Dielectric properties of thin C r2O3 films grown on elemental and oxide metallic substrates

In an attempt to optimize leakage characteristics of α-C r₂O₃ thin films, its dielectric properties were investigated at local and macroscopic scale. The films were grown on Pd(111), Pt(111), and V₂O₃ (0001), supported on A l₂O₃ substrate. The local conductivity was measured by conductive atomic force microscopy mapping of C r₂O₃ surfaces, which revealed the nature of defects that formed conducting paths with the bottom Pd or Pt layer. A strong correlation was found between these electrical defects and the grain boundaries revealed in the corresponding topographic scans. In comparison, the C r₂O₃ film on V₂O₃ exhibited no leakage paths at similar tip bias value. Electrical resistance measurements through e-beam patterned top electrodes confirmed the resistivity mismatch between the films grown on different electrodes. The x-ray analysis attributes this difference to the twin free C r₂O₃ growth on V₂O₃ seeding.