Liu Amelia C Y, Bøjesen Espen D, Tabor Rico F, Mudie Stephen T, Zaccone Alessio, Harrowell Peter, Petersen Timothy C
Monash Centre for Electron Microscopy, Monash University, Clayton, Victoria, 3800, Australia.
School of Physics and Astronomy, Monash University, Clayton, Victoria, 3800, Australia.
Sci Adv. 2022 Mar 18;8(11):eabn0681. doi: 10.1126/sciadv.abn0681.
The mechanical properties of crystals are controlled by the translational symmetry of their structures. But for glasses with a disordered structure, the link between the symmetry of local particle arrangements and stability is not well established. In this contribution, we provide experimental verification that the centrosymmetry of nearest-neighbor polyhedra in a glass strongly correlates with the local mechanical stability. We examine the distribution of local stability and local centrosymmetry in a glass during aging and deformation using microbeam x-ray scattering. These measurements reveal the underlying relationship between particle-level structure and larger-scale behavior and demonstrate that spatially connected, coordinated local transformations to lower symmetry structures are fundamental to these phenomena. While glassy structures lack obvious global symmetry breaking, local structural symmetry is a critical factor in predicting stability.
晶体的力学性能由其结构的平移对称性控制。但对于结构无序的玻璃，局部粒子排列的对称性与稳定性之间的联系尚未完全确立。在本论文中，我们提供了实验验证，即玻璃中最近邻多面体的中心对称性与局部力学稳定性密切相关。我们使用微束X射线散射研究了玻璃在老化和变形过程中局部稳定性和局部中心对称性的分布。这些测量揭示了粒子尺度结构与更大尺度行为之间的潜在关系，并表明向较低对称性结构的空间连接、协同局部转变是这些现象的基础。虽然玻璃态结构缺乏明显的全局对称性破缺，但局部结构对称性是预测稳定性的关键因素。
