STM study of a grain boundary in graphite

A grain boundary in highly oriented pyrolitic graphite has been investigated by scanning tunneling microscopy (STM). Along the boundary, a periodic structure has been observed. Crystallographic models have been constructed in order to explain the bonding between the two grains and STM theoretical simulations have been carried out. They conclude to the probable presence of pentagon heptagon chains at the boundary. (C) 2002 Elsevier Science B.V. All rights reserved.