Metal Or Alloy Magnetic Layer Patents (Class 428/836.1)
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Patent number: 12190923Abstract: A substrate for a magnetic disk includes a substrate main body having two main surfaces and an outer circumferential edge surface, and a film that is an alloy film containing Ni and P and provided on a surface of the substrate main body. A disk shape of the substrate main body has an outer diameter of 90 mm or more. A thickness T of the substrate that includes film thicknesses of sections of the film provided on the main surfaces is 0.520 mm or less. A total thickness D mm, which is a sum of the film thicknesses of the sections of the film on the main surfaces and the thickness T mm satisfy D?0.0082/T?0.0015. A surface roughness maximum height Rz of the film provided on the outer circumferential edge surface is smaller than that of the substrate main body at the outer circumferential edge surface.Type: GrantFiled: May 22, 2023Date of Patent: January 7, 2025Assignee: HOYA CORPORATIONInventor: Kinobu Osakabe
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Patent number: 11430477Abstract: A magnetic recording medium includes a nonmagnetic support body, and a magnetic layer containing magnetic powder, in which the magnetic powder contains ?-Fe2O3 crystal (including a case of substituting a portion of Fe site with a metal element M), a product of residual magnetization and a thickness of the magnetic layer is from 0.5 mA to 6.0 mA, and a squareness ratio which is measured in a longitudinal direction of the magnetic layer is 0.3 or less.Type: GrantFiled: July 31, 2020Date of Patent: August 30, 2022Assignee: Sony CorporationInventors: Masaru Terakawa, Yoichi Kanemaki, Minoru Yamaga
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Patent number: 10202480Abstract: The present application provides the block copolymers and their application. The block copolymer has an excellent self assembling property and phase separation and various required functions can be freely applied thereto as necessary.Type: GrantFiled: December 8, 2014Date of Patent: February 12, 2019Assignee: LG Chem, Ltd.Inventors: Je Gwon Lee, Jung Keun Kim, No Jin Park, Sung Soo Yoon
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Patent number: 10062404Abstract: A method for manufacturing perpendicular magnetic recording medium which includes magnetic recording layer having desired film thickness while maintaining high magnetic anisotropy and having more homogenized magnetic characteristics. The method includes: (A) preparing non-magnetic substrate; (B) laminating magnetic recording layer on the substrate; and (C) heating the substrate on which the magnetic recording layer is laminated to a temperature of 400 to 600° C. The step (B) includes at least forming a first magnetic recording layer and a second magnetic layer thereon. The first layer has a granular structure including a first magnetic crystal grain constituted by an ordered alloy surrounded by a first non-magnetic grain boundary constituted by carbon, and the second layer has a granular structure including a second magnetic crystal grain constituted by an ordered alloy surrounded by a second non-magnetic grain boundary constituted by a non-magnetic material constituted by boron and carbon.Type: GrantFiled: May 12, 2015Date of Patent: August 28, 2018Assignee: Fuji Electric Co., Ltd.Inventors: Hiroyasu Kataoka, Hiroto Kikuchi, Akira Furuta, Takehito Shimatsu
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Patent number: 9672854Abstract: A stack includes a substrate and a magnetic recording layer. Disposed between the substrate and magnetic recording layer is an MgO—Ti(ON) layer.Type: GrantFiled: October 31, 2013Date of Patent: June 6, 2017Assignee: SEAGATE TECHNOLOGY LLCInventors: Yukiko Kubota, Timothy J. Klemmer, Kai Chieh Chang, Li Gao, Yinfeng Ding, Yingguo Peng, Jan-Ulrich Thiele
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Patent number: 9034492Abstract: Systems and methods for controlling the damping of magnetic media for heat assisted magnetic recording are provided. One such system includes a heat sink layer, a growth layer on the heat sink layer, a magnetic recording layer on the growth layer, where the growth layer is configured to facilitate a growth of a preselected crystalline structure of the magnetic recording layer, and a capping magnetic recording layer on the magnetic recording layer, the capping recording layer including a first material configured to increase a damping constant of the capping recording layer to a first preselected level.Type: GrantFiled: January 11, 2013Date of Patent: May 19, 2015Assignee: WD Media, LLCInventors: Michael L. Mallary, Gerardo A. Bertero, Kumar Srinivasan
