Hard disordered phases produced at high-pressure–high-temperature treatment of C60

X-ray diffraction, hardness, conductivity, Raman and infrared studies of solid C 60 subjected simultaneously to high pressure at 8 GPa and temperatures up to 1820 K have been carried out. A hard disordered state is formed at temperatures higher than 920 K and a cross-linked layered structure is proposed for this state. Crystalline phases obtained at T 60 cages and formation of an amorphous structure. The 3-D polymerization of solid C 60 at high-pressure–high-temperature treatment is discussed.