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

Natural differentiation of borate melt components and its influence on nucleation and growth of barium metaborate (BBO) crystals

“…Major conditions of BBO crystal growth in TSSG configuration and further study of them are reported in Ref. [4].…”

Some reasons for the formation of grain boundaries and melt inclusions in growing large BBO crystals by TSSG technique

“…and the typical conditions of BBO crystal growth by the TSSG technique combined with pulling (typical temperature gradients, cooling rates of solutions, seed rotation and pulling rates, etc.) were presented in our previous works [7,12]. Only Z-oriented seeds were used for growing BBO single crystals in this study.…”

“…BBO crystals grown from solutions always have growth and post-growth defects of various types, which were described elsewhere [3][4][5][6][7][8][9][10][11]. Some of our previous works discuss general problems of BBO crystallization from solutions, formation of structural defects, and improvement of the procedure for growing BBO crystals [3][4][5][6][7]12]. The aim of this work is to analyze further the reasons for the formation of major defects during the growth of BBO single crystals, namely grain boundaries with disordered angle orientation of different scales and melt inclusions.…”

General approaches to design of a reproducible technique for the growth of large crystals of barium metaborate (BBO) for industrial application

“…5) before its further transformation into a boule with a rounded cross-section localizes these inclusions in the volume of subseed core with a diameter no more than 3-5 mm. This is also assisted by high gradT/ax and gradT/rad in melt and maximum decrease in the rate of crystal rotation [9].…”

“…In growing crystals of 70 mm in diameter, the optimal configuration of the crucible providing a stable centrosymmetrical structure of convection flows [9] is of great importance. This type of structure in furnaces with an axially symmetric thermal field forms in cylindrical crucibles with their height-diameter ratio $1.5.…”