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

摘要

(Bi0.5Na0.5)TiO3 (BNT)-based piezoceramics usually exhibit enhanced piezoelectric coefficient d(33) together with the deterioration of depolarization temperature T-d, 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. 001 oriented piezoelectric ceramics 0.94(Bi0.5Na0.5)TiO3 - 0.06BaTiO(3) 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 (d(33)similar to 297pC/N) but also improved thermal stability (T-d similar to 57 degrees C) in comparison to its randomly oriented counterparts (d(33)similar to 151pC/N and T-d similar to 32 degrees C). Moreover, the enhanced piezoelectricity in grain oriented specimens primarily originated from a high degree of non-180 degrees 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.