Transition Metal-base Component Patents (Class 428/655)
  • Patent number: 5958542
    Abstract: A thin film magnetic disc in which dot-like scattered bumps, made of a material different from that of the protective layer, are formed on the protective layer, and a lubricant layer is formed on the surfaces of the protective layer and the scattered bumps. A protective layer excellent in strength and disk durability is obtained by using a material different from that of the bumps. The functions of the protective layer and scattered bumps are separated from each other and make full use of the different materials. Such a protective layer is effective to reduce spacing between a head and the disc.
    Type: Grant
    Filed: June 3, 1996
    Date of Patent: September 28, 1999
    Assignee: Hitachi, Ltd.
    Inventors: Mitsuyoshi Ootake, Yuichi Kokaku, Yoshinori Honda, Akira Kato, Hiroaki Hagimae, Heigo Ishihara, Kenji Furusawa
  • Patent number: 5948497
    Abstract: A writable compact disk has a plastic substrate, a recording layer, a reflecting layer, and a protective overcoat, the reflecting layer is comprised of a silver-palladium alloy, a silver-copper alloy, or a silver-palladium-copper alloy. By maintaining the palladium component of the alloy less that 15 at. % and the copper component of the alloy less than 30 at. %, the reflectance of the reflecting layer can be similar to the typical gold reflecting layer while jitter and NORP levels can be reduced for illumination power levels exceeding the power normally used to write on the recording layer.
    Type: Grant
    Filed: October 19, 1992
    Date of Patent: September 7, 1999
    Assignee: Eastman Kodak Company
    Inventors: Tukaram Kisan Hatwar, Douglas Greg Stinson
  • Patent number: 5945191
    Abstract: A magnetic disc for use in a magnetic disc drive is provided. The magnetic disc includes a recording surface wherein the recording surface includes a dual phase carbon overcoat. The dual phase carbon overcoat includes an amorphous carbon film sputtered on a magnetic layer. A doped amorphous carbon film is sputtered on the amorphous carbon film. The dual phase carbon overcoat has demonstrated improved hardness, reduced stiction and superior corrosion resistance over the prior art. A method of manufacturing the magnetic disc is also provided. The method includes providing a sputtering apparatus having a process chamber, providing a partially manufactured magnetic disc having a magnetic layer thereon, placing the partially manufactured magnetic disc within the process chamber, sputtering an amorphous carbon film on the magnetic layer, and sputtering a doped amorphous carbon film on the amorphous carbon film.
    Type: Grant
    Filed: June 20, 1997
    Date of Patent: August 31, 1999
    Assignee: Seagate Technology, Inc.
    Inventors: Kuo-Hsing Hwang, Xiaohua Chen, Alexander Boris Khazanov, Abdellah Hafid, Stella Tan, Quy Cuu Nguyen
  • Patent number: 5945197
    Abstract: A magnetic recording medium is textured with a pulsed laser light beam through a multiple lens focusing system. The use of a multiple lens focusing system enables the formation of a plurality of relatively uniform protrusions smaller than those obtained with a single lens focusing system, thereby avoiding abrupt local profile changes. In an embodiment, the laser light beam is split, as by offsetting the lenses, to obtain a plurality of pairs of even smaller protrusions than obtained with a laser light beam having a centralized energy profile. The pulsed, multiple lens focused laser light beam can be used to texture a substrate, underlayer or magnetic layer. The resulting laser textured magnetic recording medium exhibits improved flying stability, glide performance and reliability.
    Type: Grant
    Filed: October 27, 1997
    Date of Patent: August 31, 1999
    Assignee: Seagate Technology
    Inventors: Jialuo Jack Xuan, Ga-Lane Chen
  • Patent number: 5939170
    Abstract: There is provided a magnetic recording medium comprising a nonmagnetic substrate (10, 20), at least one magnetic layer (30) having an upper surface (30a), and a protection layer (40) made of zirconia and having an upper surface (40a). The upper surface (30a) has a surface roughness of 3 nm or smaller defined by maximum height (R.sub.max) while the upper surface (40a) has a surface roughness ranging from 5 nm to 60 nm. When a distance Zi indicates a degree of irregularities of the upper surface (40a) of the protection layer (40), a standard deviation of the heights Zi is 5.7 nm or smaller.
    Type: Grant
    Filed: March 17, 1997
    Date of Patent: August 17, 1999
    Assignee: Hoya Corporation
    Inventors: Ken-ichi Nishimori, Shoji Matsuda, Jun-ichi Horikawa
  • Patent number: 5939164
    Abstract: The present invention relates to an aluminum alloy for a magnetic disk substrate having a composition consisting of, by percent by weight, 2.0 to 6.0% of Mg, 0.05 to 0.15% of Cu, 0.10 to 0.30% of Zn and 0.05 to 0.12% of Zr, wherein the contents of Cu, Zn and Zr satisfy the relationship: 0.15%.ltoreq.2Cu+6Zr-3Zn.ltoreq.0.32% (wherein Cu, Zr, and Zn respectively represent their contents in terms of percent by weight), and the composition further consists of one or both of 0.01 or more to less than 0.05% of Cr and 0.01 or more to less than 0.05% of Mn, impurities consisting of Si, Fe and Ti, which are respectively regulated to be 0.05% or less, 0.05% or less, and 0.02% or less, and other inevitable impurity elements respectively regulated to be 0.02% or less, with the remainder being Al. The present invention also relates to a clad material for a magnetic disk substrate, in which one or both surfaces of a core material, consisting of at least less than 3.
