Structural and electrical properties of (Bi0.9Dy0.1)(Fe0.975TM0.025)O3±δ (TM=Ni2+, Cr3+ and Ti4+) thin films

Pure BiFeO3 and rare earth and transition metal ions co-doped (Bi0.9Dy0.1)(Fe0.975TM0.025)O3±δ (TM=Ni2+, Cr3+ and Ti4+) thin films were prepared on Pt(111)/Ti/SiO2/Si(100) substrates by using a chemical solution deposition method. The changes in the microstructure and the electrical properties with doping elements were investigated. The thin films were well crystallized and randomly oriented, with no detectable impurity and secondary phases. The leakage current densities were reduced and the ferroelectric properties were improved in the co-doped thin films. Among the thin films, the (Bi0.9Dy0.1)(Fe0.975Cr0.025)O3 thin film exhibited well saturated hysteresis loops with remnant polarization (2Pr) of 36 μC/cm2 and coercive electric field (2Ec) of 954 kV/cm at 1000 kV/cm and low leakage current density of 1.91×10−5 A/cm2 at 100 kV/cm. The enhanced properties observed in the co-doped thin films could be considered as being the result of the suppression of oxygen vacancies and of the modified microstructure.