Enhanced electrical properties of BiFeO₃–PbTiO₃ based ceramics with suitable raw material

As for traditional lead-based piezoelectric ceramics, different lead raw materials have minor effect on ceramic’s properties. Meanwhile, poor electrical property is frequently observed in BiFeO₃–PbTiO₃ based ceramics due to their high leakage current. Here, Pb₃O₄ and PbO as two kinds of lead raw materials have been used for the preparation of BiFeO₃–PbTiO₃ based ceramics. The structure, composition, and electrical properties of the ceramics have been analyzed. Although both samples have the same phase structure, the BiFeO₃–PbTiO₃(PbO)sample exhibits better ferroelectric properties compared with the BiFeO₃–PbTiO₃(Pb₃O₄) sample due to the high conductivity in the BiFeO₃–PbTiO₃(Pb₃O₄) sample. Both EDS and XPS analysis can confirm the existence of Bi-rich grain boundary phase in BiFeO₃–PbTiO₃(Pb₃O₄) sample. In addition, it can be found that the concentration of oxygen vacancies and Fe²⁺ ions in BiFeO₃–PbTiO₃(Pb₃O₄) sample is significantly higher than that of in BiFeO₃–PbTiO₃(PbO) sample, which is in good consistent with the high conductivity in BiFeO₃–PbTiO₃(Pb₃O₄) sample. This result will be helpful to the suitable lead raw material for preparation of BiFeO₃–PbTiO₃ based piezoelectric ceramics with high resistivity.