    Type: Grant
    Filed: February 25, 1997
    Date of Patent: August 17, 1999
    Assignee: The Furukawa Electric Co., Ltd.
    Inventors: Yoshinari Kubo, Ken-ichi Ogura, Yoichiro Bekki, Satoru Yamada, Koji Kinoshita
  • Patent number: 5928799
    Abstract: The present invention is a metallic composite which is resistant to erosion and corrosion at the high temperatures and pressures which are encountered in gun tubes, including projectile launchers. This composite comprises a ductile layer of rhenium or a rhenium alloy containing more than 20 percent rhenium, and a layer of a lower cost high strength material such as steel, nickel, nickel alloy, cobalt, or cobalt alloy. A solid solution of the two metals is formed between the two layers making a metallurgical bond. The metallurgical bond may be enhanced through the use of a bond promoter having solubility with both metallic layers.
    Type: Grant
    Filed: June 14, 1995
    Date of Patent: July 27, 1999
    Assignee: Ultramet
    Inventors: Andrew Sherman, Victor Arrietta
  • Patent number: 5914168
    Abstract: A magnetic recording medium able to cope with low flying height of the magnetic head in a CSS system and having fine surface roughness, wherein (1) a metal layer having columnar protrusions formed by the filming of Ti or the like or (2) a resin layer or glass resin layer having irregularly distributed through-holes are provided on the substrate of a magnetic recording medium to impart roughness (texture).
    Type: Grant
    Filed: August 22, 1995
    Date of Patent: June 22, 1999
    Assignee: Fujitsu Limited
    Inventors: Hiroaki Wakamatsu, Katsuhide Sone, Kiyoshi Yamaguchi, Yoshihiro Mitobe, Yoshito Kitamoto
  • Patent number: 5908817
    Abstract: A lubricant comprising a mixture of a perfluoropolyalkyl ether and a phosphazene is described. The lubricant is useful in thin-film magnetic recording disk applications, where very low static and dynamical coefficients of friction are desired and balling effects are minimized.
    Type: Grant
    Filed: May 18, 1998
    Date of Patent: June 1, 1999
    Assignee: The Dow Chemical Company
    Inventors: Donald J. Perettie, Kenneth J. Van Heel, Ted A. Morgan
  • Patent number: 5897963
    Abstract: Disclosed Is a process for the fabrication of rare earth or rare earth alloy materials in the form of fine wires for refrigeration regenerator applications. The wire is a composite consisting of a metal core and a metal sheath. The core material is comprises of at least a 20 atomic percent portion of rare earth metal as a pure metal, an alloy with other rare earth metals, or an intermetallic compound alloy with one or more non rare earth metals. The sheath material is essentially immiscible with the rare earth in the core, has no magnetic phase transitions in the temperature range for the intended operation, and has good corrosion and oxidation resistance. The sheath material is typically a small portion of the total composite wire cross section. The composite wire is fabricated from the co-reduction of an assembled billet by conventional wire processing techniques.
    Type: Grant
    Filed: January 5, 1998
    Date of Patent: April 27, 1999
    Assignee: Composite Materials Technology, Inc.
    Inventor: Jeffrey M. Seuntjens
  • Patent number: 5897931
    Abstract: A significantly thinner boron carbide overcoat layer is provided for a magnetic disk which has the same durability as thicker prior art overcoat layers for protecting an underlying magnetic layer. By employing adhesion layers selected from the group consisting of Ge, Ru, WTiSi, WTi, Si, and Y between the magnetic layer and the overcoat layer, the durability of the overcoat layer is significantly increased over a single overcoat layer of B4C. Certain process steps in the making of the B4C overcoat layer still further enhance the durability of the B4C overcoat layer by maintaining the disk or substrate specimen at a floating potential in a plasma chamber and employing low levels of argon pressure and sputtering wattage.
    Type: Grant
    Filed: May 15, 1996
    Date of Patent: April 27, 1999
    Assignee: International Business Machines Corporation
    Inventors: Richard Henry Ahlert, James Kent Howard, Muhammad Inayet Ullah, Richard Donald Umphress
  • Patent number: 5895712
    Abstract: The coercivity of a magnetic recording medium is increased without any substantial change in magnetic remanence by depositing a fresh non-magnetic sub-underlayer on an underlayer or composite underlayer comprising a plurality of sub-underlayers, and immediately depositing a magnetic layer on the fresh sub-underlayer. In an embodiment of the present invention, a fresh chromium sub-underlayer having a thickness of about 55 .ANG. to about 135 .ANG. is sputter deposited on a chromium underlayer in the magnetic layer deposition chamber, and a cobalt magnetic layer deposited on and within 1.2 seconds after depositing the fresh sub-underlayer.
