Patents Examined by Lisa Chau
  • Patent number: 8475947
    Abstract: A perpendicular magnetic recording medium, which includes a first magnetic recording layer, a second magnetic recording layer, and a third magnetic recording layer disposed sequentially on a nonmagnetic substrate, and a coupling layer formed between the first and second magnetic recording layers. The first, second and third magnetic recording layers have an easy axis of magnetization in a direction perpendicular to a film plane of the nonmagnetic substrate. The first and second magnetic recording layers are ferromagnetically coupled via the coupling layer.
    Type: Grant
    Filed: March 6, 2008
    Date of Patent: July 2, 2013
    Assignee: Fuji Electric Co., Ltd.
    Inventors: Akira Sato, Shunji Takenoiri, Yasushi Sakai
  • Patent number: 8420236
    Abstract: A magnetic semiconductor material contains at least one type of transition metals (Mn2+, Fe3+, Ru3+, Re2+, and Os3+) having five electrons in the d atomic orbital as a magnetic ion, in which the magnetic semiconductor material exhibits n-type electrical conduction by injection of an electron carrier and p-type electric conduction by injection of a hole carrier. A specific example is a layered oxy-pnictide compound represented by LnMnOPn (wherein Ln is at least one type selected from Y and rare earth elements of La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu, and Pn is at least one selected from pnicogen elements of N, P, As, Bi, and Sb). A high-sensitivity magnetic sensor, current sensor, or memory device can be made by using a magnetic pn homojunction structure made of thin films composed of the magnetic semiconductor material.
    Type: Grant
    Filed: August 1, 2006
    Date of Patent: April 16, 2013
    Assignee: Japan Science and Technology Agency
    Inventors: Hideo Hosono, Masahiro Hirano, Hidenori Hiramatsu, Toshio Kamiya, Hiroshi Yanagi, Eiji Motomitsu
  • Patent number: 8338006
    Abstract: A method for planarizing a magnetic recording disk that has surface features of elevated lands and recessed grooves includes forming two coatings of cured perfluorinated polyether (PFPE) polymers over the surface features. The disk may have a protective carbon overcoat with a surface that replicates the topography of lands and grooves. A liquid functionalized-PFPE is applied over the disk surface and then cured to form a first coating with the functionalized end groups bonding to the carbon overcoat. A liquid non-functionalized-PFPE polymer is then applied over the functionalized-PFPE coating and cured to form a second coating. The combined coatings substantially planarize the disk surface so that there is minimal recession between the top of the coating over the lands and the top of the coating over the grooves.
    Type: Grant
    Filed: June 10, 2008
    Date of Patent: December 25, 2012
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Qing Dai, Xing-Cai Guo, Dan Saylor Kercher, Mike Suk
  • Patent number: 8313847
    Abstract: Information storage devices are provided. An information storage device includes a track including at least one Co alloy layer and a soft magnetic layer. The track further includes a plurality of magnetic domains. A current applying element is connected to the track. The track includes a plurality of layers stacked alternately.
    Type: Grant
    Filed: June 12, 2008
    Date of Patent: November 20, 2012
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Young-jin Cho, Ji-young Bae, Sung-chul Lee
  • Patent number: 8277961
    Abstract: A magnetic recording medium for thermally assisted recording is disclosed which achieves both high density writing and good control of temperature characteristics. The magnetic recording medium for thermally assisted recording comprises an underlayer, a magnetic recording layer, and a protective layer sequentially laminated on a nonmagnetic substrate. The magnetic recording layer has a structure composed of two magnetic layers and an exchange coupling control layer inserted between the magnetic layers, the two magnetic layers being magnetically coupled through the exchange coupling control layer. The coupling energy Jw in the process of writing a signal and the coupling energy Jr in the state of retaining a signal satisfy a relation 0<Jw<Jr.
    Type: Grant
    Filed: September 19, 2008
    Date of Patent: October 2, 2012
    Assignee: Fuji Electric Co., Ltd.
