He⁺ Ion Bombardment of C₇₀ Fullerene: An FT‐IR and Raman Study

Abstract

C₇₀ fullerene films deposited on a silicon substrate have been bombarded with He⁺ ions at 30 keV at room temperature in vacuum. The structural changes undergone by C₇₀ have been followed by both FT‐IR and Raman spectroscopy. The results have been compared to the behavior of C₆₀ fullerene and discussed in an astrochemical context. The main conclusion is that C₇₀, contrary to C₆₀, does not form oligomers at low radiation dose but it is directly and gradually degraded to amorphous carbon (carbon black).

Keywords:

• Fullerene
• He⁺ ions
• Implantation
• Bombardment
• Amorphization
• Carbon

Acknowledgments

Partial financial support of this work from ASI, the Italian Space Agency, Rome, Italy is gratefully acknowledged.