Effect of lanthanum, neodymium on piezoelectric, dielectric and ferroelectric properties of PZT

The effect of La³⁺ and Nd³⁺ on piezoelectric, dielectric and ferroelectric properties of PZT (Pb(Zr_0.53Ti_0.47)O₃) was studied. The powders were prepared by “wet-chemical” route followed by calcination at 800 ℃ for 4 h. XRD analysis of the calcined powders confirms the tetragonal phase in the undoped PZT, which gradually decreases with the dopant concentration and the appearance of rhombohedral phase simultaneously. SEM study of sintered pellets reveals the decrease in grain size with the increase in dopant concentration beyond 0.02 mol Nd³⁺ and 0.03 mol La³⁺ respectively. The piezoelectric constant (d₃₃) and dielectric properties were maximum for 0.02 mol Nd³⁺ and 0.03 mol La³⁺ respectively. The remnant polarization of La³⁺-doped sample was higher than Nd³⁺-doped sample, and the sample with combined dopants shows intermediate remnant polarization (P_r). Based on the above study, it is concluded that La³⁺ is more effective than Nd³⁺, including in a mixture of La³⁺ and Nd³⁺ dopants.