Records |
Author |
Agrawal, H.; Patra, B.K.; Altantzis, T.; De Backer, A.; Garnett, E.C. |
Title |
Quantifying Strain and Dislocation Density at Nanocube Interfaces after Assembly and Epitaxy |
Type |
A1 Journal article |
Year |
2020 |
Publication |
Acs Applied Materials & Interfaces |
Abbreviated Journal |
Acs Appl Mater Inter |
Volume |
12 |
Issue |
7 |
Pages |
8788-8794 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Applied Electrochemistry & Catalysis (ELCAT) |
Abstract |
Nanoparticle self-assembly and epitaxy are utilized extensively to make 1D and 2D structures with complex shapes. High-resolution transmission electron microscopy (HRTEM) has shown that single-crystalline interfaces can form, but little is known about the strain and dislocations at these interfaces. Such information is critically important for applications: drastically reducing
dislocation density was the key breakthrough enabling widespread implementation of light-emitting diodes, while strain engineering has been fundamental to modern high-performance transistors, solar cells, and thermoelectrics. In this work, the interfacial defect and strain formation after selfassembly and room temperature epitaxy of 7 nm Pd nanocubes capped with polyvinylpyrrolidone (PVP) is examined. It is observed that, during ligand removal, the cubes move over large distances on the substrate, leading to both spontaneous self-assembly and epitaxy to form single crystals. Subsequently, atomically resolved images are used to quantify the strain and dislocation density at the epitaxial interfaces between cubes with different lateral and angular misorientations. It is shown that dislocation- and strain-free interfaces form when the nanocubes align parallel to each other. Angular misalignment between adjacent cubes does not necessarily lead to grain boundaries but does cause dislocations, with higher densities associated with larger rotations. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000515214300101 |
Publication Date |
2020-02-19 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
ISSN |
1944-8244 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
9.5 |
Times cited |
|
Open Access |
OpenAccess |
Notes |
Fonds Wetenschappelijk Onderzoek; H2020 Research Infrastructures, 731019 ; Nederlandse Organisatie voor Wetenschappelijk Onderzoek, 14846 ; The work at AMOLF is part of the research program of the “Nederlandse Organisatie voor Wetenschappelijk Onderzoek” (NWO). This work was supported by the NWO VIDI grant (project no. 14846). The authors would like to thank Reinout Jaarsma and Dr. Sven Askes for helping with the XPS measurements. A.D.B. acknowledges a postdoctoral grant from the research foundation Flanders (FWO). The authors acknowledge financial support from the European Commission under the Horizon 2020 Programme by means of the grant agreement no. 731019 EUSMI. |
Approved |
Most recent IF: 9.5; 2020 IF: 7.504 |
Call Number |
EMAT @ emat @c:irua:167770 |
Serial |
6398 |
Permanent link to this record |
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Author |
Alania, M.; Altantzis, T.; De Backer, A.; Lobato, I.; Bals, S.; Van Aert, S. |
Title |
Depth sectioning combined with atom-counting in HAADF STEM to retrieve the 3D atomic structure |
Type |
A1 Journal article |
Year |
2016 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
Volume |
177 |
Issue |
177 |
Pages |
36-42 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Aberration correction in scanning transmission electron microscopy (STEM) has greatly improved the lateral and depth resolution. When using depth sectioning, a technique during which a series of images is recorded at different defocus values, single impurity atoms can be visualised in three dimensions. In this paper, we investigate new possibilities emerging when combining depth sectioning and precise atom-counting in order to reconstruct nanosized particles in three dimensions. Although the depth resolution does not allow one to precisely locate each atom within an atomic column, it will be shown that the depth location of an atomic column as a whole can be measured precisely. In this manner, the morphology of a nanoparticle can be reconstructed in three dimensions. This will be demonstrated using simulations and experimental data of a gold nanorod. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000401219800006 |
Publication Date |
2016-11-09 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
ISSN |
0304-3991 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.843 |
Times cited |
13 |
Open Access |
OpenAccess |
Notes |
The authors acknowledge financial support from the European Union under the Seventh Framework Program under a contract for an Integrated Infrastructure Initiative. Reference No. 312483-ESTEEM2. S. Bals acknowledges funding from the European Research Council (Starting Grant No. COLOURATOMS 335078). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0374.13N, G.0369.15N and G.0368.15N) and a post-doctoral grant to A. De Backer and T. Altantzis. The authors are grateful to Professor Luis M. Liz-Marzán for providing the sample.; ECAS_Sara; (ROMEO:green; preprint:; postprint:can ; pdfversion:cannot); |
Approved |
Most recent IF: 2.843 |
Call Number |
EMAT @ emat @ c:irua:138015UA @ admin @ c:irua:138015 |
Serial |
4316 |
Permanent link to this record |
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Author |
Alania, M.; De Backer, A.; Lobato, I.; Krause, F.F.; Van Dyck, D.; Rosenauer, A.; Van Aert, S. |
Title |
How precise can atoms of a nanocluster be located in 3D using a tilt series of scanning transmission electron microscopy images? |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
Volume |
181 |
Issue |
181 |
Pages |
134-143 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
Abstract |
In this paper, we investigate how precise atoms of a small nanocluster can ultimately be located in three dimensions (3D) from a tilt series of images acquired using annular dark field (ADF) scanning transmission electron microscopy (STEM). Therefore, we derive an expression for the statistical precision with which the 3D atomic position coordinates can be estimated in a quantitative analysis. Evaluating this statistical precision as a function of the microscope settings also allows us to derive the optimal experimental design. In this manner, the optimal angular tilt range, required electron dose, optimal detector angles, and number of projection images can be determined. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000411170800016 |
Publication Date |
2016-12-15 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
ISSN |
0304-3991 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.843 |
Times cited |
3 |
Open Access |
OpenAccess |
Notes |
The authors acknowledge financial support from the European Union under the Seventh Framework Program under a contract for an Integrated Infrastructure Initiative. Reference No. 312483-ESTEEM2. The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0374.13N, G.0369.15N, G.0368.15N, and WO.010.16N) and a post-doctoral grant to A. De Backer, and from the DFG under contract No. RO-2057/4-2. |
Approved |
Most recent IF: 2.843 |
Call Number |
EMAT @ emat @ c:irua:144432 |
Serial |
4618 |
Permanent link to this record |
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Author |
Altantzis, T.; Lobato, I.; De Backer, A.; Béché, A.; Zhang, Y.; Basak, S.; Porcu, M.; Xu, Q.; Sánchez-Iglesias, A.; Liz-Marzán, L.M.; Van Tendeloo, G.; Van Aert, S.; Bals, S. |
Title |
Three-Dimensional Quantification of the Facet Evolution of Pt Nanoparticles in a Variable Gaseous Environment |
Type |
A1 Journal article |
Year |
2019 |
Publication |
Nano letters |
Abbreviated Journal |
Nano Lett |
Volume |
19 |
Issue |
19 |
Pages |
