Zella Leo, Moon Jaeyun, Egami Takeshi
Department of Materials Science and Engineering, The University of Tennessee, Knoxville, TN, 37996, USA.
Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.
Nat Commun. 2024 Feb 14;15(1):1358. doi: 10.1038/s41467-024-45640-1.
In the absence of periodicity, the structure of glass is ill-defined, and a large number of structural states are found at similar energy levels. However, little is known about how these states are connected to each other in the potential energy landscape. We simulate mechanical relaxation by molecular dynamics for a prototypical [Formula: see text] metallic glass and follow the mechanical energy loss of each atom to track the change in the state. We find that the energy barriers separating these states are remarkably low, only of the order of 1 meV, implying that even quantum fluctuations can overcome these potential energy barriers. Our observation of numerous small ripples in the bottom of the potential energy landscape puts many assumptions regarding the thermodynamic states of metallic glasses into question and suggests that metallic glasses are not totally frozen at the local atomic level.
在没有周期性的情况下，玻璃的结构不明确，并且在相似的能量水平上发现了大量的结构状态。然而，对于这些状态在势能图景中如何相互连接却知之甚少。我们通过分子动力学模拟了一种典型的[化学式：见原文]金属玻璃的力学弛豫，并跟踪每个原子的机械能损失以追踪状态的变化。我们发现分隔这些状态的能垒非常低，仅为1 meV量级，这意味着即使是量子涨落也能克服这些势能垒。我们在势能图景底部观察到的众多小波动对许多关于金属玻璃热力学状态的假设提出了质疑，并表明金属玻璃在局部原子水平上并非完全冻结。
