Technique of determination of interface supercooling dependence on crystal growth rate

A brief description and analysis of methods concerning the determination of the dependence of interface supercooling on the growth rate during Bi 4 Ge 3 O 12 single crystal growth from the melt are given. The supercooling measurement is based on determination of the thermal radiation intensity of the interface by an optical pyrometer through the growing crystal. Research was carried out during crystal growth in the direction [211]. A high value of supercooling and nonlinear character of its growth rate dependence have been found. The role of some sources of systematic errors in the supercooling measurements is discussed.