Treatment In A Magnetic Field Patents (Class 148/108)
  • Patent number: 5993566
    Abstract: A spin valve (SV) sensor having a Ni--Mn antiferromagnetic (AFM) layer, a pinned layer, a free layer and a spacer layer disposed between said free and pinned layers. The pinned layer is formed over and in contact with the antiferromagnetic (AFM) Ni--Mn layer where the combination of the AFM and pinned layers is first annealed before depositing the rest of the SV layers. Carrying out the annealing process of the combination of the AFM and pinned layers prior to deposition of the rest of the SV layers provides the exchange coupling field necessary to pin the pinned layer while avoiding thermal degradation of the SV sensor giant magnetoresistive effect.
    Type: Grant
    Filed: October 10, 1997
    Date of Patent: November 30, 1999
    Assignee: International Business Machines Corporation
    Inventor: Tsann Lin
  • Patent number: 5974657
    Abstract: A method is provided for resetting the magnetization of the pinned and hard biasing layers of a spin valve read head at the row level. In a first embodiment of the invention a first magnetic field is applied substantially perpendicular to the air bearing surface (ABS) at room temperature for setting the magnetic moment of the pinned layer substantially perpendicular to the ABS followed by applying a second magnetic field substantially parallel to the ABS for setting the magnetic moments of the hard biasing layers substantially parallel to the ABS. In a second embodiment of the invention the antiferromagnetic pinning layer is also reset. This is done by heating the pinning layer with a current pulse conducted through the leads to the conductive layers of the spin valve head so that localized heating takes place adjacent the pinning layer as contrasted to ambient heating of the spin valve head.
    Type: Grant
    Filed: March 19, 1998
    Date of Patent: November 2, 1999
    Assignee: International Business Machines Corporation
    Inventors: Ciaran Fox, Hardayal Singh Gill, Virgil Simon Speriosu, Jila Tabib
  • Patent number: 5949334
    Abstract: A magnetostrictive element for use in a magnetomechanical marker has a resonant frequency characteristic that is at a minimum at a bias field level corresponding to the operating point of the magnetomechanical marker. The magnetostrictive element has a magnetomechanical coupling factor k in the range 0.28 to 0.4 at the operating point. The magnetostrictive element is formed by applying current-annealing to an iron-nickel-cobalt based amorphous metal ribbon, or by cross-field annealing an iron-nickel-cobalt alloy that includes a few percent chromium and/or niobium.
    Type: Grant
    Filed: February 14, 1997
    Date of Patent: September 7, 1999
    Assignee: Sensormatic Electronics Corporation
    Inventors: Ming-Ren Lian, Nen-Chin Liu, Kevin Coffey, Richard Copeland, Wing Ho, Robert C. O'Handley
  • Patent number: 5935346
    Abstract: Process for the heat treatment, in a magnetic field, of a magnetic component made of a low-anisotropy soft magnetic material such as, for example, a 15/80/5 FeNiMo alloy, an amorphous Co-based alloy or a nanocrystalline FeSiCuNbB alloy, in which the magnetic component is annealed at a temperature below the Curie point of the magnetic material and, during the annealing, the magnetic component is subjected to a DC or AC, unidirectional, longitudinal or transverse magnetic field, in which process the magnetic field is applied in the form of a succession of pulses each comprising a first part during which the intensity of the magnetic field reaches a maximum value and a second part during which the intensity of the magnetic field has a minimum value.
    Type: Grant
    Filed: May 21, 1998
    Date of Patent: August 10, 1999
    Assignee: Mecagis
    Inventors: Georges Couderchon, Philippe Verin
  • Patent number: 5922143
    Abstract: Process for manufacturing at least one magnetic core made of an iron-based soft magnetic alloy having a nanocrystalline structure, wherein an amorphous ribbon is manufactured from the magnetic alloy, the annealing temperature Tm which, in the case of the ribbon, leads to maximum magnetic permeability, is determined, at least one core blank is manufactured from the ribbon and at least one core blank is subjected to at least one annealing operation, said annealing being carried out at a temperature T of between Tm+10.degree. C. and Tm+50.degree. C. for a temperature hold time t of between 0.1 and 10 hours so as to cause nanocrystals to form.
    Type: Grant
    Filed: October 27, 1997
    Date of Patent: July 13, 1999
    Assignee: Mecagis
    Inventors: Philippe Verin, Georges Couderchon
  • Patent number: 5911840
    Abstract: Process for manufacturing a magnetic component made of an iron-based soft magnetic alloy having a nanocrystalline structure, the chemical composition of which is, in at. %, Fe.gtoreq.60%, 0.1%.ltoreq.Cu.ltoreq.3%, 0%.ltoreq.B.ltoreq.25%, 0%.ltoreq.Si.ltoreq.30%, and at least one element selected from niobium, tungsten, tantalum, zirconium, hafnium, titanium and molybdenum with contents of between 0.1% and 30%, the balance being impurities resulting from the smelting, the composition furthermore satisfying the relationship 5%.ltoreq.Si+B.ltoreq.30%, according to which an amorphous ribbon is manufactured from the magnetic alloy, a blank for a magnetic component is manufactured from the ribbon and the magnetic component is subjected to a crystallization heat treatment comprising at least one annealing step at a temperature of between 500.degree. C. and 600.degree. C. for a temperature hold time of between 0.
