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

TL;DR

This study uses molecular dynamics simulations to compare atomic structures and dynamics in five monatomic metallic liquids, revealing how structural differences influence glass-forming ability and crystallization.

Contribution

It provides a systematic comparison of structural and dynamical properties across five monatomic liquids, highlighting the unique features of liquid Ta related to glass formation.

Findings

Liquid Cu, Ta, and Fe have similar structures but differ in order and packing.

Liquid Ta shows more ordered, densely packed structures with specific atomic arrangements.

Liquid Ta's atomic structure and slower dynamics promote its glass-forming ability.

Abstract

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.