Metal Coating Patents (Class 427/132)
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Publication number: 20020063053Abstract: Production of a thin-film system containing at least one ultra-thin film, preferentially in the film thickness range from 1 to 10 nm, which is separated by plasma-aided chemical or physical vapor-phase deposition using magnetron discharges. The method is characterized in that in the course of deposition of the ultra-thin film the power output is introduced into the plasma in the form of a controlled number of power pulses and that the average power output during the pulse-on time is set higher by a factor of at least 3 than the averaged power output over the entire coating time during deposition of the ultra-thin film.Type: ApplicationFiled: September 26, 2001Publication date: May 30, 2002Applicant: Fraunhofer-Gesellschaft zur Forderung der angewandten Forschung e.V.Inventors: Torsten Winkler, Ralf Bluthner, Klaus Goedicke, Michael Junghahnel, Hans Buchberger, Manfred Muller, Arno Hebgen, Hans-Hermann Schneider
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Patent number: 6395349Abstract: A method for marking the defective side of a magnetic disk comprises the step of applying a set of laser pulses to the defective side to form a mark that is visible to the naked eye. Thus, disk drive manufacturers can readily see whether one side of the disk is defective, and if so, which side of the disk is defective. Thus, the disk drive manufacturer can assemble a disk drive so as to use the functional side of the disk. The laser marks are formed on the disk without generating particulate contamination.Type: GrantFiled: May 25, 1999Date of Patent: May 28, 2002Assignee: Komag, Inc.Inventor: David Vigdor Salamon
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Patent number: 6391393Abstract: A method of forming a dual-level memory material using field structured materials. The field structured materials are formed from a dispersion of ferromagnetic particles in a polymerizable liquid medium, such as a urethane acrylate-based photopolymer, which are applied as a film to a support and then exposed in selected portions of the film to an applied magnetic or electric field. The field can be applied either uniaxially or biaxially at field strengths up to 150 G or higher to form the field structured materials. After polymerizing the field-structure materials, a magnetic field can be applied to selected portions of the polymerized field-structured material to yield a dual-level memory material on the support, wherein the dual-level memory material supports read-and-write binary data memory and write once, read many memory.Type: GrantFiled: February 22, 2001Date of Patent: May 21, 2002Assignee: Sandia CorporationInventors: James E. Martin, Robert A. Anderson, Chris P. Tigges
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Patent number: 6361859Abstract: A magnetic recording media having a CrMo underlayer provides improved performance characteristics. In one embodiment, the recording media comprises a rigid substrate and an underlayer disposed over the substrate, in which the underlayer comprises CrMo. Preferably, the Mo crystals in the CrMo underlayer are at least about 140 Å in the film growth direction for the 002 crystal plane. Advantageously, recording media with such a 002 crystal size, when used in conjunction with a magnetic layer, such as CoCrTaPtNi, exhibits significantly higher parametric qualities than underlayers using other materials. Typically, Mo in the range between about 7% and 16% in the CrMo alloy, more preferably between about 9% and 11%, will provide the recited 002 crystal size.Type: GrantFiled: November 20, 2000Date of Patent: March 26, 2002Assignee: United Modular CorporationInventors: Yuanda Cheng, Xingbo Yang, Yancy Song
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Publication number: 20020015865Abstract: In a first forming process, by injecting a predetermined amount of oxygen gas, magnetic metal vapor 7a is deposited as a nonmagnetic underlayer on a base film F wound on one film winding roll 3B while advancing the base film F in a reverse direction (second direction) toward another film winding roll 3A along a cooling can roll 5 from a minimum incidence angle side to a maximum incidence angle side of an incidence angle controlling mask 9. In a second forming process, by injecting a extremely smaller amount of oxygen gas than in the first forming process, magnetic metal vapor 7a is deposited as a magnetic layer over the nonmagnetic underlayer while advancing the base film deposited with the nonmagnetic underlayer wound on the other film winding roll 3A in a forward direction (first direction) toward the film winding roll 3B along the cooling can roll 5 from the maximum incidence angle side to the minimum incidence angle side of the incidence angle controlling mask 9.Type: ApplicationFiled: June 20, 2001Publication date: February 7, 2002Applicant: VICTOR COMPANY OF JAPAN, LTD.Inventors: Masaru Segawa, Masahiko Sugiyama
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Patent number: 6335063Abstract: Very low glide height magneto-optical (LGMO) information storage and retrieval media of near field recording (NFR) and mahnetic super-resolution (MSR) types having improved tribological properties when used in ultra-high density storage/retrieval devices employing very small head flying heights on the order of less than about 2 microinches are formed in a front surface magneto-optical (FSMO) configuration utilizing a substrate having at least one deposition surface subjected to a two-step, synergistic treatment comprising tape burnishing/wiping and photolytic treatment in an ozone-containing atmosphere, followed by deposition thereon of the MO layer stack. Enhanced wear and abrasion resistance at very low flying head heights is provided by an ultra-thin, protective flash layer overcoat (FLO)/lubricant topcoat layer system on the media surface. Embodiments of the present invention include single- and dual-sided MO media.Type: GrantFiled: October 20, 1999Date of Patent: January 1, 2002Assignee: Seagate Technology LLCInventors: Ga-Lane Chen, Simon Wing-Tat Fung
