301
|
Pan L, Song B, Sun J, Zhang L, Hofer W, Du S, Gao HJ. The origin of half-metallicity in conjugated electron systems--a study on transition-metal-doped graphyne. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2013; 25:505502. [PMID: 24275545 DOI: 10.1088/0953-8984/25/50/505502] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We studied the mechanism of half-metallicity (HM) formation in transition-metal-doped conjugated carbon based structures by first-principles electronic structure simulations. It is found that the HM is a rather complex phenomenon, determined by the ligand field splitting of d-orbitals of the transition metal atoms, the exchange splitting and the number of valence electrons. Since most of the conjugated carbon based structures possess ligands with intermediate strength, the ordering of the d-orbital splitting is similar in all structures, and the HM properties evolve according to the number of valence electrons. Based on this insight we predict that Cr-, Fe- and Co-doped graphyne will show HM, while Mn- and Ni-doped graphyne will not. By tuning the number of valence electrons, we are thus able to control the emergence of HM and control the energy gaps evolving in the majority or minority spin channels.
Collapse
Affiliation(s)
- Lida Pan
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
| | | | | | | | | | | | | |
Collapse
|
302
|
Luo H, Li H, Fu Q, Chu Y, Cao X, Sun C, Yuan X, Liu L. Density functional theory study on the interactions of L-cysteine with graphene: adsorption stability and magnetism. NANOTECHNOLOGY 2013; 24:495702. [PMID: 24231132 DOI: 10.1088/0957-4484/24/49/495702] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Understanding the interactions between graphene and biomolecules is of fundamental relevance to the area of nanobiotechnology. Herein, we take l-cysteine as the probe biomolecule and investigate its adsorption on pristine graphene and B-, N-, Al-, Ni-, Ga-, Pd-doped graphene using density functional theory calculations. Three kinds of upright adsorption configurations, via unprotonated functional groups (-SH, -NH2, -COOH), are considered. The calculations reveal pristine graphene physically adsorbs l-cysteine. N-doped graphene shows physisorption towards the S-end and N-end l-cysteine, and chemisorption towards the O-end radical. Strong chemisorption, with site-specific preference, occurs on Al-, Ni-, Ga- and Pd-doped graphene, accompanied by severe structural changes. Spin polarization with an unusual mirror symmetry on Ni- and Pd-doped graphene is induced by chemisorption of unprotonated l-cysteine, except for O-end adsorption on Pd-doped graphene. The magnetization arises mainly from spin polarization of the C 2pz orbital, with a minor magnetism located on Ni or Pd. The influence of van der Waals forces is also evaluated. A thorough analysis of the adsorption stability and magnetism of these systems would be beneficial to facilitate applications in graphene-based biosensing, biomolecule immobilization, magnetic bio-separation and other fields in bionanotechnology.
Collapse
Affiliation(s)
- Huijuan Luo
- State Key Laboratory of Solidification Processing, Carbon/Carbon Composites Research Center, Northwestern Polytechnical University, Xi'an 710072, People's Republic of China
| | | | | | | | | | | | | | | |
Collapse
|
303
|
Donati F, Dubout Q, Autès G, Patthey F, Calleja F, Gambardella P, Yazyev OV, Brune H. Magnetic moment and anisotropy of individual Co atoms on graphene. PHYSICAL REVIEW LETTERS 2013; 111:236801. [PMID: 24476294 DOI: 10.1103/physrevlett.111.236801] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Indexed: 06/03/2023]
Abstract
We report on the magnetic properties of single Co atoms on graphene on Pt(111). By means of scanning tunneling microscopy spin-excitation spectroscopy, we infer a magnetic anisotropy of K=-8.1 meV with out-of-plane hard axis and a magnetic moment of 2.2μ(B). Co adsorbs on the sixfold graphene hollow site. Upon hydrogen adsorption, three differently hydrogenated species are identified. Their magnetic properties are very different from those of clean Co. Ab initio calculations support our results and reveal that the large magnetic anisotropy stems from strong ligand field effects due to the interaction between Co and graphene orbitals.
