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Takeguchi M, Hashimoto A, Mitsuishi K. Depth sectioning using environmental and atomic-resolution STEM. Microscopy (Oxf) 2024; 73:145-153. [PMID: 38252480 DOI: 10.1093/jmicro/dfae005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 01/04/2024] [Accepted: 01/15/2024] [Indexed: 01/23/2024] Open
Abstract
(Scanning) transmission electron microscopy (TEM) images of samples in gas and liquid media are acquired with an environmental cell (EC) via silicon nitride membranes. The ratio of sample signal against the background is a significant factor for resolution. Depth-sectioning scanning TEM (STEM) is a promising technique that enhances the signal for a sample embedded in a matrix. It can increase the resolution to the atomic level, thereby enabling EC-STEM applications in important areas. This review introduces depth-sectioning STEM and its applications to high-resolution EC-STEM imaging of samples in gases and in liquids.
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Affiliation(s)
- Masaki Takeguchi
- Center for Basic Research on Materials, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan
| | - Ayako Hashimoto
- Center for Basic Research on Materials, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan
| | - Kazutaka Mitsuishi
- Center for Basic Research on Materials, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan
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Nord M, Barthel J, Allen CS, McGrouther D, Kirkland AI, MacLaren I. Atomic resolution HOLZ-STEM imaging of atom position modulation in oxide heterostructures. Ultramicroscopy 2021; 226:113296. [PMID: 34004555 DOI: 10.1016/j.ultramic.2021.113296] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 03/16/2021] [Accepted: 04/24/2021] [Indexed: 11/26/2022]
Abstract
It is shown that higher order Laue zone (HOLZ) rings in high energy electron diffraction are specific to individual columns of atoms, and show different strengths, structure and radii for different atom columns along the same projection in a structure. An atomic resolution 4-dimensional STEM dataset is recorded from a <110> direction in a perovskite trilayer, where only the central LaFeO3 layer should show a period doubling that gives rise to an extra HOLZ ring. Careful comparison between experiment and multislice simulations is used to understand the origins of all features in the patterns. A strong HOLZ ring is seen for the La-O columns, indicating strong La position modulation along this direction, whereas a weaker ring is seen along the O columns, and a very weak ring is seen along the Fe columns. This demonstrates that atomic resolution HOLZ-STEM is a feasible method for investigating the 3D periodicity of crystalline materials with atomic resolution.
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Affiliation(s)
- Magnus Nord
- School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, UK; Department of Physics, NTNU, Høgskoleringen 5, 7491, Trondheim, Norway
| | - Juri Barthel
- Ernst Ruska-Centre (ER-C 2), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Christopher S Allen
- electron Physical Science Imaging Centre, Diamond Light Source Ltd., OX11 0DE, UK; Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, UK
| | - Damien McGrouther
- School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, UK
| | - Angus I Kirkland
- electron Physical Science Imaging Centre, Diamond Light Source Ltd., OX11 0DE, UK; Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, UK
| | - Ian MacLaren
- School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, UK.
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4D-Data Acquisition in Scanning Confocal Electron Microscopy for Depth-Sectioned Imaging. E-JOURNAL OF SURFACE SCIENCE AND NANOTECHNOLOGY 2018. [DOI: 10.1380/ejssnt.2018.247] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Hamaoka T, Jao CY, Takeguchi M. Annular dark-field scanning confocal electron microscopy studied using multislice simulations. Microscopy (Oxf) 2018; 67:4995666. [PMID: 29762753 DOI: 10.1093/jmicro/dfy023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Accepted: 04/25/2018] [Indexed: 11/13/2022] Open
Abstract
Annular dark-field scanning confocal electron microscopy (ADF-SCEM) has been studied using multislice simulations. Thermal diffuse scattering was considered in the calculations. Geometric aberrations of the lenses were introduced. A finite-sized pinhole was taken into consideration, in addition to an ideal point pinhole. ADF-SCEM images of Al crystals aligned along a zone-axis exhibit elongated contrast along the optic axis. Results of simulations suggest that if geometric aberrations of an imaging lens are corrected, depth resolution in ADF-SCEM can be improved by employing a large collection semi-angle of an annular aperture, even with a finite pinhole.
