101
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Shiotari A, Hamada I, Nakae T, Mori S, Okujima T, Uno H, Sakaguchi H, Hamamoto Y, Morikawa Y, Sugimoto Y. Manipulable Metal Catalyst for Nanographene Synthesis. NANO LETTERS 2020; 20:8339-8345. [PMID: 33090808 DOI: 10.1021/acs.nanolett.0c03510] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Performing bottom-up synthesis by using molecules adsorbed on a surface is an effective method to yield functional polycyclic aromatic hydrocarbons (PAHs) and nanocarbon materials. The intramolecular cyclodehydrogenation of hydrocarbons is a critical process in this synthesis; however, thus far, its elementary steps have not been elucidated thoroughly. In this study, we utilize the metal tip of a low-temperature noncontact atomic force microscope as a manipulable metal surface to locally activate dehydrogenation for PAH-forming cyclodehydrogenation. This method leads to the dissociation of a H atom of an intermediate to yield the cyclodehydrogenated product in a target-selective and reproducible manner. We demonstrate the metal-tip-catalyzed dehydrogenation for both benzenoid and nonbenzonoid PAHs, suggesting its universal applicability as a catalyst for nanographene synthesis.
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Affiliation(s)
- Akitoshi Shiotari
- Department of Advanced Materials Science, The University of Tokyo, 5-1-5 Kashiwanoha, 277-8561 Kashiwa, Japan
| | - Ikutaro Hamada
- Department of Precision Engineering, Graduate School of Engineering, Osaka University, 565-0871 Suita, Japan
| | - Takahiro Nakae
- Institute of Advanced Energy, Kyoto University, 611-0011 Uji, Japan
| | - Shigeki Mori
- Advanced Research Support Center, Ehime University, 790-8577 Matsuyama, Japan
| | - Tetsuo Okujima
- Graduate School of Science and Engineering, Ehime University, 790-8577 Matsuyama, Japan
| | - Hidemitsu Uno
- Graduate School of Science and Engineering, Ehime University, 790-8577 Matsuyama, Japan
| | | | - Yuji Hamamoto
- Department of Precision Engineering, Graduate School of Engineering, Osaka University, 565-0871 Suita, Japan
| | - Yoshitada Morikawa
- Department of Precision Engineering, Graduate School of Engineering, Osaka University, 565-0871 Suita, Japan
- Research Center for Ultra-Precision Science and Technology, Graduate School of Engineering, Osaka University, 565-0871 Suita, Japan
| | - Yoshiaki Sugimoto
- Department of Advanced Materials Science, The University of Tokyo, 5-1-5 Kashiwanoha, 277-8561 Kashiwa, Japan
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102
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Zhou B, Jia W, Sun P, Wang J, Liu W, Zhou C. Polarization-independent high diffraction efficiency two-dimensional grating based on cylindrical hole nano arrays. OPTICS EXPRESS 2020; 28:28810-28818. [PMID: 33114791 DOI: 10.1364/oe.402131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 09/01/2020] [Indexed: 06/11/2023]
Abstract
In this paper, we propose a reflective two-dimensional (2D) metal-dielectric grating based on cylindrical hole nano arrays with excellent polarization-independent high diffraction efficiency. The effects of the geometrical parameters on the polarization characteristic and diffraction efficiency are studied. Optimized results show that the (-1, 0) order diffraction efficiency of transverse electric (TE) and transverse magnetic (TM) polarizations under Littrow mounting is 98.31% and 98.05% at 780 nm incident wavelength, and the diffraction efficiency equilibrium is 99.74%, which is a significant improvement over the previously reported 2D gratings. The high efficiency in both TE and TM polarizations makes it a potential candidate as planar grating rulers for high precision multi-axis displacement measurement. Moreover, the cylindrical hole-based structure performs well in manufacturing tolerances, which provides the possibility for practical applications.
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103
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Croshaw J, Dienel T, Huff T, Wolkow R. Atomic defect classification of the H-Si(100) surface through multi-mode scanning probe microscopy. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2020; 11:1346-1360. [PMID: 32974113 PMCID: PMC7492692 DOI: 10.3762/bjnano.11.119] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 08/11/2020] [Indexed: 06/11/2023]
Abstract
The combination of scanning tunnelling microscopy (STM) and non-contact atomic force microscopy (nc-AFM) allows enhanced extraction and correlation of properties not readily available via a single imaging mode. We demonstrate this through the characterization and classification of several commonly found defects of the hydrogen-terminated silicon (100)-2 × 1 surface (H-Si(100)-2 × 1) by using six unique imaging modes. The H-Si surface was chosen as it provides a promising platform for the development of atom scale devices, with recent work showing their creation through precise desorption or placement of surface hydrogen atoms. While samples with relatively large areas of the H-Si surface are routinely created using an in situ methodology, surface defects are inevitably formed reducing the area available for patterning. By probing the surface using the different interactivity afforded by either hydrogen- or silicon-terminated tips, we are able to extract new insights regarding the atomic and electronic structure of these defects. This allows for the confirmation of literature assignments of several commonly found defects, as well as proposed classifications of previously unreported and unassigned defects. By combining insights from multiple imaging modes, better understanding of their successes and shortcomings in identifying defect structures and origins is achieved. With this, we take the first steps toward enabling the creation of superior H-Si surfaces through an improved understanding of surface defects, ultimately leading to more consistent and reliable fabrication of atom scale devices.
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Affiliation(s)
- Jeremiah Croshaw
- Department of Physics, University of Alberta, Edmonton, Alberta, T6G 2J1, Canada
- Quantum Silicon, Inc., Edmonton, Alberta, T6G 2M9, Canada
| | - Thomas Dienel
- Department of Physics, University of Alberta, Edmonton, Alberta, T6G 2J1, Canada
- Department of Materials Science and Engineering, Cornell University, Ithaca NY 14853, USA
| | - Taleana Huff
- Department of Physics, University of Alberta, Edmonton, Alberta, T6G 2J1, Canada
- Nanotechnology Research Centre, National Research Council Canada, Edmonton, Alberta, T6G 2M9, Canada
| | - Robert Wolkow
- Department of Physics, University of Alberta, Edmonton, Alberta, T6G 2J1, Canada
- Quantum Silicon, Inc., Edmonton, Alberta, T6G 2M9, Canada
- Nanotechnology Research Centre, National Research Council Canada, Edmonton, Alberta, T6G 2M9, Canada
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104
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Leinen P, Esders M, Schütt KT, Wagner C, Müller KR, Tautz FS. Autonomous robotic nanofabrication with reinforcement learning. SCIENCE ADVANCES 2020; 6:6/36/eabb6987. [PMID: 32917594 PMCID: PMC7467688 DOI: 10.1126/sciadv.abb6987] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Accepted: 07/02/2020] [Indexed: 05/27/2023]
Abstract
The ability to handle single molecules as effectively as macroscopic building blocks would enable the construction of complex supramolecular structures inaccessible to self-assembly. The fundamental challenges obstructing this goal are the uncontrolled variability and poor observability of atomic-scale conformations. Here, we present a strategy to work around both obstacles and demonstrate autonomous robotic nanofabrication by manipulating single molecules. Our approach uses reinforcement learning (RL), which finds solution strategies even in the face of large uncertainty and sparse feedback. We demonstrate the potential of our RL approach by removing molecules autonomously with a scanning probe microscope from a supramolecular structure. Our RL agent reaches an excellent performance, enabling us to automate a task that previously had to be performed by a human. We anticipate that our work opens the way toward autonomous agents for the robotic construction of functional supramolecular structures with speed, precision, and perseverance beyond our current capabilities.
