Density-temperature scaling of the fragility in a model glass-former

Thomas Schrøder, Shiladitya Sengupta, Srikanth Sastry

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

Resumé

Dynamical quantities e.g. diffusivity and relaxation time for some glass-formers may depend on density and temperature through a specific combination, rather than independently, allowing the representation of data over ranges of density and temperature as a function of a single scaling variable. Such a scaling, referred to as density-temperature (DT) scaling, is exact for liquids with inverse power law (IPL) interactions but has also been found to be approximately valid in many non-IPL liquids. We have analyzed the consequences of DT scaling on the density dependence of the fragility in a model glass-former. We find the density dependence of kinetic fragility to be weak, and show that it can be understood in terms of DT scaling and deviations of DT scaling at low densities. We also show that the Adam-Gibbs relation exhibits DT scaling and the scaling exponent computed from the density dependence of the activation free energy in the Adam-Gibbs relation, is consistent with the exponent values obtained by other means.
OriginalsprogEngelsk
Artikelnummer141
TidsskriftJournal of Chemical Physics
Vol/bind36
Udgave nummer12
ISSN0021-9606
DOI
StatusUdgivet - 19 dec. 2013

Emneord

  • forming liquids
  • molecular-dynamics
  • glassforming liquids
  • supercooled liquids
  • correlation length
  • relaxation
  • polymers
  • dependence
  • pressure
  • transition

Citer dette

Schrøder, Thomas ; Sengupta, Shiladitya ; Sastry, Srikanth. / Density-temperature scaling of the fragility in a model glass-former. I: Journal of Chemical Physics. 2013 ; Bind 36, Nr. 12.
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Density-temperature scaling of the fragility in a model glass-former. / Schrøder, Thomas; Sengupta, Shiladitya; Sastry, Srikanth.

I: Journal of Chemical Physics, Bind 36, Nr. 12, 141, 19.12.2013.

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

TY - JOUR

T1 - Density-temperature scaling of the fragility in a model glass-former

AU - Schrøder, Thomas

AU - Sengupta, Shiladitya

AU - Sastry, Srikanth

PY - 2013/12/19

Y1 - 2013/12/19

N2 - Dynamical quantities e.g. diffusivity and relaxation time for some glass-formers may depend on density and temperature through a specific combination, rather than independently, allowing the representation of data over ranges of density and temperature as a function of a single scaling variable. Such a scaling, referred to as density-temperature (DT) scaling, is exact for liquids with inverse power law (IPL) interactions but has also been found to be approximately valid in many non-IPL liquids. We have analyzed the consequences of DT scaling on the density dependence of the fragility in a model glass-former. We find the density dependence of kinetic fragility to be weak, and show that it can be understood in terms of DT scaling and deviations of DT scaling at low densities. We also show that the Adam-Gibbs relation exhibits DT scaling and the scaling exponent computed from the density dependence of the activation free energy in the Adam-Gibbs relation, is consistent with the exponent values obtained by other means.

AB - Dynamical quantities e.g. diffusivity and relaxation time for some glass-formers may depend on density and temperature through a specific combination, rather than independently, allowing the representation of data over ranges of density and temperature as a function of a single scaling variable. Such a scaling, referred to as density-temperature (DT) scaling, is exact for liquids with inverse power law (IPL) interactions but has also been found to be approximately valid in many non-IPL liquids. We have analyzed the consequences of DT scaling on the density dependence of the fragility in a model glass-former. We find the density dependence of kinetic fragility to be weak, and show that it can be understood in terms of DT scaling and deviations of DT scaling at low densities. We also show that the Adam-Gibbs relation exhibits DT scaling and the scaling exponent computed from the density dependence of the activation free energy in the Adam-Gibbs relation, is consistent with the exponent values obtained by other means.

KW - forming liquids

KW - molecular-dynamics

KW - glassforming liquids

KW - supercooled liquids

KW - correlation length

KW - relaxation

KW - polymers

KW - dependence

KW - pressure

KW - transition

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