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

Abstract

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.