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Affiliation(s)
- Philipp Leinen
- Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, 52425 Jülich, Germany
- Jülich Aachen Research Alliance (JARA)-Fundamentals of Future Information Technology, 52425 Jülich, Germany
- Experimentalphysik IV A, RWTH Aachen University, Otto-Blumenthal-Straße, 52074 Aachen, Germany
| | - Malte Esders
- Machine Learning Group, Technische Universität Berlin, 10587 Berlin, Germany
| | - Kristof T Schütt
- Machine Learning Group, Technische Universität Berlin, 10587 Berlin, Germany
| | - Christian Wagner
- Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, 52425 Jülich, Germany.
- Jülich Aachen Research Alliance (JARA)-Fundamentals of Future Information Technology, 52425 Jülich, Germany
| | - Klaus-Robert Müller
- Machine Learning Group, Technische Universität Berlin, 10587 Berlin, Germany.
- Max Planck Institute for Informatics, 66123 Saarbrücken, Germany
- Department of Brain and Cognitive Engineering, Korea University, Seoul, South Korea
| | - F Stefan Tautz
- Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, 52425 Jülich, Germany
- Jülich Aachen Research Alliance (JARA)-Fundamentals of Future Information Technology, 52425 Jülich, Germany
- Experimentalphysik IV A, RWTH Aachen University, Otto-Blumenthal-Straße, 52074 Aachen, Germany
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105
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Kawakami N, Iwata K, Shiotari A, Sugimoto Y. Intrinsic reconstruction of ice-I surfaces. SCIENCE ADVANCES 2020; 6:6/37/eabb7986. [PMID: 32917710 PMCID: PMC7486089 DOI: 10.1126/sciadv.abb7986] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Accepted: 07/24/2020] [Indexed: 06/11/2023]
Abstract
Understanding the precise atomic structure of ice surfaces is critical for revealing the mechanisms of physical and chemical phenomena at the surfaces, such as ice growth, melting, and chemical reactions. Nevertheless, no conclusive structure has been established. In this study, noncontact atomic force microscopy was used to address the characterization of the atomic structures of ice Ih(0001) and Ic(111) surfaces. The topmost hydrogen atoms are arranged with a short-range (2 × 2) order, independent of the ice thickness and growth substrates used. The electrostatic repulsion between non-hydrogen-bonded water molecules at the surface causes a reduction in the number of the topmost hydrogen atoms together with a distortion of the ideal honeycomb arrangement of water molecules, leading to a short-range-ordered surface reconstruction.
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Affiliation(s)
- N Kawakami
- Department of Advanced Materials Science, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561, Japan
| | - K Iwata
- Department of Advanced Materials Science, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561, Japan
| | - A Shiotari
- Department of Advanced Materials Science, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561, Japan
| | - Y Sugimoto
- Department of Advanced Materials Science, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561, Japan.
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106
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Liebig A, Hapala P, Weymouth AJ, Giessibl FJ. Quantifying the evolution of atomic interaction of a complex surface with a functionalized atomic force microscopy tip. Sci Rep 2020; 10:14104. [PMID: 32839507 PMCID: PMC7445177 DOI: 10.1038/s41598-020-71077-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 08/07/2020] [Indexed: 11/09/2022] Open
Abstract
Terminating the tip of an atomic force microscope with a CO molecule allows data to be acquired with a well-known and inert apex. Previous studies have shown conflicting results regarding the electrostatic interaction, indicating in some cases that the negative charge at the apex of the CO dominates, whereas in other cases the positive charge at the end of the metal tip dominates. To clarify this, we investigated [Formula: see text](111). [Formula: see text] is an ionic crystal and the (111) surface does not possess charge inversion symmetry. Far from the surface, the interaction is dominated by electrostatics via the negative charge at the apex. Closer to the surface, Pauli repulsion and CO bending dominate, which leads to an unexpected appearance of the complex 3-atom unit cell. We compare simulated data in which the electrostatics are modeled by point particles versus a charge density calculated by DFT. We also compare modeling Pauli repulsion via individual Lennard-Jones potentials versus a total charge density overlap. In doing so, we determine forcefield parameters useful for future investigations of biochemical processes.
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Affiliation(s)
- Alexander Liebig
- Institute of Experimental and Applied Physics, University of Regensburg, 93040, Regensburg, Germany.
| | - Prokop Hapala
- Department of Applied Physics, Aalto University, Aalto, Finland.,Institute of Physics, Czech Academy of Sciences, Cukrovarnická 10, 162 00, Prague 6, Czech Republic
| | - Alfred J Weymouth
- Institute of Experimental and Applied Physics, University of Regensburg, 93040, Regensburg, Germany
| | - Franz J Giessibl
- Institute of Experimental and Applied Physics, University of Regensburg, 93040, Regensburg, Germany.
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107
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Pürckhauer K, Maier S, Merkel A, Kirpal D, Giessibl FJ. Combined atomic force microscope and scanning tunneling microscope with high optical access achieving atomic resolution in ambient conditions. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2020; 91:083701. [PMID: 32872933 DOI: 10.1063/5.0013921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 07/17/2020] [Indexed: 06/11/2023]
Abstract
Performing atomic force microscopy (AFM) and scanning tunneling microscopy (STM) with atomic resolution under ambient conditions is challenging due to enhanced noise and thermal drift. We show the design of a compact combined atomic force and scanning tunneling microscope that uses qPlus sensors and discuss the stability and thermal drift. By using a material with a low thermal expansion coefficient, we can perform constant height measurements and achieve atomic resolution in both AFM and STM on various samples. Moreover, the design allows a wide angle optical access to the sensor and the sample that is of interest for combining with optical microscopes or focusing optics with a high numerical aperture.
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Affiliation(s)
- Korbinian Pürckhauer
- Institute of Experimental and Applied Physics, University of Regensburg, D-93053 Regensburg, Germany
| | - Simon Maier
- Institute of Experimental and Applied Physics, University of Regensburg, D-93053 Regensburg, Germany
| | - Anja Merkel
- Institute of Experimental and Applied Physics, University of Regensburg, D-93053 Regensburg, Germany
| | - Dominik Kirpal
- Institute of Experimental and Applied Physics, University of Regensburg, D-93053 Regensburg, Germany
| | - Franz J Giessibl
- Institute of Experimental and Applied Physics, University of Regensburg, D-93053 Regensburg, Germany
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108
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Pawlak R, Liu X, Ninova S, D'Astolfo P, Drechsel C, Sangtarash S, Häner R, Decurtins S, Sadeghi H, Lambert CJ, Aschauer U, Liu SX, Meyer E. Bottom-up Synthesis of Nitrogen-Doped Porous Graphene Nanoribbons. J Am Chem Soc 2020; 142:12568-12573. [PMID: 32589029 DOI: 10.1021/jacs.0c03946] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Although methods for a periodic perforation and heteroatom doping of graphene sheets have been developed, patterning closely spaced holes on the nanoscale in graphene nanoribbons is still a challenging task. In this work, nitrogen-doped porous graphene nanoribbons (N-GNRs) were synthesized on Ag(111) using a silver-assisted Ullmann polymerization of brominated tetrabenzophenazine. Insights into the hierarchical reaction pathways from single molecules toward the formation of one-dimensional organometallic complexes and N-GNRs are gained by a combination of scanning tunneling microscopy (STM), atomic force microscopy (AFM) with CO-tip, scanning tunneling spectroscopy (STS), and density functional theory (DFT).
