Advancing piezoelectricity and excellent thermal stability: <001>-textured 0.75BF–0.25BT lead-free ceramics for high temperature applications

There is an urgent need for piezoelectric materials possessing both high piezoelectric properties and good thermal stability to facilitate the advancement of high temperature piezoelectric devices. However, conventional strategy for enhancing piezoelectricity via chemical modifications often comes at the cost of thermal stability due to a drop in Curie temperatures. In this study, we achieved remarkable results in <001>-oriented 0.75BiFeO 3 –0.25BaTiO 3 (0.75BF–0.25BT) lead-free textured ceramics. These textured ceramics exhibit a high Curie temperatures T c of 552 °C, large piezoelectric coefficients d 33 of 265 pC/N, and exceptional piezoelectric thermal stability, with minimal variation of 8% across temperature from 25 °C to 300 °C. Compared to randomly oriented ceramics, the piezoelectric coefficient is about 2.5 times higher, marking it as one of the highest reported value for ceramics with T c near 550 °C. The enhanced piezoelectric properties can be ascribed to improvements in both intrinsic lattice distortions and extrinsic non-180 o domain motions, while the excellent piezoelectric thermal stability is attributed to the stable domain texture. These superior properties of the studied textured 0.75BF–0.25BT ceramics position them as competitive lead-free candidates for high-temperature piezoelectric applications. • The novelty of this research ware highlighted in the following: • The 0.75BiFeO 3 –0.25BaTiO 3 (BFBT) ceramics with high texture degree f [001] of 90% were fabricated. • Superior piezoelectric properties with d 33 =265 pC/N and d 33 × g 33 =18,600×10 –15 m 2 /N for BFBT textured ceramics were achieved. • Excellent piezoelectric thermal stability with the much lower variation of in-situ d 33 is about 8% from 25 °C to 300 °C. • Accelerometer with studied ceramics possess a high sensitivity of (130±10) pC/g and higher working temperature of 450 °C.