1
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Şentürk DG, De Backer A, Van Aert S. Element specific atom counting for heterogeneous nanostructures: Combining multiple ADF STEM images for simultaneous thickness and composition determination. Ultramicroscopy 2024; 259:113941. [PMID: 38387236 DOI: 10.1016/j.ultramic.2024.113941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 02/15/2024] [Accepted: 02/18/2024] [Indexed: 02/24/2024]
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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Affiliation(s)
- D G Şentürk
- Electron Microscopy for Materials Science (EMAT), University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium; NANOlab Center of Excellence, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
| | - A De Backer
- Electron Microscopy for Materials Science (EMAT), University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium; NANOlab Center of Excellence, University of Antwerp, Groenenborgerlaan 171, 2020 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, Groenenborgerlaan 171, 2020 Antwerp, Belgium.
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2
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Li C, Yan S, Fang J. Construction of Lattice Strain in Bimetallic Nanostructures and Its Effectiveness in Electrochemical Applications. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2021; 17:e2102244. [PMID: 34363320 DOI: 10.1002/smll.202102244] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Revised: 06/09/2021] [Indexed: 06/13/2023]
Abstract
Bimetallic nanocrystals (NCs), associated with various surface functions such as ligand effect, ensemble effect, and strain effect, exhibit superior electrocatalytic properties. The stress-induced surface strain effect can alter binding strength between the surface active sites and reactants as well as their intermediates, and the electrochemical performance of bimetallic NCs can be significantly facilitated by the lattice-strain modification via their morphologies, sizes, shell-thickness, surface defectiveness as well as compositions. In this review, an overview of fundamental principles, characterization techniques, and quantitative determination of the surface lattice strain is provided. Various strategies and synthesis efforts on creating lattice-strain-engineered bimetallic NCs, including the de-alloying process, atomic layer-by-layer deposition, thermal treatment evolution, one-pot synthesis, and other efforts are also discussed. It is further outlined how the lattice strain effect promotes electrochemical catalysis through the selected case studies. The reactions on oxygen reduction reaction, small molecular oxidation, water splitting reaction, and electrochemical carbon dioxide reduction reactions are focused. In particular, studies of lattice strain arisen from core-shell nanostructure and defectiveness are highlighted. Lastly, the potential challenges are summarized and the prospects of lattice-strain-based engineering on bimetallic nanocatalysts with suggestion and guidance of the future electrocatalyst design are envisioned.
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Affiliation(s)
- Can Li
- Department of Chemistry, State University of New York at Binghamton, Binghamton, NY, 13902, USA
| | - Shaohui Yan
- Department of Chemistry, State University of New York at Binghamton, Binghamton, NY, 13902, USA
| | - Jiye Fang
- Department of Chemistry, State University of New York at Binghamton, Binghamton, NY, 13902, 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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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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5
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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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6
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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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Chatterjee D, Shetty S, Müller-Caspary K, Grieb T, Krause FF, Schowalter M, Rosenauer A, Ravishankar N. Ultrathin Au-Alloy Nanowires at the Liquid-Liquid Interface. NANO LETTERS 2018; 18:1903-1907. [PMID: 29397751 DOI: 10.1021/acs.nanolett.7b05217] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Ultrathin bimetallic nanowires are of importance and interest for applications in electronic devices such as sensors and heterogeneous catalysts. In this work, we have designed a new, highly reproducible and generalized wet chemical method to synthesize uniform and monodispersed Au-based alloy (AuCu, AuPd, and AuPt) nanowires with tunable composition using microwave-assisted reduction at the liquid-liquid interface. These ultrathin alloy nanowires are below 4 nm in diameter and about 2 μm long. Detailed microstructural characterization shows that the wires have an face centred cubic (FCC) crystal structure, and they have low-energy twin-boundary and stacking-fault defects along the growth direction. The wires exhibit remarkable thermal and mechanical stability that is critical for important applications. The alloy wires exhibit excellent electrocatalytic activity for methanol oxidation in an alkaline medium.
