Simulation of the thermal fragmentation of fullerene C60

Abstract

The processes of defect formation and annealing in fullerene C 60 at T = (4000 -6000) K are studied by the molecular dynamics technique with a tight-binding potential. The cluster lifetime until fragmentation due to the loss of a C 2 dimer has been calculated as a function of temperature. The activation energy and the frequency factor in the Arrhenius equation for the fragmentation rate have been found to be E a = (9.2 ± 0.4) eV and A = (8 ± 1) · 10 19 s −1 .It is shown that fragmentation can occur after the C 60 cluster loses its spherical shape. This fact must be taken into account in theoretical calculations of E a .

Nonorthogonal tight-binding model for hydrocarbons

“…Next we calculated the coagulation energy 20 in the open-[2 + 2] isomer of a cluster molecule (C 20 ) 2 [42]. We found E = 4.9 eV.…”

“…In particular, previously we made use of a model [14] to study the thermal stability of fullerenes C 20 and C 60 , one-dimensional chains and two-dimensional complexes of fullerenes C 20 , etc. [18][19][20][21][22][23][24][25].…”

“…One should keep in mind, however, that making use of ab initio approaches do not guarantee, by itself, the reliable results since those approaches are sometimes extremely sensitive to the type of exchange-correlation potential, the set of the basis functions, the cutoff energy, etc. (for example, different modifications of DFT disagree on the most stable C 20 isomer, see references in [12]). Besides, the first principle calculations are computer-time consuming and put severe restrictions on the size of the system and/or the real-time interval during which the system evolution can be followed (usually ∼ 1-10 ps).…”

Metastable dissociative decay of fluorofullerene negative ions

“…The results of this investigation extend knowledge of the properties of fullerenes and their derivatives, consistently being inscribed into a set of previously reported phenomena of delayed fragmentation of C 60 − NI generated by electron capture [48], and by collisions with atoms [49], a similar observations for positive ions C 60 + [50,51], thermal fragmentation of neutral fullerene molecules (see in Ref. [52]) and the whole family of other phenomena caused by the statistical nature (delayed ionization of molecules [53], collective plasmon excitations [19,20], long lifetimes a of NI [8,23], etc.). Data on the behavior of fluorofullerene molecules in a collision with low-energy electrons, obtained in model gas-phase conditions, apart from analytic applications, may be of interest in the development of organic and molecular electronics devices, in particular in the choice of materials and doping agents.…”

Simulation of the structure and stability of С20 fullerene-based polymers

“…Various energy and structure characteristics of the С 60 and С 20 clusters obtained by this method are in good agreement with experimental data and first-principle calculations (see for details Refs. [5] and [6]). …”