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Patent number: 6335050Abstract: A ferrite magnetic film structure exhibiting a magnetic anisotropy, the ferrite magnetic film structure comprising, a substrate provided on one main surface thereof with a groove-like recessed portion and with a ridge-like projected portion located neighboring to the groove-like recessed portion, and a ferrite magnetic film constituted by a continuous film having a substantially flat upper surface and formed on one main surface of the substrate, wherein the ferrite magnetic film structure meets the following conditions: (a/(a+b))(h/(t−h))≧0.047 1≧(a+b) where “a” is a width of the ridge-like projected portion, b is a width of the groove-like recessed portion, h is a height of step between the groove-like recessed portion and the ridge-like projected portion, t is a thickness of the ferrite magnetic film at the recessed portion, and l is a length of the recessed portion and of the projected portion.Type: GrantFiled: June 15, 2000Date of Patent: January 1, 2002Assignee: Kabushiki Kaisha ToshibaInventor: Tetsuo Inoue
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Patent number: 6333067Abstract: A method of forming the device, includes selective area deposition of a ferromagnetic material on a substrate. The substrate surface is partially covered with material having a crystal structure having at least one symmetry relation with the crystal structure of the ferromagnetic material.Type: GrantFiled: June 13, 2001Date of Patent: December 25, 2001Assignee: International Business Machines CorporationInventors: Nestor A. Bojarczuk, Jr., Peter R. Duncombe, Supratik Guha, Arunava Gupta, Joseph M. Karasinski, Xinwei Li
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Patent number: 6319544Abstract: A method of manufacturing a MR sensor having at least an anti-ferromagnetic layer and a ferromagnetic layer, and to a method for manufacturing a magnetic head with the MR sensor. The sensor utilizes bias magnetic field provided by exchange coupling between the anti-ferromagnetic layer and the ferromagnetic layer. The sensor manufacturing method includes a step of depositing an anti-ferromagnetic layer to have a larger thickness than a target thickness, a step of ordering the deposited anti-ferromagnetic layer, and a step of thinning the ordered anti-ferromagnetic layer to have the target thickness.Type: GrantFiled: December 28, 1999Date of Patent: November 20, 2001Assignee: TDK CorporationInventors: Tetsuro Sasaki, Hiroaki Kawashima
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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: 6302940Abstract: A method and structure for forming magnetic alloy nanoparticles includes forming a metal salt solution with a reducing agent and stabilizing ligands, introducing an organometallic compound into the metal salt solution to form a mixture, heating the mixture to a temperature between 260° and 300° C., and adding a flocculent to cause the magnetic alloy nanoparticles to precipitate out of the mixture without permanent agglomeration. The deposition of the alkane dispersion of FePt alloy particles, followed by the annealing results in the formation of a shiny FePt nanocrystalline thin film with coercivity ranging from 500 Oe to 6500 Oe.Type: GrantFiled: March 5, 2001Date of Patent: October 16, 2001Assignee: International Business Machines CorporationInventors: Christopher Bruce Murray, Shouheng Sun, Dieter K. Weller
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Patent number: 6299947Abstract: A method in accordance with our invention for providing texture bumps on a substrate comprises the step of forming elliptical ridge-shaped bumps on the substrate. In one embodiment, substrate is used in the manufacture of a magnetic disk used in a disk drive. The elliptical bumps cause less vibration of the read-write head than circular bumps. The elliptical bumps also provide reduced friction between the disk and a read-write head during use.Type: GrantFiled: January 20, 1999Date of Patent: October 9, 2001Assignee: Komag, Inc.Inventors: Shoji Suzuki, David Treves, David Vigdor Salamon, Dan Frusescu, Rony Thomas
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Patent number: 6299946Abstract: A method of manufacturing a recording medium includes the steps of: a) providing an underlayer on a substrate; b) providing a magnetic layer on the under layer; c) providing a protection layer of amorphous carbon on the magnetic layer; and d) providing a lubrication layer of fluorine on the protection layer, the lubrication layer including a bonding layer part which is strongly bonded to the protection layer and a mobile layer part which is not strongly bonded to the protection layer. The method further includes the steps of: e) implementing a UV curing process on the surface of the protection layer between the step c) and d), so that a ratio of the bonding layer part in the lubrication layer is increased.Type: GrantFiled: March 6, 2000Date of Patent: October 9, 2001Assignee: Fujitsu LimitedInventors: Takashi Toyoguchi, Chiaki Okuyama
