Structural dynamics of Schottky and Frenkel defects in CeO2: a density-functional theory study

Thomas Smith, Samuel Moxon, Joshua S Tse, Jonathan M Skelton, David J Cooke, Lisa J Gillie, E Lora Da silva, Robert M Harker, Mark T Storr, Stephen C Parker, Marco Molinari

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)

Abstract

Cerium dioxide CeO 2 (ceria) is an important material in catalysis and energy applications. The intrinsic Frenkel and Schottky defects can impact a wide range of material properties including the oxygen storage capacity, the redox cycle, and the ionic and thermal transport. Here, we study the impact of Frenkel and Schottky defects on the structural dynamics and thermal properties of ceria using density functional theory. The phonon contributions to the free energy are found to reduce the defect formation free energies at elevated temperature. The phonon dispersions of defective CeO 2 show significant broadening of the main branches compared to stoichiometric ceria. Phonon modes associated with the defects are identifiable in the infrared spectra through characteristic shoulders on the main features of the stoichiometric fluorite structure.

Original languageEnglish
Article number025004
Number of pages17
JournalJournal of Physics: Energy
Volume5
Issue number2
Early online date6 Mar 2023
DOIs
Publication statusPublished - 1 Apr 2023

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