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A small-dataset-trained deep learning framework for identifying atoms on transmission electron microscopy images. Sci Rep 2023; 13:2631. [PMID: 36788257 PMCID: PMC9929221 DOI: 10.1038/s41598-023-29606-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Accepted: 02/07/2023] [Indexed: 02/16/2023] Open
Abstract
To accurately identify atoms on noisy transmission electron microscope images, a deep learning (DL) approach is employed to estimate the map of probabilities at each pixel for being an atom with element discernment. Thanks to a delicately-designed loss function and the ability to extract features, the proposed DL networks can be trained by a small dataset created from approximately 30 experimental images, each with a size of 256 × 256 pixels2. The accuracy and robustness of the network were verified by resolving the structural defects of graphene and polar structures in PbTiO3/SrTiO3 multilayers from both the general TEM images and their imitated images on which intensities of some pixels lost randomly. Such a network has the potential to identify atoms from very few images of beam-sensitive material and explosive images recorded in a dynamical atomic process. The idea of using a small-dataset-trained DL framework to resolve a specific problem may prove instructive for practical DL applications in various fields.
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2
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Botifoll M, Pinto-Huguet I, Arbiol J. Machine learning in electron microscopy for advanced nanocharacterization: current developments, available tools and future outlook. NANOSCALE HORIZONS 2022; 7:1427-1477. [PMID: 36239693 DOI: 10.1039/d2nh00377e] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
In the last few years, electron microscopy has experienced a new methodological paradigm aimed to fix the bottlenecks and overcome the challenges of its analytical workflow. Machine learning and artificial intelligence are answering this call providing powerful resources towards automation, exploration, and development. In this review, we evaluate the state-of-the-art of machine learning applied to electron microscopy (and obliquely, to materials and nano-sciences). We start from the traditional imaging techniques to reach the newest higher-dimensionality ones, also covering the recent advances in spectroscopy and tomography. Additionally, the present review provides a practical guide for microscopists, and in general for material scientists, but not necessarily advanced machine learning practitioners, to straightforwardly apply the offered set of tools to their own research. To conclude, we explore the state-of-the-art of other disciplines with a broader experience in applying artificial intelligence methods to their research (e.g., high-energy physics, astronomy, Earth sciences, and even robotics, videogames, or marketing and finances), in order to narrow down the incoming future of electron microscopy, its challenges and outlook.
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Affiliation(s)
- Marc Botifoll
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, 08193 Barcelona, Catalonia, Spain.
| | - Ivan Pinto-Huguet
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, 08193 Barcelona, Catalonia, Spain.
| | - Jordi Arbiol
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, 08193 Barcelona, Catalonia, Spain.
- ICREA, Pg. Lluís Companys 23, 08010 Barcelona, Catalonia, Spain
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4
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Comprehensive Study of Li+/Ni2+ Disorder in Ni-Rich NMCs Cathodes for Li-Ion Batteries. Symmetry (Basel) 2021. [DOI: 10.3390/sym13091628] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
The layered oxides LiNixMnyCozO2 (NMCs, x + y + z = 1) with high nickel content (x ≥ 0.6, Ni-rich NMCs) are promising high-energy density-positive electrode materials for Li-ion batteries. Their electrochemical properties depend on Li+/Ni2+ cation disordering originating from the proximity of the Li+ and Ni2+ ionic radii. We synthesized a series of the LiNi0.8Mn0.1Co0.1O2 NMC811 adopting two different disordering schemes: Ni for Li substitution at the Li site in the samples finally annealed in air, and close to Ni↔Li antisite disorder in the oxygen-annealed samples. The defect formation scenario was revealed with Rietveld refinement from powder X-ray diffraction data, and then the reliability of semi-quantitative parameters, such as I003/I104 integral intensity ratio and c/(2√6a) ratio of pseudocubic subcell parameters, was verified against the refined defect concentrations. The I003/I104 ratio can serve as a quantitative measure of g(NiLi) only after explicit correction of intensities for preferred orientation. Being normalized by the total scattering power of the unit cell, the I003/I104 ratio depends linearly on g(NiLi) for each disordering scheme. The c/(2√6a) ratio appears to be not reliable and cannot be used for a quantitative estimate of g(NiLi). In turn, the volume of the R3¯m unit cell correlates linearly with g(NiLi), at least for defect concentrations not exceeding 5%. The microscopy techniques such as high-resolution high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) and electron diffraction tomography (EDT) allow us to study the materials locally, still, there is no proper quantitative approach for comprehensive analysis of defects. In the present work, the TEM-assisted quantitative Li+/Ni2+ disordering analysis with EDT and HAADF-STEM in six Ni-rich NMC samples with various defects content is demonstrated. Noteworthy, while PXRD and EDT methods demonstrate overall defect amounts, HAADF-STEM allows us to quantitatively distinguish regions with various disordering extents. Therefore, the combination of mentioned PXRD and TEM methods gives the full picture of Li+/Ni2+ mixing defects in Ni-rich NMCs.