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Affiliation(s)
- Takumi Hamaoka
- Transmission Electron Microscopy Station, National Institute for Materials Science, Tsukuba 305-0047, Japan
| | - Chih-Yu Jao
- Transmission Electron Microscopy Station, National Institute for Materials Science, Tsukuba 305-0047, Japan
| | - Masaki Takeguchi
- Transmission Electron Microscopy Station, National Institute for Materials Science, Tsukuba 305-0047, Japan
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Gao S, Wang P, Zhang F, Martinez GT, Nellist PD, Pan X, Kirkland AI. Electron ptychographic microscopy for three-dimensional imaging. Nat Commun 2017; 8:163. [PMID: 28761117 PMCID: PMC5537274 DOI: 10.1038/s41467-017-00150-1] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 06/06/2017] [Indexed: 01/14/2023] Open
Abstract
Knowing the three-dimensional structural information of materials at the nanometer scale is essential to understanding complex material properties. Electron tomography retrieves three-dimensional structural information using a tilt series of two-dimensional images. In this paper, we report an alternative combination of electron ptychography with the inverse multislice method. We demonstrate depth sectioning of a nanostructured material into slices with 0.34 nm lateral resolution and with a corresponding depth resolution of about 24-30 nm. This three-dimensional imaging method has potential applications for the three-dimensional structure determination of a range of objects, ranging from inorganic nanostructures to biological macromolecules.Three-dimensional ptychographic imaging with electrons has remained a challenge because, unlike X-rays, electrons are easily scattered by atoms. Here, Gao et al. extend multi-slice methods to electrons in the multiple scattering regime, paving the way to nanometer-scale 3D structure determination with electrons.
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Affiliation(s)
- Si Gao
- National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, Collaborative Innovation Center of Advanced Microstructures and Center for the Microstructures of Quantum Materials, Nanjing University, Nanjing, 210093, People's Republic of China
| | - Peng Wang
- National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, Collaborative Innovation Center of Advanced Microstructures and Center for the Microstructures of Quantum Materials, Nanjing University, Nanjing, 210093, People's Republic of China. .,Research Center for Environmental Nanotechnology, Nanjing University, Nanjing, 210093, People's Republic of China.
| | - Fucai Zhang
- Department of Electrical and Electronic Engineering, Southern University of Science and Technology, Shenzhen, 518055, People's Republic of China. .,London Centre for Nanotechnology, London, WC1H 0AH, UK. .,Research Complex at Harwell, Harwell Oxford Campus, Didcot, OX11 0FA, UK.
| | - Gerardo T Martinez
- Department of Materials, University of Oxford, Parks Road, Oxford, OX1 3PH, UK
| | - Peter D Nellist
- Department of Materials, University of Oxford, Parks Road, Oxford, OX1 3PH, UK
| | - Xiaoqing Pan
- National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, Collaborative Innovation Center of Advanced Microstructures and Center for the Microstructures of Quantum Materials, Nanjing University, Nanjing, 210093, People's Republic of China.,Department of Chemical Engineering and Materials Science, University of California, Irvine, CA, 92697, USA.,Department of Physics and Astronomy, University of Califnornia, Irvine, CA, 92697, USA
| | - Angus I Kirkland
- Department of Materials, University of Oxford, Parks Road, Oxford, OX1 3PH, UK.,Electron Physical Sciences Imaging Centre, Diamond Lightsource, Diamond House, Oxfordshire, Didcot, OX11 0DE, UK
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Johnson JM, Im S, Windl W, Hwang J. Three-dimensional imaging of individual point defects using selective detection angles in annular dark field scanning transmission electron microscopy. Ultramicroscopy 2016; 172:17-29. [PMID: 27792913 DOI: 10.1016/j.ultramic.2016.10.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Revised: 09/20/2016] [Accepted: 10/16/2016] [Indexed: 10/20/2022]
Abstract
We propose a new scanning transmission electron microscopy (STEM) technique that can realize the three-dimensional (3D) characterization of vacancies, lighter and heavier dopants with high precision. Using multislice STEM imaging and diffraction simulations of β-Ga2O3 and SrTiO3, we show that selecting a small range of low scattering angles can make the contrast of the defect-containing atomic columns substantially more depth-dependent. The origin of the depth-dependence is the de-channeling of electrons due to the existence of a point defect in the atomic column, which creates extra "ripples" at low scattering angles. The highest contrast of the point defect can be achieved when the de-channeling signal is captured using the 20-40mrad detection angle range. The effect of sample thickness, crystal orientation, local strain, probe convergence angle, and experimental uncertainty to the depth-dependent contrast of the point defect will also be discussed. The proposed technique therefore opens new possibilities for highly precise 3D structural characterization of individual point defects in functional materials.
