Patents by Inventor Katsuyuki Nakada

Katsuyuki Nakada 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).

  • Patent number: 10944043
    Abstract: This magnetoresistance effect element includes a first ferromagnetic layer, a second ferromagnetic layer, and a tunnel barrier layer which is interposed between the first and second ferromagnetic layers, wherein the tunnel barrier layer has a spinel structure represented by a compositional formula X1-?Y?O?, and the tunnel barrier layer contains one or more additional elements selected from the group consisting of He, Ne, Ar, Kr, Xe, P, C, B, and Si, and in the compositional formula, X represents one or more elements selected from the group consisting of Mg, Zn, Cd, Ag, Pt, and Pb, Y represents one or more elements selected from the group consisting of Al, Ga, and In, a range of ? is 0<??1, and a range of ? is 0.35???1.7.
    Type: Grant
    Filed: July 2, 2018
    Date of Patent: March 9, 2021
    Assignee: TDK CORPORATION
    Inventors: Katsuyuki Nakada, Shinto Ichikawa
  • Patent number: 10937954
    Abstract: A magnetoresistive effect element includes a first ferromagnetic layer, a second ferromagnetic layer, a nonmagnetic layer, and at least one of a first nonmagnetic insertion layer provided directly on a lower surface of the nonmagnetic layer and a second nonmagnetic insertion layer provided directly on an upper surface of the nonmagnetic layer. The first nonmagnetic insertion layer and the second nonmagnetic insertion layer include an Ag alloy represented by General Formula (1): Ag?X1-? where X indicates one element selected from the group consisting of Al, Cu, Ga, Ge, As, Y, La, Sm, Yb, and Pt, and 0<?<1.
    Type: Grant
    Filed: November 7, 2019
    Date of Patent: March 2, 2021
    Assignee: TDK CORPORATION
    Inventors: Kazuumi Inubushi, Katsuyuki Nakada
  • Patent number: 10937451
    Abstract: A magnetoresistive effect element according to the present invention includes: a first ferromagnetic layer as a magnetization fixed layer; a second ferromagnetic layer as a magnetization free layer; and a nonmagnetic spacer layer provided between the first ferromagnetic layer and the second ferromagnetic layer. The nonmagnetic spacer layer comprises an Al alloy represented by General Formula (1), and thereby lattice mismatch between the nonmagnetic spacer layer and the first ferromagnetic layer and/or the second ferromagnetic layer is reduced, compared to lattice mismatch when the nonmagnetic spacer layer is formed of Al. Al?X1-???(1) [wherein, X indicates one element selected from the group consisting of Li, N, Mg, Si, Sc, Cr, Fe, Ni, Cu, Zn, Ga, Ge, Zr, Ru, Pd, Ag, Sn, W, Pt, Au and Th, and ? is 0.5<?<1.
    Type: Grant
    Filed: March 13, 2020
    Date of Patent: March 2, 2021
    Assignee: TDK CORPORATION
    Inventors: Kazuumi Inubushi, Katsuyuki Nakada
  • Patent number: 10937951
    Abstract: A magnetoresistance effect element according to an aspect of the present disclosure includes a first ferromagnetic layer as a magnetization fixed layer including a ferromagnetic Heusler alloy, a second ferromagnetic layer as a magnetization free layer including a ferromagnetic Heusler alloy, and a nonmagnetic spacer layer provided between the first ferromagnetic layer and the second ferromagnetic layer, and the nonmagnetic spacer layer includes a nonmagnetic Fe group, Co group, or Ni group Heusler alloy.
    Type: Grant
    Filed: March 5, 2018
    Date of Patent: March 2, 2021
    Assignee: TDK CORPORATION
    Inventors: Katsuyuki Nakada, Kazuumi Inubushi
  • Patent number: 10921392
    Abstract: A stacked structure is positioned on a nonmagnetic metal layer. The stacked structure includes a ferromagnetic layer and an intermediate layer interposed between the nonmagnetic metal layer and the ferromagnetic layer. The intermediate layer includes a NiAlX alloy layer represented by Formula (1): Ni?1Al?2X?3 . . . (1), [X indicates one or more elements selected from the group consisting of Si, Sc, Ti, Cr, Mn, Fe, Co, Cu, Zr, Nb, and Ta, and satisfies an expression of 0<?<0.5 in a case of ?=?3/(?1+?2+?3)].
    Type: Grant
    Filed: September 21, 2018
    Date of Patent: February 16, 2021
    Assignee: TDK CORPORATION
    Inventors: Kazuumi Inubushi, Katsuyuki Nakada
  • Publication number: 20210043682
    Abstract: Provided are magnetoresistance effect element and a Heusler alloy in which an amount of energy required to rotate magnetization can be reduced. The magnetoresistance effect element includes a first ferromagnetic layer, a second ferromagnetic layer, and a non-magnetic layer positioned between the first ferromagnetic layer and the second ferromagnetic layer, in which at least one of the first ferromagnetic layer and the second ferromagnetic layer is a Heusler alloy in which a portion of elements of an alloy represented by Co2Fe?Z? is substituted with a substitution element, in which Z is one or more elements selected from the group consisting of Mn, Cr, Al, Si, Ga, Ge, and Sn, ? and ? satisfy 2.3??+?, ?<?, and 0.5<?<1.9, and the substitution element is an element different from the Z element and has a smaller magnetic moment than Co.
