Patents by Inventor Hiromi Yuasa

Hiromi Yuasa 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: 7511927
    Abstract: A spin valve type magnetoresistive effect element for vertical electric conduction includes a magnetoresistive effect film in which a resistance adjustment layer made of a material containing conductive carriers not more than 1022/cm3 is inserted. Thus the resistance value of a portion in change of spin-relied conduction is raised to an adequate value, thereby to increase the resistance variable amount.
    Type: Grant
    Filed: November 21, 2005
    Date of Patent: March 31, 2009
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiromi Yuasa, Masatoshi Yoshikawa, Katsuhiko Koui, Hitoshi Iwasaki, Masashi Sahashi
  • Publication number: 20090080109
    Abstract: A magnetic recording device includes: a magnetic recording medium containing a plurality of recording layers; a magnetic recording head for conducting magnetic writing of information in the magnetic recording medium; and a magnetic reproducing head for conducting magnetic reading out of the information from the magnetic recording medium; wherein the magnetic recording head includes a high frequency oscillator for magnetically assisting the magnetic writing of the information so as to change a magnetization of at least one of the plurality of recording layers of the magnetic recording medium, thereby recording a plurality of information different from one another in the magnetic recording medium commensurate with a total amount of magnetization of the plurality of recording layers.
    Type: Application
    Filed: June 19, 2008
    Publication date: March 26, 2009
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Hideaki Fukuzawa, Hiromi Yuasa
  • Patent number: 7505234
    Abstract: A magnetoresistance effect element comprises a magnetoresistance effect film and a pair of electrode. The magnetoresistance effect film having a first magnetic layer whose direction of magnetization is substantially pinned in one direction; a second magnetic layer whose direction of magnetization changes in response to an external magnetic field; a nonmagnetic intermediate layer located between the first and second magnetic layers; and a film provided in the first magnetic layer, in the second magnetic layer, at a interface between the first magnetic layer and the nonmagnetic intermediate layer, and/or at a interface between the second magnetic layer and the nonmagnetic intermediate layer, the film having a thickness not larger than 3 nanometers, and the film has as least one selected from the group consisting of oxide, nitride, oxinitride, phosphide, and fluoride.
    Type: Grant
    Filed: October 31, 2007
    Date of Patent: March 17, 2009
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hideaki Fukuzawa, Hiromi Yuasa, Hiromi Fuke, Hitoshi Iwasaki, Masashi Sahashi
  • Patent number: 7504898
    Abstract: A high-frequency oscillator includes a high-frequency oscillation element having a magnetization pinned layer whose magnetization direction is pinned substantially in one direction, an oscillation layer formed of a magnetic material which generates a high-frequency oscillation phenomenon when a current is supplied, an intermediate layer provided between the magnetization pinned layer and the oscillation layer, the intermediate layer having an insulation layer and current paths which pass through the insulation layer in a thickness direction, and a pair of electrodes which supply a current perpendicularly to a plane of a stacked film including the magnetization pinned layer, the intermediate layer and the oscillation layer.
    Type: Grant
    Filed: September 21, 2006
    Date of Patent: March 17, 2009
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hideaki Fukuzawa, Hiromi Yuasa, Hitoshi Iwasaki
  • Publication number: 20090061105
    Abstract: The present invention relates to a method for manufacturing a magnetoresistive element having a magnetization pinned layer, a magnetization free layer, and a spacer layer including an insulating layer provided between the magnetization pinned layer and the magnetization free layer and current paths penetrating into the insulating layer. A process of forming the spacer layer in the method includes depositing a first metal layer forming the metal paths, depositing a second metal layer on the first metal layer, performing a pretreatment of irradiating the second metal layer with an ion beam or a RF plasma of a rare gas, and converting the second metal layer into the insulating layer by means of supplying an oxidation gas or a nitriding gas.