    Type: Grant
    Filed: September 12, 1996
    Date of Patent: April 20, 1999
    Assignee: Seagate Technology, Inc.
    Inventors: Qixu Chen, Ga-Lane Chen
  • Patent number: 5871850
    Abstract: A coated hard metal for a cutting tool is excellent in wear resistance and chipping resistance. The coated hard metal includes a hard coating layer on a surface of a base material of cemented carbide or cermet. The hard coating layer includes an inner layer (2) on the base material (1), an intermediate layer (3) on the inner layer (2) and an outer layer (4) on the intermediate layer (3). The inner layer (2) consists of a carbide, a nitride, a carbo-nitride, a carbo-oxide, a carbonitrogen oxide or a boronitride of Ti. The intermediate layer (3) consists of Al.sub.2 O.sub.3 or ZrO.sub.2. The outer layer (4) consists of a carbide, a nitride, a carbo-nitride, a carbo-oxide, a carbonitrogen oxide or a boronitride of Ti. The thickness of the inner layer (2) is 0.1 to 5 .mu.m, the thickness of the intermediate layer (3) is 5 to 50 .mu.m in the case of it being an Al.sub.2 O.sub.3 layer and 0.5 to 20 .mu.m in the case of it being a ZrO.sub.2 layer, and the thickness of the outer layer (4) is 5 to 100 .mu.m.
    Type: Grant
    Filed: June 3, 1996
    Date of Patent: February 16, 1999
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Hideki Moriguchi, Akihiko Ikegaya, Nobuyuki Kitagawa, Katsuya Uchino
  • Patent number: 5866227
    Abstract: A magnetic recording medium comprising a glass or glass-ceramic substrate is formed by sequentially depositing thereon a partially oxidized NiP seed layer, an underlayer and a magnetic layer. The partially oxidized NiP seed layer is formed by reactive sputtering in a gas mixture of argon and oxygen. The resulting magnetic recording medium exhibits low medium noise and high coercivity rendering it suitable for high density magnetic recording.
    Type: Grant
    Filed: August 20, 1996
    Date of Patent: February 2, 1999
    Assignee: Seagate Technology, Inc.
    Inventors: Qixu Chen, Ga-Lane Chen
  • Patent number: 5863670
    Abstract: A joint of Ti--Al intermetallic compounds, comprising a plurality of base members made of a Ti--Al intermetallic compound and having Ti--Al lamellar grains, and a junction provided between the base members, made of a Ti--Al intermetallic compound and having Ti--Al lamellar grains, wherein some of the lamellar grains of the junction extend into the base members, and some of the lamellar grains of each base member may extend into the junction or pass through the junction into the other base member.
    Type: Grant
    Filed: April 18, 1996
    Date of Patent: January 26, 1999
    Assignee: NHK Spring Co., Ltd.
    Inventors: Kohei Taguchi, Michihiko Ayada
  • Patent number: 5827613
    Abstract: Articles having a diamond-like protective film formed thereon, each comprising a substrate of a material selected from the group consisting of alloys containing at least Co, Ni, or Fe, ceramics, and glass and which has only a slight affinity for a diamond-like thin film, an Mo film formed on the substrate, and a diamond-like thin film formed further thereon. Such articles are manufactured by a method which comprises holding a grid made of Mo close to the surface of the substrate, bombarding the grid and the substrate surface with a bombarding gas consisting of inert gas atoms of Ar or the like, thereby removing contaminants from the surface and depositing Mo atoms on the substrate surface to form an Mo film thereon, ionizing a low-molecular-weight hydrocarbon or a feed gas capable of producing a low-molecular-weight hydrocarbon upon decomposition or reaction, and then accelerating the resulting ions and depositing the same on the Mo film to form a diamond-like film thereon.
    Type: Grant
    Filed: March 10, 1994
    Date of Patent: October 27, 1998
    Assignee: TDK Corporation
    Inventors: Masatoshi Nakayama, Masanori Shibahara
  • Patent number: 5824425
    Abstract: A method for joining rhenium to columbium and columbium based alloys that minimizes the formation of brittle intermetallics. First, a layer of ruthenium is applied to both the rhenium and columbium and then heated until the ruthenium diffuses with the rhenium and columbium respectively. A braze foil is place between the two outer ruthenium layers and the assembly is heated in a range of 50.degree. C. to 100.degree. C. above the liquidus of the braze, thereby joining the rhenium to the columbium. Alternatively, the ruthenium coated surfaces are placed in contact and diffused together under a compressive load of at least 1000 psi.
    Type: Grant
    Filed: June 10, 1997
    Date of Patent: October 20, 1998
    Inventor: Donald Lee Mittendorf
  • Patent number: 5824387
    Abstract: A magnetic disc for use in a disc drive data storage system is disclosed. The magnetic disc includes a layer of magnetic material deposited on a substrate and a carbon overcoat layer deposited on the layer of magnetic material. The carbon overcoat layer has a first hardness over a contact start-stop region of the disc. The carbon overcoat layer has a second hardness over a data storage region of the disc. The second hardness is softer than the first hardness and than a hardness of a diamond like coating on an associated magnetic head so that disc asperities in the data storage region of the carbon overcoat layer will wear upon impact with the magnetic head.
