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 commercial 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 radiation 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.