Abstract: A high frequency magnetic material ceramic composition including materials having the general formula (Ca, A)zCuxB8−x−zO12 is prepared. A represents Y and/or at least one element selected from the rare earth elements excluding Y; B represents metal elements which are different from A and include at least Fe and V. x has a value of 0.002<x<0.2; and z is a value of 3.0<z≦3.09. The Ca/V ratio is 2.0<Ca/V≦2.4. A irreversible circuit component containing center electrodes electrically insulated from each other in a ferrite member made of the high frequency magnetic material ceramic is provided.

Abstract: 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.

Abstract: The invention concerns a process permitting the preparation of a new powder, which as such or further processed is useful within a wide variety of different fields and which has magnetic and electric properties. The powder includes at least 0.5% by weight of iron containing silicate and at least 10% by weight of metallic iron and/or alloyed iron and is prepared by a process comprising the steps of mixing an iron containing powder and a silicon containing powder; and reducing the obtained mixture at a temperature above about 450° C.

Abstract: Soft-magnetic hexagonal ferrite composite particles composed of 100 parts by weight of soft-magnetic hexagonal ferrite particles containing a Z-type ferrite, Y-type ferrite or W-type ferrite as a main phase, 0.3 to 10 parts by weight of barium carbonate particles, strontium carbonate particles or their mixture and 0.1 to 5 parts by weight of silicon dioxide particles.

Abstract: The invention relates to a process for the preparation of magnetite particles and to their use.

Abstract: A ferrite with a high permeability and a high dielectric constant is introduced. Raw material powders, such as TiO2, Fe2O3 and the oxide of Mn, Ni, Cu, Mg, Li or Zn is prepared and combined in the proportion Tix(MFe2O4+2x/y)y, where x+y=1 and 0<×<1. M is any one of a mixture of metals selected from Mn, Ni, Cu, and Zn. The ratio between x and y can be adjusted according to practical needs to obtain ferrites with different permeabilities and dielectric constants. The ferrite can simultaneously be a magnetic material and a dielectric material in an electronic element. This can avoid the possible drawbacks due to sintering of two different materials in the prior art.

Abstract: This invention relates to magnetite particles with a mean particle size of 0.1 to 0.3 &mgr;m, a specific surface area of 6 to 9 m2/g, a coercive force of 80 to 110 Oe, a residual magnetization of 13 to 20 nTm3/g, a pH of 7 to 10 and a bulk density of 0.6 to 0.9 g/cm3, by heating an aqueous solution of an alkaline component under inert gas, to a precipitation temperature of 65-85° C., adding iron (II) and iron (III) components and oxidizing the suspension with an oxidizing agent at a speed of 7-25 mol % Fe (II)/h.

Abstract: 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.

Abstract: To use a media agitating mill of a wet internal circulation type when grinding materials, and offer oxide magnetic materials and coils in which influences of ZrO2 and Y2O3 mixing when using partially stabilized zirconia as media beads are improved. The magnetic materials and coils are characterized in that Fe2O3, ZnO, NiO and CuO are main components, and Y2O3, ZrO2 and Bi2O3 are contained with respect to these main components, where an amount of Y2O3 is 0.007 to 0.028 wt % for the total amount, an amount of ZrO2 is 0.12 to 0.55 wt % therefor and an amount of Bi2O3 is 0.03 to 10.12 wt % for the same.

Abstract: A resin-bonded magnet composed substantially of (a) an R—T—N-based magnetic powder having a basic composition of R&agr;T100−&agr;−&bgr;N&bgr;, wherein R is at least one selected form the group consisting of rare earth elements including Y, T is Fe or Fe and Co, 5≦&agr;≦20, and 5≦&bgr;≦30, (b) a ferrite magnetic powder having a substantially magnetoplumbite-type crystal structure and a basic composition represented by (A1−xR′x) O[(Fe1−yMy)2O3] by atomic ratio, wherein A is Sr and/or Ba, R′ is at least one selected from the group consisting of rare earth elements including Y, La being indispensable, M is Co or Co and Zn, 0.01≦x<0.4, 0.005≦y≦0.04, and 5.0≦n≦6.4, and (c) a binder. The ferrite magnet powder is preferably an anisotropic, granulated powder or an anisotropic, sintered ferrite magnet powder.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: The present invention provides a Mn—Zn ferrite having an electrical resistivity exceeding 1 &OHgr;m order and a low core loss in a high frequency region exceeding 1 MHz. A basic component composition of the Mn—Zn ferrite includes 44.0 to 49.8 mol % of Fe2O3, 6.0 to 15.0 mol % of ZnO (15.0 mol % is excluded), 0.1 to 3.0 mol % of CoO, 0.02 to 1.20 mol % of Mn2O3, and the remainder of MnO. The Mn—Zn ferrite achieves desired purposes by controlling Fe2O3 content to a range less than 50 mol % that is the stoichiometric composition, adding a proper amount of CoO, restraining amount of Mn2O3 formation to 1.20 mol % or less, and further setting their average grain sizes to less than 10 &mgr;m.

