Brillouin spectral line shapes of n-pentanol have been measured from -75.5°C (close to the melting point) up to 115°C (close to the boiling point) using a grating monochromator. The instrument, owing to its very high resolution, contrast, and free spectral range, has been preferred to the usually employed Fabry-Perot interferometer. The spectra, fitted with a single relaxation generalized hydrodynamic theory, support the existence of a high frequency relaxation process with an activation energy of about 9 KJ/mol. This relaxation process, which should be related to isomeric rotational relaxation, is well separated at low temperature from the structural relaxation observed at lower frequencies in ultrasonic experiments.
ASJC Scopus subject areas
- Physics and Astronomy(all)
- Physical and Theoretical Chemistry