title: Electron microscopy studies of potassium sodium niobate ceramics.
abstract: Using electron microscopy, K0.5Na0.5NbO3 (KNN) ceramics sintered at 1030 degrees C for 8 h and 1100 degrees C for 2 and 24 h was studied. The scanning electron microscopy and X-ray spectrometry revealed that the materials consisted of a matrix phase in which the (Na+K)/Nb ratio corresponded closely to the nominal composition and a small amount of Nb-rich secondary phase. A bimodal microstructure of cube-shaped grains was revealed in the fracture and thermally-etched surfaces of the KNN. In the ceramics sintered at 1100 degrees C, the larger grains (up to 30 mum across), contained angular trapped pores. The transmission electron microscopy analysis revealed that the crystal planes of the grains bordering the intragranular pore faces were of the {100} family with respect to the simple perovskite cell. Ferroelectric domains were observed in the grains of this material.
authors.affiliation: "Jozef Stefan" Institute, Electronic Ceramics Department, Jamova 39, SI-1000 Ljubljana, Slovenia. darja.jenko@ijs.si
authors.forename: Darja
authors.initials: D
authors.lastname: Jenko
authors.forename: Andreja
authors.initials: A
authors.lastname: Bencan
authors.forename: Barbara
authors.initials: B
authors.lastname: Malic
authors.forename: Janez
authors.initials: J
authors.lastname: Holc
authors.forename: Marija
authors.initials: M
authors.lastname: Kosec
mesh_terms: D002516:Ceramics / Q000138:chemical synthesis / Q000737:chemistry*; D008854:Microscopy, Electron; D008855:Microscopy, Electron, Scanning; D009556:Niobium; D011188:Potassium; D012964:Sodium
chemical_list: D009556:Niobium; D012964:Sodium; D011188:Potassium