Determination of the supercooling dependence of the (211) facet of BGO crystal on growth rate from the temporal dependence of supercooling at a prescribed melt-cooling rate

The results of determination of the supercooling dependence at the interphase boundary on the rate of growth from melt of the monocrystal Bi₄Ge₃O₁₂ in the [211] direction are presented. Determination of supercooling was based on optical pyrometer measurements of the intensity of heat emission from the interphase boundary through the growing crystal. The crystal was grown by the AHF method (axial heat flux near the front of crystallization) by cooling the AHF heater at a specified rate. The growth rate corresponding to the measured supercooling value was determined by calculations. The study has shown that the supercooling is high and varies nonlinearly with the growth rate.