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: 20150049594
    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: Application
    Filed: April 30, 2013
    Publication date: February 19, 2015
    Applicant: SHOWA DENKO K.K.
    Inventors: Tetsuya Kanbe, Kazuya Niwa, Yuji Murakami, Lei Zhang
  • Publication number: 20150036242
    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: Application
    Filed: July 17, 2014
    Publication date: February 5, 2015
    Inventors: Lei ZHANG, Tetsuya KANBE, Yuji MURAKAMI, Kazuya NIWA
  • Publication number: 20150029830
    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: Application
    Filed: July 9, 2014
    Publication date: January 29, 2015
    Inventors: Lei ZHANG, Tetsuya KANBE, Yuji MURAKAMI, Kazuya NIWA
  • Publication number: 20150009786
    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: Application
    Filed: June 27, 2014
    Publication date: January 8, 2015
    Inventors: Tetsuya KANBE, Kazuya NIWA, Yuji MURAKAMI, Lei ZHANG
  • Publication number: 20140376127
    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: Application
    Filed: June 16, 2014
    Publication date: December 25, 2014
    Inventors: Tetsuya KANBE, Kazuya NIWA, Yuji MURAKAMI, Lei ZHANG
  • Publication number: 20140308542
    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: Application
    Filed: March 20, 2014
    Publication date: October 16, 2014
    Applicant: SHOWA DENKO K.K.
    Inventors: Lei ZHANG, Tetsuya KANBE, Yuji MURAKAMI, Kazuya NIWA
  • Patent number: 8792313
    Abstract: A magnetic recording medium of the present invention includes an under layer formed on a substrate, and a magnetic layer, formed on the under layer, which contains an alloy having an L10-type crystal structure as a main component. The under layer includes, in order from the substrate side, a first under layer with a lattice constant a of 2.87 ??a<3.04 ?, a second under layer having a BCC structure with a lattice constant a of 3.04 ??a<3.18 ?, a third under layer having a BCC structure with a lattice constant a of 3.18 ??a<3.31 ?, and an upper under layer having a NaCl-type crystal structure. The first under layer has a B2 structure, or has a BCC structure containing Cr as a main component. In the magnetic recording medium of the present invention, information is recorded using a heat-assisted magnetic recording type, or a microwave-assisted magnetic recording type.
    Type: Grant
    Filed: August 21, 2013
    Date of Patent: July 29, 2014
    Assignee: Showa Denko K.K.
    Inventors: Kazuya Niwa, Tetsuya Kanbe, Yuji Murakami, Lei Zhang
  • Patent number: 8705207
    Abstract: A thermal-assist magnetic recording medium is provided which can accomplish a surface recording density of 1 Tbit/inch2. The thermal-assist magnetic recording medium includes: a substrate; a plurality of underlying layers formed on the substrate; a first magnetic layer formed on the underlying layers; a coupling control layer formed on the first magnetic layer and formed of a ferromagnetic alloy; and a second magnetic layer formed on the coupling control layer. Here, Curie temperatures of the first magnetic layer and the second magnetic layer are higher than the Curie temperature of the coupling control layer, an anisotropy magnetic field of the first magnetic layer is greater than the anisotropy magnetic field of the second magnetic layer, and a saturation magnetic field has a minimum value at a temperature of 350° C. or lower.
    Type: Grant
    Filed: November 30, 2009
    Date of Patent: April 22, 2014
    Assignee: Showa Denko K.K.
    Inventors: Tetsuya Kanbe, Yuzo Sasaki, Atsushi Hashimoto
  • Publication number: 20140064047
    Abstract: A magnetic recording medium of the present invention includes an under layer formed on a substrate, and a magnetic layer, formed on the under layer, which contains an alloy having an L10-type crystal structure as a main component. The under layer includes, in order from the substrate side, a first under layer with a lattice constant a of 2.87 ??a<3.04 ?, a second under layer having a BCC structure with a lattice constant a of 3.04 ??a<3.18 ?, a third under layer having a BCC structure with a lattice constant a of 3.18 ??a<3.31 ?, and an upper under layer having a NaCl-type crystal structure. The first under layer has a B2 structure, or has a BCC structure containing Cr as a main component. In the magnetic recording medium of the present invention, information is recorded using a heat-assisted magnetic recording type, or a microwave-assisted magnetic recording type.