    Inventor: Sadayuki Watanabe
  • Patent number: 8270110
    Abstract: A magnetic head includes a side shield layer and an encasing layer. The side shield layer has a first end face located in the medium facing surface, a second end face opposite to the first end face, and a first groove accommodating a portion of a pole layer. The first end face includes two portions located on both sides of an end face of the pole layer that are opposite to each other in a track width direction. The encasing layer is formed of a nonmagnetic material and disposed on a side of the side shield layer opposite to a medium facing surface. The encasing layer has a front end face touching the second end face of the side shield layer, and a second groove accommodating another portion of the pole layer. The distance from the medium facing surface to an arbitrary point on the second end face of the side shield layer decreases with decreasing distance from the arbitrary point to the top surface of a substrate.
    Type: Grant
    Filed: December 29, 2008
    Date of Patent: September 18, 2012
    Assignee: Headway Technologies, Inc.
    Inventors: Hironori Araki, Yoshitaka Sasaki, Hiroyuki Ito, Shigeki Tanemura, Kazuo Ishizaki, Takehiro Horinaka
  • Patent number: 8263239
    Abstract: A laminated magnetic recording structure for use in perpendicular or longitudinal recording is described. A small amount of ferromagnetic coupling is added between the two magnetic layers that are sufficiently decoupled to switch independently. In one embodiment the coupling is achieved by doping the spacer layer with a ferromagnetic material. Ruthenium (Ru), which is a preferred nonmagnetic material for spacer layers with cobalt (Co) being the preferred magnetic material. The weak ferromagnetic coupling can also be achieved through the use of platinum, palladium and alloys thereof for the spacer layer without the addition of a ferromagnetic element, but alternatively they can also be doped with ferromagnetic elements. For embodiments for perpendicular recording the spacer layer further can additionally comprise oxides of one or more elements selected from the group consisting of Si, Ta, Ti, Nb, Cr, V and B.
    Type: Grant
    Filed: June 26, 2006
    Date of Patent: September 11, 2012
    Assignee: HGST Netherlands B.V.
    Inventors: Andreas Klaus Berger, Hoa Van Do, Eric Edward Fullerton, David Thomas Margulies, Natacha Frederique Supper
  • Patent number: 8257840
    Abstract: The present invention provides a security functional thin film and a security product containing such a thin film. The security functional thin film is of an amorphous structure, and possesses soft magnetic characteristics. Large Barkhausen effect can be detected along the in-plane preferred direction of magnetization; and the Large Barkhausen effect significantly attenuates, or no such signal can be detected, in a direction perpendicular to the in-plane preferred direction of magnetization. The thin film has a thickness of 20-300 nm, and the thin film also possesses element encoding characteristics that can be authenticated by experts. The security functional thin film of the present invention can be fabricated by magnetron sputtering web coating process.
    Type: Grant
    Filed: March 24, 2008
    Date of Patent: September 4, 2012
    Assignee: China Banknote Printing And Minting Corporation
    Inventors: Xiaowei Li, Xinyu Li, Ce Li, Jing Yang, Feng Pan, Caixia Li, Yu Cao
  • Patent number: 8231987
    Abstract: Example embodiments may provide data storage devices using movement of magnetic domain walls including a first magnetic layer having at least two magnetic domains with determinable magnetization directions, and/or a soft second magnetic layer formed on a lower surface of the first magnetic layer. Magnetic domain walls may be moved even in curved regions of the first magnetic layer.
    Type: Grant
    Filed: December 11, 2007
    Date of Patent: July 31, 2012
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Chee-kheng Lim
  • Patent number: 8163405
    Abstract: Multiple anisotropy layered magnetic structures for controlling reversal mechanism and tightening of switching field distribution in bit patterned media are disclosed. The invention extends the exchange spring concept to more variable and sophisticated structures. Three or more layers with different anisotropy or anisotropy gradients increase writeability gains beyond the simple hard/soft bilayer exchange spring concept for BPM. The structures have a thin very hard, high anisotropy center layer that acts as a threshold or pinning layer for domain wall propagation through the entire media structure. In addition or alternatively, a thin very soft, low anisotropy center layer in between the commonly used soft surface layer and hard media layer allows quick initial propagation of the domain wall into the center of the media structure. Various properties of the media structures can be tuned more independently for optimization if using more advanced multi-anisotropy layer stacks.