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Patent number: 6277505Abstract: A structure which includes a ferromagnetic (FM) layer, a thin oxide layer, and an antiferromagnetic (AFM) layer is provided. The thin oxide layer, between 1 to 10 oxygen atoms in thickness, minimizes interlayer atomic diffusion between the FM layer and the antiferromagnetic layer. In a preferred embodiment, a spin valve sensor with improved thermal stability is provided by including the thin oxide layer between a FM layer and an AFM layer. The presence of the thin oxide layer also results in an improved spin valve sensor with an enhanced exchange pinning field.Type: GrantFiled: January 21, 1999Date of Patent: August 21, 2001Assignee: Read-Rite CorporationInventors: Zhupei Shi, Ming Mao, Qunwen Leng
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Patent number: 6268024Abstract: A magnetic recording medium is prepared by forming on a plastic substrate, a nickel oxide underlayer having a plane (200) which is predominantly oriented in parallel with the surface of the plastic substrate, then forming on the nickel oxide underlayer at a substrate temperature of less 240° C., a cobalt-containing magnetite thin film having a plane (400) which is predominantly oriented in parallel with the surface of the plastic substrate, and finally oxidizing the cobalt-containing magnetite thin film in a plasma-activated oxygen atmosphere containing a rare gas at a substrate temperature of less than 240° C. while incorporating the rare gas into oxygen. This results in a cobalt-containing maghemite thin film as a perpendicular magnetic film having a spacing of a plane (400) of not more than 2.082 Å. The magnetic recording medium so produced is useful for high-density recording using a plastic substrate.Type: GrantFiled: March 25, 1999Date of Patent: July 31, 2001Assignee: Toda Kogyo CorporationInventors: Takanori Doi, Kousaku Tamari, Yasuo Kakihara, Kenichi Nakata, Mitsuru Matsuura, Setsuo Yamamoto
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Patent number: 6261646Abstract: A low resistance magnetic tunnel junction with low resistance barrier layer and method of fabrication is disclosed. A first magnetic layer of material with a surface is provided and a continuous layer of material, e.g. aluminum, is formed on the surface of the first magnetic layer. The continuous layer of material is treated to produce a low resistance barrier layer of oxynitride material and a second magnetic layer is formed on the barrier layer of oxynitride material to complete the low resistance magnetic tunnel junction.Type: GrantFiled: August 14, 2000Date of Patent: July 17, 2001Assignee: Motorola, Inc.Inventors: Eugene Chen, Jon Slaughter, Renu Whig
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Patent number: 6251230Abstract: A method and a device for manufacturing a thin film by a vacuum deposition method, and a magnetic recording medium produced thereby are disclosed. A thin film of high quality is mass-produced while introducing reaction gas to a thin film forming section from a nozzle consisting of minute tubes, so that the flow of evaporated atoms is not disturbed by the reaction gas.Type: GrantFiled: February 11, 2000Date of Patent: June 26, 2001Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Kazuyoshi Honda, Yoshiharu Maezawa, Masaru Odagiri, Sadayuki Okazaki
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Patent number: 6251474Abstract: Substantially spherical magneto-plumbite ferrite (barium or strontium ferrite) particles are formed from well-dispersed ultra-fine substantially spherical iron-based oxide and/or hydroxide particles as precursor particles. The precursor particles are mixed with a colloidal barium or strontium carbonate (BaCO3 or SrCO3), and with small amounts of a byproduct, such as sodium or potassium chloride (NaCl or KCl) or hydroxide (NaOH or KOH) or nitrate (NaNO3 or KNO3), functioning as a flux to lower the calcination temperature. The particles are filtered out of the mixture, dried, and calcined for a time sufficiently long and/or at a temperature sufficiently high to form magneto-plumbite ferrite from the precursor particles, and for a time sufficiently short and/or a temperature sufficiently low to maintain the general spherical shape of the precursor particles.Type: GrantFiled: November 6, 1998Date of Patent: June 26, 2001Assignee: Idaho Research FoundationInventors: Yang-Ki Hong, Hong Sik Jung, Patrick R. Taylor
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Patent number: 6251475Abstract: A process is disclosed for the preparation of semi-soft or soft magnetic layers. The process involves chemical reduction in aqueous medium of one or more types of metal ions including nickel ions, washing the resulting dispersion of metal particles, and coating this dispersion onto a support. The resulting magnetic layers can be used in an anti-theft system.Type: GrantFiled: April 30, 1999Date of Patent: June 26, 2001Assignee: Agfa-GevaertInventors: Hieronymus Andriessen, Steven Lezy
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Patent number: 6251196Abstract: An Fe—B—R based permanent magnet and metal pieces are placed into a treating vessel, where they are vibrated and/or agitated, whereby a metal film is formed on the surface of the magnet. A sol solution produced by the hydrolytic reaction and the polymerizing reaction of a metal compound which is a starting material for a metal oxide film is applied to the metal film and subjected to a heat treatment to form a metal oxide film. Therefore, it is possible to form, on the surface of the magnet, a corrosion-resistant film which can be produced easily and at a low cost without carrying-out of a plating treatment or a treatment using hexa-valent chromium and which has an excellent adhesion to the surface of the magnet and can exhibit a stable high magnetic characteristic which cannot be degraded even if the magnet is left to stand for a long period of time under high-temperature and high-humidity conditions of a temperature of 80° C. and a relative humidity of 90%.Type: GrantFiled: August 26, 1999Date of Patent: June 26, 2001Assignee: Sumitomo Special Metals Co., Ltd.Inventors: Takeshi Nishiuchi, Kohshi Yoshimura, Fumiaki Kikui
