Synthesis and characterization of Si3N4 wires from binary carbonaceous silica aerogels

Silicon nitride ultrafine powders were synthesized from a binary sol–gel route, in which tetraethoxysilane (TEOS) and saccharose were used to prepare a carbonaceous silica xerogel, and ferric nitrate was employed as an additive. The influence of reaction temperature and mass ratio of C to Si ( C Si = 0.1, 0.5, 1) on the synthesis of Si3N4 wires was studied. After purification, the Si3N4 sample was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectrum and Fourier transform infrared spectroscopy. The results show that the Si3N4 was fully formed with two kinds of morphologies including globular and wire with a diameter of 100–500 nm and a length of several microns at reaction temperature of 1400 °C for 10 h in nitrogen flow (200 ml/min) by employing the mass ratio of C Si = 0.5.