    Type: Grant
    Filed: December 11, 1997
    Date of Patent: June 15, 1999
    Assignee: Mecagis
    Inventors: Georges Couderchon, Philippe Verin
  • Patent number: 5898253
    Abstract: A soft magnetic structure substantially comprised of a plurality of magnetic field carrying particles molded and retained in a predetermined shape, bonded in that shape by an insulating binding agent, wherein said particles have grain alignment substantially parallel to a preferred direction, and wherein said preferred direction is parallel to a direct axis providing the structure with a high direct axis to quadrature axis reactance ratio.
    Type: Grant
    Filed: June 16, 1997
    Date of Patent: April 27, 1999
    Assignee: General Motors Corporation
    Inventors: Ahmed Mostafa El-Antably, Robert Walter Ward
  • Patent number: 5885370
    Abstract: Magnetic heat treatment of steel, characterized by transforming steel containing about 0.01 to 2.0 mass % of carbon in a magnetic field having a gradient of about 0.1 T/cm or more and about 10 T/cm or less (absolute value) at the Curie point or lower, to effectively refine the microstructure by subjecting the steel to heat treatment in a strong magnetic field having a gradient, followed by advantageously improving the mechanical properties of the steel.
    Type: Grant
    Filed: April 13, 1998
    Date of Patent: March 23, 1999
    Assignee: Kawasaki Steel Corporation
    Inventors: Michio Shimotomai, Akihiro Matsuzaki, Yasunori Yonehana
  • Patent number: 5841348
    Abstract: A resonator for use in a marker, with a bias element which produces a bias field, in a magnetomechanical electronic article surveillance system is composed of an amorphous magnetostrictive alloy containing iron, cobalt, nickel, silicon and boron in quantities for giving the resonator a quality Q which is between about 100 and 600. The amorphous magnetostrictive alloy is annealed in a transverse magnetic field for giving it a B-H loop which is linear up to about 8 Oe and an anisotropy field strength of at least 10 Oe. When the resonator is excited to resonate by a signal emitted by the transmitter in the surveillance system, it produces a signal at a mechanical resonant frequency which can be detected by the receiver of the detection system. Due to the resonator having a quality Q in the above range, the signal produced by the resonator in a first detector window, beginning approximately 0.
    Type: Grant
    Filed: July 9, 1997
    Date of Patent: November 24, 1998
    Assignee: Vacuumschmelze GmbH
    Inventor: Giselher Herzer
  • Patent number: 5835016
    Abstract: A marker for a harmonic electronic article surveillance system includes three wires of magnetic material arranged in parallel. The material has a magnetic hysteresis loop with a large Barkhausen discontinuity such that, upon exposure of the marker to an external magnetic field whose field strength in the direction opposing the instantaneous magnetic polarization of the marker exceeds a predetermined threshold value, there results a regenerative reversal of the magnetic polarization in the material. The three wires are coupled at opposite ends thereof by flux concentrating elements formed of a highly permeable material so that all three wires exhibit the regenerative reversal simultaneously on exposure to the above-described magnetic field. The flux concentrators have magnetic anisotropies oriented transversely relative to the length of the wires to aid in coupling the wires for simultaneous switching.
    Type: Grant
    Filed: December 15, 1997
    Date of Patent: November 10, 1998
    Assignee: Sensormatic Electronics Corporation
    Inventors: Wing Ho, Jiro Yamasaki
  • Patent number: 5792284
    Abstract: Magnetostrictive powder composite and method for the manufacturing of the magnetostrictive powder composite. The composite comprises magnetostrictive powder grains with chemical composition (RE).sub.x T.sub.1-x, where RE represents one or a mixture of several rare earth metals, T represents iron, nickel, cobalt, manganese or a mixture of these metals and x represents atomic fraction assuming a value between 0 and 1, whereby the grains are held together by a binder. The magnetostrictive grains constitute greater than 60 percent by volume of the composite. The composite is produced by pressing together magnetostrictive powder grains and the binder. Isostatic pressure may be used in the pressing step.
    Type: Grant
    Filed: May 15, 1995
    Date of Patent: August 11, 1998
    Assignees: Fox Technology KB, Proengco AB
    Inventors: Tord Cedell, Lars Sandlund
  • Patent number: 5786762
    Abstract: A magnetostrictive element for use in a magnetomechanical article surveillance marker formed by first annealing an amorphous metal alloy, such alloy comprising iron and cobalt with the proportion of cobalt being in the range of about 5 to about 45 atomic percent, in the presence of a saturating magnetic field and then second annealing the alloy in the absence of the saturating magnetic field.
    Type: Grant
    Filed: October 22, 1996
    Date of Patent: July 28, 1998
    Assignee: Sensormatic Electronics Corporation
    Inventor: Nen-Chin Liu
  • Patent number: 5772794
    Abstract: A method of manufacturing a magnetic head apparatus with a magnetoresistive head utilizing the spin valve effect includes a final heat treatment step (S14) of heating the multi-layered spin valve structure (15) with application of a magnetic field in a direction perpendicular to a track width direction of the spin valve magnetoresistive head so that a thin film layer of soft ferromagnetic material (3, 5) to be pinned by a thin film layer of antiferromagnetic material (6) has a uniaxial anisotropy. This final heat treatment step (S14) is executed after all the steps (S1, S3, S5, S7, S8, S9, S11) each of which includes a heat treatment stage executed at a temperature which will vary a uniaxial anisotropy of the pinned thin film layer of soft ferromagnetic material (3,5) are completed.
