화학공학소재연구정보센터
Journal of Physical Chemistry B, Vol.103, No.26, 5500-5504, 1999
Surface-induced dissociation of small carbon cluster negative ions (C-n(-), n=5-12): Correlation between the dissociation patterns and stability of fragment ion-neutral pairs
We report detailed study of surface-induced dissociation (SID) of small carbon cluster negative ions (C-n(-), n = 5-12) in collision with Si substrates. Fragment mass spectra have been observed in the collision energy range of 0-10 eV/atom. Neutral C-3 loss occurred at collision energies lower than 2 eV/atom. In the medium energy range (2-6 eV/atom), a marked even-odd difference in the dissociation has been observed: even fragment ions were predominantly generated from incident odd clusters, whereas both even and odd fragment ions from incident even clusters. These results are qualitatively in good agreement with the formation energies of fragment ion-neutral pairs calculated using the experimentally determined binding energies of ions and neutrals. Ar elevated collision energies (6-10 eV/atom), further fragmentation and electron detachment from fragment ions occurred and smaller cluster ions with even n were preferentially generated.