PHASE-TRANSFORMATIONS IN SOLID C-60 AT HIGH-PRESSURE-HIGH-TEMPERATURETREATMENT AND THE STRUCTURE OF 3D POLYMERIZED FULLERITES

New data concerning the solid C-60 phase transformations in the pressu re-temperature range P=6.5-13 GPa, T=300-2100 K and nonhydrostatic con ditions are presented and plotted in the P-T coordinates. The structur e of superhard and ultrahard carbon phases obtained with these conditi ons is investigated by X-ray powder diffractometry and Raman scatterin g. New crystal structures of distorted bcc type and transient to diamo nd states are revealed in the synthesized samples. Fragments of differ ent lengths of polymerized fullerene cages are found from resonance Ra man spectra of the samples obtained at P=13 GPa and T<1200 K.