Collapse
Affiliation(s)
- F Donati
- Institute of Condensed Matter Physics (ICMP), Ecole Polytechnique Fédérale de Lausanne (EPFL), Station 3, CH-1015, Switzerland
| | - Q Dubout
- Institute of Condensed Matter Physics (ICMP), Ecole Polytechnique Fédérale de Lausanne (EPFL), Station 3, CH-1015, Switzerland
| | - G Autès
- Institute of Theoretical Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - F Patthey
- Institute of Condensed Matter Physics (ICMP), Ecole Polytechnique Fédérale de Lausanne (EPFL), Station 3, CH-1015, Switzerland
| | - F Calleja
- Institute of Condensed Matter Physics (ICMP), Ecole Polytechnique Fédérale de Lausanne (EPFL), Station 3, CH-1015, Switzerland and Madrid Institute for Advanced Studies, IMDEA Nanoscience, Calle Faraday 9, Campus Cantoblanco, E-28049 Madrid, Spain
| | - P Gambardella
- Institute of Condensed Matter Physics (ICMP), Ecole Polytechnique Fédérale de Lausanne (EPFL), Station 3, CH-1015, Switzerland and Catalan Institute of Nanoscience and Nanotechnology (ICN2), UAB Campus, E-08193 Barcelona, Spain and Department of Materials, ETH Zurich, CH-8093 Zurich, Switzerland
| | - O V Yazyev
- Institute of Theoretical Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - H Brune
- Institute of Condensed Matter Physics (ICMP), Ecole Polytechnique Fédérale de Lausanne (EPFL), Station 3, CH-1015, Switzerland
| |
Collapse
|
304
|
Gao W, Mueller JE, Anton J, Jiang Q, Jacob T. Nickel Cluster Growth on Defect Sites of Graphene: A Computational Study. Angew Chem Int Ed Engl 2013; 52:14237-41. [DOI: 10.1002/anie.201305001] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Indexed: 11/08/2022]
|
305
|
Gao W, Mueller JE, Anton J, Jiang Q, Jacob T. Das Wachstum von Nickelclustern an Graphen-Fehlstellen: eine theoretische Studie. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201305001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
306
|
Kan M, Zhou J, Sun Q, Kawazoe Y, Jena P. The Intrinsic Ferromagnetism in a MnO2 Monolayer. J Phys Chem Lett 2013; 4:3382-6. [PMID: 26705581 DOI: 10.1021/jz4017848] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
The Mn atom, because of its special electronic configuration of 3d(5)4s(2), has been widely used as a dopant in various two-dimensional (2D) monolayers such as graphene, BN, silicene and transition metal dichalcogenides (TMDs). The distributions of doped Mn atoms in these systems are highly sensitive to the synthesis process and conditions, thus suffering from problems of low solubility and surface clustering. Here we show for the first time that the MnO2 monolayer, synthetized 10 years ago, where Mn ions are individually held at specific sites, exhibits intrinsic ferromagnetism with a Curie temperature of 140 K, comparable to the highest TC value achieved experimentally for Mn-doped GaAs. The well-defined atomic configuration and the intrinsic ferromagnetism of the MnO2 monolayer suggest that it is superior to other magnetic monolayer materials.
Collapse
Affiliation(s)
- M Kan
- Department of Materials Science and Engineering, Peking University , Beijing 100871, China
| | - J Zhou
- Department of Materials Science and Engineering, Peking University , Beijing 100871, China
| | - Q Sun
- Department of Materials Science and Engineering, Peking University , Beijing 100871, China
- Center for Applied Physics and Technology, Peking University , Beijing 100871, China
- Department of Physics, Virginia Commonwealth University , Richmond, Virginia 23284, United States
| | - Y Kawazoe
- Institute for Material Research, Tohoku University , Sendai, 980-8577, Japan
| | - P Jena
- Department of Physics, Virginia Commonwealth University , Richmond, Virginia 23284, United States
| |
Collapse
|
307
|
Zheng Y, Xiao W, Cho M, Cho K. Density functional theory calculations for the oxygen dissociation on nitrogen and transition metal doped graphenes. Chem Phys Lett 2013. [DOI: 10.1016/j.cplett.2013.09.016] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
308
|
Structural and Magnetic Properties of 3d Transition-Metal-Atom Adsorption on Perfect and Defective Graphene: A Density Functional Theory Study. Chemphyschem 2013; 14:3483-8. [DOI: 10.1002/cphc.201300563] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Indexed: 11/07/2022]
|
309
|
Zhou Y, Yang C, Xiang X, Zu X. Remarkable magnetism and ferromagnetic coupling in semi-sulfuretted transition-metal dichalcogenides. Phys Chem Chem Phys 2013; 15:14202-9. [PMID: 23873448 DOI: 10.1039/c3cp51518d] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Motivated by recent investigations of semi-decorated two dimensional honeycomb structures, we demonstrated, via spin-polarized molecular-dynamics simulations and density-functional-theory calculations, that semi-sulfuretted transition-metal dichalcogenides of MX type (M = V, Nb, Ta; X = S, Se, Te) are stable and display remarkable magnetism. The unpaired d electron of the transition-metal atom arising from the breakage of the M-X bond is the mechanism behind the induction of the magnetism. The remarkable magnetism of the transition-metal atoms is caused by ferromagnetic coupling due to the competitive effects of through-bond interactions and through-space interactions. This implies the existence of an infinite ferromagnetic sheet with structural integrity and magnetic homogeneity. The estimated Curie temperatures suggest that the ferromagnetism can be achieved above room temperature in the VS, VSe, VTe, NbTe and TaTe sheets. Depending on the species of the M and X atoms, the MX sheet can be a magnetic metal, magnetic semiconductor or half-metal. Furthermore, in contrary to the recently reported semi-hydrogenated and semi-fluorinated layered materials consisting of B, C, N, etc., the MX sheets with many unpaired d electrons can offer a much stronger spin polarization and possess a more stable ferromagnetic coupling, which is critical for practical nanoscale device applications.
Collapse
Affiliation(s)
- Yungang Zhou
- Department of Applied Physics, University of Electronic Science and Technology of China, Chengdu, 610054, PR China.
| | | | | | | |
Collapse
|
310
|
Tang Q, Zhou Z, Chen Z. Graphene-related nanomaterials: tuning properties by functionalization. NANOSCALE 2013; 5:4541-83. [PMID: 23443470 DOI: 10.1039/c3nr33218g] [Citation(s) in RCA: 209] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
In this review, we discuss the most recent progress on graphene-related nanomaterials, including doped graphene and derived graphene nanoribbons, graphene oxide, graphane, fluorographene, graphyne, graphdiyne, and porous graphene, from both experimental and theoretical perspectives, and emphasize tuning their stability, electronic and magnetic properties by chemical functionalization.
