A Novel Calcining Method Used to Fabricate the K 0.5 Na 0.5 NbO 3 Ceramics.

K0.5Na0.5NbO3ceramic prepared by a conventional solid-state reaction process (calcinated at 850°C and sintered) is so fragile that it can not be used to measure dielectric properties. In this paper, we use a two-step calcining method to synthesize KNN composition, with a hydrothermal treatment (200°C for 4 hrs) preceding the calcining process (750°C and 850°C for 2 hrs). Following the hydrothermal treatment and calcining the KNN ceramic was sintered at 1100°C ∼ 1160°C. X-ray diffraction patterns for all KNN ceramics showed a perovskite structure with orthorhombic symmetry. The effects of different calcining and sintering temperatures on the properties of the resulting KNN ceramic, including surface morphology and dielectric characteristic, were recorded and analyzed. [ABSTRACT FROM AUTHOR]