A scanning tunneling microscopic and spectroscopic study was made of grain

boundaries in highly oriented pyrolytic graphite. The grain boundaries exhibited a

periodic structure and an enhanced charge density compared when to the bare

graphite surface. Two possible periodic structures were observed along the grain

boundaries. A geometrical model producing periodically distributed point defects

on the basal plane of graphite was proposed to explain the structure of grain

boundaries. Scanning tunneling spectroscopy of grain boundaries revealed two

strong localized states at −0.3 and 0.4V which extended up to 4nm from the grain

boundaries.

Structural and Electronic Properties of Grain Boundaries in Graphite: Planes of

Periodically Distributed Point Defects. J.Červenka, C.F.J.Flipse: Physical Review

B, 2009, 79[19], 195429