Measurement of effective source distribution and its importance for quantitative interpretation of STEM images

被引：62

作者：

Dwyer, C. ^{[1
,2
]}

Erni, R. ^{[3
]}

Etheridge, J. ^{[1
,2
]}

机构：

[1] Monash Univ, Monash Ctr Electron Microscopy, Clayton, Vic 3800, Australia

[2] Monash Univ, Dept Mat Engn, Clayton, Vic 3800, Australia

[3] Swiss Fed Labs Mat Testing & Res, Ctr Electron Microscopy, CH-8600 Dubendorf, Switzerland

来源：

ULTRAMICROSCOPY | 2010年 / 110卷 / 08期

基金：

澳大利亚研究理事会;

关键词：

STEM; Coherence; Convergent beam electron diffraction; ELECTRON-DIFFRACTION PATTERNS; EFFECTIVE SOURCE COHERENCE; SCAN CCD CAMERA; CONTRAST; BEAM; TEM; SCATTERING; RESOLUTION; ENERGY; SIGNAL;

D O I：

10.1016/j.ultramic.2010.01.007

中图分类号：

TH742 [显微镜];

学科分类号：

摘要：

We review the manner in which lens aberrations, partial spatial coherence, and partial temporal coherence affect the formation of a sub-angstrom electron probe in an aberration-corrected transmission electron microscope. Simulations are used to examine the effect of each of these factors on a STEM image. It is found that the effects of partial spatial coherence (resulting from finite effective source size) are dominant, while the effects of residual lens aberrations and partial temporal coherence produce only subtle changes from an ideal image. We also review the way in which partial spatial and temporal coherence effects are manifest in a Ronchigram. Finally, we provide a demonstration of the Ronchigram method for measuring the effective source distribution in a probe aberration-corrected 300 kV field-emission gun transmission electron microscope. (C) 2010 Elsevier B.V. All rights reserved.

引用

页码：952 / 957

页数：6

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