Defect formation in diamond single crystals grown from the Fe-Ni-C system at high temperature and high pressure

Some defects were formed in diamond single crystals grown from an Fe-Ni-C s ystem at high temperature high pressure (HPHT). These defects were successf ully examined by transmission electron microscopy (TEM) and a kind of indir ect lattice image called moire fringe. These defects are mainly composed of vacancy-type prismatic dislocation loops, stacking-fault tetrahedra, an ar ray of parallel dislocation lines, and dislocation networks. The formation process of these defects was analyzed briefly. It was suggested that these defects in the diamond crystal were derived from vacancies and inclusions, which were contained in the diamond single crystal during the diamond synth esis at high temperature and high pressure. (C) 2001 Elsevier Science Ltd. All rights reserved.