Thermal plasma processing -: syntheses of diamond and β"-alumina

Thermal plasma processing using a plasma jet with high speed and high heat capacity under reduced pressure (less than or equal to 100 torr) is one of the most promising methods for synthesizing new materials. We have newly developed a thermal plasma reactor composed of a forced constricted type plasma jet generator with a feed ring, and confirmed that this reactor generates stable plasma jets with a high heat capacity under various operating conditions. In this paper, to realize the large area deposition at a high rate, synthesis of diamond films from gas mixtures of CH4 and H-2 is studied. Synthesis of beta"-alumina, thermoelectric materials for the alkali metal thermoelectric converter (AMTEC), from powder mixtures is also discussed. (C) 2000 Elsevier Science B.V. All rights reserved.