Interfacial effects on the electrical properties of multiferroic BiFeO3/Pt/Si thin film heterostructures

Polycrystalline BiFeO3 thin films of various thickness were fabricated on (111)Pt/Ti/SiO2/Si substrates via chemical solution deposition. The electrical properties were investigated using impedance and leakage current measurements. X-ray photoelectron spectroscopy (XPS) combined with Ar ion milling (depth profiling) was used to investigate elemental distribution near the electrode-film interface. It is shown that the dielectric constant depends on film thickness due to the presence of an interfacial film-electrode layer evidenced by XPS investigation. Direct current conductivity is found to be governed by Schottky and/or Poole-Frenkel mechanisms.