With Boron, Aluminum, Thallium, Or Indium Patents (Class 252/62.58)
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Publication number: 20100171066Abstract: Disclosed is a magnetic material having high Hc and High Curie point, which is capable of controlling such magnetic characteristics without requiring rare or expensive raw materials. Specifically disclosed is a magnetic material composed of particles of a magnetic iron oxide which is represented by the following general formula: ?-AxByFe2?x?yO3 or ?-AxByCzFe2?x?y?zO3 (wherein A, B and C each represents a metal excluding Fe and different from each other, satisfying 0<x, y, z<1), with ?-Fe2O3 as a main phase.Type: ApplicationFiled: May 30, 2008Publication date: July 8, 2010Applicants: The University of Tokyo, Dowa Electronics Materials Co., Ltd.Inventors: Shin-ichi Ohkoshi, Shunsuke Sakurai, Takenori Yorinaga, Kazuyuki Matsumoto, Shinya Sasaki
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Patent number: 7708902Abstract: A magnetic material composed of ?-InxFe2-xO3 (wherein 0<x?0.30) crystal in which In is substituted for a portion of the Fe sites of the ?-Fe2O3 crystal. The crystal exhibits an X-ray diffraction pattern similar to that of an ?-Fe2O3 crystal structure and has the same space group as that of an ?-Fe2O3. The In content imparts to the magnetic material a magnetic phase transition temperature that is lower than that of the ?-Fe2O3 and a spin reorientation temperature that is higher than that of the ?-Fe2O3. The In content can also give the magnetic material a peak temperature of the imaginary part of the complex dielectric constant that is higher than that of the ?-Fe2O3.Type: GrantFiled: September 15, 2006Date of Patent: May 4, 2010Assignee: Dowa Electronics Materials Co., Ltd.Inventors: Shin-ichi Ohkoshi, Kazuhito Hashimoto, Shunsuke Sakurai, Shiro Kuroki
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Publication number: 20090220823Abstract: The present invention relates to ferromagnetic metal particles having a bulk density (?a) of not more than 0.25 g/cm3, a process for producing the above ferromagnetic metal particles and a magnetic recording medium comprising a non-magnetic substrate; a non-magnetic undercoat layer formed on the non-magnetic substrate which comprises non-magnetic particles and a binder resin; and a magnetic recording layer formed on the non-magnetic undercoat layer which comprises magnetic particles and a binder resin, wherein the above ferromagnetic metal particles were used as the magnetic particles.Type: ApplicationFiled: February 27, 2009Publication date: September 3, 2009Applicant: TODA KOGYO CORPORATIONInventors: Hiroko MORII, Seiji Ishitani, Keisuke Iwasaki, Hirofumi Nishikawa, Mineko Ohsugi, Toshiharu Harada, Takahiro Matsuo, Yosuke Yamamoto, Kazuyuki Hayashi
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PROCESS FOR PRODUCING MAGNETIC METAL PARTICLES FOR MAGNETIC RECORDING, AND MAGNETIC RECORDING MEDIUM
Publication number: 20090202867Abstract: The present invention relates to a process for producing magnetic metal particles for magnetic recording, comprising: heat-treating goethite particles having an aluminum content of 4 to 50 atom % in terms of Al based on whole Fe to obtain hematite particles; and heat-reducing the hematite particles at a temperature of 200 to 600° C., the goethite particles being obtained by adding a peroxodisulfate to a reaction solution comprising: a ferrous salt aqueous solution and a mixed alkali aqueous solution comprising: an alkali hydrogen carbonate aqueous solution or alkali carbonate aqueous solution and an alkali hydroxide aqueous solution before initiation of an oxidation reaction of the reaction solution, and then conducting the oxidation reaction.Type: ApplicationFiled: February 3, 2009Publication date: August 13, 2009Applicant: TODA KOGYO CORPORATIONInventors: Mineko Ohsugi, Toshiharu Harada, Takahiro Matsuo, Yosuke Yamamoto, Kazuyuki Hayashi -
Publication number: 20090140384Abstract: A thin soft magnetic film combines a high magnetization with an insulating character. The film is formed by nitriding Fe-rich ferromagnetic nanograins immersed in an amorphous substrate. A selective oxidation of the amorphous substrate is then performed. The result is a thin, insulating, soft magnetic film of high magnetization. Many types of integrated circuits can be made which include a component using a membrane incorporating the above-mentioned thin film.Type: ApplicationFiled: February 9, 2009Publication date: June 4, 2009Applicants: STMicroelectronics S.A., Commissariat a L'Energie Atomique Batiment LE PONAND DInventors: Guillaume Bouche, Pascal Ancey, Bernard Viala, Sandrine Couderc
