Patents by Inventor Kazuhiro Hono

Kazuhiro Hono has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20170229643
    Abstract: To provide a key monocrystalline magnetoresistance element necessary for accomplishing mass production and cost reduction for applying a monocrystalline giant magnetoresistance element using a Heusler alloy to practical devices. A monocrystalline magnetoresistance element of the present invention includes a silicon substrate 11, a base layer 12 having a B2 structure laminated on the silicon substrate 11, a first non-magnetic layer 13 laminated on the base layer 12 having a B2 structure, and a giant magnetoresistance effect layer 17 having at least one laminate layer including a lower ferromagnetic layer 14, an upper ferromagnetic layer 16, and a second non-magnetic layer 15 disposed between the lower ferromagnetic layer 14 and the upper ferromagnetic layer 16.
    Type: Application
    Filed: February 3, 2017
    Publication date: August 10, 2017
    Inventors: Jiamin CHEN, Yuya SAKURABA, Jun LIU, Hiroaki SUKEGAWA, Kazuhiro HONO
  • Publication number: 20170221507
    Abstract: The present invention addresses the problem of providing an element which uses the current-perpendicular-to-plane giant magnetoresistance (CPPGMR) effect of a thin film having the three-layer structure of ferromagnetic metal/non-magnetic metal/ferromagnetic metal. The problem is solved by a magnetoresistive element provided with a lower ferromagnetic layer and an upper ferromagnetic layer which contain a Heusler alloy, and a spacer layer sandwiched between the lower ferromagnetic layer and the upper ferromagnetic layer, the magnetoresistive element being characterized in that the spacer layer contains an alloy having a bcc structure. Furthermore, it is preferable for the alloy to have a disordered bcc structure.
    Type: Application
    Filed: July 28, 2015
    Publication date: August 3, 2017
    Inventors: Takao FURUBAYASHI, Yukiko TAKAHASHI, Kazuhiro HONO, Ye DU
  • Publication number: 20170140784
    Abstract: Disclosed is a perpendicularly magnetized film structure that uses a highly heat resistant underlayer film on which a cubic or tetragonal perpendicularly magnetized film can grow with high quality, the structure comprising any one substrate (5) of a cubic single crystal substrate having a (001) plane, or a substrate having a cubic oriented film that grows to have the (001) plane; an underlayer (6) formed on the substrate (5) from a thin film of a metal having an hcp structure, such as Ru or Re, in which the [0001] direction of the thin metal film forms an angle in the range of 42° to 54° with respect to the <001> direction or the (001) orientation of the substrate (5); and a perpendicularly magnetized layer (7) located on the metal underlayer (6) and formed from a cubic material selected from the group consisting of a Co-based Heusler alloy, a cobalt-iron (CoFe) alloy having a bcc structure, and the like, as a constituent material, and grown to have the (001) plane.
    Type: Application
    Filed: March 19, 2015
    Publication date: May 18, 2017
    Applicant: NATIONAL INSTITUTE FOR MATERIALS SCIENCE
    Inventors: Hiroaki SUKEGAWA, Zhenchao WEN, Seiji MITANI, Koichiro INOMATA, Takao FURUBAYASHI, Jason Paul HADORN, Tadakatsu OHKUBO, Kazuhiro HONO, Jungwoo KOO
  • Publication number: 20170092307
    Abstract: The CPPGMR element of the present invention has an orientation layer 12 formed on a substrate 11 to texture a Heusler alloy into a (100) direction, an underlying layer 13 that is an electrode for magneto-resistance measurement stacked on the orientation layer 12, a lower ferromagnetic layer 14 and an upper ferromagnetic layer 16 each stacked on the underlying layer 13 and made of a Heusler alloy, a spacer layer 15 sandwiched between the lower ferromagnetic layers 14 and the upper ferromagnetic layers 16, and a cap layer 17 stacked on the upper ferromagnetic layer 16 for surface-protection. This manner makes it possible to provide, inexpensively, an element using a current-perpendicular-to-plane giant magneto-resistance effect (CPPGMR) of a thin film having a trilayered structure of a ferromagnetic metal/a nonmagnetic metal/a ferromagnetic metal, thereby showing excellent performances.
