1
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Trentino A, Zagler G, Längle M, Madsen J, Susi T, Mangler C, Åhlgren EH, Mustonen K, Kotakoski J. Single atoms and metal nanoclusters anchored to graphene vacancies. Micron 2024; 184:103667. [PMID: 38850967 DOI: 10.1016/j.micron.2024.103667] [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: 03/18/2024] [Revised: 05/24/2024] [Accepted: 05/29/2024] [Indexed: 06/10/2024]
Abstract
Fabricating dispersed single atoms and size-controlled metal nanoclusters remains a difficult challenge due to sintering. Here, we demonstrate that atoms and clusters can be immobilized using atomically clean defect-engineered graphene as the matrix. The graphene is first cleaned of surface contamination with laser heating, after which low-energy Ar irradiation is used to create spatially well-separated vacancies into it. Metal atoms are then evaporated either via thermal or ebeam evaporation onto graphene, where they diffuse until being trapped into a vacancy. The density of embedded structures can be controlled through irradiation dose, and the size of the structures through evaporation time. The resulting structures are confirmed through atomic-resolution scanning transmission electron microscopy and electron energy loss spectroscopy. We demonstrate here incorporation of Al, Ti, Fe, Ag and Au single atoms or nanoclusters, but the method should work equally well for other elements.
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Affiliation(s)
- Alberto Trentino
- University of Vienna, Faculty of Physics, Boltzmanngasse 5, Vienna 1090, Austria; University of Vienna, Vienna Doctoral School in Physics, Boltzmanngasse 5, Vienna 1090, Austria
| | - Georg Zagler
- University of Vienna, Faculty of Physics, Boltzmanngasse 5, Vienna 1090, Austria; University of Vienna, Vienna Doctoral School in Physics, Boltzmanngasse 5, Vienna 1090, Austria
| | - Manuel Längle
- University of Vienna, Faculty of Physics, Boltzmanngasse 5, Vienna 1090, Austria; University of Vienna, Vienna Doctoral School in Physics, Boltzmanngasse 5, Vienna 1090, Austria
| | - Jacob Madsen
- University of Vienna, Faculty of Physics, Boltzmanngasse 5, Vienna 1090, Austria
| | - Toma Susi
- University of Vienna, Faculty of Physics, Boltzmanngasse 5, Vienna 1090, Austria
| | - Clemens Mangler
- University of Vienna, Faculty of Physics, Boltzmanngasse 5, Vienna 1090, Austria
| | - E Harriet Åhlgren
- University of Vienna, Faculty of Physics, Boltzmanngasse 5, Vienna 1090, Austria; University of Helsinki, Department of Physics, P.O. Box 43, Helsinki FI-00014, Finland
| | - Kimmo Mustonen
- University of Vienna, Faculty of Physics, Boltzmanngasse 5, Vienna 1090, Austria
| | - Jani Kotakoski
- University of Vienna, Faculty of Physics, Boltzmanngasse 5, Vienna 1090, Austria.
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2
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Noisternig SM, Rentenberger C, Gammer C, Karnthaler HP, Kotakoski J. Probing the interaction range of electron beam-induced etching in STEM by a non-contact electron beam. Ultramicroscopy 2024; 265:114019. [PMID: 39094366 DOI: 10.1016/j.ultramic.2024.114019] [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: 05/07/2024] [Revised: 07/11/2024] [Accepted: 07/18/2024] [Indexed: 08/04/2024]
Abstract
Beside its main purpose as a high-end tool in material analysis reaching the atomic scale for structure, chemical and electronic properties, aberration-corrected scanning transmission electron microscopy (STEM) is increasingly used as a tool to manipulate materials down to that very same scale. In order to obtain exact and reproducible results, it is essential to consider the interaction processes and interaction ranges between the electron beam and the involved materials. Here, we show in situ that electron beam-induced etching in a low-pressure oxygen atmosphere can extend up to a distance of several nm away from the Ångström-size electron beam, usually used for probing the sample. This relatively long-range interaction is related to beam tails and inelastic scattering involved in the etching process. To suppress the influence of surface diffusion, we measure the etching effect indirectly on isolated nm-sized holes in a 2 nm thin amorphous carbon foil that is commonly used as sample support in STEM. During our experiments, the electron beam is placed inside the nanoholes so that most electrons cannot directly participate in the etching process. We characterize the etching process from measuring etching rates at multiple nanoholes with different distances between the hole edge and the electron beam.
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Affiliation(s)
- Stefan Manuel Noisternig
- University of Vienna, Physics of Nanostructured Materials, Boltzmanngasse 5, 1090 Vienna, Austria; Austrian Academy of Sciences, Erich Schmid Institute of Materials Science, Jahnstraße 12, 8700, Leoben, Austria.
| | - Christian Rentenberger
- University of Vienna, Physics of Nanostructured Materials, Boltzmanngasse 5, 1090 Vienna, Austria
| | - Christoph Gammer
- Austrian Academy of Sciences, Erich Schmid Institute of Materials Science, Jahnstraße 12, 8700, Leoben, Austria
| | - H Peter Karnthaler
- University of Vienna, Physics of Nanostructured Materials, Boltzmanngasse 5, 1090 Vienna, Austria
| | - Jani Kotakoski
- University of Vienna, Physics of Nanostructured Materials, Boltzmanngasse 5, 1090 Vienna, Austria
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3
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Boebinger MG, Yilmaz DE, Ghosh A, Misra S, Mathis TS, Kalinin SV, Jesse S, Gogotsi Y, van Duin ACT, Unocic RR. Direct Fabrication of Atomically Defined Pores in MXenes Using Feedback-Driven STEM. SMALL METHODS 2024:e2400203. [PMID: 38803318 DOI: 10.1002/smtd.202400203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Revised: 05/05/2024] [Indexed: 05/29/2024]
Abstract
Controlled fabrication of nanopores in 2D materials offer the means to create robust membranes needed for ion transport and nanofiltration. Techniques for creating nanopores have relied upon either plasma etching or direct irradiation; however, aberration-corrected scanning transmission electron microscopy (STEM) offers the advantage of combining a sub-Å sized electron beam for atomic manipulation along with atomic resolution imaging. Here, a method for automated nanopore fabrication is utilized with real-time atomic visualization to enhance the mechanistic understanding of beam-induced transformations. Additionally, an electron beam simulation technique, Electron-Beam Simulator (E-BeamSim) is developed to observe the atomic movements and interactions resulting from electron beam irradiation. Using the MXene Ti3C2Tx, the influence of temperature on nanopore fabrication is explored by tracking atomic transformations and find that at room temperature the electron beam irradiation induces random displacement and results in titanium pileups at the nanopore edge, which is confirmed by E-BeamSim. At elevated temperatures, after removal of the surface functional groups and with the increased mobility of atoms results in atomic transformations that lead to the selective removal of atoms layer by layer. This work can lead to the development of defect engineering techniques within functionalized MXene layers and other 2D materials.
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Affiliation(s)
- Matthew G Boebinger
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Dundar E Yilmaz
- Department of Mechanical Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Ayana Ghosh
- Computational Sciences and Engineering Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Sudhajit Misra
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Tyler S Mathis
- A.J. Drexel Nanomaterials Institute and Department of Materials Science and Engineering, Drexel University, Philadelphia, PA, 19104, USA
| | - Sergei V Kalinin
- Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN, 37996, USA
| | - Stephen Jesse
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Yury Gogotsi
- A.J. Drexel Nanomaterials Institute and Department of Materials Science and Engineering, Drexel University, Philadelphia, PA, 19104, USA
| | - Adri C T van Duin
- Department of Mechanical Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Raymond R Unocic
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
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4
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Yan Q, Kar S, Chowdhury S, Bansil A. The Case for a Defect Genome Initiative. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2303098. [PMID: 38195961 DOI: 10.1002/adma.202303098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 08/12/2023] [Indexed: 01/11/2024]
Abstract
The Materials Genome Initiative (MGI) has streamlined the materials discovery effort by leveraging generic traits of materials, with focus largely on perfect solids. Defects such as impurities and perturbations, however, drive many attractive functional properties of materials. The rich tapestry of charge, spin, and bonding states hosted by defects are not accessible to elements and perfect crystals, and defects can thus be viewed as another class of "elements" that lie beyond the periodic table. Accordingly, a Defect Genome Initiative (DGI) to accelerate functional defect discovery for energy, quantum information, and other applications is proposed. First, major advances made under the MGI are highlighted, followed by a delineation of pathways for accelerating the discovery and design of functional defects under the DGI. Near-term goals for the DGI are suggested. The construction of open defect platforms and design of data-driven functional defects, along with approaches for fabrication and characterization of defects, are discussed. The associated challenges and opportunities are considered and recent advances towards controlled introduction of functional defects at the atomic scale are reviewed. It is hoped this perspective will spur a community-wide interest in undertaking a DGI effort in recognition of the importance of defects in enabling unique functionalities in materials.
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Affiliation(s)
- Qimin Yan
- Department of Physics, Northeastern University, Boston, MA 02115, USA
| | - Swastik Kar
- Department of Physics, Northeastern University, Boston, MA 02115, USA
- Department of Chemical Engineering, Northeastern University, Boston, MA 02115, USA
| | - Sugata Chowdhury
- Department of Physics and Astrophysics, Howard University, Washington, DC 20059, USA
| | - Arun Bansil
- Department of Physics, Northeastern University, Boston, MA 02115, USA
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5
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Smith JG, Sawant KJ, Zeng Z, Eldred TB, Wu J, Greeley JP, Gao W. Disproportionation chemistry in K 2PtCl 4 visualized at atomic resolution using scanning transmission electron microscopy. SCIENCE ADVANCES 2024; 10:eadi0175. [PMID: 38335285 PMCID: PMC10857378 DOI: 10.1126/sciadv.adi0175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Accepted: 01/10/2024] [Indexed: 02/12/2024]
Abstract
The direct observation of a solid-state chemical reaction can reveal otherwise hidden mechanisms that control the reaction kinetics. However, probing the chemical bond breaking and formation at the molecular level remains challenging because of the insufficient spatial-temporal resolution and composition analysis of available characterization methods. Using atomic-resolution differential phase-contrast imaging in scanning transmission electron microscopy, we have visualized the decomposition chemistry of K2PtCl4 to identify its transient intermediate phases and their interfaces that characterize the chemical reduction process. The crystalline structure of K2PtCl4 is found to undergo a disproportionation reaction to form K2PtCl6, followed by gradual reduction to crystalline Pt metal and KCl. By directly imaging different Pt─Cl bond configurations and comparing them to models predicted via density functional theory calculations, a causal connection between the initial and final states of a chemical reaction is established, showcasing new opportunities to resolve reaction pathways through atomistic experimental visualization.
