Defect Control for Polarization Switching in BiFeO3 Single Crystals

BiFeO3(BFO) single crystals were grown and the effects of Zn and Mn co-doping on the polarization and leakage current properties were investigated at 25 degrees C for establishing materials design based on defect chemistry. Although Zn doping or Mn doping led to a deterioration in the properties, Zn-Mn co-doping led to a large remanent polarization (36 mu C/cm(2)), a low coercive field (19 kV/cm), and a relatively low leakage current density (similar to 10(-8) A/cm(2)). It is proposed that defect dipoles composed of Zn2+ and Mn4+ act as effective nucleation sites for ferroelectric domains during polarization switching in BFO crystals.