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Yau A, Cha W, Kanan MW, Stephenson GB, Ulvestad A. Bragg coherent diffractive imaging of single-grain defect dynamics in polycrystalline films. Science 2018; 356:739-742. [PMID: 28522531 DOI: 10.1126/science.aam6168] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Accepted: 03/30/2017] [Indexed: 01/30/2023]
Abstract
Polycrystalline material properties depend on the distribution and interactions of their crystalline grains. In particular, grain boundaries and defects are crucial in determining their response to external stimuli. A long-standing challenge is thus to observe individual grains, defects, and strain dynamics inside functional materials. Here we report a technique capable of revealing grain heterogeneity, including strain fields and individual dislocations, that can be used under operando conditions in reactive environments: grain Bragg coherent diffractive imaging (gBCDI). Using a polycrystalline gold thin film subjected to heating, we show how gBCDI resolves grain boundary and dislocation dynamics in individual grains in three-dimensional detail with 10-nanometer spatial and subangstrom displacement field resolution. These results pave the way for understanding polycrystalline material response under external stimuli and, ideally, engineering particular functions.
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Affiliation(s)
- Allison Yau
- Department of Chemistry Stanford University, Stanford, CA 94305, USA
| | - Wonsuk Cha
- Materials Science Division, Argonne National Laboratory, Argonne, IL 60439, USA.,Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439, USA
| | - Matthew W Kanan
- Department of Chemistry Stanford University, Stanford, CA 94305, USA
| | - G Brian Stephenson
- Materials Science Division, Argonne National Laboratory, Argonne, IL 60439, USA.
| | - Andrew Ulvestad
- Materials Science Division, Argonne National Laboratory, Argonne, IL 60439, USA.
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2
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Hoskins BD, Adam GC, Strelcov E, Zhitenev N, Kolmakov A, Strukov DB, McClelland JJ. Stateful characterization of resistive switching TiO 2 with electron beam induced currents. Nat Commun 2017; 8:1972. [PMID: 29215006 PMCID: PMC5719452 DOI: 10.1038/s41467-017-02116-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Accepted: 11/08/2017] [Indexed: 11/23/2022] Open
Abstract
Metal oxide resistive switches are increasingly important as possible artificial synapses in next-generation neuromorphic networks. Nevertheless, there is still no codified set of tools for studying properties of the devices. To this end, we demonstrate electron beam-induced current measurements as a powerful method to monitor the development of local resistive switching in TiO2-based devices. By comparing beam energy-dependent electron beam-induced currents with Monte Carlo simulations of the energy absorption in different device layers, it is possible to deconstruct the origins of filament image formation and relate this to both morphological changes and the state of the switch. By clarifying the contrast mechanisms in electron beam-induced current microscopy, it is possible to gain new insights into the scaling of the resistive switching phenomenon and observe the formation of a current leakage region around the switching filament. Additionally, analysis of symmetric device structures reveals propagating polarization domains. Oxide-based memristors hold promise for artificial neuromorphic computing, yet the detail of the switching mechanism—filament formation—remains largely unknown. Hoskins et al. provide nanoscale imaging of this process using electron beam induced current microscopy and relate it to resistive states.
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Affiliation(s)
- Brian D Hoskins
- Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA. .,Materials Department, University of California Santa Barbara, Santa Barbara, CA, 93106, USA.
| | - Gina C Adam
- Electrical and Computer Engineering Department, University of California Santa Barbara, Santa Barbara, CA, 93106, USA.,Institute for Research and Development in Microtechnologies, 077190, Bucharest, Romania
| | - Evgheni Strelcov
- Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA.,Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, MD, 20742, USA
| | - Nikolai Zhitenev
- Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA
| | - Andrei Kolmakov
- Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA
| | - Dmitri B Strukov
- Electrical and Computer Engineering Department, University of California Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Jabez J McClelland
- Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA
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Rudneva M, Gao B, Prins F, Xu Q, van der Zant HSJ, Zandbergen HW. In situ transmission electron microscopy imaging of electromigration in platinum nanowires. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2013; 19 Suppl 5:43-48. [PMID: 23920172 DOI: 10.1017/s1431927613012300] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
In situ transmission electron microscopy was performed on the electromigration in platinum (Pt) nanowires (14 nm thick, 200 nm wide, and 300 nm long) with and without feedback control. Using the feedback control mode, symmetric electrodes are obtained and the gap usually forms at the center of the Pt nanowire. Without feedback control, asymmetric electrodes are formed, and the gap can occur at any position along the wire. The three-dimensional gap geometries of the electrodes in the Pt nanowire were determined using high-angle annular dark-field scanning transmission electron microscopy; the thickness of the nanowire is reduced from 14 nm to only a few atoms at the edge with a gap of about 5-10 nm.