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Publication number: 20090050839Abstract: The present invention relates to a metal oxide nano-composite magnetic material, fabrication method, and method for linkage, enrichment, and isolation of phosphorylated species. The metal oxide nano-composite magnetic material comprises the magnetic iron oxide nanoparticle, a silica layer immobilized onto the magnetic iron oxide nanoparticle and a metal oxide layer coated onto the silica layer. The magnetic iron oxide nanoparticles can be used for absorbing microwave radiation to accelerate the enrichment and linkage for phosphorylated species onto the metal oxide nano-composite magnetic material. Furthermore, the magnetic property of magnetic iron oxide nanoparticles leads to isolation of the metal oxide nano-composite magnetic material-target species conjugates by simply employing an external magnetic field.Type: ApplicationFiled: April 11, 2008Publication date: February 26, 2009Applicant: NATIONAL CHIAO TUNG UNIVERSITYInventors: YU-CHIE CHEN, CHENG-TAI CHEN, WEI-YU CHEN, CHUN-YUEN LO, HONG-YI LIN, CHIH CHI LIU
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Patent number: 7481947Abstract: A ferrite magnetic material comprising a main phase of W-type is provided which has magnetic properties improved through the optimization of additives. The ferrite magnetic material comprises a main constituent having a compound represented by composition formula AFe2+aFe3+bO27 (wherein A comprises at least one element selected from Sr, Ba and Pb; 1.5?a?2.1; and 12.9?b?16.3), a first additive containing a Ca constituent (0.3 to 3.0 wt % in terms of CaCO3) and/or a Si constituent (0.2 to 1.4 wt % in terms of SiO2), and a second additive containing at least one of an Al constituent (0.01 to 1.5 wt % in terms of Al2O3), a W constituent (0.01 to 0.6 wt % in terms of WO3), a Ce constituent (0.001 to 0.6 wt % in terms of CeO2), a Mo constituent (0.001 to 0.16 wt % in terms of MoO3), and a Ga constituent (0.001 to 15 wt % in terms of Ga2O3).Type: GrantFiled: December 8, 2004Date of Patent: January 27, 2009Assignee: TDK CorporationInventors: Yoshihiko Minachi, Junichi Nagaoka, Shunsuke Kurasawa, Noboru Ito, Taku Murase, Takeshi Masuda, Kenya Takagawa, Hidenobu Umeda
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Publication number: 20080057352Abstract: A magnetic material is provided that has an iron oxide phase whose principal phase is a crystal of a structure which has the same space group as ?-Fe2O3 crystal and in which Al is substituted for a portion of the Fe sites of the ?-Fe2O3 crystal. The molar ratio of Al to Fe in the iron oxide phase, when expressed as Al:Fe=x:(2?x), satisfies 0?x?1. The value of x is preferably in the range of 0.3 to 0.7. The average particle diameter of the powder determined from a TEM image is preferably 5 to 200 nm, more preferably 10 to 100 nm. The magnetic material has very high practical value because it enables the extremely high coercive force Hc of the ?-Fe2O3 crystal to be regulated to a level enabling utilization in magnetic recording medium and various other applications. The magnetic powder can be produced by a method combining the reverse micelle method and the sol-gel method.Type: ApplicationFiled: August 28, 2007Publication date: March 6, 2008Inventors: Shin-ichi Ohkoshi, Shunsuke Sakurai, Shiro Kuroki, Kimitaka Sato, Shinya Sasaki
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Patent number: 7332101Abstract: One aspect of the present invention relates to a permanently linked, rigid, magnetic chain of particles prepared by sol-gel methods. A second aspect of the present invention relates to a method of preparing a permanently linked, rigid, magnetic chain of particles comprising: coating a core material with one or more polyelectrolyte layers resulting in a coated particle; further coating the coated particle with a layer of magnetic nanoparticles resulting in a magnetic particle; coating the magnetic particle with a layer of a polycationic polyelectrolyte resulting in a coated magnetic particle; and applying a magnetic field to the coated magnetic particle in the presence of a metal oxide or metal oxide precursor capable of undergoing hydrolysis.Type: GrantFiled: June 25, 2004Date of Patent: February 19, 2008Assignee: Massachusetts Institute of TechnologyInventors: Harpreet Singh, T. Alan Hatton
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Cobalt ferrite based magnetostrictive materials for magnetic stress sensor and actuator applications
Patent number: 7326360Abstract: Magnetostrictive material based on cobalt ferrite is described. The cobalt ferrite is substituted with transition metals (such manganese (Mn), chromium (Cr), zinc (Zn) and copper (Cu) or mixtures thereof) by substituting the transition metals for iron or cobalt to form substituted cobalt ferrite that provides mechanical properties that make the substituted cobalt ferrite material effective for use as sensors and actuators. The substitution of transition metals lowers the Curie temperature of the material (as compared to cobalt ferrite) while maintaining a suitable magnetostriction for stress sensing applications.Type: GrantFiled: July 23, 2004Date of Patent: February 5, 2008Assignee: Iowa State University Research Foundation, Inc.Inventors: David C. Jiles, Jason A. Paulsen, John E. Snyder, Chester C. H. Lo, Andrew P. Ring, Keith A. Bormann -
