学术讲座（2024年11月5日10:00）：原子尺度实时探测纳米结构的功能特性和动态行为

主 持 人：张溢副教授

报告摘要：Recent advancements in aberration-correction, electron detection, and in situ techniques have propelled transmission electron microscopy (TEM) and spectroscopy into the realm of real-time, atomic-scale investigations of material structure, properties, and dynamics. In this talk, I will discuss our recent progress in developing and applying advanced electron microscopy and spectroscopy methods to visualize the atomic structure and functional properties of materials, alongside observing their dynamic responses to external forces and varying environmental conditions. We achieve direct imaging of local electric fields, charge distributions, polarization, and the behavior of domain walls in ferroelectrics [1-2], as well as grain boundaries in nanocrystalline materials [3]. Utilizing newly developed spatial and angle-resolved electron energy-loss spectroscopy (EELS), we uncover novel vibrational modes and emergent phonon behaviors at single defects [4] and interfaces [5-6], enabling nanoscale mapping of phonon momentum and heat flow. These insights provide an unprecedented view into the mechanisms governing the functional behavior of nanostructured materials.

References:

1. Li et al., “Real-time studies of ferroelectric domain switching: a review,” Rep. Prog. Phys. 82, 126502 (2019).
2. Gao et al., “Real-space charge-density imaging with sub-ångström resolution by four-dimensional electron microscopy,” Nature 575, 480–484 (2019).
3. Tian et al., “Grain rotation mechanisms in nanocrystalline materials: Multiscale observations in Pt thin films,” Science 386, 49–54 (2024).
4. Yan et al., “Single-defect phonons imaged by electron microscopy,” Nature 589, 65–69 (2021).
5. Gadre et al., “Nanoscale imaging of phonon dynamics by electron microscopy,” Nature 606, 292–297 (2022).
6. Yang et al., “Phonon modes and electron–phonon coupling at the FeSe/SrTiO3 interface,” Nature (2024). https://doi.org/10.1038/s41586-024-08118-0

报告人简介：潘晓晴，美国加州大学欧文分校Henry Samueli Endowed讲席教授，受聘于材料科学与工程学院和物理学与天文学学院，他还是欧文材料研究所（IMRI）的首任所长，以及美国国家科学基金会 （MRSEC）资助的复杂活性材料中心创始主任。潘是国际公认的材料科学家和电子显微镜专家，他率先开发并应用新型透射电子显微镜（TEM）方法来探测材料的原子尺度结构、特性和动态行为，他的工作促成了新材料和新功能的发现。潘教授曾获美国国家科学基金会 “美国杰出人才奖”（NSF CAREER Award）和中国自然科学基金 “杰出青年基金”(海外)。他目前是美国陶瓷学会、美国物理学会、美国显微镜学会和材料研究学会的会员，在高影响力学术期刊上发表了 400 多篇科学论文。