Effect of sintering temperature on structural, dielectric, piezoelectric and ferroelectric properties of sol-gel derived BZT-BCT ceramics

The effects of sintering temperature on the structural, dielectric, piezoelectric and ferroelectric properties of sol gel derived lead-free 0.5Ba (Zr0.2Ti0.8)O-3-0.5(Ba0.7Ca0.3)TiO3 (BZT-BCT) piezoelectric ceramics have been reported in this manuscript. BZT-BCT ceramics sintered at 1550 degrees C for 2 h resulted in homogeneous and highly dense microstructure with similar to 96-97% of the theoretical density and grain size of similar to 10 mu m. The results indicated a strong influence of the sintering temperature on the structural, dielectric, piezoelectric and ferroelectric properties of BZT-BCT ceramics. BZT-BCT ceramics sintered at 1550 degrees C for 2 h resulted in high piezoelectric charge coefficient d(33)similar to 617 pC/N, large planar electromechanical coupling factor k(p) similar to 54%, large piezoelectric voltage constant g(33)similar to 11.5 mV m/N, high dielectric constant epsilon(r)similar to 5000, and a low tan delta similar to 0.019. The correlation of dielectric, piezoelectric and ferroelectric properties of the BZT-BCT ceramics with sintering temperature has been explained on the basis of grain size effect and motion of the 90 degrees domain walls. (C) 2015 Elsevier Ltd and Techna Group S.r.l. All rights reserved.