AN X-RAY AND NEUTRON-SCATTERING INVESTIGATION OF PRECURSOR DERIVED SI24C43N33 CERAMICS

X-ray and neutron wide angle scattering studies of amorphous Si24C43N3 3 ceramics, annealed at different temperatures, were performed using c ontrast variation by isotopic substitution (N-nat double left right ar row N-15). The total pair correlation functions exhibit distinct peaks , which can be correlated with two phases, namely amorphous Si3N4 and amorphous carbon. Peaks due to SI-C and C-N bonds were not observed. R everse Monte Carlo simulation yields partial pair correlation function s which are consistent with the phase separation model. (C) 1998 Elsev ier Science B.V. All rights reserved.