Near field microwave microscopy for nanoscale characterization, imaging and patterning of graphene

This paper reports images of reproducible nanopatterns on hexagonal graphene flakes, produced by modulating the input power of a Near-Field Scanning Microwave Microscope, used at the same time for the characterization of the samples. We have studied the impact of different time exposures to the microwave field, and of different power levels. A possible explanation of the patterning mechanism is given by the heating-induced oxidation of the exposed graphene flakes. In order to confirm this assumption, we have developed a simplified model for the analysis of the heat distribution, and for the estimation of the temperature under the microscope probe. This effect could be the basis for an alternative nanolithographic technique.