51
|
Single-atom detection of light elements: Imaging or spectroscopy? Ultramicroscopy 2017; 180:150-155. [DOI: 10.1016/j.ultramic.2016.12.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Revised: 11/17/2016] [Accepted: 12/08/2016] [Indexed: 11/22/2022]
|
52
|
The impact of STEM aberration correction on materials science. Ultramicroscopy 2017; 180:22-33. [DOI: 10.1016/j.ultramic.2017.03.020] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 03/04/2017] [Accepted: 03/16/2017] [Indexed: 11/22/2022]
|
53
|
Ramasse QM. Twenty years after: How “Aberration correction in the STEM” truly placed a “A synchrotron in a Microscope”. Ultramicroscopy 2017; 180:41-51. [DOI: 10.1016/j.ultramic.2017.03.016] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 03/06/2017] [Accepted: 03/14/2017] [Indexed: 10/19/2022]
|
54
|
Susi T, Meyer JC, Kotakoski J. Manipulating low-dimensional materials down to the level of single atoms with electron irradiation. Ultramicroscopy 2017; 180:163-172. [DOI: 10.1016/j.ultramic.2017.03.005] [Citation(s) in RCA: 92] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 02/24/2017] [Accepted: 03/01/2017] [Indexed: 10/20/2022]
|
55
|
BEYER ANDREAS, DUSCHEK LENNART, BELZ JÜRGEN, OELERICH JANOLIVER, JANDIERI KAKHABER, VOLZ KERSTIN. Surface relaxation of strained Ga(P,As)/GaP heterostructures investigated by HAADF STEM. J Microsc 2017; 268:239-247. [DOI: 10.1111/jmi.12622] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Revised: 07/20/2017] [Accepted: 08/07/2017] [Indexed: 11/30/2022]
Affiliation(s)
- ANDREAS BEYER
- Materials Science Center and Faculty of Physics; Philipps-Universität Marburg; Marburg Germany
| | - LENNART DUSCHEK
- Materials Science Center and Faculty of Physics; Philipps-Universität Marburg; Marburg Germany
| | - JÜRGEN BELZ
- Materials Science Center and Faculty of Physics; Philipps-Universität Marburg; Marburg Germany
| | - JAN OLIVER OELERICH
- Materials Science Center and Faculty of Physics; Philipps-Universität Marburg; Marburg Germany
| | - KAKHABER JANDIERI
- Materials Science Center and Faculty of Physics; Philipps-Universität Marburg; Marburg Germany
| | - KERSTIN VOLZ
- Materials Science Center and Faculty of Physics; Philipps-Universität Marburg; Marburg Germany
| |
Collapse
|
56
|
Electron ptychographic phase imaging of light elements in crystalline materials using Wigner distribution deconvolution. Ultramicroscopy 2017; 180:173-179. [DOI: 10.1016/j.ultramic.2017.02.006] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 02/09/2017] [Accepted: 02/18/2017] [Indexed: 11/20/2022]
|
57
|
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.
Collapse
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
| |
Collapse
|
58
|
Jing Q, Zhang M, Huang X, Ren X, Wang P, Lu Z. Surface passivation of mixed-halide perovskite CsPb(Br xI 1-x) 3 nanocrystals by selective etching for improved stability. NANOSCALE 2017; 9:7391-7396. [PMID: 28405658 DOI: 10.1039/c7nr01287j] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
In recent years, there has been an unprecedented rise in the research of halide perovskites because of their important optoelectronic applications, including photovoltaic cells, light-emitting diodes, photodetectors and lasers. The most pressing question concerns the stability of these materials. Here faster degradation and PL quenching are observed at higher iodine content for mixed-halide perovskite CsPb(BrxI1-x)3 nanocrystals, and a simple yet effective method is reported to significantly enhance their stability. After selective etching with acetone, surface iodine is partially etched away to form a bromine-rich surface passivation layer on mixed-halide perovskite nanocrystals. This passivation layer remarkably stabilizes the nanocrystals, making their PL intensity improved by almost three orders of magnitude. It is expected that a similar passivation layer can also be applied to various other kinds of perovskite materials with poor stability issues.
Collapse
Affiliation(s)
- Qiang Jing
- National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | | | | | | | | | | |
Collapse
|
59
|
Electron Ptychographic Diffractive Imaging of Boron Atoms in LaB 6 Crystals. Sci Rep 2017; 7:2857. [PMID: 28588219 PMCID: PMC5460146 DOI: 10.1038/s41598-017-02778-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Accepted: 04/19/2017] [Indexed: 11/21/2022] Open
Abstract
Ptychographic diffractive imaging has the potential for structural determination of materials without the constraints of relatively small, isolated samples required for conventional coherent diffractive imaging. The increased illumination diversity introduced using multiple measurements (overlapped probe positions) also provides higher sensitivity to phase changes in weakly scattering samples. The resolution of a ptychographic reconstruction is ultimately determined by the diffraction limit for the wavelength of the radiation used. However, in practical experiments using electrons either the maximum collection angle of the detector used to record the data or the partial coherence of the source impose lower resolution limits. Nonetheless for medium energy electrons this suggests a potential sub 0.1 nm spatial resolution limit, comparable to that obtained using aberration corrected instruments. However, simultaneous visualization of light and heavier atoms in specimens using ptychography at sub 0.1 nm resolution presents a significant challenge. Here, we demonstrate a ptychographic reconstruction of a LaB6 crystal in which light B atoms were clearly resolved together with the heavy La atoms in the reconstructed phase. The technique used is general and can also be applied to non-crystalline and extended crystalline samples. As such it offers an alternative future basis for imaging the atomic structure of materials, particularly those containing low atomic number elements.
Collapse
|
60
|
Alania M, Altantzis T, De Backer A, Lobato I, Bals S, Van Aert S. Depth sectioning combined with atom-counting in HAADF STEM to retrieve the 3D atomic structure. Ultramicroscopy 2017; 177:36-42. [DOI: 10.1016/j.ultramic.2016.11.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Revised: 10/21/2016] [Accepted: 11/04/2016] [Indexed: 11/30/2022]
|
61
|
Hong J, Jin C, Yuan J, Zhang Z. Atomic Defects in Two-Dimensional Materials: From Single-Atom Spectroscopy to Functionalities in Opto-/Electronics, Nanomagnetism, and Catalysis. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2017; 29. [PMID: 28295728 DOI: 10.1002/adma.201606434] [Citation(s) in RCA: 103] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Revised: 01/13/2017] [Indexed: 05/10/2023]
Abstract
Two-dimensional layered graphene-like crystals including transition-metal dichalcogenides (TMDs) have received extensive research interest due to their diverse electronic, valleytronic, and chemical properties, with the corresponding optoelectronics and catalysis application being actively explored. However, the recent surge in two-dimensional materials science is accompanied by equally great challenges, such as defect engineering in large-scale sample synthesis. It is necessary to elucidate the effect of structural defects on the electronic properties in order to develop an application-specific strategy for defect engineering. Here, two aspects of the existing knowledge of native defects in two-dimensional crystals are reviewed. One is the point defects emerging in graphene and hexagonal boron nitride, as probed by atomically resolved electron microscopy, and their local electronic properties, as measured by single-atom electron energy-loss spectroscopy. The other will focus on the point defects in TMDs and their influence on the electronic structure, photoluminescence, and electric transport properties. This review of atomic defects in two-dimensional materials will offer a clear picture of the defect physics involved to demonstrate the local modulation of the electronic properties and possible benefits in potential applications in magnetism and catalysis.
