Facile Synthesis of Si3N4 Nanocrystals Via an Organic–Inorganic Reaction Route

Silicon nitride (Si₃N₄) nanocrystals were synthesized at about 250°C by a simple organic–inorganic reaction between CH₃SiCl₃ and NaN₃. The yield of Si₃N₄ is no <70 wt% based on the amount of precursor CH₃SiCl₃ used in the reaction and TGA analysis. X-ray diffraction indicates the formation of a mixture of α- and β-Si₃N₄. Particles with size from 40 to 100 nm are dominant in the products examined by transmission electron microscopy. X-ray photoelectron spectroscopy gives an atomic ratio of Si:N around 0.75:1. The formation of nanocrystalline Si₃N₄ during the organic–inorganic reaction goes through an intermediate product of NaSi₂N₃, which is important for understanding the reaction mechanism.