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Strobel KR, Schlegel M, Jain M, Kretschmer S, Krasheninnikov AV, Meyer JC. Temperature-dependence of beam-driven dynamics in graphene-fullerene sandwiches. Micron 2024; 184:103666. [PMID: 38850966 DOI: 10.1016/j.micron.2024.103666] [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: 03/28/2024] [Revised: 05/17/2024] [Accepted: 05/22/2024] [Indexed: 06/10/2024]
Abstract
C60 fullerenes encapsulated between graphene sheets were investigated by aberration-corrected high-resolution transmission electron microscopy at different temperatures, namely about 93 K, 293 K and 733 K, and by molecular dynamics simulations. We studied beam-induced dynamics of the C60 fullerenes and the encapsulating graphene, measured the critical doses for the initial damage to the fullerenes and followed the beam-induced polymerization. We find that, while the doses for the initial damage do not strongly depend on temperature, the clusters formed by the subsequent polymerization are more tubular at lower temperatures, while sheet-like structures are generated at higher temperatures. The experimental findings are supported by the results of first-principles and analytical potential molecular dynamics simulations. The merging of curved carbon sheets is clearly promoted at higher temperatures and proceeds at once over few-nm segments.
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Affiliation(s)
- Kevin R Strobel
- University of Tübingen, Institute of Applied Physics, Auf der Morgenstelle 10, Tübingen 72076, Germany; NMI Natural and Medical Sciences Institute at the University of Tübingen, Markwiesenstrasse 55, Reutlingen 72770, Germany.
| | - Michael Schlegel
- University of Tübingen, Institute of Applied Physics, Auf der Morgenstelle 10, Tübingen 72076, Germany; NMI Natural and Medical Sciences Institute at the University of Tübingen, Markwiesenstrasse 55, Reutlingen 72770, Germany
| | - Mitisha Jain
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Dresden 01328, Germany
| | - Silvan Kretschmer
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Dresden 01328, Germany
| | - Arkady V Krasheninnikov
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Dresden 01328, Germany
| | - Jannik C Meyer
- University of Tübingen, Institute of Applied Physics, Auf der Morgenstelle 10, Tübingen 72076, Germany; NMI Natural and Medical Sciences Institute at the University of Tübingen, Markwiesenstrasse 55, Reutlingen 72770, Germany.
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2
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Mücke D, Liang B, Wang Z, Qi H, Dong R, Feng X, Kaiser U. In-situ imaging of heat-induced phase transition in a two-dimensional conjugated metal-organic framework. Micron 2024; 184:103677. [PMID: 38878605 DOI: 10.1016/j.micron.2024.103677] [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: 04/19/2024] [Revised: 06/06/2024] [Accepted: 06/07/2024] [Indexed: 06/30/2024]
Abstract
Atomically-resolved in-situ high-resolution transmission electron microscopy (HRTEM) imaging of the structural dynamics in organic materials remains a major challenge. This difficulty persists even with aberration-corrected instruments, as HRTEM images necessitate a high electron dose that is generally intolerable for organic materials. In this study, we report the in-situ HRTEM imaging of heat-induced structural dynamics in a benzenehexathiol-based two-dimensional conjugated metal-organic framework (2D c-MOF, i.e., Cu3(BHT)). Leveraging its hydrogen-free structure and high electrical conductivity, Cu3(BHT) exhibits high electron beam resistance. We demonstrate atomic resolution imaging at an 80 kV electron accelerating voltage using our Cc/Cs-corrected SALVE instrument. However, continuous electron irradiation eventually leads to its amorphization. Intriguingly, under heating in a MEMS holder, the Cu3(BHT) undergoes a phase transition to a new crystalline phase and its phase transition, occurring within the temperature range of 480 °C to 620 °C in dependence on the electron beam illumination. Using HRTEM and energy-dispersive X-ray mapping, we identify this new phase as CuS. Our findings provide insights into the mechanisms governing structural transitions in purposefully engineered structures, potentially pivotal for future endeavours involving the production of metal oxide/sulfide nanoparticles from MOF precursors.
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Affiliation(s)
- David Mücke
- Central Facility for Materials Science Electron Microscopy, Universität Ulm, Ulm 89081, Germany; Institute for Quantum Optics, Universität Ulm, Ulm 89081, Germany.
| | - Baokun Liang
- Central Facility for Materials Science Electron Microscopy, Universität Ulm, Ulm 89081, Germany
| | - Zhiyong Wang
- Faculty of Chemistry and Food Chemistry & Center for Advancing Electronics Dresden (cfaed), Technische Universität Dresden, Dresden 01062, Germany; Max Planck Institute of Microstructure Physics, Halle (Saale) 06120, Germany.
| | - Haoyuan Qi
- Central Facility for Materials Science Electron Microscopy, Universität Ulm, Ulm 89081, Germany
| | - Renhao Dong
- Faculty of Chemistry and Food Chemistry & Center for Advancing Electronics Dresden (cfaed), Technische Universität Dresden, Dresden 01062, Germany; Key Laboratory of Colloid and Interface Chemistry of the Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China
| | - Xinliang Feng
- Faculty of Chemistry and Food Chemistry & Center for Advancing Electronics Dresden (cfaed), Technische Universität Dresden, Dresden 01062, Germany; Max Planck Institute of Microstructure Physics, Halle (Saale) 06120, Germany
| | - Ute Kaiser
- Central Facility for Materials Science Electron Microscopy, Universität Ulm, Ulm 89081, Germany; Institute for Quantum Optics, Universität Ulm, Ulm 89081, Germany.
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3
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Denninger P, Schweizer P, Spiecker E. Characterization of extended defects in 2D materials using aperture-based dark-field STEM in SEM. Micron 2024; 186:103703. [PMID: 39163748 DOI: 10.1016/j.micron.2024.103703] [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: 05/11/2024] [Revised: 07/24/2024] [Accepted: 08/04/2024] [Indexed: 08/22/2024]
Abstract
Quantitative diffraction contrast analysis with defined diffraction vectors is a well-established method in TEM for studying defects in crystalline materials. A comparable transmission technique is however not available in the more widely used SEM platforms. In this work, we transfer the aperture-based dark-field imaging method from the TEM to the SEM, thus enabling quantitative diffraction contrast studies at lower voltages in SEM. This is achieved in STEM mode by inserting a custom-made aperture between the sample and the STEM detector and centering the hole on a desired reflection. To select individual reflections for dark-field imaging, we use our Low Energy Nanodiffraction (LEND) setup [Schweizer et al., Ultramicroscopy 213, 112956 (2020)], which captures transmission diffraction patterns from a fluorescent screen positioned below the sample. The aperture-based dark-field STEM method is particularly useful for studying extended defects in 2D materials, where (i) stronger diffraction at the lower voltages used in SEM is advantageous, but (ii) two-beam conditions cannot be established, making quantitative diffraction contrast analysis with standard bright-field and annular dark-field detectors impossible. We demonstrate the method by studying basal plane dislocations in bilayer graphene, which have attracted considerable research interest due to their exceptional structural and electronic properties. Direct comparison of results obtained on identical dislocations by the established TEM method and by the new aperture-based dark-field STEM method in SEM shows that a reliable Burgers vector analysis is possible by applying the well-known g·b=0 invisibility criterion. We further use the LEND setup to acquire 4D-STEM data and show that the virtual dark-field images match well with those in aperture-based dark-field STEM images for reliable Burgers vector analysis.
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Affiliation(s)
- Peter Denninger
- Institute of Micro, and Nanostructure Research (IMN) & Center for Nanoanalysis and Electron Microscopy (CENEM), Interdisciplinary Center for Nanostructured Films (IZNF), Friedrich-Alexander-Universität Erlangen-Nürnberg, Cauerstrasse 3, Erlangen 91058, Germany
| | - Peter Schweizer
- Institute of Micro, and Nanostructure Research (IMN) & Center for Nanoanalysis and Electron Microscopy (CENEM), Interdisciplinary Center for Nanostructured Films (IZNF), Friedrich-Alexander-Universität Erlangen-Nürnberg, Cauerstrasse 3, Erlangen 91058, Germany
| | - Erdmann Spiecker
- Institute of Micro, and Nanostructure Research (IMN) & Center for Nanoanalysis and Electron Microscopy (CENEM), Interdisciplinary Center for Nanostructured Films (IZNF), Friedrich-Alexander-Universität Erlangen-Nürnberg, Cauerstrasse 3, Erlangen 91058, Germany.
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4
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Banhart F. The Formation and Transformation of Low-Dimensional Carbon Nanomaterials by Electron Irradiation. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024:e2310462. [PMID: 38700071 DOI: 10.1002/smll.202310462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 04/19/2024] [Indexed: 05/05/2024]
Abstract
Low-dimensional materials based on graphene or graphite show a large variety of phenomena when they are subjected to irradiation with energetic electrons. Since the 1990s, electron microscopy studies, where a certain irradiation dose is unavoidable, have witnessed unexpected structural transformations of graphitic nanoparticles. It is recognized that electron irradiation is not only detrimental but also bears considerable potential in the formation of new graphitic structures. With the availability of aberration-corrected electron microscopes and the discovery of techniques to produce monolayers of graphene, detailed insight into the atomic processes occurring during electron irradiation became possible. Threshold energies for atom displacements are determined and models of different types of lattice vacancies are confirmed experimentally. However, experimental evidence for the configuration of interstitial atoms in graphite or adatoms on graphene remained indirect, and the understanding of defect dynamics still depends on theoretical concepts. This article reviews irradiation phenomena in graphene- or graphite-based nanomaterials from the scale of single atoms to tens of nanometers. Observations from the 1990s can now be explained on the basis of new results. The evolution of the understanding during three decades of research is presented, and the remaining problems are pointed out.
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Affiliation(s)
- Florian Banhart
- Institut de Physique et Chimie des Matériaux, UMR 7504, Université de Strasbourg, CNRS, Strasbourg, 67034, France
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5
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Mücke D, Cooley I, Liang B, Wang Z, Park S, Dong R, Feng X, Qi H, Besley E, Kaiser U. Understanding the Electron Beam Resilience of Two-Dimensional Conjugated Metal-Organic Frameworks. NANO LETTERS 2024; 24:3014-3020. [PMID: 38427697 PMCID: PMC10941249 DOI: 10.1021/acs.nanolett.3c04125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 02/26/2024] [Accepted: 02/27/2024] [Indexed: 03/03/2024]
Abstract
Knowledge of the atomic structure of layer-stacked two-dimensional conjugated metal-organic frameworks (2D c-MOFs) is an essential prerequisite for establishing their structure-property correlation. For this, atomic resolution imaging is often the method of choice. In this paper, we gain a better understanding of the main properties contributing to the electron beam resilience and the achievable resolution in the high-resolution TEM images of 2D c-MOFs, which include chemical composition, density, and conductivity of the c-MOF structures. As a result, sub-angstrom resolution of 0.95 Å has been achieved for the most stable 2D c-MOF of the considered structures, Cu3(BHT) (BHT = benzenehexathiol), at an accelerating voltage of 80 kV in a spherical and chromatic aberration-corrected TEM. Complex damage mechanisms induced in Cu3(BHT) by the elastic interactions with the e-beam have been explained using detailed ab initio molecular dynamics calculations. Experimental and calculated knock-on damage thresholds are in good agreement.
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Affiliation(s)
- David Mücke
- Central
Facility for Materials Science Electron Microscopy, Universität Ulm, 89081 Ulm, Germany
| | - Isabel Cooley
- School
of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
| | - Baokun Liang
- Central
Facility for Materials Science Electron Microscopy, Universität Ulm, 89081 Ulm, Germany
| | - Zhiyong Wang
- Max
Planck Institute of Microstructure Physics, 06120 Halle (Saale), Germany
- Faculty
of Chemistry and Food Chemistry & Center for Advancing Electronics
Dresden, Technische Universität Dresden, 01062 Dresden, Germany
| | - SangWook Park
- Faculty
of Chemistry and Food Chemistry & Center for Advancing Electronics
Dresden, Technische Universität Dresden, 01062 Dresden, Germany
| | - Renhao Dong
- Faculty
of Chemistry and Food Chemistry & Center for Advancing Electronics
Dresden, Technische Universität Dresden, 01062 Dresden, Germany
- Key
Laboratory of Colloid and Interface Chemistry of the Ministry of Education,
School of Chemistry and Chemical Engineering, Shandong University, 250100 Jinan, China
| | - Xinliang Feng
- Max
Planck Institute of Microstructure Physics, 06120 Halle (Saale), Germany
- Faculty
of Chemistry and Food Chemistry & Center for Advancing Electronics
Dresden, Technische Universität Dresden, 01062 Dresden, Germany
| | - Haoyuan Qi
- Central
Facility for Materials Science Electron Microscopy, Universität Ulm, 89081 Ulm, Germany
- Faculty
of Chemistry and Food Chemistry & Center for Advancing Electronics
Dresden, Technische Universität Dresden, 01062 Dresden, Germany
| | - Elena Besley
- School
of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
| | - Ute Kaiser
- Central
Facility for Materials Science Electron Microscopy, Universität Ulm, 89081 Ulm, Germany
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6
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Whelan PR, De Fazio D, Pasternak I, Thomsen JD, Zelzer S, Mikkelsen MO, Booth TJ, Diekhöner L, Sassi U, Johnstone D, Midgley PA, Strupinski W, Jepsen PU, Ferrari AC, Bøggild P. Mapping nanoscale carrier confinement in polycrystalline graphene by terahertz spectroscopy. Sci Rep 2024; 14:3163. [PMID: 38326379 PMCID: PMC10850153 DOI: 10.1038/s41598-024-51548-z] [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: 08/15/2023] [Accepted: 01/06/2024] [Indexed: 02/09/2024] Open
Abstract
Terahertz time-domain spectroscopy (THz-TDS) can be used to map spatial variations in electrical properties such as sheet conductivity, carrier density, and carrier mobility in graphene. Here, we consider wafer-scale graphene grown on germanium by chemical vapor deposition with non-uniformities and small domains due to reconstructions of the substrate during growth. The THz conductivity spectrum matches the predictions of the phenomenological Drude-Smith model for conductors with non-isotropic scattering caused by backscattering from boundaries and line defects. We compare the charge carrier mean free path determined by THz-TDS with the average defect distance assessed by Raman spectroscopy, and the grain boundary dimensions as determined by transmission electron microscopy. The results indicate that even small angle orientation variations below 5° within graphene grains influence the scattering behavior, consistent with significant backscattering contributions from grain boundaries.
