Back to photostream

Chris Ewels

Escape from Graphene Flatland

 

In 2004 Graphene was considered an infinite flat two dimensional sheet. In 2007 it was shown that it flaps and waves like a flag in the wind. As we continue to learn more about this fascinating material, we increasingly realise that the world of graphene is anything but flat.

 

Conventional three-dimensional crystal lattices are terminated by surfaces, which can demonstrate complex rebonding and rehybridisation, localised strain and dislocation formation. Two dimensional crystal lattices, of which graphene is the archetype, are terminated by lines. The additional available dimension at such interfaces opens up a range of new topological interface possibilities. We show that graphene sheet edges can adopt a range of topological distortions depending on their nature. Rehybridisation, local bond reordering, chemical functionalisation with bulky, charged, or multi-functional groups can lead to edge buckling to relieve strain [1], folding, rolling [2] and even tube formation [3]. We discuss the topological possibilities at a 2D graphene edge, and under what circumstances we expect different edge topologies to occur. Density functional calculations are used to explore in more depth different graphene edge types. Finally we examine the effect of this on graphene properties, and lay out some of the challenges graphene designers face if it is to live up to its promise as the defining material of the 21st century.

 

 

Authors: Chris Ewels1, V. Ivanovskaya1, Ph. Wagner1, A. Yaya1, A. Zobelli2, M. Heggie3, P. Briddon4, 1 : Institute of Materials, CNRS, University of Nantes, France, 2: LPS, Universite Paris Sud, Orsay, Franc, 3 : Chemistry Department, University of Sussex, Brighton, UK, 4 : University of Newcastle Upon Tyne, UK

 

[1] Ph. Wagner, C. Ewels, V. V. Ivanovskaya, P. R. Briddon, A. Pateau, B. Humbert, submitted (2011)

[2] V. V. Ivanovskaya, Ph. Wagner, A. Zobelli, I. Suarez-Martinez, A. Yaya, C. P. Ewels, submitted (Proc. GraphITA 2011, Wiley, 2011)

[3] V. V. Ivanovskaya, A. Zobelli, Ph. Wagner, M. Heggie, P. R. Briddon, M. J. Rayson, C. P. Ewels, Phys. Rev. Lett. In press (2011).

441 views
0 faves
0 comments
Uploaded on July 21, 2011
Taken on July 21, 2011