Textured Sr2Nb2O7 ceramics: Microstructure design, high temperature ferroelectric and piezoelectric performance

Sr2Nb2O7 (SNO) ceramics are promising high-temperature piezoelectric materials due to their high Curie temperature (T-C), good thermal stability, and high electrical resistivity. However, SNO presents low piezoelectric activity (d(33) < 1 pC/N). Here, we successfully obtain textured SNO ceramics with an orientation factor of 0.86 by microstructure regulation. Saturated polarization-electric loop was obtained in textured ceramic with remanent polarization P-r similar to 3.56 <mu>C/cm(2) and coercive field E-C similar to 53.4 kV/cm. The piezoelectric coefficient d(33) of the textured SNO ceramics is increased to 3.2 pC/N, with a high T-C of 1342 degrees C, while the low-textured SNO ceramics exhibit no effective d(33). Meanwhile, the piezoelectric coefficient d(33) of textured SNO ceramics maintains consistency even at 1300 degrees C, showing excellent thermal stability. The underlying mechanism driving this improvement is elucidated, emphasizing the facilitated domain-wall motion enabled by the engineered microstructure. Furthermore, textured SNO ceramics exhibit high resistivity of 1.33 x 10(6) Omega & sdot;cm at 800 degrees C. This study presents a simple and feasible microstructure engineering approach to enhance the piezoelectric properties of layer-structured materials, offering valuable insights into the design and development of ceramics for diverse applications.