On the dependence of the surface tension at the crystal-melt interface on the impurity concentration
| Autor: | S. V. Barannik, V. N. Kanishchev |
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| Rok vydání: | 2009 |
| Předmět: | |
| Zdroj: | Crystallography Reports. 54:702-706 |
| ISSN: | 1562-689X 1063-7745 |
| DOI: | 10.1134/s1063774509040270 |
| Popis: | The stationary task of impurity diffusion in a melt has been solved within a two-dimensional crystallization model in a second-order approximation with respect to the amplitude of deviation from a smooth crystallization front. The dependence of the surface tension Γ at the interface on the impurity concentration C is taken into account in the form Γ = Γ0 + ζ d C, where Γ0 and ζ d are constants. The variational method is used to obtain the condition for the transition from a smooth crystallization front to a cellular one. It is shown that calculated cell sizes are in agreement with the experimental data in the literature only when the parameter ζ d ≠ 0. For binary systems with distribution coefficients k 1, ζ d should be positive and negative, respectively. |
| Databáze: | OpenAIRE |
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