Characterization of Growth Sectors in Synthetic Quartz Grown from Cylindrical Seeds Parallel to [0001] Direction

In the present study, the morphology and the impurity distribution were investigated in growth sectors formed around the [0001] axis of synthetic quartz crystals. Plates containing cylindrical holes and cylindrical bars parallel to [0001] were prepared by ultrasonic machining and further used as seed-crystals. The hydrothermal growth of synthetic quartz was carried out in a commer-cial autoclave under NaOH solution during 50 days. The morphologies of crystals grown from cylindrical seeds were characterized by X-ray diffraction topography. For both types of crystals, +X- and –X- growth sectors were distinctly observed. Infrared spectroscopy and ionizing radia-tion were adopted to reveal the distribution of point defects related to Si-Al substitution and OH-species. It was found a different distribution of Al-related centers in relation to the crystals grown from conventional Y-bar and Z-plate seeds