Collapse
Affiliation(s)
- Qing Tang
- Tianjin Key Laboratory of Metal and Molecule Based Material Chemistry, Institute of New Energy Material Chemistry, Computational Centre for Molecule Science, Nankai University, Tianjin 300071, PR China
| | | | | |
Collapse
|
311
|
Robertson AW, Montanari B, He K, Kim J, Allen CS, Wu YA, Olivier J, Neethling J, Harrison N, Kirkland AI, Warner JH. Dynamics of single Fe atoms in graphene vacancies. NANO LETTERS 2013; 13:1468-1475. [PMID: 23517297 DOI: 10.1021/nl304495v] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Focused electron beam irradiation has been used to create mono and divacancies in graphene within a defined area, which then act as trap sites for mobile Fe atoms initially resident on the graphene surface. Aberration-corrected transmission electron microscopy at 80 kV has been used to study the real time dynamics of Fe atoms filling the vacancy sites in graphene with atomic resolution. We find that the incorporation of a dopant atom results in pronounced displacements of the surrounding carbon atoms of up to 0.5 Å, which is in good agreement with density functional theory calculations. Once incorporated into the graphene lattice, Fe atoms can transition to adjacent lattice positions and reversibly switch their bonding between four and three nearest neighbors. The C atoms adjacent to the Fe atoms are found to be more susceptible to Stone-Wales type bond rotations with these bond rotations associated with changes in the dopant bonding configuration. These results demonstrate the use of controlled electron beam irradiation to incorporate dopants into the graphene lattice with nanoscale spatial control.
Collapse
Affiliation(s)
- Alex W Robertson
- Department of Materials, University of Oxford, Oxford, United Kingdom
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
312
|
Wang L, Zhang X, Chan HL, Yan F, Ding F. Formation and Healing of Vacancies in Graphene Chemical Vapor Deposition (CVD) Growth. J Am Chem Soc 2013; 135:4476-82. [DOI: 10.1021/ja312687a] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Lu Wang
- Institute
of Textile and Clothing and ‡Department of Applied Physics, Hong Kong Polytechnic University, Kowloon, Hong Kong,
People’s Republic of China
| | - Xiuyun Zhang
- Institute
of Textile and Clothing and ‡Department of Applied Physics, Hong Kong Polytechnic University, Kowloon, Hong Kong,
People’s Republic of China
| | - Helen L.W. Chan
- Institute
of Textile and Clothing and ‡Department of Applied Physics, Hong Kong Polytechnic University, Kowloon, Hong Kong,
People’s Republic of China
| | - Feng Yan
- Institute
of Textile and Clothing and ‡Department of Applied Physics, Hong Kong Polytechnic University, Kowloon, Hong Kong,
People’s Republic of China
| | - Feng Ding
- Institute
of Textile and Clothing and ‡Department of Applied Physics, Hong Kong Polytechnic University, Kowloon, Hong Kong,
People’s Republic of China
| |
Collapse
|
313
|
Ghosh A, Pinto JWM, Frota HO. Electron spin resonance in presence of a magnetic impurity in graphene. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2013; 227:87-92. [PMID: 23314256 DOI: 10.1016/j.jmr.2012.12.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2012] [Revised: 12/09/2012] [Accepted: 12/11/2012] [Indexed: 06/01/2023]
Abstract
The ESR of a magnetic probe sited at a distance R from an adatom in graphene, interacting via a RKKY interaction, is studied. The spin relaxation rate of the magnetic probe in the case of pristine graphene satisfies a T(3) dependence for all temperatures at the Dirac point. However, away from the Dirac point a T(3) dependence is observed only for high temperatures unlike the Korringa behavior at low temperatures. Moreover, the zero-temperature relaxation rate of the pristine graphene demonstrates a quadratic dependence on the chemical potential. In the presence of the magnetic adatom hybridized with one site of the graphene sublattice we observe a dip in the relaxation rate away from the Dirac point. At the Dirac point a deviation from the T(3) dependence is observed. The presence of the Coulomb interaction U also modifies the zero-temperature relaxation rate when compared to that of pristine graphene. The transition from the magnetic state to the non-magnetic state is also characterized by a minimum in the relaxation rate.
Collapse
Affiliation(s)
- Angsula Ghosh
- Departamento de Física-ICE, Universidade Federal do Amazonas, Manaus-AM, Brazil.
