Confinement Effects on the Spatially Inhomogeneous Dynamics in Metallic Glass Films

This work develops the elastically collective nonlinear Langevin equation theory to investigate, for the first time, the glassy dynamics in capped metallic glass thin films. Finite-size effects on the spatial gradient of structural relaxation time and glass transition temperature (Tg) are calculated...

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Main Author: Anh D. Phan
Format: Bài trích
Language:English
Published: ACS Publications 2022
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Online Access:https://pubs.acs.org/doi/10.1021/acs.jpcb.1c08862
https://dlib.phenikaa-uni.edu.vn/handle/PNK/5894
https://doi.org/10.1021/acs.jpcb.1c08862
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spelling oai:localhost:PNK-58942022-08-17T05:54:55Z Confinement Effects on the Spatially Inhomogeneous Dynamics in Metallic Glass Films Anh D. Phan Spatially Inhomogeneous Chemical This work develops the elastically collective nonlinear Langevin equation theory to investigate, for the first time, the glassy dynamics in capped metallic glass thin films. Finite-size effects on the spatial gradient of structural relaxation time and glass transition temperature (Tg) are calculated at different temperatures and vitrification criteria. Molecular dynamics is significantly slowed down near rough solid surfaces, and the dynamics at location far from the interfaces is sped up. In thick films, the mobility gradient normalized by the bulk value obeys the double-exponential form since interference effects between two surfaces are weak. Reducing the film thickness induces a strong dynamic coupling between two surfaces and flattens the relaxation gradient. The normalized gradient of the glass transition temperature is independent of vitrification time scale criterion and can be fitted by a superposition function as the films are not ultrathin. The local fragility is found to remain unchanged with location. This finding suggests that one can use Angell plots of bulk relaxation time and the Tg spatial gradient to characterize glassy dynamics in metallic glass films. Our computational results agree well with experimental data and simulation 2022-07-13T01:59:50Z 2022-07-13T01:59:50Z 2022 Bài trích https://pubs.acs.org/doi/10.1021/acs.jpcb.1c08862 https://dlib.phenikaa-uni.edu.vn/handle/PNK/5894 https://doi.org/10.1021/acs.jpcb.1c08862 en ACS Publications
institution Digital Phenikaa
collection Digital Phenikaa
language English
topic Spatially Inhomogeneous
Chemical
spellingShingle Spatially Inhomogeneous
Chemical
Anh D. Phan
Confinement Effects on the Spatially Inhomogeneous Dynamics in Metallic Glass Films
description This work develops the elastically collective nonlinear Langevin equation theory to investigate, for the first time, the glassy dynamics in capped metallic glass thin films. Finite-size effects on the spatial gradient of structural relaxation time and glass transition temperature (Tg) are calculated at different temperatures and vitrification criteria. Molecular dynamics is significantly slowed down near rough solid surfaces, and the dynamics at location far from the interfaces is sped up. In thick films, the mobility gradient normalized by the bulk value obeys the double-exponential form since interference effects between two surfaces are weak. Reducing the film thickness induces a strong dynamic coupling between two surfaces and flattens the relaxation gradient. The normalized gradient of the glass transition temperature is independent of vitrification time scale criterion and can be fitted by a superposition function as the films are not ultrathin. The local fragility is found to remain unchanged with location. This finding suggests that one can use Angell plots of bulk relaxation time and the Tg spatial gradient to characterize glassy dynamics in metallic glass films. Our computational results agree well with experimental data and simulation
format Bài trích
author Anh D. Phan
author_facet Anh D. Phan
author_sort Anh D. Phan
title Confinement Effects on the Spatially Inhomogeneous Dynamics in Metallic Glass Films
title_short Confinement Effects on the Spatially Inhomogeneous Dynamics in Metallic Glass Films
title_full Confinement Effects on the Spatially Inhomogeneous Dynamics in Metallic Glass Films
title_fullStr Confinement Effects on the Spatially Inhomogeneous Dynamics in Metallic Glass Films
title_full_unstemmed Confinement Effects on the Spatially Inhomogeneous Dynamics in Metallic Glass Films
title_sort confinement effects on the spatially inhomogeneous dynamics in metallic glass films
publisher ACS Publications
publishDate 2022
url https://pubs.acs.org/doi/10.1021/acs.jpcb.1c08862
https://dlib.phenikaa-uni.edu.vn/handle/PNK/5894
https://doi.org/10.1021/acs.jpcb.1c08862
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score 8.887929