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

摘要

To achieve the surface-orientation-controlled microstructure of K_(0.5)Na_(0.5)NbO3, 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 K_(0.5)Na_(0.5)NbO3 must be carefully considered. In this work, we focused on what kinds of ceramics are suitable for the fabrication of the surface-orientation-controlled K_(0.5)Na_(0.5)NbO3. First of all, BaTiO3, SrTiO3, Ba(Zr_(0.1)Ti_(0.9))O3, KNbO3l 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 K_(0.5)Na_(0.5)NbO3, the prepared candidate ceramic bulks were embedded by the K_(0.5)Na_(0.5)NbO3 powder, they were annealed at 1100 °C, and then the interface regions between candidate ceramics and K_(0.5)Na_(0.5)NbO3 were investigated using Secondary Electron Microscopy (SEM) equipped with Energy Dispersive Spectrometer (EDS). From these experimental results, BaTiO3, SrTiO3, Ba(Zr_(0.1)TiO.9)O3, KNbO3 and NaTaO3 were found to be not appropriate for the templates for the tailoring of K_(0.5)Na_(0.5)NbO3, while the NaNbO3 and KTaO3 showed a good crystallographic coherency and a chemical stability with K_(0.5)Na_(0.5)NbO3.