| | | | | |
Collapse
|
314
|
Metals on Graphene: Interactions, Growth Morphology, and Thermal Stability. CRYSTALS 2013. [DOI: 10.3390/cryst3010079] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
315
|
Indirect Exchange and Ruderman–Kittel–Kasuya–Yosida (RKKY) Interactions in Magnetically-Doped Graphene. CRYSTALS 2013. [DOI: 10.3390/cryst3010049] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
316
|
Kaukonen M, Krasheninnikov AV, Kauppinen E, Nieminen RM. Doped Graphene as a Material for Oxygen Reduction Reaction in Hydrogen Fuel Cells: A Computational Study. ACS Catal 2013. [DOI: 10.1021/cs300605t] [Citation(s) in RCA: 93] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- M. Kaukonen
- NanoMaterials Group, Department of Applied Physics and Center for
New Materials, Aalto University, P.O. Box
15100, FI- 00076 Aalto, Espoo, Finland
| | - A. V. Krasheninnikov
- COMP/Applied Physics, Aalto University, P.O. Box 1100, FI-00076 Aalto, Finland
- Department of Physics, University of Helsinki, P.O. Box 43, FI-00014 Helsinki, Finland
| | - E. Kauppinen
- NanoMaterials Group, Department of Applied Physics and Center for
New Materials, Aalto University, P.O. Box
15100, FI- 00076 Aalto, Espoo, Finland
| | - R. M. Nieminen
- COMP/Applied Physics, Aalto University, P.O. Box 1100, FI-00076 Aalto, Finland
| |
Collapse
|
317
|
Kattel S. Magnetic properties of 3d transition metals and nitrogen functionalized armchair graphene nanoribbon. RSC Adv 2013. [DOI: 10.1039/c3ra43810d] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
|
318
|
Schultz BJ, Jaye C, Lysaght PS, Fischer DA, Prendergast D, Banerjee S. On chemical bonding and electronic structure of graphene–metal contacts. Chem Sci 2013. [DOI: 10.1039/c2sc21018e] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
|
319
|
Zhou Y, Su Q, Wang Z, Deng H, Zu X. Controlling magnetism of MoS2 sheets by embedding transition-metal atoms and applying strain. Phys Chem Chem Phys 2013; 15:18464-70. [DOI: 10.1039/c3cp52832d] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
320
|
Gopiraman M, Babu SG, Khatri Z, Wei K, Endo M, Karvembu R, Kim IS. Facile and homogeneous decoration of RuO2 nanorods on graphene nanoplatelets for transfer hydrogenation of carbonyl compounds. Catal Sci Technol 2013. [DOI: 10.1039/c3cy20735h] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
321
|
Wang XQ, Li HD, Wang JT. Prediction of a new two-dimensional metallic carbon allotrope. Phys Chem Chem Phys 2013; 15:2024-30. [DOI: 10.1039/c2cp43070c] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
322
|
Luan HX, Zhang CW, Li SS, Zhang RW, Wang PJ. First-principles study on ferromagnetism in W-doped graphene. RSC Adv 2013. [DOI: 10.1039/c3ra44672g] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
|
323
|
Zhou W, Kapetanakis MD, Prange MP, Pantelides ST, Pennycook SJ, Idrobo JC. Direct determination of the chemical bonding of individual impurities in graphene. PHYSICAL REVIEW LETTERS 2012; 109:206803. [PMID: 23215517 DOI: 10.1103/physrevlett.109.206803] [Citation(s) in RCA: 113] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2012] [Indexed: 05/08/2023]
Abstract
Using a combination of Z-contrast imaging and atomically resolved electron energy-loss spectroscopy on a scanning transmission electron microscope, we show that the chemical bonding of individual impurity atoms can be deduced experimentally. We find that when a Si atom is bonded with four atoms at a double-vacancy site in graphene, Si 3d orbitals contribute significantly to the bonding, resulting in a planar sp(2) d-like hybridization, whereas threefold coordinated Si in graphene adopts the preferred sp(3) hybridization. The conclusions are confirmed by first-principles calculations and demonstrate that chemical bonding of two-dimensional materials can now be explored at the single impurity level.
Collapse
Affiliation(s)
- Wu Zhou
- Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37235, USA.
| | | | | | | | | | | |
Collapse
|
324
|
Zhang Z, Liu X, Yakobson BI, Guo W. Two-Dimensional Tetragonal TiC Monolayer Sheet and Nanoribbons. J Am Chem Soc 2012; 134:19326-9. [DOI: 10.1021/ja308576g] [Citation(s) in RCA: 161] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Zhuhua Zhang
- State Key Laboratory of Mechanics
and Control of Mechanical Structures, Key Laboratory of Intelligent
Nano Materials and Devices of MoE and Institute of Nano Science, Nanjing University of Aeronautics and Astronautics,
Nanjing 210016, China
- Department
of Mechanical Engineering
and Materials Science, Rice University,
Houston, Texas 77005, United States
| | - Xiaofei Liu
- State Key Laboratory of Mechanics
and Control of Mechanical Structures, Key Laboratory of Intelligent
Nano Materials and Devices of MoE and Institute of Nano Science, Nanjing University of Aeronautics and Astronautics,
Nanjing 210016, China
| | - Boris I. Yakobson
- Department
of Mechanical Engineering
and Materials Science, Rice University,
Houston, Texas 77005, United States
| | - Wanlin Guo
- State Key Laboratory of Mechanics
and Control of Mechanical Structures, Key Laboratory of Intelligent
Nano Materials and Devices of MoE and Institute of Nano Science, Nanjing University of Aeronautics and Astronautics,
Nanjing 210016, China
| |
Collapse
|
325
|
Nguyen NB, García-Fuente A, Lebon A, Gallego LJ, Vega A. Electronic structure and transport properties of monatomic Fe chains in a vacuum and anchored to a graphene nanoribbon. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2012; 24:455304. [PMID: 23092846 DOI: 10.1088/0953-8984/24/45/455304] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The electronic structure and transport properties of monatomic Fe wires of different characteristics are studied within the density functional theory. In both equidistant and dimerized (more stable) isolated wires, magnetism plays an important role since it leads to different shapes of the transmission coefficients for each spin component. In equidistant wires, electron localization around the Fermi level leads to symmetry breaking between d(xy) and d(x(2)-y(2)) bands. The main effect of the structural dimerization is to decrease the number of channels available for the minority spin component. When anchored to the edges of a graphene nanoribbon, the dimerization of the chain is preserved, despite the hybridization of the d states of Fe with the C atoms which gives way to a reduction in the number of d channels around the Fermi level. Most conduction is then led by an electronic channel from the ribbon and the sp(z) bands from the Fe wires. Suggestions to improve the spintronic ability of Fe wires are proposed.
