Ferroelastic domains and anisotropy in lead free piezoelectrics

Our research investigates the correlations between domain textures and microstructural features, including crystallographic textures in bulk and thin film polycrystalline materials to understand the development of piezoelectric and other anisotropic properties in a number of rapidly evolving lead free piezoelectric materials. We investigate approaches to understand polarization distributions, by starting from polarization measurements. In addition, 2D and 3D microstructural simulations are carried out in all types of ferroelectrics to rationalize and then engineer their equilibrium and kinetic response. This paper discusses recent findings associated to bulk piezoelectricity, phase stability, and ferroelastic and ferroelectric domain motion for materials such as Ba(Zr_0:2Ti_0:8)O₃-(Ba_0:7Ca _0:3)TiO₃ (BZT-BCT) and Bi_0:5Na _0:5TiO₃(BNT). Conventional and synchrotron-based x-ray diffraction, electron and optical microscopies and piezoelectric characterization techniques are employed to assess texture, both as a function of poling and temperature. The coupling between microstructure and the inherent directional biases fundamental to piezoelectric and ferroelectric performance enable consideration of orientation and anisotropy in systems with unique constraints.