Patent number: 7288497Abstract: A ceramic powder including silicon dioxide, iron oxide, iron, magnesium oxide, aluminum oxide, and a trace element group. The silicon dioxide occupies the powder of total weight from 81% to 86%; the iron oxide occupies the powder of total weight from 12% to 16%; the iron occupies the powder of total weight from 0.5% to 2%; the magnesium oxide occupies the powder of total weight from 0.2% to 0.5%; the aluminum oxide occupies the powder of total weight from 0.05% to 0.3%; and the trace element group occupies the powder of total weight of remains. The powder converts heat energy to electromagnetic radiation not being absorbed by a metallic material but disappearing in the form of light quantum, and provides for heat dissipation from electronic components. The powder converts electromagnetic radiation to far infrared electromagnetic radiation, providing for electromagnetic radiation absorption from the electronic component.Type: GrantFiled: June 30, 2006Date of Patent: October 30, 2007Inventor: San-Tsai Chueh
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Patent number: 7261949Abstract: The invention is directed to a magnetic thick film composition comprising particles of permanent magnetic materials dispersed in organic medium wherein the medium comprises a polymer selected from polyurethane, phenoxy and mixtures thereof, and organic solvent.Type: GrantFiled: July 30, 2003Date of Patent: August 28, 2007Assignee: E. I. du Pont de Nemours and CompanyInventor: John Graeme Pepin
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Patent number: 7147796Abstract: Iron oxide particles having the surface thereof coated with a layer of a complex iron oxide containing Al and Mg are disclosed. The total content of Al and Mg in the complex iron oxide layer is 0.1 to 2.5% by weight based on the whole iron oxide particles. The Mg content in the complex iron oxide layer is 0.05 to 1% by weight based on the whole iron oxide particles. The Al content in the complex iron oxide layer is 0.05 to 1.7% by weight based on the whole iron oxide particles. The Mg content in the complex iron oxide layer is 20% or more based on the total Mg content of the whole iron oxide particles.Type: GrantFiled: October 15, 2002Date of Patent: December 12, 2006Assignee: Mitsui Mining & Smelting Company, Ltd.Inventors: Hiroyuki Shimamura, Masahiro Miwa
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Patent number: 7101489Abstract: A composite magnetic material contains first magnetic particles made of a first magnetic material and second magnetic particles made of a second magnetic material, the first and second magnetic particles being mixed with each other. A frequency characteristic of the first magnetic material is different from that of the second magnetic material. The first and second magnetic particles are mixed so that, at a frequency of an intersecting point between a first curve representing a frequency characteristic of a real part of a complex magnetic permeability of the first magnetic material and a second curve representing a frequency characteristic of a real part of a complex magnetic permeability of the second magnetic material, a value of a real part of a complex magnetic permeability of the composite magnetic material is larger than a value of the intersecting point.Type: GrantFiled: May 16, 2005Date of Patent: September 5, 2006Assignee: Sanyo Electric Co., Ltd.Inventors: Takashi Umemoto, Hideki Yoshikawa, Keiichi Kuramoto, Hitoshi Hirano
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Patent number: 7011764Abstract: A magnetic device and method for making it involve a magnetic device specifically constructed of grains in a matrix. The matrix may be cement or plaster. The grains have an average diameter that is greater than their magnetic domains. The device may be applied to shielding applications for frequencies ranging from 100 kHz to 10 GHz. The shielding may be applied to walls of a building, consumer products such as magnetic disks, and the like. The grains may be any ferromagnetic material, including ferrite.Type: GrantFiled: July 25, 2003Date of Patent: March 14, 2006Assignee: Epcos AGInventors: Mauricio Esguerra, Ralph Lucke
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Patent number: 6933799Abstract: A non-reciprocal device includes at least one ferrimagnetic member (21 or 22). By controlling the FMR linewidth ?H of the ferrimagnetic members (21 and 22), intermodulation distortion is controlled.Type: GrantFiled: October 13, 2000Date of Patent: August 23, 2005Assignee: TDK CorporationInventors: Masako Nukaga, Naoyoshi Sato, Sakae Henmi
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Patent number: 6908568Abstract: An oxide magnetic material is prepared by wet molding in a magnetic field a slurry containing a particulate oxide magnetic material, water and a polyhydric alcohol having the formula: Cn(OH)nHn+2 wherein n is from 4 to 100 as a dispersant. By improving the orientation in a magnetic field upon wet molding using water, an oxide magnetic material having a high degree of orientation, typically an anisotropic ferrite magnet, is obtained at a high rate of productivity. The method is advantageous from the environmental and economical standpoints.Type: GrantFiled: June 17, 2002Date of Patent: June 21, 2005Assignee: TDK CorporationInventors: Kiyoyuki Masuzawa, Hitoshi Taguchi
