Damage and polymerization by ion bombardment of C60

Abstract

Sublimated C60 fullerite films have been implanted with 160−300 keV H, He, C, and Ar ions with doses ranging from 1×1012 to 5×1016 cm−2. Raman scattering showed a structural transformation of the fullerite to amorphous carbon at certain doses depending on the projectile. This amorphization process is correlated to the energy loss by nuclear collisions. Electronic stopping leads to no detectable disruption of fullerene molecules but to a polymerization of C60. This new phase is evidenced by several changes in the Raman spectrum, of which a new line at about 1463 cm−1 is most prominent.