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).

  • 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
  • Publication number: 20210159396
    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: Application
    Filed: February 5, 2021
    Publication date: May 27, 2021
    Applicant: TDK CORPORATION
    Inventors: Katsuyuki NAKADA, Shinto ICHIKAWA
  • Patent number: 11005035
    Abstract: A magnetoresistive effect element includes a first ferromagnetic layer and a tunnel barrier layer. The tunnel barrier layer has a main body region and a first interface region. The main body region has an oxide material of a first spinel structure represented by a general formula LM2O4. The first interface region has at least one element X selected from a group consisting of elements having a valence of 2 and elements having a valence of 3 excluding Al and has an oxide material of a second spinel structure represented by a general formula DG2O4(D represents one or more kinds of elements including Mg or the element X, and G represents one or more kinds of elements including Al or the element X). A content of the element X contained in the first interface region is larger than that of the element X contained in the main body region.
    Type: Grant
    Filed: March 26, 2019
    Date of Patent: May 11, 2021
    Assignee: TDK CORPORATION
    Inventors: Tsuyoshi Suzuki, Katsuyuki Nakada, Shinto Ichikawa
  • 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
  • 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
  • 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
  • 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
  • Publication number: 20200212295
    Abstract: A magnetoresistive effect element includes a first ferromagnetic layer and a tunnel barrier layer. The tunnel barrier layer has a main body region and a first interface region. The main body region has an oxide material of a first spinel structure represented by a general formula LM2O4. The first interface region has at least one element X selected from a group consisting of elements having a valence of 2 and elements having a valence of 3 excluding Al and has an oxide material of a second spinel structure represented by a general formula DG2O4(D represents one or more kinds of elements including Mg or the element X, and G represents one or more kinds of elements including Al or the element X). A content of the element X contained in the first interface region is larger than that of the element X contained in the main body region.
    Type: Application
    Filed: March 26, 2019
    Publication date: July 2, 2020
    Applicant: TDK CORPORATION
    Inventors: Tsuyoshi SUZUKI, Katsuyuki NAKADA, Shinto ICHIKAWA
  • Patent number: 10665776
    Abstract: Provided is a magnetoresistance effect element in which a tunnel barrier layer stably has a cation disordered spinel structure. This magnetoresistance effect element includes a first ferromagnetic layer, a second ferromagnetic layer, and a tunnel barrier layer disposed between the first ferromagnetic layer and the second ferromagnetic layer. In addition, the tunnel barrier layer is an oxide of MgxAl1-x (0?x<1) and an amount of oxygen in the tunnel barrier layer is lower than an amount of oxygen in a fully oxidized state in which the oxide has an ordered spinel structure.
    Type: Grant
    Filed: February 14, 2019
    Date of Patent: May 26, 2020
    Assignees: TDK CORPORATION, NATIONAL INSTITUTE FOR MATERIALS SCIENCE
    Inventors: Shinto Ichikawa, Katsuyuki Nakada, Seiji Mitani, Hiroaki Sukegawa, Kazuhiro Hono, Tadakatsu Ohkubo
  • Publication number: 20200035913
    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: Application
    Filed: July 8, 2019
    Publication date: January 30, 2020
    Applicant: TDK CORPORATION
    Inventors: Shinto ICHIKAWA, Katsuyuki NAKADA, Tomoyuki SASAKI
  • Publication number: 20200006642
    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: June 25, 2019
    Publication date: January 2, 2020
    Applicant: TDK CORPORATION
    Inventors: Shinto ICHIKAWA, Katsuyuki NAKADA, Tomoyuki SASAKI
  • Publication number: 20190259937
    Abstract: Provided is a magnetoresistance effect element in which a tunnel barrier layer stably has a cation disordered spinel structure. This magnetoresistance effect element includes a first ferromagnetic layer, a second ferromagnetic layer, and a tunnel barrier layer disposed between the first ferromagnetic layer and the second ferromagnetic layer. In addition, the tunnel barrier layer is an oxide of MgxAl1-x (0?x<1) and an amount of oxygen in the tunnel barrier layer is lower than an amount of oxygen in a fully oxidized state in which the oxide has an ordered spinel structure.
    Type: Application
    Filed: February 14, 2019
    Publication date: August 22, 2019
    Applicants: TDK CORPORATION, NATIONAL INSTITUTE FOR MATERIALS SCIENCE
    Inventors: Shinto ICHIKAWA, Katsuyuki NAKADA, Seiji MITANI, Hiroaki SUKEGAWA, Kazuhiro HONO, Tadakatsu OHKUBO
  • Publication number: 20190019942
    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: Application
    Filed: July 2, 2018
    Publication date: January 17, 2019
    Applicant: TDK CORPORATION
    Inventors: Katsuyuki NAKADA, Shinto ICHIKAWA