Abstract: The present invention provides a Mn—Zn ferrite having an electrical resistivity exceeding 1 &OHgr;m order and having a low core loss in a high frequency region exceeding 1 MHz. The basic component composition of the Mn—Zn ferrite includes 44.0 to 49.8 mol % Fe2O3, 6.0 to 15.0 mol % ZnO (15.0 mol % is excluded), 0.1 to 4.0 mol % at least one of TiO2 and SnO2, and remainder MnO, wherein desired results are obtained by limiting Fe2O3 content to less than 50 mol % that is the stoichiometric composition and adding a proper amount of TiO2 or SnO2 and further controlling its average grain size to less than 10 &mgr;m.

Abstract: 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.

Abstract: A magnetic composition comprised of cobalt ferrite nanoparticles dispersed in an ionic exchange resin.

Abstract: This invention provides a Mn—Zn ferrite which has a high electrical resistance and can sufficiently satisfy the use in a high frequency region exceeding 1 MHz. This invention further provides a production process of the Mn—Zn ferrite in which mixed powder whose components are adjusted so as to have a basic component composition containing 44.0 to 50.0 mol% Fe2O3, 4.0 to 26.5 mol % ZnO, 0.1 to 8.0 mol % one or two from TiO2 and SnO2 and the remainder consisting of MnO, and further to contain 0.01 to 2.00 mass % one or more of CoO, NiO, and MgO as additive is pressed, then sintered and cooled in the air or in an atmosphere containing some amount of oxygen.

Abstract: This invention relates to magnetite particles with a mean particle size of 0.1 to 0.3 &mgr;m, a specific surface area of 6 to 9 m2/g, a coercive force of 80 to 110 Oe, a residual magnetization of 13 to 20 nTm3/g, a pH of 7 to 10 and a bulk density of 0.6 to 0.9 g/cm3, by heating an aqueous solution of an alkaline component under inert gas, to a precipitation temperature of 65-85° C., adding iron (II) and iron (III) components and oxidizing the suspension with an oxidizing agent at a speed of 7-25 mol % Fe (II)/h.

Abstract: A manganese-zinc base ferrite containing iron oxide, manganese oxide and zinc oxide as main components in amounts calculated as Fe2O3, MnO and ZnO, respectively, Fe2O3 50 to 56 mol %, MnO 21 to 27 mol %, and ZnO 20 to 26 mol %, and 0.0003 to 0.003% by weight calculated as P of phosphorus as an auxiliary component, and having a mean grain size from more than 50 &mgr;m to 200 &mgr;m.

Abstract: 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.

Abstract: A process for producing Mn—Zn ferrite having large electrical resistance and being durable to the use in high frequency region exceeding 1 MHz easily and at low cost is disclosed. The process comprises pressing a mixed powder comprising a composition of 44.0 to 50.0 mol % of Fe2O3, 4.0 to 26.5 mol % of ZnO, 0.1 to 8.0 mol % of at least one member selected from the group consisting of TiO2 and SnO2, and the remainder being MnO, and if desired 0.1 to 16.0 mol % of CuO, sintering the resulting green compact in the air or an atmosphere containing an appropriate amount of oxygen, and then cooling the green compact, thereby securing the estimated high initial permeability even in a high frequency region of 1 MHz or more.

