Cargando…

Nature of excitations and defects in structural glasses

The nature of defects in amorphous materials, analogous to vacancies and dislocations in crystals, remains elusive. Here, we explore their nature in a three-dimensional microscopic model glass-former that describes granular, colloidal, atomic and molecular glasses by changing the temperature and den...

Descripción completa

Detalles Bibliográficos
Autores principales: Scalliet, Camille, Berthier, Ludovic, Zamponi, Francesco
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group UK 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6841723/
https://www.ncbi.nlm.nih.gov/pubmed/31704936
http://dx.doi.org/10.1038/s41467-019-13010-x
_version_ 1783467952322904064
author Scalliet, Camille
Berthier, Ludovic
Zamponi, Francesco
author_facet Scalliet, Camille
Berthier, Ludovic
Zamponi, Francesco
author_sort Scalliet, Camille
collection PubMed
description The nature of defects in amorphous materials, analogous to vacancies and dislocations in crystals, remains elusive. Here, we explore their nature in a three-dimensional microscopic model glass-former that describes granular, colloidal, atomic and molecular glasses by changing the temperature and density. We find that all glasses evolve in a very rough energy landscape, with a hierarchy of barrier sizes corresponding to both localized and delocalized excitations. Collective excitations dominate in the jamming regime relevant for granular and colloidal glasses. By moving gradually to larger densities describing atomic and molecular glasses, the system crosses over to a regime dominated by localized defects and relatively simpler landscapes. We quantify the energy and temperature scales associated to these defects and their evolution with density. Our results pave the way to a systematic study of low-temperature physics in a broad range of physical conditions and glassy materials.
format Online
Article
Text
id pubmed-6841723
institution National Center for Biotechnology Information
language English
publishDate 2019
publisher Nature Publishing Group UK
record_format MEDLINE/PubMed
spelling pubmed-68417232019-11-13 Nature of excitations and defects in structural glasses Scalliet, Camille Berthier, Ludovic Zamponi, Francesco Nat Commun Article The nature of defects in amorphous materials, analogous to vacancies and dislocations in crystals, remains elusive. Here, we explore their nature in a three-dimensional microscopic model glass-former that describes granular, colloidal, atomic and molecular glasses by changing the temperature and density. We find that all glasses evolve in a very rough energy landscape, with a hierarchy of barrier sizes corresponding to both localized and delocalized excitations. Collective excitations dominate in the jamming regime relevant for granular and colloidal glasses. By moving gradually to larger densities describing atomic and molecular glasses, the system crosses over to a regime dominated by localized defects and relatively simpler landscapes. We quantify the energy and temperature scales associated to these defects and their evolution with density. Our results pave the way to a systematic study of low-temperature physics in a broad range of physical conditions and glassy materials. Nature Publishing Group UK 2019-11-08 /pmc/articles/PMC6841723/ /pubmed/31704936 http://dx.doi.org/10.1038/s41467-019-13010-x Text en © The Author(s) 2019 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.
spellingShingle Article
Scalliet, Camille
Berthier, Ludovic
Zamponi, Francesco
Nature of excitations and defects in structural glasses
title Nature of excitations and defects in structural glasses
title_full Nature of excitations and defects in structural glasses
title_fullStr Nature of excitations and defects in structural glasses
title_full_unstemmed Nature of excitations and defects in structural glasses
title_short Nature of excitations and defects in structural glasses
title_sort nature of excitations and defects in structural glasses
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6841723/
https://www.ncbi.nlm.nih.gov/pubmed/31704936
http://dx.doi.org/10.1038/s41467-019-13010-x
work_keys_str_mv AT scallietcamille natureofexcitationsanddefectsinstructuralglasses
AT berthierludovic natureofexcitationsanddefectsinstructuralglasses
AT zamponifrancesco natureofexcitationsanddefectsinstructuralglasses