Pairing high piezoelectric properties and enhanced thermal stability in grain-oriented BNT-based lead-free piezoceramics

(Bi0.5Na0.5)TiO3 (BNT)-based piezoceramics usually exhibit enhanced piezoelectric coefficient d33 together with the deterioration of depolarization temperature Td, which is the common drawback limiting their use in practical application. Here, we demonstrate that harnessing the microstructure in BNT-based ceramics will be an efficient way to resolve this obstacle. <00l> oriented piezoelectric ceramics 0.94(Bi0.5Na0.5)TiO3 −0.06BaTiO3 was engineered by templated grain growth (TGG) using NaNbO3 (NN) as templates. The manufactured textured ceramics with the optimized microstructure was characterized by not only approximately 200% enhancement in the magnitude of piezoelectric response (d33~297pC/N) but also improved thermal stability (Td~57 °C) in comparison to its randomly oriented counterparts (d33~151pC/N and Td~32 °C). Moreover, the enhanced piezoelectricity in grain oriented specimens primarily originated from a high degree of non-180° domain switching as compared to the randomly axed ones. The current study opens the door to pair high piezoelectric properties and enhanced thermal stability in BNT-related materials though texture technique.