Plasma methods offer a variety of advantages to nanomaterials synthesis. The work here demonstrates nanopowder synthesis using inductively-coupled plasma to decompose precursor, which are then quenched to produce a variety of boron nitride (BN)-phase nanoparticles. Cubic BN (c-BN) powders can be generated through direct deposition onto a chilled substrate. Changing residence time can yield short-range ordered amorphous BN structures in the form of ~20nm diameter nanospheres (nano-onions). Finally, when introducing a rapid-quenching counter-flow gas against the plasma jet, high aspect ratio nanotubes are synthesized. The benefits of these morphologies are also evident in high-pressure/high-temperature consolidation experiments, where nanoparticle phases can offer a favorable conversion route to super-hard c-BN while maintaining nanocrystallinity.
