The effect of template morphologies on microstructure and properties of textured K0.5Na0.5NbO3 ceramics by RTGG method

Lead free textured K 0.5 Na 0.5 NbO 3 piezoelectric ceramics have been prepared by reactive-templated grain growth method by using NaNbO 3 with different morphologies as templates. The NaNbO 3 template particles with different edge length (10–20 µm) and thickness (0.5–2.5 µm) was synthesized through controlling Bi 1.5 Na x−1.5 Nb x O 3x+3 precursor's layer numbers x from 2 to 6 by two-step molten salt methods. The crystalline phases and microstructure of textured K 0.5 Na 0.5 NbO 3 were characterized by X-ray diffraction and scanning electron microscopy, respectively. It shows that all the K 0.5 Na 0.5 NbO 3 ceramics are orthorhombic perovskite structure with {0 0 1} orientation. By using the template particles with a ratio of edge length to thickness (l/h) =∼10, the textured ceramics with optimized piezoelectric properties was prepared. The results indicate that the enhanced properties of textured ceramics are concerned with the template morphology.