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Zhang C, Feng J, Yankovich AB, Kvit A, Berkels B, Voyles PM. Optimizing Nonrigid Registration for Scanning Transmission Electron Microscopy Image Series. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2021; 27:90-98. [PMID: 33222719 DOI: 10.1017/s1431927620024708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Achieving sub-picometer precision measurements of atomic column positions in high-resolution scanning transmission electron microscope images using nonrigid registration (NRR) and averaging of image series requires careful optimization of experimental conditions and the parameters of the registration algorithm. On experimental data from SrTiO3 [100], sub-pm precision requires alignment of the sample to the zone axis to within 1 mrad tilt and sample drift of less than 1 nm/min. At fixed total electron dose for the series, precision in the fast scan direction improves with shorter pixel dwell time to the limit of our microscope hardware, but the best precision along the slow scan direction occurs at 6 μs/px dwell time. Within the NRR algorithm, the “smoothness factor” that penalizes large estimated shifts is the most important parameter for sub-pm precision, but in general, the precision of NRR images is robust over a wide range of parameters.
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Affiliation(s)
- Chenyu Zhang
- Department of Materials Science and Engineering, University of Wisconsin - Madison, 1509 University Avenue, Madison, WI53706, USA
| | - Jie Feng
- Department of Materials Science and Engineering, University of Wisconsin - Madison, 1509 University Avenue, Madison, WI53706, USA
| | - Andrew B Yankovich
- Department of Materials Science and Engineering, University of Wisconsin - Madison, 1509 University Avenue, Madison, WI53706, USA
| | - Alexander Kvit
- Department of Materials Science and Engineering, University of Wisconsin - Madison, 1509 University Avenue, Madison, WI53706, USA
| | - Benjamin Berkels
- Aachen Institute for Advanced Study in Computational Engineering Science, RWTH Aachen University, Schinkelstr. 2, 52056Aachen, Germany
| | - Paul M Voyles
- Department of Materials Science and Engineering, University of Wisconsin - Madison, 1509 University Avenue, Madison, WI53706, USA
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Zhang Q, Zhang L, Jin C, Wang Y, Lin F. CalAtom: A software for quantitatively analysing atomic columns in a transmission electron microscope image. Ultramicroscopy 2019; 202:114-120. [DOI: 10.1016/j.ultramic.2019.04.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 03/31/2019] [Accepted: 04/10/2019] [Indexed: 10/27/2022]
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7
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Rajak P, Koch CT, Bhattacharyya S. Removal of supporting amorphous carbon film induced artefact from measured strain variation within a nanoparticle. Ultramicroscopy 2019; 199:70-80. [DOI: 10.1016/j.ultramic.2019.02.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Revised: 02/15/2019] [Accepted: 02/18/2019] [Indexed: 11/28/2022]
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8
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Zhang Q, Jin C, Xu H, Zhang L, Ren X, Ouyang Y, Wang X, Yue X, Lin F. Multiple-ellipse fitting method to precisely measure the positions of atomic columns in a transmission electron microscope image. Micron 2018; 113:99-104. [DOI: 10.1016/j.micron.2018.06.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2018] [Revised: 06/25/2018] [Accepted: 06/25/2018] [Indexed: 10/28/2022]
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Guzzinati G, Altantzis T, Batuk M, De Backer A, Lumbeeck G, Samaee V, Batuk D, Idrissi H, Hadermann J, Van Aert S, Schryvers D, Verbeeck J, Bals S. Recent Advances in Transmission Electron Microscopy for Materials Science at the EMAT Lab of the University of Antwerp. MATERIALS (BASEL, SWITZERLAND) 2018; 11:E1304. [PMID: 30060556 PMCID: PMC6117696 DOI: 10.3390/ma11081304] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 07/25/2018] [Accepted: 07/26/2018] [Indexed: 01/13/2023]
Abstract
The rapid progress in materials science that enables the design of materials down to the nanoscale also demands characterization techniques able to analyze the materials down to the same scale, such as transmission electron microscopy. As Belgium's foremost electron microscopy group, among the largest in the world, EMAT is continuously contributing to the development of TEM techniques, such as high-resolution imaging, diffraction, electron tomography, and spectroscopies, with an emphasis on quantification and reproducibility, as well as employing TEM methodology at the highest level to solve real-world materials science problems. The lab's recent contributions are presented here together with specific case studies in order to highlight the usefulness of TEM to the advancement of materials science.
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Affiliation(s)
- Giulio Guzzinati
- EMAT, University of Antwerp, Groenenborgerlaan 171, Antwerp 2020, Belgium.
| | - Thomas Altantzis
- EMAT, University of Antwerp, Groenenborgerlaan 171, Antwerp 2020, Belgium.
| | - Maria Batuk
- EMAT, University of Antwerp, Groenenborgerlaan 171, Antwerp 2020, Belgium.
| | - Annick De Backer
- EMAT, University of Antwerp, Groenenborgerlaan 171, Antwerp 2020, Belgium.
| | - Gunnar Lumbeeck
- EMAT, University of Antwerp, Groenenborgerlaan 171, Antwerp 2020, Belgium.
| | - Vahid Samaee
- EMAT, University of Antwerp, Groenenborgerlaan 171, Antwerp 2020, Belgium.
| | - Dmitry Batuk
- EMAT, University of Antwerp, Groenenborgerlaan 171, Antwerp 2020, Belgium.
| | - Hosni Idrissi
- EMAT, University of Antwerp, Groenenborgerlaan 171, Antwerp 2020, Belgium.
- Institute of Mechanics, Materials and Civil Engineering, Université catholique de Louvain, Louvain-la-Neuve 1348, Belgium.
| | - Joke Hadermann
- EMAT, University of Antwerp, Groenenborgerlaan 171, Antwerp 2020, Belgium.
| | - Sandra Van Aert
- EMAT, University of Antwerp, Groenenborgerlaan 171, Antwerp 2020, Belgium.
| | | | - Johan Verbeeck
- EMAT, University of Antwerp, Groenenborgerlaan 171, Antwerp 2020, Belgium.
| | - Sara Bals
- EMAT, University of Antwerp, Groenenborgerlaan 171, Antwerp 2020, Belgium.
