In Situ Studies of Emission Characteristics of the DC Thermal Arc Plasma Column During Synthesis of Nano-AlN Particles

The growth process of nanoparticles and nanowires of AlN by thermal-plasma-assisted gas phase condensation reaction has been investigated by optical emission spectroscopy. The concentrations of the reacting precursors in the plasma have been correlated to the crystalline phases of nanoparticles of AlN found from X-ray diffraction analysis. The size and morphology of the nanoparticles have been studied by transmission electron microscope investigations of as-synthesized powder at a set of reactor parameters, which included arc current, reactor pressure, and standoffs of the arc column. An attempt has been made to correlate the growth of AlN to that of the precursor density present in the plasma reaction zone