Co modified lead-free 0.7BiFeO₃−0.3BaTiO₃ (0.7BFO-0.3BT-xCo₂O₃；x =0, 0.3, 0.6, 0.9 and 1.2) piezoelectric ceramics were prepared by a conventional solid-state reaction. The effect of Co doping on the structural, piezoelectric properties and leakage current was investigated. A greatly reduced leakage current and dramatically improved piezoelectric properties were achieved in x=0.3 Co doped ceramic. The maximum d₃₃=151 pC/N and k_p= 0.32 were obtained at x=0.3 addition due to the co-effect of maximum applied poling electric field and large grain size. The X-ray photoelectron spectroscopy (XPS) analysis and complex impedance data indicated that the greatly reduced leakage current could be attributed to the effect of suppressing Fe²⁺ ion formation and promoting grain boundary resistance by Co doping. These results strongly suggest that low concentration of Co doping is a good strategy to improve the resistance and piezoelectric properties simultaneously in BFO-based lead-free piezoceramics.

通过常规的固态反应，制备了Co改性的无铅0.7BiFeO ₃ -0.3BaTiO ₃（0.7BFO-0.3BT- x Co ₂ O ₃；x＝0、0.3、0.6、0.9和1.2）。研究了Co掺杂对结构，压电性能和漏电流的影响。在x = 0.3 Co掺杂的陶瓷中，实现了大大降低的漏电流和显着改善的压电性能。在x处获得最大d ₃₃ = 151 pC / N和k _p = 0.32由于最大施加极化电场和大晶粒尺寸的共同影响，= 0.3添加。X射线光电子能谱（XPS）分析和复阻抗数据表明，漏电流的大大降低可归因于通过Co掺杂抑制Fe ²⁺离子形成并促进晶界电阻的作用。这些结果强烈表明，在基于BFO的无铅压电陶瓷中，低浓度的Co掺杂是一种同时提高电阻和压电性能的好方法。