Zhou Min, Lu Xiaomei, Yang Dianyuan, He Ju, Huang Fengzhen, Mei Fang, Ren Xianming, Xu Xingyu, Li Yang, Zhu Jinsong
National Laboratory of Solid State Microstructures and Physics School, Nanjing University, Nanjing 210093, People's Republic of China.
Phys Chem Chem Phys. 2017 Jan 18;19(3):1868-1874. doi: 10.1039/c6cp06111g.
The relationship among dielectric anomaly, ferroelectric response, defects, and microstructures was established for (KNa)LiNbSbO (x = 0.04, 0.00, -0.02, -0.04 and -0.08) ceramics. For x = -0.02 and -0.04, larger coercive fields and lower remnant polarizations were obtained; besides, an additional dielectric relaxation behavior was observed with the activation energy E being about 2.19 eV and 1.92 eV, respectively. Furthermore, the grain and grain boundary contributions to the capacitance were separated using impedance spectroscopy, which, combined with back-scattering characterization, firmly indicates the core-shell structure of K-deficient samples (x = -0.02 and -0.04). Unlike the cores, the shells possess a large amount of K vacancies (). This work paves a way for regulating the fine structure and more on the electrical properties of KNN-based materials.
对于(KNa)LiNbSbO（x = 0.04、0.00、-0.02、-0.04和-0.08）陶瓷，建立了介电异常、铁电响应、缺陷和微观结构之间的关系。对于x = -0.02和-0.04，获得了更大的矫顽场和更低的剩余极化；此外，还观察到一种额外的介电弛豫行为，其激活能E分别约为2.19 eV和1.92 eV。此外，使用阻抗谱分离了晶粒和晶界对电容的贡献，结合背散射表征，有力地表明了缺钾样品（x = -0.02和-0.04）的核壳结构。与核不同，壳层具有大量的钾空位（）。这项工作为调控基于KNN材料的精细结构及其更多电学性质铺平了道路。
