Properties of C₆₀ polymerized under high pressure and temperature

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polymers. Pure and mixed phase polymeric samples were synthesized by simultaneously subjecting microcrystalline C₆₀ powder or pellets to various pressures (\valunit{1}{GPa} < P < \valunit{4.8}{GPa}) and temperatures (\valunit{250}{\celsius} < T < \valunit{600}{\celsius}). The optical spectra of the orthorhombic, tetragonal, and rhombohedral C₆₀ polymer phases are observed to be quite distinct and rich. These spectra exhibit numerous lines and an overall downshift in frequency relative to C₆₀ is observed, consistent with a loss of double bonds from the fullerene cage. The LDMS spectra of a sample synthesized at \valunit{2}{GPa} under hydrostatic conditions and \valunit{350}{\celsius}, exhibited a succession of \sim 12 clear peaks at mass numbers corresponding to (\chem{C_{60}})_{{N} = 1, 2\ldots 12}, similar to the LDMS data on the C₆₀ 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.