Loading…
Oxide Ion Conductivity, Proton Conductivity, and Phase Transitions in Perovskite-Derived Ba 3- x Sr x YGa 2 O 7.5 0 ≤ x ≤ 3 Materials
We report the synthesis, structural characterization, and oxide ion and proton conductivities of the perovskite-related Ba Sr YGa O family. Single-phase samples are prepared for 0 ≤ ≤ 3 and show a complex structural evolution from 2/ to 2 space groups with an increase in . For 1.0 ≲ ≲ 2.4, average s...
Saved in:
Published in: | Chemistry of materials 2022-04, Vol.34 (7), p.3185-3196 |
---|---|
Main Authors: | , , , , , , , |
Format: | Article |
Language: | English |
Citations: | Items that this one cites Items that cite this one |
Online Access: | Get full text |
Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
Summary: | We report the synthesis, structural characterization, and oxide ion and proton conductivities of the perovskite-related Ba
Sr
YGa
O
family. Single-phase samples are prepared for 0 ≤
≤ 3 and show a complex structural evolution from
2/
to
2 space groups with an increase in
. For 1.0 ≲
≲ 2.4, average structures determined by X-ray and neutron powder diffraction show metrically orthorhombic unit cells, but HAADF-STEM imaging reveals this is caused by microstructural effects due to intergrowths of the Ba- and Sr-rich structure types. Variable-temperature powder diffraction studies suggest that 0 ≲
≲ 2.4 compositions undergo a phase transition upon being heated to space group
that involves disordering of the oxygen substructure. Thermal expansion coefficients are reported for the series. Complex impedance studies show that the Ba-rich samples are mixed proton and oxide ion conductors under moist atmospheres but are predominantly oxide ion conductors at high temperatures or under dry atmospheres. Sr-rich samples show significantly less water uptake and appear to be predominantly oxide ion conductors under the conditions studied. |
---|---|
ISSN: | 0897-4756 1520-5002 |
DOI: | 10.1021/acs.chemmater.1c04372 |