High-resolution electron microscopy and electron spin resonance studies on cubic boron nitride crystals made by high-pressure/high-temperature synthesis

Cubic boron nitride (c-BN) crystals synthesised at high pressures and temperatures are analysed by optical microscopy, transmission electron microscopy, electron diffraction and electron spin resonance. For various growth conditions, the results of these studies indicate that the c-BN crystals contain defects and impurities. This is the first time that dislocation cores have been revealed in c-BN at the atomic level. Atomic resolution at extended dislocations allows us to determine the stacking-fault energy in c-BN, yielding a mean value of 191+/-15 mJ m(-2). This value, which is reported for the first time for c-BN, is of the same order of magnitude as in diamond. (C) 1999 Elsevier Science S.A. All rights reserved.