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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Patent number: 11563169Abstract: A magnetic tunnel junction element (10) includes a configuration in which a reference layer (14) that includes a ferromagnetic material, a barrier layer (15) that includes O, a recording layer (16) that includes a ferromagnetic material including Co or Fe, a first protective layer (17) that includes O, and a second protective layer (18) that includes at least one of Pt, Ru, Co, Fe, CoB, FeB, or CoFeB are layered.Type: GrantFiled: November 18, 2016Date of Patent: January 24, 2023Assignee: TOHOKU UNIVERSITYInventors: Hideo Sato, Yoshihisa Horikawa, Shunsuke Fukami, Shoji Ikeda, Fumihiro Matsukura, Hideo Ohno, Tetsuo Endoh, Hiroaki Honjo
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Patent number: 10804457Abstract: A magnetoresistive element includes a reference layer having a fixed magnetization direction and including a ferromagnetic material containing Fe or Co, a recording layer having a variable magnetization direction and including a ferromagnetic material, and one non-magnetic layer that is formed between the reference layer and the recording layer and that contains oxygen. One of the reference layer and the recording layer contains Fe. The three layers are arranged so that a magnetization direction of the one of the reference layer and the recording layer becomes perpendicular to a layer surface by an interfacial perpendicular magnetic anisotropy at an interface between the one of the reference layer and the recording layer and the one non-magnetic layer resulting from the one of the reference layer and the recording layer having a predetermined thickness. The one of the reference layer and the recording layer has a bcc structure.Type: GrantFiled: August 30, 2016Date of Patent: October 13, 2020Assignee: TOHOKU UNIVERSITYInventors: Hideo Ohno, Shoji Ikeda, Fumihiro Matsukura, Masaki Endoh, Shun Kanai, Katsuya Miura, Hiroyuki Yamamoto
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Patent number: 10658572Abstract: A magnetoresistance effect element includes first and second magnetic layers having a perpendicular magnetization direction, and a first non-magnetic layer disposed adjacent to the first magnetic layer and on a side opposite to a side on which the second magnetic layer is disposed. An interfacial perpendicular magnetic anisotropy exists at an interface between the first magnetic layer and the first non-magnetic layer, and the anisotropy causes the first magnetic layer to have a magnetization direction perpendicular to the surface of the layers. An atomic fraction of all magnetic elements to all magnetic and non-magnetic elements included in the second magnetic layer is smaller than that of the first magnetic layer.Type: GrantFiled: November 2, 2018Date of Patent: May 19, 2020Assignee: TOHOKU UNIVERSITYInventors: Hideo Sato, Shoji Ikeda, Mathias Bersweiler, Hiroaki Honjo, Kyota Watanabe, Shunsuke Fukami, Fumihiro Matsukura, Kenchi Ito, Masaaki Niwa, Tetsuo Endoh, Hideo Ohno
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Patent number: 10651369Abstract: 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 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: December 28, 2016Date of Patent: May 12, 2020Assignee: TOHOKU UNIVERSITYInventors: Hideo Ohno, Shoji Ikeda, Fumihiro Matsukura, Masaki Endoh, Shun Kanai, Hiroyuki Yamamoto, Katsuya Miura
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Patent number: 10263180Abstract: A magnetoresistance effect element includes a reference layer made of a ferromagnetic material, a recording layer made of a ferromagnetic material, and a barrier layer disposed between the reference layer and the recording layer. The reference layer and the recording layer have an in-plane magnetization direction parallel to a surface of the layers. The recording layer has a shape that has short axis and long axis perpendicular to the short axis in plan view. A first value obtained by dividing a thickness of the recording layer by a length of the short axis of the recording layer is greater than 0.3 and smaller than 1.Type: GrantFiled: July 22, 2017Date of Patent: April 16, 2019Assignee: TOHOKU UNIVERSITYInventors: Hideo Sato, Shinya Ishikawa, Shunsuke Fukami, Shoji Ikeda, Fumihiro Matsukura, Hideo Ohno, Tetsuo Endoh
