With Post-treatment Of Coating Or Coating Material Patents (Class 427/130)
  • Patent number: 6821574
    Abstract: A multiple layer magnetic recording medium exhibiting a marked increase in skirt signal-to-noise ratios, and a method of manufacturing such magnetic recording medium including the steps of forming a lower support layer and a magnetic layer on the substrate; transporting the magnetic recording medium on a non-magnetic carrier in a transport direction; exposing the magnetic recording medium to a first magnetic field of up to about 2500 gauss when the average percent solids of the multiple layers is less than 40% collectively, and exposing the magnetic recording medium to at least one additional magnetic field of from about 3500 to about 7000 gauss as the magnetic recording medium continues to transport when the average percent solids of said multiple layers is from about 43% to about 60% collectively, wherein the magnetic pigment particles in said magnetic layer are oriented in a longitudinal direction.
    Type: Grant
    Filed: February 14, 2003
    Date of Patent: November 23, 2004
    Assignee: Imation Corp.
    Inventors: Stephen R. Ebner, Guy Tadlock
  • Patent number: 6821573
    Abstract: A flexible laminate, comprising: the light-active second layer acts without external energizing to change the properties of incident light such that the light reflected by this layer has signaling properties; a first layer serving as carrier layer; a light-active second layer situated on an outer surface of this laminate; and a permanent magnetic third layer for releasable magnetic attachment of the laminate to a ferromagnetic surface. The laminate has the feature that the light-active second layer acts without external energizing to change the properties of incident light such that the light reflected by this layer has signaling properties.
    Type: Grant
    Filed: January 24, 2001
    Date of Patent: November 23, 2004
    Assignee: Budev B.V.
    Inventor: Max G. Paping
  • Patent number: 6815098
    Abstract: A magnetic recording medium comprises, on a substrate, a soft magnetic layer, a first seed layer, a second seed layer, and a recording layer having an artificial lattice structure. The first seed layer contains oxide of Fe. The second seed layer contains one of Pd and Pt, Si, and N. The magnetic exchange coupling force in the in-plane direction of the recording layer is weakened by the first seed layer and the second seed layer. Accordingly, minute recording magnetic domains can be formed in the recording layer, and the magnetization transition area is distinct as well. Even when information is recorded at a high density, the information can be reproduced with low noise. A magnetic storage apparatus, which is provided with such a magnetic recording medium, makes it possible to achieve an areal recording density of 150 gigabits/square inch.
    Type: Grant
    Filed: April 11, 2003
    Date of Patent: November 9, 2004
    Assignee: Hitachi Maxell, Ltd.
    Inventors: Satoshi Matsunuma, Akira Yano, Tsuyoshi Onuma, Takanobu Takayama, Harumi Hieida, Kouichirou Wakabayashi
  • Patent number: 6815083
    Abstract: A perpendicular magnetic recording medium, which has a low level of recording noise and sufficiently large perpendicular magnetic anisotropy energy relative to demagnetizing field energy, includes a substrate and a multi-layered magnetic film. The multi-layered magnetic film is composed of ferromagnetic metal layers of Co alloy containing at least Cr and non-magnetic metal layers of Pd alloy, each one layer of which are laminated alternately on top of one layer of the other. The ferromagnetic metal layers and the non-magnetic metal layers have a thickness of d1 and d2, respectively, with the ratio of d1/d2 being in the range of 1.5 to 4.0. This specific layer structure reduces the magnetic exchange interaction between magnetic particles in the multi-layered magnetic film. Therefore, the perpendicular magnetic recording medium is stable against thermal disturbance and has a low level of recording noise.
    Type: Grant
    Filed: August 14, 2002
    Date of Patent: November 9, 2004
    Assignee: Hitachi, Ltd.
    Inventors: Hiroaki Nemoto, Hiroyuki Nakagawa, Yuzuru Hosoe
  • Patent number: 6808740
    Abstract: A magnetoresistance effect film includes a substrate, a plurality of ferromagnetic particles disposed on the substrate, a nonmagnetic film deposited on the substrate and covering the plurality of ferromagnetic particles, and a pair of electrodes arranged on the nonmagnetic film, in which the resistance across the pair of electrodes is changed by applying a magnetic field. The magnetoresistance effect film is manufactured by vapor-depositing ferromagnetic particle starting material on a substrate at a temperature not exceeding 300° C., the starting material being vapor-deposited in an amount enough to cover the substrate surface to a thickness ranging from 0.5 to 15 nm, and, after formation of ferromagnetic particles on the substrate, vapor-depositing at a temperature not exceeding room temperature a nonmagnetic film over the ferromagnetic particles, the nonmagnetic film having a thickness ranging from 1 to 100 nm, and providing a pair of electrodes each at a predetermined position on the nonmagnetic film.