    Type: Application
    Filed: October 9, 2008
    Publication date: March 5, 2009
    Inventors: Hideaki FUKUZAWA, Katsuhiko Koui, Hiromi Yuasa, Susumu Hashimoto, Hitoshi Iwasaki
  • Patent number: 7495870
    Abstract: A magnetoresistive effect element includes a magnetization pinned layer, a magnetization free layer; a nonmagnetic metal layer disposed between the magnetization pinned layer and the magnetization free layer, a resistance increasing layer, a spin filter layer, and a pair of electrodes. The resistance increasing layer includes a insulation portion and is disposed in at least one of the magnetization pinned layer, the magnetization free layer, and the nonmagnetic metal layer. The spin filter layer is disposed to be adjacent to the magnetization free layer and has a thickness in a range of 5 nm to 20 nm. The magnetization free layer is disposed between the spin filter layer and the nonmagnetic metal layer. The magnetization pinned layer, the magnetization free layer, the nonmagnetic layer, the resistance increasing layer, and the spin filter layer are disposed between the electrodes.
    Type: Grant
    Filed: October 1, 2004
    Date of Patent: February 24, 2009
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiromi Yuasa, Hideaki Fukuzawa, Susumu Hashimoto, Hitoshi Iwasaki
  • Publication number: 20090034134
    Abstract: A magnetoresistance effect element includes a magnetoresistance effect film including a magnetically pinned layer having a magnetic material film whose direction of magnetization is pinned substantially in one direction, a magnetically free layer having a magnetic material film whose direction of magnetization changes in response to an external magnetic field, and a nonmagnetic metal intermediate layer located between said pinned layer and said free layer. The element also includes a pair of electrodes electrically connected to the magnetoresistance effect film to supply a sense current perpendicularly to a film plane of the magnetoresistance effect film. At least one of the pinned layer and the free layer may include a thin-film insertion layer.
    Type: Application
    Filed: September 23, 2008
    Publication date: February 5, 2009
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Hiromi Yuasa, Yuzo Kamiguchi, Masatoshi Yoshikawa, Katsuhiko Koul, Hitoshi Iwasaki, Tomohiko Nagata, Takeo Sakakubo, Masashi Sahashi
  • Patent number: 7483245
    Abstract: There is provided a practical magnetoresistance effect element which has an appropriate value of resistance, which can be sensitized and which has a small number of magnetic layers to be controlled, and a magnetic head and magnetic recording and/or reproducing system using the same. In a magnetoresistance effect element wherein a sense current is caused to flow in a direction perpendicular to the plane of the film, if a pinned layer and a free layer have a stacked construction of a magnetic layer and a non-magnetic layer or a stacked construction of a magnetic layer and a magnetic layer, it is possible to provide a practical magnetoresistance effect element which has an appropriate value of resistance, which can be sensitized and which has a small number of magnetic layers, while effectively utilizing the scattering effect depending on spin.
    Type: Grant
    Filed: March 4, 2008
    Date of Patent: January 27, 2009
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yuuzo Kamiguchi, Hiromi Yuasa, Tomohiko Nagata, Hiroaki Yoda
  • Publication number: 20090021869
    Abstract: There is provided a practical magnetoresistance effect element which has an appropriate value of resistance, which can be sensitized and which has a small number of magnetic layers to be controlled, and a magnetic head and magnetic recording and/or reproducing system using the same. In a magnetoresistance effect element wherein a sense current is caused to flow in a direction perpendicular to the plane of the film, a resistance regulating layer is provided in at least one of a pinned layer, a free layer and an non-magnetic intermediate layer. The resistance regulating layer contains, as a principal component, an oxide, a nitride, a fluoride, a carbide or a boride. The resistance regulating layer may be a continuous film or may have pin holes. Thus, it is possible to provide a practical magnetoresistance effect element which has an appropriate value of resistance, which can be sensitized and which has a small number of magnetic layers, while effectively utilizing the scattering effect depending on spin.
    Type: Application
    Filed: September 17, 2008
    Publication date: January 22, 2009
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Yuuzo KAMIGUCHI, Hiromi YUASA, Tomohiko NAGATA, Hiroaki YODA, Katsuhiko KOUI, Masatoshi YOSHIKAWA, Hitoshi IWASAKI, Masashi SAHASHI, Masayuki TAKAGISHI
  • Patent number: 7471492
    Abstract: A magnetoresistive element has a first magnetic layer and a second magnetic layer separate from each other, the first magnetic layer and the second magnetic layer each having a magnetization whose direction is substantially pinned, and a non-magnetic conductive layer formed in contact with the first magnetic layer and the second magnetic layer and electrically connecting the first and second magnetic layers, the non-magnetic conductive layer forming a path of spin-polarized electrons from one of the magnetic layer to the other magnetic layer, the non-magnetic conductive layer comprising a portion located between the first magnetic layer and the second magnetic layer, the portion being a sensing area.
