SI-C-N NANOMETRIC POWDER PRODUCED IN SQUARE-WAVE MODULATED RF GLOW-DISCHARGES

Square-wave modulation of the electrical power supplied to low pressur e and low temperature radio frequency (RF) plasmas has been revealed a s a suitable method to produce nanometric powder of high purity and na nometric size (10-100 nm). Here, we present a study involving the prod uction and characterisation of silicon carbon nitride (Si-C-N) nanomet ric powder, obtained from square-wave modulated RF plasmas of SiH4 + C H4 + NH3 and SiH4 + CH4 + N-2 gas mixtures. Electron diffraction patte rns and transmission electron micrographs showed that the Si-C-N powde r particles are amorphous and have a size distribution in the range 25 -45 nm. X-ray photoelectron spectroscopy, elemental analysis and Fouri er-transform infrared spectroscopy showed important differences in the structure, hydrogenation, chemical composition and bond distribution (SiC, SiN) of the samples owing to the use of different gas mixture. T his powder could be used as a raw material to produce advanced ceramic s and composites with higher thermal and chemical stability and improv ed mechanical properties. (C) 1998 Elsevier Science S.A.