Collapse
Affiliation(s)
- Jinhua Hong
- State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang, 310027, P. R. China
| | - Chuanhong Jin
- State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang, 310027, P. R. China
| | - Jun Yuan
- State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang, 310027, P. R. China
- Department of Physics, University of York, Heslington, York, YO10 5DD, UK
| | - Ze Zhang
- State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang, 310027, P. R. China
| |
Collapse
|
62
|
Howie A. New instrumentation and cutting edge research. Ultramicroscopy 2017; 180:52-58. [PMID: 28258870 DOI: 10.1016/j.ultramic.2016.11.006] [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: 09/16/2016] [Revised: 11/04/2016] [Accepted: 11/15/2016] [Indexed: 11/16/2022]
Abstract
Stimulated by Ondrej Krivanek's contributions, the complex interaction between research and innovations in the instrumentation for electron microscopy is discussed. Specific attention is given to aberration correction and to spectroscopy in both the valence region and at the energies of localised phonons or bond vibrations. Current thinking about projection imaging and dielectric excitation theory may be challenged. More significantly in the new fields of investigation opened up to them, electron microscopists will need to build closer relations, particularly with the photonics and scanning tunnelling microscopy communities. Further improvements in instrumentation could usefully be directed towards imaging and spectroscopy at higher scattering angles as well as the incorporation of other facilities such as photon stimulation and secondary electron imaging.
Collapse
Affiliation(s)
- A Howie
- Dept. of Physics, University of Cambridge, J.J. Thomson Avenue, Cambridge CB3 0HE, UK
| |
Collapse
|
63
|
Lovejoy T, Rez P, Dellby N. Ondrej Krivanek: A pioneering visionary in electron microscopy. Ultramicroscopy 2017; 180:2-7. [PMID: 28347543 DOI: 10.1016/j.ultramic.2017.02.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2016] [Revised: 01/29/2017] [Accepted: 02/18/2017] [Indexed: 11/16/2022]
Abstract
This article is a short biographical sketch of the life and times of Ondrej Krivanek. The story starts with his early days in Prague, Czechia, and briefly outlines various events from a PhD in Cambridge to post-docs in Kyoto, Bell Labs, and building his first spectrometer at UC Berkeley. Ondrej's pioneering contributions to electron microscopy as Assistant Professor at Arizona State University and later as Director of R&D at Gatan are covered, as well as his return to academia and focusing on aberration correction. The story wraps up with the founding of Nion, the early success of the Nion aberration correctors, and subsequent progress such as building a complete cutting-edge electron microscope and later a record-breaking monochromator. Ondrej continues to be actively involved in design and in running Nion, and while this article ends at the present, further breakthroughs can be expected from him.
Collapse
Affiliation(s)
- Tracy Lovejoy
- Nion Co., 11511 NE 118th St., Kirkland, WA 98034, USA.
| | - Peter Rez
- Department of Physics, Arizona State University, Tempe, Arizona 85287, USA
| | - Niklas Dellby
- Nion Co., 11511 NE 118th St., Kirkland, WA 98034, USA
| |
Collapse
|
64
|
Agati M, Amiard G, Borgne VL, Castrucci P, Dolbec R, De Crescenzi M, El Khakani MA, Boninelli S. Self-assembly of silicon nanowires studied by advanced transmission electron microscopy. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2017; 8:440-445. [PMID: 28326234 PMCID: PMC5331248 DOI: 10.3762/bjnano.8.47] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 01/17/2017] [Indexed: 06/06/2023]
Abstract
Scanning transmission electron microscopy (STEM) was successfully applied to the analysis of silicon nanowires (SiNWs) that were self-assembled during an inductively coupled plasma (ICP) process. The ICP-synthesized SiNWs were found to present a Si-SiO2 core-shell structure and length varying from ≈100 nm to 2-3 μm. The shorter SiNWs (maximum length ≈300 nm) were generally found to possess a nanoparticle at their tip. STEM energy dispersive X-ray (EDX) spectroscopy combined with electron tomography performed on these nanostructures revealed that they contain iron, clearly demonstrating that the short ICP-synthesized SiNWs grew via an iron-catalyzed vapor-liquid-solid (VLS) mechanism within the plasma reactor. Both the STEM tomography and STEM-EDX analysis contributed to gain further insight into the self-assembly process. In the long-term, this approach might be used to optimize the synthesis of VLS-grown SiNWs via ICP as a competitive technique to the well-established bottom-up approaches used for the production of thin SiNWs.
Collapse
Affiliation(s)
- Marta Agati
- Dipartimento di Fisica e Astronomia, Università di Catania, Via S. Sofia 64, Catania 95123, Italy
- CNR IMM-MATIS, Via S. Sofia 64, Catania 95123, Italy
- Institut national de la recherche scientifique, Centre-Énergie, Matériaux et Télécommunications (INRS-EMT), 1650 Blvd. Lionel Boulet, Varennes QC-J3X 1S2, Canada
| | - Guillaume Amiard
- CNR IMM-MATIS, Via S. Sofia 64, Catania 95123, Italy
- Institut Pprime, UPR 3346, CNRS - Université de Poitiers, ISAE-ENSMA, 11 Boulevard Marie et Pierre Curie, 86962 Futuroscope-Chasseneuil, France
| | - Vincent Le Borgne
- Institut national de la recherche scientifique, Centre-Énergie, Matériaux et Télécommunications (INRS-EMT), 1650 Blvd. Lionel Boulet, Varennes QC-J3X 1S2, Canada
| | - Paola Castrucci
- Dipartimento di Fisica, Università di Roma “Tor Vergata”, Via della Ricerca Scientifica 1, Roma 00133, Italy
| | - Richard Dolbec
- Tekna Plasma Systems Inc., 2935 Industrial Blvd., Sherbrooke QC-J1L 2T9, Canada
| | - Maurizio De Crescenzi
- Dipartimento di Fisica, Università di Roma “Tor Vergata”, Via della Ricerca Scientifica 1, Roma 00133, Italy
| | - My Alì El Khakani
- Institut national de la recherche scientifique, Centre-Énergie, Matériaux et Télécommunications (INRS-EMT), 1650 Blvd. Lionel Boulet, Varennes QC-J3X 1S2, Canada
| | | |
Collapse
|
65
|
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.
