Guan Yiming, Sun Yiyang, Wang Jie, Huangfu Geng, Li Hua, Zhang Shujun, Guo Yiping
State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, P.R. China.
State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 201899, P.R. China.
ACS Appl Mater Interfaces. 2023 Oct 27. doi: 10.1021/acsami.3c12068.
Donor and acceptor ions serving as extrinsic defects in piezoelectrics are mostly used to improve the performance merits to satisfy the industrial application. However, the conventional doping strategy is unable to overcome the inherent trade-off between the piezoelectric coefficient () and mechanical quality factor (). Herein, inspired by the valence state variation observed in manganese oxides during sintering, this study focuses on manipulating intrinsic oxygen vacancies and extrinsic manganese defects in potassium sodium niobate (KNN) ceramics via heat treatment. The annealing process results in a simultaneous improvement in both (20%) and (80%), leading to comparable performance with commercial PZT-5A ceramics and enabling their application in atomizer components. Moreover, the mechanism of manganese occupation and diffusion is proposed by an extended X-ray absorption fine structure and density functional theory analysis. The improved electromechanical performance in the annealed KNN ceramic is associated with the optimized redistribution of acceptor and donor manganese defects, which is facilitated by the recombination of oxygen vacancies. This work breaks longstanding obstacles in comprehending the existing forms of manganese in KNN and offers potential in popularizing KNN-based piezoceramics to replace traditional PZT lead-based counterparts in the industrial market.
作为压电材料中本征缺陷的施主离子和受主离子大多用于改善性能优点以满足工业应用。然而，传统的掺杂策略无法克服压电系数（）和机械品质因数（）之间固有的权衡。在此，受锰氧化物在烧结过程中观察到的价态变化启发，本研究聚焦于通过热处理来调控铌酸钾钠（KNN）陶瓷中的本征氧空位和外禀锰缺陷。退火过程导致（提高2）和（提高80）同时得到改善，使其性能与商用PZT-5A陶瓷相当，并使其能够应用于雾化器部件。此外，通过扩展X射线吸收精细结构和密度泛函理论分析提出了锰占据和扩散的机制。退火后的KNN陶瓷中机电性能的改善与受主和施主锰缺陷的优化再分布有关，这是由氧空位的复合促进的。这项工作打破了长期以来理解KNN中锰存在形式的障碍，并为在工业市场上推广基于KNN的压电陶瓷以取代传统的PZT铅基同类产品提供了潜力。
