Synthesis of Nanocrystalline Chromium Nitride Powder by Direct Gas Nitridation of Cr_2O_3

摘要

Fine grained nanocrystalline Cr_2O_3, powder has been synthesised from Cr(NO_3)_3-9H_2O precursor by precipitation using ammonia solution followed by low temperature calcination. The product has been characterised by XRD technique. Mean particle size of this nanocrystalline Cr_2O_3 as determined from the XRD data was found to be -25 nm. Nanocrystalline CrN was derived from Cr_2O_3 powder by direct nitridation with Ar and ammonia gas mixture in a TGA-EGA-MS system. Conditions for synthesis of nanocrystalline CrN have been optimised. The resulting CrN powder was characterised using XRD, TEM and Raman spectroscopy. The TEM micrographs, showed a particle size distribution in the range 20-30 nm.