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Liu H, Ahmed Z, Vranjkovic S, Parschau M, Mandru AO, Hug HJ. A cantilever-based, ultrahigh-vacuum, low-temperature scanning probe instrument for multidimensional scanning force microscopy. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2022; 13:1120-1140. [PMID: 36299563 PMCID: PMC9577238 DOI: 10.3762/bjnano.13.95] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 09/20/2022] [Indexed: 06/16/2023]
Abstract
Cantilever-based atomic force microscopy (AFM) performed under ambient conditions has become an important tool to characterize new material systems as well as devices. Current instruments permit robust scanning over large areas, atomic-scale lateral resolution, and the characterization of various sample properties using multifrequency and multimodal AFM operation modes. Research of new quantum materials and devices, however, often requires low temperatures and ultrahigh vacuum (UHV) conditions and, more specifically, AFM instrumentation providing atomic resolution. For this, AFM instrumentation based on a tuning fork force sensor became increasingly popular. In comparison to microfabricated cantilevers, the more macroscopic tuning forks, however, lack sensitivity, which limits the measurement bandwidth. Moreover, multimodal and multifrequency techniques, such as those available in cantilever-based AFM carried out under ambient conditions, are challenging to implement. In this article, we describe a cantilever-based low-temperature UHV AFM setup that allows one to transfer the versatile AFM techniques developed for ambient conditions to UHV and low-temperature conditions. We demonstrate that such a cantilever-based AFM offers experimental flexibility by permitting multimodal or multifrequency operations with superior force derivative sensitivities and bandwidths. Our instrument has a sub-picometer gap stability and can simultaneously map not only vertical and lateral forces with atomic-scale resolution, but also perform rapid overview scans with the tip kept at larger tip-sample distances for robust imaging.
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Affiliation(s)
- Hao Liu
- Empa, Swiss Federal Laboratories for Materials Science and Technology, CH-8600 Dübendorf, Switzerland.
- Department of Physics, University of Basel, CH-4056 Basel, Switzerland.
| | - Zuned Ahmed
- Empa, Swiss Federal Laboratories for Materials Science and Technology, CH-8600 Dübendorf, Switzerland.
- Department of Physics, University of Basel, CH-4056 Basel, Switzerland.
| | - Sasa Vranjkovic
- Empa, Swiss Federal Laboratories for Materials Science and Technology, CH-8600 Dübendorf, Switzerland.
| | - Manfred Parschau
- Empa, Swiss Federal Laboratories for Materials Science and Technology, CH-8600 Dübendorf, Switzerland.
| | - Andrada-Oana Mandru
- Empa, Swiss Federal Laboratories for Materials Science and Technology, CH-8600 Dübendorf, Switzerland.
| | - Hans J Hug
- Empa, Swiss Federal Laboratories for Materials Science and Technology, CH-8600 Dübendorf, Switzerland.
- Department of Physics, University of Basel, CH-4056 Basel, Switzerland.
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52
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Rothe K, Néel N, Bocquet ML, Kröger J. Tracking the Interaction between a CO-Functionalized Probe and Two Ag-Phthalocyanine Conformers by Local Vertical Force Spectroscopy. J Phys Chem A 2022; 126:6890-6897. [PMID: 36154143 DOI: 10.1021/acs.jpca.2c04760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Intentionally terminating scanning probes with a single atom or molecule belongs to a rapidly growing field in the quantum chemistry and physics at surfaces. However, the detailed understanding of the coupling between the probe and adsorbate is in its infancy. Here, an atomic force microscopy probe functionalized with a single CO molecule is approached with picometer control to two conformational isomers of Ag-phthalocyanine adsorbed on Ag(111). The isomer with the central Ag atom pointing to CO exhibits a complex evolution of the distance-dependent interaction, while the conformer with Ag bonded to the metal surface gives rise to a Lennard-Jones behavior. By virtue of spatially resolved force spectroscopy and the comparison with results obtained from microscope probes terminated with a single Ag atom, the mutual coupling of the protruding O atom of the tip and the Ag atom of the phthalocyanine molecule is identified as the cause for the unconventional variation of the force. Simulations of the entire junction within density functional theory unveil the presence of ample relaxations in the case of one conformer, which represents a rationale for the peculiar vertical-distance evolution of the interaction. The simulations highlight the role of physisorption, chemisorption, and unexpected junction distortions at the verge of bond formation in the interpretation of the distance-dependent force between two molecules.
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Affiliation(s)
- Karl Rothe
- Institut für Physik, Technische Universität Ilmenau, D-98693 Ilmenau, Germany
| | - Nicolas Néel
- Institut für Physik, Technische Universität Ilmenau, D-98693 Ilmenau, Germany
| | - Marie-Laure Bocquet
- Laboratoire de Physique de l'École Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université Paris-Diderot, Sorbonne Paris Cité, F-75005 Paris, France
| | - Jörg Kröger
- Institut für Physik, Technische Universität Ilmenau, D-98693 Ilmenau, Germany
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53
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Schulze Lammers B, López-Salas N, Stein Siena J, Mirhosseini H, Yesilpinar D, Heske J, Kühne TD, Fuchs H, Antonietti M, Mönig H. Real-Space Identification of Non-Noble Single Atomic Catalytic Sites within Metal-Coordinated Supramolecular Networks. ACS NANO 2022; 16:14284-14296. [PMID: 36053675 DOI: 10.1021/acsnano.2c04439] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
With regard to the development of single atom catalysts (SACs), non-noble metal-organic layers combine a large functional variability with cost efficiency. Here, we characterize reacted layers of melamine and melem molecules on a Cu(111) surface by noncontact atomic force microscopy (nc-AFM), X-ray photoelectron spectroscopy (XPS) and ab initio simulations. Upon deposition on the substrate and subsequent heat treatments in ultrahigh vacuum (UHV), these precursors undergo a stepwise dehydrogenation. After full dehydrogenation of the amino groups, the molecular units lie flat and are strongly chemisorbed on the copper substrate. We observe a particularly extreme interaction of the dehydrogenated nitrogen atoms with single copper atoms located at intermolecular sites. In agreement with the nc-AFM measurements performed with an O-terminated copper tip on these triazine- and heptazine-based copper nitride structures, our ab initio simulations confirm a pronounced interaction of oxygen species at these N-Cu-N sites. To investigate the related functional properties of our samples regarding the oxygen reduction reaction (ORR), we developed an electrochemical setup for cyclic voltammetry experiments performed at ambient pressure within a drop of electrolyte in a controlled O2 or N2 environment. Both copper nitride structures show a robust activity in irreversibly catalyzing the reduction of oxygen. The activity is assigned to the intermolecular N-Cu-N sites of the triazine- and heptazine-based copper nitrides or corresponding oxygenated versions (N-CuO-N, N-CuO2-N). By combining nc-AFM characterization on the atomic scale with a direct electrochemical proof of performance, our work provides fundamental insights about active sites in a technologically highly relevant reaction.
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Affiliation(s)
- Bertram Schulze Lammers
- Physikalisches Institut, Westfälische Wilhelms-Universität, Wilhelm-Klemm-Straße 10, 48149 Münster, Germany
- Center for Nanotechnology, Heisenbergstraße 11, 48149 Münster, Germany
| | - Nieves López-Salas
- Max Planck Institute of Colloids and Interfaces, Am Mühlenberg 1, 14476 Potsdam, Germany
| | - Julya Stein Siena
- Max Planck Institute of Colloids and Interfaces, Am Mühlenberg 1, 14476 Potsdam, Germany
| | - Hossein Mirhosseini
- Dynamics of Condensed Matter and Center for Sustainable Systems Design, Chair of Theoretical Chemistry, University of Paderborn, Warburger Straße 100, 33098 Paderborn, Germany
| | - Damla Yesilpinar
- Physikalisches Institut, Westfälische Wilhelms-Universität, Wilhelm-Klemm-Straße 10, 48149 Münster, Germany
- Center for Nanotechnology, Heisenbergstraße 11, 48149 Münster, Germany
| | - Julian Heske
- Dynamics of Condensed Matter and Center for Sustainable Systems Design, Chair of Theoretical Chemistry, University of Paderborn, Warburger Straße 100, 33098 Paderborn, Germany
| | - Thomas D Kühne
- Dynamics of Condensed Matter and Center for Sustainable Systems Design, Chair of Theoretical Chemistry, University of Paderborn, Warburger Straße 100, 33098 Paderborn, Germany
| | - Harald Fuchs
- Physikalisches Institut, Westfälische Wilhelms-Universität, Wilhelm-Klemm-Straße 10, 48149 Münster, Germany
- Center for Nanotechnology, Heisenbergstraße 11, 48149 Münster, Germany
| | - Markus Antonietti
- Max Planck Institute of Colloids and Interfaces, Am Mühlenberg 1, 14476 Potsdam, Germany
| | - Harry Mönig
- Physikalisches Institut, Westfälische Wilhelms-Universität, Wilhelm-Klemm-Straße 10, 48149 Münster, Germany
- Center for Nanotechnology, Heisenbergstraße 11, 48149 Münster, Germany
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54
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Rothe K, Néel N, Bocquet ML, Kröger J. Extraction of Chemical Reactivity and Structural Relaxations of an Organic Dye from the Short-Range Interaction with a Molecular Probe. J Phys Chem Lett 2022; 13:8660-8665. [PMID: 36084075 DOI: 10.1021/acs.jpclett.2c02140] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
A CO-functionalized atomic force microscope tip is used to locally probe local chemical reactivity and subtle structural relaxations of a single phthalocyanine molecule at different stages of pyrrolic-H abstraction. Spatially resolved vertical force spectroscopy unveils a variation of the maximum short-range attraction between CO and intramolecular sites, which is interpreted as a measure for the local chemical reactivity. In addition, the vertical position of the point of maximum attraction is observed to vary across the molecules. These changes follow the calculated adsorption heights of the probed molecular atoms.
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Affiliation(s)
- Karl Rothe
- Institut für Physik, Technische Universität Ilmenau, D-98693 Ilmenau, Germany
| | - Nicolas Néel
- Institut für Physik, Technische Universität Ilmenau, D-98693 Ilmenau, Germany
| | - Marie-Laure Bocquet
- Laboratoire de Physique de l'École Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université Paris-Diderot, Sorbonne Paris Cité, F-75005 Paris, France
| | - Jörg Kröger
- Institut für Physik, Technische Universität Ilmenau, D-98693 Ilmenau, Germany
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55
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Kort-Kamp WJM, Murdick RA, Htoon H, Jones AC. Utilization of coupled eigenmodes in Akiyama atomic force microscopy probes for bimodal multifrequency sensing. NANOTECHNOLOGY 2022; 33:455501. [PMID: 35853401 DOI: 10.1088/1361-6528/ac8232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 07/18/2022] [Indexed: 06/15/2023]
Abstract
Akiyama atomic force microscopy probes represent a unique means of combining several of the desirable properties of tuning fork and cantilever probe designs. As a hybridized mechanical resonator, the vibrational characteristics of Akiyama probes result from a complex coupling between the intrinsic vibrational eigenmodes of its constituent tuning fork and bridging cantilever components. Through a combination of finite element analysis modeling and experimental measurements of the thermal vibrations of Akiyama probes we identify a complex series of vibrational eigenmodes and measure their frequencies, quality factors, and spring constants. We then demonstrate the viability of Akiyama probes to perform bimodal multi-frequency force sensing by performing a multimodal measurement of a surface's nanoscale photothermal response using photo-induced force microscopy imaging techniques. Further performing a parametric search over alternative Akiyama probe geometries, we propose two modified probe designs to enhance the capability of Akiyama probes to perform sensitive bimodal multifrequency force sensing measurements.
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Affiliation(s)
- Wilton J M Kort-Kamp
- Theoretical Division, Los Alamos National Laboratory, Los Alamos, United States of America
| | - Ryan A Murdick
- Renaissance Scientific, Boulder, Colorado United States of America
| | - Han Htoon
- Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, United States of America
| | - Andrew C Jones
- Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, United States of America
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56
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Reticcioli M, Wang Z, Schmid M, Wrana D, Boatner LA, Diebold U, Setvin M, Franchini C. Competing electronic states emerging on polar surfaces. Nat Commun 2022; 13:4311. [PMID: 35879300 PMCID: PMC9314351 DOI: 10.1038/s41467-022-31953-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Accepted: 07/07/2022] [Indexed: 11/28/2022] Open
Abstract
Excess charge on polar surfaces of ionic compounds is commonly described by the two-dimensional electron gas (2DEG) model, a homogeneous distribution of charge, spatially-confined in a few atomic layers. Here, by combining scanning probe microscopy with density functional theory calculations, we show that excess charge on the polar TaO2 termination of KTaO3(001) forms more complex electronic states with different degrees of spatial and electronic localization: charge density waves (CDW) coexist with strongly-localized electron polarons and bipolarons. These surface electronic reconstructions, originating from the combined action of electron-lattice interaction and electronic correlation, are energetically more favorable than the 2DEG solution. They exhibit distinct spectroscopy signals and impact on the surface properties, as manifested by a local suppression of ferroelectric distortions.
