Pure BiFeO₃ (BFO) and (Eu, V) co-doped Bi_0.9Eu_0.1Fe_0.975V_0.025O_3+δ (BEFVO) thin films were deposited on Pt(111)/Ti/SiO₂/Si(100) substrates by chemical solution deposition. The effects of co-doping were observed by X-ray diffraction, Raman spectroscopy, and scanning electron microscopy (SEM). The electrical properties of the BEFVO thin film were improved as compared to those of the pure BFO thin film. The remnant polarization (2P_r) of the BEFVO thin film was approximately 26 μC/cm² at a maximum electric field of 1,190 kV/cm with a frequency of 1 kHz. The leakage current density of the co-doped BEFVO thin film (4.81×10^-5 A/cm² at 100 kV/cm) was two orders of magnitude lower than of that of the pure BFO thin film.

Pure BiFeO₃ (BFO) and codoped Bi_0.9A_0.1Fe_0.975Zn_0.025O_3-δ (A=Eu, Dy) thin films were prepared on Pt(111)/ Ti/SiO₂/Si(100) substrates by chemical solution deposition. The remnant polarizations (2Pr) of the Bi_0.9Eu_0.1Fe_0.975Zn_0.025O_3-δ (BEFZO) and Bi_0.9Dy_0.1Fe_0.975Zn_0.025O_3-δ (BDFZO) thin films were about 36 and 26 μC/cm² at the maximum electric fields of 900 and 917 kV/cm, respectively, at 1 kHz. The codoped BEFZO and BDFZO thin films showed improved electrical properties, and leakage current densities of 3.68 and 1.21×10^-6 A/cm², respectively, which were three orders of magnitude lower than that of the pure BFO film, at 100 kV/cm.

We have evaluated the ferroelectric and electrical properties of pure BiFeO₃ (BFO) and Bi_0.9A_0.1Fe_0.975V_0.025O_3+α(A=Nd, Tb) thin films on Pt(111)/Ti/SiO₂/Si(100) substrates by using a chemical solution deposition method. The remnant polarization (2P_r) of the Bi_0.9Tb_0.1Fe_0.975V_0.025O_3+α (BTFVO) thin film was approximately 65 μC/㎠, with a maximum applied electric field of 950 kV/cm and a frequency of 10 kHz, where as that of the Bi_0.9Nd_0.1Fe_0.975V_0.025O_3+α (BNFVO) thin film was approximately 37 μC/㎠ with a maximum applied electric field of 910 kV/cm. The leakage current density of the co-doped BNFVO thin film was four orders of magnitude lower than that of the pure BFO thin film, at 2.75×10^-7 A/㎠ with an applied electric field of 100 kV/cm. The grain size and uniformity of the co-doped BNFVO and BTFVO thin films were improved, in comparison to the pure BFO thin film, through structural modificationsdue to the co-doping with Nd and Tb.