| CaO或BaO与Sm2O3共掺杂CeO2体系电子结构和氧离子迁移的DFT+U研究 | |
| Electronic Structures and Oxygen Ion Migrations of the CaO or BaO and Sm2O3 Co-doped CeO2 System: A DFT+U Study | |
| 摘要: 使用GGA+U方法研究了CaO或BaO与Sm2O3共掺杂CeO2体系几何和电子结构及氧离子迁移。计算结果表明，Ba和Sm均靠近氧空位时BaSmCe30O63体系最稳定；Sm靠近，Ca远离氧空位时CaSmCe30O63体系最稳定。BaSmCe30O63和CaSmCe30O63体系中均不存在Ce4+变价。对CaSmCe30O63体系氧离子迁移的研究发现，当氧离子迁移到空位时，迁移能大小顺序为Em(3→V)< Em(1→V)< Em(4→V)< Em(2→V)，这一规律源于氧离子与低价掺杂离子产生负电势之间的排斥作用；对BaSmCe30O63体系氧离子迁移的研究发现，当空位迁移到周围氧离子时，迁移能大小顺序为Em(V→3)< Em(V→5)< Em(V→1)，这一规律源于氧空位产生的正电势与低价掺杂离子产生的负电势之间的吸引作用。此外，CaSmCe30O63体系最小迁移能小于SmCe31O63体系，证实了CeO2-Sm2O3-CaO体系离子电导率大于CeO2-Sm2O3体系的实验结果。 | |
| 关键词: 二氧化铈 掺杂 电子结构 氧离子迁移 第一性原理 | |
| 基金项目: 国家自然科学基金（No.51474133）、内蒙古自然科学基金（No.2016MS0513）和内蒙古科技大学产学研（No.PY-201502）资助项目。 | |
| Abstract: Geometric and electronic structures and oxygen ion migrations of CaO or BaO and Sm2O3 co-doped CeO2 systems were studied using a GGA+U method. The calculated results showed that the BaSmCe30O63 structure in which Ba and Sm were close to the oxygen vacancy was the most stable, and the CaSmCe30O63 structure was the most stable when Sm was close to the oxygen vacancy and Ca was far from it. There was no the valence change of Ce4+ in the CaSmCe30O63 and BaSmCe30O63 systems. In the CaSmCe30O63 system the order for migration energies of the six oxygen ions to oxygen vacancy, Em(3→V)< Em(1→V)< Em(4→V)< Em(2→V), was obtained, which was due to the repulsion interaction between the oxygen ion and the negative potential induced from the doping of dopants with the low valence. In the CaSmCe30O63 system the order for migration energies of the oxygen vacancy to six oxygen ions, Em(V→3)< Em(V→5)< Em(V→1), was obtained, which was due to the attractive interaction between the positive potential induced from oxygen vacancy and the negative potential induced from the doping of dopants with the low valence. In addition, the smallest migration energy of the CaSmCe30O63 system was smaller than that of the SmCe31O63 system, in agreement with the fact that the ion conductivity of the CeO2-Sm2O3-CaO system was higher than that of the CeO2-Sm2O3 system in experiment. | |
| Keywords: cerium dioxide dope electronic structure oxygen ion migration first principle | |
| 投稿时间：2016-01-20 修订日期：2016-05-30 | |
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| 吴铜伟,贾桂霄,包金小,刘媛媛,安胜利.CaO或BaO与Sm2O3共掺杂CeO2体系电子结构和氧离子迁移的DFT+U研究[J].无机化学学报,2016,32(8):1363-1369. | |
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