Patents by Inventor Fumihiro Matsukura
Fumihiro Matsukura 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).
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Publication number: 20150109853Abstract: A magnetoresistance effect element including a recording layer of high thermal stability to perform perpendicular magnetic recording within a film surface, and a magnetic memory using the element. The element includes: a first ferromagnetic layer of an invariable magnetization direction; a second ferromagnetic layer of a variable magnetization direction; a first non-magnetic layer between the first and second ferromagnetic layers; current supply terminals connected to the first and second ferromagnetic layers; a non-magnetic coupling layer on a surface of the second ferromagnetic layer opposite the first non-magnetic layer; a third ferromagnetic layer of a variable magnetization direction on a surface of the non-magnetic coupling layer opposite the second ferromagnetic layer; and a second non-magnetic layer on a surface of the third ferromagnetic layer opposite the non-magnetic coupling layer.Type: ApplicationFiled: March 25, 2013Publication date: April 23, 2015Applicant: TOHOKU UNIVERSITYInventors: Hideo Sato, Shunsuke Fukami, Michihiko Yamanouchi, Shoji Ikeda, Fumihiro Matsukura, Hideo Ohno
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Patent number: 8917541Abstract: Provided are a magneto resistive effect element with a stable magnetization direction perpendicular to a film plane and with a controlled magnetoresistance ratio, and a magnetic memory using the magneto resistive effect element. Ferromagnetic layers 106 and 107 of the magneto resistive effect element are formed from a ferromagnetic material containing at least one type of 3d transition metal such that the magnetoresistance ratio is controlled, and the film thickness of the ferromagnetic layers is controlled on an atomic layer level such that the magnetization direction is changed from a direction in the film plane to a direction perpendicular to the film plane.Type: GrantFiled: May 31, 2011Date of Patent: December 23, 2014Assignees: Hitachi, Ltd., Tohoku UniversityInventors: Hideo Ohno, Shoji Ikeda, Fumihiro Matsukura, Masaki Endoh, Shun Kanai, Hiroyuki Yamamoto, Katsuya Miura
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Publication number: 20140205862Abstract: Provided are a magneto resistive effect element with a stable magnetization direction perpendicular to a film plane and with a controlled magnetoresistance ratio, and a magnetic memory using the magneto resistive effect element. Ferromagnetic layers 106 and 107 of the magneto resistive effect element are formed from a ferromagnetic material containing at least one type of 3d transition metal such that the magnetoresistance ratio is controlled, and the film thickness of the ferromagnetic layers is controlled on an atomic layer level such that the magnetization direction is changed from a direction in the film plane to a direction perpendicular to the film plane.Type: ApplicationFiled: March 25, 2014Publication date: July 24, 2014Applicant: Tohoku UniversityInventors: Hideo Ohno, Shoji Ikeda, Fumihiro Matsukura, Masaki Endoh, Shun Kanai, Hiroyuki Yamamoto, Katsuya Miura
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Publication number: 20130141966Abstract: Provided are a magnetoresistance effect element with a stable magnetization direction perpendicular to film plane and a controlled magnetoresistance ratio, in which writing can be performed by magnetic domain wall motion, and a magnetic memory including the magnetoresistance effect element. The magnetoresistance ratio is controlled by forming a ferromagnetic layer of the magnetoresistance effect element from a ferromagnetic material including at least one type of 3d transition metal or a Heusler alloy. The magnetization direction is changed from a direction in the film plane to a direction perpendicular to the film plane by controlling the film thickness of the ferromagnetic layer on an atomic layer level.Type: ApplicationFiled: May 26, 2011Publication date: June 6, 2013Inventors: Hideo Ohno, Shoji Ikeda, Fumihiro Matsukura, Masaki Endoh, Shun Kanai, Katsuya Miura, Hiroyuki Yamamoto
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Publication number: 20130094284Abstract: Provided are a magneto resistive effect element with a stable magnetization direction perpendicular to a film plane and with a controlled magnetoresistance ratio, and a magnetic memory using the magneto resistive effect element. Ferromagnetic layers 106 and 107 of the magneto resistive effect element are formed from a ferromagnetic material containing at least one type of 3d transition metal such that the magnetoresistance ratio is controlled, and the film thickness of the ferromagnetic layers is controlled on an atomic layer level such that the magnetization direction is changed from a direction in the film plane to a direction perpendicular to the film plane.Type: ApplicationFiled: May 31, 2011Publication date: April 18, 2013Inventors: Hideo Ohno, Shoji Ikeda, Fumihiro Matsukura, Masaki Endoh, Shun Kanai, Hiroyuki Yamamoto, Katsuya Miura