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Affiliation(s)
- Jacob G. Smith
- Future Material Innovation Center, Zhangjiang Institute for Advanced Study, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
- Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC 27695, USA
| | - Kaustubh J. Sawant
- Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN 47907, USA
| | - Zhenhua Zeng
- Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN 47907, USA
| | - Tim B. Eldred
- Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC 27695, USA
| | - Jianbo Wu
- Future Material Innovation Center, Zhangjiang Institute for Advanced Study, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
- State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai, P. R. China
- Center of Hydrogen Science, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Jeffrey P. Greeley
- Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN 47907, USA
| | - Wenpei Gao
- Future Material Innovation Center, Zhangjiang Institute for Advanced Study, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
- Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC 27695, USA
- State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai, P. R. China
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6
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Chen W, Chen Q, Zhang J, Zhou L, Tang W, Wang Z, Deng J, Wang S. Electronic and magnetic properties of transition-metal-doped monolayer B 2S 2 within GGA + U framework. RSC Adv 2024; 14:3390-3399. [PMID: 38259982 PMCID: PMC10801446 DOI: 10.1039/d3ra08472h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Accepted: 01/16/2024] [Indexed: 01/24/2024] Open
Abstract
Considering the significant role of magnetism induction in two-dimensional (2D) semiconductor materials, we systematically investigate the effects of various dopants from the 3d and 4d transition metal (TM) series, including Ti, V, Mn, Fe, Co, Ni, Cu, Zn, Zr, Nb, Mo, Ru, Rh, Pd, Ag and Cd, on the electronic and magnetic properties of monolayer B2S2 through first-principles calculations. The calculated formation energies indicate that substitutional doping at the B site with various TM atoms could be achieved under S-rich growth conditions. What matters is that with the exception of systems doped with Cu, Tc, and Ag elements, which exhibit non-magnetic semiconductor properties, all other doped systems demonstrate magnetism. Specifically, the Cr-, Ni- and Pd-doped monolayers are magnetic half-metals, while the rest are magnetic semiconductors. We have also performed calculations of magnetic couplings between two TM atoms with an impurity concentration of 3.12%, revealing the prevalence of weak magnetic coupling in the majority of the magnetic systems examined. Moreover, the monolayers doped with Cr, Zr and Pd atoms exhibit ferromagnetic ground states. These findings strongly support the high potential for inducing magnetism in the B2S2 monolayer through B-site doping.
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Affiliation(s)
- Wei Chen
- School of Electronic Information and Electrical Engineering, Changsha University Changsha 410022 China
| | - Qi Chen
- Zhongxiang No. 2 Middle School Jingmen 431900 China
| | - Jianming Zhang
- Institute of Physics and Electronic Information, Yunnan Normal University Kunming 650500 China
| | - Lin Zhou
- School of Electronic Information and Electrical Engineering, Changsha University Changsha 410022 China
| | - Wenxiao Tang
- School of Electronic Information and Electrical Engineering, Changsha University Changsha 410022 China
| | - Zhiyou Wang
- School of Electronic Information and Electrical Engineering, Changsha University Changsha 410022 China
| | - Jiwei Deng
- School of Electronic Information and Electrical Engineering, Changsha University Changsha 410022 China
| | - Shifeng Wang
- College of Information Engineering, Hunan Industry Polytechnic 410000 China
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7
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Dyck O, Lupini AR, Jesse S. A Platform for Atomic Fabrication and In Situ Synthesis in a Scanning Transmission Electron Microscope. SMALL METHODS 2023; 7:e2300401. [PMID: 37415539 DOI: 10.1002/smtd.202300401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 05/30/2023] [Indexed: 07/08/2023]
Abstract
The engineering of quantum materials requires the development of tools able to address various synthesis and characterization challenges. These include the establishment and refinement of growth methods, material manipulation, and defect engineering. Atomic-scale modification will be a key enabling factor for engineering quantum materials where desired phenomena are critically determined by atomic structures. Successful use of scanning transmission electron microscopes (STEMs) for atomic scale material manipulation has opened the door for a transformed view of what can be accomplished using electron-beam-based strategies. However, serious obstacles exist on the pathway from possibility to practical reality. One such obstacle is the in situ delivery of atomized material in the STEM to the region of interest for further fabrication processes. Here, progress on this front is presented with a view toward performing synthesis (deposition and growth) processes in a scanning transmission electron microscope in combination with top-down control over the reaction region. An in situ thermal deposition platform is presented, tested, and deposition and growth processes are demonstrated. In particular, it is shown that isolated Sn atoms can be evaporated from a filament and caught on the nearby sample, demonstrating atomized material delivery. This platform is envisioned to facilitate real-time atomic resolution imaging of growth processes and open new pathways toward atomic fabrication.
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Affiliation(s)
- Ondrej Dyck
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, 1 Bethel Valley Rd., Oak Ridge, TN, 37830, USA
| | - Andrew R Lupini
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, 1 Bethel Valley Rd., Oak Ridge, TN, 37830, USA
| | - Stephen Jesse
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, 1 Bethel Valley Rd., Oak Ridge, TN, 37830, USA
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8
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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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9
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Boebinger MG, Roccapriore KM, Ghosh A, Xiao K, Lupini AR, Ziatdinov M, Kalinin SV, Unocic RR. Fabrication of Atomic-scale Defect Structures within 2D Materials through Automated Electron Beam Control. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2023; 29:1380-1381. [PMID: 37613555 DOI: 10.1093/micmic/ozad067.710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/25/2023]
Affiliation(s)
- Matthew G Boebinger
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Kevin M Roccapriore
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Ayana Ghosh
- Computational Sciences and Engineering Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Kai Xiao
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Andrew R Lupini
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Maxim Ziatdinov
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, USA
- Computational Sciences and Engineering Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Sergei V Kalinin
- Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN, USA
| | - Raymond R Unocic
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, USA
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10
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Postl A, Kozyrau E, Madsen J, Susi T. Challenges for Scaling Up Electron-Beam Manipulation of Graphene Impurities. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2023; 29:1370-1371. [PMID: 37613695 DOI: 10.1093/micmic/ozad067.704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/25/2023]
Affiliation(s)
- Andreas Postl
- University of Vienna, Faculty of Physics, ViennaAustria
| | - Eugen Kozyrau
- University of Vienna, Faculty of Physics, ViennaAustria
| | - Jacob Madsen
- University of Vienna, Faculty of Physics, ViennaAustria
| | - Toma Susi
- University of Vienna, Faculty of Physics, ViennaAustria
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11
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Hudak BM, Stroud RM. Atomically Precise Detection and Manipulation of Nitrogen-Vacancy Centers in Nanodiamonds. ACS NANO 2023; 17:7241-7249. [PMID: 37027786 PMCID: PMC10134494 DOI: 10.1021/acsnano.2c10122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Accepted: 03/30/2023] [Indexed: 06/19/2023]
Abstract
Nitrogen-vacancy (NV) centers in nanodiamonds are a promising quantum communication system offering robust and discrete single photon emission, but a more thorough understanding of properties of the NV centers is critical for real world implementation in functional devices. The first step to understanding how factors such as surface, depth, and charge state affect NV center properties is to directly characterize these defects on the atomic scale. Here we use Angstrom-resolution scanning transmission electron microscopy (STEM) to identify a single NV center in a ∼4 nm natural nanodiamond through simultaneous acquisition of electron energy loss and energy dispersive X-ray spectra, which provide a characteristic NV center peak and a nitrogen peak, respectively. In addition, we identify NV centers in larger, ∼15 nm synthetic nanodiamonds, although without the single-defect resolution afforded by the lower background of the smaller natural nanodiamonds. We have further demonstrated the potential to directly position these technologically relevant defects at the atomic scale using the scanning electron beam to "herd" NV centers and nitrogen atoms across their host nanodiamonds.
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12
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Boebinger MG, Brea C, Ding LP, Misra S, Olunloyo O, Yu Y, Xiao K, Lupini AR, Ding F, Hu G, Ganesh P, Jesse S, Unocic RR. The Atomic Drill Bit: Precision Controlled Atomic Fabrication of 2D Materials. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2210116. [PMID: 36635517 DOI: 10.1002/adma.202210116] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 01/02/2023] [Indexed: 06/17/2023]
Abstract
The ability to deterministically fabricate nanoscale architectures with atomic precision is the central goal of nanotechnology, whereby highly localized changes in the atomic structure can be exploited to control device properties at their fundamental physical limit. Here, an automated, feedback-controlled atomic fabrication method is reported and the formation of 1D-2D heterostructures in MoS2 is demonstrated through selective transformations along specific crystallographic orientations. The atomic-scale probe of an aberration-corrected scanning transmission electron microscope (STEM) is used, and the shape and symmetry of the scan pathway relative to the sample orientation are controlled. The focused and shaped electron beam is used to reliably create Mo6 S6 nanowire (MoS-NW) terminated metallic-semiconductor 1D-2D edge structures within a pristine MoS2 monolayer with atomic precision. From these results, it is found that a triangular beam path aligned along the zig-zag sulfur terminated (ZZS) direction forms stable MoS-NW edge structures with the highest degree of fidelity without resulting in disordering of the surrounding MoS2 monolayer. Density functional theory (DFT) calculations and ab initio molecular dynamic simulations (AIMD) are used to calculate the energetic barriers for the most stable atomic edge structures and atomic transformation pathways. These discoveries provide an automated method to improve understanding of atomic-scale transformations while opening a pathway toward more precise atomic-scale engineering of materials.
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Affiliation(s)
- Matthew G Boebinger
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN, 37830, USA
| | - Courtney Brea
- Department of Chemistry and Biochemistry, Queens College, City University of New York, 65-30 Kissena Blvd, Flushing, NY, 11367, USA
| | - Li-Ping Ding
- Department of Physics, Shaanxi University of Science and Technology, Xi'an Weiyang University Park, Xi'an, Shaanxi Province, China
| | - Sudhajit Misra
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN, 37830, USA
| | - Olugbenga Olunloyo
- Department of Physics and Astronomy, University of Tennessee, 1408 Circle Dr, Knoxville, TN, 37996, USA
| | - Yiling Yu
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN, 37830, USA
- School of Physics and Technology, Wuhan University, Wuchang District, Wuhan, Hubei, 430072, China
| | - Kai Xiao
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN, 37830, USA
| | - Andrew R Lupini
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN, 37830, USA
| | - Feng Ding
- Centre for Multidimensional Carbon Materials, Institute for Basic Science, 50 UNIST-gil, Ulsan, 44919, South Korea
- School of Materials Science and Engineering, Ulsan Institute of Science and Technology, 50 UNIST-gil, Ulsan, 44919, South Korea
| | - Guoxiang Hu
- Department of Chemistry and Biochemistry, Queens College, City University of New York, 65-30 Kissena Blvd, Flushing, NY, 11367, USA
| | - Panchapakesan Ganesh
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN, 37830, USA
| | - Stephen Jesse
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN, 37830, USA
| | - Raymond R Unocic
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN, 37830, USA
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13
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Dyck O, Lupini AR, Jesse S. Atom-by-Atom Direct Writing. NANO LETTERS 2023; 23:2339-2346. [PMID: 36877825 DOI: 10.1021/acs.nanolett.3c00114] [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
Direct-write processes enable the alteration or deposition of materials in a continuous, directable, sequential fashion. In this work, we demonstrate an electron beam direct-write process in an aberration-corrected scanning transmission electron microscope. This process has several fundamental differences from conventional electron-beam-induced deposition techniques, where the electron beam dissociates precursor gases into chemically reactive products that bond to a substrate. Here, we use elemental tin (Sn) as a precursor and employ a different mechanism to facilitate deposition. The atomic-sized electron beam is used to generate chemically reactive point defects at desired locations in a graphene substrate. Temperature control of the sample is used to enable the precursor atoms to migrate across the surface and bond to the defect sites, thereby enabling atom-by-atom direct writing.