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Affiliation(s)
- Michele Reticcioli
- University of Vienna, Faculty of Physics, Center for Computational Materials Science, Vienna, Austria
- Institute of Applied Physics, Technische Universität Wien, Vienna, Austria
| | - Zhichang Wang
- Institute of Applied Physics, Technische Universität Wien, Vienna, Austria
- State Key Laboratory for Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, China
| | - Michael Schmid
- Institute of Applied Physics, Technische Universität Wien, Vienna, Austria
| | - Dominik Wrana
- Department of Surface and Plasma Science, Faculty of Mathematics and Physics, Charles University, 180 00, Prague 8, Czech Republic
| | - Lynn A Boatner
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Ulrike Diebold
- Institute of Applied Physics, Technische Universität Wien, Vienna, Austria
| | - Martin Setvin
- Institute of Applied Physics, Technische Universität Wien, Vienna, Austria.
- Department of Surface and Plasma Science, Faculty of Mathematics and Physics, Charles University, 180 00, Prague 8, Czech Republic.
| | - Cesare Franchini
- University of Vienna, Faculty of Physics, Center for Computational Materials Science, Vienna, Austria.
- Dipartimento di Fisica e Astronomia, Università di Bologna, 40127, Bologna, Italy.
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57
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Tian Y, Hong J, Cao D, You S, Song Y, Cheng B, Wang Z, Guan D, Liu X, Zhao Z, Li XZ, Xu LM, Guo J, Chen J, Wang EG, Jiang Y. Visualizing Eigen/Zundel cations and their interconversion in monolayer water on metal surfaces. Science 2022; 377:315-319. [DOI: 10.1126/science.abo0823] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The nature of hydrated proton on solid surfaces is of vital importance in electrochemistry, proton channels, and hydrogen fuel cells but remains unclear because of the lack of atomic-scale characterization. We directly visualized Eigen- and Zundel-type hydrated protons within the hydrogen bonding water network on Au(111) and Pt(111) surfaces, using cryogenic qPlus-based atomic force microscopy under ultrahigh vacuum. We found that the Eigen cations self-assembled into monolayer structures with local order, and the Zundel cations formed long-range ordered structures stabilized by nuclear quantum effects. Two Eigen cations could combine into one Zundel cation accompanied with a simultaneous proton transfer to the surface. Moreover, we revealed that the Zundel configuration was preferred over the Eigen on Pt(111), and such a preference was absent on Au(111).
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Affiliation(s)
- Ye Tian
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Jiani Hong
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Duanyun Cao
- Beijing Key Laboratory of Environmental Science and Engineering, School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, China
- Beijing Institute of Technology Chongqing Innovation Center, Chongqing 401120, China
| | - Sifan You
- Institute of Functional Nano and Soft Materials, Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Soochow University, Suzhou 215123, China
| | - Yizhi Song
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Bowei Cheng
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Zhichang Wang
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Dong Guan
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Xinmeng Liu
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Zhengpu Zhao
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Xin-Zheng Li
- School of Physics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing 100871, China
- Interdisciplinary Institute of Light-Element Quantum Materials and Research Center for Light-Element Advanced Materials, Peking University, Beijing 100871, China
| | - Li-Mei Xu
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
- Interdisciplinary Institute of Light-Element Quantum Materials and Research Center for Light-Element Advanced Materials, Peking University, Beijing 100871, China
| | - Jing Guo
- College of Chemistry, Beijing Normal University, Beijing 100875, China
| | - Ji Chen
- School of Physics, Peking University, Beijing 100871, China
- Interdisciplinary Institute of Light-Element Quantum Materials and Research Center for Light-Element Advanced Materials, Peking University, Beijing 100871, China
| | - En-Ge Wang
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
- Interdisciplinary Institute of Light-Element Quantum Materials and Research Center for Light-Element Advanced Materials, Peking University, Beijing 100871, China
- Songshan Lake Materials Lab, Institute of Physics, CAS and School of Physics, Liaoning University, Shenyang 110036, China
| | - Ying Jiang
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
- Interdisciplinary Institute of Light-Element Quantum Materials and Research Center for Light-Element Advanced Materials, Peking University, Beijing 100871, China
- CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100190, China
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58
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Wang D, Wang Z, Liu W, Zhong S, Feng YP, Loh KP, Wee ATS. Real-Space Investigation of the Multiple Halogen Bonds by Ultrahigh-Resolution Scanning Probe Microscopy. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 18:e2202368. [PMID: 35719029 DOI: 10.1002/smll.202202368] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Indexed: 06/15/2023]
Abstract
The chemical bond is of central interest in chemistry, and it is of significance to study the nature of intermolecular bonds in real-space. Herein, non-contact atomic force microscopy (nc-AFM) and low-temperature scanning tunneling microscopy (LT-STM) are employed to acquire real-space atomic information of molecular clusters, i.e., monomer, dimer, trimer, tetramer, formed on Au(111). The formation of the various molecular clusters is due to the diversity of halogen bonds. DFT calculation also suggests the formation of three distinct halogen bonds among the molecular clusters, which originates from the noncovalent interactions of Br-atoms with the positive potential H-atoms, neutral potential Br-atoms, and negative potential N-atoms, respectively. This work demonstrates the real-space investigation of the multiple halogen bonds by nc-AFM/LT-STM, indicating the potential use of this technique to study other intermolecular bonds and to understand complex supramolecular assemblies at the atomic/sub-molecular level.
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Affiliation(s)
- Dingguan Wang
- Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore, 117551, Singapore
| | - Zishen Wang
- Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore, 117551, Singapore
| | - Wei Liu
- School of Physics, Southeast University, 2 Southeast University Road, Nanjing, China
| | - Siying Zhong
- Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore, 117551, Singapore
| | - Yuan Ping Feng
- Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore, 117551, Singapore
| | - Kian Ping Loh
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore, 117543, Singapore
| | - Andrew Thye Shen Wee
- Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore, 117551, Singapore
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59
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Huang H, Shuai M, Yang Y, Song R, Liao Y, Yin L, Shen J. Cryogen free spin polarized scanning tunneling microscopy and magnetic exchange force microscopy with extremely low noise. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2022; 93:073703. [PMID: 35922334 DOI: 10.1063/5.0095271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2022] [Accepted: 06/12/2022] [Indexed: 06/15/2023]
Abstract
Spin polarized scanning tunneling microscopy (SP-STM) and magnetic exchange force microscopy (MExFM) are powerful tools to characterize spin structure at the atomic scale. For low temperature measurements, liquid helium cooling is commonly used, which has the advantage of generating low noise but has the disadvantage of having difficulties in carrying out measurements with long durations at low temperatures and measurements with a wide temperature range. The situation is just reversed for cryogen-free STM, where the mechanical vibration of the refrigerator becomes a major challenge. In this work, we have successfully built a cryogen-free system with both SP-STM and MExFM capabilities, which can be operated under a 9 T magnetic field provided by a cryogen-free superconducting magnet and in a wide temperature range between 1.4 and 300 K. With the help of our specially designed vibration isolation system, the noise is reduced to an extremely low level of 0.7 pm. The Fe/Ir(111) magnetic skyrmion lattice is used to demonstrate the technical novelties of our cryogen-free system.
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Affiliation(s)
- Haiming Huang
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
| | - Mingming Shuai
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
| | - Yulong Yang
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
| | - Rui Song
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
| | - Yanghui Liao
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
| | - Lifeng Yin
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
| | - Jian Shen
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
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60
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Caniglia G, Tezcan G, Meloni GN, Unwin PR, Kranz C. Probing and Visualizing Interfacial Charge at Surfaces in Aqueous Solution. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2022; 15:247-267. [PMID: 35259914 DOI: 10.1146/annurev-anchem-121521-122615] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Surface charge density and distribution play an important role in almost all interfacial processes, influencing, for example, adsorption, colloidal stability, functional material activity, electrochemical processes, corrosion, nanoparticle toxicity, and cellular processes such as signaling, absorption, and adhesion. Understanding the heterogeneity in, and distribution of, surface and interfacial charge is key to elucidating the mechanisms underlying reactivity, the stability of materials, and biophysical processes. Atomic force microscopy (AFM) and scanning ion conductance microscopy (SICM) are highly suitable for probing the material/electrolyte interface at the nanoscale through recent advances in probe design, significant instrumental (hardware and software) developments, and the evolution of multifunctional imaging protocols. Here, we assess the capability of AFM and SICM for surface charge mapping, covering the basic underpinning principles alongside experimental considerations. We illustrate and compare the use of AFM and SICM for visualizing surface and interfacial charge with examples from materials science, geochemistry, and the life sciences.
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Affiliation(s)
- Giada Caniglia
- Institute of Analytical and Bioanalytical Chemistry, Ulm University, Ulm, Germany;
| | - Gözde Tezcan
- Department of Chemistry, University of Warwick, Coventry, United Kingdom;
| | - Gabriel N Meloni
- Department of Chemistry, University of Warwick, Coventry, United Kingdom;
| | - Patrick R Unwin
- Department of Chemistry, University of Warwick, Coventry, United Kingdom;
| | - Christine Kranz
- Institute of Analytical and Bioanalytical Chemistry, Ulm University, Ulm, Germany;
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61
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Guo J, Jiang Y. Submolecular Insights into Interfacial Water by Hydrogen-Sensitive Scanning Probe Microscopy. Acc Chem Res 2022; 55:1680-1692. [PMID: 35678704 DOI: 10.1021/acs.accounts.2c00111] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
ConspectusWater-solid interfaces have attracted extensive attention because of their crucial roles in a wide range of chemical and physical processes, such as ice nucleation and growth, dissolution, corrosion, heterogeneous catalysis, and electrochemistry. To understand these processes, enormous efforts have been made to obtain a molecular-level understanding of the structure and dynamics of water on various solid surfaces. By the use of scanning probe microscopy (SPM), many remarkable structures of H-bonding networks have been directly visualized, significantly advancing our understanding of the delicate competition between water-water and water-solid interactions. Moreover, the detailed dynamics of water molecules, such as diffusion, clustering, dissociation, and intermolecular and intramolecular proton transfer, have been investigated in a well-controlled manner by tip manipulation. However, resolving the submolecular structure of surface water has remained a great challenge for a long time because of the small size and light mass of protons. Discerning the position of hydrogen in water is not only crucial for the accurate determination of the structure of H-bonding networks but also indispensable in probing the proton transfer dynamics and the quantum nature of protons.In this Account, we focus on the recent advances in the H-sensitive SPM technique and its applications in probing the structures, dynamics, and nuclear quantum effects (NQEs) of surface water and ion hydrates at the submolecular level. First, we introduce the development of high-resolution scanning tunneling microscopy/spectroscopy (STM/S) and qPlus-based atomic force microscopy (qPlus-AFM), which allow access to the degrees of freedom of protons in both real and energy space. qPlus-AFM even allows imaging of interfacial water in a weakly perturbative manner by measuring the high-order electrostatic force between the CO-terminated tip and the polar water molecule, which enables the subtle difference of OH directionality to be discerned. Next we showcase the applications of H-sensitive STM/AFM in addressing several key issues related to water-solid interfaces. The surface wetting behavior and the H-bonding structure of low-dimensional ice on various hydrophilic and hydrophobic solid surfaces are characterized at the atomic scale. Then we discuss the quantitative assessment of NQEs of surface water, including proton tunneling and quantum delocalization. Moreover, the weakly perturbative and H-sensitive SPM technique can be also extended to investigations of water-ion interactions on solid surfaces, revealing the effect of hydration structure on the interfacial ion transport. Finally, we provide an outlook on the further directions and challenges for SPM studies of water-solid interfaces.
