Investigation of nonstoichiometric Fe on the ferroelectric properties of BiFeO3-based piezoelectric ceramics.

Enhanced comprehensive performances of piezoelectric and temperature stability are obtained in 0.725Bi 1.05 Fe x O 3 -0.275BaTiO 3 -0.3%MnO 2 ceramics via tuning nonstoichiometric Fe content. The Fe content strongly affects the phase structure of ceramics, which possess rhombohedral-pseudocubic coexistence structure, boosting the high piezoelectricity in this system. The optimal comprehensive performances of ceramics are obtained at x ​= ​0.98 with a relatively large piezoelectricity (d 33 ∼158 ​pC/N) as well as a high Curie temperature (T C ∼523 ​°C). We found that the deficiency of Fe content gives rise to diffused phase boundary and oxygen vacancies, which induces strong thermal stability over a wide temperature range in the composition. This work discloses the Fe content play an important role in the crystal structure of BF-based materials. We expect that the investigation on nonstoinchiometry of Fe will lead an effective method to develop high-performance BiFeO 3 -based ceramics for lead-free electronic applications. [Display omitted] • The influence of doped Fe content in BF-BT ceramics on crystal structure has been investigated through the Rietvled refinement, especially on the distortion degree of phase. • The effect of Fe content on microstructure, especially the temperature stability of domain structure, was studied. • The BF x -BT-Mn ceramics have huge potential for application because of its excellent piezoelectric properties and high Curie temperature. [ABSTRACT FROM AUTHOR]