论文标题

通过分子动力学模拟,原子质金属液体中的原子结构特性和动力学特性

Atomic structural characteristics and dynamical properties in monatomic metallic liquids via molecular dynamics simulations

论文作者

Qin, X., Wu, J. Q., Li, M. Z.

论文摘要

进行了五种单原子金属液体进行分子动力学模拟,并系统地研究了原子结构特性和动力学特性,并进行了比较,以了解液体特性的潜在结构基础,例如玻璃形成能力。所有模拟的单一液体均表现出相似的结构特征和温度演化。但是,该度在不同液体中差异很大。发现液体Cu,TA和Fe中的原子结构非常相似。但是,液体TA具有更有序的,更密集的结构特征,具有更多的二十面体样原子订购和五倍的HA索引,较少的Voronoi熵和更常规的四面体构型。此外,与其他液体相反,液体TA中晶体样簇的增加会随温度降低而变慢,二十面体状簇的增加更快,超过了晶体样簇。相反,液体Al和Zr的原子结构更相似,更加混乱,更松散。此外,液体TA表现出更缓慢和异质的动力学,可以通过液体TA的特定原子结构来促进。液体TA中的原子结构和动力学特征都有利于其玻璃形成。我们的发现提供了全面的结构和动力学信息,以更好地了解这些典型的单一液体中的GFA和结晶。

Molecular dynamics simulations were performed for five monatomic metallic liquids and the atomic structural characteristics and dynamical properties were systematically investigated and compared for understanding the underlying structural basis of liquid properties, such as glass-forming ability. All simulated monatomic liquids exhibit similar structural characteristics and temperature evolution. However, the degree varies significantly in different liquids. It is found that the atomic structures in liquid Cu, Ta, and Fe are quite similar. However, liquid Ta exhibits more ordered and more densely packed structure features, with more populated icosahedral-like atomic ordering and five-fold HA indexes, less Voronoi entropy, and more regular tetrahedral configurations. Moreover, the increase of crystal-like clusters in liquid Ta slows down with decreasing temperature, and the icosahedral-like clusters increase more quickly, exceeding crystal-like ones, in contrast to other liquids. On the contrary, the atomic structures of liquid Al and Zr are more similar, much more disordered and more loosely packed. Furthermore, liquid Ta exhibits more slow and heterogeneous dynamics, which could be facilitated by the particular atomic structures of liquid Ta. Both the atomic structure and dynamics features in liquid Ta favor its glass formation. Our findings provide comprehensive structural and dynamical information for better understanding GFA and crystallization in these typical monatomic liquids.

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