Evaluating energy harvesting and different functional properties of microwave synthesized NBT-KNN binary solid solution

Abstract

In this study, a solid solution of(1-x)(Na0.5Bi0.5)TiO3-(x)(K0.5Na0.5)NbO3 ceramics was synthesized using a microwave synthesis method for different values of x (0 %, 1 %, 3 %, and 5 %). The investigation focused on structural phase formation, microstructure, electrical properties, ferroelectric behavior, and energy harvesting. The NBT-KNN ceramics were found to have a perovskite structure with both rhombohedral and tetragonal symmetry. The addition of KNN to NBT ceramics resulted in a decrease and broadening of the phase transition temperature. The dielectric analysis also revealed the existence of a Morphotropic Phase Boundary (MPB) for compositions between x = 3 % and 5 %, highlighting their significant potential for real-world applications. The ferroelectric behavior of NBT-KNN ceramics synthesized through microwave processing was verified using P-E loop analysis. Among the compositions, NBT-KNN3 % demonstrated the highest energy output, achieving a peak voltage of 19.55 V at an optimized load resistance of 1 M Omega, with a corresponding power density of 46.04 mu W/ cm2. A wide temperature range with enhanced dielectric and piezoelectric properties was observed due to the MPB regime's broadening caused by microwave-based synthesis's compositional inhomogeneity. The results suggest that this synthesis method can be used as an effective tool for expanding the MPB in ferroelectric compositions to improve the above properties.