Fast oxide-ion conductors in Bi2O3-V2O5 system: Bi108-xVxO162+x(x=4-9) with 3×3×3 superstructure
In this study, the possibility to stabilize O2-ion conductors in Bi2O3-V2O5 system was investigated. Six pseudo-binary Bi2O3-V2O5 mixtures [3.50 < x(V2O5) < 8.50 mol%] were thermally treated at 1000°C for 1 h. The samples were characterized by XRD, HRTEM/SAED, DTA and EIS techniques....
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
International Institute for the Science of Sintering, Beograd
2021-01-01
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| Series: | Science of Sintering |
| Subjects: | |
| Online Access: | http://www.doiserbia.nb.rs/img/doi/0350-820X/2021/0350-820X2101055D.pdf |
| Summary: | In this study, the possibility to stabilize O2-ion conductors in Bi2O3-V2O5
system was investigated. Six pseudo-binary Bi2O3-V2O5 mixtures [3.50 <
x(V2O5) < 8.50 mol%] were thermally treated at 1000°C for 1 h. The samples
were characterized by XRD, HRTEM/SAED, DTA and EIS techniques. The
high-temperature reaction between α Bi2O3 and V2O5 resulted in formation of
microcrystalline single-phase specimens containing the phase based on
δ-Bi2O3 if V2O5 content was ≥ 4.63 mol%. The obtained phases exhibited main
diffraction peaks corresponding to the simple cubic δ-Bi2O3 (space group
Fm-3m) but Rietveld refinement showed a threefold repeat on a simple cubic
sublattice indicating that the true unit cell is 3×3×3 supercell. Within
proposed supercell, the octahedrally coordinated V5+ ions fully occupy 4a
Wyckoff position and partially occupy 32f. The Bi3+ ions are placed at the
rest of 32f and at 24e and 48h with full occupation. In total, 22 % of
anionic sites are vacant. The ionic conductivity of phase with the lowest
dopant content, i.e. Bi 103V5O167, amounts 0.283 S cm-1 at 800°C with the
activation energy of 0.64(5) eV, which is comparable to the undoped δ-Bi2O3
known as the fastest ion conductor. |
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| ISSN: | 0350-820X 1820-7413 |