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|Author(s):||Pratik Dholabhai; James B. Adams; Peter A. Crozier; Renu Sharma;|
|Title:||First-principles Study of Defect Migration in RE-doped Ceria (RE = Pr, Gd)|
|Published:||February 02, 2011|
|Abstract:||Oxygen vacancy formation and migration in ceria (CeO2) is central to its performance as an ionic conductor. Ceria doped with suitable aliovalent dopants has enhanced oxygen ion conductivity ‹ higher than that of yttria stabilized zirconia (YSZ), the most widely used electrolyte material in solid oxide fuel cells (SOFC). To gain insight into atomic defect migration in this class of promising electrolyte materials, we have performed total energy calculations within the framework of density functional theory (DFT+U) to study oxygen vacancy migration in ceria, Pr-doped ceria (PDC) and Gd-doped ceria (GDC). We report activation energies for various oxygen vacancy migration pathways in PDC and GDC. Results pertaining to the preferred oxygen vacancy formation sites and migration pathways in these materials will be discussed in detail. Overall, the presence of Pr and Gd ions significantly affects oxygen vacancy formation and migration, in a complex manner requiring the investigation of many different migration events. We propose a relationship that explains the role of additional dopants in lowering the activation energy for vacancy migration in PDC and GDC.|
|Conference:||Materials Research Society of America, Fall meeting 2010|
|Proceedings:||Materials Research Society of America|
|Pages:||pp. gg05 - gg08|
|Dates:||November 28-December 3, 2010|
|Keywords:||DFT calculation, vacancy migration, ceria, doped ceris|
|Research Areas:||Alternative Energy|
|PDF version:||Click here to retrieve PDF version of paper (160KB)|