Low temperature sintering and dielectric properties of (Ba0.85Ca0.15) (Ti0.9Zr0.1)O3 - xCu2+ ceramics obtained by the sol-gel technique

Lead-free Cu2+-modified (Ba0.85Ca0.15)(Ti0.9Zr0.1)O-3 (BCZT-xCu(2+)) piezoelectric ceramics was synthesized by sol-gel method. The effects of Cu2+ additions on sintering characteristics, the phase structure, microstructure, electrical properties and complex impedance characteristic were investigated systematically. The XRD patterns exhibited a pure perovskite structure without impurity phase in all samples. SEM micrographs, temperature dependence of dielectric constant and polarization-electric field (P-E) hysteresis loops indicated that a small amount of Cu2+ addition affected the properties obviously. The results revealed that the addition of Cu2+ significantly improved the sinterability of BCZT ceramics which resulted in a reduction of sintering temperature from 1440 degrees C to 1230 degrees C. The TG-DSC was analyzed to verify the reaction process of BCZT-cu(2+) materials. (Ba0.85Ca0.15)(Ti0.9Zr0.1)O-3 ceramics with x=0.020 Cu2+ exhibited good electrical properties: epsilon(m)= 12,112, T-c=360 K, epsilon(r)=2614, tan delta=0.026, K-p= 0.47 and d(33)=382 pC/N. The results indicated that Cu2+-modified BCZT ceramics could be a promising candidate for commercial purposes. (C) 2016 Elsevier Ltd and Techna Group S.r.l. All rights reserved.