Two-stage aerosol synthesis of titanium nitride TiN and titanium oxynitride TiOxNy nanopowders of spherical particle morphology

The two-stage aerosol-assisted synthesis technique was first used to prepare titanium containing raw aerosol powders with spherical particle morphology from aqueous and methanol solutions of selected oxygen-bearing titanium precursors and from neat titanium (IV) i-propoxide. The aerosol powders were subsequently pyrolyzed under ammonia at 1000, 1100, and 1200 degrees C, giving, in some favorable cases, compositions ranging from titanium oxynitride TiOxNy to titanium nitride TiN with average crystallite sizes of 32-38 nm and a residual oxygen content in the latter below 2 wt%. The intermediate and final products were characterized by SEM, XRD, FT-IR, and XPS analytical methods. For selected materials, oxygen content, helium density, and BET surface area were also determined.