    Type: Application
    Filed: August 6, 2020
    Publication date: February 11, 2021
    Applicant: TDK CORPORATION
    Inventors: Katsuyuki NAKADA, Kazuumi INUBUSHI
  • Publication number: 20210043226
    Abstract: A magnetoresistance effect element and a Heusler alloy in which a state change due to annealing does not easily occur. The element includes a first ferromagnetic layer, a second ferromagnetic layer, and a non-magnetic layer positioned between the first ferromagnetic layer and the second ferromagnetic layer, in which at least one of the first ferromagnetic layer and the second ferromagnetic layer is a Heusler alloy in which a portion of elements of an alloy represented by Co2Fe?Z? is substituted with a substitution element, in which Z is one or more elements selected from the group consisting of Al, Si, Ga, Ge, and Sn, ? and ? satisfy 2.3??+?, ?<?, and 0.5<?<1.9, and the substitution element is one or more elements selected from the group consisting of elements having a melting point higher than that of Fe among elements of Groups 4 to 10.
    Type: Application
    Filed: August 4, 2020
    Publication date: February 11, 2021
    Applicant: TDK CORPORATION
    Inventors: Kazuumi INUBUSHI, Katsuyuki NAKADA
  • Publication number: 20210043225
    Abstract: To provide a magnetoresistance effect element that can further increase an MR ratio (Magnetoresistance ratio) and an RA (Resistance Area product). The magnetoresistance effect element includes a first ferromagnetic layer, a second ferromagnetic layer, and a non-magnetic 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 is a Heusler alloy represented by the following General Formula (1): Co2Fe?X???(1) (in Formula (1), X represents one or more elements selected from the group consisting of Mn, Cr, Si, Al, Ga and Ge, and ? and ? represent numbers that satisfy 2.3??+?, ?<?, and 0.5<?<1.9).
    Type: Application
    Filed: August 4, 2020
    Publication date: February 11, 2021
    Applicant: TDK CORPORATION
    Inventors: Kazuumi INUBUSHI, Katsuyuki NAKADA, Tetsuya UEMURA
  • Publication number: 20210028355
    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: October 1, 2020
    Publication date: January 28, 2021
    Applicant: TDK CORPORATION
    Inventors: Shinto ICHIKAWA, Katsuyuki NAKADA, Tomoyuki SASAKI
  • Publication number: 20210028354
    Abstract: A magnetoresistance effect element has a first ferromagnetic metal layer, a second ferromagnetic metal layer, and a tunnel barrier layer that is sandwiched between the first and second ferromagnetic metal layers, and the tunnel barrier layer has a spinel structure in which cations are disordered, and contains a divalent cation of a non-magnetic element, a trivalent cation of a non-magnetic element, oxygen, and one of nitrogen and fluorine.
    Type: Application
    Filed: August 24, 2020
    Publication date: January 28, 2021
    Applicant: TDK CORPORATION
    Inventors: Tomoyuki SASAKI, Tatsuo SHIBATA, Katsuyuki NAKADA, Yoshitomo TANAKA
  • Publication number: 20200388302
    Abstract: A nonmagnetic spacer layer in a magnetoresistive effect element includes a nonmagnetic metal layer that is formed of Ag and at least one of a first insertion layer that is disposed on a bottom surface of the nonmagnetic metal layer and a second insertion layer that is disposed on a top surface of the nonmagnetic metal layer. The first insertion layer and the second insertion layer include an Fe alloy that is expressed by Fe?X1-?. Here, X denotes one or more elements selected from a group consisting of O, Al, Si, Ga, Mo, Ag, and Au, and ? satisfies 0<y<1.
    Type: Application
    Filed: August 21, 2020
    Publication date: December 10, 2020
    Applicant: TDK CORPORATION
    Inventors: Kazuumi INUBUSHI, Katsuyuki NAKADA
  • Patent number: 10825985
    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: June 25, 2019
    Date of Patent: November 3, 2020
    Assignee: TDK CORPORATION
    Inventors: Shinto Ichikawa, Katsuyuki Nakada, Tomoyuki Sasaki
  • Patent number: 10790440
    Abstract: A magnetoresistance effect element has a first ferromagnetic metal layer, a second ferromagnetic metal layer, and a tunnel barrier layer that is sandwiched between the first and second ferromagnetic metal layers, and the tunnel barrier layer has a spinel structure in which cations are disordered, and contains a divalent cation of a non-magnetic element, a trivalent cation of a non-magnetic element, oxygen, and one of nitrogen and fluorine.