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Patent number: 6902685Abstract: A ferrite magnet powder and a ferrite magnet exhibiting improved magnetic properties are provided at a reduced manufacturing cost. An application product and manufacturing methods thereof are also provided. An oxide magnetic material includes, as a main phase, a ferrite having a hexagonal M-type magnetoplumbite structure. The material includes: A, which is at least one element selected from the group consisting of Sr, Ba, Pb and Ca; R, which is at least one element selected from the group consisting of Y (yttrium), the rare earth elements and Bi; Fe; and B (boron). The constituents A, R, Fe and B of the material satisfy the inequalities of 7.04 at %?A?8.68 at %, 0.07 at %?R?0.44 at %, 90.4 at %?Fe?92.5 at % and 0.015 at %?B?0.87 at % to the sum of the elements A, R, Fe and B.Type: GrantFiled: May 21, 2002Date of Patent: June 7, 2005Assignee: Neomax Co., Ltd.Inventors: Sachio Toyota, Isamu Furuchi, Yoshinori Kobayashi
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Patent number: 6897248Abstract: The present invention discloses an ultraviolet light curable ferromagnetic composition and method for making such a composition that may be used to produce a ferromagnetic coating on a suitable substrate. These coatings may be used to produce printed capacitors and inductors. The disclosed composition does not contain any significant amount of volatile organic solvents that do not become incorporated in the active layer after curing.Type: GrantFiled: February 24, 2004Date of Patent: May 24, 2005Assignee: Allied PhotoChemical, Inc.Inventor: Roy C. Krohn
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Patent number: 6893581Abstract: A composite magnetic material contains first magnetic particles made of a first magnetic material and second magnetic particles made of a second magnetic material, the first and second magnetic particles being mixed with each other. A frequency characteristic of the first magnetic material is different from that of the second magnetic material. The first and second magnetic particles are mixed so that, at a frequency of an intersecting point between a first curve representing a frequency characteristic of a real part of a complex magnetic permeability of the first magnetic material and a second curve representing a frequency characteristic of a real part of a complex magnetic permeability of the second magnetic material, a value of a real part of a complex magnetic permeability of the composite magnetic material is larger than a value of the intersecting point.Type: GrantFiled: January 28, 2003Date of Patent: May 17, 2005Assignee: Sanyo Electric Co., Ltd.Inventors: Takashi Umemoto, Hideki Yoshikawa, Keiichi Kuramoto, Hitoshi Hirano
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Patent number: 6872251Abstract: A method for manufacturing single crystal ceramic powder is provided. The method includes a powder supply step for supplying powder consisting essentially of ceramic ingredients to a heat treatment area with a carrier gas, a heat treatment step for heating the powder supplied to the heat treatment area at temperatures required for single-crystallization of the powder to form a product, and a cooling step for cooling the product obtained in the heat treatment step to form single crystal ceramic powder. The method provides single crystal ceramic powder consisting of particles with a very small particle size and a sphericity being 0.9 or higher.Type: GrantFiled: May 29, 2002Date of Patent: March 29, 2005Assignee: TDK CorporationInventors: Minoru Takaya, Yoshiaki Akachi, Hiroyuki Uematsu, Hisashi Kobuke
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Patent number: 6852245Abstract: A composition for producing granules for molding ferrite, which comprises a ferrite slurry at least having raw ferrite powders; an ethylene-modified polyvinyl alcohol whose ethylene modified amount is from 4 to 10 mol %, average polymerization degree is from 500 to 1700, and average saponification degree is from 90.0 to 99.5 mol %; and water mixed therewith, ferrite granules produced from the composition, ferrite green body produced from the granules and ferrite sintered body produced from the sintered body are disclosed.Type: GrantFiled: April 26, 2002Date of Patent: February 8, 2005Assignee: TDK CorporationInventor: Hiroshi Harada
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Patent number: 6793842Abstract: A ferrite fine powder having a mean particle size of 0.1 to 30 &mgr;m and made of spherical single-crystal particles. The ferrite fine powder has superior physical properties and excellent magnetic properties desirable for use as a raw material for a dust core of coils, transformers, etc. The powder is prepared by forming a solution or suspension containing a compound or compounds of at least one of the metals forming the ferrite into fine droplets, and thermally decomposing the droplets at elevated temperatures.Type: GrantFiled: July 6, 2001Date of Patent: September 21, 2004Assignees: Shoei Chemical Inc., TDK CorporationInventors: Yuji Akimoto, Kazuro Nagashima, Masahiro Ikemoto, Minoru Takaya, Yoshiaki Akachi, Hisashi Kobuke
