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Lebedeva IV, Popov AM. Two Phases with Different Domain Wall Networks and a Reentrant Phase Transition in Bilayer Graphene under Strain. PHYSICAL REVIEW LETTERS 2020; 124:116101. [PMID: 32242692 DOI: 10.1103/physrevlett.124.116101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Accepted: 02/21/2020] [Indexed: 06/11/2023]
Abstract
The analytical two-chain Frenkel-Kontorova model is used to describe domain wall networks in bilayer graphene upon biaxial stretching of one of the layers. We show that the commensurate-incommensurate phase transition leading to formation of a regular triangular domain wall network at the relative biaxial elongation of 3.0×10^{-3} is followed by the transition to another incommensurate phase with a striped network at the elongation of 3.7×10^{-3}. The reentrant transition to the phase with a triangular domain wall network is predicted for the elongation ∼10^{-2}.
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Affiliation(s)
| | - Andrey M Popov
- Institute for Spectroscopy of Russian Academy of Sciences, Troitsk, Moscow 108840, Russia
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2
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Thomas LK, Reichling M. Capillary force-induced superlattice variation atop a nanometer-wide graphene flake and its moiré origin studied by STM. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2019; 10:804-810. [PMID: 31019867 PMCID: PMC6466726 DOI: 10.3762/bjnano.10.80] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Accepted: 03/12/2019] [Indexed: 06/09/2023]
Abstract
We present strong experimental evidence for the moiré origin of superlattices on graphite by imaging a live transition from one superlattice to another with concurrent and direct measurement of the orientation angle before and after rotation using scanning tunneling microscopy (STM). This has been possible due to a fortuitous observation of a superlattice on a nanometer-sized graphene flake wherein we have induced a further rotation of the flake utilizing the capillary forces at play at a solid-liquid interface using STM tip motion. We propose a more "realistic" tip-surface meniscus relevant to STM at solid-liquid interfaces and show that the capillary force is sufficient to account for the total expenditure of energy involved in the process.
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Affiliation(s)
- Loji K Thomas
- Fachbereich Physik, Universität Osnabrück, Barbarastr. 7, 49076 Osnabrück, Germany
- Department of Physics, S. B College, Mahatma Gandhi University, Kerala, 686101, India
| | - Michael Reichling
- Fachbereich Physik, Universität Osnabrück, Barbarastr. 7, 49076 Osnabrück, Germany
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Sivadas N, Okamoto S, Xu X, Fennie CJ, Xiao D. Stacking-Dependent Magnetism in Bilayer CrI 3. NANO LETTERS 2018; 18:7658-7664. [PMID: 30408960 DOI: 10.1021/acs.nanolett.8b03321] [Citation(s) in RCA: 154] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
We report the connection between the stacking order and magnetic properties of bilayer CrI3 using first-principles calculations. We show that the stacking order defines the magnetic ground state. By changing the interlayer stacking order, one can tune the interlayer exchange interaction between antiferromagnetic and ferromagnetic. To measure the predicted stacking-dependent magnetism, we propose using linear magnetoelectric effect. Our results not only gives a possible explanation for the observed antiferromagnetism in bilayer CrI3 but also have direct implications in heterostructures made of two-dimensional magnets.
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Affiliation(s)
- Nikhil Sivadas
- School of Applied and Engineering Physics , Cornell University , Ithaca , New York 14853 , United States
| | - Satoshi Okamoto
- Materials Science and Technology Division , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States
| | - Xiaodong Xu
- Department of Physics , University of Washington , Seattle , Washington 98195 , United States
- Department of Materials Science and Engineering , University of Washington , Seattle , Washington 98195 , United States
| | - Craig J Fennie
- School of Applied and Engineering Physics , Cornell University , Ithaca , New York 14853 , United States
| | - Di Xiao
- Department of Physics , Carnegie Mellon University , Pittsburgh , Pennsylvania 15213 , United States
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Das SR, Nian Q, Cargill AA, Hondred JA, Ding S, Saei M, Cheng GJ, Claussen JC. 3D nanostructured inkjet printed graphene via UV-pulsed laser irradiation enables paper-based electronics and electrochemical devices. NANOSCALE 2016; 8:15870-15879. [PMID: 27510913 DOI: 10.1039/c6nr04310k] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Emerging research on printed and flexible graphene-based electronics is beginning to show tremendous promise for a wide variety of fields including wearable sensors and thin film transistors. However, post-print annealing/reduction processes that are necessary to increase the electrical conductivity of the printed graphene degrade sensitive substrates (e.g., paper) and are whole substrate processes that are unable to selectively anneal/reduce only the printed graphene-leaving sensitive device components exposed to damaging heat or chemicals. Herein a pulsed laser process is introduced that can selectively irradiate inkjet printed reduced graphene oxide (RGO) and subsequently improve the electrical conductivity (Rsheet∼0.7 kΩ□(-1)) of printed graphene above previously published reports. Furthermore, the laser process is capable of developing 3D petal-like graphene nanostructures from 2D planar printed graphene. These visible morphological changes display favorable electrochemical sensing characteristics-ferricyanide cyclic voltammetry with a redox peak separation (ΔEp) ≈ 0.7 V as well as hydrogen peroxide (H2O2) amperometry with a sensitivity of 3.32 μA mM(-1) and a response time of <5 s. Thus this work paves the way for not only paper-based electronics with graphene circuits, it enables the creation of low-cost and disposable graphene-based electrochemical electrodes for myriad applications including sensors, biosensors, fuel cells, and theranostic devices.
