Poling dependence and stability of piezoelectric properties of lead-free 0.5Ba(Zr0.2Ti0.8)O-3-0.5(Ba0.7Ca0.3) 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 d(33) 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 degrees C) and extremely high aging rate (30% and 25% loss for d(33) and k(p), respectively, 10(4) min after poling). (C) 2011 Elsevier B.V. All rights reserved.