The threshold displacement energy of buckminsterfullerene C$_{60}$ and formation of the endohedral defect fullerene He@C$_{59}$

Abstract

We have measured the threshold center-of-mass kinetic energy for knocking out a single carbon atom from C − 60 in collisions with He. Combining this experimental result with classical molecular dynamics simulations, we determine a semi-empirical value of 24.1±0.5 eV for the threshold displacement energy, the energy needed to remove a single carbon atom from the C 60 cage. We report the first observation of an endohedral complex with an odd number of carbon atoms, He@C − 59 , and discuss its formation and decay mechanisms.