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: A polycrystalline ferromagnetic metal oxide has a density of 97% or more to less than 100%; and a method of manufacturing a polycrystalline ferromagnetic metal comprises a step of treating a polycrystalline ferromagnetic metal oxide under a high pressure reducing gas for high densification.

Abstract: A method of making a magnetoplumbite-type ferrite material powder includes the step of preparing the ferrite material powder by spraying a mixed chloride solution, in which a chloride of iron and a chloride of strontium are dissolved, into a heated atmosphere. The solution of the mixed chloride contains 25% through 35% of the chloride of iron and 2.4% through 4.9% of the chloride of strontium.

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: A ferrite magnet having a basic composition represented by the following general formula: (A1-xRx)O.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, 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, and substantially having a magnetoplumbite-type crystal structure, is obtained by uniformly mixing a compound of Sr and/or Ba with an iron compound; calcining the resultant uniform mixture; adding a compound of the R element and/or the M element to the resultant calcined powder at a pulverization step thereof; and sintering the resultant mixture. The compound of the R element and/or the M element may be added at a percentage of more than 0 atomic % and 80 atomic % or less, on an element basis, at a mixing step before calcination.

Abstract: Substantially spherical magneto-plumbite ferrite (barium or strontium ferrite) particles are formed from well-dispersed ultra-fine substantially spherical iron-based oxide and/or hydroxide particles as precursor particles. The precursor particles are mixed with a colloidal barium or strontium carbonate (BaCO3 or SrCO3), and with small amounts of a byproduct, such as sodium or potassium chloride (NaCl or KCl) or hydroxide (NaOH or KOH) or nitrate (NaNO3 or KNO3), functioning as a flux to lower the calcination temperature. The particles are filtered out of the mixture, dried, and calcined for a time sufficiently long and/or at a temperature sufficiently high to form magneto-plumbite ferrite from the precursor particles, and for a time sufficiently short and/or a temperature sufficiently low to maintain the general spherical shape of the precursor particles.

Abstract: A method is disclosed for the manufacture of particles composed of an intimate admixture of barium or strontium ferrite and ferric oxide from a chloride solution containing barium or strontium ions and ferrous ions by a pyrohydrolysis reaction. The presence of carbon dioxide in the heated atmosphere in which pyrohydrolysis of an admixture of alkaline earth metal chloride and iron chloride is carried out has been discovered to substantially decrease the temperature required for reaction to occur.

Abstract: A magnetic material includes main components having Fe2O3 of 46.0 to 51.0 mol %, CuO of 0.5 to 15.0 mol % and the rest being NiO. With respect to the main components of 100 wt parts, additives are added. The additives are bismuth oxide of 4.0 to 10.0 wt part in terms of Bi2O3, magnesium oxide of 1.0 to 5.0 wt part in terms of MgO, silicon oxide of 2.0 to 8.0 wt part in terms of SiO2, and cobalt oxide of 0.2 to 0.5 wt part in terms of CoO. Further, an inductor has a core including the above magnetic material, and is composed by molding a resin.

Abstract: Ni—Cu—Zn based oxide magnetic materials, in that not only the internal conductor is stabilized at very low firing temperatures, but also the characteristics in the high frequency zones of 100 MHz or higher are excellent. The oxide magnetic materials comprises, Fe2O3: 35.0 to 51.0 mol %, CuO: 1.0 to 35 mol %, NiO: 38.0 to 64.0 mol %, ZnO: 0 to 10.0 mol % (including 0%) and Ca: 0.3 wt % or lower (not including 0%), and, optionally, CoO: 0.7 wt % or lower.

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: This invention relates to the formula and preparation method for a multi-layer chip inductor material used in very high frequencies. The main composition of this material is planar hexagonal soft magnetic ferrite, and ingredient is low temperature sintering aid. Preparation method is a synthetic method of solid phase reaction. The sintering aid is prepared by secondary doping. By the process of ball grinding, drying, pre-calcining, ball grinding, drying, granulating, forming, sintering, and so forth, very high frequency inductor material of superior quality is obtained, realizing low temperature sintering under a temperature lower than 900° C. This invention is of low cost, high performance, suitable for multi-layer chip inductors at very high frequencies of 300M-800 MHz.