    Type: Grant
    Filed: August 8, 1996
    Date of Patent: October 20, 1998
    Assignee: Seagate Technology, Inc.
    Inventors: Zine-Eddine Boutaghou, Dallas W. Meyer, Bo Wei
  • Patent number: 5783320
    Abstract: Disclosed is a magneto-optical recording medium which comprises a transparent substrate and, provided on the substrate, a magneto-optical recording film comprising a perpendicular magnetic film based on rare earth metal-transition metal and an auxiliary magnetic film having spontaneous magnetization which exerts, between itself and the magneto-optical recording film, an exchange coupling force on each other and in which the auxiliary magnetic film used is a magnetic film which readily rotates its magnetization direction toward the external magnetic field in the neighborhood of the Curie temperature of the magneto-optical recording film and has a squareness ratio of not more than 1 in the neighborhood of the Curie temperature, and a process for producing the magneto-optical recording medium.
    Type: Grant
    Filed: January 10, 1997
    Date of Patent: July 21, 1998
    Assignee: Hitachi Maxell, Ltd.
    Inventors: Katsusuke Shimazaki, Satoru Ohnuki, Masatoshi Hashimoto, Yoshinori Shirai, Norio Ohta, Hideo Fujiwara, Masafumi Yoshihiro, Yukinori Yamada, Eiji Koyama, Hitoshi Furusho
  • Patent number: 5780135
    Abstract: A magnetic disc apparatus includes a magnetic recording medium and member for recording/reproducing information in/out of the magnetic recording medium, the magnetic recording medium including a recording layer of a magnetic thin film formed on a non-magnetic substrate, and a non-magnetic protective layer formed on and thicker than the recording layer. The particular construction permits diminishing the thickness of the recording layer, making it possible to achieve a high density recording.
    Type: Grant
    Filed: September 11, 1996
    Date of Patent: July 14, 1998
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Akira Kikitsu, Katsutaro Ichihara
  • Patent number: 5750230
    Abstract: In a magnetic recording medium having a nonmagnetic disk substrate and a magnetic film formed on the surface of the non-magnetic disk substrate, a surface average roughness factor Ra(r) on the surface of the medium being from 0.3 nm to 3 nm, an orientation ratio of coercivity being from 0.1 to 0.7, and an in-plane magnetic anisotropic energy being from 3.times.10.sup.4 J/m.sup.3 to 5.times.10.sup.5 J/m.sup.3. By using such a medium, it is possible to provide a magnetic recording apparatus in which the magnetic head is capable of flying in a low position and high-density recording is achieved.
    Type: Grant
    Filed: November 22, 1993
    Date of Patent: May 12, 1998
    Assignee: Hitachi, Ltd.
    Inventors: Akira Ishikawa, Yuzuru Hosoe, Yoshihiro Shiroishi, Masatoshi Takeshita, Yotsuo Yahisa, Tomoo Yamamoto, Akira Osaki, Kiwamu Tanahashi, Jun Fumioka, Yoshiki Kato, Masaki Ohura, Yukio Katoh
  • Patent number: 5750231
    Abstract: A significantly thinner boron carbide overcoat layer is provided for a magnetic disk which has the same durability as thicker prior art overcoat layers for protecting an underlying magnetic layer. By employing adhesion layers selected from the group consisting of Ge, Ru, WTiSi, WTi, Si, and Y between the magnetic layer and the overcoat layer, the durability of the overcoat layer is significantly increased over a single overcoat layer of B4C. Certain process steps in the making of the B4C overcoat layer still further enhance the durability of the B4C overcoat layer by maintaining the disk or substrate specimen at a floating potential in a plasma chamber and employing low levels of argon pressure and sputtering wattage.
    Type: Grant
    Filed: April 3, 1996
    Date of Patent: May 12, 1998
    Assignee: International Business Machines Corporation
    Inventors: Richard Henry Ahlert, James Kent Howard, Muhammad Inayet Ullah, Richard Donald Umphress
  • Patent number: 5741560
    Abstract: A method for manufacturing a magnetic disk comprises the step of depositing a metallic layer on a glass substrate and laser texturing the metallic layer. The magnetic disk is then completed by deposition of (a) an underlayer such as Cr or sputtered NiP, (b) a magnetic layer such as a Co or Fe alloy, and (c) a protective overcoat such as ZrO.sub.2, carbon or hydrogenated carbon. By providing the above-mentioned metallic layer, laser texturing can now be used in conjunction with glass substrates.
    Type: Grant
    Filed: November 5, 1996
    Date of Patent: April 21, 1998
    Assignee: Komag, Incorporated
    Inventor: Caroline A. Ross
  • Patent number: 5707706
    Abstract: A magnetic recording has very low warp characteristics but excellent film characteristics. Particularly, the recording medium has a high coercivity with a small range of coercivity distribution, with a warp characteristic below 3 .mu.m per radial inch. The medium is formed by heating a substrate at a high temperature with a temperature distribution on the substrate that is improved by the use of a heat distribution mask, which reduces the temperature distribution of the substrate to below .+-.3%.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: January 13, 1998
    Assignee: Hitachi, Ltd.