    Type: Grant
    Filed: June 17, 2003
    Date of Patent: October 26, 2004
    Assignees: National Institute of Advanced Industrial Science and Technology, Hiroyuki Akinaga
    Inventors: Hiroyuki Akinaga, Masaharu Oshima, Masaki Mizuguchi
  • Patent number: 6805901
    Abstract: A method for manufacturing a magnetic domain wall displacement type magneto-optical medium includes forming a magnetic layer on a substrate and forming sectioning regions in which perpendicular magnetic anisotropy of the magnetic layer is reduced, and a plurality of belt-shaped recording tracks are sandwiched by the sectioning regions and are magnetically separated from each other by irradiating the magnetic layer on the substrate with a light beam or a charged particle beam of a wavelength of not more than 550 nm and scanning the light on the substrate in parallel and at a same interval and a magnetic domain wall displacement type magneto-optical medium.
    Type: Grant
    Filed: February 27, 2001
    Date of Patent: October 19, 2004
    Assignee: Canon Kabushiki Kaisha
    Inventor: Kazuyoshi Ishii
  • Patent number: 6805966
    Abstract: A dual-sided stamper/imprinter for simultaneously forming magnetic transition patterns in spaced-apart first and second layers of magnetic material by contact printing comprises a mechanically hard, substantially rigid magnetic material having high saturation magnetization and high permeability and including first and second oppositely facing imprinting surfaces, wherein each of the imprinting surfaced has a topographical pattern formed therein comprising a patterned plurality of spaced-apart recesses with a plurality of non-recessed areas therebetween, each topographical pattern corresponding to a magnetic transition pattern to be formed in a respective layer of magnetic material. Also disclosed is a method for manufacturing dual-sided stampers/imprinters.
    Type: Grant
    Filed: February 11, 2003
    Date of Patent: October 19, 2004
    Assignee: Seagate Technology LLC
    Inventors: Christopher Formato, Jing Gui
  • Publication number: 20040190201
    Abstract: Provided are a manufacturing method for a magnetic recording medium enabling efficient and reliable manufacturing of a magnetic recording medium with minimal surface roughness and good precision in recording and reading information, and a magnetic recording medium with a high degree of surface recording density and good precision in recording and reading information. The magnetic recording medium is constructed by forming a divided recording layer and the like onto a substantially flat base surface of a dummy, such that the base surface side of the dummy serves as a front surface, and a substrate is also attached, after which the dummy is removed.
    Type: Application
    Filed: March 25, 2004
    Publication date: September 30, 2004
    Applicant: TDK CORPORATION
    Inventors: Minoru Fujita, Shuichi Okawa, Mitsuru Takai
  • Patent number: 6797130
    Abstract: A magnetic disk is provided which comprises a nonmetallic glass or glass ceramic substrate having one or more under layers, a magnetic layer applied over the under layers, and a hard carbon layer applied over the magnetic layer. A plurality of bumps are formed on the magnetic disk by applying a beam from a near infrared wavelength laser to the surface of the carbon layer.
    Type: Grant
    Filed: June 27, 2003
    Date of Patent: September 28, 2004
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Iraj Kavosh, James Shuster, Andrew Ching Tam
  • Patent number: 6790509
    Abstract: A substrate for an information recording medium, wherein the period of microwaviness is 2 &mgr;m to 4 mm, and if we let wa be the maximum height of this microwaviness and Rmax be the maximum height measured by atomic force microscope, the main surface of the substrate has a wa of no more than 5 nm and an Rmax of no more than 12 nm, provided that wa is the difference between the highest and lowest points on a measurement curve of all measured points in a measurement area.
    Type: Grant
    Filed: October 4, 2001
    Date of Patent: September 14, 2004
    Assignee: Hoya Corporation
    Inventors: Tomotaka Yokoyama, Takemi Miyamoto, Hiroshi Tomiyasu, Kouji Takahashi
  • Patent number: 6790378
    Abstract: The present invention includes coating composition having magnetic properties for application to a substrate. The coating composition includes a plurality of strontium and or barium hexaferrite particles having a random magnetic pole alignment. The coating composition also includes a binder adhesive capable of suspending the strontium hexaferrite particles. The binder adhesive is a natural rubber capable of adhering in a substantially thin film to the substrate. The strontium hexaferrite particles are normally present between 50% to 98% of the coating composition's total weight when dried on the substrate. The thickness of the film of the coating composition ranges from 0.5 mils to 20 mils, and has 6 to 24 magnetic pole changes per linear inch. The binder adhesive allows for manipulation of the strontium hexaferrite particles to a non-random magnetic pole alignment after the ferromagnetic particles have dried in the binder adhesive on the substrate.
    Type: Grant
    Filed: October 5, 2001
    Date of Patent: September 14, 2004
    Inventors: R. William Graham, Daniel F. Peters, Charles E. Adams, Ricky L. Helton
  • Patent number: 6787251
    Abstract: A bi-crystal magnetic recording medium, i.e., medium with Cr(200) and Co(11.0) orientations, having a CrW-containing underlayer in which the W content increases for improved lattice matching with a Co-alloy magnetic layer has high coercivity, high SMNR and high areal recording density.
