Font Size:
Excess wing physics and nearly constant loss in glasses
Last modified: 2023-05-14
Abstract
Title
Excess wing physics and nearly constant loss in glasses
Author:
R. Hilfer
Affiliation:
Institute for Computational Physics
Universität Stuttgart
Allmandring 3
70569 Stuttgart
Germany
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
fast beta-processes, emergent Debye peaks, and the relaxation strength
of the boson peak [1]. Mathematically, the theory is based on
determining the domains of fractional differential and integral
operators precisely [2]. 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
doi.org/10.1088/1742-5468/ab38bc
[2] T. Kleiner and R. Hilfer, Analysis and Math. Physics (2021) 11:130
doi.org/10.1007/s13324-021-00504-5
Excess wing physics and nearly constant loss in glasses
Author:
R. Hilfer
Affiliation:
Institute for Computational Physics
Universität Stuttgart
Allmandring 3
70569 Stuttgart
Germany
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
fast beta-processes, emergent Debye peaks, and the relaxation strength
of the boson peak [1]. Mathematically, the theory is based on
determining the domains of fractional differential and integral
operators precisely [2]. 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
doi.org/10.1088/1742-5468/ab38bc
[2] T. Kleiner and R. Hilfer, Analysis and Math. Physics (2021) 11:130
doi.org/10.1007/s13324-021-00504-5