A magnetic sheet according to the present invention contains MnZn ferrite as a main component and is comprised of a sheet-shaped sintered body. Besides, a ratio of Z.sub.MIN to Z.sub.MAX (Z.sub.MIN/Z.sub.MAX?100) is 90% or more, in which a maximum value of a content of Zn in terms of oxide is set to Z.sub.MAX and a minimum value of the content of Zn in terms of oxide is set to Z.sub.MIN in a thickness direction of a cross section of the sintered body.

A method for producing MnZn ferrite comprising Fe, Mn and Zn as main components, and Ca, Si and Co, and at least one selected from the group consisting of Ta, Nb and Zr as sub-components, comprising a step of molding a raw material powder for the MnZn ferrite to obtain a green body, and a step of sintering the green body; the sintering step comprising a temperature-elevating step, a high-temperature-keeping step, and a cooling step; the cooling step including a slow cooling step of cooling in a temperature range of 1100 C. to 1250 C. at a cooling speed of 0 C./hour to 20 C./hour for 1 hours to 20 hours, and a cooling speed before and after the slow cooling step being higher than 20 C./hour; the MnZn ferrite having a volume resistivity of 8.5 .Math.m or more at room temperature, an average crystal grain size of 7 m to 15 m, and core loss of 420 kW/m.sup.3 or less between 23 C. and 140 C. at a frequency of 100 kHz and an exciting magnetic flux density of 200 mT.

A frequency-dependent resistance element includes an element assembly composed of a sintered magnetic material and a coil conductor embedded in the element assembly. The sintered magnetic material is composed of a primary component containing Fe, Zn, Ni, and Cu and a secondary component containing Co. In the primary component, on a percent by mole basis, the Fe content is 46.79 to 47.69, the Zn content is 12.60 to 24.84, and the Ni content is 19.21 to 32.36 in terms of Fe.sub.2O.sub.3, ZnO, and NiO, respectively. The molar ratio (Ni:Zn) of Ni to Zn is (1X):X, where X is from about 0.28 to about 0.56. The content of Co in terms of Co.sub.3O.sub.4 is 1.0 to 10.0 parts by mass relative to 100 parts by mass of the primary component containing Fe, Zn, Ni, and Cu in terms of Fe.sub.2O.sub.3, ZnO, NiO, and CuO, respectively.

A multilayer body includes a multilayer structure including a glass ceramic layer including a glass and a filler and a ferrite layer including a ferrite, in which the glass ceramic layer has a glass content of about 30.0% or more by weight and about 80.0% or less by weight and a filler content of about 20.0% or more by weight and about 70.0% or less by weight, the glass included in the glass ceramic layer includes about 0.5% or more by weight and about 5.0% or less by weight R.sub.2O (R represents at least one selected from the group consisting of Li, Na, and K), about 0% or more by weight and about 5.0% or less by weight Al.sub.2O.sub.3, about 10.0% or more by weight and about 25.0% or less by weight B.sub.2O.sub.3, and about 70.0% or more by weight and about 85.0% or less by weight SiO.sub.2 based on the total weight of the glass, and the filler included in the glass ceramic layer includes at least one of SiO.sub.2 and Al.sub.2O.sub.3 and also includes about 5.0% or more by weight and about 15.0% or less by weight of a ferrite based on the total weight of the glass and the filler.

The embodiments of the present invention disclose a method for synthesizing ceramic composite powder and ceramic composite powder, pertaining to the technical field of inorganic non-metallic materials. Among them, the method includes preparing an aqueous slurry of ceramic raw materials, the aqueous slurry including ceramic raw material, water and low polymerization degree organometallic copolymer, the ceramic raw material including at least two components; adding a crosslinking coagulant into the aqueous slurry to obtain a gel; dehydrating and drying the gel to obtain the dried gel; heating the dried gel to the synthesizing temperature of the ceramic composite powder and conducting the heat preservation to obtain ceramic composite powder or ceramic composite base powder; conducting secondary doping on ceramic composite base powder to obtain the ceramic composite powder. The multi-component ceramic composite powder prepared by the embodiments of the present invention has uniformly dispersed each component and low synthesizing temperature.

Disclosed is a method of manufacturing a ferrite magnetic substance, including: a first mixing operation of providing a first mixture composed of 47 to 49 wt % of Fe, 16 to 18 wt % of Mn, 5.2 to 7.2 wt % of Zn, and a remainder of oxygen and other inevitable impurities, a second mixing operation of providing a second mixture composed of the first mixture and an additive including, based on 100 parts by weight of the first mixture, 28 to 51 ppm of Si, 140 to 210 ppm of Nb and 155 to 185 ppm of Zr, and a finish operation of producing a ferrite magnetic substance by sintering the second mixture.

The disclosed technology generally relates dielectric materials and methods of forming the same, and more particularly to a combination of co-fireable dielectric materials that can be attached to each other without the use of adhesives. In an aspect, a composite article comprises a magnetic portion comprising a nickel zinc ferrite. The composite article additionally comprises a non-magnetic portion contacting the magnetic portion, the non-magnetic portion comprising a spinel-structured oxide comprising Mg.sub.2-xAl.sub.2xTi.sub.1-xO.sub.4 and having a dielectric constant between about 7 and 14, wherein 0<x1.

The present invention relates to a ferrite particle, containing a crystal phase component containing a perovskite crystal represented by the compositional formula: RZrO.sub.3 (provided that R represents an alkaline earth metal element), and having an apparent density in a range represented by the following formula:
1.90Y2.45
provided that Y in the formula is the apparent density (g/cm.sup.3) of the ferrite particle.

Provided is a piezoelectric material excellent in piezoelectricity. The piezoelectric material includes a perovskite-type complex oxide represented by the following General Formula (1).
A(Zn.sub.xTi.sub.(1-x)).sub.yM.sub.(1-y)O.sub.3(1)
wherein A represents at least one kind of element containing at least a Bi element and selected from a trivalent metal element; M represents at least one kind of element of Fe, Al, Sc, Mn, Y, Ga, and Yb; x represents a numerical value satisfying 0.4x0.6; and y represents a numerical value satisfying 0.1y0.9.

The present invention relates to a ferrite particle containing a crystal phase component containing a perovskite-type crystal represented by a composition formula of RZrO3 (wherein R is an alkaline earth metal element), and a Mg content of 0.45 mass % or less. The present invention also relates to a carrier core material for an electrophotographic developer, containing the ferrite particle; a carrier for an electrophotographic developer, containing the ferrite particle and a resin coating layer provided on a surface of the ferrite particle; and an electrophotographic developer containing the carrier for an electrophotographic developer and a toner.