TY - JOUR
T1 - Oxygen vacancy migration in ceria and Pr-doped ceria
T2 - A DFT+U study
AU - Dholabhai, Pratik P.
AU - Adams, James
AU - Crozier, Peter
AU - Sharma, Renu
N1 - Funding Information:
This paper is based upon the work supported by the Department of Energy under the Grant No. DE-PS02-06ER06-17. The authors gratefully acknowledge the Fulton High Performance Computing Initiative (HPCI) at the Arizona State University for the computational resources. P.P.D wishes to thank Douglas Fuller of the HPCI for technical assistance with the Saguaro cluster used for computations and Shahriar Anwar for some stimulating discussions.
PY - 2010
Y1 - 2010
N2 - Oxygen vacancy formation and migration in ceria (CeO2) is central to its performance as an ionic conductor. It has been observed that ceria doped with suitable aliovalent cationic dopants improves its ionic conductivity. To investigate this phenomenon, we present total energy calculations within the framework of density functional theory to study oxygen vacancy migration in ceria and Pr-doped ceria (PDC). We report activation energies for oxygen vacancy formation and migration in undoped ceria and for different migration pathways in PDC. The activation energy value for oxygen vacancy migration in undoped ceria was found to be in reasonable agreement with the available experimental and theoretical results. Conductivity values for reduced undoped ceria calculated using theoretical activation energy and attempt frequency were found in reasonably good agreement with the experimental data. For PDC, oxygen vacancy formation and migration were investigated at first, second, and third nearest neighbor positions to a Pr ion. The second nearest neighbor site is found to be the most favorable vacancy formation site. Vacancy migration between first, second, and third nearest neighbors was calculated (nine possible jumps), with activation energies ranging from 0.41 to 0.78 eV for first-nearest-neighbor jumps. Overall, the presence of Pr significantly affects vacancy formation and migration, in a complex manner requiring the investigation of many different migration events. We propose a relationship illuminating the role of additional dopants toward lowering the activation energy for vacancy migration in PDC.
AB - Oxygen vacancy formation and migration in ceria (CeO2) is central to its performance as an ionic conductor. It has been observed that ceria doped with suitable aliovalent cationic dopants improves its ionic conductivity. To investigate this phenomenon, we present total energy calculations within the framework of density functional theory to study oxygen vacancy migration in ceria and Pr-doped ceria (PDC). We report activation energies for oxygen vacancy formation and migration in undoped ceria and for different migration pathways in PDC. The activation energy value for oxygen vacancy migration in undoped ceria was found to be in reasonable agreement with the available experimental and theoretical results. Conductivity values for reduced undoped ceria calculated using theoretical activation energy and attempt frequency were found in reasonably good agreement with the experimental data. For PDC, oxygen vacancy formation and migration were investigated at first, second, and third nearest neighbor positions to a Pr ion. The second nearest neighbor site is found to be the most favorable vacancy formation site. Vacancy migration between first, second, and third nearest neighbors was calculated (nine possible jumps), with activation energies ranging from 0.41 to 0.78 eV for first-nearest-neighbor jumps. Overall, the presence of Pr significantly affects vacancy formation and migration, in a complex manner requiring the investigation of many different migration events. We propose a relationship illuminating the role of additional dopants toward lowering the activation energy for vacancy migration in PDC.
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U2 - 10.1063/1.3327684
DO - 10.1063/1.3327684
M3 - Article
C2 - 20210386
AN - SCOPUS:77949388438
SN - 0021-9606
VL - 132
JO - Journal of Chemical Physics
JF - Journal of Chemical Physics
IS - 9
M1 - 094104
ER -