报告题目：Capturing 3D atomic structure with pm precision: An imaging method beyond crystallography

报告人：田学增 教授 中科院物理所

时间：2021年7月7日 下午2:00

地点：知新楼C座7楼量子报告厅

邀请人：马衍东 教授

报告摘要：

Perfect crystals are rare in nature. Real materials often contain crystal defects and chemical order/disorder such as grain boundaries, dislocations, interfaces, surface reconstructions and point defects. Despite rapid development of quantitative material characterization methods, the structure-property relationship of advanced materials at the 3D atomic level remains a challenge. Here, we developed atomic electron tomography (AET) to localize the 3D atomic coordinates of materials with picometer precision. AET combines the most advanced aberration-corrected electron microscopy and our home-developed Fourier space iterative reconstruction algorithm, which is capable of determining the 3D atomic structure in materials without crystallinity. In this talk, I will firstly brief the principles of AET. Next, I will show several key advances achieved with AET, including atomic nucleation mechanism in metal, doping and heterogeneity in 2D quantum materials, and our recent results on determining the 3D atomic structure of glass materials for the first time.

References:

[1] Tian, X., et al., Nat. Mater. 19, 867-873 (2020).

[2] Zhou, J. et al., Nature 570, 500-503 (2019)

[3] Yang, Y., et al., Nature 592, 60–64 (2021).

[4] Tian, X., et al., Sci. Adv. In press

报告人简介：

Xuezeng Tian joined the IOP, CAS as a Tenure-Track Professor in Oct, 2020. Before joining IOPCAS, Tian has been working as an electron microscopist at LBNL, ORNL and UCLA for 6 years as a postdoctoral researcher. His expertise spans from experimental electron microscopy to 3D reconstruction algorithms and deep learning image processing technologies.

In IOPCAS, Tian's research will focus on the development of new imaging methodologies based on electron microscopy and their application in materials physics. The team will be targeting several critical physical problems including atomic structure of glass materials, 2D quantum materials, functional oxides and heterogeneous catalysis.