Effects of (Dy, Zn) co-doping on structural and electrical properties of BiFeO_3 thin films

摘要

Pure BiFeO_3 (BFO) and (Dy, Zn) co-doped (Bi_(0.9)Dy_(0.1))(Fe_(0.975)Zn_(0.025))O_(3-δ) (BDFZO) thin films were prepared on Pt(111)/Ti/SiO_2/Si(100) substrates by a chemical solution deposition method. Effects of (Dy, Zn) co-doping on the structural and electrical properties of BFO were studied. Both the thin films were crystallized as randomly oriented polycrystallinc distorted rhombohedral structures, with no detectable impurity and secondary phases. Large remnant polarization (2P_r) of 47 μC/crrr, low coercive electric field (2E_c) of 925 kV/cm at 1143 kV/cm and low leakage current density of 1.30 × 10~(-6) A/cm~2 at 100 kV were measured for the BDFZO thin film. The improved electrical properties of the BDFZO thin film are ascribed to the stabilization of perovskite structure, defect complex formation between acceptors Zn~(2+) and oxygen vacancies of [(Zn_(Fe~(3+))~(2+))'-(V_(O~(2-))], pronounced off-center displacement in the perovskite and structural distortion by the Dy and Zn ions doping.