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Affiliation(s)
- Dipanwita Chatterjee
- Materials Research Centre , Indian Institute of Science , Bangalore 560012 , India
| | - Shwetha Shetty
- Materials Research Centre , Indian Institute of Science , Bangalore 560012 , India
| | | | - Tim Grieb
- University of Bremen , Otto-Hahn-Allee 1 , D-28359 Bremen , Germany
| | - Florian F Krause
- University of Bremen , Otto-Hahn-Allee 1 , D-28359 Bremen , Germany
| | - Marco Schowalter
- University of Bremen , Otto-Hahn-Allee 1 , D-28359 Bremen , Germany
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8
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Fu X, Yuan J. Non-destructive detection of cross-sectional strain and defect structure in an individual Ag five-fold twinned nanowire by 3D electron diffraction mapping. Sci Rep 2017; 7:6206. [PMID: 28740257 PMCID: PMC5524976 DOI: 10.1038/s41598-017-06485-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Accepted: 06/14/2017] [Indexed: 12/03/2022] Open
Abstract
Coherent x-ray diffraction investigations on Ag five-fold twinned nanowires (FTNWs) have drawn controversial conclusions concerning whether the intrinsic 7.35° angular gap could be compensated homogeneously through phase transformation or inhomogeneously by forming disclination strain field. In those studies, the x-ray techniques only provided an ensemble average of the structural information from all the Ag nanowires. Here, using three-dimensional (3D) electron diffraction mapping approach, we non-destructively explore the cross-sectional strain and the related strain-relief defect structures of an individual Ag FTNW with diameter about 30 nm. The quantitative analysis of the fine structure of intensity distribution combining with kinematic electron diffraction simulation confirms that for such a Ag FTNW, the intrinsic 7.35° angular deficiency results in an inhomogeneous strain field within each single crystalline segment consistent with the disclination model of stress-relief. Moreover, the five crystalline segments are found to be strained differently. Modeling analysis in combination with system energy calculation further indicates that the elastic strain energy within some crystalline segments, could be partially relieved by the creation of stacking fault layers near the twin boundaries. Our study demonstrates that 3D electron diffraction mapping is a powerful tool for the cross-sectional strain analysis of complex 1D nanostructures.
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Affiliation(s)
- Xin Fu
- General Research Institute for Nonferrous Metals, Beijing, 100088, P.R. China. .,Guobiao (Beijing) Testing & Certification Co., Ltd., Beijing, 100088, P.R. China.
| | - Jun Yuan
- Department of Physics, University of York, York, YO10 5DD, United Kingdom.
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9
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Gonnissen J, De Backer A, den Dekker A, Sijbers J, Van Aert S. Atom-counting in High Resolution Electron Microscopy:TEM or STEM – That's the question. Ultramicroscopy 2017; 174:112-120. [DOI: 10.1016/j.ultramic.2016.10.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Revised: 10/14/2016] [Accepted: 10/25/2016] [Indexed: 11/24/2022]
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10
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Abstract
Understanding of the atomic structure and stability of nanowires (NWs) is critical for their applications in nanotechnology, especially when the diameter of NWs reduces to ultrathin scale (1-2 nm). Here, using aberration-corrected high-resolution transmission electron microscopy (AC-HRTEM), we report a detailed atomic structure study of the ultrathin Au NWs, which are synthesized using a silane-mediated approach. The NWs contain large amounts of generalized stacking fault defects. These defects evolve upon sustained electron exposure, and simultaneously the NWs undergo necking and breaking. Quantitative strain analysis reveals the key role of strain in the breakdown process. Besides, ligand-like morphology is observed at the surface of the NWs, indicating the possibility of using AC-HRTEM for surface ligand imaging. Moreover, the coalescence dynamic of ultrathin Au NWs is demonstrated by in situ observations. This work provides a comprehensive understanding of the structure of ultrathin metal NWs at atomic-scale and could have important implications for their applications.
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Affiliation(s)
- Yi Yu
- Department of Chemistry, University of California , Berkeley, California 94720, United States
- Materials Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
| | - Fan Cui
- Department of Chemistry, University of California , Berkeley, California 94720, United States
- Materials Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
| | - Jianwei Sun
- Department of Chemistry, University of California , Berkeley, California 94720, United States
- Materials Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
| | - Peidong Yang
- Department of Chemistry, University of California , Berkeley, California 94720, United States
- Materials Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
- Kavli Energy NanoScience Institute, Berkeley, California 94720, United States
- Department of Materials Science and Engineering, University of California , Berkeley, California 94720, United States
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11
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STEM image simulation with hybrid CPU/GPU programming. Ultramicroscopy 2016; 166:1-8. [PMID: 27093687 DOI: 10.1016/j.ultramic.2016.04.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2015] [Revised: 03/28/2016] [Accepted: 04/08/2016] [Indexed: 11/20/2022]
Abstract
STEM image simulation is achieved via hybrid CPU/GPU programming under parallel algorithm architecture to speed up calculation on a personal computer (PC). To utilize the calculation power of a PC fully, the simulation is performed using the GPU core and multi-CPU cores at the same time to significantly improve efficiency. GaSb and an artificial GaSb/InAs interface with atom diffusion have been used to verify the computation.
