Structural properties of a monolayer graphite film on the (111)Ir surface

The structural properties of a monolayer graphite film prepared on the (111)Ir surface through thermal decomposition of benzene molecules were studied. The study was carried out in ultrahigh vacuum using scanning tunneling microscopy, which allowed observation of the atomic structure of the film. It is shown that, on extended smooth regions of the Ir surface, a continuous graphite film with a regular arrangement of carbon atoms in a planar hexagonal lattice is formed. The orientation of zigzag carbon atom chains coincides with the 〈110〉 direction on the Ir surface. Structural defects of the (5, 7) configuration were revealed in the film. A comparison of the topographies of the film and the (111)Ir surface shows that the graphite layer smoothly (without discontinuities) flows over subnanometer topographical features existing on the Ir surface and that the distance between the graphite film and the metal surface in this case can reach 1 nm.