Bismuth layer‐structured ferroelectric ceramics with high mechanical quality factor

Abstract

AbstractThe 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 temperatures, 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, because of the difficulties in poling treatment due to the Ec. On the other hand, high Qm values exceeding 10,000 were obtained in the intermediate‐Tc compositions between 500 and 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. © 2009 Wiley Periodicals, Inc. Electron Comm Jpn, 91(12): 39–45, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecj.10185