The superhard crystalline three-dimensional polymerized C60 phase

The profile analysis of the diffraction patterns, obtained for C60 samples quenched from high pressure 13 GPa and temperature 670–820 K, yields proof of the formation of three-dimensional (3D) polymerized C60 phase. The superhard phase manufactured after 13 GPa, 820 K treatment is characterized by common four-sided ring and (2+2) interfullerene cycloadditions in the layer, and (3+3) bondings between layers. The unit cell parameters of its body-centred orthorhombic Immm crystal structure refined by Rietveld program are equal to: a=0.867(4), b=0.881(1), and c=1.26(0) nm. Lattice dynamics simulation of 3D polymerized C60 has shown that sound velocities, bulk modulus and broad bands in Raman spectra agree well with the measurements.