Properties of C-60 polymerized under high pressure and temperature

We discuss the Raman, infrared, photoluminescence (PL), x-ray diffraction (XRD) and laser desorption mass spectroscopic (LDMS) studies of pressure synthesized C-60 polymers. Pure and mixed phase polymeric samples were synthesized by simultaneously subjecting microcrystalline C-60 powder or pellets to various pressures (1 GPa < P < 4.8 GPa) and temperatures (250 degrees C < T < 600 degrees C). The optical spectra of the orthorhombic, tetragonal, and rhombohedral C-60 polymer phases are observed to be quite distinct and rich. These spectra exhibit numerous lines and an overall downshift in frequency relative to C-60 is observed, consistent with a loss of double bonds from the fullerene cage. The LDMS spectra of a sample synthesized at 2 GPa under hydrostatic conditions and 350 degrees C, exhibited a succession of similar to 12 clear peaks at mass numbers corresponding to (C-60)N=1,2...12, similar to the LDMS data on the C-60 photopolymer. This is taken as further evidence for interfullerene bonds in these high-pressure polymers. The XRD pattern of this sample indicates the presence of a strong texture in the sample.