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Affiliation(s)
- Rémy Pawlak
- University of Basel, Department of Physics, Klingelbergstrasse 82, Basel CH 4056, Switzerland
| | - Xunshan Liu
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, Bern, CH 3012, Switzerland
| | - Silviya Ninova
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, Bern, CH 3012, Switzerland
| | - Philipp D'Astolfo
- University of Basel, Department of Physics, Klingelbergstrasse 82, Basel CH 4056, Switzerland
| | - Carl Drechsel
- University of Basel, Department of Physics, Klingelbergstrasse 82, Basel CH 4056, Switzerland
| | | | - Robert Häner
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, Bern, CH 3012, Switzerland
| | - Silvio Decurtins
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, Bern, CH 3012, Switzerland
| | - Hatef Sadeghi
- School of Engineering, University of Warwick, Coventry, U.K
| | | | - Ulrich Aschauer
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, Bern, CH 3012, Switzerland
| | - Shi-Xia Liu
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, Bern, CH 3012, Switzerland
| | - Ernst Meyer
- University of Basel, Department of Physics, Klingelbergstrasse 82, Basel CH 4056, Switzerland
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109
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Schwenk J, Kim S, Berwanger J, Ghahari F, Walkup D, Slot MR, Le ST, Cullen WG, Blankenship SR, Vranjkovic S, Hug HJ, Kuk Y, Giessibl FJ, Stroscio JA. Achieving μeV tunneling resolution in an in-operando scanning tunneling microscopy, atomic force microscopy, and magnetotransport system for quantum materials research. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2020; 91:071101. [PMID: 32752869 PMCID: PMC7678032 DOI: 10.1063/5.0005320] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 06/04/2020] [Indexed: 06/11/2023]
Abstract
Research in new quantum materials requires multi-mode measurements spanning length scales, correlations of atomic-scale variables with a macroscopic function, and spectroscopic energy resolution obtainable only at millikelvin temperatures, typically in a dilution refrigerator. In this article, we describe a multi-mode instrument achieving a μeV tunneling resolution with in-operando measurement capabilities of scanning tunneling microscopy, atomic force microscopy, and magnetotransport inside a dilution refrigerator operating at 10 mK. We describe the system in detail including a new scanning probe microscope module design and sample and tip transport systems, along with wiring, radio-frequency filtering, and electronics. Extensive benchmarking measurements were performed using superconductor-insulator-superconductor tunnel junctions, with Josephson tunneling as a noise metering detector. After extensive testing and optimization, we have achieved less than 8 μeV instrument resolving capability for tunneling spectroscopy, which is 5-10 times better than previous instrument reports and comparable to the quantum and thermal limits set by the operating temperature at 10 mK.
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Affiliation(s)
- Johannes Schwenk
- Physical Measurement Laboratory, 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
| | - Sungmin Kim
- Physical Measurement Laboratory, 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
| | - Julian Berwanger
- Institute of Experimental and Applied Physics, University of Regensburg, 93053 Regensburg, Germany
| | - Fereshte Ghahari
- Physical Measurement Laboratory, 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
| | - Daniel Walkup
- Physical Measurement Laboratory, 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
| | - Marlou R. Slot
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
- Department of Physics, Georgetown University, Washington, DC 20007, USA
| | - Son T. Le
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
- Theiss Research, La Jolla, CA 92037, USA
| | - William G. Cullen
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - Steven R. Blankenship
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - Sasa Vranjkovic
- Institute of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel, Switzerland
| | - Hans J. Hug
- Institute of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel, Switzerland
| | - Young Kuk
- Department of Physics and Astronomy, Seoul National University, Seoul 08826, Korea
| | - Franz J. Giessibl
- Institute of Experimental and Applied Physics, University of Regensburg, 93053 Regensburg, Germany
| | - Joseph A. Stroscio
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
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110
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Sokolović I, Reticcioli M, Čalkovský M, Wagner M, Schmid M, Franchini C, Diebold U, Setvín M. Resolving the adsorption of molecular O 2 on the rutile TiO 2(110) surface by noncontact atomic force microscopy. Proc Natl Acad Sci U S A 2020; 117:14827-14837. [PMID: 32527857 PMCID: PMC7334520 DOI: 10.1073/pnas.1922452117] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Interaction of molecular oxygen with semiconducting oxide surfaces plays a key role in many technologies. The topic is difficult to approach both by experiment and in theory, mainly due to multiple stable charge states, adsorption configurations, and reaction channels of adsorbed oxygen species. Here we use a combination of noncontact atomic force microscopy (AFM) and density functional theory (DFT) to resolve [Formula: see text] adsorption on the rutile [Formula: see text](110) surface, which presents a longstanding challenge in the surface chemistry of metal oxides. We show that chemically inert AFM tips terminated by an oxygen adatom provide excellent resolution of both the adsorbed species and the oxygen sublattice of the substrate. Adsorbed [Formula: see text] molecules can accept either one or two electron polarons from the surface, forming superoxo or peroxo species. The peroxo state is energetically preferred under any conditions relevant for applications. The possibility of nonintrusive imaging allows us to explain behavior related to electron/hole injection from the tip, interaction with UV light, and the effect of thermal annealing.
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Affiliation(s)
- Igor Sokolović
- Institute of Applied Physics, Technische Universität Wien, 1040 Vienna, Austria
| | - Michele Reticcioli
- Institute of Applied Physics, Technische Universität Wien, 1040 Vienna, Austria
- Faculty of Physics, University of Vienna, 1090 Vienna, Austria
- Center for Computational Materials Science, University of Vienna, 1090 Vienna, Austria
| | - Martin Čalkovský
- Institute of Applied Physics, Technische Universität Wien, 1040 Vienna, Austria
- Institute of Physical Engineering, Brno University of Technology, 616 69 Brno, Czech Republic
| | - Margareta Wagner
- Institute of Applied Physics, Technische Universität Wien, 1040 Vienna, Austria
- Central European Institute of Technology, Brno University of Technology, 612 00 Brno, Czech Republic
| | - Michael Schmid
- Institute of Applied Physics, Technische Universität Wien, 1040 Vienna, Austria
| | - Cesare Franchini
- Faculty of Physics, University of Vienna, 1090 Vienna, Austria
- Center for Computational Materials Science, University of Vienna, 1090 Vienna, Austria
- Dipartimento di Fisica e Astronomia, Università di Bologna, 40127 Bologna, Italy
| | - Ulrike Diebold
- Institute of Applied Physics, Technische Universität Wien, 1040 Vienna, Austria
| | - Martin Setvín
- Institute of Applied Physics, Technische Universität Wien, 1040 Vienna, Austria;
- Department of Surface and Plasma Science, Faculty of Mathematics and Physics, Charles University, 180 00 Prague 8, Czech Republic
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111
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Gordon OM, Moriarty PJ. Machine learning at the (sub)atomic scale: next generation scanning probe microscopy. MACHINE LEARNING-SCIENCE AND TECHNOLOGY 2020. [DOI: 10.1088/2632-2153/ab7d2f] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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112
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Su J, Wu X, Song S, Telychko M, Lu J. Substrate induced strain for on-surface transformation and synthesis. NANOSCALE 2020; 12:7500-7508. [PMID: 32227066 DOI: 10.1039/d0nr01270j] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Intermolecular strain has long been used to steer and promote chemical reactions towards desired products in wet chemical synthesis. However, similar protocols have not been adopted for the on-surface synthesis on solid substrates due to the complexity of reaction processes. Recent advances in the sub-molecular resolution with scanning probe microscopy allow us to capture on-surface reaction pathways and to gain substantial insights into the role of strain in chemical reactions. The primary focus of this review is to highlight the recent findings on strain-induced on-surface reactions. Such substrate-induced processes can be applied to alter the chemical reactivity and to drive on-surface chemical reactions in different manners, which provides a promising alternative approach for on-surface synthesis. This review aims to shed light on the utilization of substrate-induced strain for on-surface transformation and synthesis of atomically-precise novel functional nanomaterials.
