Effect of particle sizes of starting materials on microstructure development in textured Bi0.5(Na0.5K0.5)0.5TiO3

Microstructure development in Bi-0.5(Na0.5K0.5)(0.5)TiO3 prepared by a reactive-templated grain growth process was dependent on the sizes of platelike Bi4Ti3O12 (BiT) and equiaxed TiO2 particles used as starting materials. Calcined compacts were composed of large, platelike template grains and small, equiaxed matrix grains, the sizes of which were determined by those of the BiT and TiO2 particles, respectively. Texture was developed by the growth of template grains at the expense of matrix grains during sintering, and a new mechanism of grain growth was proposed on the basis of microstructure observation. The grain growth rate was determined by the template and matrix grain sizes, and a dense ceramic with extensive texture was obtained using small BiT and TiO2 particles.