DYNAMIC-LIGHT-SCATTERING STUDY OF THE SOLID-LIQUID INTERFACE IN SUCCINONITRILE DURING GROWTH

The dynamic scattering of light by the crystal-melt interface of succinonitrile growing in a three-dimensional Bridgman setup is studied as a function of different control parameters. Strong scattering with an exponentially decaying autocorrelation function is observed during the solidification but not during the remelting. The angular dependence of the signal is characteristic of the diffusion of objects in the liquid. After pumping out gases dissolved in the liquid, we observe a striking decrease of the diffusion coefficient, up to two orders of magnitude. These results can be satisfactorily interpreted in the framework of the microbubble model recently proposed. © 1990 The American Physical Society.