OPTICAL-PROPERTIES OF C-60 SINGLE-CRYSTALS AT HIGH-PRESSURE

The Raman scattering., luminescence; and absorption spectra of Coo sin gle crystals at T = 300 K and pressures up to 15 GPa were measured. Th e pressure dependence of the Raman-active intramolecular phonons indic ates that two phase transitions are induced at pressures of 0.4 and 2. 1 GPa. The magnitude of the pressure shifts of phonon modes, luminesce nce and absorption spectra, the values of the Gruneisen parameters, an d the deformation potential have been deter mined.