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Affiliation(s)
- Jing Guo
- College of Chemistry, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Ying Jiang
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, People's Republic of China.,Collaborative Innovation Center of Quantum Matter, Beijing 100871, People's Republic of China.,Interdisciplinary Institute of Light-Element Quantum Materials and Research Center for Light-Element Advanced Materials, Peking University, Beijing 100871, People's Republic of China.,CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100190, People's Republic of China
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Zheng G, Zhang D, Chen KW, Singleton J, Li L. Resonant torque differential magnetometry with high frequency quartz oscillators. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2022; 93:063907. [PMID: 35778020 DOI: 10.1063/5.0084231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Accepted: 06/01/2022] [Indexed: 06/15/2023]
Abstract
Sensitive magnetometry has been a powerful probe for investigating quantum materials. Extreme conditions, such as sub-kelvin cryogenic temperatures and ultrahigh magnetic fields, demand further durability for sensitive magnetometry. However, significant mechanical vibrations and rapid magnetic field changes give enormous challenges to conventional magnetometry. This article presents a possible solution to this problem by developing a new magnetometry technique using high-frequency quartz oscillators. The technique takes advantage of the symmetry and geometry of mechanical vibration configurations of standard commercially available MHz quartz oscillators, and the setup keeps the high quality factor resonance with the sample mounted on the oscillator. We further demonstrate the sensitivity of the technique using bismuth single crystals and a Fe0.25TaS2 ferromagnetic material. Quantum oscillations are observed in the magnetometry response below 1 T, and the detected oscillation frequency is shown to come from the electron pockets of the bismuth.
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Affiliation(s)
- Guoxin Zheng
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Dechen Zhang
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Kuan-Wen Chen
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - John Singleton
- National High Magnetic Field Laboratory, MS E536, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - Lu Li
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
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63
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Eichhorn AL, Dietz C. Torsional and lateral eigenmode oscillations for atomic resolution imaging of HOPG in air under ambient conditions. Sci Rep 2022; 12:8981. [PMID: 35643777 PMCID: PMC9148301 DOI: 10.1038/s41598-022-13065-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Accepted: 05/12/2022] [Indexed: 11/16/2022] Open
Abstract
Combined in-plane and out-of-plane multifrequency atomic force microscopy techniques have been demonstrated to be important tools to decipher spatial differences of sample surfaces at the atomic scale. The analysis of physical properties perpendicular to the sample surface is routinely achieved from flexural cantilever oscillations, whereas the interpretation of in-plane sample properties via force microscopy is still challenging. Besides the torsional oscillation, there is the additional option to exploit the lateral oscillation of the cantilever for in-plane surface analysis. In this study, we used different multifrequency force microscopy approaches to attain better understanding of the interactions between a super-sharp tip and an HOPG surface focusing on the discrimination between friction and shear forces. We found that the lateral eigenmode is suitable for the determination of the shear modulus whereas the torsional eigenmode provides information on local friction forces between tip and sample. Based on the results, we propose that the full set of elastic constants of graphite can be determined from combined in-plane and out-of-plane multifrequency atomic force microscopy if ultrasmall amplitudes and high force constants are used.
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Affiliation(s)
- Anna L Eichhorn
- Physics of Surfaces, Institute of Materials Science, Technische Universität Darmstadt, Alarich-Weiss-Str. 2, 64287, Darmstadt, Germany
| | - Christian Dietz
- Physics of Surfaces, Institute of Materials Science, Technische Universität Darmstadt, Alarich-Weiss-Str. 2, 64287, Darmstadt, Germany.
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64
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Vilhena JG, Pawlak R, D'Astolfo P, Liu X, Gnecco E, Kisiel M, Glatzel T, Pérez R, Häner R, Decurtins S, Baratoff A, Prampolini G, Liu SX, Meyer E. Flexible Superlubricity Unveiled in Sidewinding Motion of Individual Polymeric Chains. PHYSICAL REVIEW LETTERS 2022; 128:216102. [PMID: 35687435 DOI: 10.1103/physrevlett.128.216102] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 02/22/2022] [Accepted: 04/19/2022] [Indexed: 06/15/2023]
Abstract
A combination of low temperature atomic force microcopy and molecular dynamic simulations is used to demonstrate that soft designer molecules realize a sidewinding motion when dragged over a gold surface. Exploiting their longitudinal flexibility, pyrenylene chains are indeed able to lower diffusion energy barriers via on-surface directional locking and molecular strain. The resulting ultralow friction reaches values on the order of tens of pN reported so far only for rigid chains sliding on an incommensurate surface. Therefore, we demonstrate how molecular flexibility can be harnessed to realize complex nanomotion while retaining a superlubric character. This is in contrast with the paradigm guiding the design of most superlubric nanocontacts (mismatched rigid contacting surfaces).
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Affiliation(s)
- J G Vilhena
- Department of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland
- Departamento de Física Teórica de la Materia Condensada, Universidad Autónoma de Madrid, E-28049 Madrid, Spain
| | - Rémy Pawlak
- 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, Zhejiang Sci-tech University, 314423 Hangzhou, China
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| | - Enrico Gnecco
- Marian Smoluchowski Institute of Physics, Jagiellonian University, Lojasiewicza 11, 30-348 Krakow, Poland
| | - Marcin Kisiel
- Department of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland
| | - Thilo Glatzel
- Department of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland
| | - Rúben 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
| | - Robert Häner
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| | - Silvio Decurtins
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| | - Alexis Baratoff
- Department of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland
| | - Giacomo Prampolini
- Istituto di Chimica dei Composti Organo Metallici, Consiglio Nazionale delle Ricerche (ICCOM-CNR), 56124 Pisa, Italy
| | - Shi-Xia Liu
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| | - Ernst Meyer
- Department of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland
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65
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Çiftçi HT, Verhage M, Cromwijk T, Pham Van L, Koopmans B, Flipse K, Kurnosikov O. Enhancing sensitivity in atomic force microscopy for planar tip-on-chip probes. MICROSYSTEMS & NANOENGINEERING 2022; 8:51. [PMID: 35586140 PMCID: PMC9108095 DOI: 10.1038/s41378-022-00379-x] [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: 01/25/2022] [Revised: 03/19/2022] [Accepted: 04/11/2022] [Indexed: 06/15/2023]
Abstract
We present a new approach to tuning-fork-based atomic force microscopy for utilizing advanced "tip-on-chip" probes with high sensitivity and broad compatibility. Usually, such chip-like probes with a size reaching 2 × 2 mm2 drastically perturb the oscillation of the tuning fork, resulting in poor performance in its intrinsic force sensing. Therefore, restoring initial oscillatory characteristics is necessary for regaining high sensitivity. To this end, we developed a new approach consisting of three basic steps: tuning-fork rebalancing, revamping holder-sensor fixation, and electrode reconfiguration. Mass rebalancing allows the tuning fork to recover the frequency and regain high Q-factor values up to 104 in air and up to 4 × 104 in ultra-high vacuum conditions. The floating-like holder-fixation using soft wires significantly reduces energy dissipation from the mounting elements. Combined with the soft wires, reconfigured electrodes provide electrical access to the chip-like probe without intervening in the force-sensing signal. Finally, our easy-to-implement approach allows converting the atomic force microscopy tip from a passive tool to a dedicated microdevice with extended functionality.
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Affiliation(s)
- H. Tunç Çiftçi
- Department of Applied Physics, Eindhoven University of Technology, PO Box 513,, 5600 MB Eindhoven, the Netherlands
| | - Michael Verhage
- Department of Applied Physics, Eindhoven University of Technology, PO Box 513,, 5600 MB Eindhoven, the Netherlands
| | - Tamar Cromwijk
- Department of Applied Physics, Eindhoven University of Technology, PO Box 513,, 5600 MB Eindhoven, the Netherlands
| | - Laurent Pham Van
- DRF/IRAMIS/SPEC-LEPO, Centre CEA de Saclay, 91191 Gif-sur-Yvette, France
| | - Bert Koopmans
- Department of Applied Physics, Eindhoven University of Technology, PO Box 513,, 5600 MB Eindhoven, the Netherlands
| | - Kees Flipse
- Department of Applied Physics, Eindhoven University of Technology, PO Box 513,, 5600 MB Eindhoven, the Netherlands
| | - Oleg Kurnosikov
- Department of Applied Physics, Eindhoven University of Technology, PO Box 513,, 5600 MB Eindhoven, the Netherlands
- Institut Jean Lamour, Lorraine University, 54000 Nancy, France
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66
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Sander T, Liu Y, Pham TA, Ammon M, Devarajulu M, Maier S. Ultra-high vacuum cleaver for the preparation of ionic crystal surfaces. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2022; 93:053703. [PMID: 35649805 DOI: 10.1063/5.0088802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Accepted: 04/08/2022] [Indexed: 06/15/2023]
Abstract
Cleaving single crystals in situ under ultra-high vacuum conditions provides a reliable and straightforward approach to prepare clean and atomically well-defined surfaces. Here, we present a versatile sample cleaver to efficiently prepare ionic crystal surfaces under ultra-high vacuum conditions, which is suitable for preparation of softer materials, such as alkali halides, and harder materials, such as metal oxides. One of the advantages of the presented cleaver design is that the cleaving blade and anvil to support the crystal are incorporated into the device. Therefore, no particularly strong mechanical manipulator is needed, and it is compatible with existing vacuum chambers equipped with an xyz-manipulator. We demonstrate atomically flat terraces and the atomic structure of NaCl(001), KBr(001), NiO(001), and MgO(001) cleavage planes prepared in situ under ultra-high vacuum conditions and imaged by low-temperature non-contact atomic force microscopy.
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Affiliation(s)
- Tim Sander
- Department of Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erwin-Rommel-Straße 1, 91058 Erlangen, Germany
| | - Yi Liu
- Department of Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erwin-Rommel-Straße 1, 91058 Erlangen, Germany
| | - Tuan Anh Pham
- Department of Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erwin-Rommel-Straße 1, 91058 Erlangen, Germany
| | - Maximilian Ammon
- Department of Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erwin-Rommel-Straße 1, 91058 Erlangen, Germany
| | - Mirunalini Devarajulu
- Department of Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erwin-Rommel-Straße 1, 91058 Erlangen, Germany
| | - Sabine Maier
- Department of Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erwin-Rommel-Straße 1, 91058 Erlangen, Germany
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67
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Telychko M, Edalatmanesh S, Leng K, Abdelwahab I, Guo N, Zhang C, Mendieta-Moreno JI, Nachtigall M, Li J, Loh KP, Jelínek P, Lu J. Sub-angstrom noninvasive imaging of atomic arrangement in 2D hybrid perovskites. SCIENCE ADVANCES 2022; 8:eabj0395. [PMID: 35486735 PMCID: PMC9054006 DOI: 10.1126/sciadv.abj0395] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Noninvasive imaging of the atomic arrangement in two-dimensional (2D) Ruddlesden-Popper hybrid perovskites (RPPs) is challenging because of the insulating nature and softness of the organic layers. Here, we demonstrate a sub-angstrom resolution imaging of both soft organic layers and inorganic framework in a prototypical 2D lead-halide RPP crystal via combined tip-functionalized scanning tunneling microscopy (STM) and noncontact atomic force microscopy (ncAFM) corroborated by theoretical simulations. STM measurements unveil the atomic reconstruction of the inorganic lead-halide lattice and overall twin-domain composition of the RPP crystal, while ncAFM measurements with a CO-tip enable nonperturbative visualization of the cooperative reordering of surface organic cations driven by their hydrogen bonding interactions with the inorganic lattice. Moreover, such a joint technique also allows for the atomic-scale imaging of the electrostatic potential variation across the twin-domain walls, revealing alternating quasi-1D electron and hole channels at neighboring twin boundaries, which may influence in-plane exciton transport and dissociation.
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Affiliation(s)
- Mykola Telychko
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
| | - Shayan Edalatmanesh
- Institute of Physics, The Czech Academy of Sciences, 162 00 Prague, Czech Republic
- Regional Centre of Advanced Technologies and Materials, Palacký University, 78371 Olomouc, Czech Republic
| | - Kai Leng
- Department of Applied Physics, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China
| | - Ibrahim Abdelwahab
- 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
| | - Na Guo
- Department of Physics, National University of Singapore, Blk S12, Science Drive 3, Singapore 117551, Singapore
| | - Chun Zhang
- Department of Physics, National University of Singapore, Blk S12, Science Drive 3, Singapore 117551, Singapore
| | | | - Matyas Nachtigall
- Institute of Physics, The Czech Academy of Sciences, 162 00 Prague, Czech Republic
| | - Jing Li
- Centre for Advanced 2D Materials (CA2DM), National University of Singapore, 6 Science Drive 2, Singapore 117546, Singapore
| | - Kian Ping Loh
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
- Corresponding author. (J.L.); (P.J.); (K.P.L.)
| | - Pavel Jelínek
- Institute of Physics, The Czech Academy of Sciences, 162 00 Prague, Czech Republic
- Regional Centre of Advanced Technologies and Materials, Palacký University, 78371 Olomouc, Czech Republic
- Corresponding author. (J.L.); (P.J.); (K.P.L.)
| | - 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
- Corresponding author. (J.L.); (P.J.); (K.P.L.)