    Type: Grant
    Filed: July 22, 2004
    Date of Patent: December 30, 2008
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hideaki Fukuzawa, Hiromi Yuasa, Susumu Hashimoto, Hitoshi Iwasaki
  • Publication number: 20080311431
    Abstract: A magnetic multilayered film current element includes: at least one magnetic layer; at least one film structure containing a first insulating layer where a first opening is formed, a second insulating layer where a second opening is formed and a conductor disposed between the first insulating layer and the second insulating layer under the condition that a distance “A” between the first insulating layer and a portion of the second insulating layer at a position of the second opening is set larger than a closest distance “B” between the first insulating layer and the second insulating layer; and a pair of electrodes for flowing current to a magnetic multilayered film containing the at least one magnetic layer and the at least one film structure along a stacking direction of the magnetic multilayered film.
    Type: Application
    Filed: June 11, 2008
    Publication date: December 18, 2008
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Yoshihiko Fuji, Hideaki Fukuzawa, Hiromi Yuasa
  • Patent number: 7463456
    Abstract: A spin valve type magnetoresistive effect element for vertical electric conduction includes a magnetoresistive effect film in which a resistance adjustment layer made of a material containing conductive carriers not more than 1022/cm3 is inserted. Thus the resistance value of a portion in change of spin-relied conduction is raised to an adequate valve, thereby to increase the resistance variable amount.
    Type: Grant
    Filed: April 9, 2007
    Date of Patent: December 9, 2008
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiromi Yuasa, Masatoshi Yoshikawa, Katsuhiko Koui, Hitoshi Iwasaki, Masashi Sahashi
  • Patent number: 7443004
    Abstract: In a spin valve type element, an interface insertion layer (32, 34) of a material exhibiting large spin-dependent interface scattering is inserted in a location of a magnetically pinned layer (16) or a magnetically free layer (20) closer to a nonmagnetic intermediate layer (18). A nonmagnetic back layer (36) may be additionally inserted as an interface not in contact with the nonmagnetic intermediate layer to increase the output by making use of spin-dependent interface scattering along the interface between the pinned layer and the nonmagnetic back layer or between the free layer and the nonmagnetic back layer.
    Type: Grant
    Filed: November 22, 2005
    Date of Patent: October 28, 2008
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiromi Yuasa, Yuzo Kamiguchi, Masatoshi Yoshikawa, Katsuhiko Koui, Hitoshi Iwasaki, Tomohiko Nagata, Takeo Sakakubo, Masashi Sahashi
  • Publication number: 20080239591
    Abstract: A magneto-resistance effect element, including: a fixed magnetization layer of which a magnetization is substantially fixed in one direction; a free magnetization layer of which a magnetization is rotated in accordance with an external magnetic field and which is formed opposite to the fixed magnetization layer; a spacer layer including a current confining layer with an insulating layer and a conductor to pass a current through the insulating layer in a thickness direction thereof and which is located between the fixed magnetization layer and the free magnetization layer; a thin film layer which is located in a side opposite to the spacer layer relative to the free magnetization layer; and a functional layer containing at least one element selected from the group consisting of Si, Mg, B, Al which is formed in or on at least one of the fixed magnetization layer, the free magnetization layer and the thin film layer.
    Type: Application
    Filed: March 11, 2008
    Publication date: October 2, 2008
    Applicants: KABUSHIKI KAISHA TOSHIBA, TDK CORPORATION
    Inventors: Yoshihiko Fuji, Hideaki Fukuzama, Hiromi Yuasa, Kunliang Zhang, Min Li, Michiko Hara, Yoshinari Kurosaki
  • Publication number: 20080239542
    Abstract: A magnetic recording head includes: a main magnetic pole containing a ferromagnetic layer; a main magnetic pole-magnetization fixing portion containing an antiferromagnetic layer in contact with at least one side surface of the main magnetic pole; a heater for heating at least the main magnetic pole so that a magnetic interaction between the main magnetic pole and the main magnetic pole-magnetization fixing portion can be decreased; and a magnetic field generator for generating a magnetic field so as to direct a magnetization of the main magnetic pole in one direction.
