Characterization of synthetic diamond crystals by spatially resolved rocking curve measurements

For several years the ESRF, the University of the Witwatersrand and De Beer s Industrial Diamonds (PTY) Ltd through their Diamond Research Laboratories have pursued a development programme to improve the quality of synthetic d iamond crystals. Recently, in an effort to study the influence of nitrogen impurities on the defect structure, x-ray excited optical luminescence and spatially resolved double-crystal diffractometry were employed as new techn iques. Finally, the impurity concentration distribution obtained by optical spectroscopy was superimposed on the defect structure determined by x-ray diffraction. The correlation between nitrogen impurities and the raw defect structure was clearly visible. It was confirmed that concentration variati ons are related to lattice imperfections, where tilts are much superior to lattice parameter variations.