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Patent number: 9000764Abstract: A method for producing printed magnetic functional elements for resistance sensors and printed magnetic functional elements. The invention refers to the field of electronics and relates to a method for producing resistance sensors, such as can be used, for example, in magnetic data storage for read sensors or in the automobile industry. The disclosure includes a simple and cost-effective production method and to obtain such printed magnetic functional elements with properties that can be adjusted as desire, in which a magnetic material is deposited onto a substrate as a film, is removed from the substrate and divided into several components and these components are applied on a substrate by means of printing technologies. Aspects are also directed to a printed magnetic functional element for resistance sensors of several components of a film, wherein at least 5% of the components of the functional element have a magnetoimpedance effect.Type: GrantFiled: June 20, 2012Date of Patent: April 7, 2015Assignee: Leibniz-Institut fuer Festkoerper und Werkstoffforschung Dresden e.V.Inventors: Daniil Karnaushenko, Denys Makarov, Oliver G. Schmidt
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Publication number: 20140342188Abstract: An apparatus includes a substrate and a magnetic layer coupled to the substrate. The magnetic layer includes an alloy that has magnetic hardness that is a function of the degree of chemical ordering of the alloy. The degree of chemical ordering of the alloy in a first portion of the magnetic layer is greater than the degree of chemical ordering of the alloy in a second portion of the magnetic layer, and the first portion of the magnetic layer is closer to the substrate than the second portion of the magnetic layer.Type: ApplicationFiled: August 5, 2014Publication date: November 20, 2014Inventors: Yingguo Peng, Xiaowei Wu, Ganping Ju, Bin Lu
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Patent number: 8877360Abstract: According to one embodiment, a perpendicular magnetic recording medium includes a substrate, and a multilayered magnetic recording layer formed on the substrate by alternately stacking two or more magnetic layers and two or more nonmagnetic layers. The magnetic layers and nonmagnetic layers of the multilayered magnetic recording layer are continuous layers. The magnetic layer includes a magnetic material portion, and a plurality of pinning sites dispersed in the magnetic material portion and made of a nonmagnetic metal different from a nonmagnetic material as a main component of the nonmagnetic layer. This perpendicular magnetic recording medium has magnetic characteristics by which a gradient ? of a magnetization curve near the coercive force is 5 or more.Type: GrantFiled: November 23, 2011Date of Patent: November 4, 2014Assignee: Kabushiki Kaisha ToshibaInventor: Soichi Oikawa
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Publication number: 20140287268Abstract: Provided herein is an apparatus, including a plurality of spaced apart perpendicular magnetic elements. Each of the magnetic elements includes a respective discrete magnetic domain and each of the magnetic elements includes a magnetic recording layer comprising a Co1-x-yPtxCry alloy material, where 0.05?x?0.35 and 0?y?0.15.Type: ApplicationFiled: February 12, 2014Publication date: September 25, 2014Applicant: Seagate Technology LLCInventors: Dieter K. Weller, Hans J. Richter, Samuel D. Harkness, IV, Erol Girt
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Patent number: 8815336Abstract: According to one embodiment, there is provided a magnetic recording medium manufacturing method including forming a resist layer on a magnetic recording layer, patterning the resist layer, forming a magnetic pattern by performing ion implantation through the resist layer, partially modifying the surface of the magnetic recording layer, removing the resist, applying a self-organization material to the surface of the magnetic recording layer and forming a dotted mask pattern, and patterning the magnetic recording layer.Type: GrantFiled: October 23, 2012Date of Patent: August 26, 2014Assignee: Kabushiki Kaisha ToshibaInventors: Kaori Kimura, Masatoshi Sakurai, Kazuto Kashiwagi, Akihiko Takeo
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Publication number: 20140233363Abstract: Iron-platinum (FePt) based magnetic recording media structures that provide small grain size and isolated-grain configurations suitable for high-density magnetic recording. In one of the structures, the recording media structure includes a thin film containing grains of L10 FePt and boron as a segregant contained in intergranular regions located among the FePt grains. In another structure, the recording media structure includes a thin film containing grains of L10 FePt, wherein the film is formed on an underlayer containing at least one material selected to control the size of the FePt grains in the film. Proper choices of materials, relative amounts of the materials, processing parameters, and other variables permit these structures to be formed with grain sizes, magnetization orientations, and perpendicular coercivities that allow designers to create magnetic storage devices having storage densities of 1 Tbit/in2 and greater.Type: ApplicationFiled: September 21, 2012Publication date: August 21, 2014Inventors: Mark Kryder, Steven D. Granz, Katayun Barmak Vaziri
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Publication number: 20140227561Abstract: An information recording medium glass substrate and an information recording medium are provided in which a first roll-off variation and a second roll-off variation fall within the following ranges: 180 ??first roll-off variation?990 ? (condition 1) and 650 ??second roll-off variation?3700 ? (condition 2).Type: ApplicationFiled: September 11, 2012Publication date: August 14, 2014Applicant: HOYA CORPORATIONInventor: Takeshi Endo