    Type: Grant
    Filed: August 5, 2002
    Date of Patent: September 7, 2004
    Assignee: Seagate Technology LLC
    Inventors: Zhong Stella Wu, Qixu David Chen, Samuel Dacke Harkness
  • Patent number: 6783889
    Abstract: The present invention provides a polyester film, which is composed of a polyester resin and a polyimide resin, having superior oligomer-restraining property and dimensional stability. This polyester film also has improved surface conditions, that is, has a reduced number of projections on the surface, and hence, the polyester film shows superior electromagnetic conversion characteristics when used for magnetic recording media. In particular, this polyester film is effectively used for high-density magnetic recording media. This film is composed of a polyester resin and a thermoplastic resin other than a polyester resin, and has a number H1 of coarse projections 0.28 &mgr;m or more in height of 0 to 100/100 cm2 on at least one surface of the polyester film and a number H2 of coarse projections 0.56 &mgr;m or more in height of 0 to 10/100 cm2 on the same surface.
    Type: Grant
    Filed: December 5, 2001
    Date of Patent: August 31, 2004
    Assignee: Toray Industries, Inc.
    Inventors: Akira Kubota, Kenichi Eto, Yukari Nakamori, Tetsuya Tsunekawa
  • Patent number: 6776883
    Abstract: A magnetic read head with reduced side reading characteristics is described. This design combines use of a current channeling layer (CCL) with stabilizing longitudinal bias layers whose magnetization direction is canted relative to that of the free layer easy axis and that of the pinned layer (of the GMR). This provides several advantages: First, the canting of the free layer at the side region results in a reduction of side reading by reducing magnetic sensitivity in that region. Second, the CCL leads to a narrow current flow profile at the side region, therefore producing a narrow track width definition. A process for making this device is described. Said process allows some of the requirements for interface cleaning associated with prior art processes to be relaxed.
    Type: Grant
    Filed: March 19, 2002
    Date of Patent: August 17, 2004
    Assignee: Headway Technologies, Inc.
    Inventors: Kochan Ju, You Feng Zheng, Mao-Min Chen, Cherng-Chyi Han, Charles Lin
  • Patent number: 6773745
    Abstract: A method of producing a magnetic recording medium comprising the step of forming a magnetic layer on a non-magnetic base film running at a constant speed by continuous oblique evaporation depositing metal vapor of volatilized metal incident obliquely to a surface of the non-magnetic base film, wherein the evaporation is conducted at a film forming rate, defined as an average deposition rate of the magnetic layer at a part of the non-magnetic base film exposed to the incident metal vapor, of not less than a predetermined rate to form an internal microstructure of the magnetic layer comprising columns each having a diameter of not more than about 15 nm constituted by magnetic particles having a size of not more than about 10 nm connected in chains in a direction substantially perpendicular to the magnetic layer and non-magnetic particles packed between the columns and separating the columns from each other, and a magnetic recording medium produced by the above method.
    Type: Grant
    Filed: August 14, 2002
    Date of Patent: August 10, 2004
    Assignee: Sony Corporation
    Inventors: Yuichi Arisaka, Junichi Tachibana, Takuya Ito, Yoh Iwasaki
  • Patent number: 6773556
    Abstract: A thin film magnetic recording medium, comprising: at least one ferromagnetic thin film recording layer comprising magnetic particles with substantially uniform barriers to magnetization reversal, formed by a process comprising steps of: (a) providing a precursor structure including at least one ferromagnetic thin film recording layer having a surface and a first, higher coercivity which may be greater than that which permits writing of the precursor structure, comprising magnetic particles having a distribution of energy barriers to magnetization reversal; and (b) uniformly bombarding the entire surface of the precursor structure with particles of sufficient dosage and energy to: (i) substantially equalize the energy barriers to magnetization reversal of the magnetic particles; (ii) lower the coercivity of the at least one ferromagnetic thin film recording layer from the first, higher coercivity to a second, lower coercivity within a range of coercivities permitting writing of the bombarded at least one
    Type: Grant
    Filed: April 25, 2002
    Date of Patent: August 10, 2004
    Assignee: Seagate Technology LLC
    Inventors: Richard Michael Brockie, Hans Jurgen Richter
  • Patent number: 6773764
    Abstract: A method for patterning a recording medium selectively thermally couples a recording medium and a heat source to alter a chemical composition of the recording medium. An apparatus for patterning a recording medium has a heat source for generating and directing an incident thermal wave to a recording medium so as to alter a chemical composition of the recording medium, and a controller for coordinating a mutual position of the incident thermal wave and the recording medium for inducing a direct thermal coupling between the recording medium and the heat source.
    Type: Grant
    Filed: January 3, 2002
    Date of Patent: August 10, 2004
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Ernesto E. Marinero, Hemantha K. Wickramasinghe
  • Patent number: 6773765
    Abstract: Disclosed is a process for making a flexible magnet with an induced anisotropy, and in particular to a process for making a flexible anisotropic magnet by thermal spraying in the presence of an applied magnetic field. The method may be used to fabricate a substrate having a flexible anisotropic magnetic coating or a free standing anisotropic flexible magnet.
