Last modified: 2023-06-29
Abstract
Excess wings and nearly constant loss are almost universal
nonequilibrium phenomena in glass formers. Both lack an accepted
theoretical foundation. A model-free and unified theoretical
description for these phenomena is presented that encompasses also
addition fast beta-processes, emergent Debye peaks, and the relaxation
strength of the boson peak [1]. The theory is model-free in the same
way as the classical Debye theory for orientational polarisation. It
is based on generalizing time flow from translation semigroups to
composite time translation-convolution semigroups. Composite
translation-convolution fits have less parameters than traditional
fits. They need only one dynamic scaling exponent, while four are
needed in Havriliak-Negami fits. For glycerol the single dynamic
exponent in the translation-convolution fit is found to be
temperature-independent.
[1] R. Hilfer, J. Stat. Mech. (2019) 104007
https://doi.org/10.1088/1742-5468/ab38bc