Publication
Title
Modelling ADF STEM images using elliptical Gaussian peaks and its effects on the quantification of structure parameters in the presence of sample tilt
Author
Abstract
A small sample tilt away from a main zone axis orientation results in an elongation of the atomic columns in ADF STEM images. An often posed research question is therefore whether the ADF STEM image intensities of tilted nanomaterials should be quantified using a parametric imaging model consisting of elliptical rather than the currently used symmetrical peaks. To this purpose, simulated ADF STEM images corresponding to different amounts of sample tilt are studied using a parametric imaging model that consists of superimposed 2D elliptical Gaussian peaks on the one hand and symmetrical Gaussian peaks on the other hand. We investigate the quantification of structural parameters such as atomic column positions and scattering cross sections using both parametric imaging models. In this manner, we quantitatively study what can be gained from this elliptical model for quantitative ADF STEM, despite the increased parameter space and computational effort. Although a qualitative improvement can be achieved, no significant quantitative improvement in the estimated structure parameters is achieved by the elliptical model as compared to the symmetrical model. The decrease in scattering cross sections with increasing sample tilt is even identical for both types of parametric imaging models. This impedes direct comparison with zone axis image simulations. Nonetheless, we demonstrate how reliable atom-counting can still be achieved in the presence of small sample tilt.
Language
English
Source (journal)
Ultramicroscopy. - Amsterdam
Publication
Amsterdam : 2021
ISSN
0304-3991
DOI
10.1016/J.ULTRAMIC.2021.113391
Volume/pages
230 (2021) , 8 p.
Article Reference
113391
ISI
000704334200001
Pubmed ID
34600202
Medium
E-only publicatie
Full text (Publisher's DOI)
Full text (open access)
Full text (publisher's version - intranet only)
UAntwerpen
Faculty/Department
Research group
Project info
Picometer metrology for light-element nanostructures: making every electron count (PICOMETRICS).
Enabling science and technology through European electron microscopy (ESTEEM3).
Dose-efficient fusion of imaging and analytical techniques in scanning transmission electron microscopy.
Three-dimensional atomic modelling of functional nanocrystalline structures from a single viewing direction.
Smart strategies to break the beam damage limits in transmission electron microscopy.
Quantifying the dynamics of the 3D atomic structure using hidden Markov models in scanning transmission electron microscopy.
Publication type
Subject
Affiliation
Publications with a UAntwerp address
External links
Web of Science
Record
Identifier
Creation 04.10.2021
Last edited 02.10.2024
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