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Updated: Oct 7, 2025
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Atomic Layer Deposition of Vanadium Dioxide and a Temperature-dependent Optical Model
Published on: May 23, 2018
12.1K
Variable Temperature Neutron Diffraction Study of the Oxide Ion Conductor Ba3VWO8.5.
Asma Gilane1,2, Sacha Fop1,3, Dylan N Tawse1
1The Chemistry Department, University of Aberdeen, Meston Walk, Aberdeen AB24 3UE, United Kingdom.
Inorganic Chemistry
|January 11, 2022
Summary
Barium vanadate tungstate (Ba3VWO8.5) exhibits stable cation order up to 800°C, unlike related oxide ionic conductors. This stability prevents water absorption and structural changes, crucial for advanced material applications.
Area of Science:
- Solid-state chemistry
- Materials science
- Crystallography
Background:
- Oxide ionic conductors are vital for energy applications.
- Hexagonal perovskite derivatives (Ba3M'M"O8.5) often exhibit structural flexibility and water uptake.
- Cation ordering influences material properties and stability.
Purpose of the Study:
- To investigate the structural stability and cation ordering of Ba3VWO8.5 at elevated temperatures.
- To elucidate the role of water absorption in structural rearrangements of hexagonal perovskite derivatives.
- To understand how cation distribution affects the flexibility and water uptake of Ba3M'M"O8.5 materials.
Main Methods:
- Variable temperature neutron diffraction was employed to study Ba3VWO8.5.
- Analysis of cation site occupancy and structural changes up to 800 °C.
- Comparison with related hexagonal perovskite derivatives (M' = Nb; M" = Mo, W).
Main Results:
- Ba3VWO8.5 retains its cation order (V and W on M1 sites) up to 800 °C.
- Unlike other Ba3M'M"O8.5 materials, Ba3VWO8.5 shows no significant water absorption.
- The presence of 50% V5+ on the M1 site disrupts crystal structure flexibility, preventing cation migration and water uptake.
Conclusions:
- Cation ordering in Ba3VWO8.5 provides exceptional structural stability at high temperatures.
- Water absorption in related hexagonal perovskites is linked to cation mobility and structural flexibility.
- The specific cation distribution in Ba3VWO8.5 prevents detrimental structural rearrangements, highlighting its potential as a stable oxide ionic conductor.
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