Fragmentation of C60, C70 by tight-binding molecular-dynamics approach

Abstract

We have studied fragmentation of fullerenes using tight-binding molecular dynamics approach. The C 60 and C 70 molecules form floppy phase with fluctuations ± 0.4 Å at 3000 K but do not disintegrate. We observe that a window is opened at high temperature when a bond between pentagon and hexagon is broken, forming 9 membered rings, which may play an important role for the formation of endohedral fullerene compounds. Higher membered rings such as 13 and 16 membered rings are also found, forming larger windows. The C 2 , C 4 , and C 5 are formed during the disintegration. Both form linked chains after complete disintegration at 5000 K. Possible explanation for the formation of fullerenes is given. We also find that the latent heat of C 60 and C 70 are 1.65 and 1.29 eV, respectively, larger than that of graphite (1.08 eV).