Preparation And Characterization Of Low-Dimensionals In Si-B-C-N System

Inorganic compounds in Si-B-C-N system are some of the most outstanding materials with wide bandgap, high strength, good wear-resistance, low friction coefficient and excellent thermal shock resistance. Thus, it has wide technological applications in many fields, such as cutting tools, antifriction bearings, turbocharger rotors, engine valves and electronic device. Compared to the traditional materials, nanomaterials have some novel physical and chemical properties, and have potential applications in many fields. So, it is of great significance to find a facile, economical synthesis route and study the formation mechanism of nanoscale compounds in the Si-B-C-N system.In this paper, Si₃N₄, BN, SiC and carbon nanostructured materials were successfully prepared at relatively low temperature via chemical metathesis method. All the materials were fabricated in a high pressure reaction autoclave at relatively low temperatures. These nanocrystals were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), energy dispersive x-ray spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR) and photoluminescence spectroscopy(PL).A mixture of α-Si₃N₄ and β- Si₃N₄ with good crystallinity was synthesized by the direct reaction between SiCl₄ and NaN₃ at 480℃.