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Luo X, Liang G, Li Y, Yu F, Zhao X. Regulating the Electronic Structure of Freestanding Graphene on SiC by Ge/Sn Intercalation: A Theoretical Study. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27249004. [PMID: 36558135 PMCID: PMC9788586 DOI: 10.3390/molecules27249004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 11/29/2022] [Accepted: 12/13/2022] [Indexed: 12/23/2022]
Abstract
The intrinsic n-type of epitaxial graphene on SiC substrate limits its applications in microelectronic devices, and it is thus vital to modulate and achieve p-type and charge-neutral graphene. The main groups of metal intercalations, such as Ge and Sn, are found to be excellent candidates to achieve this goal based on the first-principle calculation results. They can modulate the conduction type of graphene via intercalation coverages and bring out interesting magnetic properties to the entire intercalation structures without inducing magnetism to graphene, which is superior to the transition metal intercalations, such as Fe and Mn. It is found that the Ge intercalation leads to ambipolar doping of graphene, and the p-type graphene can only be obtained when forming the Ge adatom between Ge layer and graphene. Charge-neutral graphene can be achieved under high Sn intercalation coverage (7/8 bilayer) owing to the significantly increased distance between graphene and deformed Sn intercalation. These findings would open up an avenue for developing novel graphene-based spintronic and electric devices on SiC substrate.
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Affiliation(s)
- Xingyun Luo
- State Key Lab of Crystal Materials, Institute of Crystal Materials, Shandong University, Jinan 250100, China
| | - Guojun Liang
- State Key Lab of Crystal Materials, Institute of Crystal Materials, Shandong University, Jinan 250100, China
| | - Yanlu Li
- State Key Lab of Crystal Materials, Institute of Crystal Materials, Shandong University, Jinan 250100, China
- Correspondence: (Y.L.); (X.Z.)
| | - Fapeng Yu
- State Key Lab of Crystal Materials, Institute of Crystal Materials, Shandong University, Jinan 250100, China
| | - Xian Zhao
- Center for Optics Research and Engineering of Shandong University, Shandong University, Qingdao 266237, China
- Correspondence: (Y.L.); (X.Z.)
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2
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Tezze D, Pereira JM, Asensio Y, Ipatov M, Calavalle F, Casanova F, Bittner AM, Ormaza M, Martín-García B, Hueso LE, Gobbi M. Tuning the magnetic properties of NiPS 3 through organic-ion intercalation. NANOSCALE 2022; 14:1165-1173. [PMID: 35018950 DOI: 10.1039/d1nr07281a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Atomically thin van der Waals magnetic crystals are characterized by tunable magnetic properties related to their low dimensionality. While electrostatic gating has been used to tailor their magnetic response, chemical approaches like intercalation remain largely unexplored. Here, we demonstrate the manipulation of the magnetism in the van der Waals antiferromagnet NiPS3 through the intercalation of different organic cations, inserted using an engineered two-step process. First, the electrochemical intercalation of tetrabutylammonium cations (TBA+) results in a ferrimagnetic hybrid compound displaying a transition temperature of 78 K, and characterized by a hysteretic behavior with finite remanence and coercivity. Then, TBA+ cations are replaced by cobaltocenium via an ion-exchange process, yielding a ferrimagnetic phase with higher transition temperature (98 K) and higher remanent magnetization. Importantly, we demonstrate that the intercalation and cation exchange processes can be carried out in bulk crystals and few-layer flakes, opening the way to the integration of intercalated magnetic materials in devices.
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Affiliation(s)
| | | | | | - Mihail Ipatov
- SGIker Medidas Magnéticas Gipuzkoa, UPV/EHU, 20018 San Sebastian, Spain
| | | | - Felix Casanova
- CIC nanoGUNE BRTA, 20018 San Sebastian, Spain.
- IKERBASQUE, Basque Foundation for Science, 48013 Bilbao, Spain
| | - Alexander M Bittner
- CIC nanoGUNE BRTA, 20018 San Sebastian, Spain.
