| Crystal Research and Technology |
In this paper, microstructures of diamond single crystal grown from Ni-C system under high temperature and high pressure (HPHT) were examined by transmission electron microscopy (TEM). It was shown that there exist growth defects such as micro-inclusions, dislocation networks, an array of dislocations and dislocation pileup in the diamond. The formation process and characteristics of these defects were analyzed briefly. The micro-inclusions are composed of hexagonal Ni3C, hexagonal SiO2 and amorphous graphite, which may be derived from the starting materials and the medium (pyrophyllite) for transmitting the pressure. The dislocations are related to internal stress in the diamond, which may be correlative with the micro-inclusions in the diamond.
Keywords: diamond single crystal, high temperature-high pressure, catalyst, inclusions, dislocations, transmission electron microscopy