1
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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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2
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Zhang Z, Lobato I, De Backer A, Van Aert S, Nellist P. Fast generation of calculated ADF-EDX scattering cross-sections under channelling conditions. Ultramicroscopy 2023; 246:113671. [PMID: 36621195 DOI: 10.1016/j.ultramic.2022.113671] [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: 07/15/2022] [Revised: 12/21/2022] [Accepted: 12/26/2022] [Indexed: 12/29/2022]
Abstract
Advanced materials often consist of multiple elements which are arranged in a complicated structure. Quantitative scanning transmission electron microscopy is useful to determine the composition and thickness of nanostructures at the atomic scale. However, significant difficulties remain to quantify mixed columns by comparing the resulting atomic resolution images and spectroscopy data with multislice simulations where dynamic scattering needs to be taken into account. The combination of the computationally intensive nature of these simulations and the enormous amount of possible mixed column configurations for a given composition indeed severely hamper the quantification process. To overcome these challenges, we here report the development of an incoherent non-linear method for the fast prediction of ADF-EDX scattering cross-sections of mixed columns under channelling conditions. We first explain the origin of the ADF and EDX incoherence from scattering physics suggesting a linear dependence between those two signals in the case of a high-angle ADF detector. Taking EDX as a perfect incoherent reference mode, we quantitatively examine the ADF longitudinal incoherence under different microscope conditions using multislice simulations. Based on incoherent imaging, the atomic lensing model previously developed for ADF is now expanded to EDX, which yields ADF-EDX scattering cross-section predictions in good agreement with multislice simulations for mixed columns in a core-shell nanoparticle and a high entropy alloy. The fast and accurate prediction of ADF-EDX scattering cross-sections opens up new opportunities to explore the wide range of ordering possibilities of heterogeneous materials with multiple elements.
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Affiliation(s)
- Zezhong Zhang
- Electron Microscopy for Materials Research (EMAT), University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium; NANOlab Center of Excellence, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium; Department of Materials, University of Oxford, 16 Parks Road, Oxford OX1 3PH, United Kingdom.
| | - Ivan Lobato
- Electron Microscopy for Materials Research (EMAT), University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium; NANOlab Center of Excellence, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
| | - Annick De Backer
- Electron Microscopy for Materials Research (EMAT), University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium; NANOlab Center of Excellence, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
| | - Sandra Van Aert
- Electron Microscopy for Materials Research (EMAT), University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium; NANOlab Center of Excellence, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium.
| | - Peter Nellist
- Department of Materials, University of Oxford, 16 Parks Road, Oxford OX1 3PH, United Kingdom.
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3
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Abstract
Nucleation and growth are critical steps in crystallization, which plays an important role in determining crystal structure, size, morphology, and purity. Therefore, understanding the mechanisms of nucleation and growth is crucial to realize the controllable fabrication of crystalline products with desired and reproducible properties. Based on classical models, the initial crystal nucleus is formed by the spontaneous aggregation of ions, atoms, or molecules, and crystal growth is dependent on the monomer's diffusion and the surface reaction. Recently, numerous in situ investigations on crystallization dynamics have uncovered the existence of nonclassical mechanisms. This review provides a summary and highlights the in situ studies of crystal nucleation and growth, with a particular emphasis on the state-of-the-art research progress since the year 2016, and includes technological advances, atomic-scale observations, substrate- and temperature-dependent nucleation and growth, and the progress achieved in the various materials: metals, alloys, metallic compounds, colloids, and proteins. Finally, the forthcoming opportunities and challenges in this fascinating field are discussed.
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Affiliation(s)
- Junjie Li
- Key Laboratory of Functional Materials and Devices for Special Environments, Xinjiang Technical Institute of Physics & Chemistry, Chinese Academy of Sciences, Xinjiang Key Laboratory of Electronic Information Materials and Devices, 40-1 South Beijing Road, Urumqi830011, China.,Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing100049, China
| | - Francis Leonard Deepak
- Nanostructured Materials Group, International Iberian Nanotechnology Laboratory (INL), Av. Mestre Jose Veiga, 4715-330Braga, Portugal
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4
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Zhang Y, Yang X, Zhao SN, Zhai Y, Pang X, Lin J. Recent Developments of Microscopic Study for Lanthanide and Manganese Doped Luminescent Materials. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 18:e2205014. [PMID: 36310419 DOI: 10.1002/smll.202205014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 09/28/2022] [Indexed: 06/16/2023]
Abstract
Luminescent materials are indispensable for applications in lighting, displays and photovoltaics, which can transfer, absorb, store and utilize light energy. Their performance is closely related with their size and morphologies, exact atomic arrangement, and local configuration about photofunctional centers. Advanced electron microscopy-based techniques have enabled the possibility to study nanostructures with atomic resolution. Especially, with the advanced micro-electro-mechanical systems, it is able to characterize the luminescent materials at the atomic scale under various environments, providing a deep understanding of the luminescent mechanism. Accordingly, this review summarizes the recent achievements of microscopic study to directly image the microstructure and local environment of activators in lanthanide and manganese (Ln/Mn2+ )-doped luminescent materials, including: 1) bulk materials, the typical systems are nitride/oxynitride phosphors; and 2) nanomaterials, such as nanocrystals (hexagonal-phase NaLnF4 and perovskite) and 2D nanosheets (Ca2 Ta3 O10 and MoS2 ). Finally, the challenges and limitations are highlighted, and some possible solutions to facilitate the developments of advanced luminescent materials are provided.
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Affiliation(s)
- Yang Zhang
- School of Materials Science and Engineering, Zhengzhou University, Zhengzhou, 450001, China
| | - Xuewei Yang
- School of Materials Science and Engineering, Zhengzhou University, Zhengzhou, 450001, China
| | - Shu-Na Zhao
- School of Materials Science and Engineering, Zhengzhou University, Zhengzhou, 450001, China
| | - Yalong Zhai
- School of Materials Science and Engineering, Zhengzhou University, Zhengzhou, 450001, China
| | - Xinchang Pang
- School of Materials Science and Engineering, Zhengzhou University, Zhengzhou, 450001, China
| | - Jun Lin
- State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, China
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5
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De Backer A, Zhang Z, van den Bos KHW, Bladt E, Sánchez-Iglesias A, Liz-Marzán LM, Nellist PD, Bals S, Van Aert S. Element Specific Atom Counting at the Atomic Scale by Combining High Angle Annular Dark Field Scanning Transmission Electron Microscopy and Energy Dispersive X-ray Spectroscopy. SMALL METHODS 2022; 6:e2200875. [PMID: 36180399 DOI: 10.1002/smtd.202200875] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 08/29/2022] [Indexed: 06/16/2023]
Abstract
A new methodology is presented to count the number of atoms in multimetallic nanocrystals by combining energy dispersive X-ray spectroscopy (EDX) and high angle annular dark field scanning transmission electron microscopy (HAADF STEM). For this purpose, the existence of a linear relationship between the incoherent HAADF STEM and EDX images is exploited. Next to the number of atoms for each element in the atomic columns, the method also allows quantification of the error in the obtained number of atoms, which is of importance given the noisy nature of the acquired EDX signals. Using experimental images of an Au@Ag core-shell nanorod, it is demonstrated that 3D structural information can be extracted at the atomic scale. Furthermore, simulated data of an Au@Pt core-shell nanorod show the prospect to characterize heterogeneous nanostructures with adjacent atomic numbers.