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Affiliation(s)
- Jie Su
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore.
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113
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Ishii A, Shiotari A, Sugimoto Y. Quality control of on-surface-synthesised seven-atom wide armchair graphene nanoribbons. NANOSCALE 2020; 12:6651-6657. [PMID: 32175533 DOI: 10.1039/c9nr10942k] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
On-surface synthesis is a powerful method for fabricating atomically precise graphene nanoribbons (GNRs), but the products always include defective structures. In this study, scanning tunnelling microscopy and atomic force microscopy were used to determine the length distribution of armchair-edge GNRs with a width of seven carbon atoms (7-AGNRs) synthesised on Au(111) and to characterise defective structures. The product quality was improved by increasing the precursor deposition amount because of a preference for intermolecular polymerisation over intramolecular cyclodehydrogenation at a high coverage. However, the annealing rate had a complex effect on the quality, with a low rate elongating 7-AGNRs but degenerating the length uniformity. These insights advance the understanding of the critical parameters for obtaining high-quality products in high yield by on-surface synthesis.
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Affiliation(s)
- Ayumu Ishii
- Department of Advanced Materials Science, The University of Tokyo, 5-1-5 Kashiwanoha, 277-8561 Kashiwa, Japan.
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114
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Berwanger J, Polesya S, Mankovsky S, Ebert H, Giessibl FJ. Atomically Resolved Chemical Reactivity of Small Fe Clusters. PHYSICAL REVIEW LETTERS 2020; 124:096001. [PMID: 32202857 DOI: 10.1103/physrevlett.124.096001] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 01/17/2020] [Indexed: 06/10/2023]
Abstract
Small metal clusters have been investigated for decades due to their beneficial catalytic activity. It was found that edges are most reactive and the number of catalytic events increases with the cluster's size. However, a direct measurement of chemical reactivity of individual atoms within the clusters has not been reported yet. We combine the high-resolution capability of CO-terminated tips in scanning probe microscopy with their ability to probe chemical binding forces on single Fe atoms to study the chemical reactivity of atom-by-atom assembled Fe clusters from 1 to 15 atoms on the atomic scale. We find that the chemical reactivity of individual atoms within flat Fe clusters does not depend on the cluster size but on the coordination number of the investigated atom. Furthermore, we explain the atomic contrast of the investigated Fe clusters by relating the force spectra of individual atoms with atomic force microscopy images of the clusters.
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Affiliation(s)
- Julian Berwanger
- Institute of Experimental and Applied Physics, University of Regensburg, 93040 Regensburg, Germany
| | - Svitlana Polesya
- Department of Chemistry, Ludwig-Maximilians-University Munich, 81377 Munich, Germany
| | - Sergiy Mankovsky
- Department of Chemistry, Ludwig-Maximilians-University Munich, 81377 Munich, Germany
| | - Hubert Ebert
- Department of Chemistry, Ludwig-Maximilians-University Munich, 81377 Munich, Germany
| | - Franz J Giessibl
- Institute of Experimental and Applied Physics, University of Regensburg, 93040 Regensburg, Germany
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115
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Sun Q, Gröning O, Overbeck J, Braun O, Perrin ML, Borin Barin G, El Abbassi M, Eimre K, Ditler E, Daniels C, Meunier V, Pignedoli CA, Calame M, Fasel R, Ruffieux P. Massive Dirac Fermion Behavior in a Low Bandgap Graphene Nanoribbon Near a Topological Phase Boundary. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e1906054. [PMID: 32048409 DOI: 10.1002/adma.201906054] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 01/08/2020] [Indexed: 05/22/2023]
Abstract
Graphene nanoribbons (GNRs) have attracted much interest due to their largely modifiable electronic properties. Manifestation of these properties requires atomically precise GNRs which can be achieved through a bottom-up synthesis approach. This has recently been applied to the synthesis of width-modulated GNRs hosting topological electronic quantum phases, with valence electronic properties that are well captured by the Su-Schrieffer-Heeger (SSH) model describing a 1D chain of interacting dimers. Here, ultralow bandgap GNRs with charge carriers behaving as massive Dirac fermions can be realized when their valence electrons represent an SSH chain close to the topological phase boundary, i.e., when the intra- and interdimer coupling become approximately equal. Such a system has been achieved via on-surface synthesis based on readily available pyrene-based precursors and the resulting GNRs are characterized by scanning probe methods. The pyrene-based GNRs (pGNRs) can be processed under ambient conditions and incorporated as the active material in a field effect transistor. A quasi-metallic transport behavior is observed at room temperature, whereas at low temperature, the pGNRs behave as quantum dots showing single-electron tunneling and Coulomb blockade. This study may enable the realization of devices based on carbon nanomaterials with exotic quantum properties.
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Affiliation(s)
- Qiang Sun
- Empa, Swiss Federal Laboratories for Materials Science and Technology, 8600, Dübendorf, Switzerland
| | - Oliver Gröning
- Empa, Swiss Federal Laboratories for Materials Science and Technology, 8600, Dübendorf, Switzerland
| | - Jan Overbeck
- Empa, Swiss Federal Laboratories for Materials Science and Technology, 8600, Dübendorf, Switzerland
- Department of Physics, University of Basel, Klingelbergstrasse 80, 4056, Basel, Switzerland
| | - Oliver Braun
- Empa, Swiss Federal Laboratories for Materials Science and Technology, 8600, Dübendorf, Switzerland
- Department of Physics, University of Basel, Klingelbergstrasse 80, 4056, Basel, Switzerland
| | - Mickael L Perrin
- Empa, Swiss Federal Laboratories for Materials Science and Technology, 8600, Dübendorf, Switzerland
| | - Gabriela Borin Barin
- Empa, Swiss Federal Laboratories for Materials Science and Technology, 8600, Dübendorf, Switzerland
| | - Maria El Abbassi
- Empa, Swiss Federal Laboratories for Materials Science and Technology, 8600, Dübendorf, Switzerland
| | - Kristjan Eimre
- Empa, Swiss Federal Laboratories for Materials Science and Technology, 8600, Dübendorf, Switzerland
| | - Edward Ditler
- Empa, Swiss Federal Laboratories for Materials Science and Technology, 8600, Dübendorf, Switzerland
| | - Colin Daniels
- Rensselaer Polytechnic Institute, Department of Physics, Applied Physics and Astronomy, Troy, NY, 12180, USA
| | - Vincent Meunier
- Rensselaer Polytechnic Institute, Department of Physics, Applied Physics and Astronomy, Troy, NY, 12180, USA
| | - Carlo A Pignedoli
- Empa, Swiss Federal Laboratories for Materials Science and Technology, 8600, Dübendorf, Switzerland
| | - Michel Calame
- Empa, Swiss Federal Laboratories for Materials Science and Technology, 8600, Dübendorf, Switzerland
- Department of Physics, University of Basel, Klingelbergstrasse 80, 4056, Basel, Switzerland
| | - Roman Fasel
- Empa, Swiss Federal Laboratories for Materials Science and Technology, 8600, Dübendorf, Switzerland
- Department of Chemistry and Biochemistry, University of Bern, 3012, Bern, Switzerland
| | - Pascal Ruffieux
- Empa, Swiss Federal Laboratories for Materials Science and Technology, 8600, Dübendorf, Switzerland
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116
