Poling dependence and stability of piezoelectric properties of Ba(Zr 0.2Ti0.8)O3-(Ba0.7Ca 0.3)TiO3 ceramics with huge piezoelectric coefficients

Poling dependence and stability of piezoelectric properties of lead-free 0.5Ba(Zr_0.2Ti_0.8)O₃-0.5(Ba_0.7Ca _0.3)TiO₃ ceramics were investigated. The experimental results indicated that the poling condition has an obvious effect on the piezoelectric properties due to the existence of a phase transition near room temperature. The best piezoelectric coefficient d₃₃ and planar electromechanical coupling factor k_p could reach 630 pC/N and 56%, respectively as the poling conditions were optimized. However, these properties exhibit strong temperature and time dependences, owing to a rather low depolarization temperature (below 80-90 °C) and extremely high aging rate (30% and 25% loss for d₃₃ and k_p, respectively, 10 ⁴ min after poling). © 2011 Elsevier B.V. All rights reserved.