477-481 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Pt nanoparticles play an essential role in a wide variety of catalytic reactions. The activity of the particles strongly depends on their three-dimensional (3D) structure and exposed facets, as well as on the reactive environment. High-resolution electron microscopy has often been used to characterize nanoparticle catalysts but unfortunately most observations so far have been either performed in vacuum and/or using conventional (2D) in situ microscopy. The latter however does not provide direct 3D morphological information. We have implemented a quantitative methodology to measure variations of the 3D atomic structure of nanoparticles under the flow of a selected gas. We were thereby able to quantify refaceting of Pt nanoparticles with atomic resolution during various oxidation−reduction cycles. In a H2 environment, a more faceted surface morphology of the particles was observed with {100} and {111} planes being dominant. On the other hand, in O2 the percentage of {100} and {111} facets decreased and a significant increase of higher order facets was found, resulting in a more rounded morphology. This methodology opens up new opportunities toward in situ characterization of catalytic nanoparticles because for the first time it enables one to directly measure 3D morphology variations at the atomic scale in a specific gaseous reaction environment. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000455561300061 |
Publication Date |
2019-01-09 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
ISSN |
1530-6984 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
12.712 |
Times cited |
82 |
Open Access |
OpenAccess |
Notes |
This work was supported by the European Research Council (Grant 335078 COLOURATOM to S.B. and Grant 770887 PICOMETRICS to S.V.A.). The authors acknowledge funding from the European Commission Grant (EUSMI 731019 to S.B., L.M.L.-M., and Q.X. and MUMMERING 765604 to S.B. and Q.X.). The authors gratefully acknowledge funding from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0368.15N, G.0369.15N, and G.0267.18N), postdoctoral grants to T.A. and A.D.B, and an FWO [PEGASUS]2 Marie Sklodowska-Curie fellowship to Y.Z. (12U4917N). L.M.L.-M. acknowledges funding from the Spanish Ministerio de Economía y Competitividad (Grant MAT2017-86659-R). We gratefully acknowledge the support of NVIDIA Corporation with the donation of the Titan X Pascal GPU used for this research. ecas_sara Realnano 815128; sygma |
Approved |
Most recent IF: 12.712 |
Call Number |
EMAT @ emat @UA @ admin @ c:irua:156390 |
Serial |
5150 |
Permanent link to this record |
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Author |
Arteaga Cardona, F.; Jain, N.; Popescu, R.; Busko, D.; Madirov, E.; Arús, B.A.; Gerthsen, D.; De Backer, A.; Bals, S.; Bruns, O.T.; Chmyrov, A.; Van Aert, S.; Richards, B.S.; Hudry, D. |
Title |
Preventing cation intermixing enables 50% quantum yield in sub-15 nm short-wave infrared-emitting rare-earth based core-shell nanocrystals |
Type |
A1 Journal article |
Year |
2023 |
Publication |
Nature communications |
Abbreviated Journal |
Nat Commun |
Volume |
14 |
Issue |
1 |
Pages |
4462 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Short-wave infrared (SWIR) fluorescence could become the new gold standard in optical imaging for biomedical applications due to important advantages such as lack of autofluorescence, weak photon absorption by blood and tissues, and reduced photon scattering coefficient. Therefore, contrary to the visible and NIR regions, tissues become translucent in the SWIR region. Nevertheless, the lack of bright and biocompatible probes is a key challenge that must be overcome to unlock the full potential of SWIR fluorescence. Although rare-earth-based core-shell nanocrystals appeared as promising SWIR probes, they suffer from limited photoluminescence quantum yield (PLQY). The lack of control over the atomic scale organization of such complex materials is one of the main barriers limiting their optical performance. Here, the growth of either homogeneous (α-NaYF<sub>4</sub>) or heterogeneous (CaF<sub>2</sub>) shell domains on optically-active α-NaYF<sub>4</sub>:Yb:Er (with and without Ce<sup>3+</sup>co-doping) core nanocrystals is reported. The atomic scale organization can be controlled by preventing cation intermixing only in heterogeneous core-shell nanocrystals with a dramatic impact on the PLQY. The latter reached 50% at 60 mW/cm<sup>2</sup>; one of the highest reported PLQY values for sub-15 nm nanocrystals. The most efficient nanocrystals were utilized for in vivo imaging above 1450 nm. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
001037058500022 |
Publication Date |
2023-07-25 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2041-1723 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
16.6 |
Times cited |
1 |
Open Access |
OpenAccess |
Notes |
D.H. would like to thank Dominique Ectors (Bruker AXS GmbH, Karlsruhe, Germany) for assistance and discussion on the PXRD data and TOPAS evaluations. The authors would like to acknowledge the financial support provided by the Helmholtz Association via: i) the Professorial Recruitment Initiative Funding (B.S.R.); ii) the Research Field Energy – Program Materials and Technologies for the Energy Transition – Topic 1 Photovoltaics (F.A.C., D.B., E.M., B.S.R., D.H.). This project received funding from the European Union’s Horizon 2020 innovation programme under grant agreement 823717. This work was supported by the European Research Council (grant 770887-PICOMETRICS to S.V.A. and Grant 815128-REALNANO to S.B.). The authors acknowledge financial support from the ResearchFoundation Flanders (FWO, Belgium) through project fundings (G.0346.21 N to S.V.A. and S.B.) and a postdoctoral grant (A.D.B.). The authors (B.A.A., O.T.B. and A.C.) acknowledge funding from the Helmholtz Zentrum München, the DFG-Emmy Noether program (BR 5355/2-1) and from the CZI Deep Tissue Imaging (DTI-0000000248). The authors (O.T.B. and D.H.) would like to thank the Helmholtz Imaging (ZT-I-PF-4-038-BENIGN). |
Approved |
Most recent IF: 16.6; 2023 IF: 12.124 |
Call Number |
EMAT @ emat @c:irua:198158 |
Serial |
8808 |
Permanent link to this record |
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Author |
Bals, S.; Goris, B.; de Backer, A.; Van Aert, S.; Van Tendeloo, G. |
Title |
Atomic resolution electron tomography |
Type |
A1 Journal article |
Year |
2016 |
Publication |
MRS bulletin |
Abbreviated Journal |
Mrs Bull |
Volume |
41 |
Issue |
41 |
Pages |
525-530 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Over the last two decades, three-dimensional (3D) imaging by transmission electron microscopy or “electron tomography” has evolved into a powerful tool to investigate a variety of nanomaterials in different fields, such as life sciences, chemistry, solid-state physics, and materials science. Most of these results were obtained with nanometer-scale resolution, but different approaches have recently pushed the resolution to the atomic level. Such information is a prerequisite to understand the specific relationship between the atomic structure and the physicochemical properties of (nano) materials. We provide an overview of the latest progress in the field of atomic-resolution electron tomography. Different imaging and reconstruction approaches are presented, and state-of-the-art results are discussed. This article demonstrates the power and importance of electron tomography with atomic-scale resolution. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Pittsburgh, Pa |
Editor |
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Language |
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Wos |
000382508100012 |
Publication Date |
2016-07-07 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0883-7694 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
5.199 |
Times cited |
19 |
Open Access |
OpenAccess |
Notes |
; The authors gratefully acknowledge funding from the Research Foundation Flanders (G.0381.16N, G.036915, G.0374.13, and funding of postdoctoral grants to B.G. and A.D.B.). S.B. acknowledges the European Research Council, ERC Grant Number 335078-Colouratom. The research leading to these results received funding from the European Union Seventh Framework Program under Grant Agreements 312483 (ESTEEM2). The authors would like to thank the colleagues who have contributed to this work, including K.J. Batenburg, J. De Beenhouwer, R. Erni, M.D. Rossell, W. Van den Broek, L. Liz-Marzan, E. Carbo-Argibay, S. Gomez-Grana, P. Lievens, M. Van Bael, B. Partoens, B. Schoeters, and J. Sijbers. ; ecas_sara |
