High‐Performance Lead‐Free Ceramics With Simultaneously High Piezoelectricity and High Mechanical Quality Factor
Yang Yang, Ying Li, Dong Wang, Zhipeng Wang, Jiantuo Zhao, Yanshuang Hao, Yuanchao Ji, Xiaobing Ren
Abstract
Abstract Piezoelectric materials with a high piezoelectric coefficient ( d 33 ) and high mechanical quality factor ( Q m ) are vital for advanced high‐power applications. However, achieving this combination is challenging, particularly for lead‐free piezoelectrics, because a high d 33 value relies on mobile domain walls, which increase dissipative losses and reduce Q m . In this study, this longstanding trade‐off is overcome by introducing defect dipoles (via Mn doping) into the quadruple point (QP) composition of the lead‐free Ba(Sn, Ti)O 3 system. The resultant 0.5%Mn‐doped Ba(Sn 0.11 Ti 0.89 )O 3 (BST‐0.5%Mn) ceramic exhibits a high d 33 value of 710 pC/N and high Q m value of 929, while the BST‐1%Mn ceramic achieves a d 33 value of 614 pC/N and Q m value of 1138. These values represent a 10‐fold increase in Q m and 1.6‐fold increase in d 33 for BST‐0.5%Mn, compared to those for undoped BST. High‐resolution scanning transmission electron microscopy and phase‐field simulations reveal that the enhanced d 33 and Q m are attributable to the coexistence of multiple phases of QPs with symmetry‐conforming defect dipoles, challenging the long‐held notion of physical incompatibility between high d 33 and high Q m . These findings offer a pathway for designing eco‐friendly piezoelectric materials with unprecedented performance, paving the way for sustainable and efficient high‐power applications.