Figure 4: Local-probe conductivity analysis of a nanopillar composite film.

(a) Schematic illustration of the current mapping measurement. (b) Current–voltage curve measured on a single Ir metal nanopillar. The inset illustrates the band diagram of the Schottky junction between an Ir pillar and the Nb(0.1%):SrTiO3 substrate. The error bars in b indicate the s. d. values of the current measured at a single nanopillar site. (c) Topographic AFM image (250 × 250 nm2) of an Ir(5%):SrTiO3 nanopillar film. (d) Current mapping obtained at an applied bias of 2.5 V, simultaneously acquired with c.