Patents by Inventor Shinto ICHIKAWA

Shinto ICHIKAWA 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: 20230157183
    Abstract: A tunnel barrier layer includes a non-magnetic oxide, wherein a crystal structure of the tunnel barrier layer includes both an ordered spinel structure and a disordered spinel structure.
    Type: Application
    Filed: January 13, 2023
    Publication date: May 18, 2023
    Applicant: TDK CORPORATION
    Inventors: Shinto ICHIKAWA, Katsuyuki NAKADA
  • Publication number: 20230144429
    Abstract: A magnetoresistance effect element includes a first ferromagnetic layer, a second ferromagnetic layer, and a nonmagnetic layer. The nonmagnetic layer is between the first ferromagnetic layer and the second ferromagnetic layer. At least one of the first ferromagnetic layer and the second ferromagnetic layer is a Heusler alloy layer. The nonmagnetic layer includes a first region and a second region in a plane. Both of the first region and the second region are formed of a metal. The second region is different in constituent material from the first region. The second region has a crystal structure of a body-centered cubic lattice structure (bcc).
    Type: Application
    Filed: November 4, 2022
    Publication date: May 11, 2023
    Applicant: TDK CORPORATION
    Inventors: Shinto ICHIKAWA, Katsuyuki NAKADA, Kazuumi INUBUSHI
  • Patent number: 11621392
    Abstract: A magnetoresistance effect element includes: a first ferromagnetic layer; a second ferromagnetic layer; and a non-magnetic layer provided between the first ferromagnetic layer and the second ferromagnetic layer, wherein at least one of the first ferromagnetic layer and the second ferromagnetic layer includes a first layer and a second layer in order from the side closer to the non-magnetic layer, the first layer contains a crystallized Co-based Heusler alloy, at least a part of the second layer is crystallized, the second layer contains a ferromagnetic element, boron element and an additive element, and the additive element is any element selected from a group consisting of Ti, V, Cr, Cu, Zn, Zr, Mo, Ru, Pd, Ta, W, Ir, Pt, and Au.
    Type: Grant
    Filed: September 21, 2021
    Date of Patent: April 4, 2023
    Assignee: TDK CORPORATION
    Inventors: Shinto Ichikawa, Kazuumi Inubushi, Katsuyuki Nakada
  • Patent number: 11594674
    Abstract: A tunnel barrier layer includes a non-magnetic oxide, wherein a crystal structure of the tunnel barrier layer includes both an ordered spinel structure and a disordered spinel structure.
    Type: Grant
    Filed: March 18, 2020
    Date of Patent: February 28, 2023
    Assignee: TDK CORPORATION
    Inventors: Shinto Ichikawa, Katsuyuki Nakada
  • Patent number: 11585873
    Abstract: A magnetoresistive effect element includes: a first ferromagnetic layer; a second ferromagnetic layer; and a non-magnetic layer provided between the first ferromagnetic layer and the second ferromagnetic layer, wherein the non-magnetic layer includes a first layer and a second layer, and wherein a lattice constant ? of the first layer and a lattice constant ? of the second layer satisfy a relationship of ??0.04×??2×???+0.04×?.
    Type: Grant
    Filed: July 8, 2021
    Date of Patent: February 21, 2023
    Assignees: TDK CORPORATION, NATIONAL INSTITUTE FOR MATERIALS SCIENCE
    Inventors: Shinto Ichikawa, Katsuyuki Nakada, Hiroaki Sukegawa, Seiji Mitani, Tadakatsu Ohkubo, Kazuhiro Hono
  • Publication number: 20230025589
    Abstract: A magnetoresistance effect element of the present disclosure includes a first Ru alloy layer, a first ferromagnetic layer, a non-magnetic metal layer, and a second ferromagnetic layer in order, wherein the first Ru alloy layer contains one or more Ru alloys represented by the following general formula (1), Ru?X1-???(1) where, in the general formula (1), the symbol X represents one or more elements selected from the group consisting of Be, B, Ti, Y, Zr, Nb, Mo, Rh, In, Sn, La, Ce, Nd, Sm, Gd, Dy, Er, Ta, W, Re, Os, and Ir, and the symbol ? represents a number satisfying 0.5<?<1, the first ferromagnetic layer contains a Heusler alloy, and the second ferromagnetic layer contains a Heusler alloy.
