Patents by Inventor Takao Furubayashi

Takao Furubayashi 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: 20210020193
    Abstract: Provided is a precursor of a current-perpendicular-to-plane giant magnetoresistive element having a laminated structure of ferromagnetic metal layer/nonmagnetic metal layer/ferromagnetic metal layer, the precursor having a nonmagnetic intermediate layer containing a non-magnetic metal and an oxide in a predetermined ratio such that the distribution thereof is nearly uniform at the atomic level. Also provided is a current-perpendicular-to-plane giant magnetoresistive element having a current-confinement structure (CCP) which has: a current confinement structure region made of a conductive alloy and obtained by heat-treating a laminated structure of a ferromagnetic metal layer and a nonmagnetic intermediate layer at a predetermined temperature; and a high-resistance metal alloy region containing an oxide and surrounding the current confinement structure region.
    Type: Application
    Filed: February 26, 2019
    Publication date: January 21, 2021
    Applicant: NATIONAL INSTITUTE FOR MATERIALS SCIENCE
    Inventors: Tomoya NAKATANI, Taisuke SASAKI, Takao FURUBAYASHI, Kazuhiro HONO
  • Patent number: 10832719
    Abstract: Disclosed is a perpendicularly magnetized film structure using a highly heat resistant underlayer film on which a cubic or tetragonal perpendicularly magnetized film can grow, comprising a substrate 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 formed on the substrate from a thin film of a metal having an hcp structure 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; and a perpendicularly magnetized layer located on the metal underlayer and formed from a cubic material selected from a Co-based Heusler alloy and a cobalt-iron (CoFe) alloy having a bcc structure a constituent material, and grown to have the (001) plane.
    Type: Grant
    Filed: December 10, 2018
    Date of Patent: November 10, 2020
    Assignee: 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: 20190172486
    Abstract: Disclosed is a perpendicularly magnetized film structure using a highly heat resistant underlayer film on which a cubic or tetragonal perpendicularly magnetized film can grow, comprising a substrate 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 formed on the substrate from a thin film of a metal having an hcp structure 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; and a perpendicularly magnetized layer located on the metal underlayer and formed from a cubic material selected from a Co-based Heusler alloy and a cobalt-iron (CoFe) alloy having a bcc structure a constituent material, and grown to have the (001) plane.
    Type: Application
    Filed: December 10, 2018
    Publication date: June 6, 2019
    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
  • Patent number: 10199063
    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: Grant
    Filed: March 19, 2015
    Date of Patent: February 5, 2019
    Assignee: 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
  • Patent number: 9899044
    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: Grant
    Filed: July 28, 2015
    Date of Patent: February 20, 2018
    Assignee: NATIONAL INSTITUTE FOR MATERIALS SCIENCE
    Inventors: Takao Furubayashi, Yukiko Takahashi, Kazuhiro Hono, Ye Du
  • 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
  • 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
  • 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: 20120091548
    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: Application
    Filed: April 15, 2010
    Publication date: April 19, 2012
    Inventors: Hiroaki Sukegawa, Koichiro Inomata, Rong Shan, Masaya Kodzuka, Kazuhiro Hono, Takao Furubayashi, Wenhong Wang
  • Patent number: 5137652
    Abstract: A compound containing nitrogen is introduced into a solvent in which a metal carbonyl and a surface active agent are dissolved, and the solution is heated to generate a particle colloid or a magnetic fluid of a metal nitride. A particle colloid of a metal nitride with an even grain size, a good dispersibilitgy and a good fluidity, and a magnetic fluid thereof with an excellent properties are obtained with convenience and at high efficiency.
    Type: Grant
    Filed: December 18, 1990
    Date of Patent: August 11, 1992
    Assignee: National Research Institute For Metals
    Inventors: Isao Nakatani, Masayuki Hijikata, Tsutomu Takahashi, Kiyoshi Ozawa, Takao Furubayashi, Hiroaki Hanaoka
  • Patent number: 5012158
    Abstract: A plasma CVD apparatus having a rotary vacuum reaction vessel, a starting gas introducing port, an ambient gas introducing port, an exhaust port, electrodes or an induction coil for applying a high-frequency electric field, and a cooling pipe provided in the starting gas introducing port for cooling the starting gas introducing port, wherein the starting gas introducing port and the exhaust port are located in opposition to each other on a rotating axis of the reaction vessel.
    Type: Grant
    Filed: December 18, 1989
    Date of Patent: April 30, 1991
    Assignee: National Research Institute for Metals
    Inventors: Isao Nakatani, Takao Furubayashi