Monstoichiomatry and oxygen diffusion in cerium oxide

氧化铈中的单化学和氧扩散

• 批准号: 10650673
• 负责人: IKUMA Yasuro
• 金额: $ 1.92万
• 依托单位: Kanagawa Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10650673/
• 关键词: Cerium oxide; Neodymium; Oxgen diffusion coefficient; Surface diffusion coefficient; Inter diffusion coefficient; Hydrothermal treatment; Lattice parameter; タンタル; 固溶限界

Powders of undoped CeOィイD22ィエD2, Nd-doped CeOィイD22ィエD2, etc. were prepared. Crystal growth of these powders under hydrothermal condition was studied and some of them sintered to obtain high density materials. Lattice parameter, density, oxygen diffusion, surface diffusion, etc. of these samples were studied. In the hydrothermal treatment of undoped CeOィイD22ィエD2 and Nd-doped CeOィイD22ィエD2 at 500℃, it was found that the particle size of powder after treatment depends on the concentration of Nd additive. Performing dissolution experiment, it was found that the sample that can be dissolved into water can grew large during the hydrothemal treatment. The lattice parameter of Nd-doped CeOィイD22ィエD2 was found to follow the Vegard's law up to 35% Nd at 500℃.The oxygen diffusion coefficient of high purity CeOィイD22ィエD2 was determined over wide temperature range. Arrhenius plot of the result was divided into two regions. The high temperature region was very close to that or other stoichiometric oxide with fluorite structure and the diffusion in this range was concluded to be in intrinsic region. The slope of low temperature region was very close to those of Y-doped CeOィイD22ィエD2 and Gd-doped CeOィイD22ィエD2 reported in the literature. Plotting oxygen diffusion coefficient in undoped CEOィイD22ィエD2 and doped CEOィイD22ィエD2 as a function of concentration of trivalent cation impurities or additives, the diffusion in this region was found to be controlled by trivalent impurities in the oxide.Surface diffusion in CeOィイD22ィエD2 was determined for the first time. Chemical diffusion in Y-doped CeOィイD22ィエD2 and Y-doped ZrOィイD22ィエD2 was determined. It was slower than oxygen diffusion and close to cation diffusion of Zr in Ca-dopped ZrOィイD22ィエD2.

制备了未掺杂CeO_2的ィイ_(D22)ィエ_2、掺Nd的CeO_(ィイ)_(22)ィエ_(D2)等粉末。在水热条件下研究了这些粉末的晶体生长，并对其中一些粉末进行了烧结以获得高密度材料。对样品的晶格参数、密度、氧扩散、表面扩散等进行了研究。在未掺杂CeOィイD22ィエD2和掺Nd CeOィイD22ィエD2在500℃下的水热处理中，发现处理后的粉末颗粒大小依赖于Nd添加剂的浓度。溶出实验发现，在水热处理过程中，可溶于水的样品会长大。研究发现，掺钕CeO：ィイD22-ィエ-D2的晶格参数在35%以下符合维加德定律。在较宽的温度范围内，测定了高纯CeO-ィイ-D22-ィエ-D2的氧扩散系数。Arrhenius图的结果被分为两个区域。高温区与萤石结构的其他化学计量比氧化物非常接近，在此范围内的扩散属于本征扩散。低温区的斜率与文献报道的Y掺杂CeO：ィイD22：ィエ：D2和Gd：CeO：ィイ：D22：ィエ：D2非常接近。绘制了未掺杂CeOィイD22ィエD2和掺杂CeOィイD22ィエD2的氧扩散系数随三价阳离子杂质或添加剂浓度的变化曲线，发现氧扩散受氧化物中三价杂质的控制。首次测定了CeOィイD22ィエD2的表面扩散。测定了Y掺杂CeOィイD22ィエD2和Y掺杂ィイD22ィエD2中的化学扩散。在钙掺杂的ィイ-D22-ィエ-D2中，其扩散速度慢于氧扩散，接近于正离子扩散。

项目成果

M.Kamiya, E.Shimada, Y.Ikuma, M.Komatsu, and H.Haneda: "Intrinsic and extrinsic oxygen diffusion and surface exchange reaction in cerium oxide"J.Electrochem.Soc.. 147[3] in print.

M.Kamiya、E.Shimada、Y.Ikuma、M.Komatsu 和 H.Haneda：“氧化铈中的内在和外在氧扩散和表面交换反应”J.Electrochem.Soc.. 147[3] 印刷。

Y.Hirata: "Microstructure and electrical conductivity of rare earth-doped ceria"Ceram. Trans.. 92. 137-148 (1999)

Y.Hirata：“稀土掺杂二氧化铈的微观结构和电导率”陶瓷。

M.Kamiya: "Intrinsic and extrinsic oxygen diffusion and surface exchange reaction in cerium oxide"J. Electrochem. Soc.. 147[3](印刷中).

M. Kamiya：“氧化铈中的内在和外在氧扩散和表面交换反应”J. Electrochem。147[3]（印刷中）。

伊熊 泰郎: "セラミックス中の酸素拡散"熱処理. 40(印刷中).

Yasuro Ikuma：“陶瓷中的氧扩散”热处理 40（正在出版）。

神谷倫代: "酸化セリウム中の酸素拡散" J.Ceram.Soc.Japan. 106〔10〕. 1023-1026 (1998)

Michiyo Kamiya：“氧化铈中的氧扩散”J.Ceram.Soc.Japan 106 [10] 1023-1026 (1998)。