    Type: Application
    Filed: October 31, 2016
    Publication date: March 30, 2017
    Applicant: NATIONAL INSTITUTE FOR MATERIALS SCIENCE
    Inventors: Ye DU, Takao FURUBAYASHI, Yukiko TAKAHASHI, Kazuhiro HONO
  • Patent number: 9589583
    Abstract: The CPPGMR element of the present invention has an orientation layer 12 formed on a substrate 11 to texture a Heusler alloy into a (100) direction, an underlying layer 13 that is an electrode for magneto-resistance measurement stacked on the orientation layer 12, a lower ferromagnetic layer 14 and an upper ferromagnetic layer 16 each stacked on the underlying layer 13 and made of a Heusler alloy, a spacer layer 15 sandwiched between the lower ferromagnetic layers 14 and the upper ferromagnetic layers 16, and a cap layer 17 stacked on the upper ferromagnetic layer 16 for surface-protection. This manner makes it possible to provide, inexpensively, an element using a current-perpendicular-to-plane giant magneto-resistance effect (CPPGMR) of a thin film having a trilayered structure of a ferromagnetic metal/a nonmagnetic metal/a ferromagnetic metal, thereby showing excellent performances.
    Type: Grant
    Filed: October 31, 2016
    Date of Patent: March 7, 2017
    Assignee: NATIONAL INSTITUTE FOR MATERIALS SCIENCE
    Inventors: Ye Du, Takao Furubayashi, Yukiko Takahashi, Kazuhiro Hono
  • Patent number: 9558767
    Abstract: The CPPGMR element of the present invention has an orientation layer 12 formed on a substrate 11 to texture a Heusler alloy into a (100) direction, an underlying layer 13 that is an electrode for magneto-resistance measurement stacked on the orientation layer 12, a lower ferromagnetic layer 14 and an upper ferromagnetic layer 16 each stacked on the underlying layer 13 and made of a Heusler alloy, a spacer layer 15 sandwiched between the lower ferromagnetic layers 14 and the upper ferromagnetic layers 16, and a cap layer 17 stacked on the upper ferromagnetic layer 16 for surface-protection. This manner makes it possible to provide, inexpensively, an element using a current-perpendicular-to-plane giant magneto-resistance effect (CPPGMR) of a thin film having a trilayered structure of a ferromagnetic metal/a nonmagnetic metal/a ferromagnetic metal, thereby showing excellent performances.
    Type: Grant
    Filed: April 2, 2014
    Date of Patent: January 31, 2017
    Assignee: NATIONAL INSTITUTE FOR MATERIALS SCIENCE
    Inventors: Ye Du, Takao Furubayashi, Yukiko Takahashi, Kazuhiro Hono
  • Patent number: 9508373
    Abstract: Provided are an element structure in which a magnetic layer has a high magnetic anisotropy constant and saturated magnetization properties in a thickness of 1.5 nm or less, and a magnetic device that uses the element structure. A BCC metal nitride/CoFeB/MgO film structure that uses a nitride of a BCC metal as a seed layer is fabricated. The nitride amount in the BCC metal nitride is preferably less than 60% in terms of volume ratio based on 100% BCC metal. It is thereby possible to readily obtain a perpendicularly magnetized film having the magnetic properties that the perpendicular magnetic anisotropy is 0.1×106 erg/cm3 or more and the saturated magnetization is 200 emu/cm3 or more, even when the thickness of the magnetic layer is 0.3 nm or more and 1.5 nm or less.
    Type: Grant
    Filed: March 22, 2013
    Date of Patent: November 29, 2016
    Assignee: National Institute for Materials Science
    Inventors: Masamitsu Hayashi, Sinha Jaivardhan, Masaya Kodzuka, Tomoya Nakatani, Yukiko Takahashi, Takao Furubayashi, Seiji Mitani, Kazuhiro Hono
  • Publication number: 20160314825
    Abstract: Provided is a structure having a perpendicular magnetization film which is an (Mn1-x,Gax)4N1-y (0<x?0.5, 0<y<1) thin film having a nitrogen-deficient composition which is formed by controlling and introducing nitrogen N into an MnGa alloy or a thin film containing at least one of Ge, Zn, Sb, Ni, Ag, Sn, Pt, and Rh, instead of Ga. The perpendicular magnetization film exhibits a Curie temperature sufficiently higher than room temperature, has saturation magnetization smaller than that of existing materials, and is capable of being fabricated as a very flat film.
