Magnetic Feature Patents (Class 428/900)
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Patent number: 6340521Abstract: A magnetic medium is formed with a barrier layer between the magnetic layer and protective overcoat to prevent degradation of magnetic properties during deposition of the protective overcoat due to poisoning effects by reactive gases on the magnetic layer. Embodiments include sputter depositing a Cr or Cr alloy barrier layer, having a thickness of about 5 Å to about 25 Å, on a magnetic layer and sputter depositing a protective overcoat containing carbon and nitrogen on the barrier layer in a nitrogen-containing environment.Type: GrantFiled: November 9, 1999Date of Patent: January 22, 2002Assignee: Seagate Technology LLCInventors: Phuong Nguyen, Thanh Ha, Elsie Yang Chuang
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Patent number: 6338896Abstract: The present invention provides a magnetic recording medium, which comprises a magnetic layer having ferromagnetic powder dispersed in a binder on a non-magnetic support member, wherein the non-magnetic support member is made of aromatic polyamide, an undercoating layer is provided between said non-magnetic support member and a lower non-magnetic layer, or between the non-magnetic support member and the magnetic layer, said undercoating layer comprising polyamide resin having tertiary amino group and containing repeated structural units expressed by the following formulae (1) and (2).Type: GrantFiled: March 29, 1999Date of Patent: January 15, 2002Assignee: Fuji Photo Film Co., Ltd.Inventors: Katsuhiko Meguro, Tatsuo Ishikawa, Hiroshi Hashimoto
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Patent number: 6338911Abstract: A reproduction layer, a magnetic domain extending layer, an intermediate layer, and a recording layer are formed in this order. The magnetic domain extending layer, the intermediate layer, and the recording layer are exchange-coupled. The intermediate layer has a Curie temperature lower than that of any other magnetic layer. A non-magnetic intermediate layer is formed between the reproduction layer and the magnetic domain extending layer. Upon reproduction, magnetization information in the recording layer is transferred to and extended in the magnetic domain extending layer, where an extended magnetic domain is formed. The reproduction layer is magnetostatically coupled with the magnetic domain extending layer, so that the extended magnetic domain is transferred to the reproduction layer.Type: GrantFiled: October 29, 1999Date of Patent: January 15, 2002Assignee: Sharp Kabushiki KaishaInventors: Go Mori, Naoyasu Iketani, Michinobu Mieda, Akira Takahashi
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Patent number: 6338899Abstract: Disclosed are a high-sensitivity and high-reliability magnetoresistance effect device (MR device) in which bias point designing is easy, and also a magnetic head, a magnetic head assembly and a magnetic recording/reproducing system incorporating the MR device. In the MR device incorporating a spin valve film, the magnetization direction of the free layer is at a certain angle to the magnetization direction of a second ferromagnetic layer therein when the applied magnetic field is zero. In this, the pinned magnetic layer comprises a pair of ferromagnetic films as antiferromagnetically coupled to each other via a coupling film existing therebetween.Type: GrantFiled: June 14, 1999Date of Patent: January 15, 2002Assignee: Kabushiki Kaisha ToshibaInventors: Hideaki Fukuzawa, Yuzo Kamiguchi, Katsuhiko Koui, Shin-ichi Nakamura, Hitoshi Iwasaki, Kazuhiro Saito, Hiromi Fuke, Masatoshi Yoshikawa, Susumu Hashimoto, Masashi Sahashi
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Patent number: 6335081Abstract: In a tunnel magnetoresistance effect element comprising a tunnel multilayered film on an under layer, the tunnel multilayered film has a tunnel barrier layer, a ferromagnetic free layer and a ferromagnetic pinned layer such that the tunnel barrier layer is held between the ferromagnetic free layer and the ferromagnetic pinned layer, wherein three indexes representing a surface roughness state of a surface, which faces the tunnel multilayered film, of the under layer are set such that Ra ≦0.5 nm, Rmax ≦5 nm and Rrms ≦0.55 nm, wherein Ra is one of the three indexes and represents the center line average roughness, Rmax is one of the three indexes and represents the maximum height, and Rrms is one of the three indexes and represents the standard deviation roughness. Thus, the tunnel magnetoresistance effect element exhibits improved characteristics, particularly, a large head output.Type: GrantFiled: July 21, 2000Date of Patent: January 1, 2002Assignee: TDK CorporationInventors: Satoru Araki, Koji Shimazawa, Haruyuki Morita
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Patent number: 6335080Abstract: Lower cost magnetic recording media and disk drive systems including an improved polymeric or polymeric-based disk substrate are provided by increasing the substrate thickness sufficient to provide mechanical rigidity comparable to that provided by an aluminum-based substrate of similar diameter and forming the CSS zone on the surface of the disk at the outer rather than inner diameter thereof, with a plurality of integrally formed projections extending from the disk surface for reducing heating during head takeoff and landing. The projections are coated with diamond-like carbon (DLC) and lubricant layers for reducing heating and friction during CSS operation and providing good tribological performance when utilized with a cooperating head slider having DLC contact pads.Type: GrantFiled: December 29, 1999Date of Patent: January 1, 2002Assignee: Seagate Technology LLCInventors: Joel Weiss, Koji Shima, Zine-Eddine Boutaghou
