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Arshad M, Sorba L, Rudolf P, Cepek C. Growth and Characterization of Carbon Nanofibers Grown on Vertically Aligned InAs Nanowires via Chemical Vapour Deposition. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:3083. [PMID: 38132981 PMCID: PMC10746074 DOI: 10.3390/nano13243083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 11/24/2023] [Accepted: 11/27/2023] [Indexed: 12/23/2023]
Abstract
The integration of carbon nanostructures with semiconductor nanowires holds significant potential for energy-efficient integrated circuits. However, achieving precise control over the positioning and stability of these interconnections poses a major challenge. This study presents a method for the controlled growth of carbon nanofibers (CNFs) on vertically aligned indium arsenide (InAs) nanowires. The CNF/InAs hybrid structures, synthesized using chemical vapor deposition (CVD), were successfully produced without compromising the morphology of the pristine nanowires. Under optimized conditions, preferential growth of the carbon nanofibers in the direction perpendicular to the InAs nanowires was observed. Moreover, when the CVD process employed iron as a catalyst, an increased growth rate was achieved. With and without the presence of iron, carbon nanofibers nucleate preferentially on the top of the InAs nanowires, indicating a tip growth mechanism presumably catalysed by a gold-indium alloy that selectively forms in that region. These results represent a compelling example of controlled interconnections between adjacent InAs nanowires formed by carbon fibers.
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Affiliation(s)
- Muhammad Arshad
- Istituto Officina dei Materiali—CNR, Laboratorio TASC Area Science Park—Basovizza, Edificio MM, Strada Statale 14, Km.163.5, I-34149 Trieste, Italy;
- Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, NL-9747AG Groningen, The Netherlands;
- Nanosciences and Technology Department, National Center for Physics, Quaid-i-Azam University Campus, Islamabad 2141, Pakistan
| | - Lucia Sorba
- NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore, Piazza S. Silvestro 12, I-56127 Pisa, Italy;
| | - Petra Rudolf
- Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, NL-9747AG Groningen, The Netherlands;
| | - Cinzia Cepek
- Istituto Officina dei Materiali—CNR, Laboratorio TASC Area Science Park—Basovizza, Edificio MM, Strada Statale 14, Km.163.5, I-34149 Trieste, Italy;
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2
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Wang G, Glazov MM, Robert C, Amand T, Marie X, Urbaszek B. Double resonant Raman scattering and valley coherence generation in monolayer WSe_{2}. PHYSICAL REVIEW LETTERS 2015; 115:117401. [PMID: 26406852 DOI: 10.1103/physrevlett.115.117401] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Indexed: 06/05/2023]
Abstract
The electronic states at the direct band gap of monolayer transition metal dichalcogenides such as WSe_{2} at the K^{+} and K^{-} valleys are related by time reversal and may be viewed as pseudospins. The corresponding optical interband transitions are governed by robust excitons. Excitation with linearly polarized light yields the coherent superposition of exciton pseudospin states, referred to as coherent valley states. Here, we uncover how and why valley coherence can be generated efficiently. In double resonant Raman spectroscopy, we show that the optically generated 2s exciton state differs from the 1s state by exactly the energy of the combination of several prominent phonons. Superimposed on the exciton photoluminescence (PL), we observe the double resonant Raman signal. This spectrally narrow peak shifts with the excitation laser energy as incoming photons match the 2s and outgoing photons the 1s exciton transition. The multiphonon resonance has important consequences: following linearly polarized excitation of the 2s exciton, a superposition of valley states is efficiently transferred from the 2s to 1s state. This explains the high degree of valley coherence measured for the 1s exciton PL.