Collapse
Affiliation(s)
- Mark P Oxley
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | | | | |
Collapse
|
66
|
Thomas JM. Reflections on the value of electron microscopy in the study of heterogeneous catalysts. Proc Math Phys Eng Sci 2017; 473:20160714. [PMID: 28265196 DOI: 10.1098/rspa.2016.0714] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Electron microscopy (EM) is arguably the single most powerful method of characterizing heterogeneous catalysts. Irrespective of whether they are bulk and multiphasic, or monophasic and monocrystalline, or nanocluster and even single-atom and on a support, their structures in atomic detail can be visualized in two or three dimensions, thanks to high-resolution instruments, with sub-Ångstrom spatial resolutions. Their topography, tomography, phase-purity, composition, as well as the bonding, and valence-states of their constituent atoms and ions and, in favourable circumstances, the short-range and long-range atomic order and dynamics of the catalytically active sites, can all be retrieved by the panoply of variants of modern EM. The latter embrace electron crystallography, rotation and precession electron diffraction, X-ray emission and high-resolution electron energy-loss spectra (EELS). Aberration-corrected (AC) transmission (TEM) and scanning transmission electron microscopy (STEM) have led to a revolution in structure determination. Environmental EM is already playing an increasing role in catalyst characterization, and new advances, involving special cells for the study of solid catalysts in contact with liquid reactants, have recently been deployed.
Collapse
Affiliation(s)
- John Meurig Thomas
- Department of Materials Science and Metallurgy , University of Cambridge , 27 Charles Babbage Road, Cambridge CB3 0FS , UK
| |
Collapse
|
67
|
Shorokhov D, Zewail AH. Perspective: 4D ultrafast electron microscopy--Evolutions and revolutions. J Chem Phys 2016; 144:080901. [PMID: 26931672 DOI: 10.1063/1.4941375] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
In this Perspective, the evolutionary and revolutionary developments of ultrafast electron imaging are overviewed with focus on the "single-electron concept" for probing methodology. From the first electron microscope of Knoll and Ruska [Z. Phys. 78, 318 (1932)], constructed in the 1930s, to aberration-corrected instruments and on, to four-dimensional ultrafast electron microscopy (4D UEM), the developments over eight decades have transformed humans' scope of visualization. The changes in the length and time scales involved are unimaginable, beginning with the micrometer and second domains, and now reaching the space and time dimensions of atoms in matter. With these advances, it has become possible to follow the elementary structural dynamics as it unfolds in real time and to provide the means for visualizing materials behavior and biological functions. The aim is to understand emergent phenomena in complex systems, and 4D UEM is now central for the visualization of elementary processes involved, as illustrated here with examples from past achievements and future outlook.
Collapse
Affiliation(s)
- Dmitry Shorokhov
- Physical Biology Center for Ultrafast Science and Technology, Arthur Amos Noyes Laboratory for Chemical Physics, California Institute of Technology, Pasadena, California 91125, USA
| | - Ahmed H Zewail
- Physical Biology Center for Ultrafast Science and Technology, Arthur Amos Noyes Laboratory for Chemical Physics, California Institute of Technology, Pasadena, California 91125, USA
| |
Collapse
|
68
|
Fabrication of thin TEM sample of ionic liquid for high-resolution ELNES measurements. Ultramicroscopy 2016; 178:81-87. [PMID: 27793468 DOI: 10.1016/j.ultramic.2016.10.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Revised: 09/25/2016] [Accepted: 10/18/2016] [Indexed: 11/21/2022]
Abstract
Investigation of the local structure, ionic and molecular behavior, and chemical reactions at high spatial resolutions in liquids has become increasingly important. Improvements in these areas help to develop efficient batteries and improve organic syntheses. Transmission electron microscopy (TEM) and scanning-TEM (STEM) have excellent spatial resolution, and the electron energy-loss near edge structure (ELNES) measured by the accompanied electron energy-loss spectroscopy (EELS) is effective to analyze the liquid local structure owing to reflecting the electronic density of states. In this study, we fabricate a liquid-layer-only sample with thickness of single to tens nanometers using an ionic liquid. Because the liquid film has a thickness much less than the inelastic mean free path (IMFP) of the electron beam, the fine structure of the C-K edge electron energy loss near edge structure (ELNES) can be measured with sufficient resolution to allow meaningful analysis. The ELNES spectrum from the thin liquid film has been interpreted using first principles ELNES calculations.
Collapse
|
69
|
Isotope analysis in the transmission electron microscope. Nat Commun 2016; 7:13040. [PMID: 27721420 PMCID: PMC5476802 DOI: 10.1038/ncomms13040] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Accepted: 08/26/2016] [Indexed: 11/08/2022] Open
Abstract
The Ångström-sized probe of the scanning transmission electron microscope can visualize and collect spectra from single atoms. This can unambiguously resolve the chemical structure of materials, but not their isotopic composition. Here we differentiate between two isotopes of the same element by quantifying how likely the energetic imaging electrons are to eject atoms. First, we measure the displacement probability in graphene grown from either 12C or 13C and describe the process using a quantum mechanical model of lattice vibrations coupled with density functional theory simulations. We then test our spatial resolution in a mixed sample by ejecting individual atoms from nanoscale areas spanning an interface region that is far from atomically sharp, mapping the isotope concentration with a precision better than 20%. Although we use a scanning instrument, our method may be applicable to any atomic resolution transmission electron microscope and to other low-dimensional materials.
Collapse
|
70
|
Savitzky BH, Hovden R, Whitham K, Yang J, Wise F, Hanrath T, Kourkoutis LF. Propagation of Structural Disorder in Epitaxially Connected Quantum Dot Solids from Atomic to Micron Scale. NANO LETTERS 2016; 16:5714-5718. [PMID: 27540863 DOI: 10.1021/acs.nanolett.6b02382] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Epitaxially connected superlattices of self-assembled colloidal quantum dots present a promising route toward exquisite control of electronic structure through precise hierarchical structuring across multiple length scales. Here, we uncover propagation of disorder as an essential feature in these systems, which intimately connects order at the atomic, superlattice, and grain scales. Accessing theoretically predicted exotic electronic states and highly tunable minibands will therefore require detailed understanding of the subtle interplay between local and long-range structure. To that end, we developed analytical methods to quantitatively characterize the propagating disorder in terms of a real paracrystal model and directly observe the dramatic impact of angstrom scale translational disorder on structural correlations at hundreds of nanometers. Using this framework, we discover improved order accompanies increasing sample thickness and identify the substantial effect of small fractions of missing epitaxial bonds on statistical disorder. These results have significant experimental and theoretical implications for the elusive goals of long-range carrier delocalization and true miniband formation.
