层间滑移与扭转的相互作用：旋转孪晶驱动的扭转范德华纳米线
Interplay between Interlayer Shift and Twist: Twisted van der Waals Nanowires Driven by Rotational Twinning
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中文总结 AI 辅助
本研究揭示了vdW晶体中由旋转孪晶驱动的自发扭转机制，通过实验和理论证实扭转源于层间堆叠与应变代价的竞争，为扭转工程化vdW材料提供了设计原则。
中文摘要 AI 辅助
在范德华（vdW）层状材料中，层间滑移和扭转已通过多型体和莫尔工程实现了对材料性质的控制。包括自下而上合成和手动逐层堆叠在内的多种方法已被用于构建目标堆叠构型。然而，层间滑移与扭转之间的相互作用，以及精细调控这些参数的可靠机制，在很大程度上仍未被探索。在此，我们报道了一种先前未被认识的、由vdW晶体中优选的倾斜堆叠和孪晶产生的扭转机制。电子衍射和原子分辨扫描透射电子显微镜（STEM）成像揭示，IV族硫属化物GeSe_{2-x}Te_x的晶格面沿纳米线生长轴连续旋转，其扭转速率系统地依赖于纳米线半径。原子尺度成像进一步识别出沿纳米线中心区域延伸的连续旋转孪晶界。第一性原理计算和结构弛豫模拟证实，扭转形变源于优选层间堆叠配准与旋转孪晶所施加的应变代价之间的能量竞争。这些发现确立了旋转孪晶作为自发扭转形成的固有途径，并为实现具有兼容晶体对称性和堆叠基序的扭转工程化vdW晶体提供了设计原则。
英文摘要
In van der Waals(vdW) layered materials, interlayer shift and twist have enabled the control of material properties through polytype and moire engineering. Various approaches, including bottom-up synthesis and manual layer-by-layer stacking, have been utilized to engineer targeted stacking configurations. However, the interplay between interlayer shift and twist, as well as reliable mechanisms for fine-tuning these parameters, remains largely unexplored. Here, we report a previously unrecognized twisting mechanism arising from preferred tilted stacking and twinning in vdW crystals. Electron diffraction and atomic-resolution scanning transmission electron microscopy(STEM) imaging reveal that the lattice planes of group-IV chalcogenide GeSe_{2-x}Te_x rotate continuously along the nanowire growth axis, with twist rates depending systematically on nanowire radius. Atomic-scale imaging further identifies a continuous rotational twin boundary extending along the central region of the nanowire. First-principles calculations and structural relaxation simulations confirm that the twisting deformation originates from energetic competition between the preferred interlayer stacking registry and the strain cost imposed by rotational twinning. These findings establish rotational twinning as an intrinsic route to spontaneous twist formation and provide a design principle for realizing twist-engineered vdW crystals with compatible crystal symmetries and stacking motifs.
发表机构
- Yonsei University（延世大学）
- Chonnam National University（全南国立大学）
- Korea Institute of Science and Technology (KIST)（韩国科学技术院）
机构由 AI 辅助整理，请以论文原文为准。
