The edges of nanoscopic objects determine most of their properties. For this reason the edges of honeycomb carbon--always considered either zigzag- or armchair-like--need special attention. In this report we provide experimental evidence confirming a previous unexpected prediction: zigzag is a metastable edge, as its planar reconstruction lowers energy and forms the most stable graphene edge. Our evidence is based on re-analyzing a recent experiment. Since the reconstructed edge, along with other unconventional edges we discuss, has distinct chemical properties, this discovery urges for care in experiments and theory--we must enter the realm beyond zigzag and armchair.
@article{arxiv.0906.0688,
title = {Evidence for Graphene Edges Beyond Zigzag and Armchair},
author = {Pekka Koskinen and Sami Malola and Hannu Häkkinen},
journal= {arXiv preprint arXiv:0906.0688},
year = {2010}
}