Please use this identifier to cite or link to this item:
http://hdl.handle.net/20.500.11960/3022
Title: | Microstructure and electrical properties of aluminium-substituted La(Sr)Ga(Mg)O3-δ-based solid electrolytes |
Authors: | Gomes, Eduarda Mather, Glenn C. Figueiredo, Filipe M. Marques, Fernando M. B. |
Keywords: | Solid electrolytes Grain boundaries Impedance spectroscopy Oxides Electrochemistry Ceramics |
Issue Date: | 2009 |
Citation: | Gomes, E., Mather, G. C., Figueiredo, F. M., & Marques, F. M. B. (2009). Microstructure and electrical properties of aluminium-substituted La(Sr)Ga(Mg)O3-δ-based solid electrolytes. Monatshefte für Chemie, 140(9), 1041-1052. https://doi.org/10.1007/s00706-009-0139-1 |
Abstract: | A study of the influence of the substitution of Al for Ga in the ceramic processing and electrical properties of La0.95Sr0.05Ga0.90–xAlxMg0.10O3–d (0 B x B 0.3) solid electrolytes is presented. The materials retained orthorhombic symmetry over the entire substitution range, whereas a deviation from Vegard’s law for x[0.20 suggested a maximum Al solubility of x = 0.20. Scanning electron microscopy analysis of ceramic samples revealed that grain growth was inhibited for x C 0.2. This microstructural change was related to an apparent deterioration of mechanical properties, as suggested by room-temperature Vickers hardness measurements. Impedance spectroscopy revealed a significant degradation of the grain-boundary electrical properties for x C 0.20, whereas the bulk conductivity was enhanced for 0.10 B x B 0.15. Oxygenpermeability measurements confirmed that the studied materials remain essentially pure ionic conductors. An ionic conductivity maximum of 0.047 S/cm at 700 C was obtained for x = 0.10. The effect of aluminium in the grainbulk ionic conductivity is discussed in terms of defect cluster models and assuming fast oxygen diffusion along domain walls. |
URI: | http://hdl.handle.net/20.500.11960/3022 |
ISSN: | 0026-9247 |
Appears in Collections: | ESTG - Artigos indexados à WoS/Scopus |
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