Approved |
Most recent IF: 5.199 |
Call Number |
UA @ lucian @ c:irua:135690 |
Serial |
4299 |
Permanent link to this record |
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Author |
de Backer, A. |
Title |
Quantitative atomic resolution electron microscopy using advanced statistical techniques |
Type |
Doctoral thesis |
Year |
2015 |
Publication |
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Abbreviated Journal |
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Volume |
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Issue |
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Pages |
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Keywords |
Doctoral thesis; Electron microscopy for materials research (EMAT) |
Abstract |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Antwerpen |
Editor |
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Language |
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Wos |
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Publication Date |
0000-00-00 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
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ISBN |
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Additional Links |
UA library record |
Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
Most recent IF: NA |
Call Number |
UA @ lucian @ c:irua:125636 |
Serial |
2747 |
Permanent link to this record |
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Author |
De Backer, A.; Bals, S.; Van Aert, S. |
Title |
A decade of atom-counting in STEM: From the first results toward reliable 3D atomic models from a single projection |
Type |
A1 Journal article |
Year |
2023 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
|
Volume |
|
Issue |
|
Pages |
113702 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Quantitative structure determination is needed in order to study and understand nanomaterials at the atomic scale. Materials characterisation resulting in precise structural information is a crucial point to understand the structure–property relation of materials. Counting the number of atoms and retrieving the 3D atomic structure of nanoparticles plays an important role here. In this paper, an overview will be given of the atom-counting methodology and its applications over the past decade. The procedure to count the number of atoms will be discussed in detail and it will be shown how the performance of the method can be further improved. Furthermore, advances toward mixed element nanostructures, 3D atomic modelling based on the atom-counting results, and quantifying the nanoparticle dynamics will be highlighted. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000953765800001 |
Publication Date |
2023-02-10 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0304-3991 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.2 |
Times cited |
3 |
Open Access |
OpenAccess |
Notes |
This work was supported by the European Research Council (Grant 770887 PICOMETRICS to S. Van Aert, Grant 815128 REALNANO to S. Bals, and Grant 823717 ESTEEM3). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0267.18N, G.0502.18N, G.0346.21N, and EOS 30489208) and a postdoctoral grant to A. De Backer. S. Van Aert acknowledges funding from the University of Antwerp Research fund (BOF) . The authors also thank the colleagues who have contributed to this work over the years, including T. Altantzis, E. Arslan Irmak, K.J. Batenburg, E. Bladt, A. De wael, R. Erni, C. Faes, B. Goris, L. Jones, L.M. Liz-Marzán, I. Lobato, G.T. Martinez, P.D. Nellist, M.D. Rosell, A. Rosenauer, K.H.W. van den Bos, A. Varambhia, and Z. Zhang.; esteem3reported; esteem3JRA |
Approved |
Most recent IF: 2.2; 2023 IF: 2.843 |
Call Number |
EMAT @ emat @c:irua:195896 |
Serial |
7236 |
Permanent link to this record |
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Author |
De Backer, A.; De Wael, A.; Gonnissen, J.; Martinez, G.T.; Béché, A.; MacArthur, K.E.; Jones, L.; Nellist, P.D.; Van Aert, S. |
Title |
Quantitative annular dark field scanning transmission electron microscopy for nanoparticle atom-counting: What are the limits? |
Type |
P1 Proceeding |
Year |
2015 |
Publication |
Journal of physics : conference series |
Abbreviated Journal |
|
Volume |
644 |
Issue |
644 |
Pages |
012034 |
Keywords |
P1 Proceeding; Electron microscopy for materials research (EMAT) |
Abstract |
Quantitative atomic resolution annular dark field scanning transmission electron microscopy (ADF STEM) has become a powerful technique for nanoparticle atom-counting. However, a lot of nanoparticles provide a severe characterisation challenge because of their limited size and beam sensitivity. Therefore, quantitative ADF STEM may greatly benefit from statistical detection theory in order to optimise the instrumental microscope settings such that the incoming electron dose can be kept as low as possible whilst still retaining single-atom precision. The principles of detection theory are used to quantify the probability of error for atom-counting. This enables us to decide between different image performance measures and to optimise the experimental detector settings for atom-counting in ADF STEM in an objective manner. To demonstrate this, ADF STEM imaging of an industrial catalyst has been conducted using the near-optimal detector settings. For this experiment, we discussed the limits for atom-counting diagnosed by combining a thorough statistical method and detailed image simulations. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000366826200034 |
Publication Date |
2015-10-13 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
Electron Microscopy and Analysis Group Conference (EMAG), JUN 02-JUL 02, 2015, Manchester, ENGLAND |
Series Volume |
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Series Issue |
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Edition |
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ISSN |
1742-6588 |
ISBN |
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Additional Links |
UA library record; WoS full record |
Impact Factor |
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Times cited |
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Open Access |
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Notes |
The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project funding (G.0368.15N, G.0369.15N, and G.0374.15N) and a PhD research grant to A De Backer. The research leading to these results has received funding from the European Union Seventh Framework Programme under Grant Agreement 312483 – ESTEEM2 (Integrated Infrastructure Initiative-I3), ERC Starting Grant 278510 Vortex, and the UK Engineering and Physical Sciences Research Council (EP/K032518/1). The authors acknowledge Johnson-Matthey for providing the sample and PhD funding to K E MacArthur. A Rosenauer is acknowledged for providing the STEMsim program.; esteem2jra2; ECASJO; |
Approved |
Most recent IF: NA |
Call Number |
c:irua:130314 c:irua:130314 |
Serial |
4050 |
Permanent link to this record |
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Author |
de Backer, A.; De wael, A.; Gonnissen, J.; Martinez, G.T.; Béché, A.; MacArthur, K.E.; Jones, L.; Nellist, P.D.; Van Aert, S. |
Title |
Quantitative annular dark field scanning transmission electron microscopy for nanoparticle atom-counting : what are the limits? |
Type |
A1 Journal article |
Year |
2015 |
Publication |
Journal of physics : conference series |
Abbreviated Journal |
|
Volume |
644 |
Issue |
|
Pages |
012034-4 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Quantitative atomic resolution annular dark field scanning transmission electron microscopy (ADF STEM) has become a powerful technique for nanoparticle atom-counting. However, a lot of nanoparticles provide a severe characterisation challenge because of their limited size and beam sensitivity. Therefore, quantitative ADF STEM may greatly benefit from statistical detection theory in order to optimise the instrumental microscope settings such that the incoming electron dose can be kept as low as possible whilst still retaining single-atom precision. The principles of detection theory are used to quantify the probability of error for atom-counting. This enables us to decide between different image performance measures and to optimise the experimental detector settings for atom-counting in ADF STEM in an objective manner. To demonstrate this, ADF STEM imaging of an industrial catalyst has been conducted using the near-optimal detector settings. For this experiment, we discussed the limits for atomcounting diagnosed by combining a thorough statistical method and detailed image simulations. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Bristol |
