titanium oxide film which contains at least one of nitrogen and silicon.
    Type: Application
    Filed: November 17, 2008
    Publication date: June 18, 2009
    Inventor: Tomio IWASAKI
  • Publication number: 20090147399
    Abstract: An arbitrary gap thin film magnetic recording head is fabricated by forming a substrate based on traditional vertical planar thin film head wafer technology which is designed to produce an integrated subgap and subpole substrate structure. The wafer is then processed into row bars to reveal, in a plane parallel to the transducing direction of the medium, the subgap and subpoles at the surface of the row bar and to bring the structure to a certain coil depth or gap depth. A flat or cylindrical contour may be utilized. This thin film subgap row bar is taken through a film deposition or growth process that deposits the magnetic film on a plane perpendicular to the wafer plane, horizontal planar processing, forming a surface film recording head where an arbitrary gap structure can be made in-between the subpoles and generally directly on top of the subgap.
    Type: Application
    Filed: November 10, 2008
    Publication date: June 11, 2009
    Inventors: Matthew P. Dugas, Theodore A. Schwarz