Origin(s) of the apparent high permittivity in CaCu3Ti4O12 ceramics: clarification on the contributions from internal barrier layer capacitor and sample-electrode contact effects
Origin(s) of the apparent high permittivity in CaCu3Ti4O12 ceramics: clarification on the contributions from internal barrier layer capacitor and sample-electrode contact effects
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DOI：
10.1063/1.3253743
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发表时间：
2009-11-15
影响因子：
3.2
通讯作者：
West, Anthony R.
中科院分区：
文献类型：
--
作者：
Li, Ming;Shen, Zhijian;West, Anthony R.
采用传统烧结和火花等离子烧结两种方法制备了具有一定电阻率的cuu3ti4o12陶瓷。在所有情况下，高有效介电常数主要与内部势垒层电容器机制有关。与电极-样品界面相关的额外极化可能出现，但其可见性取决于陶瓷的晶界电阻率（R-gb）。如果R-gb较大，电极极化被样品相关效应遮蔽；如果R-gb很小，则可以看到与电极极化相关的单独阻抗。文献中关于有效介电常数的大小和来源的差异归因于加工条件、电极接触材料和测量频率范围的差异。(C) 2009年美国物理研究所。(doi: 10.1063/1.3253743)
CaCu3Ti4O12 ceramics with a range of resistivities have been prepared using both conventional sintering and spark plasma sintering. For all cases, the high effective permittivity is associated primarily with an internal barrier layer capacitor mechanism. Additional polarization associated with the electrode-sample interface may appear but its visibility depends on the grain boundary resistivity (R-gb) of the ceramic. If the R-gb is large, the electrode polarization is obscured by sample-related effects; if the R-gb is small, a separate impedance associated with the electrode polarization may be seen. Discrepancies in the literature regarding the magnitude and origin of the high effective permittivity are attributed to a combination of differences in processing conditions, electrode contact material and measuring frequency range. (C) 2009 American Institute of Physics. [doi: 10.1063/1.3253743]