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68
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Gao W, Kang F, Qiu X, Yi Z, Shang L, Liu M, Qiu X, Luo Y, Xu W. On-Surface Debromination of C 6Br 6: C 6 Ring versus C 6 Chain. ACS NANO 2022; 16:6578-6584. [PMID: 35377612 DOI: 10.1021/acsnano.2c00945] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Carbon allotropes comprising sp-hybridized carbon atoms have been investigated for decades for their molecular structure. One of the unsolved mysteries is whether they should take a linear or cyclic configuration in condensed phases due to the lack of atomistic characterizations. Herein, we designed a molecule with a C6 skeleton as a model system to address this issue, which was achieved by eliminating Br atoms from hexabromobenzene (C6Br6) molecule on the Ag(111) substrate via thermal treatment. It is found that the C6 ring intermediate resulting from complete debromination is energetically unstable at room temperature based on theoretical calculations. It subsequently transforms into the C6 polyynic chain via a ring-opening process and ultimately polymerizes into the organometallic polyyne, whose triyne structural unit is revealed by bond-resolved noncontact atomic force microscopy. Theoretical calculations demonstrated an energetically favorable pathway in which the ring-opening process occurs after complete debromination of C6Br6. Our study provides a platform for the synthesis of elusive carbon-rich materials.
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Affiliation(s)
- Wenze Gao
- Interdisciplinary Materials Research Center, College of Materials Science and Engineering, Tongji University, Shanghai 201804, People's Republic of China
| | - Faming Kang
- Interdisciplinary Materials Research Center, College of Materials Science and Engineering, Tongji University, Shanghai 201804, People's Republic of China
| | - Xia Qiu
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, People's Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, People's Republic of China
| | - Zewei Yi
- Interdisciplinary Materials Research Center, College of Materials Science and Engineering, Tongji University, Shanghai 201804, People's Republic of China
| | - Lina Shang
- Interdisciplinary Materials Research Center, College of Materials Science and Engineering, Tongji University, Shanghai 201804, People's Republic of China
| | - Mengxi Liu
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, People's Republic of China
| | - Xiaohui Qiu
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, People's Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Yi Luo
- Hefei National Laboratory for Physical Sciences at the Microscale & Department of Chemical Physics, iChEM, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
| | - Wei Xu
- Interdisciplinary Materials Research Center, College of Materials Science and Engineering, Tongji University, Shanghai 201804, People's Republic of China
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69
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Martin-Jimenez D, Ruppert MG, Ihle A, Ahles S, Wegner HA, Schirmeisen A, Ebeling D. Chemical bond imaging using torsional and flexural higher eigenmodes of qPlus sensors. NANOSCALE 2022; 14:5329-5339. [PMID: 35348167 DOI: 10.1039/d2nr01062c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Non-contact atomic force microscopy (AFM) with CO-functionalized tips allows visualization of the chemical structure of adsorbed molecules and identify individual inter- and intramolecular bonds. This technique enables in-depth studies of on-surface reactions and self-assembly processes. Herein, we analyze the suitability of qPlus sensors, which are commonly used for such studies, for the application of modern multifrequency AFM techniques. Two different qPlus sensors were tested for submolecular resolution imaging via actuating torsional and flexural higher eigenmodes and via bimodal AFM. The torsional eigenmode of one of our sensors is perfectly suited for performing lateral force microscopy (LFM) with single bond resolution. The obtained LFM images agree well with images from the literature, which were scanned with customized qPlus sensors that were specifically designed for LFM. The advantage of using a torsional eigenmode is that the same molecule can be imaged either with a vertically or laterally oscillating tip without replacing the sensor simply by actuating a different eigenmode. Submolecular resolution is also achieved by actuating the 2nd flexural eigenmode of our second sensor. In this case, we observe particular contrast features that only appear in the AFM images of the 2nd flexural eigenmode but not for the fundamental eigenmode. With complementary laser Doppler vibrometry measurements and AFM simulations we can rationalize that these contrast features are caused by a diagonal (i.e. in-phase vertical and lateral) oscillation of the AFM tip.
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Affiliation(s)
- Daniel Martin-Jimenez
- Institute of Applied Physics (IAP), Justus Liebig University Giessen, Heinrich-Buff-Ring 16, Giessen 35392, Germany.
- Center for Materials Research (LaMa), Justus Liebig University Giessen, Heinrich-Buff-Ring 16, Giessen 35392, Germany
| | | | - Alexander Ihle
- Institute of Applied Physics (IAP), Justus Liebig University Giessen, Heinrich-Buff-Ring 16, Giessen 35392, Germany.
- Center for Materials Research (LaMa), Justus Liebig University Giessen, Heinrich-Buff-Ring 16, Giessen 35392, Germany
| | - Sebastian Ahles
- Institute of Organic Chemistry, Justus Liebig University Giessen, Heinrich-Buff-Ring 17, Giessen 35392, Germany
- Center for Materials Research (LaMa), Justus Liebig University Giessen, Heinrich-Buff-Ring 16, Giessen 35392, Germany
| | - Hermann A Wegner
- Institute of Organic Chemistry, Justus Liebig University Giessen, Heinrich-Buff-Ring 17, Giessen 35392, Germany
- Center for Materials Research (LaMa), Justus Liebig University Giessen, Heinrich-Buff-Ring 16, Giessen 35392, Germany
| | - André Schirmeisen
- Institute of Applied Physics (IAP), Justus Liebig University Giessen, Heinrich-Buff-Ring 16, Giessen 35392, Germany.
- Center for Materials Research (LaMa), Justus Liebig University Giessen, Heinrich-Buff-Ring 16, Giessen 35392, Germany
| | - Daniel Ebeling
- Institute of Applied Physics (IAP), Justus Liebig University Giessen, Heinrich-Buff-Ring 16, Giessen 35392, Germany.
- Center for Materials Research (LaMa), Justus Liebig University Giessen, Heinrich-Buff-Ring 16, Giessen 35392, Germany
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70
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Cheng B, Wu D, Bian K, Tian Y, Guo C, Liu K, Jiang Y. A qPlus-based scanning probe microscope compatible with optical measurements. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2022; 93:043701. [PMID: 35489886 DOI: 10.1063/5.0082369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 03/10/2022] [Indexed: 06/14/2023]
Abstract
We design and develop a scanning probe microscope (SPM) system based on the qPlus sensor for atomic-scale optical experiments. The microscope operates under ultrahigh vacuum and low temperature (6.2 K). In order to obtain high efficiency of light excitation and collection, two front lenses with high numerical apertures (N.A. = 0.38) driven by compact nano-positioners are directly integrated on the scanner head without degrading its mechanical and thermal stability. The electric noise floor of the background current is 5 fA/Hz1/2, and the maximum vibrational noise of the tip height is below 200 fm/Hz1/2. The drift of the tip-sample spacing is smaller than 0.1 pm/min. Such a rigid scanner head yields small background noise (oscillation amplitude of ∼2 pm without excitation) and high quality factor (Q factor up to 140 000) for the qPlus sensor. Atomic-resolution imaging and inelastic electron tunneling spectroscopy are obtained under the scanning tunneling microscope mode on the Au(111) surface. The hydrogen-bonding structure of two-dimensional (2D) ice on the Au(111) surface is clearly resolved under the atomic force microscope (AFM) mode with a CO-terminated tip. Finally, the electroluminescence spectrum from a plasmonic AFM tip is demonstrated, which paves the way for future photon-assisted SPM experiments.
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Affiliation(s)
- Bowei Cheng
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Da Wu
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Ke Bian
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Ye Tian
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Chaoyu Guo
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Kaihui Liu
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Ying Jiang
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
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71
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Tan X, Pan J, Wu Y, Xu P, Sun L, Hu K, Qiu X, Li M, Liu M, Ma D, Qiu X. Formation of Unconventional Stoichiometric Na-Cl Magic-Number Nanoclusters and 2D Assembly on Ir(111). SMALL METHODS 2022; 6:e2101252. [PMID: 35084118 DOI: 10.1002/smtd.202101252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 01/04/2022] [Indexed: 06/14/2023]
Abstract
Sodium chlorides in non-1:1 stoichiometry are counterintuitive but recently their existence has been found under the high pressure condition or in the confined space between graphene sheets. Here the direct observation of the formation of Na3 Cl nanoclusters, a stable magic-number structure, is reported on an Ir(111) surface using scanning tunneling microscopy and noncontact atomic force microscopy. The stability of Na3 Cl nanoclusters in the free and adsorbed state is corroborated by density functional theory calculations. It is also found that a density of nanoclusters together with Cl adatoms may further aggregate and self-assemble into a Na3 Cl4 monolayer, forming a novel metastable phase of NaCl(111) with a honeycomb lattice. Further calculations suggest that charge transfer between the polar nanoclusters and the metal substrate stabilizes NaCl of non-1:1 stoichiometry. The work exhibits the possibility of exploring unconventional ionic crystals on the surface with atomically precise control of structure and composition.
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Affiliation(s)
- Xin Tan
- Department of Physics, Capital Normal University, Beijing, 100048, P. R. China
| | - Jinliang Pan
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Yangfan Wu
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Peng Xu
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Luye Sun
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Kui Hu
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Xia Qiu
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Menglei Li
- Department of Physics, Capital Normal University, Beijing, 100048, P. R. China
| | - Mengxi Liu
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Donglin Ma
- Department of Physics, Capital Normal University, Beijing, 100048, P. R. China
| | - Xiaohui Qiu
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
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Ruppert MG, Martin-Jimenez D, Yong YK, Ihle A, Schirmeisen A, Fleming AJ, Ebeling D. Experimental analysis of tip vibrations at higher eigenmodes of QPlus sensors for atomic force microscopy. NANOTECHNOLOGY 2022; 33:185503. [PMID: 34972093 DOI: 10.1088/1361-6528/ac4759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 12/30/2021] [Indexed: 06/14/2023]
Abstract
QPlus sensors are non-contact atomic force microscope probes constructed from a quartz tuning fork and a tungsten wire with an electrochemically etched tip. These probes are self-sensing and offer an atomic-scale spatial resolution. Therefore, qPlus sensors are routinely used to visualize the chemical structure of adsorbed organic molecules via the so-called bond imaging technique. This is achieved by functionalizing the AFM tip with a single CO molecule and exciting the sensor at the first vertical cantilever resonance mode. Recent work using higher-order resonance modes has also resolved the chemical structure of single organic molecules. However, in these experiments, the image contrast can differ significantly from the conventional bond imaging contrast, which was suspected to be caused by unknown vibrations of the tip. This work investigates the source of these artefacts by using a combination of mechanical simulation and laser vibrometry to characterize a range of sensors with different tip wire geometries. The results show that increased tip mass and length cause increased torsional rotation of the tuning fork beam due to the off-center mounting of the tip wire, and increased flexural vibration of the tip. These undesirable motions cause lateral deflection of the probe tip as it approaches the sample, which is rationalized to be the cause of the different image contrast. The results also provide a guide for future probe development to reduce these issues.
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Affiliation(s)
- Michael G Ruppert
- School of Engineering, University of Newcastle, Callaghan, NSW, 2308, Australia
| | - Daniel Martin-Jimenez
- Institute of Applied Physics, Justus Liebig University Giessen, Giessen, Germany
- Center for Materials Research, Justus Liebig University Giessen, Giessen, Germany
| | - Yuen K Yong
- School of Engineering, University of Newcastle, Callaghan, NSW, 2308, Australia
| | - Alexander Ihle
- Institute of Applied Physics, Justus Liebig University Giessen, Giessen, Germany
- Center for Materials Research, Justus Liebig University Giessen, Giessen, Germany
| | - André Schirmeisen
- Institute of Applied Physics, Justus Liebig University Giessen, Giessen, Germany
- Center for Materials Research, Justus Liebig University Giessen, Giessen, Germany
| | - Andrew J Fleming
- School of Engineering, University of Newcastle, Callaghan, NSW, 2308, Australia
| | - Daniel Ebeling
- Institute of Applied Physics, Justus Liebig University Giessen, Giessen, Germany
- Center for Materials Research, Justus Liebig University Giessen, Giessen, Germany
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73
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Barr KB, Chiang N, Bertozzi AL, Gilles J, Osher SJ, Weiss PS. Extraction of Hidden Science from Nanoscale Images. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2022; 126:3-13. [PMID: 35633819 PMCID: PMC9135097 DOI: 10.1021/acs.jpcc.1c08712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Scanning probe microscopies and spectroscopies enable investigation of surfaces and even buried interfaces down to the scale of chemical-bonding interactions, and this capability has been enhanced with the support of computational algorithms for data acquisition and image processing to explore physical, chemical, and biological phenomena. Here, we describe how scanning probe techniques have been enhanced by some of these recent algorithmic improvements. One improvement to the data acquisition algorithm is to advance beyond a simple rastering framework by using spirals at constant angular velocity then switching to constant linear velocity, which limits the piezo creep and hysteresis issues seen in traditional acquisition methods. One can also use image-processing techniques to model the distortions that appear from tip motion effects and to make corrections to these images. Another image-processing algorithm we discuss enables researchers to segment images by domains and subdomains, thereby highlighting reactive and interesting disordered sites at domain boundaries. Lastly, we discuss algorithms used to examine the dipole direction of individual molecules and surface domains, hydrogen bonding interactions, and molecular tilt. The computational algorithms used for scanning probe techniques are still improving rapidly and are incorporating machine learning at the next level of iteration. That said, the algorithms are not yet able to perform live adjustments during data recording that could enhance the microscopy and spectroscopic imaging methods significantly.
