Studies on the structural and piezoelectric properties of ZnO added on Na_0.47K_0.47Li_0.06NbO₃ ceramics prepared by ceramic method using high energy ball milling

Sodium potassium niobate (KNN) based piezoceramics added with different amount of ZnO were prepared by ceramic method using high energy ball milling. The samples prepared have compositional formula Na_{0. 47}K_0.47Li_0.06NbO₃ + (x) ZnO (x = 0 wt%, 0.5 wt%, 1 wt%, 1.5 wt%, and 2 wt%) and sintered at 1000 ^°C for 2 h. The crystalline phase, microstructure, electrical properties of the samples such as dielectric constant, dielectric loss as well as a.c conductivity of the prepared samples were investigated. It was observed that the addition of ZnO to Na_0.47K_0.47Li_0.06NbO₃ ceramics enhanced the density, electrical properties as well as piezoelectric property. X-ray diffraction (XRD) confirmed a perovskite tetragonal phase in all the samples. The X-ray density was found increased and the maximum value was obtained at 1 wt% ZnO addition Polarization–electric field (P-E) loop for the samples was traced and the remnant polarization value is found to be highest at 1 wt% ZnO addition with maximum piezoelectric constant, d₃₃ ~ 86 pC/N amongst all the samples under study. The results of the various measurements were explained in this paper.