    Type: Grant
    Filed: October 7, 1996
    Date of Patent: June 30, 1998
    Assignee: TDK Corporation
    Inventors: Yasufumi Uno, Daisuke Miyauchi, Mikio Matsuzaki
  • Patent number: 5757272
    Abstract: For security against theft or for identification of products using an electronic alternating field in an interrogation zone, a pulse generator, upon magnetic reversal due to a Barkhausen jump, exhibits an impulse behavior that produces characteristic harmonics and largely prevents confusion with other magnetically soft materials in the interrogation zone. This pulse generator is formed of an amorphous strip or an amorphous wire with a cobalt content of at least 20 at-%, subjected to a heat treatment by a current flowing through the strip or wire, to produce a ratio of remanence induction to saturation induction of between 0.2 and 0.9.
    Type: Grant
    Filed: September 9, 1996
    Date of Patent: May 26, 1998
    Assignee: Vacuumschmelze GmbH
    Inventors: Giselher Herzer, Gerd Rauscher
  • Patent number: 5689797
    Abstract: Structure and a method for producing very dense bodies from particulate materials. An electrically conductive drive member is positioned adjacent the particulate material. A significant magnitude of electrical current is caused to flow through the electrically conductive drive member. A magnetic field is established and large magnitudes of magnetic pressure are created, and pressure directly from or indirectly from the magnetic pressure is applied upon the particulate material, and the particulate material is compressed and compacted. In one embodiment of the invention electrical current creates a magnetic field which is applied to an electrically conductive pressure member which moves and applies compaction pressure upon the particulate material. Electromagnetic pressure in accordance with this invention may be applied to a compacted body of particulate material, and the compressibility and density of the body of particulate material is increased.
    Type: Grant
    Filed: April 6, 1995
    Date of Patent: November 18, 1997
    Assignee: IAP Research, Inc.
    Inventors: Bhanumathi Chelluri, John P. Barber, Duane Charles Newman
  • Patent number: 5676767
    Abstract: A magnetostrictive element for use in a magnetomechanical electronic article surveillance marker is formed by annealing a continuous ribbon of an amorphous metal alloy. The alloy ribbon is transported from reel to reel through an oven in which a transverse saturating magnetic field is applied to the ribbon. The annealed ribbon is cut into discrete strips which are suitable for use as magnetostrictive elements.
    Type: Grant
    Filed: April 12, 1995
    Date of Patent: October 14, 1997
    Assignee: Sensormatic Electronics Corporation
    Inventors: Nen-Chin Liu, Larry Speciale
  • Patent number: 5650023
    Abstract: A glassy metal alloy consists essentially of the formula Fe.sub.a Co.sub.b Ni.sub.c M.sub.d B.sub.c Si.sub.f C.sub.g, where "M" is at least one member selected from the group consisting of molybdenum, chromium and manganese, "a-g" are in atom percent, "a" ranges from about 30 to about 45, "b" ranges from about 4 to about 40, "c" ranges from about 5 to about 45, "d" ranges from about 0 to about 3, "3" ranges from about 10 to about 25, "f" ranges from about 0 to about 15 and "g" ranges from about 0 to about 2. The alloy can be cast by rapid solidification into ribbon, annealed to enhance magnetic properties, and formed into a marker that is especially suited for use in magneto-mechanically actuated article surveillance systems. Advantageously, the marker is characterized by relatively linear magnetization response in the frequency regime wherein harmonic marker systems operate magnetically.
    Type: Grant
    Filed: June 6, 1995
    Date of Patent: July 22, 1997
    Inventors: Ryusuke Hasegawa, Ronald Martis
  • Patent number: 5611871
    Abstract: A method for producing a nanocrystalline alloy wherein an amorphous alloy is heat-treated by keeping the temperature at a first heat treatment temperature higher than the crystallization temperature of the amorphous alloy for 0 to less than 5 minutes, and is cooled to room temperature at a cooling rate of 20.degree. C./min or more at least until the temperature falls to 400.degree. C. The amorphous alloy subjected to the first heat treatment may be further heat-treated at a second heat treatment temperature not higher than 500.degree. C. and lower than the first heat treatment temperature while applying a magnetic field. The nanocrystalline alloy produced by the method of the invention has a extremely high specific initial permeability as compared with the conventional nanocrystalline alloy, and is suitable for use in magnetic core of transformers, choke coils, etc.
    Type: Grant
    Filed: July 19, 1995
    Date of Patent: March 18, 1997
    Assignee: Hitachi Metals, Ltd.
