Synthesis, structural and electrical properties of La modified PZT system

Lead zirconate titanate (PZT) ceramics with Zr/Ti (70:30) have been synthesized with the substitution of (8, 10 and 12 mole%) of La. Polycrystalline samples were prepared by high temperature solid-state reaction technique. XRD study reveals the formation of single-phase perovskite structure for all the compositions. There is a transformation in crystal structure observed from tetragonal to co-existence of tetragonal and orthorhombic to single orthorhombic phase with the increase in lanthanum concentration in the basic PZT composition. Detailed dielectric study has been performed and results indicate the shift in transition temperature from lower to the higher side. Ferroelectric hysteresis behaviour was also studied as a function of applied electric field for all the three compositions. Slimming behaviour of the loops was found with the increase in La concentration, which may be attributed to the tendency towards the antiferroelectric nature of the material.