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Affiliation(s)
- Ondrej Dyck
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States
| | - Andrew R Lupini
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States
| | - Stephen Jesse
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States
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14
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Zhang W, Chao P, Chen D, Yang Z, Dong L. A Core-Shell MWCNT-Pt Nanowire Electron Source with Anomalously Long-Term Stable Field Emission. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:532. [PMID: 36770493 PMCID: PMC9921140 DOI: 10.3390/nano13030532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 01/25/2023] [Accepted: 01/26/2023] [Indexed: 06/18/2023]
Abstract
A hybrid core-shell structured nanowire is proposed for a long-term stable electron source based on an isolated platinum/multi-walled carbon nanotube (Pt/MWCNT). This hybrid nanowire is prepared by growing a Pt shell on a metallic MWCNT through a field-emission-induced deposition (FEID) method. An in situ field emission (FE) platform was constructed inside a scanning electron microscope (SEM) equipped with two nanorobotic manipulators (NRMs) for the preparation and testing of the hybrid nanowire. An in situ fatigue test was conducted with high current intensity (500 nA) to show the influence of the Pt shell. Compared with the pristine bare MWCNT, our hybrid-nanowire-based electron source has a lifetime of hundreds of times longer and can work continuously for up to 48 h under relatively high pressure (3.6×10-3 Pa) without having an apparent change in its structure or emission currents, demonstrating good stability and tolerance to poor working conditions. The anomalous long-term stability is attributed mainly to the shielding of oxygen by Pt from the carbon shells and less heating due to the work function lowering by Pt.
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Affiliation(s)
- Wenqi Zhang
- Jiangsu Provincial Key Laboratory of Advanced Robotics, School of Mechanical and Electric Engineering, Soochow University; Suzhou 215000, China
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong 999077, China
| | - Peidong Chao
- Jiangsu Provincial Key Laboratory of Advanced Robotics, School of Mechanical and Electric Engineering, Soochow University; Suzhou 215000, China
| | - Donglei Chen
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong 999077, China
| | - Zhan Yang
- Jiangsu Provincial Key Laboratory of Advanced Robotics, School of Mechanical and Electric Engineering, Soochow University; Suzhou 215000, China
| | - Lixin Dong
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong 999077, China
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15
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Grushevskaya H, Timoshchenko A, Lipnevich I. Topological Defects Created by Gamma Rays in a Carbon Nanotube Bilayer. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:410. [PMID: 36770369 PMCID: PMC9921100 DOI: 10.3390/nano13030410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 12/29/2022] [Accepted: 01/07/2023] [Indexed: 06/18/2023]
Abstract
Graphene sheets are a highly radiation-resistant material for prospective nuclear applications and nanoscale defect engineering. However, the precise mechanism of graphene radiation hardness has remained elusive. In this paper, we study the origin and nature of defects induced by gamma radiation in a graphene rolled-up plane. In order to reduce the environmental influence on graphene and reveal the small effects of gamma rays, we have synthesized a novel graphene-based nanocomposite material containing a bilayer of highly aligned carbon nanotube assemblies that have been decorated by organometallic compounds and suspended on nanoporous Al2O3 membranes. The bilayer samples were irradiated by gamma rays from a 137Cs source with a fluence rate of the order of 105 m-2s-1. The interaction between the samples and gamma quanta results in the appearance of three characteristic photon escape peaks in the radiation spectra. We explain the mechanism of interaction between the graphene sheets and gamma radiation using a pseudo-Majorana fermion graphene model, which is a quasi-relativistic N=3-flavor graphene model with a Majorana-like mass term. This model admits the existence of giant charge carrier currents that are sufficient to neutralize the impact of ionizing radiation. Experimental evidence is provided for the prediction that the 661.7-keV gamma quanta transfer enough energy to the electron subsystem of graphene to bring about the deconfinement of the bound pseudo-Majorana modes and involve C atoms in a vortical motion of the electron density flows in the graphene plane. We explain the radiation hardness of graphene by the topological non-triviality of the pseudo-Majorana fermion configurations comprising the graphene charge carriers.
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16
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Biswas H, Mahalingam H, Rodin A. Numerical package for QFT calculations of defect-induced phenomena in graphene. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2022; 51:025902. [PMID: 36327462 DOI: 10.1088/1361-648x/aca002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Accepted: 11/03/2022] [Indexed: 06/16/2023]
Abstract
We introduce a computationally efficient method based on the path integral formalism to describe defect-modified graphene. By taking into account the entire Brillouin zone, our approach respects the lattice symmetry and can be used to investigate both short-range and long-range effects. The proposed method's key advantage is that the computational complexity does not increase with the system size, scaling, instead, with the number of defects. Our aim is to make the quantum-field calculations in graphene accessible to the experimental community. We demonstrate our method's capabilities by exploring the well-known graphene-mediated Ruderman-Kittel-Kasuya-Yoshida interaction and by performing a detailed study of the atomic collapse in the presence of defects.
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Affiliation(s)
- Hillol Biswas
- Department of Physics, National University of Singapore, 2 Science Drive 3, 117542, Singapore
- Centre for Advanced 2D Materials, National University of Singapore, 6 Science Drive 2, 117546, Singapore
| | - Harshitra Mahalingam
- Institute for Functional Intelligent Materials, National University of Singapore, 4 Science Drive 2, 117544, Singapore
| | - Aleksandr Rodin
- Centre for Advanced 2D Materials, National University of Singapore, 6 Science Drive 2, 117546, Singapore
- Yale-NUS College, 16 College Avenue West, 138527, Singapore
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17
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Telychko M, Noori K, Biswas H, Dulal D, Chen Z, Lyu P, Li J, Tsai HZ, Fang H, Qiu Z, Yap ZW, Watanabe K, Taniguchi T, Wu J, Loh KP, Crommie MF, Rodin A, Lu J. Gate-Tunable Resonance State and Screening Effects for Proton-Like Atomic Charge in Graphene. NANO LETTERS 2022; 22:8422-8429. [PMID: 36214509 DOI: 10.1021/acs.nanolett.2c02235] [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
The ability to create a robust and well-defined artificial atomic charge in graphene and understand its carrier-dependent electronic properties represents an important goal toward the development of graphene-based quantum devices. Herein, we devise a new pathway toward the atomically precise embodiment of point charges into a graphene lattice by posterior (N) ion implantation into a back-gated graphene device. The N dopant behaves as an in-plane proton-like charge manifested by formation of the characteristic resonance state in the conduction band. Scanning tunneling spectroscopy measurements at varied charge carrier densities reveal a giant energetic renormalization of the resonance state up to 220 meV with respect to the Dirac point, accompanied by the observation of gate-tunable long-range screening effects close to individual N dopants. Joint density functional theory and tight-binding calculations with modified perturbation potential corroborate experimental findings and highlight the short-range character of N-induced perturbation.
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Affiliation(s)
- Mykola Telychko
- Department of Chemistry, National University of Singapore, 117543, Singapore
| | - Keian Noori
- Institute for Functional Intelligent Materials, National University of Singapore, 117544, Singapore
- Centre for Advanced 2D Materials, National University of Singapore, 117543, Singapore
| | - Hillol Biswas
- Centre for Advanced 2D Materials, National University of Singapore, 117543, Singapore
- Department of Physics, National University of Singapore, 2 Science Drive 3, 117542, Singapore
| | - Dikshant Dulal
- Yale-NUS College, 16 College Avenue West, 138527, Singapore
| | - Zhaolong Chen
- Institute for Functional Intelligent Materials, National University of Singapore, 117544, Singapore
| | - Pin Lyu
- Department of Chemistry, National University of Singapore, 117543, Singapore
| | - Jing Li
- Centre for Advanced 2D Materials, National University of Singapore, 117543, Singapore
| | - Hsin-Zon Tsai
- Department of Physics, University of California, Berkeley94720, California, United States
| | - Hanyan Fang
- Department of Chemistry, National University of Singapore, 117543, Singapore
| | - Zhizhan Qiu
- Department of Chemistry, National University of Singapore, 117543, Singapore
| | - Zhun Wai Yap
- Yale-NUS College, 16 College Avenue West, 138527, Singapore
| | - Kenji Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba305-0044, Japan
| | - Takashi Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba305-0044, Japan
| | - Jing Wu
- Institute of Materials Research and Engineering, Agency for Science, Technology and Research, 08-03, 2 Fusionopolis Way, Singapore138634, Singapore
| | - Kian Ping Loh
- Department of Chemistry, National University of Singapore, 117543, Singapore
| | - Michael F Crommie
- Department of Physics, University of California, Berkeley94720, California, United States
| | - Aleksandr Rodin
- Centre for Advanced 2D Materials, National University of Singapore, 117543, Singapore
- Yale-NUS College, 16 College Avenue West, 138527, Singapore
| | - Jiong Lu
- Department of Chemistry, National University of Singapore, 117543, Singapore
- Institute for Functional Intelligent Materials, National University of Singapore, 117544, Singapore
- Centre for Advanced 2D Materials, National University of Singapore, 117543, Singapore
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18
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Susi T. Identifying and manipulating single atoms with scanning transmission electron microscopy. Chem Commun (Camb) 2022; 58:12274-12285. [PMID: 36260089 PMCID: PMC9632407 DOI: 10.1039/d2cc04807h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 09/28/2022] [Indexed: 08/25/2023]
Abstract
The manipulation of individual atoms has developed from visionary speculation into an established experimental science. Using focused electron irradiation in a scanning transmission electron microscope instead of a physical tip in a scanning probe microscope confers several benefits, including thermal stability of the manipulated structures, the ability to reach into bulk crystals, and the chemical identification of single atoms. However, energetic electron irradiation also presents unique challenges, with an inevitable possibility of irradiation damage. Understanding the underlying mechanisms will undoubtedly continue to play an important role to guide experiments. Great progress has been made in several materials including graphene, carbon nanotubes, and crystalline silicon in the eight years since the discovery of electron-beam manipulation, but the important challenges that remain will determine how far we can expect to progress in the near future.
