Piezoelectric performance and domain structure of epitaxial PbTiO ₃ thin film deposited by hydrothermal method

The hydrothermal method enables the high quality epitaxial PbTiO ₃ deposition at 150°C and we have already reported on the ferroelectric properties of an about 100-nm-thick PbTiO₃ film. In this study, the piezoelectric properties of a 430-nm-thick PbTiOj epitaxial film were examined. The domain structure was composed of predominantly the +c-domain and a small amount of the a-domain. The DE hysteresis curve and piezoelectric strain were asymmetrical because the initial domain structure was stable and difficult to reverse perfectly with an external electric field. The strain has an excellent linearity, and d_33effec coefficient was found to be 97 pC/N, which is larger than the predicted value. The large-piezoelectric performance and excellent linearity are suitable for ultrasonic transducers applications.