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Stanfill BA, Reehl SM, Johnson MC, Browning ND, Mehdi BL, Caragea PC, Bramer LM. Quantitative Mapping of Nanoscale Chemical Dynamics in Sub‐Sampled Operando (S)TEM Images using Spatio‐Temporal Analytics. ChemCatChem 2018. [DOI: 10.1002/cctc.201800333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Bryan A. Stanfill
- National Security Directorate Pacific Northwest National Laboratory Richland WA 99352 USA
| | - Sarah M. Reehl
- National Security Directorate Pacific Northwest National Laboratory Richland WA 99352 USA
| | | | - Nigel D. Browning
- School of Engineering University of Liverpool Liverpool United Kingdom
| | - B. Layla Mehdi
- School of Engineering University of Liverpool Liverpool United Kingdom
| | | | - Lisa M. Bramer
- National Security Directorate Pacific Northwest National Laboratory Richland WA 99352 USA
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11
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Influence of atomic site-specific strain on catalytic activity of supported nanoparticles. Nat Commun 2018; 9:2722. [PMID: 30006550 PMCID: PMC6045581 DOI: 10.1038/s41467-018-05055-1] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Accepted: 06/11/2018] [Indexed: 11/23/2022] Open
Abstract
Heterogeneous catalysis is an enabling technology that utilises transition metal nanoparticles (NPs) supported on oxides to promote chemical reactions. Structural mismatch at the NP–support interface generates lattice strain that could affect catalytic properties. However, detailed knowledge about strain in supported NPs remains elusive. We experimentally measure the strain at interfaces, surfaces and defects in Pt NPs supported on alumina and ceria with atomic resolution using high-precision scanning transmission electron microscopy. The largest strains are observed at the interfaces and are predominantly compressive. Atomic models of Pt NPs with experimentally measured strain distributions are used for first-principles kinetic Monte Carlo simulations of the CO oxidation reaction. The presence of only a fraction of strained surface atoms is found to affect the turnover frequency. These results provide a quantitative understanding of the relationship between strain and catalytic function and demonstrate that strain engineering can potentially be used for catalyst design. Detailed knowledge of how strain influences catalytic reactions remains elusive. Here, the authors experimentally measure the strain in supported Pt nanoparticles on alumina and ceria with atomic resolution and computationally explore how the strain affects the CO oxidation reaction.
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12
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Claes N, Asapu R, Blommaerts N, Verbruggen SW, Lenaerts S, Bals S. Characterization of silver-polymer core-shell nanoparticles using electron microscopy. NANOSCALE 2018; 10:9186-9191. [PMID: 29726570 DOI: 10.1039/c7nr09517a] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Silver-polymer core-shell nanoparticles show interesting optical properties, making them widely applicable in the field of plasmonics. The uniformity, thickness and homogeneity of the polymer shell will affect the properties of the system which makes a thorough structural characterization of these core-shell silver-polymer nanoparticles of great importance. However, visualizing the shell and the particle simultaneously is far from straightforward due to the sensitivity of the polymer shell towards the electron beam. In this study, we use different 2D and 3D electron microscopy techniques to investigate different structural aspects of the polymer coating.
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Affiliation(s)
- Nathalie Claes
- Electron Microscopy for Materials Science (EMAT), Department Physics, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium.
| | - Ramesh Asapu
- Sustainable Energy, Air and Water Technology (DuEL), Department of Bioscience Engineering, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium
| | - Natan Blommaerts
- Sustainable Energy, Air and Water Technology (DuEL), Department of Bioscience Engineering, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium
| | - Sammy W Verbruggen
- Sustainable Energy, Air and Water Technology (DuEL), Department of Bioscience Engineering, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium
| | - Silvia Lenaerts
- Sustainable Energy, Air and Water Technology (DuEL), Department of Bioscience Engineering, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium
| | - Sara Bals
- Electron Microscopy for Materials Science (EMAT), Department Physics, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium.
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13
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Measurement of Barium Ion Displacement Near Surface in a Barium Titanate Nanoparticle by Scanning Transmission Electron Microscopy. Appl Microsc 2018. [DOI: 10.9729/am.2018.48.1.27] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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14
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Campanini M, Erni R, Yang CH, Ramesh R, Rossell MD. Periodic Giant Polarization Gradients in Doped BiFeO 3 Thin Films. NANO LETTERS 2018; 18:717-724. [PMID: 29314853 DOI: 10.1021/acs.nanolett.7b03817] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The ultimate challenge for the development of new multiferroics with enhanced properties lies in achieving nanoscale control of the coupling between different ordering parameters. In oxide-based multiferroics, substitutional cation dopants offer the unparalleled possibility to modify both the electric and magnetic properties at a local scale. Herein it is demonstrated the formation of a dopant-controlled polar pattern in BiFeO3 leading to the spontaneous instauration of periodic polarization waves. In particular, nonpolar Ca-doped rich regions act as spacers between consecutive dopant-depleted regions displaying coupled ferroelectric states. This alternation of layers with different ferroelectric state creates a novel vertical polar structure exhibiting giant polarization gradients as large as 70 μC cm-2 across 30 Å thick domains. The drastic change in the polar state of the film is visualized using high-resolution differential phase-contrast imaging able to map changes in ferroelectric polarization at atomic scale. Furthermore, a periodic distortion in the Fe-O-Fe bonding angle suggests a local variation in the magnetic ordering. The findings provide a new insight into the role of doping and reveal hitherto unexplored means to tailor the functional properties of multiferroics by doping engineering.