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Patent number: 6238731Abstract: Thin-film magnetic head having a head face (103) and comprising a magnetoresistive element (109) oriented transversely to the head face and a flux-guiding element (107) of a magnetically permeable material terminating in the head face. A peripheral area (109a) of the magnetoresistive element extending parallel to the head face is present opposite the flux-guiding element for forming a magnetic connection between the magnetoresistive element and the flux-guiding element. The flux-guiding element and the peripheral area of the magnetoresistive element constitute a common magnetic contact face (111), while the magnetically permeable material of the flux-guiding element is electrically insulating.Type: GrantFiled: September 7, 1999Date of Patent: May 29, 2001Assignee: U.S. Philips CorporationInventors: Jacobus J. M. Ruigrok, Pieter J. Van Der Zaag, Wiepke Folkerts, Lambertus Postma, Ronald M. Wolf, Johannes F. M. Cillessen
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Patent number: 6221508Abstract: In a magnetic storage apparatus having a magnetic recording medium, a drive unit for driving this medium in a prespecified recording direction, a magnetic head assembly including a recorder section and reproduction section, means for causing the magnetic head to move relatively with respect to the magnetic record medium, and a record/playback signal processor means for performing signal inputting to the magnetic head and for effecting reproduction of an output signal from the magnetic head, the reproduction section of said magnetic head is composed of a magnetic head of the magneto-resistance effect type, while said magnetic record medium is structured including a substrate and a magnetic layer formed thereover with one or several underlayers being sandwiched therebetween, wherein at least one of the underlayers is a specific layer that is made of amorphous or microcrystalline materials containing therein Ni as the principal or main component thereof and further containing at least one kind of element as seleType: GrantFiled: December 8, 1998Date of Patent: April 24, 2001Assignee: Hitachi, Ltd.Inventors: Tetsuya Kanbe, Ichiro Tamai, Yuzuru Hosoe, Kiwamu Tanahashi, Yoshio Takahashi, Fumiyoshi Kirino, Nagatugu Koiso, Satoshi Matsunuma
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Patent number: 6221218Abstract: An inductive write head includes a first pole and a second pole that form a yoke having a write gap between the first pole and second pole. The second pole is formed of a particular Co100-a-bZRaCRb compound. More specifically, the second pole is formed where “a” is in the range of about 2 atomic percent to about 18 atomic percent, and “b” is in the range of about 0.5 atomic percent to about 6 atomic percent. The magnetic write element also includes a conductive coil which lies between the first pole and the second pole. The inductive write head also includes a first yoke pedestal attached to the first pole, and a second yoke pedestal attached to the second pole, with the write gap formed therebetween. Further, the first yoke pedestal has a pedestal width that defines the write element trackwidth and that is smaller than the pedestal width of the second yoke pedestal.Type: GrantFiled: February 17, 1999Date of Patent: April 24, 2001Assignee: Read-Rite CorporationInventors: Zhupei Shi, Chun He, Syed Hossain, Mark S. Miller
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Patent number: 6207223Abstract: In a method for producing a multilayer magnetic recording medium having at least three coating layers on a side of a magnetic recording layer side, the at least three coating layers are formed on the magnetic layer side at least two times dividedly.Type: GrantFiled: July 21, 1999Date of Patent: March 27, 2001Assignee: Fuji Photo Film Co., Ltd.Inventors: Kazunori Komatsu, Seiji Kasahara
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Patent number: 6204995Abstract: The present invention provides a magnetic disc apparatus comprising a vertical two-layered magnetic recording (MR) medium and a mono-pole/MR composite head or ID/MR composite head, wherein the vertical two-layered magnetic recording medium includes a vertical magnetization film formed on an undercoat soft magnetic film having no magnetic domain wall structure. This eliminates the fatal defect of a conventional vertical two-layered medium that an undercoat soft magnetic film domain wall is easily shifted by an external magnetic field generated by motors for disc rotation and head positioning, causing demagnetization of the recording magnetization to lower the output. The magnetic disc apparatus according to the present invention enables to obtain a high output stability.Type: GrantFiled: February 16, 1999Date of Patent: March 20, 2001Assignee: NEC CorporationInventors: Hirotaka Hokkyo, Shinzo Tsuboi, Katsumichi Tagami
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Patent number: 6195872Abstract: A method of manufacturing a thin film magnetic head including a first magnetic layer, a second magnetic layer, a gap layer, and a thin film coil consisting of one or more thin film coil layers.Type: GrantFiled: June 1, 1998Date of Patent: March 6, 2001Assignee: TDK CorporationInventor: Yoshitaka Sasaki
