Patents by Inventor Tetsuya Kanbe

Tetsuya Kanbe 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).

  • Publication number: 20180261245
    Abstract: The invention provides a magnetic recording medium with an excellent signal-to-noise ratio during reading by reducing the noise produced during writing of data onto the magnetic recording medium, and increasing the signal level. The assisted magnetic recording medium according to one embodiment comprising a substrate, a base layer, and a magnetic layer composed mainly of an alloy with an L10-type crystal structure, the assisted magnetic recording medium having a pinning layer in contact with the magnetic layer, and the pinning layer including Co or an alloy composed mainly of Co.
    Type: Application
    Filed: January 31, 2018
    Publication date: September 13, 2018
    Applicant: SHOWA DENKO K.K.
    Inventors: Kazuya NIWA, Tetsuya KANBE, Yuji MURAKAMI, Lei ZHANG, Hisato SHIBATA, Takayuki FUKUSHIMA, Satoru NAKAJIMA, Takehiro YAMAGUCHI
  • Publication number: 20180240487
    Abstract: A magnetic recording medium includes a substrate, a first heat sink layer, a barrier layer, a second heat sink layer, and a magnetic layer that are successively stacked. The magnetic layer is made of a material including a first main component that is an alloy having a L10 crystal structure and a content of 50 at % or higher, or content of 50 mol % or higher. The barrier layer is made of a material including a second main component that is one of an oxide, a nitride, and a carbide having a content of 50 at % or higher, or content of 50 mol % or higher.
    Type: Application
    Filed: January 11, 2018
    Publication date: August 23, 2018
    Inventors: Kazuya NIWA, Lei ZHANG, Yuji MURAKAMI, Hisato SHIBATA, Takayuki FUKUSHIMA, Takehiro YAMAGUCHI, Tetsuya KANBE
  • Publication number: 20180226092
    Abstract: A magnetic recording medium includes: a substrate; an underlayer; and a magnetic layer including an alloy having a L10 type crystal structure whose plane orientation is (001). The substrate, the underlayer, and the magnetic layer are stacked in this order. The underlayer includes a first underlayer. The first underlayer is a crystalline layer that includes a material containing Al, Ag, Cu, W, or Mo as a main component element and includes an oxide of the main component element, a content of the oxide of the main component element in the first underlayer being in a range of from 2 mol % to 30 mol %.
    Type: Application
    Filed: January 2, 2018
    Publication date: August 9, 2018
    Inventors: Takayuki FUKUSHIMA, Haruhisa OHASHI, Lei ZHANG, Yuji MURAKAMI, Hisato SHIBATA, Takehiro YAMAGUCHI, Tetsuya KANBE
  • Publication number: 20180211688
    Abstract: A magnetic recording medium includes: a substrate; a first underlayer; a second underlayer; and a magnetic layer including an alloy having a L10 type crystal structure with a (001) orientation. The substrate, the first underlayer, the second underlayer, and the magnetic layer are stacked in this order. The first underlayer is a crystalline layer that includes Mo as a main component. The second underlayer is a crystalline layer that includes a material containing Mo as a main component and that includes an oxide. The content of the oxide in the second underlayer is in a range of from 2 mol % to 30 mol %. The oxide is an oxide of one or more kinds of elements selected from a group consisting of Cr, Mo, Nb, Ta, V, and W.
    Type: Application
    Filed: January 2, 2018
    Publication date: July 26, 2018
    Inventors: Takayuki FUKUSHIMA, Haruhisa OHASHI, Lei ZHANG, Yuji MURAKAMI, Hisato SHIBATA, Takehiro YAMAGUCHI, Tetsuya KANBE
  • Publication number: 20180204591
    Abstract: A magnetic recording medium includes: a substrate; a first underlayer; a second underlayer; and a magnetic layer including an alloy having a L10 type crystal structure with a (001) orientation. The substrate, the first underlayer the second underlayer, and the magnetic layer are stacked in this order. The first underlayer is a crystalline layer that includes W as a main component. The second underlayer is a crystalline layer that includes a material containing W as a main component and that includes an oxide. The content of the oxide in the second underlayer is in a range of from 2 mol % to 30 mol %. The oxide is an oxide of one or more kinds of elements selected from a group consisting of Cr, Mo, Nb, Ta, V, and W.
