Eur. Phys. J. B 49, 59-65 (2006)
https://doi.org/10.1140/epjb/e2006-00030-4

Spectroscopic study of phase transformations between orthorhombic and tetragonal C₆₀ polymers

¹ Department of Physics, Umeå University, 90187 Umeå, Sweden
² Jefferson Laboratory, Harvard University, Cambridge, MA 02138, USA
³ Department of Physics, Luleå University of Technology, SE-951 87, Sweden

Corresponding author: ^a Thomas.Wagberg@physics.umu.se

Received: 24 October 2005
Published online: 31 January 2006

Abstract

We present a detailed study of transformations between the orthorhombic and tetragonal polymeric states of C₆₀. The transformations are characterised by Raman spectroscopy and X-ray diffraction. We show that the transformation from the orthorhombic (O) phase to the tetragonal (T) phase is very fast and our results indicate that the transformation goes via an intermediate dimer (D) state in a two-stage process, and, transformations, where the second process is slower than the first. On the other hand, the transformation from the tetragonal to the orthorhombic phase is significantly slower, indicating a high-energy threshold to break the polymer bonds at the temperatures used. The results also support earlier suggestions that the tetragonal phase contains disordered dimers that can be viewed as lattice defects in the formation of higher polymers.