Institute of Condensed Matter and Nanosciences, Université catholique de Louvain (UCLouvain), 1348 Louvain-la-Neuve, Belgium.
Physics Department, Lancaster University, Lancaster, UK.
Nanoscale. 2023 May 11;15(18):8134-8140. doi: 10.1039/d3nr00388d.
Nanomechanical measurements of minimally twisted van der Waals materials remained elusive despite their fundamental importance for device realisation. Here, we use Ultrasonic Force Microscopy (UFM) to locally quantify the variation of out-of-plane Young's modulus in minimally twisted double bilayer graphene (TDBG). We reveal a softening of the Young's modulus by 7% and 17% along single and double domain walls, respectively. Our experimental results are confirmed by force-field relaxation models. This study highlights the strong tunability of nanomechanical properties in engineered twisted materials, and paves the way for future applications of designer 2D nanomechanical systems.
尽管最小扭曲的范德华材料对于器件实现具有重要意义，但对其进行纳米力学测量仍然难以实现。在这里，我们使用超声力显微镜（UFM）局部量化最小扭曲双层石墨烯（TDBG）中面外杨氏模量的变化。我们发现，单域壁和双域壁处的杨氏模量分别软化了 7%和 17%。我们的实验结果得到了力场弛豫模型的证实。这项研究强调了工程化扭曲材料中纳米力学性能的强可调性，为未来设计的二维纳米力学系统的应用铺平了道路。
