Abstract
Domain switching process of bismuth titanate single crystals was investigated under application of electric field along the crystallographic c axis through polarization measurements and domain observations by optical microscope and piezoelectric force microscope. While unpoled crystals exhibited a poor polarization hysteresis, the crystals which were poled at 150°C showed a well-saturated polarization hysteresis with a remanent polarization of 4.4 micro C/cm2 and a coercive field of 4.7 kV/cm. Domain observations reveal that lenticular domain acts as an initial nucleus both in the poled and unpoled crystals during polarization switching of the c-axis component. The sidewise motion of the lenticular-domain walls and resultant single domain state were easily established for the poled crystals, while the lenticular domains observed in unpoled crystals were clamped even though a high electric field was applied to them.
