Significantly enhanced d33 together with high Td in Bi0.5Na0.5TiO3-BaTiO3 ceramic via AC cycles poling-induced polarization wake-up

The incomplete preferred orientation polarization and partially back-switching reoriented domains during/after poling with electrical loading and unloading were ubiquitous and suppressed both piezoelectric constant ( d 33 ) and depolarization temperature ( T d ) of piezoelectric ceramics. In this work, a simple poling strategy with multi-cycles of AC electric field is proposed to realize polarization wake-up in unmodified 0.92Bi 0.5 Na 0.5 TiO 3 -0.08BaTiO 3 (BNT-8BT) with significantly enhanced d 33 from 65 pC/N to 161 pC/N and high T d of 200 °C simultaneously. Through comprehensive analysis on the polarization wake-up and polarization switching process, it is demonstrated that remarkably improved d 33 originates from AC cycles poling induced coexistence of P 4 bm and P 4 mm phases, depinned domains and defect dipoles orientation polarization. The internal bias field (E i ) resulted from defect dipoles orientation aids the d 33 and its high temperature stability. Our work provides a convenient and inexpensive method that there need not commonly delicate compositions control in lead-free piezoceramics on advancing to alleviate the trade-off between d 33 and T d .