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Fatermans J, Romolini G, Altantzis T, Hofkens J, Roeffaers MBJ, Bals S, Van Aert S. Atomic-scale detection of individual lead clusters confined in Linde Type A zeolites. NANOSCALE 2022; 14:9323-9330. [PMID: 35687327 DOI: 10.1039/d2nr01819e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Structural analysis of metal clusters confined in nanoporous materials is typically performed by X-ray-driven techniques. Although X-ray analysis has proved its strength in the characterization of metal clusters, it provides averaged structural information. Therefore, we here present an alternative workflow for bringing the characterization of confined metal clusters towards the local scale. This workflow is based on the combination of aberration-corrected transmission electron microscopy (TEM), TEM image simulations, and powder X-ray diffraction (XRD) with advanced statistical techniques. In this manner, we were able to characterize the clustering of Pb atoms in Linde Type A (LTA) zeolites with Pb loadings as low as 5 wt%. Moreover, individual Pb clusters could be directly detected. The proposed methodology thus enables a local-scale characterization of confined metal clusters in zeolites. This is important for further elucidation of the connection between the structure and the physicochemical properties of such systems.
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Affiliation(s)
- Jarmo Fatermans
- Electron Microscopy for Materials Science (EMAT), University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium.
- NANOlab Center of Excellence, University of Antwerp, Belgium.
| | - Giacomo Romolini
- Molecular Imaging and Photonics, Department of Chemistry, KU Leuven, Celestijnenlaan 200F, 3001 Leuven, Belgium
| | - Thomas Altantzis
- Electron Microscopy for Materials Science (EMAT), University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium.
- NANOlab Center of Excellence, University of Antwerp, Belgium.
- Applied Electrochemistry and Catalysis Group (ELCAT), University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium
| | - Johan Hofkens
- Molecular Imaging and Photonics, Department of Chemistry, KU Leuven, Celestijnenlaan 200F, 3001 Leuven, Belgium
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Maarten B J Roeffaers
- Centre for Membrane Separations, Adsorption, Catalysis, And Spectroscopy for Sustainable Solutions (cMACS), KU Leuven, Celestijnenlaan 200F, Box 2461, 3001, Leuven, Belgium.
| | - Sara Bals
- Electron Microscopy for Materials Science (EMAT), University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium.
- NANOlab Center of Excellence, University of Antwerp, Belgium.
| | - Sandra Van Aert
- Electron Microscopy for Materials Science (EMAT), University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium.
- NANOlab Center of Excellence, University of Antwerp, Belgium.
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2
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Liu JJ. Advances and Applications of Atomic-Resolution Scanning Transmission Electron Microscopy. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2021; 27:1-53. [PMID: 34414878 DOI: 10.1017/s1431927621012125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Although scanning transmission electron microscopy (STEM) images of individual heavy atoms were reported 50 years ago, the applications of atomic-resolution STEM imaging became wide spread only after the practical realization of aberration correctors on field-emission STEM/TEM instruments to form sub-Ångstrom electron probes. The innovative designs and advances of electron optical systems, the fundamental understanding of electron–specimen interaction processes, and the advances in detector technology all played a major role in achieving the goal of atomic-resolution STEM imaging of practical materials. It is clear that tremendous advances in computer technology and electronics, image acquisition and processing algorithms, image simulations, and precision machining synergistically made atomic-resolution STEM imaging routinely accessible. It is anticipated that further hardware/software development is needed to achieve three-dimensional atomic-resolution STEM imaging with single-atom chemical sensitivity, even for electron-beam-sensitive materials. Artificial intelligence, machine learning, and big-data science are expected to significantly enhance the impact of STEM and associated techniques on many research fields such as materials science and engineering, quantum and nanoscale science, physics and chemistry, and biology and medicine. This review focuses on advances of STEM imaging from the invention of the field-emission electron gun to the realization of aberration-corrected and monochromated atomic-resolution STEM and its broad applications.