    Type: Application
    Filed: December 21, 2017
    Publication date: July 19, 2018
    Inventors: Takayuki FUKUSHIMA, Haruhisa OHASHI, Lei ZHANG, Yuji MURAKAMI, Hisato SHIBATA, Takehiro YAMAGUCHI, Tetsuya KANBE
  • Publication number: 20180182423
    Abstract: A magnetic recording medium includes a substrate, multiple underlayers formed on the substrate, and a magnetic layer foisted on the multiple underlayers. A main component of the magnetic layer is an alloy having a L10 structure. At least one of the multiple underlayers is a crystalline underlayer containing W. The W is a main component of the crystalline underlayer. The crystalline underlayer further contains 1 mol % or more to 20 mol % or less of one or more kinds of elements selected from B, Si, and C. A barrier layer including a material having a NaCl structure is formed between the crystalline underlayer and the magnetic layer.
    Type: Application
    Filed: February 23, 2018
    Publication date: June 28, 2018
    Inventors: Lei ZHANG, Tetsuya KANBE, Yuji MURAKAMI, Kazuya NIWA
  • Publication number: 20180182421
    Abstract: A magnetic recording medium includes a substrate, an underlayer, and a magnetic layer including an alloy having a L10 type crystal structure with a (001) orientation, wherein the substrate, the underlayer, and the magnetic layer are stacked in this order, the underlayer includes a first underlayer, the first underlayer is a crystalline layer that includes a material containing W as a main component and a nitride whose content ranges from 1 mol % to 80 mol %, and the nitride includes one or more elements selected from a group consisting of Al, B, Si, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W.
    Type: Application
    Filed: December 14, 2017
    Publication date: June 28, 2018
    Inventors: Takayuki FUKUSHIMA, Kazuya NIWA, Lei ZHANG, Yuji MURAKAMI, Hisato SHIBATA, Takehiro YAMAGUCHI, Tetsuya KANBE
  • Patent number: 10008220
    Abstract: A magnetic recording medium includes a substrate; a lower base layer formed on the substrate; and a (001) oriented L10 magnetic layer formed on the lower base layer and including a first magnetic layer formed on the lower base layer and having a granular structure of magnetic grains and a grain boundary portion, the grain boundary portion containing C, and a second magnetic layer formed on the first magnetic layer and having a granular structure of magnetic grains and a grain boundary portion, the grain boundary portion containing oxide or nitride, the second magnetic layer further containing one or more elements selected from a group consisting of Mg, Ni, Zn, Ge, Pd, Sn, Ag, Re, Au and Pb as an additive.
    Type: Grant
    Filed: May 16, 2017
    Date of Patent: June 26, 2018
    Assignee: SHOWA DENKO K.K.
    Inventors: Takayuki Fukushima, Yuji Murakami, Tetsuya Kanbe, Lei Zhang, Kazuya Niwa, Hisato Shibata
  • Patent number: 9934810
    Abstract: A magnetic recording medium includes a substrate, multiple underlayers formed on the substrate, and a magnetic layer formed on the multiple underlayers. A main component of the magnetic layer is an alloy having a L10 structure. At least one of the multiple underlayers is a crystalline underlayer containing W. The W is a main component of the crystalline underlayer. The crystalline underlayer further contains 1 mol % or more to 20 mol % or less of one or more kinds of elements selected from B, Si, and C. A barrier layer including a material having a NaCl structure is formed between the crystalline underlayer and the magnetic layer.
    Type: Grant
    Filed: March 20, 2014
    Date of Patent: April 3, 2018
    Assignee: SHOWA DENKO K.K.
