Optical and Electron Paramagnetic Resonance Study of Sponge Silicon Carbide Prepared by Direct Synthesis
The objective of the present work is to examine the preparation and characterization of the SiC sponge obtained by direct synthesis of high purity graphite and silicon powder in inert atmosphere at 1900 - 2000 0C for 2-3 hours. To burn out the carbon excess the samples were subsequently heated in oxygen atmosphere at 800 -900 0C resulting in a weight loss of SiC. The relative density of SiC sponge is 1.5-1.7 g/cm 3. The advantages of the proposed method are the high rate of ceramic yield and capability to create the ceramic samples of preliminary selected shape by using a graphite cell of different configurations. Raman scattering spectroscopy and electron paramagnetic resonance (EPR) data have shown that SiC sponge produced by direct synthesis of graphite and silicon powder consists of 6H and 3C SiC polytypes.
N. Wright, C.M. Johnson, K. Vassilevski, I. Nikitina and A. Horsfall
V.S. Kiselov et al., "Optical and Electron Paramagnetic Resonance Study of Sponge Silicon Carbide Prepared by Direct Synthesis", Materials Science Forum, Vols. 556-557, pp. 399-402, 2007