Embodiments disclosed herein relate to using cobalt (Co) to fine tune the magnetic properties, such as permeability and magnetic loss, of nickel-zinc ferrites to improve the material performance in electronic applications. The method comprises replacing nickel (Ni) with sufficient Co.sup.+2 such that the relaxation peak associated with the Co.sup.+2 substitution and the relaxation peak associated with the nickel to zinc (Ni/Zn) ratio are into near coincidence. When the relaxation peaks overlap, the material permeability can be substantially maximized and magnetic loss substantially minimized. The resulting materials are useful and provide superior performance particularly for devices operating at the 13.56 MHz ISM band.

A ferrite composition includes main-phase particles, first sub-phase particles, second sub-phase particles, and a grain boundary. At least 10% or more of the main-phase particles contain a portion whose Zn concentrations monotonously decrease from a particle surface toward a particle central part along a length of 50 nm or more. The first sub-phase particles contain Zn.sub.2SiO.sub.4. The second sub-phase particles contain SiO.sub.2. A total area ratio of the first sub-phase particles and the second sub-phase particles is 30.5% or more.

The present invention provides: a ferrite particle containing a crystal phase component containing a perovskite crystal represented by the compositional formula RZrO.sub.3 (where R is an alkaline earth metal element); and an electrophotographic developer carrier core material, an electrophotographic developer carrier, and an electrophotographic developer containing the ferrite particles.

A ferrite composition includes a main component and a sub-component. The main component includes 10.0 to 38.0 mol % of a Fe compound in terms of Fe.sub.2O.sub.3, 3.0 to 11.0 mol % of a Cu compound in terms of CuO, 39.0 to 80.0 mol % (excluding 39.0 mol %) of a Zn compound in terms of ZnO, and a balance of a Ni compound. The sub-component includes 10.0 to 23.0 parts by weight of a Si compound in terms of SiO.sub.2, 0 to 3.0 parts by weight (including 0 parts by weight) of a Co compound in terms of Co.sub.3O.sub.4, and 0.1 to 3.0 parts by weight of a Bi compound in terms of Bi.sub.2O.sub.3 with respect to 100 parts by weight of the main component.

The present application relates to a magnesium oxide based dielectric ceramics with ultrahigh dielectric breakdown strength and a preparation method thereof. The composition of the magnesium oxide based dielectric ceramic material comprises: (1−x)MgO—xAl.sub.2O.sub.3, wherein 0<x≤0.12 and x is a mole percentage. The material has a specific composite structure with magnesium aluminate spinel acting as a second phase surrounding a principal crystalline phase, MgO.

The use of magnesium oxide, reactive alumina and aluminium oxide as a base provides for a new erosion-resistant material upon sintering.

A sintered body comprises zirconia including a stabilizer element dissolved therein and a lanthanoid element dissolved therein, the lanthanoid element having an ionic radius larger than the atomic radius of zirconium. The content of monoclinic zirconia after a hydrothermal treatment at 140° C. for 24 hours is less than 25%. The sintered body includes a spinel compound including aluminum and a coloring element.

Embodiments disclosed herein relate to using cobalt (Co) to fine tune the magnetic properties, such as permeability and magnetic loss, of nickel-zinc ferrites to improve the material performance in electronic applications. The method comprises replacing nickel (Ni) with sufficient Co.sup.+2 such that the relaxation peak associated with the Co.sup.+2 substitution and the relaxation peak associated with the nickel to zinc (Ni/Zn) ratio are into near coincidence. When the relaxation peaks overlap, the material permeability can be substantially maximized and magnetic loss substantially minimized. The resulting materials are useful and provide superior performance particularly for devices operating at the 13.56 MHz ISM band.

An NTC compound, a thermistor and a method for producing a thermistor are disclosed. In an embodiment an NTC compound includes a ceramic material of a Mn—Ni—O system as a main constituent, wherein the Mn—Ni—O system has a general composition Ni.sub.xMn.sub.2O.sub.4-δ, wherein y corresponds to a molar fraction of Ni of a total metal content of the ceramic material of the Mn—Ni—O system, which is defined as c(Ni):(c(Ni)+c(Mn)), and wherein the following applies: 0.500<x<0.610 and 0.197<y<0.240.

The invention relates to a refractory product, a batch composition for producing said product, a method for producing the product and the use of the refractory product.