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Affiliation(s)
- Suprem R Das
- Department of Mechanical Engineering, Iowa State University, Ames, Iowa 50011, USA.
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Kratzer M, Teichert C. Thin film growth of aromatic rod-like molecules on graphene. NANOTECHNOLOGY 2016; 27:292001. [PMID: 27299472 DOI: 10.1088/0957-4484/27/29/292001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Research on graphene (Gr) is a vastly expanding field due to its potential for technological applications. Its close structural and chemical relationship to conjugated organic molecules makes it a superior candidate as a transparent electrode material in organic electronics and optoelectronics. The growth of organic thin films-intensively investigated in the past few decades-has demonstrated the complexity in growth and nucleation processes arising from the anisotropy and spatial extension of the molecular building blocks. Choosing the small, conjugated rod-like molecules para-hexaphenyl and pentacene as model representatives for small organic molecules, we review recent findings in organic thin film growth on a variety of Gr substrates. Special attention is paid to the differences in the resulting growth arising from the various methods of Gr fabrication and support that affect both the Gr-molecule interfacing and the involved molecular diffusion processes.
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Affiliation(s)
- M Kratzer
- Institute of Physics, Montanuiversität Leoben, Franz Josef Straße 18, 8700 Leoben, Austria
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Choe J, Lee Y, Fang L, Lee GD, Bao Z, Kim K. Direct imaging of rotating molecules anchored on graphene. NANOSCALE 2016; 8:13174-13180. [PMID: 27333828 DOI: 10.1039/c6nr04251a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
There has been significant research interest in controlling and imaging molecular dynamics, such as translational and rotational motions, especially at a single molecular level. Here we applied aberration-corrected transmission electron microscopy (ACTEM) to actuate and directly image the rotational motions of molecules anchored on a single-layer-graphene sheet. Nanometer-sized carbonaceous molecules anchored on graphene provide ideal systems for monitoring rotational motions via ACTEM. We observed the preferential registry of longer molecular axis along graphene zigzag or armchair lattice directions due to the stacking-dependent molecule-graphene energy landscape. The calculated cross section from elastic scattering theory was used to experimentally estimate the rotational energy barriers of molecules on graphene. The observed energy barrier was within the range of 1.5-12 meV per atom, which is in good agreement with previous calculation results. We also performed molecular dynamics simulations, which revealed that the edge atoms of the molecule form stably bonds to graphene defects and can serve as a pivot point for rotational dynamics. Our study demonstrates the versatility of ACTEM for the investigation of molecular dynamics and configuration-dependent energetics at a single molecular level.
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Affiliation(s)
- Jeongheon Choe
- Department of Physics, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, South Korea.
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Lebedev AV, Lebedeva IV, Knizhnik AA, Popov AM. Interlayer interaction and related properties of bilayer hexagonal boron nitride: ab initio study. RSC Adv 2016. [DOI: 10.1039/c5ra20882c] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Properties of hexagonal boron nitride bilayer related to interlayer interaction (width and formation energy of dislocations, shear mode frequency, etc.) are estimated by approximation of potential energy surface by first Fourier harmonics.
