Patents by Inventor Takehito Shimatsu
Takehito Shimatsu 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: 20160267934Abstract: The purpose of the present invention is to provide a magnetic recording medium including a magnetic recording layer having more excellent magnetic properties and including an L1o type ordered alloy. One constitutional example of the magnetic recording medium includes a substrate, a first seed layer comprising ZnO, a second seed layer comprising MgO, and a magnetic recording layer comprising an ordered alloy, in this order.Type: ApplicationFiled: August 10, 2015Publication date: September 15, 2016Inventors: Akira Furuta, Shinji Uchida, Tomohiro Moriya, Hitoshi Nakata, Takehito Shimatsu
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Publication number: 20160254017Abstract: The purpose of the present invention is to provide a magnetic recording medium including a first magnetic recording layer having a large coercive force and a granular structure in which magnetic crystal grains are well separated from each other. The magnetic recording medium of the present invention includes a non-magnetic substrate, a first seed layer, and a first magnetic recording layer formed on the first seed layer, wherein the first seed layer includes Pt, the first magnetic recording layer includes one or more magnetic layers, the magnetic layer in contact with the first seed layer includes Fe, Pt and Ti, and the magnetic layer in contact with the first seed layer has a granular structure consisting of magnetic crystal grains of a L10 type ordered alloy including Fe and Pt, and a non-magnetic grain boundary including Ti.Type: ApplicationFiled: January 13, 2015Publication date: September 1, 2016Inventors: Hitoshi Nakata, Takehito Shimatsu
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Publication number: 20160225394Abstract: The present invention provides a magnetic recording layer that has a high magnetic anisotropy constant Ku and a low Curie temperature Tc, as well as a magnetic recording medium that incorporates such a magnetic recording layer. The magnetic recording medium of the present invention includes a nonmagnetic substrate and a magnetic recording layer containing an ordered alloy. The ordered alloy may contain at least one element selected from the group consisting of Fe and Ni; at least one element selected from the group consisting of Pt, Pd, Au, Rh and Ir; and Ru.Type: ApplicationFiled: April 8, 2016Publication date: August 4, 2016Applicant: FUJI ELECTRIC CO., LTD.Inventors: Tomohiro MORIYA, Hitoshi NAKATA, Hiroto KIKUCHI, Hiroyasu KATAOKA, Akira FURUTA, Takehito SHIMATSU
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Publication number: 20160190417Abstract: A semiconductor device includes an insulating substrate,a semiconductor element disposed on an upper surface of the substrate, a heat dissipation member, and a metal bonding layer that bonds the lower surface of the substrate to the upper surface of the heat dissipation member, and the area of the upper surface of the heat dissipation member is larger than the area of the lower surface of the substrate, and the metal bonding layer contacts the whole of the lower surface of the substrate and has an area larger than the area of the lower surface of the substrate, and the heat conductivity of the metal bonding layer is higher than the heat conductivity of the heat dissipation member.Type: ApplicationFiled: December 21, 2015Publication date: June 30, 2016Applicant: NICHIA CORPORATIONInventors: Masatsugu ICHIKAWA, Satoshi SHICHIJO, Takehito SHIMATSU
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Patent number: 9257619Abstract: To provide a light-emitting device that is provided with an optical member firmly bonded to a semiconductor light-emitting element and has a high light extraction efficiency, the light-emitting device includes a light-emitting element having a semiconductor layer and an optical member bonded to the light-emitting surface of the light-emitting element with a metal film being interposed therebetween wherein the metal film has a thickness in a film-forming rate conversion not less than 0.05 nm nor more than 2 times of an atomic diameter of the metal atoms forming the metal film.Type: GrantFiled: June 25, 2014Date of Patent: February 9, 2016Assignee: NICHIA CORPORATIONInventors: Masatsugu Ichikawa, Takehito Shimatsu
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Publication number: 20150213821Abstract: A perpendicular magnetic recording medium includes a non-magnetic substrate; and a magnetic recording layer that includes magnetic crystal grains and a non-magnetic crystal grain boundary that surrounds the magnetic crystal grains, wherein the magnetic crystal grains contain an ordered alloy and the non-magnetic crystal grain boundary contains Ge oxides. The magnetic recording layer may have a granular structure. The magnetic crystal grains may be micronized to be sufficiently ordered and separated, and the perpendicular magnetic recording medium may have a high magnetic anisotropy constant Ku and high coercivity Hc.Type: ApplicationFiled: April 6, 2015Publication date: July 30, 2015Applicant: FUJI ELECTRIC CO., LTD.Inventors: Takuya ONO, Takehito SHIMATSU
