CRYSTALLIZATION OF AMORPHOUS CARBON AT HIGH STATIC PRESSURE AND HIGH TEMPERATURE.

Article abstract of DOI:10.1007/BF01174666

Amorphous carbons prepared from furfuryl alcohol resin have been studied in a high pressure apparatus of octahedral anvil type at pressures up to 18 GPa and at temperatures up to 2000 degree C. The amorphous carbons, when heated under pressure, crystallized first into graphite at 450 to 600 degree C and then into diamond at 1120 to 2000 degree C. The temperatures for the onset of these crystallizations, T//g and T//d, were determined. As the temperature for the preparation of the amorphous carbons was raised from 700 to 1000 degree C, T//g at 15 GPa increased slightly whereas T//d at the same pressure turned from a decrease into an increase beyond 750 degree C for the preparation temperature. For amorphous carbon prepared at 850 degree C, T//g increased a little while T//d decreased markedly with increasing pressure.