Intermolecular bridges and carrier traps in defective C<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msub><mml:mrow /><mml:mn>60</mml:mn></mml:msub></mml:math>crystals

Tsetseris, Leonidas; Pantelides, Sokrates T.

doi:10.1103/physrevb.84.195202

Cited by 18 publications

(19 citation statements)

References 62 publications

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“…The structures of the fullerene before and after the migration event shown in Figure S2 of Supplementary Information are indicated. correspond to the barriers of hopping of the same sp atom in the odd C61 fullerene between the 5-6 and 6-6 positions 73 . Such a hopping, which is another possible way to switch the position of the sp atom relative to the sp 2 structure of the corresponding even fullerene (in addition to the sp-defect migration), has not been observed in our MD simulations.…”

Section: Iiib Dft Study Of Sp-defect Migration Energeticsmentioning

confidence: 99%

Molecular Dynamics Study of sp-Defect Migration in Odd Fullerene: Possible Role in Synthesis of Abundant Isomers of Fullerenes

et al. 2020

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To explain recent experiment showing the role of odd fullerenes in formation of abundant fullerene isomers a reactive molecular dynamics (MD) study has been performed. Three types of bond rearrangement reactions are found by MD simulations at 3000 K in odd fullerenes which contain an extra sp atom among all other sp 2 atoms. The first type is stochastic sp-defect migration analogous to exchange mechanism of adatom migration on a surface. The second type corresponds to changes in the ring configuration of the sp 2-structure assisted by the sp atom which can lead to annealing of seven-membered rings or separation of five-membered rings. The third type is formation of short-living one-coordinated atoms or two additional sp atoms. Annihilation of a pair of sp defects has been also observed in the MD simulations. It is shown that the frequency of sp-defect migration at a lower temperature, as estimated from performed density functional theory calculations of the barriers of sp-defect migration events, is sufficient to deliver the sp atom to defects of sp 2 structure during the fullerene formation time. Based on these results, we propose to supplement the self-organization paradigm of fullerene formation by the following four-stage atomistic mechanism of formation of abundant isomers of fullerenes: 1) attachment of single carbon atoms, 2) sp-defect migration to sp 2-structure defects, 3) sp 2-defect annealing assisted by the sp atom and 4) subsequent annihilation of pairs of sp defects. I.

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Section: Iiib Dft Study Of Sp-defect Migration Energeticsmentioning

confidence: 99%

Molecular Dynamics Study of sp-Defect Migration in Odd Fullerene: Possible Role in Synthesis of Abundant Isomers of Fullerenes

et al. 2020

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“…However, this is based on assumptions which, it has been seen here, are not necessarily correct. Moreover, although corrections to GGAs have a significant effect on the weak interatomic forces responsible for the interlayer binding of graphite, this is small in comparison with the strength of bonds between atoms in defects and their host [98,99]. An equally practical approach to this problem is to accept that the LDA provides a better description of interlayer binding in graphite than GGAs.…”

Section: Interlayer Bondingmentioning

confidence: 99%

The contribution made by lattice vacancies to the Wigner effect in radiation-damaged graphite

Latham

Heggie

Alatalo

et al. 2013

J. Phys.: Condens. Matter

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Models for radiation damage in graphite are reviewed and compared, leading to a re-examination of the contribution made by vacancies to annealing processes. A method based on density functional theory, using large supercells with orthorhombic and hexagonal symmetry, is employed to calculate properties and behaviour of lattice vacancies and displacement defects. It is concluded that annihilation of intimate Frenkel defects marks the onset of recovery in electrical resistivity, which occurs when the temperature exceeds about 160 K. Migration of isolated monovacancies is estimated to have an activation energy of E a ≈ 1.1 eV. Coalescence into divacancy defects occurs in several stages, with different barriers at each stage, depending on the path. The formation of pairs ultimately yields up to 8.9 eV energy, which is nearly 1.0 eV more than the formation energy for an isolated monovacancy. Processes resulting in vacancy coalescence and annihilation appear to be responsible for the main Wigner energy release peak in radiation-damaged graphite, occurring at about 475 K.

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“…32 Later density functional theory (DFT) calculations identified the [6,5] bridge as the most stable favored by 0.3 eV. 33 Our own DFT calculations with results summarized in Table 1S in the Supporting Information agree with this latter stability order; we found that the [6,5] bond is slightly preferred to the [6,6] bond with a bond energy D e (dissociation energy of the carbon adatom) of 2.82 eV on the [6,5] bond. This compares with 3.52 eV for the cation and 3.39 eV for the anion.…”

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confidence: 99%

Building Carbon Bridges on and between Fullerenes in Helium Nanodroplets

Krasnokutski

Kühn

Kaiser

et al. 2016

J. Phys. Chem. Lett.

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We report the observation of sequential encounters of fullerenes with C atoms in an extremely cold environment. Experiments were performed with helium droplets at 0.37 K doped with C60 molecules and C atoms derived from a novel, pure source of C atoms. Very high-resolution mass spectra revealed the formation of carbenes of the type C60(C:)n with n up to 6. Bridge-type bonding of the C adatoms to form the known dumbbell C60=C=C60 also was observed. Density functional theory calculations were performed that elucidated the carbene character of the C60(C:)n species and their structures. Mass spectra taken in the presence of water impurities and in separate experiments with added H2 also revealed the formation of the adducts C60Cn(H2O)n and C60Cn(H2)n probably by H–OH and H–H bond insertion, respectively, and nonreactivity for the dumbell. So C adatoms that form carbenes C60(C:)n can endow pristine C60 with a higher chemical reactivity.

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Intermolecular bridges and carrier traps in defective C60crystals

Cited by 18 publications

References 62 publications

Molecular Dynamics Study of sp-Defect Migration in Odd Fullerene: Possible Role in Synthesis of Abundant Isomers of Fullerenes

Molecular Dynamics Study of sp-Defect Migration in Odd Fullerene: Possible Role in Synthesis of Abundant Isomers of Fullerenes

The contribution made by lattice vacancies to the Wigner effect in radiation-damaged graphite

Building Carbon Bridges on and between Fullerenes in Helium Nanodroplets

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