Lattice distortion and parameter variation in quartz and berlinite crystals: methods for improving the quality

X-ray transmission topography and a plane-wave imaging technique using synchrotron radiation are employed to reveal lattice defects and to measure minute distortions in plates of synthetic quartz and berlinite crystals. For the berlinite, studies of the optimal conditions of growth are performed in order to obtain larger crystals. This is done using an extension of different techniques previously applied to quartz crystals. To control the quality of the obtained crystals, X-ray topographic studies are performed, and typical features of the samples are presented