Formation of nanocrystalline niobium carbide (NbC) with a convenient route at low temperature

Abstract Nanocrystalline NbC has been prepared via a convenient route by the reaction of metallic magnesium powders with niobium pentoxide and basic magnesium carbonate in an autoclave at 550 °C. X-ray powder diffraction pattern indicated that the product was cubic niobium carbide, and the cell constant was a  = 4.461 A. Transmission electron microscopy (TEM) image showed that it consisted of particles with an average size of about 30 nm in diameter. The product was also studied by BET and TGA. It had good thermal stability and oxidation resistance below 400 °C in air.