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Affiliation(s)
- G Wang
- Université de Toulouse, INSA-CNRS-UPS, LPCNO, 135 avenue de Rangueil, 31077 Toulouse, France
| | - M M Glazov
- Université de Toulouse, INSA-CNRS-UPS, LPCNO, 135 avenue de Rangueil, 31077 Toulouse, France
- Ioffe Institute, 26 Polytechnicheskaya, 194021 St.-Petersburg, Russia
| | - C Robert
- Université de Toulouse, INSA-CNRS-UPS, LPCNO, 135 avenue de Rangueil, 31077 Toulouse, France
| | - T Amand
- Université de Toulouse, INSA-CNRS-UPS, LPCNO, 135 avenue de Rangueil, 31077 Toulouse, France
| | - X Marie
- Université de Toulouse, INSA-CNRS-UPS, LPCNO, 135 avenue de Rangueil, 31077 Toulouse, France
| | - B Urbaszek
- Université de Toulouse, INSA-CNRS-UPS, LPCNO, 135 avenue de Rangueil, 31077 Toulouse, France
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Peica N, Thomsen C, Maultzsch J. Studying the local character of Raman features of single-walled carbon nanotubes along a bundle using TERS. NANOSCALE RESEARCH LETTERS 2011; 6:174. [PMID: 21711681 PMCID: PMC3211227 DOI: 10.1186/1556-276x-6-174] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2010] [Accepted: 02/25/2011] [Indexed: 05/26/2023]
Abstract
Here, we show that the Raman intensity of the G-mode in tip-enhanced Raman spectroscopy (TERS) is strongly dependent on the height of the bundle. Moreover, using TERS we are able to position different single-walled carbon nanotubes along a bundle, by correlating the observed radial breathing mode (RBM) with the AFM topography at the measuring point. The frequency of the G- mode behaves differently in TERS as compared to far-field Raman. Using the RBM frequency, the diameters of the tubes were calculated and a very good agreement with the G--mode frequency was observed.
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Affiliation(s)
- Niculina Peica
- Institut für Festkörperphysik, Technische Universität Berlin, Hardenbergstr. 36, 10623 Berlin, Germany
| | - Christian Thomsen
- Institut für Festkörperphysik, Technische Universität Berlin, Hardenbergstr. 36, 10623 Berlin, Germany
| | - Janina Maultzsch
- Institut für Festkörperphysik, Technische Universität Berlin, Hardenbergstr. 36, 10623 Berlin, Germany
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Dresselhaus MS, Jorio A, Souza Filho AG, Saito R. Defect characterization in graphene and carbon nanotubes using Raman spectroscopy. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2010; 368:5355-77. [PMID: 21041218 DOI: 10.1098/rsta.2010.0213] [Citation(s) in RCA: 145] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
This review discusses advances that have been made in the study of defect-induced double-resonance processes in nanographite, graphene and carbon nanotubes, mostly coming from combining Raman spectroscopic experiments with microscopy studies and from the development of new theoretical models. The disorder-induced peak frequencies and intensities are discussed, with particular emphasis given to how the disorder-induced features evolve with increasing amounts of disorder. We address here two systems, ion-bombarded graphene and nanographite, where disorder is represented by point defects and boundaries, respectively. Raman spectroscopy is used to study the 'atomic structure' of the defect, making it possible, for example, to distinguish between zigzag and armchair edges, based on selection rules of phonon scattering. Finally, a different concept is discussed, involving the effect that defects have on the lineshape of Raman-allowed peaks, owing to local electron and phonon energy renormalization. Such effects can be observed by near-field optical measurements on the G' feature for doped single-walled carbon nanotubes.
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Affiliation(s)
- M S Dresselhaus
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139-4307, USA.
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Kalbac M, Hsieh YP, Farhat H, Kavan L, Hofmann M, Kong J, Dresselhaus MS. Defects in individual semiconducting single wall carbon nanotubes: Raman spectroscopic and in situ Raman spectroelectrochemical study. NANO LETTERS 2010; 10:4619-4626. [PMID: 20939607 DOI: 10.1021/nl102727f] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Raman spectroscopy and in situ Raman spectroelectrochemistry have been used to study the influence of defects on the Raman spectra of semiconducting individual single-walled carbon nanotubes (SWCNTs). The defects were created intentionally on part of an originally defect-free individual semiconducting nanotube, which allowed us to analyze how defects influence this particular nanotube. The formation of defects was followed by Raman spectroscopy that showed D band intensity coming from the defective part and no D band intensity coming from the original part of the same nanotube. It is shown that the presence of defects also reduces the intensity of the symmetry-allowed Raman features. Furthermore, the changes to the Raman resonance window upon the introduction of defects are analyzed. It is demonstrated that defects lead to both a broadening of the Raman resonance profile and a decrease in the maximum intensity of the resonance profile. The in situ Raman spectroelectrochemical data show a doping dependence of the Raman features taken from the defective part of the tested SWCNT.
