One step convenient synthesis of crystalline β-Si3N4

Abstract

Well-crystallized β-Si₃N₄ was directly prepared at an initial reaction temperature of 150 °C through the reaction of SiCl₄ and NaN₃ in the presence of a small amount of CCl₄. Characterization by X-ray diffraction, high-resolution electron microscopy, X-ray photoelectron spectroscopy and energy dispersive X-ray spectroscopy indicates that the product synthesized is crystalline β-Si₃N₄. The yield of β-Si₃N₄ is about 86% based on the amount of precursor SiCl₄ used at the initial reaction temperature of 150 °C, and is more than 90% at the reaction temperature of 200 °C with the product β-Si₃N₄ in high crystallinity. The dominant morphology of the product is short rods with the growth axis along the [001] direction. The formation mechanism of crystalline β-Si₃N₄ was discussed briefly, and the role of CCl₄ in the formation process of β-Si₃N₄ was analyzed.