Structure and transport properties of nanocarbon films prepared by sublimation on a 6H-SiC surface

The transport properties of nanocarbon layers on a 6H-SiC substrate, grown by vacuum sublimation, are studied. It is found that these layers consist of a graphene layer adjacent to the substrate and a multigraphene layer coated with a polycrystalline carbine-like phase. In this case, the magnetoresistance and Shubnikov-de-Haas oscillation curves exhibit features inherent to single-layer graphene. The resistance at low temperatures is demonstrated to increase with temperature, which also corresponds to the behavior of single-layer graphene (antilocalization). At the same time, the resistance decreased with temperature at higher temperatures, which corresponds to weak localization. We believe that the observed behavior can be explained by the parallel combination of contributions of single-layer graphene and multigraphene to the conductance.