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首页> 外文会议>Fourth International Symposium on Ionic and Mixed Conducting Ceramics, null >ELECTRON-ION TRANSPORT IN ZrO_2-Y_2O_3-CeO_2 CERAMICS
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ELECTRON-ION TRANSPORT IN ZrO_2-Y_2O_3-CeO_2 CERAMICS

机译：ZrO_2-Y_2O_3-CeO_2陶瓷中的电子迁移

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摘要

Simultaneous conduction of oxide ions and electrons in solid ceramic systems provides the capability for oxygen transport under a concentration gradient without the need for an externally applied electric field. In the present study, ionic transference numbers have been measured in the ZrO_2-5.8%Y_2O_3-10%CeO_2 system by open circuit Emf measurements involving different metal/metal oxide electrodes. In order to correlate the ionic transference number with grain size, high-density ceramic discs of different grain sizes (50 nm～5 μm) were prepared by sintering pressed powders at various temperatures and times. Hydrothermal synthesis was used to prepare nanocrystalline powders of the above material with uniform crystallite size (10 nm) and chemistry. Emf measurements on the samples suggested both ionic and electronic transport, the ionic transference number decreasing with increase in the grain size. This observation was attributed to an increase in the amount of continuous crystalline grain boundary phase in the ceramics as the grain size increased. The presence of crystalline silicate and zirconate phases in the grain boundary region was confirmed by electron microscopic imaging combined with microanalysis. In the large grain (5μm) ceramics, the ionic transference number decreased linearly with temperature. As the grain size decreased, a maximum occurred in the ionic transference number vs. temperature curve. This maximum became more pronounced at smaller grain sizes. Better grain-grain contact and the doping effect of trivalent Ce in the grain boundary core are proposed to explain this observation.
机译：固体陶瓷系统中氧化物离子和电子的同时传导提供了在浓度梯度下进行氧气传输的能力，而无需外部施加电场。在本研究中，已通过涉及不同金属/金属氧化物电极的开路电动势测量在ZrO_2-5.8％Y_2O_3-10％CeO_2系统中测量了离子迁移数。为了使离子转移数与晶粒尺寸相关，通过在不同温度和时间下烧结压粉制备了不同晶粒尺寸（50 nm〜5μm）的高密度陶瓷圆盘。水热合成用于制备具有均匀的微晶尺寸（10nm）和化学性质的上述材料的纳米晶体粉末。样品上的电动势测量表明离子和电子都有迁移，离子转移数随晶粒尺寸的增加而降低。该观察结果归因于随着晶粒尺寸的增加，陶瓷中的连续结晶晶界相的数量增加。通过电子显微镜成像结合显微分析证实了晶界区域中存在结晶硅酸盐和锆酸盐相。在大颗粒（5μm）陶瓷中，离子转移数随温度线性降低。随着晶粒尺寸的减小，离子转移数与温度的关系曲线出现最大值。在较小的晶粒尺寸下，该最大值变得更加明显。为了更好地解释这一现象，提出了更好的晶界接触和三价铈在晶界核中的掺杂作用。

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