Patents by Inventor Yukiko Takahashi
Yukiko Takahashi 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: 20160225393Abstract: A perpendicular magnetic recording medium which has a magnetic layer comprising a material having FePt alloy as a main component on a substrate, characterized in that the magnetic layer is an FePtAg—C or FePt—C granular thin film obtained by laminating a unit in multiple stages, the unit being a laminate film obtained by forming, on an FePtAg—C layer or an FePt—C layer, at least one layer of (A) FePtAg layer or FePt layer or (B) FePtAg—C layer or FePt—C layer which has carbon concentration different from the above FePtAg—C layer or FePt—C layer. Consequently, a perpendicular magnetic recording medium using an FePtAg—C or FePt—C granular thin film which satisfies both the high order and columnar structure required for achieving recording density of more than 1 Tbit/in2, for example, can be provided.Type: ApplicationFiled: August 25, 2014Publication date: August 4, 2016Applicant: NATIONAL INSTITUTE FOR MATERIALS SCIENCEInventors: Bollapragada VARAPRASAD, Yukiko TAKAHASHI, Kazuhiro HONO
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Patent number: 9336937Abstract: To realize a spintronics device with high performance, it is an object of the present invention to provide a Co2Fe-based Heusler alloy having a spin polarization larger than 0.65, and a high performance spintronics devices using the same. A Co2Fe(GaxGe1-x) Heusler alloy shows a spin polarization higher than 0.65 by a PCAR method in a region of 0.25<x<0.60 and it has a Curie temperature as high as 1288K. A CPP-GMR device that uses the Co2Fe(GaxGe1-x) Heusler alloy as an electrode exhibits the world's highest MR ratio, an STO device exhibits high output, and an NLSV device exhibits a high spin signal.Type: GrantFiled: July 3, 2013Date of Patent: May 10, 2016Assignee: NATIONAL INSTITUTE FOR MATERIALS SCIENCEInventors: Yukiko Takahashi, Srinivasan Ananthakrishnan, Varaprasad Bollapragada, Rajanikanth Ammanabrolu, Jaivardhan Sinha, Masamitsu Hayashi, Takao Furubayashi, Shinya Kasai, Shigeyuki Hirayama, Seiji Mitani, Kazuhiro Hono
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Publication number: 20160019917Abstract: The CPPGMR element of the present invention has an orientation layer 12 formed on a substrate 11 to texture a Heusler alloy into a (100) direction, an underlying layer 13 that is an electrode for magneto-resistance measurement stacked on the orientation layer 12, a lower ferromagnetic layer 14 and an upper ferromagnetic layer 16 each stacked on the underlying layer 13 and made of a Heusler alloy, a spacer layer 15 sandwiched between the lower ferromagnetic layers 14 and the upper ferromagnetic layers 16, and a cap layer 17 stacked on the upper ferromagnetic layer 16 for surface-protection. This manner makes it possible to provide, inexpensively, an element using a current-perpendicular-to-plane giant magneto-resistance effect (CPPGMR) of a thin film having a trilayered structure of a ferromagnetic metal/a nonmagnetic metal/a ferromagnetic metal, thereby showing excellent performances.Type: ApplicationFiled: April 2, 2014Publication date: January 21, 2016Applicant: NATIONAL INSTITUTE FOR MATERIALS SCIENCEInventors: Ye DU, Takao FURUBAYASHI, Yukiko TAKAHASHI, Kazuhiro HONO
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Publication number: 20150132609Abstract: Provided are an element structure in which a magnetic layer has a high magnetic anisotropy constant and saturated magnetization properties in a thickness of 1.5 nm or less, and a magnetic device that uses the element structure. A BCC metal nitride/CoFeB/MgO film structure that uses a nitride of a BCC metal as a seed layer is fabricated. The nitride amount in the BCC metal nitride is preferably less than 60% in terms of volume ratio based on 100% BCC metal. It is thereby possible to readily obtain a perpendicularly magnetized film having the magnetic properties that the perpendicular magnetic anisotropy is 0.1×106 erg/cm3 or more and the saturated magnetization is 200 emu/cm3 or more, even when the thickness of the magnetic layer is 0.3 nm or more and 1.5 nm or less.Type: ApplicationFiled: March 22, 2013Publication date: May 14, 2015Applicant: NATIONAL INSTITUTE FOR MATERIALS SCIENCEInventors: Masamitsu Hayashi, Sinha Jaivardhan, Masaya Kodzuka, Tomoya Nakatani, Yukiko Takahashi, Takao Furubayashi, Seiji Mitani, Kazuhiro Hono
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Patent number: 8993134Abstract: A perpendicular magnetic recording medium, comprising: a substrate; a buffer layer deposited in a first orientation on top of the substrate; an underlayer deposited in a second orientation on top of the buffer layer, the underlayer comprising an electrically conductive oxide; and a magnetic recording layer deposited on top of the underlayer and having an axis of magnetic anisotropy substantially perpendicular to the surface thereof.Type: GrantFiled: June 29, 2012Date of Patent: March 31, 2015Assignee: Western Digital Technologies, Inc.Inventors: Bollapragada Varaprasad, Yukiko Takahashi, Kazuhiro Hono, Antony Ajan, Hua Yuan, Alexander S. Chernyshov