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Patent number: 6780555Abstract: Black magnetic iron oxide particles having an average particle diameter of 0.05 to 1.0 &mgr;m have a three-phase structure comprising: a core portion containing at least one metal element other than Fe selected from the group consisting of Mn, Zn, Cu, Ni, Cr, Cd, Sn, Mg, Ti, Ca and Al in an amount of 0.1 to 10% by weight based on whole Fe contained in the particles; a surface coat portion containing at least one metal element other than Fe selected from the group consisting of Mn, Zn, Cu, Ni, Cr, Cd, Sn, Mg, Ti, Ca and Al in an amount of 0.1 to 10% by weight based on whole Fe contained in the particles; and an intermediate layer disposed between the core portion and the surface coat portion, containing substantially none of the metal elements other than Fe.Type: GrantFiled: January 22, 2002Date of Patent: August 24, 2004Assignee: Toda Kogyo CorporationInventors: Naoki Uchida, Minoru Kouzawa, Hiromitsu Misawa, Koso Aoki, Suehiko Miura
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Patent number: 6773620Abstract: An oxide magnetic material of the invention is an oxide magnetic material of a hexagonal ferrite containing Sr, has grain boundary phases in the surrounding of the crystal grains, contains not less than 2% by weight, preferably not less than 5% by weight, of Sr in the grain boundary phases and not less than 10% by weight, preferably not less than 25% by weight, of at least one additive element selected from Bi, V, B and Cu.Type: GrantFiled: May 30, 2003Date of Patent: August 10, 2004Assignee: Sanyo Electric Co., Ltd.Inventors: Takashi Umemoto, Hideki Yoshikawa, Hitoshi Hirano
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Patent number: 6767478Abstract: The Mn—Zn ferrite of the present invention contains basic components of 44.0 to 50.0 mol % (50.0 mol % is excluded) Fe2O3, 4.0 to 26.5 mol % ZnO and the remainder MnO, and has a real part &egr;′ of complex relative permittivity of 20,000 or less at 1 kHz and 50 or less at 1 MHz, thereby maintaining initial permeability in a wide frequency band, showing a low stray capacitance with a coil provided, and ensuring an excellent impedance in a wide frequency band. And a coil using the Mn—Zn ferrite as a magnetic core is also provided.Type: GrantFiled: August 2, 2002Date of Patent: July 27, 2004Assignee: Minebea Co., Ltd.Inventors: Kiyoshi Ito, Osamu Kobayashi, Yukio Suzuki
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Patent number: 6716893Abstract: The present invention discloses an ultraviolet light curable ferromagnetic composition and method for making such a composition that may be used to produce a ferromagnetic coating on a suitable substrate. These coatings may be used to produce printed capacitors and inductors. The disclosed composition does not contain any significant amount of volatile organic solvents that do not become incorporated in the active layer after curing.Type: GrantFiled: July 11, 2002Date of Patent: April 6, 2004Assignee: UV Specialties, Inc.Inventor: Roy C. Krohn
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Publication number: 20040026654Abstract: A ferrite magnet powder and a ferrite magnet exhibiting improved magnetic properties are provided at a reduced manufacturing cost. An application product and manufacturing methods thereof are also provided. An oxide magnetic material includes, as a main phase, a ferrite having a hexagonal M-type magnetoplumbite structure. The material includes: A, which is at least one element selected from the group consisting of Sr, Ba, Pb and Ca; R, which is at least one element selected from the group consisting of Y (yttrium), the rare earth elements and Bi; Fe; and B (boron). The constituents A, R, Fe and B of the material satisfy the inequalities of 7.04 at %≦A=8.68 at %, 0.07 at %≦R≦0.44 at %, 90.4 at %≦Fe≦92.5 at % and 0.015 at %≦B≦0.87 at % to the sum of the elements A, R, Fe and B.Type: ApplicationFiled: March 24, 2003Publication date: February 12, 2004Inventors: Sachio Toyota, Isamu Furuchi, Yoshinori Kobayashi
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Patent number: 6689287Abstract: The subject invention includes a composite material comprising a ferroelectric material and a ferromagnetic material having a loss factor (tan &dgr;) for the composite material which includes a dielectric loss factor of the ferroelectric material and a magnetic loss factor of the ferromagnetic material. The composite material achieves the loss factor of from 0 to about 1.0 for a predetermined frequency range greater than 1 MHz. The ferroelectric material has a dielectric loss factor of from 0 to about 0.5 and the ferromagnetic material has a magnetic loss factor of from 0 to about 0.5 for the predetermined frequency range. The ferroelectric material is present in an amount from 10 to 90 parts by volume based on 100 parts by volume of the composite material and the ferromagnetic material is present in an amount from 10 to 90 parts by volume based upon 100 parts by volume of the composite material such that the amount of the ferroelectric material and the ferromagnetic material equals 100 parts by volume.Type: GrantFiled: November 1, 2001Date of Patent: February 10, 2004Assignee: Delphi Technologies, Inc.Inventors: Norman W. Schubring, Joseph V. Mantese, Adolph L. Micheli
