Comparison of Raman scattering in non-polymerized and photo-polymerized fullerene films at temperatures of 5–300 K

Raman spectra of non-polymerized and photo-polymerized fullerene films are studied in the region of the Ag(2) mode (energy range 1380–1500 cm−2) at temperatures of 5–300 K. The temperature dependence of the energy of the Ag(2) mode for non-polymerized C60 films undergoes an inflection on passing through the orientational phase transition. As opposed to the case of non-polymerized film, the energy of the monomers, dimers, linear chains, and trimers of fullerenes in photo-polymerized films increases monotonically as the temperature is lowered. It is shown that a difference in the energies of the Ag(2) mode for the monomer in photo-polymerized films and for the monomer in non-polymerized C60 appears below the structural phase transition temperature TC. This difference is caused by the appearance of an orientational phase transition in the non-polymerized film (TC ∼ 235 K), while this transition is absent in the polymerized film. It has been found that the temperature of the orientational phase transition for...