Topographic study by scanning-tunneling microscopy of a two-dimensional graphite film on $$(10\bar 10)$$

Abstract

Two-dimensional graphite films on $$(10\bar 10)$$ were produced in ultrahigh vacuum by adsorption of benzene vapor on the metal heated to T=1800 K. High-resolution Auger spectroscopy used for the film characterization showed the film indeed to have graphitic structure and monolayer thickness. The surface topography was studied in air by scanning-tunneling microscopy. The monolayer thickness was confirmed, and it was shown that a two-dimensional graphite film has a complex topography featuring numerous hillocks with linear dimensions of ∼3000 A and height differences of ∼300 A, while retaining graphitic structure on the atomic scale. The lack of planarity of such a film at room temperature is considered to be due to deformation occurring under cooling from the temperature of formation down to 300 K, which is caused by the difference in thermal expansion coefficients between the graphite sheet and rhenium.