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Patent number: 6333111Abstract: The present invention provides a method for producing layered aluminum fine particles, and applications to single electron tunneling quantum devices, and the present invention further relates to a method for producing spherical metallic aluminum fine particles (layered aluminum fine particles), characterized in that metallic aluminum is supplied into a mixed gas of helium and 1×10−7 to 3×10−7 torr water vapor by sputtering induced by argon gas discharge to generate aggregates, after which this product is released into a vacuum to generate single crystals in which the surface layer is covered with alumina.Type: GrantFiled: March 13, 2000Date of Patent: December 25, 2001Assignee: Agency of Industrial Science and TechnologyInventors: Junichi Murakami, Yutaka Tai, Kazuki Yoshimura, Kazuo Igarashi, Sakae Tanemura, Masahiro Goto
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Patent number: 6333113Abstract: Cards which contain any one of the following thermoplastic resin compositions I to III in its material can be used as magnetic cards, IC cards, etc. since they are excellent in heat resistance, processability and embossability: a composition consisting of ingredients (A) and (B); a composition consisting of ingredients (A), (B) and (D); and a composition consisting of 100 parts by weight of one or more selected from the following ingredients (A), (B) and (D) and 2 to 25 parts by weight of the following ingredient (C), wherein ingredient (A) is a polyester composed of dicarboxylic acid components with terephthalic acid component as a main dicarboxylic acid component and ethylene glycol component (I) and 1,4-cyclohexanedimethanol component (II) as main glycol components, wherein the molar ratio (I)/(II) of ethylene glycol component (I) to 1,4-cyclohexanedimethanol component (II) is 1 or more; ingredient (B) is an aromatic polycarbonate; ingredient (C) is an inorganic sheet-like filler of 0.Type: GrantFiled: April 13, 1998Date of Patent: December 25, 2001Assignee: Toray Industries, Inc.Inventors: Ryuichi Sugie, Toru Nishimura, Motoki Hiratsuka
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Patent number: 6331363Abstract: A bulk amorphous metal magnetic component has a plurality of layers of amorphous metal strips laminated together to form a generally three-dimensional part having the shape of a polyhedron. The bulk amorphous metal magnetic component may include an arcuate surface, and preferably includes two arcuate surfaces that are disposed opposite each other. The magnetic component is operable at frequencies ranging from between approximately 60 Hz and 20,000 Hz and exhibits a core-loss of between less than or equal to approximately 1 watt-per-kilogram of amorphous metal material for a flux density of 1.4 T and when operated at a frequency of approximately 60 Hz, and a core-loss of less than or approximately equal to 70 watts-per-kilogram of amorphous metal material for a flux density of 0.30T and when operated at a frequency of approximately 20,000 Hz.Type: GrantFiled: November 6, 1998Date of Patent: December 18, 2001Assignee: Honeywell International Inc.Inventors: Nicholas John DeCristofaro, Peter Joseph Stamatis
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Patent number: 6331342Abstract: A magnetic recording medium according to the present invention includes a nonmagnetic supporting base, a nonmagnetic layer coated on the nonmagnetic supporting base, and a magnetic layer coated on the nonmagnetic layer. A mean roughness from a center line as a surface roughness of the nonmagnetic supporting base ranges from 8.0 nm to 15 nm. A mean particle size of carbon black contained in the nonmagnetic layer is set to 300 nm or smaller. A thickness of the coated nonmagnetic layer obtained after it is dried is set smaller than 0.5 &mgr;m.Type: GrantFiled: July 7, 1997Date of Patent: December 18, 2001Assignee: Sony CorporationInventor: Satoru Inoue
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Patent number: 6331364Abstract: A patterned magnetic recording disk, i.e., a disk with discrete magnetically recordable regions that can function as discrete magnetic bits, is formed by ion irradiating a continuous magnetic film of a chemically-ordered alloy having a tetragonal crystalline structure through a patterned non-contact mask. The ions cause disordering in the film and produce regions in the film that have no magnetocrystalline anisotropy. The regions of the film not impacted by the ions retain their chemical ordering and magnetocrystalline anisotropy and thus serve as the discrete magnetic regions that can be recorded as individual magnetic bits. The chemically-ordered alloy is preferably Co (or Fe) and Pt (or Pd) with the c-axis of the tetragonal crystalline film oriented at an angle less than 45 degrees relative to the plane of the film, so that after patterning the discrete magnetic regions can be recorded by horizontal magnetic recording.Type: GrantFiled: July 9, 1999Date of Patent: December 18, 2001Assignees: International Business Machines Corporation, University of New Orleans FoundationsInventors: John Edward Eric Baglin, Andrew John Kellock, Bruce David Terris, Dieter Klaus Weller, Liesl Folks
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Patent number: 6329037Abstract: A magnetic recording medium includes at least a substrate, a recording layer formed of a non-magnetic underlying layer and a ferromagnetic thin film, deposited on the substrate, and a protective layer and a lubricant layer overlying the recording layer, a laminate layer is used as the protective layer, wherein a Young's modulus in a head pressing direction is twice or more larger than a Young's modulus in a head running direction. In this way, the durability of the magnetic disk can be significantly improved, and consequently, the protective layer can be made extremely thin, so that it can also contribute to an increased recording density.Type: GrantFiled: April 14, 2000Date of Patent: December 11, 2001Assignee: Hitachi, Ltd.Inventors: Yuuichi Kokaku, Yoshinori Honda, Toshinori Ono