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Affiliation(s)
- Toma Susi
- University of Vienna, Faculty of Physics, Boltzmanngasse 5, 1090 Vienna, Austria.
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19
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Roccapriore KM, Huang N, Oxley MP, Sharma V, Taylor T, Acharya S, Pashov D, Katsnelson MI, Mandrus D, Musfeldt JL, Kalinin SV. Electron-Beam Induced Emergence of Mesoscopic Ordering in Layered MnPS 3. ACS NANO 2022; 16:16713-16723. [PMID: 36174128 DOI: 10.1021/acsnano.2c06253] [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
Ordered mesoscale structures in 2D materials induced by small misorientations have allowed for a wide variety of electronic, ferroelectric, and quantum phenomena to be explored. Until now, the only mechanism to induce this periodic ordering was via mechanical rotations between the layers, with the periodicity of the resulting moiré pattern being directly related to twist angle. Here we report a fundamentally distinct mechanism for emergence of mesoscopic periodic patterns in multilayer sulfur-containing metal phosphorus trichalcogenide, MnPS3, induced by the electron beam. The formation under the beam of periodic hexagonal patterns with several characteristic length scales, nucleation and transitions between the phases, and local dynamics are demonstrated. The associated mechanisms are attributed to the relative contraction of the layers caused by beam-induced sulfur vacancy formation with subsequent ordering and lattice parameter change. As a result, the plasmonic response of the system is locally altered, suggesting an element of control over plasmon resonances by electron beam patterning. We pose that harnessing this phenomenon provides both insight into fundamental physics of quantum materials and enables device applications by enabling controlled periodic potentials on the atomic scale.
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Affiliation(s)
- Kevin M Roccapriore
- The Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Nan Huang
- Department of Materials Science and Engineering, University of Tennessee, Knoxville Tennessee 37916, United States
| | - Mark P Oxley
- The Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Vinit Sharma
- Computational Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
- National Institute for Computational Sciences, University of Tennessee, Knoxville Tennessee 37831, United States
| | - Timothy Taylor
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Swagata Acharya
- Institute for Molecules and Materials, Radboud University, NL-6525 AJ Nijmegen, The Netherlands
| | - Dimitar Pashov
- Theory and Simulation of Condensed Matter, King's College London, The Strand, WC2R 2LS London, U.K
| | - Mikhail I Katsnelson
- Institute for Molecules and Materials, Radboud University, NL-6525 AJ Nijmegen, The Netherlands
| | - David Mandrus
- Department of Materials Science and Engineering, University of Tennessee, Knoxville Tennessee 37916, United States
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Janice L Musfeldt
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Sergei V Kalinin
- Department of Materials Science and Engineering, University of Tennessee, Knoxville Tennessee 37916, United States
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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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Ugartemendia A, Garcia Lekue A, Jimenez Izal E. Tailoring magnetism in silicon-doped zigzag graphene edges. Sci Rep 2022; 12:13032. [PMID: 35906454 PMCID: PMC9338279 DOI: 10.1038/s41598-022-16902-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 07/18/2022] [Indexed: 11/18/2022] Open
Abstract
Recently, the edges of single-layer graphene have been experimentally doped with silicon atoms by means of scanning transmission electron microscopy. In this work, density functional theory is applied to model and characterize a wide range of experimentally inspired silicon doped zigzag-type graphene edges. The thermodynamic stability is assessed and the electronic and magnetic properties of the most relevant edge configurations are unveiled. Importantly, we show that silicon doping of graphene edges can induce a reversion of the spin orientation on the adjacent carbon atoms, leading to novel magnetic properties with possible applications in the field of spintronics.
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Affiliation(s)
- Andoni Ugartemendia
- Polimero eta Material Aurreratuak Fisika, Kimika eta Teknologia Saila, Kimika Fakultatea, Euskal Herriko Unibertsitatea (UPV/EHU), M. de Lardizabal Pasealekua 3, Donostia, Euskadi, Spain.,Donostia International Physics Center (DIPC), M. de Lardizabal Pasealekua 3, Donostia, Euskadi, Spain
| | - Aran Garcia Lekue
- Donostia International Physics Center (DIPC), M. de Lardizabal Pasealekua 3, Donostia, Euskadi, Spain. .,IKERBASQUE, Basque Foundation for Science, Bilbao, Euskadi, Spain.
| | - Elisa Jimenez Izal
- Polimero eta Material Aurreratuak Fisika, Kimika eta Teknologia Saila, Kimika Fakultatea, Euskal Herriko Unibertsitatea (UPV/EHU), M. de Lardizabal Pasealekua 3, Donostia, Euskadi, Spain. .,Donostia International Physics Center (DIPC), M. de Lardizabal Pasealekua 3, Donostia, Euskadi, Spain. .,IKERBASQUE, Basque Foundation for Science, Bilbao, Euskadi, Spain.
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22
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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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23
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Haas J, Ulrich F, Hofer C, Wang X, Braun K, Meyer JC. Aligned Stacking of Nanopatterned 2D Materials for High-Resolution 3D Device Fabrication. ACS NANO 2022; 16:1836-1846. [PMID: 35104934 DOI: 10.1021/acsnano.1c09122] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Two-dimensional materials can be combined by placing individual layers on top of each other, so that they are bound only by their van der Waals interaction. The sequence of layers can be chosen arbitrarily, enabling an essentially atomic-level control of the material and thereby a wide choice of properties along one dimension. However, simultaneous control over the structure in the in-plane directions is so far still rather limited. Here, we combine spatially controlled modifications of 2D materials, using focused electron irradiation or electron beam induced etching, with the layer-by-layer assembly of van der Waals heterostructures. The presented assembly process makes it possible to structure each layer with an arbitrary pattern prior to the assembly into the heterostructure. Moreover, it enables a stacking of the layers with accurate lateral alignment, with an accuracy of currently 10 nm, under observation in an electron microscope. Together, this enables the fabrication of almost arbitrary 3D structures with highest spatial resolution.
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Affiliation(s)
- Jonas Haas
- Institute of Applied Physics, Eberhard Karls University of Tuebingen, Auf der Morgenstelle 10, D-72076, Tuebingen, Germany
- Natural and Medical Sciences Institute at the University of Tuebingen, Markwiesenstr. 55, D-72770 Reutlingen, Germany
| | - Finn Ulrich
- Institute of Applied Physics, Eberhard Karls University of Tuebingen, Auf der Morgenstelle 10, D-72076, Tuebingen, Germany
- Natural and Medical Sciences Institute at the University of Tuebingen, Markwiesenstr. 55, D-72770 Reutlingen, Germany
| | - Christoph Hofer
- Institute of Applied Physics, Eberhard Karls University of Tuebingen, Auf der Morgenstelle 10, D-72076, Tuebingen, Germany
- Natural and Medical Sciences Institute at the University of Tuebingen, Markwiesenstr. 55, D-72770 Reutlingen, Germany
| | - Xiao Wang
- School of Physics and Electronics, Hunan University, Changsha, Hunan 410082, China
| | - Kai Braun
- Institute of Physical and Theoretical Chemistry, Eberhard Karls University of Tuebingen, Auf der Morgenstelle 18, D-72076, Tuebingen, Germany
| | - Jannik C Meyer
- Institute of Applied Physics, Eberhard Karls University of Tuebingen, Auf der Morgenstelle 10, D-72076, Tuebingen, Germany
- Natural and Medical Sciences Institute at the University of Tuebingen, Markwiesenstr. 55, D-72770 Reutlingen, Germany
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24
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Creange N, Dyck O, Vasudevan RK, Ziatdinov M, Kalinin SV. Towards automating structural discovery in scanning transmission electron microscopy
*. MACHINE LEARNING: SCIENCE AND TECHNOLOGY 2022. [DOI: 10.1088/2632-2153/ac3844] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
Scanning transmission electron microscopy is now the primary tool for exploring functional materials on the atomic level. Often, features of interest are highly localized in specific regions in the material, such as ferroelectric domain walls, extended defects, or second phase inclusions. Selecting regions to image for structural and chemical discovery via atomically resolved imaging has traditionally proceeded via human operators making semi-informed judgements on sampling locations and parameters. Recent efforts at automation for structural and physical discovery have pointed towards the use of ‘active learning’ methods that utilize Bayesian optimization with surrogate models to quickly find relevant regions of interest. Yet despite the potential importance of this direction, there is a general lack of certainty in selecting relevant control algorithms and how to balance a priori knowledge of the material system with knowledge derived during experimentation. Here we address this gap by developing the automated experiment workflows with several combinations to both illustrate the effects of these choices and demonstrate the tradeoffs associated with each in terms of accuracy, robustness, and susceptibility to hyperparameters for structural discovery. We discuss possible methods to build descriptors using the raw image data and deep learning based semantic segmentation, as well as the implementation of variational autoencoder based representation. Furthermore, each workflow is applied to a range of feature sizes including NiO pillars within a La:SrMnO3 matrix, ferroelectric domains in BiFeO3, and topological defects in graphene. The code developed in this manuscript is open sourced and will be released at github.com/nccreang/AE_Workflows.
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25
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Vasudevan RK, Ghosh A, Ziatdinov M, Kalinin SV. Exploring electron beam induced atomic assembly via reinforcement learning in a molecular dynamics environment . NANOTECHNOLOGY 2021; 33:115301. [PMID: 34768249 DOI: 10.1088/1361-6528/ac394a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Accepted: 11/12/2021] [Indexed: 06/13/2023]
Abstract
Atom-by-atom assembly of functional materials and devices is perceived as one of the ultimate targets of nanotechnology. Recently it has been shown that the beam of a scanning transmission electron microscope can be used for targeted manipulation of individual atoms. However, the process is highly dynamic in nature rendering control difficult. One possible solution is to instead train artificial agents to perform the atomic manipulation in an automated manner without need for human intervention. As a first step to realizing this goal, we explore how artificial agents can be trained for atomic manipulation in a simplified molecular dynamics environment of graphene with Si dopants, using reinforcement learning. We find that it is possible to engineer the reward function of the agent in such a way as to encourage formation of local clusters of dopants under different constraints. This study shows the potential for reinforcement learning in nanoscale fabrication, and crucially, that the dynamics learned by agents encode specific elements of important physics that can be learned.
