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.

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.

A ceramic powder material containing: a first garnet-type compound containing Li, La, and Zr; and a second garnet-type compound containing Li, La, and Zr and having a composition different from a composition of the first garnet-type compound, in which the first garnet-type compound and the second garnet-type compound are represented by Formula [1] Li.sub.7-(3x+y)M1.sub.xLa.sub.3Zr.sub.2-yM2.sub.yO.sub.12, where Ml is Al or Ga, M2 is Nb or Ta, the first garnet-type compound satisfies 0≤(3x+y)≤0.5, and the second garnet-type compound satisfies 0.5<(3x+y)≤1.5.

A dielectric composition includes a dielectric grain including a perovskite compound and a first segregation phase including at least Ca, Al, Si, and O.

Provided are a composite oxide powder from which dense solid electrolyte objects having a high ion conductivity can be produced and a method for producing the composite oxide powder. The composite oxide powder is composed of particles comprising lithium (Li), lanthanum (La), zirconium (Zr), and oxygen (O) and having a cubic garnet-type crystal structure, and has a volume particle size distribution in which the 50% diameter (D50) is 1,000 nm or smaller, the composite oxide powder having a pyrochlore phase content of 10 mass % or less.

Provided are a composite oxide powder from which dense solid electrolyte objects having a high ion conductivity can be produced and a method for producing the composite oxide powder. The composite oxide powder is composed of particles comprising lithium (Li), lanthanum (La), zirconium (Zr), and oxygen (O) and having a cubic garnet-type crystal structure, and has a volume particle size distribution in which the 50% diameter (D50) is 1,000 nm or smaller, the composite oxide powder having a pyrochlore phase content of 10 mass % or less.

This invention provides resin formulations which may be used for 3D printing and pyrolyzing to produce a ceramic matrix composite. The resin formulations contain a solid-phase filler, to provide high thermal stability and mechanical strength (e.g., fracture toughness) in the final ceramic material. The invention provides direct, free-form 3D printing of a preceramic polymer loaded with a solid-phase filler, followed by converting the preceramic polymer to a 3D-printed ceramic matrix composite with potentially complex 3D shapes or in the form of large parts. Other variations provide active solid-phase functional additives as solid-phase fillers, to perform or enhance at least one chemical, physical, mechanical, or electrical function within the ceramic structure as it is being formed as well as in the final structure. Solid-phase functional additives actively improve the final ceramic structure through one or more changes actively induced by the additives during pyrolysis or other thermal treatment.

This invention provides resin formulations which may be used for 3D printing and pyrolyzing to produce a ceramic matrix composite. The resin formulations contain a solid-phase filler, to provide high thermal stability and mechanical strength (e.g., fracture toughness) in the final ceramic material. The invention provides direct, free-form 3D printing of a preceramic polymer loaded with a solid-phase filler, followed by converting the preceramic polymer to a 3D-printed ceramic matrix composite with potentially complex 3D shapes or in the form of large parts. Other variations provide active solid-phase functional additives as solid-phase fillers, to perform or enhance at least one chemical, physical, mechanical, or electrical function within the ceramic structure as it is being formed as well as in the final structure. Solid-phase functional additives actively improve the final ceramic structure through one or more changes actively induced by the additives during pyrolysis or other thermal treatment.

Thermal barrier coatings consist of a tantala-zirconia mixture that is stabilized with two or more stabilizers. An exemplary thermal barrier coating consists of, by mole percent: about 8% to about 30% YO.sub.1.5; about 8% to about 30% YbO.sub.1.5 or GdO.sub.1.5 or combination thereof; about 8% to about 30% TaO.sub.2.5; about 0% to about 10% HfO.sub.2; and a balance of ZrO.sub.2.

Thermal barrier coatings consist of a tantala-zirconia mixture that is stabilized with two or more stabilizers. An exemplary thermal barrier coating consists of, by mole percent: about 8% to about 30% YO.sub.1.5; about 8% to about 30% YbO.sub.1.5 or GdO.sub.1.5 or combination thereof; about 8% to about 30% TaO.sub.2.5; about 0% to about 10% HfO.sub.2; and a balance of ZrO.sub.2.