- IKERBASQUE, Basque Foundation for Science, 48013 Bilbao, Spain
| | - Maider Ormaza
- Departamento de Polímeros y Materiales Avanzados: Física, Química y Tecnología, Universidad del País Vasco, Paseo Manuel de Lardizabal 3, San Sebastián 20018, Spain.
| | | | - Luis E Hueso
- CIC nanoGUNE BRTA, 20018 San Sebastian, Spain.
- IKERBASQUE, Basque Foundation for Science, 48013 Bilbao, Spain
| | - Marco Gobbi
- CIC nanoGUNE BRTA, 20018 San Sebastian, Spain.
- IKERBASQUE, Basque Foundation for Science, 48013 Bilbao, Spain
- Materials Physics Center CSIC-UPV/EHU, 20018 Donostia-San Sebastian, Spain
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Brack N, Spencer MJS, Mapleback B, Herries AIR, Kappen P, Rider AN. Zero valence iron nanocube decoration of graphitic nanoplatelets. NANOTECHNOLOGY 2021; 33:025704. [PMID: 34610590 DOI: 10.1088/1361-6528/ac2d0d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 10/05/2021] [Indexed: 06/13/2023]
Abstract
Graphitic nanoplatelets (GNPs) have been treated using an ultrasonicated ozonolysis procedure to produce stable aqueous dispersions that facilitate deposition of thin films using electrophoretic deposition. The thin GNP films were then coated with zero valence (ZV) iron nanocubes using a pulsed electrodeposition technique. Characterization of the ZV-iron coating with deposition time revealed that the changing magnetic character of the ferromagnetic-graphitic hybrid material was related to the nucleation density and growth of the ZV-iron nanocubes. Density functional theory calculations show a preference for ZV-iron adsorption at the oxygen sites of the GNPs, with ZV-iron displacement of oxygen groups favored in some configurations. Transmission electron microscopy studies confirm ZV-iron growth nucleates preferentially at the graphite nanoplatelet edges and the hybrid material magnetism is affected by the convergent crystalline grain boundaries formed between adjacent ZV-iron nanocubes.
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Affiliation(s)
- Narelle Brack
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC 3086, Australia
| | - Michelle J S Spencer
- School of Applied Sciences, RMIT University, GPO Box 2476, Melbourne VIC 3001, Australia
| | - Benjamin Mapleback
- Defence Science and Technology Group, 506 Lorimer St, Fisherman's Bend, VIC 3207, Australia
| | - Andy I R Herries
- The Australian Archaeomagnetism Laboratory, Department of Archaeology and History, La Trobe University, Melbourne, VIC 3086, Australia
| | - Peter Kappen
- Australian Synchrotron, 800 Blackburn Road, Clayton, VIC 3168, Australia
| | - Andrew N Rider
- Defence Science and Technology Group, 506 Lorimer St, Fisherman's Bend, VIC 3207, Australia
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Li W, Huang L, Tringides MC, Evans JW, Han Y. Thermodynamic Preference for Atom Adsorption on versus Intercalation into Multilayer Graphene. J Phys Chem Lett 2020; 11:9725-9730. [PMID: 33137260 DOI: 10.1021/acs.jpclett.0c02887] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The thermodynamic preference of a foreign atom for adsorption on versus intercalation into a graphitic surface is of fundamental and widespread interest. From an exhaustive first-principles density functional theory investigation for 38 typical elements over the periodic table, we reveal a quasilinear correlation between the Shannon effective ionic radius and the chemical-potential difference for a single atom from adsorption to intercalation at multilayer graphene surfaces. A critical Shannon radius is found to be around 0.10 nm, below (above) which intercalation (adsorption) is more favorable for elements with ionic-like bonding after intercalation. Single atoms with van der Waals-biased bonding show some deviation from the linear relationship, while single atoms for the elements with covalent-like bonding do not favor intercalation relative to adsorption. An energy decomposition analysis indicates that the chemical-potential difference determining the thermodynamic preference of a foreign atom for adsorption versus intercalation results from the competition between the electronic and elastic strain effects.
