Preparation and Characterization of Textured (K0.5Na0.5)NbO3Ceramics by Reactive Templated Grain Growth

NaNbO3 platelets were synthesized by the topochemical microcrystal conversion method from platelike precursor particles of layer-structured Bi2.5Na3.5Nb5O18 at 950°C in a molten NaCl-salt. The obtained NaNbO3 platelets remained the shape of precursors with width of 5–10 μm, length of 20–30 μm and thickness of 0.5–1 μm. Textured (K0.5Na0.5)NbO3 ceramics were fabricated by using the NaNbO3 platelets as template in the reactive templated grain growth method. The microstructure and piezoelectric properties of textured (K0.5Na0.5)NbO3-based piezoelectric ceramics were investigated. The textured samples consists of bricklayer-like grains with sizes of 10–20μm and were found to have {001} orientation degree of 69% and higher piezoelectric constant.