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Affiliation(s)
- Martin Kalbac
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States.
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Mu M, Osswald S, Gogotsi Y, Winey KI. An in situ Raman spectroscopy study of stress transfer between carbon nanotubes and polymer. NANOTECHNOLOGY 2009; 20:335703. [PMID: 19636105 DOI: 10.1088/0957-4484/20/33/335703] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
The transfer mechanism of applied stress in single-wall carbon nanotube (SWCNT)/poly(methyl methacrylate) (PMMA) nanocomposites was investigated using in situ Raman spectroscopy on composite fibers. These SWCNT/PMMA nanocomposite fibers have no specific SWCNT-polymer interactions and the high degree of nanotube alignment minimizes the contributions from nanotube-nanotube interactions. Although tensile testing found significantly improved overall mechanical properties of the fibers, effective stress transfer to SWCNTs is limited to a small strain regime (epsilon<0.2%). At higher strains, the stress on the SWCNTs decreases due to the slippage at the nanotube-polymer interface. Slippage was also evident in scanning electron micrographs of fracture surfaces produced by tensile testing of the composite fibers. Above epsilon = 0.2%, the strain-induced slippage was accompanied by irreversible responses in stress and Raman peak shifts. This paper shows that efficient stress transfer to nanotubes as monitored by Raman spectroscopy is crucial to improving the mechanical properties of polymer nanocomposites and to detecting internal damage in nanocomposites.
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Affiliation(s)
- Minfang Mu
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA 19104-6272, USA
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Dong X, Shi Y, Zhao Y, Chen D, Ye J, Yao Y, Gao F, Ni Z, Yu T, Shen Z, Huang Y, Chen P, Li LJ. Symmetry breaking of graphene monolayers by molecular decoration. PHYSICAL REVIEW LETTERS 2009; 102:135501. [PMID: 19392367 DOI: 10.1103/physrevlett.102.135501] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2008] [Indexed: 05/22/2023]
Abstract
Aromatic molecules can effectively exfoliate graphite into graphene monolayers, and the resulting graphene monolayers sandwiched by the aromatic molecules exhibit a pronounced Raman G-band splitting, similar to that observed in single-walled carbon nanotubes. Raman measurements and calculations based on the force-constant model demonstrate that the absorbed aromatic molecules are responsible for the G-band splitting by removing the energy degeneracy of in-plane longitudinal and transverse optical phonons at the Gamma point.
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Affiliation(s)
- Xiaochen Dong
- School of Materials Science and Engineering, Nanyang Technological University, Singapore
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Fouquet M, Telg H, Maultzsch J, Wu Y, Chandra B, Hone J, Heinz TF, Thomsen C. Longitudinal optical phonons in metallic and semiconducting carbon nanotubes. PHYSICAL REVIEW LETTERS 2009; 102:075501. [PMID: 19257684 DOI: 10.1103/physrevlett.102.075501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2008] [Indexed: 05/06/2023]
Abstract
We analyze the high-energy Raman modes, G+ and G-, in a pair of one metallic and one semiconducting nanotubes. By combining Rayleigh scattering with Raman resonance profiles of the radial breathing mode and the high-energy modes, we show that the observed G- and G+ peaks can originate from longitudinal optical phonons of different tubes. The G- peak is the longitudinal mode of the metallic tube; it is broadened and downshifted due to strong electron-phonon coupling in the metallic nanotube. The G+ peak is due to the longitudinal mode in the semiconducting tube. This result resolves an ongoing debate in the literature.
