Abstract
The paper reports the influence of lanthanum substitution on the structural, dielectric and piezoelectric properties of PZT. Polycrystalline samples were synthesized by solid state reaction technique. XRD analysis shows all the samples to be single phase with perovskite structure, initially showing rhombohedral structure and then transforming into rhombohedral. The transition temperature (Tc) was observed to decrease monotonically with increasing x. The results showed that, after poling, the dielectric constant decreased for rhombohedral composition but increased for tetragonal compositions. Electromechanical coupling factor (kp) was found to increase with x and becomes saturate at x = 0.07 mol%. Composition with x = 0.07 gives maximum value of kp = 52% and d33 = 450 pC/N. All the samples depict well defined ferroelectric behavior.