The role of defects on the electronic structure of a graphite surface

We have observed one-dimensional (1D) superlattices at the grain boundary of highly ordered pyrolytic graphite (HOPG) with a scanning tunneling microscopy (STM). Observed 1D superlattices extend over micrometer length and have periodicities from 0.5 nm to 10 nm with a height corrugation up to 1.5 nm, due to electron density effects, which is 15 times larger than the graphite lattice corrugation observed with STM. Experimental observations are well explained by a simple model based on the complex electron interference at the grain boundary between two misoriented graphite layers.