Patents by Inventor Hisazumi Akai

Hisazumi Akai 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: 11721479
    Abstract: A rare earth magnet including a magnetic phase having the composition represented by (Nd(1?x?y)LaxCey)2(Fe(1?z)Coz)14B. When the saturation magnetization at absolute zero and the Curie temperature calculated by Kuzmin's formula based on the measured values at finite temperature and the saturation magnetization at absolute zero and the Curie temperature calculated by first principles calculation are respectively subjected to data assimilation. The saturation magnetization M(x, y, z, T=0) at absolute zero and the Curie temperature obtained by machine learning using the assimilated data group are applied again to Kuzmin's formula and the saturation magnetization at finite temperature is represented by a function M(x, y, z, T), x, y, and z of the formula in an atomic ratio are in a range of satisfying M(x, y, z, T)>M(x, y, z=0, T) and 400?T?453.
    Type: Grant
    Filed: August 24, 2020
    Date of Patent: August 8, 2023
    Assignees: TOYOTA JIDOSHA KABUSHIKI KAISHA, THE UNIVERSITY OF TOKYO
    Inventors: Kazuya Yokota, Tetsuya Syoji, Noritsugu Sakuma, Takashi Miyake, Yosuke Harashima, Hisazumi Akai, Naoki Kawashima, Keiichi Tamai, Munehisa Matsumoto
  • Publication number: 20210065973
    Abstract: A rare earth magnet including a magnetic phase having the composition represented by (Nd(1?x?y)LaxCey)2(Fe(1?z)Coz)14B. When the saturation magnetization at absolute zero and the Curie temperature calculated by Kuzmin's formula based on the measured values at finite temperature and the saturation magnetization at absolute zero and the Curie temperature calculated by first principles calculation are respectively subjected to data assimilation. The saturation magnetization M(x, y, z, T=0) at absolute zero and the Curie temperature obtained by machine learning using the assimilated data group are applied again to Kuzmin's formula and the saturation magnetization at finite temperature is represented by a function M(x, y, z, T), x, y, and z of the formula in an atomic ratio are in a range of satisfying M(x, y, z, T)>M(x, y, z=0, T) and 400?T?453.
    Type: Application
    Filed: August 24, 2020
    Publication date: March 4, 2021
    Applicants: TOYOTA JIDOSHA KABUSHIKI KAISHA, THE UNIVERSITY OF TOKYO
    Inventors: Kazuya YOKOTA, Tetsuya SYOJI, Noritsugu SAKUMA, Takashi MIYAKE, Yosuke HARASHIMA, Hisazumi AKAI, Naoki KAWASHIMA, Keiichi TAMAI, Munehisa MATSUMOTO
  • Publication number: 20120177564
    Abstract: A half-metallic antiferromagnetic material that is chemically stable and has a stable magnetic structure is provided. The half metallic antiferromagnetic material according the present invention is a compound containing two or more magnetic elements and a halogen, the two or more magnetic elements containing a magnetic element having fewer than 5 effective d electrons and a magnetic element having more than 5 effective d electrons. In addition, a total number of effective d electrons of the two or more magnetic elements is 10 or a value close to 10.
    Type: Application
    Filed: September 17, 2010
    Publication date: July 12, 2012
    Inventors: Hisazumi Akai, Long Hoang Nguyen, Masako Ogura
  • Publication number: 20110017938
    Abstract: A half-metallic antiferromagnetic material according to the present invention is a compound that has a crystal structure of a nickel arsenic type, a zinc blende type, a wurtzite type, a chalcopyrite type or a rock salt type and is constituted of two or more magnetic elements and a chalocogen or a pnictogen. The two or more magnetic elements contain a magnetic element having fewer than 5 effective d electrons and a magnetic element having more than 5 effective d electrons, and a total number of effective d electrons of the two or more magnetic elements is 10 or a value close to 10.
    Type: Application
    Filed: March 18, 2009
    Publication date: January 27, 2011
    Applicant: OSAKA UNIVERSITY
    Inventors: Hisazumi Akai, Masako Ogura, Long Hoang Nguyen
  • Patent number: 7790585
    Abstract: An antiferromagnetic half-metallic semiconductor of the present invention is manufactured by adding to a semiconductor two or more types of magnetic elements including a magnetic element with a d-electron number of less than five and a magnetic element with a d-electron number of more than five, and substituting a part of elements of the semiconductor with the two or more types of magnetic elements.
    Type: Grant
    Filed: September 9, 2005
    Date of Patent: September 7, 2010
    Assignee: Osaka University
    Inventors: Hisazumi Akai, Masako Ogura
  • Publication number: 20090224340
    Abstract: An antiferromagnetic half-metallic semiconductor of the present invention is manufactured by adding to a semiconductor two or more types of magnetic elements including a magnetic element with a d-electron number of less than five and a magnetic element with a d-electron number of more than five, and substituting a part of elements of the semiconductor with the two or more types of magnetic elements.
    Type: Application
    Filed: September 9, 2005
    Publication date: September 10, 2009
    Applicant: OSAKA UNIVERSITY
    Inventors: Hisazumi Akai, Masako Ogura