Abstract: A soft hexagonal ferrite sintered material includes crystal particles of M-type hexagonal ferrite corresponding to a general chemical formula MFe12O19 wherein M is at least one element selected from the group consisting of Ba, Sr and Pb. Crystal particles having particle diameters of 5 &mgr;m to 100 &mgr;m are extracted from a sintered material produced from a precursor powder mixture. The extracted particles as seed crystals are mixed with a calcined powder comprising fine crystals having the above composition and particle diameters of 0.5 &mgr;m to 3 &mgr;m, then is sintered until the intended particle growth of the crystal particles in the sintered material is achieved to give an average particle diameter of 30 &mgr;m to 500 &mgr;m.

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: The ferrite magnet powder of the present invention is magnet powder having, as the major phase, a La—Co magnetoplumbite ferrite where La and Co are substituted for Sr and Fe, respectively, represented by (1−x)SrO.(x/2)La2O3.(n−y/2)Fe2O3.yMO wherein x, y, and n represent mole ratios and satisfy 0.22−0.02≦x≦0.22+0.02, 0.18−0.02≦y≦0.18+0.02, and 5.2≦n≦6.0, where x>y.

Abstract: Rubber compositions filled with an unusually high content of solid magnetizable particles such as iron oxide or strontium ferrite but having great resistance to crack initiation and crack growth. This allows generation of strongly magnetized areas in rubber articles built with a rubber composition according this invention. This gives—also in those applications where a large distance between a row of magnetized areas and a sensor is necessary due to deformation—well-reproducible and well-recognizable signals despite existence of disturbing magnetic fields. The magnetizable particles are bonded to a rubber matrix by a bonding agent, namely an organo-functional silane.

Abstract: BaTiO3—PbTiO3 series single crystal is single-crystallized by heating BaTiO3—PbTiO3 compact powder member or sintered member having a smaller Pb-containing mol number than Ba-containing mol number, while keeping the powder or substance in non-molten condition. In this way, this single crystal can be manufactured at a crystal growing speed faster still and stabilized more, significantly contributing to improving the dielectric loss and electromechanical coupling coefficient for the provision of excellent BaTiO3—PbTiO3 series single crystal in various properties, as well as for the provision of piezoelectric material having a small ratio of lead content, which is particularly excellent in piezoelectric property and productivity.

Abstract: Porous composite particles contain 80 to 98% by weight of a filling material and 2 to 20% by weight of carbon, and have an average pore diameter of not more than 5 nm when measured with respect to pores existing in both the surface and inside portions thereof, an average particle size of 1 to 1,000 &mgr;m and a specific surface area of 45 to 200 m2/g. These porous composite particles individually contain the filling material in as large an amount as possible, so they have not only a high catalytic but also a high adsorption ability, thereby exhibiting an excellent catalytic activity.

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: An La—Co ferrite magnet powder, in which Sr and Fe are replaced with La and Co, respectively, is made by carrying out a calcination process at a temperature higher than 1300° C. and equal to or lower than 1450° C. Fe has a magnetic moment oriented upwardly with respect to a crystal c-axis at a number of sites thereof, and also has an opposite magnetic moment oriented downwardly with respect to the crystal c-axis at another number of sites thereof. And Fe is replaced with Co at the greater number of sites thereof. As a result, high coercivity is attained. In this manner, coercivity can be increased while suppressing decrease in saturation magnetization &sgr;s.

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: The present invention relates to methods of producing synthetic crystals (typically minerals) or comparable inorganic compounds by reactions of metal salts and metal oxyhydroxides under near-critical, critical or supercritical solvent conditions, avoiding thereby many of the difficulties associated with conventional solid state or wet chemistry synthesis. The metal oxyhydroxides are typically divalent or trivalent metals and the preferred solvent is typically (but not exclusively) water under near-critical, critical or supercritical conditions. The crystals so produced have a controlled particle size distribution. The crystals produced by the present invention also have morphologies with favorable properties for compaction into green bodies for subsequent sintering into near-net-shapes, approaching maximum theoretical densities. Avoidance of noxious by-products is another advantage of the present synthetic methods.

Abstract: The present invention provides an oxide magnetic material, which includes a primary phase of a hexagonal ferrite containing metallic elements Ca, R, Fe and M, where M represents at least one element selected from the group including Co, Ni and Zn, and R represents at least one element selected from the group including Bi and rare earth elements including Y, with La being essentially included in R; wherein the proportions of the metallic elements Ca, R, Fe and M with respect to the total amount of the metallic elements are from 1 to 13 atomic % for Ca, from 0.05 to 10 atomic % for R, from 80 to 95 atomic % for Fe, and from 1 to 7 atomic % for M. The present invention also provides ferrite particles, a bonded magnet, a sintered magnet, a process for producing them, and a magnetic recording medium, which contain the oxide magnetic material.