    Type: Application
    Filed: March 18, 2008
    Publication date: October 2, 2008
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Hiromi Yuasa, Tomoko Taguchi, Hideaki Fukuzawa
  • Publication number: 20080239587
    Abstract: A magneto-resistance effect element includes: a first magnetic layer of which a first magnetization is fixed in one direction; a second magnetic layer of which a second magnetization is fixed in one direction; a spacer layer located between the first magnetic layer and the second magnetic layer and made of at least one selected from the group consisting of an oxide, a nitride, an oxynitride and a metal; and a current bias generating portion, which is located adjacent to the spacer layer, for applying a bias magnetic field to the spacer layer.
    Type: Application
    Filed: March 6, 2008
    Publication date: October 2, 2008
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Junichi Ito, Hideaki Fukuzawa, Hiromi Yuasa, Yoshihiro Fuji
  • Patent number: 7426098
    Abstract: A magnetoresistive element includes a magnetoresistive film having a magnetization pinned layer whose magnetization is substantially pinned to one direction, a nonmagnetic intermediate layer, and a magnetization free layer whose magnetization is changed in direction depending on an external magnetic field, in which the magnetization pinned layer or nonmagnetic intermediate layer includes an insulator, and a pair of electrodes electrically connected to the magnetoresistive film so as to supply a sense current in a direction substantially perpendicular to a plane of the magnetoresistive film. The magnetization free layer includes a body-centered cubic layer with a body-centered cubic structure, and the thickness of the body-centered cubic layer is 2 nm or more.
    Type: Grant
    Filed: December 22, 2004
    Date of Patent: September 16, 2008
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiromi Yuasa, Hideaki Fukuzawa, Susumu Hashimoto, Hitoshi Iwasaki
  • Publication number: 20080204943
    Abstract: A magnetoresistive element includes: a first magnetic layer whose magnetization direction is substantially pinned toward one direction; a second magnetic layer whose magnetization direction is changed in response to an external magnetic field; and a spacer layer provided between the first magnetic layer and the second magnetic layer. At least one of the first magnetic layer and the second magnetic layer has a magnetic compound that is expressed by M1aM2bXc (where 5?a?68, 10?b?73, and 22?c?85) M1 is at least one element selected from the group consisting of Co, Fe, and Ni. M2 is at least one element selected from the group consisting of Ti, V, Cr, and Mn. X is at least one element selected from the group consisting of N, O, and C.
    Type: Application
    Filed: September 24, 2007
    Publication date: August 28, 2008
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Yoshihiko Fuji, Hideaki Fukuzawa, Hiromi Yuasa
  • Publication number: 20080158737
    Abstract: There is provided a practical magnetoresistance effect element which has an appropriate value of resistance, which can be sensitized and which has a small number of magnetic layers to be controlled, and a magnetic head and magnetic recording and/or reproducing system using the same. In a magnetoresistance effect element wherein a sense current is caused to flow in a direction perpendicular to the plane of the film, if a pinned layer and a free layer have a stacked construction of a magnetic layer and a non-magnetic layer or a stacked construction of a magnetic layer and a magnetic layer, it is possible to provide a practical magnetoresistance effect element which has an appropriate value of resistance, which can be sensitized and which has a small number of magnetic layers, while effectively utilizing the scattering effect depending on spin.
    Type: Application
    Filed: March 4, 2008
    Publication date: July 3, 2008
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Yuuzo KAMIGUCHI, Hiromi YUASA, Tomohiko NAGATA, Hiroaki YODA
  • Publication number: 20080129401
    Abstract: A high-frequency oscillator includes a high-frequency oscillation element having a magnetization pinned layer whose magnetization direction is pinned substantially in one direction, an oscillation layer formed of a magnetic material which generates a high-frequency oscillation phenomenon when a current is supplied, an intermediate layer provided between the magnetization pinned layer and the oscillation layer, the intermediate layer having an insulation layer and current paths which pass through the insulation layer in a thickness direction, and a pair of electrodes which supply a current perpendicularly to a plane of a stacked film including the magnetization pinned layer, the intermediate layer and the oscillation layer.
    Type: Application
    Filed: February 7, 2008
    Publication date: June 5, 2008
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Hideaki Fukuzawa, Hiromi Yuasa, Hitoshi Iwasaki