    Type: Grant
    Filed: November 4, 1999
    Date of Patent: August 10, 2004
    Assignee: The Research Foundation of State University of New York
    Inventors: Richard J. Gambino, Dongil Shin, Jeffrey A. Brogan
  • Patent number: 6770386
    Abstract: A magnetic recording medium with a high recording density has a first ferromagnetic layer, a non-magnetic layer, and a second ferromagnetic layer successively deposited as the recording layer on a non-magnetic substrate. The recording layer is heated in concentric circular shapes to divide it into regions in which the magnetic interactions between the ferromagnetic layers exhibit ferromagnetism and regions that exhibit anti-ferromagnetism. The ferromagnetic regions are used for recording tracks, and the anti-ferromagnetic regions function as guard bands. In this manner track density is increased without roughening the surface of the recording medium.
    Type: Grant
    Filed: September 1, 2000
    Date of Patent: August 3, 2004
    Assignee: Fujitsu Limited
    Inventors: Yoshiaki Hara, Takahiko Sugawara, Yutaka Shimizu, Takuya Uzumaki, Atsushi Tanaka
  • Publication number: 20040146684
    Abstract: The optical disk has the resin material layer provided between the metal layer of the first substrate and the thin layer of the material capable of transmitting light of a predetermined wavelength of the second substrate. The resin material layer has different properties imparted thereto between a location close to the opening and a location away from the opening.
    Type: Application
    Filed: December 23, 2003
    Publication date: July 29, 2004
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventor: Nobuhisa Yoshida
  • Patent number: 6767655
    Abstract: The present invention provides a vertical current-type magneto-resistive element. The element includes an intermediate layer and a pair of magnetic layers sandwiching the intermediate layer, and at least one of a free magnetic layer and a pinned magnetic layer is a multilayer film including at least one non-magnetic layer and magnetic layers sandwiching the non-magnetic layer. The element area defined by the area of the intermediate layer through which current flows perpendicular to the film is not larger than 1000 &mgr;m2.
    Type: Grant
    Filed: August 16, 2001
    Date of Patent: July 27, 2004
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Masayoshi Hiramoto, Nozomu Matukawa, Akihiro Odagawa, Kenji Iijima, Hiroshi Sakakima
  • Patent number: 6759081
    Abstract: A structure and method of fabricating a magnetic read head, comprises forming a fill layer for a magnetic read head gap using atomic layer deposition (ALD). The fill layer comprises an insulator, preferably aluminum oxide, aluminum nitride, mixtures thereof and layered structures thereof. Materials having higher thermal conductivity than aluminum oxide, such as berylium oxide and boron nitride, can also be employed in layers within an aluminum oxide structure. The thickness of the ALD-formed head gap fill layer is between approximately 5 nm and 100 nm, preferably between approximately 10 nm and 40 nm.
    Type: Grant
    Filed: April 30, 2002
    Date of Patent: July 6, 2004
    Assignee: ASM International, N.V.
    Inventors: Juha Huganen, Tapio Kanniainen
  • Patent number: 6759084
    Abstract: It is important for a CPP GMR read head that it have both high resistance as well as high cross-sectional area. This has been achieved by inserting a NOL (nano-oxide layer) though the middle of one or both of the two non-magnetic conductive layers. A key feature is that the NOL is formed by first depositing the conductive layer to about half its normal thickness. Then a metallic film is deposited thereon to a thickness that is low enough for it to still consist of individual islands. The latter are then fully oxidized without significantly oxidizing the conductive layer on which they lie. The remainder of the conductive layer is then deposited to a thickness sufficient to fully enclose the islands of oxide.
    Type: Grant
    Filed: June 5, 2003
    Date of Patent: July 6, 2004
    Assignee: Headway Technologies, Inc.
    Inventors: Kochan Ju, Min Li, Simon Liao, Jeiwei Chang
  • Patent number: 6759097
    Abstract: Methods and devices for producing images on coated articles are provided. The methods generally comprise applying a layer of magnetizable pigment coating in liquid form on a substrate, with the magnetizable pigment coating containing a plurality of magnetic non-spherical particles or flakes. A magnetic field is then applied to selected regions of the pigment coating while the coating is in liquid form, with the magnetic field altering the orientation of selected magnetic particles or flakes. Finally, the pigment coating is solidified, affixing the reoriented particles or flakes in a non-parallel position to the surface of the pigment coating to produce an image such as a three dimensional-like image on the surface of the coating. The pigment coating can contain various interference or non-interference magnetic particles or flakes, such as magnetic color shifting pigments.
    Type: Grant
    Filed: December 23, 2002
    Date of Patent: July 6, 2004
    Assignee: Flex Products, Inc.
