Boosting electric-field-induced strain of dual templates-textured (Na1/2Bi1/2)TiO3-based lead-free piezoceramics by polarization coupling

The templated grain-growth method is an effective technique to fabricate textured (Na1/2Bi1/2)TiO3-based ceramics for enhancing the electric-field-induced strain response, where the commonly used templates are plate-like (Na1/2Bi1/2)TiO3 (NBT) or NaNbO3 (NN). However, the textured samples prepared by one of the templates are usually not up to expectations due to the chemical composition deviations or lattice distortions. Herein, we propose a new approach to boost the texturing effect by integrating NBT-textured grains and NN-textured grains into one <001>-oriented (Na1/2Bi1/2)TiO3-26SrTiO3 ceramic using dual templates (both NBT and NN templates). Benefiting from the complementary effect and polarization coupling effect of these two different types of textured grains, the sample achieves a 56% increase in d33* (650 pm/V at 60 kV/cm) with preferred temperature stability, while showing the same relaxor ferroelectric characteristic as the randomly oriented counterpart. The finding is expected to provide a novel paradigm for lead-free piezoceramics with excellent properties.