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Affiliation(s)
- Kristopher B Barr
- California NanoSystems Institute and Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California 90095, United States
| | - Naihao Chiang
- Department of Chemistry, University of Houston, Houston Texas 77204, United States
| | - Andrea L Bertozzi
- Department of Mathematics, University of California, Los Angeles, Los Angeles, California 90095, United States
| | - Jérôme Gilles
- Department of Mathematics and Statistics, San Diego State University, San Diego, California 92182, United States
| | - Stanley J Osher
- Department of Mathematics, University of California, Los Angeles, Los Angeles, California 90095, United States
| | - Paul S Weiss
- California NanoSystems Institute, Department of Chemistry and Biochemistry, Department of Bioengineering, and Materials Science and Engineering Department, University of California, Los Angeles, Los Angeles, California 90095, United States
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74
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Abbasi-Pérez D, Sang H, Junqueira FLQ, Sweetman A, Recio JM, Moriarty P, Kantorovich L. Cyclic Single Atom Vertical Manipulation on a Nonmetallic Surface. J Phys Chem Lett 2021; 12:11383-11390. [PMID: 34784484 DOI: 10.1021/acs.jpclett.1c02271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Motivated by the quest for experimental procedures capable of controlled manipulation of single atoms on surfaces, we set up a computational strategy that explores the cyclical vertical manipulation of a broad set of single atoms on the GaAs(110) surface. First-principles simulations of atomic force microscope tip-sample interactions were performed considering families of GaAs and Au-terminated tip apexes with varying crystalline termination. We identified a subset of tips capable of both picking up and depositing an adatom (Ga, As, Al, and Au) any number of times via a modify-restore cycle that "resets" the apex of the scanning probe to its original structure at the end of each cycle. Manipulation becomes successful within a certain window of lateral and vertical tip distances that are observed to be different for extracting and depositing each atom. A practical experimental protocol of special utility for potential cyclical manipulation of single atoms on a nonmetallic surface is proposed.
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Affiliation(s)
| | - Hongqian Sang
- Department of Physics, King's College London, London WC2R 2LS, U.K
- Institute for Interdisciplinary Research, Jianghan University, Wuhan 430056, China
| | - Filipe L Q Junqueira
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, U.K
| | - Adam Sweetman
- School of Physics & Astronomy, University of Leeds, Leeds LS2 9JT, U.K
| | - J Manuel Recio
- MALTA-Consolider Team and Department of Analytical and Physical Chemistry, Universidad de Oviedo, Oviedo 33006, Spain
| | - Philip Moriarty
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, U.K
| | - Lev Kantorovich
- Department of Physics, King's College London, London WC2R 2LS, U.K
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75
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Mallada B, Gallardo A, Lamanec M, de la Torre B, Špirko V, Hobza P, Jelinek P. Real-space imaging of anisotropic charge of σ-hole by means of Kelvin probe force microscopy. Science 2021; 374:863-867. [PMID: 34762455 DOI: 10.1126/science.abk1479] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
[Figure: see text].
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Affiliation(s)
- B Mallada
- Regional Centre of Advanced Technologies and Materials, Czech Advanced Technology and Research Institute (CATRIN), Palacký University Olomouc, 78371 Olomouc, Czech Republic.,Institute of Physics, Academy of Sciences of the Czech Republic, Prague, Czech Republic.,Department of Physical Chemistry, Palacký University Olomouc, tr. 17. listopadu 12, 771 46 Olomouc, Czech Republic
| | - A Gallardo
- Institute of Physics, Academy of Sciences of the Czech Republic, Prague, Czech Republic.,Department of Condensed Matter Physics, Faculty of Mathematics and Physics, Charles University, V Holešovičkách 2, 180 00 Prague, Czech Republic
| | - M Lamanec
- Department of Physical Chemistry, Palacký University Olomouc, tr. 17. listopadu 12, 771 46 Olomouc, Czech Republic.,Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo Námĕstí 542/2, 16000 Prague, Czech Republic
| | - B de la Torre
- Regional Centre of Advanced Technologies and Materials, Czech Advanced Technology and Research Institute (CATRIN), Palacký University Olomouc, 78371 Olomouc, Czech Republic.,Institute of Physics, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - V Špirko
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo Námĕstí 542/2, 16000 Prague, Czech Republic.,Department of Chemical Physics and Optics, Faculty of Mathematics and Physics, Charles University in Prague, Ke Karlovu 3, 12116 Prague, Czech Republic
| | - P Hobza
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo Námĕstí 542/2, 16000 Prague, Czech Republic.,IT4Innovations, VŠB-Technical University of Ostrava, 17. listopadu 2172/15, 70800 Ostrava-Poruba, Czech Republic
| | - P Jelinek
- Regional Centre of Advanced Technologies and Materials, Czech Advanced Technology and Research Institute (CATRIN), Palacký University Olomouc, 78371 Olomouc, Czech Republic.,Institute of Physics, Academy of Sciences of the Czech Republic, Prague, Czech Republic
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76
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Knol M, Arefi HH, Corken D, Gardner J, Tautz FS, Maurer RJ, Wagner C. The stabilization potential of a standing molecule. SCIENCE ADVANCES 2021; 7:eabj9751. [PMID: 34757779 PMCID: PMC8580301 DOI: 10.1126/sciadv.abj9751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 09/21/2021] [Indexed: 06/13/2023]
Abstract
The part-by-part assembly of functional nanoscale machinery is a central goal of nanotechnology. With the recent fabrication of an isolated standing molecule with a scanning probe microscope, the third dimension perpendicular to the surface will soon become accessible to molecule-based construction. Beyond the flatlands of the surface, a wealth of structures and functionalities is waiting for exploration, but issues of stability are becoming more critical. Here, we combine scanning probe experiments with ab initio potential energy calculations to investigate the thermal stability of a prototypical standing molecule. We reveal its generic stabilization mechanism, a fine balance between covalent and van der Waals interactions including the latter’s long-range screening by many-body effects, and find a remarkable agreement between measured and calculated stabilizing potentials. Beyond their relevance for the design and construction of three-dimensional molecular devices at surfaces, our results also indicate that standing molecules may serve as tunable mechanical gigahertz oscillators.
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Affiliation(s)
- Marvin Knol
- 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
| | - Hadi H. Arefi
- Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, 52425 Jülich, Germany
- Jülich Aachen Research Alliance (JARA)–Fundamentals of Future Information Technology, 52425 Jülich, Germany
| | - Daniel Corken
- Department of Chemistry, University of Warwick, Gibbet Hill Road, CV4 7AL Coventry, UK
| | - James Gardner
- Department of Chemistry, University of Warwick, Gibbet Hill Road, CV4 7AL Coventry, UK
| | - 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
| | - Reinhard J. Maurer
- Department of Chemistry, University of Warwick, Gibbet Hill Road, CV4 7AL Coventry, UK
| | - 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
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77
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Zeng Q, Huang Q, Wang H, Li C, Fan Z, Chen D, Cheng Y, Zeng K. Breaking the Fundamental Limitations of Nanoscale Ferroelectric Characterization: Non-Contact Heterodyne Electrostrain Force Microscopy. SMALL METHODS 2021; 5:e2100639. [PMID: 34927968 DOI: 10.1002/smtd.202100639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 09/09/2021] [Indexed: 06/14/2023]
Abstract
Perceiving nanoscale ferroelectric phenomena from real space is of great importance for elucidating underlying ferroelectric physics. During the past decades, nanoscale ferroelectric characterization has mainly relied on the Piezoresponse Force Microscopy (PFM) invented in 1992, however, the fundamental limitations of PFM have made the nanoscale ferroelectric studies encounter significant bottlenecks. In this study, a high-resolution non-contact ferroelectric measurement, named Non-Contact Heterodyne Electrostrain Force Microscopy (NC-HEsFM), is introduced. It is demonstrated that NC-HEsFM can operate on multiple eigenmodes to perform ideal high-resolution ferroelectric domain mapping, standard ferroelectric hysteresis loop measurement, and controllable domain manipulation. By using a quartz tuning fork (QTF) sensor, multi-frequency operation, and heterodyne detection schemes, NC-HEsFM achieves a real non-contact yet non-destructive ferroelectric characterization with negligible electrostatic force effect and hence breaks the fundamental limitations of the conventional PFM. It is believed that NC-HEsFM can be extensively used in various ferroelectric or piezoelectric studies with providing substantially improved characterization performance. Meanwhile, the QTF-based force detection makes NC-HEsFM highly compatible for high-vacuum and low-temperature environments, providing ideal conditions for investigating the intrinsic ferroelectric phenomena with the possibility of achieving an atomically resolved ferroelectric characterization.
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Affiliation(s)
- Qibin Zeng
- Department of Mechanical Engineering, National University of Singapore, Singapore, 117576, Singapore
| | - Qicheng Huang
- Institute for Advanced Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, 510006, China
| | - Hongli Wang
- Department of Mechanical Engineering, National University of Singapore, Singapore, 117576, Singapore
- The Key Lab of Guangdong for Modern Surface Engineering Technology, National Engineering Laboratory for Modern Materials Surface Engineering Technology, Institute of New Materials, Guangdong Academy of Sciences, Guangzhou, 510650, China
| | - Caiwen Li
- Institute for Advanced Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, 510006, China
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, 510006, China
| | - Zhen Fan
- Institute for Advanced Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, 510006, China
| | - Deyang Chen
- Institute for Advanced Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, 510006, China
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, 510006, China
| | - Yuan Cheng
- Institute of High-Performance Computing, Agency for Science Technology and Research, Singapore, 138632, Singapore
- Monash Suzhou Research Institute, Suzhou, 215123, China
| | - Kaiyang Zeng
- Department of Mechanical Engineering, National University of Singapore, Singapore, 117576, Singapore
- NUS (Suzhou) Research Institute (NUSRI), Suzhou, 215123, China
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78
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Besenbacher F, Lauritsen J. Applications of high-resolution scanning probe microscopy in hydroprocessing catalysis studies. J Catal 2021. [DOI: 10.1016/j.jcat.2021.02.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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79
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Yesilpinar D, Schulze Lammers B, Timmer A, Hu Z, Ji W, Amirjalayer S, Fuchs H, Mönig H. Mechanical and Chemical Interactions in Atomically Defined Contacts. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2021; 17:e2101637. [PMID: 34288402 DOI: 10.1002/smll.202101637] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 05/12/2021] [Indexed: 06/13/2023]
Abstract
Providing fundamental insights in atomic interactions, dedicated methods in atomic force microscopy allow measuring the threshold forces needed to move single adsorbed atoms or molecules. However, the chemical and structural properties of the probe-tip can drastically influence the results. Establishing atomically defined contacts in such experiments, the tips in the present study are functionalized with various chemically and structurally different terminations. Xenon atoms are moved along an atomically defined metal/metal-oxide boundary where all tips show a pulling mechanism and slight force variations, which are assigned to polarization effects within the tip-sample junction. Detaching Xe atoms from the boundary involves a significantly higher energy barrier where chemical reactive Cu-tips cause Xe pickup before any lateral manipulation. Passivating the tip by inert probe particles (Xe or CO) allows further approaching the surface Xe atom. Yet, the small vertical attraction and pronounced tip relaxations prevent reaching sufficient threshold forces inducing manipulation. In contrast, the high structural rigidity of oxygen-terminated Cu-tips allows manipulations even beyond the threshold where they evolve from initial pulling, via sliding to pushing mode. The detailed quantitative analysis of the processes in the atomically defined junctions emphasizes the mechanical and chemical interactions for highly controlled experiments with piconewton sensitivity.
