Reaction Kinetics and Mechanisms between La0.65Sr0.3MnO3 and 8 mol% Yttria-Stabilized Zirconia |
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Authors: | Chih-Chung T Yang Wen-Cheng J Wei reas Roosen |
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Affiliation: | Institute of Materials Science and Engineering, National Taiwan University, Taipei, Taiwan 10617, Republic of China;Department of Materials Science, Glass and Ceramics, University of Erlangen-Nuremberg, D-91054 Erlangen, Germany |
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Abstract: | The reaction kinetics and mechanisms between 8 mol% yttria-stabilized zirconia (YSZ) and 30 mol% Sr-doped lanthanum manganite (La0.65Sr0.30MnO3, LSM) with A-site deficiency for the application of planar solid oxide fuel cells (SOFCs) were investigated. The LSM/YSZ green tapes were cofired from 1200° to 1400°C for 1 to 48 h and then annealed at 1000°C for up to 1000 h. The results showed that the diffusion of manganese cations first caused the amorphization of YSZ, and then the formation of small La2Zr2O7 (LZ) or SrZrO3 (SZ) crystals if treated for a longer time at 1400°C. The ambipolar diffusion of the Mn–O pair, transported through the migration of oxygen vacancy, plays an important role in the formation of secondary phases. The diffusion of LSM to YSZ and substitution of Mn for Zr both result in the enhanced concentration of oxygen vacancy, leading to the formation of a void-free zone (VFZ). No additional reaction products in annealed LSM/YSZ specimens, treated at 1000°C for 1000 h, were detected. The interfacial reactions, detailed reaction kinetics, and mechanisms are reported. |
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Keywords: | zirconia yttria stabilized solid oxide fuel cell kinetics |
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