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Patent number: 8771846Abstract: An intermetallic or iron aluminide magnetically readable medium and a method of forming and reading the same are provided herein. Also provided is an identification card or tag, a key, an anti-counterfeiting measure, an anti-forging measure. The intermetallic or iron aluminide magnetically readable medium includes a magnetically readable surface, wherein the magnetically readable surface contains one or more first magnetically readable regions of the intermetallic or iron aluminide surrounded by one or more second magnetically readable regions. Additionally, the intermetallic or iron aluminide magnetically readable medium can be coated, encapsulated or concealed within a material.Type: GrantFiled: May 23, 2006Date of Patent: July 8, 2014Assignee: Philip Morris USA Inc.Inventors: Seetharama C. Deevi, Kudumboor V. Rao, Valter Ström, Ziyan Gu
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Publication number: 20140153128Abstract: According to one embodiment, a magnetic recording medium includes a magnetic recording layer formed on a substrate and including magnetic grains and a grain boundary formed between the magnetic grains, the grain boundary includes a first grain boundary having a first thermal conductivity, and a second grain boundary formed on the first grain boundary and having a second thermal conductivity different from the first thermal conductivity, and at least one of the first and second grain boundaries suppresses thermal conduction.Type: ApplicationFiled: March 11, 2013Publication date: June 5, 2014Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Hironori TEGURI, Akira WATANABE, Tomoko TAGUCHI
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Publication number: 20140147702Abstract: An apparatus and associated method are generally described as a thin film exhibiting a tuned anisotropy and magnetic moment. Various embodiments may form a magnetic layer that is tuned to a predetermined anisotropy and magnetic moment through deposition of a material on a substrate cooled to a predetermined substrate temperature.Type: ApplicationFiled: November 29, 2012Publication date: May 29, 2014Applicant: SEAGATE TECHNOLOGY LLCInventors: Venkateswara Rao Inturi, Wei Tian, Joseph Mundenar
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Patent number: 8673466Abstract: A bit patterned magnetic recording medium comprises a substrate having a surface, and a plurality of spaced apart magnetic elements on the surface, each element constituting a discrete magnetic domain or bit of the same structure and comprised of a stack of thin film layers including in order from the substrate surface: a seed layer; and a perpendicular magnetic recording layer in contact with a surface of the seed layer and comprising a Co 1-x-yPtxCry alloy material, where 0.05?x?0.35 and 0?y?0.15. The Co1-x-yPtxCry alloy material has a first order magnetic anisotropy constant K1 up to about 2×107 erg/cm3, a saturation magnetization Ms up to about 1200 emu/cm3, an anisotropy field HK=2K1/Ms up to about 35 kOe, a hexagonal (0001) crystal structure with c-axis perpendicular to a surface thereof, and an X-Ray diffraction (XRD) rocking curve with a full width at half maximum (FWHM) of ˜5° or less.Type: GrantFiled: September 25, 2006Date of Patent: March 18, 2014Assignee: Seagate Technology LLCInventors: Dieter K. Weller, Hans J. Richter, Samuel D. Harkness, IV, Erol Girt
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Patent number: 8658293Abstract: A magnetic recording medium includes: a substrate, and a magnetic recording layer that is made from a material having the chemical formula of FexMnyPtz, and that has a bottom surface and an upper surface; wherein x, y, and z indicate average atomic concentrations for Fe, Mn, and Pt, and x+y+z is 100, x and y being greater than 0 and not greater than 65, z being in the range from 35 to 60; and wherein atomic concentration of Fe is gradually decreased from the upper surface to the bottom surface, and atomic concentration of Mn is gradually increased from the upper surface to the bottom surface so that the ferromagnetic property of the magnetic recording layer is gradually reduced from the upper surface to the bottom surface.Type: GrantFiled: June 11, 2012Date of Patent: February 25, 2014Assignee: National Tsing Hua UniversityInventors: Chih-Huang Lai, Hao-Cheng Hou, Chao-Chien Chiang
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Patent number: 8658292Abstract: Systems and methods for controlling the damping of magnetic media for magnetic recording are described. One such system includes a magnetic media structure for magnetic recording, the media structure including at least one base layer including an interlayer, a bottom magnetic recording layer positioned on the interlayer, and an exchange coupling layer positioned on the bottom layer; and a capping magnetic recording layer positioned on the at least one base layer, the capping recording layer including a first material configured to increase a damping constant of the capping recording layer to a first preselected level.Type: GrantFiled: June 10, 2011Date of Patent: February 25, 2014Assignee: Western Digital Technologies, Inc.Inventors: Michael L. Mallary, Gerardo A. Bertero
