ANSTO Publications Online >
Journal Publications >
Journal Articles >
Please use this identifier to cite or link to this item:
|Title: ||Combined Experimental and Computational Study of Oxide Ion Conduction Dynamics in Sr2Fe2O5 Brownmillerite|
|Authors: ||Auckett, JE|
|Issue Date: ||13-Aug-2013|
|Publisher: ||American Chemical Society|
|Citation: ||Auckett, J.E., Studer, A.J., Pellegrini, E., Ollivier, J., Johnson, M.R., Schober, H., Miiller, W., & Ling, C.D. Combined Experimental and Computational Study of Oxide Ion Conduction Dynamics in Sr2Fe2O5 Brownmillerite. Chemistry of Materials, 2013. 25(15), 3080-3087.|
|Abstract: ||We report a detailed study of the dynamics of oxide ionic conduction in brownmillerite-type Sr2Fe2O5, including lattice anisotropy, based on neutron scattering studies of a large (partially twinned) single crystal in combination with ab initio molecular dynamics simulations. Single-crystal diffraction reveals supercell peaks due to long-range ordering among chains of corner-sharing FeO4 tetrahedra, which disappears on heating above 540 °C due to confined local rotations of tetrahedra. Our simulations show that these rotations are essentially isotropic, but are a precondition for the anisotropic motion that moves oxide ions into the tetrahedral layers from the octahedral layers, which we observe experimentally as a Lorentzian broadening of the quasielastic neutron scattering spectrum. This continual but incoherent movement of oxide ions in turn creates conduction pathways and activates long-range diffusion at the interface between layers, which appears to be largely isotropic in two dimensions, in contrast with previously proposed mechanisms that suggest diffusion occurs preferentially along the c axis.© 2013, American Chemical Society.|
|Appears in Collections:||Journal Articles|
Files in This Item:
There are no files associated with this item.
Items in APO are protected by copyright, with all rights reserved, unless otherwise indicated.