Karpov D, Djeghdi K, Holler M, Abdollahi S Narjes, Godlewska K, Donnelly C, Yuasa T, Sai H, Wiesner U B, Wilts B D, Steiner U, Musya M, Fukami S, Ohno H, Gunkel I, Diaz A, Llandro J
Paul Scherrer Institute, Villigen, Switzerland.
European Synchrotron Radiation Facility, Grenoble, France.
Nat Nanotechnol. 2024 Oct;19(10):1499-1506. doi: 10.1038/s41565-024-01735-w. Epub 2024 Jul 23.
Topological defects-extended lattice deformations that are robust against local defects and annealing-have been exploited to engineer novel properties in both hard and soft materials. Yet, their formation kinetics and nanoscale three-dimensional structure are poorly understood, impeding their benefits for nanofabrication. We describe the fabrication of a pair of topological defects in the volume of a single-diamond network (space group Fd m) templated into gold from a triblock terpolymer crystal. Using X-ray nanotomography, we resolve the three-dimensional structure of nearly 70,000 individual single-diamond unit cells with a spatial resolution of 11.2 nm, allowing analysis of the long-range order of the network. The defects observed morphologically resemble the comet and trefoil patterns of equal and opposite half-integer topological charges observed in liquid crystals. Yet our analysis of strain in the network suggests typical hard matter behaviour. Our analysis approach does not require a priori knowledge of the expected positions of the nodes in three-dimensional nanostructured systems, allowing the identification of distorted morphologies and defects in large samples.
拓扑缺陷——对局部缺陷和退火具有鲁棒性的扩展晶格变形——已被用于在硬质和软质材料中设计新特性。然而，它们的形成动力学和纳米级三维结构仍知之甚少，这阻碍了它们在纳米制造中的应用。我们描述了从三嵌段三元共聚物晶体模板化为金的单金刚石网络（空间群Fd m）体积中一对拓扑缺陷的制造。使用X射线纳米断层扫描，我们以11.2纳米的空间分辨率解析了近70,000个单个单金刚石晶胞的三维结构，从而能够分析网络的长程有序性。从形态上观察到的缺陷类似于在液晶中观察到的具有相等和相反半整数拓扑电荷的彗星和三叶形图案。然而，我们对网络中应变的分析表明其具有典型的硬质材料行为。我们的分析方法不需要三维纳米结构系统中节点预期位置的先验知识，从而能够识别大样本中的扭曲形态和缺陷。