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Patent number: 8634153Abstract: According to one embodiment, a magnetic recording medium includes a substrate, an auxiliary layer formed on the substrate, and at least one perpendicular magnetic recording layer formed on the auxiliary layer. The perpendicular magnetic recording layer includes a magnetic dot pattern. The perpendicular magnetic recording layer is made of an alloy material containing one element selected from iron and cobalt, and one element selected from platinum and palladium. This alloy material has the L10 structure, and is (001)-oriented. The auxiliary layer includes a dot-like first region covered with the magnetic dot pattern, and a second region not covered with the magnetic dot pattern. The first region is made of one metal selected from (100)-oriented nickel and (100)-oriented iron. The second region contains an oxide of the metal used in the first region.Type: GrantFiled: January 16, 2012Date of Patent: January 21, 2014Assignee: Kabushiki Kaisha ToshibaInventors: Tomoyuki Maeda, Yousuke Isowaki, Akira Watanabe
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Publication number: 20130202915Abstract: A method is disclosed for defining discrete magnetic and non-magnetic regions on the magnetic film layer of a storage media substrate. The method applies anodic oxidation of a cobalt-containing magnetic film layer to remove cobalt, followed by controlled deposition of a non-magnetic matrix into the regions where the cobalt has been removed. Deposition may either be electrodeposition, collimated vacuum deposition, or other methods depending upon the composition of the non-magnetic matrix being deposited. The method may be performed in a single electrochemical cell.Type: ApplicationFiled: March 15, 2013Publication date: August 8, 2013Applicant: SEAGATE TECHNOLOGY, LLCInventor: Seagate Technology, LLC
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Perpendicular magnetic recording media with magnetic anisotropy gradient and local exchange coupling
Patent number: 8501330Abstract: A perpendicular magnetic recording medium adapted for high recording density and high data recording rate comprises a non-magnetic substrate having at least one surface with a layer stack formed thereon, the layer stack including a perpendicular recording layer containing a plurality of columnar-shaped magnetic grains extending perpendicularly to the substrate surface for a length, with a first end distal the surface and a second end proximal the surface, wherein each of the magnetic grains has: (1) a gradient of perpendicular magnetic anisotropy field Hk extending along its length between the first end and second ends; and (2) predetermined local exchange coupling strengths along the length.Type: GrantFiled: October 11, 2011Date of Patent: August 6, 2013Assignee: Seagate Technology LLCInventors: Shaoping Li, Kaizhong Gao, Lei Wang, Wenzhong Zhu, Xiaobin Wang -
Patent number: 8481181Abstract: Approaches to reduce switching field distribution in energy assisted magnetic storage devices involve first and second exchange coupled magnetic elements. The first magnetic elements have anisotropy, Hk1, volume, V1 and the second magnetic elements are magnetically exchange coupled to the first magnetic elements and have anisotropy Hk2, and volume V2. The thermal stability of the exchange coupled magnetic elements is greater than about 60 kBT at a storage temperature of about 300 K. The magnetic switching field distribution, SFD, of the exchange coupled magnetic elements is less than about 200% at a predetermined magnetic switching field and a predetermined assisting switching energy.Type: GrantFiled: March 31, 2011Date of Patent: July 9, 2013Assignee: Seagate Technology LLCInventors: Xiaobin Wang, Kaizhong Gao
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Publication number: 20130084469Abstract: A magnetic recording medium includes: a substrate, and a magnetic recording layer that is made from a material having the chemical formula of FexMnyPtz, and that has a bottom surface and an upper surface; wherein x, y, and z indicate average atomic concentrations for Fe, Mn, and Pt, and x+y+z is 100, x and y being greater than 0 and not greater than 65, z being in the range from 35 to 60; and wherein atomic concentration of Fe is gradually decreased from the upper surface to the bottom surface, and atomic concentration of Mn is gradually increased from the upper surface to the bottom surface so that the ferromagnetic property of the magnetic recording layer is gradually reduced from the upper surface to the bottom surface.Type: ApplicationFiled: June 11, 2012Publication date: April 4, 2013Inventors: Chih-Huang LAI, Hao-Cheng Hou, Chao-Chien Chiang
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Patent number: 8404369Abstract: A disk for a hard disk drive is provided. The disk comprises a substrate comprising aluminum, and a coating layer disposed over the substrate. The coating layer comprises an alloy of Ni, X1 and X2, wherein X1 comprises one or more elements selected from the group consisting of Ag, Au, B, Cr, Cu, Ga, In, Mn, Mo, Nb, Pb, Sb, Se, Sn, Te, W, Zn and Zr, and wherein X2 comprises either B or P, and wherein X1 and X2 do not comprise the same elements.Type: GrantFiled: August 3, 2010Date of Patent: March 26, 2013Assignee: WD Media, LLCInventors: Alan J. Ruffini, Lindsey A. Hamilton, Dorothea Buechel-Rimmel, Jean M. LaPlante, Ambrose Schaffer, Frederick Lowes
