Calcium, Barium, Strontium, Or Lead Patents (Class 252/62.63)
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Publication number: 20130169488Abstract: A new magnetic substance having a high magnetic permeability and a low magnetic permeability loss over a wide frequency bandwidth, a composite material for antennas using the new magnetic substance and a polymer, and an antenna using the composite material for antennas.Type: ApplicationFiled: September 6, 2012Publication date: July 4, 2013Applicant: SAMSUNG ELECTRONICS CO., LTD.Inventors: Jun-sig KUM, Nak-hyun KIM, Hyun-jin KIM, Seung-kee YANG, Joong-hee LEE
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Publication number: 20130164563Abstract: An aspect of the present invention relates to a method of manufacturing magnetic particles, which comprises adding a carboxylic acid compound to a water-based magnetic liquid, wherein the water-based magnetic liquid comprises magnetic particles dispersed in an acidic water-based solvent, and the carboxylic acid compound is selected from the group consisting of aromatic compounds and aliphatic compounds having one or more carboxylic acid (salt) groups denoted by: —COOM wherein M denotes a hydrogen atom or an alkali metal atom, when the number of the carboxylic acid (salt) group contained within the molecule thereof is 1, the number of carbon atoms, excluding the carboxylic acid (salt) group portion, ranges from 1 to 13; and then collecting the magnetic particles from the water-based magnetic liquid to obtain the magnetic particles the surfaces of which have been modified by being coated with the carboxylic acid compound.Type: ApplicationFiled: December 26, 2012Publication date: June 27, 2013Applicant: FUJIFILM CORPORATIONInventor: FUJIFILM Corporation
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Patent number: 8444872Abstract: 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: GrantFiled: May 30, 2008Date of Patent: May 21, 2013Assignees: 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: 8419966Abstract: An aspect of the present invention relates to a method of manufacturing a hexagonal ferrite magnetic powder comprising preparing a melt by melting a starting material mixture comprising a hexagonal ferrite-forming component and a glass-forming component; rapidly cooling the melt to obtain an amorphous material comprising 0.3 to 2.0 weight percent of carbon atoms; heating the amorphous material to a temperature range of 580 to 700° C. and maintaining the amorphous material within the temperature range to precipitate hexagonal ferrite magnetic particles; and collecting the hexagonal ferrite magnetic particles precipitated.Type: GrantFiled: March 30, 2010Date of Patent: April 16, 2013Assignee: FUJIFILM CorporationInventors: Shiho Kamisawa, Toshio Tada, Nobuo Yamazaki
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Patent number: 8398880Abstract: An aspect of the present invention relates to a method of modifying a surface of a powder, comprising mixing a powder with a compound denoted by general formula (I): wherein, in general formula (I), each of R10 and R13 independently denotes a hydrogen atom, alkyl group, or aryl group, each of R11 and R12 independently denotes an alkyl group or an aryl group, and L denotes a single bond or an oxygen atom.Type: GrantFiled: August 26, 2009Date of Patent: March 19, 2013Assignee: FUJIFILM CorporationInventor: Kazufumi Omura
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Publication number: 20130050041Abstract: Disclosed are synthetic garnets and related devices that can be used in radio-frequency (RF) applications. In some embodiments, such RF devices can include garnets having reduced or substantially nil Yttrium or other rare earth metals. Such garnets can be configured to yield high dielectric constants, and ferrite devices, such as TM-mode circulators/isolators, formed from such garnets can benefit from reduced dimensions. Further, reduced or nil rare earth content of such garnets can allow cost-effective fabrication of ferrite-based RF devices. In some embodiments, such ferrite devices can include other desirable properties such as low magnetic resonance linewidths. Examples of fabrication methods and RF-related properties are also disclosed.Type: ApplicationFiled: May 30, 2012Publication date: February 28, 2013Applicant: SKYWORKS SOLUTIONS, INC.Inventors: David Bowie CRUICKSHANK, Rickard Paul O'DONOVAN, Iain Alexander MACFARLANE, Brian MURRAY, Michael David HILL
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Patent number: 8303837Abstract: A rotating machine comprising a sintered ferrite magnet having an M-type ferrite structure, comprising Ca, an R element that is at least one of rare earth elements and indispensably includes La, Ba, Fe and Co as indispensable elements, and having a composition represented by the formula: Ca1-x-yRxBayFe2n-zCoz, wherein (1?x?y), x, y, z and n represent the contents of Ca, the R element, Ba and Co, and a molar ratio, meeting 0.3?1?x?y?0.65, 0.2?x?0.65, 0.001?y?0.2, 0.03?z?0.65, 4?n?7, and 1?x?y>y; a bonded magnet comprising ferrite powder having the above composition and a binder, and a magnet roll, at least one magnetic pole portion of which is made of the above bonded magnet.Type: GrantFiled: February 13, 2007Date of Patent: November 6, 2012Assignee: Hitachi Metals, Ltd.Inventors: Takashi Takami, Hiroshi Iwasaki, Yoshinori Kobayashi, Naoki Mochi, Ryuji Gotoh
