Special Features of Preparation of Nanosized Zirconium Diboride Powders of Various Dispersity

Products of the zirconium powder reaction with amorphous boron in a Na 2 B 4 O 7 ionic melt at 650–850°C and those of the ZrCl 4 reaction with NaBH 4 at 300–725°C have been studied by means of X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, thermogravimetry, and elemental analysis. At temperature ≥750°C, single-phase ZrB 2 with the particle size of 60–80 nm is formed in a Na 2 B 4 O 7 ionic melt, whereas the ZrB 2 powder obtained via the reaction of ZrCl 4 with NaBH 4 at temperature ≥575°C consists of particles differing in the shape, some of which are close to spherical with diameter of 10–35 nm.