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Patent number: 6197364Abstract: This invention provides a method and solution for the electroless deposition of Co(P) with a designed coercivity via the programmed addition of supporting electrolytes comprising such sulfur containing compounds as sulfamic acid, potassium sulfate or sodium sulfate to a solution having a source of cobalt ions, a source of citrate ions, a buffering compound to stabilize the pH of the solution, a source of hypophosphite ions and sufficient hydroxide anions to obtain a pH of between about 7 and 9. The magnetized Co(P) material is useful in, for example, rigid magnetic storage disks, hard bias layers for MR thin film heads and magnetic detector tags.Type: GrantFiled: August 9, 1999Date of Patent: March 6, 2001Assignee: International Business Machines CorporationInventors: Milan Paunovic, Christopher Jahnes
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Patent number: 6197439Abstract: Non-magnetic transition metal spacer layers 2.5 to 50 Angstroms thick with compositions of Os, Ru and Re are used in laminated magnetic structures. The ultra-thin non-magnetic transition metal spacer layers are useful to fabricate micron and sub-micron laminated magnetic devices. The laminated magnetic structures using ultra-thin non-magnetic transition metal spacer layers of Os, Ru and Re have anti-ferromagnetic coupling between the magnetic layers. The anti-ferromagnetic coupling provides a mechanism for reduced edge curling and efficient directional magnetization. Alloying the non-magnetic transition metal layer provides a method for engineering coupling strengths, coercivities and remanences in magnetic structures useful for high frequency applications. These laminated magnetic structure have applications in magnetic read head, magnetic write head, magnetic memory, and miniature transformer devices.Type: GrantFiled: January 28, 1999Date of Patent: March 6, 2001Assignee: International Business Machines CorporationInventors: Stuart Stephen Papworth Parkin, David Allen Thompson
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Patent number: 6197367Abstract: A magnetic recording medium having first undercoating layers 40, 40′ formed directly or via substrate face undercoating layers on a substrate 40, second undercoating layers 42, 42′ directly formed on the first undercoating layers 40, 40′, magnetic films 43, 43′ formed on the second undercoating layers 42, 42′, and protective films 44, 44′ formed on the magnetic films 43, 43′. Clusters having a large amount of oxygen are dispersed on the boundary face of the first and second undercoating layers. Preferably, the first undercoating layer is made of an alloy which includes two kinds of elements in which the difference between oxide formation standard free energies &Dgr;G° of the elements at the temperature of 250° C. is large.Type: GrantFiled: October 29, 1997Date of Patent: March 6, 2001Assignee: Hitachi, Ltd.Inventors: Yoshibumi Matsuda, Akira Ishikawa, Yotsuo Yahisa, Yuzuru Hosoe, Tetsuya Kanbe, Koji Sakamoto
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Patent number: 6197440Abstract: A magnetic recording medium comprises a stack of four magnetic layers. The first magnetic layer 11 is a layer for reproducing information recorded on the medium. The third magnetic layer 13 is a storage layer for storing information recorded on the medium in the form of domain walls. The second magnetic layer 12 has a lower Curie temperature Ts than the first and third magnetic layers and is interposed between the first and third magnetic layers. The fourth magnetic layer 14 is interposed between the first 11 and second 12 magnetic layers, and has a larger domain wall energy density than that of the first magnetic layer 11.Type: GrantFiled: October 15, 1999Date of Patent: March 6, 2001Assignee: Canon Kabushiki KaishaInventor: Tsutomu Shiratori
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Patent number: 6194025Abstract: A lubricant film is formed on the surface of a substrate of a magnetic recording medium. The substrate consists of a non-magnetic base layer, a magnetic layer and a protective film, in that order. The substrate is immersed in a lubricant solution in a sealed container. The sealed container is pressurized with an inert gas introduced in the sealed container. The lubricant solution is then discharged, thereby forming a lubricant film on the surface of the protective film. Lubricant film thickness is varied by controlling a discharge rate, either by controlling the gas pressure, or the outflow rate of the lubricant solution.Type: GrantFiled: January 28, 2000Date of Patent: February 27, 2001Assignee: Fuji Electric Co., Ltd.Inventor: Kazuo Nimura
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Patent number: 6194048Abstract: A magnetic recording disk having on its surface a texture structure of fine surface irregularities with reduced variations, which is suitable for high-density magnetic recording, and a method of manufacturing such a magnetic recording disk are provided. The magnetic recording disk has a substrate 11, 12 (16) coated on a surface thereof with a magnetic layer 13, a carbon layer 14, and a lubricating film 15. The substrate has on a surface thereof a texture structure of fine surface irregularities for reducing friction when the substrate is brought into contact with a head and controlling an amount of lift of the head. The fine surface irregularities have a height of 20 nm or less and are formed from a pattern shape or profile of a shield with a high-speed atomic beam emitted from a high-speed atomic beam source.Type: GrantFiled: October 2, 1998Date of Patent: February 27, 2001Assignee: Ebara CorporationInventors: Masahiro Hatakeyama, Katsunori Ichiki, Kenji Watanabe, Kazuo Yamauchi, Shinta Kunitomo, Yasushi Tohma, Tohru Satake
