On the formation process of silicon carbide nanophases via hydrogenated thermally induced templated synthesis

Abstract

A thermally induced templated synthesis for SiC nanotubes and nanofibers using ammonia or nitrogen as a carrier gas, single wall carbon nanotubes (SWCNT) as templates as well as gaseous Si is presented. The bundles of SWCNT act as both the carbon source and as a nanoframe from which SiC structuctures form. Depending on the duration of the thermally induced templated reaction, for a fixed temperature, carrier gas, and gas pressure, various SiC nanostructures are obtained. These structures include SiC nanorods coated in C, SiC nanorods, SiC nanotubes, and SiC nanocrytals. From our analysis using transmission electron microscopy (TEM) and scanning electron microscopy (SEM), electron energy-loss spectroscopy (EELS), electron diffraction (EDX), optical absorption spectroscopy and Raman spectroscopy as probes we prove that H has a key role on the morphology and stochiometry of the different SiC nanostructures.