DISINTEGRATION OF C-60 BY HEAVY-ION IRRADIATION

The changes in resistivity in fullerene(C-60) films subjected to 320-k eV Xe ion irradiation are investigated as a function of ion dose. From a comparison of this dependence with similar data on Xe irradiated di amond and with data on C implanted fused quartz, it is concluded that upon ion impact C-60 clusters completely disintegrate. This disintegra tion releases about 60 carbon atoms which disperse among the remaining intact C-60 spheres giving rise to hopping conductivity between isola ted C atoms. The present finding may explain the negative results in t he search for fullerenes conjectured to exist in instellar dust and ma y establish limitations on the use of ion implantation to dope fullere nes with the aim of synthesizing new forms of high-T-c superconductors .