2008 年 33 巻 1 号 p. 53-56
We have investigated the effects of high-oxygen-pressure crystal growth of ferroelectric Bi4Ti3O12 on the polarization properties along the a(b) axis. Domain observations by piezoresponse force microscope demonstrated that a small remanent polarization (Pr) for the crystals grown with 0.02 MPa oxygen pressure is attributed to the clamping of 90° domain walls by oxygen vacancies. The vacancy formation of Bi and 0 during crystal growth at high temperatures is suppressed at a higher oxygen pressure, leading to a larger Pr of 47 C/cm2 for the crystals grown at I MPa oxygen. High-oxygen-pressure sintering is proposed to be effective for obtaining Bi4Ti3O12-based devices with enhanced polarization properties.
