The ionic conductivity of acceptor doped ceria is strongly influenced by grain boundaries and interfaces. Most experiments show a decrease in ionic conductivity and an increase in electronic conductivity in these regions. Classical models explain this observation by the formation of space charge layers that are depleted of mobile ionic charge carriers and enriched in small polarons. However, some experiments demonstrate an increase in ionic conductivity and recent models show that the space charge layers can also be enriched in mobile ionic species. Because of these contradictions, it is still not clear whether nanocrystalline or thin film ceria can offer superior ionic conductivity or not. To aid this debate, we calculate the ionic conductivity of yttrium doped ceria in regions of net charge density using kinetic Monte Carlo simulations. Through an appropriate choice of the charge densities, these calculations allow to demarcate the possible conductivity gains from space charge layers.

掺杂受体的二氧化铈的离子电导率受晶界和界面的强烈影响。大多数实验表明，这些区域的离子电导率降低，电子电导率提高。经典模型通过形成空间电荷层来解释此现象，该空间电荷层贫乏可移动的离子电荷载流子，并富含小极化子。但是，一些实验表明离子电导率有所提高，最近的模型表明，空间电荷层也可以富集可移动的离子物种。由于这些矛盾，尚不清楚纳米晶或薄膜二氧化铈能否提供优异的离子传导性。为了帮助进行辩论，我们使用动力学蒙特卡罗模拟计算了净电荷密度区域中钇掺杂二氧化铈的离子电导率。