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Patent number: 8282853Abstract: A novel NiMnZn-based ferrite which can reduce magnetic loss (core loss) at a high frequency of about 2 MHz or higher and achieve higher saturated magnetic flux density while forming high sintered density is provided. The NiMnZn-based ferrite contains a main component comprising 54.0 to 57.5 mol % of iron oxide in terms of Fe2O3, 2.0 to 7.0 mol % of zinc oxide in terms of ZnO, 0.5 to 4.7 mol % of nickel oxide in terms of NiO, and a remainder of manganese oxide (in terms of MnO); and an accessory component comprising 100 to 1000 ppm by weight of Si in terms of SiO2, 800 to 3000 ppm by weight of Ca in terms of CaCO3, and 520 to 1000 ppm by weight of Nb in terms of Nb2O5 with respect to the main component; while having an average ferrite crystal particle size of 2.1 to 8.5 ?m.Type: GrantFiled: September 22, 2009Date of Patent: October 9, 2012Assignee: TDK CorporationInventors: Kentaro Mori, Takuya Aoki
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Patent number: 8263224Abstract: Disclosed is a resin composition containing a hexagonal ferrite and a resin, which is characterized in that the hexagonal ferrite is contained in an amount of 50-98 parts by weight per 100 parts by weight of the total of the resin composition.Type: GrantFiled: November 28, 2007Date of Patent: September 11, 2012Assignee: Asahi Kasei Chemicals CorporationInventor: Tetsuji Tokiwa
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Publication number: 20120225264Abstract: A magnetic fluid composition include a suspension of nano-particles including cross-crystallized multi-metal compounds dispersed in a solvent, the cross-crystallized multi-metal compounds including at least two or more metals having different valencies or oxidation states, the metals selected from the group consisting of a monovalent metal (Me+), a divalent metal (Me2+), a trivalent metal (Me3+), a quadrivalent metal (Me4+) and a rare earth metal. The magnetic fluid having a viscosity and surface tension that permits dispensing from an inkjet printer at a rate of at least 2.5 m/s, at a resolution of at least 600 dpi, supporting jetting pulse frequencies of at least 15 KHz per nozzle (enabling high speed inkjet printing applications of at least 0.6 m/sec per individual nozzle row per print head), and enabling uninterrupted, industrial level print output of magnetic ink character recognition (MICR) code lines suitable for high speed magnetic data scanning per established industry regulations (ANSI X9).Type: ApplicationFiled: March 1, 2012Publication date: September 6, 2012Inventor: Thomas Villwock
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Publication number: 20120199782Abstract: A hexagonal crystal ferrite magnetic powder having high magnetic characteristics while having a small particle volume and a high specific surface area is provided, and a high-density magnetic recording medium using the powder. A method for producing a hexagonal crystal ferrite formed using a glass crystallization method includes the steps of: mixing a glass matrix with raw materials including iron, bismuth, a divalent metal (M1), a tetravalent metal (M2), any one kind (A) of barium, strontium, calcium, and lead, and at least one kind of rare earth element (represented by R) having a mole equal to or less than that of the iron; heating the mixed raw material to obtain a glass body; quenching the glass body, pulverizing the glass body, and performing a heat treatment, and washing the glass body after the heat treatment with an acid solution.Type: ApplicationFiled: January 29, 2010Publication date: August 9, 2012Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.Inventors: Kenji Masada, Tomoyuki Ishiyama, Gousuke Iwasaki
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Patent number: 8236192Abstract: An ink including stabilized magnetic single-crystal nanoparticles, wherein the value of the magnetic anisotropy of the magnetic nanoparticles is greater than or equal to 2×104 J/m3. The magnetic nanoparticle may be a ferromagnetic nanoparticle, such as FePt. The ink includes a magnetic material that minimizes the size of the particle, resulting in excellent magnetic pigment dispersion stability, particularly in non-aqueous inkjet inks. The smaller sized magnetic particles of the ink also maintains excellent magnetic properties, thereby reducing the amount of magnetic particle loading required in the ink.Type: GrantFiled: June 26, 2008Date of Patent: August 7, 2012Assignee: Xerox CorporationInventors: Marcel P. Breton, Richard P. N. Veregin, Karen A. Moffat, Peter M. Kazmaier, Patricia A. Burns, Paul F. Smith
