Mg. Mitch et Js. Lannin, RAMAN-SCATTERING AND ELECTRON-PHONON COUPLING IN A3C60, Journal of physics and chemistry of solids, 54(12), 1993, pp. 1801-1816
Raman scattering measurements performed in situ in UHV on thin and ult
rathin films of doped C60 are reported for variations in alkali-metal
type, composition and temperature. The results emphasize the important
role of disorder on Raman processes and the probing of electron-phono
n coupling relevant to superconductivity. Detailed comparisons of free
carrier phonon damping effects on selected radial and tangential intr
amolecular phonons are discussed in Rb3C60 and K3C60 using nonmetallic
Na3C60 as a reference. Elevated temperature studies of Na3C60 suggest
a transition to a more metallic state. Intermolecular Raman scatterin
g associated with alkali-metal motion, weakly coupled to C60 clusters
is reported. The effects of alkali size, lattice thermal expansion and
disorder are discussed.