Dynamics at the crystal-melt interface in a supercooled chalcogenide liquid near the glass transition
Dynamics at the crystal-melt interface in a supercooled chalcogenide liquid near the glass transition
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DOI：
10.1038/s41598-020-62783-5
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发表时间：
2020-04
影响因子：
4.6
通讯作者：
Jianheng Li;R. Jangid;Weidi Zhu;Chris Kohne;A. Fluerasu;Yugang Zhang;S. Sen;R. Kukreja
中科院分区：
文献类型：
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作者：
Jianheng Li;R. Jangid;Weidi Zhu;Chris Kohne;A. Fluerasu;Yugang Zhang;S. Sen;R. Kukreja
直接定量测量与玻璃化转变附近的结构松弛和结晶相关的纳米级动力学过程是一个主要的实验挑战。这些类型的过程主要被视为现象学模型和批量实验框架内的宏观现象。在这里，我们报告了在纯 Se 和接近玻璃化转变温度的二元 AsSe4 玻璃形成液体中辐射诱导形成 Se 纳米微晶过程中晶体-熔体界面动力学的 X 射线光子相关光谱测量。我们观察到一种异质动力学行为，其中强度相关函数 g2(q, t) 表现出压缩或拉伸的指数衰减，具体取决于 Se 纳米微晶的尺寸。随着温度升高，AsSe4 液体相应的弛豫时间尺度增加，这可归因于随着 Se 纳米微晶的生长，晶体-熔体界面处熔体的化学成分发生变化。
Direct quantitative measurements of nanoscale dynamical processes associated with structural relaxation and crystallization near the glass transition are a major experimental challenge. These type of processes have been primarily treated as macroscopic phenomena within the framework of phenomenological models and bulk experiments. Here, we report x-ray photon correlation spectroscopy measurements of dynamics at the crystal-melt interface during the radiation induced formation of Se nano-crystallites in pure Se and in binary AsSe4glass-forming liquids near their glass transition temperature. We observe a heterogeneous dynamical behaviour where the intensity correlation functions g2(q, t) exhibits either a compressed or a stretched exponential decay, depending on the size of the Se nano-crystallites. The corresponding relaxation timescale for the AsSe4liquid increases as the temperature is raised, which can be attributed to changes in the chemical composition of the melt at the crystal-melt interface with the growth of the Se nano-crystallites.