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Affiliation(s)
- Patrick R Whelan
- DTU Physics, Technical University of Denmark, Fysikvej, Bld. 309, 2800, Kongens Lyngby, Denmark
- Department of Materials and Production, Aalborg University, Skjernvej 4A, 9220, Aalborg, Denmark
| | - Domenico De Fazio
- Cambridge Graphene Centre, University of Cambridge, 9 JJ Thomson Avenue, Cambridge, CB3 0FA, UK
- Department of Molecular Sciences and Nanosystems, Ca' Foscari University of Venice, 30172, Venice, Italy
| | - Iwona Pasternak
- Faculty of Physics, Warsaw University of Technology, Koszykowa 75, 00-662, Warsaw, Poland
- Vigo System S.A., 129/133 Poznanska Str, 05-850, Ozarow Mazowiecki, Poland
| | - Joachim D Thomsen
- DTU Physics, Technical University of Denmark, Fysikvej, Bld. 309, 2800, Kongens Lyngby, Denmark
| | - Steffen Zelzer
- Department of Materials and Production, Aalborg University, Skjernvej 4A, 9220, Aalborg, Denmark
| | - Martin O Mikkelsen
- Department of Materials and Production, Aalborg University, Skjernvej 4A, 9220, Aalborg, Denmark
| | - Timothy J Booth
- DTU Physics, Technical University of Denmark, Fysikvej, Bld. 309, 2800, Kongens Lyngby, Denmark
- Center for Nanostructured Graphene (CNG), Technical University of Denmark, Ørsteds Plads 345C, 2800, Kongens Lyngby, Denmark
| | - Lars Diekhöner
- Department of Materials and Production, Aalborg University, Skjernvej 4A, 9220, Aalborg, Denmark
| | - Ugo Sassi
- Cambridge Graphene Centre, University of Cambridge, 9 JJ Thomson Avenue, Cambridge, CB3 0FA, UK
| | - Duncan Johnstone
- Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge, CB3 0FS, UK
| | - Paul A Midgley
- Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge, CB3 0FS, UK
| | - Wlodek Strupinski
- Faculty of Physics, Warsaw University of Technology, Koszykowa 75, 00-662, Warsaw, Poland
- Vigo System S.A., 129/133 Poznanska Str, 05-850, Ozarow Mazowiecki, Poland
| | - Peter U Jepsen
- Center for Nanostructured Graphene (CNG), Technical University of Denmark, Ørsteds Plads 345C, 2800, Kongens Lyngby, Denmark
- DTU Fotonik, Technical University of Denmark, Ørsteds Plads 343, 2800, Kongens Lyngby, Denmark
| | - Andrea C Ferrari
- Cambridge Graphene Centre, University of Cambridge, 9 JJ Thomson Avenue, Cambridge, CB3 0FA, UK
| | - Peter Bøggild
- DTU Physics, Technical University of Denmark, Fysikvej, Bld. 309, 2800, Kongens Lyngby, Denmark.
- Center for Nanostructured Graphene (CNG), Technical University of Denmark, Ørsteds Plads 345C, 2800, Kongens Lyngby, Denmark.
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7
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Liu Q, Lin YC, Kretschmer S, Ghorbani-Asl M, Solís-Fernández P, Siao MD, Chiu PW, Ago H, Krasheninnikov AV, Suenaga K. Molybdenum Chloride Nanostructures with Giant Lattice Distortions Intercalated into Bilayer Graphene. ACS NANO 2023. [PMID: 38007700 DOI: 10.1021/acsnano.3c06958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2023]
Abstract
The nanospace of the van der Waals (vdW) gap between structural units of two-dimensional (2D) materials serves as a platform for growing unusual 2D systems through intercalation and studying their properties. Various kinds of metal chlorides have previously been intercalated for tuning the properties of host layered materials, but the atomic structure of the intercalants remains still unidentified. In this study, we investigate the atomic structural transformation of molybdenum(V) chloride (MoCl5) after intercalation into bilayer graphene (BLG). Using scanning transmission electron microscopy, we found that the intercalated material represents MoCl3 networks, MoCl2 chains, and Mo5Cl10 rings. Giant lattice distortions and frequent structural transitions occur in the 2D MoClx that have never been observed in metal chloride systems. The trend of symmetric to nonsymmetric structural transformations can cause additional charge transfer from BLG to the intercalated MoClx, as suggested by our density functional theory calculations. Our study deepens the understanding of the behavior of matter in the confined space of the vdW gap in BLG and provides hints at a more efficient tuning of material properties by intercalation for potential applications, including transparent conductive films, optoelectronics, and energy storage.
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Affiliation(s)
- Qiunan Liu
- The Institute of Scientific and Industrial Research (ISIR-SANKEN), Osaka University, Osaka 567-0047, Japan
| | - Yung-Chang Lin
- The Institute of Scientific and Industrial Research (ISIR-SANKEN), Osaka University, Osaka 567-0047, Japan
- Nanomaterials Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba 305-8565, Japan
| | - Silvan Kretschmer
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
| | - Mahdi Ghorbani-Asl
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
| | | | - Ming-Deng Siao
- Department of Electrical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Po-Wen Chiu
- Department of Electrical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
| | - Hiroki Ago
- Global Innovation Center (GIC), Kyushu University, Fukuoka 816-8580, Japan
- Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Fukuoka 816-8580, Japan
| | - Arkady V Krasheninnikov
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
- Department of Applied Physics, Aalto University, P.O. Box 11100, 00076 Aalto, Finland
| | - Kazu Suenaga
- The Institute of Scientific and Industrial Research (ISIR-SANKEN), Osaka University, Osaka 567-0047, Japan
- Nanomaterials Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba 305-8565, Japan
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8
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Ederer M, Löffler S. Optimizing experimental parameters for orbital mapping. Ultramicroscopy 2023; 256:113866. [PMID: 37866278 DOI: 10.1016/j.ultramic.2023.113866] [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: 05/25/2023] [Revised: 09/29/2023] [Accepted: 10/08/2023] [Indexed: 10/24/2023]
Abstract
A new material characterization technique is emerging for the transmission electron microscope (TEM). Using electron energy-loss spectroscopy, real space mappings of the underlying electronic transitions in the sample, so called orbital maps, can be produced. Thus, unprecedented insight into the electronic orbitals responsible for most of the electrical, magnetic and optical properties of bulk materials can be gained. However, the incredibly demanding requirements on spatial as well as spectral resolution paired with the low signal-to-noise ratio severely limits the day-to-day use of this new technique. With the use of simulations, we strive to alleviate these challenges as much as possible by identifying optimal experimental parameters. In this manner, we investigate representative examples of a transition metal oxide, a material consisting entirely of light elements, and an interface between two different materials to find and compare acceptable ranges for sample thickness, acceleration voltage and electron dose for a scanning probe as well as for parallel illumination.
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Affiliation(s)
- Manuel Ederer
- University Service Centre for Transmission Electron Microscopy, TU Wien, Wiedner Hauptstraße 8-10/E057-02, 1040 Wien, Austria.
| | - Stefan Löffler
- University Service Centre for Transmission Electron Microscopy, TU Wien, Wiedner Hauptstraße 8-10/E057-02, 1040 Wien, Austria
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9
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Bui TA, Leuthner GT, Madsen J, Monazam MRA, Chirita AI, Postl A, Mangler C, Kotakoski J, Susi T. Creation of Single Vacancies in hBN with Electron Irradiation. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2301926. [PMID: 37259696 DOI: 10.1002/smll.202301926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 05/16/2023] [Indexed: 06/02/2023]
Abstract
Understanding electron irradiation effects is vital not only for reliable transmission electron microscopy characterization, but increasingly also for the controlled manipulation of 2D materials. The displacement cross sections of monolayer hexagonal boron nitride (hBN) are measured using aberration-corrected scanning transmission electron microscopy in near ultra-high vacuum at primary beam energies between 50 and 90 keV. Damage rates below 80 keV are up to three orders of magnitude lower than previously measured at edges under poorer residual vacuum conditions, where chemical etching appears to dominate. Notably, it is possible to create single vacancies in hBN using electron irradiation, with boron almost twice as likely as nitrogen to be ejected below 80 keV. Moreover, any damage at such low energies cannot be explained by elastic knock-on, even when accounting for the vibrations of the atoms. A theoretical description is developed to account for the lowering of the displacement threshold due to valence ionization resulting from inelastic scattering of probe electrons, modeled using charge-constrained density functional theory molecular dynamics. Although significant reductions are found depending on the constrained charge, quantitative predictions for realistic ionization states are currently not possible. Nonetheless, there is potential for defect-engineering of hBN at the level of single vacancies using electron irradiation.
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Affiliation(s)
- Thuy An Bui
- University of Vienna, Faculty of Physics, Boltzmanngasse 5, Vienna, 1090, Austria
| | - Gregor T Leuthner
- University of Vienna, Faculty of Physics, Boltzmanngasse 5, Vienna, 1090, Austria
| | - Jacob Madsen
- University of Vienna, Faculty of Physics, Boltzmanngasse 5, Vienna, 1090, Austria
| | - Mohammad R A Monazam
- University of Vienna, Faculty of Physics, Boltzmanngasse 5, Vienna, 1090, Austria
| | - Alexandru I Chirita
- University of Vienna, Faculty of Physics, Boltzmanngasse 5, Vienna, 1090, Austria
| | - Andreas Postl
- University of Vienna, Faculty of Physics, Boltzmanngasse 5, Vienna, 1090, Austria
| | - Clemens Mangler
- University of Vienna, Faculty of Physics, Boltzmanngasse 5, Vienna, 1090, Austria
| | - Jani Kotakoski
- University of Vienna, Faculty of Physics, Boltzmanngasse 5, Vienna, 1090, Austria
| | - Toma Susi
- University of Vienna, Faculty of Physics, Boltzmanngasse 5, Vienna, 1090, Austria
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10
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Dyck O, Yeom S, Lupini AR, Swett JL, Hensley D, Yoon M, Jesse S. Top-Down Fabrication of Atomic Patterns in Twisted Bilayer Graphene. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2302906. [PMID: 37309684 DOI: 10.1002/adma.202302906] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 05/23/2023] [Indexed: 06/14/2023]
Abstract
Atomic-scale engineering typically involves bottom-up approaches, leveraging parameters such as temperature, partial pressures, and chemical affinity to promote spontaneous arrangement of atoms. These parameters are applied globally, resulting in atomic-scale features scattered probabilistically throughout the material. In a top-down approach, different regions of the material are exposed to different parameters, resulting in structural changes varying on the scale of the resolution. In this work, the application of global and local parameters is combined in an aberration-corrected scanning transmission electron microscope (STEM) to demonstrate atomic-scale precision patterning of atoms in twisted bilayer graphene. The focused electron beam is used to define attachment points for foreign atoms through the controlled ejection of carbon atoms from the graphene lattice. The sample environment is staged with nearby source materials such that the sample temperature can induce migration of the source atoms across the sample surface. Under these conditions, the electron-beam (top-down) enables carbon atoms in the graphene to be replaced spontaneously by diffusing adatoms (bottom-up). Using image-based feedback control, arbitrary patterns of atoms and atom clusters are attached to the twisted bilayer graphene with limited human interaction. The role of substrate temperature on adatom and vacancy diffusion is explored by first-principles simulations.
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Affiliation(s)
- Ondrej Dyck
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
| | - Sinchul Yeom
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
| | - Andrew R Lupini
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
| | - Jacob L Swett
- Biodesign Institute, Arizona State University, Tempe, AZ, 87287, USA
| | - Dale Hensley
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
| | - Mina Yoon
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
| | - Stephen Jesse
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
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11
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Ma H, Kang S, Lee S, Park G, Bae Y, Park G, Kim J, Li S, Baek H, Kim H, Yu JS, Lee H, Park J, Yang J. Moisture-Induced Degradation of Quantum-Sized Semiconductor Nanocrystals through Amorphous Intermediates. ACS NANO 2023. [PMID: 37399231 DOI: 10.1021/acsnano.3c03103] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/05/2023]
Abstract
Elucidating the water-induced degradation mechanism of quantum-sized semiconductor nanocrystals is an important prerequisite for their practical application because they are vulnerable to moisture compared to their bulk counterparts. In-situ liquid-phase transmission electron microscopy is a desired method for studying nanocrystal degradation, and it has recently gained technical advancement. Herein, the moisture-induced degradation of semiconductor nanocrystals is investigated using graphene double-liquid-layer cells that can control the initiation of reactions. Crystalline and noncrystalline domains of quantum-sized CdS nanorods are clearly distinguished during their decomposition with atomic-scale imaging capability of the developed liquid cells. The results reveal that the decomposition process is mediated by the involvement of the amorphous-phase formation, which is different from conventional nanocrystal etching. The reaction can proceed without the electron beam, suggesting that the amorphous-phase-mediated decomposition is induced by water. Our study discloses unexplored aspects of moisture-induced deformation pathways of semiconductor nanocrystals, involving amorphous intermediates.