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Patent number: 9093099Abstract: Provided are a perpendicular magnetic recording medium and a method for manufacturing the same, the perpendicular magnetic recording medium including an alloy (FePt, FePd, or CoPt) having a large Ku value with an L10 type ordered structure, and obtained with achievement of controlled crystal orientation and thin film formation without heating. Specifically, in the perpendicular magnetic recording medium, at least a nonmagnetic seed layer, a nonmagnetic underlayer, and a magnetic layer are formed in this order on a nonmagnetic substrate. The nonmagnetic seed layer includes a MgO layer and a metal layer having a body-centered cubic (bcc) structure. The nonmagnetic underlayer has a NaCl type structure of one selected from the group consisting of MgO, NiO, TiO, CrN, Ti carbides, and Ti nitrides. The magnetic layer includes an alloy selected from the group consisting of FePt, FePd, and CoPt having an L10 type ordered structure.Type: GrantFiled: July 8, 2013Date of Patent: July 28, 2015Assignee: FUJI ELECTRIC CO., LTD.Inventors: Yuki Inaba, Takehito Shimatsu
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Publication number: 20150132608Abstract: A perpendicular magnetic recording medium includes at least a nonmagnetic substrate and a magnetic recording layer. The magnetic recording layer is constituted by a plurality of layers that includes at least a first magnetic recording layer and a second magnetic recording layer. The first magnetic recording layer has a granular structure that includes first magnetic crystal grains and first nonmagnetic crystal grain boundaries surrounding the first magnetic crystal grains. The first magnetic crystal grains include an ordered alloy, and the first nonmagnetic crystal grain boundaries are constituted by carbon. The second magnetic recording layer has a granular structure that includes second magnetic crystal grains and a second nonmagnetic crystal grain boundaries that surround the second magnetic crystal grains. The second magnetic crystal grains include an ordered alloy, and the second nonmagnetic crystal grain boundaries are constituted by a carbon-containing nonmagnetic material.Type: ApplicationFiled: December 4, 2014Publication date: May 14, 2015Applicant: FUJI ELECTRIC CO., LTD.Inventors: Hiroyasu KATAOKA, Hiroto KIKUCHI, Akira FURUTA, Shinji UCHIDA, Takehito SHIMATSU
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Publication number: 20150048398Abstract: To provide a light-emitting device that is provided with an optical member firmly bonded to a semiconductor light-emitting element and has a high light extraction efficiency, the light-emitting device includes a light-emitting element having a semiconductor layer and an optical member bonded to the light-emitting surface of the light-emitting element with a metal film being interposed therebetween wherein the metal film has a thickness in a film-forming rate conversion not less than 0.05 nm nor more than 2 times of an atomic diameter of the metal atoms forming the metal film.Type: ApplicationFiled: June 25, 2014Publication date: February 19, 2015Inventors: Masatsugu Ichikawa, Takehito Shimatsu
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Patent number: 8691402Abstract: A perpendicular magnetic recording medium according to which both the thermal stability of the magnetization is good and writing with a magnetic head is easy, and moreover the SNR is improved. In the case of a perpendicular magnetic recording medium comprising a nonmagnetic substrate (1), and at least a nonmagnetic underlayer (2), a magnetic recording layer (3), and a protective layer (4) formed in this order on the nonmagnetic substrate (1), the magnetic recording layer (3) comprises a low Ku region (31) layer having a perpendicular magnetic anisotropy constant (Ku value) of not more than 1×105 erg/cm3, and a high Ku region (32) layer having a Ku value of at least 1×106 erg/cm3. Moreover, the magnetic recording layer (3) is made to have therein nonmagnetic grain boundaries that contain a nonmagnetic oxide and magnetically isolate crystal grains, which are made of a ferromagnetic metal, from one another.Type: GrantFiled: November 2, 2012Date of Patent: April 8, 2014Assignees: Fuji Electric Co., Ltd., National University Corporation Tohoku UniversityInventors: Osamu Kitakami, Yutaka Shimada, Satoshi Okamoto, Takehito Shimatsu, Hajime Aoi, Hiroaki Muraoka, Yoshihisa Nakamura, Hiroyuki Uwazumi, Tadaaki Oikawa