    Inventors: Shinji Fukaya, Yoshinori Honda, Akira Kato, Shuichi Kojima
  • Patent number: 5705283
    Abstract: A rocket engine component is formed as a tungsten-copper composite substrate, and a functionally-gradient material coating overlying and contacting the substrate. The functionally-gradient material coating has a composition that varies nonlinearly through a thickness of the coating so as to minimize thermal stresses through the coating, and such that the functionally-gradient material coating is tungsten adjacent to the substrate and is rhenium remote from the substrate. In a preferred form, the functionally-gradient material coating includes a tungsten sublayer overlying and contacting the substrate, a tungsten-rhenium sublayer overlying and contacting the tungsten sublayer; and a rhenium sublayer overlying and contacting the tungsten-rhenium sublayer. The functionally-gradient material coating is preferably applied by a low-temperature deposition technique such as plasma enhanced chemical vapor deposition.
    Type: Grant
    Filed: June 13, 1996
    Date of Patent: January 6, 1998
    Assignee: Hughes Electronics
    Inventor: Kamleshwar Upadhya
  • Patent number: 5695864
    Abstract: In the present invention, electrons flow through a free or excitable magnet, or reflect from it, to make its magnetization respond. To accomplish this, the spin vectors of the flowing electrons are preferentially polarized by an auxiliary ferromagnet, whose moment orientation is fixed. The electrons flow between the fixed and free ferromagnets through a non-magnetic metallic spacer which is thick enough to make the static inter-magnetic exchange coupling negligible. While transmitting thru or reflecting from the free ferromagnet, the spins of the moving electrons interact by quantum-mechanical exchange with the local, permanently present, spontaneously-polarized electron spins of the free magnet. This interaction causes a transfer of vectorial angular momentum between the several metallic layers in the device which causes the magnetization vector of the free magnet to change its direction continually with time. Thus excited, the magnetization vector will precess about its original axis.
    Type: Grant
    Filed: September 28, 1995
    Date of Patent: December 9, 1997
    Assignee: International Business Machines Corporation
    Inventor: John Casimir Slonczewski
  • Patent number: 5691071
    Abstract: A metal wire, having a steel core and being provided with a layer of cladding of a zinc/manganese alloy containing between 5% and 80% of manganese. The wire is used as a reinforcement structure for tires or other products of elastomer material. Several embodiments of a process for applying the cladding on the steel core by electrodeposition of the zinc/manganese alloy are also described.
    Type: Grant
    Filed: July 27, 1995
    Date of Patent: November 25, 1997
    Assignee: Pirelli Coordinamento Pneumatici S.p.A.
    Inventors: Pietro Cavallotti, Federico Pavan
  • Patent number: 5679431
    Abstract: A thin-film magnetic recording medium having a carbon overcoat composed of an overcoat sublayer and an overcoat surface layer is described. The overcoat surface layer is a hydrogen- or nitrogen-containing sputtered carbon layer with high wear-resistance. The overcoat sublayer functions to reduce the diffusion of nitrogen or hydrogen from the surface layer to the magnetic recording layer. Also described is a method of sputtering the nitrogen-containing surface layer in which the graphite target is attached to the target electrode by thermally conducting, electrically conducting materials.
    Type: Grant
    Filed: April 1, 1994
    Date of Patent: October 21, 1997
    Assignee: HMT Technology Corporation
    Inventors: Ga-Lane Chen, Hoa Van Do
  • Patent number: 5656382
    Abstract: An oriented conductive thin film useful as a thin film electrode or a thin film resistor is disclosed, comprising an epitaxial or oriented ABO.sub.3 type oxide (e.g., BaPbO.sub.3) conductive thin film which is obtained by coating a single crystal oxide substrate or a single crystal semiconductor substrate with a solution of a metal oxide precursor comprising an organometallic compound, thermally decomposing the coating layer, followed by annealing. An epitaxial or oriented ABO.sub.3 type ferroelectric thin film may further be provided on the conductive thin film.
    Type: Grant
    Filed: March 18, 1996
    Date of Patent: August 12, 1997
    Assignee: Fuji Xerox Co., Ltd.
    Inventor: Keiichi Nashimoto
  • Patent number: 5656349
    Abstract: A magnetic disk has a magnetic layer and a protective layer disposed on the magnetic layer. A multiplicity of lands having sizes within a predetermined range of sizes and generally equal heights within a predetermined range are formed on the surface of the protective layer at a density within a predetermined range. The lands serve to effectively remove contaminants attached to the floating surface of a magnetic head to ensure a desired sliding reliability and floating stability of the head during a long period of time even in the case of a high-density magnetic disk apparatus in which the extent of floating of the head is small. The reliability with which the magnetic disk apparatus operates is thereby improved. The lands are formed on the surface of the protective layer by a process of forming a mask of fine particles on the protective layer surface and etching the protective layer surface through this mask.
