DELAYED ELECTRON-EMISSION FROM HIGHER FULLERENES CN(N-LESS-THAN-OR-EQUAL-TO-96) FOLLOWING EXCITATION AT 1064 NM

Excitation of gas-phase fullerenes with laser pulses at 1064 nm yields large amounts of higher fullerene ions C(n)+, 72 less-than-or-equal-to n less-than-or-equal-to 96, even though their neutral precursors are only minor contaminants in the vapor over the toluene extract of soot. The ions are particularly prominent in the size distribution of delayed ions recorded at low fluence. Comparison with data obtained at 532 nm suggests that the size-dependent variations in the onset of photoabsorption are responsible for the observed phenomena. We propose that delayed ionization may be utilized to distinguish between higher fullerenes and other, more loosely bound, carbon aggregates.