SILICON-CARBIDE NANOPARTICLES FOR ADVANCED MATERIALS PRODUCED IN RADIO-FREQUENCY MODULATED GLOW-DISCHARGES

Nanometric powder of silicon carbide has been produced in a radiofrequ ency square wave-modulated glow discharge of SiH4 and CH4 gases. The t ransient behavior observed in the power absorbed during the discharge has been related to the various steps of the formation of particles. A t the transmission electron microscope, two populations of particles w ere found: around 70 and 300 nm. Electron diffraction patterns showed that the particles were amorphous although the short-range order was s imilar to that of beta-SiC micrometric powder. The atomic concentratio ns of Si, C and H were determined by elemental analysis. The chemical composition was determined by X-ray photoelectron spectroscopy. The po lymeric character of the powder was evident from the presence of CH, a nd CH, species as indicated by RAMAN and FTIR spectroscopies. (C) 1997 Elsevier Science Ltd. All rights reserved.