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Affiliation(s)
- Marco Campanini
- Electron Microscopy Center, Empa , Überlandstrasse 129, Dübendorf 8600, Switzerland
| | - Rolf Erni
- Electron Microscopy Center, Empa , Überlandstrasse 129, Dübendorf 8600, Switzerland
| | - Chan Ho Yang
- Department of Physics, KAIST , Daejeon 305-701, Republic of Korea
| | - Ramamoorthy Ramesh
- Materials Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
| | - Marta D Rossell
- Electron Microscopy Center, Empa , Überlandstrasse 129, Dübendorf 8600, Switzerland
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15
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Madsen J, Liu P, Wagner JB, Hansen TW, Schiøz J. Accuracy of surface strain measurements from transmission electron microscopy images of nanoparticles. ACTA ACUST UNITED AC 2017; 3:14. [PMID: 29104851 PMCID: PMC5656738 DOI: 10.1186/s40679-017-0047-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Accepted: 10/05/2017] [Indexed: 11/25/2022]
Abstract
Strain analysis from high-resolution transmission electron microscopy (HRTEM) images offers a convenient tool for measuring strain in materials at the atomic scale. In this paper we present a theoretical study of the precision and accuracy of surface strain measurements directly from aberration-corrected HRTEM images. We examine the influence of defocus, crystal tilt and noise, and find that absolute errors of at least 1–2% strain should be expected. The model structures include surface relaxations determined using molecular dynamics, and we show that this is important for correctly evaluating the errors introduced by image aberrations.
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Affiliation(s)
- Jacob Madsen
- Department of Physics, Technical University of Denmark, Fysikvej, Building 311, 2800 Kongens Lyngby, Denmark
| | - Pei Liu
- Center for Electron Nanoscopy, Technical University of Denmark, Fysikvej, Building 311, 2800 Kongens Lyngby, Denmark
| | - Jakob B Wagner
- Center for Electron Nanoscopy, Technical University of Denmark, Fysikvej, Building 311, 2800 Kongens Lyngby, Denmark
| | - Thomas W Hansen
- Center for Electron Nanoscopy, Technical University of Denmark, Fysikvej, Building 311, 2800 Kongens Lyngby, Denmark
| | - Jakob Schiøz
- Department of Physics, Technical University of Denmark, Fysikvej, Building 311, 2800 Kongens Lyngby, Denmark
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16
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Determining oxygen relaxations at an interface: A comparative study between transmission electron microscopy techniques. Ultramicroscopy 2017; 181:178-190. [DOI: 10.1016/j.ultramic.2017.06.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Revised: 05/18/2017] [Accepted: 06/01/2017] [Indexed: 11/18/2022]
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17
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Picometer-scale atom position analysis in annular bright-field STEM imaging. Ultramicroscopy 2017; 184:177-187. [PMID: 28934631 DOI: 10.1016/j.ultramic.2017.09.001] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 09/05/2017] [Accepted: 09/10/2017] [Indexed: 11/23/2022]
Abstract
We study the effects of specimen mistilt on the picometer-scale measurement of local structure by combing experiment and simulation in annular bright-field scanning transmission electron microscopy (ABF-STEM). A relative distance measurement method is proposed to separate the tilt effects from the scan noise and sample drift induced image distortion. We find that under a typical experimental condition a small specimen tilt (∼6 mrad) in 25 nm thick SrTiO3 along [001] causes 11.9 pm artificial displacement between O and Sr/TiO columns in ABF image, which is more than 3 times of scan noise and sample drift induced image distortion ∼3.2 pm, suggesting the tilt effect could be dominant for the quantitative analysis of ABF images. The artifact depends on the crystal mistilt angle, specimen thickness, defocus, convergence angle and uncorrected aberration. Our study provides useful insights into detecting and correcting tilt effects during both experiment operation and data analysis to extract the real structure information and avoid mis-interpretations of atomic structure as well as the properties such as oxygen octahedral distortion/shift.
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18
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Bárcena-González G, Guerrero-Lebrero MP, Guerrero E, Yañez A, Fernández-Reyes D, González D, Galindo PL. Evaluation of high-quality image reconstruction techniques applied to high-resolution Z-contrast imaging. Ultramicroscopy 2017; 182:283-291. [PMID: 28783580 DOI: 10.1016/j.ultramic.2017.07.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2017] [Revised: 07/11/2017] [Accepted: 07/25/2017] [Indexed: 10/19/2022]
Abstract
High-quality image reconstruction techniques allow the generation of high pixel density images from a set of low-resolution micrographs. In general, these techniques consist of two main steps, namely, accurate registration, and formulation of an appropriate forward image model via some restoration method. There exist a wide variety of algorithms to cope with both stages and depending on their practical applications, some methods can outperform others, since they can be sensitive to the assumed data model, noise, drift, etc. When dealing with images generated by Z-contrast scanning transmission electron microscopes, a current trend is based on non-rigid approximations in the registration stage. In our work we aimed at reaching similar accuracy but addressing the most complex calculations in the reconstruction stage, instead of in the registration stage (as the non-rigid approaches do), but using a much smaller number of images. We review some of the most significant methods and address their shortcomings when they are applied to the field of microscopy. Simulated images with known targets will be used to evaluate and compare the main approaches in terms of quality enhancement and computing time. In addition, a procedure to determine the reference image will be proposed to minimise the global drift on the series. The best registration and restoration strategies will be applied to experimental images in order to point up the enhanced capability of this high quality image reconstruction methodology in this field.
