Study On The Experimentation Of Synchrotron Radiation Topography And The Defects In Diamond Crystals

An approach to calculate the orientation of the crystal defects using continuous spectra synchrotron radiation was proposed in this paper. By this method, with the addition of FTIR, SEM, et al, natural diamonds from South Africa and Liaoning as well as some synthetic diamonds were studied.Monochromic spectrum of synchrotron radiation was previously used to determine the crystallographic directions of the defects. However, continuous spectra were adopted instead in this paper. Compared with the former, the efficiency was greatly improved and the experiment was easier to implement Experiment techniques, computing philosophy and calculation process were introduced in detail. Calculation errors might be brought in the experiment was estimated in this paper.Crystal defects in natural and synthetic diamonds were analyzed by synchrotron radiation topography. It was found that the dislocation directions of natural diamonds were parallel to {111} and their Burgers vectors were <110>2 while the orientations of the dislocations in synthetic diamonds were parallel to <100>or <110>and their Burgers vectors were in different directions. Hereby, {111} are the main crystal planes in natural diamonds while in synthetic diamonds the main crystal faces were {100} and {110}. Spike images appeared in synchrotron radiation topographs of some natural diamonds and their genesis were studied. Such images were never seen in the topographs of synthetic diamonds. The possible causations of the spike images were discussed. Further more, the history of the diamonds of South Africa and Liaoning were speculated. White synthetic diamond grains were studied. Only gas was found in the inclusions in white grains.