Wu Pengkun, Wang Dandan, Zhou Fengzi, Ren Yongpeng, Zhang Junhu, Zang Guozhong, Wang Xiaofei, Cao Xingzhong
School of Physics and Engineering, Henan University of Science and Technology, Luoyang 471023, China.
School of Materials Science and Engineering, Henan University of Science and Technology, Luoyang 471023, China.
Materials (Basel). 2025 Apr 11;18(8):1760. doi: 10.3390/ma18081760.
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 () is smaller than 0.05 for ≤ 0.003 ceramic samples. Meanwhile, the optimized piezoelectric charge coefficient = 128 pC/N, and piezoelectric voltage coefficient = 18.9 × 10 Vm/N are obtained when = 0.001. Compared with the undoped sample, the of = 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 = 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.
采用放电等离子烧结法制备了稀土元素（Sm）掺杂的铌酸钾钠（KNN）基陶瓷，并对其性能进行了研究。结果表明，所有样品均结晶为具有单一正交相的典型钙钛矿结构。随着Sm掺杂量的增加，陶瓷逐渐向弛豫铁电态转变，对于≤0.003的陶瓷样品，介电损耗角正切值（）小于0.05。同时，当=0.001时，获得了优化的压电电荷系数=128 pC/N和压电电压系数=18.9×10 Vm/N。与未掺杂样品相比，=0.001的陶瓷的提高了28%。正电子湮没寿命结果表明，陶瓷中的主要缺陷类型为A位空位和缺陷偶极子。基于上述结果，=0.001时优化的压电性能和最低的缺陷偶极子浓度，可能归因于其内部较低的氧空位浓度。这项工作可能为进一步研究KNN基压电陶瓷提供思路。
