Effect of reaction time in direct nitridation of Si powders

Si₃N₄ nanomaterials have been synthesised via direct nitridation of Si powders at 1300°C for different reaction time. The purified Si₃N₄ samples were characterised by Fourier transform infrared spectroscopy, X-ray diffraction and transmission electron microscopy. The results showed that the samples obtained for different reaction time are mixtures of α- and α-Si₃N₄ phases. The percentage of β-Si₃N₄ in the Si₃N₄ samples has obviously increased with the reaction time. The Si₃N₄ samples are mainly composed of nanobelts with different width.