Diffusivity and short-time dynamics in two models of silica

Erik Lascaris, Mahin Hemmati, Sergey V. Buldyrev, H. Eugene Stanley, Charles Angell

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

We discuss the dynamic behavior of two silica models, the BKS model (by van Beest, Kramer, and van Santen) and the WAC model (by Woodcock, Angell, and Cheeseman). Although BKS is considered the more realistic model for liquid silica, the WAC model has the unique property that it is very close to having a liquid-liquid critical point (LLCP), and this makes it particularly useful in studying the dynamics of models that do have a LLCP. We find that the diffusivity is a good indicator of how close a liquid is to criticality - the Si diffusivity shows a jump of 3-4 orders of magnitude when the pressure is reduced, which may be interpreted as an abrupt (though not first-order) transition from a high-density liquid state to a low-density liquid state. We show that this transition is captured by the Adam-Gibbs relation, which also allows us to estimate the configurational entropy of the system.

Original languageEnglish (US)
Article number10506
JournalJournal of Chemical Physics
Volume142
Issue number10
DOIs
StatePublished - Mar 14 2015

Fingerprint

Silicon Dioxide
diffusivity
silicon dioxide
Liquids
liquids
trucks
critical point
Entropy
entropy
estimates

ASJC Scopus subject areas

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

Cite this

Lascaris, E., Hemmati, M., Buldyrev, S. V., Stanley, H. E., & Angell, C. (2015). Diffusivity and short-time dynamics in two models of silica. Journal of Chemical Physics, 142(10), [10506]. https://doi.org/10.1063/1.4913747

Diffusivity and short-time dynamics in two models of silica. / Lascaris, Erik; Hemmati, Mahin; Buldyrev, Sergey V.; Stanley, H. Eugene; Angell, Charles.

In: Journal of Chemical Physics, Vol. 142, No. 10, 10506, 14.03.2015.

Research output: Contribution to journalArticle

Lascaris, E, Hemmati, M, Buldyrev, SV, Stanley, HE & Angell, C 2015, 'Diffusivity and short-time dynamics in two models of silica', Journal of Chemical Physics, vol. 142, no. 10, 10506. https://doi.org/10.1063/1.4913747
Lascaris, Erik ; Hemmati, Mahin ; Buldyrev, Sergey V. ; Stanley, H. Eugene ; Angell, Charles. / Diffusivity and short-time dynamics in two models of silica. In: Journal of Chemical Physics. 2015 ; Vol. 142, No. 10.
@article{7f83ab4012774c138029f0c6c29f9155,
title = "Diffusivity and short-time dynamics in two models of silica",
abstract = "We discuss the dynamic behavior of two silica models, the BKS model (by van Beest, Kramer, and van Santen) and the WAC model (by Woodcock, Angell, and Cheeseman). Although BKS is considered the more realistic model for liquid silica, the WAC model has the unique property that it is very close to having a liquid-liquid critical point (LLCP), and this makes it particularly useful in studying the dynamics of models that do have a LLCP. We find that the diffusivity is a good indicator of how close a liquid is to criticality - the Si diffusivity shows a jump of 3-4 orders of magnitude when the pressure is reduced, which may be interpreted as an abrupt (though not first-order) transition from a high-density liquid state to a low-density liquid state. We show that this transition is captured by the Adam-Gibbs relation, which also allows us to estimate the configurational entropy of the system.",
author = "Erik Lascaris and Mahin Hemmati and Buldyrev, {Sergey V.} and Stanley, {H. Eugene} and Charles Angell",
year = "2015",
month = "3",
day = "14",
doi = "10.1063/1.4913747",
language = "English (US)",
volume = "142",
journal = "Journal of Chemical Physics",
issn = "0021-9606",
publisher = "American Institute of Physics Publising LLC",
number = "10",

}

TY - JOUR

T1 - Diffusivity and short-time dynamics in two models of silica

AU - Lascaris, Erik

AU - Hemmati, Mahin

AU - Buldyrev, Sergey V.

AU - Stanley, H. Eugene

AU - Angell, Charles

PY - 2015/3/14

Y1 - 2015/3/14

N2 - We discuss the dynamic behavior of two silica models, the BKS model (by van Beest, Kramer, and van Santen) and the WAC model (by Woodcock, Angell, and Cheeseman). Although BKS is considered the more realistic model for liquid silica, the WAC model has the unique property that it is very close to having a liquid-liquid critical point (LLCP), and this makes it particularly useful in studying the dynamics of models that do have a LLCP. We find that the diffusivity is a good indicator of how close a liquid is to criticality - the Si diffusivity shows a jump of 3-4 orders of magnitude when the pressure is reduced, which may be interpreted as an abrupt (though not first-order) transition from a high-density liquid state to a low-density liquid state. We show that this transition is captured by the Adam-Gibbs relation, which also allows us to estimate the configurational entropy of the system.

AB - We discuss the dynamic behavior of two silica models, the BKS model (by van Beest, Kramer, and van Santen) and the WAC model (by Woodcock, Angell, and Cheeseman). Although BKS is considered the more realistic model for liquid silica, the WAC model has the unique property that it is very close to having a liquid-liquid critical point (LLCP), and this makes it particularly useful in studying the dynamics of models that do have a LLCP. We find that the diffusivity is a good indicator of how close a liquid is to criticality - the Si diffusivity shows a jump of 3-4 orders of magnitude when the pressure is reduced, which may be interpreted as an abrupt (though not first-order) transition from a high-density liquid state to a low-density liquid state. We show that this transition is captured by the Adam-Gibbs relation, which also allows us to estimate the configurational entropy of the system.

UR - http://www.scopus.com/inward/record.url?scp=84924872333&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84924872333&partnerID=8YFLogxK

U2 - 10.1063/1.4913747

DO - 10.1063/1.4913747

M3 - Article

AN - SCOPUS:84924872333

VL - 142

JO - Journal of Chemical Physics

JF - Journal of Chemical Physics

SN - 0021-9606

IS - 10

M1 - 10506

ER -