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Affiliation(s)
- Rama K Vasudevan
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States of America
| | - Ayana Ghosh
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States of America
- Computational Sciences and Engineering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States of America
| | - Maxim Ziatdinov
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States of America
- Computational Sciences and Engineering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States of America
| | - Sergei V Kalinin
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States of America
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26
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Thiemann FL, Rowe P, Zen A, Müller EA, Michaelides A. Defect-Dependent Corrugation in Graphene. NANO LETTERS 2021; 21:8143-8150. [PMID: 34519502 DOI: 10.1021/acs.nanolett.1c02585] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Graphene's intrinsically corrugated and wrinkled topology fundamentally influences its electronic, mechanical, and chemical properties. Experimental techniques allow the manipulation of pristine graphene and the controlled production of defects which allows one to control the atomic out-of-plane fluctuations and thus tune graphene's properties. Here, we perform large scale machine learning-driven molecular dynamics simulations to understand the impact of defects on the structure of graphene. We find that defects cause significantly higher corrugation leading to a strongly wrinkled surface. The magnitude of this structural transformation strongly depends on the defect concentration and specific type of defect. Analyzing the atomic neighborhood of the defects reveals that the extent of these morphological changes depends on the preferred geometrical orientation and the interactions between defects. While our work highlights that defects can strongly affect graphene's morphology, it also emphasizes the differences between distinct types by linking the global structure to the local environment of the defects.
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Affiliation(s)
- Fabian L Thiemann
- Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, United Kingdom
- Thomas Young Centre and London Centre for Nanotechnology, 17-19 Gordon Street, London WC1H 0AH, United Kingdom
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
- Department of Chemical Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom
| | - Patrick Rowe
- Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, United Kingdom
- Thomas Young Centre and London Centre for Nanotechnology, 17-19 Gordon Street, London WC1H 0AH, United Kingdom
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
| | - Andrea Zen
- Thomas Young Centre and London Centre for Nanotechnology, 17-19 Gordon Street, London WC1H 0AH, United Kingdom
- Dipartimento di Fisica Ettore Pancini, Università di Napoli Federico II, Monte S. Angelo, I-80126 Napoli, Italy
- Department of Earth Sciences, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Erich A Müller
- Department of Chemical Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom
| | - Angelos Michaelides
- Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, United Kingdom
- Thomas Young Centre and London Centre for Nanotechnology, 17-19 Gordon Street, London WC1H 0AH, United Kingdom
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
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27
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Elibol K, Mangler C, O’Regan DD, Mustonen K, Eder D, Meyer JC, Kotakoski J, Hobbs RG, Susi T, Bayer BC. Single Indium Atoms and Few-Atom Indium Clusters Anchored onto Graphene via Silicon Heteroatoms. ACS NANO 2021; 15:14373-14383. [PMID: 34410707 PMCID: PMC8482752 DOI: 10.1021/acsnano.1c03535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 08/10/2021] [Indexed: 06/13/2023]
Abstract
Single atoms and few-atom nanoclusters are of high interest in catalysis and plasmonics, but pathways for their fabrication and placement remain scarce. We report here the self-assembly of room-temperature-stable single indium (In) atoms and few-atom In clusters (2-6 atoms) that are anchored to substitutional silicon (Si) impurity atoms in suspended monolayer graphene membranes. Using atomically resolved scanning transmission electron microscopy (STEM), we find that the symmetry of the In structures is critically determined by the three- or fourfold coordination of the Si "anchors". All structures are produced without electron-beam induced materials modification. In turn, when activated by electron beam irradiation in the STEM, we observe in situ the formation, restructuring, and translation of the Si-anchored In structures. Our results on In-Si-graphene provide a materials system for controlled self-assembly and heteroatomic anchoring of single atoms and few-atom nanoclusters on graphene.
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Affiliation(s)
- Kenan Elibol
- University
of Vienna, Faculty of Physics, Boltzmanngasse 5, A-1090, Vienna, Austria
- Centre
for Research on Adaptive Nanostructures and Nanodevices (CRANN) and
the SFI Advanced Materials and Bio-Engineering Research Centre (AMBER), Dublin 2, Ireland
- School
of Chemistry, Trinity College Dublin, The
University of Dublin, Dublin 2, Ireland
| | - Clemens Mangler
- University
of Vienna, Faculty of Physics, Boltzmanngasse 5, A-1090, Vienna, Austria
| | - David D. O’Regan
- Centre
for Research on Adaptive Nanostructures and Nanodevices (CRANN) and
the SFI Advanced Materials and Bio-Engineering Research Centre (AMBER), Dublin 2, Ireland
- School
of Physics, Trinity College Dublin, The
University of Dublin, Dublin 2, Ireland
| | - Kimmo Mustonen
- University
of Vienna, Faculty of Physics, Boltzmanngasse 5, A-1090, Vienna, Austria
| | - Dominik Eder
- Institute
of Materials Chemistry, Vienna University
of Technology (TU Wien), Getreidemarkt 9/165, A-1060 Vienna, Austria
| | - Jannik C. Meyer
- University
of Vienna, Faculty of Physics, Boltzmanngasse 5, A-1090, Vienna, Austria
- Institute
for Applied Physics, University of Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany
| | - Jani Kotakoski
- University
of Vienna, Faculty of Physics, Boltzmanngasse 5, A-1090, Vienna, Austria
| | - Richard G. Hobbs
- Centre
for Research on Adaptive Nanostructures and Nanodevices (CRANN) and
the SFI Advanced Materials and Bio-Engineering Research Centre (AMBER), Dublin 2, Ireland
- School
of Chemistry, Trinity College Dublin, The
University of Dublin, Dublin 2, Ireland
| | - Toma Susi
- University
of Vienna, Faculty of Physics, Boltzmanngasse 5, A-1090, Vienna, Austria
| | - Bernhard C. Bayer
- University
of Vienna, Faculty of Physics, Boltzmanngasse 5, A-1090, Vienna, Austria
- Institute
of Materials Chemistry, Vienna University
of Technology (TU Wien), Getreidemarkt 9/165, A-1060 Vienna, Austria
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28
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Dyck O, Lupini AR, Rack PD, Fowlkes J, Jesse S. Controlling hydrocarbon transport and electron beam induced deposition on single layer graphene: Toward atomic scale synthesis in the scanning transmission electron microscope. NANO SELECT 2021. [DOI: 10.1002/nano.202100188] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Affiliation(s)
- Ondrej Dyck
- Oak Ridge National Laboratory Center for Nanophase Materials Science Oak Ridge Tennessee USA
| | - Andrew R. Lupini
- Oak Ridge National Laboratory Center for Nanophase Materials Science Oak Ridge Tennessee USA
| | - Philip D. Rack
- Oak Ridge National Laboratory Center for Nanophase Materials Science Oak Ridge Tennessee USA
- Department of Materials Science and Engineering University of Tennessee Knoxville Tennessee USA
| | - Jason Fowlkes
- Oak Ridge National Laboratory Center for Nanophase Materials Science Oak Ridge Tennessee USA
| | - Stephen Jesse
- Oak Ridge National Laboratory Center for Nanophase Materials Science Oak Ridge Tennessee USA
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29
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Markevich A, Hudak BM, Madsen J, Song J, Snijders PC, Lupini AR, Susi T. Mechanism of Electron-Beam Manipulation of Single-Dopant Atoms in Silicon. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2021; 125:16041-16048. [PMID: 34354792 PMCID: PMC8327312 DOI: 10.1021/acs.jpcc.1c03549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 06/25/2021] [Indexed: 05/10/2023]
Abstract
The precise positioning of dopant atoms within bulk crystal lattices could enable novel applications in areas including solid-state sensing and quantum computation. Established scanning probe techniques are capable tools for the manipulation of surface atoms, but at a disadvantage due to their need to bring a physical tip into contact with the sample. This has prompted interest in electron-beam techniques, followed by the first proof-of-principle experiment of bismuth dopant manipulation in crystalline silicon. Here, we use first-principles modeling to discover a novel indirect exchange mechanism that allows electron impacts to non-destructively move dopants with atomic precision within the silicon lattice. However, this mechanism only works for the two heaviest group V donors with split-vacancy configurations, Bi and Sb. We verify our model by directly imaging these configurations for Bi and by demonstrating that the promising nuclear spin qubit Sb can be manipulated using a focused electron beam.
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Affiliation(s)
- Alexander Markevich
- Faculty
of Physics, University of Vienna, Boltzmanngasse 5, 1090 Vienna, Austria
| | - Bethany M. Hudak
- Naval
Research Laboratory, Material Sciences and Technology, 4555 Overlook Ave SW, Washington, District of Columbia 20375, United States
| | - Jacob Madsen
- Faculty
of Physics, University of Vienna, Boltzmanngasse 5, 1090 Vienna, Austria
| | - Jiaming Song
- School
of Physics, Northwest University, 1 Xuefu Avenue, Xi’an, Shaanxi 710127, China
| | - Paul C. Snijders
- Materials
Science and Technology Division, Oak Ridge
National Laboratory, Oak Ridge, Tennessee 37830, United States
| | - Andrew R. Lupini
- Center
for Nanophase Materials Sciences, Oak Ridge
National Laboratory, Oak Ridge, Tennessee 37830, United States
| | - Toma Susi
- Faculty
of Physics, University of Vienna, Boltzmanngasse 5, 1090 Vienna, Austria
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30
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Adhikary S, Dutta S, Mohakud S. Antiferromagnetic spin ordering in two-dimensional honeycomb lattice of SiP 3. NANOSCALE ADVANCES 2021; 3:2217-2221. [PMID: 36133774 PMCID: PMC9417914 DOI: 10.1039/d1na00101a] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Accepted: 03/20/2021] [Indexed: 06/16/2023]
Abstract
Magnetism in low-dimensional materials has been of sustained interest due to its intriguing quantum mechanical origin and promising device applications. Here, we propose a buckled honeycomb lattice of stoichiometry SiP3, a two-dimensional binary group-IV and V material that exhibits an antiferromagnetic ground state with itinerant electrons. Here we perform elemental Si substitution in pristine blue phosphorene to downshift the Fermi energy and induce the Fermi instability that results in a spin polarized ground state. Within first-principles calculations, we observe antiferromagnetic spin alignment between adjacent ferromagnetic triangular domains where each Si atom is coupled with three neighboring P atoms with a ferromagnetic interaction. Such unique spin structure and resulting magnetic ground state are unprecedented in defect-free two-dimensional materials made of only p-block elements. This metal-free magnetism can be exploited for advanced spintronic and memory storage applications.