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Affiliation(s)
- G Bárcena-González
- Department of Computer Science and Engineering, University of Cádiz, Spain.
| | | | - E Guerrero
- Department of Computer Science and Engineering, University of Cádiz, Spain
| | - A Yañez
- Department of Computer Science and Engineering, University of Cádiz, Spain
| | - D Fernández-Reyes
- Department of Material Science and Metallurgy Engineering and Inorganic Chemistry, University of Cádiz, Spain
| | - D González
- Department of Material Science and Metallurgy Engineering and Inorganic Chemistry, University of Cádiz, Spain
| | - P L Galindo
- Department of Computer Science and Engineering, University of Cádiz, Spain
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19
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Quantification by aberration corrected (S)TEM of boundaries formed by symmetry breaking phase transformations. Ultramicroscopy 2017; 176:194-199. [PMID: 28162832 DOI: 10.1016/j.ultramic.2016.12.022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2016] [Revised: 12/08/2016] [Accepted: 12/10/2016] [Indexed: 11/23/2022]
Abstract
The present contribution gives a review of recent quantification work of atom displacements, atom site occupations and level of crystallinity in various systems and based on aberration corrected HR(S)TEM images. Depending on the case studied, picometer range precisions for individual distances can be obtained, boundary widths at the unit cell level determined or statistical evolutions of fractions of the ordered areas calculated. In all of these cases, these quantitative measures imply new routes for the applications of the respective materials.
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20
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Locating light and heavy atomic column positions with picometer precision using ISTEM. Ultramicroscopy 2017; 172:75-81. [DOI: 10.1016/j.ultramic.2016.10.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Revised: 09/13/2016] [Accepted: 10/02/2016] [Indexed: 11/21/2022]
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21
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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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22
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Wang Y, Salzberger U, Sigle W, Eren Suyolcu Y, van Aken PA. Oxygen octahedra picker: A software tool to extract quantitative information from STEM images. Ultramicroscopy 2016; 168:46-52. [DOI: 10.1016/j.ultramic.2016.06.001] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Revised: 04/21/2016] [Accepted: 06/06/2016] [Indexed: 10/21/2022]
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Van Aert S, De Backer A, Martinez GT, den Dekker AJ, Van Dyck D, Bals S, Van Tendeloo G. Advanced electron crystallography through model-based imaging. IUCRJ 2016; 3:71-83. [PMID: 26870383 PMCID: PMC4704081 DOI: 10.1107/s2052252515019727] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Accepted: 10/19/2015] [Indexed: 05/30/2023]
Abstract
The increasing need for precise determination of the atomic arrangement of non-periodic structures in materials design and the control of nanostructures explains the growing interest in quantitative transmission electron microscopy. The aim is to extract precise and accurate numbers for unknown structure parameters including atomic positions, chemical concentrations and atomic numbers. For this purpose, statistical parameter estimation theory has been shown to provide reliable results. In this theory, observations are considered purely as data planes, from which structure parameters have to be determined using a parametric model describing the images. As such, the positions of atom columns can be measured with a precision of the order of a few picometres, even though the resolution of the electron microscope is still one or two orders of magnitude larger. Moreover, small differences in average atomic number, which cannot be distinguished visually, can be quantified using high-angle annular dark-field scanning transmission electron microscopy images. In addition, this theory allows one to measure compositional changes at interfaces, to count atoms with single-atom sensitivity, and to reconstruct atomic structures in three dimensions. This feature article brings the reader up to date, summarizing the underlying theory and highlighting some of the recent applications of quantitative model-based transmisson electron microscopy.
