Is ReO3 a mixed ionic–electronic conductor? A DFT study of defect formation and migration in a B(VI)O3 perovskite-type oxideWednesday (26.09.2018) 16:30 - 16:45 S1/03 - 223 Part of:
Density functional theory (DFT) calculations within the generalized gradient approximation (GGA) were used to examine the behaviour of point defects in the cubic B(VI)O3 perovskite-type oxide, ReO3. Energies of reduction and of hydration were calculated, and the results are compared with literature data for ABO3 perovskite oxides. The activation energies of migration for O2–, H+, Li+, Na+, K+ and H3O+ were also determined. The empty A site in ReO3 is found to be detrimental to oxide-ion migration by a vacancy mechanism as well as to proton migration by a Grotthuss mechanism. Na+, K+ and H3O+ exhibit activation energies of migration higher than 2 eV, whereas Li+ is characterised by a very low migration barrier of 0.1 eV. Reasons for this behaviour are discussed. Our results suggest that H+, O2–, and especially Li+, are high mobile ions in ReO3. In general, our results have strong implications for the mechanisms of ion migration in ABO3 perovskite oxides.
 J. P. Parras, A. R. Genreith-Schriever, H. Zhang, M. T. Elm, T. Norby and R. A. De Souza, Phys. Chem. Chem. Phys., 2018, DOI: 10.1039/C7CP08214B.