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Affiliation(s)
- Souren Adhikary
- Department of Physics, Indian Institute of Science Education and Research (IISER) Tirupati Tirupati - 517507 Andhra Pradesh India
| | - Sudipta Dutta
- Department of Physics, Indian Institute of Science Education and Research (IISER) Tirupati Tirupati - 517507 Andhra Pradesh India
- Center for Atomic, Molecular and Optical Sciences & Technologies, Indian Institute of Science Education and Research (IISER) Tirupati Tirupati - 517507 Andhra Pradesh India
| | - Sasmita Mohakud
- Department of Physics, Indian Institute of Science Education and Research (IISER) Tirupati Tirupati - 517507 Andhra Pradesh India
- Center for Atomic, Molecular and Optical Sciences & Technologies, Indian Institute of Science Education and Research (IISER) Tirupati Tirupati - 517507 Andhra Pradesh India
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31
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Kalinin SV, Dyck O, Jesse S, Ziatdinov M. Exploring order parameters and dynamic processes in disordered systems via variational autoencoders. SCIENCE ADVANCES 2021; 7:7/17/eabd5084. [PMID: 33883126 DOI: 10.1126/sciadv.abd5084] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 03/05/2021] [Indexed: 06/12/2023]
Abstract
We suggest and implement an approach for the bottom-up description of systems undergoing large-scale structural changes and chemical transformations from dynamic atomically resolved imaging data, where only partial or uncertain data on atomic positions are available. This approach is predicated on the synergy of two concepts, the parsimony of physical descriptors and general rotational invariance of noncrystalline solids, and is implemented using a rotationally invariant extension of the variational autoencoder applied to semantically segmented atom-resolved data seeking the most effective reduced representation for the system that still contains the maximum amount of original information. This approach allowed us to explore the dynamic evolution of electron beam-induced processes in a silicon-doped graphene system, but it can be also applied for a much broader range of atomic scale and mesoscopic phenomena to introduce the bottom-up order parameters and explore their dynamics with time and in response to external stimuli.
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Affiliation(s)
- Sergei V Kalinin
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.
| | - Ondrej Dyck
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Stephen Jesse
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Maxim Ziatdinov
- Computational Sciences and Engineering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.
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32
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Dyck O, Swett JL, Lupini AR, Mol JA, Jesse S. Imaging Secondary Electron Emission from a Single Atomic Layer. SMALL METHODS 2021; 5:e2000950. [PMID: 34927845 DOI: 10.1002/smtd.202000950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 12/17/2020] [Indexed: 06/14/2023]
Abstract
Graphene-based devices hold promise for a wide range of technological applications. Yet characterizing the structure and the electrical properties of a material that is only one atomic layer thick still poses technical challenges. Recent investigations indicate that secondary-electron electron-beam-induced current (SE-EBIC) imaging can reveal subtle details regarding electrical conductivity and electron transport with high spatial resolution. Here, it is shown that the SEEBIC imaging mode can be used to detect suspended single layers of graphene and distinguish between different numbers of layers. Pristine and contaminated areas of graphene are also compared to show that pristine graphene exhibits a substantially lower SE yield than contaminated regions. This SEEBIC imaging mode may provide valuable information for the engineering of surface coatings where SE yield is a priority.
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Affiliation(s)
- Ondrej Dyck
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
| | - Jacob L Swett
- Department of Materials, University of Oxford, Oxford, OX1 3PH, UK
| | - Andrew R Lupini
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
| | - Jan A Mol
- Department of Materials, University of Oxford, Oxford, OX1 3PH, UK
- School of Physics and Astronomy, Queen Mary University of London, London, E1 4NS, UK
| | - Stephen Jesse
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
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33
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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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34
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Maxim Z, Jesse S, Sumpter BG, Kalinin SV, Dyck O. Tracking atomic structure evolution during directed electron beam induced Si-atom motion in graphene via deep machine learning. NANOTECHNOLOGY 2021; 32:035703. [PMID: 32932246 DOI: 10.1088/1361-6528/abb8a6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Using electron beam manipulation, we enable deterministic motion of individual Si atoms in graphene along predefined trajectories. Structural evolution during the dopant motion was explored, providing information on changes of the Si atom neighborhood during atomic motion and providing statistical information of possible defect configurations. The combination of a Gaussian mixture model and principal component analysis applied to the deep learning-processed experimental data allowed disentangling of the atomic distortions for two different graphene sublattices. This approach demonstrates the potential of e-beam manipulation to create defect libraries of multiple realizations of the same defect and explore the potential of symmetry breaking physics. The rapid image analytics enabled via a deep learning network further empowers instrumentation for e-beam controlled atom-by-atom fabrication. The analysis described in the paper can be reproduced via an interactive Jupyter notebook at https://git.io/JJ3Bx.
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Affiliation(s)
- Ziatdinov Maxim
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States of America
- Computational Sciences and Engineering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States of America
| | - Stephen Jesse
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States of America
| | - Bobby G Sumpter
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States of America
| | - Sergei V Kalinin
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States of America
| | - Ondrej Dyck
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States of America
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35
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Yu T, Lingerfelt D, Jakowski J, Jabed MA, Ganesh P, Sumpter BG. Electron-Beam-Induced Molecular Plasmon Excitation and Energy Transfer in Silver Molecular Nanowires. J Phys Chem A 2021; 125:74-87. [PMID: 33389995 DOI: 10.1021/acs.jpca.0c08314] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We investigate (1) electron-beam-induced plasmon absorption spectra of Ag molecular nanowire dimers and (2) electron-beam-induced energy transfer between two nanowires. We employ linear-response time-dependent density functional theory (TDDFT) and real-time TDDFT methods to simulate the electron-beam-induced plasmonic excitations, dynamics, and corresponding electron energy loss spectrum for small models of a single molecular nanowire with four Ag atoms and for two Ag nanowires. An array of different relative orientations of nanowires and of different initial excitation conditions resulting from applying an electron beam at different positions with respect to the Ag nanowires is investigated. The results demonstrate (1) an electron beam can induce plasmonic excitations from the molecular Ag nanowire ground state to the excited states that are both optically allowed and forbidden, (2) a tunability for selective excitations that can be controlled by the position of a focused electron beam, and (3) kinetic and dynamic behaviors of time-dependent electron-beam-induced energy transfer between two Ag molecular nanowires depend on the position of the beam source and nanowire separation distance, providing insights into the spatial dependences of plasmonic couplings in nanowire arrays.
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Affiliation(s)
- Tao Yu
- Department of Chemistry, University of North Dakota, Grand Forks, North Dakota 58202, United States
| | - David Lingerfelt
- Center of Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States
| | - Jacek Jakowski
- Computational Sciences and Engineering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States
| | - Mohammed A Jabed
- Department of Chemistry, University of North Dakota, Grand Forks, North Dakota 58202, United States
| | - Panchapakesan Ganesh
- Center of Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States
| | - Bobby G Sumpter
- Center of Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States
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36
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Lingerfelt DB, Yu T, Yoshimura A, Ganesh P, Jakowski J, Sumpter BG. Nonadiabatic Effects on Defect Diffusion in Silicon-Doped Nanographenes. NANO LETTERS 2021; 21:236-242. [PMID: 33337886 DOI: 10.1021/acs.nanolett.0c03587] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Single atom impurities in graphene, substitutional silicon defects in particular, have been observed to diffuse under electron beam irradiation. However, the relative importance of elastic and inelastic scattering in facilitating their mobility remains unclear. Here, we employ excited-state electronic structure calculations to explore potential inelastic effects, and find an electronically nonadiabatic excited-state silicon diffusion pathway involving "softened" Si-C bonding that presents an ∼2 eV lower diffusion barrier than the ground-state pathway. Beam-induced transition rates to this state indicate that the excited-state pathway is accessible through irradiation of the defect site. However, even in the limit of fully elastic scattering, upward nonadiabatic transitions are also possible along the diffusion coordinate, increasing the diffusion barrier and further demonstrating the potential for electronic nonadiabaticity to influence beam-induced atomic transformations in materials. We also propose some experimentally testable signatures of such excited-state pathways.
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Affiliation(s)
- David B Lingerfelt
- Nanomaterials Theory Institute, Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Tao Yu
- Department of Chemistry, University of North Dakota, Grand Forks, North Dakota 58202, United States
| | - Anthony Yoshimura
- Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
| | - Panchapakesan Ganesh
- Nanomaterials Theory Institute, Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Jacek Jakowski
- Computational Sciences and Engineering Division Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Bobby G Sumpter
- Nanomaterials Theory Institute, Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
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37
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Clancy AJ, Au H, Rubio N, Coulter GO, Shaffer MSP. Understanding and controlling the covalent functionalisation of graphene. Dalton Trans 2020; 49:10308-10318. [PMID: 32643711 DOI: 10.1039/d0dt01589j] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Chemical functionalisation is one of the most active areas of graphene research, motivated by fundamental science, the opportunities to adjust or supplement intrinsic properties, and the need to assemble materials for a broad array of applications. Historically, the primary consideration has been the degree of functionalisation but there is growing interest in understanding how and where modification occurs. Reactions may proceed preferentially at edges, defects, or on graphitic faces; they may be correlated, uncorrelated, or anti-correlated with previously grafted sites. A detailed collation of existing literature data indicates that steric effects play a strong role in limiting the extent of reaction. However, the pattern of functionalisation may have important effects on the resulting properties. This article addresses the unifying principles of current graphene functionalisation technologies, with emphasis on understanding and controlling the locus of functionalisation.
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Affiliation(s)
- Adam J Clancy
- Dept. Chemistry, UCL, Gower Street, London, WC1H 0AJ, UK.
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38
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Dyck O, Jesse S, Delby N, Kalinin SV, Lupini AR. Variable voltage electron microscopy: Toward atom-by-atom fabrication in 2D materials. Ultramicroscopy 2020; 211:112949. [DOI: 10.1016/j.ultramic.2020.112949] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 01/07/2020] [Accepted: 01/26/2020] [Indexed: 10/25/2022]
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39
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Dyck O, Lingerfelt D, Kim S, Jesse S, Kalinin SV. Direct matter disassembly via electron beam control: electron-beam-mediated catalytic etching of graphene by nanoparticles. NANOTECHNOLOGY 2020; 31:245303. [PMID: 32160595 DOI: 10.1088/1361-6528/ab7ef8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We report electron-beam activated motion of a catalytic nanoparticle along a graphene step edge and associated etching of the edge. The catalytic hydrogenation process was observed to be activated by a combination of elevated temperature and electron beam irradiation. Reduction of beam fluence on the particle was sufficient to stop the process, leading to the ability to switch on and off the etching. Such an approach enables the targeting of individual nanoparticles to induce motion and beam-controlled etching of matter through activated electrocatalytic processes. The applications of electron-beam control as a paradigm for molecular-scale robotics are discussed.
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Affiliation(s)
- Ondrej Dyck
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, United States of America
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40
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Cao K, Skowron ST, Biskupek J, Stoppiello CT, Leist C, Besley E, Khlobystov AN, Kaiser U. Imaging an unsupported metal-metal bond in dirhenium molecules at the atomic scale. SCIENCE ADVANCES 2020; 6:eaay5849. [PMID: 32010771 PMCID: PMC6968940 DOI: 10.1126/sciadv.aay5849] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Accepted: 11/19/2019] [Indexed: 06/10/2023]
Abstract
Metallic bonds remain one of the most important and least understood of the chemical bonds. In this study, we generated Re2 molecules in which the Re-Re core is unsupported by ligands. Real-time imaging of the atomic-scale dynamics of Re2 adsorbed on a graphitic lattice allows direct measurement of Re-Re bond lengths for individual molecules that changes in discrete steps correlating with bond order from one to four. Direct imaging of the Re-Re bond breaking process reveals a new bonding state with the bond order less than one and a high-amplitude vibrational stretch, preceding the bond dissociation. The methodology, based on aberration-corrected transmission electron microscopy imaging, is shown to be a powerful analytical tool for the investigation of dynamics of metallic bonding at the atomic level.
