Ferroelectric polarization and defect-dipole switching in an epitaxial (111) BiFeO3 thin film

Abstract

The time and field control of defect-dipole alignment as well as ferroelectric polarization switching has been investigated in an epitaxial BiFeO3 thin film. Under electric field poling, a double hysteresis loop arising from individual ferroelectric domain switching and defect dipole alignment can be artificially induced after one long enough pre-poling time. Meanwhile, the alignment of defects dipoles can increase the leakage current of the film. The activation field for the defect dipole alignment is extracted to be around 192 MV/m. These results demonstrate the possibility of strengthened polarization contributed by defect dipole poling in ferroelectric thin films.