    Inventors: Yoshihito Yoshizawa, Yoshio Bizen, Shin Nakajima, Shunsuke Arakawa
  • Patent number: 5611139
    Abstract: Structure and a method for producing very dense bodies from particulate materials. An electrically conductive drive member is positioned adjacent the particulate material. A significant magnitude of electrical current is caused to flow through the electrically conductive drive member. A magnetic field is established and large magnitudes of magnetic pressure are created, and pressure directly from or indirectly from the magnetic pressure is applied upon the particulate material, and the particulate material is compressed and compacted. In one embodiment of the invention electrical current creates a magnetic field which is applied to an electrically conductive pressure member which moves and applies compaction pressure upon the particulate material. Electromagnetic pressure in accordance with this invention may be applied to a compacted body of particulate material, and the compressibility and density of the body of particulate material is increased.
    Type: Grant
    Filed: April 6, 1995
    Date of Patent: March 18, 1997
    Assignee: IAP Research, Inc.
    Inventors: Bhanumathi Chelluri, John P. Barber, Duane C. Newman
  • Patent number: 5601662
    Abstract: There is disclosed a method of introducing magnetic anisotropy into a magnetic material, in which a laser beam is selectively radiated on the surface of a magnetic material to locally heat it, thereby forming a pattern of boundary phases for magnetically dividing a main phase of the magnetic material into a plurality of regions, and magnetic domains of the divided main phase regions are controlled to induce magnetic anisotropy in the main phase regions.
    Type: Grant
    Filed: June 29, 1990
    Date of Patent: February 11, 1997
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Takahiro Hirai, Tadahiko Kobayashi, Masashi Sahashi
  • Patent number: 5585170
    Abstract: Disclosed is a process using an electric field for contacting a substantially neutrally charged material, that is responsive to an electric field, with a substrate. Also disclosed is a disposable absorbent product, including the electrically responsive material, that is intended for the absorption of body fluids, prepared by the process.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: December 17, 1996
    Assignee: Kimberly-Clark Corporation
    Inventors: Marion C. Morris, Robert R. Bomber, Franklin M. C. Chen, Ronald H. Wideman
  • Patent number: 5568125
    Abstract: A two-step continuous annealing process is applied to an amorphous metal alloy ribbon. During the first annealing step, a saturating transverse magnetic field is applied, and the field is omitted during the second annealing step. After the two annealing steps, the material is cut into discrete strips suitable for use as active elements in pulsed-field magnetomechanical EAS markers. The resulting markers exhibit satisfactory total frequency shift and ring-down signal amplitude characteristics, without excessive sensitivity to bias field variations.
    Type: Grant
    Filed: July 28, 1995
    Date of Patent: October 22, 1996
    Assignee: Sensormatic Electronics Corporation
    Inventor: Nen-Chin Liu
  • Patent number: 5565849
    Abstract: A self-biasing magnetostrictive element for a magnetomechanical EAS marker is formed by first annealing a ribbon of ferromagnetic material in the presence of a magnetic field applied in a transverse direction relative to the ribbon's longitudinal axis, and then annealing the ribbon a second time in the presence of a magnetic field applied in the direction of the longitudinal axis. The twice-annealed ribbon exhibits remanent magnetization along the longitudinal axis and has plural magnetic domains situated along the longitudinal axis. The orientation of magnetization in each domain is canted by .+-..theta..degree.<90.degree. from the ribbon axis with the direction of canting alternating from domain to domain.
    Type: Grant
    Filed: February 22, 1995
    Date of Patent: October 15, 1996
    Assignee: Sensormatic Electronics Corporation
    Inventors: Wing Ho, Nen-chin Liu, Robert O'Handley
  • Patent number: 5549973
    Abstract: A metal or alloy nanoparticle is provided which exhibits hysteresis at room temperature having a carbon coating. The nanoparticle has a diameter in the range of approximately 0.5 to 50 nm, and may crystalline or amorphous. The metal, alloy, or metal carbide nanoparticle is formed by preparing graphite rods which are packed with the magnetic metal or alloy. or an oxide of the metal or alloy. The packed graphite rods are subjected to a carbon arc discharge to produce soot containing metal, alloy, or metal carbide nanoparticles and non-magnetic species. The spot is subsequently subjected to a magnetic field gradient to separate the metal, alloy, or metal carbide nanoparticles from the non-magnetic species.
    Type: Grant
    Filed: June 24, 1994
    Date of Patent: August 27, 1996
    Assignee: Carnegie Mellon University
    Inventors: Sara Majetich, Michael McHenry, John H. Scott, Elaine Brunsman, Scott Kirkpatrick
  • Patent number: 5503686
    Abstract: A magnetic recording head that includes a combined IN element and an MR element is heat treated under two types of magnetic fields. A rotating magnetic field, having a first magnetic field intensity, is applied for a time while the magnetic recording head is at an elevated temperature. Then, part-way during cooling of the magnetic head, the rotating magnetic field is replaced by a direct (non-rotating) magnetic field having a second magnetic field intensity. The second magnetic field intensity is lower than the first magnetic field intensity, whereby the properties of both the IN element and the MR element are maintained at high values.
    Type: Grant
    Filed: March 13, 1995
    Date of Patent: April 2, 1996
    Assignee: Fuji Electric Co., Ltd.
