The hydrodynamic behaviour in the GHz frequency region has been analzsed for the non-ideal CH3CN-CCl4 liquid mixture around the azeotropic composition. Rayleigh-Brillouin spectra have been measured as a function of temperature and composition, at fixed value of transferred wave vector in the 90° scattering geometry, and also at different scattering angles to study dispersion with frequency of the spectral observables. These measurements have been complemented by those of refractive index, density and viscosity at the same temperatures and mole fraction values. Very interesting behaviour of the classic Brillouin spectral observables, such as the hypersonic propagation speeds and the acoustic absorption coefficients, has been revealed near the azeotropic composition of the mixture at the investigated temperatures, namely 15°C, 25°C, 40°C and 60°C. These effects have been interpreted at the light of the Mountain and Deutch theory of binary solutions and the forecast behaviour of the intermolecular forces around the azeotropic point composition of these very different molecular liquids.
- Brillouin scattering
- Molecular liquids
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering