Abstract
The piezoelectric properties in some bismuth layer-structured ferroelectric (BLSF) ceramics were investigated focusing on a mechanical quality factor, Qm. Many BLSF compositions with various Curie temperature, Tc, were selected in this study, and the Qm values of (33) mode were plotted as a function of their Curie temperature, Tc. The Qm increased with increasing the Tc in the low Tc compositions below 500°C. It is considered to relate with the domain wall pinning because the coercive field, Ec also increased with increasing the Tc. However, in the high Tc compositions above 750°C, the Qm decreased with increasing the Tc contrary, because of the difficulties in poling treatment due to the Ec. On the other hand, high Qm values more than 10,000 were obtained in the intermediate Tc compositions between at 500 to 750°C. These values are quite high as the piezoelectric ceramics. The key point of the high Qm in these compositions is the poling process at high temperature of 300°C.
