Pressure-induced irreversible amorphization of C-70 fullerene

We report Raman scattering study of Cio fullerene polycrystals undertaken at high static pressures up to 51 GPa using a diamond-anvil cell. Above 12 GPa, a majority of the intramolecular vibrational modes lost their intensities and only one broad peak initially centered at 1567 cm(-1) was found to persist, indicating an occurrence of amorphization. Analysis of the line width of the 1567 cm(-1) peak showed the amorphization to be completed by about 18 cpa. The amorphous phase was irreversibly retained to the ambient pressure after pressures higher than 35 GPa were applied. (C) 2000 Elsevier Science Ltd. All rights reserved.