FUSION OF 2 C-60 MOLECULES AND FRAGMENTATION OF THE FUSION PRODUCT CAUSED BY C-60-C-60 COLLISIONS

Molecular fusion of two C-60 molecules in C-60-C-60 collisions and the stability of the reaction products are studied using molecular dynami cs simulations. It shows that the shape of the fusion product depends on the collision energy and the classical impact parameter between the mass centres of the two colliding partners. At impact parameter b = 0 , two C-60 molecules, colliding at energy E(0) = 50 eV in the laborato ry frame, coalesce to form a very stable dumbbell-shaped C-120 cluster , which never fragments. When the incident energy increases to 400 eV, the two C-60 molecules fuse to form a common larger C-120 cluster, co mpletely losing the geometry of the original C-60 cages. However, the C-120 formed in this case is highly deformed and the intrinsic 'heat' energy stored in it is increasing gradually until the 'temperature' of the cluster goes high enough to result in a fragmentation process,whi ch starts with a sequential evaporation of C-dimers, C-trimers,individ ually C atoms and other small C clusters. Collisions of C-60 molecules at larger impact parameters cause rotating motion of the coalescence products. All these coalescence reactions induced by the collisions of C-60 molecules are shown to have deep inelastic behaviour.