Ferroelectric domain structures in strained BiFeO3 ceramics synthesized by spark plasma sintering

The ferroelectric domain structures were analyzed in strained multiferroic BiFeO3 ceramics via X-ray diffraction (XRD), scanning electron microscope (SEM) and electron backscatter diffraction (EBSD). XRD refinements indicate that the SPS method introduced the large strain into the ceramic samples even though similar to 50% strain reduction could be conducted through annealing process. The large strain increased the contents of unusual 71 degrees +/- 1 degrees grain boundaries and deformed 71 degrees domain walls (similar to 89 degrees twin boundaries) both in the as-sintered sample and the annealed sample, which could accommodate the grain boundary energy and the large thermal strain. The large strain was more conducive to form typical curved and bridge-like 180 degrees domain morphologies. And the domain topographies heavily relied on the grain orientations.