Rate exchange rather than relaxation controls structural recovery

Birte Riechers, Ranko Richert

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

We observe structural recovery after an electric field step by probing the dielectric loss profile near its maximum, which displays a field-induced shift towards lower frequencies. These dynamics display time aging-time superposition (TaTS) for the majority of relaxation modes, thus implying homogeneous recovery dynamics. Although assumed by generally accepted models, the same modes can not be responsible for structural relaxation and for structural recovery, as the former is heterogeneous and the latter is homogeneous regarding the nature of the dynamics. This conflict is resolved by proposing that structural recovery is governed by rate exchange, a process that refers to the homogeneous fluctuations of rate constants in equilibrium and restores ergodicity more slowly than the relaxation observed as a simple correlation decay. This recognition has wide-ranging consequences on how aging and nonlinear dynamics such as scanning calorimetry should be modeled.

Original languageEnglish (US)
Pages (from-to)32-37
Number of pages6
JournalPhysical Chemistry Chemical Physics
Volume21
Issue number1
DOIs
StatePublished - Jan 1 2019

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recovery
Recovery
Aging of materials
Structural relaxation
Calorimetry
Dielectric losses
dielectric loss
Rate constants
heat measurement
Electric fields
low frequencies
Scanning
scanning
electric fields
shift
decay
profiles

ASJC Scopus subject areas

  • Physics and Astronomy(all)
  • Physical and Theoretical Chemistry

Cite this

Rate exchange rather than relaxation controls structural recovery. / Riechers, Birte; Richert, Ranko.

In: Physical Chemistry Chemical Physics, Vol. 21, No. 1, 01.01.2019, p. 32-37.

Research output: Contribution to journalArticle

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