| Autor: |
Iwanowski, I., Sattarow, A., Behrends, R., Mirzaev, S. Z., Kaatze, U. |
| Předmět: |
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| Zdroj: |
Journal of Chemical Physics; 4/14/2006, Vol. 124 Issue 14, p144505, 7p, 8 Graphs |
| Abstrakt: |
Acoustical attenuation spectrometry, dynamic light scattering, shear viscosity, density, and heat capacity measurements of the methanol/n-hexane mixture of critical composition have been performed. The critical part in the sonic attenuation coefficients nicely fits to the empirical scaling function of the Bhattacharjee-Ferrell [Phys. Rev. A 24, 1643 (1981)] dynamic scaling model if the theoretically predicted scaled half-attenuation frequency Ω1/2BF=2.1 is used. The relaxation rates of order parameter fluctuations, as resulting from the acoustical spectra, within the limits of experimental error agree with those from a combined evaluation of the light scattering and shear viscosity measurements. Both series of data display power law with amplitude Γ0=44×109 s-1. The amplitude of the fluctuation correlation length follows as ξ0=0.33 nm from the light scattering data and as ξ0=0.32 nm from the amplitude of the singular part of the heat capacity if the two-scale factor universality relation is used. The adiabatic coupling constant g=0.11 results from the amplitude of the critical contribution to the acoustical spectrum near the critical point, in conformity with g=0.12 as following from the variation of the critical temperature with pressure along the critical line and the thermal expansion coefficient. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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