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Publication number: 20190074433Abstract: A magnetoresistance effect element includes first and second magnetic layers having a perpendicular magnetization direction, and a first non-magnetic layer disposed adjacent to the first magnetic layer and on a side opposite to a side on which the second magnetic layer is disposed. An interfacial perpendicular magnetic anisotropy exists at an interface between the first magnetic layer and the first non-magnetic layer, and the anisotropy causes the first magnetic layer to have a magnetization direction perpendicular to the surface of the layers. An atomic fraction of all magnetic elements to all magnetic and non-magnetic elements included in the second magnetic layer is smaller than that of the first magnetic layer.Type: ApplicationFiled: November 2, 2018Publication date: March 7, 2019Applicant: TOHOKU UNIVERSITYInventors: Hideo SATO, Shoji IKEDA, Mathias BERSWEILER, Hiroaki HONJO, Kyota WATANABE, Shunsuke FUKAMI, Fumihiro MATSUKURA, Kenchi ITO, Masaaki NIWA, Tetsuo ENDOH, Hideo OHNO
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Publication number: 20190019944Abstract: A magnetic tunnel junction element (10) includes a configuration in which a reference layer (14) that includes a ferromagnetic material, a barrier layer (15) that includes O, a recording layer (16) that includes a ferromagnetic material including Co or Fe, a first protective layer (17) that includes O, and a second protective layer (18) that includes at least one of Pt, Ru, Co, Fe, CoB, FeB, or CoFeB are layered.Type: ApplicationFiled: November 18, 2016Publication date: January 17, 2019Inventors: Hideo Sato, Yoshihisa Horikawa, Shunsuke Fukami, Shoji Ikeda, Fumihiro Matsukura, Hideo Ohno, Tetsuo Endoh, Hiroaki Honjo
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Patent number: 10164174Abstract: A magnetoresistance effect element includes first and second magnetic layers having a perpendicular magnetization direction, and a first non-magnetic layer disposed adjacent to the first magnetic layer and on a side opposite to a side on which the second magnetic layer is disposed. An interfacial perpendicular magnetic anisotropy exists at an interface between the first magnetic layer and the first non-magnetic layer, and the anisotropy causes the first magnetic layer to have a magnetization direction perpendicular to the surface if the layers. The second magnetic layer has a saturation magnetization lower than that of the first magnetic layer, and an interfacial magnetic anisotropy energy density (Ki) at the interface between the first magnetic layer and the first non-magnetic layer is greater than that of an interface between the first non-magnetic layer and second magnetic layers if being disposed adjacent each other.Type: GrantFiled: January 16, 2018Date of Patent: December 25, 2018Assignee: TOHOKU UNIVERSITYInventors: Hideo Sato, Shoji Ikeda, Mathias Bersweiler, Hiroaki Honjo, Kyota Watanabe, Shunsuke Fukami, Fumihiro Matsukura, Kenchi Ito, Masaaki Niwa, Tetsuo Endoh, Hideo Ohno
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Patent number: 10127957Abstract: A control method for a magnetoresistance effect element and a control device for the magnetoresistance effect element that provide a higher writing speed and lower power consumption. When the magnetization direction of a second magnetic layer is nearly parallel to the magnetization direction of a first magnetic layer, a first voltage is applied across the first and second magnetic layer so that the magnetization direction of the second magnetic layer is reversed by modifying the direction of the magnetization easy axis thereof, followed by the application of a second voltage. When the magnetization direction of the second magnetic layer is nearly antiparallel to the magnetization direction of the first magnetic layer, a third voltage is applied across the first magnetic layer and the second magnetic layer, followed by the application of a fourth voltage so that current flows from the second magnetic layer toward the first magnetic layer.Type: GrantFiled: November 13, 2014Date of Patent: November 13, 2018Assignee: TOHOKU UNIVERSITYInventors: Shun Kanai, Fumihiro Matsukura, Hideo Ohno, Michihiko Yamanouchi, Shoji Ikeda, Hideo Sato