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Patent number: 8383254Abstract: An apparatus includes a substrate, a magnetically soft underlayer on the substrate, and a plurality of generally cubic FePt nanoparticles on the magnetically soft underlayer, wherein the nanoparticles have a magnetization in a direction substantially normal to a surface of the magnetically soft underlayer. The FePt nanoparticles can have magnetically easy axes perpendicular to the surface of the soft underlayer.Type: GrantFiled: September 28, 2010Date of Patent: February 26, 2013Assignee: Seagate Technology LLCInventors: Nisha Shukla, Timothy John Klemmer, Dieter Klaus Weller, Chao Liu
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Patent number: 8383253Abstract: Embodiments of the present invention produce discrete track media and bit patterned media having both excellent read/write performance and reliability. According to one embodiment, the medium comprises a magnetic layers formed by at least two ferromagnetic alloy layers with different compositions on a substrate. The ferromagnetic alloy layer located closest to the medium surface has more concentrated parts and less concentrated parts of nonmagnetic element in the in-plane direction. The more concentrated parts of the nonmagnetic element contain more nonmagnetic elements than the other parts except for an intermediate layer in the magnetic recording layer. The more concentrated parts and the less concentrated parts of the nonmagnetic element in the ferromagnetic alloy layer located closest to the medium surface are formed substantially concentric. The more concentrated parts of the nonmagnetic element is formed by being doped with ions of nonmagnetic element.Type: GrantFiled: February 18, 2009Date of Patent: February 26, 2013Assignee: HGST Netherlands B.V.Inventors: Tatsuya Hinoue, Hiroshi Kanai, Toshinori Ono, Hiroyuki Suzuki, Hiroshi Inaba
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Patent number: 8377580Abstract: A magnetic recording medium 1 includes a substrate 11; and a metallic glassy layer 12 that is arranged on the substrate 11 and has a plurality of convex portions 12A and concave portions 12B. The metallic glassy layer 12 has a chemical composition represented by any one of the formulae (1) to (3): FemPtnSixByPz (wherein, 20<m?60 at %, 20<n?55 at %, 11?x<19 at %, 0?y<8 at %, and 0<z<8 at %) (1); Fe55Pt25(SixByPz)20 (wherein, 11?x<19 at %, 0?y<8 at %, and 0<z<8 at %) (2); and (Fe0.55Pt0.25Si0.16B0.02P0.02)100-xMx (wherein 0<X?6 at %; and M represents an element or a combination of an two or more of the elements selected from Zr, Nb, Ta, Hf, Ti, Mo, W, V, Cr, Mn, Al, Y, Ag, and rare earth elements.) (3).Type: GrantFiled: September 17, 2008Date of Patent: February 19, 2013Assignee: Japan Science and Technology AgencyInventors: Akihiro Makino, Akihisa Inoue, Wei Zhang, Hisamichi Kimura
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Patent number: 8329319Abstract: The invention relates to a phase change magnetic composite material for use in an information recording medium, said material comprising a phase change material component, and a ferromagnetic material component, wherein said material exhibits both magnetic effects and phase change effects, and is usable for optical media, phase change random access memory (PCRAM) devices, magnetic random access memory (MRAM) devices, solid state memory devices, sensor devices, logical devices, cognitive devices, artificial neuron network, three level device, control device, SOC (system on chip) device, and semiconductors.Type: GrantFiled: October 17, 2005Date of Patent: December 11, 2012Assignee: Agency for Science, Technology and ResearchInventors: Luping Shi, Wendong Song, Xiangshui Miao, Tow Chong Chong
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Publication number: 20120214021Abstract: There is provided a magnetic recording medium including an MgO underlayer that can be formed by a mass production process and has a thickness of 3 nm or less as well as including a magnetic recording layer made of an L10-type FePt ordered alloy having excellent magnetic properties. A conductive compound having a crystal structure belonging to a cubic system is used as a material of an underlayer provided at the bottom of the MgO underlayer. The thickness of the MgO layer is 1 nm or more and 3 nm or less.Type: ApplicationFiled: February 2, 2012Publication date: August 23, 2012Inventors: Junichi Sayama, Ikuko Takekuma, Hiroaki Nemoto
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Publication number: 20120188663Abstract: An aspect of the present invention relates to a glass substrate for a magnetic recording medium, which is comprised of glass with a glass transition temperature of equal to or greater than 600° C., an average coefficient of linear expansion at 100 to 300° C. of equal to or greater than 70×10?7/° C., a Young's modulus of equal to or greater than 81 GPa, a specific modulus of elasticity of equal to or greater than 30 MNm/kg, and a fracture toughness value of equal to or greater than 0.9 MPa·m1/2.Type: ApplicationFiled: December 20, 2011Publication date: July 26, 2012Applicant: HOYA CORPORATIONInventors: Hideki ISONO, Kinobu OSAKABE, Katsuyuki IWATA, Mikio IKENISHI, Naomi MATSUMOTO