    Inventors: Roger W. Phillips, Charlotte R. LeGallee, Charles T. Markantes, Paul G. Coombs, Matthew R. Witzman
  • Patent number: 6756071
    Abstract: A GMR spin valve is provided for reading a magnetic signal from a magnetic recording medium. The spin valve includes a non-magnetic layer such as for example copper, separated by first and second magnetic layers. The spin valve includes a pinned magnetic layer and a free magnetic layer, the resistance of the spin valve changing with the relative angle between the direction of magnetization of free and pinned layers. Extremely smooth surfaces are provided at the interfaces between the non-magnetic layer and the adjacent magnetic layers. This smooth interface greatly enhances the performance and reliability of the spin valve by allowing extremely tight control of the thickness of the non-magnetic layer and by preventing atomic diffusion between the non-magnetic and magnetic layers. This smooth interface is achieved by including a surfactant in the deposition of the non-magnetic layer.
    Type: Grant
    Filed: September 12, 2002
    Date of Patent: June 29, 2004
    Assignee: Western Digital (Fremont), Inc.
    Inventors: Zhupei Shi, Ming Mao, Qunwen Leng
  • Patent number: 6753043
    Abstract: A servo-patterned magnetic recording medium, comprising: a magnetic layer having a surface with substantially uniform topography, the magnetic layer including a data zone and a servo pattern, the servo pattern comprising: (a) a first patterned plurality of regions of first, higher values of magnetic coercivity Hc and magnetic remanence-thickness product Mrt; and (b) a second patterned plurality of ion-implanted regions of second, lower values of Hc. and Mrt; wherein the second, lower values of Hc and Mrt are sufficiently lower than the first, higher values of Hc and Mrt as to permit sensing for enabling accurate positioning of a read/write transducer head in the data zone but sufficiently high for providing the medium with thermal stability, high amplitude of magnetic transition, and high signal-to-noise ratio.
    Type: Grant
    Filed: October 12, 2001
    Date of Patent: June 22, 2004
    Assignee: Seagate Technology LLC
    Inventors: David S. Kuo, Xinwei Li
  • Patent number: 6743465
    Abstract: This invention provides a magnetic optical member that can obtain a large magneto-optical effect using a rare-earth iron-garnet-based material and a method of producing the same.
    Type: Grant
    Filed: October 12, 2001
    Date of Patent: June 1, 2004
    Assignee: Minebea Co., Ltd.
    Inventors: Mitsuteru Inoue, Toshitaka Fujii, Akio Takayama, Atsushi Kitamura, Shigeyuki Adachi, Hideki Kato
  • Patent number: 6743529
    Abstract: A process for producing a glass substrate for a magnetic recording medium by forming a surface roughness in a main surface of a glass plate that has been formed into a disk shape, includes: imparting a processing mark having a permanent strain to the main surface of the glass plate in a circumferential direction thereof; and chemically etching the whole main surface of the glass plate, so as to form the surface roughness.
    Type: Grant
    Filed: December 17, 2001
    Date of Patent: June 1, 2004
    Assignee: Nippon Sheet Glass Co., Ltd.
    Inventors: Yasuhiro Saito, Hiroshi Ikeda, Junji Kurachi, Kazuishi Mitani
  • Patent number: 6740414
    Abstract: The disclosed invention provides a high-reliability magnetic recording apparatus, magnetic recording medium, and a method of manufacturing such a medium in a high-density magnetic recording apparatus which comprises a magnetic disk revolving at a high speed and a magnetic head which flies as low as possible over the magnetic disk. A lubricant layer formed on the outermost surface of a magnetic recording medium is constituted by a lubricant which comprises fluoropolyether as the principal ingredient. The fluoropolyether lubricant is characterized in that alcohol hydration distribution which corresponds to difference between the greatest and smallest alcohol valences among the component molecules of the fluoropolyether is adjusted to 0.48 or less and an average alcohol valence among the component molecules is adjusted to fall within a range of 3.00 to 3.91.
    Type: Grant
    Filed: February 20, 2003
    Date of Patent: May 25, 2004
    Assignee: Hitachi, Ltd.
    Inventor: Toru Yatsue
  • Patent number: 6740353
    Abstract: A process for producing a magnetic recording medium having a non-magnetic layer on a non-magnetic support and having a magnetic layer on the non-magnetic layer is provided. A process for producing a magnetic recording medium which comprises applying a non-magnetic layer coating material onto a non-magnetic support and drying the coating material to form a non-magnetic layer, and then applying a magnetic layer coating material more excessively than an intended magnetic layer-wet thickness onto the non-magnetic layer by using a die nozzle coating followed by scraping excess amounts of the magnetic layer coating material to the intended magnetic layer-wet thickness by means of a bar to form a magnetic coating layer.
    Type: Grant
    Filed: May 4, 2001
    Date of Patent: May 25, 2004
    Assignee: TDK Corporation
    Inventor: Hideki Sasaki
  • Patent number: 6730395
    Abstract: A fundamentally new magnetic tunnel junction technology based on the use of magnetic nanoparticles is disclosed. The hard layer of the device is composed of the nanoparticles, while the junction insulating barrier is composed of a carbon-based coating on the nanoparticles. This device offers a markedly different approach of tunnel junction fabrication and offers many advantages over the prior art technology, which is based on the use of oxidized aluminum as the insulating barrier.
