Influence of Stacking Faults on Diffraction Properties of Diamond by Synchrotron Topographic Imaging

摘要

Abstract Diamond crystals are becoming more important or indispensable as critical 3rd- and 4th-generation synchrotron optical components. However, diamond generally contains various defects, among which stacking faults (SFs) are most detrimental since they are planar defects that can exist in all kinds of diamonds with dimensions up to square millimeters. Here we introduce our topographic studies of common defects and particularly SFs in diamonds. In monochromatic topography, SFs show strong black contrast on the rocking curve tails, thus broadening the rocking curve width and reducing the cleanness of the diffraction spectrum. On the Bragg peak, SFs appear as white-line contrast (absence of diffraction), indicating that they can significantly reduce the Bragg reflectivity. SFs always show black contrast in white-beam topography caused by the simultaneous diffraction of a range of wavelengths from the SFs. These results may provide clear guidelines for understanding the performance of diamonds in synchrotron optics and also for diamond crystal growth.