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Su J, Telychko M, Song S, Lu J. Triangulenes: From Precursor Design to On‐Surface Synthesis and Characterization. Angew Chem Int Ed Engl 2020; 59:7658-7668. [DOI: 10.1002/anie.201913783] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Indexed: 11/06/2022]
Affiliation(s)
- Jie Su
- Department of Chemistry National University of Singapore 3 Science Drive 3 Singapore 117543 Singapore
- Centre for Advanced 2D Materials (CA2DM) National University of Singapore 6 Science Drive 2 Singapore 117546 Singapore
| | - Mykola Telychko
- Department of Chemistry National University of Singapore 3 Science Drive 3 Singapore 117543 Singapore
- Centre for Advanced 2D Materials (CA2DM) National University of Singapore 6 Science Drive 2 Singapore 117546 Singapore
| | - Shaotang Song
- Department of Chemistry National University of Singapore 3 Science Drive 3 Singapore 117543 Singapore
| | - Jiong Lu
- Department of Chemistry National University of Singapore 3 Science Drive 3 Singapore 117543 Singapore
- Centre for Advanced 2D Materials (CA2DM) National University of Singapore 6 Science Drive 2 Singapore 117546 Singapore
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117
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Su J, Telychko M, Song S, Lu J. Triangulenes: From Precursor Design to On‐Surface Synthesis and Characterization. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.201913783] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Jie Su
- Department of Chemistry National University of Singapore 3 Science Drive 3 Singapore 117543 Singapore
- Centre for Advanced 2D Materials (CA2DM) National University of Singapore 6 Science Drive 2 Singapore 117546 Singapore
| | - Mykola Telychko
- Department of Chemistry National University of Singapore 3 Science Drive 3 Singapore 117543 Singapore
- Centre for Advanced 2D Materials (CA2DM) National University of Singapore 6 Science Drive 2 Singapore 117546 Singapore
| | - Shaotang Song
- Department of Chemistry National University of Singapore 3 Science Drive 3 Singapore 117543 Singapore
| | - Jiong Lu
- Department of Chemistry National University of Singapore 3 Science Drive 3 Singapore 117543 Singapore
- Centre for Advanced 2D Materials (CA2DM) National University of Singapore 6 Science Drive 2 Singapore 117546 Singapore
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118
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Yesilpinar D, Schulze Lammers B, Timmer A, Amirjalayer S, Fuchs H, Mönig H. High resolution noncontact atomic force microscopy imaging with oxygen-terminated copper tips at 78 K. NANOSCALE 2020; 12:2961-2965. [PMID: 31970359 DOI: 10.1039/c9nr10450j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Functionalizing atomic force microscopy (AFM) tips by picking up single inert probe particles like CO or Xe from the surface drastically increase the resolution. In particular, this approach allows imaging organic molecules with submolecular resolution revealing their internal bonding structure. However, due to the weak coupling of these probe particles to both, the surface they are picked up from and the tip apex, these experiments require liquid helium temperatures (i.e.≈5 K). In the present study we demonstrate that functionalizing an AFM tip with an atomically defined O-terminated copper tip (CuOx tip) allows performing such experiments at liquid nitrogen temperatures (i.e.≈78 K) with outstanding quality. We show that it is possible to utilize CuOx tips for chemically selective imaging of a copper oxide nanodomain on a partially oxidized Cu(110) surface in the repulsive force regime at elevated temperatures. Moreover, the high structural and chemical stability of CuOx tips allow even ex situ investigations where these tips are used to perform experiments on other, non-Cu, non-oxidized, substrates. In particular, we present results obtained from a dicoronylene (DCLN) molecule with submolecular resolution. An analysis of inner and peripheral bond lengths of the DCLN molecule shows excellent agreement with theoretical gas phase simulations emphasizing the exceptional imaging properties of CuOx tips also at elevated temperatures.
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Affiliation(s)
- Damla Yesilpinar
- Physikalisches Institut, Westfälische Wilhelms-Universität, Wilhelm-Klemm-Straße 10, 48149 Münster, Germany.
| | - Bertram Schulze Lammers
- Physikalisches Institut, Westfälische Wilhelms-Universität, Wilhelm-Klemm-Straße 10, 48149 Münster, Germany.
| | - Alexander Timmer
- Physikalisches Institut, Westfälische Wilhelms-Universität, Wilhelm-Klemm-Straße 10, 48149 Münster, Germany.
| | - Saeed Amirjalayer
- Physikalisches Institut, Westfälische Wilhelms-Universität, Wilhelm-Klemm-Straße 10, 48149 Münster, Germany.
| | - Harald Fuchs
- Physikalisches Institut, Westfälische Wilhelms-Universität, Wilhelm-Klemm-Straße 10, 48149 Münster, Germany.
| | - Harry Mönig
- Physikalisches Institut, Westfälische Wilhelms-Universität, Wilhelm-Klemm-Straße 10, 48149 Münster, Germany.
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119
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Gordon OM, Junqueira FLQ, Moriarty PJ. Embedding human heuristics in machine-learning-enabled probe microscopy. MACHINE LEARNING-SCIENCE AND TECHNOLOGY 2020. [DOI: 10.1088/2632-2153/ab42ec] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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120
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Chandrasekhar V. A microchip microcontroller-based transducer controller for non-contact scanning probe microscopy with phase-locked loop, amplitude, and Q control. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2020; 91:023705. [PMID: 32113447 DOI: 10.1063/1.5131657] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 01/23/2020] [Indexed: 06/10/2023]
Abstract
An inexpensive yet versatile transducer controller for non-contact scanning probe microscopy (SPM) based on a PIC32 microcontroller from Microchip Technology, Inc is described. In addition to feedback control using the amplitude or phase of the signal from the non-contact transducer, the controller includes a phase-locked loop for frequency-shift feedback, as well as fixed-amplitude, quality factor (Q) control, and self-excitation modes. Apart from the input amplifiers, output buffers, and the Q-control circuit, all other functions of the controller are instantiated in software on the microchip, enabling rapid changes in operating parameters if needed. The controller communicates with a host personal computer via a simple serial connection. The controller has been tested with a quartz tuning-fork transducer but can be used with any oscillating non-contact transducer.
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121
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Pawlak R, Vilhena JG, D'Astolfo P, Liu X, Prampolini G, Meier T, Glatzel T, Lemkul JA, Häner R, Decurtins S, Baratoff A, Pérez R, Liu SX, Meyer E. Sequential Bending and Twisting around C-C Single Bonds by Mechanical Lifting of a Pre-Adsorbed Polymer. NANO LETTERS 2020; 20:652-657. [PMID: 31797665 DOI: 10.1021/acs.nanolett.9b04418] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Bending and twisting around carbon-carbon single bonds are ubiquitous in natural and synthetic polymers. Force-induced changes were so far not measured at the single-monomer level, owing to limited ways to apply local forces. We quantified down to the submolecular level the mechanical response within individual poly-pyrenylene chains upon their detachment from a gold surface with an atomic force microscope at 5 K. Computer simulations based on a dedicated force field reproduce the experimental traces and reveal symmetry-broken bent and rotated conformations of the sliding physisorbed segment besides steric hindrance of the just lifted monomer. Our study also shows that the tip-molecule bond remains intact but remarkably soft and links force variations to complex but well-defined conformational changes.