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12
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Morgan K, Touitou J, Choi JS, Coney C, Hardacre C, Pihl JA, Stere CE, Kim MY, Stewart C, Goguet A, Partridge WP. Evolution and Enabling Capabilities of Spatially Resolved Techniques for the Characterization of Heterogeneously Catalyzed Reactions. ACS Catal 2016. [DOI: 10.1021/acscatal.5b02602] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Kevin Morgan
- School
of Mechanical and Aerospace Engineering, Queen’s University Belfast, Ashby Building, Stranmillis Road, Belfast BT9 5AH, United Kingdom
| | - Jamal Touitou
- Department
of Chemical and Materials Engineering, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Jae-Soon Choi
- Fuels,
Engines and Emissions Research Center, Oak Ridge National Laboratory, P.O. Box 2008,
MS-6472, Oak Ridge, Tennessee 37831-6472, United States
| | - Ciarán Coney
- School
of Chemistry and Chemical Engineering, Queen’s University Belfast, David
Keir Building, Stranmillis Road, Belfast BT9 5AG, United Kingdom
| | - Christopher Hardacre
- School
of Chemistry and Chemical Engineering, Queen’s University Belfast, David
Keir Building, Stranmillis Road, Belfast BT9 5AG, United Kingdom
| | - Josh A. Pihl
- Fuels,
Engines and Emissions Research Center, Oak Ridge National Laboratory, P.O. Box 2008,
MS-6472, Oak Ridge, Tennessee 37831-6472, United States
| | - Cristina E. Stere
- School
of Chemistry and Chemical Engineering, Queen’s University Belfast, David
Keir Building, Stranmillis Road, Belfast BT9 5AG, United Kingdom
| | - Mi-Young Kim
- Fuels,
Engines and Emissions Research Center, Oak Ridge National Laboratory, P.O. Box 2008,
MS-6472, Oak Ridge, Tennessee 37831-6472, United States
| | - Caomhán Stewart
- School
of Chemistry and Chemical Engineering, Queen’s University Belfast, David
Keir Building, Stranmillis Road, Belfast BT9 5AG, United Kingdom
| | - Alexandre Goguet
- School
of Chemistry and Chemical Engineering, Queen’s University Belfast, David
Keir Building, Stranmillis Road, Belfast BT9 5AG, United Kingdom
| | - William P. Partridge
- Fuels,
Engines and Emissions Research Center, Oak Ridge National Laboratory, P.O. Box 2008,
MS-6472, Oak Ridge, Tennessee 37831-6472, United States
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13
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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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14
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Imura Y, Furukawa S, Ozawa K, Morita-Imura C, Kawai T, Komatsu T. Surface clean gold nanoflower obtained by complete removal of capping agents: an active catalyst for alcohol oxidation. RSC Adv 2016. [DOI: 10.1039/c5ra27146k] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Morphological stability and catalytic activity of Au nanoflowers (NFs) were improved by using γ-Al2O3 support and water extraction procedure. Formation rate of acetophenone on Au NFs/γ-Al2O3 was ten-fold higher than that on spherical Au NPs/γ-Al2O3.
