A new phase in photopolymerized C60

The process of phototransformation was analyzed by Raman spectroscopy. Characteristic features in the spectra were found to depend on the transformation temperature. A comparison with ab initio calculations by Porezag et al. was performed, from which the material irradiated at elevated temperatures was assigned to a C60 dimer. The material is stable against further phototransformation at room temperature. The room temperature irradiated material matches best with triangular models indicating a zig zag structure, which is in good agreement with recent AFM measurements.