Mass-spectrometric investigation of Ba + –induced fragmentation and possible Ba–carbon association in C 60 thin films

Abstract The present work analyzes secondary-ion mass distributions produced by sputtering C 60 thin films with Ba + ions in the 1–4 keV range. The fragment-ion distribution was found to depend strongly on projectile energy. At 1 keV, Ba + bombardment produced intense low-mass fragment ions together with weaker intermediate- and high-mass fullerene-related signals, whereas at 3–4 keV the spectra were dominated by low-mass fragments and showed strong depletion of larger cluster ions. Some high-mass peaks are discussed as tentative Ba − C n + candidates on the basis of nominal mass agreement, although alternative contributions from overlapping carbon-cluster or background signals cannot be excluded. The energy dependence of selected fragment-ion intensities shows that the relative yields of C 2 + and C 5 + increase with increasing Ba + projectile energy, indicating enhanced low-mass fragmentation of the C 60 film in the low-keV sputtering regime. The results provide a basis for further studies of energy-dependent C 60 fragmentation and possible Ba–carbon association under low-keV ion bombardment.

Hali tarjima qilinmagan