Examination of selectivity of templates for the textured potassium sodium niobate ceramics

To achieve the surface-orientation-controlled microstructure of K0.5Na0.5NbO3, not only the template must exhibit the high anisotropy like a plate-shape but the reactive stability as well as the crystallographic coherency between the template and the K0.5Na0.5NbO3 must be carefully considered. In this work, we focused on what kinds of ceramics are suitable for the fabrication of the surface-orientation-controlled K0.5Na0.5NbO3. First of all, BaTiO3, SrTiO3, Ba(Zr0.1Ti0.9)O3, KNbO3, NaNbO3, KTaO3 and NaTaO3 were chosen as the candidates in the regard of the crystallographic coherency. To verify the chemical stability between candidate ceramics and K0.5Na0.5NbO3, the prepared candidate ceramic bulks were embedded by the K0.5Na0.5NbO3 powder, they were annealed at 1100 °C, and then the interface regions between candidate ceramics and K0.5Na0.5NbO3 were investigated using Secondary Electron Microscopy (SEM) equipped with Energy Dispersive Spectrometer (EDS). From these experimental results, BaTiO3, SrTiO3, Ba(Zr0.1Ti0.9)O3, KNbO3 and NaTaO3 were found to be not appropriate for the templates for the tailoring of K0.5Na0.5NbO3, while the NaNbO3 and KTaO3 showed a good crystallographic coherency and a chemical stability with K0.5Na0.5NbO3.