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Patent number: 6329818Abstract: The present invention is characterized in that a first giant magnetoresistive effect element and a second giant magnetoresistive effect element are provided along a first straight line with the magnetization of the pinned magnetic layer c oriented in a fixed direction, and that a third giant magnetoresistive effect element and a fourth giant magnetoresistive effect element are provided along a second straight line, which is parallel to the first straight line, with the magnetization of the pinned magnetic layer oriented 180° opposite to the directions of magnetization of the pinned magnetic layers in the first and second giant magnetoresistive effect elements.Type: GrantFiled: July 14, 1999Date of Patent: December 11, 2001Assignee: Alps Electric Co., Ltd.Inventors: Ichirou Tokunaga, Seiji Kikuchi, Yoshito Sasaki, Takashi Hatanai
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Patent number: 6326087Abstract: A rare earth metal-based permanent magnet has a metal oxide film formed on the surface thereof by a sol-gel coating process. The rare earth metal-based permanent magnet is produced by forming a metal oxide film on the surface thereof by a sol-gel coating process. The metal oxide film is thin and dense. The adhesion of the film to the surface of the magnet is excellent. The film exhibits an excellent corrosion resistance. Typical examples of the metal oxide films are Al, Si, Ti and Zr oxide films. An interfacial layer with an R (rare earth element) atom chemically bonded with a film forming metal atom through an oxygen atom is formed between the metal oxide film and the entire surface of the magnet.Type: GrantFiled: December 15, 1999Date of Patent: December 4, 2001Assignee: Sumitomo Special Metals Co., Ltd.Inventors: Takeshi Nishiuchi, Fumiaki Kikui
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Patent number: 6326092Abstract: A magnetoresistance device comprising at least two ferromagnetic layers separated by a non-magnetic layer, the coercive force of one of the ferromagnetic layers being enhanced by a coercive force enhancement layer of an antiferromagnetic material disposed adjacent to the one of the ferromagnetic layer thereby pinning magnetization inversion in the one of the ferromagnetic layer, the other ferromagnetic layer serving as a free ferromagnetic layer in which magnetization inversion is allowed, wherein the spin orientation in the coercive force enhancement layer is aligned in a multilayer fashion into a direction substantially parallel to the plane of the coercive force enhancement layer. A method of producing such a device is also disclosed.Type: GrantFiled: June 13, 2000Date of Patent: December 4, 2001Assignee: Alps Electric Co., Ltd.Inventors: Kazuaki Ikarashi, Naoya Hasegawa, Akihiro Makino
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Patent number: 6322676Abstract: Magnetic composites exhibit distinct flux properties due to gradient interfaces. The composites can be used to improve fuel cells and effect transport and separation of different species of materials. A variety of devices can be made utilizing the composites including a separator, a cell, an electrode for channeling flux of magnetic species, an electrode for effecting electrolysis of magnetic species, a system for channeling electrolyte species, a system for separating particles with different magnetic susceptibilities. Some composites can be used to make a dual sensor for distinguishing between two species of materials and a flux switch to regulate the flow of a redox species and a flux switch to regulate the flow of a chemical species. Some composites can control chemical species transport and distribution.Type: GrantFiled: March 25, 1998Date of Patent: November 27, 2001Assignee: University of Iowa Research FoundationInventors: Johna Leddy, Sudath Amarasinghe
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Patent number: 6322880Abstract: A magnetic recording medium is provided with a dual protective overcoat system, comprising a foundation layer and a carbon overcoat thereon, for improved tribological properties at very low glide heights and long term durability. Embodiments include magnetic recording media comprising a silicon oxide foundation layer over a magnetic layer and an amorphous hydrogenated carbon or an amorphous hydrogen-nitrogenated carbon overcoat on the foundation layer. Other embodiments include magnetic recording media with a foundation layer comprising silicon nitride over a magnetic layer and an amorphous hydrogenated carbon or an amorphous hydrogen-nitrogenated carbon overcoat on the foundation layer.Type: GrantFiled: June 17, 1999Date of Patent: November 27, 2001Assignee: Seagate Technology LLCInventor: Ga-Lane Chen
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Patent number: 6322911Abstract: The present invention provides a spin-valve magnetic resistance sensor in which an underlayer, which has a second underlayer film with an fcc structure consisting of an alloy formed by combining one or more elements selected from a set consisting of elements of group VIIIa and group Ib of the periodic table, and one or more elements selected from a set consisting of elements of groups IIa, IVa, Va, VIa, IIb, Ib and IVb of the periodic table, such as NiFeCrTi or NiCrTi, etc., is formed on the substrate, and a magnetic resistance (MR) film which has an antiferromagnetic layer consisting of a Pt1−xMnx alloy or an Ir1−xMnx alloy is laminated on top of this underlayer. The composition ratio of the element with the smallest free energy of oxide formation among the elements contained in the alloy of the second underlayer film is in the range of 0.1 atomic % to 15 atomic %.Type: GrantFiled: February 1, 2000Date of Patent: November 27, 2001Assignee: Read-Rite CorporationInventors: Tomoki Fukagawa, Hiroshi Nishida, Masanori Ueno, Masateru Nose, Hideyasu Nagai, Fuminori Higami
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Patent number: 6319622Abstract: Magnetoresistive and spin valve heads have a layered structure. Common to each of the layered structures of these heads is the combination of a soft-magnetic layer of essentially NiFe near a spacer layer of essentially Ta, which is used for insuring (111) crystal orientation of the NiFe layer. An isolate layer is interposed between the spacer layer and the soft-magnetic layer to prevent a diffusion boundary from being created at the interface of these layers which tends to degrade the soft-magnetic property of the NiFe layer, especially when the thickness of the soft-magnetic layer is 10 and nm or less.Type: GrantFiled: August 4, 2000Date of Patent: November 20, 2001Assignee: Hitachi, Ltd.Inventors: Satoshi Shigematsu, Takao Imagawa, Koichi Nishioka, Hiroshi Kamio, Katsuhisa Usami