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Patent number: 8206606Abstract: An oxide magnetic material includes a ferrite with a hexagonal structure as its main phase. Metallic elements included in the oxide magnetic material are represented by the formula: Ca1-x-x?LaxSrx?Fe2n-yCoy, where atomic ratios x, x? and y and a molar ratio n satisfy 0.4?x?0.6, 0.01?x??0.3, 0.2?y?0.45 and 5.2?n?5.8, respectively.Type: GrantFiled: June 25, 2008Date of Patent: June 26, 2012Assignee: Hitachi Metals, Ltd.Inventors: Seiichi Hosokawa, Yoshinori Kobayashi, Yasunobu Ogata, Etsushi Oda
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Publication number: 20120091702Abstract: The present invention is related to magnetic pigments comprising a transparent flaky homogeneously composed substrate having two parallel major surfaces and a coating comprising maghemite, to a process for the production of said pigments as well as to their use.Type: ApplicationFiled: June 8, 2010Publication date: April 19, 2012Applicant: Merck Patent Gesellschaft Mit Beschrankter HaftungInventors: Kaiman Shimizu, Tamio Noguchi, Fumiko Sasaki, Yukitaka Watanabe, Masahiko Yazawa
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Publication number: 20120085963Abstract: Disclosed herein are a ferrite composition for a high frequency bead in that a part of Fe in M-type hexagonal ferrite represented by BaFe12O19 is substituted with at least one metal selected from a group consisting of 2-valence, 3-valence and 4-valence metals, as well as a chip bead material using the same. According to embodiments of the present invention, the dielectric composition is characterized in that a part of Fe as a constituent of M-type hexagonal barium ferrite is substituted by other metals, to thus decrease a sintering temperature to 920° C. or less without using any additive for low temperature sintering. Moreover, because of high SRF properties, the inventive composition is applicable to a multilayer type chip bead used at a high frequency of more than several hundreds MHz and a magnetic antenna.Type: ApplicationFiled: October 3, 2011Publication date: April 12, 2012Inventors: Sung Yong AN, Jin Woo HAHN, Jeong Wook KIM, Sung Lyoung KIM, So Yeon SONG, Soo Hwan SON, Ic Seob KIM
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Patent number: 8153097Abstract: A method for manufacturing ferrite powder comprises a step (a) of causing a precursor, obtained by a liquid-phase reaction method, to pass through a sieve with openings of 2 mm or less, and a step (b) of causing free fall, through the interior of a furnace tube heated to the range 750 to 1250° C. by a heater, of the precursor which has passed through the sieve. In the process of causing free fall through the interior of the furnace tube heated by the heater, ferrite powder, which is a single phase of hexagonal ferrite, is obtained by heating the precursor to a prescribed temperature and holding the precursor at the prescribed temperature.Type: GrantFiled: September 25, 2008Date of Patent: April 10, 2012Assignee: TDK CorporationInventor: Mamoru Satoh
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Patent number: 8154464Abstract: A magnetic material antenna using a ferrite sintered body comprising one or more conductors disposed at least on a surface or in internal portion of the ferrite sintered body, wherein the ferrite sintered body is a sintered body of Y-type ferrite containing BaO, CoO, and Fe2O3 as main components and wherein the ferrite sintered body contains Cu and, in a cross section for the sintered body, an area rate of a cubic Co-rich phase, which has a ration of an amount of Co being higher than a Y-type ferrite phase being a mother phase, is 1% or less.Type: GrantFiled: June 21, 2007Date of Patent: April 10, 2012Assignee: Hitachi Metals, Ltd.Inventors: Masayuki Gonda, Shigeo Fujii, Hiroyuki Aoyama
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Publication number: 20120080638Abstract: An aspect of the present invention relates to a magnetic recording medium comprising a magnetic layer comprising ferromagnetic powder and a binder, wherein the ferromagnetic powder is magnetic powder comprised of gathering magnetic particles, the magnetic particles are a reduction product of hexagonal ferrite magnetic particles wherein a ratio Dc/Dtem of a crystallite size Dc obtained from a diffraction peak of a (220) plane to a particle diameter Dtem in a direction perpendicular to a (220) plane as determined by a transmission electron microscope ranges from 0.90 to 0.75.Type: ApplicationFiled: September 23, 2011Publication date: April 5, 2012Applicant: FUJIFILM CORPORATIONInventor: Yasushi HATTORI
