The vibrational spectrum of saturation-doped insulating Rb6C60has been measured by inelastic neutron scattering at nonzero momentum transfer in the energy range (5 ¸ 200) meV at 20 K. The two lowest-energy fivefold degenerate Hgmodes sharpen substantially in comparison with superconducting K3C60, acquiring comparable widths to those found in pristine C60. This is interpreted as evidence for the importance of these modes in the pairing interaction for superconductivity. We estimate that the radial Hgmodes make a substantial contribution to the total electron-phonon coupling strength in the superconducting fullerides.
ASJC Scopus subject areas
- Physics and Astronomy(all)