ABSTRACT BiFeO 3 –BaTiO 3 ceramics are known for their promising piezoelectric properties and high Curie temperatures, which make them suitable for advanced engineering applications. In this work, a series of lead‐free ceramics with the composition 0.7BiFeO 3 –0.3BaTiO 3 – x CaBi 2 Nb 2 O 9 (0.7BF–0.3BT– x CBN) were prepared through a direct reaction sintering (DRS) approach. A detailed characterization was performed, focusing on the phase structure and electrical performance. The incorporation of CBN mitigates the reduction of Fe 3+ to Fe 2+ , leading to a lower concentration of oxygen vacancies and restraint of abnormal grain growth. Among the compositions studied, the 0.7BF–0.3BT–0.1CBN ceramic exhibits the most favorable properties, achieving a high piezoelectric coefficient ( d 33 = 195 pC/N) and an elevated Curie temperature ( T C = 473°C). Furthermore, in situ d 33 measurement demonstrates excellent depolarization temperature, with the d 33 value reaching 462 pC/N at the depolarization temperature ( T d = 331°C). These results demonstrate that the 0.7BF–0.3BT–0.1CBN ceramic exhibits both outstanding high‐temperature piezoelectric properties and structural stability, highlighting the significant value of the CBN single‐doping strategy in enhancing the high‐temperature application potential of BF‐BT‐based ceramics.
Lin et al. (Wed,) studied this question.