Collapse
Affiliation(s)
- N B Nguyen
- Laboratoire de Magnétisme de Bretagne, FRE CNRS 3137 Université de Bretagne Occidentale, 6 Avenue Victor Le Gorgeu, F-29285 Brest Cedex, France
| | | | | | | | | |
Collapse
|
326
|
Choi JK, Huh JH, Kim SD, Moon D, Yoon D, Joo K, Kwak J, Chu JH, Kim SY, Park K, Kim YW, Yoon E, Cheong H, Kwon SY. One-step graphene coating of heteroepitaxial GaN films. NANOTECHNOLOGY 2012; 23:435603. [PMID: 23059535 DOI: 10.1088/0957-4484/23/43/435603] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Today, state-of-the-art III-Ns technology has been focused on the growth of c-plane nitrides by metal-organic chemical vapor deposition (MOCVD) using a conventional two-step growth process. Here we show that the use of graphene as a coating layer allows the one-step growth of heteroepitaxial GaN films on sapphire in a MOCVD reactor, simplifying the GaN growth process. It is found that the graphene coating improves the wetting between GaN and sapphire, and, with as little as ~0.6 nm of graphene coating, the overgrown GaN layer on sapphire becomes continuous and flat. With increasing thickness of the graphene coating, the structural and optical properties of one-step grown GaN films gradually transition towards those of GaN films grown by a conventional two-step growth method. The InGaN/GaN multiple quantum well structure grown on a GaN/graphene/sapphire heterosystem shows a high internal quantum efficiency, allowing the use of one-step grown GaN films as 'pseudo-substrates' in optoelectronic devices. The introduction of graphene as a coating layer provides an atomic playground for metal adatoms and simplifies the III-Ns growth process, making it potentially very useful as a means to grow other heteroepitaxial films on arbitrary substrates with lattice and thermal mismatch.
Collapse
Affiliation(s)
- Jae-Kyung Choi
- School of Mechanical and Advanced Materials Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Korea
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
327
|
Wu Y, Jiang W, Ren Y, Cai W, Lee WH, Li H, Piner RD, Pope CW, Hao Y, Ji H, Kang J, Ruoff RS. Tuning the doping type and level of graphene with different gold configurations. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2012; 8:3129-3136. [PMID: 22826024 DOI: 10.1002/smll.201200520] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2012] [Revised: 06/11/2012] [Indexed: 06/01/2023]
Abstract
Au nanoparticles and films are deposited onto clean graphene surfaces to study the doping effect of different Au configurations. Micro-Raman spectra show that both the doping type and level of graphene can be tuned by fine control of the Au deposition. The morphological structures of Au on graphene are imaged by transmission electron microscopy, which indicate a size-dependent electrical characteristic: isolated Au nanoparticles produce n-type doping of graphene, while continuous Au films produce p-type doping. Accordingly, graphene field-effect transistors are fabricated, with the in situ measurements suggesting the tunable conductivity type and level by contacting with different Au configurations. For interpreting the experimental observations, the first-principles approach is used to simulate the interaction within graphene-Au systems. The results suggest that, different doping properties of Au-graphene systems are induced by the chemical interactions between graphene and the different Au configurations (isolated nanoparticle and continuous film).
Collapse
Affiliation(s)
- Yaping Wu
- Department of Physics, Xiamen University, Xiamen 361005, People's Republic of China
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
328
|
|
329
|
|
330
|
Sen FG, Qi Y, Alpas AT. Anchoring platinum on graphene using metallic adatoms: a first principles investigation. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2012; 24:225003. [PMID: 22534238 DOI: 10.1088/0953-8984/24/22/225003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
First principles calculations based on spin-polarized density functional theory were used to identify metallic adatoms that would strengthen the Pt(111)/graphene interface (with a low work of separation of 0.009 J m(-2)), when the adatom was placed between the Pt(111) and the graphene. It was shown that the strength of the Pt-adatom bond, which had a metallic character, increased with the amount of charge transferred from the adatom to the Pt. The carbon-adatom bond, on the other hand, had a mixed ionic and covalent character and was weaker than the Pt-adatom bond for each of the 25 elements considered. Consequently, the total Pt(111)/graphene interface strength and, hence, the anchoring effect of the adatom were controlled by the carbon-adatom bond strength. Metals with unfilled d orbitals increased the Pt/graphene interface strength to above 0.5 J m(-2). The carbon-adatom bond strength was proportional to the ratio between the charge transferred from the adatom to the graphene (ΔZ(C)) and the charge transferred to the Pt surface (ΔZ(Pt)); i.e., the ΔZ(C)/ΔZ(Pt) ratio defined the ability of an adatom to anchor Pt to graphene. For Ir, Os, Ru, Rh and Re, ΔZ(C)/ΔZ(Pt) > 1.0, making these elements the most effective adatoms for anchoring Pt to graphene.
