Highly-efficient shock-wave diamond synthesis from fullerenes

Shock-wave synthesis of micron-size diamonds from fullerenes C-60-C-150 was performed using the explosive compaction technique with plane shock-wave loading at pressures in the range of 24-40 GPa. The coarsest diamond crystallites were of size up to 6 mu m. A modified explosive compaction technique was found with a very high efficiency of diamond synthesis from fullerenes due to intensive shear deformation of samples at shock-compaction. The quantity of recovered diamonds approached 90%. By supplementary modification of the explosive compaction technique, the fullerene constituent was transformed into coarse-grained (up to a few hundred of microns) amorphous diamond which had a hardness which was estimated directly and was found to be higher than that of crystallite diamond. (C) 1997 Elsevier Science Ltd.