High-performance BF-BT-based lead-free piezoceramics with local polar nanoregions of room-temperature ergodic state

The present work highlights the successful fabrication of the (1-x)(BF-BHT)-xLST lead-free piezoelectric ceramics by the conventional solid-state method. The composition (x = 0.03) was found with a high Curie temperature of T-c similar to 435 degrees C and a superior electric field-induced strain as high as 0.42 %. The piezoelectric force microscopy (PFM) and transmission electron microscopy (TEM) measurement revealed the existence of polar nano-regions (PNRs) due to the local compositional heterogeneity which is attributed to the introduced relaxor (La0.1Sr0.8)TiO3-delta. Moreover, the superior temperature stability of piezoelectric strain S*% with the maximum 31 % was obtained in the temperature range of 25-245 degrees C, indicating that the recipe possesses outstanding high-temperature reliability. The findings in this work provide a novel design philosophy to prepare high-performance BF-BT-based lead-free piezoceramics. (C) 2022 Elsevier B.V. All rights reserved.