title: Internal and external atomic steps in graphite exhibit dramatically different physical and chemical properties.
abstract: We report on the physical and chemical properties of atomic steps on the surface of highly oriented pyrolytic graphite (HOPG) investigated using atomic force microscopy. Two types of step edges are identified: internal (formed during crystal growth) and external (formed by mechanical cleavage of bulk HOPG). The external steps exhibit higher friction than the internal steps due to the broken bonds of the exposed edge C atoms, while carbon atoms in the internal steps are not exposed. The reactivity of the atomic steps is manifested in a variety of ways, including the preferential attachment of Pt nanoparticles deposited on HOPG when using atomic layer deposition and KOH clusters formed during drop casting from aqueous solutions. These phenomena imply that only external atomic steps can be used for selective electrodeposition for nanoscale electronic devices.
authors: †Center for Nanomaterials and Chemical Reactions, Institute for Basic Science (IBS), Daejeon 305-701, Republic of Korea.|‡Graduate School of EEWS, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Republic of Korea.
authors: Hyunsoo
authors: H
authors: Lee
authors: §Department of Materials Science and Engineering, Incheon National University, Incheon 406-772, Republic of Korea.
authors: Han-Bo-Ram
authors: HB
authors: Lee
authors: †Center for Nanomaterials and Chemical Reactions, Institute for Basic Science (IBS), Daejeon 305-701, Republic of Korea.|‡Graduate School of EEWS, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Republic of Korea.
authors: Sangku
authors: S
authors: Kwon
authors: ∥Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.
authors: Miquel
authors: M
authors: Salmeron
authors: †Center for Nanomaterials and Chemical Reactions, Institute for Basic Science (IBS), Daejeon 305-701, Republic of Korea.|‡Graduate School of EEWS, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Republic of Korea.
authors: Jeong Young
authors: JY
authors: Park
keywords: atomic layer deposition; external and internal step edges; frictional force microscopy; highly oriented pyrolytic graphite; surface reactivity