Optical and X-Ray Topographic Studies of Dislocations, Growth-Sector Boundaries, and Stacking Faults in Synthetic Diamonds

The characterization of growth features and defects in various high-pressure high-temperature (HPHT) synthetic diamonds has been achieved with optical and X-ray topographic techniques. For the X-ray studies, both characteristic and synchrotron radiation were used. The defects include dislocations, stacking faults, growth banding, growth sector boundaries, and metal inclusions. The directions of the Burgers vectors of many dislocations (edge, screw, and mixed 30 degrees, 60 degrees, and 73.2 degrees), and the fault vectors of stacking faults, were determined as < 110 > and 1/3 < 111 > respectively. Some dislocations were generated at metallic inclusions; and some dislocations split with the formation of stacking faults.