Temperature dependence of Raman scattering in K3Ba3C60

Raman spectra at different temperatures are reported for K3Ba3C60. A system atic change of the Raman spectra with temperature is observed. The developm ent of the linewidth and intensity for all modes with decreasing temperatur e is in sharp contrast to the case for pure C-60 For the two lowest-frequen cy Hg modes, the appearance of the low-frequency components and an increase in their intensity are observed as temperature decreases. This could be re lated to an internal strain between the doped part of the crystal and the u ndoped part of the crystal, and the Jahn-Teller effect. An anomalously larg e upshift of 9 cm(-1) between 20 K and room temperature for the pinch A(g)( 2) mode suggests the existence of hybridization between the C-60 molecules and the intercalants. The doublet of A(g)(1) at low temperature could arise from the splitting of the crystal field.