Abstract
Abstract(K1–xNax)NbO3 (x = 0.01, 0.24, 0.89, 0.91, 0.99) single crystalline powders with perovskite structure were synthesized by a hydrothermal method with Nb2O5 in a mixed solution of KOH and NaOH at 220 °C for 24 h. XRD investigations showed that the structure of the synthesized (K1–xNax)NbO3 ceramics changed from a KNbO3‐type orthorhombic phase (space group Bmm2) to a NaNbO3‐type monoclinic phase (space group Pm) with the increase of Na content. The present results confirmed that (K1–xNax)NbO3 exhibited a morphotropic phase boundary (MPB) at around 50 %K separating the orthorhombic phase and monoclinic phase. FE‐SEM images showed that the morphological structures of niobates were cubes and nanofingers. The TEM image and the selected area electron diffraction pattern of (K0.01Na0.99)NbO3 showed the as‐synthesized powder was single crystalline and indexed to be monoclinic. The phase evolution of the products in the hydrothermal route revealed that the hydrothermal synthesis of (K1–xNax)NbO3 underwent two steps, where an intermediate product (K8–8xNa8x)Nb6O19·n H2O was found in the early stage and then pure (K1–xNax)NbO3 was obtained after another 30 min of hydrothermal treatment.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