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Patent number: 6183893Abstract: The present invention relates to a perpendicular magnetic recording medium and a magnetic storage apparatus which are improved to be suitable for high-density magnetic recording. An object thereof is to provide the perpendicular magnetic recording medium and the magnetic storage apparatus which have a low noise property for realizing a recording density of 10 Gb/in.2 or more and a high stability against thermal fluctuation. The perpendicular magnetic recording medium comprising a perpendicular magnetic film formed through an underlayer on a nonmagnetic substrate, wherein the underlayer comprises a material having a hexagonal close packed structure or an amorphous structure, and has a first underlayer nearer to the substrate, and a second underlayer having a hexagonal close packed structure formed on the first underlayer and a preferred growth orientation of [0001] and comprising a material capable of hetero-epitaxy growth onto the perpendicular magnetic film.Type: GrantFiled: April 5, 1999Date of Patent: February 6, 2001Assignee: Hitachi, Ltd.Inventors: Masaaki Futamoto, Yoshiyuki Hirayama, Kenya Ito, Kazuetsu Yoshida, Yukio Honda, Nobuyuki Inaba
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Patent number: 6183891Abstract: Method of manufacturing a thin-film magnetic head comprising an inductive transducing system. A non-magnetic, insulating material for forming a first insulation layer (13), on which an inductive transducing element (15) is formed, is deposited on a plane basic surface (11). Subsequently, a non-magnetic, insulating material for forming a second insulation layer (19) is deposited on the first insulation layer and the inductive transducing element formed thereon. Subsequently, material is removed in an area proximate to a head face (30) to be formed for forming an aperture extending through the first and the second insulation layer and reaching as far as the basic surface, whereafter a non-magnetic, insulating material for forming a gap layer (29) is deposited in the aperture.Type: GrantFiled: June 19, 1997Date of Patent: February 6, 2001Assignee: Onstream, Inc.Inventors: Eeltje A. Draaisma, Franciscus A. Pronk
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Patent number: 6183860Abstract: A magnetic recording media having a CrMo underlayer provides improved performance characteristics. In one embodiment, the recording media comprises a rigid substrate and an underlayer disposed over the substrate, in which the underlayer comprises CrMo. Preferably, the Mo crystals in the CrMo underlayer are at least about 140 Å in the film growth direction for the 002 crystal plane. Advantageously, recording media with such a 002 crystal size, when used in conjunction with a magnetic layer, such as CoCrTaPtNi, exhibits significantly higher parametric qualities than underlayers using other materials. Typically, Mo in the range between about 7% and 16% in the CrMo alloy, more preferably between about 9% and 11%, will provide the recited 002 crystal size.Type: GrantFiled: May 4, 1998Date of Patent: February 6, 2001Assignee: Stormedia, Inc.Inventors: Yuanda Cheng, Xingbo Yang, Yancy Song
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Patent number: 6180226Abstract: The present invention provides a number of interrelated methods for the production of random and ordered arrays of particles and recesses as well as films containing such arrays and recesses. The present invention also relates to the random and ordered arrays of particles and films prepared therefrom. The ordered arrays are obtained by the use of ferrofluid compositions which may be curable, solidifiable on non-curing/non-solidifiable. The arrays and films may contain electrically-conductive particles useful in electronic applications for effecting contact between leads or pads.Type: GrantFiled: March 31, 1998Date of Patent: January 30, 2001Assignee: Loctite (R&D) LimitedInventors: Ciaran B. McArdle, Joseph Burke, Edward K. Welch, II
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Patent number: 6171716Abstract: A soft magnetic film includes Fe as a major constituent; at least one element M selected from the group consisting of Zr, Hr, V, Nb, Ta, W, Mo, and rare earth elements (excluding Sm); at least one element L selected from the group consisting of Ti, Sn, Sm, and Si: and at least one element R selected from the group consisting of O, C, and N. The film has a structure including a mixture of an amorphous phase containing a large amount of the oxide of the element M and a fine crystalline phase containing a large amount of Fe, and the fine crystalline phase further contains the element L. Thin film magnetic heads, planar magnetic elements, and filters using the soft magnetic film are also disclosed.Type: GrantFiled: May 18, 1999Date of Patent: January 9, 2001Assignee: ALPS Electric Co., Ltd.Inventors: Yoshito Sasaki, Makoto Nakazawa, Takashi Hatanai, Akihiro Makino
