Giant piezoelectric voltage coefficient in grain-oriented modified PbTiO 3 material

A rapid surge in the research on piezoelectric sensors is occurring with the arrival of the Internet of Things. Single-phase oxide piezoelectric materials with giant piezoelectric voltage coefficient (g, induced voltage under applied stress) and high Curie temperature (T_c) are crucial towards providing desired performance for sensing, especially under harsh environmental conditions. Here, we report a grain-oriented (with 95% texture) modified PbTiO₃ ceramic that has a high T_c (364 °C) and an extremely large g₃₃ (115×10^-3VmN^-1) in comparison with other known single-phase oxide materials. Our results reveal that selfpolarization due to grain orientation along the spontaneous polarization direction plays an important role in achieving large piezoelectric response in a domain motion-confined material. The phase field simulations confirm that the large piezoelectric voltage coefficient g₃₃ originates from maximized piezoelectric strain coefficient d₃₃ and minimized dielectric permittivity e₃₃ in [001]-textured PbTiO₃ ceramics where domain wall motions are absent.