Abstract: The present invention provides a hollow shape strontium iron oxide particle powder. Not only is the particle powder high in safety and excellent in workability, but exhibits a large dielectric constant when formed into an artificial dielectric material utilizing electrical conduction by being dispersed in an organic medium such as a rubber.

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−xRx)O.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 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: A composite magnetic material comprises a ferrite powder and a resin, in which the ferrite powder comprises a cobalt substituted Y type hexagonal ferrite (2BaO.2CoO.6Fe2O3) or cobalt substituted Z type hexagonal ferrite (3BaO.2CoO.12Fe2O3), and the permeability at 2 GHz is 90% or more of that at 1 MHz.

Abstract: The invention aims to provide a manganese-zinc ferrite exhibiting a high initial permeability over a broad band and especially in a low-frequency region of about 10 kHz and a method for preparing the same. A method for preparing a manganese-zinc ferrite by firing is characterized in that the firing includes a main temperature holding step at 1,200-1,450° C. and a thermal ramp-down step prior to the main temperature holding step, and the lowest temperature reached by the mid-firing thermal ramp-down step is set in the range of 1,000-1,400° C. and lower by at least 50° C. than the hold temperature of the main holding step, thereby obtaining a manganese-zinc ferrite comprising 50-56 mol % calculated as Fe2O3 of iron oxide, 22-39 mol % calculated as MnO of manganese oxide, and 8-25 mol % calculated as ZnO of zinc oxide as main components, and having a mean crystal grain size of more than 50 &mgr;m to 150 &mgr;m.

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 method of producing a single crystal of the composition M3NbGa3Si2O14 (where M is an alkaline earth metal) comprising growing in a lattice direction inclined at an angle of 50.8 to 90 degrees from a [001] axis. The single crystal obtained in this way may be suitably used as a component of a resonator, filter, or other various piezoelectric elements.

Abstract: The present invention provides manganese-zinc-ferrite core fabrication process which can fabricate a manganese-zinc-ferrite core having high surface electrical resistance and low magnetic core losses without recourse to the introduction of nitrogen gas from the outside yet within a short time period, and such a manganese-zinc-ferrite core. To achieve this, manganese-zinc-ferrite core is formed into a given core shape. The core compact is fired in a firing atmosphere having an oxygen concentration controlled with carbonic acid gas and steam. Then, the compact is rapidly cooled at a cooling rate of 350° C./hour to 850° C./hour. In this way, a manganese-zinc-ferrite core is obtained.

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-xRx)O.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: 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 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: Substantially spherical magneto-plumbite ferrite (barium or strontium ferrite) particles are formed from well-dispersed ultra-fine substantially spherical iron-based oxide and/or hydroxide particles as precursor particles. The precursor particles are mixed with a colloidal barium or strontium carbonate (BaCO3 or SrCO3), and with small amounts of a byproduct, such as sodium or potassium chloride (NaCl or KCl) or hydroxide (NaOH or KOH) or nitrate (NaNO3 or KNO3), functioning as a flux to lower the calcination temperature. The particles are filtered out of the mixture, dried, and calcined for a time sufficiently long and/or at a temperature sufficiently high to form magneto-plumbite ferrite from the precursor particles, and for a time sufficiently short and/or a temperature sufficiently low to maintain the general spherical shape of the precursor particles.

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: Conductive hard magnetic carrier particles are disclosed which contain a single-phase hexagonal crystal structure doped with at least one metal that, upon substitution of said metal into said crystal structure, produces a multi-valent ion of the formula Mn+, wherein n=4, 5, or 6. The carrier particles are useful in making developers for the development of electrostatic latent image patterns in an electrographic process. Also disclosed are methods for using such carrier particles in an electrographic process. Such carriers can display levels of conductivity such that the development efficiency, i.e., speed, of an electrographic process is improved.

Abstract: The Mn—Zn system ferrite according to the present invention contains main components comprising manganese oxide, zinc oxide and iron oxide, and subordinate components comprising bismuth oxide and molybdenum oxide. It comprises 22.0 to 25.0 mol % c of manganese oxide calculated as MnO, 22.0 to 25.0 mol% of zinc oxide calculated as ZnO and the remainder calculated as Fe2O3 in main components. It has been sintered after adding thereto 50 to 400 ppm of a bismuth oxide component calculated as Bi2O3 and 50 to 400 ppm of a molybdenum oxide component calculated as MoO3 as subordinate component source materials. An initial magnetic permeability at 10 KHz is 8,500 or more at −20 to 20° C. and 10,000 or more at 20 to 100° C., and the temperature characteristics of magnetic permeability is excellent.

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 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.