The present invention relates a coating powder comprising a rare earth oxyfluoride (Ln-OF) and having: an average particle size (D.sub.50) of 0.1 to 10 m, a pore volume of pores having a diameter of 10 m or smaller of 0.1 to 0.5 cm.sup.3/g as measured by mercury intrusion porosimetry, and a ratio of the maximum peak intensity (S0) assigned to a rare earth oxide (Ln.sub.xO.sub.y) in the 2 angle range of from 20 to 40 to the maximum peak intensity (S1) assigned to the rare earth oxyfluoride (Ln-OF) in the same range, S0/S1, of 1.0 or smaller in powder X-ray diffractometry using Cu-K rays or Cu-K.sub.1 rays.

A sprayed article is prepared by thermally spraying ceramic particles of rare earth oxide or fluoride or metal particles of W, Mo or Ta onto an outer or inner surface of a cylindrical carbon substrate to form a sprayed coating, and burning out the carbon substrate, thus leaving the ceramic or metal-base sprayed coating of cylindrical shape having a wall thickness of 0.5-5 mm.

Disclosed herein are methods for producing an ultra-dense and ultra-smooth ceramic coating. A method includes feeding a slurry of ceramic particles into a plasma sprayer. The plasma sprayer generates a stream of particles directed toward the substrate, forming a ceramic coating on the substrate upon contact.

A cermet body, including a ceramic portion and a plurality of high magnetic permeability magnetic metallic particles distributed throughout the ceramic portion. Each respective high magnetic permeability magnetic metallic particle has a magnetic permeability of at least 0.0001 H/m. The magnetic metallic particles define a contiguous metallic phase, wherein the cermet body enjoys sufficient bulk electrical conductivity to be machined via electrical discharge machining.

A mold and a method of manufacturing GOS ceramic scintillator by using the mold are provided. The mold comprises: a female outer sleeve having a cavity disposed inside; a plurality of female blocks disposed inside the cavity, the plurality of female blocks being put together to form a composite structure having a vertical through hole; and a male upper pressing head and a male lower pressing head, wherein each of the male upper pressing head and the male lower pressing head has a shape consistent with that of the vertical through hole. The disclosure may reduce defects of the related art in hot-pressing-sintering such as a mold has a short retirement period and a high material waste, significantly reduce the cost for production of the GOS ceramic scintillator, and significantly improve a process economy.

A structure includes a polycrystalline substance of yttrium fluoride, wherein an average crystallite size in the polycrystalline substance is less than 100 nanometers. When taking a peak intensity detected near diffraction angle 2=24.3 by X-ray diffraction as , and taking a peak intensity detected near diffraction angle 2=25.7 as , a peak intensity ratio / of the structure is not less than 0% and less than 100%.

Fluoride-based nanocomposite materials, optical articles made therefrom, and methods of making the fluoride-nanocomposite materials and optical articles. In certain examples, a fluoride-based nanocomposite material includes two or more interspersed fluoride-based nanograin materials with grains having one, two, or three dimensions that are less than 1 micrometer.

A spray coating containing a rare earth fluoride and/or a rare earth acid fluoride contains, carbon at 0.01-2% by mass or titanium or molybdenum at 1-1000 ppm. When an acid fluoride is not contained, the spray coating is gray to black in which, in terms of the L*a*b* chromaticity, L* is 25-64, a* is 3.0 to +5.0, and b* is 4.0 to +8.0. When an acid fluoride is contained, the spray coating is white or gray to black in which, in terms of the L*a*b* chromaticity, L* is equal to or greater than 25 and less than 91, a* is 3.0 to +5.0, and b* is 6.0 to +8.0. By forming this coating on a plasma resistant member, a partial color change is reduced, thus, a member that is capable of reliably realizing the original longevity is obtained.

A spray coating containing a rare earth fluoride and/or a rare earth acid fluoride contains carbon at 0.01-2% by mass or titanium or molybdenum at 1-1000 ppm. When an acid fluoride is not contained, the spray coating is gray to black in which, in terms of the L*a*b* chromaticity, L* is 25-64, a* is ?3.0 to +5.0, and b* is ?4.0 to +8.0. When an acid fluoride is contained, the spray coating is white or gray to black in which, in terms of the L*a*b* chromaticity, L* is equal to or greater than 25 and less than 91, a* is ?3.0 to +5.0, and b* is ?6.0 to +8.0. By forming this coating on a plasma resistant member, a partial color change is reduced, thus, a member that is capable of reliably realizing the original longevity is obtained.

An antiferroelectric and a method for manufacturing an antiferroelectric are disclosed herein. The antiferroelectric may have high permittivity and breakdown voltage by having a Pb.sub.xLa.sub.1-x([Zr.sub.1-YSn.sub.Y].sub.ZTi.sub.1-Z) composition. The manufacturing of the antiferroelectric may be performed through appropriate mixing and dysprosium addition.