Editor |
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Language |
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Wos |
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Publication Date |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1742-6588; 1742-6596 |
ISBN |
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Additional Links |
UA library record |
Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
Most recent IF: NA |
Call Number |
UA @ lucian @ c:irua:129198 |
Serial |
4506 |
Permanent link to this record |
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Author |
de Backer, A.; De wael, A.; Gonnissen, J.; Van Aert, S. |
Title |
Optimal experimental design for nano-particle atom-counting from high-resolution STEM images |
Type |
A1 Journal article |
Year |
2015 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
Volume |
151 |
Issue |
151 |
Pages |
46-55 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
In the present paper, the principles of detection theory are used to quantify the probability of error for atom-counting from high resolution scanning transmission electron microscopy (HR STEM) images. Binary and multiple hypothesis testing have been investigated in order to determine the limits to the precision with which the number of atoms in a projected atomic column can be estimated. The probability of error has been calculated when using STEM images, scattering cross-sections or peak intensities as a criterion to count atoms. Based on this analysis, we conclude that scattering cross-sections perform almost equally well as images and perform better than peak intensities. Furthermore, the optimal STEM detector design can be derived for atom-counting using the expression for the probability of error. We show that for very thin objects LAADF is optimal and that for thicker objects the optimal inner detector angle increases. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
Language |
|
Wos |
000351237800007 |
Publication Date |
2014-11-11 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0304-3991; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.843 |
Times cited |
24 |
Open Access |
|
Notes |
312483 Esteem2; Fwo G039311; G037413; esteem2_jra2 |
Approved |
Most recent IF: 2.843; 2015 IF: 2.436 |
Call Number |
c:irua:123926 c:irua:123926 |
Serial |
2481 |
Permanent link to this record |
|
|
|
Author |
de Backer, A.; Fatermans, J.; den Dekker, A.J.; Van Aert, S. |
Title |
Atom counting |
Type |
H2 Book chapter |
Year |
2021 |
Publication |
Advances in imaging and electron physics
T2 – Advances in imaging and electron physics |
Abbreviated Journal |
|
Volume |
|
Issue |
|
Pages |
91-144 |
Keywords |
H2 Book chapter; Electron microscopy for materials research (EMAT); Vision lab |
Abstract |
In this chapter, a statistical model-based method to count the number of atoms of monotype crystalline nanostructures from high-resolution annular dark-field (ADF) scanning transmission electron microscopy (STEM) images is discussed in detail together with a thorough study on the possibilities and inherent limitations. We show that this method can be applied to nanocrystals of arbitrary shape, size, and atom type. The validity of the atom-counting results is confirmed by means of detailed image simulations and it is shown that the high sensitivity of our method enables us to count atoms with single atom sensitivity. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
|
Publication Date |
2021-03-06 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
217 |
Series Issue |
|
Edition |
|
ISSN |
|
ISBN |
978-0-12-824607-8; 1076-5670 |
Additional Links |
UA library record |
Impact Factor |
|
Times cited |
|
Open Access |
Not_Open_Access |
Notes |
ERC Consolidator project funded by the European Union grant #770887 Picometrics |
Approved |
Most recent IF: NA |
Call Number |
UA @ admin @ c:irua:177529 |
Serial |
6776 |
Permanent link to this record |
|
|
|
Author |
de Backer, A.; Fatermans, J.; den Dekker, A.J.; Van Aert, S. |
Title |
Efficient fitting algorithm |
Type |
H2 Book chapter |
Year |
2021 |
Publication |
Advances in imaging and electron physics
T2 – Advances in imaging and electron physics |
Abbreviated Journal |
|
Volume |
|
Issue |
|
Pages |
73-90 |
Keywords |
H2 Book chapter; Electron microscopy for materials research (EMAT) |
Abstract |
An efficient model-based estimation algorithm is introduced to quantify the atomic column positions and intensities from atomic-resolution (scanning) transmission electron microscopy ((S)TEM) images. This algorithm uses the least squares estimator on image segments containing individual columns fully accounting for overlap between neighboring columns, enabling the analysis of a large field of view. To provide end-users with this well-established quantification method, a user friendly program, StatSTEM, is developed which is freely available under a GNU public license. In this chapter, this efficient algorithm is applied to three different nanostructures for which the analysis of a large field of view is required. |
Address |
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Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
|
Publication Date |
2021-03-06 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
217 |
Series Issue |
|
Edition |
|
ISSN |
|
ISBN |
978-0-12-824607-8; 1076-5670 |
Additional Links |
UA library record |
Impact Factor |
|
Times cited |
|
Open Access |
Not_Open_Access |
Notes |
ERC Consolidator project funded by the European Union grant #770887 Picometrics |
Approved |
Most recent IF: NA |
Call Number |
UA @ admin @ c:irua:177528 |
Serial |
6778 |
Permanent link to this record |
|
|
|
Author |
de Backer, A.; Fatermans, J.; den Dekker, A.J.; Van Aert, S. |
Title |
General conclusions and future perspectives |
Type |
H2 Book chapter |
Year |
2021 |
Publication |
Advances in imaging and electron physics
T2 – Advances in imaging and electron physics |
Abbreviated Journal |
|
Volume |
|
Issue |
|
Pages |
243-253 |
Keywords |
H2 Book chapter; Electron microscopy for materials research (EMAT); Vision lab |
Abstract |
This chapter provides an overview of statistical and quantitative methodologies that have pushed (scanning) transmission electron microscopy ((S)TEM) toward accurate and precise measurements of unknown structure parameters for understanding the relation between the structure of a material and its properties. Hereby, statistical parameter estimation theory has extensively been used which enabled not only measuring atomic column positions, but also quantifying the number of atoms, and detecting atomic columns as accurately and precisely as possible from experimental images. As a general conclusion, it can be stated that advanced statistical techniques are ideal tools to perform quantitative electron microscopy at the atomic scale. In the future, statistical methods will continue to be developed and novel quantification procedures will open up new possibilities for studying material structures at the atomic scale. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
|
Editor |
|
Language |
|
Wos |
|
Publication Date |
2021-03-06 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
217 |
Series Issue |
|
Edition |
|
ISSN |
|
ISBN |
978-0-12-824607-8; 1076-5670 |
Additional Links |
UA library record |
Impact Factor |
|
Times cited |
|
Open Access |
Not_Open_Access |
Notes |
ERC Consolidator project funded by the European Union grant #770887 Picometrics |
Approved |
Most recent IF: NA |
Call Number |
UA @ admin @ c:irua:177533 |
Serial |
6781 |
Permanent link to this record |
|
|
|
Author |
de Backer, A.; Fatermans, J.; den Dekker, A.J.; Van Aert, S. |
Title |
Introduction |
Type |
H2 Book chapter |
