Structural characterization of corrugated anisotropic graphene-based carbons obtained from the collapse of 2D C-60 polymers

Abstract

The structural organization and the transformation mechanism of the layered carbon phase produced from the tetragonal and rhombohedral variants of the 2D polymers of C-60 were investigated. High Resolution Transmission Electron Microscopy imaging combined with Electron Diffraction analysis were performed for samples synthesized at 2.6, 5.0 and 8.5 GPa and 1100 K. The structure of this layered carbon phase is composed of corrugated layers in a pseudo-epitaxial relationship with the {1 1 1}(cubic) planes of the parent polymer phase. A pseudo-martensitic transformation mechanism is proposed with a partial C-C bond reconstruction, as indicated by measurements of the angles between textured 001 reflections. The distribution of dense polymeric planes in tetragonal, rhombohedral and distorted pseudo-cubic 2D polymers as well as the crystallographic relationships between different layered carbon microstructures indicate that the carbon layers are generated from the polymerized dense planes of each structure. (C) 2012 Elsevier Ltd. All rights reserved.