Improved piezoelectric properties in Bi(Mg2/3Nb1/3)O3-modified BiFeO3–BaTiO3 lead-free piezoelectric ceramics

The investigation of lead-free ceramics with exceptional piezoelectric properties holds great importance in the substitution of lead-based materials, hence promoting the development of green technology and fostering an environmentally sustainable society. This study successfully synthesized two series of Bi(Mg 2/3 Nb 1/3 )O 3 (BMN)-modified BiFeO 3 –BaTiO 3 (BF–BT) lead-free piezoelectric ceramics using the conventional solid-state reaction approach. The phase structure, microstructure, dielectric, and piezoelectric properties of these ceramics were comprehensively investigated. A typical perovskite structure is observed in all probed compositions, and the associated phase structure undergoes a gradual transition from a rhombohedral-cubic phase mixture to a cubic-dominant phase structure as increases the content of BMN and BT. All compositions exhibit obvious core–shell microstructures with inhomogeneous element distributions. Most importantly, the BF–0.30BT–0.005BMN and BF–0.34BT–0.03BMN piezoelectric ceramics presented remarkable values for the piezoelectric coefficient (225 pC/N) and converse piezoelectric coefficient (396 pm/V), respectively. These findings highlight the potential of BMN-modified BF–BT ceramics for use in high-performance piezoelectric applications.