Year |
2021 |
Publication |
Advances in imaging and electron physics
T2 – Advances in imaging and electron physics |
Abbreviated Journal |
|
Volume |
|
Issue |
|
Pages |
1-28 |
Keywords |
H2 Book chapter; Electron microscopy for materials research (EMAT) |
Abstract |
|
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
|
Publication Date |
2021-03-06 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
217 |
Series Issue |
|
Edition |
|
ISSN |
|
ISBN |
978-0-12-824607-8; 1076-5670 |
Additional Links |
UA library record |
Impact Factor |
|
Times cited |
|
Open Access |
Not_Open_Access |
Notes |
ERC Consolidator project funded by the European Union grant #770887 Picometrics |
Approved |
Most recent IF: NA |
Call Number |
UA @ admin @ c:irua:177525 |
Serial |
6784 |
Permanent link to this record |
|
|
|
Author |
de Backer, A.; Fatermans, J.; den Dekker, A.J.; Van Aert, S. |
Title |
Optimal experiment design for nanoparticle atom counting from ADF STEM images |
Type |
H2 Book chapter |
Year |
2021 |
Publication |
Advances in imaging and electron physics
T2 – Advances in imaging and electron physics |
Abbreviated Journal |
|
Volume |
|
Issue |
|
Pages |
145-175 |
Keywords |
H2 Book chapter; Electron microscopy for materials research (EMAT); Vision lab |
Abstract |
In this chapter, the principles of detection theory are used to quantify the probability of error for atom counting from high-resolution scanning transmission electron microscopy (HRSTEM) images. Binary and multiple hypothesis testing have been investigated in order to determine the limits to the precision with which the number of atoms in a projected atomic column can be estimated. The probability of error has been calculated when using STEM images, scattering cross-sections or peak intensities as a criterion to count atoms. Based on this analysis, we conclude that scattering cross-sections perform almost equally well as images and perform better than peak intensities. Furthermore, the optimal STEM detector design can be derived for atom counting using the expression of the probability of error. We show that for very thin objects the low-angle annular dark-field (LAADF) regime is optimal and that for thicker objects the optimal inner detector angle increases. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
|
Publication Date |
2021-03-06 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
217 |
Series Issue |
|
Edition |
|
ISSN |
|
ISBN |
978-0-12-824607-8; 1076-5670 |
Additional Links |
UA library record |
Impact Factor |
|
Times cited |
|
Open Access |
Not_Open_Access |
Notes |
ERC Consolidator project funded by the European Union grant #770887 Picometrics |
Approved |
Most recent IF: NA |
Call Number |
UA @ admin @ c:irua:177530 |
Serial |
6785 |
Permanent link to this record |
|
|
|
Author |
de Backer, A.; Fatermans, J.; den Dekker, A.J.; Van Aert, S. |
Title |
Statistical parameter estimation theory : principles and simulation studies |
Type |
H2 Book chapter |
Year |
2021 |
Publication |
Advances in imaging and electron physics
T2 – Advances in imaging and electron physics |
Abbreviated Journal |
|
Volume |
|
Issue |
|
Pages |
29-72 |
Keywords |
H2 Book chapter; Electron microscopy for materials research (EMAT); Vision lab |
Abstract |
In this chapter, the principles of statistical parameter estimation theory for a quantitative analysis of atomic-resolution electron microscopy images are introduced. Within this framework, electron microscopy images are described by a parametric statistical model. Here, parametric models are introduced for different types of electron microscopy images: reconstructed exit waves, annular dark-field (ADF) scanning transmission electron microscopy (STEM) images, and simultaneously acquired ADF and annular bright-field (ABF) STEM images. Furthermore, the Cramér-Rao lower bound (CRLB) is introduced, i.e. a theoretical lower bound on the variance of any unbiased estimator. This CRLB is used to quantify the precision of the structure parameters of interest, such as the atomic column positions and the integrated atomic column intensities. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
|
Publication Date |
2021-03-06 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
217 |
Series Issue |
|
Edition |
|
ISSN |
|
ISBN |
978-0-12-824607-8; 1076-5670 |
Additional Links |
UA library record |
Impact Factor |
|
Times cited |
|
Open Access |
Not_Open_Access |
Notes |
ERC Consolidator project funded by the European Union grant #770887 Picometrics |
Approved |
Most recent IF: NA |
Call Number |
UA @ admin @ c:irua:177527 |
Serial |
6788 |
Permanent link to this record |
|
|
|
Author |
De Backer, A.; Jones, L.; Lobato, I.; Altantzis, T.; Goris, B.; Nellist, P.D.; Bals, S.; Van Aert, S. |
Title |
Three-dimensional atomic models from a single projection using Z-contrast imaging: verification by electron tomography and opportunities |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Nanoscale |
Abbreviated Journal |
Nanoscale |
Volume |
9 |
Issue |
9 |
Pages |
8791-8798 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
In order to fully exploit structure–property relations of nanomaterials, three-dimensional (3D) characterization at the atomic scale is often required. In recent years, the resolution of electron tomography has reached the atomic scale. However, such tomography typically requires several projection images demanding substantial electron dose. A newly developed alternative circumvents this by counting the number of atoms across a single projection. These atom counts can be used to create an initial atomic model with which an energy minimization can be applied to obtain a relaxed 3D reconstruction of the nanoparticle. Here, we compare, at the atomic scale, this single projection reconstruction approach with tomography and find an excellent agreement. This new approach allows for the characterization of beam-sensitive materials or where the acquisition of a tilt series is impossible. As an example, the utility is illustrated by the 3D atomic scale characterization of a nanodumbbell on an in situ heating holder of limited tilt range. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000404614700031 |
Publication Date |
2017-06-09 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2040-3364 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
7.367 |
Times cited |
33 |
Open Access |
OpenAccess |
Notes |
The authors gratefully acknowledge funding from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0374.13N, G.0369.15N, G.0368.15N, and WO.010.16N) and postdoctoral grants to T. Altantzis, A. De Backer, and B. Goris. S. Bals acknowledges financial support from the European Research Council (Starting Grant No. COLOURATOM 335078). Funding from the European Union Seventh Framework Programme under Grant Agreement 312483 – ESTEEM2 (Integrated Infrastructure Initiatieve-I3) is acknowledged. The authors would also like to thank Luis Liz-Marzán, Marek Grzelczak, and Ana Sánchez-Iglesias for sample provision. (ROMEO:yellow; preprint:; postprint:restricted ; pdfversion:cannot); saraecas; ECAS_Sara; |
Approved |
Most recent IF: 7.367 |
Call Number |
EMAT @ emat @ c:irua:144436UA @ admin @ c:irua:144436 |
Serial |
4617 |
Permanent link to this record |
|
|
|
Author |
de Backer, A.; Martinez, G.T.; MacArthur, K.E.; Jones, L.; Béché, A.; Nellist, P.D.; Van Aert, S. |
Title |
Dose limited reliability of quantitative annular dark field scanning transmission electron microscopy for nano-particle atom-counting |
Type |
A1 Journal article |
Year |
2015 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
Volume |
151 |
Issue |
151 |
Pages |
56-61 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Quantitative annular dark field scanning transmission electron microscopy (ADF STEM) has become a powerful technique to characterise nano-particles on an atomic scale. Because of their limited size and beam sensitivity, the atomic structure of such particles may become extremely challenging to determine. Therefore keeping the incoming electron dose to a minimum is important. However, this may reduce the reliability of quantitative ADF STEM which will here be demonstrated for nano-particle atom-counting. Based on experimental ADF STEM images of a real industrial catalyst, we discuss the limits for counting the number of atoms in a projected atomic column with single atom sensitivity. We diagnose these limits by combining a thorough statistical method and detailed image simulations. |