    Type: Grant
    Filed: July 2, 1991
    Date of Patent: August 12, 1997
    Assignee: Hitachi, Ltd.
    Inventors: Kenichi Gomi, Hideaki Tanaka, Hiroyuki Sugimoto, Shoichi Sawahata, Masaki Ohura, Yoshihiko Miyake, Yoshiki Kato, Hiroshi Yashiki, Youichi Inomata, Yoshihiro Moriguchi
  • Patent number: 5648162
    Abstract: A magneto-optical recording medium including a base; a readout layer formed on the base; a recording layer formed on the readout layer; and an auxiliary recording layer formed on the recording layer, each of the readout layer, recording layer and auxiliary recording layer being made of an alloy of rare-earth metal and transition metal showing ferrimagnetism.
    Type: Grant
    Filed: December 30, 1993
    Date of Patent: July 15, 1997
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Junji Hirokane, Hiroyuki Katayama, Akira Takahashi, Kenji Ohta
  • Patent number: 5637373
    Abstract: A magnetic recording medium having a diamond-like carbon (DLC) film added therein a Group IV element of the periodic table such as silicon, particularly in the vicinity of the boundary between the magnetic material and the formed DLC film. Since a DLC having low friction coefficient can be formed, the centerline average roughness can be reduced to 30 nm or even less. Accordingly, a magnetic recording medium improved in magnetic properties and in lubricity can be obtained.
    Type: Grant
    Filed: November 18, 1993
    Date of Patent: June 10, 1997
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventor: Shigenori Hayashi
  • Patent number: 5637411
    Abstract: Disclosed is a magneto-optical recording medium which comprises a transparent substrate and, provided on the substrate, a magneto-optical recording film comprising a perpendicular magnetic film based on rare earth metal-transition metal and an auxiliary magnetic film having spontaneous magnetization which exerts, between itself and the magneto-optical recording film, an exchange coupling force and wherein the auxiliary magnetic film is a magnetic film which readily rotates its magnetization direction toward the external magnetic field in the neighborhood of the Curie temperature of the magneto-optical recording film and has a squareness ratio of not more than 1 in the neighborhood of the Curie temperature. Also disclosed is a process for producing the magneto-optical recording medium.
    Type: Grant
    Filed: April 14, 1994
    Date of Patent: June 10, 1997
    Assignee: Hitachi Maxell, Ltd.
    Inventors: Katsusuke Shimazaki, Satoru Ohnuki, Masatoshi Hashimoto, Yoshinori Shirai, Norio Ohta, Hideo Fujiwara, Masafumi Yoshihiro, Yukinori Yamada, Eiji Koyama, Hitoshi Furusho
  • Patent number: 5631058
    Abstract: According to the present invention, a blank of an aluminum alloy is partially cut so as to form several disks maintained in the blank by portions of the remaining uncut aluminum. This results in the disks being supported in the blank during formation of the thin films, yet easily separated from the blank into individual disks after the thin films have been deposited. Therefore, multiple disks can be processed during a single manufacturing step.
    Type: Grant
    Filed: August 12, 1992
    Date of Patent: May 20, 1997
    Assignee: International Business Machines Corporation
    Inventors: Richard H. Flachbart, Albert P. Lee, Stafford Miller, Chester C. Oldakowski, Swie-In Tan
  • Patent number: 5631041
    Abstract: A magnetic disc manufacturing apparatus is includes a polishing device for conducting a surface polishing treatment on a disc, a supply device for supplying lubricant onto the polished disc, and a feeding mechanism for feeding the disc between the devices. If necessary, it is provided with a curing device for curing the lubricant on the disc. The treatments of the devices and the disc feeding operation are synchronized with one another, and a disc processed in each device is fed to a next device at a constant time interval by the feeding mechanism, thereby performing a continuous disc manufacturing process.
    Type: Grant
    Filed: May 24, 1996
    Date of Patent: May 20, 1997
    Assignee: Sumitomo Metal Mining Co., Ltd.
    Inventors: Tadahito Kanaizuka, Atsushi Kawamoto, Koichi Yamagishi, Shinichi Yasuda, Yasunori Yamanobe, Shinichi Hayashi
  • Patent number: 5629066
    Abstract: A resin article comprising a shaped body of a synthetic resin having a surface, and a coated resin layer covering the surface of the shaped body, said coated resin layer being made of an amino group-containing polymer and/or a polymer containing (meth) acrylate of (iso)cyanuric acid as a constituent unit and having a top surface, wherein the top surface of the coated resin layer is chemically converted to have an anti-static property by chemical reaction with a quaternary compound-forming reagent. Alternatively, a resin article having stable anti-static properties may comprise a shaped body of a synthetic resin covered with an anti-static coating layer made of a reaction product of at least one of an amino group-containing alkoxy silane, an amino group-containing alkoxy titanium compund, or an oligomer thereof, with a quaternary compound-forming reagent.