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Affiliation(s)
- Wei Li
- Department of Physics, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Li Huang
- Department of Physics, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Michael C Tringides
- Ames Laboratory, U.S. Department of Energy, Ames, Iowa 50011, United States
- Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, United States
| | - James W Evans
- Ames Laboratory, U.S. Department of Energy, Ames, Iowa 50011, United States
- Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, United States
| | - Yong Han
- Ames Laboratory, U.S. Department of Energy, Ames, Iowa 50011, United States
- Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, United States
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Briggs N, Gebeyehu ZM, Vera A, Zhao T, Wang K, De La Fuente Duran A, Bersch B, Bowen T, Knappenberger KL, Robinson JA. Epitaxial graphene/silicon carbide intercalation: a minireview on graphene modulation and unique 2D materials. NANOSCALE 2019; 11:15440-15447. [PMID: 31393495 DOI: 10.1039/c9nr03721g] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Intercalation of atomic species through epitaxial graphene on silicon carbide began only a few years following its initial report in 2004. The impact of intercalation on the electronic properties of the graphene is well known; however, the intercalant itself can also exhibit intriguing properties not found in nature. This realization has inspired new interest in epitaxial graphene/silicon carbide (EG/SiC) intercalation, where the scope of the technique extends beyond modulation of graphene properties to the creation of new 2D forms of 3D materials. The mission of this minireview is to provide a concise introduction to EG/SiC intercalation and to demonstrate a simplified approach to EG/SiC intercalation. We summarize the primary techniques used to achieve and characterize EG/SiC intercalation, and show that thermal evaporation-based methods can effectively substitute for more complex synthesis techniques, enabling large-scale intercalation of non-refractory metals and compounds including two-dimensional silver (2D-Ag) and gallium nitride (2D-GaNx).
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Affiliation(s)
- Natalie Briggs
- Department of Materials Science & Engineering, Pennsylvania State University, University Park, PA 16802, USA. and Center for 2-Dimensional and Layered Materials, Pennsylvania State University, University Park, PA 16802, USA and 2-Dimensional Crystal Consortium Materials Innovation Platform, Pennsylvania State University, University Park, PA 16802, USA
| | - Zewdu M Gebeyehu
- Department of Materials Science & Engineering, Pennsylvania State University, University Park, PA 16802, USA. and Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC, The Barcelona Institute of Science and Technology (BIST), Campus UAB, Bellaterra, Barcelona, Spain and Universitat Autònoma de Barcelona (UAB), Bellaterra, Spain
| | - Alexander Vera
- Department of Materials Science & Engineering, Pennsylvania State University, University Park, PA 16802, USA. and Center for 2-Dimensional and Layered Materials, Pennsylvania State University, University Park, PA 16802, USA
| | - Tian Zhao
- Department of Chemistry, Pennsylvania State University, University Park, PA 16802, USA
| | - Ke Wang
- Materials Characterization Laboratory, University Park, PA 16802, USA
| | - Ana De La Fuente Duran
- Department of Materials Science & Engineering, Pennsylvania State University, University Park, PA 16802, USA.
