Impurities identification in a synthetic diamond by transmission electron microscopy

Three types of impurities, which were trapped in diamond single crystal dur ing process of the diamond crystal growth under high temperature and high p ressure in the presence of iron-nickel solvent catalyst, have been successf ully and directly investigated by transmission electron microscopy (TEM) an d scanning electron microscopy (SEM). Both the chemical composition and the crystal structure of the impurities were identified and determined. The im purities may be derived from the starting materials and the medium (pyrophi llite) for transmitting the pressure, they consisted of amorphous graphite, f.c.c. (FeNi)(23)C-6 and orthorhombic FeSi2. (C) 2000 Elsevier Science B.V . All rights reserved.