    Type: Grant
    Filed: January 23, 1995
    Date of Patent: May 13, 1997
    Assignee: Teijin Limited
    Inventors: Utami Yonemura, Tsuneo Hagiwara
  • Patent number: 5624725
    Abstract: A sputter-deposited wear-resistant protective coating for magnetic-recording alloy thin films is disclosed. The protective coating includes a protective layer and an interfacial adhesion layer. The protective layer is preferably titanium diboride or amorphous nitrided carbon, and the interfacial adhesion layer is preferably titanium, but can alternatively be other metals, such as zirconium or hafnium, which share characteristics similar to titanium. More broadly, the protective layer may be a nitride, carbide, or boride, or mixture thereof, of titanium, zirconium, hafnium, tantalum, vanadium, niobium, tantalum, chromium, molybdenum, or tungsten, and the interfacial adhesion layer may be the corresponding metal of the protective layer compound.
    Type: Grant
    Filed: August 11, 1995
    Date of Patent: April 29, 1997
    Assignee: Tulip Memory Systems, Inc.
    Inventors: Carl W. Nelson, Richard D. Weir
  • Patent number: 5607740
    Abstract: A magnetic disc according to this invention is of a structure in which underlying layer and magnetic layer are formed in succession on non-magnetic substrate, and one non-magnetic intermediate layer or more and one second magnetic layer or more are further stacked one after another thereon. The non-magnetic intermediate layer is formed as film layer by sputtering, and film thickness calculated by film formation rate and film formation time is 0.2 nm.about.1.0 nm. Thus, with this magnetic disc, coercive force is improved. Accordingly, signals can be recorded at higher density. As a result, application to magnetic disc devices of larger memory capacity can be made.
    Type: Grant
    Filed: October 14, 1994
    Date of Patent: March 4, 1997
    Assignee: Sony Corporation
    Inventor: Makoto Noda
  • Patent number: 5587217
    Abstract: A thin-film magnetic recording disc for use with a read/write head in a disc drive is disclosed. To reduce the static and dynamic frictional coefficients of the disc surface, the disc is coated with a lubricant layer composed of a mixture of a polyphenoxycyclotriphosphazene lubricant and a perfluoropolyether oil. Also disclosed is a lubricant composition containing these two components, as well as a method for improving the lubricating properties of a perfluoropolyether oil.
    Type: Grant
    Filed: June 30, 1995
    Date of Patent: December 24, 1996
    Assignee: HMT Technology Corporation
    Inventors: James L. Chao, Yu-Cheun Lee, Chao Gao
  • Patent number: 5582927
    Abstract: Certain alloys of CoFeCu are provided in film and laminate form which have a unique combination of electromagnetic properties which enable them to be used as magnetic thin films in magnetic recording heads, shields and flux guides. The films and laminates thereof are electrodeposited from a plating bath in a DC or pulsed current electrodeposition process.
    Type: Grant
    Filed: December 5, 1994
    Date of Patent: December 10, 1996
    Assignee: International Business Machines Corporation
    Inventors: Panayotis C. Andricacos, Jei-Wei Chang, Wilma J. Horkans, Judith D. Olsen, Bojan Petek, Lubomyr T. Romankiw
  • Patent number: 5580633
    Abstract: A magneto-optical recording disc adapted for magneto-optical recording in the magnetic field modulation system by means of a magnetic head in continuous contact with the disc includes a recording layer on a substrate and a wear resistant resinous coating thereon. The coating is formed of a resin containing carbon particles having a mean particle size of 1 to 15 .mu.m. The magnetic head is in sliding contact with the surface of the coating during operation. The coating is effective for reducing friction with the magnetic head and retains such reduced friction over a long time.
    Type: Grant
    Filed: July 19, 1994
    Date of Patent: December 3, 1996
    Assignee: TDK Corporation
    Inventors: Tsuneo Kuwahara, Hiroyuki Endo, Isamu Kuribayashi, Hideki Hirata
  • Patent number: 5569506
    Abstract: A thin film metal alloy magnetic recording disk has an improved protective overcoat that creates a low level of static friction in a contact start/stop disk drive. The disk has an amorphous carbon overcoat containing a transition liquid metal interlayer (TLMI). The carbon overcoat is formed by depositing an initial amorphous carbon layer to a first thickness, then depositing an interlayer material of a low-melting point metal or metal alloy (such as In or In--Nb) while maintaining the temperature of the disk substrate above the melting point of the interlayer material, and then depositing a top additional layer of amorphous carbon. Because the initial carbon layer presents a nonwetting surface, the interlayer material "balls up" on the carbon and forms discontinuous spheres of the interlayer material. The additional top layer of carbon bonds to the initial carbon layer and to the metal or metal alloy spheres.
    Type: Grant
    Filed: October 6, 1993
    Date of Patent: October 29, 1996
    Assignee: International Business Machines Corporation
    Inventors: Christopher V. Jahnes, James H. Kaufman, Serhat Metin, Mohammad T. Mirzamaani, Anthony W. Wu
  • Patent number: 5569533
    Abstract: A longitudinal magnetic recording medium formed on a non-metallic substrate and a method of forming the medium is disclosed. A sublayer formed of a chromium alloy having a thickness between 3-50 .ANG. is deposited on the substrate, followed by a chromium-based underlayer. A cobalt-based magnetic recording layer is sputtered over the underlayer. The medium is characterized by improved coercivity, HF signal amplitude and signal-to-noise ratio.
