Temperature dependence of dielectric and piezoelectric properties of PLZT-PZN ceramic tapes

Ferroelectric compounds of (Pb0.95La0.05) [(Zr0.52Ti0.48)(0.9)(Zn2/3Nb1/3)(0.1)](1-x/4)O-3, PLZT-PZN, were prepared using tape casting. After sintered at 1250-1350 degrees C, both dielectric and piezoelectric properties of PLZT-PZN ceramic tapes were studied at a temperature range from 20 to 230 degrees C. It was observed that the addition of PZN not only decreased the sintering temperature but also increased the dielectric constant. When the samples were sintered at a higher temperature of 1350 degrees C, the Cure point was shifted to a lower temperature probably related to composition fluctuation. It was found that the anti-resonant frequencies (f(p)) decreased with increasing temperature but the trend was reverse for resonant frequency (f(s)) that is related to the increased domain activities at higher test temperatures. The electromechanical coupling factor (K-p) was found to decrease but mechanical quality factor (Q(m)) to increase with increasing test temperature. The variation in both values of K-p and Q(m) with temperature can be elucidated using equivalent circuit evaluation and attributed to the compressed frequency difference (Delta f) and increased resonance resistance (R-1) value based on the analysis of equivalent piezoelectric parameter evaluation. (C) 2007 Published by Elsevier B.V.