Correlation of the structural imperfection and morphology of Bi4Ge3O12 crystals grown by the low-gradient Czochralski method

This paper reports on the results of investigations into the morphological structure of the facets of Bi4Ge3O12 crystals grown by the Czochralski method under the conditions of low temperature gradient (0.1–1 K/cm). A correlation between the morphological features of the facets at the crystallization front and the formation of defects in the bulk of the crystal is revealed. It is demonstrated that the {112} facets remain regular while the growing surface deviates from the (112) crystallographic plane by an angle of up to 1°. At larger deviations, there occurs a crossover from the stable facet growth to the growth of macrosteps or normal growth depending on the growth conditions.