%0 Journal Article %A Auckett, Josie E. %A Lee, Wai Tung %A Rule, Kirrily C. %A Bosak, Alexey %A Ling, Chris D. %D 2019 %T Order, Disorder, and Dynamics in Brownmillerite Sr2Fe2O5 %U https://acs.figshare.com/articles/journal_contribution/Order_Disorder_and_Dynamics_in_Brownmillerite_Sr_sub_2_sub_Fe_sub_2_sub_O_sub_5_sub_/9725030 %R 10.1021/acs.inorgchem.9b01846.s001 %2 https://acs.figshare.com/ndownloader/files/17417714 %K room-temperature structure %K Brownmillerite Sr 2 Fe 2 O 5 %K Sr 2 Fe 2 O 5 %K electron diffraction data %K brownmillerite-type Sr 2 Fe 2 O 5 %K satellite reflections %K neutron diffraction %K diffraction images %K X-ray %K length scales %K tetrahedral chain %K disagreements concern %K b axis %K FeO 4 tetrahedral chains %K oxide ion transport %K oxide-ionic conductivity %K powder samples %X The room-temperature structure of brownmillerite-type Sr2Fe2O5 remains controversial, despite numerous published crystallographic studies utilizing X-ray, neutron, and electron diffraction data collected on single-crystalline and powder samples. The main disagreements concern the ordering of twisted FeO4 tetrahedral chains within and between the layers stacked along the b axis, and the impact of this ordering on oxide-ionic conductivity. Here, we present new data along with a reinterpretation of previously published diffraction images, including the reassignment of satellite reflections, which harmonize the results of past studies in a unified description of tetrahedral chain ordering in Sr2Fe2O5 at length scales relevant to X-ray and neutron diffraction. Implications for the prevailing model of oxide ion transport in this material are also discussed. %I ACS Publications