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Patent number: 8123973Abstract: A method of manufacturing magnetic material is described hereinafter. Firstly, Fe(NO3)3.9H2O and other metal nitrate compounds are dissolved in an alcohol solvent to form a mixed solution. Secondly, the mixed solution is heated to 60˜100 degrees Centigrade. Next, citric acid is added into the mixed solution for being reacted with each other under the temperature of 60˜100 degrees Centigrade so that can make the alcohol solvent volatilized and further obtain brown solid powder. Lastly, the solid powder is further heated for a period of time so as to obtain the magnetic material having a fluffy powdery form.Type: GrantFiled: December 10, 2008Date of Patent: February 28, 2012Assignee: Cheng Uei Precision Industry Co.Inventor: Chih-Hao Huang
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Patent number: 8092705Abstract: The present invention provides a simple method for introducing magnetic particles into a polymer for further preparing a magnetic polymer, the method using the capability of polymer to absorb Fe3+ and other divalent metal ions M2+, adding alkali immediately each time after absorbing Fe3+ or M2+, thereby generating hydrated oxide of the Fe3+ and hydrated oxide of the divalent metal ions in sequence inside the polymer, and then heating, so that the hydrated oxide of the Fe3+ and the hydrated oxide of the divalent metal ions are transformed into magnetic particles MFexOy, where M may be Fe2+, Zn2+, Mg2+, Cu2+, Ca2+, Ba2+, Sr2+, Ni2+, Co2+, Mn2+ and the like, and x=1.0˜2.0; y=3.0˜4.0. Compared with the prior art method, the present one is simpler, wider in application, and more operable.Type: GrantFiled: May 18, 2007Date of Patent: January 10, 2012Assignee: Beijing Dingguochangsheng Biotech, Co. Ltd.Inventors: Congyun Zhang, Weidong Zhou
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Patent number: 8021567Abstract: A sintered ferrite magnet having an M-type ferrite structure and comprising Ca, an R element which is at least one rare earth element indispensably including La, Ba, Fe and Co as indispensable elements, which is represented by Ca1-x-yRxBayFe2n-zCoz, wherein (1?x?y), x, y, z and n are numbers representing the amounts of Ca, the R element, Ba and Co and a molar ratio, meeting 0.2?x?0.65, 0.001?y?0.2, 0.03?z?0.65, and 4?n?7.Type: GrantFiled: October 12, 2010Date of Patent: September 20, 2011Assignee: Hitachi Metals, Ltd.Inventors: Takashi Takami, Hiroshi Iwasaki, Naoki Mochi
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Patent number: 7919007Abstract: The present invention provides a ferrite magnetic material capable of attaining such magnetic properties that Br+(?)HcJ is 6200 or more even by sintering at a temperature of 1150° C. or lower. The ferrite magnetic material includes as a main phase thereof a ferrite phase having a hexagonal structure, the main phase being represented by the following composition formula (1): LaxCam?1?x?m(Fe12?yCoy)z with ? representing one or two of Ba and Sr; wherein the constituent ratios of the metal elements constituting the main phase satisfy the following conditions: x and m are the values in a region bounded by the points, A: (0.53, 0.27), B: (0.64, 0.27), C: (0.64, 0.35), D: (0.53, 0.45), E: (0.47, 0.45) and F: (0.47, 0.32) in the (x, m) coordinates shown in FIG. 2; 1.3?x/yz?1.8; and 9.5?12z?11.0.Type: GrantFiled: December 15, 2006Date of Patent: April 5, 2011Assignee: TDK CorporationInventors: Yoshihiko Minachi, Noboru Ito, Yuuki Aburakawa, Yoshinori Fujikawa, Satoko Ueda
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Patent number: 7906036Abstract: A sintered ferrite magnet having a basic composition represented by the general formula: A1?x?y+aCax+bRy+cFe2n?zCoz+dO19 (atomic ratio), wherein a, b, c and d represent the amounts of an A element, Ca, an R element and Co added in the pulverization step of an oxide magnet material, which are numerals meeting the conditions of 0.03?x?0.4, 0.1?y?0.6, 0?z?0.4, 4?n?10, x+y<1, 0.03?x+b?0.4, 0.1?y+c?0.6, 0.1?z+d?0.4, 0.50?[(1?x?y+a)/(1?y+a+b)]?0.97, 1.1?(y+c)/(z+d)?1.8, 1.0?(y+c)/x?20, and 0.1?x/(z+d)?1.2.Type: GrantFiled: September 13, 2004Date of Patent: March 15, 2011Assignee: Neomax Co., Ltd.Inventors: Takashi Takami, Yasunobu Ogata
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Patent number: 7883637Abstract: A composite sintered body of dielectric substance and magnetic substance comprises a hexagonal Ba ferrite crystal, a perovskite type crystal containing at least one element selected from Ca, Sr, and Ba, and Ti, and Li element, and the relative magnetic permeability is 1.4 or more at 1 GHz. LC composite electronic component comprises the composite sintered body, a condenser circuit formed in the inside or the surface of the composite sintered body, and an inductor circuit formed in the inside or the surface of the composite sintered body.Type: GrantFiled: December 21, 2007Date of Patent: February 8, 2011Assignee: Kyocera CorporationInventors: Hirofumi Terazono, Takeshi Matsui
