Pressure-induced phase transformations in tetragonal and rhombohedral C60 polymers
Alexandr Talyzin, Leonid Dubrovinsky
Tetragonal and rhombohedral 2D polymers of C60 were studied by Raman spectroscopy in situ under high-pressure conditions. Unlike previous reports, no new phase was observed upon compression of the tetragonal polymer to 32 GPa. Above 20 GPa both tetragonal and rhombohedral polymers undergo irreversible amorphisation. The same results were obtained for samples studied without a pressure-transmitting medium and when a methanol – ethanol mixture was used. In the pressure range below 20 GPa, both tetragonal and rhombohedral polymers partially decompose to chains and monomers during compression.