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Publication number: 20140072829Abstract: The present invention provides: a thin film structure including an ordered alloy in which atoms are orderly arranged using an inexpensive substrate; and a method for manufacturing the thin film structure. Specifically, the thin film structure includes a substrate, a plating layer formed on the substrate and made of one selected from the group consisting of NiPMo and NiPW, and an ordered alloy disposed on the plating layer. The method for manufacturing the thin film structure includes the steps of: forming a plating layer on a substrate, the plating layer being made of one selected from the group consisting of NiPMo and NiPW; and forming an ordered alloy on the plating layer. The vacuum degree immediately before the ordered alloy is formed is 7.0×10?7 Pa or less. In the step of forming the ordered alloy, a process gas has an impurity concentration of 5 ppb or lower.Type: ApplicationFiled: July 8, 2013Publication date: March 13, 2014Inventors: Yuki INABA, Takehito SHIMATSU
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Publication number: 20140072828Abstract: Provided are a perpendicular magnetic recording medium and a method for manufacturing the same, the perpendicular magnetic recording medium including an alloy (FePt, FePd, or CoPt) having a large Ku value with an L10 type ordered structure, and obtained with achievement of controlled crystal orientation and thin film formation without heating. Specifically, in the perpendicular magnetic recording medium, at least a nonmagnetic seed layer, a nonmagnetic underlayer, and a magnetic layer are formed in this order on a nonmagnetic substrate. The nonmagnetic seed layer includes a MgO layer and a metal layer having a body-centered cubic (bcc) structure. The nonmagnetic underlayer has a NaCl type structure of one selected from the group consisting of MgO, NiO, TiO, CrN, Ti carbides, and Ti nitrides. The magnetic layer includes an alloy selected from the group consisting of FePt, FePd, and CoPt having an L10 type ordered structure.Type: ApplicationFiled: July 8, 2013Publication date: March 13, 2014Applicant: Fuji Electric Co., Ltd.Inventors: Yuki INABA, Takehito SHIMATSU
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Patent number: 8323808Abstract: There is provided a perpendicular magnetic recording medium according to which both the thermal stability of the magnetization is good and writing with a magnetic head is easy, and moreover the SNR is improved. In the case of a perpendicular magnetic recording medium comprising a nonmagnetic substrate 1, and at least a nonmagnetic underlayer 2, a magnetic recording layer 3 and a protective layer 4 formed in this order on the nonmagnetic substrate 1, the magnetic recording layer 3 comprises a low Ku region 31 layer having a perpendicular magnetic anisotropy constant (Ku value) of not more than 1×105 erg/cm3, and a high Ku region 32 layer having a Ku value of at least 1×106 erg/cm3. Moreover, the magnetic recording layer 3 is made to have therein nonmagnetic grain boundaries that contain a nonmagnetic oxide and magnetically isolate crystal grains, which are made of a ferromagnetic metal, from one another.Type: GrantFiled: January 10, 2005Date of Patent: December 4, 2012Assignees: Fuji Electric Co., Ltd., National University Corporation Tohoku UniversityInventors: Osamu Kitakami, Yutaka Shimada, Satoshi Okamoto, Takehito Shimatsu, Hajime Aoi, Hiroaki Muraoka, Yoshihisa Nakamura, Hiroyuki Uwazumi, Tadaaki Oikawa
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Patent number: 8076012Abstract: Disclosed are a magnetic thin film capable of providing a high uniaxial magnetic anisotropy, Ku, while suppressing the saturation magnetization Ms thereof, and a method for forming the film; and also disclosed are various devices to which the magnetic thin film is applied. The magnetic thin film comprises a Co-M-Pt alloy having an L11-type ordered structure (wherein M represents one or more metal elements except Co and Pt). For example, the Co-M-Pt alloy is a Co—Ni—Pt alloy of which the composition comprises from 10 to 35 at. % of Co, from 20 to 55 at. % of Ni and a balance of Pt. The magnetic thin film is applicable to perpendicular magnetic recording media, tunnel magneto-resistance (TMR) devices, magnetoresistive random access memories (MRAM), microelectromechanical system (MEMS) devices, etc.Type: GrantFiled: July 28, 2009Date of Patent: December 13, 2011Assignees: Tohoku University, Fuji Electric Co., Ltd.Inventors: Takehito Shimatsu, Hideo Sato, Osamu Kitakami, Satoshi Okamoto, Hajime Aoi, Hiroyasu Kataoka
