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

Abstract The effects of sintering temperature on the structural, dielectric, piezoelectric and ferroelectric properties of sol–gel derived lead-free 0.5Ba(Zr 0.2 Ti 0.8 )O 3 -0.5(Ba 0.7 Ca 0.3 )TiO 3 (BZT-BCT) piezoelectric ceramics have been reported in this manuscript. BZT-BCT ceramics sintered at 1550 °C for 2 h resulted in homogeneous and highly dense microstructure with ~96–97% of the theoretical density and grain size of ~10 µm. 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 °C for 2 h resulted in high piezoelectric charge coefficient d 33 ~617 pC/N, large planar electromechanical coupling factor k p ~54%, large piezoelectric voltage constant g 33 ~11.5 mV m/N, high dielectric constant e r ~5000, and a low tan δ ~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° domain walls.