The effects of Zr/Ti ratio on the dielectric and piezoelectric properties of the sintered Pb(Zr_xTi_(1−x))_0.99Nb_0.01O₃ piezoelectric ceramics across the entire range of phase diagram of the PZT solid solution was studied systematically. The materials were prepared by the conventional mixed oxide process. The phase purity and crystal structure of the calcined powders and sintered ceramics was analysed using X-ray diffraction. The microstructure of the sintered ceramics has been investigated using scanning electron microscopy. It is seen that even though there is a significant increase in dielectric constant (ϵ_r) and piezoelectric charge coefficient (d₃₃) at the PZT-52 (MPB) composition, the voltage sensitivity (g₃₃) of the PZT-0 (lead titanate) ceramics are higher than that of MPB.

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A high-voltage coefficient has been found in lead-free piezoelectric particulate composites based on epoxy with lead-free (K_0.50Na_0.50)_0.94Li_0.06NbO₃ (KNLN) piezoceramic particles with a natural cubic morphology. The KNLN powder used in the composites has been prepared using a new solid-state double calcination processing route. These particles were subsequently used to create random and structured KNLN-epoxy composites. Using dielectrophoresis, these natural cubical KNLN particles were structured into one-dimensional chains inside the epoxy matrix. Composites produced with these powders showed piezoelectric properties about a factor of 2 higher than those of composites processed with conventionally calcined KNLN powders. The dielectrophoretically structured KNLN-epoxy composites with optimized particle size and morphology showed excellent piezoelectric properties, which can replace lead containing piezoelectric composites for sensor and energy harvesting applications in future.

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Modern flexible and sensitive sensors based on polymer–ceramic composites employ lead zirconate titanate (PZT) granulates having the morphotropic phase boundary (MPB) composition as the piezo active ingredient, as this composition gives the best properties in fully ceramic piezoelectric sensors. In this study, the possibility of using PZT granulates with compositions, which are not in the MPB region of the PZT phase diagram was investigated. Random 0–3 PZT–epoxy composites were prepared for the complete composition range of PZT ceramics [Pb(ZrxTi(1−x))0.99Nb0.01O3] with x ranging from x = 0 to x = 0.80. Piezoelectric and dielectric properties of such composites were systematically studied. It is shown that the highest voltage sensitivity (i.e. g33) of the piezoelectric composites is obtained for composition with much lower Zr levels (x @en