Host: The Ceramic Society of Japan
We have investigated the interaction between oxygen vacancies (Vo••) and domain dynamics in ferroelectric Bi4Ti3O12 (BiT) crystals during the a-axis polarization switching. Piezoresponse force microscope (PFM) observations showed that, even after a high electric field of 100 kV/cm was applied along the a(b) axis, a large number of unswitched 90-deg domains were present in the BiT crystals grown in air. The 90-deg domain walls with irregularly curved configurations were observed, which suggests that the motion of 90-deg domain walls was clamped by Vo•• in the crystals. PFM observations also revealed that the number of unswitched 90-deg domains were significantly reduced in the crystals grown at a higher oxygen pressure. These results demonstrate that the 90-deg domain walls are clamped by Vo••, leading to a lower remanent polarization in the BiT system.