| | - Brian Bersch
- Department of Materials Science & Engineering, Pennsylvania State University, University Park, PA 16802, USA. and Center for 2-Dimensional and Layered Materials, Pennsylvania State University, University Park, PA 16802, USA
| | - Timothy Bowen
- Department of Materials Science & Engineering, Pennsylvania State University, University Park, PA 16802, USA. and Center for 2-Dimensional and Layered Materials, Pennsylvania State University, University Park, PA 16802, USA
| | | | - Joshua A Robinson
- Department of Materials Science & Engineering, Pennsylvania State University, University Park, PA 16802, USA. and Center for 2-Dimensional and Layered Materials, Pennsylvania State University, University Park, PA 16802, USA and 2-Dimensional Crystal Consortium Materials Innovation Platform, Pennsylvania State University, University Park, PA 16802, USA and Center for Atomically-Thin Multifunctional Coatings, Pennsylvania State University, University Park, PA 16802, USA
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6
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Hönig R, Roese P, Shamout K, Ohkochi T, Berges U, Westphal C. Structural, chemical, and magnetic properties of cobalt intercalated graphene on silicon carbide. NANOTECHNOLOGY 2019; 30:025702. [PMID: 30382025 DOI: 10.1088/1361-6528/aae8c9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
We report on a study of the Co intercalation process underneath the [Formula: see text] R30° reconstructed 6H-SiC(0001) surface for Co film-thicknesses in a range of 0.4-12 nm using a combination of surface sensitive imaging, diffractive, and spectroscopic methods. In situ photoemission electron microscopy reveals a dependence of the intercalation temperature on the Co film-thickness. Using low energy electron diffraction and photoemission spectroscopy (XPS), we find that the SiC surface reconstruction is partially lifted and transformed. We show that the [Formula: see text] R30° reconstruction does not prevent silicide formation for Co film-thicknesses ≥0.4 nm according to XPS and x-ray absorption spectra. Our results indicate that the silicide formation is self-limited to a thin interface region and is followed by Co intercalation between graphene and silicide. Furthermore, we analyze the magnetic properties using x-ray magnetic circular dichroism at the Co L-edge. In-plane magnetization is observed for all analyzed film-thicknesses. For ultra-thin Co films, self-assembled magnetic wires with a width of the order of 100 nm form at the step-edges.
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Affiliation(s)
- R Hönig
- Fakultät Physik/DELTA, TU Dortmund University, D-44221 Dortmund, Germany
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7
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Han J, Kang D, Dai J. Stability and local magnetic moment of bilayer graphene by intercalation: first principles study. RSC Adv 2018; 8:19732-19738. [PMID: 35540980 PMCID: PMC9080694 DOI: 10.1039/c8ra03343a] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Accepted: 05/22/2018] [Indexed: 11/21/2022] Open
Abstract
The migration and magnetic properties of the bilayer graphene with intercalation compounds (BGICs) with magnetic elements are theoretically investigated based on first principles study. Firstly, we find that BGICs with transition metals (Sc-Zn) generate distinct magnetic properties. The intercalation with most of the transition metal atoms (TMAs) gives rise to large magnetic moments from 1.0 to 4.0 μ B, which is valuable for the spintronics. Moreover, graphene can protect the intrinsic properties of the intercalated TMAs, which can be important for applications in catalysis. These phenomena can be explained by theory of spd hybridization definitely. Secondly, weak coupling between TMAs and the surroundings indicates the possibility of implementing quantum information processing and generating controlled entanglements. For the possibility of using these materials in ultrafast electronic transistors, spintronics, catalysis, spin qubit and important applications for the extensions of graphene, we believe that BGICs can provide a significant path to synthesize novel materials.
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Affiliation(s)
- Jinsen Han
- Department of Physics, National University of Defense Technology Changsha Hunan 410073 People's Republic of China
| | - Dongdong Kang
- Department of Physics, National University of Defense Technology Changsha Hunan 410073 People's Republic of China
| | - Jiayu Dai
- Department of Physics, National University of Defense Technology Changsha Hunan 410073 People's Republic of China
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Zhigalina VG, Kumskov AS, Falaleev NS, Vasiliev AL, Kiselev NA. Diffusion of One-Dimensional Crystals in Channels of Single-Walled Carbon Nanotubes. CRYSTALLOGR REP+ 2018. [DOI: 10.1134/s1063774518030355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Rezapour MR, Myung CW, Yun J, Ghassami A, Li N, Yu SU, Hajibabaei A, Park Y, Kim KS. Graphene and Graphene Analogs toward Optical, Electronic, Spintronic, Green-Chemical, Energy-Material, Sensing, and Medical Applications. ACS APPLIED MATERIALS & INTERFACES 2017; 9:24393-24406. [PMID: 28678466 DOI: 10.1021/acsami.7b02864] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
