A zinc oxide powder for producing a zinc oxide sintered body is provided with which it is possible to obtain a zinc oxide sintered body that has a small sintered particle size and high strength. This zinc oxide powder for producing a zinc oxide sintered body is used for producing a zinc oxide sintered body, wherein the Al content represented in formula (I) is greater than or equal to 20 mol ppm and less than or equal to 2 mol %. (I){nAl/(n.sub.Zn+n.sub.Al)}×100. In formula (I), n.sub.Al represents the Al content in the zinc oxide powder, n.sub.Zn represents the Zn content in the zinc oxide powder, and the unit of n.sub.Zn and n.sub.Al is moles in both cases.

A sintered material comprises cubic boron nitride and a first material that is a partially stabilized ZrO.sub.2 with Al.sub.2O.sub.3 dispersed therein at crystal grain boundaries and/or in crystal grains, the sintered material comprising 20% by volume or more and 80% by volume or less of the cubic boron nitride, the sintered material comprising 0.001% by mass or more and 1% by mass or less of nitrogen in the first material when the first material is measured through secondary ion mass spectrometry.

A zinc oxide powder for producing a zinc oxide sintered body is provided with which it is possible to obtain a zinc oxide sintered body that has a large sintered particle size and excellent conductivity. This zinc oxide powder for producing a zinc oxide sintered body is used for producing a zinc oxide sintered body, wherein the Ga content represented in formula (I) is greater than or equal to 30 mol ppm and less than 3 mol %. (I) {n.sub.Ga/(n.sub.Zn+n.sub.Ga)}×100 In formula (I), n.sub.Ga represents the Ga content in the zinc oxide powder, n.sub.Zn represents the Zn content in the zinc oxide powder, and the unit of n.sub.Zn and n.sub.Ga is moles in both cases.

The ceramic sintered body contains Zr, Al, Y, and Mg. A Zr content is 7.5 mass % or more and 23.5 mass % or less in terms of ZrO.sub.2. An Al content is 74.9 mass % or more and 91.8 mass % or less in terms of Al.sub.2O.sub.3. A Y content is 0.41 mass % or more and 1.58 mass % or less in terms of Y.sub.2O.sub.3. A Mg content is 0.10 mass % or more and 0.80 mass % or less in terms of MgO. A ZrO.sub.2 crystal phase as a crystal phase has a monoclinic phase and a tetragonal phase as crystal structures. When a thermal aging treatment is performed for 100 hours in an environment of 180 degrees C., a ratio of a peak intensity of the monoclinic phase to a sum of peak intensities of the monoclinic phase and the tetragonal phase is 15% or less in the X-ray diffraction pattern.

A polycrystalline ferrite composition comprises a formula of M.sub.5Me.sub.2Ti.sub.3Fe.sub.12O.sub.31, wherein M is Ba.sup.2+, Se.sup.+, or a combination thereof; and Me is Mg.sup.2+, Zn.sup.2+, Cu.sup.2+, Co.sup.2+, or a combination thereof; and has an average grain size of 1 micrometer to 100 micrometers. A composite comprises a polymer matrix; and the polycrystalline ferrite composition. Methods of making the polycrystalline ferrite composition and the composite are also disclosed.

A cubic boron nitride (cBN)-based composite including about 30-65 vol. % cBN, about 3-30 vol. % zirconium (Zr)-containing compounds, about 0-10 vol. % cobalt-tungsten-borides (Co.sub.xW.sub.yB.sub.z), about 2-30 vol. % aluminum oxide (Al.sub.2O.sub.3), about 0.5-10 vol. % tungsten borides, and less than or equal to about 5 vol. % aluminum nitride (AlN).

This composite sintered body is a ceramic composite sintered body which includes aluminum oxide which is a main phase, and silicon carbide which is a sub-phase, the composite sintered body including an interface layer which includes, as a forming material, a material other than the aluminum oxide and the silicon carbide, at an interface between a crystal grain of the aluminum oxide and a crystal grain of the silicon carbide in a grain boundary.

A ferrite sintered magnet including ferrite grains having a hexagonal crystal structure. The ferrite grains satisfy 0.56≤W≤0.68 where W is an average value of circularities of the ferrite grains in a cross section parallel to an axis of easy magnetization.

A ferrite sintered magnet including 0.010 mass % or more and 0.090 mass % or less of Mg in terms of MgO.

The present invention is directed to a porous pre-densified CeO.sub.2-stabilized ZrO.sub.2 ceramic having a density of 50.0 to 95.0%, relative to the theoretical density of zirconia, and an open porosity of 5 to 50% as well as to a densified CeO.sub.2-stabilized ZrO.sub.2 ceramic having a density of 97.0 to 100.0%, relative to the theoretical density of zirconia, and wherein the grains of the ceramic have an average grain size of 50 to 1000 nm, methods for the preparation of the pre-densified and densified ceramics and their use for the manufacture of dental restorations.