State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, 122 Luoshi Road, Wuhan 430070, PR China.
ChemSusChem. 2011 Oct 17;4(10):1470-4. doi: 10.1002/cssc.201100451.
Lead-free (1-x)Ba(Zr₀.₁₅Ti₀.₈₅)O₃-x(K₀.₅Na₀.₅)NbO₃ ; x=0-0.05) (BZT-KNN) perovskite ceramics, a materials with potential applications for energy storage, are investigated. The samples are prepared by a solid-state reaction method. Powder X-ray diffraction (XRD) and scanning electron microscopy (SEM) are used to study the microstructure of the samples. Their dielectric properties and impedance spectra are reported as functions of temperature and frequency. The addition of 1 mol % (K₀.₅Na₀.₅)NbO₃ to Ba(Zr₀.₁₅Ti₀.₈₅)O₃ improves the dielectric constant and enhances its diffuseness in a wide temperature range. The small amount of (K₀.₅Na₀.₅)NbO₃ is found to markedly affect the microstructure of the Ba(Zr₀.₁₅Ti₀.₈₅)O₃ ceramic (grain size and other characteristics) without changing the phase or crystal symmetry. In addition, we report that fine substructures in the grains, so-called sheet structures, are responsible for the dielectric properties (both diffuseness and dielectric constant) of (1-x)Ba(Zr₀.₁₅Ti₀.₈₅)O₃-x(K₀.₅Na₀.₅)NbO₃ (x=0-0.03; especially x=0.01) ceramics.
无铅（1-x）Ba(Zr₀.₁₅Ti₀.₈₅)O₃-x(K₀.₅Na₅₅)NbO₃（BZT-KNN）钙钛矿陶瓷，具有储能应用潜力的材料，被研究。样品通过固态反应法制备。粉末 X 射线衍射（XRD）和扫描电子显微镜（SEM）用于研究样品的微观结构。它们的介电性能和阻抗谱作为温度和频率的函数被报道。向 Ba(Zr₀.₁₅Ti₀.₈₅)O₃ 添加 1 摩尔%（K₀.₅Na₅₅）NbO₃可提高介电常数并在宽温度范围内增强其弥散性。少量的（K₅₅）NbO₃明显影响 Ba(Zr₀.₁₅Ti₀.₈₅)O₃陶瓷的微观结构（晶粒尺寸和其他特性），而不改变相或晶体对称性。此外，我们报告称，晶粒中的精细亚结构，所谓的片状结构，是（1-x）Ba(Zr₀.₁₅Ti₀.₈₅)O₃-x（K₅₅）NbO₃（x=0-0.03；特别是 x=0.01）陶瓷介电性能（弥散性和介电常数）的原因。