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Affiliation(s)
- Maria Rudneva
- Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands.
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Rudneva M, Kozlova T, Zandbergen HW. The use of STEM imaging to analyze thickness variations due to electromigration-induced mass transport in thin polycrystalline nanobridges. Ultramicroscopy 2013; 134:155-9. [PMID: 23820593 DOI: 10.1016/j.ultramic.2013.05.022] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Revised: 05/28/2013] [Accepted: 05/31/2013] [Indexed: 10/26/2022]
Abstract
Scanning transmission electron microscopy (STEM) imaging is applied to analyze the electromigration-induced thickness variations of thin polycrystalline films. It is shown that a high angle annular dark field (HAADF) detector is required to minimize the effect of diffraction contact. A further reduction of the diffraction contrast can be obtained using a tilt series. A correlation between the intensity of the STEM signal obtained with the HAADF detector and the real thickness value was found by comparing corresponding STEM and AFM images. STEM in combination with a tilt series can determine the material distribution in polycrystalline films and can accurately analyze 1-3 nm gaps of nanoelectrodes formed by electromigration.
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Affiliation(s)
- Maria Rudneva
- Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ, Delft, The Netherlands.
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Xu Q, Wu MY, Schneider GF, Houben L, Malladi SK, Dekker C, Yucelen E, Dunin-Borkowski RE, Zandbergen HW. Controllable atomic scale patterning of freestanding monolayer graphene at elevated temperature. ACS NANO 2013; 7:1566-1572. [PMID: 23343745 DOI: 10.1021/nn3053582] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We show that by operating a scanning transmission electron microscope (STEM) with a 0.1 nm 300 kV electron beam, one can sculpt free-standing monolayer graphene with close-to-atomic precision at 600 °C. The same electron beam that is used for destructive sculpting can be used to image the sculpted monolayer graphene nondestructively. For imaging, a scanning dwell time is used that is about 1000 times shorter than for the sculpting. This approach allows for instantaneous switching between sculpting and imaging and thus fine-tuning the shape of the sculpted lattice. Furthermore, the sculpting process can be automated using a script. In this way, free-standing monolayer graphene can be controllably sculpted into patterns that are predefined in position, size, and orientation while maintaining defect-free crystallinity of the adjacent lattice. The sculpting and imaging processes can be fully computer-controlled to fabricate complex assemblies of ribbons or other shapes.
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Affiliation(s)
- Qiang Xu
- Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
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Tsutsui M, Kawai T, Taniguchi M. Unsymmetrical hot electron heating in quasi-ballistic nanocontacts. Sci Rep 2012; 2:217. [PMID: 22355731 PMCID: PMC3253854 DOI: 10.1038/srep00217] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2011] [Accepted: 12/16/2011] [Indexed: 11/09/2022] Open
Abstract
Electrons are allowed to pass through a single atom connected to two electrodes without being scattered as the characteristic size is much smaller than the inelastic mean free path. In this quasi-ballistic regime, it is difficult to predict where and how power dissipation occurs in such current-carrying atomic system. Here, we report direct assessment of electrical heating in a metallic nanocontact. We find asymmetric electrical heating effects in the essentially symmetric single-atom contact. We simultaneously identified the voltage polarity independent onset of the local heating by conducting the inelastic noise spectroscopy. As a result, we revealed significant heat dissipation by hot electrons transmitting ballistically through the junction that creates a hot spot at the current downstream. This technique can be used as a platform for studying heat dissipation and transport in atomic/molecular systems.
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Affiliation(s)
- Makusu Tsutsui
- The Institute of Scientific and Industrial Research, Osaka University , 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
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Prins F, Shaikh AJ, van Esch JH, Eelkema R, van der Zant HSJ. Platinum-nanogaps for single-molecule electronics: room-temperature stability. Phys Chem Chem Phys 2011; 13:14297-301. [DOI: 10.1039/c1cp20555b] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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