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Affiliation(s)
- Kecheng Cao
- Central Facility for Materials Science Electron Microscopy, Ulm University, Albert-Einstein-Allee 11, Ulm 89081, Germany
| | - Stephen T. Skowron
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - Johannes Biskupek
- Central Facility for Materials Science Electron Microscopy, Ulm University, Albert-Einstein-Allee 11, Ulm 89081, Germany
| | - Craig T. Stoppiello
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - Christopher Leist
- Central Facility for Materials Science Electron Microscopy, Ulm University, Albert-Einstein-Allee 11, Ulm 89081, Germany
| | - Elena Besley
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - Andrei N. Khlobystov
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - Ute Kaiser
- Central Facility for Materials Science Electron Microscopy, Ulm University, Albert-Einstein-Allee 11, Ulm 89081, Germany
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41
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Chen J, Ryu GH, Zhang Q, Wen Y, Tai KL, Lu Y, Warner JH. Spatially Controlled Fabrication and Mechanisms of Atomically Thin Nanowell Patterns in Bilayer WS 2 Using in Situ High Temperature Electron Microscopy. ACS NANO 2019; 13:14486-14499. [PMID: 31794193 DOI: 10.1021/acsnano.9b08220] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We show controlled production of atomically thin nanowells in bilayer WS2 using an in situ heating holder combined with a focused electron beam in a scanning transmission electron microscope (STEM). We systematically study the formation and evolvement mechanism involved in removing a single layer of WS2 within a bilayer region with 2 nm accuracy in location and without punching through to the other layer to create a hole. Best results are found when using a high temperature of 800 °C, because it enables thermally activated atomic migration and eliminates the interference from surface carbon contamination. We demonstrate precise control over spatial distributions with 5 nm accuracy of patterning and the width of nanowells adjustable by dose-dependent parameters. The mechanism of removing a monolayer of WS2 within a bilayer region is different than removing equivalent sections in a monolayer film due to the van der Waals interaction of the underlying remaining layer in the bilayer system that stabilizes the excess W atom stoichiometry within the edges of the nanowell structure and facilitates expansion. This study offers insights for the nanoengineering of nanowells in two-dimensional (2D) transitional metal dichalcogenides (TMDs), which could hold potential as selective traps to localize 2D reactions in molecules and ions, underpinning the broader utilization of 2D material membranes.
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Affiliation(s)
- Jun Chen
- Department of Materials , University of Oxford , Parks Road , Oxford OX1 3PH , United Kingdom
| | - Gyeong Hee Ryu
- Department of Materials , University of Oxford , Parks Road , Oxford OX1 3PH , United Kingdom
| | - Qianyang Zhang
- Department of Materials , University of Oxford , Parks Road , Oxford OX1 3PH , United Kingdom
| | - Yi Wen
- Department of Materials , University of Oxford , Parks Road , Oxford OX1 3PH , United Kingdom
| | - Kuo-Lun Tai
- Department of Materials , University of Oxford , Parks Road , Oxford OX1 3PH , United Kingdom
| | - Yang Lu
- Department of Materials , University of Oxford , Parks Road , Oxford OX1 3PH , United Kingdom
| | - Jamie H Warner
- Department of Materials , University of Oxford , Parks Road , Oxford OX1 3PH , United Kingdom
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42
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Kalinin SV, Dyck O, Balke N, Neumayer S, Tsai WY, Vasudevan R, Lingerfelt D, Ahmadi M, Ziatdinov M, McDowell MT, Strelcov E. Toward Electrochemical Studies on the Nanometer and Atomic Scales: Progress, Challenges, and Opportunities. ACS NANO 2019; 13:9735-9780. [PMID: 31433942 DOI: 10.1021/acsnano.9b02687] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Electrochemical reactions and ionic transport underpin the operation of a broad range of devices and applications, from energy storage and conversion to information technologies, as well as biochemical processes, artificial muscles, and soft actuators. Understanding the mechanisms governing function of these applications requires probing local electrochemical phenomena on the relevant time and length scales. Here, we discuss the challenges and opportunities for extending electrochemical characterization probes to the nanometer and ultimately atomic scales, including challenges in down-scaling classical methods, the emergence of novel probes enabled by nanotechnology and based on emergent physics and chemistry of nanoscale systems, and the integration of local data into macroscopic models. Scanning probe microscopy (SPM) methods based on strain detection, potential detection, and hysteretic current measurements are discussed. We further compare SPM to electron beam probes and discuss the applicability of electron beam methods to probe local electrochemical behavior on the mesoscopic and atomic levels. Similar to a SPM tip, the electron beam can be used both for observing behavior and as an active electrode to induce reactions. We briefly discuss new challenges and opportunities for conducting fundamental scientific studies, matter patterning, and atomic manipulation arising in this context.
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Affiliation(s)
- Sergei V Kalinin
- 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
| | - Nina Balke
- Center for Nanophase Materials Sciences , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States
| | - Sabine Neumayer
- Center for Nanophase Materials Sciences , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States
| | - Wan-Yu Tsai
- Center for Nanophase Materials Sciences , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States
| | - Rama Vasudevan
- Center for Nanophase Materials Sciences , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States
| | - David Lingerfelt
- Center for Nanophase Materials Sciences , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States
| | - Mahshid Ahmadi
- Joint Institute for Advanced Materials, Department of Materials Science and Engineering , University of Tennessee , Knoxville , Tennessee 37996 , United States
| | - Maxim Ziatdinov
- Center for Nanophase Materials Sciences , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States
| | - Matthew T McDowell
- George W. Woodruff School of Mechanical Engineering and School of Materials Science and Engineering , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
| | - Evgheni Strelcov
- Institute for Research in Electronics and Applied Physics , University of Maryland , College Park , Maryland 20742 , United States
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43
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Chirita Mihaila AI, Susi T, Kotakoski J. Influence of temperature on the displacement threshold energy in graphene. Sci Rep 2019; 9:12981. [PMID: 31506494 PMCID: PMC6736860 DOI: 10.1038/s41598-019-49565-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Accepted: 08/24/2019] [Indexed: 11/09/2022] Open
Abstract
The atomic structure of nanomaterials is often studied using transmission electron microscopy. In addition to image formation, the energetic electrons impinging on the sample may also cause damage. In a good conductor such as graphene, the damage is limited to the knock-on process caused by elastic electron-nucleus scattering. This process is determined by the kinetic energy an atom needs to be sputtered, i.e. its displacement threshold energy Ed. This is typically assumed to have a fixed value for all electron impacts on equivalent atoms within a crystal. Here we show using density functional tight-binding simulations that the displacement threshold energy is affected by thermal perturbations of atoms from their equilibrium positions. This effect can be accounted for in the estimation of the displacement cross section by replacing the constant threshold energy value with a distribution. Our refined model better describes previous precision measurements of graphene knock-on damage, and should be considered also for other low-dimensional materials.
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Affiliation(s)
| | - Toma Susi
- University of Vienna, Faculty of Physics, Boltzmanngasse 5, 1090, Vienna, Austria
| | - Jani Kotakoski
- University of Vienna, Faculty of Physics, Boltzmanngasse 5, 1090, Vienna, Austria.
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44
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Ziatdinov M, Dyck O, Li X, Sumpter BG, Jesse S, Vasudevan RK, Kalinin SV. Building and exploring libraries of atomic defects in graphene: Scanning transmission electron and scanning tunneling microscopy study. SCIENCE ADVANCES 2019; 5:eaaw8989. [PMID: 31598551 PMCID: PMC6764837 DOI: 10.1126/sciadv.aaw8989] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Accepted: 09/04/2019] [Indexed: 05/24/2023]
Abstract
The presence and configurations of defects are primary components determining materials functionality. Their population and distribution are often nonergodic and dependent on synthesis history, and therefore rarely amenable to direct theoretical prediction. Here, dynamic electron beam-induced transformations in Si deposited on a graphene monolayer are used to create libraries of possible Si and carbon vacancy defects. Deep learning networks are developed for automated image analysis and recognition of the defects, creating a library of (meta) stable defect configurations. Density functional theory is used to estimate atomically resolved scanning tunneling microscopy (STM) signatures of the classified defects from the created library, allowing identification of several defect types across imaging platforms. This approach allows automatic creation of defect libraries in solids, exploring the metastable configurations always present in real materials, and correlative studies with other atomically resolved techniques, providing comprehensive insight into defect functionalities.
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Affiliation(s)
- Maxim Ziatdinov
- Computational Sciences and Engineering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Ondrej Dyck
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Xin Li
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Bobby G. Sumpter
- Computational Sciences and Engineering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Stephen Jesse
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Rama K. Vasudevan
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Sergei V. Kalinin
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
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45
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Inani H, Mustonen K, Markevich A, Ding EX, Tripathi M, Hussain A, Mangler C, Kauppinen EI, Susi T, Kotakoski J. Silicon Substitution in Nanotubes and Graphene via Intermittent Vacancies. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2019; 123:13136-13140. [PMID: 31156738 PMCID: PMC6539548 DOI: 10.1021/acs.jpcc.9b01894] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 04/25/2019] [Indexed: 05/25/2023]
Abstract
The chemical and electrical properties of single-walled carbon nanotubes (SWCNTs) and graphene can be modified by the presence of covalently bound impurities. Although this can be achieved by introducing chemical additives during synthesis, it often hinders growth and leads to limited crystallite size and quality. Here, through the simultaneous formation of vacancies with low-energy argon plasma and the thermal activation of adatom diffusion by laser irradiation, silicon impurities are incorporated into the lattice of both materials. After an exposure of ∼1 ion/nm2, we find Si-substitution densities of 0.15 nm-2 in graphene and 0.05 nm-2 in nanotubes, as revealed by atomically resolved scanning transmission electron microscopy. In good agreement with predictions of Ar irradiation effects in SWCNTs, we find Si incorporated in both mono- and divacancies, with ∼2/3 being of the first type. Controlled inclusion of impurities in the quasi-1D and -2D carbon lattices may prove useful for applications such as gas sensing, and a similar approach might also be used to substitute other elements with migration barriers lower than that of carbon.