    Inventors: Lei Zhang, Tetsuya Kanbe, Yuji Murakami, Kazuya Niwa
  • Publication number: 20170365279
    Abstract: A magnetic recording medium includes a substrate; a lower base layer formed on the substrate; and a (001) oriented L10 magnetic layer formed on the lower base layer and including a first magnetic layer formed on the lower base layer and having a granular structure of magnetic grains and a grain boundary portion, the grain boundary portion containing C, and a second magnetic layer formed on the first magnetic layer and having a granular structure of magnetic grains and a grain boundary portion, the grain boundary portion containing oxide or nitride, the second magnetic layer further containing one or more elements selected from a group consisting of Mg, Ni, Zn, Ge, Pd, Sn, Ag, Re, Au and Pb as an additive.
    Type: Application
    Filed: May 16, 2017
    Publication date: December 21, 2017
    Inventors: Takayuki FUKUSHIMA, Yuji MURAKAMI, Tetsuya KANBE, Lei ZHANG, Kazuya NIWA, Hisato SHIBATA
  • Patent number: 9818441
    Abstract: Disclosed is a thermally assisted magnetic recording medium comprising a substrate, a plurality of underlayers formed on the substrate, and a magnetic layer which is formed on the underlayers and predominantly comprised of an alloy having a L10 structure, characterized in that at least one of the underlayers is predominantly comprised of MgO and comprises at least one oxide selected from SiO2, TiO2, Cr2O3, Al2O3, Ta2O5, ZrO2, Y2O3, CeO2, MnO, TiO and ZnO. The thermally assisted magnetic recording medium has a magnetic layer comprised of fine magnetic crystal grains, exhibiting a sufficiently weak exchange coupling between magnetic grains, and having a minimized coercive force dispersion.
    Type: Grant
    Filed: February 3, 2011
    Date of Patent: November 14, 2017
    Assignee: SHOWA DENKO K.K.
    Inventors: Tetsuya Kanbe, Atsushi Hashimoto, Takayuki Fukushima
  • Patent number: 9384772
    Abstract: A magnetic recording medium includes a substrate, a magnetic layer including an alloy having a L10 type crystal structure as a main component thereof, and a plurality of underlayers arranged between the substrate and the magnetic layer. The plurality of underlayers include a first underlayer including two or more elements selected from a group consisting of Ta, Nb, Ti, and V, and one or more elements selected from a group consisting of W and Mo, and a second underlayer including MgO.
    Type: Grant
    Filed: July 17, 2014
    Date of Patent: July 5, 2016
    Assignee: SHOWA DENKO K.K.
    Inventors: Lei Zhang, Tetsuya Kanbe, Yuji Murakami, Kazuya Niwa
  • Patent number: 9361924
    Abstract: A thermally-assisted magnetic recording medium or a microwave-assisted magnetic recording medium includes: an orientation control layer (104) that is formed on a substrate (101); an underlayer (10) that is formed on the orientation control layer (104); and a magnetic layer (108) that is formed on the underlayer (10) and contains an alloy having an L10 type crystal structure as a main component, in which the underlayer (10) includes an MgO underlayer (107) that contains MgO and has a (100) orientation and a nitride underlayer (106) that contains at least one nitride selected from the group consisting of TaN, NbN, and HfN and has a (100) orientation.
    Type: Grant
    Filed: May 10, 2013
    Date of Patent: June 7, 2016
    Assignee: SHOWA DENKO K.K.
    Inventors: Kazuya Niwa, Tetsuya Kanbe, Yuji Murakami, Lei Zhang
  • Patent number: 9251834
    Abstract: A magnetic recording medium includes a substrate, a magnetic layer including an alloy having an L10 type crystal structure as a main component thereof, and a plurality of underlayers arranged between the substrate and the magnetic layer. The plurality of underlayers include at least one crystalline underlayer which has a (100) orientation, and includes W as a main component thereof and one or more kinds of elements selected from a group consisting of Fe, Ni, Co, Hf, Zr, Y, Be, Ce, La, and Sc.
    Type: Grant
    Filed: October 1, 2014
    Date of Patent: February 2, 2016
    Assignee: SHOWA DENKO K.K.
    Inventors: Lei Zhang, Tetsuya Kanbe, Yuji Murakami, Kazuya Niwa
  • Patent number: 9245567
    Abstract: A magnetic recording medium includes a substrate, a magnetic layer including a FePt alloy having a L10 type structure, and a plurality of underlayers arranged between the substrate and the magnetic layer, wherein at least one of the plurality of underlayers includes TiO2.
