DETERMINATION OF TIME CHARACTERISTICS OF SOLIDIFICATION OF
P. Deom1,2, A.M. Sveshnikov1, K. Nitsch1, M. Rodová1 and Z. Kozíšek1
SUPERCOOLED HALIDE MELT FROM MEASUREMENTS OF ITS ELECTRICAL CONDUCTIVITY
1 Institute of Physics, Academy of Sciences of the Czech Republic,
Cukrovarnická 10, 162 53 Praha, 6, Chech Republic
2 Chech Technical University in Prague, Faculty of Civil Engineering,
Dept. of Physics, Thákurova 7, 166 29 Praha, 6, Chech Republic
Origin of supercoolability in metallic and halide melts is discussed.
While the level of supercooling in metals is closely connected with the structural
incompatibilities between the molten state and product crystal, respectively, the
supercoolability of halide melts is caused by their strong complex-forming nature.
The investigation of processes in supercooled melts is important, because the
supercooling of melt strongly influences the nucleation and growth of crystals from
the melt and their final quality. Electrical resistance is a suitable quantity to
study the solidification of melts, since it can be measured both in liquid state
(including supercooled melt) and during the solidification. The early stage of
solidification of PbBr2 melt was analyzed within the context of nonstationary
nucleation theory. The proposed model describes the time dependence of electrical
conductivity of the melt. The time lag of nucleation is calculated and compared with
the experimental value.
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