    Type: Grant
    Filed: September 30, 2019
    Date of Patent: September 29, 2020
    Assignee: TDK CORPORATION
    Inventors: Tomoyuki Sasaki, Tatsuo Shibata, Katsuyuki Nakada, Yoshitomo Tanaka
  • Publication number: 20200303634
    Abstract: A magnetoresistive effect element according to the present invention includes: a first ferromagnetic layer as a magnetization fixed layer; a second ferromagnetic layer as a magnetization free layer; and a nonmagnetic spacer layer provided between the first ferromagnetic layer and the second ferromagnetic layer. The nonmagnetic spacer layer comprises an Al alloy represented by General Formula (1), and thereby lattice mismatch between the nonmagnetic spacer layer and the first ferromagnetic layer and/or the second ferromagnetic layer is reduced, compared to lattice mismatch when the nonmagnetic spacer layer is formed of Al. Al?X1-???(1) [wherein, X indicates one element selected from the group consisting of Li, N, Mg, Si, Sc, Cr, Fe, Ni, Cu, Zn, Ga, Ge, Zr, Ru, Pd, Ag, Sn, W, Pt, Au and Th, and ? is 0.5<?<1.
    Type: Application
    Filed: March 13, 2020
    Publication date: September 24, 2020
    Applicant: TDK CORPORATION
    Inventors: Kazuumi INUBUSHI, Katsuyuki NAKADA
  • Publication number: 20200303630
    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: March 18, 2020
    Publication date: September 24, 2020
    Applicant: TDK CORPORATION
    Inventors: Shinto ICHIKAWA, Katsuyuki NAKADA
  • Patent number: 10783906
    Abstract: A nonmagnetic spacer layer in a magnetoresistive effect element includes a nonmagnetic metal layer that is formed of Ag and at least one of a first insertion layer that is disposed on a bottom surface of the nonmagnetic metal layer and a second insertion layer that is disposed on a top surface of the nonmagnetic metal layer. The first insertion layer and the second insertion layer include an Fe alloy that is expressed by Fe?X1-?. Here, X denotes one or more elements selected from a group consisting of O, Al, Si, Ga, Mo, Ag, and Au, and ? satisfies 0<?<1.
    Type: Grant
    Filed: September 10, 2019
    Date of Patent: September 22, 2020
    Assignee: TDK CORPORATION
    Inventors: Kazuumi Inubushi, Katsuyuki Nakada
  • Patent number: 10784438
    Abstract: A magnetoresistive effect element according to one aspect of the present disclosure includes a first ferromagnetic layer, a second ferromagnetic layer, and a spacer layer. The spacer layer is provided between the first ferromagnetic layer and the second ferromagnetic layer. The spacer layer includes an Mn alloy represented by General Formula (1). Mn?X1-???(1) (in the Formula, X is at least one metal selected from the group consisting of Al, V, Cr, Cu, Zn, Ag, Au, an NiAl alloy, an AgMg alloy, and an AgZn alloy, and ? is 0<?<0.5.
    Type: Grant
    Filed: December 4, 2018
    Date of Patent: September 22, 2020
    Assignee: TDK CORPORATION
    Inventors: Kazuumi Inubushi, Katsuyuki Nakada
  • Publication number: 20200266336
    Abstract: This spin-orbit-torque magnetization rotating element includes a spin-orbit torque wiring extending in a first direction and a first ferromagnetic layer laminated on the spin-orbit torque wiring, wherein the spin-orbit torque wiring includes a compound represented by XYZ or X2YZ with respect to a stoichiometric composition.
    Type: Application
    Filed: October 30, 2018
    Publication date: August 20, 2020
    Applicant: TDK CORPORATION
    Inventors: Katsuyuki NAKADA, Yohei SHIOKAWA
  • Publication number: 20200251268
    Abstract: A magnetoresistance effect element includes a first ferromagnetic layer, a second ferromagnetic layer, and a nonmagnetic spacer layer between the first ferromagnetic layer and the second ferromagnetic layer, in which at least one of the first ferromagnetic layer and the second ferromagnetic layer contains a metal compound having a half-Heusler type crystal structure, the metal compound contains a functional material, and X atoms, Y atoms, and Z atoms which form a unit lattice of the half-Heusler type crystal structure, and the functional material has an atomic number lower than an atomic number of any of the X atoms, the Y atoms, and the Z atoms.
    Type: Application
    Filed: January 30, 2020
    Publication date: August 6, 2020
    Applicant: TDK Corporation
    Inventor: Katsuyuki NAKADA
  • Patent number: 10720178
    Abstract: A magnetoresistance effect element has a first ferromagnetic metal layer, a second ferromagnetic metal layer, and a tunnel barrier layer that is sandwiched between the first and second ferromagnetic metal layers, and the tunnel barrier layer has a spinel structure represented by a composition formula AGa2Ox (0<x?4), and an A-site is a non-magnetic divalent cation which is one or more selected from a group consisting of magnesium, zinc and cadmium.
    Type: Grant
    Filed: February 15, 2019
    Date of Patent: July 21, 2020
    Assignee: TDK CORPORATION
    Inventors: Tomoyuki Sasaki, Katsuyuki Nakada, Tatsuo Shibata