An EELS study of fullerite — C60/C70

Hansen, P.L.; Fallon, P.; Krätschmer, Wolfgang

doi:10.1016/0009-2614(91)80086-d

Cited by 98 publications

(28 citation statements)

References 18 publications

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“…Raman spectra of the films revealed all the expected peaks due to C 60 , 7,8 with no evidence of peaks due to amorphous carbon or other fullerenes. For comparison to well ordered graphite, samples of freshly cleaved highly oriented pyrolytic graphite ͑HOPG͒ were also analyzed.…”

Section: Methodsmentioning

confidence: 95%

Ion-beam-induced modification of fullerene films as studied by electron-energy-loss spectroscopy

et al. 1996

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The ion-beam ͑2 keV Ar͒ -induced amorphization of thin fullerene films has been studied by in situ electron-energy-loss spectroscopy ͑EELS͒. With due care to the electron-beam current, the EELS spectrum may be measured without degradation during the electron bombardment to provide an EELS fingerprint of C 60 films. The diminution of the intensity of characteristic peaks in the EELS spectrum upon ion impact was used to deduce a cross section for the destruction of the C 60 molecules of ͑0.85Ϯ0.2͒ϫ10 Ϫ14 cm 2 . This value corresponds closely to the geometric size of one C 60 molecule, suggesting that each incident Ar ion destroys one C 60 molecule upon ion impact. This cross section is somewhat smaller than that expected using scaling arguments from the results of more energetic ion bombardment ͑100-300 keV͒. The difference may be due to surface processes, which become important for low-energy ion-beam irradiation.

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Section: Methodsmentioning

confidence: 95%

Ion-beam-induced modification of fullerene films as studied by electron-energy-loss spectroscopy

et al. 1996

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“…If a margin of about 10% is acceptable, this shows that PDI, only requiring QM calculations on single solute and solvent molecules, does pretty well. [65,[77][78][79], and with the results the PDI model [30]. The local field factors presented in Table II needed to evaluate the third-order nonlinear susceptibilities came from the frequency-dependent refractive index, using Eq.…”

Section: Microscopic Propertiesmentioning

confidence: 99%

Refractive index and third‐order nonlinear susceptibility of C₆₀ in the condensed phase calculated with the discrete solvent reaction field model

Jensen

Duijnen

2005

Int J of Quantum Chemistry

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ABSTRACT:We have calculated the frequency-dependent refractive index and the third-order nonlinear susceptibility for C 60 in the condensed phase, which is related to third-harmonic generation (THG) and degenerate four-wave mixing (DFWM) experiments. This was done using the recently developed discrete solvent reaction field (DRF) model, which combines a time-dependent density functional theory (TD-DFT) description of the central C 60 molecule with a classical polarizable MM model for the rest of the fullerene cluster. Using this model, effective microscopic properties can be calculated that, combined with calculated local field factors, give macroscopic susceptibilities. The largest calculation was for a cluster of 63 C 60 molecules in which the central molecule was treated with TD-DFT. For this molecule, the effective polarizability was increased with about 15% and the effective second hyperpolarizability with about 60% compared with the gas phase. The calculated refractive index was found to be in good agreement with experiments and other theoretical results. The agreement with THG experiments was within a factor of two, whereas for DFWM the agreement was less good due to the neglect of vibrational contributions in the calculations. It was found that it is more important to account for the dispersion in the third-order susceptibilities than in the corresponding second hyperpolarizability.

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“…Response properties of the fullerenes C 60 and C 70 have also been studied in quite some detail experimentally. 32,25,[33][34][35][36][37][38][39][40] However, only a few experimental studies of optical response properties of C-NTs have been reported. 20,21 The symmetry of carbon nanotubes has great influence on the (hyper)polarizability leading to larger values for armchair than for zigzag tubes with an equal number of atoms.…”

Section: Introductionmentioning

confidence: 99%

Frequency-Dependent Polarizability of Boron Nitride Nanotubes: A Theoretical Study

et al. 2001

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In the present work, we have calculated the static and frequency-dependent polarizability tensors for a series of single-walled boron nitride nanotubes and compared them with corresponding results for carbon nanotubes. The calculations have been performed by employing a dipole-dipole interaction model based on classical electrostatics and an Unsöld dispersion formula. In comparison, we have carried out ab intio calculations at the SCF level of the static polarizability of the smaller nanotubes with the STO-3G basis set. For the frequencydependent polarizability of C 60 , we found excellent agreement among the most accurate SCF calculations in the literature, the interaction model, and experimental results. In particular, the frequency dependence is modeled accurately indicating that the interaction model is a useful tool for studying the frequency dependence of materials. For the nanotubes, we observe the same trends in the interaction model and in the SCF STO-3G results when the number of atoms is increased. However, the values obtained with the interaction model are about 100% larger than the corresponding SCF STO-3G results, due to the small size of the STO-3G basis set. We also find that the boron nitride nanotubes have smaller magnitudes of the polarizability tensor components than the corresponding components for the carbon nanotubes with the same geometry and number of atoms. Furthermore, we find that the geometry of the tube has a large influence on the anisotropy of the polarizability components, whereas the mean polarizability remains almost unaffected when the geometrical configuration is modified. Finally, we observe a relatively small frequency dependence of the polarizability tensor of BN nanotubes.

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An EELS study of fullerite — C60/C70

Cited by 98 publications

References 18 publications

Ion-beam-induced modification of fullerene films as studied by electron-energy-loss spectroscopy

Ion-beam-induced modification of fullerene films as studied by electron-energy-loss spectroscopy

Refractive index and third‐order nonlinear susceptibility of C₆₀ in the condensed phase calculated with the discrete solvent reaction field model

Frequency-Dependent Polarizability of Boron Nitride Nanotubes: A Theoretical Study

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An EELS study of fullerite — C60/C70

Cited by 98 publications

References 18 publications

Ion-beam-induced modification of fullerene films as studied by electron-energy-loss spectroscopy

Ion-beam-induced modification of fullerene films as studied by electron-energy-loss spectroscopy

Refractive index and third‐order nonlinear susceptibility of C60 in the condensed phase calculated with the discrete solvent reaction field model

Frequency-Dependent Polarizability of Boron Nitride Nanotubes: A Theoretical Study

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Refractive index and third‐order nonlinear susceptibility of C₆₀ in the condensed phase calculated with the discrete solvent reaction field model