    Type: Application
    Filed: April 21, 2016
    Publication date: October 27, 2016
    Applicants: NATIONAL INSTITUTE FOR MATERIALS SCIENCE, SAMSUNG ELECTRONICS COMPANY LIMITED
    Inventors: Hiroaki SUKEGAWA, Hwachol LEE, Kazuhiro HONO, Seiji MITANI, Tadakatsu OHKUBO, Jun LIU, Shinya KASAI, Kwangseok KIM
  • Publication number: 20160225393
    Abstract: A perpendicular magnetic recording medium which has a magnetic layer comprising a material having FePt alloy as a main component on a substrate, characterized in that the magnetic layer is an FePtAg—C or FePt—C granular thin film obtained by laminating a unit in multiple stages, the unit being a laminate film obtained by forming, on an FePtAg—C layer or an FePt—C layer, at least one layer of (A) FePtAg layer or FePt layer or (B) FePtAg—C layer or FePt—C layer which has carbon concentration different from the above FePtAg—C layer or FePt—C layer. Consequently, a perpendicular magnetic recording medium using an FePtAg—C or FePt—C granular thin film which satisfies both the high order and columnar structure required for achieving recording density of more than 1 Tbit/in2, for example, can be provided.
    Type: Application
    Filed: August 25, 2014
    Publication date: August 4, 2016
    Applicant: NATIONAL INSTITUTE FOR MATERIALS SCIENCE
    Inventors: Bollapragada VARAPRASAD, Yukiko TAKAHASHI, Kazuhiro HONO
  • Publication number: 20160155919
    Abstract: Provided is a thermoelectric material which can increase its anomalous Nernst angle. The thermoelectric material of a magnetic material for a thermoelectric power generation device employs the anomalous Nernst effect, including iron doped with iridium.
    Type: Application
    Filed: November 20, 2015
    Publication date: June 2, 2016
    Applicants: TOYOTA JIDOSHA KABUSHIKI KAISHA, NATIONAL INSTITUTE FOR MATERIALS SCIENCE
    Inventors: Yohei KINOSHITA, Yuya SAKURABA, Taisuke SASAKI, Kazuhiro HONO
  • Patent number: 9336937
    Abstract: To realize a spintronics device with high performance, it is an object of the present invention to provide a Co2Fe-based Heusler alloy having a spin polarization larger than 0.65, and a high performance spintronics devices using the same. A Co2Fe(GaxGe1-x) Heusler alloy shows a spin polarization higher than 0.65 by a PCAR method in a region of 0.25<x<0.60 and it has a Curie temperature as high as 1288K. A CPP-GMR device that uses the Co2Fe(GaxGe1-x) Heusler alloy as an electrode exhibits the world's highest MR ratio, an STO device exhibits high output, and an NLSV device exhibits a high spin signal.
    Type: Grant
    Filed: July 3, 2013
    Date of Patent: May 10, 2016
    Assignee: NATIONAL INSTITUTE FOR MATERIALS SCIENCE
    Inventors: Yukiko Takahashi, Srinivasan Ananthakrishnan, Varaprasad Bollapragada, Rajanikanth Ammanabrolu, Jaivardhan Sinha, Masamitsu Hayashi, Takao Furubayashi, Shinya Kasai, Shigeyuki Hirayama, Seiji Mitani, Kazuhiro Hono
  • Publication number: 20160019917
    Abstract: The CPPGMR element of the present invention has an orientation layer 12 formed on a substrate 11 to texture a Heusler alloy into a (100) direction, an underlying layer 13 that is an electrode for magneto-resistance measurement stacked on the orientation layer 12, a lower ferromagnetic layer 14 and an upper ferromagnetic layer 16 each stacked on the underlying layer 13 and made of a Heusler alloy, a spacer layer 15 sandwiched between the lower ferromagnetic layers 14 and the upper ferromagnetic layers 16, and a cap layer 17 stacked on the upper ferromagnetic layer 16 for surface-protection. This manner makes it possible to provide, inexpensively, an element using a current-perpendicular-to-plane giant magneto-resistance effect (CPPGMR) of a thin film having a trilayered structure of a ferromagnetic metal/a nonmagnetic metal/a ferromagnetic metal, thereby showing excellent performances.