Collapse
Affiliation(s)
- Benjamin H Savitzky
- Department of Physics, Cornell University , Ithaca, New York 14853, United States
| | - Robert Hovden
- School of Applied and Engineering Physics, Cornell University , Ithaca, New York 14853, United States
| | - Kevin Whitham
- Department of Materials Science & Engineering, Cornell University , Ithaca, New York 14853, United States
| | - Jun Yang
- School of Applied and Engineering Physics, Cornell University , Ithaca, New York 14853, United States
| | - Frank Wise
- School of Applied and Engineering Physics, Cornell University , Ithaca, New York 14853, United States
| | - Tobias Hanrath
- School of Chemical & Biomolecular Engineering, Cornell University , Ithaca, New York 14853, United States
| | - Lena F Kourkoutis
- School of Applied and Engineering Physics, Cornell University , Ithaca, New York 14853, United States
- Kavli Institute for Nanoscale Science, Cornell University , Ithaca, New York 14853, United States
| |
Collapse
|
71
|
Titze B, Genoud C. Volume scanning electron microscopy for imaging biological ultrastructure. Biol Cell 2016; 108:307-323. [DOI: 10.1111/boc.201600024] [Citation(s) in RCA: 132] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Revised: 07/13/2016] [Accepted: 07/14/2016] [Indexed: 12/01/2022]
Affiliation(s)
- Benjamin Titze
- Friedrich Miescher Institute for Biomedical Research; Basel Switzerland
| | - Christel Genoud
- Friedrich Miescher Institute for Biomedical Research; Basel Switzerland
| |
Collapse
|
72
|
Nord M, Vullum PE, Hallsteinsen I, Tybell T, Holmestad R. Assessing electron beam sensitivity for SrTiO3 and La0.7Sr0.3MnO3 using electron energy loss spectroscopy. Ultramicroscopy 2016; 169:98-106. [PMID: 27454005 DOI: 10.1016/j.ultramic.2016.07.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Revised: 06/23/2016] [Accepted: 07/03/2016] [Indexed: 11/19/2022]
Abstract
Thresholds for beam damage have been assessed for La0.7Sr0.3MnO3 and SrTiO3 as a function of electron probe current and exposure time at 80 and 200kV acceleration voltage. The materials were exposed to an intense electron probe by aberration corrected scanning transmission electron microscopy (STEM) with simultaneous acquisition of electron energy loss spectroscopy (EELS) data. Electron beam damage was identified by changes of the core loss fine structure after quantification by a refined and improved model based approach. At 200kV acceleration voltage, damage in SrTiO3 was identified by changes both in the EEL fine structure and by contrast changes in the STEM images. However, the changes in the STEM image contrast as introduced by minor damage can be difficult to detect under several common experimental conditions. No damage was observed in SrTiO3 at 80kV acceleration voltage, independent of probe current and exposure time. In La0.7Sr0.3MnO3, beam damage was observed at both 80 and 200kV acceleration voltages. This damage was observed by large changes in the EEL fine structure, but not by any detectable changes in the STEM images. The typical method to validate if damage has been introduced during acquisitions is to compare STEM images prior to and after spectroscopy. Quantifications in this work show that this method possibly can result in misinterpretation of beam damage as changes of material properties.
Collapse
Affiliation(s)
- Magnus Nord
- Department of Physics, NTNU, Trondheim, Norway.
| | - Per Erik Vullum
- Department of Physics, NTNU, Trondheim, Norway; Materials and Chemistry, SINTEF, Trondheim, Norway
| | | | - Thomas Tybell
- Department of Electronics and Telecommunications, NTNU, Trondheim, Norway
| | | |
Collapse
|
73
|
Wang Z, Saito M, McKenna KP, Fukami S, Sato H, Ikeda S, Ohno H, Ikuhara Y. Atomic-Scale Structure and Local Chemistry of CoFeB-MgO Magnetic Tunnel Junctions. NANO LETTERS 2016; 16:1530-1536. [PMID: 26905782 DOI: 10.1021/acs.nanolett.5b03627] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Magnetic tunnel junctions (MTJs) constitute a promising building block for future nonvolatile memories and logic circuits. Despite their pivotal role, spatially resolving and chemically identifying each individual stacking layer remains challenging due to spatially localized features that complicate characterizations limiting understanding of the physics of MTJs. Here, we combine advanced electron microscopy, spectroscopy, and first-principles calculations to obtain a direct structural and chemical imaging of the atomically confined layers in a CoFeB-MgO MTJ, and clarify atom diffusion and interface structures in the MTJ following annealing. The combined techniques demonstrate that B diffuses out of CoFeB electrodes into Ta interstitial sites rather than MgO after annealing, and CoFe bonds atomically to MgO grains with an epitaxial orientation relationship by forming Fe(Co)-O bonds, yet without incorporation of CoFe in MgO. These findings afford a comprehensive perspective on structure and chemistry of MTJs, helping to develop high-performance spintronic devices by atomistic design.
Collapse
Affiliation(s)
- Zhongchang Wang
- WPI Advanced Institute for Materials Research, Tohoku University , 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
| | - Mitsuhiro Saito
- WPI Advanced Institute for Materials Research, Tohoku University , 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
- Institute of Engineering Innovation, University of Tokyo , 2-11-16, Yayoi, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Keith P McKenna
- WPI Advanced Institute for Materials Research, Tohoku University , 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
- Department of Physics, University of York , Heslington, York YO10 5DD, United Kingdom
| | - Shunsuke Fukami
- Center for Spintronics Integrated Systems, Tohoku University , 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
- Center for Innovative Integrated Electronic Systems, Tohoku University , 468-1 Aramaki, Aza, Aoba-ku, Sendai 980-8577, Japan
| | - Hideo Sato
- Center for Spintronics Integrated Systems, Tohoku University , 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
- Center for Innovative Integrated Electronic Systems, Tohoku University , 468-1 Aramaki, Aza, Aoba-ku, Sendai 980-8577, Japan
| | - Shoji Ikeda
- Center for Spintronics Integrated Systems, Tohoku University , 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
- Center for Innovative Integrated Electronic Systems, Tohoku University , 468-1 Aramaki, Aza, Aoba-ku, Sendai 980-8577, Japan
- Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University , 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
| | - Hideo Ohno
- WPI Advanced Institute for Materials Research, Tohoku University , 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
- Center for Spintronics Integrated Systems, Tohoku University , 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
- Center for Innovative Integrated Electronic Systems, Tohoku University , 468-1 Aramaki, Aza, Aoba-ku, Sendai 980-8577, Japan
- Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University , 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
| | - Yuichi Ikuhara
- WPI Advanced Institute for Materials Research, Tohoku University , 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
- Institute of Engineering Innovation, University of Tokyo , 2-11-16, Yayoi, Bunkyo-ku, Tokyo 113-8656, Japan
- Nanostructures Research Laboratory, Japan Fine Ceramics Center , 2-4-1 Mutsuno, Atsuta, Nagoya 456-8587, Japan
| |
Collapse
|
74
|
Brief history of the Cambridge STEM aberration correction project and its progeny. Ultramicroscopy 2015; 157:88-90. [DOI: 10.1016/j.ultramic.2015.06.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2015] [Revised: 06/03/2015] [Accepted: 06/05/2015] [Indexed: 11/23/2022]
|
75
|
Lobato I, Van Dyck D. MULTEM: A new multislice program to perform accurate and fast electron diffraction and imaging simulations using Graphics Processing Units with CUDA. Ultramicroscopy 2015; 156:9-17. [DOI: 10.1016/j.ultramic.2015.04.016] [Citation(s) in RCA: 85] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Revised: 04/21/2015] [Accepted: 04/26/2015] [Indexed: 11/17/2022]
|
76
|
Daio T, Staykov A, Guo L, Liu J, Tanaka M, Lyth SM, Sasaki K. Lattice Strain Mapping of Platinum Nanoparticles on Carbon and SnO2 Supports. Sci Rep 2015; 5:13126. [PMID: 26283473 PMCID: PMC4539540 DOI: 10.1038/srep13126] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Accepted: 07/20/2015] [Indexed: 12/02/2022] Open
Abstract
It is extremely important to understand the properties of supported metal nanoparticles at the atomic scale. In particular, visualizing the interaction between nanoparticle and support, as well as the strain distribution within the particle is highly desirable. Lattice strain can affect catalytic activity, and therefore strain engineering via e.g. synthesis of core-shell nanoparticles or compositional segregation has been intensively studied. However, substrate-induced lattice strain has yet to be visualized directly. In this study, platinum nanoparticles decorated on graphitized carbon or tin oxide supports are investigated using spherical aberration-corrected scanning transmission electron microscopy (Cs-corrected STEM) coupled with geometric phase analysis (GPA). Local changes in lattice parameter are observed within the Pt nanoparticles and the strain distribution is mapped. This reveals that Pt nanoparticles on SnO2 are more highly strained than on carbon, especially in the region of atomic steps in the SnO2 lattice. These substrate-induced strain effects are also reproduced in density functional theory simulations, and related to catalytic oxygen reduction reaction activity. This study suggests that tailoring the catalytic activity of electrocatalyst nanoparticles via the strong metal-support interaction (SMSI) is possible. This technique also provides an experimental platform for improving our understanding of nanoparticles at the atomic scale.