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Affiliation(s)
- Annick De Backer
- EMAT, University of Antwerp, 2020, Antwerp, Belgium
- NANOlab Center of Excellence, University of Antwerp, 2020, Antwerp, Belgium
| | - Zezhong Zhang
- EMAT, University of Antwerp, 2020, Antwerp, Belgium
- NANOlab Center of Excellence, University of Antwerp, 2020, Antwerp, Belgium
| | - Karel H W van den Bos
- EMAT, University of Antwerp, 2020, Antwerp, Belgium
- NANOlab Center of Excellence, University of Antwerp, 2020, Antwerp, Belgium
| | - Eva Bladt
- EMAT, University of Antwerp, 2020, Antwerp, Belgium
- NANOlab Center of Excellence, University of Antwerp, 2020, Antwerp, Belgium
| | - Ana Sánchez-Iglesias
- CIC biomaGUNE, Basque Research and Technology Alliance (BRTA), 20014, Donostia-San Sebastián, Spain
- Centro de Investigación Biomédica en Red de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), 20014, Donostia-San Sebastián, Spain
| | - Luis M Liz-Marzán
- CIC biomaGUNE, Basque Research and Technology Alliance (BRTA), 20014, Donostia-San Sebastián, Spain
- Centro de Investigación Biomédica en Red de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), 20014, Donostia-San Sebastián, Spain
- Ikerbasque, Basque Foundation for Science, 48009, Bilbao, Spain
| | - Peter D Nellist
- Department of Materials, University of Oxford, Parks Road, Oxford, OX1 3PH, UK
| | - Sara Bals
- EMAT, University of Antwerp, 2020, Antwerp, Belgium
- NANOlab Center of Excellence, University of Antwerp, 2020, Antwerp, Belgium
| | - Sandra Van Aert
- EMAT, University of Antwerp, 2020, Antwerp, Belgium
- NANOlab Center of Excellence, University of Antwerp, 2020, Antwerp, Belgium
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6
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Atomic-scale 3D imaging of individual dopant atoms in an oxide semiconductor. Nat Commun 2022; 13:4783. [PMID: 35970843 PMCID: PMC9378652 DOI: 10.1038/s41467-022-32189-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 07/20/2022] [Indexed: 11/18/2022] Open
Abstract
The physical properties of semiconductors are controlled by chemical doping. In oxide semiconductors, small variations in the density of dopant atoms can completely change the local electric and magnetic responses caused by their strongly correlated electrons. In lightly doped systems, however, such variations are difficult to determine as quantitative 3D imaging of individual dopant atoms is a major challenge. We apply atom probe tomography to resolve the atomic sites that donors occupy in the small band gap semiconductor Er(Mn,Ti)O3 with a nominal Ti concentration of 0.04 at. %, map their 3D lattice positions, and quantify spatial variations. Our work enables atomic-level 3D studies of structure-property relations in lightly doped complex oxides, which is crucial to understand and control emergent dopant-driven quantum phenomena. Small variations in the density of dopants change the physical properties of complex oxides. Here, the authors resolve doping levels in three dimension, imaging the atomic sites that donors occupy in the small band gap semiconductor Er(Mn,Ti)O3.
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7
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Liu JJ. Advances and Applications of Atomic-Resolution Scanning Transmission Electron Microscopy. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2021; 27:1-53. [PMID: 34414878 DOI: 10.1017/s1431927621012125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Although scanning transmission electron microscopy (STEM) images of individual heavy atoms were reported 50 years ago, the applications of atomic-resolution STEM imaging became wide spread only after the practical realization of aberration correctors on field-emission STEM/TEM instruments to form sub-Ångstrom electron probes. The innovative designs and advances of electron optical systems, the fundamental understanding of electron–specimen interaction processes, and the advances in detector technology all played a major role in achieving the goal of atomic-resolution STEM imaging of practical materials. It is clear that tremendous advances in computer technology and electronics, image acquisition and processing algorithms, image simulations, and precision machining synergistically made atomic-resolution STEM imaging routinely accessible. It is anticipated that further hardware/software development is needed to achieve three-dimensional atomic-resolution STEM imaging with single-atom chemical sensitivity, even for electron-beam-sensitive materials. Artificial intelligence, machine learning, and big-data science are expected to significantly enhance the impact of STEM and associated techniques on many research fields such as materials science and engineering, quantum and nanoscale science, physics and chemistry, and biology and medicine. This review focuses on advances of STEM imaging from the invention of the field-emission electron gun to the realization of aberration-corrected and monochromated atomic-resolution STEM and its broad applications.
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Affiliation(s)
- Jingyue Jimmy Liu
- Department of Physics, Arizona State University, Tempe, AZ85287, USA
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8
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Ilton ES, Kovarik L, Nakouzi E, Mergelsberg ST, McBriarty ME, Bylaska EJ. Using Atom Dynamics to Map the Defect Structure Around an Impurity in Nano-Hematite. J Phys Chem Lett 2020; 11:10396-10400. [PMID: 33238102 DOI: 10.1021/acs.jpclett.0c02798] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The bulk behavior of materials is often controlled by minor impurities that create nonperiodic localized defect structures due to ionic size, symmetry, and charge balance mismatches. Here, we used transmission electron microscopy (TEM) of atom-resolved dynamics to directly map the topology of Fe vacancy clusters surrounding structurally incorporated U6+ in nanohematite (α-Fe2O3). Ab initio molecular dynamic simulations provided additional independent constraints on coupled U, Fe, and vacancy mobility in the solid. A clearer understanding of how such an apparently incompatible element can be accommodated by hematite emerged. The results were readily interpretable without the need for sophisticated data reconstruction methods, model structures, or ultrathin samples, and with the proliferation of aberration-corrected TEM facilities, the approach is accessible. Given sufficient z-contrast, the ability to observe impurity-vacancy structures by means of atom hopping can be used to directly probe the association of impurities and such defects in other materials, with promising applications across a broad range of disciplines.
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Affiliation(s)
- Eugene S Ilton
- Pacific Northwest National Laboratory, Richland, Washington 99352 United States
| | - Libor Kovarik
- Pacific Northwest National Laboratory, Richland, Washington 99352 United States
| | - Elias Nakouzi
- Pacific Northwest National Laboratory, Richland, Washington 99352 United States
| | | | - Martin E McBriarty
- Pacific Northwest National Laboratory, Richland, Washington 99352 United States
| | - Eric J Bylaska
- Pacific Northwest National Laboratory, Richland, Washington 99352 United States
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9
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Bao H, Wang JA, Yuan W, Luo J. Estimation of the spatial distribution of Frenkel defects in NiFe 2O 4 by simulation of HAADF-STEM images. NANOSCALE 2020; 12:22668-22673. [PMID: 33155601 DOI: 10.1039/d0nr06183b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Accurate determination of the atomic spatial configuration of Frenkel defects is important for understanding the mechanism and fully utilizing these defects to optimize the material properties. In this study, aberration-corrected scanning transmission electron microscopy (STEM) was used to identify the Fe vacancies and Fe Frenkel defect pairs, which have not been previously investigated, in NiFe2O4 (NFO). The spatial distribution of these point defects is determined by comparing the experimental and simulated images, where the experimental image intensities are consistent with the calculated image intensities. We confirmed the stabilities of the observed point defect configurations and calculated their electronic structures using density functional theory. A comprehensive understanding of the relationship between the Frenkel defect spatial configurations and electronic properties is obtained, which provides an alternative method to regulate the NFO performance.
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Affiliation(s)
- Haihong Bao
- Center for Electron Microscopy and Tianjin Key Lab of Advanced Functional Porous Materials, Institute for New Energy Materials & Low-Carbon Technologies, School of Materials Science and Engineering, Tianjin University of Technology, Tianjin 300384, China.
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10
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Local thickness and composition measurements from scanning convergent-beam electron diffraction of a binary non-crystalline material obtained by a pixelated detector. Ultramicroscopy 2020; 217:113077. [PMID: 32795865 DOI: 10.1016/j.ultramic.2020.113077] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2020] [Revised: 07/07/2020] [Accepted: 07/11/2020] [Indexed: 11/22/2022]
Abstract
The nanometer-scale spatial distributions of local thickness or composition of noncrystalline materials are generally measured by spectroscopy with scanning transmission electron microscopy (STEM). Since spectroscopy requires a high electron dose and causes irradiation damage, alternative non-spectroscopic methods are required to measure the local thickness or composition of electron-sensitive noncrystalline materials. Here, we focus on the radial distribution function (RDF) of the electron diffraction of non-crystalline materials. We confirm that the RDF of the electron diffraction obtained by simulation contains information on the thickness and composition. Next, we demonstrate the determination of both thickness and composition from experimentally obtained RDFs. Although some constraints are required, we determine the local thickness and composition of a BaO-SiO2 glass sample by comparing the RDFs of diffraction measured by a high-speed pixelated detector with those of the simulated diffractions. Collaterally, this determination method can improve the quality of STEM images.