    Type: Application
    Filed: April 2, 2014
    Publication date: January 21, 2016
    Applicant: NATIONAL INSTITUTE FOR MATERIALS SCIENCE
    Inventors: Ye DU, Takao FURUBAYASHI, Yukiko TAKAHASHI, Kazuhiro HONO
  • Publication number: 20150132609
    Abstract: Provided are an element structure in which a magnetic layer has a high magnetic anisotropy constant and saturated magnetization properties in a thickness of 1.5 nm or less, and a magnetic device that uses the element structure. A BCC metal nitride/CoFeB/MgO film structure that uses a nitride of a BCC metal as a seed layer is fabricated. The nitride amount in the BCC metal nitride is preferably less than 60% in terms of volume ratio based on 100% BCC metal. It is thereby possible to readily obtain a perpendicularly magnetized film having the magnetic properties that the perpendicular magnetic anisotropy is 0.1×106 erg/cm3 or more and the saturated magnetization is 200 emu/cm3 or more, even when the thickness of the magnetic layer is 0.3 nm or more and 1.5 nm or less.
    Type: Application
    Filed: March 22, 2013
    Publication date: May 14, 2015
    Applicant: NATIONAL INSTITUTE FOR MATERIALS SCIENCE
    Inventors: Masamitsu Hayashi, Sinha Jaivardhan, Masaya Kodzuka, Tomoya Nakatani, Yukiko Takahashi, Takao Furubayashi, Seiji Mitani, Kazuhiro Hono
  • Patent number: 8993134
    Abstract: A perpendicular magnetic recording medium, comprising: a substrate; a buffer layer deposited in a first orientation on top of the substrate; an underlayer deposited in a second orientation on top of the buffer layer, the underlayer comprising an electrically conductive oxide; and a magnetic recording layer deposited on top of the underlayer and having an axis of magnetic anisotropy substantially perpendicular to the surface thereof.
    Type: Grant
    Filed: June 29, 2012
    Date of Patent: March 31, 2015
    Assignee: Western Digital Technologies, Inc.
    Inventors: Bollapragada Varaprasad, Yukiko Takahashi, Kazuhiro Hono, Antony Ajan, Hua Yuan, Alexander S. Chernyshov
  • Publication number: 20150008998
    Abstract: The invention provides a nanocomposite magnet, which has achieved high coercive force and high residual magnetization. The magnet is a non-ferromagnetic phase that is intercalated between a hard magnetic phase with a rare-earth magnet composition and a soft magnetic phase, wherein the non-ferromagnetic phase reacts with neither the hard nor soft magnetic phase. A hard magnetic phase contains Nd2Fe14B, a soft magnetic phase contains Fe or Fe2Co, and a non-ferromagnetic phase contains Ta. The thickness of the non-ferromagnetic phase containing Ta is 5 nm or less, and the thickness of the soft magnetic phase containing Fe or Fe2Co is 20 nm or less. Nd, or Pr, or an alloy of Nd and any one of Cu, Ag, Al, Ga, and Pr, or an alloy of Pr and any one of Cu, Ag, Al, and Ga is diffused into a grain boundary phase of the hard magnetic phase of Nd2Fe14B.
    Type: Application
    Filed: December 27, 2012
    Publication date: January 8, 2015
    Applicants: NATIONAL INSTITUTE FOR MATERIALS SCIENCE, TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Hidefumi Kishimoto, Noritsugu Sakuma, Masao Yano, Weibin Cui, Yukiko Takahashi, Kazuhiro Hono
  • Publication number: 20140335376
    Abstract: A perpendicular magnetic recording medium, comprising: a substrate; a buffer layer deposited in a first orientation on top of the substrate; an underlayer deposited in a second orientation on top of the buffer layer, the underlayer comprising an electrically conductive oxide; and a magnetic recording layer deposited on top of the underlayer and having an axis of magnetic anisotropy substantially perpendicular to the surface thereof.
    Type: Application
    Filed: June 29, 2012
    Publication date: November 13, 2014
    Applicant: Western Digital Technologies, Inc.
    Inventors: BOLLAPRAGADA VALAPRASAD, Yukiko Takahashi, Kazuhiro Hono, Antony Ajan, Hua Yuan, Alexander S. Chernyshov
  • Patent number: 8872291
    Abstract: A ferromagnetic tunnel junction structure comprising a first ferromagnetic layer, a second ferromagnetic layer, and a tunnel barrier layer that is interposed between the first ferromagnetic layer and the second ferromagnetic layer, wherein the tunnel barrier layer includes a crystalline non-magnetic material having constituent elements that are similar to those of an crystalline oxide that has spinel structure as a stable phase structure; the non-magnetic material has a cubic structure having a symmetry of space group Fm-3m or F-43m in which atomic arrangement in the spinel structure is disordered; and an effective lattice constant of the cubic structure is substantially half of the lattice constant of the oxide of the spinel structure.