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Affiliation(s)
- Rémy Pawlak
- Department of Physics , University of Basel , Klingelbergstrasse 82 , 4056 Basel , Switzerland
| | - J G Vilhena
- Department of Physics , University of Basel , Klingelbergstrasse 82 , 4056 Basel , Switzerland
| | - Philipp D'Astolfo
- Department of Physics , University of Basel , Klingelbergstrasse 82 , 4056 Basel , Switzerland
| | - Xunshan Liu
- Department of Chemistry and Biochemistry , University of Bern , Freiestrasse 3 , Bern , CH 3012 , Switzerland
| | - Giacomo Prampolini
- CNR-Consiglio Nazionale delle Ricerche , Istituto di Chimica dei Composti Organo Metallici (ICCOM-CNR) , Pisa , Italy
| | - Tobias Meier
- Department of Physics , University of Basel , Klingelbergstrasse 82 , 4056 Basel , Switzerland
| | - Thilo Glatzel
- Department of Physics , University of Basel , Klingelbergstrasse 82 , 4056 Basel , Switzerland
| | - Justin A Lemkul
- Department of Biochemistry , Virginia Tech , 303 Engel Hall, 340 West Campus Drive , Blacksburg , Virginia 24061 , United States
| | - Robert Häner
- Department of Chemistry and Biochemistry , University of Bern , Freiestrasse 3 , Bern , CH 3012 , Switzerland
| | - Silvio Decurtins
- Department of Chemistry and Biochemistry , University of Bern , Freiestrasse 3 , Bern , CH 3012 , Switzerland
| | - Alexis Baratoff
- Department of Physics , University of Basel , Klingelbergstrasse 82 , 4056 Basel , Switzerland
| | - Rubén Pérez
- Departamento de Física Teórica de la Materia Condensada , Universidad Autónoma de Madrid , E-28049 Madrid , Spain
- Condensed Matter Physics Center (IFIMAC) , Universidad Autónoma de Madrid , E-28049 Madrid , Spain
| | - Shi-Xia Liu
- Department of Chemistry and Biochemistry , University of Bern , Freiestrasse 3 , Bern , CH 3012 , Switzerland
| | - Ernst Meyer
- Department of Physics , University of Basel , Klingelbergstrasse 82 , 4056 Basel , Switzerland
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122
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Scherb S, Hinaut A, Pawlak R, Vilhena JG, Liu Y, Freund S, Liu Z, Feng X, Müllen K, Glatzel T, Narita A, Meyer E. Giant thermal expansion of a two-dimensional supramolecular network triggered by alkyl chain motion. COMMUNICATIONS MATERIALS 2020; 1:8. [PMID: 32259137 PMCID: PMC7099928 DOI: 10.1038/s43246-020-0009-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Accepted: 01/05/2020] [Indexed: 05/14/2023]
Abstract
Thermal expansion, the response in shape, area or volume of a solid with heat, is usually large in molecular materials compared to their inorganic counterparts. Resulting from the intrinsic molecule flexibility, conformational changes or variable intermolecular interactions, the exact interplay between these mechanisms is however poorly understood down to the molecular level. Here, we investigate the structural variations of a two-dimensional supramolecular network on Au(111) consisting of shape persistent polyphenylene molecules equipped with peripheral dodecyl chains. By comparing high-resolution scanning probe microscopy and molecular dynamics simulations obtained at 5 and 300 K, we determine the thermal expansion coefficient of the assembly of 980 ± 110 × 10-6 K-1, twice larger than other molecular systems hitherto reported in the literature, and two orders of magnitude larger than conventional materials. This giant positive expansion originates from the increased mobility of the dodecyl chains with temperature that determine the intermolecular interactions and the network spacing.
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Affiliation(s)
- Sebastian Scherb
- Department of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland
| | - Antoine Hinaut
- Department of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland
| | - Rémy Pawlak
- Department of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland
| | - J. G. Vilhena
- Department of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland
| | - Yi Liu
- Max Plank Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Sara Freund
- Department of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland
| | - Zhao Liu
- Department of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland
| | - Xinliang Feng
- Faculty of Chemistry and Food Chemistry, TU Dresden, Mommsenstrasse 4, 01069 Dresden, Germany
| | - Klaus Müllen
- Max Plank Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Thilo Glatzel
- Department of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland
| | - Akimitsu Narita
- Max Plank Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Ernst Meyer
- Department of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland
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123
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Sweetman A, Champness NR, Saywell A. On-surface chemical reactions characterised by ultra-high resolution scanning probe microscopy. Chem Soc Rev 2020; 49:4189-4202. [DOI: 10.1039/d0cs00166j] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The impact of high resolution scanning probe microscopy on imaging individual molecules with intramolecular resolution is reviewed.
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Affiliation(s)
- Adam Sweetman
- School of Physics and Astronomy
- University of Leeds
- Leeds
- UK
| | | | - Alex Saywell
- School of Physics and Astronomy
- University of Nottingham
- Nottingham
- UK
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124
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Quantitative determination of atomic buckling of silicene by atomic force microscopy. Proc Natl Acad Sci U S A 2019; 117:228-237. [PMID: 31871150 DOI: 10.1073/pnas.1913489117] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The atomic buckling in 2D "Xenes" (such as silicene) fosters a plethora of exotic electronic properties such as a quantum spin Hall effect and could be engineered by external strain. Quantifying the buckling magnitude with subangstrom precision is, however, challenging, since epitaxially grown 2D layers exhibit complex restructurings coexisting on the surface. Here, we characterize using low-temperature (5 K) atomic force microscopy (AFM) with CO-terminated tips assisted by density functional theory (DFT) the structure and local symmetry of each prototypical silicene phase on Ag(111) as well as extended defects. Using force spectroscopy, we directly quantify the atomic buckling of these phases within 0.1-Å precision, obtaining corrugations in the 0.8- to 1.1-Å range. The derived band structures further confirm the absence of Dirac cones in any of the silicene phases due to the strong Ag-Si hybridization. Our method paves the way for future atomic-scale analysis of the interplay between structural and electronic properties in other emerging 2D Xenes.
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125
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Peronio A, Okabayashi N, Griesbeck F, Giessibl F. Radio frequency filter for an enhanced resolution of inelastic electron tunneling spectroscopy in a combined scanning tunneling- and atomic force microscope. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2019; 90:123104. [PMID: 31893785 DOI: 10.1063/1.5119888] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Accepted: 11/10/2019] [Indexed: 06/10/2023]
Abstract
The combination of inelastic electron tunneling spectroscopy (IETS), also used for IET spectrum based on scanning tunneling microscopy with atomic force microscopy (AFM) enables us to measure the vibrational energies of a single molecule along with the force exerted by the tip of a microscope, which deepens our understanding on the interaction between the tip and the molecule on a surface. The resolution of IETS is a crucial factor in determining the vibrational energies of a molecule. However, radio frequency (RF) noise from the environment significantly deteriorates the resolution. We introduce an RF noise filtering technique, which enables high resolution IETS while maintaining uncompromised AFM performance, demonstrated by vibrational measurements of a CO molecule on a copper surface.
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Affiliation(s)
- Angelo Peronio
- Institute of Experimental and Applied Physics, University of Regensburg, D-93053 Regensburg, Germany
| | - Norio Okabayashi
- Graduate School of Natural Science and Technology, Kanazawa University, 920-1192 Ishikawa, Japan
| | - Florian Griesbeck
- Institute of Experimental and Applied Physics, University of Regensburg, D-93053 Regensburg, Germany
| | - Franz Giessibl
- Institute of Experimental and Applied Physics, University of Regensburg, D-93053 Regensburg, Germany
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126
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Contact Resonance Atomic Force Microscopy Using Long, Massive Tips. SENSORS 2019; 19:s19224990. [PMID: 31731825 PMCID: PMC6891549 DOI: 10.3390/s19224990] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 11/08/2019] [Accepted: 11/12/2019] [Indexed: 12/14/2022]
Abstract
In this work, we present a new theoretical model for use in contact resonance atomic force microscopy. This model incorporates the effects of a long, massive sensing tip and is especially useful to interpret operation in the so-called trolling mode. The model is based on traditional Euler-Bernoulli beam theory, whereby the effect of the tip as well as of the sample in contact, modeled as an elastic substrate, are captured by appropriate boundary conditions. A novel interpretation of the flexural and torsional modes of vibration of the cantilever, when not in contact with the sample, is used to estimate the inertia properties of the long, massive tip. Using this information, sample elastic properties are then estimated from the in-contact resonance frequencies of the system. The predictive capability of the proposed model is verified via finite element analysis. Different combinations of cantilever geometry, tip geometry, and sample stiffness are investigated. The model's accurate predictive ranges are discussed and shown to outperform those of other popular models currently used in contact resonance atomic force microscopy.