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Affiliation(s)
- Martin Fouquet
- Institut für Festkörperphysik, Technische Universität Berlin, Hardenbergstrasse 36, 10623 Berlin, Germany
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Wu Y, Maultzsch J, Knoesel E, Chandra B, Huang M, Sfeir MY, Brus LE, Hone J, Heinz TF. Variable electron-phonon coupling in isolated metallic carbon nanotubes observed by Raman scattering. PHYSICAL REVIEW LETTERS 2007; 99:027402. [PMID: 17678258 DOI: 10.1103/physrevlett.99.027402] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2007] [Indexed: 05/16/2023]
Abstract
We report the existence of broad and weakly asymmetric features in the high-energy (G) Raman modes of freely suspended metallic carbon nanotubes of defined chiral index. A significant variation in peak width (from 12 cm(-1) to 110 cm(-1)) is observed as a function of the nanotube's chiral structure. When the nanotubes are electrostatically gated, the peak widths decrease. The broadness of the Raman features is understood as the consequence of coupling of the phonon to electron-hole pairs, the strength of which varies with the nanotube chiral index and the position of the Fermi energy.
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Affiliation(s)
- Yang Wu
- Department of Physics, Columbia University, New York, New York 10027, USA
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10
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Nguyen KT, Gaur A, Shim M. Fano lineshape and phonon softening in single isolated metallic carbon nanotubes. PHYSICAL REVIEW LETTERS 2007; 98:145504. [PMID: 17501287 DOI: 10.1103/physrevlett.98.145504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2006] [Indexed: 05/06/2023]
Abstract
Evolution of G-band modes of single metallic carbon nanotubes with the Fermi level shift is examined by simultaneous Raman and electron transport studies. Narrow Lorentzian line shape and upshifted frequencies are observed near the van Hove singularities. However, all G modes soften and broaden at the band crossing point. The concurrent appearance of an asymmetric Fano line shape at this point indicates that phonon-continuum coupling is intrinsic to single metallic tubes. The apparent Lorentzian line shapes of as-synthesized metallic tubes are induced by O2 adsorption causing the Fermi level shift.
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Affiliation(s)
- Khoi T Nguyen
- Department of Materials Science and Engineering and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
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11
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Gupta A, Chen G, Joshi P, Tadigadapa S, Eklund PC. Raman scattering from high-frequency phonons in supported n-graphene layer films. NANO LETTERS 2006; 6:2667-73. [PMID: 17163685 DOI: 10.1021/nl061420a] [Citation(s) in RCA: 302] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Results of room-temperature Raman scattering studies of ultrathin graphitic films supported on Si (100)/SiO2 substrates are reported. The results are significantly different from those known for graphite. Spectra were collected using 514.5 nm radiation on films containing from n = 1 to 20 graphene layers, as determined by atomic force microscopy. Both the first- and second-order Raman spectra show unique signatures of the number of layers in the film. The nGL film analogue of the Raman G-band in graphite exhibits a Lorentzian line shape whose center frequency shifts linearly relative to graphite as approximately 1/n (for n = 1 omegaG approximately 1587 cm-1). Three weak bands, identified with disorder-induced first-order scattering, are observed at approximately 1350, 1450, and 1500 cm-1. The approximately 1500 cm-1 band is weak but relatively sharp and exhibits an interesting n-dependence. In general, the intensity of these D-bands decreases dramatically with increasing n. Three second-order bands are also observed (approximately 2450, approximately 2700, and 3248 cm-1). They are analogues to those observed in graphite. However, the approximately 2700 cm-1 band exhibits an interesting and dramatic change of shape with n. Interestingly, for n < 5 this second-order band is more intense than the G-band.
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Affiliation(s)
- A Gupta
- Department of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
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12
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Oron-Carl M, Hennrich F, Kappes MM, Löhneysen HV, Krupke R. On the electron-phonon coupling of individual single-walled carbon nanotubes. NANO LETTERS 2005; 5:1761-7. [PMID: 16159220 DOI: 10.1021/nl051107t] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
We show that the phonon coupling to the electronic system in individual metallic single-walled carbon nanotubes is not due to coupling to low-energy plasmons. The evidence stems from the measured Raman-Stokes G-mode, which for metallic and semiconducting tubes could be fitted well by the superposition of only two Lorentzian lines associated with vibrational modes along the nanotube axis and the nanotube circumference. In the case of metallic tubes the lower-energy G mode is significantly broadened, however maintaining the Lorentzian line shape, in contrast to the theoretically expected asymmetric Breit-Wigner-Fano line shape from phonon-plasmon coupling. The results were obtained by studying 25 individual metallic and semiconducting single-walled carbon nanotubes with atomic force microscopy, electron transport measurements, and resonant Raman spectroscopy.
