Evidence of high fluorine ion conductivity in SrF2-rich SrF2-TiO2 based compounds
Author(s)
Sadia, yatir
Kerherve, Gwilherm
Skinner, Stephen
Type
Journal Article
Abstract
Materials based on Sr–Ti–O have shown remarkable properties and have been used in a wide diversity of applications. However, very little investigation has gone into the Sr–Ti–O–F system, mainly due to the very high stability of its constituents such as SrF2 and TiO2. In this work, solid-state reactions under reducing atmospheres on SrF2 and TiO2 showed highly interesting properties for the system, including high mixed electronic and ionic conductivity. XPS data further illuminate the results with the Ti 2p peaks shifting to higher binding energy due to fluorine interaction, possibly hinting at the formation of a TiOxFy phase. Testing using both ion blocking and electron blocking layers allowed the distinction between the ionic and electronic conductivity of the materials, showing very high ionic conductivity compared to most SrF2-based compounds. Ionic conductivities of up to 1 mS cm–1 for 2SrF2:TiO2 samples near room temperature were obtained. The ionic transport numbers were found to be 20–60% over the 50–300 °C temperature range. The apparent activation energy for ionic conduction was surprisingly low with Ea (ionic) = 0.05–0.10 eV for the different samples, whereas for electronic conductivity, Ea (electron) = 0.11–0.32 eV.
Date Issued
2025-04-28
Date Acceptance
2025-04-16
Citation
ACS Omega, 2025, 10 (18), pp.19214-19223
ISSN
2470-1343
Publisher
American Chemical Society
Start Page
19214
End Page
19223
Journal / Book Title
ACS Omega
Volume
10
Issue
18
Copyright Statement
© 2025 The Authors. Published by American Chemical Society. This publication is licensed under CC-BY 4.0 (https://creativecommons.org/licenses/by/4.0/).
License URL
Identifier
10.1021/acsomega.5c02253
Publication Status
Published