Study of inclusions and causes of their formation during growth of barium metaborate crystals

The complex study of barium metaborate crystals has been undertaken with the aim to determine the conditions of their growth with the minimum density of inclusions. It is shown that almost all the inclusions are multiphase formations of the melt type, and, in addition to the mixture of the main components of the quasieutectic composition, they can also be enriched with gas-forming impurities not removed during barium metaborate synthesis. It is shown that the amount and the composition of melt-like inclusions in crystals depends on the removal of by-products of the reactions used for barium metaborate synthesis from the system, the patterns of the convective flows in the flux, the character of its flow under the interface, the axial temperature gradient in the solution, and the temperature fluctuations at the crystallization front.