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Transition vitreuse, hétérogénéité dynamique et vieillissement dans les systèmes a dynamique lente
(37) Production(s) de l'année 2023
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Creating bulk ultrastable glasses by random particle bonding 
Auteur(s): Ozawa M., Iwashita Yasutaka, Kob W., Zamponi Francesco
(Article) Publié:
Nature Communications, vol. 14 p.113 (2023)
Texte intégral en Openaccess : 
Ref HAL: hal-03929003_v1
PMID 36611023
Ref Arxiv: 2203.14604
DOI: 10.1038/s41467-023-35812-w
Ref. & Cit.: NASA ADS
Exporter : BibTex | endNote
Résumé: A recent breakthrough in glass science has been the synthesis of ultrastable glasses via physical vapor deposition techniques. These samples display enhanced thermodynamic, kinetic and mechanical stability, with important implications for fundamental science and technological applications. However, the vapor deposition technique is limited to atomic, polymer and organic glass-formers and is only able to produce thin film samples. Here, we propose a novel approach to generate ultrastable glassy configurations in the bulk, via random particle bonding, and using computer simulations we show that this method does indeed allow for the production of ultrastable glasses. Our technique is in principle applicable to any molecular or soft matter system, such as colloidal particles with tunable bonding interactions, thus opening the way to the design of a large class of ultrastable glasses.
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Microscopic observation of two-level systems in a metallic glass model
Auteur(s): Mocanu Felix, Berthier L., Ciarella Simone, Khomenko Dmytro, Reichman David, Scalliet C., Zamponi Francesco
(Article) Publié:
The Journal Of Chemical Physics, vol. 158 p.014501 (2023)
Texte intégral en Openaccess :
Ref HAL: hal-03920514_v1
Ref Arxiv: 2209.09579
DOI: 10.1063/5.0128820
Ref. & Cit.: NASA ADS
Exporter : BibTex | endNote
Résumé: The low-temperature quasi-universal behavior of amorphous solids has been attributed to the existence of spatially localized tunneling defects found in the low-energy regions of the potential energy landscape. Computational models of glasses can be studied to elucidate the microscopic nature of these defects. Recent simulation work has demonstrated the means of generating stable glassy configurations for models that mimic metallic glasses using the swap Monte Carlo algorithm. Building on these studies, we present an extensive exploration of the glassy metabasins of the potential energy landscape of a variant of the most widely used model of metallic glasses. We carefully identify tunneling defects and reveal their depletion with increased glass stability. The density of tunneling defects near the experimental glass transition temperature appears to be in good agreement with experimental measurements.
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