    Inventors: Yuko Okamura, Keiji Ohkubo, Osamu Saito, Toyoji Ataka
  • Patent number: 5494534
    Abstract: Two-stage heat treatment is used to improve the initial permeability and core loss of a soft amorphous magnetic article. The first-stage heat treatment is performed at a temperature less than the curie temperature of the amorphous soft magnetic article by 0.degree.-50.degree. C. for 0-10 hours, while applying a static magnetic field which is larger than 1000 Oe in a first direction which is generally perpendicular to the direction the magnetic article is to be magnetized when used or measured. The second-stage heat treatment is performed at a temperature less than the crystallization temperature of the amorphous soft magnetic article by 0.degree.-100.degree. C. for 0-10 hours, while applying a static magnetic field which is between 50 Oe and 1000 Oe in the first direction. Prior to performing the second-stage heat treatment, the temperature is lowered to room temperature.
    Type: Grant
    Filed: March 17, 1995
    Date of Patent: February 27, 1996
    Assignee: Industrial Technology Research Institute
    Inventor: Ming-Sheng Leu
  • Patent number: 5492754
    Abstract: Disclosed is an absorbent composition including a hydrogel-forming polymeric material and a magnetically-responsive material; disposable absorbent products, including the absorbent composition, intended for the absorption of body fluids; and a method for incorporating the absorbent composition into disposable absorbent products.
    Type: Grant
    Filed: December 15, 1993
    Date of Patent: February 20, 1996
    Assignee: Kimberly-Clark Corporation
    Inventor: Franklin M. C. Chen
  • Patent number: 5469140
    Abstract: A ribbon-shaped strip of an amorphous magnetic alloy is heat treated, while applying a transverse saturating magnetic field. The treated strip is used in a marker for a pulsed-interrogation electronic article surveillance system. A preferred material for the strip is formed of iron, cobalt, silicon and boron with the proportion of cobalt exceeding 30% by atomic percent.
    Type: Grant
    Filed: June 30, 1994
    Date of Patent: November 21, 1995
    Assignee: Sensormatic Electronics Corporation
    Inventors: Nen-chin Liu, Ming-Ren Lian, Jimmy Cantey
  • Patent number: 5456986
    Abstract: A magnetic metal or metal carbide nanoparticle is provided having a carbon coating. The nanoparticle has a diameter in the range of approximately 5 to 60 nm, and may be crystalline or amorphous. The magnetic metal or metal carbide nanoparticle is formed by preparing graphite rods which are packed with a magnetic metal oxide. The packed graphite rods are subjected to a carbon arc discharge to produce soot containing magnetic metal or metal carbide nanoparticles and non-magnetic species. The soot is subsequently subjected to a magnetic field gradient to separate the magnetic metal or metal carbide nanoparticles from the non-magnetic species. Ferromagnetic or paramagnetic compounds are made by starting with graphite rods packed with the oxides of iron, cobalt, nickel and manganese bismuth, or a rare earth element excluding lanthanum, lutetium and promethium, or a paramagnetic transition metal.
    Type: Grant
    Filed: June 30, 1993
    Date of Patent: October 10, 1995
    Assignee: Carnegie Mellon University
    Inventors: Sara Majetich, Michael McHenry, Joseph Artman, Stuart Staley
  • Patent number: 5428888
    Abstract: A manufacturing process for use in manufacturing magnetic field sensor head cores, comprises: providing a core formed of an amorphous ferromagnetic material on which is placed an insulating layer; mounting, a first winding that functions as a drive coil for the core over said insulating layer; providing second (37) and third (38) coils on said core (31) that respectively function as a sensor and a compensating coil for the sensor head; both the second and third coils being wound in form of a hollow cylinder 36 inside of which is positioned an assembly formed by the core 31 and the drive coil 32; supplying a first electric current to the core 31 of the sensor head, said core heating up as said first current flows through said drive winding, supplying a second and alternating electric current to that the one 38 of compensating and sensor coils 37 and 38 that surrounds the core 31 and functions as the compensating winding 38; monitoring a signal induced in the other coil 37 that functions as the sensor winding a
    Type: Grant
    Filed: January 3, 1994
    Date of Patent: July 4, 1995
    Assignee: Alcatel Standard Electrica, S.A.
    Inventors: Claudio A. Hernandez-Ros, Ma Carmen S. Trujilio, Eloisa L. Perez, Pedro S. Sanchez
  • Patent number: 5399311
    Abstract: A magnet is formed as a ring magnet and magnetized by radial application of a magnetic field while the intensity of the magnetic field is changed periodically along the circumference of the ring magnet to give a circumferentially sinusoidal waveform distribution of magnetic flux density to the ring magnet in the magnetized state of the magnet.
    Type: Grant
    Filed: November 12, 1992
    Date of Patent: March 21, 1995
    Assignee: Daido Tokushuko Kabushiki Kaisha
    Inventors: Yasuaki Kasai, Hiyoshi Yamada, Norio Yoshikawa
  • Patent number: 5395460
    Abstract: The present invention discloses a process for enhancing the harmonic output of a marker comprising the steps of providing an amorphous alloy having a composition (Fe.sub.1-x Ni.sub.x).sub.a M.sub.b (B.sub.1-y Si.sub.y).sub.c wherein "x" ranges from about 0.2 to about 0.9, "y" ranges from 0 up to about 0.5, "a" is between about 60 and about 90 atomic %, "b" is between about 0.1 to about 10 atomic %, "c" is between about 0.1 to about 30 atomic percent, and M is at least one metal selected from the group consisting of Mo, Cr, Hf, Nb, Ta, Ti, V, W, and Zr, the amorphous alloy having at least two crystallization temperatures, a first crystallization temperature at which a nanocrystalline phase is formed, and a second crystallization temperature at which a second crystalline phase is formed; annealing the amorphous alloy at a temperature between the first and the second crystallization temperatures for a time sufficient to increase at least one harmonic characteristic of the element.
