The present invention relates a coating powder comprising a rare earth oxyfluoride (Ln-O—F) and having: an average particle size (D.sub.50) of 0.1 to 10 μm, a pore volume of pores having a diameter of 10 μm 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 2θ angle range of from 20° to 40° to the maximum peak intensity (S1) assigned to the rare earth oxyfluoride (Ln-O—F) in the same range, S0/S1, of 1.0 or smaller in powder X-ray diffractometry using Cu-Kα rays or Cu-Kα.sub.1 rays.

A sintered body of the present invention contains yttrium oxyfluoride. The yttrium oxyfluoride is preferably YOF and/or Y.sub.5O.sub.4F.sub.7. The sintered body of the present invention preferably contains 50% by mass or more of yttrium oxyfluoride. The sintered body of the present invention has a relative density of preferably 70% or more and an open porosity of preferably 10% or less. Furthermore, the sintered body of the present invention has a three-point bending strength of preferably 10 MPa or more and 300 MPa or less.

Provided are a sintered material having high corrosion resistance, a method of manufacturing the sintered material, a member for a semiconductor manufacturing apparatus, a method of manufacturing a member for a semiconductor manufacturing apparatus, a semiconductor manufacturing apparatus, and a method of manufacturing a semiconductor manufacturing apparatus. The sintered material according to an embodiment includes 50 mass% or more of yttrium oxyfluoride, has a relative density of 97.0% or more, and has a Vickers hardness of 5.0 GPa or more. The method of manufacturing a sintered material according to an embodiment includes forming a molded body including yttrium oxyfluoride powder having a particle size of 0.3 .Math.m or less, and sintering the molded body under an atmospheric pressure at a temperature of 800° C. or less.

A method of treating a preceramic material includes providing a preceramic polycarbosilane or polycarbosiloxane material that includes a moiety Si—O-M, where Si is silicon, O is oxygen and M is at least one metal that includes at least one transition metal, and thermally converting the preceramic polycarbosilane or polycarbosiloxane that includes the moiety Si—O-M material into a ceramic material.

The present disclosure is directed to a rapid process for the preparation of gadolinium oxysulfide having a general formula of Gd.sub.2O.sub.2S, referred to as GOS, scintillation ceramics by using the combination of spark plasma primary sintering (SPS) and hot isostatic pressing secondary sintering.

The present invention relates a coating powder comprising a rare earth oxyfluoride (Ln-O—F) and having: an average particle size (D.sub.50) of 0.1 to 10 μm, a pore volume of pores having a diameter of 10 μm 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 2θ angle range of from 20° to 40° to the maximum peak intensity (S1) assigned to the rare earth oxyfluoride (Ln-O—F) in the same range, S0/S1, of 1.0 or smaller in powder X-ray diffractometry using Cu-Kα rays or Cu-Kα.sub.1 rays.

A high permittivity antiferroelectric composition and a manufacturing method thereof aim to provide an antiferroelectric, which has a Pb.sub.xLa.sub.1-x([Zr.sub.1-YSn.sub.Y].sub.ZTi.sub.1-Z) composition, is sintered at low temperatures, and has a high density and a high permittivity.

Described are coatings that contain of fluorinated yttrium oxide and a metal oxide; methods of preparing these coatings; substrates, surfaces, equipment, and components of equipment that include a coating that contains a combination of fluorinated yttrium oxide and a metal oxide; and methods of preparing and using the coatings and coated substrates.

Disclosed are a material for spray for plasma spray coating having high plasma resistance and a method for producing the same. The material for plasma spray comprises an yttrium compound, and the numbers of moles of Y (yttrium), O (oxygen), and F (fluorine) in the yttrium compound satisfy 1.5<(O+F)/Y<2.0.

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.