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Patent number: 6168845Abstract: A new method for making patterned magnetic storage media with magnetic and substantially non-magnetic zones utilizes a selective oxidation processes. Selective oxidation is achieved by subjecting a magnetic layer to an oxygen plasma through voids in a patterned mask. A high resolution patterned mask is made by embossing and reactive ion etch processes. The method is used to fabricate patterned magnetic disks media with alternating magnetic and non-magnetic zones ranging from 10 to 1000 Nanometers in width. Magnetic storage disks produced by this method have high-bit densities, minimal topography and reduced signal noise.Type: GrantFiled: January 19, 1999Date of Patent: January 2, 2001Assignee: International Business Machines CorporationInventors: Robert Edward Fontana, Jr., Richard Hsiao, Ernesto Esteban Marinero, Hugo Alberto Emilio Santini, Bruce David Terris
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Patent number: 6165329Abstract: Multilayer magnetic transducer and structure and process for the production of the structure. The magnetic structure only has one stack of layers of a magnetic material separated by layers of a non-magnetic metallic material having a thickness such that there is an anti-ferromagnetic coupling between the magnetic layers, the magnetic material being chosen from among the alloys FeNi, FeNiCo, and NiCo and the non-magnetic material is silver.Type: GrantFiled: May 27, 1999Date of Patent: December 26, 2000Assignee: Commissariat a l'Energie AtomiqueInventors: Bernard Rodmacq, Andre Pierrot, Philippe Gerard, Jean Mouchot
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Patent number: 6156375Abstract: A combined sunken magnetoresistive (MR) read/write head is provided wherein first and second shield layers are eliminated or thinned down in an insulation stack region just behind a pole tip region. This provides a depression behind the pole tip region where head components, such as the write coil, insulation stack and pole pieces of a write head, are located. Leads for an MR sensor of the head extend parallel to an air bearing surface (ABS) where they connect to first and second conductors beyond the limits of the shield layers. The conductors extend back into the head normal to the air bearing surface without any danger of shorting to the shield layers.Type: GrantFiled: February 5, 1999Date of Patent: December 5, 2000Assignee: International Business Machines CorporationInventors: Hung-Liang Hu, Rodney Edgar Lee, Hugo Alberto Emilio Santini, Ching Hwa Tsang
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Patent number: 6153320Abstract: A magnetic device uses laminated ferromagnetic layers containing antiferromagnetically coupled ferromagnetic films coupled together with improved antiferromagnetically coupling (AFC) films. The AFC films are formed of the binary and ternary alloys comprising combinations of Ru, Os and Re. The ferromagnetic film thicknesses, the AFC film thicknesses and the compositions of the films in the laminated layer can be varied to engineer the magnetic properties of the device. The magnetic devices whose properties are improved with the improved laminated layers include spin valve magnetoresistive read heads and magnetic tunnel junction (MTJ) devices for use as magnetic memory cells and magnetoresistive read heads.Type: GrantFiled: May 5, 1999Date of Patent: November 28, 2000Assignee: International Business Machines CorporationInventor: Stuart Stephen Papworth Parkin
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Patent number: 6150038Abstract: A reproducing layer, an intermediate layer, and a recording layer are successively stacked. The reproducing layer is made of a perpendicularly magnetized film whose domain wall coercivity is relatively smaller and whose domain wall mobility is relatively larger as compared with the recording layer around a reproducing temperature. When the reproducing layer, the intermediate layer, and the recording layer have Curie temperatures of Tc1, Tc2, and Tc3, Tc1, Tc2, and Tc3 satisfy a relationship of Tc2<Tc1<Tc3. Upon reproducing information, the reproducing layer is partially heated to more than the Curie temperature by irradiating with a light beam. This arrangement makes it possible to expand and reproduce a domain without causing a repetition of reproduction and to reproduce a signal having a period which is not more than an optical diffraction limit without reducing an amplitude of the reproduced signal, thereby dramatically improving a recording density.Type: GrantFiled: April 27, 1999Date of Patent: November 21, 2000Assignee: Sharp Kabushiki KaishaInventors: Junji Hirokane, Noboru Iwata
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Patent number: 6146691Abstract: A composite electromagnetic absorber provides increased EMR absorption while being thinner and/or lighter than prior art EMR absorbers. To accomplish this, synthetic dielectric materials are combined with either synthetic magnetic materials or magnetically lossy materials in such a way that the permittivity and permeability of the composite material are substantially matched over the desired range of frequency. The match in the permittivity and permeability allows the majority of the electromagnetic fields to enter the material where the electric and magnetic loss components absorb the electromagnetic energy.Type: GrantFiled: January 4, 1995Date of Patent: November 14, 2000Assignee: Northrop Grumman CorporationInventors: Rodolfo E. Diaz, Michael C. Miller, Michael M. Lo Re', James P. K. Gilb, Shahriar Alam
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Patent number: 6143375Abstract: 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: GrantFiled: January 28, 1999Date of Patent: November 7, 2000Assignee: Komag, IncorporatedInventors: Caroline A. Ross, Martin Philip Rosenblum