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Publication number: 20150008998Abstract: The invention provides a nanocomposite magnet, which has achieved high coercive force and high residual magnetization. The magnet is a non-ferromagnetic phase that is intercalated between a hard magnetic phase with a rare-earth magnet composition and a soft magnetic phase, wherein the non-ferromagnetic phase reacts with neither the hard nor soft magnetic phase. A hard magnetic phase contains Nd2Fe14B, a soft magnetic phase contains Fe or Fe2Co, and a non-ferromagnetic phase contains Ta. The thickness of the non-ferromagnetic phase containing Ta is 5 nm or less, and the thickness of the soft magnetic phase containing Fe or Fe2Co is 20 nm or less. Nd, or Pr, or an alloy of Nd and any one of Cu, Ag, Al, Ga, and Pr, or an alloy of Pr and any one of Cu, Ag, Al, and Ga is diffused into a grain boundary phase of the hard magnetic phase of Nd2Fe14B.Type: ApplicationFiled: December 27, 2012Publication date: January 8, 2015Applicants: NATIONAL INSTITUTE FOR MATERIALS SCIENCE, TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Hidefumi Kishimoto, Noritsugu Sakuma, Masao Yano, Weibin Cui, Yukiko Takahashi, Kazuhiro Hono
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Publication number: 20140335376Abstract: A perpendicular magnetic recording medium, comprising: a substrate; a buffer layer deposited in a first orientation on top of the substrate; an underlayer deposited in a second orientation on top of the buffer layer, the underlayer comprising an electrically conductive oxide; and a magnetic recording layer deposited on top of the underlayer and having an axis of magnetic anisotropy substantially perpendicular to the surface thereof.Type: ApplicationFiled: June 29, 2012Publication date: November 13, 2014Applicant: Western Digital Technologies, Inc.Inventors: BOLLAPRAGADA VALAPRASAD, Yukiko Takahashi, Kazuhiro Hono, Antony Ajan, Hua Yuan, Alexander S. Chernyshov
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Publication number: 20130302649Abstract: [Problem to be Solved] To realize a spintronics device with high performance, it is an object of the present invention to provide a Co2Fe-based Heusler alloy having a spin polarization larger than 0.65, and a high performance spintronics devices using the same. [Solution] A Co2Fe(GaxGe1-x) Heusler alloy shows a spin polarization higher than 0.65 by a PCAR method in a region of 0.25<x<0.60 and it has a Curie temperature as high as 1288K. A CPP-GMR device that uses the Co2Fe(GaxGe1-x) Heusler alloy as an electrode exhibits the world's highest MR ratio, an STO device exhibits high output, and an NLSV device exhibits a high spin signal.Type: ApplicationFiled: July 3, 2013Publication date: November 14, 2013Inventors: Yukiko Takahashi, Srinivasan Ananthakrishnan, Varaprasad Bollapragada, Rajanikanth Ammanabrolu, Jaivardhan Sinha, Masamitsu Hayashi, Takao Furubayashi, Shinya Kasai, Shigeyuki Hirayama, Seiji Mitani, Kazuhiro Hono
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Publication number: 20130040167Abstract: It is aimed to provide a perpendicular magnetic recording medium capable of dealing with an ultra-higher recording density than before and its manufacturing method. The present invention concerns a perpendicular magnetic recording medium including at least a seed layer made of noncrystalline ceramic, a crystalline orientation control layer and a magnetic layer made of a material mainly containing a FePt alloy in this order on a substrate. This perpendicular magnetic recording medium is suitably manufactured by forming at least the seed layer, the orientation control layer and the magnetic layer made of the material mainly containing the FePt alloy in this order on the substrate by sputtering, wherein the magnetic layer is formed at a predetermined temperature of 500° C. or less.Type: ApplicationFiled: January 12, 2011Publication date: February 14, 2013Applicants: WD MEDIA (SINGAPORE) PTE. LTD., NATIONAL INSTITUTE FOR MATERIALS SCIENCEInventors: Perumal Alagarsamy, Yukiko Takahashi, Kazuhiro Hono, Tomoko Seki
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Patent number: 8309196Abstract: An optical recording medium having excellent light resistance that includes a substrate; and a recording layer which is provided on the substrate directly or on another layer provided on the substrate, wherein the recording layer is capable of recording and/or reading information by irradiating light thereon, the recording layer including a metal complex compound comprising an azo compound having a coupler component with a Meldrum's acid structure and a diazo component with a nitrogen-containing heterocyclic aromatic ring structure, and a metal ion coordinated to the azo compound.Type: GrantFiled: August 25, 2011Date of Patent: November 13, 2012Assignee: Mitsubishi Kagaku Media Co., Ltd.Inventors: Takashi Miyazawa, Yutaka Kurose, Hisashi Shoda, Kenichi Satake, Yukiko Takahashi, Mayumi Kimura, Naoyuki Uchida, Hideki Tamagawa