    Type: Application
    Filed: July 6, 2022
    Publication date: January 26, 2023
    Applicant: TDK CORPORATION
    Inventors: Kazuumi INUBUSHI, Katsuyuki NAKADA, Shinto ICHIKAWA
  • Publication number: 20230009284
    Abstract: A magnetoresistive effect element includes: a first ferromagnetic layer; a second ferromagnetic layer; and a non-magnetic layer provided between the first ferromagnetic layer and the second ferromagnetic layer, wherein the non-magnetic layer includes a first layer and a second layer, and wherein a lattice constant ? of the first layer and a lattice constant ? of the second layer satisfy a relationship of ??0.04×??2×???+0.04 ×?.
    Type: Application
    Filed: July 8, 2021
    Publication date: January 12, 2023
    Applicants: TDK CORPORATION, NATIONAL INSTITUTE FOR MATERIALS SCIENCE
    Inventors: Shinto ICHIKAWA, Katsuyuki NAKADA, Hiroaki SUKEGAWA, Seiji MITANI, Tadakatsu OHKUBO, Kazuhiro HONO
  • Patent number: 11525873
    Abstract: A magnetoresistance effect element includes a first ferromagnetic layer, a second ferromagnetic layer, a first non-magnetic layer; and a second non-magnetic layer, wherein, the first ferromagnetic layer and the second ferromagnetic layer are formed so that at least one of them includes a Heusler alloy layer, the first non-magnetic layer is provided between the first ferromagnetic layer and the second ferromagnetic layer, the second non-magnetic layer is in contact with any surface of the Heusler alloy layer and has a discontinuous portion with respect to a lamination surface, and the second non-magnetic layer is made of a material different from that of the first non-magnetic layer and is a (001)-oriented oxide containing Mg.
    Type: Grant
    Filed: February 2, 2021
    Date of Patent: December 13, 2022
    Assignee: TDK CORPORATION
    Inventors: Shinto Ichikawa, Kazuumi Inubushi, Katsuyuki Nakada
  • Publication number: 20220278271
    Abstract: In the magnetoresistance effect element according to one aspect, the metal oxide constituting the metal oxide layer has the ratio of oxygen higher than the total ratio of metal when the composition is expressed in the stoichiometric composition; and the resistivity of the metal oxide layer is higher than that of the tunnel barrier layer.
    Type: Application
    Filed: June 24, 2020
    Publication date: September 1, 2022
    Applicant: TDK CORPORATION
    Inventors: Shinto ICHIKAWA, Tsuyoshi SUZUKI, Katsuyuki NAKADA, Tomoyuki SASAKI
  • Publication number: 20220278272
    Abstract: A magnetoresistance effect element includes 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. The tunnel barrier layer is a stacked body including one or more first oxide layers having a spinel structure and one or more second oxide layers having a spinel structure with a composition which is different from a composition of the first oxide layer.
    Type: Application
    Filed: May 17, 2022
    Publication date: September 1, 2022
    Applicant: TDK CORPORATION
    Inventors: Shinto ICHIKAWA, Katsuyuki NAKADA, Tomoyuki SASAKI
  • Patent number: 11362270
    Abstract: A magnetoresistance effect element includes 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. The tunnel barrier layer is a stacked body including one or more first oxide layers having a spinel structure and one or more second oxide layers having a spinel structure with a composition which is different from a composition of the first oxide layer.
