Abstract: BiFe_1-xTi_xO₃ (x=0,0.05,0.10,0.15 and 0.20) (BFT_xO) ceramics were prepared by the solid-state reaction technology. The effects of Ti doping on the microstructure, morphology, the ferroelectric properties and ferroelectric-paraelectric phase transition were investigated. The result of X-ray diffraction pattern implies that the rhombohedral structure is distorted to an orthorhombic structure by Ti doping. The measured Raman scattering spectra also show that Ti doping modifies the ceramic structure from rhombohedral to orthorhombic. Compared with the pure counterparts, the average grain sizes of the BiFe_1-xTi_xO₃ (x=0.05、0.10) ceramics decrease with the increase of Ti⁴⁺ concentration. The leakage current density and the remnant polarization of the BiFe_1-xTi_xO₃ (x=0.05,0.10) are improved due to the decreased oxygen vacancies by Ti⁴⁺ doping. The current density values for the pure BiFeO₃ and BiFe_0.95Ti_0.05O₃ ceramics are 1.4×10^－4A/cm² and 7.3×10^－6A/cm² at 100V, respectively. The remnant polarization (2P_r) of BiFe_0.95Ti_0.05O₃ ceramic is 2.78μC/cm² at 8kV/mm. DTA and Raman scattering spectra results indicate that the ferroelectric transition temperature (T_c) of the BFT_xO crystal is influenced by the content of Ti ions. With the increase of Ti content, the ferroelectric transition temperature decreases.

Key words: BiFe_1-xTi_xO₃ ceramics, ferroelectric property, leakage conduction