Dielectric properties and impedance analysis in Aurivillius-type (Na0.25K0.25Bi0.5)1−x(LiCe)x/2[]x/2Bi4Ti4O15 ceramics
Dielectric properties and impedance analysis in Aurivillius-type (Na0.25K0.25Bi0.5)1−x(LiCe)x/2[]x/2Bi4Ti4O15 ceramics
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DOI：
10.1016/j.jallcom.2012.07.019
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发表时间：
2012-11
影响因子：
6.2
通讯作者：
Zhihang Peng;Qiang Chen;Jiagang Wu;Dan Liu;D. Xiao;Jianguo Zhu
中科院分区：
文献类型：
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作者：
Zhihang Peng;Qiang Chen;Jiagang Wu;Dan Liu;D. Xiao;Jianguo Zhu
采用常规固相烧结法制备了（Na0.25K0.25Bi0.5）1−x(LiCe)x/2[]x/2Bi4Ti4O15（NKBTLC-x）陶瓷。x射线衍射结果表明，所有样品均为单一的四层aurivillius型结构，且晶格畸变随x的增加而增加，从而引起居里温度（TC）的变化。为了阐明导电和弛豫过程的基本机理，在宽频率（100Hz-1MHz）和温度（450-750℃）范围内进行了介电和电学性能研究。热激活跳变机制解释了弛豫过程，并在TC周围表现出异常，交流电导率的温度依赖性可分为三个区域，活化能ea由Arrhenius定律计算。此外，交流电导率随频率的变化规律符合普遍幂律，属于跳频传导机制。
(Na0.25K0.25Bi0.5)1−x(LiCe)x/2[]x/2Bi4Ti4O15(NKBTLC-x) ceramics were prepared using the conventional solid state sintering method. X-ray diffraction results demonstrated that all samples have a single four-layered Aurivillius-type structure and the lattice distortion increases with increasing x, which induces the variation of Curie temperature (TC). Dielectric and electrical properties have been carried out over a wide range of frequency (100Hz–1MHz) and temperature (450–750°C) in order to elucidate the basic mechanism on the conduction and relaxation process. The relaxation process was explained by thermal activated hopping mechanism and shows an anomaly around the TC, temperature dependence of ac conductivity can be separated into three regions and the activation energy Eawas calculated from the Arrhenius law. Moreover, the behavior of ac conductivity as a function of frequency was obeyed the universal power law and attributed to hopping conduction mechanism.