Influence of Zinc Oxide on the Conductivity of Ceria
Influence of Zinc Oxide on the Conductivity of Ceria
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DOI：
10.1149/2.119309jes
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发表时间：
2013-01-01
影响因子：
3.9
通讯作者：
Wiemhoefer, Hans-Dieter
中科院分区：
文献类型：
--
作者：
Schmale, Kerstin;Daniels, Maximilian;Wiemhoefer, Hans-Dieter
研究了ZnO作为CeO 2的掺杂剂或添加剂，其浓度范围为x = 0.00至x = 0.95，参照（CeO 2）（1-x）（ZnO）（x）。根据XRD，在室温下ZnO在CeO 2本体中的溶解度极限估计为3 +/- 0.7摩尔%。通过阻抗谱法测量所有组合物在空气中的总电导率。分别评价了体边界和晶界的贡献。此外，使用Hebb-Wagner技术与微电极测量电子电导率。直到溶解度极限，从300摄氏度到800摄氏度，本体在空气中的总电导率随着ZnO含量几乎线性地增加，这同样适用于p型电子电导率（在600摄氏度-800摄氏度的范围内）。因此，锌离子在铈位上起受主作用，锌掺杂氧化铈是一种中等混合导体。在从3摩尔%到20摩尔%的两相域中，总电导率略有增加，部分电子电导率依赖性保持几乎恒定。从30摩尔% ZnO开始，晶界电导率急剧上升，并且电子电导率占总电导率的主导地位，对于具有x = 0.95摩尔%的组成的样品，在800 ℃下在空气中达到0.03 S/cm的更高ZnO含量。(C)2013年电化学学会。All rights reserved.
ZnO was studied as dopant or additive for CeO2 in the concentration range x = 0.00 to x = 0.95 referred to (CeO2)(1-x)(ZnO)(x). From XRD, the solubility limit of ZnO in the bulk of CeO2 estimated as 3 +/- 0.7 mol% at room temperature. The total conductivity was measured for all compositions in air by impedance spectroscopy. The contributions from bulk and grain boundaries were evaluated separately. Additionally, the electronic conductivities were measured using a Hebb-Wagner technique with microelectrodes. Up to the solubility limit, the total conductivity of the bulk in air increases almost linearly with the ZnO content from 300 degrees C to 800 degrees C, the same holds for the p-type electronic conductivity (in the range 600 degrees C-800 degrees C). Hence, zinc ions act as acceptors on cerium sites, zinc doped ceria is a moderate mixed conductor. In the two-phase domain from 3 mol% up to 20 mol%, the total conductivity increases slightly and the partial electronic conductivity dependence remains nearly constant. Starting at 30 mol% ZnO, the grain boundary conduction rises steeply and the electronic conductivity predominates the total conductivity for this and higher ZnO contents reaching 0.03 S/cm at 800 degrees C in air for a sample with the composition x = 0.95 mol%. (C) 2013 The Electrochemical Society. All rights reserved.