Collapse
Affiliation(s)
- Takeshi Daio
- 1] International Research Center for Hydrogen Energy, Kyushu University, Fukuoka 819-0395, Japan [2] Next-Generation Fuel Cell Research Center (NEXT-FC), Kyushu University, Fukuoka 819-0395, Japan [3] Faculty of Engineering, Department of Hydrogen Energy Systems, Kyushu University, Fukuoka 819-0395, Japan
| | - Aleksandar Staykov
- International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University, Fukuoka 819-0395, Japan
| | - Limin Guo
- International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University, Fukuoka 819-0395, Japan
| | - Jianfeng Liu
- International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University, Fukuoka 819-0395, Japan
| | - Masaki Tanaka
- Faculty of Engineering, Department of Materials Science and Engineering, Kyushu University, Fukuoka 819-0395, Japan
| | - Stephen Matthew Lyth
- International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University, Fukuoka 819-0395, Japan
| | - Kazunari Sasaki
- 1] International Research Center for Hydrogen Energy, Kyushu University, Fukuoka 819-0395, Japan [2] Next-Generation Fuel Cell Research Center (NEXT-FC), Kyushu University, Fukuoka 819-0395, Japan [3] Faculty of Engineering, Department of Hydrogen Energy Systems, Kyushu University, Fukuoka 819-0395, Japan [4] International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University, Fukuoka 819-0395, Japan
| |
Collapse
|
77
|
He D, Li Z, Yuan J. Kinematic HAADF-STEM image simulation of small nanoparticles. Micron 2015; 74:47-53. [DOI: 10.1016/j.micron.2015.04.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Revised: 04/13/2015] [Accepted: 04/13/2015] [Indexed: 11/28/2022]
|
78
|
Yang H, Lozano JG, Pennycook TJ, Jones L, Hirsch PB, Nellist PD. Imaging screw dislocations at atomic resolution by aberration-corrected electron optical sectioning. Nat Commun 2015; 6:7266. [PMID: 26041257 PMCID: PMC4468905 DOI: 10.1038/ncomms8266] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Accepted: 04/23/2015] [Indexed: 11/10/2022] Open
Abstract
Screw dislocations play an important role in materials' mechanical, electrical and optical properties. However, imaging the atomic displacements in screw dislocations remains challenging. Although advanced electron microscopy techniques have allowed atomic-scale characterization of edge dislocations from the conventional end-on view, for screw dislocations, the atoms are predominantly displaced parallel to the dislocation line, and therefore the screw displacements are parallel to the electron beam and become invisible when viewed end-on. Here we show that screw displacements can be imaged directly with the dislocation lying in a plane transverse to the electron beam by optical sectioning using annular dark field imaging in a scanning transmission electron microscope. Applying this technique to a mixed [a+c] dislocation in GaN allows direct imaging of a screw dissociation with a 1.65-nm dissociation distance, thereby demonstrating a new method for characterizing dislocation core structures.
Collapse
Affiliation(s)
- H Yang
- Department of Materials, University of Oxford, 16 Parks Road, Oxford OX1 3PH, UK
| | - J G Lozano
- Department of Materials, University of Oxford, 16 Parks Road, Oxford OX1 3PH, UK
| | - T J Pennycook
- Department of Materials, University of Oxford, 16 Parks Road, Oxford OX1 3PH, UK.,EPSRC SuperSTEM Facility, STFC Daresbury, WA4 4AD, UK
| | - L Jones
- Department of Materials, University of Oxford, 16 Parks Road, Oxford OX1 3PH, UK
| | - P B Hirsch
- Department of Materials, University of Oxford, 16 Parks Road, Oxford OX1 3PH, UK
| | - P D Nellist
- Department of Materials, University of Oxford, 16 Parks Road, Oxford OX1 3PH, UK.,EPSRC SuperSTEM Facility, STFC Daresbury, WA4 4AD, UK
| |
Collapse
|
79
|
Sun R, Wang Z, Saito M, Shibata N, Ikuhara Y. Atomistic mechanisms of nonstoichiometry-induced twin boundary structural transformation in titanium dioxide. Nat Commun 2015; 6:7120. [PMID: 25958793 PMCID: PMC4432645 DOI: 10.1038/ncomms8120] [Citation(s) in RCA: 77] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 04/02/2015] [Indexed: 11/20/2022] Open
Abstract
Grain boundary (GB) phase transformations often occur in polycrystalline materials while exposed to external stimuli and are universally implicated in substantially affecting their properties, yet atomic-scale knowledge on the transformation process is far from developed. In particular, whether GBs loaded with defects due to treatments can still be conventionally considered as disordered areas with kinetically trapped structure or turn ordered is debated. Here we combine advanced electron microscopy, spectroscopy and first-principles calculations to probe individual TiO2 GB subject to different atmosphere, and to demonstrate that stimulated structural defects can self-assemble at GB, forming an ordered structure, which results in GB nonstoichiometry and structural transformations at the atomic scale. Such structural transformation is accompanied with electronic transition at GB. The three-dimensional transformations afford new perspectives on the structural defects at GBs and on the development of strategies to manipulate practically significant GB transformations. Grain boundaries in polycrystalline materials strongly influence their mechanical properties. Here, the authors investigate polycrystalline TiO2 by high-resolution electron microscopy and observe that structural defects form ordered structures at grain boundaries influencing their properties.