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Affiliation(s)
- Hyeonjong Ma
- Department of Energy Science and Engineering, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Republic of Korea
| | - Sungsu Kang
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
- School of Chemical and Biological Engineering, and Institute of Chemical Processes, Seoul National University, Seoul 08826, Republic of Korea
| | - Seunghan Lee
- Department of Physics, Konkuk University, Seoul 05029, Korea
| | - Gisang Park
- Department of Energy Science and Engineering, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Republic of Korea
| | - Yuna Bae
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
- School of Chemical and Biological Engineering, and Institute of Chemical Processes, Seoul National University, Seoul 08826, Republic of Korea
| | - Gyuri Park
- Department of Energy Science and Engineering, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Republic of Korea
| | - Jihoon Kim
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
- School of Chemical and Biological Engineering, and Institute of Chemical Processes, Seoul National University, Seoul 08826, Republic of Korea
| | - Shi Li
- Department of Energy Science and Engineering, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Republic of Korea
| | - Hayeon Baek
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
- School of Chemical and Biological Engineering, and Institute of Chemical Processes, Seoul National University, Seoul 08826, Republic of Korea
| | - Hyeongseung Kim
- Department of Energy Science and Engineering, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Republic of Korea
| | - Jong-Sung Yu
- Department of Energy Science and Engineering, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Republic of Korea
- Energy Science and Engineering Research Center, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Republic of Korea
| | - Hoonkyung Lee
- Department of Physics, Konkuk University, Seoul 05029, Korea
| | - Jungwon Park
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
- School of Chemical and Biological Engineering, and Institute of Chemical Processes, Seoul National University, Seoul 08826, Republic of Korea
- Institute of Engineering Research, College of Engineering, Seoul National University, Seoul 08826, Republic of Korea
- Advanced Institute of Convergence Technology, Seoul National University, Suwon-si, Gyeonggi-do 16229, Republic of Korea
| | - Jiwoong Yang
- Department of Energy Science and Engineering, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Republic of Korea
- Energy Science and Engineering Research Center, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Republic of Korea
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12
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Jiang N. Electron irradiation effects in transmission electron microscopy: Random displacements and collective migrations. Micron 2023; 171:103482. [PMID: 37167653 DOI: 10.1016/j.micron.2023.103482] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 05/02/2023] [Accepted: 05/02/2023] [Indexed: 05/13/2023]
Abstract
Electron beam damage in transmission electron microscopy (TEM) is complicated because the damage phenomena can be the result of random atomic displacements or collective migrations. The former is categorized as the primary beam effects and the latter is the secondary beam effects. The mechanisms for these two distinguishing atomic processes of damage are different. The primary beam effects can be caused by the mechanisms of knock-on and/or radiolysis, while the secondary effects must be driven by a field that is induced by electron irradiation. One such field has been identified to be the electric field produced by the accumulated charges due to the ejection of secondary and Auger electrons from the irradiated region. One convincing example is the electron irradiation-induced domain switch in ferroelectric materials, in which the collective cation displacements are driven by the induced electric field. A detailed interpretation is given in this review. The sintering of metal NPs under electron irradiation is a secondary beam effect and is most likely also caused by the induced electric fields. The interactions between the charged NP and substrate, and between charged NPs, result in NP motion. Interchanging atoms between NPs during the sintering may also be driven by the electric fields. Although many beam-damage phenomena in C nanotubes and layered materials, such as graphene, BN, and transition metal dichalcogenides, are caused by the primary beam effects and have been well studied experimentally and theoretically in the literature, some phenomena from the secondary beam effects have also been identified in this review. These phenomena are sensitive to electron current density, the shape and orientation of the specimen, and even the illumination mode (i.e., TEM or STEM). Unfortunately, the mechanisms responsible for these phenomena still need to be clarified.
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Affiliation(s)
- Nan Jiang
- Department of Physics, Arizona State University, Tempe, AZ 85281-1504, USA.
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13
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Fung KLY, Skowron ST, Hayter R, Mason SE, Weare BL, Besley NA, Ramasse QM, Allen CS, Khlobystov AN. Direct measurement of single-molecule dynamics and reaction kinetics in confinement using time-resolved transmission electron microscopy. Phys Chem Chem Phys 2023; 25:9092-9103. [PMID: 36920796 DOI: 10.1039/d2cp05183d] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
We report experimental methodologies utilising transmission electron microscopy (TEM) as an imaging tool for reaction kinetics at the single molecule level, in direct space and with spatiotemporal continuity. Using reactions of perchlorocoronene (PCC) in nanotubes of different diameters and at different temperatures, we found a period of molecular movement to precede the intermolecular addition of PCC, with a stronger dependence of the reaction rate on the nanotube diameter, controlling the local environments around molecules, than on the reaction temperature (-175, 23 or 400 °C). Once initiated, polymerisation of PCC follows zero-order reaction kinetics with the observed reaction cross section σobs of 1.13 × 10-9 nm2 (11.3 ± 0.6 barn), determined directly from time-resolved TEM image series acquired with a rate of 100 frames per second. Polymerisation was shown to proceed from a single point, with molecules reacting sequentially, as in a domino effect, due to the strict conformational requirement of the Diels-Alder cycloaddition creating the bottleneck for the reaction. The reaction mechanism was corroborated by correlating structures of reaction intermediates observed in TEM images, with molecular weights measured by using mass spectrometry (MS) when the same reaction was triggered by UV irradiation. The approaches developed in this study bring the imaging of chemical reactions at the single-molecule level closer to traditional concepts of chemistry.
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Affiliation(s)
- Kayleigh L Y Fung
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
| | - Stephen T Skowron
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
| | - Ruth Hayter
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
| | - Stephen E Mason
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
| | - Benjamin L Weare
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
| | - Nicholas A Besley
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
| | - Quentin M Ramasse
- SuperSTEM Laboratory, SciTech Daresbury Campus, Keckwick Lane, Daresbury WA4 4AD, UK.,School of Chemical and Process Engineering and School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, UK
| | - Christopher S Allen
- Electron Physical Sciences Imaging Centre, Diamond Light Source Ltd., Oxfordshire OX11 0DE, UK.,Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, UK
| | - Andrei N Khlobystov
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
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14
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Storm A, Köster J, Ghorbani-Asl M, Kretschmer S, Gorelik TE, Kinyanjui MK, Krasheninnikov AV, Kaiser U. Electron-Beam- and Thermal-Annealing-Induced Structural Transformations in Few-Layer MnPS 3. ACS NANO 2023; 17:4250-4260. [PMID: 36802543 DOI: 10.1021/acsnano.2c05895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Quasi-two-dimensional (2D) manganese phosphorus trisulfide, MnPS3, which exhibits antiferromagnetic ordering, is a particularly interesting material in the context of magnetism in a system with reduced dimensionality and its potential technological applications. Here, we present an experimental and theoretical study on modifying the properties of freestanding MnPS3 by local structural transformations via electron irradiation in a transmission electron microscope and by thermal annealing under vacuum. In both cases we find that MnS1-xPx phases (0 ≤ x < 1) form in a crystal structure different from that of the host material, namely that of the α- or γ-MnS type. These phase transformations can both be locally controlled by the size of the electron beam as well as by the total applied electron dose and simultaneously imaged at the atomic scale. For the MnS structures generated in this process, our ab initio calculations indicate that their electronic and magnetic properties strongly depend on both in-plane crystallite orientation and thickness. Moreover, the electronic properties of the MnS phases can be further tuned by alloying with phosphorus. Therefore, our results show that electron beam irradiation and thermal annealing can be utilized to grow phases with distinct properties starting from freestanding quasi-2D MnPS3.
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Affiliation(s)
- Alexander Storm
- Electron Microscopy Group of Materials Science, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | - Janis Köster
- Electron Microscopy Group of Materials Science, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | - Mahdi Ghorbani-Asl
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Centre Dresden-Rossendorf, 01328 Dresden, Germany
| | - Silvan Kretschmer
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Centre Dresden-Rossendorf, 01328 Dresden, Germany
| | - Tatiana E Gorelik
- Electron Microscopy Group of Materials Science, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | - Michael Kiarie Kinyanjui
- Electron Microscopy Group of Materials Science, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | - Arkady V Krasheninnikov
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Centre Dresden-Rossendorf, 01328 Dresden, Germany
- Department of Applied Physics, Aalto University, PO Box 14100, 00076 Aalto, Finland
| | - Ute Kaiser
- Electron Microscopy Group of Materials Science, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
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15
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Bianco F, Corte E, Ditalia Tchernij S, Forneris J, Fabbri F. Engineering Multicolor Radiative Centers in hBN Flakes by Varying the Electron Beam Irradiation Parameters. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:739. [PMID: 36839108 PMCID: PMC9960900 DOI: 10.3390/nano13040739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 02/10/2023] [Accepted: 02/13/2023] [Indexed: 06/18/2023]
Abstract
Recently, hBN has become an interesting platform for quantum optics due to the peculiar defect-related luminescence properties. In this work, multicolor radiative emissions are engineered and tailored by position-controlled low-energy electron irradiation. Varying the irradiation parameters, such as the electron beam energy and/or area dose, we are able to induce light emissions at different wavelengths in the green-red range. In particular, the 10 keV and 20 keV irradiation levels induce the appearance of broad emission in the orange-red range (600-660 nm), while 15 keV gives rise to a sharp emission in the green range (535 nm). The cumulative dose density increase demonstrates the presence of a threshold value. The overcoming of the threshold, which is different for each electron beam energy level, causes the generation of non-radiative recombination pathways.
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Affiliation(s)
- Federica Bianco
- NEST Laboratory, Istituto Nanoscienze-CNR and Scuola Normale Superiore, Piazza San Silvestro 12, 56127 Pisa, Italy
| | - Emilio Corte
- Physics Department, University of Torino and Istituto Nazionale di Fisica Nucleare Sez. Torino, Via P. Giuria 11, 10125 Torino, Italy
| | - Sviatoslav Ditalia Tchernij
- Physics Department, University of Torino and Istituto Nazionale di Fisica Nucleare Sez. Torino, Via P. Giuria 11, 10125 Torino, Italy
| | - Jacopo Forneris
- Physics Department, University of Torino and Istituto Nazionale di Fisica Nucleare Sez. Torino, Via P. Giuria 11, 10125 Torino, Italy
| | - Filippo Fabbri
- NEST Laboratory, Istituto Nanoscienze-CNR and Scuola Normale Superiore, Piazza San Silvestro 12, 56127 Pisa, Italy
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16
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Yoshimura A, Lamparski M, Giedt J, Lingerfelt D, Jakowski J, Ganesh P, Yu T, Sumpter BG, Meunier V. Quantum theory of electronic excitation and sputtering by transmission electron microscopy. NANOSCALE 2023; 15:1053-1067. [PMID: 35703316 DOI: 10.1039/d2nr01018f] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Many computational models have been developed to predict the rates of atomic displacements in two-dimensional (2D) materials under electron beam irradiation. However, these models often drastically underestimate the displacement rates in 2D insulators, in which beam-induced electronic excitations can reduce the binding energies of the irradiated atoms. This bond softening leads to a qualitative disagreement between theory and experiment, in that substantial sputtering is experimentally observed at beam energies deemed far too small to drive atomic dislocation by many current models. To address these theoretical shortcomings, this paper develops a first-principles method to calculate the probability of beam-induced electronic excitations by coupling quantum electrodynamics (QED) scattering amplitudes to density functional theory (DFT) single-particle orbitals. The presented theory then explicitly considers the effect of these electronic excitations on the sputtering cross section. Applying this method to 2D hexagonal BN and MoS2 significantly increases their calculated sputtering cross sections and correctly yields appreciable sputtering rates at beam energies previously predicted to leave the crystals intact. The proposed QED-DFT approach can be easily extended to describe a rich variety of beam-driven phenomena in any crystalline material.
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Affiliation(s)
- Anthony Yoshimura
- Lawrence Livermore National Laboratory, Livermore, CA 94550, USA.
- Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
| | - Michael Lamparski
- Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
| | - Joel Giedt
- Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
| | - David Lingerfelt
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Jacek Jakowski
- Computational Sciences and Engineering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Panchapakesan Ganesh
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Tao Yu
- Department of Chemistry, University of North Dakota, Grand Forks, ND 58202, USA
| | - Bobby G Sumpter
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Vincent Meunier
- Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
- Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
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17
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Huang S, Villalobos LF, Li S, Vahdat MT, Chi HY, Hsu KJ, Bondaz L, Boureau V, Marzari N, Agrawal KV. In Situ Nucleation-Decoupled and Site-Specific Incorporation of Å-Scale Pores in Graphene Via Epoxidation. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2206627. [PMID: 36271513 DOI: 10.1002/adma.202206627] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 10/10/2022] [Indexed: 06/16/2023]
Abstract
Generating pores in graphene by decoupled nucleation and expansion is desired to achieve a fine control over the porosity, and is desired to advance several applications. Herein, epoxidation is introduced, which is the formation of nanosized epoxy clusters on the graphitic lattice as nucleation sites without forming pores. In situ gasification of clusters inside a transmission electron microscope shows that pores are generated precisely at the site of the clusters by surpassing an energy barrier of 1.3 eV. Binding energy predictions using ab initio calculations combined with the cluster nucleation theory reveal the structure of the epoxy clusters and indicate that the critical cluster is an epoxy dimer. Finally, it is shown that the cluster gasification can be manipulated to form Å-scale pores which then effectively sieve gas molecules based on their size. This decoupled cluster nucleation and pore formation will likely pave the way for an independent control of pore size and density.
