三维胶体晶体中缺陷引起的非线性应力的测量
Measuring nonlinear stresses generated by defects in 3D colloidal crystals
摘要：
晶体的机械、结构和功能特性由其缺陷决定，这些缺陷周围的应力分布对于理解输运现象具有广泛的意义。当缺陷密度上升到现实世界材料中常见的水平时，传输由主要是非线性的局部应力控制。然而，这样的应力场不能使用常规的整体和局部测量技术来测量。在这里，我们报告直接和空间分辨的实验测量周围的胶体晶体缺陷核心的非线性应力，并表明，在空位核心的应力产生有吸引力的相互作用。我们还直接可视化周围的位错核心的结晶区域的软化，并发现在静态多晶体的应力波动是均匀分布的，而不是本地化的晶界，是在应变原子多晶体的情况下。非线性应力测量对应变硬化、屈服和疲劳具有重要意义。
英文摘要：
The mechanical, structural and functional properties of crystals are determined by their defects and the distribution of stresses surrounding these defects has broad implications for the understanding of transport phenomena. When the defect density rises to levels routinely found in real-world materials, transport is governed by local stresses that are predominantly nonlinear. Such stress fields however, cannot be measured using conventional bulk and local measurement techniques. Here, we report direct and spatially resolved experimental measurements of the nonlinear stresses surrounding colloidal crystalline defect cores, and show that the stresses at vacancy cores generate attractive interactions between them. We also directly visualize the softening of crystalline regions surrounding dislocation cores, and find that stress fluctuations in quiescent polycrystals are uniformly distributed rather than localized at grain boundaries, as is the case in strained atomic polycrystals. Nonlinear stress measurements have important implications for strain hardening, yield, and fatigue.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
