Scanning microwave microscopy (SMM) is a novel metrological tool that advances the quantitative, nanometric, high-frequency, electrical characterization of a broad range of materials of technological importance. In this work, we report an inverted near-field scanning microwave microscopy (iSMM) investigation of a graphene oxide-based epoxy nanocomposite material at a nanoscopic level. The high-resolution spatial mapping of local conductance provides a quantitative analysis of the sample's electrical properties. In particular, the electrical conductivity in the order of ∼10-1 S/m as well as the mapping of the dielectric constant with a value of ∼4.7 ± 0.2 are reported and validated by the full-wave electromagnetic modeling of the tip-sample interaction.
Keywords: epoxy nanocomposites; graphene oxide (GO); inverted scanning microwave microscopy (iSMM); nanoscale electrical properties.