An alumina sintered body of the present invention has a degree of c-plane orientation of 5% or more, which is determined by a Lotgering method using an X-ray diffraction profile in a range of 2=20 to 70 obtained under X-ray irradiation, and an XRC half width of 15.0 or less in rocking curve measurement, an F content of less than 0.99 mass ppm when measured by D-SIMS, a crystal grain diameter of 15 to 200 m, and 25 or less pores having a diameter of 0.2 m to 1.0 m when a photograph of a viewing area 370.0 m in a vertical direction and 372.0 m in a horizontal direction taken at a magnification factor of 1000 is visually observed.

The present invention relates to a new process for manufacturing a silicon carbide (SiC) coated body by depositing SiC in a chemical vapor deposition method using dimethyldichlorosilane (DMS) as the silane source on a graphite substrate. A further aspect of the present invention relates to the new silicon carbide coated body, which can be obtained by the new process of the present invention, and to the use thereof for manufacturing articles for high temperature applications, susceptors and reactors, semiconductor materials, and wafer.

A method for producing a transparent alumina sintered body includes (a) the step of preparing an alumina raw material powder containing a plate-like alumina powder having an aspect ratio of 3 or more so that the mass ratio R1 of F to Al in the alumina raw material powder is 5 ppm or more, and forming a compaction raw material containing the alumina raw material powder into a compact, and (b) the step of pressure-sintering the compact at a temperature at which F evaporate to yield a transparent alumina sintered body.

An oxide sintered compact made of indium (In), gallium (Ga), zinc (Zn) and oxygen (O) and represented by a formula of InxGayZnzOa [wherein x/(x+y) is 0.2 to 0.8, z/(x+y+z) is 0.1 to 0.5, and a=(3/2)x+(3/2)y+z], wherein the concentration of volatile impurities contained in the oxide sintered compact is 20 ppm or less. Provided is technology for application to the production of an IGZO target capable of achieving high densification and low bulk resistance of the sputtering target, preventing swelling and cracks of the target during the production process, minimizing the generation of nodules, inhibiting abnormal discharge, and enabling DC sputtering.

A method for producing a polysilane includes a disproportionation reaction of a methylchlorodisilane mixture to form chlorine-containing oligosilane, a substitution reaction of the chlorine atoms contained in the oligosilane by the reaction with a primary amine and a cross-linking reaction of the oligosilanes using a chain former to form polysilanes. The obtained polysilanes are infusible and are very suitable for being spun to form green fibers and processed to form silicon carbide fibers and fiber composites. The method is characterized in that it can be carried out cost-effectively and quickly and with very high yields.

The present invention relates to a new process for manufacturing a silicon carbide (SiC) coated body by depositing SiC in a chemical vapor deposition method using dimethyldichlorosilane (DMS) as the silane source on a graphite substrate. A further aspect of the present invention relates to the new silicon carbide coated body, which can be obtained by the new process of the present invention, and to the use thereof for manufacturing articles for high temperature applications, susceptors and reactors, semiconductor materials, and wafer.

Disclosed is a multilayered capacitor including a capacitor body including a dielectric layer and an internal electrode and an external electrode disposed outside the capacitor body. The dielectric layer includes a plurality of dielectric crystal grains, the dielectric crystal grains include barium titanate as a main component and Dy.sub.2O.sub.3 as a subcomponent, and the barium titanate includes about 0.005 to about 0.065 wt % of Cl.