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(Zr0.53Ti0.47)O-3) was studied. The powders were prepared by "wet-chemical" route followed by calcination at 800 degrees C 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 (d(33)) 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.