Provided is a method for producing a wavelength conversion sintered body that emits light under irradiation of excitation light. The method for producing a wavelength conversion sintered body includes: preparing a molded body obtained by molding a mixture containing an α-SiAlON fluorescent material and aluminum oxide particles and having a content of Ga of 15 ppm by mass or less; and primary calcining the molded body at a temperature in a range of 1,370° C. or more and 1,600° C. or less to obtain a first sintered body.

The present invention provides a ferrite sintered magnet comprising ferrite crystal grains having a hexagonal structure, wherein the ferrite sintered magnet comprises metallic elements at an atomic ratio represented by formula (1). In formula (1), R is at least one element selected from the group consisting of Bi and rare-earth elements, and R comprises at least La. In formula (1), w, x, z and m satisfy formulae (2) to (5). The above-mentioned ferrite sintered magnet further has a coefficient of variation of a size of the crystal grains in a section parallel to a c axis of less than 45%.
Ca.sub.1-w-xR.sub.wSr.sub.xFe.sub.zCo.sub.m  (1)
0.360≤w≤0.420  (2)
0.110≤x≤0.173  (3)
8.51≤z≤9.71  (4)
0.208≤m≤0.269  (5)

A silicon nitride sintered body includes a silicon nitride crystal grains and grain boundary phases. Further, when D stands for width of the silicon nitride sintered body before being subjected to surface processing, relations between an average grain diameter dA and an average aspect ratio rA of the silicon nitride crystal grain in a first region from an outermost surface to a depth of 0 to 0.01D and an average grain diameter dB and an average aspect ratio rB of the silicon nitride crystal grain in a second region inside the first region satisfy the inequalities:

0.8≤ dA/dB≤ 1.2; and

0.8≤ rA/rB≤ 1.2.

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 alumina particles containing molybdenum and with their shape controlled. The alumina particles contain phosphorus and molybdenum. The alumina particles are preferably plate-like or card house-like. The phosphorus is preferably unevenly distributed in surface layers of the alumina particles. Also provided are a resin composition containing the alumina particles and a resin, a molded body made by molding the resin composition, and a method for producing the alumina particle including a step of firing the aluminum compound in the presence of a molybdenum compound and a phosphorous compound.

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.

A solid electrolyte ceramic material that includes sintered solid electrolyte particles containing, at least, lithium (Li), lanthanum (La), bismuth (Bi), and oxygen (O), wherein the Bi is at a higher concentration in a vicinity of a grain boundary of the sintered solid electrolyte particles than in a grain interior of the sintered solid electrolyte particles.

An alumina/titanium silicon carbide composite material is prepared by making titanium aluminum carbide (Ti.sub.3AlC.sub.2) in uniform contact with silicon monoxide (SiO), and carrying out vacuum sintering. The composite material is obtained through mutual diffusion of aluminum and silicon and has high compactness and stable performance. In the composite material, the alumina is generated by means of a reaction between the titanium aluminum carbide and the silicon monoxide, and can be uniformly wrapped around surfaces of titanium silicon carbide crystals to form a relatively compact oxide film, such that substance exchange between a matrix and the outside is hindered, and overall antioxidation of the composite material is improved. Toughness of the composite material is enhanced by means of the titanium silicon carbide. The prepared composite material has relatively high purity, relatively low sintering temperature, and relatively high bending strength. The process is simple and convenient for industrial production.

A cubic boron nitride sintered body including cubic boron nitride and a binder phase, wherein a content of the cubic boron nitride is 40 volume % or more and 70 volume % or less; a content of the binder phase is 30 volume % or more and 60 volume % or less; an average particle size of the cubic boron nitride is 0.1 μm or more and 3.0 μm or less; the binder phase contains TiN and/or TiCN, and TiB.sub.2 and contains substantially no AIN and/or Al.sub.2O.sub.3, the binder phase has a TiB.sub.2 (101) plane that shows a maximum peak position (2θ) in X-ray diffraction of 44.2° or more; and I.sub.2/I.sub.1 is 0.10 or more and 0.55 or less, where denotes an X-ray diffraction intensity of a (111) plane of the cubic boron nitride and I.sub.2 denotes an X-ray diffraction intensity of a (101) plane of TiB.sub.2 of the binder phase.

Provided is a piezoelectric ceramic composition including a potassium sodium niobate-based perovskite type complex oxide represented by Compositional Formula ABO.sub.3, as a main component. Further, the piezoelectric ceramic composition contains Bi in an A site and Zr in a B site. Further, the piezoelectric ceramic composition includes a segregation portion positioned in a crystal grain. At least one of Zr or Bi is localized in the segregation portion.