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127
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Kirpal DJ, Pürckhauer K, Weymouth AJ, Giessibl FJ. Ion mobility and material transport on KBr in air as a function of the relative humidity. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2019; 10:2084-2093. [PMID: 31728256 PMCID: PMC6839551 DOI: 10.3762/bjnano.10.203] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 10/09/2019] [Indexed: 06/10/2023]
Abstract
Surfaces exposed to air can change their structure due to external influences such as chemical reactions or material exchange and movement. The adsorbed water layer that is present under ambient conditions plays an important role especially for highly soluble materials. Surface atoms can easily diffuse into the thin water layer and, when surface conditions are favorable, they can re-attach to the surface. We collected atomic force microscopy images of KBr surfaces in a humidity-controlled glove box at various relative humidities below 40%. By scratching and poking the surface with the AFM tip, we constructed energetically unfavorable holes or scratch sites and material accumulations and recorded the evolution of these defects as a function of the time. We observed an exponential decay of the size of the defects and material accumulations, and from this data we determined energy barriers to dissolution and aggregation of approximately 0.9 eV.
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Affiliation(s)
- Dominik J Kirpal
- Institute of Experimental and Applied Physics, University of Regensburg, 93040 Regensburg, Germany
| | - Korbinian Pürckhauer
- Institute of Experimental and Applied Physics, University of Regensburg, 93040 Regensburg, Germany
| | - Alfred J Weymouth
- Institute of Experimental and Applied Physics, University of Regensburg, 93040 Regensburg, Germany
| | - Franz J Giessibl
- Institute of Experimental and Applied Physics, University of Regensburg, 93040 Regensburg, Germany
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128
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Huff TR, Dienel T, Rashidi M, Achal R, Livadaru L, Croshaw J, Wolkow RA. Electrostatic Landscape of a Hydrogen-Terminated Silicon Surface Probed by a Moveable Quantum Dot. ACS NANO 2019; 13:10566-10575. [PMID: 31386340 DOI: 10.1021/acsnano.9b04653] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
With nanoelectronics reaching the limit of atom-sized devices, it has become critical to examine how irregularities in the local environment can affect device functionality. Here, we characterize the influence of charged atomic species on the electrostatic potential of a semiconductor surface at the subnanometer scale. Using noncontact atomic force microscopy, two-dimensional maps of the contact potential difference are used to show the spatially varying electrostatic potential on the (100) surface of hydrogen-terminated highly doped silicon. Three types of charged species, one on the surface and two within the bulk, are examined. An electric field sensitive spectroscopic signature of a single probe atom reports on nearby charged species. The identity of one of the near-surface species has been uncertain in the literature, and we suggest that its character is more consistent with either a negatively charged interstitial hydrogen or a hydrogen vacancy complex.
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Affiliation(s)
- Taleana R Huff
- Department of Physics , University of Alberta , Edmonton , Alberta T6G 2J1 , Canada
- Quantum Silicon, Inc. , Edmonton , Alberta T6G 2M9 , Canada
| | - Thomas Dienel
- Department of Physics , University of Alberta , Edmonton , Alberta T6G 2J1 , Canada
| | - Mohammad Rashidi
- Department of Physics , University of Alberta , Edmonton , Alberta T6G 2J1 , Canada
| | - Roshan Achal
- Department of Physics , University of Alberta , Edmonton , Alberta T6G 2J1 , Canada
- Quantum Silicon, Inc. , Edmonton , Alberta T6G 2M9 , Canada
| | | | - Jeremiah Croshaw
- Department of Physics , University of Alberta , Edmonton , Alberta T6G 2J1 , Canada
| | - Robert A Wolkow
- Department of Physics , University of Alberta , Edmonton , Alberta T6G 2J1 , Canada
- Nanotechnology Research Centre , National Research Council Canada , Edmonton , Alberta T6G 2M9 , Canada
- Quantum Silicon, Inc. , Edmonton , Alberta T6G 2M9 , Canada
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129
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Zhao Y, Yuan B, Li C, Zhang P, Mai Y, Guan D, Li Y, Zheng H, Liu C, Wang S, Jia J. On-Surface Synthesis of Iron Phthalocyanine Using Metal-Organic Coordination Templates. Chemphyschem 2019; 20:2394-2397. [PMID: 31025456 DOI: 10.1002/cphc.201900238] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2019] [Revised: 04/19/2019] [Indexed: 11/06/2022]
Abstract
On-surface synthesis provides a convenient route to many kinds of conjugated molecular nanostructures, but it has remained challenging to precisely control the reaction pathway for using multicomponent precursors. Herein, we demonstrate a two-step strategy to synthesize iron phthalocyanine (FePc) molecules using metal-organic coordination for templating by using high-resolution scanning tunnelling microscopy and non-contact atomic force microscopy. In a first step, 1,2,4,5-tetracyanobenzene (TCNB) precursors and Fe atoms self-assembly into Fe(TCNB)4 coordination complexes on a clean Au(111) surface. The Fe(TCNB)4 complexes further undergo cyclic tetramerization upon thermal annealing, forming single FePc molecules. We expect that our demonstrated synthetic strategy may shed light on the design and synthesis of two-dimensional extended conjugated systems.
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Affiliation(s)
- Yan Zhao
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University, 800 DongChuan Road, Shanghai, 200240, China
| | - Bingkai Yuan
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University, 800 DongChuan Road, Shanghai, 200240, China
| | - Can Li
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University, 800 DongChuan Road, Shanghai, 200240, China
| | - Pengfei Zhang
- School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, 800 DongChuan Road, Shanghai, 200240, China
| | - Yiyong Mai
- School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, 800 DongChuan Road, Shanghai, 200240, China
| | - Dandan Guan
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University, 800 DongChuan Road, Shanghai, 200240, China
| | - Yaoyi Li
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University, 800 DongChuan Road, Shanghai, 200240, China
| | - Hao Zheng
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University, 800 DongChuan Road, Shanghai, 200240, China
| | - Canhua Liu
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University, 800 DongChuan Road, Shanghai, 200240, China
| | - Shiyong Wang
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University, 800 DongChuan Road, Shanghai, 200240, China
| | - Jinfeng Jia
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University, 800 DongChuan Road, Shanghai, 200240, China
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130
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Huber F, Berwanger J, Polesya S, Mankovsky S, Ebert H, Giessibl FJ. Chemical bond formation showing a transition from physisorption to chemisorption. Science 2019; 366:235-238. [PMID: 31515246 DOI: 10.1126/science.aay3444] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Accepted: 08/29/2019] [Indexed: 11/02/2022]
Abstract
Surface molecules can transition from physisorption through weak van der Waals forces to a strongly bound chemisorption state by overcoming an energy barrier. We show that a carbon monoxide (CO) molecule adsorbed to the tip of an atomic force microscope enables a controlled observation of bond formation, including its potential transition from physisorption to chemisorption. During imaging of copper (Cu) and iron (Fe) adatoms on a Cu(111) surface, the CO was not chemically inert but transited through a physisorbed local energy minimum into a chemisorbed global minimum, and an energy barrier was seen for the Fe adatom. Density functional theory reveals that the transition occurs through a hybridization of the electronic states of the CO molecule mainly with s-, p z -, and d z 2-type states of the Fe and Cu adatoms, leading to chemical bonding.
