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))Nb-k]O-3 (PLSZTN), where y=0,0.5, 1.0 and 1.5mol% 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 Si2+ at Pb-site and donor pentavalent Nb5+ at Zr/Ti-site enhanced the dielectric constant (epsilon(RT) = 2384) while decreasing the Curie temperature (T-c). The substitution of 1.5 mol% Sr evidently increased ferroelectric properties (remanent (P-r = 32.66 mu C/cm(2)) and spontaneous (P-s = 38.54 mu C/cm(2)) 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. (C) 2007 Elsevier B.V. All rights reserved.