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11
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Ishikawa R, Jimbo Y, Terao M, Nishikawa M, Ueno Y, Morishita S, Mukai M, Shibata N, Ikuhara Y. High spatiotemporal-resolution imaging in the scanning transmission electron microscope. Microscopy (Oxf) 2020; 69:240-247. [DOI: 10.1093/jmicro/dfaa017] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 03/12/2020] [Accepted: 03/30/2020] [Indexed: 11/13/2022] Open
Abstract
AbstractThe temporal resolution in scanning transmission electron microscopy (STEM) is limited by the scanning system of an electron probe, leading to only a few frames per second (fps) at most in the current microscopes. To push the boundary of atomic-resolution STEM imaging into dynamic observations, an unprecedentedly faster scanning system combined with fast electron detection systems should be a prerequisite. Here we develop a new scanning probe system with the acquisition time of 83 nanoseconds per pixel and the fly-back time of 35 microseconds, leading to 25 fps STEM imaging with the image size of 512 × 512 pixels that is faster than a human perception speed. Using such high-speed probe scanning system, we have demonstrated the observations of shape-transformation of Pt nanoparticles and Pt single atomic motions on TiO2 (110) surface at atomic-resolution with the temporal resolution of 40 milliseconds. The present probe scanning system opens the door to use atomic-resolution STEM imaging for in situ observations of material dynamics under the temperatures of cooling or heating, the atmosphere of liquid or gas, electric-basing or mechanical test.
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Affiliation(s)
- Ryo Ishikawa
- Institute of Engineering Innovation, University of Tokyo, Bunkyo, Tokyo, 113-8656, Japan
- Japan Science and Technology Agency, PRESTO, Kawaguchi, Saitama 332-0012, Japan
| | - Yu Jimbo
- JEOL Ltd, 3-1-2 Akishima, Tokyo 196-8558, Japan
| | | | | | - Yujiro Ueno
- Institute of Engineering Innovation, University of Tokyo, Bunkyo, Tokyo, 113-8656, Japan
| | | | | | - Naoya Shibata
- Institute of Engineering Innovation, University of Tokyo, Bunkyo, Tokyo, 113-8656, Japan
- Nanostructures Research Laboratory, Japan Fine Ceramics Center, Nagoya, Aichi 456-8587, Japan
| | - Yuichi Ikuhara
- Institute of Engineering Innovation, University of Tokyo, Bunkyo, Tokyo, 113-8656, Japan
- Nanostructures Research Laboratory, Japan Fine Ceramics Center, Nagoya, Aichi 456-8587, Japan
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12
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Feng Y, Wu J, Chi Q, Li W, Yu Y, Fei W. Defects and Aliovalent Doping Engineering in Electroceramics. Chem Rev 2020; 120:1710-1787. [DOI: 10.1021/acs.chemrev.9b00507] [Citation(s) in RCA: 88] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Yu Feng
- Key Laboratory of Engineering Dielectrics and Its Application, Ministry of Education, Harbin University of Science and Technology, Harbin 150080, P. R. China
- State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001, P. R. China
- School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
| | - Jiagang Wu
- Department of Materials Science, Sichuan University, Chengdu 610064, P. R. China
| | - Qingguo Chi
- Key Laboratory of Engineering Dielectrics and Its Application, Ministry of Education, Harbin University of Science and Technology, Harbin 150080, P. R. China
| | - Weili Li
- State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001, P. R. China
| | - Yang Yu
- Key Laboratory of Engineering Dielectrics and Its Application, Ministry of Education, Harbin University of Science and Technology, Harbin 150080, P. R. China
| | - Weidong Fei
- State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001, P. R. China
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13
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Aarholt T, Frodason YK, Prytz Ø. Imaging defect complexes in scanning transmission electron microscopy: Impact of depth, structural relaxation, and temperature investigated by simulations. Ultramicroscopy 2019; 209:112884. [PMID: 31756598 DOI: 10.1016/j.ultramic.2019.112884] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 10/25/2019] [Accepted: 11/01/2019] [Indexed: 10/25/2022]
Affiliation(s)
- Thomas Aarholt
- Department of Physics, Centre for Materials Science and Nanotechnology, University of Oslo, P. O. Box 1048, Blindern, N-0316 Oslo, Norway.
| | - Ymir K Frodason
- Department of Physics, Centre for Materials Science and Nanotechnology, University of Oslo, P. O. Box 1048, Blindern, N-0316 Oslo, Norway
| | - Øystein Prytz
- Department of Physics, Centre for Materials Science and Nanotechnology, University of Oslo, P. O. Box 1048, Blindern, N-0316 Oslo, Norway
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14
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Yun H, Prakash A, Jalan B, Jeong JS, Mkhoyan KA. STEM beam channeling in BaSnO 3/LaAlO 3 perovskite bilayers and visualization of 2D misfit dislocation network. Ultramicroscopy 2019; 208:112863. [PMID: 31683082 DOI: 10.1016/j.ultramic.2019.112863] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 09/03/2019] [Accepted: 10/22/2019] [Indexed: 11/26/2022]
Abstract
A study of the STEM probe channeling in a heterostructured crystalline bilayer specimens is presented here with a goal to guide STEM-based characterization of multilayer structures. STEM analysis of perovskite BaSnO3/LaAlO3 bilayers is performed and the dominating effects of beam channeling on HAADF- and LAADF-STEM are illustrated. To study the electron beam channeling through BaSnO3/LaAlO3 bilayers, probe intensity depth profiles are calculated, and the effects of probe defocus and atomic column alignment are discussed. Characteristics of the beam channeling are correlated to resulting ADF-STEM images, which is then tested by comparing focal series of plan-view HAADF-STEM images to those recorded experimentally. Additionally, discussions on how to visualize the misfit dislocation network at the BaSnO3/LaAlO3 interface using HAADF- and LAADF-STEM images are provided.
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Affiliation(s)
- Hwanhui Yun
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455, USA.
| | - Abhinav Prakash
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455, USA
| | - Bharat Jalan
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455, USA
| | - Jong Seok Jeong
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455, USA; Analytical Sciences Center, LG Chem Ltd., Daejeon, Republic of Korea.
| | - K Andre Mkhoyan
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455, USA.
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15
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Yokoya T, Terashima K, Takeda A, Fukura T, Fujiwara H, Muro T, Kinoshita T, Kato H, Yamasaki S, Oguchi T, Wakita T, Muraoka Y, Matsushita T. Asymmetric Phosphorus Incorporation in Homoepitaxial P-Doped (111) Diamond Revealed by Photoelectron Holography. NANO LETTERS 2019; 19:5915-5919. [PMID: 31373825 DOI: 10.1021/acs.nanolett.9b01481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Diamond has two crystallographically inequivalent sites in the unit cell. In doped diamond, dopant occupation in the two sites is expected to be equal. Nevertheless, preferential dopant occupation during growth under nonequilibrium conditions is of fundamental importance, for example, to enhance the properties of nitrogen-vacancy (N-V) centers; therefore, this is a promising candidate for a qubit. However, the lack of suitable experimental techniques has made it difficult to study the crystal- and chemical-site-resolved local structures of dopants. Here, we confirm the identity of two chemical sites with asymmetric dopant incorporation in the diamond structure, via the photoelectron holography (PEH) of heavily phosphorus (P)-doped diamond prepared by chemical vapor deposition. One is substitutionally incorporated P with preferential site occupations and the other can be attributed to a PV split vacancy complex with preferential orientation. The present study shows that PEH is a valuable technique to study the local structures around dopants with a resolution of crystallographically inequivalent but energetically equivalent sites/orientations. Such information provides strategies to improve the properties of dopant related-complexes in which alignment is crucial for sensing of magnetic field or quantum spin register using N-V centers in diamond.
