LAUSR

Abstract Silicon nitride (Si3N4) nanowires were synthesised using H2-treated SiC fibres as raw materials and a graphite cylinder as the substrate at 1500 °C in N2 atmosphere. The nanowires were characterised by X-ray photoelectron spectroscopy, chemical analysis, X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and high-resolution transmission electron microscopy. The results showed that the Si3N4 nanowires have diameters ranging from a few tens to hundreds of nanometres and lengths of several hundred micrometres. The preferred growth direction of the nanowires was (010), and the nanowires comprised single-crystalline α-Si3N4. In addition, the formation mechanism of Si3N4 nanowires was discussed. The free silicon in the H2-treated SiC fibres was found to react with N2 to form Si3N4 nanowires, leading us to speculate that the growth mechanism involves a vapour-solid process.