Collapse
Affiliation(s)
- Rong Sun
- Institute of Engineering Innovation, The University of Tokyo, 2-11-16, Yayoi, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Zhongchang Wang
- Advanced Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
| | - Mitsuhiro Saito
- Advanced Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
| | - Naoya Shibata
- Institute of Engineering Innovation, The University of Tokyo, 2-11-16, Yayoi, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Yuichi Ikuhara
- 1] Institute of Engineering Innovation, The University of Tokyo, 2-11-16, Yayoi, Bunkyo-ku, Tokyo 113-8656, Japan [2] Advanced Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan [3] Nanostructures Research Laboratory, Japan Fine Ceramics Center, 2-4-1 Mutsuno, Atsuta, Nagoya 456-8587, Japan
| |
Collapse
|
80
|
KRIVANEK O, LOVEJOY T, DELLBY N. Aberration-corrected STEM for atomic-resolution imaging and analysis. J Microsc 2015; 259:165-72. [DOI: 10.1111/jmi.12254] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Accepted: 03/22/2015] [Indexed: 11/29/2022]
Affiliation(s)
- O.L. KRIVANEK
- Nion Co.; Kirkland Washington U.S.A
- Department of Physics; Arizona State University; Tempe Arizona U.S.A
| | | | | |
Collapse
|
81
|
The correction of electron lens aberrations. Ultramicroscopy 2015; 156:A1-64. [PMID: 26025209 DOI: 10.1016/j.ultramic.2015.03.007] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Revised: 03/07/2015] [Accepted: 03/12/2015] [Indexed: 11/23/2022]
Abstract
The progress of electron lens aberration correction from about 1990 onwards is chronicled. Reasonably complete lists of publications on this and related topics are appended. A present for Max Haider and Ondrej Krivanek in the year of their 65th birthdays. By a happy coincidence, this review was completed in the year that both Max Haider and Ondrej Krivanek reached the age of 65. It is a pleasure to dedicate it to the two leading actors in the saga of aberration corrector design and construction. They would both wish to associate their colleagues with such a tribute but it is the names of Haider and Krivanek (not forgetting Joachim Zach) that will remain in the annals of electron optics, next to that of Harald Rose. I am proud to know that both regard me as a friend as well as a colleague.
Collapse
|
82
|
Gu L, Xiao D, Hu YS, Li H, Ikuhara Y. Atomic-scale structure evolution in a quasi-equilibrated electrochemical process of electrode materials for rechargeable batteries. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2015; 27:2134-2149. [PMID: 25677246 DOI: 10.1002/adma.201404620] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Revised: 12/13/2014] [Indexed: 06/04/2023]
Abstract
Lithium-ion batteries have proven to be extremely attractive candidates for applications in portable electronics, electric vehicles, and smart grid in terms of energy density, power density, and service life. Further performance optimization to satisfy ever-increasing demands on energy storage of such applications is highly desired. In most of cases, the kinetics and stability of electrode materials are strongly correlated to the transport and storage behaviors of lithium ions in the lattice of the host. Therefore, information about structural evolution of electrode materials at an atomic scale is always helpful to explain the electrochemical performances of batteries at a macroscale. The annular-bright-field (ABF) imaging in aberration-corrected scanning transmission electron microscopy (STEM) allows simultaneous imaging of light and heavy elements, providing an unprecedented opportunity to probe the nearly equilibrated local structure of electrode materials after electrochemical cycling at atomic resolution. Recent progress toward unraveling the atomic-scale structure of selected electrode materials with different charge and/or discharge state to extend the current understanding of electrochemical reaction mechanism with the ABF and high angle annular dark field STEM imaging is presented here. Future research on the relationship between atomic-level structure evolution and microscopic reaction mechanisms of electrode materials for rechargeable batteries is envisaged.
Collapse
Affiliation(s)
- Lin Gu
- Institute of Physics, Chinese Academy of Sciences/Beijing National Laboratory for Condensed, Matter Physics, Beijing, 100190, P. R. China; Collaborative Innovation Center of Quantum Matter, Beijing, 100190, P. R. China
| | | | | | | | | |
Collapse
|
83
|
Sawada H, Shimura N, Hosokawa F, Shibata N, Ikuhara Y. Resolving 45-pm-separated Si–Si atomic columns with an aberration-corrected STEM. Microscopy (Oxf) 2015; 64:213-7. [DOI: 10.1093/jmicro/dfv014] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Accepted: 03/08/2015] [Indexed: 11/12/2022] Open
|
84
|
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]
|
85
|
Sun R, Wang Z, Shibata N, Ikuhara Y. A dislocation core in titanium dioxide and its electronic structure. RSC Adv 2015. [DOI: 10.1039/c4ra15278f] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
We provide a direct atomic-resolution imaging of the core structure of a dislocation in technologically important TiO2 and predict that every individual impurity-free dislocation exhibits electric conductivity in an otherwise insulating TiO2.
Collapse
Affiliation(s)
- Rong Sun
- Institute of Engineering Innovation
- The University of Tokyo
- Tokyo 113-8656
- Japan
| | - Zhongchang Wang
- Advanced Institute for Materials Research
- Tohoku University
- Sendai 980-8577
- Japan
| | - Naoya Shibata
- Institute of Engineering Innovation
- The University of Tokyo
- Tokyo 113-8656
- Japan
| | - Yuichi Ikuhara
- Institute of Engineering Innovation
- The University of Tokyo
- Tokyo 113-8656
- Japan
- Advanced Institute for Materials Research
| |
Collapse
|
86
|
Atomic scale dynamics of a solid state chemical reaction directly determined by annular dark-field electron microscopy. Sci Rep 2014; 4:7555. [PMID: 25532123 PMCID: PMC4273600 DOI: 10.1038/srep07555] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Accepted: 11/07/2014] [Indexed: 11/08/2022] Open
Abstract
Dynamic processes, such as solid-state chemical reactions and phase changes, are ubiquitous in materials science, and developing a capability to observe the mechanisms of such processes on the atomic scale can offer new insights across a wide range of materials systems. Aberration correction in scanning transmission electron microscopy (STEM) has enabled atomic resolution imaging at significantly reduced beam energies and electron doses. It has also made possible the quantitative determination of the composition and occupancy of atomic columns using the atomic number (Z)-contrast annular dark-field (ADF) imaging available in STEM. Here we combine these benefits to record the motions and quantitative changes in the occupancy of individual atomic columns during a solid-state chemical reaction in manganese oxides. These oxides are of great interest for energy-storage applications such as for electrode materials in pseudocapacitors. We employ rapid scanning in STEM to both drive and directly observe the atomic scale dynamics behind the transformation of Mn3O4 into MnO. The results demonstrate we now have the experimental capability to understand the complex atomic mechanisms involved in phase changes and solid state chemical reactions.
