Atomistic mechanisms of dynamics in a two-dimensional dodecagonal quasicrystal

Fuente: arXiv
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Autori principali: Zhao, Kun, Baggioli, Matteo, Xu, Wen-Sheng, Douglas, Jack F., Wang, Yun-Jiang
Natura: Preprint
Pubblicazione: 2024
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author Zhao, Kun
Baggioli, Matteo
Xu, Wen-Sheng
Douglas, Jack F.
Wang, Yun-Jiang
author_facet Zhao, Kun
Baggioli, Matteo
Xu, Wen-Sheng
Douglas, Jack F.
Wang, Yun-Jiang
contents Quasicrystals have been observed in a variety of materials ranging from metal alloys to block copolymers. However, their structural and dynamical properties cannot be readily described in terms of conventional solid-state models of liquids and solids. We may expect the dynamics of this specific class of quasicrystalline materials to be more like glass-forming liquids in the sense of exhibiting large fluctuations in the local mobility ("dynamic heterogeneity") and non-Arrhenius temperature dependence of relaxation and diffusion. In this work, we investigate a model dodecagonal quasicrystal material in two dimensions (2D) using molecular dynamics (MD) simulations, with a focus on heterogeneous dynamics and non-Arrhenius relaxation and diffusion. As observed in glass-forming liquids and heated crystals, we observe a two-stage relaxation dynamics in the self-intermediate scattering function $F_s(k,t)$ of our quasicrystal material. It involves a fast $β$-relaxation and $α$ relaxation process having a highly temperature dependent relaxation time whose activation energy varies in concert with the extent of string-like collective motion, a phenomenon recognized to occur in glass-forming liquids at low temperatures and crystalline materials at elevated temperatures. After examining the dynamics of our dodecagonal quasicrystalline material in great detail, we conclude that the dynamics of these materials more closely resembles observations on metallic glass-forming liquids than crystalline materials.
format Preprint
id arxiv_https___arxiv_org_abs_2402_10295
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Atomistic mechanisms of dynamics in a two-dimensional dodecagonal quasicrystal
Zhao, Kun
Baggioli, Matteo
Xu, Wen-Sheng
Douglas, Jack F.
Wang, Yun-Jiang
Materials Science
Soft Condensed Matter
Quasicrystals have been observed in a variety of materials ranging from metal alloys to block copolymers. However, their structural and dynamical properties cannot be readily described in terms of conventional solid-state models of liquids and solids. We may expect the dynamics of this specific class of quasicrystalline materials to be more like glass-forming liquids in the sense of exhibiting large fluctuations in the local mobility ("dynamic heterogeneity") and non-Arrhenius temperature dependence of relaxation and diffusion. In this work, we investigate a model dodecagonal quasicrystal material in two dimensions (2D) using molecular dynamics (MD) simulations, with a focus on heterogeneous dynamics and non-Arrhenius relaxation and diffusion. As observed in glass-forming liquids and heated crystals, we observe a two-stage relaxation dynamics in the self-intermediate scattering function $F_s(k,t)$ of our quasicrystal material. It involves a fast $β$-relaxation and $α$ relaxation process having a highly temperature dependent relaxation time whose activation energy varies in concert with the extent of string-like collective motion, a phenomenon recognized to occur in glass-forming liquids at low temperatures and crystalline materials at elevated temperatures. After examining the dynamics of our dodecagonal quasicrystalline material in great detail, we conclude that the dynamics of these materials more closely resembles observations on metallic glass-forming liquids than crystalline materials.
title Atomistic mechanisms of dynamics in a two-dimensional dodecagonal quasicrystal
topic Materials Science
Soft Condensed Matter
url https://arxiv.org/abs/2402.10295