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Publication number: 20120141713Abstract: [Problems] To provide a package excellent in barrier property, transparency and appearance, and having a layer forming an island-in-the-sea structure of a small domain diameter and a high domain density without impairing the formability into containers. [Means for Solution] A package having a mixed layer of a mixture of a base resin and a functional resin composition containing inorganic fine particles, wherein the mixed layer forms an island-in-the-sea structure in which the base resin is forming a continuous phase and the functional resin composition is forming discontinuous phases, and the area percentage of the functional resin composition in cross section is 25 to 55%.Type: ApplicationFiled: April 16, 2010Publication date: June 7, 2012Applicant: TOYO SEIKAN KAISHA, LTD.Inventors: Atsushi Kikuchi, Misa Sasai, Shinichiro Funaoka, Yukiko Takahashi
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Publication number: 20110311752Abstract: [Problem]: An optical recording medium having a capability of recording and/or reading high density optical information using a short wavelength laser light is provided. [Means to Address the Problem]: The optical recording medium has a capability of recording and/or reading high density optical information using a short wavelength laser light having a wavelength of 350 nm to 530 nm. The optical recording medium has a recording layer containing a metal complex compound and formed on a substrate. The metal complex compound is composed of a cyclic ?-diketone azo compound represented by the general formula (I) or general formula (II) and a divalent metal ion coordinated to the cyclic ?-diketone azo compound.Type: ApplicationFiled: August 25, 2011Publication date: December 22, 2011Applicant: Mitsubishi Kagaku Media Co., Ltd.Inventors: Takashi MIYAZAWA, Yutaka KUROSE, Hisashi SHODA, Kenichi SATAKE, Yukiko TAKAHASHI, Mayumi KIMURA, Naoyuki UCHIDA, Hideki TAMAGAWA
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Patent number: 8075976Abstract: An optical recording medium having excellent light resistance that includes a substrate; and a recording layer which is provided on the substrate directly or on another layer provided on the substrate, wherein the recording layer is capable of recording and/or reading information by irradiating light thereon, the recording layer includes a metal complex compound with an azo compound having a coupler component with indandione and a diazo component with a nitrogen-containing heterocyclic aromatic ring structure, and a nickel or cobalt ion coordinated to the azo compound.Type: GrantFiled: July 11, 2006Date of Patent: December 13, 2011Assignee: Mitsubishi Kagaku Media Co., Ltd.Inventors: Takashi Miyazawa, Yutaka Kurose, Hisashi Shoda, Kenichi Satake, Yukiko Takahashi, Mayumi Kimura, Naoyuki Uchida, Hideki Tamagawa
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Publication number: 20090263611Abstract: [Problem]: An optical recording medium having a capability of recording and/or reading high density optical information using a short wavelength laser light is provided. [Means to Address the Problem]: The optical recording medium has a capability of recording and/or reading high density optical information using a short wavelength laser light having a wavelength of 350 nm to 530 nm. The optical recording medium has a recording layer containing a metal complex compound and formed on a substrate. The metal complex compound is composed of a cyclic ?-diketone azo compound represented by the general formula (I) or general formula (II) and a divalent metal ion coordinated to the cyclic ?-diketone azo compound.Type: ApplicationFiled: July 11, 2006Publication date: October 22, 2009Applicant: Mitsubishi Kagaku Media Co., Ltd.Inventors: Takashi Miyazawa, Yutaka Kurose, Hisashi Shoda, Kenichi Satake, Yukiko Takahashi, Mayumi Kimura, Naoyuki Uchida, Hideki Tamagawa
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Patent number: 4929633Abstract: As new compounds are provided a class of derivatives of actinonin represented by the general formula ##STR1## where R is a hydrogen or a lower alkyl group, which can exhibit the enzyme-inhibitory activities to a limited range of peptidases and show a remarkable enzyme-specificity, and which are effective to treat a cycloheximide-induced experimental amnesia in mice and are expectable to be useful to treat an amnesia in a mammalian animal, including human.Type: GrantFiled: June 8, 1988Date of Patent: May 29, 1990Assignees: Zaidan Hojin Biseibutsu Kagaku Kenkyu Kai, Meiji Seika Kaisha, Ltd.Inventors: Seiji Shibahara, Yukiko Takahashi, Yuji Matsuhashi, Mitsugu Hachisu, Shinichi Kondo, Tomio Takeuchi, Takaaki Aoyagi