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Affiliation(s)
- T Yokoya
- Research Institute for Interdisciplinary Science (RIIS) , Okayama University , Okayama 700-8530 , Japan
- Graduate School of Science and Technology , Okayama University , Okayama 700-8530 , Japan
| | - K Terashima
- Research Institute for Interdisciplinary Science (RIIS) , Okayama University , Okayama 700-8530 , Japan
| | - A Takeda
- Graduate School of Science and Technology , Okayama University , Okayama 700-8530 , Japan
| | - T Fukura
- Graduate School of Science and Technology , Okayama University , Okayama 700-8530 , Japan
| | - H Fujiwara
- Graduate School of Science and Technology , Okayama University , Okayama 700-8530 , Japan
| | - T Muro
- Japan Synchrotron Radiation Research Institute (JASRI) , 1-1-1 Kouto, Sayo , Hyogo 679-5198 , Japan
| | - T Kinoshita
- Japan Synchrotron Radiation Research Institute (JASRI) , 1-1-1 Kouto, Sayo , Hyogo 679-5198 , Japan
| | - H Kato
- Advanced Power Electronics Research Center , National Institute of Advanced Industrial Science and Technology (AIST) , Tsukuba Center 2, Tsukuba , Ibaraki 305-8568 , Japan
| | - S Yamasaki
- Advanced Power Electronics Research Center , National Institute of Advanced Industrial Science and Technology (AIST) , Tsukuba Center 2, Tsukuba , Ibaraki 305-8568 , Japan
| | - T Oguchi
- Institute of Scientific and Industrial Research , Osaka University , 8-1 Mihogaoka, Ibaraki , Osaka 567-0047 , Japan
| | - T Wakita
- Research Institute for Interdisciplinary Science (RIIS) , Okayama University , Okayama 700-8530 , Japan
| | - Y Muraoka
- Research Institute for Interdisciplinary Science (RIIS) , Okayama University , Okayama 700-8530 , Japan
- Graduate School of Science and Technology , Okayama University , Okayama 700-8530 , Japan
| | - T Matsushita
- Japan Synchrotron Radiation Research Institute (JASRI) , 1-1-1 Kouto, Sayo , Hyogo 679-5198 , Japan
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16
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van den Bos K, Janssens L, De Backer A, Nellist P, Van Aert S. The atomic lensing model: New opportunities for atom-by-atom metrology of heterogeneous nanomaterials. Ultramicroscopy 2019; 203:155-162. [DOI: 10.1016/j.ultramic.2018.12.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 11/21/2018] [Accepted: 12/05/2018] [Indexed: 10/27/2022]
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17
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Influence of Dislocations in Transition Metal Oxides on Selected Physical and Chemical Properties. CRYSTALS 2018. [DOI: 10.3390/cryst8060241] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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18
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Pennycook SJ, Li C, Li M, Tang C, Okunishi E, Varela M, Kim YM, Jang JH. Material structure, properties, and dynamics through scanning transmission electron microscopy. J Anal Sci Technol 2018; 9:11. [PMID: 31258949 PMCID: PMC6560782 DOI: 10.1186/s40543-018-0142-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 03/14/2018] [Indexed: 12/03/2022] Open
Abstract
Scanning transmission electron microscopy (STEM) has advanced rapidly in the last decade thanks to the ability to correct the major aberrations of the probe-forming lens. Now, atomic-sized beams are routine, even at accelerating voltages as low as 40 kV, allowing knock-on damage to be minimized in beam sensitive materials. The aberration-corrected probes can contain sufficient current for high-quality, simultaneous, imaging and analysis in multiple modes. Atomic positions can be mapped with picometer precision, revealing ferroelectric domain structures, composition can be mapped by energy-dispersive X-ray spectroscopy (EDX) and electron energy loss spectroscopy (EELS), and charge transfer can be tracked unit cell by unit cell using the EELS fine structure. Furthermore, dynamics of point defects can be investigated through rapid acquisition of multiple image scans. Today STEM has become an indispensable tool for analytical science at the atomic level, providing a whole new level of insights into the complex interplays that control material properties.
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Affiliation(s)
- Stephen J. Pennycook
- Department of Materials Science and Engineering, National University of Singapore, Block EA 07-14, 9 Engineering Drive 1, Singapore, 117575 Singapore
| | - Changjian Li
- Department of Materials Science and Engineering, National University of Singapore, Block EA 07-14, 9 Engineering Drive 1, Singapore, 117575 Singapore
| | - Mengsha Li
- Department of Materials Science and Engineering, National University of Singapore, Block EA 07-14, 9 Engineering Drive 1, Singapore, 117575 Singapore
| | - Chunhua Tang
- Department of Materials Science and Engineering, National University of Singapore, Block EA 07-14, 9 Engineering Drive 1, Singapore, 117575 Singapore
| | | | - Maria Varela
- Dpt. Física de Materiales, Instituto de Magnetismo Aplicado & Instituto Pluridisciplinar, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Young-Min Kim
- Department of Energy Science, Sungkyunkwan University (SKKU), Suwon, 16419 Republic of Korea
| | - Jae Hyuck Jang
- Electron Microscopy Research Center, Korea Basic Science Institute, Daejeon, 34133 South Korea
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19
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Tsutsui K, Matsushita T, Natori K, Muro T, Morikawa Y, Hoshii T, Kakushima K, Wakabayashi H, Hayashi K, Matsui F, Kinoshita T. Individual Atomic Imaging of Multiple Dopant Sites in As-Doped Si Using Spectro-Photoelectron Holography. NANO LETTERS 2017; 17:7533-7538. [PMID: 29149568 DOI: 10.1021/acs.nanolett.7b03467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The atomic scale characterization of dopant atoms in semiconductor devices to establish correlations with the electrical activation of these atoms is essential to the advancement of contemporary semiconductor process technology. Spectro-photoelectron holography combined with first-principles simulations can determine the local three-dimensional atomic structures of dopant elements, which in turn affect their electronic states. In the work reported herein, this technique was used to examine arsenic (As) atoms doped into a silicon (Si) crystal. As 3d core level photoelectron spectroscopy demonstrated the presence of three types of As atoms at a total concentration of approximately 1020 cm-3, denoted as BEH, BEM, and BEL. On the basis of Hall effect measurements, the BEH atoms corresponded to electrically active As occupying substitutional sites and exhibiting larger thermal fluctuations than the Si atoms, while the BEM atoms corresponded to electrically inactive As embedded in the AsnV (n = 2-4) type clusters. Finally, the BEL atoms were assigned to electrically inactive As in locally disordered structures.