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Affiliation(s)
- Jared M Johnson
- Department of Materials Science and Engineering, The Ohio State University, Columbus, OH 43212, USA
| | - Soohyun Im
- Department of Materials Science and Engineering, The Ohio State University, Columbus, OH 43212, USA
| | - Wolfgang Windl
- Department of Materials Science and Engineering, The Ohio State University, Columbus, OH 43212, USA
| | - Jinwoo Hwang
- Department of Materials Science and Engineering, The Ohio State University, Columbus, OH 43212, USA.
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Zheng C, Zhu Y, Lazar S, Etheridge J. Fast imaging with inelastically scattered electrons by off-axis chromatic confocal electron microscopy. PHYSICAL REVIEW LETTERS 2014; 112:166101. [PMID: 24815659 DOI: 10.1103/physrevlett.112.166101] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Indexed: 06/03/2023]
Abstract
We introduce off-axis chromatic scanning confocal electron microscopy, a technique for fast mapping of inelastically scattered electrons in a scanning transmission electron microscope without a spectrometer. The off-axis confocal mode enables the inelastically scattered electrons to be chromatically dispersed both parallel and perpendicular to the optic axis. This enables electrons with different energy losses to be separated and detected in the image plane, enabling efficient energy filtering in a confocal mode with an integrating detector. We describe the experimental configuration and demonstrate the method with nanoscale core-loss chemical mapping of silver (M4,5) in an aluminium-silver alloy and atomic scale imaging of the low intensity core-loss La (M4,5@840 eV) signal in LaB6. Scan rates up to 2 orders of magnitude faster than conventional methods were used, enabling a corresponding reduction in radiation dose and increase in the field of view. If coupled with the enhanced depth and lateral resolution of the incoherent confocal configuration, this offers an approach for nanoscale three-dimensional chemical mapping.
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Affiliation(s)
- Changlin Zheng
- Monash Centre for Electron Microscopy, Monash University, Victoria 3800, Australia
| | - Ye Zhu
- Department of Materials Engineering, Monash University, Victoria 3800, Australia
| | - Sorin Lazar
- FEI Electron Optics, 5600 KA Eindhoven, The Netherlands
| | - Joanne Etheridge
- Monash Centre for Electron Microscopy, Monash University, Victoria 3800, Australia and Department of Materials Engineering, Monash University, Victoria 3800, Australia
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Hwang J, Zhang JY, D'Alfonso AJ, Allen LJ, Stemmer S. Three-dimensional imaging of individual dopant atoms in SrTiO3. PHYSICAL REVIEW LETTERS 2013; 111:266101. [PMID: 24483805 DOI: 10.1103/physrevlett.111.266101] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2013] [Revised: 11/20/2013] [Indexed: 06/03/2023]
Abstract
We report on three-dimensional (3D) imaging of individual Gd dopant atoms in a thin (∼2.3 nm) foil of SrTiO3, using quantitative scanning transmission electron microscopy. Uncertainties in the depth positions of individual dopants are less than 1 unit cell. The overall dopant concentration measured from atom column intensities agrees quantitatively with electrical measurements. The method is applied to analyze the 3D arrangement of dopants within small clusters containing 4-5 Gd atoms.
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Affiliation(s)
- Jinwoo Hwang
- Materials Department, University of California, Santa Barbara, California 93106-5050, USA
| | - Jack Y Zhang
- Materials Department, University of California, Santa Barbara, California 93106-5050, USA
| | | | - Leslie J Allen
- School of Physics, University of Melbourne, Victoria 3010, Australia
| | - Susanne Stemmer
- Materials Department, University of California, Santa Barbara, California 93106-5050, USA
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