Phase transition, formation and fragmentation of fullerenes

Abstract

We present a statistical mechanics model treating the formation and the fragmentation of fullerenes as a phase transition. Based on this model, we investigate the formation and fragmentation of C60 and C240 fullerenes from and to a gas of carbon dimers by means of molecular dynamics (MD) simulations. These simulations were conducted for 500 ns using a topologically-constrained forcefield. At the phase transition temperature, both the cage and gaseous phases were found to coexist and the system continuously oscillates between the two phases. Combining the results of the MD simulations and the statistical mechanics approach, we obtain the dependence of the phase transition temperature on pressure and compare the results of our model with arc-discharge experiments.