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Affiliation(s)
- Kazuo Tsutsui
- Institute of Innovative Research, Tokyo Institute of Technology , 4259-J2-69, Nagatsuta, Midori-ku, Yokohama 227-8503, Japan
| | - Tomohiro Matsushita
- Japan Synchrotron Radiation Research Institute (JASRI) , 1-1-1 Kouto, Sayo, Hyogo 679-5198, Japan
| | - Kotaro Natori
- School of Engineering, Tokyo Institute of Technology , 4259-J2-69, Nagatsuta, Midori-ku, Yokohama 227-8502, Japan
| | - Takayuki Muro
- Japan Synchrotron Radiation Research Institute (JASRI) , 1-1-1 Kouto, Sayo, Hyogo 679-5198, Japan
| | - Yoshitada Morikawa
- Department of Precision Science and Technology, Osaka University , 2-1, Yamada-oka, Suita, Osaka 565-0871, Japan
| | - Takuya Hoshii
- School of Engineering, Tokyo Institute of Technology , 4259-J2-69, Nagatsuta, Midori-ku, Yokohama 227-8502, Japan
| | - Kuniyuki Kakushima
- School of Engineering, Tokyo Institute of Technology , 4259-J2-69, Nagatsuta, Midori-ku, Yokohama 227-8502, Japan
| | - Hitoshi Wakabayashi
- School of Engineering, Tokyo Institute of Technology , 4259-J2-69, Nagatsuta, Midori-ku, Yokohama 227-8502, Japan
| | - Kouichi Hayashi
- Department of Physical Science and Engineering, Nagoya Institute of Technology , Gokiso-cho, Showa-ku, Nagoya, Aichi 466-8555, Japan
| | - Fumihiko Matsui
- Graduate School of Materials Science, Nara Institute of Science and Technology , Takayama-cho, Ikoma, Nara 630-0192, Japan
| | - Toyohiko Kinoshita
- Japan Synchrotron Radiation Research Institute (JASRI) , 1-1-1 Kouto, Sayo, Hyogo 679-5198, Japan
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20
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MacArthur KE, Brown HG, Findlay SD, Allen LJ. Probing the effect of electron channelling on atomic resolution energy dispersive X-ray quantification. Ultramicroscopy 2017; 182:264-275. [DOI: 10.1016/j.ultramic.2017.07.020] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Revised: 07/28/2017] [Accepted: 07/30/2017] [Indexed: 11/29/2022]
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21
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Vlcek L, Maksov A, Pan M, Vasudevan RK, Kalinin SV. Knowledge Extraction from Atomically Resolved Images. ACS NANO 2017; 11:10313-10320. [PMID: 28953356 DOI: 10.1021/acsnano.7b05036] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Tremendous strides in experimental capabilities of scanning transmission electron microscopy and scanning tunneling microscopy (STM) over the past 30 years made atomically resolved imaging routine. However, consistent integration and use of atomically resolved data with generative models is unavailable, so information on local thermodynamics and other microscopic driving forces encoded in the observed atomic configurations remains hidden. Here, we present a framework based on statistical distance minimization to consistently utilize the information available from atomic configurations obtained from an atomically resolved image and extract meaningful physical interaction parameters. We illustrate the applicability of the framework on an STM image of a FeSexTe1-x superconductor, with the segregation of the chalcogen atoms investigated using a nonideal interacting solid solution model. This universal method makes full use of the microscopic degrees of freedom sampled in an atomically resolved image and can be extended via Bayesian inference toward unbiased model selection with uncertainty quantification.
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Affiliation(s)
- Lukas Vlcek
- Chemical Sciences Division, Oak Ridge National Laboratory , Oak Ridge Tennessee 37831, United States
- Joint Institute for Computational Sciences, University of Tennessee, Oak Ridge National Laboratory , Oak Ridge Tennessee 37831, United States
| | - Artem Maksov
- Bredesen Center for Interdisciplinary Research, University of Tennessee , Knoxville, Tennessee 37996, United States
| | - Minghu Pan
- School of Physics, Huazhong University of Science & Technology , Wuhan 430074, China
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22
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Zhang J, Di Q, Liu J, Bai B, Liu J, Xu M, Liu J. Heterovalent Doping in Colloidal Semiconductor Nanocrystals: Cation-Exchange-Enabled New Accesses to Tuning Dopant Luminescence and Electronic Impurities. J Phys Chem Lett 2017; 8:4943-4953. [PMID: 28925707 DOI: 10.1021/acs.jpclett.7b00351] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Heterovalent doping in colloidal semiconductor nanocrystals (CSNCs), with provisions of extra electrons (n-type doping) or extra holes (p-type doping), could enhance their performance of optical and electronical properties. In view of the challenges imposed by the intrinsic self-purification, self-quenching, and self-compensation effects of CSNCs, we outline the progress on heterovalent doping in CSNCs, with particular focus on the cation-exchange-enabled tuning of dopant luminescence and electronic impurities. Thus, the well-defined substitutional or interstitial heterovalent doping in a deep position of an isolated nanocrystal has been fulfilled. We also envision that new coordination ligand-initiated cation exchange would bring about more choices of heterovalent dopants. With the aid of high-resolution characterization methods, the accurate atom-specific dopant location and distribution could be confirmed clearly. Finally, new applications, some of the remaining unanswered questions, and future directions of this field are presented.
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Affiliation(s)
- Jiatao Zhang
- Beijing Key Laboratory of Construction Tailorable Advanced Functional Materials and Green Applications, School of Materials Science and Engineering, Beijing Institute of Technology , Beijing 100081, China
| | - Qiumei Di
- Beijing Key Laboratory of Construction Tailorable Advanced Functional Materials and Green Applications, School of Materials Science and Engineering, Beijing Institute of Technology , Beijing 100081, China
| | - Jia Liu
- Beijing Key Laboratory of Construction Tailorable Advanced Functional Materials and Green Applications, School of Materials Science and Engineering, Beijing Institute of Technology , Beijing 100081, China
| | - Bing Bai
- Beijing Key Laboratory of Construction Tailorable Advanced Functional Materials and Green Applications, School of Materials Science and Engineering, Beijing Institute of Technology , Beijing 100081, China
| | - Jian Liu
- Beijing Key Laboratory of Construction Tailorable Advanced Functional Materials and Green Applications, School of Materials Science and Engineering, Beijing Institute of Technology , Beijing 100081, China
| | - Meng Xu
- Beijing Key Laboratory of Construction Tailorable Advanced Functional Materials and Green Applications, School of Materials Science and Engineering, Beijing Institute of Technology , Beijing 100081, China
| | - Jiajia Liu
- Beijing Key Laboratory of Construction Tailorable Advanced Functional Materials and Green Applications, School of Materials Science and Engineering, Beijing Institute of Technology , Beijing 100081, China
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23
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Wu RJ, Mittal A, Odlyzko ML, Mkhoyan KA. Simplifying Electron Beam Channeling in Scanning Transmission Electron Microscopy (STEM). MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2017; 23:794-808. [PMID: 28673372 DOI: 10.1017/s143192761700068x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Sub-angstrom scanning transmission electron microscopy (STEM) allows quantitative column-by-column analysis of crystalline specimens via annular dark-field images. The intensity of electrons scattered from a particular location in an atomic column depends on the intensity of the electron probe at that location. Electron beam channeling causes oscillations in the STEM probe intensity during specimen propagation, which leads to differences in the beam intensity incident at different depths. Understanding the parameters that control this complex behavior is critical for interpreting experimental STEM results. In this work, theoretical analysis of the STEM probe intensity reveals that intensity oscillations during specimen propagation are regulated by changes in the beam's angular distribution. Three distinct regimes of channeling behavior are observed: the high-atomic-number (Z) regime, in which atomic scattering leads to significant angular redistribution of the beam; the low-Z regime, in which the probe's initial angular distribution controls intensity oscillations; and the intermediate-Z regime, in which the behavior is mixed. These contrasting regimes are shown to exist for a wide range of probe parameters. These results provide a new understanding of the occurrence and consequences of channeling phenomena and conditions under which their influence is strengthened or weakened by characteristics of the electron probe and sample.
