A ferrite sintered magnet comprising an M type Sr ferrite having a hexagonal structure as a main phase, wherein the ferrite sintered magnet does not substantially comprise a rare earth element and Co, a content of B is 0.005 to 0.9% by mass in terms of B.sub.2O.sub.3, and a content of Zn is 0.01 to 1.2% by mass in terms of ZnO.

Provided is an aluminum nitride powder useful as a raw material when an aluminum nitride sintered body excellent as an insulating high thermal conductive member is manufactured, particularly, by press molding.

An aluminum nitride powder includes particles having a sphericity of 0.8 or more, in which a median size D.sub.50 obtained by a laser diffraction method is 0.5 to 1.5 μm, a ratio D.sub.90/D.sub.50 of a particle size D.sub.90 corresponding to a cumulative undersize distribution of 90% to the D.sub.50 is 2.2 or less, a BET specific surface area is 2 to 4 m.sup.2/g, and a total oxygen concentration is 0.6 to 1.2% by mass.

A zirconia sintered body is provided and includes yttria and zirconia, containing yttria by a content ranging from 4.5 mol % or more to 6.5 mol % or less and zirconia as the remainder, the total light transmittance of a 1-mm thick sample measured in compliance with JIS K 7361-1 being 46.5% or higher, the three-point bending strength being 700 MPa or higher, and a ratio of an integrated value for the total light transmittance to an integrated value for the parallel light transmittance of a 1-mm thick sample measured at the measurement wavelength ranging from 400 to 700 nm being 1.3% or less.

SiC matrix composite material, where heat-resistant long fiber such as carbon fiber is employed as a material for reinforcement and SiC is employed for the matrix, which significantly improves mechanical properties such as strength and toughness. The SiC matrix composite material, includes a SiC matrix and heat-resistant long fiber, wherein the SiC matrix includes both of alpha-type SiC and beta-type SiC, and the alpha-type SiC and the beta-type SiC are detected by micro-region X-ray diffraction with an X-ray beam diameter of no greater than 300 micrometers substantially at every region of every cross-section of the SiC matrix, the beta-type SiC has an average crystallite size that is no greater than 500 nm and greater than an average crystallite size of the alpha-type SiC, and the SiC matrix composite material has a porosity of no greater than 20% by volume.

A sintered bead with the following crystal phases, in percentages by mass based on crystal phases: 25%≤zircon, or “Z.sub.1”, ≤94%; 4%≤stabilized zirconia+stabilized hafnia, or “Z.sub.2”, ≤61%; monoclinic zirconia+monoclinic hafnia, or “Z.sub.3”≤50%; corundum≤57%; crystal phases other than Z.sub.1, Z.sub.2, Z.sub.3 and corundum<10%; the following chemical composition, in percentages by mass based on oxides: 33%≤ZrO.sub.2+HfO.sub.2, or “Z.sub.4”≤83.4%; HfO.sub.2≤2%; 10.6%≤SiO.sub.2≤34.7%; Al.sub.2O.sub.3≤50%; 0%≤Y.sub.2O.sub.3, or “Z.sub.5”; 0%≤CeO.sub.2, or “Z.sub.6”; 0.3%≤CeO.sub.2+Y.sub.2O.sub.3≤19%, provided that (1) CeO.sub.2+3.76*Y.sub.2O.sub.3≥0.128*Z, and (2) CeO.sub.2+1.3*Y.sub.2O.sub.3≤0.318*Z, with Z=Z.sub.4+Z.sub.5+Z.sub.6−(0.67*Z.sub.1*(Z.sub.4+Z.sub.5+Z.sub.6)/(0.67*Z.sub.1+Z.sub.2+Z.sub.3)); MgO≤5%; CaO≤2%; oxides other than ZrO.sub.2, HfO.sub.2, SiO.sub.2, Al.sub.2O.sub.3, MgO, CaO, CeO.sub.2 and Y.sub.2O.sub.3<5.0%.

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 M1 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 ceramic powder material containing a garnet-type compound containing Li, wherein the ceramic powder material has a pore volume of 0.4 mL/g or more and 1.0 mL/g or less.

Provided is a boron nitride sintered body having a porous structure, the boron nitride sintered body including a lump particle formed by aggregation of primary particles of boron nitride and having a particle diameter of 15 μm or more. Provided is a method for manufacturing a boron nitride sintered body, the method including: a nitriding step of firing a raw material powder containing boron carbide in an atmosphere containing nitrogen to obtain a fired product including lump particles each having a core part with primary particles of boron carbonitride aggregated and a shell part surrounding the core part; and a firing step of molding and heating a blend containing the fired product including lump particles and a sintering aid to obtain the boron nitride sintered body having a porous structure and including lump particles of boron nitride.

A Li ion conductor having a composition different from a conventional composition is provided. The Li ion conductor contains at least one selected from a group Q consisting of Ga, V, and Al, Li, La and O. A part of an Li site is optionally substituted with a metal element D, a part of an La site is optionally substituted with a metal element E, and parts of Ga, V and Al sites are optionally substituted with a metal element J. A mole ratio of an amount of Li to a total amount of La, the element E, Ga, V, Al, and the element J is not lower than 8.1/5 and not higher than 9.5/5. A mole ratio of a total amount of Ga, V, and Al to a total amount of La and the element E is not lower than 1.1/3 and not higher than 2/3.

Disclosed is a cordierite sintered body comprising from 90 to 98% by volume of a cordierite crystal phase as measured using x ray diffraction, SEM and image processing methods wherein the cordierite sintered body has at least one surface comprising pores having a diameter of from 0.1 to 5 um as measured using SEM and image processing methods. The cordierite sintered body has a Young's modulus of about 125 GPa or greater, and volumetric porosity of less than about 4%. Methods of making the cordierite sintered body are also disclosed.