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Affiliation(s)
- Sandra Van Aert
- Electron Microscopy for Materials Research (EMAT), University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium
| | - Annick De Backer
- Electron Microscopy for Materials Research (EMAT), University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium
| | - Gerardo T. Martinez
- Electron Microscopy for Materials Research (EMAT), University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium
| | - Arnold J. den Dekker
- iMinds-Vision Lab, University of Antwerp, Universiteitsplein 1, B-2610 Wilrijk, Belgium
- Delft Center for Systems and Control (DCSC), Delft University of Technology, Mekelweg 2, 2628 CD Delft, The Netherlands
| | - Dirk Van Dyck
- Electron Microscopy for Materials Research (EMAT), University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium
| | - Sara Bals
- Electron Microscopy for Materials Research (EMAT), University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium
| | - Gustaaf Van Tendeloo
- Electron Microscopy for Materials Research (EMAT), University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium
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24
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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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25
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Effects of non-rotationally symmetric aberrations on the quantitative measurement of lattice positions in a graphene monolayer using high-resolution transmission electron microscopy. Microscopy (Oxf) 2015; 64:311-8. [DOI: 10.1093/jmicro/dfv025] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2015] [Accepted: 05/09/2015] [Indexed: 11/12/2022] Open
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26
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Tang YL, Zhu YL, Ma XL, Borisevich AY, Morozovska AN, Eliseev EA, Wang WY, Wang YJ, Xu YB, Zhang ZD, Pennycook SJ. Observation of a periodic array of flux-closure quadrants in strained ferroelectric PbTiO3 films. Science 2015; 348:547-51. [DOI: 10.1126/science.1259869] [Citation(s) in RCA: 332] [Impact Index Per Article: 36.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Accepted: 03/24/2015] [Indexed: 11/02/2022]
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27
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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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28
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High-precision scanning transmission electron microscopy at coarse pixel sampling for reduced electron dose. ACTA ACUST UNITED AC 2015. [DOI: 10.1186/s40679-015-0003-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Abstract
Determining the precise atomic structure of materials’ surfaces, defects, and interfaces is important to help provide the connection between structure and important materials’ properties. Modern scanning transmission electron microscopy (STEM) techniques now allow for atomic resolution STEM images to have down to sub-picometer precision in locating positions of atoms, but these high-precision techniques generally require large electron doses, making them less useful for beam-sensitive materials. Here, we show that 1- to 2-pm image precision is possible by non-rigidly registering and averaging a high-angle dark field image series of a 5- to 6-nm Au nanoparticle even though a very coarsely sampled image and decreased exposure time was used to minimize the electron dose. These imaging conditions minimize the damage to the nanoparticle and capture the whole nanoparticle in the same image. The high-precision STEM image reveals bond length contraction around the entire nanoparticle surface, and no bond length variation along a twin boundary that separates the nanoparticle into two grains. Surface atoms at the edges and corners exhibit larger bond length contraction than atoms near the center of surface facets.
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29
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Yankovich AB, Berkels B, Dahmen W, Binev P, Sanchez SI, Bradley SA, Li A, Szlufarska I, Voyles PM. Picometre-precision analysis of scanning transmission electron microscopy images of platinum nanocatalysts. Nat Commun 2014; 5:4155. [DOI: 10.1038/ncomms5155] [Citation(s) in RCA: 203] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Accepted: 05/19/2014] [Indexed: 11/09/2022] Open
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30
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Tang YL, Zhu YL, Wang YJ, Wang WY, Xu YB, Ren WJ, Zhang ZD, Ma XL. Atomic-scale mapping of dipole frustration at 90° charged domain walls in ferroelectric PbTiO3 films. Sci Rep 2014; 4:4115. [PMID: 24534846 PMCID: PMC3927212 DOI: 10.1038/srep04115] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Accepted: 01/23/2014] [Indexed: 11/17/2022] Open
Abstract
The atomic-scale structural and electric parameters of the 90° domain-walls in tetragonal ferroelectrics are of technological importance for exploring the ferroelectric switching behaviors and various domain-wall-related novel functions. We have grown epitaxial PbTiO3/SrTiO3 multilayer films in which the electric dipoles at 90° domain-walls of ferroelectric PbTiO3 are characterized by means of aberration-corrected scanning transmission electron microscopy. Besides the well-accepted head-to-tail 90° uncharged domain-walls, we have identified not only head-to-head positively charged but also tail-to-tail negatively charged domain-walls. The widths, polarization distributions, and strains across these charged domain-walls are mapped quantitatively at atomic scale, where remarkable difference between these domain-walls is presented. This study is expected to provide fundamental information for understanding numerous novel domain-wall phenomena in ferroelectrics.
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Affiliation(s)
- Y. L. Tang
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Wenhua Road 72, 110016 Shenyang, China
- These authors contributed equally to this work
| | - Y. L. Zhu
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Wenhua Road 72, 110016 Shenyang, China
- These authors contributed equally to this work
| | - Y. J. Wang
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Wenhua Road 72, 110016 Shenyang, China
| | - W. Y. Wang
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Wenhua Road 72, 110016 Shenyang, China
| | - Y. B. Xu
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Wenhua Road 72, 110016 Shenyang, China
| | - W. J. Ren
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Wenhua Road 72, 110016 Shenyang, China
| | - Z. D. Zhang
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Wenhua Road 72, 110016 Shenyang, China
| | - X. L. Ma
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Wenhua Road 72, 110016 Shenyang, China
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31
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Kundu P, Turner S, Van Aert S, Ravishankar N, Van Tendeloo G. Atomic structure of quantum gold nanowires: quantification of the lattice strain. ACS NANO 2014; 8:599-606. [PMID: 24289167 DOI: 10.1021/nn4052315] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Theoretical studies exist to compute the atomic arrangement in gold nanowires and the influence on their electronic behavior with decreasing diameter. Experimental studies, e.g., by transmission electron microscopy, on chemically synthesized ultrafine wires are however lacking owing to the unavailability of suitable protocols for sample preparation and the stability of the wires under electron beam irradiation. In this work, we present an atomic scale structural investigation on quantum single crystalline gold nanowires of 2 nm diameter, chemically prepared on a carbon film grid. Using low dose aberration-corrected high resolution (S)TEM, we observe an inhomogeneous strain distribution in the crystal, largely concentrated at the twin boundaries and the surface along with the presence of facets and surface steps leading to a noncircular cross section of the wires. These structural aspects are critical inputs needed to determine their unique electronic character and their potential as a suitable catalyst material. Furthermore, electron-beam-induced structural changes at the atomic scale, having implications on their mechanical behavior and their suitability as interconnects, are discussed.
