A dielectric ceramic composition includes a barium titanate (BaTiO.sub.3)-based base material main ingredient and an accessory ingredient, the accessory ingredient including dysprosium (Dy) and praseodymium (Pr) as first accessory ingredients. A content of the Pr satisfies 0.233 mol≤Pr≤0.699 mol, based on 100 mol of the barium titanate base material main ingredient.

A method of producing a core-shell particle includes introducing a barium titanate-based base powder and an additive to a reactor, and exposing the barium titanate-based base powder and the additive to a thermal plasma torch to obtain core-shell particles including a core portion having barium titanate (BaTiO.sub.3) and a shell portion including the additive and formed on a surface of the core portion.

An antimicrobial material including a substrate and an antimicrobial mixed metal oxide, mixed metal sulfide, or mixed metal oxysulfide in and/or on the substrate is described, as well as antimicrobial coating materials and coatings formed therefrom. The antimicrobial material may be constituted in an antimicrobial surface of a surface-presenting substrate, to combat transmission and spread of microbial disease, e.g., disease mediated by microbial pathogens such as bacteria, viruses, and fungi. Antimicrobial mixed metal oxide, mixed metal sulfide, or mixed metal oxysulfide as described may be contacted with microorganisms to effect inactivation thereof.

The disclosed technology relates to a ceramic composition and an article formed therefrom. A ceramic article for radio frequency applications is formed of a ceramic material having a chemical formula represented by: Bi.sub.1.0+aY.sub.2.0-a-x-2yCa.sub.x+2yFe.sub.5-x-yM.sup.IV.sub.xV.sub.yO.sub.12 or Bi.sub.1.0+aY.sub.2.0-a-2yCa.sub.2yFe.sub.5-y-zV.sub.yIn.sub.zO.sub.12. The ceramic material has a composition such that a normalized change in saturation magnetization (Δ4πMs), defined as Δ4πMs=[(4πMs at 20° C.)-(4πMs at 120° C.)]/(4πMs at 20° C.), is less than about 0.35.

This disclosure relates to polycrystalline cubic boron nitride material with cBN particles in a metal matrix comprising zirconium nitride and/or vanadium nitride precipitates or grains.

A process for manufacturing ceramic-metal composite material, comprises dissolving ceramic powder into water to obtain an aqueous solution of ceramic; mixing metal powder having a multimodal particle size where largest particle size is one fourth of the minimum dimension of a device, with the aqueous solution of ceramic to obtain a powder containing ceramic precipitated on the surface of metal particles; mixing the powder containing ceramic precipitated on the surface of the metal particles, with ceramic powder having a particle size below 50μ.Math.τ.Math., to obtain a powder mixture; adding saturated aqueous solution of ceramic to the powder mixture to obtain an aqueous composition containing ceramic and metal; compressing the aqueous composition to form a disc of ceramic-metal composite material containing ceramic and metal; and removing water from the ceramic-metal composite material; wherein ceramic content of the disc is 10 vol-% to 35 vol-%. Alternatively, ceramic-ceramic composite material may be manufactured.

A ceramic contains, in mass percent: Si.sub.3N.sub.4: 20.0 to 60.0%, ZrO.sub.2: 25.0 to 70.0%, and one or more oxides selected from MgO, Y.sub.2O.sub.3, CeO.sub.2, CaO, HfO.sub.2, TiO.sub.2, Al.sub.2O.sub.3, SiO.sub.2, MoO.sub.3, CrO, CoO, ZnO, Ga.sub.2O.sub.3, Ta.sub.2O.sub.5, NiO, and V.sub.2O.sub.5: 5.0 to 15.0%. The ceramic has a coefficient of thermal expansion as high as that of silicon and an excellent mechanical strength, allows fine machining with high precision, and prevents particles from being produced.

Provided are a high-entropy carbide ceramic, a rare earth-containing high-entropy carbide ceramic, fibers thereof, precursors thereof, and preparation methods thereof. The precursor includes at least four elements selected from Ti, Zr, Hf, V, Nb, Ta, Mo, and W, with each metal element accounting for 5-35% of the total molar quantity of metal elements in the precursor. The rare earth-containing high-entropy carbide ceramic precursor includes at least four transition metal elements and at least one rare-earth metal element. The high-entropy ceramic is a single-crystal-phase high-performance ceramic prepared from the precursor, with each element being homogenously distributed at molecular level. The method for preparing the high-entropy ceramic fiber includes uniformly mixing high-entropy carbide ceramic precursor containing target metal elements with spinning aid and solvent to prepare a spinnable precursor solution, followed by spinning, pyrolyzation, and high-temperature solid solution to prepare the high-entropy carbide ceramic fiber.

Provided is a dielectric composition containing: a main component expressed by {Ba.sub.xSr.sub.(1-x)}.sub.mTa.sub.4O.sub.12; and a first subcomponent, m satisfying a relationship of 1.95≤m≤2.40. The first subcomponent includes silicon and manganese. When the amount of the main component contained in the dielectric composition is set to 100 parts by mole, the amount of silicon contained in the dielectric composition is 5.0 to 20.0 parts by mole in terms of SiO.sub.2, and the amount of manganese contained in the dielectric composition is 1.0 to 4.5 parts by mole in terms of MnO.

A dielectric composition includes a main ingredient having a perovskite structure represented by ABO.sub.3, where A is at least one of Ba, Sr, and Ca and B is at least one of Ti, Zr, and Hf, and a first accessory ingredient. The first accessory ingredient comprises 0.1 mole or more of a rare earth element, 0.02 mole or more of Nb, and 0.25 mole or more and 0.9 mole or less of Mg, a sum of contents of the rare earth element and Nb is 1.5 mole or less.