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Publication number: 20120320666Abstract: There is provided a magnetoresistive element whose magnetization direction is stable in a direction perpendicular to the film surface and whose magnetoresistance ratio is controlled, as well as magnetic memory using such a magnetoresistive element. By having the material of a ferromagnetic layer forming the magnetoresistive element comprise a ferromagnetic material containing at least one type of 3d transition metal, or a Heusler alloy, to control the magnetoresistance ratio, and by controlling the thickness of the ferromagnetic layer on an atomic layer level, the magnetization direction is changed from being in-plane with the film surface to being perpendicular to the film surface.Type: ApplicationFiled: February 14, 2011Publication date: December 20, 2012Applicants: Tohoku University, Hitachi, Ltd.Inventors: Hideo Ohno, Shoji Ikeda, Fumihiro Matsukura, Masaki Endoh, Shun Kanai, Katsuya Miura, Hiroyuki Yamamoto
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Patent number: 8331140Abstract: The present invention provides a current injection-type magnetic domain wall-motion device which requires no external magnetic field for reversing the magnetization direction of a ferromagnetic body and which has low power consumption. The current injection-type magnetic domain wall-motion device includes a microjunction structure including two magnetic bodies (a first magnetic body 1 and a second magnetic body 2) having magnetization directions antiparallel to each other and a third magnetic body 3 sandwiched therebetween. The magnetization direction of the device is controlled in such a manner that a pulse current (a current density of 104-107 A/cm2) is applied across junction interfaces present in the microjunction structure such that a magnetic domain wall is moved by the interaction between the magnetic domain wall and the current in the same direction as that of the current or in the direction opposite to that of the current.Type: GrantFiled: January 14, 2005Date of Patent: December 11, 2012Assignees: Japan Science and Technology Agency, Tohoku UniversityInventors: Hideo Ohno, Fumihiro Matsukura, Daichi Chiba, Michihiko Yamanouchi
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Patent number: 8310867Abstract: A nonvolatile solid state magnetic memory with a ultra-low power consumption and a recording method thereof, the memory including a magnetic material having a magnetic anisotropy that can be changed by increasing or decreasing a carrier concentration, wherein a direction of an easy axis of magnetization, in which the magnetization is oriented easily, is controlled by increasing or decreasing the carrier concentration. The nonvolatile solid state magnetic memory including a recording layer of a magnetic material, and a recording method thereof, in which a carrier (electron or hole) concentration in the recording layer is increased and/or decreased, whereby the magnetization is rotated or reversed and the recording operation is performed.Type: GrantFiled: October 3, 2008Date of Patent: November 13, 2012Assignees: Japan Science and Technology Agency, Tohoku UniversityInventors: Hideo Ohno, Fumihiro Matsukura, Daichi Chiba
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Publication number: 20100246252Abstract: A nonvolatile solid state magnetic memory with a ultra-low power consumption and a recording method thereof, the memory including a magnetic material having a magnetic anisotropy that can be changed by increasing or decreasing a carrier concentration, wherein a direction of an easy axis of magnetization, in which the magnetization is oriented easily, is controlled by increasing or decreasing the carrier concentration. The nonvolatile solid state magnetic memory including a recording layer of a magnetic material, and a recording method thereof, in which a carrier (electron or hole) concentration in the recording layer is increased and/or decreased, whereby the magnetization is rotated or reversed and the recording operation is performed.Type: ApplicationFiled: October 3, 2008Publication date: September 30, 2010Applicants: Tohoku University, JAPAN SCIENCE AND TECHNOLOGY AGENCYInventors: Hideo Ohno, Fumihiro Matsukura, Daichi Chiba
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Publication number: 20080137405Abstract: The present invention provides a current injection-type magnetic domain wall-motion device which requires no external magnetic field for reversing the magnetization direction of a ferromagnetic body and which has low power consumption. The current injection-type magnetic domain wall-motion device includes a microjunction structure including two magnetic bodies (a first magnetic body 1 and a second magnetic body 2) having magnetization directions antiparallel to each other and a third magnetic body 3 sandwiched therebetween. The magnetization direction of the device is controlled in such a manner that a pulse current (a current density of 104-107 A/cm2) is applied across junction interfaces present in the microjunction structure such that a magnetic domain wall is moved by the interaction between the magnetic domain wall and the current in the same direction as that of the current or in the direction opposite to that of the current.Type: ApplicationFiled: January 14, 2005Publication date: June 12, 2008Applicants: JAPAN SCIENCE AND TECHNOLOGY AGENCY, Tohoku UniversityInventors: Hideo Ohno, Fumihiro Matsukura, Daichi Chiba, Michihiko Yamanouchi