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Affiliation(s)
- Damla Yesilpinar
- Physikalisches Institut, Westfälische Wilhelms-Universität, Wilhelm-Klemm-Straße 10, 48149, Münster, Germany
- Center for Nanotechnology, Heisenbergstraße 11, 48149, Münster, Germany
| | - Bertram Schulze Lammers
- Physikalisches Institut, Westfälische Wilhelms-Universität, Wilhelm-Klemm-Straße 10, 48149, Münster, Germany
- Center for Nanotechnology, Heisenbergstraße 11, 48149, Münster, Germany
| | - Alexander Timmer
- Physikalisches Institut, Westfälische Wilhelms-Universität, Wilhelm-Klemm-Straße 10, 48149, Münster, Germany
- Center for Nanotechnology, Heisenbergstraße 11, 48149, Münster, Germany
| | - Zhixin Hu
- Center for Joint Quantum Studies and Department of Physics, Tianjin University, Tianjin, 300350, China
| | - Wei Ji
- Department of Physics and Beijing Key Laboratory of Optoelectronic Functional Materials and Micro-Nano Devices, Renmin University of China, Beijing, 100872, China
| | - Saeed Amirjalayer
- Physikalisches Institut, Westfälische Wilhelms-Universität, Wilhelm-Klemm-Straße 10, 48149, Münster, Germany
- Center for Nanotechnology, Heisenbergstraße 11, 48149, Münster, Germany
- Center for Multiscale Theory and Computation, 48149, Münster, Germany
| | - Harald Fuchs
- Physikalisches Institut, Westfälische Wilhelms-Universität, Wilhelm-Klemm-Straße 10, 48149, Münster, Germany
- Center for Nanotechnology, Heisenbergstraße 11, 48149, Münster, Germany
| | - Harry Mönig
- Physikalisches Institut, Westfälische Wilhelms-Universität, Wilhelm-Klemm-Straße 10, 48149, Münster, Germany
- Center for Nanotechnology, Heisenbergstraße 11, 48149, Münster, Germany
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80
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Schulze Lammers B, Yesilpinar D, Timmer A, Hu Z, Ji W, Amirjalayer S, Fuchs H, Mönig H. Benchmarking atomically defined AFM tips for chemical-selective imaging. NANOSCALE 2021; 13:13617-13623. [PMID: 34477636 DOI: 10.1039/d1nr04080d] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Controlling the identity of the tip-terminating atom or molecule in low-temperature atomic force microscopy has led to ground breaking progress in surface chemistry and nanotechnology. Lacking a comparative tip-performance assessment, a profound standardization in such experiments is highly desirable. Here we directly compare the imaging and force-spectroscopy capabilities of four atomically defined tips, namely Cu-, Xe-, CO-, and O-terminated Cu-tips (CuOx-tips). Using a nanostructured copper-oxide surface as benchmark system, we found that Cu-tips react with surface oxygen, while chemically inert Xe- and CO-tips allow entering the repulsive force regime enabling increased resolution. However, their high flexibility leads to imaging artifacts and their strong passivation suppresses the chemical contrast. The higher rigidity and selectively increased chemical reactivity of CuOx-tips prevent tip-bending artifacts and generate a distinct chemical contrast. This result is particularly promising in view of future studies on other metal-oxide surfaces.
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Affiliation(s)
- Bertram Schulze Lammers
- Physikalisches Institut, Westfälische Wilhelms-Universität, 48149 Münster, Germany.
- Center for Nanotechnology, 48149 Münster, Germany
| | - Damla Yesilpinar
- Physikalisches Institut, Westfälische Wilhelms-Universität, 48149 Münster, Germany.
- Center for Nanotechnology, 48149 Münster, Germany
| | | | - Zhixin Hu
- Center for Quantum Joint Studies and Department of Physics, Tianjin University, Tianjin, China.
| | - Wei Ji
- Department of Physics and Beijing Key Laboratory of Optoelectronic Functional Materials & Micro-Nano Devices, Renmin University of China, Beijing, China
| | - Saeed Amirjalayer
- Physikalisches Institut, Westfälische Wilhelms-Universität, 48149 Münster, Germany.
- Center for Nanotechnology, 48149 Münster, Germany
- Center for Multiscale Theory and Computation, 48149 Münster, Germany
| | - Harald Fuchs
- Physikalisches Institut, Westfälische Wilhelms-Universität, 48149 Münster, Germany.
- Center for Nanotechnology, 48149 Münster, Germany
| | - Harry Mönig
- Physikalisches Institut, Westfälische Wilhelms-Universität, 48149 Münster, Germany.
- Center for Nanotechnology, 48149 Münster, Germany
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81
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Giessibl FJ. Probing the Nature of Chemical Bonds by Atomic Force Microscopy. Molecules 2021; 26:4068. [PMID: 34279408 PMCID: PMC8271455 DOI: 10.3390/molecules26134068] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 06/24/2021] [Accepted: 06/26/2021] [Indexed: 11/16/2022] Open
Abstract
The nature of the chemical bond is important in all natural sciences, ranging from biology to chemistry, physics and materials science. The atomic force microscope (AFM) allows to put a single chemical bond on the test bench, probing its strength and angular dependence. We review experimental AFM data, covering precise studies of van-der-Waals-, covalent-, ionic-, metallic- and hydrogen bonds as well as bonds between artificial and natural atoms. Further, we discuss some of the density functional theory calculations that are related to the experimental studies of the chemical bonds. A description of frequency modulation AFM, the most precise AFM method, discusses some of the experimental challenges in measuring bonding forces. In frequency modulation AFM, forces between the tip of an oscillating cantilever change its frequency. Initially, cantilevers were made mainly from silicon. Most of the high precision measurements of bonding strengths by AFM became possible with a technology transfer from the quartz watch technology to AFM by using quartz-based cantilevers ("qPlus force sensors"), briefly described here.
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Affiliation(s)
- Franz J Giessibl
- Chair for Quantum Nanoscience, Institute of Experimental and Applied Physics, University of Regensburg, D-93040 Regensburg, Germany
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82
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Li X, Wang Y, Wu Y, Wang H, Wang Q, Zhu X, Liu X, Sun H, Fan L. Effect of Graphene on Modified Asphalt Microstructures Based on Atomic Force Microscopy. MATERIALS 2021; 14:ma14133677. [PMID: 34279247 PMCID: PMC8269809 DOI: 10.3390/ma14133677] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Revised: 06/20/2021] [Accepted: 06/25/2021] [Indexed: 11/17/2022]
Abstract
Atomic force microscopy (AFM) was used to explore the effects of graphene modifier on the microstructure of asphalt. The morphologies of the before- and after-aged base asphalt and modified asphalt were performed and compared with analysis. The formation mechanism of asphaltic “bee structures” and the influence mechanism of graphene on asphalt were discussed from the classical theory of material science (phase transformation theory and diffusion theory). The results show that graphene facilitates the nucleation of “bee structures”, resulting in an increasing number and decreasing volume of “bee structures” in modified asphalt. Additionally, the anti-aging performance of the modified asphalt improved significantly because of graphene incorporation.
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Affiliation(s)
- Xian Li
- School of Traffic and Civil Engineering, Shandong Jiaotong University, Jinan 250300, China; (X.L.); (Y.W.); (H.W.); (Q.W.); (X.Z.); (X.L.); (H.S.)
| | - Yanmin Wang
- School of Traffic and Civil Engineering, Shandong Jiaotong University, Jinan 250300, China; (X.L.); (Y.W.); (H.W.); (Q.W.); (X.Z.); (X.L.); (H.S.)
- Correspondence: or ; Tel.: +86-185-0541-9501
| | - Yanling Wu
- School of Traffic and Civil Engineering, Shandong Jiaotong University, Jinan 250300, China; (X.L.); (Y.W.); (H.W.); (Q.W.); (X.Z.); (X.L.); (H.S.)
| | - Huiru Wang
- School of Traffic and Civil Engineering, Shandong Jiaotong University, Jinan 250300, China; (X.L.); (Y.W.); (H.W.); (Q.W.); (X.Z.); (X.L.); (H.S.)
| | - Qingliang Wang
- School of Traffic and Civil Engineering, Shandong Jiaotong University, Jinan 250300, China; (X.L.); (Y.W.); (H.W.); (Q.W.); (X.Z.); (X.L.); (H.S.)
| | - Xingxing Zhu
- School of Traffic and Civil Engineering, Shandong Jiaotong University, Jinan 250300, China; (X.L.); (Y.W.); (H.W.); (Q.W.); (X.Z.); (X.L.); (H.S.)
| | - Xiaocun Liu
- School of Traffic and Civil Engineering, Shandong Jiaotong University, Jinan 250300, China; (X.L.); (Y.W.); (H.W.); (Q.W.); (X.Z.); (X.L.); (H.S.)
| | - Huadong Sun
- School of Traffic and Civil Engineering, Shandong Jiaotong University, Jinan 250300, China; (X.L.); (Y.W.); (H.W.); (Q.W.); (X.Z.); (X.L.); (H.S.)
| | - Liang Fan
- Shandong Transportation Institute, Jinan 250031, China;
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83
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Behn WA, Krebs ZJ, Smith KJ, Watanabe K, Taniguchi T, Brar VW. Measuring and Tuning the Potential Landscape of Electrostatically Defined Quantum Dots in Graphene. NANO LETTERS 2021; 21:5013-5020. [PMID: 34096737 DOI: 10.1021/acs.nanolett.1c00791] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
We use Kelvin probe force microscopy (KPFM) to probe the carrier-dependent potential of an electrostatically defined quantum dot (QD) in a graphene/hexagonal boron nitride (hBN) heterostructure. We show that gate-dependent measurements enable a calibration scheme that corrects for uncertainty inherent in typical KPFM measurements and accurately reconstructs the potential well profile. Our measurements reveal how the well changes with carrier concentration, which we associate with the nonlinear dependence of graphene's work function on carrier density. These changes shift the energy levels of quasi-bound states in the QD which we can measure via scanning tunneling spectroscopy (STS). We show that the experimentally extracted energy levels closely compare with wave functions calculated from the reconstructed KPFM data. This methodology, where KPFM and STS data are simultaneously acquired from 2D materials, allows the quasiparticle response to an electrostatic potential to be determined in a self-consistent way.
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Affiliation(s)
- Wyatt A Behn
- Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, Wisconsin 53706, United States
| | - Zachary J Krebs
- Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, Wisconsin 53706, United States
| | - Keenan J Smith
- Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, Wisconsin 53706, United States
| | - Kenji Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Takashi Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Victor W Brar
- Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, Wisconsin 53706, United States
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84
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Dagdeviren OE. Confronting interatomic force measurements. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2021; 92:063703. [PMID: 34243578 DOI: 10.1063/5.0052126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 06/03/2021] [Indexed: 06/13/2023]
Abstract
The quantitative interatomic force measurements open a new pathway to materials characterization, surface science, and chemistry by elucidating the tip-sample interaction forces. Atomic force microscopy is the ideal platform to gauge interatomic forces between the tip and the sample. For such quantitative measurements, either the oscillation frequency or the oscillation amplitude and the phase of a vibrating cantilever are recorded as a function of the tip-sample separation. These experimental quantities are subsequently converted into the tip-sample interaction force, which can be compared with interatomic force laws to reveal the governing physical phenomena. Recently, it has been shown that the most commonly applied mathematical conversion techniques may suffer a significant deviation from the actual tip-sample interaction forces. To avoid the assessment of unphysical interatomic forces, the use of either very small (i.e., a few picometers) or very large oscillation amplitudes (i.e., a few nanometers) has been proposed. However, the use of marginal oscillation amplitudes gives rise to another problem as it lacks the feasibility due to the adverse signal-to-noise ratios. Here, we show a new mathematical conversion principle that confronts interatomic force measurements while preserving the oscillation amplitude within the experimentally achievable and favorable limits, i.e., tens of picometers. Our theoretical calculations and complementary experimental results demonstrate that the proposed technique has three major advantages over existing methodologies: (I) eliminating mathematical instabilities of the reconstruction of tip-sample interaction force, (II) enabling accurate conversion deep into the repulsive regime of tip-sample interaction force, and (III) being robust to the uncertainty of the oscillation amplitude and the measurement noise. Due to these advantages, we anticipate that our methodology will be the nucleus of a reliable evaluation of material properties with a more accurate measurement of tip-sample interaction forces.
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Affiliation(s)
- Omur E Dagdeviren
- Department of Mechanical Engineering, École de technologie supérieure, University of Quebec, Montreal, Quebec H3C 1K3, Canada
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85
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Gretz O, Weymouth AJ, Holzmann T, Pürckhauer K, Giessibl FJ. Determining amplitude and tilt of a lateral force microscopy sensor. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2021; 12:517-524. [PMID: 34136327 PMCID: PMC8182685 DOI: 10.3762/bjnano.12.42] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 05/18/2021] [Indexed: 06/12/2023]
Abstract
In lateral force microscopy (LFM), implemented as frequency-modulation atomic force microscopy, the tip oscillates parallel to the surface. Existing amplitude calibration methods are not applicable for mechanically excited LFM sensors at low temperature. Moreover, a slight angular offset of the oscillation direction (tilt) has a significant influence on the acquired data. To determine the amplitude and tilt we make use of the scanning tunneling microscopy (STM) channel and acquire data without and with oscillation of the tip above a local surface feature. We use a full two-dimensional current map of the STM data without oscillation to simulate data for a given amplitude and tilt. Finally, the amplitude and tilt are determined by fitting the simulation output to the data with oscillation.