    Type: Grant
    Filed: September 26, 2012
    Date of Patent: October 28, 2014
    Assignee: National Institute For Materials Science
    Inventors: Hiroaki Sukegawa, Seiji Mitani, Tomohiko Niizeki, Tadakatsu Ohkubo, Kouichiro Inomata, Kazuhiro Hono, Masafumi Shirai, Yoshio Miura, Kazutaka Abe, Shingo Muramoto
  • Publication number: 20130302649
    Abstract: [Problem to be Solved] To realize a spintronics device with high performance, it is an object of the present invention to provide a Co2Fe-based Heusler alloy having a spin polarization larger than 0.65, and a high performance spintronics devices using the same. [Solution] A Co2Fe(GaxGe1-x) Heusler alloy shows a spin polarization higher than 0.65 by a PCAR method in a region of 0.25<x<0.60 and it has a Curie temperature as high as 1288K. A CPP-GMR device that uses the Co2Fe(GaxGe1-x) Heusler alloy as an electrode exhibits the world's highest MR ratio, an STO device exhibits high output, and an NLSV device exhibits a high spin signal.
    Type: Application
    Filed: July 3, 2013
    Publication date: November 14, 2013
    Inventors: Yukiko Takahashi, Srinivasan Ananthakrishnan, Varaprasad Bollapragada, Rajanikanth Ammanabrolu, Jaivardhan Sinha, Masamitsu Hayashi, Takao Furubayashi, Shinya Kasai, Shigeyuki Hirayama, Seiji Mitani, Kazuhiro Hono
  • Patent number: 8575674
    Abstract: Disclosed is a ferromagnetic tunnel junction structure which is characterized by having a tunnel barrier layer that comprises a non-magnetic material having a spinel structure. The ferromagnetic tunnel junction structure is also characterized in that the non-magnetic material is substantially MgAl2O4. The ferromagnetic tunnel junction is also characterized in that at least one of the ferromagnetic layers comprises a Co-based full Heusler alloy having an L21 or B2 structure. The ferromagnetic tunnel junction structure is also characterized in that the Co-based full Heusler alloy comprises a substance represented by the following formula: Co2FeAlxSi1-x (0?x?1). Also disclosed are a magnetoresistive element and a spintronics device, each of which utilizes the ferromagnetic tunnel junction structure and can achieve a high TMR value, that cannot be achieved by employing conventional tunnel barrier layers other than a MgO barrier.
    Type: Grant
    Filed: April 15, 2010
    Date of Patent: November 5, 2013
    Assignee: National Institute for Materials Science
    Inventors: Hiroaki Sukegawa, Koichiro Inomata, Rong Shan, Masaya Kodzuka, Kazuhiro Hono, Takao Furubayashi, Wenhong Wang
  • Publication number: 20130068992
    Abstract: An R-T-B based permanent magnet powder, which has been made by an HDDR process and which has an average crystal grain size of 0.1 ?m to 1 ?m and a crystal grain aspect ratio (ratio of the major axis size to the minor axis size) of 2 or less, is provided (Step (A)). R is a rare-earth element, of which at least 95 at % is Nd and/or Pr, and T is either Fe alone or Fe partially replaced with Co and/or Ni and is a transition metal element, of which at least 50 at % is Fe. Meanwhile, an R?—Cu based alloy powder, which is made up of R? and Cu, which accounts for 2 at % to 50 at % of the alloy powder, is also provided (Step (B)). R? is a rare-earth element, of which at least 90 at % is Nd and/or Pr but which includes neither Dy nor Tb. The R-T-B based permanent magnet powder and the R?—Cu based alloy powder are mixed together to obtain a mixed powder (Step (C)). And then the mixed powder is subjected to a heat treatment process at a temperature of 500° C. to 900° C.
    Type: Application
    Filed: May 19, 2011
    Publication date: March 21, 2013
    Inventors: Kazuhiro Hono, Tadakatsu Ohkubo, Hossein Sepehri Amin, Noriyuki Nozawa, Takeshi Nishiuchi, Satoshi Hirosawa