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Publication number: 20110024672Abstract: A sintered ferrite magnet having an M-type ferrite structure and comprising Ca, an R element which is at least one rare earth element indispensably including La, Ba, Fe and Co as indispensable elements, which is represented by Ca1?x?yRxBayFe2n?zCoz, wherein (1?x?y), x, y, z and n are numbers representing the amounts of Ca, the R element, Ba and Co and a molar ratio, meeting 0.2?x?0.65, 0.001?y?0.2, 0.03?z?0.65, and 4?n?7.Type: ApplicationFiled: October 12, 2010Publication date: February 3, 2011Applicant: HITACHI METALS, LTDInventors: Takashi TAKAMI, Hiroshi IWASAKI, Naoki MOCHI
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Patent number: 7879469Abstract: A ferrite magnet powder is represented by the composition formula AFe2+a(1-x)MaxFe3+bO27, wherein A represents at least one element selected from the group consisting of Sr, Ba, and Pb; and M represents at least one element selected from the group consisting of Zn, Co, Mn, and Ni, and wherein 0.05?x?0.80, 1.5?a?2.2, and 12?b?17. A high saturation magnetization 4?Is can be achieved by the partial substitution of the Fe2+ site of a W-type ferrite with an element M such as Zn within a certain range.Type: GrantFiled: February 5, 2004Date of Patent: February 1, 2011Assignee: TDK CorporationInventors: Yoshihiko Minachi, Noboru Ito
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Patent number: 7837893Abstract: A sintered ferrite magnet having an M-type ferrite structure and comprising Ca, an R element which is at least one rare earth element indispensably including La, Ba, Fe and Co as indispensable elements, which is represented by Ca1-x-yRxBayFe2n-zCoz, wherein (1-x-y), x, y, z and n are numbers representing the amounts of Ca, the R element, Ba and Co and a molar ratio, meeting 0.2?x?0.65, 0.001?y?0.2, 0.03?z?0.65, and 4?n?7.Type: GrantFiled: March 10, 2006Date of Patent: November 23, 2010Assignee: Hitachi Metals, Ltd.Inventors: Takashi Takami, Hiroshi Iwasaki, Naoki Mochi
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Patent number: 7837892Abstract: Rubber compound containing at least one nanoscale, magnetic filler and at least one non-magnetic filler. Vulcanizable mixture containing the rubber compound and at least one crosslinking agent and/or vulcanization accelerator. Molding obtainable from the vulcanizable mixture by heat treatment or action of an electrical, magnetic or electromagnetic alternating field.Type: GrantFiled: August 20, 2005Date of Patent: November 23, 2010Assignee: Evonik Degussa GmbHInventors: Markus Pridoehl, Guido Zimmermann, Joachim Froehlich, Achim Gruber, Gregor Grun, Thomas Ruehle, Dirk W. Schubert
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Patent number: 7811465Abstract: The present invention relates to a magnetic garnet single crystal prepared by the liquid phase epitaxial (LPE) process and an optical element using the same as well as a method of producing the single crystal, for the purpose of providing a magnetic garnet single crystal at a reduced Pb content and an optical element using the same, as well as a method of producing the single crystal. The magnetic garnet single crystal is grown by the liquid phase epitaxial process and is represented by the chemical formula BixNayPbzM13?x?y?zFe5?wM2wO12 (M1 is at least one element selected from Y, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu; and M2 is at least one element selected from Ga, Al, In, Ti, Ge, Si and Pt, provided that 0.5<x?2.0, 0<y?0.8, 0?z<0.01, 0.19?3?x?y?z<2.5, and 0?w?1.6).Type: GrantFiled: November 17, 2005Date of Patent: October 12, 2010Assignee: TDK CorporationInventor: Atsushi Ohido
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Publication number: 20100230630Abstract: To provide ferrite magnetic powders for bond magnet capable of surely suppressing residual hexavalent chrome, being an environmental load substance, having no adverse influence on the magnetic characteristics, which is an obstacle in use, and without damaging productivity and at a low cost. The method includes the steps of obtaining sintered powders by sintering raw material powders; wet-pulverizing the sintered powders; wet-cleaning the sintered powders; and annealing the cleaned sintered powders, wherein in the step of the wet-pulverization and in the step of wet-cleaning, generation of the hexavalent chrome, being an environmental load substance, is suppressed by performing the pulverization and cleaning while maintaining pH of a dispersion solvent at 8.5 or less, at the time of pulverization and cleaning.Type: ApplicationFiled: March 6, 2007Publication date: September 16, 2010Applicants: DOWA F-TEC CO., LTD., DOWA ELECTRONICS MATERIALS CO., LTD.Inventors: Shuichi Kohayashi, Hiroya Ikeda, Hideki Katayama, Keisuke Ayabe
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Patent number: 7758766Abstract: It is an object of the present invention to provide a magnetic garnet single crystal capable of reducing the optical loss of the resulting rotator even when the magnetic garnet single crystal is grown using a solvent containing Na by the liquid phase epitaxial process, as well as a Faraday rotator using the same. A magnetic garnet single crystal represented by the chemical formula Bi?Na?M13-?-?-?M2?Fe5-?-?Mg?M3?O12 (M1 is at least one element or more selected from Y, Eu, Gd, Tb, Dy, Ho, Yb and Lu; and M2 is at least one element or more selected from Ca and Sr; M3 is at least one element or more selected from Si, Ge, Ti, Pt, Ru, Sn, Hf and Zr, provided that 0.60<??1.50, 0<??0.05, 1.35<3??????<2.40, 0???0.10, 0???0.10, 0<??0.10, 0<?+??0.10, 0<?+??0.10).Type: GrantFiled: September 17, 2007Date of Patent: July 20, 2010Assignee: TDK CorporationInventor: Atsushi Ohido