    Type: Grant
    Filed: March 27, 2009
    Date of Patent: April 24, 2012
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Thomas Hauet, Olav Hellwig, Manfred Ernst Schabes
  • Patent number: 8071228
    Abstract: Embodiments of the present invention provide a perpendicular magnetic recording medium which does not cause medium noise to increase due to soft magnetic underlayers, is capable of easily controlling the thickness of a nonmagnetic layer disposed between soft magnetic underlayers, and capable of improving the corrosion resistance of the soft magnetic underlayers. According to one embodiment, in a perpendicular magnetic recording medium, an adhesion layer is formed on a substrate, a soft magnetic underlayer is formed on the adhesion layer, a seed layer and an intermediate layer are formed above the soft magnetic underlayer, and a perpendicular layer is formed on the intermediate layer.
    Type: Grant
    Filed: November 9, 2007
    Date of Patent: December 6, 2011
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Reiko Arai, Hiroyuki Suzuki, Masayoshi Shimizu
  • Patent number: 8029921
    Abstract: A semiconductor device including a ferrite layer, a widebandgap semiconductor material layer, and a buffer layer. The buffer layer comprises an interweaving of MgO and BaM. In addition the buffer layer allows a gradual reduction of the interfacial stress, and mediates the strain between a silicon substrate and a ferrite layer of the device. In addition, the buffer layer allows for high crystal alignment resulting in high crystal quality and thereby producing a low microwave loss semiconductor device. The buffer layer also minimizes chemical interdiffusion of atoms between the substrate and the ferrite layer.
    Type: Grant
    Filed: October 4, 2006
    Date of Patent: October 4, 2011
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Vincent G Harris, Zhaohui Chen
  • Patent number: 8003236
    Abstract: A method for making a master mold to be used for nanoimprinting patterned-media magnetic recording disks results in a master mold having topographic pillars arranged in a pattern of annular bands of concentric rings. The ratio of circumferential density of the pillars to the radial density of the concentric rings in a band is greater than 1. The method uses sidewall lithography to first form a pattern of generally radially-directed pairs of parallel lines on the master mold substrate, with the lines being grouped into annular zones or bands. The sidewall lithography process can be repeated, resulting in a doubling of the number of lines each time the process is repeated. Conventional lithography is used to form concentric rings over the radially-directed pairs of parallel lines. After etching and resist removal, the master mold has pillars arranged in circular rings, with the rings grouped into annular bands.
    Type: Grant
    Filed: June 17, 2008
    Date of Patent: August 23, 2011
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Thomas R. Albrecht, Barry Cushing Stipe, Henry Hung Yang
  • Patent number: 7981528
    Abstract: A water-repelling layer is formed on a resin film, and a stripe pattern region is formed so as to be positioned within a surface region of the water-repelling layer and so as to be relatively hydrophilic with respect to water repellency of the water-repelling layer. A magnetic stripe pattern is formed of needle-shaped magnetic grains oriented and aggregated in the stripe pattern region. The needle-shaped magnetic grains are arranged in a desirable state in a predetermined stripe pattern, with a high magnetic permeability and a magnetic sheet with stripe-arranged magnetic grains that is thin and flexible is obtained.
    Type: Grant
    Filed: August 31, 2007
    Date of Patent: July 19, 2011
    Assignee: Panasonic Corporation
    Inventors: Seiichi Nakatani, Yoshihisa Yamashita, Takashi Ichiryu, Koichi Hirano
  • Patent number: 7943248
    Abstract: Perpendicular magnetic recording media enabling high-density recording and reproduction of information, as well as a production process thereof, and a magnetic recording and reproducing apparatus, are provided. Perpendicular magnetic recording media, having at least a soft magnetic underlayer and perpendicular magnetic recording layer on a disc-shaped nonmagnetic substrate, in which the soft magnetic underlayer has at least two soft magnetic layers, and Ru or Re between the two soft magnetic layers, are provided; the easy axis of magnetization of the soft magnetic underlayer has a desired direction; the easy axis of magnetization of the soft magnetic underlayer is substantially distributed in a direction except a radial direction of the nonmagnetic substrate, and, the bias magnetic field of the antiferromagnetic coupling in the direction of the easy axis of magnetization of the soft magnetic underlayer is 10 Oersteds (790 A/m) or greater.