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Affiliation(s)
- Ryan J Wu
- Department of Chemical Engineering and Materials Science,University of Minnesota,Minneapolis,MN 55455,USA
| | - Anudha Mittal
- Department of Chemical Engineering and Materials Science,University of Minnesota,Minneapolis,MN 55455,USA
| | - Michael L Odlyzko
- Department of Chemical Engineering and Materials Science,University of Minnesota,Minneapolis,MN 55455,USA
| | - K Andre Mkhoyan
- Department of Chemical Engineering and Materials Science,University of Minnesota,Minneapolis,MN 55455,USA
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24
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Pollock JA, Weyland M, Taplin DJ, Allen LJ, Findlay SD. Accuracy and precision of thickness determination from position-averaged convergent beam electron diffraction patterns using a single-parameter metric. Ultramicroscopy 2017; 181:86-96. [PMID: 28527314 DOI: 10.1016/j.ultramic.2017.05.001] [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: 02/02/2017] [Revised: 04/26/2017] [Accepted: 05/09/2017] [Indexed: 10/19/2022]
Abstract
Position-averaged convergent beam electron diffraction patterns are formed by averaging the transmission diffraction pattern while scanning an atomically-fine electron probe across a sample. Visual comparison between experimental and simulated patterns is increasingly being used for sample thickness determination. We explore automating the comparison via a simple sum square difference metric. The thickness determination is shown to be accurate (i.e. the best-guess deduced thickness generally concurs with the true thickness), though factors such as noise, mistilt and inelastic scattering reduce the precision (i.e. increase the uncertainty range). Notably, the precision tends to be higher for smaller probe-forming aperture angles.
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Affiliation(s)
- J A Pollock
- School of Physics and Astronomy, Monash University, Clayton, Victoria 3800, Australia
| | - M Weyland
- Monash Centre for Electron Microscopy, Monash University, Clayton, Victoria 3800, Australia; Department of Materials Science and Engineering, Monash University, Clayton, Victoria 3800, Australia
| | - D J Taplin
- School of Physics and Astronomy, Monash University, Clayton, Victoria 3800, Australia
| | - L J Allen
- School of Physics, University of Melbourne, Parkville, Victoria 3010, Australia
| | - S D Findlay
- School of Physics and Astronomy, Monash University, Clayton, Victoria 3800, Australia.
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25
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Composition measurement in substitutionally disordered materials by atomic resolution energy dispersive X-ray spectroscopy in scanning transmission electron microscopy. Ultramicroscopy 2017; 176:52-62. [DOI: 10.1016/j.ultramic.2016.10.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Revised: 09/20/2016] [Accepted: 10/08/2016] [Indexed: 11/20/2022]
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26
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Saito G, Yamaki F, Kunisada Y, Sakaguchi N, Akiyama T. Three-dimensional analysis of Eu dopant atoms in Ca-α-SiAlON via through-focus HAADF-STEM imaging. Ultramicroscopy 2017; 175:97-104. [DOI: 10.1016/j.ultramic.2017.01.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Revised: 01/23/2017] [Accepted: 01/29/2017] [Indexed: 11/29/2022]
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27
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Simulation in elemental mapping using aberration-corrected electron microscopy. Ultramicroscopy 2017; 180:142-149. [PMID: 28314556 DOI: 10.1016/j.ultramic.2017.03.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Revised: 02/24/2017] [Accepted: 03/01/2017] [Indexed: 11/21/2022]
Abstract
Elemental mapping at the atomic scale in aberration-corrected electron microscopes is becoming increasingly widely used. In this paper we describe the essential role of simulation in understanding the underlying physics and thus in correctly interpreting these maps, both qualitatively and quantitatively.
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28
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Effects of small-angle mistilts on dopant visibility in ADF-STEM imaging of nanocrystals. Ultramicroscopy 2017; 177:53-57. [PMID: 28292686 DOI: 10.1016/j.ultramic.2017.03.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2016] [Revised: 02/03/2017] [Accepted: 03/05/2017] [Indexed: 11/20/2022]
Abstract
Quantitative ADF-STEM imaging paired with image simulations has proven to be a powerful technique for determining the three dimensional location of substitutionally doped atoms in thin films. Expansion of this technique to lightly-doped nanocrystals requires an understanding of the influence of specimen mistilt on dopant visibility due to the difficulty of accurate orientation determination in such systems as well as crystal movement under the beam. In this study, the effects of specimen mistilt on ADF-STEM imaging are evaluated using germanium-doped silicon nanocrystals as model systems. It is shown that dopant visibility is a strong function of specimen mistilt, and the accuracy of specimen orientation is an important factor in the analysis of three-dimensional dopant location, but the sensitivity to mistilt can be weakened by increasing the STEM probe convergence angle and optimizing ADF detector inner angle.
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29
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Zhan W, Granerød CS, Venkatachalapathy V, Johansen KMH, Jensen IJT, Kuznetsov AY, Prytz Ø. Nanoscale mapping of optical band gaps using monochromated electron energy loss spectroscopy. NANOTECHNOLOGY 2017; 28:105703. [PMID: 28085004 DOI: 10.1088/1361-6528/aa5962] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Using monochromated electron energy loss spectroscopy in a probe-corrected scanning transmission electron microscope we demonstrate band gap mapping in ZnO/ZnCdO thin films with a spatial resolution below 10 nm and spectral precision of 20 meV.
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Affiliation(s)
- W Zhan
- Department of Physics, Centre for Materials Science and Nanotechnology, University of Oslo, PO Box 1048-Blindern, NO-0316 Oslo, Norway
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30
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Oxley MP, Lupini AR, Pennycook SJ. Ultra-high resolution electron microscopy. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2017; 80:026101. [PMID: 28008874 DOI: 10.1088/1361-6633/80/2/026101] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The last two decades have seen dramatic advances in the resolution of the electron microscope brought about by the successful correction of lens aberrations that previously limited resolution for most of its history. We briefly review these advances, the achievement of sub-Ångstrom resolution and the ability to identify individual atoms, their bonding configurations and even their dynamics and diffusion pathways. We then present a review of the basic physics of electron scattering, lens aberrations and their correction, and an approximate imaging theory for thin crystals which provides physical insight into the various different imaging modes. Then we proceed to describe a more exact imaging theory starting from Yoshioka's formulation and covering full image simulation methods using Bloch waves, the multislice formulation and the frozen phonon/quantum excitation of phonons models. Delocalization of inelastic scattering has become an important limiting factor at atomic resolution. We therefore discuss this issue extensively, showing how the full-width-half-maximum is the appropriate measure for predicting image contrast, but the diameter containing 50% of the excitation is an important measure of the range of the interaction. These two measures can differ by a factor of 5, are not a simple function of binding energy, and full image simulations are required to match to experiment. The Z-dependence of annular dark field images is also discussed extensively, both for single atoms and for crystals, and we show that temporal incoherence must be included accurately if atomic species are to be identified through matching experimental intensities to simulations. Finally we mention a few promising directions for future investigation.
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Affiliation(s)
- Mark P Oxley
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
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31
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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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32
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van den Bos KHW, De Backer A, Martinez GT, Winckelmans N, Bals S, Nellist PD, Van Aert S. Unscrambling Mixed Elements using High Angle Annular Dark Field Scanning Transmission Electron Microscopy. PHYSICAL REVIEW LETTERS 2016; 116:246101. [PMID: 27367396 DOI: 10.1103/physrevlett.116.246101] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2016] [Indexed: 05/16/2023]
Abstract
The development of new nanocrystals with outstanding physicochemical properties requires a full three-dimensional (3D) characterization at the atomic scale. For homogeneous nanocrystals, counting the number of atoms in each atomic column from high angle annular dark field scanning transmission electron microscopy images has been shown to be a successful technique to get access to this 3D information. However, technologically important nanostructures often consist of more than one chemical element. In order to extend atom counting to heterogeneous materials, a new atomic lensing model is presented. This model takes dynamical electron diffraction into account and opens up new possibilities for unraveling the 3D composition at the atomic scale. Here, the method is applied to determine the 3D structure of Au@Ag core-shell nanorods, but it is applicable to a wide range of heterogeneous complex nanostructures.