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Affiliation(s)
- Shiqi Huang
- Laboratory of Advanced Separations (LAS), École Polytechnique Fédérale de Lausanne (EPFL), Sion, CH-1950, Switzerland
| | - Luis Francisco Villalobos
- Laboratory of Advanced Separations (LAS), École Polytechnique Fédérale de Lausanne (EPFL), Sion, CH-1950, Switzerland
| | - Shaoxian Li
- Laboratory of Advanced Separations (LAS), École Polytechnique Fédérale de Lausanne (EPFL), Sion, CH-1950, Switzerland
| | - Mohammad Tohidi Vahdat
- Laboratory of Advanced Separations (LAS), École Polytechnique Fédérale de Lausanne (EPFL), Sion, CH-1950, Switzerland
- Theory and Simulation of Materials (THEOS) and National Centre for Computational Design and Discovery of Novel Materials (MARVEL), EPFL, Lausanne, CH-1015, Switzerland
| | - Heng-Yu Chi
- Laboratory of Advanced Separations (LAS), École Polytechnique Fédérale de Lausanne (EPFL), Sion, CH-1950, Switzerland
| | - Kuang-Jung Hsu
- Laboratory of Advanced Separations (LAS), École Polytechnique Fédérale de Lausanne (EPFL), Sion, CH-1950, Switzerland
| | - Luc Bondaz
- Laboratory of Advanced Separations (LAS), École Polytechnique Fédérale de Lausanne (EPFL), Sion, CH-1950, Switzerland
| | - Victor Boureau
- Interdisciplinary Center for Electron Microscopy, EPFL, Lausanne, CH-1015, Switzerland
| | - Nicola Marzari
- Theory and Simulation of Materials (THEOS) and National Centre for Computational Design and Discovery of Novel Materials (MARVEL), EPFL, Lausanne, CH-1015, Switzerland
| | - Kumar Varoon Agrawal
- Laboratory of Advanced Separations (LAS), École Polytechnique Fédérale de Lausanne (EPFL), Sion, CH-1950, Switzerland
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18
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Wang H, Xu Z, Mao S, Granick S. Experimental Guidelines to Image Transient Single-Molecule Events Using Graphene Liquid Cell Electron Microscopy. ACS NANO 2022; 16:18526-18537. [PMID: 36256532 DOI: 10.1021/acsnano.2c06766] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
In quest of the holy grail to "see" how individual molecules interact in liquid environments, single-molecule imaging methods now include liquid-phase electron microscopy, whose resolution can be nanometers in space and several frames per second in time using an ordinary electron microscope that is routinely available to many researchers. However, with the current state of the art, protocols that sound similar to those described in the literature lead to outcomes that can differ. The key challenge is to achieve sample contrast under a safe electron dose within a frame rate adequate to capture the molecular process. Here, we present such examples from different systems─synthetic polymer, lipid assembly, DNA-enzyme─in which we have done this using graphene liquid cells. We describe detailed experimental procedures and share empirical experience for conducting successful experiments, starting from fabrication of a graphene liquid cell, to identification of high-quality liquid pockets from desirable shapes and sizes, to effective searching for target sample pockets under electron microscopy, and to discrimination of sample molecules and molecular processes of interest. These experimental tips can assist others who wish to make use of this method.
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Affiliation(s)
- Huan Wang
- College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, People's Republic of China
- Beijing National Laboratory for Molecular Sciences, Center for Spectroscopy, Beijing Key Laboratory of Polymer Chemistry & Physics of Ministry of Education, Center for Soft Matter Science and Engineering, National Biomedical Imaging Center, Peking University, Beijing 100871, People's Republic of China
| | - Zhun Xu
- College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, People's Republic of China
| | - Sheng Mao
- Department of Mechanics and Engineering Sciences, College of Engineering, Peking University, Beijing 100871, People's Republic of China
| | - Steve Granick
- Center for Soft and Living Matter, Institute for Basic Science, Ulsan, Korea, 44919
- Department of Chemistry and Physics, Ulsan National Institute of Science and Technology, Ulsan, Korea 44919
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19
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Villalobos LF, Babu DJ, Hsu KJ, Van Goethem C, Agrawal KV. Gas Separation Membranes with Atom-Thick Nanopores: The Potential of Nanoporous Single-Layer Graphene. ACCOUNTS OF MATERIALS RESEARCH 2022; 3:1073-1087. [PMID: 36338295 PMCID: PMC9623591 DOI: 10.1021/accountsmr.2c00143] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 08/30/2022] [Indexed: 06/16/2023]
Abstract
Gas separation is one of the most important industrial processes and is poised to take a larger role in the transition to renewable energy, e.g., carbon capture and hydrogen purification. Conventional gas separation processes involving cryogenic distillation, solvents, and sorbents are energy intensive, and as a result, the energy footprint of gas separations in the chemical industry is extraordinarily high. This has motivated fundamental research toward the development of novel materials for high-performance membranes to improve the energy efficiency of gas separation. These novel materials are expected to overcome the intrinsic limitations of the conventional membrane material, i.e., polymers, where a longstanding trade-off between the separation selectivity and the permeance has motivated research into nanoporous materials as the selective layer for the membranes. In this context, atom-thick materials such as nanoporous single-layer graphene constitute the ultimate limit for the selective layer. Gas transport from atom-thick nanopores is extremely fast, dependent primarily on the energy barrier that the gas molecule experiences in translocating the nanopore. Consequently, the difference in the energy barriers for two gas molecules determines the gas pair selectivity. In this Account, we summarize the development in the field of nanoporous single-layer graphene membranes for gas separation. We start by discussing the mechanism for gas transport across atom-thick nanopores, which then yields the crucial design elements needed to achieve high-performance membranes: (i) nanopores with an adequate electron-density gap to sieve the desired gas component (e.g., smaller than 0.289, 0.33, 0.346, 0.362, and 0.38 nm for H2, CO2, O2, N2, and CH4, respectively), (ii) narrow pore size distribution to limit the nonselective effusive transport from the tail end of the distribution, and (iii) high density of selective pores. We discuss and compare the state-of-the-art bottom-up and top-down routes for the synthesis of nanoporous graphene films. Mechanistic insights and parameters controlling the size, distribution, and density of nanopores are discussed. Fundamental insights are provided into the reaction of ozone with graphene, which has been successfully used by our group to develop membranes with record-high carbon capture performance. Postsynthetic modifications, which allow the tuning of the transport by (i) tailoring the relative contributions of adsorbed-phase and gas-phase transport, (ii) competitive adsorption, and (iii) molecular cutoff adjustment, are discussed. Finally, we discuss practical aspects that are crucial in successfully preparing practical membranes using atom-thick materials as the selective layer, allowing the eventual scale-up of these membranes. Crack- and tear-free preparation of membranes is discussed using the approach of mechanical reinforcement of graphene with nanoporous carbon and polymers, which led to the first reports of millimeter- and centimeter-scale gas-sieving membranes in the year 2018 and 2021, respectively. We conclude with insights and perspectives highlighting the key scientific and technological gaps that must be addressed in the future research.
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Affiliation(s)
- Luis Francisco Villalobos
- Laboratory
of Advanced Separations, École Polytechnique
Fédérale de Lausanne, Sion 1950, Switzerland
| | - Deepu J. Babu
- Laboratory
of Advanced Separations, École Polytechnique
Fédérale de Lausanne, Sion 1950, Switzerland
- Department
of Materials Science and Metallurgical Engineering, Indian Institute of Technology, Hyderabad, Telangana 502 284, India
| | - Kuang-Jung Hsu
- Laboratory
of Advanced Separations, École Polytechnique
Fédérale de Lausanne, Sion 1950, Switzerland
| | - Cédric Van Goethem
- Laboratory
of Advanced Separations, École Polytechnique
Fédérale de Lausanne, Sion 1950, Switzerland
| | - Kumar Varoon Agrawal
- Laboratory
of Advanced Separations, École Polytechnique
Fédérale de Lausanne, Sion 1950, Switzerland
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20
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Roccapriore KM, Boebinger MG, Dyck O, Ghosh A, Unocic RR, Kalinin SV, Ziatdinov M. Probing Electron Beam Induced Transformations on a Single-Defect Level via Automated Scanning Transmission Electron Microscopy. ACS NANO 2022; 16:17116-17127. [PMID: 36206357 DOI: 10.1021/acsnano.2c07451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
A robust approach for real-time analysis of the scanning transmission electron microscopy (STEM) data streams, based on ensemble learning and iterative training (ELIT) of deep convolutional neural networks, is implemented on an operational microscope, enabling the exploration of the dynamics of specific atomic configurations under electron beam irradiation via an automated experiment in STEM. Combined with beam control, this approach allows studying beam effects on selected atomic groups and chemical bonds in a fully automated mode. Here, we demonstrate atomically precise engineering of single vacancy lines in transition metal dichalcogenides and the creation and identification of topological defects in graphene. The ELIT-based approach facilitates direct on-the-fly analysis of the STEM data and engenders real-time feedback schemes for probing electron beam chemistry, atomic manipulation, and atom by atom assembly.
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Affiliation(s)
- Kevin M Roccapriore
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee37831, United States
| | - Matthew G Boebinger
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee37831, United States
| | - Ondrej Dyck
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee37831, United States
| | - Ayana Ghosh
- Computational Sciences and Engineering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee37831, United States
| | - Raymond R Unocic
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee37831, United States
| | - Sergei V Kalinin
- Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee37916, United States
| | - Maxim Ziatdinov
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee37831, United States
- Computational Sciences and Engineering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee37831, United States
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21
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Melchioni N, Fabbri F, Tredicucci A, Bianco F. Periodic Structural Defects in Graphene Sheets Engineered via Electron Irradiation. MICROMACHINES 2022; 13:1666. [PMID: 36296019 PMCID: PMC9606931 DOI: 10.3390/mi13101666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 09/23/2022] [Accepted: 09/29/2022] [Indexed: 06/16/2023]
Abstract
Artificially-induced defects in the lattice of graphene are a powerful tool for engineering the properties of the crystal, especially if organized in highly-ordered structures such as periodic arrays. A method to deterministically induce defects in graphene is to irradiate the crystal with low-energy (<20 keV) electrons delivered by a scanning electron microscope. However, the nanometric precision granted by the focused beam can be hindered by the pattern irradiation itself due to the small lateral separation among the elements, which can prevent the generation of sharp features. An accurate analysis of the achievable resolution is thus essential for practical applications. To this end, we investigated patterns generated by low-energy electron irradiation combining atomic force microscopy and micro-Raman spectroscopy measurements. We proved that it is possible to create well-defined periodic patterns with precision of a few tens of nanometers. We found that the defected lines are influenced by electrons back-scattered by the substrate, which limit the achievable resolution. We provided a model that takes into account such substrate effects. The findings of our study allow the design and easily accessible fabrication of graphene devices featuring complex defect engineering, with a remarkable impact on technologies exploiting the increased surface reactivity.
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Affiliation(s)
- Nicola Melchioni
- NEST Laboratory, Istituto Nanoscienze-CNR and Scuola Normale Superiore, Piazza San Silvestro 12, I-56127 Pisa, Italy
| | - Filippo Fabbri
- NEST Laboratory, Istituto Nanoscienze-CNR and Scuola Normale Superiore, Piazza San Silvestro 12, I-56127 Pisa, Italy
| | - Alessandro Tredicucci
- Istituto Nanoscienze-CNR, Piazza San Silvestro 12, I-56127 Pisa, Italy
- Dipartimento di Fisica “E. Fermi”, Università di Pisa, Largo Bruno Pontecorvo 3, I-56127 Pisa, Italy
| | - Federica Bianco
- NEST Laboratory, Istituto Nanoscienze-CNR and Scuola Normale Superiore, Piazza San Silvestro 12, I-56127 Pisa, Italy
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22
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Zheng F, Guo D, Huang L, Wong LW, Chen X, Wang C, Cai Y, Wang N, Lee C, Lau SP, Ly TH, Ji W, Zhao J. Sub-Nanometer Electron Beam Phase Patterning in 2D Materials. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2200702. [PMID: 35723437 PMCID: PMC9376820 DOI: 10.1002/advs.202200702] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 05/18/2022] [Indexed: 05/17/2023]
Abstract
Phase patterning in polymorphic two-dimensional (2D) materials offers diverse properties that extend beyond what their pristine structures can achieve. If precisely controllable, phase transitions can bring exciting new applications for nanometer-scale devices and ultra-large-scale integrations. Here, the focused electron beam is capable of triggering the phase transition from the semiconducting T'' phase to metallic T' and T phases in 2D rhenium disulfide (ReS2 ) and rhenium diselenide (ReSe2 ) monolayers, rendering ultra-precise phase patterning technique even in sub-nanometer scale is found. Based on knock-on effects and strain analysis, the phase transition mechanism on the created atomic vacancies and the introduced substantial in-plane compressive strain in 2D layers are clarified. This in situ high-resolution scanning transmission electron microscopy (STEM) and in situ electrical characterizations agree well with the density functional theory (DFT) calculation results for the atomic structures, electronic properties, and phase transition mechanisms. Grain boundary engineering and electrical contact engineering in 2D are thus developed based on this patterning technique. The patterning method exhibits great potential in ultra-precise electron beam lithography as a scalable top-down manufacturing method for future atomic-scale devices.
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Affiliation(s)
- Fangyuan Zheng
- Department of Applied PhysicsThe Hong Kong Polytechnic UniversityKowloon999077Hong Kong
- China & Polytechnic University of Hong Kong Shenzhen Research InstituteShenzhen518000China
| | - Deping Guo
- Beijing Key Laboratory of Optoelectronic Functional Materials & Micro‐nano DevicesDepartment of PhysicsRenmin University of ChinaBeijing100872China
| | - Lingli Huang
- Department of Chemistry and Center of Super‐Diamond & Advanced Films (COSDAF)City University of Hong KongKowloon999077Hong Kong
- China & City University of Hong Kong Shenzhen Research InstituteShenzhen518000China
| | - Lok Wing Wong
- Department of Applied PhysicsThe Hong Kong Polytechnic UniversityKowloon999077Hong Kong
- China & Polytechnic University of Hong Kong Shenzhen Research InstituteShenzhen518000China
| | - Xin Chen
- Department of Chemistry and Center of Super‐Diamond & Advanced Films (COSDAF)City University of Hong KongKowloon999077Hong Kong
- China & City University of Hong Kong Shenzhen Research InstituteShenzhen518000China
| | - Cong Wang
- Beijing Key Laboratory of Optoelectronic Functional Materials & Micro‐nano DevicesDepartment of PhysicsRenmin University of ChinaBeijing100872China
| | - Yuan Cai
- Department of PhysicsHong Kong University of Science and TechnologyClear water bayHong Kong999077China
| | - Ning Wang
- Department of PhysicsHong Kong University of Science and TechnologyClear water bayHong Kong999077China
| | - Chun‐Sing Lee
- Department of Chemistry and Center of Super‐Diamond & Advanced Films (COSDAF)City University of Hong KongKowloon999077Hong Kong
- China & City University of Hong Kong Shenzhen Research InstituteShenzhen518000China
| | - Shu Ping Lau
- Department of Applied PhysicsThe Hong Kong Polytechnic UniversityKowloon999077Hong Kong
- China & Polytechnic University of Hong Kong Shenzhen Research InstituteShenzhen518000China
| | - Thuc Hue Ly
- Department of Chemistry and Center of Super‐Diamond & Advanced Films (COSDAF)City University of Hong KongKowloon999077Hong Kong
- China & City University of Hong Kong Shenzhen Research InstituteShenzhen518000China
| | - Wei Ji
- Beijing Key Laboratory of Optoelectronic Functional Materials & Micro‐nano DevicesDepartment of PhysicsRenmin University of ChinaBeijing100872China
| | - Jiong Zhao
- Department of Applied PhysicsThe Hong Kong Polytechnic UniversityKowloon999077Hong Kong
- China & Polytechnic University of Hong Kong Shenzhen Research InstituteShenzhen518000China
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23
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Kirubasankar B, Won YS, Adofo LA, Choi SH, Kim SM, Kim KK. Atomic and structural modifications of two-dimensional transition metal dichalcogenides for various advanced applications. Chem Sci 2022; 13:7707-7738. [PMID: 35865881 PMCID: PMC9258346 DOI: 10.1039/d2sc01398c] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 05/18/2022] [Indexed: 12/14/2022] Open
Abstract
Two-dimensional (2D) transition metal dichalcogenides (TMDs) and their heterostructures have attracted significant interest in both academia and industry because of their unusual physical and chemical properties. They offer numerous applications, such as electronic, optoelectronic, and spintronic devices, in addition to energy storage and conversion. Atomic and structural modifications of van der Waals layered materials are required to achieve unique and versatile properties for advanced applications. This review presents a discussion on the atomic-scale and structural modifications of 2D TMDs and their heterostructures via post-treatment. Atomic-scale modifications such as vacancy generation, substitutional doping, functionalization and repair of 2D TMDs and structural modifications including phase transitions and construction of heterostructures are discussed. Such modifications on the physical and chemical properties of 2D TMDs enable the development of various advanced applications including electronic and optoelectronic devices, sensing, catalysis, nanogenerators, and memory and neuromorphic devices. Finally, the challenges and prospects of various post-treatment techniques and related future advanced applications are addressed.
