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首页> 外文会议>International symposium on Ionic and Mixed Conducting Ceramics >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陶瓷中的电子离子输送

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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：固体陶瓷系统中的氧化物离子和电子的同时传导提供浓度梯度下的氧气输送的能力，而无需外部施加的电场。在本研究中，通过涉及不同金属/金属氧化物电极的开路EMF测量，在ZrO_2-5.8％Y_2O_3-10％CEO_2系统中测量离子转移数。为了将离子转移数与晶粒尺寸相关，通过在各种温度和时间烧结压制粉末制备不同晶粒尺寸的高密度陶瓷盘（50nm〜5μm）。使用水热合成用均匀的微晶尺寸（10nm）和化学制备上述材料的纳米晶体粉末。样品上的EMF测量表明离子和电子传输，离子转移数随晶粒尺寸的增加而降低。该观察结果归因于晶粒尺寸增加的陶瓷中连续晶粒边界相的量增加。通过电子显微镜成像与微量分析结合的电子显微成像证实了晶界区域中结晶硅酸盐和锆胺的存在。在大颗粒（5μm）陶瓷中，离子转移数与温度线性降低。随着晶粒尺寸的降低，在离子转移数与温度曲线中发生最大值。在较小的粒度尺寸下，这种最大值变得更加明显。提出了更好的粒状接触和三价Ce在晶界核心中的掺杂效果，以解释这一观察。

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