Ishino Seiichiro, Hu Yuan-Chao, Tanaka Hajime
Department of Fundamental Engineering, Institute of Industrial Science, The University of Tokyo, Tokyo, Japan.
Songshan Lake Materials Laboratory, Dongguan, China.
Nat Mater. 2025 Feb;24(2):268-277. doi: 10.1038/s41563-024-02068-8. Epub 2025 Jan 8.
Supercooled liquids display sluggish dynamics, often attributed to their structural characteristics, yet the underlying mechanism remains elusive. Here we conduct numerical investigations into the structure-dynamics relationship in model glass-forming liquids, with a specific focus on an elementary particle rearrangement mode known as the 'T1 process'. We discover that the ability of a T1 process to preserve glassy structural order before and after is pivotal towards determining a liquid's fragility-whether it exhibits super-Arrhenius-like or Arrhenius-like behaviour. If a T1 process disrupts local structural order, it must occur independently without cooperativity, resulting in Arrhenius-like behaviour. By contrast, if it can maintain order, it sequentially propagates from disordered peripheries to the middle of high-structural-order regions, leading to cooperativity and super-Arrhenius-like behaviour. Our study establishes a microscopic link between liquid-structure ordering, dynamic cooperativity and super-Arrhenius-like dynamics, extending the understanding of the structure-dynamics relationships in supercooled liquids.
过冷液体表现出缓慢的动力学，这通常归因于它们的结构特征，但其潜在机制仍然难以捉摸。在这里，我们对模型玻璃形成液体中的结构-动力学关系进行了数值研究，特别关注一种被称为“T1过程”的基本粒子重排模式。我们发现，T1过程在前后保持玻璃态结构有序的能力对于确定液体的脆性至关重要——即它表现出类超阿仑尼乌斯行为还是类阿仑尼乌斯行为。如果一个T1过程破坏了局部结构有序，它必须独立发生而没有协同作用，从而导致类阿仑尼乌斯行为。相比之下，如果它能够保持有序，它会从无序的外围依次传播到高结构有序区域的中间，导致协同作用和类超阿仑尼乌斯行为。我们的研究建立了液体结构有序、动态协同作用和类超阿仑尼乌斯动力学之间的微观联系，扩展了对过冷液体中结构-动力学关系的理解。
