Formation mechanism of silicide nanoparticles by induction thermal plasmas

The condensation mechanism of metal mixture in thermal plasmas was investigated experimentally and numerically to prepare nanoparticles of silicon base intermetallic compounds. Silicon powder premixed with metal powder (Mo, Ti, Co, Fe, Cr, or Mn) was introduced into the plasma. The nanoparticles were prepared on condition that metal vapor was quickly quenched by the water-cooled copper coil. The nucleation rate expression was used for the estimation of critical saturation ratio. The nucleation temperature of the metal almost corresponds to the melting temperature, while silicon has wide liquid range between the nucleation and melting temperature, resulting in better preparation of silicide. For Mo–Si system, nucleation position of Mo is different from that of Si. Therefore, quenching position has strong effect on the particle composition of molybdenum silicide nanoparticles.