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arXiv · 1204.6190

From boiling point to glass transition temperature: transport coefficients in molecular liquids follow three-parameter scaling

B. Schmidtke·N. Petzold·R. Kahlau·M. Hofmann·E. A. Rossler
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Abstract

The phenomenon of the glass transition is an unresolved problem of condensed matter physics. Its prominent feature, the super-Arrhenius temperature dependence of the transport coefficients remains a challenge to be described over the full temperature range. For a series of molecular glass formers, we combined tau(T) from dielectric spectroscopy and dynamic light scattering covering the range 10_-12 s < tau(T) < 10^2s. Describing the dynamics in terms of an activation energy E(T), we distinguish a high-temperature regime characterized by an Arrhenius law with a constant activation energy E_inf and a low-temperature regime for which E_coop(T):= E(T) - E_inf increases while cooling. A two-parameter scaling is introduced, specifically E_coop(T)/E_inf = f[lambda(T/T_A -1)], where f is an exponential function, lambda a dimensionless parameter, and T_A a reference temperature proportional to E_inf. In order to describe tau(T), in addition, the attempt time tau_inf has to be specified. Thus, a single interaction parameter E_inf extracted from the high-temperature regime together with lambda controls the temperature dependence of low-temperature cooperative dynamics.

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B. Schmidtke, N. Petzold, R. Kahlau, M. Hofmann, E. A. Rossler. 2012-04-27. From boiling point to glass transition temperature: transport coefficients in molecular liquids follow three-parameter scaling. https://doi.org/10.1103/physreve.86.041507

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