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Affiliation(s)
- Matti Oron-Carl
- Institut für Physikalische Chemie, Universität Karlsruhe, D-76128 Karlsruhe, Germany
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Paillet M, Poncharal P, Zahab A, Sauvajol JL, Meyer JC, Roth S. Vanishing of the Breit-Wigner-Fano component in individual single-wall carbon nanotubes. PHYSICAL REVIEW LETTERS 2005; 94:237401. [PMID: 16090500 DOI: 10.1103/physrevlett.94.237401] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2004] [Indexed: 05/03/2023]
Abstract
In order to decide definitely on the dependence of the intensity of the Breit-Wigner-Fano (BWF) component with the size of the bundle, we have measured the radial breathing modes and tangential modes (TMs) of well defined metallic individual single-wall carbon nanotubes (SWCNTs) and individual SWCNT bundles. In this aim, a complete procedure including the preparation of the substrates, the sample preparation, atomic-force-microscopy imaging and Raman spectroscopy has been developed. From this procedure, we show unambiguously that the BWF component vanishes in isolated metallic SWCNTs. In other words, the observation of a BWF component in the TM bunch is an intrinsic feature of the metallic SWCNT bundle.
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Affiliation(s)
- M Paillet
- Groupe de Dynamique des Phases Condensées, UMR CNRS 5581, Université Montpellier II, 34095 Montpellier Cedex 5, France
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Reich S, Thomsen C. Raman spectroscopy of graphite. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2004; 362:2271-88. [PMID: 15482979 DOI: 10.1098/rsta.2004.1454] [Citation(s) in RCA: 306] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
We present a review of the Raman spectra of graphite from an experimental and theoretical point of view. The disorder-induced Raman bands in this material have been a puzzling Raman problem for almost 30 years. Double-resonant Raman scattering explains their origin as well as the excitation-energy dependence, the overtone spectrum and the difference between Stokes and anti-Stokes scattering. We develop the symmetry-imposed selection rules for double-resonant Raman scattering in graphite and point out misassignments in previously published works. An excellent agreement is found between the graphite phonon dispersion from double-resonant Raman scattering and other experimental methods.
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Affiliation(s)
- Stephanie Reich
- Department of Engineering, University of Cambridge, Trumpington Street, Cambridge CB2 1PZ, UK.
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Thomsen C, Reich S, Maultzsch J. Resonant Raman spectroscopy of nanotubes. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2004; 362:2337-2359. [PMID: 15482982 DOI: 10.1098/rsta.2004.1444] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Single and double resonances in Raman scattering are introduced and six criteria for the observation and identification of double resonances stated. The experimental situation in carbon nanotubes is reviewed in view of these criteria. The evidence for the D mode and the high-energy mode is found to be overwhelming for a double-resonance process to take place, whereas the nature of the radial breathing-mode Raman process remains undecided at this point. Consequences for the application of Raman scattering to the characterization of nanotubes are discussed.
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Affiliation(s)
- Christian Thomsen
- Technische Universität Berlin, Hardenbergstrasse 36, 10623 Berlin, Germany
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Maultzsch J, Reich S, Thomsen C, Requardt H, Ordejón P. Phonon dispersion in graphite. PHYSICAL REVIEW LETTERS 2004; 92:075501. [PMID: 14995866 DOI: 10.1103/physrevlett.92.075501] [Citation(s) in RCA: 110] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2003] [Indexed: 05/24/2023]
Abstract
We measured the dispersion of the graphite optical phonons in the in-plane Brillouin zone by inelastic x-ray scattering. The longitudinal and transverse optical branches cross along the Gamma-K as well as the Gamma-M direction. The dispersion of the optical phonons was, in general, stronger than expected from the literature. At the K point the transverse optical mode has a minimum and is only approximately 70 cm(-1) higher in frequency than the longitudinal mode. We show that first-principles calculations describe very well the vibrational properties of graphene once the long-range character of the dynamical matrix is taken into account.
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Affiliation(s)
- J Maultzsch
- Institut für Festkörperphysik, Technische Universität Berlin, Hardenbergstrasse 36, 10623 Berlin, Germany
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