Address |
|
Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
Language |
|
Wos |
000351237800008 |
Publication Date |
2014-12-03 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0304-3991; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.843 |
Times cited |
29 |
Open Access |
|
Notes |
312483 Esteem2; 278510 Vortex; Fwo G039311; G006410; G037413; esteem2ta; ECASJO; |
Approved |
Most recent IF: 2.843; 2015 IF: 2.436 |
Call Number |
c:irua:123927 c:irua:123927 |
Serial |
753 |
Permanent link to this record |
|
|
|
Author |
de Backer, A.; Martinez, G.T.; Rosenauer, A.; Van Aert, S. |
Title |
Atom counting in HAADF STEM using a statistical model-based approach : methodology, possibilities, and inherent limitations |
Type |
A1 Journal article |
Year |
2013 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
Volume |
134 |
Issue |
|
Pages |
23-33 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
In the present paper, a statistical model-based method to count the number of atoms of monotype crystalline nanostructures from high resolution high-angle annular dark-field (HAADF) scanning transmission electron microscopy (STEM) images is discussed in detail together with a thorough study on the possibilities and inherent limitations. In order to count the number of atoms, it is assumed that the total scattered intensity scales with the number of atoms per atom column. These intensities are quantitatively determined using model-based statistical parameter estimation theory. The distribution describing the probability that intensity values are generated by atomic columns containing a specific number of atoms is inferred on the basis of the experimental scattered intensities. Finally, the number of atoms per atom column is quantified using this estimated probability distribution. The number of atom columns available in the observed STEM image, the number of components in the estimated probability distribution, the width of the components of the probability distribution, and the typical shape of a criterion to assess the number of components in the probability distribution directly affect the accuracy and precision with which the number of atoms in a particular atom column can be estimated. It is shown that single atom sensitivity is feasible taking the latter aspects into consideration. |
Address |
|
Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
Language |
|
Wos |
000324474900005 |
Publication Date |
2013-05-17 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0304-3991; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.843 |
Times cited |
48 |
Open Access |
|
Notes |
FWO; Esteem2; FP 2007-2013; esteem2_jra2 |
Approved |
Most recent IF: 2.843; 2013 IF: 2.745 |
Call Number |
UA @ lucian @ c:irua:109916 |
Serial |
162 |
Permanent link to this record |
|
|
|
Author |
De Backer, A.; Van Aert, S.; Faes, C.; Arslan Irmak, E.; Nellist, P.D.; Jones, L. |
Title |
Experimental reconstructions of 3D atomic structures from electron microscopy images using a Bayesian genetic algorithm |
Type |
A1 Journal article |
Year |
2022 |
Publication |
N P J Computational Materials |
Abbreviated Journal |
npj Comput Mater |
Volume |
8 |
Issue |
1 |
Pages |
216 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
We introduce a Bayesian genetic algorithm for reconstructing atomic models of monotype crystalline nanoparticles from a single projection using Z-contrast imaging. The number of atoms in a projected atomic column obtained from annular dark field scanning transmission electron microscopy images serves as an input for the initial three-dimensional model. The algorithm minimizes the energy of the structure while utilizing a priori information about the finite precision of the atom-counting results and neighbor-mass relations. The results show promising prospects for obtaining reliable reconstructions of beam-sensitive nanoparticles during dynamical processes from images acquired with sufficiently low incident electron doses. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
|
Editor |
|
Language |
|
Wos |
000866500900001 |
Publication Date |
2022-10-12 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2057-3960 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
|
Times cited |
|
Open Access |
OpenAccess |
Notes |
This work was supported by the European Research Council (Grant 770887 PICOMETRICS to S.V.A. and Grant 823717 ESTEEM3). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0267.18N, G.0502.18N, G.0346.21N) and a postdoctoral grant to A.D.B. L.J. acknowledges Science Foundation Ireland (SFI – grant number URF/RI/191637), the Royal Society, and the AMBER Centre. The authors acknowledge Aakash Varambhia for his assistance and expertise with the experimental recording and use of characterization facilities within the David Cockayne Centre for Electron Microscopy, Department of Materials, University of Oxford, and in particular the EPSRC (EP/K040375/1 South of England Analytical Electron Microscope).; esteem3reported; esteem3JRA |
Approved |
Most recent IF: NA |
Call Number |
EMAT @ emat @c:irua:191398 |
Serial |
7114 |
Permanent link to this record |
|
|
|
Author |
de Backer, A.; Van Aert, S.; van Dyck, D. |
Title |
High precision measurements of atom column positions using model-based exit wave reconstruction |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
Volume |
111 |
Issue |
9/10 |
Pages |
1475-1482 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
Abstract |
In this paper, it has been investigated how to measure atom column positions as accurately and precisely as possible using a focal series of images. In theory, it is expected that the precision would considerably improve using a maximum likelihood estimator based on the full series of focal images. As such, the theoretical lower bound on the variances of the unknown atom column positions can be attained. However, this approach is numerically demanding. Therefore, maximum likelihood estimation has been compared with the results obtained by fitting a model to a reconstructed exit wave rather than to the full series of focal images. Hence, a real space model-based exit wave reconstruction technique based on the channelling theory is introduced. Simulations show that the reconstructed complex exit wave contains the same amount of information concerning the atom column positions as the full series of focal images. Only for thin samples, which act as weak phase objects, this information can be retrieved from the phase of the reconstructed complex exit wave. |
Address |
|
Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
Language |
|
Wos |
000300461200004 |
Publication Date |
2011-07-28 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0304-3991; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.843 |
Times cited |
8 |
Open Access |
|
Notes |
Fwo |
Approved |
Most recent IF: 2.843; 2011 IF: 2.471 |
Call Number |
UA @ lucian @ c:irua:91879 |
Serial |
1438 |
Permanent link to this record |
|
|
|
Author |
De Backer, A.; van den Bos, K.H.W.; Van den Broek, W.; Sijbers, J.; Van Aert, S. |
Title |
StatSTEM: An efficient approach for accurate and precise model-based quantification of atomic resolution electron microscopy images |
Type |
A1 Journal article |
Year |
2016 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
Volume |
171 |
Issue |
171 |
Pages |
104-116 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
Abstract |