Collapse
Affiliation(s)
- F G Sen
- Department of Mechanical, Automotive and Materials Engineering, University of Windsor, Windsor, ON, Canada.
| | | | | |
Collapse
|
331
|
Ramasse QM, Zan R, Bangert U, Boukhvalov DW, Son YW, Novoselov KS. Direct experimental evidence of metal-mediated etching of suspended graphene. ACS NANO 2012; 6:4063-4071. [PMID: 22533553 DOI: 10.1021/nn300452y] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Atomic resolution high angle annular dark field imaging of suspended, single-layer graphene, onto which the metals Cr, Ti, Pd, Ni, Al, and Au atoms had been deposited, was carried out in an aberration-corrected scanning transmission electron microscope. In combination with electron energy loss spectroscopy, employed to identify individual impurity atoms, it was shown that nanoscale holes were etched into graphene, initiated at sites where single atoms of all the metal species except for gold come into close contact with the graphene. The e-beam scanning process is instrumental in promoting metal atoms from clusters formed during the original metal deposition process onto the clean graphene surface, where they initiate the hole-forming process. Our observations are discussed in the light of calculations in the literature, predicting a much lowered vacancy formation in graphene when metal ad-atoms are present. The requirement and importance of oxygen atoms in this process, although not predicted by such previous calculations, is also discussed, following our observations of hole formation in pristine graphene in the presence of Si-impurity atoms, supported by new calculations which predict a dramatic decrease of the vacancy formation energy, when SiO(x) molecules are present.
Collapse
Affiliation(s)
- Quentin M Ramasse
- SuperSTEM Laboratory, STFC Daresbury Campus , Daresbury WA4 4AD, United Kingdom.
| | | | | | | | | | | |
Collapse
|
332
|
Huang B, Xiang H, Yu J, Wei SH. Effective control of the charge and magnetic states of transition-metal atoms on single-layer boron nitride. PHYSICAL REVIEW LETTERS 2012; 108:206802. [PMID: 23003164 DOI: 10.1103/physrevlett.108.206802] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2011] [Indexed: 06/01/2023]
Abstract
Developing approaches to effectively control the charge and magnetic states is critical to the use of magnetic nanostructures in quantum information devices but is still challenging. Here we suggest that the magnetic and charge states of transition-metal (TM) doped single-layer boron-nitride (SLBN) systems can be easily controlled by the (internal) defect engineering and (external) electric fields (Eext). The relative positions and symmetries of the in-gap levels induced by defect engineering and the TM d-orbital energy levels effectively determine the charge states and magnetic properties of the TM/SLBN system. Remarkably, the application of an Eext can easily control the size of the crystal field splitting of the TM d orbitals and thus, leading to the spin crossover in TM/SLBN, which could be used as Eext-driven nonvolatile memory devices. Our conclusion obtained from TM/SLBN is valid generally in other TM adsorbed layered semiconductors.
Collapse
Affiliation(s)
- Bing Huang
- National Renewable Energy Laboratory, 1617 Cole Boulevard, Golden, Colorado 80401, USA
| | | | | | | |
Collapse
|
333
|
Lisenkov S, Andriotis AN, Menon M. Magnetic anisotropy and engineering of magnetic behavior of the edges in Co embedded graphene nanoribbons. PHYSICAL REVIEW LETTERS 2012; 108:187208. [PMID: 22681116 DOI: 10.1103/physrevlett.108.187208] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2011] [Indexed: 06/01/2023]
Abstract
Using first-principles calculations, we demonstrate the existence of anisotropic ferromagnetic interactions in Co embedded graphene nanoribbons (GNRs). Spin polarization of the edge states is found to alter significantly compared to the metal-free cases. Our findings can all be well-justified as the output of the interplay between the development of an induced spin polarization in the neighborhood of the Co atoms and the maintaining of the polarization picture of the Co-free GNR. Based on our results, we propose an efficient pathway for graphene-based spintronics applications.
Collapse
Affiliation(s)
- Sergey Lisenkov
- Department of Physics, University of South Florida, Tampa, Florida 33620-5700, USA.
| | | | | |
Collapse
|
334
|
Bittencourt C, Ke X, Van Tendeloo G, Thiess S, Drube W, Ghijsen J, Ewels CP. Study of the interaction between copper and carbon nanotubes. Chem Phys Lett 2012. [DOI: 10.1016/j.cplett.2012.03.045] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
335
|
Zan R, Bangert U, Ramasse Q, Novoselov KS. Interaction of Metals with Suspended Graphene Observed by Transmission Electron Microscopy. J Phys Chem Lett 2012; 3:953-958. [PMID: 26286426 DOI: 10.1021/jz201653g] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
In this Perspective, we present an overview of how different metals interface with suspended graphene, providing a closer look into the metal-graphene interaction by employing high-resolution transmission electron microscopy, especially using high-angle dark field imaging. All studied metals favor sites on the omnipresent hydrocarbon surface contamination rather than on the clean graphene surface and present nonuniform distributions, which never result in continuous films but instead in clusters or nanocrystals, indicating a weak interaction between the metal and graphene. This behavior can be altered to some degree by surface pretreatment (hydrogenation) and high-temperature vacuum annealing. Graphene etching is observed in a scanning transmission electron microscope (STEM) under high vacuum and 60 kV electron beam acceleration voltage conditions for all metals, except for Au. This unusual metal-mediated etching sheds new light on the metal-graphene interaction; it might explain the observed higher frequency of cluster nucleation for certain transition metals and might have implications regarding controlled nanomanipulation, that is, for self-assembly and sculpturing of future graphene-based devices.