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Publication number: 20120141837Abstract: A magnetic recording medium for use in storing information is described, the medium comprising the use of a manganese-gallium alloy. More specifically, in one embodiment there is provided a magnetic recording medium comprising a substrate having a surface upon which is placed a magnetic recording layer, wherein the magnetic recording layer comprises a Manganese-Gallium alloy material with uniaxial anisotropy.Type: ApplicationFiled: December 1, 2011Publication date: June 7, 2012Applicant: The Provost Fellows, Foundation Scholars, & Other Members of Board, of the College of the Holy & UndInventors: Huseyin KURT, Karsten RODE, John Michael David COEY
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Patent number: 8158276Abstract: Disclosed are magnetic thin films, sputtering targets and vapor deposition materials, each of which is composed of 40-60 at % of Pt, 40-60 at % of Fe, 0.05-1.0 at % of P and furthermore depending on the occasions, 0.4-19.5 at % of Cu and/or Ni.Type: GrantFiled: August 3, 2007Date of Patent: April 17, 2012Assignee: Ishifuku Metal Industry Co., Ltd.Inventor: Koichi Hasegawa
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Patent number: 8119266Abstract: Provided are a magnetic recording medium substrate whereupon a magnetic layer can be regularly formed in a recording area, a magnetic recording medium and a method for manufacturing the magnetic recording medium substrate. A plurality of recording areas wherein the magnetic layer is to be formed are formed on the surface of the disk-shaped magnetic recording medium substrate. The size of the recording area is an integral multiple of a lattice constant of a unit lattice of a single crystal structure constituting the magnetic layer. For instance, the width of a protruding section (3) to be used as the recording area is an integral multiple of the lattice constant of the unit lattice of the single crystal structure configuring the magnetic layer.Type: GrantFiled: October 31, 2007Date of Patent: February 21, 2012Assignee: Konica Minolta Opto, Inc.Inventor: Hideki Kawai
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Patent number: 8105704Abstract: A memory is provided that is improved in cost, life, energy consumption and recording density over existing optical disks and hard disks and operates under novel principles, as well as its manufacturing method. A nonvolatile phase change magnetic memory comprises a substrate and a film loaded on the substrate, which film is of a crystalline transition metal chalcogenide compound that in composition is deficient in transition metal from its stoichiometric ratio composition and expressed by formula: AyX where A is a transition metal, X is a chalcogen element and 0<y<1, and in which film a minute portion subjected to a temperature history is made to form a ferromagnetic phase (1) or an antiferromagnetic phase (7) in which holes (4) for transition metal (2) are orderly or disorderly arranged and is stored with information as a magnetization based on the ferromagnetic phase (1) or antiferromagnetic phase (7).Type: GrantFiled: August 30, 2005Date of Patent: January 31, 2012Assignee: Japan Science and Technology AgencyInventors: Hidenori Takagi, Tomohiro Takayama
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Publication number: 20120019960Abstract: According to one embodiment, a bit patterned medium includes a substrate, and a magnetic recording layer disposed above the substrate and including patterns of protrusions. Each of the protrusions contains a plurality of crystal grains. An average distance between the crystal grains is 0.5 to 3.0 nm in each of the protrusions. The protrusions include first protrusions each having a length of 1 ?m or more in a radial direction of the medium and second protrusions each having a length in the radial direction shorter than the length of the first protrusion in the radial direction. Each of the first protrusions has a nucleation field Hn for magnetization reversal and a coercive force Hc satisfying the inequalities, Hn?1.5 kOe and 0.5 kOe?Hc?Hn?1.5 kOe.Type: ApplicationFiled: July 1, 2011Publication date: January 26, 2012Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Masatoshi Sakurai, Yousuke Isowaki, Soichi Oikawa
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Publication number: 20110308580Abstract: Ferroic materials and methods for diverse applications including nanoscale memory, logic and photovoltaic devices are described. In one aspect, ferroic thin films including insulating domains separated by conducting domain walls are provided, with both the insulating domains and conducting domain walls intrinsic to the ferroic thin films. The walls are on the order of about 2 nm wide, providing virtually two dimensional conducting sheets through the insulating material. Also provided are methods of writing, reading, erasing and manipulating conducting domain walls. According to various embodiments, logic and memory devices having conducting domain walls as nanoscale features are provided. In another aspect, ferroic thin films having photovoltaic activity are provided. According to various embodiments, photovoltaic and optoelectronic devices are provided.Type: ApplicationFiled: January 7, 2011Publication date: December 22, 2011Applicant: The Regents of the University of CaliforniaInventors: Jan Seidel, Ramamoorthy Ramesh, Lane Martin, Seung-Yeul Yang
