Slow dynamics of salol: a pressure- and temperature-dependent light scattering study.
We study the slow dynamics of salol by varying both temperature and pressure using photon correlation spectroscopy and pressure-volume-temperature measurements, and compare the behavior of the structural relaxation time with equations derived within the Adam-Gibbs entropy theory and the Cohen-Grest free volume theory. We find that pressure-dependent data are crucial to assess the validity of these model equations. Our analysis supports the entropy-based equation, and estimates the configurational entropy of salol at ambient pressure approximately 70% of the excess entropy. Finally, we investigate the evolution of the shape of the structural relaxation process, and find that a time-temperature-pressure superposition principle holds over the range investigated.
Dipartimento di Fisica and INFM, Università di Perugia, I-06123, Perugia, Italy.
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Comez
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Corezzi
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Fioretto
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Kriegs
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Best
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Steffen