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Affiliation(s)
- Heena Inani
- Faculty
of Physics, University of Vienna, Boltzmanngasse 5, 1090 Vienna, Austria
| | - Kimmo Mustonen
- Faculty
of Physics, University of Vienna, Boltzmanngasse 5, 1090 Vienna, Austria
| | - Alexander Markevich
- Faculty
of Physics, University of Vienna, Boltzmanngasse 5, 1090 Vienna, Austria
| | - Er-Xiong Ding
- Department
of Applied Physics, Aalto University School
of Science, P.O. Box 15100, FI-00076 Aalto, Finland
| | - Mukesh Tripathi
- Faculty
of Physics, University of Vienna, Boltzmanngasse 5, 1090 Vienna, Austria
| | - Aqeel Hussain
- Department
of Applied Physics, Aalto University School
of Science, P.O. Box 15100, FI-00076 Aalto, Finland
| | - Clemens Mangler
- Faculty
of Physics, University of Vienna, Boltzmanngasse 5, 1090 Vienna, Austria
| | - Esko I. Kauppinen
- Department
of Applied Physics, Aalto University School
of Science, P.O. Box 15100, FI-00076 Aalto, Finland
| | - Toma Susi
- Faculty
of Physics, University of Vienna, Boltzmanngasse 5, 1090 Vienna, Austria
| | - Jani Kotakoski
- Faculty
of Physics, University of Vienna, Boltzmanngasse 5, 1090 Vienna, Austria
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46
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Su C, Tripathi M, Yan QB, Wang Z, Zhang Z, Hofer C, Wang H, Basile L, Su G, Dong M, Meyer JC, Kotakoski J, Kong J, Idrobo JC, Susi T, Li J. Engineering single-atom dynamics with electron irradiation. SCIENCE ADVANCES 2019; 5:eaav2252. [PMID: 31114798 PMCID: PMC6524980 DOI: 10.1126/sciadv.aav2252] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Accepted: 04/09/2019] [Indexed: 05/24/2023]
Abstract
Atomic engineering is envisioned to involve selectively inducing the desired dynamics of single atoms and combining these steps for larger-scale assemblies. Here, we focus on the first part by surveying the single-step dynamics of graphene dopants, primarily phosphorus, caused by electron irradiation both in experiment and simulation, and develop a theory for describing the probabilities of competing configurational outcomes depending on the postcollision momentum vector of the primary knock-on atom. The predicted branching ratio of configurational transformations agrees well with our atomically resolved experiments. This suggests a way for biasing the dynamics toward desired outcomes, paving the road for designing and further upscaling atomic engineering using electron irradiation.
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Affiliation(s)
- Cong Su
- Department of Nuclear Science and Engineering and Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Research Lab of Electronics (RLE), Massachusetts Institutes of Technology, Cambridge, MA 02139, USA
| | - Mukesh Tripathi
- University of Vienna, Faculty of Physics, Vienna 1090, Austria
| | - Qing-Bo Yan
- College of Materials Science and Opto-Electronic Technology, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zegao Wang
- Interdisciplinary Nanoscience Center (iNano), Aarhus University, Aarhus 8000, Denmark
- College of Materials Science and Engineering, Sichuan University, Chengdu 610065, China
| | - Zihan Zhang
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Christoph Hofer
- University of Vienna, Faculty of Physics, Vienna 1090, Austria
| | - Haozhe Wang
- Research Lab of Electronics (RLE), Massachusetts Institutes of Technology, Cambridge, MA 02139, USA
| | - Leonardo Basile
- Department of Physics, Escuela Politécnica Nacional, Quito 170517, Ecuador
| | - Gang Su
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
- Kavli Institute for Theoretical Sciences, and CAS Center of Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Mingdong Dong
- Interdisciplinary Nanoscience Center (iNano), Aarhus University, Aarhus 8000, Denmark
| | - Jannik C. Meyer
- University of Vienna, Faculty of Physics, Vienna 1090, Austria
| | - Jani Kotakoski
- University of Vienna, Faculty of Physics, Vienna 1090, Austria
| | - Jing Kong
- Research Lab of Electronics (RLE), Massachusetts Institutes of Technology, Cambridge, MA 02139, USA
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Juan-Carlos Idrobo
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Toma Susi
- University of Vienna, Faculty of Physics, Vienna 1090, Austria
| | - Ju Li
- Department of Nuclear Science and Engineering and Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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47
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Kar M, Sarkar R, Pal S, Sarkar P. Engineering the magnetic properties of PtSe 2 monolayer through transition metal doping. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2019; 31:145502. [PMID: 30650400 DOI: 10.1088/1361-648x/aaff40] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Using first-principles calculations, we have studied the energetic feasibility and magnetic properties of transition metal (TM) doped PtSe2 monolayers. Our study shows that TM doped PtSe2 layers with 6.25% doping exhibit versatile spintronic behaviour depending on the nature of the dopant TM atoms. Groups IVB and VIII10 TM doped PtSe2 layers are non magnetic semiconductors, while groups IIIB, VB, VIII8, VIII9, IB TM doped PtSe2 layers are half-metals and finally, groups VIB, VIIB and IIB TM doped PtSe2 layers are spin polarized semiconductors. The presence of half-metallic and magnetic semiconducting characteristics suggest that TM doped PtSe2 layers can be considered as a new kind of dilute magnetic semiconductor and thus have the promise to be used in spintronics. By studying the magnetic interactions between two TM dopants in PtSe2 monolayers for dopant concentration of 12.5% and dopant distance of 12.85 [Formula: see text], we have found that in particular, Fe and Ru doped PtSe2 systems are ferromagnetic half-metal having above-room-temperature Curie point of 422 and 379.9 K, respectively. By varying the dopant distance and concentration we have shown that the magnetic interaction is strongly dependent on dopant distance and concentration. Interestingly, the Curie temperature of TM doped PtSe2 layers is affected by the correlation effects on the TM d states and also spin-orbit coupling. We have also studied the magnetic properties of defect complex composed of one TM dopant and one Pt vacancy (TMPt + VPt) which shows novel magnetism.
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Affiliation(s)
- Moumita Kar
- Department of Chemistry, Visva-Bharati University, Santiniketan-731 235, India
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48
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Yang SZ, Sun W, Zhang YY, Gong Y, Oxley MP, Lupini AR, Ajayan PM, Chisholm MF, Pantelides ST, Zhou W. Direct Cation Exchange in Monolayer MoS_{2} via Recombination-Enhanced Migration. PHYSICAL REVIEW LETTERS 2019; 122:106101. [PMID: 30932633 DOI: 10.1103/physrevlett.122.106101] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 12/04/2018] [Indexed: 06/09/2023]
Abstract
In addition to their unique optical and electronic properties, two-dimensional materials provide opportunities to directly observe atomic-scale defect dynamics. Here we use scanning transmission electron microscopy to observe substitutional Re impurities in monolayer MoS_{2} undergo direct exchanges with neighboring Mo atoms in the lattice. Density-functional-theory calculations find that the energy barrier for direct exchange, a process that has only been studied as a diffusion mechanism in bulk materials, is too large for either thermal activation or energy directly transferred from the electron beam. The presence of multiple sulfur vacancies next to the exchanged Re-Mo pair, as observed by electron microscopy, does not lower the energy barrier sufficiently to account for the observed atomic exchange. Instead, the calculations find that a Re dopant and surrounding sulfur vacancies introduce an ever-changing set of deep levels in the energy gap. We propose that these levels mediate an "explosive" recombination-enhanced migration via multiple electron-hole recombination events. As a proof of concept, we also show that Re-Mo direct exchange can be triggered via controlled creation of sulfur vacancies. The present experimental and theoretical findings lay a fundamental framework towards manipulating single substitutional dopants in two-dimensional materials.
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Affiliation(s)
- Shi-Ze Yang
- Center for Nanophase Materials Science, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Weiwei Sun
- Center for Nanophase Materials Science, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
- Department of Physics and Astronomy and Department of Electrical Engineering and Computer Science, Vanderbilt University, Nashville, Tennessee 37235, USA
| | - Yu-Yang Zhang
- Department of Physics and Astronomy and Department of Electrical Engineering and Computer Science, Vanderbilt University, Nashville, Tennessee 37235, USA
- School of Physical Sciences and CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yongji Gong
- School of Materials Science and Engineering, Beihang University, Beijing 100191, China
| | - Mark P Oxley
- Center for Nanophase Materials Science, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Andrew R Lupini
- Center for Nanophase Materials Science, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Pulickel M Ajayan
- Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, USA
| | - Matthew F Chisholm
- Center for Nanophase Materials Science, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Sokrates T Pantelides
- Department of Physics and Astronomy and Department of Electrical Engineering and Computer Science, Vanderbilt University, Nashville, Tennessee 37235, USA
- School of Physical Sciences and CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wu Zhou
- Center for Nanophase Materials Science, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
- School of Physical Sciences and CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100049, China
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49
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Jiang J, Xu T, Lu J, Sun L, Ni Z. Defect Engineering in 2D Materials: Precise Manipulation and Improved Functionalities. RESEARCH (WASHINGTON, D.C.) 2019; 2019:4641739. [PMID: 31912036 PMCID: PMC6944491 DOI: 10.34133/2019/4641739] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Accepted: 11/07/2019] [Indexed: 05/01/2023]
Abstract
Two-dimensional (2D) materials have attracted increasing interests in the last decade. The ultrathin feature of 2D materials makes them promising building blocks for next-generation electronic and optoelectronic devices. With reducing dimensionality from 3D to 2D, the inevitable defects will play more important roles in determining the properties of materials. In order to maximize the functionality of 2D materials, deep understanding and precise manipulation of the defects are indispensable. In the recent years, increasing research efforts have been made on the observation, understanding, manipulation, and control of defects in 2D materials. Here, we summarize the recent research progress of defect engineering on 2D materials. The defect engineering triggered by electron beam (e-beam), plasma, chemical treatment, and so forth is comprehensively reviewed. Firstly, e-beam irradiation-induced defect evolution, structural transformation, and novel structure fabrication are introduced. With the assistance of a high-resolution electron microscope, the dynamics of defect engineering can be visualized in situ. Subsequently, defect engineering employed to improve the performance of 2D devices by means of other methods of plasma, chemical, and ozone treatments is reviewed. At last, the challenges and opportunities of defect engineering on promoting the development of 2D materials are discussed. Through this review, we aim to build a correlation between defects and properties of 2D materials to support the design and optimization of high-performance electronic and optoelectronic devices.
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Affiliation(s)
- Jie Jiang
- School of Physics, Southeast University, Nanjing 211189, China
| | - Tao Xu
- SEU-FEI Nano-Pico Center, Key Laboratory of MEMS of Ministry of Education, Southeast University, Nanjing 210096, China
| | - Junpeng Lu
- School of Physics, Southeast University, Nanjing 211189, China
| | - Litao Sun
- SEU-FEI Nano-Pico Center, Key Laboratory of MEMS of Ministry of Education, Southeast University, Nanjing 210096, China
| | - Zhenhua Ni
- School of Physics, Southeast University, Nanjing 211189, China
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50
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