    Type: Grant
    Filed: October 16, 1992
    Date of Patent: March 7, 1995
    Assignee: AlliedSignal Inc.
    Inventor: Ronald J. Martis
  • Patent number: 5382301
    Abstract: A thin-film magnetic head is disclosed that includes a lower magnetic core and an upper magnet core formed on the surface of a substrate and connected together at a first end thereof, a magnetic gap is formed between the lower and upper magnetic cores at a second end thereof, and a coil-form electric conductive layer is located between the lower magnetic core and the upper magnet core. The lower and upper magnetic cores have a saturated magnetic flux density from 10,000 G to 18,000 G, while the magnetic permeability along the magnetic path of the magnetic head is 3,000 or higher at a frequency of 10 MHz. The unique characteristics of the magnetic head are obtained by heating an arrangement comprising the lower and upper magnetic cores, the magnetic gap layer, and the electric conductive layer to a temperature above 325.degree. C., and applying an external magnetic field greater than 0.
    Type: Grant
    Filed: October 15, 1992
    Date of Patent: January 17, 1995
    Assignee: Fuji Electric Co., Ltd.
    Inventors: Keiji Ohkubo, Yuko Arimoto, Hiroyuki Uwazumi, Hisashi Yamasaki
  • Patent number: 5366566
    Abstract: A method for preparing a sample of a magnetic susceptibility compound .chi. comprises the steps of providing a vertical magnetic induction B which has a magnetic induction gradient dB/dz and which is such that B.dB/dz has a sign opposite to that to the weight of the sample and such that the magnetic force (.chi..B.dB/dz)/.sub..mu.0 is higher than the weight and heating at a temperature close to the melting temperature.
    Type: Grant
    Filed: July 31, 1991
    Date of Patent: November 22, 1994
    Assignee: Centre National de la Recherche Scientifique
    Inventor: Robert Tournier
  • Patent number: 5328523
    Abstract: The invention relates to a composite, multilayer magnetic material incorporating at least one thin polymer support film, which is mechanically and thermally strong, coated on at least one of its faces with a thin deposit of an amorphous ferromagnetic compound having a magnetic permeability higher than 30, in which the density d and the permeability of the magnetic material are such that 5.ltoreq..mu./d.ltoreq.100.
    Type: Grant
    Filed: May 28, 1992
    Date of Patent: July 12, 1994
    Assignee: Commissariat A L'Energie Atomique
    Inventors: Jean-Marie Fontaine, Arnaud Varoquauz
  • Patent number: 5313192
    Abstract: A marker for use in an electronic article surveillance system in which the marker comprises a magnetically soft component and exhibits a pinned wall hysteresis characteristic with a step change in flux at a threshold value of applied field and in which the marker further comprises a magnetically hard or semi-hard component integral with the soft component and whose magnetic state can be switched between activating and deactivating states to switch the marker between active and deactive states.
    Type: Grant
    Filed: July 2, 1992
    Date of Patent: May 17, 1994
    Assignee: Sensormatic Electronics Corp.
    Inventors: Wing Ho, Jiro Yamasaki
  • Patent number: 5304983
    Abstract: A responder for electronic article surveillance apparatus is made by subjecting a plurality of magnetizable elements to heating in the presence of a magnetic field and maintaining the field at a different intensity for each element as it is cooled to provide different magnetic characteristics so that when the responder is subjected to a cyclically varying magnetic interrogation field its several elements produce spaced apart pulses in each cycle.
    Type: Grant
    Filed: December 4, 1991
    Date of Patent: April 19, 1994
    Assignee: Knogo Corporation
    Inventors: Peter Y. Zhou, John Dunn, Charles D. Graham, Kyung-Ho Shin
  • Patent number: 5296049
    Abstract: A magnetic metallic glass alloy exhibits, in combination, high saturation induction and low magnetic anisotropy energy. The alloy has a composition described by the formula Fe.sub.a Co.sub.b B.sub.c Si.sub.d C.sub.e, where "a"-"e" are in atom percent, "a" ranges from about 72 to about 84, "b" ranges from about 2 to about 8, "c" ranges from about 11 to about 16, "d" ranges from about 1 to about 4, and "e" ranges from 0 to about 4, with up to about 1 atom percent of Mn being optionally present. Such an alloy is especially suited for use in large magnetic cores associated with pulse power applications requiring high magnetization rates. Examples of such applications include high power pulse sources for linear induction particle accelerators, induction modules for coupling energy from the pulse source to the beam of these accelerators, magnetic switches in power generators in inertial confinement fusion research, magnetic modulators for driving excimer lasers, and the like.
    Type: Grant
    Filed: May 25, 1993
    Date of Patent: March 22, 1994
    Assignee: Allied-Signal Inc.
