The effect of lanthanum substitution on εr and kp aging rates of niobium doped Pb(Zr0.95Ti0.05)O3 ceramics

Lead zirconate titanate (PZT)-based piezoelectric ceramics with a composition of (Pb0.99-3x/2Lax)(Zr0.95Ti0.05)(0.98)Nb0.02O3, where x = 0.0, 0.004, 0.005, and 0.006 were prepared by a combined method of B-site precursor, whereby ZrO2, TiO2, Nb2O5, and La2O3 were pre-reacted, prior to reaction with PbO. Then the wet mechanically activated PZT calcinates prepared using a planetary ball mill were pressed into pellets and sintered at 1275 degrees C for 2 h in air. The effect of lanthanum substitution on the microstructure and dielectric constant and electromechanical coupling coefficient aging rate of the samples were studied. The results showed that lanthanum substitution was beneficial for reduction dielectric constant and electromechanical coupling coefficient aging rate of the samples and the samples with 0.4 mol% lanthanum exhibited the minimum er and k(p) aging rates of -0.86 and -6.28%, respectively, less than that of La free samples(-1.49 and -11.19%, respectively).