High-temperature and high-power piezoelectric characteristics of (Bi0.5Na0.5)TiO3-Based lead-free piezoelectric ceramics

The high-power piezoelectric characteristics of (Bi0.5Na0.5)TiO3 (BNT)-based solid solutions at a high temperature (similar to 130 degrees C) were studied, by comparing them with those of hard Pb(Zr, Ti)O-3 (PZT) ceramics. The vibration velocity v(0-p) of the BNT-based ceramics was stable as the temperature increased to 130 degrees C, whereas that of the PZT-based ceramics markedly decreased with increasing temperature. It is generally known that the stability of v(0-p) under high-amplitude vibration is related to mechanical losses caused by domain wall motion. Therefore, the temperature dependence of the mechanical quality factor Q(m) of these ceramics was measured by electric transient response measurement. The measured Q(m) values of the BNT-based ceramics were nearly constant or slightly decreased with increasing temperature, whereas Q(m) for the PZT ceramic markedly decreased with increasing temperature. (C) 2014 The Ceramic Society of Japan. All rights reserved.