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Patent number: 7993762Abstract: The present invention relates to a magnetic thin film containing a L11 type Co—Pt—C alloy in which atoms are orderly arranged, and can realize an order degree excellent in regard to the L11 type Co—Pt—C alloy to achieve excellent magnetic anisotropy of the magnetic thin film. Therefore, in the various application devices using the magnetic thin film, it is possible to achieve a large capacity process and/or a high density process thereof in a high level.Type: GrantFiled: December 4, 2009Date of Patent: August 9, 2011Assignees: Tohoku University, Fuji Electric Device Technology Co., Ltd.Inventors: Takehito Shimatsu, Hideo Sato, Osamu Kitakami, Satoshi Okamoto, Hajime Aoi, Hiroyasu Kataoka
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Publication number: 20110020669Abstract: A magnetic recording medium having excellent stability of recorded magnetic signals and capable of recording magnetic signals by a thermally assisted magnetic recording system in which a magnetic recording layer of the magnetic recording medium contains ferromagnetic crystal grains of a Co—Ni—Pt alloy with a Pt content of 44 at % or more and 55 at % or less and with an atom content ratio: Ni/(Co+Ni) of 0.64 or more and 0.8 or less. The magnetic recording medium has extremely excellent stability of recorded magnetic signals since the Co—Ni—Pt alloy constituting the magnetic recording layer has an extremely high anisotropy field at a normal temperature. Further, the magnetic recording medium can perform signal recording based on the thermally assisted magnetic recording system since the Co—Ni—Pt alloy constituting the magnetic recording layer has a Curie point within an appropriate temperature range.Type: ApplicationFiled: July 21, 2010Publication date: January 27, 2011Inventors: Junichi SAYAMA, Hiroaki Nemoto, Hiroshi Ide, Hiroyasu Kataoka, Nobuyukl Takahashi, Takehito Shimatsu, Osamu Kitakami, Satoshi Okamoto, Hajime Aoi
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Publication number: 20100140727Abstract: The present invention relates to a magnetic thin film containing a L11 type Co—Pt—C alloy in which atoms are orderly arranged, and can realize an order degree excellent in regard to the L11 type Co—Pt—C alloy to achieve excellent magnetic anisotropy of the magnetic thin film. Therefore, in the various application devices using the magnetic thin film, it is possible to achieve a large capacity process and/or a high density process thereof in a high level.Type: ApplicationFiled: December 4, 2009Publication date: June 10, 2010Applicants: Tohoku University, Fuji Electric Device Technology Co., Ltd.Inventors: Takehito SHIMATSU, Hideo SATO, Osamu KITAKAMI, Satoshi OKAMOTO, Hajime AOI, Hiroyasu KATAOKA
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Publication number: 20100055503Abstract: Disclosed are a magnetic thin film capable of providing a high uniaxial magnetic anisotropy, Ku, while suppressing the saturation magnetization Ms thereof, and a method for forming the film; and also disclosed are various devices to which the magnetic thin film is applied. The magnetic thin film comprises a Co-M-Pt alloy having an L11-type ordered structure (wherein M represents one or more metal elements except Co and Pt). For example, the Co-M-Pt alloy is a Co—Ni—Pt alloy of which the composition comprises from 10 to 35 at. % of Co, from 20 to 55 at. % of Ni and a balance of Pt. The magnetic thin film is applicable to perpendicular magnetic recording media, tunnel magneto-resistance (TMR) devices, magnetoresistive random access memories (MRAM), microelectromechanical system (MEMS) devices, etc.Type: ApplicationFiled: July 28, 2009Publication date: March 4, 2010Applicants: TOHOKU UNIVERSITY, FUJI ELECTRIC DEVICE TECHNOLOGY CO., LTD.Inventors: Takehito SHIMATSU, Hideo SATO, Osamu KITAKAMI, Satoshi OKAMOTO, Hajime AOI, Hiroyasu KATAOKA
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Publication number: 20050181237Abstract: There is provided a perpendicular magnetic recording medium according to which both the thermal stability of the magnetization is good and writing with a magnetic head is easy, and moreover the SNR is improved. In the case of a perpendicular magnetic recording medium comprising a nonmagnetic substratel, and at least a nonmagnetic underlayer 2, a magnetic recording layer 3 and a protective layer 4 formed in this order on the nonmagnetic substrate 1, the magnetic recording layer 3 comprises a low Ku region 31 layer having a perpendicular magnetic anisotropy constant (Ku value) of not more than 1×105 erg/cm3, and a high Ku region 32 layer having a Ku value of at least 1×106 erg/cm3. Moreover, the magnetic recording layer 3 is made to have therein nonmagnetic grain boundaries that contain a nonmagnetic oxide and magnetically isolate crystal grains, which are made of a ferromagnetic metal, from one another.Type: ApplicationFiled: January 10, 2005Publication date: August 18, 2005Inventors: Osamu Kitakami, Yutaka Shimada, Satoshi Okamoto, Takehito Shimatsu, Hajime Aoi, Hiroaki Muraoka, Yoshihisa Nakamura, Hiroyuki Uwazumi, Tadaaki Oikawa