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Patent number: 6319624Abstract: In the resin roll 5 for calendering a magnetic recording medium, a surface portion 3a of a thermosetting resin outer layer 3 has high storage elastic modulus (E′) of 5×1010 to 5×1011 dyn/cm2 at a temperature of 50° to 150° C. at a frequency of 10 hertz (Hz). At the surface portion of the thermosetting resin outer layer, the expression representing the relation between storage elastic modulus (E′) and the Poisson's ratio (&ngr;) is within the following range, under the same conditions: 2×10−12 cm2/dyn<(1−&ngr;2)/E′<2×10−11 cm2/dyn.Type: GrantFiled: February 17, 1998Date of Patent: November 20, 2001Assignee: Yamauchi CorporationInventors: Atsuo Watanabe, Kenjiro Nakayama, Tatsuyuki Abe
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Patent number: 6319583Abstract: Magneto-optical information storage media having improved tribological properties when used in high-density storage devices employing very small head flying heights are formed by providing by a protective overcoat/lubricant topcoat layer system on the media surface. Embodiments of the present invention include forming the protective overcoat layer of an amorphous, abrasion resistant, carbon-based, diamond-like material less than about 50 Å thick selected from CNx, CHx, and CNxHy, and forming the lubricant topcoat at a thickness of 15-25 Å, of a medium molecular weight linear chain perfluoro polyalkylene polymer having reactive end groups for bonding the polymer molecules to the protective overcoat layer.Type: GrantFiled: March 16, 1999Date of Patent: November 20, 2001Assignee: Seagate Technology LLCInventor: Ga-Lane Chen
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Patent number: 6319623Abstract: A magneto-optical recording medium is disclosed with which magneto-optical recording is performed by a magnetic-field modulation method and which enables stable recording characteristics to be realized even if the intensity of the recording magnetic field is somewhat changed. When a magneto-optical recording medium incorporating a signal recording layer made of TbFeCoCr and arranged such that a magneto-optical recording operation is performed with respect to the signal recording layer by the magnetic-field modulation method is manufactured, the signal recording layer is formed such that the total quantity of Tb and Cr contained in the signal recording layer is 24±1 at %. After the signal recording layer has been formed, exposure to stem by 30×10−6 Torr·sec to 10000×10−6 Torr·sec or exposure to oxygen by 10×10−6 Torr·sec to 50×10−6 Torr·sec is performed to oxidize the surface of the signal recording layer.Type: GrantFiled: February 4, 2000Date of Patent: November 20, 2001Assignee: Sony CorporationInventors: Etsuro Ikeda, Hiroshi Miura
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Patent number: 6316097Abstract: Magnetic recording media including an alternative substrate material having a Young's Modulus greater than that of Al-based substrate materials and a preselected average surface roughness (Ra) are formed by depositing a continuous, adherent, non-magnetic, catalytically active layer on a surface of the substrate and electrolessly plating an amorphous seed layer on the catalytically active layer, the Ra of the resultant surface of the amorphous seed layer being reduced from that of the substrate, thereby providing a substantially defect-free surface for deposition thereon of magnetic recording media layers thereon. Embodiments include sputter depositing an catalytically active layer of Ni—Al or Ni—P and electrolessly plating an amorphous seed layer of Ni—P thereon.Type: GrantFiled: September 15, 1999Date of Patent: November 13, 2001Assignee: Seagate Technology LLCInventors: Connie C. Liu, Linda L. Zhong, Jeff D. St. John, Samuel D. Harkness, Qixu Chen
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Patent number: 6316131Abstract: The heavily-doped silver chalcogenides, Ag2+&dgr;Se and Ag2+&dgr;Te, show magnetoresistance effects on a scale comparable to the “colossal” magnetoresistance (CMR) compounds. Hall coefficient, magnetoconductivity, and hydrostatic pressure experiments establish that elements of narrow-gap semiconductor physics apply, but both the size of the effects at room temperature and the linear field dependence down to fields of a few Oersteds are surprising new features.Type: GrantFiled: September 10, 1998Date of Patent: November 13, 2001Assignee: The United States of America as represented by the United States Department of EnergyInventors: Marie-Louis Saboungi, David C. L. Price, Thomas F. Rosenbaum, Rong Xu, Anke Husmann
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Publication number: 20010038161Abstract: A fastening component of a separable fastener has some portion that is necessary for its fastening function, such as the hooks, the base to which the hooks are attached or a substrate that is used for another purpose, comprised of a magnetically attractive constituent. Another portion of the fastening component is comprised of a magnetically inert constituent. The fastening element may be the hook portion or the loop portion of a typical fastener. The fastening elements and the base may be unitary, or of different precursors, such as in a woven fastener component. The magnetically inert constituent may comprise a polymeric plastic or a thermoplastic elastomer. The magnetic attractant may impregnate the magnetically inert constituent, or it may coat or be coated by the magnetically inert constituent. The magnetic attractant may comprise a metal powder. The metal may be selected from the group consisting of iron powder. The magnetic attractant may be an organo-iron or a rare earth metal.Type: ApplicationFiled: June 29, 2001Publication date: November 8, 2001Applicant: Velcro Industries B.V., a Neitherlands corporationInventors: Randall B. Kenney, Brian J. Routhier, Martin I Jacobs