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Affiliation(s)
| | - Annick De Backer
- EMAT, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
| | - Gerardo T Martinez
- EMAT, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
| | - Naomi Winckelmans
- EMAT, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
| | - Sara Bals
- EMAT, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
| | - Peter D Nellist
- Department of Materials, University of Oxford, 16 Parks Road, Oxford OX1 3PH, United Kingdom
| | - Sandra Van Aert
- EMAT, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
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33
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Wade CA, McLean MJ, Vinci RP, Watanabe M. Aberration-Corrected Scanning Transmission Electron Microscope (STEM) Through-Focus Imaging for Three-Dimensional Atomic Analysis of Bismuth Segregation on Copper [001]/33° Twist Bicrystal Grain Boundaries. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2016; 22:679-689. [PMID: 27145975 DOI: 10.1017/s1431927616000696] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Scanning transmission electron microscope (STEM) through-focus imaging (TFI) has been used to determine the three-dimensional atomic structure of Bi segregation-induced brittle Cu grain boundaries (GBs). With TFI, it is possible to observe single Bi atom distributions along Cu [001] twist GBs using an aberration-corrected STEM operating at 200 kV. The depth resolution is ~5 nm. Specimens with GBs intentionally inclined with respect to the microscope's optic axis were used to investigate Bi segregant atom distributions along and through the Cu GB. It was found that Bi atoms exist at most once per Cu unit cell along the GB, meaning that no continuous GB film is present. Therefore, the reduced fracture toughness of this particular Bi-doped Cu boundary would not be caused by fracture of Bi-Bi bonds.
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Affiliation(s)
- Charles Austin Wade
- 1Department of Materials Science and Engineering,Lehigh University,Bethlehem, PA 18015,USA
| | - Mark J McLean
- 1Department of Materials Science and Engineering,Lehigh University,Bethlehem, PA 18015,USA
| | - Richard P Vinci
- 1Department of Materials Science and Engineering,Lehigh University,Bethlehem, PA 18015,USA
| | - Masashi Watanabe
- 1Department of Materials Science and Engineering,Lehigh University,Bethlehem, PA 18015,USA
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34
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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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35
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Interfacial Atomic Structure of Twisted Few-Layer Graphene. Sci Rep 2016; 6:21273. [PMID: 26888259 PMCID: PMC4758067 DOI: 10.1038/srep21273] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2015] [Accepted: 01/20/2016] [Indexed: 12/02/2022] Open
Abstract
A twist in bi- or few-layer graphene breaks the local symmetry, introducing a number of intriguing physical properties such as opening new bandgaps. Therefore, determining the twisted atomic structure is critical to understanding and controlling the functional properties of graphene. Combining low-angle annular dark-field electron microscopy with image simulations, we directly determine the atomic structure of twisted few-layer graphene in terms of a moiré superstructure which is parameterized by a single twist angle and lattice constant. This method is shown to be a powerful tool for accurately determining the atomic structure of two-dimensional materials such as graphene, even in the presence of experimental errors. Using coincidence-site-lattice and displacement-shift-complete theories, we show that the in-plane translation state between layers is not a significant structure parameter, explaining why the present method is adequate not only for bilayer graphene but also a few-layered twisted graphene.
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36
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Krause FF, Schowalter M, Grieb T, Müller-Caspary K, Mehrtens T, Rosenauer A. Effects of instrument imperfections on quantitative scanning transmission electron microscopy. Ultramicroscopy 2016; 161:146-160. [DOI: 10.1016/j.ultramic.2015.10.026] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Revised: 10/26/2015] [Accepted: 10/29/2015] [Indexed: 10/22/2022]
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37
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Zhai Y, Shim M. Benefitting from Dopant Loss and Ostwald Ripening in Mn Doping of II-VI Semiconductor Nanocrystals. NANOSCALE RESEARCH LETTERS 2015; 10:423. [PMID: 26510444 PMCID: PMC4624686 DOI: 10.1186/s11671-015-1123-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 10/15/2015] [Indexed: 06/05/2023]
Abstract
Annealing or growth at high temperatures for an extended period of time is considered detrimental for most synthetic strategies for high-quality Mn-doped II-VI semiconductor nanocrystals. It can lead to the broadening of size distribution and, more importantly, to the loss of dopants. Here, we examine how ripening can be beneficial to doping in a simple "heat-up" approach, where high dopant concentrations can be achieved. We discuss the interplay of the loss of dopants, Ostwald ripening, and the clustering of Mn near the surface during nanocrystal growth. Smaller nanocrystals in a reaction batch, on average, exhibit higher undesirable band-edge photoluminescence (PL) and lower desirable dopant PL. The optimization of dopant loss and the removal of such smaller undesirable nanocrystals through Ostwald ripening along with surface exchange/passivation to remove Mn clustering lead to high Mn PL quantum yields (45 to 55 %) for ZnSxSe1-x, ZnS, CdS, and CdSxSe1-x host nanocrystals. These results provide an improved understanding of the doping process in a simple and potentially scalable synthetic strategy for achieving "pure" and bright dopant emission.
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Affiliation(s)
- You Zhai
- Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Moonsub Shim
- Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
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38
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He Q, Belianinov A, Dziaugys A, Maksymovych P, Vysochanskii Y, Kalinin SV, Borisevich AY. Antisite defects in layered multiferroic CuCr(0.9)In(0.1)P2S6. NANOSCALE 2015; 7:18579-18583. [PMID: 26489774 DOI: 10.1039/c5nr04779j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The CuCr1-xInxP2S6 system represents a large family of metal chalcogenophosphates that are unique and promising candidates for 2D materials with functionalities such as ferroelectricity. In this work, we carried out detailed microstructural and chemical characterization of these compounds using aberration-corrected STEM, in order to understand the origin of these different ordering phenomena. Quantitative STEM-HAADF imaging and analysis identified the stacking order of an 8-layer thin flake, which leads to the identification of anti-site In(3+)(Cu(+)) doping. We believe that these findings will pave the way towards understanding the ferroic coupling phenomena in van der Waals lamellar compounds, as well as their potential applications in 2-D electronics.
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Affiliation(s)
- Qian He
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
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39
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Yamashita S, Koshiya S, Nagai T, Kikkawa J, Ishizuka K, Kimoto K. Quantitative annular dark-field imaging of single-layer graphene-II: atomic-resolution image contrast. Microscopy (Oxf) 2015; 64:409-18. [PMID: 26347577 PMCID: PMC4711290 DOI: 10.1093/jmicro/dfv053] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Accepted: 08/13/2015] [Indexed: 11/12/2022] Open
Abstract
We have investigated how accurately atomic-resolution annular dark-field (ADF) images match between experiments and simulations to conduct more reliable crystal structure analyses. Quantitative ADF imaging, in which the ADF intensity at each pixel represents the fraction of the incident probe current, allows us to perform direct comparisons with simulations without the use of fitting parameters. Although the conventional comparison suffers from experimental uncertainties such as an amorphous surface layer and specimen thickness, in this study we eliminated such uncertainties by using a single-layer graphene as a specimen. Furthermore, to reduce image distortion and shot noises in experimental images, multiple acquisitions with drift correction were performed, and the atomic ADF contrast was quantitatively acquired. To reproduce the experimental ADF contrast, we used three distribution functions as the effective source distribution in simulations. The optimum distribution function and its full-width at half-maximum were evaluated by measuring the residuals between the experimental and simulated images. It was found that the experimental images could be explained well by a linear combination of a Gaussian function and a Lorentzian function with a longer tail than the Gaussian function.
