| 摘要 |
PURPOSE:To obtain a raw material for a superconductor excellent in heat shock resistance and strength by baking amorphous fine powders consisting of Si, C, N and H and synthesized by CVD method from an organosilicon compound having limited impurities such as Fe, Ca, Al and Na. CONSTITUTION:An organosilicon compound (e.g. hexamethyldisilazane [(CH3)3 Si]2NH] containing <=10ppm each of Fe, Ca, Al and Na as impurities is used as a raw material. From this raw material, amorphous fine powders consisting of Si, C, N and H are synthesized by using a CVD reaction tube made by installing a graphite sheet or tube containing <=100ppm above-mentioned impurities in an inner wall of the reaction tube. Then, the fine powders are baked in a non-oxidative atmosphere at 1000-1600 deg.C. Thus, silicon nitride - silicon carbide complex powders containing <=5ppm each impurity of Fe, Ca, Al and Na, <=0.01ppm B and 0.2<=C<=29wt.%. are obtained. |
