10.1021/acs.inorgchem.9b01846.s001
Josie E. Auckett
Josie E.
Auckett
Wai Tung Lee
Wai Tung
Lee
Kirrily C. Rule
Kirrily C.
Rule
Alexey Bosak
Alexey
Bosak
Chris D. Ling
Chris D.
Ling
Order, Disorder, and Dynamics in Brownmillerite Sr<sub>2</sub>Fe<sub>2</sub>O<sub>5</sub>
American Chemical Society
2019
room-temperature structure
Brownmillerite Sr 2 Fe 2 O 5
Sr 2 Fe 2 O 5
electron diffraction data
brownmillerite-type Sr 2 Fe 2 O 5
satellite reflections
neutron diffraction
diffraction images
X-ray
length scales
tetrahedral chain
disagreements concern
b axis
FeO 4 tetrahedral chains
oxide ion transport
oxide-ionic conductivity
powder samples
2019-08-23 12:09:24
Journal contribution
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
The room-temperature
structure of brownmillerite-type Sr<sub>2</sub>Fe<sub>2</sub>O<sub>5</sub> 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 FeO<sub>4</sub> tetrahedral chains within
and between the layers stacked along the <i>b</i> 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 Sr<sub>2</sub>Fe<sub>2</sub>O<sub>5</sub> 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.