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Affiliation(s)
| | - Irina V. Lebedeva
- Nano-Bio Spectroscopy Group and ETSF Scientific Development Centre
- Departamento de Física de Materiales
- Universidad del País Vasco UPV/EHU
- San Sebastian E-20018
- Spain
| | - Andrey A. Knizhnik
- Kintech Lab Ltd
- Moscow 123182
- Russia
- National Research Centre “Kurchatov Institute”
- Moscow 123182
| | - Andrey M. Popov
- Institute for Spectroscopy of Russian Academy of Sciences
- Moscow 142190
- Russia
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Throckmorton J, Palmese G. Direct Preparation of Few Layer Graphene Epoxy Nanocomposites from Untreated Flake Graphite. ACS APPLIED MATERIALS & INTERFACES 2015; 7:14870-14877. [PMID: 26076058 DOI: 10.1021/acsami.5b03465] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The natural availability of flake graphite and the exceptional properties of graphene and graphene-polymer composites create a demand for simple, cost-effective, and scalable methods for top-down graphite exfoliation. This work presents a novel method of few layer graphite nanocomposite preparation directly from untreated flake graphite using a room temperature ionic liquid and laminar shear processing regimen. The ionic liquid serves both as a solvent and initiator for epoxy polymerization and is incorporated chemically into the matrix. This nanocomposite shows low electrical percolation (0.005 v/v) and low thickness (1-3 layers) graphite/graphene flakes by TEM. Additionally, the effect of processing conditions by rheometry and comparison with solvent-free conditions reveal the interactions between processing and matrix properties and provide insight into the theory of the chemical and physical exfoliation of graphite crystals and the resulting polymer matrix dispersion. An interaction model that correlates the interlayer shear physics of graphite flakes and processing parameters is proposed and tested.
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Affiliation(s)
- James Throckmorton
- Department of Chemical and Biological Engineering, Drexel University, 3141 Chestnut Street, Philadelphia, Pennsylvania 19104, United States
| | - Giuseppe Palmese
- Department of Chemical and Biological Engineering, Drexel University, 3141 Chestnut Street, Philadelphia, Pennsylvania 19104, United States
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Wang LF, Ma TB, Hu YZ, Zheng Q, Wang H, Luo J. Superlubricity of two-dimensional fluorographene/MoS2 heterostructure: a first-principles study. NANOTECHNOLOGY 2014; 25:385701. [PMID: 25180979 DOI: 10.1088/0957-4484/25/38/385701] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The atomic-scale friction of the fluorographene (FG)/MoS2 heterostructure is investigated using first-principles calculations. Due to the intrinsic lattice mismatch and formation of periodic Moiré patterns, the potential energy surface of the FG/MoS2 heterostructure is ultrasmooth and the interlayer shear strength is reduced by nearly two orders of magnitude, compared with both FG/FG and MoS2/MoS2 bilayers, entering the superlubricity regime. The size dependency of superlubricity is revealed as being based on the relationship between the emergence of Moiré patterns and the lattice mismatch ratio for heterostructures.
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Affiliation(s)
- Lin-Feng Wang
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, People's Republic of China. Institute of Bio-inspired Structure and Surface Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, People's Republic of China
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Popov AM, Lebedeva IV, Knizhnik AA, Lozovik YE, Potapkin BV, Poklonski NA, Siahlo AI, Vyrko SA. AA stacking, tribological and electronic properties of double-layer graphene with krypton spacer. J Chem Phys 2013; 139:154705. [DOI: 10.1063/1.4824298] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Feng X, Kwon S, Park JY, Salmeron M. Superlubric sliding of graphene nanoflakes on graphene. ACS NANO 2013; 7:1718-1724. [PMID: 23327483 DOI: 10.1021/nn305722d] [Citation(s) in RCA: 146] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The lubricating properties of graphite and graphene have been intensely studied by sliding a frictional force microscope tip against them to understand the origin of the observed low friction. In contrast, the relative motion of free graphene layers remains poorly understood. Here we report a study of the sliding behavior of graphene nanoflakes (GNFs) on a graphene surface. Using scanning tunneling microscopy, we found that the GNFs show facile translational and rotational motions between commensurate initial and final states at temperatures as low as 5 K. The motion is initiated by a tip-induced transition of the flakes from a commensurate to an incommensurate registry with the underlying graphene layer (the superlubric state), followed by rapid sliding until another commensurate position is reached. Counterintuitively, the average sliding distance of the flakes is larger at 5 K than at 77 K, indicating that thermal fluctuations are likely to trigger their transitions from superlubric back to commensurate ground states.
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Affiliation(s)
- Xiaofeng Feng
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
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Tsurumi J, Saito Y, Verma P. Evaluation of the interlayer interactions of few layers of graphene. Chem Phys Lett 2013. [DOI: 10.1016/j.cplett.2012.12.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Popov AM, Lebedeva IV, Knizhnik AA, Lozovik YE, Potapkin BV. Ab initio study of edge effect on relative motion of walls in carbon nanotubes. J Chem Phys 2013; 138:024703. [PMID: 23320709 DOI: 10.1063/1.4774083] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Andrey M Popov
- Institute of Spectroscopy, Russian Academy of Science, Fizicheskaya Street 5, Troitsk, Moscow Region 142190, Russia.
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