关于举办沙特阿卜杜拉国王科技大学韩宇教授学术报告的通知

发布时间:2017-12-29设置

报告题目:Advancing atomic-resolution TEM of electron beam-sensitive crystalline materials from “impossible” to “routine”

报 告 人:韩宇教授(沙特阿卜杜拉国王科技大学)

报告时间:20181410:00-11:00

报告地点:逸夫工程馆105会议室

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化学与化工学院

20171229

 

报告人简介:

韩宇教授2003年博士毕业于吉林大学,并先后在新加坡生物工程和纳米科技研究所、帝国理工学院及沙特阿卜杜拉国王科技大学从事科研工作。现任沙特阿卜杜拉国王科技大学教授。主要从事纳米多孔和纳米结构材料,包括有序介孔材料、多级结构分子筛、多孔有机聚合物等多孔碳的结构及形貌的精确控制,用以提高它们在气体吸附/分离、多相催化等相关应用的效率。韩教授也是电子显微技术分析的专家,先后在scienceNatureNature Materials Nature ChemistryJACS等著名期刊发表论文150余篇,被引用11000余次;H-index50,并被授予了TR100 Young Innovator (麻省理工学院创新杂志)、Young Scientist Award(新加坡国家科学院)等,2016年获得了国家教育部授予长江学者奖励计划

 

报告摘要:

High-resolution imaging of electron beam-sensitive crystalline materials is one of the most difficult applications of transmission electron microscopy (TEM). The challenges are manifold, including the acquisition of images with an extremely low beam dose, the timeconstrained search for crystal zone axes, the precise alignment of successive images, and the accurate determination of the defocus value. We reported that using a direct-detection electron-counting (DDEC) camera, it is possible to acquire useful high-resolution TEM images with electron dose as low as a few electrons per square angstrom to ensure that the intact structure was captured before damage occurred.

In this talk, we will present a suite of new methods that we recently developed to address the rest challenges mentioned above. Our methods advance the HRTEM of extremely beamsensitive materials from “occasionally possible” to “routine”. We demonstrate the effectiveness of our methodology by capturing atomic-resolution (~ 1.5 Å) TEM images of several metal organic frameworks (MOFs) that are generally recognized as highly sensitive to electron beams. In the case of MOF UiO-66, individual metal atomic columns, various types of surface termination, and benzene rings in the organic linkers, are clearly identified. We also successfully apply our methods to other electron beam-sensitive materials, and achieve atomicresolution TEM imaging of the organic-inorganic hybrid perovskite CH3NH3PbBr3 for the first time.


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