Abstract: In NiMnZn based ferrite, main components range within the scopes of Fe2O3=53 to 59 mol %, MnO=22 to 41 mol %, ZnO=4 to 12 mol %, and NiO=2 to 7 mol %, and sub-components of said NiMnZn based ferrite range within the scopes of SiO2: 0.005 to 0.03 wt %, CaO: 0.008 to 0.17 wt % and P: 0.0004 to 0.01 wt %.

Abstract: The present invention provides a magnetic film expressed by a composition formula TaMbXcNdOe (T is a magnetic metal such as Fe, M is an alkaline earth metal such as Be, Mg, and Ca, and X is at least one selected from the group consisting of Y, Ti, Zr, Hf, V, Nb, Ta and lanthanoid), where a+b+c+d+e=100, 45 ≦a≦85, 5.5≦b≦28, 0.5≦c≦16, 6≦b+c≦28.5, 0.4 <b/c ≦56, 0≦d≦10, and 8≦d+e≦40. The magnetic film comprises mainly metal magnetic crystal grains having an average crystal grain diameter of not more than 15 nm and a grain boundary product. The grain boundary product substantially separates the metal magnetic crystal grains. The main component of the metal magnetic crystal grains is the T. The grain boundary product contains at least an oxide or a nitride of the M and the X. The magnetic film has a saturation magnetic flux density of not less than 0.8 T and an electric resistivity of not less than 80 &mgr;&OHgr;cm.

Abstract: Tin-containing granular magnetic oxide particles comprising spinel-type crystal represented by the formula:

Abstract: The invention aims to provide a manganese-zinc base ferrite having a high permeability over a broad band, especially in a frequency band near 10 kHz. The object is achieved by a manganese-zinc base ferrite which contains iron oxide, manganese oxide and zinc oxide as main components in amounts calculated as Fe2O3, MnO and ZnO, respectively, of 50-56 mol % Fe2O3, 21-27 mol % MnO, and 20-26 mol % ZnO, contains 0.0003-0.003% by weight calculated as P of phosphorus as an auxiliary component, and has a mean grain size from more than 50 &mgr;m to 200 &mgr;m.

Abstract: A process for producing Mn—Zn ferrite is disclosed, which enables regeneration and reuse of scraps of a sintered product. The process comprises reusing a powder obtained by milling the sintered product of Mn—Zn ferrite, subjecting the powder to a component adjustment so as to have a composition of 44.0 to 50.0 mol % of Fe2O3, 4.0 to 26.5 mol % of ZnO, 0.1 to 8.0 mol % of at least one member selected from the group consisting of TiO2 and SnO2, and the remainder being MnO, and optionally 0.1 to 16.0 mol % of CuO, pressing the resulting mixed powder after the component adjustment, and then sintered a green compact.

Abstract: Magnetic ceramic compositions include a Fe compound, a Zn compound, a Ni compound and a Cu compound as primary components, and also includes a bismuth compound and a cobalt compound as additive components. The primary component composition ratio (Fe2O3, ZnO, NiO+CuO) represented by molar percent of Fe2O3, ZnO, and (NiO and CuO), is in the region enclosed by point A (48.0, 0.5, 51.5), point B (48.0, 1.5, 50.5), point C (45.5, 4.0, 50.5), point D (44.0, 4.0, 52.0), and point E (44.0, 0.5, 55.5) in a ternary diagram. About 8.0 to 14.0 molar percent of the Cu compound is included in 100 molar percent of the primary components as Fe2O3, ZnO, NiO, and CuO. About 0.25 to 1.0 part by weight of the bismuth compound as Bi2O3 and about 0.25 to 3.0 parts by weight of the cobalt compound as Co3O4 with respect to 100 parts by weight of the primary components are included.

Abstract: 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.

Abstract: The present invention relates to a method of producing magnetite particles useful for the production of toners by (a) placing an alkaline component in the form of an aqueous solution in a vessel under a protective gas, (b) adding 1.0 to 3.0 mol %, relative to Fe of the magnetite, of a silicate component to form a reaction mixture, (c) heating the reaction mixture to a precipitation temperature of 60 to 80° C., (d) adding an iron(II) component at a rate of 0.5 to 1.5 mol of Fe/hour per mol of the alkaline component until the pH of the suspension is 7.0 to 8.5, and (e) oxidizing the suspension with an oxidizing agent at a rate of 20 to 5 mol % of Fe(II)/hour to an Fe(III) content of 65 to 75 mol % of Fe(III).