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Patent number: 6312840Abstract: A magnetic tunnelling element in which the tunnel current flows reliably in an insulating layer to exhibit a stable magnetic tunnelling effect. To this end, the magnetic tunnelling element at least includes a first magnetic layer, a tunnel barrier layer formed on the first magnetic layer and a second magnetic layer formed on the tunnel barrier layer. The tunnel current flows via the tunnel barrier layer between the first magnetic metal layer and the second magnetic metal layer. The surface of the first magnetic layer carrying the tunnel barrier layer has a surface roughness (Ra) of 0.3 nm or less.Type: GrantFiled: September 16, 1999Date of Patent: November 6, 2001Assignee: Sony CorporationInventors: Seiji Kumagai, Eiji Nakashio, Junichi Sugawara, Yoshito Ikeda
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Patent number: 6312785Abstract: A magnetic recording medium exhibiting an excellent electromagnetic conversion characteristic and a satisfactory movement characteristic if an aromatic polyamide film is employed as a non-magnetic support member thereof. The magnetic recording medium according to the present invention incorporates a non-magnetic support member on which a magnetic layer constituted by a thin metal magnetic film is formed, wherein at least either main surface of the non-magnetic support member has small projections, and the either main surface of the non-magnetic support member having the small projections formed thereon has a kurtosis (Ku) which is 10.0 to 50.0, average roughness Ra at the central surface of either main surface of the non-magnetic support member is 1.0 nm to 5.0 nm, and average roughness Rz of ten points on either main surface of the non-magnetic support member is 15 nm to 50 nm.Type: GrantFiled: January 14, 2000Date of Patent: November 6, 2001Assignee: Sony CorporationInventor: Satoshi Sato
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Patent number: 6312781Abstract: The present invention provides an apparatus and method for forming a protective film on a disc-shaped recording medium including providing a turnable having a center aperture, setting the disc-shaped recording medium having a center opening on the turnable with the center opening being aligned with the center aperture, covering at least the center opening of the disc-shaped recording medium with a rotating disc having a portion larger in diameter than the center opening of the disc-shaped recording medium, and supplying a protective film material to the center of the rotating disc and simultaneously rotating the turnable, the disc-shaped recording medium, and the disc to cause an outward radial flow of the protective film material off the disc and onto the disc-shaped recording medium so that the protective film is obtained and has thickness with a small variation.Type: GrantFiled: September 24, 1999Date of Patent: November 6, 2001Assignee: Sony CorporationInventor: Minoru Kikuchi
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Patent number: 6312796Abstract: Disclosed is a magnetic recording medium which comprises a support having provided thereon a magnetic layer containing at least a ferromagnetic powder and a diamond particle, wherein the diamond particle has an average particle diameter of from 3 to 200 nm and a variation coefficient of the particle diameter of from 3 to 60%.Type: GrantFiled: November 8, 1999Date of Patent: November 6, 2001Assignee: Fuji Photo Film Co., Ltd.Inventor: Noboru Zinbo
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Patent number: 6312841Abstract: To produce a substrate for information recording media, a substrate consisting essentially of glass for information recording media is subjected to treatment for retarding the extract of the glass component from the substrate by contacting it with a molten salt that contains at least one of hydrogensulfates and pyrosulfates, while being subjected to additional treatment for retarding the crystallization of the molten salt. In the method, preferably, the glass component to be prevented from being extracted from the substrate is a group of alkali ions, and the treatment for retarding the crystallization of the molten salt is water addition treatment of any one of treatment of supplying water to the molten salt or treatment of compensating for water being away from the molten salt.Type: GrantFiled: June 28, 1999Date of Patent: November 6, 2001Assignee: Hoya CorporationInventors: Takashi Watanabe, Kazuaki Hashimoto
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Patent number: 6309557Abstract: An object is to provide a magnetic garnet material, even if a thickness of an element is made thin, in which a sufficient Faraday rotation capacity can be obtained, a magnetic field for saturation can be controlled to be less than 200 (Oe), and a magnetic compensation temperature can be controlled to be less than 0° C. as well as to provide a Faraday rotator which can be made thin, suppresses a manufacturing cost and achieves a high yielding. The above object can be achieved by a magnetic garnet material known as the general chemical formula BixYbyGdzM13-x-y-zFewM2uM35-w-uO12 and the Faraday rotator using the above material. However, M1 is more than one kind of chemical elements which can replace Bi, Yb or Gd, M2 is more than one kind of non-magnetic chemical elements which can replace Fe, and M3 is more than one kind of chemical elements which can replace Fe and M2. Further, x, y, z, w and u respectively satisfies 1.0≦x≦1.6, 0.3≦y≦0.7, 0.9≦z≦1.6, 4.0≦w≦4.3 and 0.7≦u≦1.0.Type: GrantFiled: February 23, 2000Date of Patent: October 30, 2001Assignee: TDK CorporationInventors: Atsushi Ooido, Kazuhito Yamasawa, Masanori Goto, Shinji Iwatsuka