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Affiliation(s)
- Ferdinand Huber
- Institute of Experimental and Applied Physics, Department of Physics, University of Regensburg, 93040 Regensburg, Germany
| | - Julian Berwanger
- Institute of Experimental and Applied Physics, Department of Physics, University of Regensburg, 93040 Regensburg, Germany
| | - Svitlana Polesya
- Department of Chemistry, Ludwig-Maximilians-Universität München, 81377 Munich, Germany
| | - Sergiy Mankovsky
- Department of Chemistry, Ludwig-Maximilians-Universität München, 81377 Munich, Germany
| | - Hubert Ebert
- Department of Chemistry, Ludwig-Maximilians-Universität München, 81377 Munich, Germany
| | - Franz J Giessibl
- Institute of Experimental and Applied Physics, Department of Physics, University of Regensburg, 93040 Regensburg, Germany.
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131
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Fan D, Sakai Y, Chelikowsky JR. Discrimination of Bond Order in Organic Molecules Using Noncontact Atomic Force Microscopy. NANO LETTERS 2019; 19:5562-5567. [PMID: 31340648 DOI: 10.1021/acs.nanolett.9b02097] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Noncontact atomic force microscopy (nc-AFM) with a CO-functionalized tip can image submolecular structures through high-resolution images with the possibility of discriminating bond order. We employ real-space pseudopotential calculations to simulate nc-AFM images of molecules containing double (dibenzo(cd,n)naphtho(3,2,1,8-pqra)perylene (DBNP), hexabenzo(bc,ef,hi,kl,no,qr)coronene (HBC)) and triple (1,2-bis[2-(2-ethynylphenyl)ethynyl]-benzene (BEEB), 6-phenylhexa-1,3,5-triynylbenzene (PHTB)) bonds. We find (1) triple bonds can be unambiguously distinguished from other interatomic interactions based on a characteristic image and (2) the degree of double bond character can be directly determined from the image. We propose that large lateral forces acting on the tip may induce specific image distortions in the cases of DBNP and BEEB.
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132
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Sun T, Wu Z, Li Z, Zheng Q, Lin L. A Hybrid Two-Axis Force Sensor for the Mesoscopic Structural Superlubricity Studies. SENSORS (BASEL, SWITZERLAND) 2019; 19:s19153431. [PMID: 31387294 PMCID: PMC6696239 DOI: 10.3390/s19153431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Revised: 07/26/2019] [Accepted: 08/02/2019] [Indexed: 06/10/2023]
Abstract
Structural superlubricity (SSL) is a state of nearly zero friction and zero wear between two directly contacted solid surfaces. Recently, SSL was achieved in mesoscale and thus opened the SSL technology which promises great applications in Micro-electromechanical Systems (MEMS), sensors, storage technologies, etc. However, load issues in current mesoscale SSL studies are still not clear. The great challenge is to simultaneously measure both the ultralow shear forces and the much larger normal forces, although the widely used frictional force microscopes (FFM) and micro tribometers can satisfy the shear forces and normal forces requirements, respectively. Here we propose a hybrid two-axis force sensor that can well fill the blank between the capabilities of FFM and micro tribometers for the mesoscopic SSL studies. The proposed sensor can afford 1mN normal load with 10 nN lateral resolution. Moreover, the probe of the sensor is designed at the edge of the structure for the convenience of real-time optical observation. Calibrations and preliminary experiments are conducted to validate the performance of the design.
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Affiliation(s)
- Taotao Sun
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, China
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
| | - Zhanghui Wu
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, China
- Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
| | - Zhihong Li
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, China
- National Key Laboratory of Science and Technology on Micro/Nano Fabrication, Institute of Microelectronics, Peking University, Beijing 100871, China
| | - Quanshui Zheng
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, China
- Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
| | - Li Lin
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, China.
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China.
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133
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Sader JE. What is the oscillation amplitude of a vibrating cantilever? THE REVIEW OF SCIENTIFIC INSTRUMENTS 2019; 90:086103. [PMID: 31472639 DOI: 10.1063/1.5115768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 08/12/2019] [Indexed: 06/10/2023]
Abstract
Resonant amplification of vibrational amplitude underpins the application of nanomechanical sensors. For cantilever sensors, this amplification is widely reported to be equal to the sensor's quality factor, which strongly underestimates its true value. Here, we present a simple analytical formula for this amplification factor, valid for three-dimensional resonators of arbitrary shape, that will find utility in practice.
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Affiliation(s)
- John Elie Sader
- ARC Centre of Excellence in Exciton Science, School of Mathematics and Statistics, The University of Melbourne, Victoria 3010, Australia
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134
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Lee M, Kim B, An S, Jhe W. Dynamic Responses of Electrically Driven Quartz Tuning Fork and qPlus Sensor: A Comprehensive Electromechanical Model for Quartz Tuning Fork. SENSORS (BASEL, SWITZERLAND) 2019; 19:E2686. [PMID: 31207882 PMCID: PMC6630222 DOI: 10.3390/s19122686] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 06/10/2019] [Accepted: 06/11/2019] [Indexed: 11/16/2022]
Abstract
A quartz tuning fork and its qPlus configuration show different characteristics in their dynamic features, including peak amplitude, resonance frequency, and quality factor. Here, we present an electromechanical model that comprehensively describes the dynamic responses of an electrically driven tuning fork and its qPlus configuration. Based on the model, we theoretically derive and experimentally validate how the peak amplitude, resonance frequency, quality factor, and normalized capacitance are changed when transforming a tuning fork to its qPlus configuration. Furthermore, we introduce two experimentally measurable parameters that are intrinsic for a given tuning fork and not changed by the qPlus configuration. The present model and analysis allow quantitative prediction of the dynamic characteristics in tuning fork and qPlus, and thus could be useful to optimize the sensors' performance.
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Affiliation(s)
- Manhee Lee
- Department of Physics, Chungbuk National University, Cheongju, Chungbuk 28644, Korea.
| | - Bongsu Kim
- Department of Physics and Astronomy, Seoul National University, Gwanak-gu, Seoul 08826, Korea.
| | - Sangmin An
- Department of Physics and Astronomy, Seoul National University, Gwanak-gu, Seoul 08826, Korea.
| | - Wonho Jhe
- Department of Physics and Astronomy, Seoul National University, Gwanak-gu, Seoul 08826, Korea.
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135
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Abstract
Ionic liquids have become of significant relevance in chemistry, as they can serve as environmentally-friendly solvents, electrolytes, and lubricants with bespoke properties. In particular for electrochemical applications, an understanding of the interface structure between the ionic liquid and an electrified interface is needed to model and optimize the reactions taking place on the solid surface. As with ionic liquids, the interplay between electrostatic forces and steric effects leads to an intrinsic heterogeneity, as the structure of the ionic liquid above an electrified interface cannot be described by the classical electrical double layer model. Instead, a layered solvation layer is present with a structure that depends on the material combination of the ionic liquid and substrate. In order to experimentally monitor this structure, atomic force spectroscopy (AFS) has become the method of choice. By measuring the force acting on a sharp microfabricated tip while approaching the surface in an ionic liquid, it has become possible to map the solvation layers with sub-nanometer resolution. In this review, we provide an overview of the AFS studies on ionic liquids published in recent years that illustrate how the interface is formed and how it can be modified by applying electrical potential or by adding impurities and solvents.
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