Barium modified lead lanthanum strontium zirconium niobium titanate for dielectric and piezoelectric properties

The isovalent Ba2+ modified lead lanthanum strontium zirconium niobium titanate (PLSZNT) solid solutions were prepared by solid-state reaction method with the compositional formula [Pb1−x−w−yLaxSrwBay][(ZrzTi1−z)(1−(x/4)−(5/4)k)Nbk]O3 where Ba content, y, was varied from 0, 0.5, 1 and 1.5 mol%. X-ray diffraction (XRD) studies revealed that all the samples have ferroelectric tetragonal structure (FETET). The presence of multiple ions at Pb-site enhanced grain growth and further addition of Ba concentration resulted in restrained grain growth. Dielectric studies suggested that the ɛRT increased up to 1 mol% Ba while Tc has shown a continuous decreasing trend throughout the series. The piezoelectric parameters as a function of grain growth were characterized. The optimum piezoelectric charge coefficient (d33 = 538 pC/N) and piezoelectric planar coupling coefficient (kp = 0.521) was found to be in 1 mol% Ba modified PLSZNT ceramic, respectively, and this composition may be suitable for possible sensor and actuator applications.