Collapse
|
87
|
Moody MP, Ceguerra AV, Breen AJ, Cui XY, Gault B, Stephenson LT, Marceau RKW, Powles RC, Ringer SP. Atomically resolved tomography to directly inform simulations for structure–property relationships. Nat Commun 2014; 5:5501. [DOI: 10.1038/ncomms6501] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Accepted: 10/08/2014] [Indexed: 11/09/2022] Open
|
88
|
Bao L, Zang J, Wang G, Li X. Atomic-scale imaging of cation ordering in inverse spinel Zn2SnO4 nanowires. NANO LETTERS 2014; 14:6505-6509. [PMID: 25300009 DOI: 10.1021/nl503077y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
By using high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) coupled with density functional theory (DFT) calculations, we demonstrate the atomic-level imaging of cation ordering in inverse spinel Zn2SnO4 nanowires. This cation ordering was identified as 1:1 ordering of Zn(2+) and Sn(4+) at the octahedral sites of the inverse spinel crystal with microscopic symmetry transition from original cubic Fd3̅m to orthorhombic Imma group. This ordering generated a 67.8% increase in the elastic modulus and 1-2 order of magnitude lower in the electric conductivity and electron mobility compared to their bulk counterpart.
Collapse
Affiliation(s)
- Lihong Bao
- Department of Mechanical Engineering, University of South Carolina , Columbia, South Carolina 29208, United States
| | | | | | | |
Collapse
|
89
|
Wang Z, Saito M, Chen C, Matsubara Y, Ueno K, Kawasaki M, Ikuhara Y. Full determination of individual reconstructed atomic columns in intermixed heterojunctions. NANO LETTERS 2014; 14:6584-6589. [PMID: 25351564 DOI: 10.1021/nl503212j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Heterojunctions offer a tremendous opportunity for fundamental as well as applied research, ranging from the unique electronic phases in between oxides to the contact issues in semiconductor devices. Despite their pivotal roles, determining individual building atom of matter in heterojunctions is still challenging, especially for those between highly dissimilar structures, in which breaking of symmetry, chemistry, and bonds may give rise to complex reconstruction and intermixing at the junction. Here, we combine electron microscopy, spectroscopy, and first-principles calculations to determine individual reconstructed atomic columns and their charge states in a complex, multicomponent heterojunction between the delafossite CuScO2 and spinel MgAl2O4. The high resolution enables us to demonstrate that the reconstructed region can accommodate a highly selective intermixing of Cu cations at specific Sc cation sites with half atomic density, forming a complex ordered superstructure. Such ability to resolve reconstructed heterojunctions to the atomic dimensions helps elucidate atomistic mechanisms and discover novel properties with applications in a diverse range of scientific disciplines.
Collapse
Affiliation(s)
- Zhongchang Wang
- Advanced Institute for Materials Research, Tohoku University , 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
| | | | | | | | | | | | | |
Collapse
|
90
|
Hsiao CN, Kuo SY, Lai FI, Chen WC. Interfacial atomic structure analysis at sub-angstrom resolution using aberration-corrected STEM. NANOSCALE RESEARCH LETTERS 2014; 9:578. [PMID: 25426003 PMCID: PMC4240948 DOI: 10.1186/1556-276x-9-578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Accepted: 10/08/2014] [Indexed: 06/04/2023]
Abstract
The atomic structure of a SiGe/Si epitaxial interface grown via molecular beam epitaxy on a single crystal silicon substrate was investigated using an aberration-corrected scanning transmittance electron microscope equipped with a high-angle annular dark-field detector and an energy-dispersive spectrometer. The accuracy required for compensation of the various residual aberration coefficients to achieve sub-angstrom resolution with the electron optics system was also evaluated. It was found that the interfacial layer was composed of a silicon single crystal, connected coherently to epitaxial SiGe nanolaminates. In addition, the distance between the dumbbell structures of the Si and Ge atoms was approximately 0.136 nm at the SiGe/Si interface in the [110] orientation. The corresponding fast Fourier transform exhibited a sub-angstrom scale point resolution of 0.78 Å. Furthermore, the relative positions of the atoms in the chemical composition line scan signals could be directly interpreted from the corresponding incoherent high-angle annular dark-field image.
Collapse
Affiliation(s)
- Chien-Nan Hsiao
- Instrument Technology Research Center, National Applied Research Laboratories, Hsinchu 30076, Taiwan
| | - Shou-Yi Kuo
- Department of Electronic Engineering, Chang Gung University, Gueishan 33302, Taiwan
| | - Fang-I Lai
- Department of Photonics Engineering, Yuan Ze University, Taoyuan 32003, Taiwan
| | - Wei-Chun Chen
- Instrument Technology Research Center, National Applied Research Laboratories, Hsinchu 30076, Taiwan
| |
Collapse
|
91
|
Majert S, Kohl H. High-resolution STEM imaging with a quadrant detector--conditions for differential phase contrast microscopy in the weak phase object approximation. Ultramicroscopy 2014; 148:81-86. [PMID: 25461584 DOI: 10.1016/j.ultramic.2014.09.009] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Revised: 09/24/2014] [Accepted: 09/29/2014] [Indexed: 11/19/2022]
Abstract
Differential phase contrast is a contrast mechanism that can be utilized in the scanning transmission electron microscope (STEM) to determine the distribution of magnetic or electric fields. In practice, several different detector geometries can be used to obtain differential phase contrast. As recent high resolution differential phase contrast experiments with the STEM are focused on ring quadrant detectors, we evaluate the contrast transfer characteristics of different quadrant detector geometries, namely two ring quadrant detectors with different inner detector angles and a conventional quadrant detector, by calculating the corresponding phase gradient transfer functions. For an ideal microscope and a weak phase object, this can be done analytically. The calculated phase gradient transfer functions indicate that the barely illuminated ring quadrant detector setup used for imaging magnetic fields in the specimen reduces the resolution limit to about 2.5Å for an aberration corrected STEM. Our results show that the resolution can be drastically improved by using a conventional quadrant detector instead.