    Type: Grant
    Filed: January 31, 2006
    Date of Patent: May 17, 2011
    Assignees: Tohoku University, Showa Denko K.K., Kabushiki Kaisha Toshiba
    Inventors: Migaku Takahashi, Masahiro Oka, Akira Kikitsu
  • Patent number: 7919200
    Abstract: This rare earth magnet having high strength and high electrical resistance has a structure including an R—Fe—B-based rare earth magnet particles 18 which are enclosed with a high strength and high electrical resistance composite layer 12. The high strength and high electrical resistance composite layer 12 is constituted from a glass-based layer 16 that has a structure comprising a glass phase or R oxide particles 13 dispersed in glass phase, and R oxide particle-based mixture layers 17 that are formed on both sides of the glass-based layer 16 and contain an R-rich alloy phase 14 which contains 50 atomic % or more of R in the grain boundary of the R oxide particles.
    Type: Grant
    Filed: June 9, 2006
    Date of Patent: April 5, 2011
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Katsuhiko Mori, Ryoji Nakayama, Muneaki Watanabe, Koichiro Morimoto, Tetsurou Tayu, Yoshio Kawashita, Makoto Kano
  • Patent number: 7862914
    Abstract: Metal alloy heatsink films for magnetic recording media are disclosed. The metal alloy heatsink films possess both high thermal conductivity and improved mechanical properties such as relatively high hardness. The metal alloy heatsink films also have controlled microstructures which are compatible with subsequently deposited crystalline magnetic recording layers. The films may comprise single phase CuZr or AgPd alloys having a selected crystal structure and orientation. The combination of high thermal conductivity, good mechanical properties and controlled microstructures makes the metal alloy heatsink films suitable for various applications including heat assisted magnetic recording systems.
    Type: Grant
    Filed: July 26, 2005
    Date of Patent: January 4, 2011
    Assignee: Seagate Technology LLC
    Inventors: Yukiko Kubota, Bin Lu, Jai-Young Kim, Julius Kurt Hohlfeld
  • Patent number: 7820307
    Abstract: A recording paper having a magnetic material-containing layer, that includes a magnetic material that generates a large Barkhausen effect and a filler, and is disposed between pulp layers containing a pulp.
    Type: Grant
    Filed: February 29, 2008
    Date of Patent: October 26, 2010
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Eizo Kurihara, Tsukasa Matsuda, Mario Fuse, Shoji Yamaguchi, Kunihiro Takahashi
  • Patent number: 7781082
    Abstract: A magnetic material is provided that has an iron oxide phase whose principal phase is a crystal of a structure which has the same space group as ?-Fe2O3 crystal and in which Al is substituted for a portion of the Fe sites of the ?-Fe2O3 crystal. The molar ratio of Al to Fe in the iron oxide phase, when expressed as Al:Fe=x:(2?x), satisfies 0?x?1. The value of x is preferably in the range of 0.3 to 0.7. The average particle diameter of the powder determined from a TEM image is preferably 5 to 200 nm, more preferably 10 to 100 nm. The magnetic material has very high practical value because it enables the extremely high coercive force Hc of the ?-Fe2O3 crystal to be regulated to a level enabling utilization in magnetic recording medium and various other applications. The magnetic powder can be produced by a method combining the reverse micelle method and the sol-gel method.
    Type: Grant
    Filed: August 28, 2007
    Date of Patent: August 24, 2010
    Assignees: The University of Tokyo, Dowa Electronics Materials Co., Ltd.
    Inventors: Shin-ichi Ohkoshi, Shunsuke Sakurai, Shiro Kuroki, Kimitaka Sato, Shinya Sasaki
  • Patent number: 7771846
    Abstract: An ME composite laminate of at least one (1-3) piezo-fiber layer coupled with high-permeability alloy magnetostrictive layers, optionally formed of FeBSiC or equivalent. The composite laminate alternates the (1-3) piezo-fiber and high-permeability alloy magnetostrictive layers in a stacked manner. Optionally, the magnetization direction of the high-permeability alloy magnetostrictive layers and polarization direction of the piezo-fiber layer are an (L-L) arrangement. Optionally, thin film polymer layers are between the (1-3) piezo-fiber layer and high-permeability alloy magnetostrictive layers. Optionally, piezo-electric fibers within the (1-3) piezo-fiber layer are poled by inter-digitated electrodes supported by the thin film polymer, arranged as alternating symmetric longitudinally-poled “push-pull” units.
    Type: Grant
    Filed: August 1, 2007
    Date of Patent: August 10, 2010
    Assignee: Virginia Tech Intellectual Properties, Inc.
    Inventors: Dwight Viehland, Shuxiang Dong, Jie-Fang Li, Junyi Zhai