Quasi-static 3D structure of graphene ripple measured using aberration-corrected TEM
Quasi-static 3D structure of graphene ripple measured using aberration-corrected TEM
复制标题
使用像差校正 TEM 测量石墨烯波纹的准静态 3D 结构
DOI：
10.1039/d1nr00237f
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发表时间：
2021
期刊：
影响因子：
6.7
通讯作者：
Gohara Kazutoshi
中科院分区：
文献类型：
--
作者：
Segawa Yuhiro;Yamazaki Kenji;Yamasaki Jun;Gohara Kazutoshi
独立式石墨烯具有三维（3D）结构，称为涟漪，而不是完美的二维（2D）晶体。由于理论计算表明涟漪强烈影响石墨烯的各种基本物理化学性质，因此在实验中定量地阐明涟漪结构是重要的。提出了一种利用像差校正透射电子显微镜（TEM）测量涟漪三维原子结构的新方法。该方法利用TEM图像的2D对比度对六元环的高度敏感的事实。该方法被实验应用到单层石墨烯，连续获取的TEM图像的三维原子排列重建。在那个实验中，发现样品向上移动。此外，原子排列可以近似为由3D涟漪和2D平面组成的两种结构的复合物。涟漪被表示为正弦波的叠加，其波矢量与六元环的特定方向一致。还测量了涟漪的高度和横向尺寸的时间依赖性。
Free-standing graphene has a three-dimensional (3D) structure, called a ripple, rather than a perfect two-dimensional (2D) crystal. Since theoretical calculations suggest that a ripple strongly influences various fundamental physicochemical properties of graphene, it is important to clarify the ripple structure quantitatively in experiments. This paper proposes a new method of measuring the 3D atomic structure of a ripple by using aberration-corrected transmission electron microscopy (TEM). The method utilizes the fact that the 2D contrast of a TEM image is sensitive to the height of a six-membered ring. The proposed method is experimentally applied to a monolayer graphene, and the 3D atomic arrangements of consecutively acquired TEM images are reconstructed. In that experiment, the specimen is found to be moving upward. Furthermore, the atomic arrangement can be approximated as a composite of two structures consisting of a 3D ripple and a 2D plane. The ripple is represented as a superposition of sinusoidal waves, with their wave vectors coinciding with the specific direction of the six-membered ring. The time dependences of the height and lateral size of the ripple are also measured.