    Type: Grant
    Filed: December 18, 2001
    Date of Patent: May 4, 2004
    Assignee: Seagate Technology LLC
    Inventor: Mark William Covington
  • Patent number: 6720036
    Abstract: A production method of the present invention is a method of producing a spin valve type giant magnetoresistive thin film. In this production method, a buffer layer, an antiferromagnetic layer, a fixed magnetization layer, a nonmagnetic conductive layer, a free magnetization layer, and a protective layer are consecutively stacked on a substrate. Furter, plasma treatment is performed on predetermined stacked interfaces in the spin valve type giant magnetoresistive thin film to reduce the interlayer coupling magnetic field acting between the fixed magnetization layer and the free magnetization layer and to obtain a high MR ratio. The above production method can achieve both of the high MR ratio and low interlayer coupling magnetic field (Hin) in the thin film produced.
    Type: Grant
    Filed: September 10, 2002
    Date of Patent: April 13, 2004
    Assignee: Anelva Corporation
    Inventors: Koji Tsunekawa, Daisuke Nakajima
  • Patent number: 6716489
    Abstract: A manufacturing method of a domain wall displacement type magneto-optical recording medium comprises the steps of depositing a magnetic layer on a substrate to prepare a disc, and irradiating the magnetic layer with a converged light beam while applying a magnetic field and annealing the magnetic layer a converged light beam between information tracks.
    Type: Grant
    Filed: January 14, 2002
    Date of Patent: April 6, 2004
    Assignee: Canon Kabushiki Kaisha
    Inventor: Yasuyuki Miyaoka
  • Patent number: 6716488
    Abstract: A ferrite layer formation process that may be performed at a lower temperature than conventional ferrite formation processes. The formation process may produce highly anisotropic structures. A ferrite layer is deposited on a substrate while the substrate is exposed to a magnetic field. An intermediate layer may be positioned between the substrate and the ferrite to promote bonding of the ferrite to the substrate. The process may be performed at temperatures less than 300° C. Ferrite film anisotropy may be achieved by embodiments of the invention in the range of about 1000 dyn-cm/cm3 to about 2×106 dyn-cm/cm3.
    Type: Grant
    Filed: June 22, 2001
    Date of Patent: April 6, 2004
    Assignee: Agere Systems Inc.
    Inventors: Debra Anne Fleming, Gideon S. Grader, David Wilfred Johnson, Jr., John Thomson, Jr., Robert Bruce Van Dover
  • Publication number: 20040058198
    Abstract: A method of manufacturing a magnetic recording medium comprises steps of providing a non-magnetic substrate for a magnetic recording medium, the substrate including at least one major surface; forming a layer of a sol-gel on the at least one major surface; forming a pattern, e.g., a servo pattern in an exposed surface of the layer of said sol-gel; and converting the layer of sol-gel to a glass or glass-like layer while preserving the pattern in an exposed surface of said glass or glass-like layer. Embodiments of the invention include magnetic media including a patterned glass or glass-like layer formed from a layer of a hydrophilic sol-gel with the pattern embossed therein by means of a stamper having a hydrophilic surface including a negative image of the pattern.
    Type: Application
    Filed: September 16, 2003
    Publication date: March 25, 2004
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Hong Ying Wang, Neil Deeman, Gene Gauzner
  • Publication number: 20040058060
    Abstract: A method of manufacturing a magnetic recording medium, comprises steps of providing a non-magnetic substrate for a magnetic medium, the substrate including at least one major surface having a contact start/stop (CSS) or landing zone and a data zone; and forming a pattern of recesses in the substrate surface in said CSS or landing zone by embossing utilizing a stamper having a surface including a negative image pattern of said pattern of recesses. Embodiments of the invention include magnetic media comprising a non-magnetic substrate including at least one major surface having a contact start/stop (CSS) or landing zone and a data zone, said substrate surface in said CSS or landing zone comprising an embossed pattern of recesses. In addition, the data zone of the substrate surface may include an embossed servo pattern formed simultaneously with the embossed pattern of recesses formed in the landing zone.
    Type: Application
    Filed: September 25, 2003
    Publication date: March 25, 2004
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: James Edward Angelo, Mukund Channagiri Rao, Alexi Hiram Sacks, Timothy Francis Ellis, David Kuo, Serge Jacques Fayeulle
  • Patent number: 6709745
    Abstract: A method for effectively decreasing electromagnetic radiation by means of active absorbing material in a broad frequency band, preferably from 100 MHz-10 GHz, is provided wherein the material combines the desired shielding properties with the heat insulating properties of a porous material in addition to providing a favourable ratio between density and resistance. The method includes use of an absorber granulate which consists of a highly porous glass and/or ceramic granulate which is coated or filled with ferrite and/or an electrically conductive material.