    Type: Grant
    Filed: October 1, 2020
    Date of Patent: June 14, 2022
    Assignee: TDK CORPORATION
    Inventors: Shinto Ichikawa, Katsuyuki Nakada, Tomoyuki Sasaki
  • Publication number: 20220006007
    Abstract: A magnetoresistance effect element includes: a first ferromagnetic layer; a second ferromagnetic layer; and a non-magnetic layer provided between the first ferromagnetic layer and the second ferromagnetic layer, wherein at least one of the first ferromagnetic layer and the second ferromagnetic layer includes a first layer and a second layer in order from the side closer to the non-magnetic layer, the first layer contains a crystallized Co-based Heusler alloy, at least a part of the second layer is crystallized, the second layer contains a ferromagnetic element, boron element and an additive element, and the additive element is any element selected from a group consisting of Ti, V, Cr, Cu, Zn, Zr, Mo, Ru, Pd, Ta, W, Ir, Pt, and Au.
    Type: Application
    Filed: September 21, 2021
    Publication date: January 6, 2022
    Applicant: TDK CORPORATION
    Inventors: Shinto ICHIKAWA, Kazuumi INUBUSHI, Katsuyuki NAKADA
  • Patent number: 11158785
    Abstract: A magnetoresistance effect element includes: a first ferromagnetic layer; a second ferromagnetic layer; and a non-magnetic layer provided between the first ferromagnetic layer and the second ferromagnetic layer, wherein at least one of the first ferromagnetic layer and the second ferromagnetic layer includes a first layer and a second layer in order from the side closer to the non-magnetic layer, the first layer contains a crystallized Co-based Heusler alloy, at least a part of the second layer is crystallized, the second layer contains a ferromagnetic element, boron element and an additive element, and the additive element is any element selected from a group consisting of Ti, V, Cr, Cu, Zn, Zr, Mo, Ru, Pd, Ta, W, Ir, Pt, and Au.
    Type: Grant
    Filed: December 22, 2020
    Date of Patent: October 26, 2021
    Assignee: TDK CORPORATION
    Inventors: Shinto Ichikawa, Kazuumi Inubushi, Katsuyuki Nakada
  • Publication number: 20210318394
    Abstract: A magnetoresistance effect element includes a first ferromagnetic layer, a second ferromagnetic layer, a nonmagnetic layer that is disposed between the first ferromagnetic layer and the second ferromagnetic layer, and an insertion layer that is disposed at least one of a position between the first ferromagnetic layer and the nonmagnetic layer and a position between the second ferromagnetic layer and the nonmagnetic layer, in which the nonmagnetic layer is composed of an oxide containing Mg and Ga, and the insertion layer is a ferromagnetic component containing Ga.
    Type: Application
    Filed: March 8, 2021
    Publication date: October 14, 2021
    Applicant: TDK CORPORATION
    Inventors: Shogo Yonemura, Tomoyuki Sasaki, Shinto Ichikawa
  • Publication number: 20210304940
    Abstract: A magnetoresistive effect element includes: a first ferromagnetic layer; a second ferromagnetic layer; and a non-magnetic layer located between the first ferromagnetic layer and the second ferromagnetic layer, wherein a crystal structure of the non-magnetic layer is a spinel structure, wherein the non-magnetic layer contains Mg, Al, X, and O as elements constituting the spinel structure, and wherein the X is at least one or more elements selected from a group consisting of Ti, Pt, and W.
    Type: Application
    Filed: March 26, 2021
    Publication date: September 30, 2021
    Applicant: TDK CORPORATION
    Inventors: Tsuyoshi SUZUKI, Shinto ICHIKAWA, Katsuyuki NAKADA
  • Publication number: 20210286028
    Abstract: A magnetoresistance effect element includes a first ferromagnetic layer, a second ferromagnetic layer, a first non-magnetic layer; and a second non-magnetic layer, wherein, the first ferromagnetic layer and the second ferromagnetic layer are formed so that at least one of them includes a Heusler alloy layer, the first non-magnetic layer is provided between the first ferromagnetic layer and the second ferromagnetic layer, the second non-magnetic layer is in contact with any surface of the Heusler alloy layer and has a discontinuous portion with respect to a lamination surface, and the second non-magnetic layer is made of a material different from that of the first non-magnetic layer and is a (001)-oriented oxide containing Mg.
