Environmentally friendly BiFeO ₃ -based piezoceramics: Processing, optimization, and electromechanical properties for high-temperature applications

High-temperature piezoelectrics are indispensable parts of modern technology. In this work, a new 0.7Bi 1.03 FeO₃-0.3Ba 0.99 La 0.01 TiO₃ lead-free piezoceramic material was created near the morphotrophic phase boundary (MPB), and its electromechanical properties were tuned by sintering temperature ( T s ). The optimized T s of 970°C resulted in a completely dense microstructure with a large average grain-size of 5 µm and a significant remnant polarization of ( P r ) 30.2 μC/cm 2 . The alternating current (AC) and direct current (DC) poling method resulted in a fairly high static piezoelectric constant ( d 33 ) of 344 pC/N. A large dynamic piezoelectric constant ( d 33 * ) of 450 pm/V is achieved under the 50 kV/cm with decent thermal stability. High Curie temperature ( T C ) of 530°C and low dielectric losses throughout a wide range are advantageous for high-temperature applications. The simultaneous enhancement of d 33 , d 33 * , and T C is a promising finding in lead-free piezoceramic materials.