STRUCTURAL TRANSITIONS IN C-60 FILMS ON HIGH-TEMPERATURE ANNEALING

X-ray diffraction analysis on the structure of C-60 films was carried our, and the effects of annealing on the structure of C-60 films were discussed. We found a new crystalline phase with a planar spacing of 0.95 nm of the crystal planes parallel to the substrate. This crystalline phase may be related to stressed internal C-60 molecules packed between fee C-60 crystallites, i.e. may be an intercrystalline phase stabilized by a small amount of C-70 due to sublimation at relatively high temperature. In addition, the structure of the films is sensitive to the deposition conditions and the hcp phase can exist either as an independent phase or as stacking faults along the fee [111] axis.