This spotlight discusses intriguing properties and diverse applications of graphene (Gr) and Gr analogs. Gr has brought us two-dimensional (2D) chemistry with its exotic 2D features of density of states. Yet, some of the 2D or 2D-like features can be seen on surfaces and at interfaces of bulk materials. The substrate on Gr and functionalization of Gr (including metal decoration, intercalation, doping, and hybridization) modify the unique 2D features of Gr. Despite abundant literature on physical properties and well-known applications of Gr, spotlight works based on the conceptual understanding of the 2D physical and chemical nature of Gr toward vast-ranging applications are hardly found. Here we focus on applications of Gr, based on conceptual understanding of 2D phenomena toward 2D chemistry. Thus, 2D features, defects, edges, and substrate effects of Gr are discussed first. Then, to pattern Gr electronic circuits, insight into differentiating conducting and nonconducting regions is introduced. By utilizing the unique ballistic electron transport properties and edge spin states of Gr, Gr nanoribbons (GNRs) are exploited for the design of ultrasensitive molecular sensing electronic devices (including molecular fingerprinting) and spintronic devices. The highly stable nature of Gr can be utilized for protection of corrosive metals, moisture-sensitive perovskite solar cells, and highly environment-susceptible topological insulators (TIs). Gr analogs have become new types of 2D materials having novel features such as half-metals, TIs, and nonlinear optical properties. The key insights into the functionalized Gr hybrid materials lead to the applications for not only energy storage and electrochemical catalysis, green chemistry, and electronic/spintronic devices but also biosensing and medical applications. All these topics are discussed here with the focus on conceptual understanding. Further possible applications of Gr, GNRs, and Gr analogs are also addressed in a section on outlook and future challenges.
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Affiliation(s)
- M Reza Rezapour
- Center for Superfunctional Materials, Department of Chemistry, School of Natural Science, Ulsan National Institute of Science and Technology (UNIST) , 50 UNIST-gil, Ulsan 44919, Republic of Korea
| | - Chang Woo Myung
- Center for Superfunctional Materials, Department of Chemistry, School of Natural Science, Ulsan National Institute of Science and Technology (UNIST) , 50 UNIST-gil, Ulsan 44919, Republic of Korea
| | - Jeonghun Yun
- Center for Superfunctional Materials, Department of Chemistry, School of Natural Science, Ulsan National Institute of Science and Technology (UNIST) , 50 UNIST-gil, Ulsan 44919, Republic of Korea
| | - Amirreza Ghassami
- Center for Superfunctional Materials, Department of Chemistry, School of Natural Science, Ulsan National Institute of Science and Technology (UNIST) , 50 UNIST-gil, Ulsan 44919, Republic of Korea
| | - Nannan Li
- Center for Superfunctional Materials, Department of Chemistry, School of Natural Science, Ulsan National Institute of Science and Technology (UNIST) , 50 UNIST-gil, Ulsan 44919, Republic of Korea
| | - Seong Uk Yu
- Center for Superfunctional Materials, Department of Chemistry, School of Natural Science, Ulsan National Institute of Science and Technology (UNIST) , 50 UNIST-gil, Ulsan 44919, Republic of Korea
| | - Amir Hajibabaei
- Center for Superfunctional Materials, Department of Chemistry, School of Natural Science, Ulsan National Institute of Science and Technology (UNIST) , 50 UNIST-gil, Ulsan 44919, Republic of Korea
| | - Youngsin Park
- Center for Superfunctional Materials, Department of Chemistry, School of Natural Science, Ulsan National Institute of Science and Technology (UNIST) , 50 UNIST-gil, Ulsan 44919, Republic of Korea
| | - Kwang S Kim
- Center for Superfunctional Materials, Department of Chemistry, School of Natural Science, Ulsan National Institute of Science and Technology (UNIST) , 50 UNIST-gil, Ulsan 44919, Republic of Korea
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Sung S, Kim S, Lee P, Kim J, Ryu M, Park H, Kim K, Min BI, Chung J. Observation of variable hybridized-band gaps in Eu-intercalated graphene. NANOTECHNOLOGY 2017; 28:205201. [PMID: 28345532 DOI: 10.1088/1361-6528/aa6951] [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
We report europium (Eu)-induced changes in the π-band of graphene (G) formed on the 6H-SiC(0001) surface by a combined study of photoemission measurements and density functional theory (DFT) calculations. Our photoemission data reveal that Eu intercalates upon annealing at 120 °C into the region between the graphene and the buffer layer (BL) to form a G/Eu/BL system, where a band gap of 0.29 eV opens at room temperature. This band gap is found to increase further to 0.48 eV upon cooling down to 60 K. Our DFT calculations suggest that the increased band gap originates from the enhanced hybridization of the graphene π-band with the Eu 4f band due to the increased magnetic ordering upon cooling. These Eu atoms continue to intercalate further down below the BL to produce bilayer graphene (G/BL/Eu) upon annealing at 300 °C. The π-band stemming from the BL then exhibits another band gap of 0.37 eV, which appears to be due to the strong hybridization between the π-band of the BL and the Eu 4f band. The Eu-intercalated graphene thus illustrates an example of versatile band gaps formed under different thermal treatments, which may play a critical role for future applications in graphene-based electronics.