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Affiliation(s)
- Paromita Kundu
- Electron Microscopy for Materials Science (EMAT), University of Antwerp , Groenenborgerlaan 171, 2020 Antwerp, Belgium
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32
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den Dekker A, Gonnissen J, De Backer A, Sijbers J, Van Aert S. Estimation of unknown structure parameters from high-resolution (S)TEM images: What are the limits? Ultramicroscopy 2013; 134:34-43. [DOI: 10.1016/j.ultramic.2013.05.017] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Revised: 05/16/2013] [Accepted: 05/20/2013] [Indexed: 10/26/2022]
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33
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De Backer A, Martinez G, Rosenauer A, Van Aert S. Atom counting in HAADF STEM using a statistical model-based approach: Methodology, possibilities, and inherent limitations. Ultramicroscopy 2013; 134:23-33. [DOI: 10.1016/j.ultramic.2013.05.003] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Revised: 05/07/2013] [Accepted: 05/09/2013] [Indexed: 10/26/2022]
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34
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Jia CL, Barthel J, Gunkel F, Dittmann R, Hoffmann-Eifert S, Houben L, Lentzen M, Thust A. Atomic-scale measurement of structure and chemistry of a single-unit-cell layer of LaAlO3 embedded in SrTiO3. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2013; 19:310-318. [PMID: 23452378 DOI: 10.1017/s1431927612014407] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
A single layer of LaAlO3 with a nominal thickness of one unit cell, which is sandwiched between a SrTiO3 substrate and a SrTiO3 capping layer, is quantitatively investigated by high-resolution transmission electron microscopy. By the use of an aberration-corrected electron microscope and by employing sophisticated numerical image simulation procedures, significant progress is made in two aspects. First, the structural as well as the chemical features of the interface are determined simultaneously on an atomic scale from the same specimen area. Second, the evaluation of the structural and chemical data is carried out in a fully quantitative way on the basis of the absolute image contrast, which has not been achieved so far in materials science investigations using high-resolution electron microscopy. Considering the strong influence of even subtle structural details on the electronic properties of interfaces in oxide materials, a fully quantitative interface analysis, which makes positional data available with picometer precision together with the related chemical information, can contribute to a better understanding of the functionality of such interfaces.
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Affiliation(s)
- Chun-Lin Jia
- Peter Grünberg Institute, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany.
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35
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Van Tendeloo G, Bals S, Van Aert S, Verbeeck J, Van Dyck D. Advanced electron microscopy for advanced materials. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2012; 24:5655-5675. [PMID: 22907862 DOI: 10.1002/adma.201202107] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Indexed: 06/01/2023]
Abstract
The idea of this Review is to introduce newly developed possibilities of advanced electron microscopy to the materials science community. Over the last decade, electron microscopy has evolved into a full analytical tool, able to provide atomic scale information on the position, nature, and even the valency atoms. This information is classically obtained in two dimensions (2D), but can now also be obtained in 3D. We show examples of applications in the field of nanoparticles and interfaces.
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36
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Van Dyck D, Jinschek JR, Chen FR. ‘Big Bang’ tomography as a new route to atomic-resolution electron tomography. Nature 2012; 486:243-6. [DOI: 10.1038/nature11074] [Citation(s) in RCA: 102] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2011] [Accepted: 03/22/2012] [Indexed: 11/09/2022]
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37
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Klingstedt M, Sundberg M, Eriksson L, Haigh S, Kirkland A, Grüner D, De Backer A, Van Aert S, Terasaki O. Exit wave reconstruction from focal series of HRTEM images, single crystal XRD and total energy studies on SbxWO3+y(x∼ 0.11). Z KRIST-CRYST MATER 2012. [DOI: 10.1524/zkri.2012.1517] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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38
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Wang A, Chen F, Van Aert S, Van Dyck D. Direct structure inversion from exit waves. Part II: A practical example. Ultramicroscopy 2012. [DOI: 10.1016/j.ultramic.2012.03.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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39
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Wang A, Van Aert S, Goos P, Van Dyck D. Precision of three-dimensional atomic scale measurements from HRTEM images: What are the limits? Ultramicroscopy 2012; 114:20-30. [DOI: 10.1016/j.ultramic.2011.12.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2011] [Revised: 12/14/2011] [Accepted: 12/22/2011] [Indexed: 11/25/2022]
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40
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Van Aert S, Van den Broek W, Goos P, Van Dyck D. Model-based electron microscopy: From images toward precise numbers for unknown structure parameters. Micron 2012. [DOI: 10.1016/j.micron.2011.10.019] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
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41
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Van Aert S, Turner S, Delville R, Schryvers D, Van Tendeloo G, Salje EKH. Direct observation of ferrielectricity at ferroelastic domain boundaries in CaTiO3 by electron microscopy. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2012; 24:523-7. [PMID: 22223264 DOI: 10.1002/adma.201103717] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2011] [Revised: 11/16/2011] [Indexed: 05/12/2023]
Abstract
High-resolution aberration-corrected transmission electron microscopy aided by statistical parameter estimation theory is used to quantify localized displacements at a (110) twin boundary in orthorhombic CaTiO(3). The displacements are 3-6 pm for the Ti atoms and confined to a thin layer. This is the first direct observation of the generation of ferroelectricity by interfaces inside this material which opens the door for domain boundary engineering.
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Affiliation(s)
- Sandra Van Aert
- Electron Microscopy for Materials Research (EMAT), University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium.