    Type: Application
    Filed: August 21, 2013
    Publication date: March 6, 2014
    Applicant: SHOWA DENKO K.K.
    Inventors: Kazuya NIWA, Tetsuya KANBE, Yuji MURAKAMI, Lei ZHANG
  • Patent number: 8582416
    Abstract: The heat-assisted magnetic recording medium of the present invention has a substrate, an under layer formed on the substrate, and a magnetic layer formed on the under layer, in which the magnetic layer includes an alloy having a L10 structure as a principle component, and the under layer is constituted by a first under layer made of an amorphous alloy or an alloy having a microcrystalline structure, a second under layer made of Cr or an alloy which contains Cr as a principle component and has a BCC structure, a third under layer made of a metal or an alloy having a BCC structure with a lattice constant of 2.98 ? or more, and a fourth under layer made of MgO.
    Type: Grant
    Filed: January 25, 2013
    Date of Patent: November 12, 2013
    Assignee: Showa Denko K.K.
    Inventors: Tetsuya Kanbe, Atsushi Hashimoto, Takayuki Fukushima
  • Patent number: 8542569
    Abstract: A heat-assisted magnetic recording medium includes a substrate, a plurality of foundation layers, and a magnetic layer. The plurality of foundation layers are provided on the substrate and include a first layer containing MnO. The magnetic layer is provided on the plurality of layers and includes an alloy as a main ingredient. The alloy has an L10 structure.
    Type: Grant
    Filed: February 14, 2012
    Date of Patent: September 24, 2013
    Assignee: Showa Denko K.K.
    Inventors: Tetsuya Kanbe, Kazuya Niwa, Katsuya Hara
  • Patent number: 8351309
    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 kind of a metal element having a melting point of at least 2,000° C., such as Nb, Mo, Ru, Ta or W. The thermally assisted magnetic recording medium has magnetic crystal grains having uniform size in the magnetic layer, and has a narrow switching field distribution (SFD), and a magnetic recording storage provided with the thermally assisted magnetic recording medium exhibits a high SN ratio.
    Type: Grant
    Filed: February 23, 2011
    Date of Patent: January 8, 2013
    Assignee: Showa Denko K.K.
    Inventors: Tetsuya Kanbe, Atsushi Hashimoto, Takayuki Fukushima
  • Publication number: 20120307398
    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: Application
    Filed: February 3, 2011
    Publication date: December 6, 2012
    Applicant: SHOWA DENKO K.K.
    Inventors: Tetsuya Kanbe, Atsushi Hashimoto, Takayuki Fukushima
  • Publication number: 20120300600
    Abstract: A thermally assisted magnetic recording medium having a structure in which a first magnetic layer 106 and a second magnetic layer 107 are formed on a substrate 101 in this order, wherein the first magnetic layer 106 has a granular structure containing a FePt alloy having a L10 structure, a CoPt alloy having a L10 crystal lattice structure or a CoPt alloy having a L11 crystal lattice structure, and at least one material for causing grain boundary segregation selected from the group consisting of SiO2, TiO2, Cr2O3, Al2O3, Ta2O5, ZrO2, Y2O3, CeO2, MnO, TiO, ZnO, and MgO, and the content of the material for causing grain boundary segregation in the first magnetic layer 106 is decreased from the substrate side to the second magnetic layer 107 side.
    Type: Application
    Filed: January 24, 2011
    Publication date: November 29, 2012
    Applicant: SHOWA DENKO K.K.
    Inventors: Tetsuya Kanbe, Atsushi Hashimoto, Takayuki Fukushima
  • Patent number: 8279739
    Abstract: A heat-assisted magnetic recording medium that includes a substrate, underlayers formed on the substrate, and a magnetic layer which is formed on the underlayers and contains either an FePt alloy having an L10 structure or a CoPt alloy having an L10 structure as a main component, wherein the underlayers include a first underlayer formed from an amorphous alloy, a second underlayer formed from an alloy having a BCC structure containing Cr as a main component and also containing at least one element selected from among Ti, Mo, W, V, Mn and Ru, and a third underlayer formed from MgO. Also, a magnetic storage device that uses the heat-assisted magnetic recording medium.
