FORMATION AND SPUTTERING OF FULLERENES BY MEV ATOMIC IONS

Positive pure carbon cluster ions (C2n+, n from 20 to above 200) are e jected from solid films of poly(vinylidene-difluoride) when bombarded by MeV atomic ions. Similar results are obtained in the MeV ion intera ction with a film of synthetic C60F2m (m = 12-24) fullerenes. Measurem ents of the yield and the initial radial velocities of the ejected clu ster ions are performed in a reflectron time-of-flight mass spectromet er. Carbon cluster ions are formed and ejected as a result of a single MeV ion impact. The distribution of cluster sizes suggests that the c lusters have closed carbon cage (fullerene) structure. Results on diff erent types of coalescence reactions from synthetic C60 fullerene targ ets and from blends of pure (synthetic) C60 with a polystyrene polymer leading to ejection of higher mass positive fullerene ions (C(m)+, m from 60 to >200) are reported. The coalescence reactions are also indu ced by the interaction of a single MeV ion with the solid. These exper iments, providing information on the MeV ion-induced sputtering, may i n its turn also contribute to the understanding of the fullerene forma tion mechanism in general.