THE TRANSFORMATION OF FULLERENES INTO DIAMOND UNDER DIFFERENT PROCESSING CONDITIONS

Three processes were used to transform fullerenes into diamond. (a) La ser irradiation processing: Diamond particles dispersed in an Fe-C all oy system were obtained by CO2 continuous laser-induced quenching of f ullerene coatings on carbon steel (C content 0.45%). The so-made fullr ite, which achieved an average hardness of HRC65, contained a great de al of polygonal crystallites on the order of 0.1 micron, most of these being well-faceted cubic diamond. (b) Phase transition under high pre ssure processing: Fullerene carbon can transform to diamond with a goo d crystal morphology at high temperature (1450 degrees C) and high pre ssure (5-6GPa). Furthermore, this kind of phase transition is easier a nd faster than that of graphite to diamond, both in homogeneous nuclea tion and in diamond crystal growth. (c) HF-CVD processing: Coating a S i wafer with fullerenes, a high quality diamond film can be deposited easily and quickly through the processing of HF-CVD (Hot filament chem ical vapour deposition). Both buckyballs and buckytube used as a coati ng agent have a significant effect on the diamond nucleation rate on S i substrates, buckytube performing better than buckyballs.