Growth and defect structure of seeded solution grown Sc-substituted barium hexaferrite crystals using different seed orientation

Large Sc-substituted barium hexaferrite crystals were grown by submerged-seeded solution growth (SSSG) and top-seeded solution growth (TSSG) techniques using various seed orientations. The influence of the seed position and seed orientation on the defect formation was studied in detail. Growth defects like inclusions, growth striations, growth sector boundaries, and growth-induced dislocations have been observed at cleaved and polished crystal surfaces by DIC microscopy after selective wet-etching. X-ray topography studies show these defects in more detail. It was found that the seeding process results in the formation of inclusions, which are nucleation centres of growth-induced dislocations. The application of small seed crystals with [2−1−10] and [01−10] seed orientation enables the dislocations, generated by the inclusion, to “grow out” at the side faces of the bulk crystal.