Ferroelectric domain wall pinning at a bicrystal grain boundary in bismuth ferrite

The ferroelectric polarization switching behavior at the 24° (100) tilt grain boundary (GB) in an epitaxial multiferroic BiFeO3 bicrystal film is studied using piezoresponse force microscopy (PFM). The PFM amplitudes across positively and negatively poled GB regions suggest the presence of a frozen polarization component at the interface. The switching experiments demonstrate that the GB attracts the domain wall and acts as a pinning center. The PFM results are compared with conductive atomic force microscopy and spectroscopy, which suggest domain wall pinning at the GB can be partially attributed to increased conductance at the GB. © 2008 American Institute of Physics.