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

Abstract

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 T_e and number density n_e 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 T_g, 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.