Synthesis and properties of multiferroic 0.7BiFeO3−0.3BaTiO3 thin films by Mn doping

Multiferroic BiFeO3−BaTiO3 thin films that simultaneously exhibit ferroelectricity and ferromagnetism at room temperature were prepared by chemical solution deposition. Perovskite single-phase 0.7BiFeO3−0.3BaTiO3 thin films were successfully fabricated in the temperature range 600–700 °C on Pt/TiOx/SiO2/Si substrates. As the crystallization temperature was increased, grain growth proceeded, resulting in higher crystallinity at 700 °C. Although the 0.7BiFeO3−0.3BaTiO3 thin films exhibited poor polarization (P)−electric field (E) hysteresis loops owing to their low insulating resistance. The leakage current at high applied fields was effectively reduced by Mn doping at the Fe site of the 0.7BiFeO3−0.3BaTiO3 thin films, leading to improved ferroelectric properties. The 5 mol% Mn-doped 0.7BiFeO3−0.3BaTiO3 thin films simultaneously exhibited ferroelectric polarization and ferromagnetic magnetization hysteresis loops at room temperature.