Depolarized-light-scattering study of orthoterphenyl and comparison with the mode-coupling model
Authors:
- W. Steffen,
- Adam Patkowski,
- H. Gläser,
- G. Meier,
- E.W. Fischer
Abstract
The dynamics of the molecular glass-forming liquid orthoterphenyl above the glass-transition temperature was studied combining several experimental techniques: depolarized Raman, depolarized Rayleigh-Brillouin light scattering, and photon correlation spectroscopy in the temperature range from 250 to 440 K. The combined spectra covering a frequency range from 10-2 to 1013 Hz were analyzed using the mode-coupling theory. The coordinates of the susceptibility minimum, ωmin and χmin, as well as the position of the maximum, ωmax (α peak), scale with temperature according to the mode-coupling theory, resulting in Tc=290 K. The construction of the predicted master curve in the vicinity of the minimum of the rescaled susceptibility was possible in a narrow frequency range only if the values of ωmin resulting from the mode-coupling-theory force fit were used. The width of the α peak appears to increase with increasing temperatures for temperatures above Tc, although when the effects of fast processes on the high-frequency wing are included, the corrected width appears to decrease instead approaching a Debye relaxation shape at high temperatures. Below Tc it was not possible to fit objectively the data using the mode-coupling theory; thus it was impossible to corroborate the divergence of the scaling time of the mode-coupling β relaxation on both sides of Tc. Assuming a priori that the mode-coupling model is correct, it is possible to make the data compatible with the mode-coupling theory. © 1994 The American Physical Society.
- Record ID
- UAM9c2230b0d9294dfd8c3f71cf235e2fa6
- Author
- Journal series
- Physical Review E - Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics, ISSN 1063-651X
- Issue year
- 1994
- Vol
- 49
- Pages
- 2992-3002
- ASJC Classification
- ; ; ;
- DOI
- DOI:10.1103/PhysRevE.49.2992 Opening in a new tab
- Language
- (en) English
- Score (nominal)
- 0
- Score source
- journalList
- Publication indicators
- = 139; = 139
- Uniform Resource Identifier
- https://researchportal.amu.edu.pl/info/article/UAM9c2230b0d9294dfd8c3f71cf235e2fa6/
- URN
urn:amu-prod:UAM9c2230b0d9294dfd8c3f71cf235e2fa6
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