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Affiliation(s)
- Oliver Gretz
- Institute of Experimental and Applied Physics, Department of Physics, University of Regensburg, 93053 Regensburg, Germany
| | - Alfred J Weymouth
- Institute of Experimental and Applied Physics, Department of Physics, University of Regensburg, 93053 Regensburg, Germany
| | - Thomas Holzmann
- Institute of Experimental and Applied Physics, Department of Physics, University of Regensburg, 93053 Regensburg, Germany
| | - Korbinian Pürckhauer
- Institute of Experimental and Applied Physics, Department of Physics, University of Regensburg, 93053 Regensburg, Germany
| | - Franz J Giessibl
- Institute of Experimental and Applied Physics, Department of Physics, University of Regensburg, 93053 Regensburg, Germany
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86
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Stilp F, Bereczuk A, Berwanger J, Mundigl N, Richter K, Giessibl FJ. Very weak bonds to artificial atoms formed by quantum corrals. Science 2021; 372:1196-1200. [PMID: 34010141 DOI: 10.1126/science.abe2600] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 03/10/2021] [Accepted: 05/03/2021] [Indexed: 11/02/2022]
Abstract
We explored the bonding properties of the quantum corral (a circle of 48 iron atoms placed on a copper surface) reported by Crommie et al. in 1993, along with variants, as an artificial atom using an atomic force microscope (AFM). The original corral geometry confines 102 electrons to 28 discrete energy states, and we found that these states can form a bond to the front atom of the AFM with an energy of about 5 millielectron volts. The measured forces are about 1/1000 of typical forces in atomically resolved AFM. The confined electrons showed covalent attraction to metal tips and Pauli repulsion to CO-terminated tips. The repulsion at close distance was evident from the response of corral states created by deliberately placing single iron atoms inside the corral. The forces scaled appropriately with a 24-atom corral.
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Affiliation(s)
- Fabian Stilp
- Institute of Experimental and Applied Physics, Department of Physics, University of Regensburg, 93040 Regensburg, Germany
| | - Andreas Bereczuk
- Institute of Theoretical 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
| | - Nadine Mundigl
- Institute of Experimental and Applied Physics, Department of Physics, University of Regensburg, 93040 Regensburg, Germany
| | - Klaus Richter
- Institute of Theoretical Physics, Department of Physics, University of Regensburg, 93040 Regensburg, Germany
| | - Franz J Giessibl
- Institute of Experimental and Applied Physics, Department of Physics, University of Regensburg, 93040 Regensburg, Germany.
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87
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Bian K, Gerber C, Heinrich AJ, Müller DJ, Scheuring S, Jiang Y. Scanning probe microscopy. ACTA ACUST UNITED AC 2021. [DOI: 10.1038/s43586-021-00033-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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88
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Guo M, Wang M, Wang P, Wu D, Ye X, Yu P, Huang Y, Shi F, Wang Y, Du J. A flexible nitrogen-vacancy center probe for scanning magnetometry. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2021; 92:055001. [PMID: 34243241 DOI: 10.1063/5.0040679] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 04/10/2021] [Indexed: 06/13/2023]
Abstract
The key component of the scanning magnetometry based on nitrogen-vacancy centers is the diamond probe. Here, we designed and fabricated a new type of probe with an array of pillars on a (100 µm)2 × 50 µm diamond chip. The probe features high yield, convertibility to be a single pillar, and expedient reusability. Our fabrication is dramatically simplified by using ultraviolet laser cutting to shape the chip from a diamond substrate instead of additional lithography and time-consuming reactive ion etching. As an example, we demonstrate the imaging of a single magnetic skyrmion with nanoscale resolution. In the future, this flexible probe will be particularly well-suited for commercial applications.
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Affiliation(s)
- Maosen Guo
- CAS Key Laboratory of Microscale Magnetic Resonance and Department of Modern Physics, University of Science and Technology of China, Hefei 230026, China; Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230026, China; and Synergetic Innovation Centre of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Mengqi Wang
- CAS Key Laboratory of Microscale Magnetic Resonance and Department of Modern Physics, University of Science and Technology of China, Hefei 230026, China; Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230026, China; and Synergetic Innovation Centre of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Pengfei Wang
- CAS Key Laboratory of Microscale Magnetic Resonance and Department of Modern Physics, University of Science and Technology of China, Hefei 230026, China; Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230026, China; and Synergetic Innovation Centre of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Diguang Wu
- CAS Key Laboratory of Microscale Magnetic Resonance and Department of Modern Physics, University of Science and Technology of China, Hefei 230026, China; Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230026, China; and Synergetic Innovation Centre of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Xiangyu Ye
- CAS Key Laboratory of Microscale Magnetic Resonance and Department of Modern Physics, University of Science and Technology of China, Hefei 230026, China; Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230026, China; and Synergetic Innovation Centre of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Pei Yu
- CAS Key Laboratory of Microscale Magnetic Resonance and Department of Modern Physics, University of Science and Technology of China, Hefei 230026, China; Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230026, China; and Synergetic Innovation Centre of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - You Huang
- CAS Key Laboratory of Microscale Magnetic Resonance and Department of Modern Physics, University of Science and Technology of China, Hefei 230026, China; Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230026, China; and Synergetic Innovation Centre of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Fazhan Shi
- CAS Key Laboratory of Microscale Magnetic Resonance and Department of Modern Physics, University of Science and Technology of China, Hefei 230026, China; Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230026, China; and Synergetic Innovation Centre of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Ya Wang
- CAS Key Laboratory of Microscale Magnetic Resonance and Department of Modern Physics, University of Science and Technology of China, Hefei 230026, China; Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230026, China; and Synergetic Innovation Centre of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Jiangfeng Du
- CAS Key Laboratory of Microscale Magnetic Resonance and Department of Modern Physics, University of Science and Technology of China, Hefei 230026, China; Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230026, China; and Synergetic Innovation Centre of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
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89
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Shiotari A, Putra SEM, Shiozawa Y, Hamamoto Y, Inagaki K, Morikawa Y, Sugimoto Y, Yoshinobu J, Hamada I. Role of Intermolecular Interactions in the Catalytic Reaction of Formic Acid on Cu(111). SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2021; 17:e2008010. [PMID: 33759365 DOI: 10.1002/smll.202008010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 02/10/2021] [Indexed: 06/12/2023]
Abstract
Formic acid (HCOOH) can be catalytically decomposed into H2 and CO2 and is a promising hydrogen storage material. As H2 production catalysts, Cu surfaces allow selective HCOOH decarboxylation; however, the on-surface HCOOH decomposition reaction pathway remains controversial. In this study, the temperature dependence of the HCOOH/Cu(111) adsorption structures is elucidated by scanning tunneling microscopy and non-contact atomic force microscopy, establishing the adsorbate chemical species using density functional theory. 2D HCOOH islands at 80 K, linear chains of HCOOH and monodentate formate at 150 K, chain-like assemblies of monodentate and bidentate formate at 200 K, and bidentate formate clusters at 300 K are observed. At each temperature, the adsorbates experience attractive interactions among themselves. Such aggregation stabilizes them against desorption and decomposition. Thus, accurate evaluation of intermolecular interactions is essential to understand catalytic reactivity.
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Affiliation(s)
- Akitoshi Shiotari
- Department of Advanced Materials Science, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8561, Japan
| | - Septia Eka Marsha Putra
- Department of Precision Engineering, Graduate School of Engineering, Osaka University, 2-1, Yamada-oka, Suita, Osaka, 565-0871, Japan
| | - Yuichiro Shiozawa
- The Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8581, Japan
| | - Yuji Hamamoto
- Department of Precision Engineering, Graduate School of Engineering, Osaka University, 2-1, Yamada-oka, Suita, Osaka, 565-0871, Japan
- Elements Strategy Initiative for Catalysts and Batteries (ESICB), Kyoto University, Katsura, Kyoto, 615-8520, Japan
| | - Kouji Inagaki
- Department of Precision Engineering, Graduate School of Engineering, Osaka University, 2-1, Yamada-oka, Suita, Osaka, 565-0871, Japan
- Elements Strategy Initiative for Catalysts and Batteries (ESICB), Kyoto University, Katsura, Kyoto, 615-8520, Japan
| | - Yoshitada Morikawa
- Department of Precision Engineering, Graduate School of Engineering, Osaka University, 2-1, Yamada-oka, Suita, Osaka, 565-0871, Japan
- Elements Strategy Initiative for Catalysts and Batteries (ESICB), Kyoto University, Katsura, Kyoto, 615-8520, Japan
- Research Center for Ultra-Precision Science and Technology, Graduate School of Engineering, Osaka University, 2-1, Yamada-oka, Suita, Osaka, 565-0871, Japan
| | - Yoshiaki Sugimoto
- Department of Advanced Materials Science, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8561, Japan
| | - Jun Yoshinobu
- The Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8581, Japan
| | - Ikutaro Hamada
- Department of Precision Engineering, Graduate School of Engineering, Osaka University, 2-1, Yamada-oka, Suita, Osaka, 565-0871, Japan
- Elements Strategy Initiative for Catalysts and Batteries (ESICB), Kyoto University, Katsura, Kyoto, 615-8520, Japan
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90
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Nanoscale electric-field imaging based on a quantum sensor and its charge-state control under ambient condition. Nat Commun 2021; 12:2457. [PMID: 33911073 PMCID: PMC8080810 DOI: 10.1038/s41467-021-22709-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 03/24/2021] [Indexed: 02/02/2023] Open
Abstract
Nitrogen-vacancy (NV) centers in diamond can be used as quantum sensors to image the magnetic field with nanoscale resolution. However, nanoscale electric-field mapping has not been achieved so far because of the relatively weak coupling strength between NV and electric field. Here, using individual shallow NVs, we quantitatively image electric field contours from a sharp tip of a qPlus-based atomic force microscope (AFM), and achieve a spatial resolution of ~10 nm. Through such local electric fields, we demonstrated electric control of NV's charge state with sub-5 nm precision. This work represents the first step towards nanoscale scanning electrometry based on a single quantum sensor and may open up the possibility of quantitatively mapping local charge, electric polarization, and dielectric response in a broad spectrum of functional materials at nanoscale.
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91
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Wagner M, Meyer B, Setvin M, Schmid M, Diebold U. Direct assessment of the acidity of individual surface hydroxyls. Nature 2021; 592:722-725. [PMID: 33911267 DOI: 10.1038/s41586-021-03432-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Accepted: 03/08/2021] [Indexed: 11/10/2022]
Abstract
The state of deprotonation/protonation of surfaces has far-ranging implications in chemistry, from acid-base catalysis1 and the electrocatalytic and photocatalytic splitting of water2, to the behaviour of minerals3 and biochemistry4. An entity's acidity is described by its proton affinity and its acid dissociation constant pKa (the negative logarithm of the equilibrium constant of the proton transfer reaction in solution). The acidity of individual sites is difficult to assess for solids, compared with molecules. For mineral surfaces, the acidity is estimated by semi-empirical concepts, such as bond-order valence sums5, and increasingly modelled with first-principles molecular dynamics simulations6,7. At present, such predictions cannot be tested-experimental measures, such as the point of zero charge8, integrate over the whole surface or, in some cases, individual crystal facets9. Here we assess the acidity of individual hydroxyl groups on In2O3(111)-a model oxide with four different types of surface oxygen atom. We probe the strength of their hydrogen bonds with the tip of a non-contact atomic force microscope and find quantitative agreement with density functional theory calculations. By relating the results to known proton affinities of gas-phase molecules, we determine the proton affinity of the different surface sites of In2O3 with atomic precision. Measurements on hydroxylated titanium dioxide and zirconium oxide extend our method to other oxides.
