Low-temperature sintering of (1–<i>x</i>)Pb(Zr_0.53Ti_0.47)O₃–<i>x</i>BiYO₃ ceramics with nano-powder for piezo-speaker

Abstract

(1−x)Pb(Zr0.53Ti0.47)O3−xBiYO3 (PZT–x·BY) ceramics were synthesized by conventional bulk ceramic processing technology with various BiYO3 (BY) doping contents. The maximum values of the piezoelectric properties were obtained in the PZT–0.01BY samples sintered at 1160 °C. After optimizing the composition of the PZT–0.01BY piezoelectrics, the sintering temperature could be lowered down to 1000 °C by applying a nano-powder technique. The maximum values of the piezoelectric properties achieved by this novel process were: d33 of 580 pC/N, kp of 67%, and g33 of 95 mV · m N−1. Finally we fabricated a thick-film piezo-speaker with optimized PZT–0.01BY nano-powders using multi-layered ceramic capacitor processes. The sound pressure level (SPL) of the speaker was analyzed at a distance of 50 cm with a driving voltage of 5 Vrms in the frequency range of 100 Hz–11 kHz. The measured SPLmax was very high at 87 dB, which is superior quality compared with other commercial products.