Textured BiScO₃-PbTiO₃ piezoelectric ceramics with both high electromechanical coupling factor and high curie temperature

High-temperature piezoelectric devices require piezoelectric ceramics with high Curie temperatures and high-temperature stability of piezoelectric properties to avoid the depolarization of piezoelectric ceramics during application. However, piezoelectric materials with high Curie temperatures usually have restrained piezoelectric properties. Crystallographic orientation via texture engineering is a practicable way to improve piezoelectric performance. Here, we propose a sintering-aid-assisted template grain growth strategy to texture BiScO3-PbTiO3 ceramics to overcome the low orientation issue that challenges the texturing of BS-PT for decades. By judiciously selecting B2O3-CuO as sintering aids, we fabricated highly < 001 >-textured 0.43BS-0.57PT ceramics with Logtering factors >99.0% that possess high piezoelectric coefficients d(33) of 474-612 pC/N while maintaining relatively high Curie temperatures of 370-402 degrees C. Importantly, this work addresses a long-standing issue presented in BS-PT ceramics, i.e., the low electromechanical coupling property of BS-PT ceramics (k(33) < 0.70) by improving the electromechanical coupling factor k(33) to 81.2%. The newly designed textured BS-PT ceramics are thought to be promising candidates for the design of high-temperature piezoelectric transducers and actuators.