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Affiliation(s)
- Sijin Sung
- Department of Physics, Pohang University of Science and Technology, Pohang 37673, Korea
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Ryu M, Lee P, Kim J, Park H, Chung J. Modification of thermal and electronic properties of bilayer graphene by using slow Na + ions. NANOTECHNOLOGY 2016; 27:485704. [PMID: 27796276 DOI: 10.1088/0957-4484/27/48/485704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Bilayer graphene (BLG) has an extensive list of industrial applications in graphene-based nanodevices such as energy storage devices, flexible displays, and thermoelectric devices. By doping slow Na+ ions on Li-intercalated BLG, we find significantly improved thermal and electronic properties of BLG by using angle-resolved photoemission and high-resolution core level spectroscopy (HRCLS) with synchrotron photons. Our HRCLS data reveal that the adsorbed Na+ ions on a BLG produced by Li-intercalation through single layer graphene (SLG) spontaneously intercalate below the BLG, and substitute Li atoms to form Na-Si bonds at the SiC interface while preserving the same phase of BLG. This is in sharp contrast with no intercalation of Na+ ions on SLG though neutral Na atoms intercalate. The Na+-induced BLG is found to be stable upon heating up to T = 400 °C, but returns to SLG when heated at T d = 500 °C. The evolution of the π-bands upon doping the Na+ ions followed by thermal annealing shows that the carrier concentration of the π-band may be artificially controlled without damaging the Dirac nature of the π-electrons. The doubled desorption temperature from that (T d = 250 °C) of the Na-intercalated SLG together with the electronic stability of the Na+-intercalated BLG may find more practical and effective applications in advancing graphene-based thermoelectric devices and anode materials for rechargeable batteries.
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Affiliation(s)
- Mintae Ryu
- Department of Physics, Pohang University of Science and Technology, Pohang 37673, Korea
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12
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Ryu M, Lee P, Kim J, Park H, Chung J. Band gap engineering for single-layer graphene by using slow Li(+) ions. NANOTECHNOLOGY 2016; 27:31LT03. [PMID: 27345294 DOI: 10.1088/0957-4484/27/31/31lt03] [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
In order to utilize the superb electronic properties of graphene in future electronic nano-devices, a dependable means of controlling the transport properties of its Dirac electrons has to be devised by forming a tunable band gap. We report on the ion-induced modification of the electronic properties of single-layer graphene (SLG) grown on a SiC(0001) substrate by doping low-energy (5 eV) Li(+) ions. We find the opening of a sizable and tunable band gap up to 0.85 eV, which depends on the Li(+) ion dose as well as the following thermal treatment, and is the largest band gap in the π-band of SLG by any means reported so far. Our Li 1s core-level data together with the valence band suggest that Li(+) ions do not intercalate below the topmost graphene layer, but cause a significant charge asymmetry between the carbon sublattices of SLG to drive the opening of the band gap. We thus provide a route to producing a tunable graphene band gap by doping Li(+) ions, which may play a pivotal role in the utilization of graphene in future graphene-based electronic nano-devices.
