Synthesis of nanosized zirconium diboride powder via oxide-borohydride solid state coupling

A novel solid-state reaction was investigated to achieve nanosized ZrB2 particles in reducing atmosphere. We propose a metal oxide-borohydride system as an alternative to the metal halide-borohydride metathesis. ZrO2 and NaBH4, were dry mixed and thermally treated at increasing temperatures and B:Zr molar ratio to study the reaction yield. X-Ray diffraction and FE-SEM/EDS techniques were used to analyses powders before and after synthesis. It was found that the reaction was completed after 30 min at 900°C, with a 4:1 B:Zr ratio. Microstructural observation revealed ZrB2 particles with dimensions around 100 nm.