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Affiliation(s)
- Shunsuke Yamashita
- Surface Physics and Structure Unit, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan Department of Applied Chemistry, Kyushu University, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
| | - Shogo Koshiya
- Surface Physics and Structure Unit, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
| | - Takuro Nagai
- Surface Physics and Structure Unit, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
| | - Jun Kikkawa
- Surface Physics and Structure Unit, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
| | - Kazuo Ishizuka
- Surface Physics and Structure Unit, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan HREM Research Inc., 14-48 Matsukazedai, Higashimatsuyama, Saitama 355-0055, Japan
| | - Koji Kimoto
- Surface Physics and Structure Unit, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan Department of Applied Chemistry, Kyushu University, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
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40
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MacArthur K, D’Alfonso A, Ozkaya D, Allen L, Nellist P. Optimal ADF STEM imaging parameters for tilt-robust image quantification. Ultramicroscopy 2015; 156:1-8. [DOI: 10.1016/j.ultramic.2015.04.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Revised: 04/15/2015] [Accepted: 04/23/2015] [Indexed: 10/23/2022]
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41
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Zhang JY, Hwang J, Isaac BJ, Stemmer S. Variable-angle high-angle annular dark-field imaging: application to three-dimensional dopant atom profiling. Sci Rep 2015. [PMID: 26206489 PMCID: PMC4513304 DOI: 10.1038/srep12419] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Variable-angle high-angle annular dark-field (HAADF) imaging in scanning transmission electron microscopy is developed for precise and accurate determination of three-dimensional (3D) dopant atom configurations. Gd-doped SrTiO3 films containing Sr columns containing zero, one, or two Gd dopant atoms are imaged in HAADF mode using two different collection angles. Variable-angle HAADF significantly increases both the precision and accuracy of 3D dopant profiling. Using image simulations, it is shown that the combined information from the two detectors reduces the uncertainty in the dopant depth position measurement and can uniquely identify certain atomic configurations that are indistinguishable with a single detector setting. Additional advances and applications are discussed.
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Affiliation(s)
- Jack Y Zhang
- Materials Department, University of California, Santa Barbara, California 93106-5050, U. S. A
| | - Jinwoo Hwang
- Materials Department, University of California, Santa Barbara, California 93106-5050, U. S. A
| | - Brandon J Isaac
- Materials Department, University of California, Santa Barbara, California 93106-5050, U. S. A
| | - Susanne Stemmer
- Materials Department, University of California, Santa Barbara, California 93106-5050, U. S. A
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42
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Ishikawa R, Lupini AR, Hinuma Y, Pennycook SJ. Large-angle illumination STEM: Toward three-dimensional atom-by-atom imaging. Ultramicroscopy 2015; 151:122-129. [DOI: 10.1016/j.ultramic.2014.11.009] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Revised: 10/30/2014] [Accepted: 11/06/2014] [Indexed: 11/29/2022]
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43
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Lugg N, Kothleitner G, Shibata N, Ikuhara Y. On the quantitativeness of EDS STEM. Ultramicroscopy 2015; 151:150-159. [DOI: 10.1016/j.ultramic.2014.11.029] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Revised: 11/22/2014] [Accepted: 11/24/2014] [Indexed: 10/24/2022]
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44
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Lu X, Gao W, Zuo JM, Yuan J. Atomic resolution tomography reconstruction of tilt series based on a GPU accelerated hybrid input–output algorithm using polar Fourier transform. Ultramicroscopy 2015; 149:64-73. [DOI: 10.1016/j.ultramic.2014.10.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Accepted: 10/13/2014] [Indexed: 10/24/2022]
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45
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Allen LJ. Electron microscopy: Shape of a crystal from one image. NATURE MATERIALS 2014; 13:1000-1001. [PMID: 25342528 DOI: 10.1038/nmat4120] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Affiliation(s)
- Leslie J Allen
- School of Physics, University of Melbourne, Victoria 3010, Australia
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46
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Rotunno E, Albrecht M, Markurt T, Remmele T, Grillo V. Three dimensional analysis of the composition in solid alloys by variable probe in scanning transmission electron microscopy. Ultramicroscopy 2014; 146:62-70. [DOI: 10.1016/j.ultramic.2014.07.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Revised: 06/24/2014] [Accepted: 07/06/2014] [Indexed: 10/25/2022]
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47
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Jia CL, Mi SB, Barthel J, Wang DW, Dunin-Borkowski RE, Urban KW, Thust A. Determination of the 3D shape of a nanoscale crystal with atomic resolution from a single image. NATURE MATERIALS 2014; 13:1044-9. [PMID: 25242534 DOI: 10.1038/nmat4087] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Accepted: 08/12/2014] [Indexed: 05/16/2023]
Abstract
Although the overall atomic structure of a nanoscale crystal is in principle accessible by modern transmission electron microscopy, the precise determination of its surface structure is an intricate problem. Here, we show that aberration-corrected transmission electron microscopy, combined with dedicated numerical evaluation procedures, allows the three-dimensional shape of a thin MgO crystal to be determined from only one single high-resolution image. The sensitivity of the reconstruction procedure is not only sufficient to reveal the surface morphology of the crystal with atomic resolution, but also to detect the presence of adsorbed impurity atoms. The single-image approach that we introduce offers important advantages for three-dimensional studies of radiation-sensitive crystals.
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Affiliation(s)
- C L Jia
- 1] International Center for Dielectric Research, Xi'an Jiaotong University, Xi'an 710049, China [2] Peter Grünberg Institute, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany [3] Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - S B Mi
- International Center for Dielectric Research, Xi'an Jiaotong University, Xi'an 710049, China
| | - J Barthel
- 1] Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany [2] Central Facility for Electron Microscopy, RWTH Aachen University, Ahornstr. 55 52074 Aachen, Germany
| | - D W Wang
- International Center for Dielectric Research, Xi'an Jiaotong University, Xi'an 710049, China
| | - R E Dunin-Borkowski
- 1] Peter Grünberg Institute, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany [2] Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - K W Urban
- 1] Peter Grünberg Institute, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany [2] Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - A Thust
- 1] Peter Grünberg Institute, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany [2] Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
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48
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Kim S, Jung Y, Lee S, Jung Kim J, Byun G, Lee S, Lee H. 3D strain measurement in electronic devices using through-focal annular dark-field imaging. Ultramicroscopy 2014; 146:1-5. [DOI: 10.1016/j.ultramic.2014.04.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Revised: 04/27/2014] [Accepted: 04/29/2014] [Indexed: 11/25/2022]
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49
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Ishikawa R, Mishra R, Lupini AR, Findlay SD, Taniguchi T, Pantelides ST, Pennycook SJ. Direct observation of dopant atom diffusion in a bulk semiconductor crystal enhanced by a large size mismatch. PHYSICAL REVIEW LETTERS 2014; 113:155501. [PMID: 25375721 DOI: 10.1103/physrevlett.113.155501] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Indexed: 06/04/2023]
Abstract
Diffusion is one of the fundamental processes that govern the structure, processing, and properties of materials and it plays a crucial role in determining device lifetimes. However, direct observations of diffusion processes have been elusive and limited only to the surfaces of materials. Here we use an aberration-corrected electron microscope to locally excite and directly image the diffusion of single Ce and Mn dopants inside bulk wurtzite-type AlN single crystals, identifying correlated vacancy-dopant and interstitial-dopant kick-out mechanisms. Using a 200 kV electron beam to supply energy, we observe a higher frequency of dopant jumps for the larger and heavier Ce atoms than the smaller Mn atoms. These observations confirm density-functional-theory-based predictions of a decrease in diffusion barrier for large substitutional atoms. The results show that combining depth sensitive microscopy with theoretical calculations represents a new methodology to investigate diffusion mechanisms, not restricted to surface phenomena, but within bulk materials.
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Affiliation(s)
- Ryo Ishikawa
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA and Institute of Engineering Innovation, University of Tokyo, Bunkyo, Tokyo 113-8656, Japan
| | - Rohan Mishra
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA and Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37235, USA
| | - Andrew R Lupini
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Scott D Findlay
- School of Physics, Monash University, Victoria 3800, Australia
| | - Takashi Taniguchi
- Advanced Key Technologies Division, National Institute for Materials Science, Tsukuba 305-0044, Japan
| | - Sokrates T Pantelides
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA and Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37235, USA
| | - Stephen J Pennycook
- Department of Materials Science and Engineering, The University of Tennessee, Knoxville, Tennessee 37996, USA
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50
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Ida S, Koga S, Daio T, Hagiwara H, Ishihara T. Direct Imaging of Light Emission Centers in Two-Dimensional Crystals and Their Luminescence and Photocatalytic Properties. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201406638] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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