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Patent number: 7754094Abstract: A sintered ferrite body having a main composition comprising 63-80% by mol of Fe2O3, and 3-15% by mol of ZnO, the balance being manganese oxide; Rcal determined from the Fe2O3 content X (% by mol) by the formula (1) of Rcal=[200(X?50)]/(3X), and the ratio R (%) of Fe2+ per the total amount of Fe in the sintered body meeting the condition of Rcal?2.0?R?Rcal+0.3; and the sintered body having a density of 4.9 g/cm3 or more.Type: GrantFiled: December 24, 2004Date of Patent: July 13, 2010Assignee: Hitachi Metals Ltd.Inventors: Masahiro Takahashi, Syuichi Takano
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Patent number: 7713433Abstract: W-type ferrite has improved magnetic properties, in particular, coercive force. A high coercive force (HcJ) and a high residual magnetic flux density (Br) can be simultaneously attained by a ferrite magnetic material comprising an oxide having a composition wherein metal elements Sr, Ba and Fe in total have a composition ratio represented by the formula Sr(1?x)BaxFe2+aFe3+b in which 0.03 ?x?0.80, 1.1?a?2.4, and 12.3?b?16.1. The ferrite magnetic material can form any of a ferrite sintered magnet, a ferrite magnet powder, a bonded magnet as a ferrite magnet powder dispersed in a resin, and a magnetic recording medium as a film-type magnetic phase. As for the ferrite sintered magnet, there can be attained a fine sintered structure that has a mean grain size of 0.6 ?m or less.Type: GrantFiled: March 3, 2005Date of Patent: May 11, 2010Assignee: TDK CorporationInventors: Yoshihiko Minachi, Noboru Ito, Junichi Nagaoka, Shunsuke Kurasawa, Taku Murase
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Publication number: 20100108935Abstract: The present invention relates to ferrite particles for bonded magnets and a resin composition for bonded magnets which exhibit a good moldability, in particular, a good mechanical strength even when rapidly quenched upon injection-cooling, and is capable of producing a bonded magnet molded product having excellent magnetic properties, as well as a bonded magnet molded product such as a magnet roll using the ferrite particles and the resin composition. There are provided ferrite particles for bonded magnets which comprise phosphorus adsorbed and/or incorporated in ferrite, in which a content of the phosphorus in the ferrite is 120 to 5000 mg/kg (0.012 to 0.50% by weight) in terms of P; a resin composition for bonded magnets; and a magnet roll.Type: ApplicationFiled: March 14, 2008Publication date: May 6, 2010Inventors: Yasuhiko Fujii, Yasushi Nishio, Kazuhisa Kanefuji, Tatsuya Ishida, Shigeru Takaragi
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Patent number: 7651626Abstract: There is provided Y-type hexagonal ferrite having a high density of sintered body and a low level of loss and an antenna. The hexagonal ferrite having Y-type ferrite as the main phase is characterized in that main components of the hexagonal ferrite are M1O (M1 stands for at least one of Ba and Sr), M2O (M2 stands for at least one of Co, Ni, Cu, Zn and Mn) and Fe2O3, and the loss factor and the density of sintered body are 0.15 or lower and 4.6×103 kg/m3 or higher, respectively. The hexagonal ferrite is used to configure an antenna and a communication apparatus.Type: GrantFiled: December 14, 2006Date of Patent: January 26, 2010Assignee: Hitachi Metals, Ltd.Inventors: Masayuki Gonda, Hiroyuki Aoyama
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Publication number: 20090273534Abstract: A magnetic material antenna using a ferrite sintered body comprising one or more conductors disposed at least on a surface or in internal portion of the ferrite sintered body, wherein the ferrite sintered body is a sintered body of Y-type ferrite containing BaO, CoO, and Fe2O3 as main components and wherein the ferrite sintered body contains Cu and, in a cross section for the sintered body, an area rate of a cubic Co-rich phase, which has a ration of an amount of Co being higher than a Y-type ferrite phase being a mother phase, is 1% or less.Type: ApplicationFiled: June 21, 2007Publication date: November 5, 2009Inventors: Masayuki Gonda, Shigeo Fujii, Hiroyuki Aoyama
