Synthesis of 28SiC from 28SiF4 and Methane in Radiofrequency (13.56 MHz) Arc Hydrogen Plasma

Resumo

Some features of atmospheric-pressure radiofrequency (13.56 MHz) arc discharge and its use for obtaining bulk samples of isotope-enriched silicon carbide via the reaction between SiF₄ and methane in a hydrogen medium have been considered. It has been shown that power in this type of discharge is released mainly in the near-electrode regions. The deposition of silicon and graphite occurs in a layer-by-layer mode, so that the product carbide contains up to 40% free carbon; therefore, the process requires optimization. At the same time, the proposed type of RF arc discharge with the product deposition zone localized at the ends of the electrodes makes it possible to avoid not only additional heating of the reactor space and walls, but also the loss of expensive isotope-enriched silicon fluoride.