The mechanism of formation of light-scattering centers in sapphire crystals grown in gas atmospheres

The mechanism of the formation of light-scattering centers in sapphire crystals grown by horizontal directed crystallization in gas atmospheres reducing with respect to the Al₂O₃ melt was studied. The experimental regularities here significantly differ from those observed upon formation of other conventional defects in sapphire crystals (vacancy pores, gas bubbles, and so on). It is shown that the known formation mechanisms of macroscopic ≥1 mm) inclusions in crystals are not acceptable in this case. Using the model of bulk crystallization is proposed to describe the obtained regularities.