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Patent number: 6139906Abstract: This invention is directed to methods for depositing multilayered thin films onto substrates, for example in making thin film magnetic heads. In accordance with the invention a first film, such as Cr, is deposited onto the substrate at a first angle and a second layer, such as CoCrPt is deposited at a second angle.Type: GrantFiled: October 7, 1999Date of Patent: October 31, 2000Assignee: Veeco Instruments, Inc.Inventors: Hari Hegde, Adrian Devasahayam, Jinsong Wang
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Patent number: 6136458Abstract: A ferrite magnetic film structure exhibiting a magnetic anisotropy, the ferrite magnetic film structure comprising, a substrate provided on one main surface thereof with a groove-like recessed portion and with a ridge-like projected portion located neighboring to the groove-like recessed portion, and a ferrite magnetic film constituted by a continuous film having a substantially flat upper surface and formed on one main surface of the substrate, wherein the ferrite magnetic film structure meets the following conditions:(a/(a+b)) (h/t-h)).gtoreq.0.0471.gtoreq.(a+b)where "a" is a width of the ridge-like projected portion, b is a width of the groove-like recessed portion, h is a height of step between the groove-like recessed portion and the ridge-like projected portion, t is a thickness of the ferrite magnetic film at the recessed portion, and 1 is a length of the recessed portion and of the projected portion.Type: GrantFiled: September 11, 1998Date of Patent: October 24, 2000Assignee: Kabushiki Kaisha ToshibaInventor: Tetsuo Inoue
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Patent number: 6133047Abstract: The superparamagnetic monodispersed particles comprise a core of a first polymer, an internal layer of a second polymer coating the core and in which a magnetic material is distributed, and an external layer of a third polymer coating the magnetic layer and capable of interacting with at least one biological molecule. At least the second polymer is heat sensitive and has a predetermined lower critical solubility temperature (LCST) of 15-65.degree. C. These particles may be used to isolate at least one biological molecule from a liquid specimen.Type: GrantFiled: January 15, 1998Date of Patent: October 17, 2000Assignee: Bio MerieuxInventors: Abdelhamid Elaissari, Christian Pichot, Bernard Mandrand, Florence Sauzedde
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Patent number: 6129957Abstract: A method of manufacturing a magnetoresistive head comprises forming a magnetoresistive structure with a magnetoresistive element with a first AFM element. Perform a first annealing step at a high temperature with a high magnetic field. Form the remaining MR structure including second AFM elements. Perform a low magnetic field (H.sub.ann) annealing step following the fabrication of the second AFM elements. Then perform a no externally applied field (H.sub.ann =0) annealing step at a high temperature to increase the H.sub.ex of the second AFM element to full strength, whereby the stability of the first AFM element is enhanced or increases its H.sub.ex if there were a decrease during the low magnetic field annealing step.Type: GrantFiled: October 12, 1999Date of Patent: October 10, 2000Assignee: Headway Technologies, Inc.Inventors: Rongfu Xiao, Chyu-Jiuh Torng, Tai Min, Hui-Chuan Wang, Cherng-Chyi Han, Mao-Min Chen, Po-Kang Wan
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Patent number: 6126990Abstract: A method for producing a magnetic recording medium having low head abrasion loss and excellent mechanical strength characteristics, said medium having a magnetic layer mainly composed of a ferromagnetic powder and a binder on one surface of a non-magnetic support and a backcoat layer on the other surface of the support, wherein said ferromagnetic powder comprises chromium dioxide and cobalt-containing iron oxide within the weight ratio (wt %) range of 40:60 to 70:30, and said magnetic layer is formed of a paint prepared by a process comprising kneading cobalt-containing iron oxide and the binder at a solid concentration of 65% to 85% by weight, subsequently diluting the resulting product with the binder and a solvent, then, adding chromium dioxide thereto, followed by stirring to obtain a mixture, and subjecting the mixture to dispersion.Type: GrantFiled: March 18, 1998Date of Patent: October 3, 2000Assignee: TDK CorporationInventors: Kiyonori Hinoki, Kiyoto Fukushima
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Patent number: 6127045Abstract: A magnetic tunnel junction (MTJ) device is usable as a magnetic field sensor in magnetic disk drives or as a memory cell in a magnetic random access (MRAM) array. The MTJ device has a "pinned" ferromagnetic layer whose magnetization is oriented in the plane of the layer but is fixed so as not to be able to rotate in the presence of an applied magnetic field in the range of interest, a "free" ferromagnetic layer whose magnetization is able to be rotated in the plane of the layer relative to the fixed magnetization of the pinned ferromagnetic layer, and an insulating tunnel barrier layer located between and in contact with both ferromagnetic layers. The pinned ferromagnetic layer is pinned by interfacial exchange coupling with an adjacent antiferromagnetic layer. A high spin polarization ferromagnetic layer (Ni.sub.40 --Fe.sub.60) is placed near the tunnel barrier layer in both the pinned and free layers to enhance the magnetoresistive effect. The undesirable positive magnetostriction coefficient of the Ni.sub.Type: GrantFiled: May 13, 1998Date of Patent: October 3, 2000Assignee: International Business Machines CorporationInventor: Hardayal Harry Singh Gill