Highly ordered pyrolytic graphite (HOPG) is a lamellar material and consists of stacked planes. Carbon atoms within a single plane interact more strongly than with those in adjacent planes.
Each atom within a plane has three nearest neighbors, resulting in a honeycomb-like structure. This two-dimensional single-atom thick plane is called graphene.
HOPG terminated with a graphene layer can serve as an ideal atomically flat surface to be used as a substrate or standard for SPM investigations. This is also an easily “cleavable” material with a