Effects of Zn2+ and Mn4+ Co-doping in BiFeO3 Thin Films

Bi(Fe0.99−xZn0.01Mnx)O3 (x = 0.01, 0.03, 0.05) thin films were deposited on Pt(111)/Ti/Si)₂/Si(100) substrates by using a pulsed laser deposition method. The effects of Mn4+ content in the BiFeO3 thin films on their leakage current and their ferroelectric properties were mainly investigated. Bi(Fe0.96Zn0.01Mn0.03)O3 thin film exhibited the best ferroelectric properties among them. The leakage current density of the film capacitor was 2.0 × 10−5 A/cm2 at 200 kV/cm. The remnant polarization (2Pr) and the coercive electric field (2Ec) of the film capacitor were 83 μC/cm2 and 577 kV/cm at an applied electric field of 695 kV/cm, respectively. This can be explained based on the Fe2+ concentration associated with oxygen vacancies and the grain size caused by doping of Zn2+ and Mn4+ in BiFeO3 thin films.