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Patent number: 6309765Abstract: A magnetic recording medium comprising a non-ferromagnetic substrate and a magnetic recording layer formed on the substrate with an underlayer of Cr or a Cr alloy interposed therebetween, which has a seed layer between the substrate and the underlayer, wherein said seed layer is made of a material which contains at least 30 ppm of oxygen and which has a B2 crystal structure.Type: GrantFiled: March 4, 1999Date of Patent: October 30, 2001Assignee: Asahi Komag Co., Ltd.Inventors: Michinobu Suekane, Makoto Imakawa, Takehiko Hiruma, Kazuhiko Mitarai
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Patent number: 6303218Abstract: According to the another aspect of the invention, a magnetoresistance effect element having a magnetoresistance effect film which includes a crystal growth controlling layer as one of films therein, characterized in that a roughness along a boundary between films overlying said crystal growth controlling layer is smaller than a roughness along a boundary between films underlying said crystal growth controlling layer is provided. According to the another aspect of the invention, a magnetoresistance effect element comprising a free layer, pinned layer and a non-magnetic intermediate layer interposed between said free layer and pinned layer, characterized in further comprising a metal barrier layer provided adjacent to said first magnetic layer, and an electron reflecting layer located adjacent to said metal barrier layer and containing at least one selected from oxides, nitrides, carbides, fluorides, chlorides, sulfides and borides is also provided.Type: GrantFiled: March 22, 1999Date of Patent: October 16, 2001Assignee: Kabushiki Kaisha ToshibaInventors: Yuzo Kamiguchi, Akiko Saito, Katsuhiko Koui, Masatoshi Yoshikawa, Hiromi Yuasa, Hideaki Fukuzawa, Susumu Hashimoto, Hitoshi Iwasaki, Hiroaki Yoda, Masashi Sahashi
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Patent number: 6303240Abstract: A soft magnetic thin film having a compositional formula FeaBbNc, wherein a, b and c each denote atomic percent and B denotes at least one of Co, Ni and Ru, and wherein the compositional range is given by 0<b≦5, and 0<c≦5. The film may exhibit uniaxial anisotropy with a uniaxial anisotropy field strength of 1-5 Oe. The film has a coercivity 2.5-4 Oe or less and a saturated magnetic flux density B25 of at least 16 kG measured at a magnetic field of 25 Oe. The film is produced by subjecting a deposited thin film of the compositional formula to heat treatment at a temperature of 220 to 450° C., within or without magnetic field and, has an average crystal grain size of not more than 50 nm.Type: GrantFiled: June 7, 1995Date of Patent: October 16, 2001Assignee: Fuji Photo Film Co., Ltd.Inventors: Osamu Shimizu, Kanji Nakanishi
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Patent number: 6303214Abstract: A magnetic recording medium is formed with dual carbon-containing protective layers having a combined thickness of less than about 100 Å with high corrosion resistance and superior magnetic performance. Embodiments of the present invention include sputter depositing a first protective layer of hydrogenated carbon at a density of at least 1.9 while applying a DC bias of about 250V to about 400V to the substrate, and sputter depositing a second protective layer comprising nitrogen-doped hydrogenated carbon on the first protective layer.Type: GrantFiled: January 4, 2000Date of Patent: October 16, 2001Assignee: Seagate Technology LLCInventors: Kueir-Weei Chour, Liji Huang, Jie-Ming Yu, Kuo-Hsing Hwang, Chung Shih
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Patent number: 6303280Abstract: There is disclosed a transparent magnetic recording medium comprising at least one magnetic recording layer containing ferromagnetic particles, on a support, wherein an overcoat solution which comprises at least one kind of lubricant wax dispersion and at least one kind of anionic surfactant in an amount of 0.1% to 30%, based on the total weight of the lubricant wax dispersion, is coated on the at least one magnetic recording layer. There is also disclosed a silver halide photographic light-sensitive material having the transparent magnetic recording layer. The transparent magnetic recording medium can exhibit both a good state of coated surface and secure magnetic input/output performance. The silver halide photographic light-sensitive material can provide a silver halide photographic light-sensitive material having the transparent magnetic recording layer with the above-described property.Type: GrantFiled: May 23, 2000Date of Patent: October 16, 2001Assignee: Fuji Photo Film Co., Ltd.Inventors: Naohiro Matsunaga, Tsutomu Arai, Tomokazu Yasuda
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Patent number: 6303205Abstract: A magnetic disk includes a substrate, a magnetic layer, and a protective layer. At least one region of a surface of the magnetic disk has protrusions. A height of each of the protrusions is not less than 5 nm and not greater than 40 nm, and is within ±30% of an average height of the protrusions. A density of the protrusions is not less than 200/mm2 and is not greater than 250,000/mm2. A width of a surface of each of the protrusions in a radial direction of the magnetic disk is not less than 0.1 &mgr;m and is not greater than 10 &mgr;m. The protrusions are discrete protrusions aligned in a spiral direction of the magnetic disk at a predetermined spacing in the radial direction of the magnetic disk. The at least one region of the surface of the magnetic disk includes flat areas between the protrusions.Type: GrantFiled: May 18, 1999Date of Patent: October 16, 2001Assignee: Hitachi, Ltd.Inventors: Hideaki Tanaka, Kenichi Gomi, Yoshihiko Miyake, Sigeru Sano, Youichi Inomata, Hiroshi Yashiki, Yoshiki Kato, Masaki Ohura
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Lubricant composition magnetic recording medium, and process for producing magnetic recording medium