    Type: Grant
    Filed: August 13, 2002
    Date of Patent: March 23, 2004
    Assignees: Hermsdorfer Institut Fuer Technische Karamik E.V., Colfirmit Rajasil GmbH & Co. KG
    Inventors: Josef Kuchler, Jan-Thomas Kuehnert, Klaus Kupfer, Stefan Rossmayer, Wolfgang Schoeps, Hans-Werner Zier
  • Patent number: 6706318
    Abstract: A perpendicular magnetic recording media and method of manufacturing therefore includes a nonmagnetic substrate, an underlayer deposited on the nonmagnetic substrate, and a magnetic recording layer formed on the underlayer, quickly heated, and quenched. A protective layer is deposited on the magnetic recording layer, and a liquid lubricant layer is deposited on the protective layer, to improve an uniaxial anisotropy Ku and a coercive force Hc of the magnetic recording layer.
    Type: Grant
    Filed: July 5, 2002
    Date of Patent: March 16, 2004
    Assignee: Fuji Electric Co., Ltd.
    Inventors: Shunji Takenoiri, Yasushi Sakai
  • Patent number: 6699332
    Abstract: A method of producing a magnetic recording medium comprising the steps of providing a substrate having a layer of a non-magnetic material that can be converted into a magnetic state by annealing, and then converting selected portions of the non-magnetic layer to a magnetic state by subjecting them to annealing by directing a focussed beam of radiation onto the substrate to form a patterned magnetic layer comprising an ordered array of magnetic regions separated by non-magnetic regions.
    Type: Grant
    Filed: November 13, 2000
    Date of Patent: March 2, 2004
    Assignee: Data Storage Institute
    Inventors: Seidikkurippu N. Piramanayagam, Jian Ping Wang
  • Patent number: 6699601
    Abstract: A magnetic recording medium which has higher S/N and lower manufacturing cost includes a first underlayer including at least one of Co or Cu and P on a non-magnetic substrate, a second underlayer consisting of a non-magnetic material using Cr, and a magnetic layer on the second underlayer.
    Type: Grant
    Filed: March 15, 2000
    Date of Patent: March 2, 2004
    Assignee: Fujitsu Limited
    Inventors: Kenji Sato, Yuki Yoshida
  • Patent number: 6699602
    Abstract: An amorphous magnetic recording medium comprising a substrate and an amorphous magnetic layer, where a magnetic domain formation-controlling layer comprising a main phase and 1 to 3 kinds of discrete spherical isolating phases arranged horizontally in lines in the main phase or 1 to 3 kinds of discrete spherical phases vertically stacked one upon another in the main phase is formed on the top side or the bottom side directly or through at least one of other layers to bring the amorphous magnetic layer into a finer magnetic domain structure, can satisfy high density recording.
    Type: Grant
    Filed: March 1, 2002
    Date of Patent: March 2, 2004
    Assignee: Hitachi Maxell, Ltd.
    Inventors: Mitsutoshi Honda, Hiroki Yamamoto, Takashi Naito, Tatsumi Hirano, Tetsuo Nakazawa, Fumiyoshi Kirino, Teruaki Takeuchi, Akira Yano, Nobuyuki Inaba, Satoshi Matsunuma
  • Patent number: 6689496
    Abstract: A magnetic recording medium includes a substrate, a nonmagnetic seed layer provided on the substrate, and a magnetic layer provided on the nonmagnetic seed layer via one or a plurality of layers. The nonmagnetic seed layer is made of NiAl having an oxygen concentration of approximately 1500 to 4000 ppm.
    Type: Grant
    Filed: November 20, 2000
    Date of Patent: February 10, 2004
    Assignee: Fujitsu Limited
    Inventors: Haruhiro Komura, Yuki Yoshida, Hisashi Umeda, Iwao Okamoto
  • Patent number: 6686019
    Abstract: A method of in situ stabilizing a composite lubricant in order to reduce or subtantially eliminate phase separation of the components of the composite lubricant, comprising sequential steps of: (a) providing a substrate including a surface; (b) applying a thin layer or film of the composite lubricant to the substrate surface, the composite lubricant comprising at least two lubricant components which are normally mutually immiscible; and (c) treating the thin layer or film of composite lubricant solely with UV radiation for an interval sufficient to reduce or substantially eliminate phase separation of the at least two normally mutually immiscible lubricant components. Embodiments of the invention include magnetic and magneto-optical (MO) media including stabilized composite lubricant layers formed in situ according to the inventive process.
    Type: Grant
    Filed: November 13, 2001
    Date of Patent: February 3, 2004
    Assignee: Seagate Technology LLC
    Inventors: Jianwei Liu, Michael Joseph Stirniman
  • Patent number: 6682834
    Abstract: A magnetic storage medium includes a magnetic layer of a Co alloy of a system Co—Cr—Pt—B—Cu, wherein the magnetic layer has a thickness t and a remnant magnetic flux density Br satisfying a relationship (t×Br) 2.0 nT·m≦(t×Br)≦7.0 nT·m, wherein the Co alloy contains, in addition to Co, Cr with a concentration &bgr; of 20-26 at % (20 at %≦&bgr;≦26 at %), Pt with a concentration &ggr; of 6-20 at % (6 at %≦&ggr;≦20 at %), B with a concentration &dgr; of 1-7 at % (1 at %≦&dgr;≦7 at %), and Cu with a concentration &egr; of 2-7 at % (2 at %≦&egr;≦7 at %).
