Fabrication and high-power piezoelectric characteristics of textured (Sr0.7Ca0.3)2Bi4Ti5O18 ceramics

Abstract

High-power piezoelectric characteristics under continuous driving were studied for lead-free piezoelectric ceramics of a textured bismuth layer-structured ferroelectric, (Sr0.7Ca0.3)2Bi4Ti5O18 + 0.2 wt % MnCO3 (abbreviated to HF-SCBT) and a non-oriented specimen (OF-SCBT). The orientation of the grains can improve their high-power piezoelectric properties such as the vibration velocity, v0–p. The value of v0–p for the HF-SCBT ceramic exceeded 2.0 m/s at an applied electric field of 3 V/mm under short- and long-time driving. We also observed that the change in resonance frequency under long-time driving for OF- and HF-SCBT was less than 0.15% at a v0–p of 2.0 m/s. Thus, the force factor, A, of HF-SCBT was superior to that of OF-SCBT. The reason for these results is considered to be that d33 for HF-SCBT was 1.5 times as large as that for OF-SCBT.