Grain size dependent grain boundary defect structure: case of doped zirconia
Grain size dependent grain boundary defect structure: case of doped zirconia
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DOI：
10.1016/s1359-6454(03)00052-1
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发表时间：
2003-05-23
期刊：
影响因子：
9.4
通讯作者：
Zhang, ZL
中科院分区：
文献类型：
--
作者：
Guo, X;Zhang, ZL
通过阻抗谱测量了 3 mol% Y2O3 掺杂的 ZrO2 的电性能与晶粒尺寸的关系，并通过 SEM 和 HREM 研究了微观结构。尽管晶界非常干净，但晶界电导率仍然比体电导率低两个数量级，但随着晶粒尺寸的减小而增加。根据肖特基势垒模型，低晶界电导率是由于晶界空间电荷层中氧空位的耗尽所致。在此框架内，计算了晶界空间电荷电势和空间电荷层中氧空位的浓度；研究发现，随着晶粒尺寸的减小，空间电荷势降低，但氧空位浓度增加。对 8.2 mol% Y2O3 和 15 mol% CaO 掺杂 ZrO2 的文献结果的分析分别揭示了类似的现象。 (C) 2003 年由 Elsevier Science Ltd 代表 Acta Materialia Inc. 出版。
The electrical properties of 3 mol% Y2O3 doped ZrO2 were measured by impedance spectroscopy as a function of grain size, and the microstructure studied by SEM and HREM. In spite of the very clean grain boundaries, the grain boundary conductivity was still found to be similar to2 orders of magnitude lower than the bulk conductivity, while it increased with decreasing grain size. The low grain boundary conductivity, according to the Schottky barrier model, is due to the depletion of oxygen vacancies in the grain boundary space charge layers. Within this framework, the grain boundary space charge potential and the concentration of oxygen vacancies in the space charge layers were calculated; it was found that the space charge potential decreased, but the oxygen vacancy concentration increased with decreasing grain size. Analyses of literature results for 8.2 mol% Y2O3 and 15 mol% CaO doped ZrO2, respectively, revealed similar phenomena. (C) 2003 Published by Elsevier Science Ltd on behalf of Acta Materialia Inc.