Monstoichiomatry and oxygen diffusion in cerium oxide

Powders of undoped CeOイD22イD2， Nd-doped CeOイD22イD2， etc. were prepared。这些能量在水热条件下的晶体生长已经被研究和发现了一些能量，以获得高密度材料。晶格参数，密度，氧扩散，表面扩散等，这些样本已经被研究过。In the hydrothermal treatment of undoped CeOイD22イD2 and Nd-doped CeOイD22イD2 at 500， it was found that the particle size of powder after treatment depends on the concentration of Nd additive。在执行溶解实验时，发现了一个样本，即可以溶解在水中的水在水治疗期间的大规模生长。The lattice parameter of Nd-doped CeOイD22イエD2 was found to follow the Vegard's law up to 35%Nd at 500？。Oxygen diffusion coefficient of high purity CeOイD22イD2 was determined over wide temperature range。Arrhenius的结果被分成两个地区。高温度区域非常接近于该区域或其他含氟结构和这一范围内的扩散扩散，将被合并到内陆区域。The slope of low temperature region was very close to those of Y-doped CeOイD22イD2 and Gd-doped CeOイD22イD2 reported in the literature。Plotting oxygen diffusion coefficient in undoped首席执行官E-D22和doped首席执行官E-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. CeO中的Surface diffusion in D22 is determined for the first time。Chemical diffusion in Y-doped CeO-D22-D2 and Y-doped ZrO-D22-D2 was determined。It was slower than oxygen diffusion and close to cation diffusion of Zr in Ca-dopped ZrO-D22-D2。

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.