Numerical simulation of the thermal fragmentation process in fullerene C60

TL;DR

This study uses molecular dynamics simulations to analyze the thermal fragmentation of fullerene C60 at high temperatures, calculating key kinetic parameters and revealing shape changes before fragmentation.

Contribution

It provides new insights into the fragmentation process of C60, including the activation energy, frequency factor, and the importance of shape deformation prior to breakup.

Findings

Fragmentation occurs after loss of a C2 dimer.

Activation energy for fragmentation is approximately 9.2 eV.

Shape deformation precedes cluster breakup.

Abstract

The processes of defect formation and annealing in fullerene C60 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 C2 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 Ea = (9.2 +- 0.4) eV and A = (8 +- 1)10^{19} 1/s. It is shown that fragmentation can occur after the C60 cluster loses its spherical shape. This fact must be taken into account in theoretical calculations of Ea.