Temperature dependence of thermal diffusion in lithium borate melts from light scattering data
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It has been established that a constant temperature gradient increases the intensity of light scattering by lithium borate melts containing 1.2 and 1.6 mol % Li2O. It has been shown that the change of the light scattering intensity is characterized by some general regularities that are in accord with the predictions of the theory of light scattering by liquids in an inhomogeneous temperature field. Using the obtained experimental data and the conclusions of this theory, the thermal diffusion coefficients have been determined and the temperature coefficients of the diffusion process have been calculated. It has been found that the mass thermal diffusion coefficients of the studied melts almost coincide in magnitude, and the thermal coefficients of the diffusion processes are close to the activation energy of the viscous flow of boron oxide. The obtained results indicate the applicability of the light scattering method for determination of the thermal diffusion coefficients in oxide melts.
Keywordslight scattering glassforming lithium borate melts thermal diffusion fluctuation
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- 3.Sengers, J.V., Gammon, R.W., and Ortiz de Zárate, J.M., Thermal-Diffusion Driven Concentration Fluctuations in a Polymer Solution, in Computational Studies, Nanotechnology, and Solution Thermodynamics of Polymer Systems, Dadmun, M., Noid, D., Sumpter, B., and Melnichenko, Y., Eds., New York: Kluwer, 2000, pp. 37–44.Google Scholar
- 4.Sengers, J.V. and Ortiz de Zárate, J.M., in Nonequilibrium Concentration Fluctuations in Binary Liquid Systems Induced by Soret Effect, Köhler, W. and Viegand, S., Eds., Berlin: Springer-Verlag, 2002, LNP 584, pp. 121–145.Google Scholar
- 6.Bokov, N.A., Andreev, N.S., and Shakhmatkin, B.A., Light Scattering Investigation of the Fluctuations in Melts of Alkali Borate Glasses, Fiz. Khim. Stekla, 1989, vol. 15, no. 6, pp. 832–837.Google Scholar