Stability of defects in lead-zirconate-titanate after unipolar fatigue

Bipolar fatigue in ferroelectric lead-zirconate-titanate was previously shown to induce stable pinning centers for ferroelectric domain walls resulting in a significant loss in switchable polarization, but only fairly weak offsets were induced. The corresponding scenario after unipolar fatigue is reversed inducing fairly stable offsets while hardly any loss in domain mobility is encountered. The charged defects inducing the offsets are suggested to be located at grain boundaries, while pinning centers reducing domain wall mobility predominantly reside within the grain. (C) 2002 American Institute of Physics.