Abstract: 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.

Abstract: The magnetic powder and the sintered magnet of the invention contains a primary phase of a hexagonal ferrite containing A, Co or R wherein A represents Sr, Ba or Ca, and R represents at least one element which may be rare earth elements including Y, and Bi, and have at least two different Curie temperatures. wherein the two different Curie temperatures are present within a range of from 400 to 480° C., and an absolute value of a difference therebetween is 5° C. or more. As both the saturation magnetization and the magnetic anisotropy of the M type ferrite therein are increased, the magnetic powder and the wintered magnet have a high residual magnetic flux density and a high coercive force, which conventional M type ferrite magnets could not have, while having excellent temperature characteristics of coercive force.

Abstract: An object of the invention is to simultaneously increase the saturation magnetization and magnetic anisotropy of M type ferrite, thereby realizing a hexagonal ferrite magnet having a high remanence and high coercivity which could never be achieved in prior art M type hexagonal ferrite magnets. The object is attained by a hexagonal ferrite magnet comprising A, R, and Fe, wherein A represents at least one element selected from among Sr, Ba, and Ca, and R represents an element capable of assuming a valence of +3 or +4 and having an ionic radius of at least 1.00 angstrom, and n/N is up to 0.35 provided that N is the total number of crystal grains and n is the number of crystal grains having stacking faults.

Abstract: A BALUN transformer core material contains a Z-type hexagonal system ferrite having an in-plane anisotropy and a high magnetic permeability and such a high resonance frequency as to be in excess of a Snake's limiting line, and therefore, in the BALUN transformer core material, the frequency properties of the magnetic permeability are extremely good. A BALUN transformer core obtained by pressing and sintering this BALUN transformer core material has a high initial magnetic permeability and specific resistance. Moreover, a BALUN transformer obtained by applying a winding to the BALUN transformer core is provided with superior properties which are not poorer as compared with a BALUN transformer constituted of a conventional spinel ferrite, and it is a BALUN transformer having high properties which can be used in a high-frequency band of 300 MHz or more.

Abstract: 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.

Abstract: A magnetic ceramic composition containing ferrite serving as a primary component and a sintering aid. The composition can be sintered at low temperature. The sintering aid contains about 2-45 mol % Li2O; about 5-40 mol % RO, with R being at least one of Ba, Sr, Ca, and Mg; and about 30-70 mol % (Ti, Si)O2 with SiO2 accounting for at least about 15 mol %. The resultant composition provides inductor elements in which migration of inner conductors is suppressed, and insulation deterioration and increase of direct-current resistance is restrained.

Abstract: There is disclosed an MnMgCuZn ferrite material which contains ranges of 46.5 to 50.4 mol % of iron oxide, 10.5 to 22.0 mol % of magnesium oxide, 22.5 to 25.0 mol % of zinc oxide, 6.0 to 16.0 mol % of copper oxide, and 0.1 to 3.5 mol % of manganese oxide. Advantages of an MnMgCuZn ferrite material that resistivity is relatively high and material cost is low are utilized to realize a superior MnMgCuZn ferrite material which is much smaller in magnetic loss than conventional materials of the same series and which has a sufficient saturated magnetic flux density.

Abstract: A ferrite oxide magnetic material containing, as basic composition, 11 to 19 mol % of iron oxide calculated in terms of Fe2O3, 11 to 25 mol % of zinc oxide calculated in terms of ZnO, 0 to 10 mol % of copper oxide calculated in terms of CuO, and a residual part of nickel oxide, and further containing, as components subsidiary to the basic composition, 0.01 to 15 wt % of lead oxide calculated in terms of PbO, and 0.01 to 15 wt % of silicon oxide and/or talc calculated in terms of SiO2, wherein the ferrite oxide magnetic material has an initial magnetic permeability of not higher than 8, a sintered density of not lower than 4.8 g/cm3 and a stress-resisting and magnetic-field-resisting characteristic in a range of ±5% calculated in terms of the rate &Dgr;L/L of the change of inductance due to the condition of a magnetic field of 1000 G under a compressive stress P=5 (kg/mm2) parallel with a direction of magnetization.

Abstract: 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.