Synthesis of titanium boride (TiB)₂ nanocrystallites by solution-phase processing

Nanocrystalline TiB₂ is prepared by reaction of NaBH₄ and TiCl₄. The initial solution-phase reaction affords an amorphous precursor powder from which 5-100 nm TiB₂ crystallites are obtained upon annealing at 900-1100 °C. Crystallite sizes depend on the annealing temperature and other processing parameters. Crystallite morphology is size dependent; crystallites smaller than 12-15 nm are cuboidal, whereas crystallites larger than 12-15 nm are hexagonal platelets. The procedure affords gram quantities of the smallest available TiB₂ nanocrystallites.