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Affiliation(s)
- Jingyue Jimmy Liu
- Department of Physics, Arizona State University, Tempe, AZ85287, USA
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3
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Fatermans J, den Dekker AJ, Müller-Caspary K, Gauquelin N, Verbeeck J, Van Aert S. Atom column detection from simultaneously acquired ABF and ADF STEM images. Ultramicroscopy 2020; 219:113046. [PMID: 32927326 DOI: 10.1016/j.ultramic.2020.113046] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 05/20/2020] [Accepted: 05/27/2020] [Indexed: 12/11/2022]
Abstract
In electron microscopy, the maximum a posteriori (MAP) probability rule has been introduced as a tool to determine the most probable atomic structure from high-resolution annular dark-field (ADF) scanning transmission electron microscopy (STEM) images exhibiting low contrast-to-noise ratio (CNR). Besides ADF imaging, STEM can also be applied in the annular bright-field (ABF) regime. The ABF STEM mode allows to directly visualize light-element atomic columns in the presence of heavy columns. Typically, light-element nanomaterials are sensitive to the electron beam, limiting the incoming electron dose in order to avoid beam damage and leading to images exhibiting low CNR. Therefore, it is of interest to apply the MAP probability rule not only to ADF STEM images, but to ABF STEM images as well. In this work, the methodology of the MAP rule, which combines statistical parameter estimation theory and model-order selection, is extended to be applied to simultaneously acquired ABF and ADF STEM images. For this, an extension of the commonly used parametric models in STEM is proposed. Hereby, the effect of specimen tilt has been taken into account, since small tilts from the crystal zone axis affect, especially, ABF STEM intensities. Using simulations as well as experimental data, it is shown that the proposed methodology can be successfully used to detect light elements in the presence of heavy elements.
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Affiliation(s)
- J Fatermans
- Electron Microscopy for Materials Science (EMAT), University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium; NANOlab Center of Excellence, University of Antwerp, Belgium; imec-Vision Lab, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium
| | - A J den Dekker
- imec-Vision Lab, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium
| | - K Müller-Caspary
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - N Gauquelin
- Electron Microscopy for Materials Science (EMAT), University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium; NANOlab Center of Excellence, University of Antwerp, Belgium
| | - J Verbeeck
- Electron Microscopy for Materials Science (EMAT), University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium; NANOlab Center of Excellence, University of Antwerp, Belgium
| | - S Van Aert
- Electron Microscopy for Materials Science (EMAT), University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium; NANOlab Center of Excellence, University of Antwerp, Belgium.
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4
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Fatermans J, Van Aert S, den Dekker AJ. The maximum a posteriori probability rule for atom column detection from HAADF STEM images. Ultramicroscopy 2019; 201:81-91. [PMID: 30991277 DOI: 10.1016/j.ultramic.2019.02.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 01/23/2019] [Accepted: 02/02/2019] [Indexed: 10/27/2022]
Abstract
Recently, the maximum a posteriori (MAP) probability rule has been proposed as an objective and quantitative method to detect atom columns and even single atoms from high-resolution high-angle annular dark-field (HAADF) scanning transmission electron microscopy (STEM) images. The method combines statistical parameter estimation and model-order selection using a Bayesian framework and has been shown to be especially useful for the analysis of the structure of beam-sensitive nanomaterials. In order to avoid beam damage, images of such materials are usually acquired using a limited incoming electron dose resulting in a low contrast-to-noise ratio (CNR) which makes visual inspection unreliable. This creates a need for an objective and quantitative approach. The present paper describes the methodology of the MAP probability rule, gives its step-by-step derivation and discusses its algorithmic implementation for atom column detection. In addition, simulation results are presented showing that the performance of the MAP probability rule to detect the correct number of atomic columns from HAADF STEM images is superior to that of other model-order selection criteria, including the Akaike Information Criterion (AIC) and the Bayesian Information Criterion (BIC). Moreover, the MAP probability rule is used as a tool to evaluate the relation between STEM image quality measures and atom detectability resulting in the introduction of the so-called integrated CNR (ICNR) as a new image quality measure that better correlates with atom detectability than conventional measures such as signal-to-noise ratio (SNR) and CNR.
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Affiliation(s)
- J Fatermans
- Electron Microsopy for Materials Science (EMAT), University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium; imec-Vision Lab, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium
| | - S Van Aert
- Electron Microsopy for Materials Science (EMAT), University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium.
| | - A J den Dekker
- imec-Vision Lab, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium; Delft Center for Systems and Control (DCSC), Delft University of Technology, Mekelweg 2, 2628 CD Delft, The Netherlands
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5
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Martinez GT, van den Bos KHW, Alania M, Nellist PD, Van Aert S. Thickness dependence of scattering cross-sections in quantitative scanning transmission electron microscopy. Ultramicroscopy 2018; 187:84-92. [PMID: 29413416 DOI: 10.1016/j.ultramic.2018.01.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Revised: 01/16/2018] [Accepted: 01/17/2018] [Indexed: 11/16/2022]
Abstract
In quantitative scanning transmission electron microscopy (STEM), scattering cross-sections have been shown to be very sensitive to the number of atoms in a column and its composition. They correspond to the integrated intensity over the atomic column and they outperform other measures. As compared to atomic column peak intensities, which saturate at a given thickness, scattering cross-sections increase monotonically. A study of the electron wave propagation is presented to explain the sensitivity of the scattering cross-sections. Based on the multislice algorithm, we analyse the wave propagation inside the crystal and its link to the scattered signal for the different probe positions contained in the scattering cross-section for detector collection in the low-, middle- and high-angle regimes. The influence to the signal from scattering of neighbouring columns is also discussed.