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Patent number: 6682834Abstract: A magnetic storage medium includes a magnetic layer of a Co alloy of a system Co—Cr—Pt—B—Cu, wherein the magnetic layer has a thickness t and a remnant magnetic flux density Br satisfying a relationship (t×Br) 2.0 nT·m≦(t×Br)≦7.0 nT·m, wherein the Co alloy contains, in addition to Co, Cr with a concentration &bgr; of 20-26 at % (20 at %≦&bgr;≦26 at %), Pt with a concentration &ggr; of 6-20 at % (6 at %≦&ggr;≦20 at %), B with a concentration &dgr; of 1-7 at % (1 at %≦&dgr;≦7 at %), and Cu with a concentration &egr; of 2-7 at % (2 at %≦&egr;≦7 at %).Type: GrantFiled: March 13, 2001Date of Patent: January 27, 2004Assignee: Fujitsu LimitedInventors: Chiaki Okuyama, Reiko Murao, Atsushi Endo, Akira Kikuchi
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Patent number: 6666991Abstract: A fluorescent or luminous composition, comprising a multilayered film-coated powder having at least two coating films on a base particle, and a fluorescent or luminous substance; the composition, wherein at least one layer of the coating films contains the fluorescent or luminous substance; a genuine/counterfeit discrimination object, in which the fluorescent or luminous composition; and a genuine/counterfeit discrimination method, comprising recognizing fluorescence or luminescence by irradiating, with a light, the genuine/counterfeit discrimination object.Type: GrantFiled: May 29, 2001Date of Patent: December 23, 2003Assignees: Nittetsu Mining Co., Ltd.Inventors: Takafumi Atarashi, Kiyoshi Hoshino, Katsuto Nakatsuka
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Patent number: 6652767Abstract: In a composition for a plastic magnet, containing an Nd—Fe—B based alloy powder and a ferrite magnetic material powder mixed to a resin material, the Nd—Fe—B based alloy powder has particle sizes distributed in a range of 100 to 400 &mgr;m, and the ferrite magnetic material powder has an average particle size of approximately 1 &mgr;m. The weight ratio of the Nd—Fe—B based alloy powder to the ferrite magnetic material powder is in a range of 30:70 to 70:30. Further, the ratio of the total weight of the Nd—Fe—B based alloy powder 2 and the ferrite magnetic material powder 3 to the weight of the resin material is in a range of 90:10 to 80:20. Thus, in a plastic magnet 1 formed using the composition, peripheries of particles of the Nd—Fe—B based alloy powder 2 are surrounded by particles of the ferrite magnetic material powder 3 and the resin material.Type: GrantFiled: April 9, 2002Date of Patent: November 25, 2003Assignee: Enplas CorporationInventor: Satoshi Kazamaturi
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Patent number: 6641751Abstract: The present invention relates to a magnetic garnet single crystal and a Faraday rotator using the magnetic garnet single crystal and the object of the present invention is to provide a magnetic garnet single crystal which suppresses a generation of crystal defects and a Faraday rotator which improves an extinction ratio. A magnetic garnet single crystal grown by a liquid-phase epitaxial growth method and having the general formula represented by BiaPbbA3−a−bFe5−c−dBcPtdO12 is used, wherein A is at least one kind of element selected from Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu, B is at least one kind of element selected from Ga, Al, Sc, Ge and Si, and a, b, c and d are represented by 0.8<a<1.4, 0<b≦20, 0≦c≦0.9 and 0<d≦2.0 respectively.Type: GrantFiled: July 25, 2000Date of Patent: November 4, 2003Assignee: TKD CorporationInventors: Atsushi Ooido, Kazuhito Yamasawa
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Publication number: 20030085375Abstract: The subject invention includes a composite material comprising a ferroelectric material and a ferromagnetic material having a loss factor (tan &dgr;) for the composite material which includes a dielectric loss factor of the ferroelectric material and a magnetic loss factor of the ferromagnetic material. The composite material achieves the loss factor of from 0 to about 1.0 for a predetermined frequency range greater than 1 MHz. The ferroelectric material has a dielectric loss factor of from 0 to about 0.5 and the ferromagnetic material has a magnetic loss factor of from 0 to about 0.5 for the predetermined frequency range. The ferroelectric material is present in an amount from 10 to 90 parts by volume based on 100 parts by volume of the composite material and the ferromagnetic material is present in an amount from 10 to 90 parts by volume based upon 100 parts by volume of the composite material such that the amount of the ferroelectric material and the ferromagnetic material equals 100 parts by volume.Type: ApplicationFiled: November 1, 2001Publication date: May 8, 2003Applicant: Delphi Technologies Inc.Inventors: Norman W. Schubring, Joseph V. Mantese, Adolph L. Micheli