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Publication number: 20180175286Abstract: A magnetoresistance effect element includes first and second magnetic layers having a perpendicular magnetization direction, and a first non-magnetic layer disposed adjacent to the first magnetic layer and on a side opposite to a side on which the second magnetic layer is disposed. An interfacial perpendicular magnetic anisotropy exists at an interface between the first magnetic layer and the first non-magnetic layer, and the anisotropy causes the first magnetic layer to have a magnetization direction perpendicular to the surface if the layers. The second magnetic layer has a saturation magnetization lower than that of the first magnetic layer, and an interfacial magnetic anisotropy energy density (Ki) at the interface between the first magnetic layer and the first non-magnetic layer is greater than that of an interface between the first non-magnetic layer and second magnetic layers if being disposed adjacent each other.Type: ApplicationFiled: January 16, 2018Publication date: June 21, 2018Applicant: TOHOKU UNIVERSITYInventors: Hideo SATO, Shoji IKEDA, Mathias BERSWEILER, Hiroaki HONJO, Kyota WATANABE, Shunsuke FUKAMI, Fumihiro MATSUKURA, Kenchi ITO, Masaaki NIWA, Tetsuo ENDOH, Hideo OHNO
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Publication number: 20170324030Abstract: A magnetoresistance effect element includes a reference layer made of a ferromagnetic material, a recording layer made of a ferromagnetic material, and a barrier layer disposed between the reference layer and the recording layer. The reference layer and the recording layer have an in-plane magnetization direction parallel to a surface of the layers. The recording layer has a shape that has short axis and long axis perpendicular to the short axis in plan view. A first value obtained by dividing a thickness of the recording layer by a length of the short axis of the recording layer is greater than 0.3 and smaller than 1.Type: ApplicationFiled: July 22, 2017Publication date: November 9, 2017Applicant: TOHOKU UNIVERSITYInventors: Hideo SATO, Shinya ISHIKAWA, Shunsuke FUKAMI, Shoji IKEDA, Fumihiro MATSUKURA, Hideo OHNO, Tetsuo ENDOH
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Publication number: 20170110654Abstract: 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 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: December 28, 2016Publication date: April 20, 2017Applicant: TOHOKU UNIVERSITYInventors: Hideo OHNO, Shoji IKEDA, Fumihiro MATSUKURA, Masaki ENDOH, Shun KANAI, Hiroyuki YAMAMOTO, Katsuya MIURA
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Patent number: 9577182Abstract: A magnetoresistance effect element and a magnetic memory having thermal stability expressed by a thermal stability factor of 70 or more even with a fine junction size. The magnetoresistance effect element includes a first magnetic layer of an invariable magnetization direction forming a reference layer, a second magnetic layer of a variable magnetization direction forming a recording layer, and a first non-magnetic layer disposed between the first and second magnetic layers in a thickness direction of the first and second magnetic layers. At least one of the first and second magnetic layers has the following relationship between D (nm) and t (nm): D<0.9t+13, where D is a junction size corresponding to the length of a longest straight line on an end surface perpendicular to the thickness direction, and t is a layer thickness. The junction size is 30 nm or less.Type: GrantFiled: October 20, 2014Date of Patent: February 21, 2017Assignee: TOHOKU UNIVERSITYInventors: Shoji Ikeda, Hideo Sato, Shunsuke Fukami, Michihiko Yamanouchi, Fumihiro Matsukura, Hideo Ohno, Shinya Ishikawa
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Patent number: 9564152Abstract: 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: March 25, 2014Date of Patent: February 7, 2017Assignee: TOHOKU UNIVERSITYInventors: Hideo Ohno, Shoji Ikeda, Fumihiro Matsukura, Masaki Endoh, Shun Kanai, Hiroyuki Yamamoto, Katsuya Miura