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Affiliation(s)
- Margareta Wagner
- Institute of Applied Physics, TU Wien, Vienna, Austria.,Central European Institute of Technology (CEITEC), Brno University of Technology, Brno, Czech Republic
| | - Bernd Meyer
- Interdisciplinary Center for Molecular Materials, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany.,Computer Chemistry Center, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Martin Setvin
- Institute of Applied Physics, TU Wien, Vienna, Austria.,Department of Surface and Plasma Science, Faculty of Mathematics and Physics, Charles University, Prague, Czech Republic
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92
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Kirpal D, Qiu J, Pürckhauer K, Weymouth AJ, Metz M, Giessibl FJ. Biaxial atomically resolved force microscopy based on a qPlus sensor operated simultaneously in the first flexural and length extensional modes. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2021; 92:043703. [PMID: 34243447 DOI: 10.1063/5.0041369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 03/14/2021] [Indexed: 06/13/2023]
Abstract
Frequency-modulation atomic force microscopy (AFM) with a qPlus sensor allows one to atomically resolve surfaces in a variety of environments ranging from low-temperature in ultra-high vacuum to ambient and liquid conditions. Typically, the tip is driven to oscillate vertically, giving a measure of the vertical force component. However, for many systems, the lateral force component provides valuable information about the sample. Measuring lateral and vertical force components simultaneously by oscillating vertically and laterally has so far only been demonstrated with relatively soft silicon cantilevers and optical detection. Here, we show that the qPlus sensor can be used in a biaxial mode with electrical detection by making use of the first flexural mode and the length extensional mode. We describe the necessary electrode configuration as well as the electrical detection circuit and compare the length extensional mode to the needle sensor. Finally, we show atomic resolution in ambient conditions of a mica surface and in ultra-high vacuum of a silicon surface. In addition to this, we show how any qPlus AFM setup can be modified to work as a biaxial sensor, allowing two independent force components to be recorded.
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Affiliation(s)
- Dominik Kirpal
- Institute of Experimental and Applied Physics, University of Regensburg, D-93053 Regensburg, Germany
| | - Jinglan Qiu
- Institute of Experimental and Applied Physics, University of Regensburg, D-93053 Regensburg, Germany
| | - Korbinian Pürckhauer
- Institute of Experimental and Applied Physics, University of Regensburg, D-93053 Regensburg, Germany
| | - Alfred J Weymouth
- Institute of Experimental and Applied Physics, University of Regensburg, D-93053 Regensburg, Germany
| | - Michael Metz
- 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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93
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Croshaw J, Huff T, Rashidi M, Wood J, Lloyd E, Pitters J, Wolkow RA. Ionic charge distributions in silicon atomic surface wires. NANOSCALE 2021; 13:3237-3245. [PMID: 33533379 DOI: 10.1039/d0nr08295c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Using a non-contact atomic force microscope (nc-AFM), we examine continuous dangling bond (DB) wire structures patterned on the hydrogen terminated silicon (100)-2 × 1 surface. By probing the DB structures at varying energies, we identify the formation of previously unobserved ionic charge distributions which are correlated to the net charge of DB wires and their predicted degrees of freedom in lattice distortions. Performing spectroscopic analysis, we identify higher energy configurations corresponding to alternative lattice distortions as well as tip-induced charging effects. By varying the length and orientation of these DB structures, we further highlight key features in the formation of these ionic surface phases.
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Affiliation(s)
- Jeremiah Croshaw
- Department of Physics, University of Alberta, Edmonton, Alberta T6G 2J1, Canada. and Quantum Silicon Inc., Edmonton, Alberta T6G 2M9, Canada
| | - Taleana Huff
- Nanotechnology Research Centre, National Research Council Canada, Edmonton, Alberta T6G 2M9, Canada
| | - Mohammad Rashidi
- Department of Physics, University of Alberta, Edmonton, Alberta T6G 2J1, Canada.
| | - John Wood
- Department of Physics, University of Alberta, Edmonton, Alberta T6G 2J1, Canada.
| | - Erika Lloyd
- Department of Physics, University of Alberta, Edmonton, Alberta T6G 2J1, Canada.
| | - Jason Pitters
- Nanotechnology Research Centre, National Research Council Canada, Edmonton, Alberta T6G 2M9, Canada
| | - Robert A Wolkow
- Department of Physics, University of Alberta, Edmonton, Alberta T6G 2J1, Canada. and Quantum Silicon Inc., Edmonton, Alberta T6G 2M9, Canada and Nanotechnology Research Centre, National Research Council Canada, Edmonton, Alberta T6G 2M9, Canada
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94
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Lainé A, Vanossi A, Niguès A, Tosatti E, Siria A. Amplitude nanofriction spectroscopy. NANOSCALE 2021; 13:1955-1960. [PMID: 33442717 DOI: 10.1039/d0nr07925a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Atomic scale friction, an indispensable element of nanotechnology, requires a direct access to, under actual growing shear stress, its successive live phases: from static pinning, to depinning and transient evolution, eventually ushering in steady state kinetic friction. Standard tip-based atomic force microscopy generally addresses the steady state, but the prior intermediate steps are much less explored. Here we present an experimental and simulation approach, where an oscillatory shear force of increasing amplitude leads to a one-shot investigation of all these successive aspects. Demonstration with controlled gold nanocontacts sliding on graphite uncovers phenomena that bridge the gap between initial depinning and large speed sliding, of potential relevance for atomic scale time and magnitude dependent rheology.
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Affiliation(s)
- Antoine Lainé
- Laboratoire de Physique de l'École Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université Paris-Diderot, Sorbonne Paris Cité, UMR CNRS 8550, 24 Rue Lhomond, 75005 Paris, France.
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95
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Chen K, Liu Z, Xie Y, Zhang C, Xu G, Song W, Xu K. Numerical analysis of vibration modes of a qPlus sensor with a long tip. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2021; 12:82-92. [PMID: 33564605 PMCID: PMC7849263 DOI: 10.3762/bjnano.12.7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Accepted: 12/20/2020] [Indexed: 05/14/2023]
Abstract
We study the oscillatory behavior of qPlus sensors with a long tilted tip by means of finite element simulations. The vibration modes of a qPlus sensor with a long tip are quite different from those of a cantilever with a short tip. Flexural vibration of the tungsten tip will occur. The tip can no longer be considered as a rigid body that moves with the prong of the tuning fork. Instead, it oscillates both horizontally and vertically. The vibration characteristics of qPlus sensors with different tip sizes were studied. An optimized tip size was derived from obtained values of tip amplitude, ratio between vertical and lateral amplitude components, output current, and quality factor. For high spatial resolution the optimal diameter was found to be 0.1 mm.
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Affiliation(s)
- Kebei Chen
- School of Nano Technology and Nano Bionics, University of Science and Technology of China, Suzhou 215123, China
- Platform for Characterization and Test, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences (CAS), Suzhou 215123, China
- CAS Key Laboratory of Nanophotonic Materials and Devices, Suzhou Institute of Nano-Tech and Nano-Bionics, Suzhou 215123, China
| | - Zhenghui Liu
- Platform for Characterization and Test, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences (CAS), Suzhou 215123, China
- CAS Key Laboratory of Nanophotonic Materials and Devices, Suzhou Institute of Nano-Tech and Nano-Bionics, Suzhou 215123, China
| | - Yuchen Xie
- Platform for Characterization and Test, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences (CAS), Suzhou 215123, China
| | - Chunyu Zhang
- Platform for Characterization and Test, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences (CAS), Suzhou 215123, China
- CAS Key Laboratory of Nanophotonic Materials and Devices, Suzhou Institute of Nano-Tech and Nano-Bionics, Suzhou 215123, China
| | - Gengzhao Xu
- Platform for Characterization and Test, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences (CAS), Suzhou 215123, China
- CAS Key Laboratory of Nanophotonic Materials and Devices, Suzhou Institute of Nano-Tech and Nano-Bionics, Suzhou 215123, China
| | - Wentao Song
- Platform for Characterization and Test, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences (CAS), Suzhou 215123, China
- CAS Key Laboratory of Nanophotonic Materials and Devices, Suzhou Institute of Nano-Tech and Nano-Bionics, Suzhou 215123, China
| | - Ke Xu
- Platform for Characterization and Test, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences (CAS), Suzhou 215123, China
- CAS Key Laboratory of Nanophotonic Materials and Devices, Suzhou Institute of Nano-Tech and Nano-Bionics, Suzhou 215123, China
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96
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Telychko M, Li G, Mutombo P, Soler-Polo D, Peng X, Su J, Song S, Koh MJ, Edmonds M, Jelínek P, Wu J, Lu J. Ultrahigh-yield on-surface synthesis and assembly of circumcoronene into a chiral electronic Kagome-honeycomb lattice. SCIENCE ADVANCES 2021; 7:7/3/eabf0269. [PMID: 33523911 PMCID: PMC7810380 DOI: 10.1126/sciadv.abf0269] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 11/20/2020] [Indexed: 05/16/2023]
Abstract
On-surface synthesis has revealed remarkable potential in the fabrication of atomically precise nanographenes. However, surface-assisted synthesis often involves multiple-step cascade reactions with competing pathways, leading to a limited yield of target nanographene products. Here, we devise a strategy for the ultrahigh-yield synthesis of circumcoronene molecules on Cu(111) via surface-assisted intramolecular dehydrogenation of the rationally designed precursor, followed by methyl radical-radical coupling and aromatization. An elegant electrostatic interaction between circumcoronenes and metallic surface drives their self-organization into an extended superlattice, as revealed by bond-resolved scanning probe microscopy measurements. Density functional theory and tight-binding calculations reveal that unique hexagonal zigzag topology of circumcoronenes, along with their periodic electrostatic landscape, confines two-dimensional electron gas in Cu(111) into a chiral electronic Kagome-honeycomb lattice with two emergent electronic flat bands. Our findings open up a new route for the high-yield fabrication of elusive nanographenes with zigzag topologies and their superlattices with possible nontrivial electronic properties.
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Affiliation(s)
- Mykola Telychko
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
| | - Guangwu Li
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
| | - Pingo Mutombo
- Institute of Physics, The Czech Academy of Sciences, 162 00 Prague, Czech Republic
- Department of Petrochemistry and Refining, University of Kinshasa, Kinshasa, Democratic Republic of Congo
| | - Diego Soler-Polo
- Universidad Autónoma de Madrid, Campus Cantoblanco, Madrid, Spain
| | - Xinnan Peng
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
| | - Jie Su
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
| | - Shaotang Song
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
| | - Ming Joo Koh
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
| | - Mark Edmonds
- School of Physics and Astronomy, Monash University, Clayton, Victoria, Australia
| | - Pavel Jelínek
- Institute of Physics, The Czech Academy of Sciences, 162 00 Prague, Czech Republic.
- Regional Centre of Advanced Technologies and Materials, Palacký University, 78371 Olomouc, Czech Republic
| | - Jishan Wu
- 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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97
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Choi JIJ, Kim TS, Kim D, Lee SW, Park JY. Operando Surface Characterization on Catalytic and Energy Materials from Single Crystals to Nanoparticles. ACS NANO 2020; 14:16392-16413. [PMID: 33210917 DOI: 10.1021/acsnano.0c07549] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Modern surface science faces two major challenges, a materials gap and a pressure gap. While studies on single crystal surface in ultrahigh vacuum have uncovered the atomic and electronic structures of the surface, the materials and environmental conditions of commercial catalysis are much more complicated, both in the structure of the materials and in the accessible pressure range of analysis instruments. Model systems and operando surface techniques have been developed to bridge these gaps. In this Review, we highlight the current trends in the development of the surface characterization techniques and methodologies in more realistic environments, with emphasis on recent research efforts at the Korea Advanced Institute of Science and Technology. We show principles and applications of the microscopic and spectroscopic surface techniques at ambient pressure that were used for the characterization of atomic structure, electronic structure, charge transport, and the mechanical properties of catalytic and energy materials. Ambient pressure scanning tunneling microscopy and X-ray photoelectron spectroscopy allow us to observe the surface restructuring that occurs during oxidation, reduction, and catalytic processes. In addition, we introduce the ambient pressure atomic force microscopy that revealed the morphological, mechanical, and charge transport properties that occur during the catalytic and energy conversion processes. Hot electron detection enables the monitoring of catalytic reactions and electronic excitations on the surface. Overall, the information on the nature of catalytic reactions obtained with operando spectroscopic and microscopic techniques may bring breakthroughs in some of the global energy and environmental problems the world is facing.
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Affiliation(s)
- Joong Il Jake Choi
- Center for Nanomaterials and Chemical Reactions, Institute for Basic Science (IBS), Daejeon 34141, South Korea
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, South Korea
| | - Taek-Seung Kim
- Center for Nanomaterials and Chemical Reactions, Institute for Basic Science (IBS), Daejeon 34141, South Korea
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, South Korea
| | - Daeho Kim
- Center for Nanomaterials and Chemical Reactions, Institute for Basic Science (IBS), Daejeon 34141, South Korea
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, South Korea
| | - Si Woo Lee
- Center for Nanomaterials and Chemical Reactions, Institute for Basic Science (IBS), Daejeon 34141, South Korea
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, South Korea
| | - Jeong Young Park
- Center for Nanomaterials and Chemical Reactions, Institute for Basic Science (IBS), Daejeon 34141, South Korea
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, South Korea
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98
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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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99
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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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100
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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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