    Type: Grant
    Filed: March 14, 1994
    Date of Patent: October 29, 1996
    Assignee: HMT Technology Corporation
    Inventors: Brij B. Lal, Allen J. Bourez, Tadashi Shinohara
  • Patent number: 5556713
    Abstract: The present invention provides a method for forming a diffusion barrier at one or more surfaces of a protective coating. In a preferred embodiment, the protective coating is an MCrAlY coating, and the diffusion barrier is a submicron layer of rhenium atoms. The rhenium diffusion barrier is formed by condensing vaporized rhenium onto the surface of the component and substantially simultaneously bombarding the surface with an energetic beam of inert ions. The high, localized concentration of rhenium atoms at the surface(s) of the protective coating dramatically slows the diffusion of constituent elements from the coating.
    Type: Grant
    Filed: April 6, 1995
    Date of Patent: September 17, 1996
    Assignee: Southwest Research Institute
    Inventor: Gerald R. Leverant
  • Patent number: 5552203
    Abstract: A magnetic disk having an underlayer, a layer of magnetic material, and a protective layer applied on a substrate. The protective layer comprises sputtered particles of two differently controlled grain sizes wherein the particles of one grain size are at least two times greater than the particles of the other grain size.
    Type: Grant
    Filed: December 30, 1994
    Date of Patent: September 3, 1996
    Assignee: Fujitsu Limited
    Inventor: Eiji Takaike
  • Patent number: 5552204
    Abstract: A significantly thinner boron carbide overcoat layer is provided for a magnetic disk which has the same durability as thicker prior art overcoat layers for protecting an underlying magnetic layer. By employing adhesion layers selected from the group consisting of Ge, Ru, WTiSi, WTi, Si, and Y between the magnetic layer and the overcoat layer, the durability of the overcoat layer is significantly increased over a single overcoat layer of B4C. Certain process steps in the making of the B4C overcoat layer still further enhance the durability of the B4C overcoat layer by maintaining the disk or substrate specimen at a floating potential in a plasma chamber and employing low levels of argon pressure and sputtering wattage.
    Type: Grant
    Filed: January 13, 1995
    Date of Patent: September 3, 1996
    Assignee: International Business Machines Corporation
    Inventors: Richard H. Ahlert, James K. Howard, Muhammad I. Ullah, Richard D. Umphress
  • Patent number: 5549954
    Abstract: A magnetic disc having one or multiple undercoat layers, a continuous thin film magnetic layer or continuous thin film multiple magnetic layers, a protective layer and a lubricant layer sequentially laminated on a non-magnetic disc substrate, which has surface roughness on the surface of the magnetic disc, said surface roughness being such that when the surface roughness is measured by an atomic force microscope or a scanning tunnel microscope, the maximum peak height is from 150 .ANG. to 800 .ANG. based on the height giving the highest frequency in the height distribution of the surface roughness, and the depth (D.sub.0.5) at a bearing ratio of 0.5% from the highest point is from 80 .ANG. to 450 .ANG..
    Type: Grant
    Filed: August 31, 1994
    Date of Patent: August 27, 1996
    Assignee: AG Technology Co., Ltd.
    Inventors: Haruhiko Otsuka, Yuzo Murayama, Akihiko Tashiro, Kyoko Hyomi, Naohiko Ishimaru
  • Patent number: 5543203
    Abstract: The magnetic recording medium includes at least a substrate, a magnetic film formed on the substrate for storing data, a protective film and a lubricant film. The protective film has two regions of a predetermined pattern each having a different surface energy. The lubricant film including polar groups is formed on the protective film including the regions. The degree of adhesion of the lubricant film to the protective film is thus changed at the two regions each having a different surface energy so that the lubricant film can be prevented from being scattered.
    Type: Grant
    Filed: August 4, 1994
    Date of Patent: August 6, 1996
    Assignee: Hitachi, Ltd.
    Inventors: Hiroshi Tani, Heigo Ishihara, Hiroyuki Matsumoto
  • Patent number: 5534322
    Abstract: A recording medium, showing sufficient resistance to contamination and having excellent reproducing characteristics, comprises a film provided on a surface thereof and this film comprises a copolymer formed by polymerizing a composition which comprises a compound A having a (meth)acryloyl group and a reactive antistatic agent B having a quaternary ammonium salt group, an alkylene glycol chain, a hydrocarbon group of which carbon number is four or more and a copolymerizable group.
    Type: Grant
    Filed: April 25, 1994
    Date of Patent: July 9, 1996
    Assignee: Kao Corporation
    Inventors: Kenichi Ueyama, Hiroshi Kawamukai
  • Patent number: 5525392
    Abstract: The present invention relates to a process for coating a magnetic recording device with a lubricating polymeric film using an ion beam generator.
    Type: Grant
    Filed: August 11, 1995
    Date of Patent: June 11, 1996
    Assignee: International Business Machines Corporation
    Inventors: Thomas H. Baum, Paul B. Comita, Mark S. Crowder, George W. Tyndall, III