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Publication number: 20170025600Abstract: A magnetoresistive element includes a reference layer having a fixed magnetization direction and including a ferromagnetic material containing Fe or Co, a recording layer having a variable magnetization direction and including a ferromagnetic material, and one non-magnetic layer that is formed between the reference layer and the recording layer and that contains oxygen. One of the reference layer and the recording layer contains Fe. The three layers are arranged so that a magnetization direction of the one of the reference layer and the recording layer becomes perpendicular to a layer surface by an interfacial perpendicular magnetic anisotropy at an interface between the one of the reference layer and the recording layer and the one non-magnetic layer resulting from the one of the reference layer and the recording layer having a predetermined thickness. The one of the reference layer and the recording layer has a bcc structure.Type: ApplicationFiled: August 30, 2016Publication date: January 26, 2017Applicant: TOHOKU UNIVERSITYInventors: Hideo OHNO, Shoji IKEDA, Fumihiro MATSUKURA, Masaki ENDOH, Shun KANAI, Katsuya MIURA, Hiroyuki YAMAMOTO
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Publication number: 20160329086Abstract: A control method for a magnetoresistance effect element and a control device for the magnetoresistance effect element that provide a higher writing speed and lower power consumption. When the magnetization direction of a second magnetic layer is nearly parallel to the magnetization direction of a first magnetic layer, a first voltage is applied across the first and second magnetic layer so that the magnetization direction of the second magnetic layer is reversed by modifying the direction of the magnetization easy axis thereof, followed by the application of a second voltage. When the magnetization direction of the second magnetic layer is nearly antiparallel to the magnetization direction of the first magnetic layer, a third voltage is applied across the first magnetic layer and the second magnetic layer, followed by the application of a fourth voltage so that current flows from the second magnetic layer toward the first magnetic layer.Type: ApplicationFiled: November 13, 2014Publication date: November 10, 2016Applicant: Tohoku UniversityInventors: Shun KANAI, Fumihiro MATSUKURA, Hideo OHNO, Michihiko YAMANOUCHI, Shoji IKEDA, Hideo SATO
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Patent number: 9450177Abstract: 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: GrantFiled: February 14, 2011Date of Patent: September 20, 2016Assignee: TOHOKU UNIVERSITYInventors: Hideo Ohno, Shoji Ikeda, Fumihiro Matsukura, Masaki Endoh, Shun Kanai, Katsuya Miura, Hiroyuki Yamamoto
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Publication number: 20160233416Abstract: A magnetoresistance effect element and a magnetic memory having thermal stability expressed by a thermal stability factor of 70 or more even with a fine junction size. The magnetoresistance effect element includes a first magnetic layer of an invariable magnetization direction forming a reference layer, a second magnetic layer of a variable magnetization direction forming a recording layer, and a first non-magnetic layer disposed between the first and second magnetic layers in a thickness direction of the first and second magnetic layers. At least one of the first and second magnetic layers has the following relationship between D (nm) and t (nm): D<0.9t+13, where D is a junction size corresponding to the length of a longest straight line on an end surface perpendicular to the thickness direction, and t is a layer thickness. The junction size is 30 nm or less.Type: ApplicationFiled: October 20, 2014Publication date: August 11, 2016Applicant: TOHOKU UNIVERSITYInventors: Shoji IKEDA, Hideo SATO, Shunsuke FUKAMI, Michihiko YAMANOUCHI, Fumihiro MATSUKURA, Hideo OHNO, Shinya ISHIKAWA
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Patent number: 9202545Abstract: 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: GrantFiled: March 25, 2013Date of Patent: December 1, 2015Assignee: TOHOKU UNIVERSITYInventors: Hideo Sato, Shunsuke Fukami, Michihiko Yamanouchi, Shoji Ikeda, Fumihiro Matsukura, Hideo Ohno
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Patent number: 9135973Abstract: 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: GrantFiled: May 26, 2011Date of Patent: September 15, 2015Assignee: TOHOKU UNIVERSITYInventors: Hideo Ohno, Shoji Ikeda, Fumihiro Matsukura, Masaki Endoh, Shun Kanai, Katsuya Miura, Hiroyuki Yamamoto