Self-poling and electromechanical response of crystallographically textured PMN-32PT prepared by templated grain growth

Crystallographic texturing of ferroelectrics is known to improve the piezoelectrics response due to the alignment of optimal grain orientations in polycrystalline materials. Using high-energy x-ray diffraction, a ferroelastic self-poling effect was observed in crystallographically textured 0.68 Pb(Mg_1/3Nb_2/3)O₃− 0.32PbTiO₃ ceramic. It is shown that the BaTiO₃ platelet templates used to induce crystallographic texture imposed a biaxial strain causing ferroelastic domains to re-orient parallel to the template plate normal. In-situ high-energy x-ray diffraction was then used to characterize the response mechanisms of the material with applied electric fields. The textured ceramic produced a (111) lattice strain of 0.13% in the remanent state, and a 0.16% (111) unipolar lattice strain at 2 kV/mm while the untextured ceramic had a higher (111) lattice strain of 0.18% in the remanent state and a smaller (111) unipolar lattice strain at 2 kV/mm of 0.096%. This contrast in the strain magnitudes can be linked to the self-poling effect. A strain mechanism incorporating the self-poling effect is proposed, furthering our understanding of how crystallographic texture impacts the piezoelectric properties and providing a pathway for engineering the self-poling effect to further enhance material response. © 2022 The American Ceramic Society.