Collapse
Affiliation(s)
| | | | - Quentin Ramasse
- §SuperSTEM Laboratory, STFC Daresbury, Daresbury WA4 4AD, United Kingdom
| | | |
Collapse
|
336
|
Ma Y, Dai Y, Guo M, Niu C, Zhu Y, Huang B. Evidence of the existence of magnetism in pristine VX₂ monolayers (X = S, Se) and their strain-induced tunable magnetic properties. ACS NANO 2012; 6:1695-1701. [PMID: 22264067 DOI: 10.1021/nn204667z] [Citation(s) in RCA: 277] [Impact Index Per Article: 23.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
First-principles calculations are performed to study the electronic and magnetic properties of VX(2) monolayers (X = S, Se). Our results unveil that VX(2) monolayers exhibit exciting ferromagnetic behavior, offering evidence of the existence of magnetic behavior in pristine 2D monolayers. Furthermore, interestingly, both the magnetic moments and strength of magnetic coupling increase rapidly with increasing isotropic strain from -5% to 5% for VX(2) monolayers. It is proposed that the strain-dependent magnetic moment is related to the strong ionic-covalent bonds, while both the ferromagnetism and the variation in strength of magnetic coupling with strain arise from the combined effects of both through-bond and through-space interactions. These findings suggest a new route to facilitate the design of nanoelectronic devices for complementing graphene.
Collapse
Affiliation(s)
- Yandong Ma
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, People's Republic of China
| | | | | | | | | | | |
Collapse
|
337
|
Zoberbier T, Chamberlain TW, Biskupek J, Kuganathan N, Eyhusen S, Bichoutskaia E, Kaiser U, Khlobystov AN. Interactions and Reactions of Transition Metal Clusters with the Interior of Single-Walled Carbon Nanotubes Imaged at the Atomic Scale. J Am Chem Soc 2012; 134:3073-9. [DOI: 10.1021/ja208746z] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Thilo Zoberbier
- Group of Electron Microscopy
of Materials Science, Central Facility for Electron Microscopy, Ulm University, Albert Einstein Allee 11, Ulm 89081,
Germany
| | - Thomas W. Chamberlain
- School of Chemistry, University of Nottingham, University Park, Nottingham
NG7 2RD, United Kingdom
| | - Johannes Biskupek
- Group of Electron Microscopy
of Materials Science, Central Facility for Electron Microscopy, Ulm University, Albert Einstein Allee 11, Ulm 89081,
Germany
| | | | - Soeren Eyhusen
- Carl Zeiss NTS GmbH, Carl-Zeiss-Strasse 56, 73447 Oberkochen,
Germany
| | - Elena Bichoutskaia
- School of Chemistry, University of Nottingham, University Park, Nottingham
NG7 2RD, United Kingdom
| | - Ute Kaiser
- Group of Electron Microscopy
of Materials Science, Central Facility for Electron Microscopy, Ulm University, Albert Einstein Allee 11, Ulm 89081,
Germany
| | - Andrei N. Khlobystov
- School of Chemistry, University of Nottingham, University Park, Nottingham
NG7 2RD, United Kingdom
| |
Collapse
|
338
|
Wang H, Wang Q, Cheng Y, Li K, Yao Y, Zhang Q, Dong C, Wang P, Schwingenschlögl U, Yang W, Zhang XX. Doping monolayer graphene with single atom substitutions. NANO LETTERS 2012; 12:141-144. [PMID: 22136503 DOI: 10.1021/nl2031629] [Citation(s) in RCA: 236] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Functionalized graphene has been extensively studied with the aim of tailoring properties for gas sensors, superconductors, supercapacitors, nanoelectronics, and spintronics. A bottleneck is the capability to control the carrier type and density by doping. We demonstrate that a two-step process is an efficient way to dope graphene: create vacancies by high-energy atom/ion bombardment and fill these vacancies with desired dopants. Different elements (Pt, Co, and In) have been successfully doped in the single-atom form. The high binding energy of the metal-vacancy complex ensures its stability and is consistent with in situ observation by an aberration-corrected and monochromated transmission electron microscope.
