Nanoscale electrical properties of cluster-assembled palladium oxide thin films

The electrical properties of cluster-assembled nanostructured palladium oxide (ns-PdOx) thin films grown by supersonic cluster beam deposition have been characterized by means of a customized ac current-sensing atomic force microscope. Scanning impedance microscopy is shown to provide a deep picture of the electrical properties of thin nanostructured interfaces even in the case of very soft and poorly adherent films. In particular, the dielectric constant of ns-PdOx can be quantitatively determined as well as its I-V characteristics. Moreover, the measurement of the tip-sample parasitic capacitance can be exploited to probe the overall mesoscale conductive character of thin films and to give a complementary and more precise view of the oxidation of ns-PdOx obtained by x-ray photoemission spectroscopy.