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

C. Dwyer; R. Erni; J. Etheridge

doi:10.1016/j.ultramic.2010.01.007

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

C. Dwyer, R. Erni, J. Etheridge

Research output: Contribution to journal › Article › peer-review

59 Scopus citations

Abstract

We review the manner in which lens aberrations, partial spatial coherence, and partial temporal coherence affect the formation of a sub-̊A. 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.

Original language	English (US)
Pages (from-to)	952-957
Number of pages	6
Journal	Ultramicroscopy
Volume	110
Issue number	8
DOIs	https://doi.org/10.1016/j.ultramic.2010.01.007
State	Published - Jul 2010
Externally published	Yes

Keywords

Coherence
Convergent beam electron diffraction
STEM

ASJC Scopus subject areas

Electronic, Optical and Magnetic Materials
Atomic and Molecular Physics, and Optics
Instrumentation

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10.1016/j.ultramic.2010.01.007

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@article{d69608eaf58a4a96b579c3267d80a0fb,

title = "Measurement of effective source distribution and its importance for quantitative interpretation of STEM images",

abstract = "We review the manner in which lens aberrations, partial spatial coherence, and partial temporal coherence affect the formation of a sub-̊A. 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.",

keywords = "Coherence, Convergent beam electron diffraction, STEM",

author = "C. Dwyer and R. Erni and J. Etheridge",

note = "Funding Information: The authors wish to express their gratitude to C.J. Rossouw for providing access to his Bloch-state computer code, and to P. Nakashima and M. Weyland for enabling measurement of the CCD PSF. C.D. and J.E. gratefully acknowledge financial support from FEI Company and the Australian Research Council (ARC Linkage Project LP0990059). Copyright: Copyright 2010 Elsevier B.V., All rights reserved.",

year = "2010",

month = jul,

doi = "10.1016/j.ultramic.2010.01.007",

language = "English (US)",

volume = "110",

pages = "952--957",

journal = "Ultramicroscopy",

issn = "0304-3991",

publisher = "Elsevier",

number = "8",

}

TY - JOUR

T1 - Measurement of effective source distribution and its importance for quantitative interpretation of STEM images

AU - Dwyer, C.

AU - Erni, R.

AU - Etheridge, J.

N1 - Funding Information: The authors wish to express their gratitude to C.J. Rossouw for providing access to his Bloch-state computer code, and to P. Nakashima and M. Weyland for enabling measurement of the CCD PSF. C.D. and J.E. gratefully acknowledge financial support from FEI Company and the Australian Research Council (ARC Linkage Project LP0990059). Copyright: Copyright 2010 Elsevier B.V., All rights reserved.

PY - 2010/7

Y1 - 2010/7

N2 - We review the manner in which lens aberrations, partial spatial coherence, and partial temporal coherence affect the formation of a sub-̊A. 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.

AB - We review the manner in which lens aberrations, partial spatial coherence, and partial temporal coherence affect the formation of a sub-̊A. 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.

KW - Coherence

KW - Convergent beam electron diffraction

KW - STEM

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U2 - 10.1016/j.ultramic.2010.01.007

DO - 10.1016/j.ultramic.2010.01.007

M3 - Article

AN - SCOPUS:77955516179

SN - 0304-3991

VL - 110

SP - 952

EP - 957

JO - Ultramicroscopy

JF - Ultramicroscopy

IS - 8

ER -

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

Abstract

Keywords

ASJC Scopus subject areas

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