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Patent number: 6528166Abstract: Nickel composite particles having a layer of a nickel-containing spinel on at least a part of the surface of nickel particles, or nickel composite particles having an oxide layer of metals other than nickel on at least a part of the surface of nickel particles and a layer of a nickel-containing spinel at an interface between the nickel particles and the metal oxide layer. The nickel composite particles are produced by forming fine liquid droplets from a solution containing (a) at least one thermally decomposable nickel compound and (b) at least one thermally decomposable metal compound capable of forming a spinel together with nickel; and heating the liquid droplets at a temperature higher than the decomposition temperatures of the compound (a) and (b) to nickel particles and simultaneously deposit a nickel-containing spinel layer, or further a metal oxide layer on the spinel layer.Type: GrantFiled: November 15, 2001Date of Patent: March 4, 2003Assignee: Shoei Chemical Inc.Inventors: Yuji Akimoto, Kazuro Nagashima, Hiroshi Yoshida, Yiyi Ma
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Patent number: 6527973Abstract: A magnetooptical device which defines a Faraday rotation angle &thgr; expressed by 44 deg.≦&thgr;≦46 deg. when light having a wavelength &lgr; (1570 nm≦&lgr;≦1620 nm) impinges thereupon. A magnetic garnet material expressed by a general formula: BiaM13−a Fe5−bM2bO12 is used. M1 is at least one kind of element that is selected from among Y, La, Eu, Gd, Ho, Yb, Lu and Pb; M2 is at least one kind of element that is selected from among Ga, Al, Ti, Ge, Si and Pt; and a and b satisfy 1.0≦a≦1.5 and 0≦b≦0.5, respectively.Type: GrantFiled: December 11, 2000Date of Patent: March 4, 2003Assignee: TDK CorporationInventors: Atsushi Ohido, Kazuhito Yamasawa
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Patent number: 6517934Abstract: A rare earth-iron-boron magnetic powder comprising a rare earth element, iron and boron, which has a coercive force of 80 to 400 kA/m, a saturation magnetization of 10 to 25 &mgr;W/g, an average particle size of 5 to 200 nm, and a particulate or ellipsoidal particle shape, and a magnetic recording medium having a magnetic layer which contains this magnetic powder and a binder, in which magnetic recording medium it is possible to practically use a very thin magnetic layer of 0.3 &mgr;m or less.Type: GrantFiled: October 10, 2000Date of Patent: February 11, 2003Assignee: Hitachi Maxell, Ltd.Inventor: Mikio Kishimoto
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Publication number: 20030024605Abstract: A magnetic substance having the maximum value of complex permeability in quasi-microwave range is provided for suppressing a high frequency noise in a small-sized (electronic apparatus. The magnetic substance is of a magnetic composition comprising M, X and Y, where M is a metallic magnetic material consisting of Fe, Co, and/or Ni, X being element or elements other than M and Y, and Y being F, N, and/or O. The M-X-Y magnetic composition has a concentration of M in the composition so that said M-X-Y magnetic composition has a saturation magnetization of 35-80% of that of the metallic bulk of magnetic material comprising M alone. The magnetic composition has the maximum &mgr;″max of complex.Type: ApplicationFiled: September 4, 2001Publication date: February 6, 2003Inventors: Shigeyoshi Yoshida, Hiroshi Ono, Shinsuke Andoh, Wei-Dong Li, Yutaka Shimada
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Patent number: 6495483Abstract: Transition metal-containing ceramic or carbonaeous material are formed from novel linear polymers containing a random distribution of repeating acetylenic units, organotransition metal complexes, siloxane, boron, silicon, and/or carborane-siloxane units. The precursor thermosets are formed by crosslinking of the linear polymers through the acetylenic units in the polymer backbone. The ceramics may also be formed directly by pyrolysis of the linear polymers. The preceramic polymers are potentially useful for fabricating ceramic fibers and composite materials having enhanced strength, hardness and toughness as well as superior mechanical, optical, electrical and/or magnetic properties.Type: GrantFiled: March 14, 1997Date of Patent: December 17, 2002Assignee: The United States of America as represented by the Secretary of the NavyInventors: Teddy M. Keller, Eric J. Houser
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Patent number: 6458286Abstract: MnZn ferrite comprises a main component comprising iron oxide 52.5 to 54.0 mol % in terms of Fe2O3, zinc oxide 7.7 to 10.8 mol % in terms of ZnO, and manganese oxide of the remaining, and sub-components of silicon oxide 60 to 140 ppm in terms of SiO2 and calcium oxide 350 to 700 ppm in terms of CaO, and further contains nickel oxide 4500 ppm or lower (not including 0) in terms of NiO.Type: GrantFiled: August 29, 2000Date of Patent: October 1, 2002Assignee: TDK CorporationInventors: Kenya Takagawa, Katsushi Yasuhara