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42
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De Backer A, Van Aert S, Van Dyck D. High precision measurements of atom column positions using model-based exit wave reconstruction. Ultramicroscopy 2011; 111:1475-82. [PMID: 21930019 DOI: 10.1016/j.ultramic.2011.07.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2011] [Revised: 07/06/2011] [Accepted: 07/14/2011] [Indexed: 11/29/2022]
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.
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Affiliation(s)
- A De Backer
- Electron Microscopy for Materials Science (EMAT), University of Antwerp, Belgium.
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43
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A method to determine the local surface profile from reconstructed exit waves. Ultramicroscopy 2011; 111:1352-9. [PMID: 21864776 DOI: 10.1016/j.ultramic.2011.04.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2010] [Revised: 04/19/2011] [Accepted: 04/24/2011] [Indexed: 11/21/2022]
Abstract
Reconstructed exit waves are useful to quantify unknown structure parameters such as the position and composition of the atom columns at atomic scale. Existing techniques provide a complex wave in a flat plane which is close to the plane where the electrons leave the atom columns. However, due to local deviation in the flatness of the exit surface, there will be an offset between the plane of reconstruction and the actual exit of a specific atom column. Using the channelling theory, it has been shown that this defocus offset can in principle be determined atom column-by-atom column. As such, the surface roughness could be quantified at atomic scale. However, the outcome strongly depends on the initial plane of reconstruction especially in a crystalline structure. If this plane is further away from the true exit, the waves of the atom columns become delocalized and interfere mutually which strongly complicates the interpretation of the exit wave in terms of the local structure. In this paper, we will study the delocalization with defocus using the channelling theory in a more systematic way.
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44
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Garbrecht M, Spiecker E, Tillmann K, Jäger W. Quantitative atom column position analysis at the incommensurate interfaces of a (PbS)1.14NbS2 misfit layered compound with aberration-corrected HRTEM. Ultramicroscopy 2011; 111:245-50. [DOI: 10.1016/j.ultramic.2010.11.031] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2010] [Revised: 10/31/2010] [Accepted: 11/23/2010] [Indexed: 11/24/2022]
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45
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Linear versus non-linear structural information limit in high-resolution transmission electron microscopy. Ultramicroscopy 2010; 110:1404-10. [DOI: 10.1016/j.ultramic.2010.07.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2009] [Revised: 04/23/2010] [Accepted: 07/08/2010] [Indexed: 11/18/2022]
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46
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Chang LY, Barnard AS, Gontard LC, Dunin-Borkowski RE. Resolving the structure of active sites on platinum catalytic nanoparticles. NANO LETTERS 2010; 10:3073-6. [PMID: 20666362 DOI: 10.1021/nl101642f] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Accurate understanding of the structure of active sites is fundamentally important in predicting catalytic properties of heterogeneous nanocatalysts. We present an accurate determination of both experimental and theoretical atomic structures of surface monatomic steps on industrial platinum nanoparticles. This comparison reveals that the edges of nanoparticles can significantly alter the atomic positions of monatomic steps in their proximity, which can lead to substantial deviations in the catalytic properties compared with the extended surfaces.
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Affiliation(s)
- Lan Yun Chang
- Monash Centre for Electron Microscopy and School of Chemistry, Monash University, Clayton, Victoria, Australia
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47
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Van Aert S, Verbeeck J, Erni R, Bals S, Luysberg M, Dyck DV, Tendeloo GV. Quantitative atomic resolution mapping using high-angle annular dark field scanning transmission electron microscopy. Ultramicroscopy 2009; 109:1236-44. [DOI: 10.1016/j.ultramic.2009.05.010] [Citation(s) in RCA: 133] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2009] [Revised: 05/07/2009] [Accepted: 05/13/2009] [Indexed: 10/20/2022]
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48
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Aert SV, Chang L, Bals S, Kirkland A, Tendeloo GV. Effect of amorphous layers on the interpretation of restored exit waves. Ultramicroscopy 2009; 109:237-46. [DOI: 10.1016/j.ultramic.2008.10.024] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2008] [Revised: 10/20/2008] [Accepted: 10/29/2008] [Indexed: 11/27/2022]
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49
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Avila-Brande D, Landa-Cánovas AR, Otero-Díaz LC. Order, disorder and structural modulations in Bi-Fe-W-O-Br Sillén-Aurivillius intergrowths. ACTA CRYSTALLOGRAPHICA SECTION B: STRUCTURAL SCIENCE 2008; 64:438-47. [PMID: 18641445 DOI: 10.1107/s0108768108019022] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2008] [Accepted: 06/23/2008] [Indexed: 11/11/2022]
Abstract
Transmission electron microscopy observations on a new complex oxybromide with nominal composition Bi(4)Fe(1/3)W(2/3)O(8)Br, heated at high temperature, reveal the transformation of its basic structure yielding two types of crystals. The first crystal type shows ordered and disordered extended defects leading to a new family of intergrowths between one Sillén block and n Aurivillius blocks and occasionally between one Aurivillius block and n Sillén blocks. The second type presents a compositionally modulated structure, determined by electron diffraction, with an average composition Bi(4)Fe(1/2)W(1/2)O(8 - delta)Br and unit-cell parameters a = (1/gamma) 3.8, b = 3.8, c = 14.5 A (gamma = 0.10-0.15) in the superspace group Immm[(1 - gamma)00] no. 71.1.
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Affiliation(s)
- David Avila-Brande
- Departamento Química Inorgánica, Fac. CC. Químicas, Universidad Complutense, E-28040, Madrid, Spain.
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