A theory for the beta-relaxation process near the liquid-to-glass crossover

Fuchs, Matthias; Götze, Wolfgang; Hildebrand, S.; Latz, Arnulf

A theory for the beta-relaxation process near the liquid-to-glass crossover

Dateien

a_theory_for_the_beta_relaxation_process.pdfGröße: 1.54 MBDownloads: 621

Datum

1992

Autor:innen

Fuchs, Matthias

Götze, Wolfgang

Hildebrand, S.

Latz, Arnulf

Open Access-Veröffentlichung

Open Access Green

Sammlungen

Physik

Publikationstyp

Zeitschriftenartikel

Publikationsstatus

Published

Erschienen in

Journal of Physics: Condensed Matter. 1992, 4, pp. 7709-7744. Available under: doi: 10.1088/0953-8984/4/38/007

Zusammenfassung

The mode coupling theory for supercooled liquid dynamics finds a beta-relaxation regime on mesoscopic timeseales. It is caused by the interplay between nonlinear interadions of density fluctuations and phonon-assisted hopping transport. In this regime all correlation functions and spectra can be expressed in terms of a single ß-correlator G, which is a homogeneous function of lime and two relevant control parameters. It is specified by a single number, namely the exponent parameter. Eight regions can be identified, where the equation for G can be solved by series expansions. The various possibilities are discussed in comparison with representative numerical solutions. For temperatures T sufficiently above the critical value Tc hopping effects can be neglected and a stretched susceptibility minimum is found as a crossover from von Sehweidler decay to critical decay. For T near Tc hopping effects balance the cage effect and this results on logarithmic scales in a rather abrupt crossover from the high-frequency delta-peak tail to the critical spectrum. For T telow Tc there appears a frequency window between two knees in the susceptibility spectrum, where hopping effects suppress the enhanced fractal spectra. There occurs a crossover from Debye relaxation to white noise. The resulting susceptibility minimum in the strongly supercooled state exhibits a subtle power law dependence on the separation parameter T - Tc. The measurable features in the susceptibilily, such as position and strength of the minimum, are evaluated and shown to characterize transparently the liquid-to-glass crossover as caused by the underlying glass transition singularity.

Fachgebiet (DDC)

530 Physik

Zitieren

ISO 690

FUCHS, Matthias, Wolfgang GÖTZE, S. HILDEBRAND, Arnulf LATZ, 1992. A theory for the beta-relaxation process near the liquid-to-glass crossover. In: Journal of Physics: Condensed Matter. 1992, 4, pp. 7709-7744. Available under: doi: 10.1088/0953-8984/4/38/007

BibTex

@article{Fuchs1992theor-5178,
  year={1992},
  doi={10.1088/0953-8984/4/38/007},
  title={A theory for the beta-relaxation process near the liquid-to-glass crossover},
  volume={4},
  journal={Journal of Physics: Condensed Matter},
  pages={7709--7744},
  author={Fuchs, Matthias and Götze, Wolfgang and Hildebrand, S. and Latz, Arnulf}
}

RDF

<rdf:RDF
    xmlns:dcterms="http://purl.org/dc/terms/"
    xmlns:dc="http://purl.org/dc/elements/1.1/"
    xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
    xmlns:bibo="http://purl.org/ontology/bibo/"
    xmlns:dspace="http://digital-repositories.org/ontologies/dspace/0.1.0#"
    xmlns:foaf="http://xmlns.com/foaf/0.1/"
    xmlns:void="http://rdfs.org/ns/void#"
    xmlns:xsd="http://www.w3.org/2001/XMLSchema#" > 
  <rdf:Description rdf:about="https://kops.uni-konstanz.de/server/rdf/resource/123456789/5178">
    <dc:creator>Fuchs, Matthias</dc:creator>
    <dcterms:bibliographicCitation>First publ. in: Journal of Physics: Condensed Matter  4 (1992), pp. 7709-7744</dcterms:bibliographicCitation>
    <dcterms:hasPart rdf:resource="https://kops.uni-konstanz.de/bitstream/123456789/5178/1/a_theory_for_the_beta_relaxation_process.pdf"/>
    <dc:date rdf:datatype="http://www.w3.org/2001/XMLSchema#dateTime">2011-03-24T14:53:47Z</dc:date>
    <dcterms:isPartOf rdf:resource="https://kops.uni-konstanz.de/server/rdf/resource/123456789/41"/>
    <dc:contributor>Fuchs, Matthias</dc:contributor>
    <dc:creator>Latz, Arnulf</dc:creator>
    <dcterms:issued>1992</dcterms:issued>
    <dcterms:abstract xml:lang="eng">The mode coupling theory for supercooled liquid dynamics finds a beta-relaxation regime on mesoscopic timeseales. It is caused by the interplay between nonlinear interadions of density fluctuations and phonon-assisted hopping transport. In this regime all correlation functions and spectra can be expressed in terms of a single ß-correlator G, which is a homogeneous function of lime and two relevant control parameters. It is specified by a single number, namely the exponent parameter. Eight regions can be identified, where the equation for G can be solved by series expansions. The various possibilities are discussed in comparison with representative numerical solutions. For temperatures T sufficiently above the critical value Tc hopping effects can be neglected and a stretched susceptibility minimum is found as a crossover from von Sehweidler decay to critical decay. For T near Tc hopping effects balance the cage effect and this results on logarithmic scales in a rather abrupt crossover from the high-frequency delta-peak tail to the critical spectrum. For T telow Tc there appears a frequency window between two knees in the susceptibility spectrum, where hopping effects suppress the enhanced fractal spectra. There occurs a crossover from Debye relaxation to white noise. The resulting susceptibility minimum in the strongly supercooled state exhibits a subtle power law dependence on the separation parameter T - Tc. The measurable features in the susceptibilily, such as position and strength of the minimum, are evaluated and shown to characterize transparently the liquid-to-glass crossover as caused by the underlying glass transition singularity.</dcterms:abstract>
    <dc:rights>Attribution-NonCommercial-NoDerivs 2.0 Generic</dc:rights>
    <dc:format>application/pdf</dc:format>
    <dc:contributor>Hildebrand, S.</dc:contributor>
    <dcterms:rights rdf:resource="http://creativecommons.org/licenses/by-nc-nd/2.0/"/>
    <dspace:isPartOfCollection rdf:resource="https://kops.uni-konstanz.de/server/rdf/resource/123456789/41"/>
    <dcterms:available rdf:datatype="http://www.w3.org/2001/XMLSchema#dateTime">2011-03-24T14:53:47Z</dcterms:available>
    <dc:language>eng</dc:language>
    <dc:contributor>Götze, Wolfgang</dc:contributor>
    <dcterms:title>A theory for the beta-relaxation process near the liquid-to-glass crossover</dcterms:title>
    <dc:contributor>Latz, Arnulf</dc:contributor>
    <dc:creator>Hildebrand, S.</dc:creator>
    <dc:creator>Götze, Wolfgang</dc:creator>
    <dspace:hasBitstream rdf:resource="https://kops.uni-konstanz.de/bitstream/123456789/5178/1/a_theory_for_the_beta_relaxation_process.pdf"/>
    <bibo:uri rdf:resource="http://kops.uni-konstanz.de/handle/123456789/5178"/>
    <void:sparqlEndpoint rdf:resource="http://localhost/fuseki/dspace/sparql"/>
    <foaf:homepage rdf:resource="http://localhost:8080/"/>
  </rdf:Description>
</rdf:RDF>

Universitätsbibliographie

Nein