Effect of NaCl on the microstructure and electrical properties of K_0.5Na_0.5NbO₃ ceramics prepared by cold sintering process

K_0.5Na_0.5NbO₃ ceramics are considered as a potential candidate for PZT due to its excellent electrical properties and high Curie temperature. In this work, Cold sintering process (CSP) has been used in preparing the K_0.5Na_0.5NbO₃-NaCl ceramics. Based on the experimental characterization, utilizing NaCl aqueous solutions as a transient solvent can change the grain microstructure of KNN ceramics, inhibit the volatilization of alkali metal elements, and lower the sintering temperature. As sintering at 900 °C, the electrical properties of the ceramic were T_c= 448 °C, d₃₃= 115 pC/N, k_p= 32%, and the obtained sample had an average grain size of 0.5 μm. The results indicate that CSP with NaCl aqueous solutions is an efficient method for low-temperature sintering of KNN ceramics with uniform grain size as well as good performance in electrical properties.