The Effect of Texture and Microstructure on the Macroscopic Properties of Polycrystalline Piezoelectrics: Application to Barium Titanate and PZN–PT

Abstract

The effects of crystallographic texture and microstructure are analyzed for polycrystalline tetragonal BaTiO3, pseudotetragonal PZN–PT, and cubic BaTiO3. For tetragonal BaTiO3 and pseudotetragonal PZN–PT, we demonstrate that a high anisotropy of the single‐crystal properties induces an apparent enhancement in the macroscopic piezoelectric response. For tetragonal BaTiO3, the predicted macroscopic piezoelectric constants d31 and d33 are enhanced with respect to its single‐crystal value at the expense of the spatial contributions from d15. For samples possessing fiber texture, an optimal response is predicted for samples that are not perfectly textured. Similarly, an apparent enhancement of the macroscopic value of d15 is predicted for PZN–PT. For cubic BaTiO3, the low anisotropy of the underlying crystal properties induces a uniform decrease of the macroscopic electrostrictive constant, Q11, with decreasing texture. A completely random polycrystal provides 0.85±0.05 times its single‐crystal response.