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Patent number: 7540972Abstract: For the purpose of providing a Mn—Zn based ferrite material that is small in magnetic field degradation in high frequency bands of 1 MHz or more, the Mn—Zn based ferrite material includes: as main constituents, Fe2O3: 53 to 56 mol %, ZnO: 7 mol % or less (inclusive of 0 mol %), and the balance: MnO; and as additives, Co: 0.15 to 0.65% by weight in terms of Co3O4, Si: 0.01 to 0.045% by weight in terms of SiO2 and Ca: 0.05 to 0.40% by weight in terms of CaCO3; wherein the ? value (the cation defect amount) defined in the present specification satisfies the relation 3×10?3???7×10?3; and the mean grain size is larger than 8 ?m and 15 ?m or less.Type: GrantFiled: January 23, 2007Date of Patent: June 2, 2009Assignee: TDK CorporationInventors: Tomokazu Ishikura, Shinichi Sakano, Masahiko Watanabe
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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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Patent number: 7476482Abstract: This invention provides an Mg-based ferrite having a high dielectric breakdown voltage and a saturation magnetization suitable for electrophotographic development, a carrier containing the ferrite, and an electrophotographic developer containing the carrier. The Mg-based ferrite material of this invention comprises Li, Na, K, Rb, Cs, Ca, Sr, Ba, Y, La, Ti, Zr, Hf, V, Nb, Ta, Al, Ga, Si, Ge, P, Sb, Bi or a combination thereof. The Mg-based ferrite material has a saturation magnetization of 30 to 80 emu/g, and a dielectric breakdown voltage of 1.5 to 5.0 kV. The Mg-based ferrite material can realize high image quality, and be in compliance with environmental regulations.Type: GrantFiled: November 5, 2004Date of Patent: January 13, 2009Assignee: Kanto Denka Kogyo Co., Ltd.Inventors: Hidehiko Iinuma, Masatomo Hayashi, Natsuki Matsuura, Yukinari Oguma
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Patent number: 7470498Abstract: This invention provides an Mg-based ferrite carrier composed of an environment-friendly material meeting environmental regulations, and an electrophotographic developer comprising the carrier. The carrier and the developer of this invention realize high image quality and improved gradation properties. This invention also provides a method for producing the Mg-based ferrite material having a saturation magnetization of from 30 to 80 emu/g and a dielectric breakdown voltage of from 1.0 to 5.0 kV, and having the composition of the formula (1). The above properties are obtained by controlling conditions of sintering and heating treatments. CaaMgbFecOd (1) wherein a, b, and c satisfy 0.10 b/(b+c/2) 0.85 and 0 R(Ca) 0.10; R(Ca) is expressed as R(Ca)=a˜Fw(CaO)/(a˜Fw(CaO)+b˜Fw(MgO)+(c/2)˜Fw(Fc2O3)) (Fw(A): formula weight of A j; and d is determined by oxidation numbers of Ca, Mg and Fe.Type: GrantFiled: March 26, 2004Date of Patent: December 30, 2008Assignee: Kanto Denka Kogyo Co., Ltd.Inventors: Hidehiko Iinuma, Kenkichi Hara, Masatomo Hayashi
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Patent number: 7465409Abstract: Hard magnetic core particles for use in the development of electrostatic latent images are produced by combining ferric oxide, a strontium oxide precursor, an oxygenated boron compound and a binder to form a mixture, wherein the strontium oxide precursor is preferably present in an amount that provides SrO in a molar amount that is in excess of a stoichiometric amount that provides a ratio of Fe2O3 to SrO of 6/1. The mixture can be formed into green beads and the green beads can be fired to form the hard magnetic core particles.Type: GrantFiled: September 21, 2005Date of Patent: December 16, 2008Assignee: Eastman Kodak CompanyInventor: Patrick M. Lambert
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Patent number: 7425280Abstract: The present invention provides a ferrite magnet material comprising, as a main phase, a ferrite having a hexagonal structure, the main phase containing A, La, R, Fe and Co, wherein A is at least one element selected from Sr, Ba and Pb, R is Pr and/or Nd, and the proportions of the total metal elements A, La, R, Fe and Co in the main phase are respectively A: 1 to 13 atomic %, La: 0.003 to 10 atomic %, R: 0 to 10 atomic % (excluding 0) Fe: 80 to 95 atomic % and Co: 0.05 to 5 atomic % based on the total amounts of metal elements. The residual magnetic flux density Br and coercive force HcJ can be improved without increasing the content of Co by incorporating Pr and/or Nd along with La and Co in the ferrite magnet material.Type: GrantFiled: October 28, 2005Date of Patent: September 16, 2008Assignee: TDK CorporationInventors: Junichi Nagaoka, Shigeki Yanagida, Kunio Ohno, Syunsuke Kurasawa, Yoshihiko Minachi
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Publication number: 20080210899Abstract: Provided are magnetic core-ceramic shell (e.g., magnetite (Fe3O4) core-calcium phosphate (Ca3(PO4)2) shell) nanocrystals with high crystallization degree, uniform size, and high chemical stability and a method for synthesizing the same. A core-shell structure is synthesized in a process of forming magnetite seeds corresponding to cores by the reduction of magnetite precursors and then, sequentially, coating the magnetite with Ca3(PO4)2 by the reduction of Ca3(PO4)2 precursors.Type: ApplicationFiled: January 4, 2008Publication date: September 4, 2008Applicant: Korea University FoundationInventors: Young Keun Kim, Hong Ling Liu, Jun Hua Wu, Ji Hyun Min, You Song Kim