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Affiliation(s)
- Mintae Ryu
- Department of Physics, Pohang University of Science and Technology, Pohang 37673, Korea
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13
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Yurtsever A, Onoda J, Iimori T, Niki K, Miyamachi T, Abe M, Mizuno S, Tanaka S, Komori F, Sugimoto Y. Effects of Pb Intercalation on the Structural and Electronic Properties of Epitaxial Graphene on SiC. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2016; 12:3956-3966. [PMID: 27295020 DOI: 10.1002/smll.201600666] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2016] [Revised: 05/13/2016] [Indexed: 06/06/2023]
Abstract
The effects of Pb intercalation on the structural and electronic properties of epitaxial single-layer graphene grown on SiC(0001) substrate are investigated using scanning tunneling microscopy (STM), noncontact atomic force microscopy, Kelvin probe force microscopy (KPFM), X-ray photoelectron spectroscopy, and angle-resolved photoemission spectroscopy (ARPES) methods. The STM results show the formation of an ordered moiré superstructure pattern induced by Pb atom intercalation underneath the graphene layer. ARPES measurements reveal the presence of two additional linearly dispersing π-bands, providing evidence for the decoupling of the buffer layer from the underlying SiC substrate. Upon Pb intercalation, the Si 2p core level spectra show a signature for the existence of PbSi chemical bonds at the interface region, as manifested in a shift of 1.2 eV of the bulk SiC component toward lower binding energies. The Pb intercalation gives rise to hole-doping of graphene and results in a shift of the Dirac point energy by about 0.1 eV above the Fermi level, as revealed by the ARPES measurements. The KPFM experiments have shown that decoupling of the graphene layer by Pb intercalation is accompanied by a work function increase. The observed increase in the work function is attributed to the suppression of the electron transfer from the SiC substrate to the graphene layer. The Pb intercalated structure is found to be stable in ambient conditions and at high temperatures up to 1250 °C. These results demonstrate that the construction of a graphene-capped Pb/SiC system offers a possibility of tuning the graphene electronic properties and exploring intriguing physical properties such as superconductivity and spintronics.
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Affiliation(s)
- Ayhan Yurtsever
- Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka, 560-8531, Japan
- The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka, 567-0047, Japan
| | - Jo Onoda
- Graduate School of Engineering, Osaka University, 2-1 Yamada, Oka, Suita, Osaka, 565-0871, Japan
- Department of Advanced Materials Science, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8561, Japan
| | - Takushi Iimori
- The Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8581, Japan
| | - Kohei Niki
- Graduate School of Engineering, Osaka University, 2-1 Yamada, Oka, Suita, Osaka, 565-0871, Japan
- Department of Advanced Materials Science, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8561, Japan
| | - Toshio Miyamachi
- The Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8581, Japan
| | - Masayuki Abe
- Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka, 560-8531, Japan
| | - Seigi Mizuno
- Department of Molecular and Material Sciences, Kyushu University, Kasuga, Fukuoka, 816-8580, Japan
| | - Satoru Tanaka
- Department of Applied Quantum Physics and Nuclear Engineering, Kyushu University, Fukuoka, 819-0395, Japan
| | - Fumio Komori
- The Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8581, Japan
| | - Yoshiaki Sugimoto
- Graduate School of Engineering, Osaka University, 2-1 Yamada, Oka, Suita, Osaka, 565-0871, Japan
- Department of Advanced Materials Science, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8561, Japan
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14
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Abstract
By doping magnetic Ce atoms on a single layer graphene, we report a new and efficient means of modifying structural and electronic properties of graphene that opens a temperature-dependent band gap of size up to 0.5 eV.
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Affiliation(s)
- Jingul Kim
- Department of Physics
- Pohang University of Science and Technology
- Pohang 37673
- Korea
| | - Paengro Lee
- Department of Physics
- Pohang University of Science and Technology
- Pohang 37673
- Korea
| | - Mintae Ryu
- Department of Physics
- Pohang University of Science and Technology
- Pohang 37673
- Korea
| | - Heemin Park
- Department of Physics
- Pohang University of Science and Technology
- Pohang 37673
- Korea
| | - Jinwook Chung
- Department of Physics
- Pohang University of Science and Technology
- Pohang 37673
- Korea
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15
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Sung S, Lee SH, Lee P, Kim J, Park H, Ryu M, Kim N, Hwang C, Jhi SH, Chung J. Band modification of graphene by using slow Cs+ ions. RSC Adv 2016. [DOI: 10.1039/c5ra24482j] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
We report new wide band gap engineering for graphene using slow Cs+ ions, which allows both fine-tuning and on–off switching capability of the band gap in a range suitable for most applications sustaining the nature of Dirac fermions.