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Affiliation(s)
- Yoshiro Imura
- Department of Chemistry and Material Science
- Tokyo Institute of Technology
- Tokyo 152-8551
- Japan
- Department of Industrial Chemistry
| | - Shinya Furukawa
- Department of Chemistry
- Tokyo Institute of Technology
- Tokyo 152-8551
- Japan
| | - Kenichi Ozawa
- Department of Chemistry and Material Science
- Tokyo Institute of Technology
- Tokyo 152-8551
- Japan
| | - Clara Morita-Imura
- Department of Industrial Chemistry
- Tokyo University of Science
- Tokyo 162-8601
- Japan
| | - Takeshi Kawai
- Department of Industrial Chemistry
- Tokyo University of Science
- Tokyo 162-8601
- Japan
| | - Takayuki Komatsu
- Department of Chemistry and Material Science
- Tokyo Institute of Technology
- Tokyo 152-8551
- Japan
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15
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Itoi M, Jike T, Nishio-Hamane D, Udagawa S, Tsuda T, Kuwabata S, Boukheddaden K, Andrus MJ, Talham DR. Direct Observation of Short-Range Structural Coherence During a Charge Transfer Induced Spin Transition in a CoFe Prussian Blue Analogue by Transmission Electron Microscopy. J Am Chem Soc 2015; 137:14686-93. [DOI: 10.1021/jacs.5b08242] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Miho Itoi
- Division
of Physics, Institute of Liberal Education, Nihon University School of Medicine, Tokyo 173-8610, Japan
| | - Toyoharu Jike
- Division
of Physics, Institute of Liberal Education, Nihon University School of Medicine, Tokyo 173-8610, Japan
| | | | - Seiichi Udagawa
- Division
of Physics, Institute of Liberal Education, Nihon University School of Medicine, Tokyo 173-8610, Japan
| | - Tetsuya Tsuda
- Department
of Applied Chemistry, Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871, Japan
| | - Susumu Kuwabata
- Department
of Applied Chemistry, Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871, Japan
| | - Kamel Boukheddaden
- Groupe
d’Etudes de la Matière Condensée, UMR 8635, CNRS-Université de Versailles Saint-Quentin-en-Yvelines, 45 Avenue des Etats Unis, 78035 Versailles, France
| | - Matthew J. Andrus
- Department
of Chemistry, University of Florida, P.O. Box 117200, Gainesville, Florida 32611-7200, United States
| | - Daniel R. Talham
- Department
of Chemistry, University of Florida, P.O. Box 117200, Gainesville, Florida 32611-7200, United States
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16
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De Backer A, Martinez G, MacArthur K, Jones L, Béché A, Nellist P, Van Aert S. Dose limited reliability of quantitative annular dark field scanning transmission electron microscopy for nano-particle atom-counting. Ultramicroscopy 2015; 151:56-61. [DOI: 10.1016/j.ultramic.2014.11.028] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Revised: 11/23/2014] [Accepted: 11/28/2014] [Indexed: 11/26/2022]
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17
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Lacroix LM, Arenal R, Viau G. Dynamic HAADF-STEM observation of a single-atom chain as the transient state of gold ultrathin nanowire breakdown. J Am Chem Soc 2014; 136:13075-7. [PMID: 25188861 DOI: 10.1021/ja507728j] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Ultrathin chemically grown gold nanowires undergo irremediable structural modification under external stimuli. Thanks to dynamic high-angle annular dark-field imaging, electron-beam-induced damage was followed, revealing the formation of linear chains of gold atoms as well as reactive clusters on the side, opening fascinating prospects for applications in both catalysis and electronic transport.
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Affiliation(s)
- Lise-Marie Lacroix
- Laboratoire de Physique et Chimie des Nano-Objets, INSA, UPS, CNRS, UMR 5215, Université de Toulouse , F-31077 Toulouse, France
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Roy A, Kundu S, Müller K, Rosenauer A, Singh S, Pant P, Gururajan MP, Kumar P, Weissmüller J, Singh AK, Ravishankar N. Wrinkling of atomic planes in ultrathin Au nanowires. NANO LETTERS 2014; 14:4859-4866. [PMID: 25004463 DOI: 10.1021/nl502259w] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
A detailed understanding of structure and stability of nanowires is critical for applications. Atomic resolution imaging of ultrathin single crystalline Au nanowires using aberration-corrected microscopy reveals an intriguing relaxation whereby the atoms in the close-packed atomic planes normal to the growth direction are displaced in the axial direction leading to wrinkling of the (111) atomic plane normal to the wire axis. First-principles calculations of the structure of such nanowires confirm this wrinkling phenomenon, whereby the close-packed planes relax to form saddle-like surfaces. Molecular dynamics studies of wires with varying diameters and different bounding surfaces point to the key role of surface stress on the relaxation process. Using continuum mechanics arguments, we show that the wrinkling arises due to anisotropy in the surface stresses and in the elastic response, along with the divergence of surface-induced bulk stress near the edges of a faceted structure. The observations provide new understanding on the equilibrium structure of nanoscale systems and could have important implications for applications in sensing and actuation.
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Affiliation(s)
- Ahin Roy
- Materials Research Centre, Indian Institute of Science , Bangalore, Karnataka 560012, India
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