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

Abstract

Some defects were formed in diamond single crystals grown from an Fe-Ni-C system at high temperature high pressure (HPHT). These defects were successfully examined by transmission electron microscopy (TEM) and a kind of indirect lattice image called moiré fringe. These defects are mainly composed of vacancy-type prismatic dislocation loops, stacking-fault tetrahedra, an array 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 synthesis at high temperature and high pressure.