Effect of La on piezoelectric properties of Pb(Ni1/3Sb2/3)O3–Pb(ZrTi)O3 ferroelectric ceramics

Abstract

Piezoceramic compositions Pb1−zLaz(NiSb)0.05[(Zr0.52Ti0.48)1−Z/4]0.95O3 with Z = 0.01–0.05 were synthesized by mixed oxide route to study the effect of Lanthanum (La) on crystal structure, microstructure, piezoelectric and ferroelectric properties. Calcination was performed at 1,060 °C and sintering at 1,270 °C for 1 h. X-Ray diffraction pattern indicated the polycrystalline microstructure along with co-existence of tetragonal and rhombohedral perovskite phases. Dielectric constant ( $$ K_{3}^{T} $$ ) was increased whereas piezoelectric voltage constant (g 33) was decreased with increase in lanthanum. Dense microstructure was observed for the composition containing 3 mol% of lanthanum. This was resulted in optimum piezoelectric charge constant (d 33 = 468 × 10−12 C/N), electromechanical coupling factor (k p = 0.68), remanent polarization (P r = 24.65 μC/cm2) and displacement (D = 2,012 nm). Results indicated that the composition Pb0.97La0.03(NiSb)0.05[(Zr0.52Ti0.48)0.9925]0.95O3 could be suitable for actuator applications. The composition Pb0.98La0.02(NiSb)0.05[(Zr0.52Ti0.48)0.995]0.95O3 resulted into moderately high value of voltage constant (g 33 = 39.3 × 10−12 V m/N) and optimum value of Figure of Merit (d 33 × g 33 = 16.2 × 10−12 C V m/N2) indicated the usefulness for sensor and power harvesting applications.