Our previous investigations by instrumental neutron activation analysis (INAA) of a great variety of C 60. C 70 fullerenes and fullerene precursors as graphite and graphite soot have revealed that along with higher carbon homologue impurities all these compounds contain non-negligible amounts of about 35 elemental trace impurities, ranging from the limits of detection (LoD) levels up to about 0.1 %. These elemental impurities may be distributed on the surface of the C 60 and C 70 samples and/or at some interstitial positions of the crystal lattice. We have shown that some of these impurity atoms can penetrate the fullerene cages by nuclear recoil during the neutron irradiation. The energy of the recoiling atom depends on the type of the emitted particle, on its energy and on the mass of the target atom. In case of gamma quanta the recoil energies may range from about 50 to 106 eV. The recoiled impurity atoms move with a large kinetic energy which they successively lose upon excitation and ionization on the atoms of the fullerene crystals. After reduction of the kinetic energy of the recoiled atom to below approx. 100 eV, this energy is enough for the atom to penetrate the fullerene cages. Results are described on the formation of some endohedral radioactive metal fullerenes.
|Number of pages||5|
|Journal||Magyar Kemiai Folyoirat, Kemiai Kozlemenyek|
|Publication status||Published - Dec 1 1998|
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