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Physique Statistique
(37) Production(s) de l'année 2019
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A new characteristic temperature for glassy dynamics
Auteur(s): Coslovich D.
Conférence invité: Viscous Liquids and the Glass Transition (XVI) (Holbaek, DK, 2019-05-09)
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Configurational entropy of glass-forming liquids
Auteur(s): Berthier L., Ozawa M., Scalliet C.
(Article) Publié:
The Journal Of Chemical Physics, vol. 150 p.160902 (2019)
Texte intégral en Openaccess :
Ref HAL: hal-02123889_v1
Ref Arxiv: 1902.07679
DOI: 10.1063/1.5091961
WoS: WOS:000466698700002
Ref. & Cit.: NASA ADS
Exporter : BibTex | endNote
13 Citations
Résumé: The configurational entropy is one of the most important thermodynamic quantities characterizing supercooled liquids approaching the glass transition. Despite decades of experimental, theoretical, and computational investigation, a widely accepted definition of the configurational entropy is missing, its quantitative characterization remains fraud with difficulties, misconceptions and paradoxes, and its physical relevance is vividly debated. Motivated by recent computational progress, we offer a pedagogical perspective on the configurational entropy in glass-forming liquids. We first explain why the configurational entropy has become a key quantity to describe glassy materials, from early empirical observations to modern theoretical treatments. We explain why practical measurements necessarily require approximations that make its physical interpretation delicate. We then demonstrate that computer simulations have become an invaluable tool to obtain precise, non-ambiguous, and experimentally-relevant measurements of the configurational entropy. We describe a panel of available computational tools, offering for each method a critical discussion. This perspective should be useful to both experimentalists and theoreticians interested in glassy materials and complex systems.
Commentaires: 20 pages, 11 figures, submitted to the Journal of Chemical Physics. Réf Journal: J. Chem. Phys. 150, 160902 (2019)
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New interaction potentials for alkali and alkaline-earth aluminosilicate glasses
Auteur(s): Sundararaman Siddharth, Huang Liping, Ispas S., Kob W.
(Article) Publié:
The Journal Of Chemical Physics, vol. 150 p.154505 (2019)
Texte intégral en Openaccess :
Ref HAL: hal-02121330_v1
DOI: 10.1063/1.5079663
WoS: 000465442100042
Exporter : BibTex | endNote
7 Citations
Résumé: We apply a recently developed optimization scheme to obtain effective potentials for alkali andalkaline-earth aluminosilicate glasses that contains lithium, sodium, potassium, or calcium asmodifiers. As input data for the optimization, we used the radial distribution functions of theliquid at high temperature generated by means of ab initio molecular dynamics simulations anddensity and elastic modulus of glass at room temperature from experiments. The new interactionpotentials are able to reproduce reliably the structure and various mechanical and vibrationalproperties over a wide range of compositions for binary silicates. We have tested these potentialsfor various ternary systems and find that they are transferable and can be mixed, thus allowing toreproduce and predict the structure and properties of multi-component glasses.
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Zero-temperature glass transition in two dimensions
Auteur(s): Berthier L., Charbonneau Patrick, Ninarello A. S., Ozawa M., Yaida Sho
(Article) Publié:
Nature Communications, vol. 10 p.1508 (2019)
Texte intégral en Openaccess :
Ref HAL: hal-02101358_v1
Ref Arxiv: 1805.09035
DOI: 10.1038/s41467-019-09512-3
WoS: 000463170600007
Ref. & Cit.: NASA ADS
Exporter : BibTex | endNote
16 Citations
Résumé: The nature of the glass transition is theoretically understood in the mean-field limit of infinite spatial dimensions, but the problem remains totally open in physical dimensions. Nontrivial finite-dimensional fluctuations are hard to control analytically, and experiments fail to provide conclusive evidence regarding the nature of the glass transition. Here, we use Monte Carlo simulations that fully bypass the glassy slowdown, and access equilibrium states in two-dimensional glass-forming liquids at low enough temperatures to directly probe the transition. We find that the liquid state terminates at a thermodynamic glass transition at zero temperature, which is associated with an entropy crisis and a diverging static correlation length.
Commentaires: 23 pages, 18 figures. Réf Journal: Nat. Commun. 10, 1508 (2019)
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