Synchrotron diffraction study of high-pressure C₆₀ polymerization

Abstract

C₆₀ polymerization under high pressure and high temperature was studied in situ by angle-dispersive synchrotron diffraction employing a two-dimensional (2D) image plate detector. Preliminary results of this study show that heating fullerene C₆₀ up to 450 °C at 7 GPa leads essentially to the well-known rhombohedral 2D-polymerized phase. In addition, in situ diffraction measurements show that the texture exhibited by the transformed sample results from the anisotropic polymerization occurring on the sample, which in turn is induced by the uniaxial stress component of the applied pressure. The polymerized lattice planes in the transformed sample are then aligned to the compression (uniaxial) axis. Diffraction analysis of the recovered sample has permitted us to identify the presence of a minor phase, the tetragonal 2D polymer.

Keywords:

• fullerite
• high pressure
• high temperature
• X-ray diffraction