像差校正扫描透射电子显微镜中的原子分辨率电子能量损失谱成像

Atomic-resolution electron energy loss spectroscopy imaging in aberration corrected scanning transmission electron microscopy.

作者信息

Allen L J, Findlay S D, Lupini A R, Oxley M P, Pennycook S J

机构信息

School of Physics, University of Melbourne, Victoria 3010, Australia.

出版信息

Phys Rev Lett. 2003 Sep 5;91(10):105503. doi: 10.1103/PhysRevLett.91.105503.

DOI:10.1103/PhysRevLett.91.105503

PMID:14525490

Abstract

The "delocalization" of inelastic scattering is an important issue for the ultimate spatial resolution of innershell spectroscopy in the electron microscope. It is demonstrated in a nonlocal model for electron energy loss spectroscopy (EELS) that delocalization of scanning transmission electron microscopy (STEM) images for single, isolated atoms is primarily determined by the width of the probe, even for light atoms. We present experimental data and theoretical simulations for Ti L-shell EELS in a [100] SrTiO3 crystal showing that, in this case, delocalization is not significantly increased by dynamical propagation. Issues relating to the use of aberration correctors in the STEM geometry are discussed.

摘要

非弹性散射的“离域化”是电子显微镜内壳层光谱最终空间分辨率的一个重要问题。在一个用于电子能量损失谱（EELS）的非局部模型中表明，即使对于轻原子，单个孤立原子的扫描透射电子显微镜（STEM）图像的离域化主要由探针宽度决定。我们给出了[100] SrTiO3晶体中Ti L壳层EELS的实验数据和理论模拟，结果表明，在这种情况下，动态传播不会显著增加离域化。讨论了在STEM几何结构中使用像差校正器的相关问题。