Department of Precision Science and Technology and Applied Physics, Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871, Japan.
J Phys Condens Matter. 2013 Jun 5;25(22):225401. doi: 10.1088/0953-8984/25/22/225401. Epub 2013 May 9.
First-principles calculations based on density functional theory were performed to investigate the co-doping effects of Sm and Gd in ceria on its oxygen ion conduction. The focus of this study is on the interactions between the cation dopants and an oxygen vacancy within the two adjacent tetrahedral sites of fluorite structure surrounding the oxygen migration path. Vacancy formation energies, dopant-vacancy association energies, and migration energies were calculated to elucidate the doping effects on oxygen ion conduction. The migration energies show remarkable dependences on the ionic radii of the cations located at the edges of the migration path. A simple relation between migration energy and vacancy formation energy is proposed. This work provides an informative insight into vacancy diffusion that could be useful in optimizing doping materials for improving oxygen ion conductivity in doped ceria.
基于密度泛函理论的第一性原理计算研究了 Sm 和 Gd 在 CeO2 中的共掺杂对其氧离子传导的影响。本研究的重点是阳离子掺杂剂与位于氧迁移路径相邻的萤石结构四面体位置中氧空位之间的相互作用。计算了空位形成能、掺杂剂-空位缔合能和迁移能，以阐明掺杂对氧离子传导的影响。迁移能显著依赖于位于迁移路径边缘的阳离子的离子半径。提出了迁移能与空位形成能之间的简单关系。这项工作为空位扩散提供了有价值的见解，这对于优化掺杂材料以提高掺杂 CeO2 中的氧离子电导率可能是有用的。