Patent number: 6303227Abstract: A lubricant composition having excellent lubricity and comprising at least one compound selected among fluorine compounds each having a perfluoroalkyl or perfluoroether group and an alkyl or alkenyl group in the molecule and at least one compound selected among fluorine compounds each having a perfluoropolyether group in the molecule; and a magnetic recording medium excellent in running durability and still durability and comprising a nonmagnetic substrate (1) and, formed thereon in this order, a ferromagnetic thin metal film (2), a carbon film (3), and a lubricant layer (4), wherein the lubricant layer (4) contains the lubricant composition.Type: GrantFiled: January 14, 2000Date of Patent: October 16, 2001Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Kenji Kuwahara, Yukikazu Ohchi, Tetuo Fuchi, Mikio Murai -
Patent number: 6303217Abstract: A magnetic recording medium having a dual underlayer structure is described. The underlayer structure is composed of a first underlayer of chromium and a second underlayer of a chromium alloy.Type: GrantFiled: October 2, 1998Date of Patent: October 16, 2001Assignee: HMT Technology, CorporationInventors: Sudhir S. Malhotra, Brij Bihari Lal, Michael A. Russak
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Patent number: 6303241Abstract: A wear plate retainer having upper and lower layers. The lower layer is formed of a relatively soft, shock-absorbent material and the upper layer is formed of a relatively hard, impact and abrasion resistant material. A plurality of magnets are embedded in the upper layer to removably magnetically retain a wear plate atop the upper layer. A pair of pole pieces are positioned on opposed sides of each magnet and embedded in the upper layer. The pole pieces extend above the magnet, protecting it from impact forces. The pole pieces also focus the magnetic field forces emanating from the magnet. The magnets are arranged in rows, with adjacent poles of adjacent pairs of magnets in adjacent pairs of the rows having alternate polarity. The rows are parallel to one another and extend transversely to the direction in which material flows across the wear plate.Type: GrantFiled: December 2, 1998Date of Patent: October 16, 2001Assignees: Rampage Ventures, Inc.Inventor: David Roger Miles
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Patent number: 6299990Abstract: A ferromagnetic material can be formed in a very small size on the order of an atomic size and is capable of being stably magnetized. The ferromagnetic material comprises basic unit structures each consisting of a first atom (11), a second atom (12) of the same kind as the first atom (11), and a third atom (or atomic group) (13) of the same kind as the first atom (11) or of a kind different from that of the first atom (11). In each of the basic unit structures, the atoms are arranged on a surface of a substrate so that a chemical bond (14) is formed between the first atom or molecule and the third atom or molecule, a chemical bond (14) is formed between the second atom or molecule and the third atom or molecule, and a chemical bond or an electron path (15) not passing the third atom is formed between the first and the second atom or molecule, wherein said third atoms or molecules consist of As atoms.Type: GrantFiled: August 17, 1999Date of Patent: October 9, 2001Assignee: Hitachi, Ltd.Inventors: Satoshi Watanabe, Toshiyuki Onogi, Masahiko Ichimura, Yoshimasa Ono, Tomihiro Hashizume, Yasuo Wada, Yuji Suwa
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Patent number: 6299989Abstract: The present invention relates to a high stack factor amorphous metal transformer core, and to a process for constructing a high stack factor amorphous metal transformer core. The process uses high lamination factor amorphous metal ribbon (the term lamination factor is generally used to express the smoothness and uniformity of the ribbon, whereas the term stack factor is applied to cores made from ribbon); that is, amorphous metal ribbon with a highly smooth surface and a highly uniform thickness as measured across the ribbon width. High stack factor amorphous metal ribbon can be efficiently packed, by winding or stacking operations, into compact transformer core shapes. The transformer core can then be clamped, to further reduce overall dimensions, and annealed, to relieve residual mechanical stresses and to generate a desired magnetic anisotropy, without detriment to the final magnetic properties.Type: GrantFiled: May 13, 1999Date of Patent: October 9, 2001Assignee: AlliedSignal Inc.Inventors: Nicholas De Cristofaro, Richard L. Bye, Jr., Dung A. Ngo, Michael L. Briggs
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Acicular hematite particles having a low sodium content and their use in a magnetic recording medium
Patent number: 6299973Abstract: The present invention provides particles for a non-magnetic undercoat layer of a magnetic recording medium, which comprises particular hematite particles having an average major axial diameter of not more than 0.3 &mgr;m, a geometrical standard deviation in the major axial diameter of not more than 1.50 and a BET specific surface area of not less than 40 m2/g, and containing a total amount of sodium of not more than 50 ppm calculated as Na. The particular hematite particles have an excellent dispersibility in a vehicle so that a non-magnetic undercoat layer containing the particles is excellent in surface smoothness and strength. A magnetic recording medium using the non-magnetic undercoat layer is excellent not only in electromagnetic performance, but in storage stability.Type: GrantFiled: October 18, 1999Date of Patent: October 9, 2001Assignee: Toda Kogyo CorporationInventors: Kazuyuki Hayashi, Keisuke Iwasaki, Hiroko Morii -
Patent number: 6299954Abstract: An adhesive body, for the production of a junction with a foam material molded body during the molding process involving foam materials, has individual adhesive elements arranged on a support strip and covered to avoid the penetration of foam material with a covering. The covering is an adhesive material, adhering to the front side of the adhesive elements and can be removed therefrom to expose the adhesive elements. The adhesive body can be used at lower cost, can be in tight junction with the foam material molded body, and can guarantee with greater certainty that no foam material gets onto the adhesive elements during the foaming.Type: GrantFiled: August 10, 1999Date of Patent: October 9, 2001Assignee: Firma Gottlieb Binder GmbH & Co.Inventor: Axel Schulte
