Interface-based reduced coercivity and leakage currents of BiFeO3 thin films: A comparative study

Abstract Obtaining high quality BiFeO 3 thin-films by low-cost scalable chemical solution deposition (CSD) is still challenging and currently relevant. Here we provide a comprehensive set of experimental evidences on the role of metallic (Pt) and oxide (IrO 2 and LaNiO 3 ) electrode interfaces on the texture development and functional properties improvement of CSD-derived BiFeO 3 films. All BiFeO 3 films are composed of columnar grains, which lateral size is dependent on the bottom electrode/interface. Whereas no texture was observed for 320 nm thick films fabricated on (111) oriented Pt, films on oxide electrodes, particularly on non-textured LaNiO 3 , are highly (012) oriented. Moreover, 400 nm thick BiFeO 3 films on LaNiO 3 possess a large remanent polarization 50 μC/cm 2 , a small coercive field 150 kV/cm and a low leakage current density ~4 × 10 −6  A/cm 2 at room temperature. In contrast, BiFeO 3 films on the other electrodes reveal polarization hysteresis with high leakage current that increases with film thickness decrease. We demonstrate that LaNiO 3 interfaces enhance crystallinity and orientation of BiFeO 3 thin-films reflected in optimization of their functional properties. We advocate that besides the need of monophasic films, oxide electrodes and their interfaces have a relevant role on the development of high-quality BiFeO 3 thin-films fabricated by CSD and derived devices.