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Author |
Şentürk, D.G.; De Backer, A.; Van Aert, S. |
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Title |
Element specific atom counting for heterogeneous nanostructures: Combining multiple ADF STEM images for simultaneous thickness and composition determination |
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A1 Journal article |
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Year |
2024 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
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Volume |
259 |
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Pages |
113941 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
In this paper, a methodology is presented to count the number of atoms in heterogeneous nanoparticles based on the combination of multiple annular dark field scanning transmission electron microscopy (ADF STEM) images. The different non-overlapping annular detector collection regions are selected based on the principles of optimal statistical experiment design for the atom-counting problem. To count the number of atoms, the total intensities of scattered electrons for each atomic column, the so-called scattering cross-sections, are simultaneously compared with simulated library values for the different detector regions by minimising the squared differences. The performance of the method is evaluated for simulated Ni@Pt and Au@Ag core-shell nanoparticles. Our approach turns out to be a dose efficient alternative for the investigation of beam-sensitive heterogeneous materials as compared to the combination of ADF STEM and energy dispersive X-ray spectroscopy. |
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Wos |
001205863200001 |
Publication Date |
2024-02-19 |
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0304-3991 |
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Additional Links |
UA library record; WoS full record |
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Impact Factor |
2.2 |
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Open Access |
OpenAccess |
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Notes |
This work was supported by the European Research Council (Grant 770887 PICOMETRICS to S. Van Aert). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0346.21N, GOA7723N, and EOS 40007495) and a postdoctoral grant to A. De Backer. S. Van Aert acknowledges funding from the University of Antwerp Research fund (BOF). |
Approved |
Most recent IF: 2.2; 2024 IF: 2.843 |
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Call Number |
EMAT @ emat @c:irua:204353 |
Serial |
8996 |
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Author |
Stoops, T.; De Backer, A.; Lobato, I.; Van Aert, S. |
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Title |
Obtaining 3D Atomic Reconstructions from Electron Microscopy Images Using a Bayesian Genetic Algorithm: Possibilities, Insights, and Limitations |
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A1 Journal Article |
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Year |
2024 |
Publication |
Microscopy and Microanalysis |
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Keywords |
A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ; |
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The Bayesian genetic algorithm (BGA) is a powerful tool to reconstruct the 3D structure of mono-atomic single-crystalline metallic nanoparticles imaged using annular dark field scanning transmission electron microscopy. The number of atoms in a projected atomic column in the image is used as input to obtain an accurate and atomically precise reconstruction of the nanoparticle, taking prior knowledge and the finite precision of atom counting into account. However, as the number of parameters required to describe a nanoparticle with atomic detail rises quickly with the size of the studied particle, the computational costs of the BGA rise to prohibitively expensive levels. In this study, we investigate these computational costs and propose methods and control parameters for efficient application of the algorithm to nanoparticles of at least up to 10 nm in size. |
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Publication Date |
2024-10-02 |
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ISSN |
1431-9276 |
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Impact Factor |
2.8 |
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Notes |
European Research Council, 770887 ; Research Foundation Flanders, G034621N G0A7723N 40007495 ; FWO and F.R.S-FNRS; Flemish Government; |
Approved |
Most recent IF: 2.8; 2024 IF: 1.891 |
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Call Number |
EMAT @ emat @ |
Serial |
9270 |
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Author |
Schrenker, N.J.; Braeckevelt, T.; De Backer, A.; Livakas, N.; Yu, C.-P.; Friedrich, T.; Roeffaers, M.B.J.; Hofkens, J.; Verbeeck, J.; Manna, L.; Van Speybroeck, V.; Van Aert, S.; Bals, S. |
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Title |
Investigation of the Octahedral Network Structure in Formamidinium Lead Bromide Nanocrystals by Low-Dose Scanning Transmission Electron Microscopy |
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A1 Journal Article |
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Year |
2024 |
Publication |
Nano Letters |
Abbreviated Journal |
Nano Lett. |
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24 |
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35 |
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10936-10942 |
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Keywords |
A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ; |
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Metal halide perovskites (MHP) are highly promising semiconductors. In this study, we focus on FAPbBr3 nanocrystals, which are of great interest for green light-emitting diodes. Structural parameters significantly impact the properties of MHPs and are linked to phase instability, which hampers long-term applications. Clearly, there is a need for local and precise characterization techniques at the atomic scale, such as transmission electron microscopy. Because of the high electron beam sensitivity of MHPs, these investigations are extremely challenging. Here, we applied a low-dose method based on four-dimensional scanning transmission electron microscopy. We quantified the observed elongation of the projections of the Br atomic columns, suggesting an alternation in the position of the Br atoms perpendicular to the Pb–Br–Pb bonds. Together with molecular dynamics simulations, these results remarkably reveal local distortions in an on-average cubic structure. Additionally, this study provides an approach to prospectively investigating the fundamental degradation mechanisms of MHPs. |
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Wos |
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Publication Date |
2024-09-04 |
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ISSN |
1530-6984 |
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Impact Factor |
10.8 |
Times cited |
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Notes |
The authors acknowledge financial support from the Research Foundation-Flanders (FWO) through project fundings (G0A7723N) and a postdoctoral fellowship to N.J.S. (FWO Grants 1238622N and V413524N). The authors acknowledge financial support from iBOF-21-085 PERSIST. S.B. and S.V.A. acknowledge financial support from the European Commission by ERC Consolidator Grant 815128 (REALNANO) and Grant 770887 (PICOMETRICS). L.M. acknowledges financial support from the European Commission by ERC Advanced Grant 101095974 (NEHA). V.V.S. furthermore acknowledges the Research Fund of Ghent University (BOF) for its financial support. The computational resources and services used in this work were provided by VSC (Flemish Supercomputer Center), funded by the Research Foundation-Flanders (FWO), and the Flemish Government. |
Approved |
Most recent IF: 10.8; 2024 IF: 12.712 |
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Call Number |
EMAT @ emat @ |
Serial |
9273 |
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