PHOTOELECTRON-SPECTRA OF METAL FULLERENES - ARE METAL FULLERENES MOLECULAR-CRYSTALS OR NOT

Ultraviolet photoelectron spectra (UPS) of GdC82 and La2C80 were measu red using synchrotron radiation. The specimens for the measurement wer e not evaporated films but drying up films obtained from the metal ful lerene solutions. Although the effect of the contamination to the spec imens remains even after heat treatment, the UPS of the GdC82 film sho w several characteristic structures that are essentially identical to those of LaC82. This suggests that the interaction between the GdC82 m olecules are small and GdC82 Can be treated as a molecular crystal, Th e spectrum of La2C80 differs from those of other fullerenes, which ind icates either that the interaction among the La2C80 molecules are too large to give a sharp spectrum or that the molecule does not have so-c alled cage structure.