An efficient model-based estimation algorithm is introduced to quantify the atomic column positions and intensities from atomic resolution (scanning) transmission electron microscopy ((S)TEM) images. This algorithm uses the least squares estimator on image segments containing individual columns fully accounting for overlap between neighbouring columns, enabling the analysis of a large field of view. For this algorithm, the accuracy and precision with which measurements for the atomic column positions and scattering cross-sections from annular dark field (ADF) STEM images can be estimated, has been investigated. The highest attainable precision is reached even for low dose images. Furthermore, the advantages of the model-based approach taking into account overlap between neighbouring columns are highlighted. This is done for the estimation of the distance between two neighbouring columns as a function of their distance and for the estimation of the scattering cross-section which is compared to the integrated intensity from a Voronoi cell. To provide end-users this well-established quantification method, a user friendly program, StatSTEM, is developed which is freely available under a GNU public license. |
Address |
|
Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000389106200014 |
Publication Date |
2016-09-09 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0304-3991 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.843 |
Times cited |
43 |
Open Access |
|
Notes |
The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0393.11, G.0064.10 and G.0374.13), a Ph.D. research grant to K.H.W. van den Bos, and a postdoctoral research grant to A. De Backer. The research leading to these results has received funding from the European Union Seventh Framework Programme under Grant Agreement 312483 – ESTEEM2 (Integrated Infrastructure Initiative-I3). A. Rosenauer is acknowledged for providing the STEMsim program.; esteem2_jra2 |
Approved |
Most recent IF: 2.843 |
Call Number |
EMAT @ emat @ c:irua:135516 |
Serial |
4280 |
Permanent link to this record |
|
|
|
Author |
De Backer, A.; van den Bos, K.H.W.; Van den Broek, W.; Sijbers, J.; Van Aert, S. |
Title |
StatSTEM: An efficient program for accurate and precise model-based quantification of atomic resolution electron microscopy images |
Type |
P1 Proceeding |
Year |
2017 |
Publication |
Journal of physics : conference series
T2 – Electron Microscopy and Analysis Group Conference 2017 (EMAG2017), 3-6 July 2017, Manchester, UK |
Abbreviated Journal |
J. Phys.: Conf. Ser. |
Volume |
902 |
Issue |
|
Pages |
012013 |
Keywords |
P1 Proceeding; Electron microscopy for materials research (EMAT); Vision lab |
Abstract |
An efficient model-based estimation algorithm is introduced in order to quantify the atomic column positions and intensities from atomic resolution (scanning) transmission electron microscopy ((S)TEM) images. This algorithm uses the least squares estimator on image segments containing individual columns fully accounting for the overlap between neighbouring columns, enabling the analysis of a large field of view. For this algorithm, the accuracy and precision with which measurements for the atomic column positions and scattering cross-sections from annular dark field (ADF) STEM images can be estimated, is investigated. The highest attainable precision is reached even for low dose images. Furthermore, advantages of the model- based approach taking into account overlap between neighbouring columns are highlighted. To provide end-users this well-established quantification method, a user friendly program, StatSTEM, is developed which is freely available under a GNU public license. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
|
Editor |
|
Language |
|
Wos |
000416370700013 |
Publication Date |
2017-10-16 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1742-6588 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
|
Times cited |
1 |
Open Access |
OpenAccess |
Notes |
The authors acknowledge nancial support from the Research Foundation Flanders (FWO, Belgium) through project funding (G.0374.13N, G.0368.15N, G.0369.15N, WO.010.16N) and a PhD research grant to K H W van den Bos, and a postdoctoral research grant to A De Backer. The research leading to these results has received funding from the European Union Seventh Framework Programme under Grant Agreement 312483 – ESTEEM2 (Integrated Infrastructure Initiative-I3). A Rosenauer is acknowledged for providing the STEMsim program. |
Approved |
Most recent IF: NA |
Call Number |
EMAT @ emat @c:irua:147188 |
Serial |
4764 |
Permanent link to this record |
|
|
|
Author |
De Backer, A.; Zhang, Z.; van den Bos, K.H.W.; Bladt, E.; Sánchez‐Iglesias, A.; Liz‐Marzán, L.M.; Nellist, P.D.; Bals, S.; Van Aert, S. |
Title |
Element Specific Atom Counting at the Atomic Scale by Combining High Angle Annular Dark Field Scanning Transmission Electron Microscopy and Energy Dispersive X‐ray Spectroscopy |
Type |
A1 Journal article |
Year |
2022 |
Publication |
Small methods |
Abbreviated Journal |
Small Methods |
Volume |
|
Issue |
|
Pages |
2200875 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
A new methodology is presented to count the number of atoms in multimetallic nanocrystals by combining energy dispersive X-ray spectroscopy (EDX) and high angle annular dark field scanning transmission electron microscopy (HAADF STEM). For this purpose, the existence of a linear relationship between the incoherent HAADF STEM and EDX images is exploited. Next to the number of atoms for each element in the atomic columns, the method also allows quantification of the error in the obtained number of atoms, which is of importance given the noisy nature of the acquired EDX signals. Using experimental images of an Au@Ag core–shell nanorod, it is demonstrated that 3D structural information can be extracted at the atomic scale. Furthermore, simulated data of an Au@Pt core–shell nanorod show the prospect to characterize heterogeneous nanostructures with adjacent atomic numbers. |
Address |
|
Corporate Author |
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Thesis |
|
Publisher |
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Place of Publication |
|
Editor |
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Language |
|
Wos |
000862072700001 |
Publication Date |
2022-09-30 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2366-9608 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
12.4 |
Times cited |
5 |
Open Access |
OpenAccess |
Notes |
This work was supported by the European Research Council (Grant 770887 PICOMETRICS to S.V.A., Grant 815128 REALNANO to S.B., and Grant 823717 ESTEEM3). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0267.18N, G.0502.18N, G.0346.21N) and a postdoctoral grant to A.D.B.; esteem3reported; esteem3JRA |
Approved |
Most recent IF: 12.4 |
Call Number |
EMAT @ emat @c:irua:191570 |
Serial |
7109 |
Permanent link to this record |
|
|
|
Author |
De wael, A.; De Backer, A.; Jones, L.; Nellist, P.D.; Van Aert, S. |
Title |
Hybrid statistics-simulations based method for atom-counting from ADF STEM images |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
Volume |
177 |
Issue |
177 |
Pages |
69-77 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
A hybrid statistics-simulations based method for atom-counting from annular dark field scanning transmission electron microscopy (ADF STEM) images of monotype crystalline nanostructures is presented. Different atom-counting methods already exist for model-like systems. However, the increasing relevance of radiation damage in the study of nanostructures demands a method that allows atom-counting from low dose images with a low signal-to-noise ratio. Therefore, the hybrid method directly includes prior knowledge from image simulations into the existing statistics-based method for atom-counting, and accounts in this manner for possible discrepancies between actual and simulated experimental conditions. It is shown by means of simulations and experiments that this hybrid method outperforms the statistics-based method, especially for low electron doses and small nanoparticles. The analysis of a simulated low dose image of a small nanoparticle suggests that this method allows for far more reliable quantitative analysis of beam-sensitive materials. |
Address |
|
Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000401219800010 |
Publication Date |
2017-01-25 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0304-3991 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.843 |
Times cited |
8 |
Open Access |
OpenAccess |
Notes |