    Inventors: V. R. V. Ramanan, Carl H. Smith
  • Patent number: 5256211
    Abstract: The present invention is directed to a process for rapidly field annealing ferromagnetic cores and the cores produced thereby. A current is applied across a magnetizing source associated with a magnetizing core which induces a flux/voltage in the ferromagnetic core which is disposed about a leg of the magnetizing core. The flux/voltage in the second core induces a current in the second core which in turn induces a field in, and transverse to the width direction of, the ferromagnetic core. A second field may e applied to the ferromagnetic core during cooling. The cores produced display low core loss and either sheared over or square loop properties which are suitable for current and distribution type transformers respectively.
    Type: Grant
    Filed: December 19, 1991
    Date of Patent: October 26, 1993
    Assignee: Allied Signal
    Inventors: John Silgailis, Davidson M. Nathasingh, Carl H. Smith
  • Patent number: 5225005
    Abstract: A method of heat treating an amorphous metal alloy by immersing the alloy in a fluidized bed to heat the alloy to a temperature below its recrystallization temperature. The alloy is maintained in the fluidized bed for a time sufficient to reduce internal stresses while minimizing crystal growth and nucleation of crystallites in the alloy. Then, the alloy is removed from the fluidized bed and cooled. A magnetic field can be applied to the alloy before, during or after heating the alloy in the fluidized bed. The magnetic field is applied for a time sufficient to achieve substantial magnetic domain alignment while minimizing crystal growth and nucleation of crystallites in the alloy. The cooling step is effective to maintain the magnetic domain alignment in the alloy. The cooling step can be performed with a chill bath or a fluidized bed which is cooled by a circulating gas such as nitrogen or air. The alloy can be slowly cooled by convection and radiation after it is removed from the first fluidized bed.
    Type: Grant
    Filed: March 28, 1991
    Date of Patent: July 6, 1993
    Assignee: Cooper Power Systems, Inc.
    Inventors: Lawrence M. Burrage, John F. Baranowski, Lawrence G. Wilson, Gary L. Goedde, James V. White
  • Patent number: 5214840
    Abstract: A method of fabricating a thin film magnetic head including a bottom magnetic core formed on a substrate, a top magnetic core laminated through an insulation layer, with one end of the top and bottom magnetic cores being joined and another end forming a magnetic gap, and a conductor coil layer which winds around the joined section for a plurality of number of turns. At least one of the top and bottom magnetic cores has its magnetization easy axis oriented substantially orthogonal to the magnetic path direction of the magnetic head by the magnetic annealing process, so that the magnetic head has an increased output and an enhanced write ability.
    Type: Grant
    Filed: July 10, 1990
    Date of Patent: June 1, 1993
    Assignee: Hitachi, Ltd.
    Inventors: Takao Imagawa, Masaaki Sano, Katsuya Mitsuoka, Kouichi Nishioka, Shinji Narishige, Tetsuo Kobayashi
  • Patent number: 5204526
    Abstract: A magnetic marker has a plurality of thin strips or wires of saturatable magnetic material having square .phi.-H characteristics and coercive forces different from each other. Amorphous magnetic material may be used. When the marker is subjected to magnetization reversal by an external magnetic field, variations of magnetic flux corresponding to a plurality of magnetization reversals can be chronologically detected as a voltage pulse train by detecting coils. By processing this voltage pulse train, a pattern can be made, recognized, so that the magnetic marker effectively identifies the kind of article to which it is attached. A magnetic marker reading and identifying apparatus has a plurality of exciting coils for producing a rotating magnetic field, with the axis of at least one of the exciting coils being orthogonal to the axis of at least one other exciting coil. The rotating a.c.
    Type: Grant
    Filed: February 18, 1992
    Date of Patent: April 20, 1993
    Assignee: Fuji Electric Co., Ltd.
    Inventors: Mitsuo Yamashita, Kaneo Mohri, Osamu Saito
  • Patent number: 5201964
    Abstract: Magnetostrictive wire having a low surface-to-volume ratio established by a onstant non-planar cross-section, is helically deformed into contact with a shaft under a stress maintaining the wire in fixed relation to the shaft surface. Magnetic anisotropy is imparted to the wire by twist thereof about its cross-sectional axis while the wire is being helically deformed into contact with the shaft surface to form a torque sensor through which accurate torque detection is achieved.
    Type: Grant
    Filed: June 21, 1989
    Date of Patent: April 13, 1993
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Howard T. Savage, Arthur E. Clark, Marilyn Wun-Fogle, Lawrence T. Kabacoff, Antonio Hernando, Bruce Beihoff
  • Patent number: 5176806
    Abstract: A soft magnetic alloy film has a composition formula expressed by Fex Mz Cw. M is at least one metallic element selected from a group consisting of Ti, Zr, Hf, Nb, Ta, Mo or W, or a mixture of these metallic elements. The composition ratio of x, z and w satisfies the relation expressed by 50 atomic % .ltoreq.x.ltoreq.96 atomic %, 2 atomic % .ltoreq.z.ltoreq.30 atomic %, 0.5 atomic % .ltoreq.w.ltoreq.25 atomic %, and x+z+w=100. The metallic structure of the soft magnetic alloy film basically consists of crystal grains having an average grain size of 0.08 .mu.m or below. The metallic structure contains the crystal phase of carbide of the element M.