    Type: Application
    Filed: February 2, 2021
    Publication date: September 16, 2021
    Applicant: TDK CORPORATION
    Inventors: Shinto ICHIKAWA, Kazuumi INUBUSHI, Katsuyuki NAKADA
  • Publication number: 20210265562
    Abstract: A magnetoresistive effect element includes a first ferromagnetic layer, a second ferromagnetic layer, a non-magnetic layer disposed between the first ferromagnetic layer and the second ferromagnetic layer, and an additive-containing layer disposed at any position in a laminating direction, at least one of the first ferromagnetic layer and the second ferromagnetic layer is a Heusler alloy containing at least one of boron and carbon, at least part of which is crystallized, and the additive-containing layer is a non-magnetic layer containing at least one of boron and carbon, and any one element selected from the group made of Ti, V, Cr, Cu, Zn, Zr, Mo, Ru, Pd, Ta, W, Ir, Pt and Au.
    Type: Application
    Filed: December 9, 2020
    Publication date: August 26, 2021
    Applicant: TDK CORPORATION
    Inventors: Shinto ICHIKAWA, Kazuumi INUBUSHI, Katsuyuki NAKADA
  • Patent number: 11069852
    Abstract: A magnetoresistance effect element includes 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. The tunnel barrier layer is a stacked body including one or more high-barrier-height layers and one or more low-barrier-height layers, the one or more high-barrier-height layers having a relatively high barrier height with respect to the one or more low-barrier-height layers and the one or more low-barrier-height layers having a relatively low barrier height with respect to the one or more high-barrier-height layers. A minimum difference of barrier height between the one or more high-barrier-height layers and the one or more low-barrier-height layers is equal to or higher than 0.5 eV.
    Type: Grant
    Filed: July 8, 2019
    Date of Patent: July 20, 2021
    Assignee: TDK CORPORATION
    Inventors: Shinto Ichikawa, Katsuyuki Nakada, Tomoyuki Sasaki
  • Publication number: 20210193913
    Abstract: A magnetoresistance effect element includes: a first ferromagnetic layer; a second ferromagnetic layer; and a non-magnetic layer provided between the first ferromagnetic layer and the second ferromagnetic layer, wherein at least one of the first ferromagnetic layer and the second ferromagnetic layer includes a first layer and a second layer in order from the side closer to the non-magnetic layer, the first layer contains a crystallized Co-based Heusler alloy, at least a part of the second layer is crystallized, the second layer contains a ferromagnetic element, boron element and an additive element, and the additive element is any element selected from a group consisting of Ti, V, Cr, Cu, Zn, Zr, Mo, Ru, Pd, Ta, W, Ir, Pt, and Au.
    Type: Application
    Filed: December 22, 2020
    Publication date: June 24, 2021
    Applicant: TDK CORPORATION
    Inventors: Shinto ICHIKAWA, Kazuumi INUBUSHI, Katsuyuki NAKADA
  • Publication number: 20210184103
    Abstract: The magnetoresistive effect element includes a first ferromagnetic layer, a second ferromagnetic layer, and a nonmagnetic layer positioned between the first ferromagnetic layer and the second ferromagnetic layer, and at least one of the first ferromagnetic layer and the second ferromagnetic layer includes a Heusler alloy layer including a crystal region and an amorphous region.
    Type: Application
    Filed: December 8, 2020
    Publication date: June 17, 2021
    Applicant: TDK CORPORATION
    Inventors: Kazuumi INUBUSHI, Katsuyuki NAKADA, Shinto ICHIKAWA