Synthesis and characterization of Si3N4 wires from binary carbonaceous silica aerogels.

Abstract: 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 ( =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 100–500nm and a length of several microns at reaction temperature of 1400°C for 10h in nitrogen flow (200ml/min) by employing the mass ratio of =0.5. [Copyright &y& Elsevier]