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Affiliation(s)
- Sijin Sung
- Department of Physics
- Pohang University of Science and Technology
- Pohang 790-784
- Korea
| | - Sang-Hoon Lee
- Department of Physics
- Pohang University of Science and Technology
- Pohang 790-784
- Korea
| | - Paengro Lee
- Department of Physics
- Pohang University of Science and Technology
- Pohang 790-784
- Korea
| | - Jingul Kim
- Department of Physics
- Pohang University of Science and Technology
- Pohang 790-784
- Korea
| | - Heemin Park
- Department of Physics
- Pohang University of Science and Technology
- Pohang 790-784
- Korea
| | - Mintae Ryu
- Department of Physics
- Pohang University of Science and Technology
- Pohang 790-784
- Korea
| | - Namdong Kim
- Beamline Research Division
- Pohang Accelerator Laboratory
- Pohang 790-784
- Korea
| | - Choongyu Hwang
- Department of Physics
- Pusan National University
- Busan 609-735
- Korea
| | - Seung-Hoon Jhi
- Department of Physics
- Pohang University of Science and Technology
- Pohang 790-784
- Korea
| | - Jinwook Chung
- Department of Physics
- Pohang University of Science and Technology
- Pohang 790-784
- Korea
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16
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Sun Y, Ma J, Tian D, Li H. Macroscopic switches constructed through host–guest chemistry. Chem Commun (Camb) 2016; 52:4602-12. [DOI: 10.1039/c6cc00338a] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In this feature article, we discuss recent developments in macroscopic contact angle switches formed by different macrocyclic hosts and highlight the properties of these new functional surfaces and their potential applications.
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Affiliation(s)
- Yue Sun
- Key Laboratory of Pesticide and Chemical Biology (CCNU)
- Ministry of Education
- College of Chemistry
- Central China Normal University
- Wuhan
| | - Junkai Ma
- Key Laboratory of Pesticide and Chemical Biology (CCNU)
- Ministry of Education
- College of Chemistry
- Central China Normal University
- Wuhan
| | - Demei Tian
- Key Laboratory of Pesticide and Chemical Biology (CCNU)
- Ministry of Education
- College of Chemistry
- Central China Normal University
- Wuhan
| | - Haibing Li
- Key Laboratory of Pesticide and Chemical Biology (CCNU)
- Ministry of Education
- College of Chemistry
- Central China Normal University
- Wuhan
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17
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Cattelan M, Peng GW, Cavaliere E, Artiglia L, Barinov A, Roling LT, Favaro M, Píš I, Nappini S, Magnano E, Bondino F, Gavioli L, Agnoli S, Mavrikakis M, Granozzi G. The nature of the Fe-graphene interface at the nanometer level. NANOSCALE 2015; 7:2450-2460. [PMID: 25565421 DOI: 10.1039/c4nr04956j] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The emerging fields of graphene-based magnetic and spintronic devices require a deep understanding of the interface between graphene and ferromagnetic metals. This paper reports a detailed investigation at the nanometer level of the Fe-graphene interface carried out by angle-resolved photoemission, high-resolution photoemission from core levels, near edge X-ray absorption fine structure, scanning tunnelling microscopy and spin polarized density functional theory calculations. Quasi-free-standing graphene was grown on Pt(111), and the iron film was either deposited atop or intercalated beneath graphene. Calculations and experimental results show that iron strongly modifies the graphene band structure and lifts its π band spin degeneracy.
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Affiliation(s)
- M Cattelan
- Department of Chemical Sciences, University of Padova, via Marzolo 1, I-35131 Padova, Italy.
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