High pressure study of the 2D polymeric phase of C₆₀ by means of raman spectroscopy

Abstract

The effect of high hydrostatic pressure, up to 12GPa, on the intramolecular phonon frequencies and the material stability of the two-dimensional tetragonal Cm polymer has been studied by means of Raman spectroscopy in the spectral range of the radial intramolecular modes (200-800cm⁻¹). A number of new Raman modes appear in the spectrum for pressures ∼ 1.4 and ∼ 5.0 GPa. The pressure coefficients for the majority of the phonon modes exhibit changes to lower values at P=4.0 GPa, which may be related to a structural modification of the 2D polymer to a more isotropic phase. The peculiarities observed in the Raman spectra are reversible and the material is stable in the pressure region investigated.

Key Words:

• Fullerenes
• 2D tetragonal polymer
• Raman spectroscopy
• high pressure