Raman-scattering studies of homogeneousK3C60films

Raman-scattering studies (T=300 K) have been carried out on homogeneous ${\mathrm{K}}_3$ ${\mathrm{C}}_{60}$ films grown on Suprasil substrates. Seven Raman lines have been observed in the range of 200<ω<1800 ${\mathrm{cm}}^{\mathrm{-}1}$. Substantial broadening of the ${\mathit{H}}_{\mathit{g}}$-derived modes has been observed and tentatively identified with electron-phonon coupling. The lowest-frequency mode in the ${\mathrm{K}}_3$ ${\mathrm{C}}_{60}$ spectrum exhibits a Breit-Wigner-Fano line shape, indicating a coupling between the lowest-frequency intramolecular mode of ${\mathrm{C}}_{60}$ and a broad continuum with the same symmetry lying lower in frequency.