Collapse
Affiliation(s)
- Hongtao Wang
- Institute of Applied Mechanics, Zhejiang University, Hangzhou 310027, China
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
339
|
Ao ZM, Hernández-Nieves AD, Peeters FM, Li S. The electric field as a novel switch for uptake/release of hydrogen for storage in nitrogen doped graphene. Phys Chem Chem Phys 2012; 14:1463-7. [DOI: 10.1039/c1cp23153g] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
|
340
|
Liu X, Meng C, Han Y. Unique reactivity of Fe nanoparticles–defective graphene composites toward NHx (x = 0, 1, 2, 3) adsorption: a first-principles study. Phys Chem Chem Phys 2012; 14:15036-45. [DOI: 10.1039/c2cp42141k] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
341
|
Wang XQ, Li HD, Wang JT. Structural stabilities and electronic properties of planar C4 carbon sheet and nanoribbons. Phys Chem Chem Phys 2012; 14:11107-11. [PMID: 22763793 DOI: 10.1039/c2cp41464c] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- Xin-Quan Wang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
| | | | | |
Collapse
|
342
|
Liu X, Yao KX, Meng C, Han Y. Graphene substrate-mediated catalytic performance enhancement of Runanoparticles: a first-principles study. Dalton Trans 2012; 41:1289-96. [DOI: 10.1039/c1dt11186h] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
343
|
Zhang M, Yan Z, Sun Q, Xie J, Jing J. Synthetic core–shell Ni@Pd nanoparticles supported on graphene and used as an advanced nanoelectrocatalyst for methanol oxidation. NEW J CHEM 2012. [DOI: 10.1039/c2nj40651a] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
344
|
Tang Y, Yang Z, Dai X. A theoretical simulation on the catalytic oxidation of CO on Pt/graphene. Phys Chem Chem Phys 2012; 14:16566-72. [DOI: 10.1039/c2cp41441d] [Citation(s) in RCA: 269] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
|
345
|
Tang Y, Yang Z, Dai X. Trapping of metal atoms in the defects on graphene. J Chem Phys 2011; 135:224704. [DOI: 10.1063/1.3666849] [Citation(s) in RCA: 108] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
346
|
Zan R, Bangert U, Ramasse Q, Novoselov KS. Evolution of gold nanostructures on graphene. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2011; 7:2868-2872. [PMID: 21990192 DOI: 10.1002/smll.201101169] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2011] [Indexed: 05/31/2023]
Affiliation(s)
- Recep Zan
- School of Physics and Astronomy, The University of Manchester, Manchester M13 9PL, UK
| | | | | | | |
Collapse
|
347
|
Zhou M, Lu YH, Cai YQ, Zhang C, Feng YP. Adsorption of gas molecules on transition metal embedded graphene: a search for high-performance graphene-based catalysts and gas sensors. NANOTECHNOLOGY 2011; 22:385502. [PMID: 21869463 DOI: 10.1088/0957-4484/22/38/385502] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
We report an investigation on the adsorption of small gas molecules (O(2), CO, NO(2) and NH(3)) on pristine and various transition metal embedded graphene samples using a first-principles approach based on density-functional theory (DFT). The most stable adsorption geometry, energy, charge transfer, and magnetic moment of these molecules on graphene embedded with different transition metal elements are thoroughly discussed. Our calculations found that embedded transition metal elements in general can significantly enhance the interactions between gas molecules and graphene, and for applications of graphene-based catalysis, Ti and Au may be the best choices among all transition metal elements. We also expect a detailed analysis of the electronic structures and magnetic properties of these systems to shed light on future applications of graphene-based gas sensing and spintronics.
Collapse
Affiliation(s)
- Miao Zhou
- Department of Physics, National University of Singapore, Singapore
| | | | | | | | | |
Collapse
|
348
|
Kang J, Deng HX, Li SS, Li J. First-principles study of magnetic properties in Mo-doped graphene. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2011; 23:346001. [PMID: 21841239 DOI: 10.1088/0953-8984/23/34/346001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The geometric structure, electronic structure and magnetic properties of substitutionally Mo-doped graphene are studied based on first-principles calculations. Mo introduces a magnetic moment of 2 μB in graphene. The magnetic properties and band structure can be well understood using a hybridization model. Magnetic coupling between two Mo impurities is also discussed. Depending on the relative position of the two Mo impurities, the ground state of the system can be ferromagnetic, antiferromagnetic or paramagnetic. A Ruderman-Kittel-Kasuya-Yosida (RKKY)-like behavior is observed when the distance between Mo atoms is relatively large. However, when the distance between Mo atoms is rather small, the RKKY model is not suitable to describe the magnetic ordering due to their non-neglectable direct interactions.
Collapse
Affiliation(s)
- Jun Kang
- State Key Laboratory for Superlattices and Microstructures, Institute of Semiconductors,Chinese Academy of Sciences, PO Box 912, Beijing 100083, People's Republic of China
| | | | | | | |
Collapse
|
349
|
Plachinda P, Evans DR, Solanki R. Electronic properties of metal-arene functionalized graphene. J Chem Phys 2011; 135:044103. [DOI: 10.1063/1.3613649] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
350
|
Berseneva N, Krasheninnikov AV, Nieminen RM. Mechanisms of postsynthesis doping of boron nitride nanostructures with carbon from first-principles simulations. PHYSICAL REVIEW LETTERS 2011; 107:035501. [PMID: 21838374 DOI: 10.1103/physrevlett.107.035501] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2011] [Revised: 05/02/2011] [Indexed: 05/31/2023]
Abstract
Electron-beam-mediated postsynthesis doping of boron-nitride nanostructures with carbon atoms [Nature (London) 464, 571 (2010); J. Am. Chem. Soc. 132, 13 692 (2010)] was recently demonstrated, thus opening a new way to control the electronic properties of these systems. Using density-functional theory static and dynamic calculations, we show that the substitution process is governed not only by the response of such systems to irradiation, but also by the energetics of the atomic configurations, especially when the system is electrically charged. We suggest using spatially localized electron irradiation for making carbon islands and ribbons embedded into BN sheets. We further study the magnetic and electronic properties of such hybrid nanostructures and show that triangular carbon islands embedded into BN sheets possess magnetic moments, which can be switched on and off by electrically charging the structure.
Collapse
Affiliation(s)
- Natalia Berseneva
- Department of Applied Physics, Post Office Box 1100, FI-00076 Aalto University, Finland
| | | | | |
Collapse
|