Ionisation and fragmentation of fullerene ions by electron impact

Abstract

Summary. -Absolute cross-sections for electron impact induced fragmentation, fragmentation-single-ionisation and fragmentation-double-ionisation were measured for the fullerene ions C + 60 and C + 58 . For the fullerene ion C 2+ 60 , fragmentation-singleionisation was measured with a loss of n C2 molecules n = 1 ; 2 ; 3. The cross-sections were determined from the respective threshold up to an electron energy of 1 keV using the animated crossed-beams technique.PACS 34.80.Gs -Molecular excitation and ionisation by electron impact. PACS 36.40.Qv -Stability and fragmentation of clusters. PACS 01.30.Cc -Conference proceedings. -IntroductionMany collision experiments with fullerene ions have been carried out in the past few years due to the possibility of the production of intense mass-to-charge-selected fullerene ion beams. Interesting and unexpected results were discovered in these studies. One of the most remarkable features of a singly ionised C + 60 cluster is its exceptional stability against unimolecular decomposition. Nevertheless, the main fragmentation chan-

Fullerene reactions

“…Also, the cross sections for production of all doubly charged fragment ions are higher than those for the respective singly charged fragments. Similar behaviour is also observed in the electron energy dependence of ionization/fragmentation cross sections for electron impact excitation of positive fullerene ions (Schäfer et al 1998, Völpel et al 1993.…”

Asymmetric fission and evaporation of C60r+(r= 2–4) fullerene ions in ion–C60collisions: I. Proton results

“…Numerous studies have been devoted during the last few years to the stability and fragmentation of multicharged C 60 r+ fullerene ions using various collisional techniques: electron impact [1][2][3][4][5][6], photon impact [7], multicharged heavy ion impact at low velocity [8][9][10][11][12][13], fast ion collisions [5,14], monocharged light ion impact [15][16][17][18], and also the reverse collision of multicharged fullerene ions with gas targets [19][20][21][22]. A lot of detailed results have been obtained for the dissociation channels of these ions including neutral evaporation [2,11,14,16,23], multifragmentation [17] and AF [9-12, 18, 24].…”

Electron-beam-induced fragmentation in ultrathinC60films onSi(100)−2×Hunt1, Schmidt2, Palmer3 1999Phys. Rev. B28050View full textAdd to dashboardCite

“…However, as the very recent nature of their discovery 1 attests, they are far from abundant in the environment. It is now known that the fullerene molecules may be destroyed under a number of conditions, including irradiation by light in ambient atmosphere, [2][3][4][5] heating to elevated temperatures, [6][7][8][9][10][11][12] irradiation with energetic particles both in the solid [13][14][15][16][17][18][19][20][21][22] and in the gas phase, [23][24][25][26][27][28][29][30][31][32][33] absorption of photons, [34][35][36] and electron and/or photon stimulated reaction with other molecules. 37,38 This sensitivity to a wide variety of environmental conditions is the most likely explanation of the lack of environmental abundance of the fullerenes, despite the discovery of a number of methods by which they may be produced.…”