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Perpendicular magnetic recording media with magnetic anisotropy gradient and local exchange coupling
Patent number: 8048545Abstract: A perpendicular magnetic recording medium adapted for high recording density and high data recording rate comprises a non-magnetic substrate having at least one surface with a layer stack formed thereon, the layer stack including a perpendicular recording layer containing a plurality of columnar-shaped magnetic grains extending perpendicularly to the substrate surface for a length, with a first end distal the surface and a second end proximal the surface, wherein each of the magnetic grains has: (1) a gradient of perpendicular magnetic anisotropy field Hk extending along its length between the first end and second ends; and (2) predetermined local exchange coupling strengths along the length.Type: GrantFiled: December 7, 2010Date of Patent: November 1, 2011Assignee: Seagate Technology LLCInventors: Shaoping Li, Kaizhong Gao, Lei Wang, Wenzhong Zhu, Xiaobin Wang -
Patent number: 8007931Abstract: A perpendicular magnetic recording medium including: a substrate; a perpendicular magnetic recording layer disposed over the substrate; a soft magnetic underlayer disposed between the substrate and the perpendicular magnetic recording layer; a shunting layer disposed under the soft magnetic underlayer; and an isolation layer disposed between the soft magnetic underlayer and the shunting layer and providing magnetic isolation between the shunting layer and the other layers disposed over the shunting layer are provided. The shunting layer is magnetically separated from the other magnetic layers disposed over the shunting layer, and shunts a magnetic field generated by the magnetic domain walls of the soft magnetic underlayer such that the magnetic field cannot reach a magnetic head, thereby increasing a signal-to-noise ratio (SNR).Type: GrantFiled: January 26, 2007Date of Patent: August 30, 2011Assignee: Samsung Electronics Co., Ltd.Inventors: Hoo-san Lee, Chee-kheng Lim, Hoon-sang Oh, Sok-hyun Kong
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Patent number: 7993766Abstract: A magnetic recording medium is provided in the present invention. The magnetic recording medium including a substrate; a base layer disposed on the substrate; an intermediate layer disposed on the base layer; and a recording layer disposed on the intermediate layer and including a magnetic matrix and a plurality of non-magnetic particles percolated in the magnetic matrix.Type: GrantFiled: March 25, 2008Date of Patent: August 9, 2011Assignee: Ching-Ray CHANGInventors: An-Cheng Sun, Po-Cheng Kuo, Jen-Hwa Hsu, Huei-Li Huang, Ching-Ray Chang
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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: 20110177360Abstract: A method of producing a perpendicular magnetic recording medium with a magnetic recording layer formed from ferromagnetic crystal grains and oxide-including non-magnetic crystal grain boundaries and provided on a non-magnetic substrate. The method is initiated by forming the magnetic recording layer by a reactive sputtering method using rare gas containing 2% by volume to 10% by volume (both inclusively) of oxygen gas at an initial stage of film formation. The method continues by successively forming the magnetic recording layer by reactive sputtering while reducing the concentration of the oxygen gas. The method may further include forming an undercoat layer of Ru or a Ru-alloy under the magnetic recording layer. In this manner, a granular magnetic layer having high characteristic coercive force (Hc) can be formed, while reducing the amount of expensive Pt or Ru required.Type: ApplicationFiled: January 10, 2011Publication date: July 21, 2011Applicant: Fuji Electric Device Technology Co., Ltd.Inventor: Naoki TAKIZAWA
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Publication number: 20110171494Abstract: The present invention discloses a discontinuous islanded ferromagnetic recording film with perpendicular magnetic anisotropy. The discontinuous islanded ferromagnetic recording film includes a substrate and a ferromagnetic layer. The ferromagnetic layer is formed on the substrate and annealed by a high-temperature vacuum annealing process. After annealing, a surface energy difference existed between the ferromagnetic layer and the substrate turns the ferromagnetic layer into well-separated and discontinuous islanded ferromagnetic particles. Each islanded ferromagnetic particle is thought of a single magnetic domain, which is beneficial to achieve a discontinuous islanded ferromagnetic recording film with perpendicular magnetic anisotropy.Type: ApplicationFiled: April 5, 2010Publication date: July 14, 2011Inventors: GER-PIN LIN, Po-Cheng Kuo, Sheng-Chi Chen, Chih-Lung Shen, Kai-Tze Huang, Ching-Ray Chang