Collapse
Affiliation(s)
- S Majert
- Physikalisches Institut und Interdisziplinäres Centrum für Elektronenmikroskopie und Mikroanalyse (ICEM), Westfälische Wilhelms-Universität Münster, Wilhelm-Klemm-Straße 10, 48149 Münster, Germany
| | - H Kohl
- Physikalisches Institut und Interdisziplinäres Centrum für Elektronenmikroskopie und Mikroanalyse (ICEM), Westfälische Wilhelms-Universität Münster, Wilhelm-Klemm-Straße 10, 48149 Münster, Germany.
| |
Collapse
|
92
|
Lee Z, Rose H, Lehtinen O, Biskupek J, Kaiser U. Electron dose dependence of signal-to-noise ratio, atom contrast and resolution in transmission electron microscope images. Ultramicroscopy 2014; 145:3-12. [DOI: 10.1016/j.ultramic.2014.01.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Revised: 12/23/2013] [Accepted: 01/27/2014] [Indexed: 10/25/2022]
|
93
|
Li J, Lv S, Chen C, Huang S, Wang Z. Interfacial defect complex at the MgO/SrTiO3heterojunction and its electronic impact. RSC Adv 2014. [DOI: 10.1039/c4ra08961h] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
|
94
|
Lehtinen O, Tsai IL, Jalil R, Nair RR, Keinonen J, Kaiser U, Grigorieva IV. Non-invasive transmission electron microscopy of vacancy defects in graphene produced by ion irradiation. NANOSCALE 2014; 6:6569-6576. [PMID: 24802077 DOI: 10.1039/c4nr01918k] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Irradiation with high-energy ions has been widely suggested as a tool to engineer properties of graphene. Experiments show that it indeed has a strong effect on graphene's transport, magnetic and mechanical characteristics. However, to use ion irradiation as an engineering tool requires understanding of the type and detailed characteristics of the produced defects which is still lacking, as the use of high-resolution transmission microscopy (HRTEM)--the only technique allowing direct imaging of atomic-scale defects--often modifies or even creates defects during imaging, thus making it impossible to determine the intrinsic atomic structure. Here we show that encapsulating the studied graphene sample between two other (protective) graphene sheets allows non-invasive HRTEM imaging and reliable identification of atomic-scale defects. Using this simple technique, we demonstrate that proton irradiation of graphene produces reconstructed monovacancies, which explains the profound effect that such defects have on graphene's magnetic and transport properties. This finding resolves the existing uncertainty with regard to the effect of ion irradiation on the electronic structure of graphene.
Collapse
Affiliation(s)
- Ossi Lehtinen
- Central Facility for Electron Microscopy, Group of Electron Microscopy of Materials Science, University of Ulm, 89081 Ulm, Germany.
| | | | | | | | | | | | | |
Collapse
|
95
|
Large magnetoelectric coupling in magnetically short-range ordered Bi₅Ti₃FeO₁₅ film. Sci Rep 2014; 4:5255. [PMID: 24918357 PMCID: PMC4052738 DOI: 10.1038/srep05255] [Citation(s) in RCA: 128] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Accepted: 05/22/2014] [Indexed: 12/05/2022] Open
Abstract
Multiferroic materials, which offer the possibility of manipulating the magnetic state by an electric field or vice versa, are of great current interest. However, single-phase materials with such cross-coupling properties at room temperature exist rarely in nature; new design of nano-engineered thin films with a strong magneto-electric coupling is a fundamental challenge. Here we demonstrate a robust room-temperature magneto-electric coupling in a bismuth-layer-structured ferroelectric Bi5Ti3FeO15 with high ferroelectric Curie temperature of ~1000 K. Bi5Ti3FeO15 thin films grown by pulsed laser deposition are single-phase layered perovskit with nearly (00l)-orientation. Room-temperature multiferroic behavior is demonstrated by a large modulation in magneto-polarization and magneto-dielectric responses. Local structural characterizations by transmission electron microscopy and Mössbauer spectroscopy reveal the existence of Fe-rich nanodomains, which cause a short-range magnetic ordering at ~620 K. In Bi5Ti3FeO15 with a stable ferroelectric order, the spin canting of magnetic-ion-based nanodomains via the Dzyaloshinskii-Moriya interaction might yield a robust magneto-electric coupling of ~400 mV/Oe·cm even at room temperature.
Collapse
|
96
|
Oxley MP, Kapetanakis MD, Prange MP, Varela M, Pennycook SJ, Pantelides ST. Simulation of probe position-dependent electron energy-loss fine structure. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2014; 20:784-797. [PMID: 24685384 DOI: 10.1017/s1431927614000610] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We present a theoretical framework for calculating probe-position-dependent electron energy-loss near-edge structure for the scanning transmission electron microscope by combining density functional theory with dynamical scattering theory. We show how simpler approaches to calculating near-edge structure fail to include the fundamental physics needed to understand the evolution of near-edge structure as a function of probe position and investigate the dependence of near-edge structure on probe size. It is within this framework that density functional theory should be presented, in order to ensure that variations of near-edge structure are truly due to local electronic structure and how much from the diffraction and focusing of the electron beam.
Collapse
Affiliation(s)
- Mark P Oxley
- 1Department of Physics and Astronomy,Vanderbilt University,Nashville,Tennessee 37235,USA
| | - Myron D Kapetanakis
- 1Department of Physics and Astronomy,Vanderbilt University,Nashville,Tennessee 37235,USA
| | - Micah P Prange
- 1Department of Physics and Astronomy,Vanderbilt University,Nashville,Tennessee 37235,USA
| | - Maria Varela
- 2Materials Science and Technology Division,Oak Ridge National Laboratory,Oak Ridge,Tennessee 37831,USA
| | - Stephen J Pennycook
- 2Materials Science and Technology Division,Oak Ridge National Laboratory,Oak Ridge,Tennessee 37831,USA
| | - Sokrates T Pantelides
- 1Department of Physics and Astronomy,Vanderbilt University,Nashville,Tennessee 37235,USA
| |
Collapse
|
97
|
de Jonge N. Introduction to special issue on electron microscopy of specimens in liquid. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2014; 20:315-316. [PMID: 24641962 DOI: 10.1017/s143192761400052x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Affiliation(s)
- Niels de Jonge
- Leibniz Institute for New Materials (INM), 66123 Saarbr̈cken, Germany
| |
Collapse
|
98
|
Ishikawa R, Lupini AR, Findlay SD, Taniguchi T, Pennycook SJ. Three-dimensional location of a single dopant with atomic precision by aberration-corrected scanning transmission electron microscopy. NANO LETTERS 2014; 14:1903-1908. [PMID: 24646109 DOI: 10.1021/nl500564b] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Materials properties, such as optical and electronic response, can be greatly enhanced by isolated single dopants. Determining the full three-dimensional single-dopant defect structure and spatial distribution is therefore critical to understanding and adequately tuning functional properties. Combining quantitative Z-contrast scanning transmission electron microscopy images with image simulations, we show the direct determination of the atomic-scale depth location of an optically active, single atom Ce dopant embedded within wurtzite-type AlN. The method represents a powerful new tool for reconstructing three-dimensional information from a single, two-dimensional image.
Collapse
Affiliation(s)
- Ryo Ishikawa
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | | | | | | | | |
Collapse
|
99
|
Chen C, Wang Z, Saito M, Tohei T, Takano Y, Ikuhara Y. Fluorine in Shark Teeth: Its Direct Atomic-Resolution Imaging and Strengthening Function. Angew Chem Int Ed Engl 2014; 53:1543-7. [DOI: 10.1002/anie.201307689] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2013] [Revised: 10/27/2013] [Indexed: 11/09/2022]
|
100
|
Chen C, Wang Z, Saito M, Tohei T, Takano Y, Ikuhara Y. Fluorine in Shark Teeth: Its Direct Atomic-Resolution Imaging and Strengthening Function. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201307689] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|