Effect of strontium doping on dielectric, ferroelectric and piezoelectric properties of PLZTN ceramics

Ceramic compositions of [Pb1−x−yLaxSry][(ZrzTi1−z)(1−(x/4)−(5/4)k)Nbk]O3 (PLSZTN), where y = 0, 0.5, 1.0 and 1.5 mol% have been fabricated by solid-state reaction method. Introduction of strontium in PLZTN lattice showed ferroelectric tetragonal nature and further increment of Sr2+ favored intensified tetragonality. Microstructure studies revealed that grain growth enhanced with the addition of Sr2+ and inter-diffusion between multiple ions promoted apparent density in the ceramics. The substitution of isovalent Sr2+ at Pb-site and donor pentavalent Nb5+ at Zr/Ti-site enhanced the dielectric constant (ɛRT = 2384) while decreasing the Curie temperature (Tc). The substitution of 1.5 mol% Sr evidently increased ferroelectric properties (remanent (Pr = 32.66 μC/cm2) and spontaneous (Ps = 38.54 μC/cm2) polarization), respectively. Sr-modified PLZTN showed a significant influence on the piezoelectric properties which enhanced till 1.5 mol% Sr in PLZTN ceramic system, which may be applicable for possible sensor and actuator applications.