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Publication number: 20110104517Abstract: The present invention discloses a single-layered recording film with perpendicular magnetic anisotropy. The single-layered recording film includes a substrate and a ferromagnetic layer. The ferromagnetic layer is formed on the substrate and annealed by a rapid thermal annealing process. After annealing, the average grain size of the single-layered recording film is close to the film thickness of ferromagnetic layer, which is beneficial to achieve a single-layered recording film with perpendicular magnetic anisotropy.Type: ApplicationFiled: March 23, 2010Publication date: May 5, 2011Inventors: SHENG-CHI CHEN, Chih-Lung Shen, Ger-Pin Lin, Ta-Huang Sun, Tsung-Yen Kuo, Po-Cheng Kuo, Ching-Ray Chang
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Patent number: 7923136Abstract: According to one embodiment, a magnetic recording medium includes magnetic patterns made of a ferromagnetic recording layer containing Co, and a nonmagnetic layer which separates the magnetic patterns and has a lower Co concentration than the magnetic patterns.Type: GrantFiled: April 28, 2009Date of Patent: April 12, 2011Assignee: Kabushiki Kaisha ToshibaInventors: Kaori Kimura, Yoshiyuki Kamata, Satoshi Shirotori, Masatoshi Sakurai
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Patent number: 7879466Abstract: The invention provides a perpendicular recording medium with high recording density, and a magnetic recording and reproducing apparatus, by improving the function of magnetic anisotropy of a soft magnetic underlayer. The perpendicular recording medium has at least a soft magnetic underlayer and a perpendicular magnetic recording layer on a non-magnetic substrate, wherein when Ku? (erg/cm3) is defined as a perpendicular magnetic anisotropic energy, and Ms (emu/cm 3) is defined as a saturation magnetization of the soft magnetic underlayer, Ku? of the soft magnetic underlayer has a negative value and Ku?<?2?Ms2. As a result, the easy axis of a magnetization of a soft magnetic underlayer is oriented strongly in the substrate surface plane, which is effective to suppress the WATE phenomena and spike noise.Type: GrantFiled: March 29, 2006Date of Patent: February 1, 2011Assignees: Tohoku University, Showa Denko K.K., Kabushiki Kaisha ToshibaInventors: Migaku Takahashi, Masahiro Oka, Akira Kikitsu
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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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Patent number: 7846564Abstract: A perpendicular magnetic recording medium adapted for high recording density and high data recording rate comprises a non-magnetic substrate having at least one surface with a layer stack formed thereon, the layer stack including a perpendicular recording layer containing a plurality of columnar-shaped magnetic grains extending perpendicularly to the substrate surface for a length, with a first end distal the surface and a second end proximal the surface, wherein each of the magnetic grains has: (1) a gradient of perpendicular magnetic anisotropy field Hk extending along its length between the first end and second ends; and (2) predetermined local exchange coupling strengths along the length.Type: GrantFiled: September 27, 2005Date of Patent: December 7, 2010Assignee: Seagate Technology LLCInventors: Shaoping Li, Kaizhong Gao, Lei Wang, Wenzhong Zhu, Xiaobin Wang
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Patent number: 7813071Abstract: A thermally assisted magnetic recording system is provided to achieve excellent thermal resistance and low noise. In one embodiment, a magnetic recording medium is used, in which the magnetic intergrain exchange coupling is large to let the magnetization be thermally stable by coupling the magnetic grains constituting the recording layer at room temperature (the temperature maintaining the magnetization) and reduced by heating during recording to let the recording magnetization transition slope become steep. Parameter A normalizing the slope around the coercivity of the MH-loop of the medium is 1.5?A<6.0 at room temperature, and it becomes approximately 1.0 with heating.Type: GrantFiled: October 2, 2008Date of Patent: October 12, 2010Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Fumiko Akagi, Masukazu Igarashi, Hideki Saga
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Publication number: 20100151275Abstract: This invention relates to a L10-ordered FePt nanodot array which is manufactured using capillary force lithography, to a method of manufacturing the L10-ordered FePt nanodot array and to a high density magnetic recording medium using the L10-ordered FePt nanodot array. This method includes depositing a FePt thin film on a MgO substrate, forming a thin film made of a polymer material on the deposited FePt thin film using spin coating, bringing a mold into contact with the spin coated FePt thin film, annealing the mold and a polymer pattern which are in contact with each other, cooling and separating the mold and the polymer pattern which are annealed, controlling a size of the polymer pattern through reactive ion etching, ion milling a portion of the FePt thin film uncovered with the polymer pattern thus forming a FePt nanodot array and then removing a remaining polymer layer, and annealing the FePt nanodot array.Type: ApplicationFiled: September 28, 2009Publication date: June 17, 2010Applicant: Korea Advanced Institute of Science and TechnologyInventors: Sung Chul SHIN, Hee-Tae JUNG, Hyun-Seok KO, Jin-Mi JUNG