    Type: Grant
    Filed: June 16, 2014
    Date of Patent: January 26, 2016
    Assignee: SHOWA DENKO K.K.
    Inventors: Tetsuya Kanbe, Kazuya Niwa, Yuji Murakami, Lei Zhang
  • Patent number: 9230588
    Abstract: A magnetic recording medium includes a substrate, a magnetic layer including an alloy having an L10 type crystal structure as a main component thereof, a plurality of underlayers arranged between the substrate and the magnetic layer, and a barrier layer made of a material having an NaCl structure. The plurality of underlayers include at least one crystalline underlayer including Mo as a main component thereof, and at least one of Si and C in a range of 1 mol % to 20 mol % and an oxide in a range of 1 vol % to 50 vol %. The barrier layer is provided between the magnetic layer and the at least one crystalline underlayer including Mo.
    Type: Grant
    Filed: July 9, 2014
    Date of Patent: January 5, 2016
    Assignee: SHOWA DENKO K.K.
    Inventors: Lei Zhang, Tetsuya Kanbe, Yuji Murakami, Kazuya Niwa
  • Publication number: 20150117166
    Abstract: A magnetic recording medium includes a substrate, a magnetic layer including an alloy having an L10 type crystal structure as a main component thereof, and a plurality of underlayers arranged between the substrate and the magnetic layer. The plurality of underlayers include at least one crystalline underlayer which has a (100) orientation, and includes W as a main component thereof and one or more kinds of elements selected from a group consisting of Fe, Ni, Co, Hf, Zr, Y, Be, Ce, La, and Sc.
    Type: Application
    Filed: October 1, 2014
    Publication date: April 30, 2015
    Inventors: Lei ZHANG, Tetsuya KANBE, Yuji MURAKAMI, Kazuya NIWA
  • Patent number: 9007880
    Abstract: A thermally assisted magnetic recording medium (1) includes a substrate (101), an underlayer (3) that is formed above the substrate (101), and a magnetic layer (107) that is formed on the underlayer (3) and contains an alloy having an L10 structure as a main component. The underlayer (3) is formed by continuously laminating a first underlayer (104) having a BCC structure with a lattice constant that is 0.302 to 0.332 nm, a second underlayer (105) that has a NaCl structure including C, and a third underlayer (106) that is composed of MgO.
    Type: Grant
    Filed: April 30, 2013
    Date of Patent: April 14, 2015
    Assignee: Showa Denko K.K.
    Inventors: Tetsuya Kanbe, Kazuya Niwa, Yuji Murakami, Lei Zhang
  • Publication number: 20150085628
    Abstract: A thermally-assisted magnetic recording medium or a microwave-assisted magnetic recording medium includes: an orientation control layer (104) that is formed on a substrate (101); an underlayer (10) that is formed on the orientation control layer (104); and a magnetic layer (108) that is formed on the underlayer (10) and contains an alloy having an L10 type crystal structure as a main component, in which the underlayer (10) includes an MgO underlayer (107) that contains MgO and has a (100) orientation and a nitride underlayer (106) that contains at least one nitride selected from the group consisting of TaN, NbN, and HfN and has a (100) orientation.
    Type: Application
    Filed: May 10, 2013
    Publication date: March 26, 2015
    Applicant: SHOWA DENKO K.K.
    Inventors: Kazuya Niwa, Tetsuya Kanbe, Yuji Murakami, Lei Zhang
  • Patent number: 8988828
    Abstract: A magnetic recording medium includes a substrate, a magnetic layer including an alloy having an L10 type crystal structure, and a plurality of underlayers arranged between the substrate and the magnetic layer. At least one of the plurality of underlayers is a soft magnetic underlayer formed by an alloy having a hexagonal close packed (hcp) structure and including Co metal or Co as its main component, with a (11•0) plane oriented parallel to a surface of the substrate.
    Type: Grant
    Filed: June 27, 2014
    Date of Patent: March 24, 2015
    Assignee: Showa Denko K.K.
    Inventors: Tetsuya Kanbe, Kazuya Niwa, Yuji Murakami, Lei Zhang