Dramatic Enhancement of Long-Term Stability of Erbia-Stabilized Bismuth Oxides via Quadrivalent Hf Doping
| Autor: | Chan-Woo Lee, Incheol Jeong, Byung-Hyun Yun, Kang Taek Lee |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Materials science
Ionic radius Dopant General Chemical Engineering Diffusion Doping Oxide Analytical chemistry chemistry.chemical_element 02 engineering and technology General Chemistry Conductivity 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences Bismuth chemistry.chemical_compound chemistry Phase (matter) Materials Chemistry 0210 nano-technology |
| Zdroj: | Chemistry of Materials. 29:10289-10293 |
| ISSN: | 1520-5002 0897-4756 |
| Popis: | The Er2O3-stabilized Bi2O3 (ESB) exhibits a superior oxygen ion conductivity below 750 oC. However, there is significant conductivity decay due to a cubic-to-rhombohedral phase transformation over time at ~ 600oC. Thus, to enhance the kinetic stability of ESB, we develop a novel double-doped bismuth oxide through additional quadrivalent doping in ESB. Surprisingly, 1 mol.% of Hf-doped ESB shows no conductivity degradation without a phase transition for 1200 h at 600 °C, while the conductivity of pure ESB drops to less than 5% of the initial value within 200 h. Additionally, the stability improvement effect is strongly correlated to the ionic radius of the aliovalent dopant with an optimum value at ~ 0.85A. When the Bi3+ diffusivity in the cation sublattice of ESB is measured using the Boltzmann-Matano method, Hf doping greatly reduces the diffusion coefficient by ~53% compared to pure ESB. This result suggests that the control of the cation interdiffusion coefficient is the key parameter for suppression o... |
| Databáze: | OpenAIRE |
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