Effects of thermal and laser annealing on silicon carbide nanopowder produced in radio frequency glow discharge

Abstract

Hydrogenated SiC nanoparticles of high purity have been produced in radio frequency (RF) glow discharges from silane and methane gas mixtures. These nanoparticles show high surface reactivity and can undergo spontaneous oxidation when exposed to the atmosphere. In order to analyze the chemical stability of SiC particles, we present a study of the structural, chemical and compositional modifications induced by thermal annealing at different temperatures (400, 600 and 800 °C). The post-treated powder was analyzed by RAMAN, FTIR and XPS spectroscopy. The effects of the thermal annealing of SiC powder include: change of colour from yellow to dark brown; hydrogen desorption; and an increase in CC and SiC bonds in detriment to SiSi bonds. In addition, annealing with a KrF excimer laser induced the presence of Si and SiC nanocrystallites.