Abstract: 0.7BiFeO₃-0.3BaTiO₃+x%Sb₂O₃ (mass fraction) ceramics (BFO-BTO+xSb, x=0.00~0.20) were synthesized by the conventional solid state reaction method, and the effect of Sb₂O₃ doping on the crystalline phase structure, dielectric, conductive, piezoelectric and ferroelectric properties of BFO-BTO ceramics was investigated, along with doping mechanism. The results indicate that Sb doping change the crystal structure from a pesodocubic lattice to a rhombohedral lattice. Sb substitution for B site increases ferroelectric relaxation, decreases dielectric loss at high temperature, and also lowers the Curie temperature. The conductive characteristics demonstrate that Sb doping changes the concentration of $V_O^×$ and Fe²⁺, and decreases the conductivity, without changing the conductive mechanism with oxygen vacancy as the dominant carrier. BFO-BTO+xSb ceramics exhibit optimum electric properties at x=0.05: d₃₃=213 pC/N, k_p=28.8%, Q_m=38, T_c=520 ℃, P_r=24.7 μC/cm².

Key words: BiFeO₃-BaTiO₃, Sb₂O₃ doping, solid state method, dielectric property, piezoelectric property, relaxation behavior