Reduction of Boron Trichloride in Atmospheric-Pressure Argon–Hydrogen Radiofrequency Induction Plasma

The main operating modes of a radiofrequency induction plasma torch with a vortex stabilization of the atmospheric-pressure gas discharge at have been studied in an argon-hydrogen mixture in the range of Ar/H2 = 12–4. The dependences of the electron temperature Te and number density ne on the Ar/H2 ratio have been experimentally studied. It has been found that the electron temperature and concentration in pure argon plasma are 0.88 eV and 7.6 × 1014 cm−3, respectively. When the Ar/H2 ratio decreases, the electron temperature decreases to 0.42 eV, and the electron number density is 8 × 1012 cm−3. The calorimetric method used to estimate the gas temperature Tg, has given a value of 2500 K. The process of BCl3 reduction with hydrogen has been studied at the implemented operating modes of the induction plasma torch. The main products of the reduction of boron trichloride are a polycrystalline boron powder and dichloroborane. The morphology of boron and its phase composition and impurities have been studied. The average particle size of the boron powder is 200 nm.