    Type: Grant
    Filed: March 13, 2001
    Date of Patent: January 27, 2004
    Assignee: Fujitsu Limited
    Inventors: Chiaki Okuyama, Reiko Murao, Atsushi Endo, Akira Kikuchi
  • Patent number: 6680079
    Abstract: A magnetic recording medium is formed with a distribution of servo-marks in the form of pits or indentations with an attendant reduction in potential corrosion and increased tribology. Embodiments providing a protective overcoat, e.g. containing carbon, over a magnetic recording medium having a servo-patterned substrate; applying a fluoropolyether comprising one or more acrylate groups on the protective overcoat by dip coating the magnetic recording medium in a solution of the fluoropolyether and polymerizing the fluoropolyether by ultraviolet radiation.
    Type: Grant
    Filed: June 4, 2001
    Date of Patent: January 20, 2004
    Assignee: Seagate Technology LLC
    Inventors: Michael Stirniman, Li-Ping Wang, Gary Rauch
  • Patent number: 6677023
    Abstract: A non-magnetic substrate for a magnetic recording medium is formed or molded within a die. The die is designed to define embedment depressions on the surface of the resulting non-magnetic substrate. Any bumps or lugs formed on the inner surface of the die can be employed to form the embedment depressions on the non-magnetic substrate. A magnetic material fills the individual embedment depression so as to establish a magnetic block embedded into the surface of the non-magnetic substrate. The magnetic block can be utilized as a positional mark in a tracking servo control for a corresponding read/write head in a magnetic storage system.
    Type: Grant
    Filed: March 20, 2001
    Date of Patent: January 13, 2004
    Assignee: Fujitsu Limited
    Inventors: Hiroto Takeshita, Hitoshi Komoriya
  • Patent number: 6676813
    Abstract: A method for coating the tip of a mechanical resonator for use in magnetic force microscopy and magnetic resonance force microscopy in which the tip is coated with a ferromagnetic material and the cantilever is not, and the product resulting from the method. A cantilever and incorporated tip are coated with a photoresist, except that surface tension keeps photoresist off the tip. The cantilever and tip are then coated with a magnetic material. Next, acetone is used to lift off the magnetic material from the cantilever but not from the tip.
    Type: Grant
    Filed: March 13, 2002
    Date of Patent: January 13, 2004
    Assignee: The Regents of the University of California
    Inventors: Denis V. Pelekhov, P. Chris Hammel, Geoffrey Nunes, Jr., Melissa M. Midzor, Michael Roukes
  • Patent number: 6673474
    Abstract: A medium substrate comprising a borosilicate glass containing silica as a main component and having on the surface thereof a continuous texture derived from the porous structure, the medium substrate being used as a substrate in the production of a magnetic recording medium and other. The method for the production of the textured medium substrate is also disclosed, along with a magnetic recording medium using the medium substrate and a magnetic disk device.
    Type: Grant
    Filed: March 27, 2001
    Date of Patent: January 6, 2004
    Assignee: Fujitsu Limited
    Inventor: Kenrou Yamamoto
  • Patent number: RE38474
    Abstract: A magnetic layer structure with a layer of cobalt-chromium-platinum-boron composite alloy containing 10% to 20% B in the magnetic layer. The useful magnetic properties of the magnetic layer structure are achieved by the incorporation of a nucleation layer prior to the deposition of the magnetic layer. The resultant magnetic layer structures have coercivity Hc values in between 2,000 and 5,000 Oe, grain sizes between 30 and 200 Angstroms and anisotropic crystallographic orientation with the c-axis of the cobalt-chromium-platinum-boron in the plane of the medium. These magnetic layer structures are suitable for magnetic data storage devices including magnetic disks.
    Type: Grant
    Filed: August 27, 2002
    Date of Patent: March 23, 2004
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: David T. Margulies, Ernesto E. Marinero, Hal J. Rosen, Brian R. York, Kurt A. Rubin
  • Patent number: RE38544
    Abstract: A Co-Pt based magnetic alloy which has been doped with a relatively high amount of nitrogen, e.g., or above 1 at. % is obtained having high coercivity, for example in the range of 1400 Oe or above, and an increased signal-to-noise ratio as compared to the same Co-Pt based alloy which has not been doped with nitrogen. The alloy is vacuum deposited, for example, by sputtering, and the nitrogen may be introduced from the sputtering gas or from the sputtering target. Other low-solubility elements providing the grain uniformity and isolation include: B, P, S, C, Si, As, Se and Te.
    Type: Grant
    Filed: July 17, 2000
    Date of Patent: July 6, 2004
    Assignee: Komag, Inc.
    Inventors: Tu Chen, Tsutomu Tom Yamashita, Rajiv Yadav Ranjan, John Ko-Chen Chen, Keith Kadokura, Ting Joseph Yuen