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arXiv · 1801.09272

On the breakdown of the simple Arrhenius law in the normal liquid state

Erik Thoms·Andrzej Grzybowski·Sebastian Pawlus·Marian Paluch
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Abstract

It is common practice to discuss the temperature effect on molecular dynamics of glass formers above the melting temperature in terms of the Arrhenius law. Using dielectric spectroscopy measurements of dc-conductivity and structural relaxation time on the example of the typical glass former propylene carbonate, we provide experimental evidence that this practice is not justified. Our conclusions are supported by employing thermodynamic density scaling and the occurrence of inflection points in isothermal dynamic data measured at elevated pressure. Additionally, we propose a more suitable approach to describe the dynamics both above and below the inflection point based upon a modified MYEGA model.

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Erik Thoms, Andrzej Grzybowski, Sebastian Pawlus, Marian Paluch. 2018-01-28. On the breakdown of the simple Arrhenius law in the normal liquid state. https://doi.org/10.1021/acs.jpclett.8b00583

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