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Affiliation(s)
- Balakrishnan Kirubasankar
- Department of Energy Science, Sungkyunkwan University Suwon 16419 South Korea
- Department of Chemistry, Sookmyung Women's University Seoul 14072 South Korea
| | - Yo Seob Won
- Department of Energy Science, Sungkyunkwan University Suwon 16419 South Korea
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Sungkyunkwan University Suwon 16419 South Korea
| | - Laud Anim Adofo
- Department of Energy Science, Sungkyunkwan University Suwon 16419 South Korea
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Sungkyunkwan University Suwon 16419 South Korea
| | - Soo Ho Choi
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Sungkyunkwan University Suwon 16419 South Korea
| | - Soo Min Kim
- Department of Chemistry, Sookmyung Women's University Seoul 14072 South Korea
| | - Ki Kang Kim
- Department of Energy Science, Sungkyunkwan University Suwon 16419 South Korea
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Sungkyunkwan University Suwon 16419 South Korea
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24
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Zagler G, Stecher M, Trentino A, Kraft F, Su C, Postl A, Längle M, Pesenhofer C, Mangler C, Åhlgren EH, Markevich A, Zettl A, Kotakoski J, Susi T, Mustonen K. Beam-driven Dynamics of Aluminium Dopants in Graphene. 2D MATERIALS 2022; 9:035009. [PMID: 35694040 PMCID: PMC9186522 DOI: 10.1088/2053-1583/ac6c30] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Substituting heteroatoms into graphene can tune its properties for applications ranging from catalysis to spintronics. The further recent discovery that covalent impurities in graphene can be manipulated at atomic precision using a focused electron beam may open avenues towards sub-nanometer device architectures. However, the preparation of clean samples with a high density of dopants is still very challenging. Here, we report vacancy-mediated substitution of aluminium into laser-cleaned graphene, and without removal from our ultra-high vacuum apparatus, study their dynamics under 60 keV electron irradiation using aberration-corrected scanning transmission electron microscopy and spectroscopy. Three- and four-coordinated Al sites are identified, showing excellent agreement with ab initio predictions including binding energies and electron energy-loss spectrum simulations. We show that the direct exchange of carbon and aluminium atoms predicted earlier occurs under electron irradiation, although unexpectedly it is less probable than the same process for silicon. We also observe a previously unknown nitrogen-aluminium exchange that occurs at Al─N double-dopant sites at graphene divacancies created by our plasma treatment.
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Affiliation(s)
- Georg Zagler
- University of Vienna, Faculty of Physics, Boltzmanngasse 5, 1090, Austria
| | - Maximilian Stecher
- University of Vienna, Faculty of Physics, Boltzmanngasse 5, 1090, Austria
| | - Alberto Trentino
- University of Vienna, Faculty of Physics, Boltzmanngasse 5, 1090, Austria
| | - Fabian Kraft
- University of Vienna, Faculty of Physics, Boltzmanngasse 5, 1090, Austria
| | - Cong Su
- Department of Physics, University of California, Berkeley, CA 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
- Kavli Energy NanoSciences Institute at the University of California, Berkeley, CA 94720, USA
| | - Andreas Postl
- University of Vienna, Faculty of Physics, Boltzmanngasse 5, 1090, Austria
| | - Manuel Längle
- University of Vienna, Faculty of Physics, Boltzmanngasse 5, 1090, Austria
| | | | - Clemens Mangler
- University of Vienna, Faculty of Physics, Boltzmanngasse 5, 1090, Austria
| | - E. Harriet Åhlgren
- University of Vienna, Faculty of Physics, Boltzmanngasse 5, 1090, Austria
| | | | - Alex Zettl
- Department of Physics, University of California, Berkeley, CA 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
- Kavli Energy NanoSciences Institute at the University of California, Berkeley, CA 94720, USA
| | - Jani Kotakoski
- University of Vienna, Faculty of Physics, Boltzmanngasse 5, 1090, Austria
| | - Toma Susi
- University of Vienna, Faculty of Physics, Boltzmanngasse 5, 1090, Austria
| | - Kimmo Mustonen
- University of Vienna, Faculty of Physics, Boltzmanngasse 5, 1090, Austria
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25
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Lee K, Park J, Choi S, Lee Y, Lee S, Jung J, Lee JY, Ullah F, Tahir Z, Kim YS, Lee GH, Kim K. STEM Image Analysis Based on Deep Learning: Identification of Vacancy Defects and Polymorphs of MoS 2. NANO LETTERS 2022; 22:4677-4685. [PMID: 35674452 DOI: 10.1021/acs.nanolett.2c00550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Scanning transmission electron microscopy (STEM) is an indispensable tool for atomic-resolution structural analysis for a wide range of materials. The conventional analysis of STEM images is an extensive hands-on process, which limits efficient handling of high-throughput data. Here, we apply a fully convolutional network (FCN) for identification of important structural features of two-dimensional crystals. ResUNet, a type of FCN, is utilized in identifying sulfur vacancies and polymorph types of MoS2 from atomic resolution STEM images. Efficient models are achieved based on training with simulated images in the presence of different levels of noise, aberrations, and carbon contamination. The accuracy of the FCN models toward extensive experimental STEM images is comparable to that of careful hands-on analysis. Our work provides a guideline on best practices to train a deep learning model for STEM image analysis and demonstrates FCN's application for efficient processing of a large volume of STEM data.
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Affiliation(s)
- Kihyun Lee
- Department of Physics, Yonsei University, Seoul 03722, Korea
| | - Jinsub Park
- Department of Physics, Yonsei University, Seoul 03722, Korea
| | - Soyeon Choi
- Department of Physics, Yonsei University, Seoul 03722, Korea
| | - Yangjin Lee
- Department of Physics, Yonsei University, Seoul 03722, Korea
- Center for Nanomedicine, Institute for Basic Science (IBS), Seoul 03722, Korea
| | - Sol Lee
- Department of Physics, Yonsei University, Seoul 03722, Korea
- Center for Nanomedicine, Institute for Basic Science (IBS), Seoul 03722, Korea
| | - Joowon Jung
- Department of Physics, Yonsei University, Seoul 03722, Korea
| | - Jong-Young Lee
- Department of Material Science and Engineering, Seoul National University, Seoul 08826, Korea
| | - Farman Ullah
- Department of Physics and Energy Harvest Storage Research Center, University of Ulsan, Ulsan 44610, Korea
| | - Zeeshan Tahir
- Department of Physics and Energy Harvest Storage Research Center, University of Ulsan, Ulsan 44610, Korea
| | - Yong Soo Kim
- Department of Physics and Energy Harvest Storage Research Center, University of Ulsan, Ulsan 44610, Korea
| | - Gwan-Hyoung Lee
- Department of Material Science and Engineering, Seoul National University, Seoul 08826, Korea
- Research Institute of Advanced Materials, Seoul National University, Seoul 08826, Korea
- Institute of Engineering Research, Seoul National University, Seoul 08826, Korea
- Institute of Applied Physics, Seoul National University, Seoul 08826, Korea
| | - Kwanpyo Kim
- Department of Physics, Yonsei University, Seoul 03722, Korea
- Center for Nanomedicine, Institute for Basic Science (IBS), Seoul 03722, Korea
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26
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Wang H, Liu L, Wang J, Li C, Hou J, Zheng K. The Development of iDPC-STEM and Its Application in Electron Beam Sensitive Materials. Molecules 2022; 27:3829. [PMID: 35744947 PMCID: PMC9231126 DOI: 10.3390/molecules27123829] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Revised: 05/31/2022] [Accepted: 06/01/2022] [Indexed: 11/16/2022] Open
Abstract
The main aspects of material research: material synthesis, material structure, and material properties, are interrelated. Acquiring atomic structure information of electron beam sensitive materials by electron microscope, such as porous zeolites, organic-inorganic hybrid perovskites, metal-organic frameworks, is an important and challenging task. The difficulties in characterization of the structures will inevitably limit the optimization of their synthesis methods and further improve their performance. The emergence of integrated differential phase contrast scanning transmission electron microscopy (iDPC-STEM), a STEM characterization technique capable of obtaining images with high signal-to-noise ratio under lower doses, has made great breakthroughs in the atomic structure characterization of these materials. This article reviews the developments and applications of iDPC-STEM in electron beam sensitive materials, and provides an outlook on its capabilities and development.
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Affiliation(s)
| | - Linlin Liu
- Beijing Key Laboratory of Microstructure and Properties of Solids, Faculty of Materials and Manufacturing, Beijing University of Technique, Beijing 100124, China; (H.W.); (J.W.); (C.L.); (J.H.)
| | | | | | | | - Kun Zheng
- Beijing Key Laboratory of Microstructure and Properties of Solids, Faculty of Materials and Manufacturing, Beijing University of Technique, Beijing 100124, China; (H.W.); (J.W.); (C.L.); (J.H.)
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27
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Roccapriore KM, Dyck O, Oxley MP, Ziatdinov M, Kalinin SV. Automated Experiment in 4D-STEM: Exploring Emergent Physics and Structural Behaviors. ACS NANO 2022; 16:7605-7614. [PMID: 35476426 DOI: 10.1021/acsnano.1c11118] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Automated experiments in 4D scanning transmission electron microscopy (STEM) are implemented for rapid discovery of local structures, symmetry-breaking distortions, and internal electric and magnetic fields in complex materials. Deep kernel learning enables active learning of the relationship between local structure and 4D-STEM-based descriptors. With this, efficient and "intelligent" probing of dissimilar structural elements to discover desired physical functionality is made possible. This approach allows effective navigation of the sample in an automated fashion guided by either a predetermined physical phenomenon, such as strongest electric field magnitude, or in an exploratory fashion. We verify the approach first on preacquired 4D-STEM data and further implement it experimentally on an operational STEM. The experimental discovery workflow is demonstrated using graphene and subsequently extended toward a lesser-known layered 2D van der Waals material, MnPS3. This approach establishes a pathway for physics-driven automated 4D-STEM experiments that enable probing the physics of strongly correlated systems and quantum materials and devices, as well as exploration of beam-sensitive materials.
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Affiliation(s)
- Kevin M Roccapriore
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Ondrej Dyck
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Mark P Oxley
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Maxim Ziatdinov
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
- Computational Sciences and Engineering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Sergei V Kalinin
- Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37916, United States
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28
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Atomic-number ( Z)-correlated atomic sizes for deciphering electron microscopic molecular images. Proc Natl Acad Sci U S A 2022; 119:e2114432119. [PMID: 35349339 PMCID: PMC9168473 DOI: 10.1073/pnas.2114432119] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Atomic resolution transmission electron microscopy (TEM) has opened up a new era of molecular science by providing atomic video images of dynamic motions of single organic and inorganic molecules. However, the images often look different from the images of molecular models, because these models are designed to visualize the electronic properties of the molecule instead of nuclear electrostatic potentials that are felt by the e-beam in TEM imaging. Here, we propose a molecular model that reproduces TEM images using atomic radii correlated to atomic number (Z). The model serves to provide a priori a useful idea of how a single molecule, molecular assemblies, and thin crystals of organic or inorganic materials look in TEM. With the advent of atomic resolution transmission electron microscopy (AR-TEM) achieving sub-Ångstrom image resolution and submillisecond time resolution, an era of cinematic molecular science where chemists can visually study the time evolution of molecular motions and reactions at atomistic precision has arrived. However, the appearance of experimental TEM images often differs greatly from that of conventional molecular models, and the images are difficult to decipher unless we know in advance the structure of the specimen molecules. The difference arises from the fundamental design of the molecular models that represent atomic connectivity and/or the electronic properties of molecules rather than the nuclear charge of atoms and electrostatic potentials that are felt by the e-beam in TEM imaging. We found a good correlation between the atomic number (Z) and the atomic size seen in TEM images when we consider shot noise in digital images. We propose Z-correlated (ZC) atomic radii for modeling AR-TEM images of single molecules and ultrathin crystals with which we can develop a good estimate of the molecular structure from the TEM image much more easily than with conventional molecular models. Two parameter sets were developed for TEM images recorded under high-noise (ZCHN) and low-noise (ZCLN) conditions. The molecular models will stimulate the imaginations of chemists planning to use AR-TEM for their research.