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Patent number: 7410625Abstract: A method and structure for making magnetite nanoparticle materials by mixing iron salt with alcohol, carboxylic acid and amine in an organic solvent and heating the mixture to 200-360° C. is described. The size of the particles can be controlled either by changing the iron salt to acid/amine ratio or by coating small nanoparticles with more iron oxide. Magnetite nanoparticles in the size ranging from 2 nm to 20 nm with a narrow size distribution are obtained with the invention.Type: GrantFiled: August 29, 2006Date of Patent: August 12, 2008Assignee: International Business Machines CorporationInventor: Shouheng Sun
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Publication number: 20080149882Abstract: A composite sintered body of dielectric substance and magnetic substance comprises a hexagonal Ba ferrite crystal, a perovskite type crystal containing at least one element selected from Ca, Sr, and Ba, and Ti, and Li element, and the relative magnetic permeability is 1.4 or more at 1 GHz. LC composite electronic component comprises the composite sintered body, a condenser circuit formed in the inside or the surface of the composite sintered body, and an inductor circuit formed in the inside or the surface of the composite sintered body.Type: ApplicationFiled: December 21, 2007Publication date: June 26, 2008Applicant: KYOCERA CORPORATIONInventors: Hirofumi Terazono, Takeshi Matsui
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Patent number: 7390425Abstract: The ferrite sintered body of hexagonal Z-type ferrite contains 17 mol % to 21 mol % of BaO, 6 mol % to 13 mol % of CoO, the remainder being Fe2O3 as its main components and also contains 0.05% to 1.0% by mass of Li, based on the main components, in terms of Li2CO3 and 0.05% to 0.5% by mass of Si, based on the main components, in terms of SiO2. Further, the rate of a spinel-type ferrite phase to entire phases including a Z-type ferrite phase and the spinel-type ferrite phase is 5% or less in terms of an area ratio in the cross section of the sintered body.Type: GrantFiled: February 28, 2006Date of Patent: June 24, 2008Assignee: Hitachi Metals, Ltd.Inventor: Tomotsugu Kato
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Patent number: 7384571Abstract: A ferrite magnetic powder for bond magnet that experiences only small decrease in coercivity when molded into a bond magnet is provided, which is a ferrite magnetic powder that includes an alkaline-earth metal constituent and exhibits a decrease in coercivity of not greater than 600 Oe when subjected to a prescribed molding test. The magnetic powder can be obtained by mixing a fine ferrite powder of an average particle diameter of greater than 0.50 to 1.0 ?m and a coarse ferrite powder of an average particle diameter of greater than 2.50 to 5.0 ?m at ratio to incorporate the fine powder at a content ratio of 15-40 wt %.Type: GrantFiled: February 6, 2007Date of Patent: June 10, 2008Assignees: Dowa Electronics Materials Co., Ltd., Nippon Bengara Kogyo Co., Ltd.Inventors: Masayasu Senda, Shinichi Suenaga, Keisuke Ayabe, Toshiyuki Sakai
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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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Publication number: 20070231722Abstract: A ferromagnetic material powder comprising a magnetic oxide which is a complex of a magnetite phase and a ferrite phase, wherein the ferromagnetic material powder has a spinel crystal structure and a magnetoplumbite crystal structure, and in the spinel crystal structure, the content of Fe3+ in site A is 35 to 50% and the content of Fe2+ in site B is 30 to 45%, a carrier for an electrophotographic developer, a process for producing them and an electrophotographic developer.Type: ApplicationFiled: March 30, 2007Publication date: October 4, 2007Applicant: Powdertech Co., Ltd.Inventors: Takao Sugiura, Kanao Kayamoto
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Publication number: 20070205390Abstract: For the purpose of providing a Mn—Zn based ferrite material that is small in loss in high frequency bands of 1 MHz or more and in the vicinity of 100° C., the Mn—Zn based ferrite material includes: as main constituents, Fe2O3: 53 to 56 mol %, ZnO: 7 mol % or less (inclusive of 0 mol %), and the balance: MnO; and as additives, Co: 0.15 to 0.65% by weight in terms of CoO, Si: 0.01 to 0.045% by weight in terms of SiO2 and Ca: 0.05 to 0.40% by weight in terms of CaCO3; wherein the 6 value (the cation defect amount) defined in the present specification defined in the present specification.Type: ApplicationFiled: February 6, 2007Publication date: September 6, 2007Applicant: TDK CORPORATIONInventors: Tomokazu Ishikura, Shinichi Sakano, Isao Nakahata, Masahiko Watanabe