Experimental Investigation of Symmetry Reduction and Electron#x2014;Molecular Vibration Coupling in Various RbC60Phases

摘要

In the monomer, dimer and polymer phase of RbC60the principal infrared modes exhibit significant shifts and splittings. We compare the positions of the main components of the four T1μmodes of C60in these three phases. Hie frequency shifts are determined by two competing effects: lattice hardening due to the formation—of chemical bonds between the balls, and softening induced by electron-molecular vibration (EMV) coupling. The behavior of the individual modes correlates with their sensitivity to pressure and their EMV coupling constants.