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Affiliation(s)
- G T Martinez
- Electron Microscopy for Materials Science (EMAT), University of Antwerp, Gronenborgerlaan 171, 2020, Antwerp, Belgium
| | - K H W van den Bos
- Electron Microscopy for Materials Science (EMAT), University of Antwerp, Gronenborgerlaan 171, 2020, Antwerp, Belgium
| | - M Alania
- Electron Microscopy for Materials Science (EMAT), University of Antwerp, Gronenborgerlaan 171, 2020, Antwerp, Belgium
| | - P D Nellist
- Department of Materials, Oxford University, Parks Road, Oxford OX1 3PH, United Kingdom
| | - S Van Aert
- Electron Microscopy for Materials Science (EMAT), University of Antwerp, Gronenborgerlaan 171, 2020, Antwerp, Belgium.
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6
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De Backer A, van den Bos K, Van den Broek W, Sijbers J, Van Aert S. StatSTEM: An efficient approach for accurate and precise model-based quantification of atomic resolution electron microscopy images. Ultramicroscopy 2016; 171:104-116. [DOI: 10.1016/j.ultramic.2016.08.018] [Citation(s) in RCA: 94] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Revised: 08/22/2016] [Accepted: 08/29/2016] [Indexed: 10/21/2022]
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7
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Goris B, De Beenhouwer J, De Backer A, Zanaga D, Batenburg KJ, Sánchez-Iglesias A, Liz-Marzán LM, Van Aert S, Bals S, Sijbers J, Van Tendeloo G. Measuring Lattice Strain in Three Dimensions through Electron Microscopy. NANO LETTERS 2015; 15:6996-7001. [PMID: 26340328 PMCID: PMC4877113 DOI: 10.1021/acs.nanolett.5b03008] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The three-dimensional (3D) atomic structure of nanomaterials, including strain, is crucial to understand their properties. Here, we investigate lattice strain in Au nanodecahedra using electron tomography. Although different electron tomography techniques enabled 3D characterizations of nanostructures at the atomic level, a reliable determination of lattice strain is not straightforward. We therefore propose a novel model-based approach from which atomic coordinates are measured. Our findings demonstrate the importance of investigating lattice strain in 3D.
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Affiliation(s)
- Bart Goris
- Electron
Microscopy for Materials Research (EMAT), University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
| | - Jan De Beenhouwer
- iMinds-Vision
Lab, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium
| | - Annick De Backer
- Electron
Microscopy for Materials Research (EMAT), University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
| | - Daniele Zanaga
- Electron
Microscopy for Materials Research (EMAT), University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
| | - K. Joost Batenburg
- Centrum Wiskunde
& Informatica, P.O. Box 94079, 1090 GB Amsterdam, The Netherlands
| | - Ana Sánchez-Iglesias
- Bionanoplasmonics
Laboratory, CIC biomaGUNE, Paseo de Miramón 182, 20009 Donostia - San Sebastian, Spain
| | - Luis M. Liz-Marzán
- Bionanoplasmonics
Laboratory, CIC biomaGUNE, Paseo de Miramón 182, 20009 Donostia - San Sebastian, Spain
- Ikerbasque, Basque
Foundation for Science, 48013 Bilbao, Spain
| | - Sandra Van Aert
- Electron
Microscopy for Materials Research (EMAT), University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
| | - Sara Bals
- Electron
Microscopy for Materials Research (EMAT), University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
- E-mail:
| | - Jan Sijbers
- iMinds-Vision
Lab, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium
| | - Gustaaf Van Tendeloo
- Electron
Microscopy for Materials Research (EMAT), University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
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8
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Optimal experimental design for nano-particle atom-counting from high-resolution STEM images. Ultramicroscopy 2015; 151:46-55. [DOI: 10.1016/j.ultramic.2014.10.015] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Revised: 10/29/2014] [Accepted: 10/30/2014] [Indexed: 11/22/2022]
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9
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The effect of probe inaccuracies on the quantitative model-based analysis of high angle annular dark field scanning transmission electron microscopy images. Micron 2014; 63:57-63. [DOI: 10.1016/j.micron.2013.12.009] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Revised: 12/13/2013] [Accepted: 12/15/2013] [Indexed: 11/19/2022]
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