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Patent number: 6451220Abstract: A magnetic composition comprised of cobalt ferrite nanoparticles dispersed in an ionic exchange resin.Type: GrantFiled: January 21, 1997Date of Patent: September 17, 2002Assignee: Xerox CorporationInventors: Ronald F. Ziolo, Javier Tejada Palacios, Elizabeth C. Kroll, Xixiang Zhang, Rachel Pieczynski
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Patent number: 6416681Abstract: Granule for forming ferrite is provided by mixing powders of ferrite raw material, polyvinyl alcohol as a binder and polyethylene glycol added as plasticizer and having molecular weight being 1000 to 6000, and forming granules.Type: GrantFiled: August 23, 2000Date of Patent: July 9, 2002Assignee: TDK CorporationInventor: Hiroshi Harada
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Publication number: 20010051129Abstract: Spindle-shaped goethite particles of the present invention uniformly contain cobalt of 1 to 20 atm %, calculated as Co, based on whole Fe and aluminum of 1 to 15 atm %, calculated as Al, based on whole Fe, and have an X-ray crystallite size ratio (D020:D110) of not less than 1.0:1 and less than 2.0:1, an average major axial diameter of 0.05 to 0.20 &mgr;m, an average minor axial diameter of 0.010 to 0.020 &mgr;m and an average aspect ratio (average major axial diameter:average minor axial diameter) of 4:1 to 10:1.Type: ApplicationFiled: March 2, 1999Publication date: December 13, 2001Inventor: KENJI OKINAKA
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Patent number: 6284150Abstract: A ferrite powder for bonded magnets having a substantially magnetoplumbite-type crystal structure and an average diameter of 0.9-2 &mgr;m, the ferrite powder having a basic composition represented by the following general formula: (A1-xRxO.n[Fe1-yMy)2O3] by atomic ratio, wherein A is Sr and/or Ba; R is at least one of rare earth elements including Y, La being indispensable; M is at least one element selected from the group consisting of Co, Mn, Ni and Zn; and x, y and n are numbers meeting the conditions of 0.01≦x≦0.4, [x/(2.6n)]≦y≦[x/(1.6n)], and 5≦n≦6, (Si+Ca) being 0.2 weight % or less, and (Al+Cr) being 0.13 weight % or less, can be produced by mixing iron oxide containing 0.06 weight % or less of (Si+Ca) and 0.Type: GrantFiled: September 23, 1999Date of Patent: September 4, 2001Assignee: Hitachi Metals, Ltd.Inventors: Yasunobu Ogata, Yutaka Kubota, Takashi Takami, Shuichi Shiina
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Patent number: 6264875Abstract: The present invention relates to a method for preparing multi-purpose magnetized and sintered ceramics, comprising the steps of adding water to a mixture of Maek-Ban Stone and soft sericite, stirring and maturing at a room temperature, sintering, and irradiating with a magnetic field. The ceramics obtained by the present invention produce various effects such as keeping food fresh, deodorization and purification.Type: GrantFiled: December 14, 1999Date of Patent: July 24, 2001Inventor: Sang-Yool Pyun
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Patent number: 6210598Abstract: A Mn—Zn ferrite having large electrical resistance, which can withstand use in high frequency region exceeding 1 MHz, is provided. The Mn—Zn ferrite comprises the following basic components: 44.0 to 50.0 mol % Fe2O3, 4.0 to 26.5 mol % ZnO, 0.1 to 8.0 mol % at least one member selected from the group consisting of TiO2 and SnO2, and the remainder being MnO. By the addition of TiO2 and SnO2, even if the material is sintered in air, electrical resistance of 103 times that of the conventional Mn—Zn ferrite can be obtained, and high initial permeability of 300 to 400 as estimated can be secured even at high frequency of 5 MHz.Type: GrantFiled: August 16, 1999Date of Patent: April 3, 2001Assignee: Minebea Co., Ltd.Inventors: Osamu Kobayashi, Koji Honda, Shunji Kawasaki
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Patent number: 6180022Abstract: A Mn—Zn ferrite having large electrical resistance, which can withstand the use in high frequency region exceeding 1 MHz, is provided. The Mn—Zn ferrite comprises the following basic components: 44.0 to 50.0 mol % Fe2O3, 4.0 to 26.5 mol % ZnO, 0.1 to 8.0 mol % at least one member selected from the group consisting of TiO2 and SnO2, 0.1 to 16.0 mol % CuO, and the remainder being MnO. By the addition of TiO2, SnO2 and CuO, even if the material is sintered in the air, electrical resistance of 103 times or more as high as that of the conventional Mn—Zn ferrite can be obtained, and a high initial permeability of 300-400 as estimated can be secured even at high frequency of 5 MHz.Type: GrantFiled: August 16, 1999Date of Patent: January 30, 2001Assignee: Minebea Co., Ltd.Inventors: Osamu Kobayashi, Koji Honda, Shunji Kawasaki