High-power piezoelectric properties of quenched (Bi0.5Na0.5)TiO3-based solid-solution ceramics

Abstract

Lead-free piezoelectric ceramics based on 0.90(Bi0.5Na0.5)TiO3 – 0.04(Bi0.5Li0.5)TiO3 – 0.06BaTiO3 with additives MnCO3 (0.1 wt%) [BNLBT4-6 + Mn0.1], which have a morphotropic phase boundary composition, were prepared by controlling the quenching rate (QR) and, their high-power piezoelectric and electrical properties were examined. The depolarization temperature Td could be increased by controlling the QR. The Td with QR = 15.0 and 0.05 °C/s was 166 and 119 °C, respectively. Thus, Td was increased by about ∼40 °C due to the quenching effect. Moreover, vibration velocities (v0−p) were observed at 1.3 m/s even after quenching. Additionally, the values of d31, ɛ33T/ɛ0, and s11E decreased, whereas Qm increased after quenching. The quenching effect promoted the dielectric and elastic hardening of BNLBT4-6 + Mn0.1 ceramics. After quenching, Td increased, and the value of d31 × Qm maintained the same value as for ordinary firing (OF) with QR = 0.05. Consequently, quenching was found to be effective for increasing the Td and Qm, hence, a promising effect for high-power piezoelectric applications.