Duration of nucleation process in supercooled halide melts.
We present a model allowing to estimate the so-called time lag of nucleating halide melts using electrical conductivity measurements. Due to the complex-forming nature of molten halide salts we suppose two basic types of charge carriers in the melt: complexes (playing the role of monomers-building units) and clusters of a newly forming solid phase. Within context of the nonstationary nucleation theory we determined a formula expressing the time dependency of electrical conductivity of such a system and compared this result with the experimental data obtained for the melts of PbBr2, PbCl2, and KPb2Cl5. In terms of this formula the time lag of nucleation may be estimated. This important quantity characterizing the moment from which the nucleated clusters only grow to the macroscopic sizes has been found to be approximately 75% of the total duration of the nucleation process itself.
Demo
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Institute of Physics, Academy of Sciences of the Czech Republic, Cukrovarnická 10, 162 53 Praha 6, Czech Republic. demo@fzu.cz
Sveshnikov
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Nitsch
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Rodová
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M
Kozísek
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