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STEM Diffraction and its applications on material characterization

Date: 2019-01-17
Time: 16:00
Venue: 中科院物理研究所ABII404会议室(A、B楼连接处)
Speaker: 穆晓柯 博士

卡尔斯鲁厄科技大学纳米技术研究所

报告摘要

Scanning-/Transmission electron microscopy (S/TEM) offers sophisticated methods helping material scientists understand the microscopic structure of various interesting materials. Electron diffraction provides abundant structural information being one of the most traditional TEM methods. It brings together sensitive measures in d-spaces, crystal symmetry and orientation. Its intrinsic drawback is the lack of spatial resolution comparing to atomic resolved high resolution techniques (HR(S)TEM).

With increasing potential of electron detecting cameras, scanning diffraction (4DSTEM) in a modern STEM microscope becomes feasible. It records individual two dimensional (2D) diffraction patterns by 2D stepwise scanning a fine electron probe on the specimen. The 4D data array can be used to map the atomic structure and crystal orientation without compromising between the spatial resolution and large area specimens which is often highly demanded for statistical analysis. In addition, pair distribution function (PDF) analysis of the 4D diffraction data provides the possibility to map phases of (low-contrast) organic blends at low-dose conditions.

After a brief introduction of the methodology, this talk would like to show the power of 4DSTEM on solving real material questions. Examples will include phase mapping and interface orientation analysis of partially dis/charged battery, metallic glass, low-dose characterization of amorphous polymers for solar cell application, in-situ differential phase contrast (DPC) imaging of material inner mean potentials, such as for magnetic field measurements.

报告人简介

穆晓柯博士,2006年本科毕业于中国石油大学物理学院,2009年英国谢菲尔德大学材料工程系硕士毕业,2014年德国马普固体所电子显微学中心博士毕业。同年于法国斯特拉斯堡物理化学材料科学所交流,2014年9月起博士后职位工作于卡尔斯鲁厄科技学纳米技术研究所。2017年获得德国科学基金会资助成为“4D 扫描衍射研究金属玻璃剪切带”项目的 Principal Investigator。从事透射电子显微学方法的开发,以及在纳米材料表征上的应用。目前感兴趣于使用空间分辨的衍射方法解决电池材料,金属玻璃,非晶体材料,有机半导体,以及原位实验中电磁场的测量。

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联系人: 姚 湲  副研究员(电话:82648002)