Figures of merit of PLZT ferroelectric ceramics for practical applications

Structural, microstructural and pyroelectric properties were investigated in PZT-based ferroelectric ceramics for a composition close to the morphotropic phase boundary (Zr/Ti = 53/47), as a function of the lanthanum content. The samples were prepared via the conventional solid-state reaction sintering method. Three compositions were synthetized and studied following the PbZr0.53Ti0.47O3 + x mole% La nominal formula(,) where x = 0.0, 2.5 and 5.0. The structural characterization confirmed the presence of both tetragonal and rhombohedral phases for all the studied compositions, showing a decrease in the tetragonality factor (c/a) with the increase of the lanthanum concentration. The observed decrease in the stability of the ferroelectric phase (in favor of the paraelectric one) have been discussed in light of the solubility of the doping cation into the studied PZT perovskite structure. Microstructural properties revealed low pores concentration micrographs, showing homogeneous microstructures and uniform grain-sizes. The pyroelectric response of the as-prepared PLZT samples was also investigated in a wide temperature interval. The lower lanthanum content composition exhibited the best properties, characterized by a high pyroelectric coefficient and enhanced figures of merit. These characteristics make such a composition a promising material for practical applications.