Dependence of dielectric behavior in BiFeO3 ceramics on intrinsic defects

► BiFeO3 ceramics were sintered using a rapid heating and quenching technique. ► The XRD and XPS analyses showed the changeable valence of Fe component. ► The unavoidable Fe2+ ions may play a fundamental role in BFO ceramics. ► The high Fe2+ ions led to high dielectric loss and large dielectric dispersion.