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29
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Romi S, Fanetti S, Alabarse F, Mio AM, Haines J, Bini R. Towards custom built double core carbon nanothreads using stilbene and pseudo-stilbene type systems. NANOSCALE 2022; 14:4614-4625. [PMID: 35266485 DOI: 10.1039/d1nr08188h] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Until recently, saturated carbon nanothreads were the missing tile in the world of low-dimension carbon nanomaterials. These one-dimensional fully saturated polymers possess superior mechanical properties by combining high tensile strength with flexibility and resilience. They can be obtained by compressing aromatic and heteroaromatic crystals above 15 GPa exploiting the anisotropic stress that can be achieved by the diamond anvil cell technique. Recently, double-core nanothreads were synthesized by compressing azobenzene crystals, achieving the remarkable result of preserving the azo group as a linker of the resulting double thread. Herein, we demonstrate the generality of these findings through the synthesis of double carbon nanothreads from trans stilbene and azobenzene-stilbene mixed crystals. Employment of Fourier transform infrared spectroscopy and synchrotron X-ray diffraction enabled a comprehensive characterization of the reactivity identifying threshold conditions, kinetics and structure-reaction relationship. In particular, the reaction is anticipated by a phase transition characterized by a sudden increase of the monoclinic angle and a collapse along the b axis direction. Large bidimensional crystalline areas extending several tens of nanometers are evidenced by transmission electron microscopy also confirming the monoclinic unit cell derived from X-ray diffraction data in which threads possessing the polymer 1 structure, as suggested by density functional theory calculations, are packed. The most exciting result of this study is the demonstration of viable synthesis of double nanothreads where the number and the nature of chromophoric groups linking the threads can be tuned by preparing starting crystals of desired composition, thanks to the isomorphism typical of the pseudo-stilbene molecules. This is extremely important in tailoring nanothreads with tunable optical properties and an adjustable band gap, also exploiting the possibility of introducing substituents in the phenyl groups.
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Affiliation(s)
- Sebastiano Romi
- LENS, European Laboratory for Non-linear Spectroscopy, Via N. Carrara 1, I-50019 Sesto Fiorentino, Firenze, Italy
| | - Samuele Fanetti
- LENS, European Laboratory for Non-linear Spectroscopy, Via N. Carrara 1, I-50019 Sesto Fiorentino, Firenze, Italy
- ICCOM-CNR, Istituto di Chimica dei Composti OrganoMetallici, Via Madonna del Piano 10, I-50019 Sesto Fiorentino, Firenze, Italy.
| | - Frederico Alabarse
- ELETTRA, Elettra Sincrotrone Trieste S.C.p.A, in AREA Science Park, 34149 Basovizza, Trieste, Italy
| | - Antonio M Mio
- IMM-CNR, Istituto per la Microelettronica e Microsistemi, VIII Strada 5 - Zona Industriale, 95121 Catania, Italy
| | - Julien Haines
- Institut Charles Gerhardt Montpellier, CNRS, Université de Montpellier, 34095 Montpellier, France
| | - Roberto Bini
- LENS, European Laboratory for Non-linear Spectroscopy, Via N. Carrara 1, I-50019 Sesto Fiorentino, Firenze, Italy
- ICCOM-CNR, Istituto di Chimica dei Composti OrganoMetallici, Via Madonna del Piano 10, I-50019 Sesto Fiorentino, Firenze, Italy.
- Dipartimento di Chimica "Ugo Schiff", Università di Firenze, Via della Lastruccia 3, I-50019 Sesto Fiorentino, Italy.
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30
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In situ STEM analysis of electron beam induced chemical etching of an ultra-thin amorphous carbon foil by oxygen during high resolution scanning. Ultramicroscopy 2022; 235:113483. [DOI: 10.1016/j.ultramic.2022.113483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 01/20/2022] [Accepted: 01/30/2022] [Indexed: 11/19/2022]
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31
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Rajput NS, Sloyan K, Anjum DH, Chiesa M, Ghaferi AA. A User-Friendly FIB lift-out Technique to Prepare plan-view TEM Sample of Thin Layered Materials. Ultramicroscopy 2022; 235:113496. [DOI: 10.1016/j.ultramic.2022.113496] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Revised: 01/12/2022] [Accepted: 02/15/2022] [Indexed: 10/19/2022]
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32
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Kretschmer S, Ghaderzadeh S, Facsko S, Krasheninnikov AV. Threshold Ion Energies for Creating Defects in 2D Materials from First-Principles Calculations: Chemical Interactions Are Important. J Phys Chem Lett 2022; 13:514-519. [PMID: 35005978 DOI: 10.1021/acs.jpclett.1c03995] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The characteristics of two-dimensional (2D) materials can be tuned by low-energy ion irradiation provided that the ion energy is correctly chosen. The optimum ion energy is related to Ethion, the minimum kinetic energy the ion should have to displace an atom from the material. Ethion can be assessed using the binary collision approximation (BCA) when the displacement threshold of the atom is known. However, for some ions the experimental data contradict the BCA results. Using density functional theory molecular dynamics (DFT-MD), we study the collisions of low-energy ions with graphene and hexagonal boron nitride and demonstrate that the BCA can strongly overestimate Ethion because energy transfer takes a finite time, and therefore, chemical interactions of the ion with the target are important. Finally, for all projectiles from H up to Ar, we calculate the values of Ethion required to displace an atom from graphene and h-BN, the archetypal 2D materials.
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Affiliation(s)
- Silvan Kretschmer
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
| | - Sadegh Ghaderzadeh
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
| | - Stefan Facsko
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
| | - Arkady V Krasheninnikov
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
- Department of Applied Physics, Aalto University, 00076 Aalto, Finland
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33
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Muhammad Jahanzaib S, Jalil A, Aisida SO, Tingkai Z, Dee CF, Sorokin M, Ahmad I, Ul-Hamid A. Cu ions irradiation-induced defects in graphene and their effects on optical properties. Radiat Phys Chem Oxf Engl 1993 2022. [DOI: 10.1016/j.radphyschem.2022.110008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Exponentially selective molecular sieving through angstrom pores. Nat Commun 2021; 12:7170. [PMID: 34887395 PMCID: PMC8660907 DOI: 10.1038/s41467-021-27347-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Accepted: 11/12/2021] [Indexed: 11/09/2022] Open
Abstract
Two-dimensional crystals with angstrom-scale pores are widely considered as candidates for a next generation of molecular separation technologies aiming to provide extreme, exponentially large selectivity combined with high flow rates. No such pores have been demonstrated experimentally. Here we study gas transport through individual graphene pores created by low intensity exposure to low kV electrons. Helium and hydrogen permeate easily through these pores whereas larger species such as xenon and methane are practically blocked. Permeating gases experience activation barriers that increase quadratically with molecules' kinetic diameter, and the effective diameter of the created pores is estimated as ∼2 angstroms, about one missing carbon ring. Our work reveals stringent conditions for achieving the long sought-after exponential selectivity using porous two-dimensional membranes and suggests limits on their possible performance.
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35
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Lehnert T, Kretschmer S, Bräuer F, Krasheninnikov AV, Kaiser U. Quasi-two-dimensional NaCl crystals encapsulated between graphene sheets and their decomposition under an electron beam. NANOSCALE 2021; 13:19626-19633. [PMID: 34816852 DOI: 10.1039/d1nr04792b] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Quasi-two-dimensional (2D) sodium chloride (NaCl) crystals of various lateral sizes between graphene sheets were manufactured via supersaturation from a saline solution. Aberration-corrected transmission electron microscopy was used for systematic in situ investigations of the crystals and their decomposition under an 80 kV electron beam. Counterintuitively, bigger clusters were found to disintegrate faster under electron irradiation, but in general no correlation between crystal sizes and electron doses at which the crystals decompose was found. As for the destruction process, an abrupt decomposition of the crystals was observed, which can be described by a logistic decay function. Density-functional theory molecular dynamics simulations provide insights into the destruction mechanism, and indicate that even without account for ionization and electron excitations, free-standing NaCl crystals must quickly disintegrate due to the ballistic displacement of atoms from their surface and edges during imaging. However, graphene sheets mitigate damage development by stopping the displaced atoms and enable the immediate recombination of defects at the surface of the crystal. At the same time, once a hole in graphene appears, the displaced atoms escape, giving rise to the quick destruction of the crystal. Our results provide quantitative data on the stability of encapsulated quasi 2D NaCl crystals under electron irradiation and allow the conclusion that only high-quality graphene is suitable for protecting ionic crystals from beam damage in electron microscopy studies.
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Affiliation(s)
- Tibor Lehnert
- Electron Microscopy Group of Materials Science, Ulm University, 89081 Ulm, Germany.
- Institute for Quantum Optics, Ulm University, 89081 Ulm, Germany
| | - Silvan Kretschmer
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
| | - Fredrik Bräuer
- Electron Microscopy Group of Materials Science, Ulm University, 89081 Ulm, Germany.
| | - Arkady V Krasheninnikov
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
- Department of Applied Physics, Aalto University, P.O. Box 11100, 00076 Aalto, Finland
| | - Ute Kaiser
- Electron Microscopy Group of Materials Science, Ulm University, 89081 Ulm, Germany.
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Kidambi PR, Chaturvedi P, Moehring NK. Subatomic species transport through atomically thin membranes: Present and future applications. Science 2021; 374:eabd7687. [PMID: 34735245 DOI: 10.1126/science.abd7687] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
[Figure: see text].
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Affiliation(s)
- Piran R Kidambi
- Department of Chemical and Bimolecular Engineering, Vanderbilt University, Nashville, TN, USA.,Vanderbilt Institute of Nanoscale Sciences and Engineering, Vanderbilt University, Nashville, TN, USA.,Department of Mechanical Engineering, Vanderbilt University, Nashville, TN, USA.,Interdisciplinary Graduate Program in Material Science, Vanderbilt University, Nashville, TN, USA
| | - Pavan Chaturvedi
- Department of Chemical and Bimolecular Engineering, Vanderbilt University, Nashville, TN, USA
| | - Nicole K Moehring
- Vanderbilt Institute of Nanoscale Sciences and Engineering, Vanderbilt University, Nashville, TN, USA.,Interdisciplinary Graduate Program in Material Science, Vanderbilt University, Nashville, TN, USA
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Fung KLY, Skowron ST, Allen CS, Khlobystov AN. Counting molecules in nano test tubes: a method for determining the activation parameters of thermally driven reactions through direct imaging. Chem Commun (Camb) 2021; 57:10628-10631. [PMID: 34580683 DOI: 10.1039/d1cc03827c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A methodology for measuring activation parameters of a thermally driven chemical reaction by direct imaging and counting reactant molecules has been developed. The method combines the use of single walled carbon nanotubes (SWNTs) as a nano test tube, transmission electron microscopy (TEM) as an imaging tool, and a heating protocol that decouples the effect of the electron beam from the thermal activation. Polycyclic aromatic perchlorocoronene molecules are stable within SWNTs at room temperature, allowing imaging of individual molecules before and after each heating cycle between 500-600 °C. Polymerisation reaction rates can be determined at different temperatures simply by counting the number of molecules, resulting in an enthalpy of activation of 104 kJ mol-1 and very large entropic contributions to the Gibbs free energy of activation. This experimental methodology provides a link between reactions at the single-molecule level and macroscopic chemical kinetics parameters, through filming the chemical reaction in direct space.
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Affiliation(s)
- Kayleigh L Y Fung
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
| | - Stephen T Skowron
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
| | - Christopher S Allen
- Electron Physical Sciences Imaging Centre, Diamond Light Source Ltd., Oxfordshire OX11 0DE, UK.,Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, UK
| | - Andrei N Khlobystov
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
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Vats N, Negi DS, Singh D, Sigle W, Abb S, Sen S, Szilagyi S, Ochner H, Ahuja R, Kern K, Rauschenbach S, van Aken PA. Catalyzing Bond-Dissociation in Graphene via Alkali-Iodide Molecules. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2021; 17:e2102037. [PMID: 34528384 DOI: 10.1002/smll.202102037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 06/21/2021] [Indexed: 06/13/2023]
Abstract
Atomic design of a 2D-material such as graphene can be substantially influenced by etching, deliberately induced in a transmission electron microscope. It is achieved primarily by overcoming the threshold energy for defect formation by controlling the kinetic energy and current density of the fast electrons. Recent studies have demonstrated that the presence of certain species of atoms can catalyze atomic bond dissociation processes under the electron beam by reducing their threshold energy. Most of the reported catalytic atom species are single atoms, which have strong interaction with single-layer graphene (SLG). Yet, no such behavior has been reported for molecular species. This work shows by experimentally comparing the interaction of alkali and halide species separately and conjointly with SLG, that in the presence of electron irradiation, etching of SLG is drastically enhanced by the simultaneous presence of alkali and iodine atoms. Density functional theory and first principles molecular dynamics calculations reveal that due to charge-transfer phenomena the CC bonds weaken close to the alkali-iodide species, which increases the carbon displacement cross-section. This study ascribes pronounced etching activity observed in SLG to the catalytic behavior of the alkali-iodide species in the presence of electron irradiation.