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Patent number: 6861342Abstract: An underlayer made of a III-V semiconductor compound is formed on a given substrate, and a CrSb compound is epitaxially grown on the underlayer by means of MBE method to fabricate a zinc blend type CrSb compound.Type: GrantFiled: June 18, 2002Date of Patent: March 1, 2005Assignee: Tohoku UniversityInventors: Hideo Ohno, Fumihiro Matsukura
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Publication number: 20040085811Abstract: On a given substrate are successively formed a buffer layer, a recording layer made of carrier induced ferromagnetic material, a metallic electrode layer via an insulating layer, to complete a nonvolatile solid-state magnetic memory as an electric field effect transistor. For recording, a first electric field is applied to the recording layer via the metallic electrode layer under a given external magnetic field, and then, a second electric field is applied to the recording layer via the metallic electrode layer so that the hole carrier concentration of the recording layer can be reduced lower than at the application of the first electric field, thereby to invert the magnetization of the recording layer and thus, realize recording operation for the recording layer.Type: ApplicationFiled: July 16, 2003Publication date: May 6, 2004Applicant: Tohoku UniversityInventors: Hideo Ohno, Fumihiro Matsukura, Daichi Chiba
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Publication number: 20040085827Abstract: On a given substrate are successively formed a buffer layer, a recording layer made of carrier induced ferromagnetic material, a metallic electrode layer via an insulating layer, to complete a nonvolatile solid-state magnetic memory as an electric field effect transistor. For recording, a given electric field is applied to the recording layer via the metallic electrode layer so that the hole carrier concentration can be reduced to decrease the coercive force of the recording layer and thus, perform recording operation through the magnetic inversion of the recording layer with a relatively small external magnetic field.Type: ApplicationFiled: July 16, 2003Publication date: May 6, 2004Applicant: TOHOKU UNIVERSITYInventors: Hideo Ohno, Fumihiro Matsukura, Daichi Chiba
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Publication number: 20030003704Abstract: An underlayer made of a III-V semiconductor compound is formed on a given substrate, and a CrSb compound is epitaxially grown on the underlayer by means of MBE method to fabricate a zinc blende type CrSb compound.Type: ApplicationFiled: June 18, 2002Publication date: January 2, 2003Applicant: TOHOKU UNIVERSITYInventors: Hideo Ohno, Fumihiro Matsukura
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Patent number: 6482729Abstract: A semiconductor device for generating spin-polarized conduction electrons including a ferromagnetic semiconductor layer and a non-magnetic semiconductor layer having a band alignment of Type II with respect to the ferromagnetic semiconductor, said ferromagnetic semiconductor layer and non-magnetic semiconductor layer being connected together directly or with interposing therebetween another non-magnetic semiconductor layer or energy barrier layer such that a spin splitting of a conduction band of the non-magnetic semiconductor layer is induced by a spontaneous spin splitting of a valence band of the ferromagnetic semiconductor layer, and spin-polarized conduction electrons are generated in the non-magnetic semiconductor layer by the spin splitting of the conduction band of the non-magnetic semiconductor layer.Type: GrantFiled: March 7, 2001Date of Patent: November 19, 2002Assignee: Tohoku UniversityInventors: Hideo Ohno, Fumihiro Matsukura
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Publication number: 20010031547Abstract: A semiconductor device for generating spin-polarized conduction electrons including a ferromagnetic semiconductor layer and a non-magnetic semiconductor layer having a band alignment of Type II with respect to the ferromagnetic semiconductor, said ferromagnetic semiconductor layer and non-magnetic semiconductor layer being connected together directly or with interposing therebetween another non-magnetic semiconductor layer or energy barrier layer such that a spin splitting of a conduction band of the non-magnetic semiconductor layer is induced by a spontaneous spin splitting of a valence band of the ferromagnetic semiconductor layer, and spin-polarized conduction electrons are generated in the non-magnetic semiconductor layer by the spin splitting of the conduction band of the non-magnetic semiconductor layer.Type: ApplicationFiled: March 7, 2001Publication date: October 18, 2001Applicant: TOHOKU UNIVERSITYInventors: Hideo Ohno, Fumihiro Matsukura