    Type: Grant
    Filed: August 19, 2010
    Date of Patent: October 2, 2012
    Assignee: Showa Denko K.K.
    Inventors: Tetsuya Kanbe, Yuzo Sasaki, Atsushi Hashimoto
  • Patent number: 8270286
    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 an L10 structure, characterized in that at least one of said underlayers is predominantly comprised of MgO and comprises at least one kind of an element having a free energy for oxidation of, per mol of oxygen, not higher than ?120 kcal/mol·O2 at 1000° C. The element having the free energy for oxidation is preferably selected from Al, Si, Ti, V, Cr, Mn, Zr and B. The thermally assisted magnetic recording medium has a magnetic layer comprised of magnetic crystal grains with uniform diameters, and exhibiting a sufficiently weak exchange coupling between magnetic grains.
    Type: Grant
    Filed: March 28, 2011
    Date of Patent: September 18, 2012
    Assignee: Showa Denko K.K.
    Inventors: Tetsuya Kanbe, Atsushi Hashimoto, Takayuki Fukushima
  • Publication number: 20120207003
    Abstract: A heat-assisted magnetic recording medium includes a substrate, a plurality of foundation layers, and a magnetic layer. The plurality of foundation layers are provided on the substrate and include a first layer containing MnO. The magnetic layer is provided on the plurality of layers and includes an alloy as a main ingredient. The alloy has an L10 structure.
    Type: Application
    Filed: February 14, 2012
    Publication date: August 16, 2012
    Applicant: Showa Denko K.K.
    Inventors: Tetsuya Kanbe, Kazuya Niwa, Katsuya Hara
  • Publication number: 20120113768
    Abstract: A heat-assisted magnetic recording medium that includes a substrate 1, underlayers formed on the substrate 1, and a magnetic layer 5 which is formed on the underlayers and contains either an FePt alloy having an L10 structure or a CoPt alloy having an L10 structure as a main component, wherein the underlayers include a first underlayer 2 formed from an amorphous alloy, a second underlayer 3 formed from an alloy having a BCC structure containing Cr as a main component and also containing at least one element selected from among Ti, Mo, W, V, Mn and Ru, and a third underlayer 4 formed from MgO. Also, a magnetic storage device that uses the heat-assisted magnetic recording medium.
    Type: Application
    Filed: August 19, 2010
    Publication date: May 10, 2012
    Applicant: SHOWA DENKO K.K.
    Inventors: Tetsuya Kanbe, Yuzo Sasaki, Atsushi Hashimoto
  • Publication number: 20110235479
    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 an L10 structure, characterized in that at least one of said underlayers is predominantly comprised of MgO and comprises at least one kind of an element having a free energy for oxidation of, per mol of oxygen, not higher than ?120 kcal/mol·O2 at 1000° C. The element having the free energy for oxidation is preferably selected from Al, Si, Ti, V, Cr, Mn, Zr and B . The thermally assisted magnetic recording medium has a magnetic layer comprised of magnetic crystal grains with uniform diameters, and exhibiting a sufficiently weak exchange coupling between magnetic grains.
    Type: Application
    Filed: March 28, 2011
    Publication date: September 29, 2011
    Applicant: SHOWA DENKO K.K.
    Inventors: Tetsuya KANBE, Atsushi HASHIMOTO, Takayuki FUKUSHIMA
  • Publication number: 20110205862
    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 kind of a metal element having a melting point of at least 2,000° C., such as Nb, Mo, Ru, Ta or W. The thermally assisted magnetic recording medium has magnetic crystal grains having uniform size in the magnetic layer, and has a narrow switching field distribution (SFD), and a magnetic recording storage provided with the thermally assisted magnetic recording medium exhibits a high SN ratio.
    Type: Application
    Filed: February 23, 2011
    Publication date: August 25, 2011
    Applicant: SHOWA DENKO K.K.
    Inventors: Tetsuya KANBE, Atsushi HASHIMOTO, Takayuki FUKUSHIMA