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Affiliation(s)
- Nilesh Vats
- Max Planck Institute for Solid State Research, Heisenberstr.1, 70569, Stuttgart, Germany
| | - Devendra S Negi
- Max Planck Institute for Solid State Research, Heisenberstr.1, 70569, Stuttgart, Germany
| | - Deobrat Singh
- Condensed Matter Theory Group, Materials Theory Division, Department of Physics and Astronomy, Uppsala University, Box 516, Uppsala, 75120, Sweden
| | - Wilfried Sigle
- Max Planck Institute for Solid State Research, Heisenberstr.1, 70569, Stuttgart, Germany
| | - Sabine Abb
- Max Planck Institute for Solid State Research, Heisenberstr.1, 70569, Stuttgart, Germany
| | - Suman Sen
- Max Planck Institute for Solid State Research, Heisenberstr.1, 70569, Stuttgart, Germany
| | - Sven Szilagyi
- Max Planck Institute for Solid State Research, Heisenberstr.1, 70569, Stuttgart, Germany
| | - Hannah Ochner
- Max Planck Institute for Solid State Research, Heisenberstr.1, 70569, Stuttgart, Germany
| | - Rajeev Ahuja
- Max Planck Institute for Solid State Research, Heisenberstr.1, 70569, Stuttgart, Germany
- Condensed Matter Theory Group, Materials Theory Division, Department of Physics and Astronomy, Uppsala University, Box 516, Uppsala, 75120, Sweden
- Department of Physics, Indian Institute of Technology Ropar, Rupnagar, Punjab, 140001, India
| | - Klaus Kern
- Max Planck Institute for Solid State Research, Heisenberstr.1, 70569, Stuttgart, Germany
- Institut de Physique de la Matière Condensée, École Polytechnique Fédérale de Lausanne, Lausanne, CH-1015, Switzerland
| | - Stephan Rauschenbach
- Max Planck Institute for Solid State Research, Heisenberstr.1, 70569, Stuttgart, Germany
- Department of Chemistry, University of Oxford, 12, Mansfield Road, Oxford, OX1 3TA, UK
| | - Peter A van Aken
- Max Planck Institute for Solid State Research, Heisenberstr.1, 70569, Stuttgart, Germany
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Tyukalova E, Vimal Vas J, Ignatans R, Mueller AD, Medwal R, Imamura M, Asada H, Fukuma Y, Rawat RS, Tileli V, Duchamp M. Challenges and Applications to Operando and In Situ TEM Imaging and Spectroscopic Capabilities in a Cryogenic Temperature Range. Acc Chem Res 2021; 54:3125-3135. [PMID: 34339603 DOI: 10.1021/acs.accounts.1c00078] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
ConspectusIn this Account, we describe the challenges and promising applications of transmission electron microscopy (TEM) imaging and spectroscopy at cryogenic temperatures. Our work focuses on two areas of application: the delay of electron-beam-induced degradation and following low-temperature phenomena in a continuous and variable temperature range. For the former, we present a study of LiMn1.5Ni0.5O4 lithium ion battery cathode material that undergoes electron beam-induced degradation when studied at room temperature by TEM. Cryogenic imaging reveals the true structure of LiMn1.5Ni0.5O4 nanoparticles in their discharged state. Improved stability under electron beam irradiation was confirmed by following the evolution of the O K-edge fine structure by electron energy-loss spectroscopy. Our results demonstrate that the effect of radiation damage on discharged LiMn1.5Ni0.5O4 was previously underestimated and that atomic-resolution imaging at cryogenic temperature has a potential to be generalized to most of the Li-based materials and beyond. For the latter, we present two studies in the imaging of low-temperature phenomena on the local scale, namely, the evolution of ferroelectric and ferromagnetic domains walls, in BaTiO3 and Y3Fe5O12 systems, respectively, in a continuous and variable temperature range. Continuous imaging of the phase transition in BaTiO3, a prototypical ferroelectric system, from the low-temperature orthorhombic phase continuously up to the centrosymmetric high-temperature phase is shown to be possible inside a TEM. Similarly, the propagation of domain walls in Y3Fe5O12, a magnetic insulator, is studied from ∼120 to ∼400 K and combined with the application of a magnetic field and electrical current pulses to mimic the operando conditions as in domain wall memory and logic devices for information technology. Such studies are promising for studying the pinning of the ferroelectric and magnetic domains versus temperature, spin-polarized current, and externally applied magnetic field to better manipulate the domain walls. The capability of combining operando TEM stimuli such as current, voltage, and/or magnetic field with in situ TEM imaging in a continuous cryogenic temperature range will allow the uncovering of fundamental phenomena on the nanometer scale. These studies were made possible using a MEMS-based TEM holder that allowed an electron-transparent sample to be transferred and electrically contacted on a MEMS chip. The six-contact double-tilt holder allows the alignment of the specimen into its zone axis while simultaneously using four electrical contacts to regulate the temperature and two contacts to apply the electrical stimuli, i.e., operando TEM imaging. This Account leads to the demonstration of (i) the high-resolution imaging and spectroscopy of nanoparticles oriented in the desired [110] zone-axis direction at cryogenic temperatures to mitigate the electron beam degradation, (ii) imaging of low-temperature transitions with accurate and continuous control of the temperature that allowed single-frame observation of the presence of both the orthorhombic and tetragonal phases in the BaTiO3 system, and (iii) magnetic domain wall propagation as a function of temperature, magnetic field, and current pulses (100 ns with a 100 kHz repetition rate) in the Y3Fe5O12 system.
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Affiliation(s)
| | | | - Reinis Ignatans
- Institute of Materials, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | | | | | - Masaaki Imamura
- Department of Electrical Engineering, Fukuoka Institute of Technology, Fukuoka 811-0295, Japan
| | - Hironori Asada
- Graduate School of Sciences and Technology for Innovation, Yamaguchi University, Ube 755-8611, Japan
| | - Yasuhiro Fukuma
- Department of Physics and Information Technology, Kyushu Institute of Technology, Iizuka 820-8502, Japan
- Research Center for Neuromorphic AI Hardwares, Kyushu Institute of Technology, Kitakyushu 808-0196, Japan
| | | | - Vasiliki Tileli
- Institute of Materials, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
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40
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Sajja R, You Y, Qi R, Goutham S, Bhardwaj A, Rakowski A, Haigh S, Keerthi A, Radha B. Hydrocarbon contamination in angström-scale channels. NANOSCALE 2021; 13:9553-9560. [PMID: 34018493 DOI: 10.1039/d1nr00001b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Nonspecific molecular adsorption such as airborne contamination occurs on most surfaces including those of 2D materials and alters their properties. While surface contamination is studied using a plethora of techniques, the effect of contamination on confined systems such as nanochannels/pores leading to their clogging is still lacking. We report a systematic investigation of hydrocarbon adsorption in angstrom (Å) slit channels of varying heights. Hexane is chosen to mimic the hydrocarbon contamination and the clogging of the Å-channels is evaluated via a helium gas flow measurement. The level of hexane adsorption, in other words, the degree of clogging depends on the size difference between the channels and hexane. A dynamic transition of the clogging and revival process is shown in sub-2 nm thin channels. Long-term storage and stability of our Å-channels are demonstrated here for up to three years, alleviating the contamination and unclogging the channels using thermal treatment. This study highlights the importance of the nanochannels' stability and demonstrates the self-cleansing nature of sub-2 nm thin channels enabling a robust platform for molecular transport and separation studies. We provide a method to assess the cleanliness of nanoporous membranes, which is vital for the practical applications of nanofluidics in various fields such as molecular sensing, separation and power generation.
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Affiliation(s)
- Ravalika Sajja
- Department of Physics and Astronomy, School of Natural Sciences, The University of Manchester, Oxford Road, Manchester M13 9PL, UK.
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41
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Park H, Wen Y, Li SX, Choi W, Lee GD, Strano M, Warner JH. Atomically Precise Control of Carbon Insertion into hBN Monolayer Point Vacancies using a Focused Electron Beam Guide. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2021; 17:e2100693. [PMID: 33960117 DOI: 10.1002/smll.202100693] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 03/16/2021] [Indexed: 06/12/2023]
Abstract
Precise controlled filling of point vacancies in hBN with carbon atoms is demonstrated using a focused electron beam method, which guides mobile C atoms into the desired defect site. Optimization of the technique enables the insertion of a single C atom into a selected monovacancy, and preferential defect filling with sub-2 nm accuracy. Increasing the C insertion process leads to thicker 3D C nanodots seeded at the hBN point vacancy site. Other light elements are also observed to bind to hBN vacancies, including O, opening up a wide range of complex defect structures that include B, C, N, and O atoms. The ability to selectively fill point vacancies in hBN with C atoms provides a pathway for creating non-hydrogenated covalently bonded C molecules embedded in the insulating hBN.
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Affiliation(s)
- Hyoju Park
- Texas Materials Institute, The University of Texas at Austin, 204 East Dean Keeton Street, Austin, TX, 78712, USA
- Walker Department of Mechanical Engineering, The University of Texas at Austin, 204 East Dean Keeton Street, Austin, TX, 78712, USA
| | - Yi Wen
- Department of Materials, University of Oxford, Parks Road, Oxford, OX1 3PH, UK
| | - Sylvia Xin Li
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Woojin Choi
- Department of Materials Science and Engineering, Seoul National University, Gwanak-gu, Seoul, 08826, Republic of Korea
| | - Gun-Do Lee
- Department of Materials Science and Engineering, Seoul National University, Gwanak-gu, Seoul, 08826, Republic of Korea
- Research Institute of Advanced Materials, Seoul National University, Gwanak-gu, Seoul, 08826, Republic of Korea
| | - Michael Strano
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Jamie H Warner
- Texas Materials Institute, The University of Texas at Austin, 204 East Dean Keeton Street, Austin, TX, 78712, USA
- Walker Department of Mechanical Engineering, The University of Texas at Austin, 204 East Dean Keeton Street, Austin, TX, 78712, USA
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Computer vision AC-STEM automated image analysis for 2D nanopore applications. Ultramicroscopy 2021; 231:113249. [PMID: 33902953 DOI: 10.1016/j.ultramic.2021.113249] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 01/15/2021] [Accepted: 02/27/2021] [Indexed: 01/17/2023]
Abstract
Transmission electron microscopy (TEM) has led to important discoveries in atomic imaging and as an atom-by-atom fabrication tool. Using electron beams, atomic structures can be patterned, annealed and crystallized, and nanopores can be drilled in thin membranes. We review current progress in TEM analysis and implement a computer vision nanopore-detection algorithm that achieves a 96% pixelwise precision in TEM images of nanopores in 2D membranes (WS2), and discuss parameter optimization including a variation on the traditional grid search and gradient ascent. Such nanopores have applications in ion detection, water filtration, and DNA sequencing, where ionic conductance through the pore should be concordant with its TEM-measured size. Standard computer vision methods have their advantages as they are intuitive and do not require extensive training data. For completeness, we briefly comment on related machine learning for 2D materials analysis and discuss relevant progress in these fields. Image analysis alongside TEM allows correlated fabrication and analysis done simultaneously in situ to engineer devices at the atomic scale.
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43
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Jordan JW, Fung KLY, Skowron ST, Allen CS, Biskupek J, Newton GN, Kaiser U, Khlobystov AN. Single-molecule imaging and kinetic analysis of intermolecular polyoxometalate reactions. Chem Sci 2021; 12:7377-7387. [PMID: 34163827 PMCID: PMC8171355 DOI: 10.1039/d1sc01874d] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2021] [Accepted: 04/12/2021] [Indexed: 11/21/2022] Open
Abstract
We induce and study reactions of polyoxometalate (POM) molecules, [PW12O40]3- (Keggin) and [P2W18O62]6- (Wells-Dawson), at the single-molecule level. Several identical carbon nanotubes aligned side by side within a bundle provided a platform for spatiotemporally resolved imaging of ca. 100 molecules encapsulated within the nanotubes by transmission electron microscopy (TEM). Due to the entrapment of POM molecules their proximity to one another is effectively controlled, limiting molecular motion in two dimensions but leaving the third dimension available for intermolecular reactions between pairs of neighbouring molecules. By coupling the information gained from high resolution structural and kinetics experiments via the variation of key imaging parameters in the TEM, we shed light on the reaction mechanism. The dissociation of W-O bonds, a key initial step of POM reactions, is revealed to be reversible by the kinetic analysis, followed by an irreversible bonding of POM molecules to their nearest neighbours, leading to a continuous tungsten oxide nanowire, which subsequently transforms into amorphous tungsten-rich clusters due to progressive loss of oxygen atoms. The overall intermolecular reaction can therefore be described as a step-wise reductive polycondensation of POM molecules, via an intermediate state of an oxide nanowire. Kinetic analysis enabled by controlled variation of the electron flux in TEM revealed the reaction to be highly flux-dependent, which leads to reaction rates too fast to follow under the standard TEM imaging conditions. Although this presents a challenge for traditional structural characterisation of POM molecules, we harness this effect by controlling the conditions around the molecules and tuning the imaging parameters in TEM, which combined with theoretical modelling and image simulation, can shed light on the atomistic mechanisms of the reactions of POMs. This approach, based on the direct space and real time chemical reaction analysis by TEM, adds a new method to the arsenal of single-molecule kinetics techniques.
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Affiliation(s)
- Jack W Jordan
- School of Chemistry, University of Nottingham University Park Nottingham NG7 2RD UK
| | - Kayleigh L Y Fung
- School of Chemistry, University of Nottingham University Park Nottingham NG7 2RD UK
| | - Stephen T Skowron
- School of Chemistry, University of Nottingham University Park Nottingham NG7 2RD UK
| | - Christopher S Allen
- Electron Physical Science Imaging Center, Diamond Light Source Ltd. Didcot OX11 0DE UK
- Department of Materials, University of Oxford Oxford OX1 3HP UK
| | - Johannes Biskupek
- Electron Microscopy Group of Materials Science, Ulm University 89081 Ulm Germany
| | - Graham N Newton
- GSK Carbon Neutral Laboratories for Sustainable Chemistry, University of Nottingham Nottingham NG7 2TU UK
| | - Ute Kaiser
- Electron Microscopy Group of Materials Science, Ulm University 89081 Ulm Germany
| | - Andrei N Khlobystov
- School of Chemistry, University of Nottingham University Park Nottingham NG7 2RD UK
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Ibragimova R, Lv ZP, Komsa HP. First principles study of the stability of MXenes under an electron beam. NANOSCALE ADVANCES 2021; 3:1934-1941. [PMID: 36133102 PMCID: PMC9418968 DOI: 10.1039/d0na00886a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Accepted: 01/30/2021] [Indexed: 06/16/2023]
Abstract
Interactions between two-dimensional MXene sheets and electron beams of a (scanning) transmission electron microscope are studied by first-principles calculations. We simulated the knock-on sputtering threshold for Ti3C2 MXene sheets via ab initio molecular dynamics simulations and for five other MXenes (Ti2C, Ti2N, Nb2C, Mo2TiC2, and Ti3CN) approximately from defect formation energies. We evaluated the sputtering cross section and sputtering rates and based on those evaluated the surface composition. We find that at the exit surface and for "low" TEM energies H and F sputter at equal rates, but at "high" TEM energies the F is sputtered most strongly. In the entry surface, H sputtering dominates. The results were found to be largely similar for all studied MXenes, and although the sputtering thresholds varied between the different metal atoms the thresholds were always too high to lead to significant sputtering of the metal atoms. We simulated electron microscope images at the successive stages of sputtering and found that while it is likely difficult to identify surface groups based on the spot intensities, the local contraction of the lattice around O groups should be observable. We also studied MXenes encapsulated with graphene and found them to provide efficient protection from knock-on damage for all surface group atoms except H.
