Effect of Defects on Piezoelectric Properties of Sm-Doped K0.47Na0.53NbO3 Ceramics

作者：P.B. Wu, Dandan Wang, Fengzi Zhou, Yongpeng Ren, Junhu Zhang, Guo‐Zhong Zang, Xiaofei Wang, Xingzhong Cao · 发表于：Materials · 年份：2025 · DOI：10.3390/ma18081760 · 被引用次数：5 · 研究领域：Acoustic Wave Resonator Technologies、Ferroelectric and Piezoelectric Materials、Ultrasonics and Acoustic Wave Propagation

Rare earth element (Sm)-doped potassium sodium niobate (KNN)-based ceramics are fabricated using spark plasma sintering method and their properties are investigated. The results show that all the samples crystallize in a typical perovskite structure with a single orthorhombic phase. With increasing the Sm doping, the ceramics gradually shift toward the relaxor ferroelectric state and the value of dielectric loss angle tangent (tanδ) is smaller than 0.05 for x ≤ 0.003 ceramic samples. Meanwhile, the optimized piezoelectric charge coefficient d33 = 128 pC/N, and piezoelectric voltage coefficient g33 = 18.9 × 10−3 Vm/N are obtained when x = 0.001. Compared with the undoped sample, the d33 of x = 0.001 ceramics has been significantly enhanced by 28%. The positron annihilation lifetime results indicate that the main defect types in the ceramics are the A-site vacancies and defect dipoles. Based on the aforementioned results, the optimized piezoelectric performance and the lowest defect dipoles concentration in x = 0.001, may be attributed to the low internal oxygen vacancy concentration in it. This work may provide insights for the further study of KNN-based piezoelectric ceramics.