The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0374.13N, G.0368.15N, G.0369.15N, and WO.010.16N), and a postdoctoral research Grant to A. De Backer. The research leading to these results has received funding from the European Union Seventh Framework Programme under Grant Agreement 312483 – ESTEEM2 (Integrated Infrastructure Initiative-I3). The authors are grateful to G.T. Martinez for providing image simulations. |
Approved |
Most recent IF: 2.843 |
Call Number |
EMAT @ emat @ c:irua:141718 |
Serial |
4486 |
Permanent link to this record |
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|
|
Author |
De wael, A.; De Backer, A.; Jones, L.; Varambhia, A.; Nellist, P.D.; Van Aert, S. |
Title |
Measuring Dynamic Structural Changes of Nanoparticles at the Atomic Scale Using Scanning Transmission Electron Microscopy |
Type |
A1 Journal article |
Year |
2020 |
Publication |
Physical Review Letters |
Abbreviated Journal |
Phys Rev Lett |
Volume |
124 |
Issue |
10 |
Pages |
106105 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
We propose a new method to measure atomic scale dynamics of nanoparticles from experimental high-resolution annular dark field scanning transmission electron microscopy images. By using the so-called hidden Markov model, which explicitly models the possibility of structural changes, the number of atoms in each atomic column can be quantified over time. This newly proposed method outperforms the current atom-counting procedure and enables the determination of the probabilities and cross sections for surface diffusion. This method is therefore of great importance for revealing and quantifying the atomic structure when it evolves over time via adatom dynamics, surface diffusion, beam effects, or during in situ experiments. |
Address |
|
Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000519718100015 |
Publication Date |
2020-03-13 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0031-9007 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
8.6 |
Times cited |
|
Open Access |
OpenAccess |
Notes |
This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (Grant Agreement No. 770887 and No. 823717 ESTEEM3). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through grants to A.D.w. and A.D.B. and projects G.0502.18N and EOS 30489208. L.J. acknowledges the SFI AMBER Centre for support. A.V. and P.D.N. acknowledge the UK Engineering and Physical Sciences Council (EPSRC) for support (EP/K040375/1 and 1772738). A.V. also acknowledges Johnson-Matthey for support. We would like to thank Brian Theobald and Jonathan Sharman from JMTC Sonning for provision of the Pt sample. |
Approved |
Most recent IF: 8.6; 2020 IF: 8.462 |
Call Number |
EMAT @ emat @c:irua:167148 |
Serial |
6347 |
Permanent link to this record |
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|
Author |
De wael, A.; De Backer, A.; Lobato, I.; Van Aert, S. |
Title |
Modelling ADF STEM images using elliptical Gaussian peaks and its effects on the quantification of structure parameters in the presence of sample tilt |
Type |
A1 Journal article |
Year |
2021 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
Volume |
|
Issue |
|
Pages |
113391 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000704334200001 |
Publication Date |
2021-09-24 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0304-3991 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.843 |
Times cited |
|
Open Access |
OpenAccess |
Notes |
This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (Grant Agreement No. 770887 and No. 823717 ESTEEM3). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through grants to A.D.w. and A.D.B. and projects G.0502.18N, G.0267.18N, and EOS 30489208. S.V.A. acknowledges TOP BOF funding from the University of Antwerp.; esteem3JRA; esteem3reported |
Approved |
Most recent IF: 2.843 |
Call Number |
EMAT @ emat @c:irua:181462 |
Serial |
6810 |
Permanent link to this record |
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|
|
Author |
De wael, A.; De Backer, A.; Van Aert, S. |
Title |
Hidden Markov model for atom-counting from sequential ADF STEM images: Methodology, possibilities and limitations |
Type |
A1 Journal article |
Year |
2020 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
Volume |
219 |
Issue |
|
Pages |
113131 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
We present a quantitative method which allows us to reliably measure dynamic changes in the atomic structure of monatomic crystalline nanomaterials from a time series of atomic resolution annular dark field scanning transmission electron microscopy images. The approach is based on the so-called hidden Markov model and estimates the number of atoms in each atomic column of the nanomaterial in each frame of the time series. We discuss the origin of the improved performance for time series atom-counting as compared to the current state-of-the-art atom-counting procedures, and show that the so-called transition probabilities that describe the probability for an atomic column to lose or gain one or more atoms from frame to frame are particularly important. Using these transition probabilities, we show that the method can also be used to estimate the probability and cross section related to structural changes. Furthermore, we explore the possibilities for applying the method to time series recorded under variable environmental conditions. The method is shown to be promising for a reliable quantitative analysis of dynamic processes such as surface diffusion, adatom dynamics, beam effects, or in situ experiments. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
|
Editor |
|
Language |
|
Wos |
000594770500003 |
Publication Date |
2020-10-03 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0304-3991 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.2 |
Times cited |
|
Open Access |
OpenAccess |
Notes |
This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (Grant Agreement No. 770887 and No. 823717 ESTEEM3). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through grants to A.D.w. and A.D.B. and projects G.0502.18N and EOS 30489208. |
Approved |
Most recent IF: 2.2; 2020 IF: 2.843 |
Call Number |
EMAT @ emat @c:irua:172449 |
Serial |
6417 |
Permanent link to this record |
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Author |
De wael, A.; De Backer, A.; Yu, C.-P.; Sentürk, D.G.; Lobato, I.; Faes, C.; Van Aert, S. |
Title |
Three Approaches for Representing the Statistical Uncertainty on Atom-Counting Results in Quantitative ADF STEM |
Type |
A1 Journal article |
Year |
2022 |
Publication |
Microscopy and microanalysis |
Abbreviated Journal |
Microsc Microanal |
Volume |
|
Issue |
|
Pages |
1-9 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
A decade ago, a statistics-based method was introduced to count the number of atoms from annular dark-field scanning transmission electron microscopy (ADF STEM) images. In the past years, this method was successfully applied to nanocrystals of arbitrary shape, size, and composition (and its high accuracy and precision has been demonstrated). However, the counting results obtained from this statistical framework are so far presented without a visualization of the actual uncertainty about this estimate. In this paper, we present three approaches that can be used to represent counting results together with their statistical error, and discuss which approach is most suited for further use based on simulations and an experimental ADF STEM image. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000854930500001 |
Publication Date |
2022-09-19 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1431-9276 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
Impact Factor |
2.8 |
Times cited |
|
Open Access |
OpenAccess |
Notes |
This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (Grant Agreement No. 770887 and No. 823717 ESTEEM3). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through grants to A.D.w. and A.D.B. and projects G.0502.18N, G.0267.18N, and EOS 30489208. S.V.A. acknowledges TOP BOF funding from the University of Antwerp. The authors are grateful to L.M. Liz-Marzán (CIC biomaGUNE and Ikerbasque) for providing the samples. esteem3reported; esteem3jra |
Approved |
Most recent IF: 2.8 |
Call Number |
EMAT @ emat @c:irua:190585 |
Serial |
7119 |
Permanent link to this record |