Templated grain growth of textured Sr2Nb2O 7

Sr₂Nb₂O₇, a candidate material for high temperature piezoelectric applications, is difficult to pole as a polycrystalline ceramic. To circumvent this problem, a process based on templated grain growth (TGG) for producing textured samples was developed. To accomplish TGG, fine matrix powder, single crystal template particles, and a fabrication technique for orienting template particles in the matrix are required. Single crystal template particles were synthesized by a molten salt technique. The matrix powder was synthesized by solid state reaction of SrCO₃ and Nb₂ O₅ in a 2:1 molar ratio. The template particles were dispersed in the matrix powder and tape cast. The initial orientation was induced by the shear field during tape casting and subsequent lamination. Sintering leads to the growth of oriented template particles in the dense matrix, thereby increasing the degree of grain-orientation. The effect of processing parameters and starting powders on the microstructure and texture is presented