Moving boundary diffusion problem for hydration kinetics evidenced in non-monotonic conductivity relaxations of proton conducting perovskites
| Autor: | Ji Haeng Yu, Gye-Rok Kim, Eui-Chol Shin, Hyun-Ho Seo, Jung-Mo Jo, Jong-Sook Lee |
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| Rok vydání: | 2015 |
| Předmět: |
Chemistry
Diffusion Doping Kinetics Thermodynamics chemistry.chemical_element General Chemistry Yttrium Conductivity Condensed Matter Physics Condensed Matter::Materials Science Van der Pauw method visual_art visual_art.visual_art_medium General Materials Science Ceramic Physics::Chemical Physics Spectroscopy |
| Zdroj: | Solid State Ionics. 272:60-73 |
| ISSN: | 0167-2738 |
| DOI: | 10.1016/j.ssi.2015.01.003 |
| Popis: | A high temperature van der Pauw method using a bulk disk sample was applied for a more reliable kinetic investigation in a protonic ceramic conductor, barium zirconate doped with 20 m/o yttrium. Similarly activated faster hydrogenation and slower oxygenation process can be explained by the moving boundary diffusion mechanism previously evidenced by in-situ optical spectroscopy where the hydrogenation kinetics is limited by the hydration front. The mechanism generally applies to all protonic ceramic conductors exhibiting non-monotonic conductivity relaxations. Defect-chemical consideration on the humidity, oxygen activity and temperature dependence of chemical diffusivities is provided. |
| Databáze: | OpenAIRE |
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