Patents by Inventor Hiroaki Sukegawa

Hiroaki Sukegawa 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: 20170330668
    Abstract: Embodiments of the inventive concepts provide a flat perpendicular magnetic layer having a low saturation magnetization and a perpendicular magnetization-type tunnel magnetoresistive element using the same. The perpendicular magnetic layer is a nitrogen-poor (Mn1?xGax)Ny layer (0<x?0.5 and 0<y<0.1) formed by providing nitrogen (N) into a MnGa alloy while adjusting a nitrogen amount. The perpendicular magnetic layer can be formed flat.
    Type: Application
    Filed: May 10, 2017
    Publication date: November 16, 2017
    Inventors: Shigeki TAKAHASHI, Yoshiaki SONOBE, Hiroaki SUKEGAWA, Hwachol LEE, Kazuhiro HONO, Seiji MITANI, Jun LIU
  • 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: 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: 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
  • 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
  • Patent number: 8866243
    Abstract: For the present ferromagnetic tunnel junction structure, employed is a means characterized by using an MgO barrier and using a Co2FeAl full-Heusler alloy for any of the ferromagnetic layers therein. The ferromagnetic tunnel junction structure is characterized in that Co2FeAl includes especially a B2 structure and one of the ferromagnetic layers is formed on a Cr buffer layer. The magnetoresistive element is characterized in that the ferromagnetic tunnel junction structure therein is any of the above-mentioned ferromagnetic tunnel junction structure. Accordingly, a large TMR, especially a TMR over 100% at room temperature can be attained, using Co2FeAl having a smallest ? though not a half-metal.
    Type: Grant
    Filed: May 7, 2010
    Date of Patent: October 21, 2014
    Assignee: National Institute for Materials Science
    Inventors: Koichiro Inomata, Wenhong Wang, Hiroaki Sukegawa
  • 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: 20120112299
    Abstract: For the present ferromagnetic tunnel junction structure, employed is a means characterized by using an MgO barrier and using a Co2FeAl full-Heusler alloy for any of the ferromagnetic layers therein. The ferromagnetic tunnel junction structure is characterized in that Co2FeAl includes especially a B2 structure and one of the ferromagnetic layers is formed on a Cr buffer layer. The magnetoresistive element is characterized in that the ferromagnetic tunnel junction structure therein is any of the above-mentioned ferromagnetic tunnel junction structure. Accordingly, a large TMR, especially a TMR over 100% at room temperature can be attained, using Co2FeAl having a smallest ? though not a half-metal.
    Type: Application
    Filed: May 7, 2010
    Publication date: May 10, 2012
    Applicant: NATIONAL INSTITUTE FOR MATERIALS SCIENCE
    Inventors: Koichiro Inomata, Wenhong Wang, Hiroaki Sukegawa
  • 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