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Affiliation(s)
- Rina Ibragimova
- Department of Applied Physics, Aalto University 00076 Aalto Finland
| | - Zhong-Peng Lv
- Department of Applied Physics, Aalto University 00076 Aalto Finland
| | - Hannu-Pekka Komsa
- Department of Applied Physics, Aalto University 00076 Aalto Finland
- Microelectronics Research Unit, University of Oulu 90014 Oulu Finland hannu-pekka.komsa@oulu
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Lin PC, Villarreal R, Achilli S, Bana H, Nair MN, Tejeda A, Verguts K, De Gendt S, Auge M, Hofsäss H, De Feyter S, Di Santo G, Petaccia L, Brems S, Fratesi G, Pereira LMC. Doping Graphene with Substitutional Mn. ACS NANO 2021; 15:5449-5458. [PMID: 33596385 DOI: 10.1021/acsnano.1c00139] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
We report the incorporation of substitutional Mn atoms in high-quality, epitaxial graphene on Cu(111), using ultralow-energy ion implantation. We characterize in detail the atomic structure of substitutional Mn in a single carbon vacancy and quantify its concentration. In particular, we are able to determine the position of substitutional Mn atoms with respect to the Moiré superstructure (i.e., local graphene-Cu stacking symmetry) and to the carbon sublattice; in the out-of-plane direction, substitutional Mn atoms are found to be slightly displaced toward the Cu surface, that is, effectively underneath the graphene layer. Regarding electronic properties, we show that graphene doped with substitutional Mn to a concentration of the order of 0.04%, with negligible structural disorder (other than the Mn substitution), retains the Dirac-like band structure of pristine graphene on Cu(111), making it an ideal system in which to study the interplay between local magnetic moments and Dirac electrons. Our work also establishes that ultralow-energy ion implantation is suited for substitutional magnetic doping of graphene. Given the flexibility, reproducibility, and scalability inherent to ion implantation, our work creates numerous opportunities for research on magnetic functionalization of graphene and other two-dimensional materials.
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Affiliation(s)
- Pin-Cheng Lin
- Quantum Solid State Physics, KU Leuven, 3001 Leuven, Belgium
| | | | - Simona Achilli
- ETSF and Dipartimento di Fisica "Aldo Pontremoli", Università degli Studi di Milano, Via Celoria, 16, I-20133 Milano, Italy
| | - Harsh Bana
- Quantum Solid State Physics, KU Leuven, 3001 Leuven, Belgium
| | - Maya N Nair
- CUNY Advanced Science Research Center, 85 St. Nicholas Terrace, New York, New York 10031, United States
| | - Antonio Tejeda
- Laboratoire de Physique des Solides, CNRS, Université Paris-Sud, 91405 Orsay, France
| | - Ken Verguts
- imec vzw, 3001 Leuven, Belgium
- Department of Chemistry, Division of Molecular Design and Synthesis, KU Leuven, 3001 Leuven, Belgium
| | - Stefan De Gendt
- imec vzw, 3001 Leuven, Belgium
- Department of Chemistry, Division of Molecular Design and Synthesis, KU Leuven, 3001 Leuven, Belgium
| | - Manuel Auge
- II.Institute of Physics, University of Göttingen, 37077 Göttingen, Germany
| | - Hans Hofsäss
- II.Institute of Physics, University of Göttingen, 37077 Göttingen, Germany
| | - Steven De Feyter
- Department of Chemistry, Division of Molecular Imaging and Photonics, KU Leuven, 3001 Leuven, Belgium
| | - Giovanni Di Santo
- Elettra Sincrotrone Trieste, Strada Statale 14 km 163.5, 34149 Trieste, Italy
| | - Luca Petaccia
- Elettra Sincrotrone Trieste, Strada Statale 14 km 163.5, 34149 Trieste, Italy
| | | | - Guido Fratesi
- ETSF and Dipartimento di Fisica "Aldo Pontremoli", Università degli Studi di Milano, Via Celoria, 16, I-20133 Milano, Italy
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Emmrich D, Wolff A, Meyerbröker N, Lindner JKN, Beyer A, Gölzhäuser A. Scanning transmission helium ion microscopy on carbon nanomembranes. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2021; 12:222-231. [PMID: 33728240 PMCID: PMC7934706 DOI: 10.3762/bjnano.12.18] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 02/12/2021] [Indexed: 06/12/2023]
Abstract
A dark-field scanning transmission ion microscopy detector was designed for the helium ion microscope. The detection principle is based on a secondary electron conversion holder with an exchangeable aperture strip allowing its acceptance angle to be tuned from 3 to 98 mrad. The contrast mechanism and performance were investigated using freestanding nanometer-thin carbon membranes. The results demonstrate that the detector can be optimized either for most efficient signal collection or for maximum image contrast. The designed setup allows for the imaging of thin low-density materials that otherwise provide little signal or contrast and for a clear end-point detection in the fabrication of nanopores. In addition, the detector is able to determine the thickness of membranes with sub-nanometer precision by quantitatively evaluating the image signal and comparing the results with Monte Carlo simulations. The thickness determined by the dark-field transmission detector is compared to X-ray photoelectron spectroscopy and energy-filtered transmission electron microscopy measurements.
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Affiliation(s)
- Daniel Emmrich
- Physics of Supramolecular Systems and Surfaces, Bielefeld University, 33615 Bielefeld, Germany
| | - Annalena Wolff
- Central Analytical Research Facility, Institute for Future Environments, Queensland University of Technology, 2 George St, Brisbane 4000, QLD, Australia
| | | | | | - André Beyer
- Physics of Supramolecular Systems and Surfaces, Bielefeld University, 33615 Bielefeld, Germany
| | - Armin Gölzhäuser
- Physics of Supramolecular Systems and Surfaces, Bielefeld University, 33615 Bielefeld, Germany
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Zhao X, Loh KP, Pennycook SJ. Electron beam triggered single-atom dynamics in two-dimensional materials. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 33:063001. [PMID: 33007771 DOI: 10.1088/1361-648x/abbdb9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Controlling atomic structure and dynamics with single-atom precision is the ultimate goal in nanoscience and nanotechnology. Despite great successes being achieved by scanning tunneling microscopy (STM) over the past a few decades, fundamental limitations, such as ultralow temperature, and low throughput, significantly hinder the fabrication of a large array of atomically defined structures by STM. The advent of aberration correction in scanning transmission electron microscopy (STEM) revolutionized the field of nanomaterials characterization pushing the detection limit down to single-atom sensitivity. The sub-angstrom focused electron beam (e-beam) of STEM is capable of interacting with an individual atom, thereby it is the ideal platform to direct and control matter at the level of a single atom or a small cluster. In this article, we discuss the transfer of energy and momentum from the incident e-beam to atoms and their subsequent potential dynamics under different e-beam conditions in 2D materials, particularly transition metal dichalcogenides (TMDs). Next, we systematically discuss the e-beam triggered structural evolutions of atomic defects, line defects, grain boundaries, and stacking faults in a few representative 2D materials. Their formation mechanisms, kinetic paths, and practical applications are comprehensively discussed. We show that desired structural evolution or atom-by-atom assembly can be precisely manipulated by e-beam irradiation which could introduce intriguing functionalities to 2D materials. In particular, we highlight the recent progress on controlling single Si atom migration in real-time on monolayer graphene along an extended path with high throughput in automated STEM. These results unprecedentedly demonstrate that single-atom dynamics can be realized by an atomically focused e-beam. With the burgeoning of artificial intelligence and big data, we can expect that fully automated microscopes with real-time data analysis and feedback could readily design and fabricate large scale nanostructures with unique functionalities in the near future.
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Affiliation(s)
- Xiaoxu Zhao
- Department of Materials Science and Engineering, National University of Singapore, 9 Engineering Drive 1, 117575, Singapore
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543, Singapore
| | - Kian Ping Loh
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543, Singapore
| | - Stephen J Pennycook
- Department of Materials Science and Engineering, National University of Singapore, 9 Engineering Drive 1, 117575, Singapore
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Park J, Koo K, Noh N, Chang JH, Cheong JY, Dae KS, Park JS, Ji S, Kim ID, Yuk JM. Graphene Liquid Cell Electron Microscopy: Progress, Applications, and Perspectives. ACS NANO 2021; 15:288-308. [PMID: 33395264 DOI: 10.1021/acsnano.0c10229] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Graphene liquid cell electron microscopy (GLC-EM), a cutting-edge liquid-phase EM technique, has become a powerful tool to directly visualize wet biological samples and the microstructural dynamics of nanomaterials in liquids. GLC uses graphene sheets with a one carbon atom thickness as a viewing window and a liquid container. As a result, GLC facilitates atomic-scale observation while sustaining intact liquids inside an ultra-high-vacuum transmission electron microscopy chamber. Using GLC-EM, diverse scientific results have been recently reported in the material, colloidal, environmental, and life science fields. Here, the developments of GLC fabrications, such as first-generation veil-type cells, second-generation well-type cells, and third-generation liquid-flowing cells, are summarized. Moreover, recent GLC-EM studies on colloidal nanoparticles, battery electrodes, mineralization, and wet biological samples are also highlighted. Finally, the considerations and future opportunities associated with GLC-EM are discussed to offer broad understanding and insight on atomic-resolution imaging in liquid-state dynamics.
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Affiliation(s)
- Jungjae Park
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Kunmo Koo
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Namgyu Noh
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Joon Ha Chang
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Jun Young Cheong
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Kyun Seong Dae
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Ji Su Park
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Sanghyeon Ji
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Il-Doo Kim
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Jong Min Yuk
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
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49
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Parent LR, Gnanasekaran K, Korpanty J, Gianneschi NC. 100th Anniversary of Macromolecular Science Viewpoint: Polymeric Materials by In Situ Liquid-Phase Transmission Electron Microscopy. ACS Macro Lett 2021; 10:14-38. [PMID: 35548998 DOI: 10.1021/acsmacrolett.0c00595] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A century ago, Hermann Staudinger proposed the macromolecular theory of polymers, and now, as we enter the second century of polymer science, we face a different set of opportunities and challenges for the development of functional soft matter. Indeed, many fundamental questions remain open, relating to physical structures and mechanisms of phase transformations at the molecular and nanoscale. In this Viewpoint, we describe efforts to develop a dynamic, in situ microscopy tool suited to the study of polymeric materials at the nanoscale that allows for direct observation of discrete structures and processes in solution, as a complement to light, neutron, and X-ray scattering methods. Liquid-phase transmission electron microscopy (LPTEM) is a nascent in situ imaging technique for characterizing and examining solvated nanomaterials in real time. Though still under development, LPTEM has been shown to be capable of several modes of imaging: (1) imaging static solvated materials analogous to cryo-TEM, (2) videography of nanomaterials in motion, (3) observing solutions or nanomaterials undergoing physical and chemical transformations, including synthesis, assembly, and phase transitions, and (4) observing electron beam-induced chemical-materials processes. Herein, we describe opportunities and limitations of LPTEM for polymer science. We review the basic experimental platform of LPTEM and describe the origin of electron beam effects that go hand in hand with the imaging process. These electron beam effects cause perturbation and damage to the sample and solvent that can manifest as artefacts in images and videos. We describe sample-specific experimental guidelines and outline approaches to mitigate, characterize, and quantify beam damaging effects. Altogether, we seek to provide an overview of this nascent field in the context of its potential to contribute to the advancement of polymer science.
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Affiliation(s)
- Lucas R. Parent
- Innovation Partnership Building, The University of Connecticut, Storrs, Connecticut 06269, United States
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Liu C, Zhang J, Zhang X, Muruganathan M, Mizuta H, Oshima Y. In-situ electrical conductance measurement of suspended ultra-narrow graphene nanoribbons observed via transmission electron microscopy. NANOTECHNOLOGY 2021; 32:025710. [PMID: 32992312 DOI: 10.1088/1361-6528/abbca7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Graphene nanoribbon is an attractive material for nano-electronic devices, as their electrical transport performance can be controlled by their edge structures. However, in most cases, the electrical transport has been investigated only for graphene nanoribbons fabricated on a substrate, which hinders the appearance of intrinsic electrical transport due to screening effects. In this study, we developed special devices based on silicon chips for transmission electron microscopy to observe a monolayer graphene nanoribbon suspended between two gold electrodes. Moreover, with the development of an in-situ transmission electron microscopy holder, the current-voltage characteristics were achieved simultaneously with observing and modifying the structure. We found that the current-voltage characteristics differed between 1.5 nm-wide graphene nanoribbons with armchair and zigzag edge structures. The energy gap of the zigzag edge was more than two-fold larger than that of the armchair edge and exhibited an abrupt jump above a critical bias voltage in the differential conductance curve. Thus, our in-situ transmission electron microscopy method is promising for elucidating the structural dependence of electrical conduction in two-dimensional materials.
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Affiliation(s)
- Chunmeng Liu
- School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1292, Japan
| | - Jiaqi Zhang
- School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1292, Japan
| | - Xiaobin Zhang
- College of Engineering, Shibaura Institute of Technology, 3-7-5 Toyosu, Koto-ku, Tokyo 135-8548, Japan
| | - Manoharan Muruganathan
- School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1292, Japan
| | - Hiroshi Mizuta
- School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1292, Japan
- Hitachi Cambridge Laboratory, J J Thomson Avenue, Cambridge CB3: 0HE, United Kingdom
| | - Yoshifumi Oshima
- School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1292, Japan
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