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Patent number: 6296917Abstract: A lubricating film is provided for a magnetic disk having a data region and a CSS region formed on its surface. The lubricating film ensures low stiction and good resistance to contact sliding in the data region and also ensures good CSS durability in the CSS region. Therefore, it is possible to provide a magnetic disk and a magnetic recording/reproducing device which do not cause problems with sliding between the magnetic head and the magnetic disk while the apparatus is running normally and even when the apparatus stops accidentally. The lubricating film formed in the data region of the magnetic disk is firmly fixed to the surface of the magnetic disk and is hardly liable to stiction. In addition, it is thick enough to ensure good durability even in the case of contact sliding.Type: GrantFiled: April 17, 1998Date of Patent: October 2, 2001Assignee: Hitachi, Ltd.Inventors: Takayuki Nakakawaji, Mitsuyoshi Shouji, Tomoe Takamura, Hiroshi Sasaki, Shuji Imazeki, Yutaka Ito
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Patent number: 6296955Abstract: Magnetically permeable, high magnetic saturation, primarily iron NiFe alloys are formed on thin seed layers by sputtering and electroplating. Pole layers a few microns in thickness can be formed of magnetically superlative, primarily iron NiFe alloys in this manner for transducers that may be used in information storage systems. The seed layers may include Ni0.55Fe0.45 or Cr, and the magnetically superlative NiFe alloy may be Ni0.45Fe0.55. The magnetically superlative NiFe alloy has increased concentration of a body centered cubic crystalline phase and/or a decreased concentration of a face centered cubic crystalline phase compared with conventional Ni0.45Fe0.55. A laminated pole structure has a dielectric interlayer along with seed layers and magnetically superlative, primarily iron NiFe layers.Type: GrantFiled: May 24, 1999Date of Patent: October 2, 2001Assignee: Read-Rite CorporationInventors: Syed A. Hossain, Mark S. Miller, Devendra P. Rathi
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Patent number: 6294242Abstract: A magnetic recording medium of the present invention comprises: a non-magnetic base film; and a magnetic recording layer comprising a binder resin and black magnetic acicular composite particles having an average particle diameter of 0.051 to 0.72 &mgr;m, comprising: magnetic acicular core particles; a coating formed on surface of said magnetic acicular core particles, comprising at least one organosilicon compound selected from the group consisting of: (1) organosilane compounds obtainable from alkoxysilane compounds, (2) polysiloxanes or modified polysiloxanes, and (3) fluoroalkyl organosilane compounds obtainable from fluoroalkylsilane compounds; and a carbon black coat formed on said coating layer comprising said organosilicon compound, in an amount of 0.5 to 10 parts by weight based on 100 parts by weight of said magnetic acicular particles.Type: GrantFiled: April 21, 2000Date of Patent: September 25, 2001Assignee: Toda Kogyo CorporationInventors: Kazuyuki Hayashi, Hiroko Morii, Mamoru Kamigaki, Yasuyuki Tanaka, Keisuke Iwasaki
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Patent number: 6291087Abstract: A method for forming a magnetoresistive (MR) sensor element, and a magnetoresistive sensor element fabricated in accord with the method. There is first provided a substrate. There is then formed over the substrate a magnetoresistive (MR) layer comprising: (1) a bulk layer of the magnetoresistive (MR) layer formed of a first magnetoresistive (MR) material optimized to provide an enhanced magnetoresistive (MR) resistivity sensitivity of the magnetoresistive (MR) layer; and (2) a surface layer of the magnetoresistive (MR) layer formed of a second magnetoresistive (MR) material optimized to provide an enhanced magnetic exchange bias when forming a magnetic exchange bias layer upon the surface layer of the magnetoresistive (MR) layer. Finally, there is then formed upon the surface layer of the magnetoresistive (MR) layer the magnetic exchange bias layer. The method contemplates an magnetoresistive (MR) sensor element fabricated in accord with the method.Type: GrantFiled: June 21, 1999Date of Patent: September 18, 2001Assignee: Headway Technologies, Inc.Inventors: Rongfu Xiao, Chyu-Jiuh Torng, Kochan Ju, Cheng Horng, Jei-Wei Chang
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Patent number: 6291052Abstract: A magnetic recording medium which comprises a support having thereon a substantially nonmagnetic lower layer and a magnetic layer comprising a ferromagnetic metal powder or a ferromagnetic hexagonal ferrite powder dispersed in a binder provided on the lower layer, which is a magnetic recording medium for recording signals of from 0.17 to 2 G bit/inch2 of areal recording density, wherein the coercive force of the magnetic layer is 1,800 Oe or more, and the thickness unevenness of the support is 5% or less of the thickness of the support.Type: GrantFiled: June 29, 1998Date of Patent: September 18, 2001Assignee: Fuji Photo Film Co., Ltd.Inventors: Masatoshi Takahashi, Hitoshi Noguchi, Junichi Nakamikawa, Hiroaki Doushita
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Patent number: 6290868Abstract: The present application is directed to a new class of composite materials, called field-structured composite (FSC) materials, which comprise a oriented aggregate structure made of magnetic particles suspended in a nonmagnetic medium, and to a new class of processes for their manufacture. FSC materials have much potential for application, including use in chemical, optical, environmental, and mechanical sensors.Type: GrantFiled: May 27, 1999Date of Patent: September 18, 2001Assignee: Sandia CorporationInventors: James E. Martin, Robert C. Hughes, Robert A. Anderson