    Type: Grant
    Filed: September 27, 1990
    Date of Patent: January 5, 1993
    Assignee: Alps Electric Co., Ltd.
    Inventor: Naoya Hasegawa
  • Patent number: 5160379
    Abstract: An Fe-base soft magnetic alloy having the composition represented by the general formula:(Fe.sub.1-a M.sub.a).sub.100-x-y-z-.alpha.-.beta.-.gamma. Cu.sub.x Si.sub.y B.sub.z M'.sub..alpha. M".sub..beta. X.sub..gamma.wherein M is Co and/or Ni, M' is at least one element selected from the group consisting of Nb, W, Ta, Zr, Hf, Ti and Mo, M" is at least one element selected from the group consisting of V, Cr, Mn, Al, elements in the platinum group, Sc, Y, rare earth elements, Au, Zn, Sn and Re, X is at least one element selected from the group consisting of C, Ge, P, Ga, Sb, In, Be and As, and a, x, y, z, .alpha., .beta. and .gamma. respectively satisfy 0.ltoreq.a.ltoreq.0.5, 0.1.ltoreq.x.ltoreq.3, 0.ltoreq.y.ltoreq.30, 0.ltoreq.z.ltoreq.25, 5.ltoreq.y+z.ltoreq.30, 0.1.ltoreq..alpha..ltoreq.30, .beta..ltoreq.10 and .gamma..ltoreq.10, at least 50% of the alloy structure being fine crystalline particles having an average particle size 1000 .ANG. or less.
    Type: Grant
    Filed: January 22, 1991
    Date of Patent: November 3, 1992
    Assignee: Hitachi Metals, Ltd.
    Inventors: Yoshihito Yoshizawa, Kiyotaka Yamauchi, Shigeru Oguma
  • Patent number: 5157232
    Abstract: Metal workpieces having portions of different mass are sequentially stepped through a series of induction heating units having differently contoured inductors for inductively heating the workpiece portions of different mass so as to progressively elevate the portions of different mass to a uniform temperature.
    Type: Grant
    Filed: May 18, 1990
    Date of Patent: October 20, 1992
    Assignee: Tocco, Inc.
    Inventor: George D. Pfaffmann
  • Patent number: 5151137
    Abstract: A magnetic alloy with ultrafine crystal grains having a composition represented by the general formula:Co.sub.100.sub.-x-y-z-a-b Fe.sub.a M.sub.x B.sub.y X.sub.z T.sub.b (atomic %)wherein M represents at least one element selected from Ti, Zr, Hf, V, Nb, Mo, Ta, Cr, W and Mn, X represents at least one element selected from Si, Ge, P, Ga, Al and N, T represents at least one element selected from Cu, Ag, Au, platinum group elements, Ni, Sn, Be, Mg, Ca, Sr and Ba, 0<a.ltoreq.30, 2.ltoreq.x.ltoreq.15, 10.ltoreq.y.ltoreq.25, 0.ltoreq.z.ltoreq.10, 0<b.ltoreq.10, and 12<x+y+z+b.ltoreq.35. Such a magnetic alloy can be produced by producing an amorphous alloy having the above composition, and subjecting the resulting amorphous alloy to a heat treatment to cause crystallization, thereby providing the resulting alloy having a structure, at least 50% of which is occupied by crystal grains having an average grain size of 500 .ANG. or less.
    Type: Grant
    Filed: November 16, 1990
    Date of Patent: September 29, 1992
    Assignee: Hitachi Metals Ltd.
    Inventors: Yoshihito Yoshizawa, Yoshio Bizen, Kiyotaka Yamauchi, Toshikazu Nishiyama, Shigekazu Suwabe
  • Patent number: 5123974
    Abstract: In one embodiment this invention provides a process for decreasing the resistivity of an electrical conductor.The process involves the application of high temperature and an external field to a conductor to induce a current flow and physicochemical transition in the conducting matrix.
    Type: Grant
    Filed: April 30, 1991
    Date of Patent: June 23, 1992
    Inventor: Dominic J. Giancola
  • Patent number: 5080326
    Abstract: A method is provided for improving the electrical characteristics of grain-oriented silicon steel sheet by heating the steel to temperatures above 1000.degree. F. and then deforming grooves to refine the magnetic domains, optionally, post heat treating to form fine recrystallized grains in the vicinity of the hot deformations, preferably using protrusions on a scribing roll as the sheet moves between a scribing roll and a back-up anvil roll at deforming pressures range up to 120,000 pounds per square inch.
    Type: Grant
    Filed: January 4, 1991
    Date of Patent: January 14, 1992
    Assignee: Allegheny Ludlum Corporation
    Inventors: Leroy R. Price, Jeffrey M. Breznak
  • Patent number: RE34322
    Abstract: A method of preparing alloy of a transition metal and lanthanide comprising the steps of alloying a transition metal, boron, at least one lower-weight lanthanide having none or few stable compounds with iron, optionally one or more higher-weight lanthanides, a glass former, and optionally the pseudo lanthanide, yttrium; forming an amorphous or nearly amorphous metastable microstructure in the alloy; and heating the amorphous alloy to form a polycrystalline, multiphase, fine-grain single-domain structure.
    Type: Grant
    Filed: January 31, 1989
    Date of Patent: July 27, 1993
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventor: Norman C. Koon