Characterization of diamond single crystals for synchrotron radiation monochromators

The diamond crystals with a (100) or a (111) surface are characterized by t he uses of rocking curve measurements, reciprocal lattice mapping and Lang topography method. The full widths at the half maxima of the rocking curves at the X-ray energy of 8.04 keV have been measured to be 6.5 arcsec and 6. 3 arcsec for 400 and 111 Bragg reflection, respectively. While the value fo r 400 reflection is 1.3 times larger than the theoretical value, that for 1 11 reflection is almost the same as the theoretical one. A sub-peak of abou t 15 arcsec leaning to the main peak is clearly seen in the reciprocal latt ice maps of (100) crystals. No sub-peak can be seen in those of (111) cryst al. In addition, some streaky intensity distribution due to a dynamical eff ect of the X-ray diffraction, being elongated in the radial direction from the reflection point, is clearly seen. This means that crystallinity of(111 ) planes is more perfect. From the (100) Lang's topographs, it has also bee n clarified that the diamond crystals include some defect bundles inside th e crystals.