Redox cycling and metastability of La<sub>2</sub>Mo<sub>2</sub>O<sub>9</sub>-based ceramics - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Solid State Ionics Année : 2008

Redox cycling and metastability of La2Mo2O9-based ceramics

Résumé

This paper aims at providing a better understanding of the electrical properties and mechanical behavior in reducing atmosphere (Ar–H2) of La2Mo2O9-type ceramics in order to clarify their potential use as either SOFC electrolyte or anode. A careful analysis of the available literature on this topic is provided.

The electrical properties, crystal structure and ceramic microstructure of reduced La1.9Y0.1Mo1.5W0.5O9 are investigated by AC Impedance Spectroscopy (IS), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDX) and X-Ray diffraction (XRD). At 400 °C, La1.9Y0.1Mo1.5W0.5O9 is metastable in 10% Ar–H2. The reduction yields an electronic conductivity and results in a disappearance of all the electrical phenomena of interfacial nature. On severe reduction, the mass loss and particles ejection lead to an important contraction of the grains yielding strong damages at grain boundaries, where reduced phases and/or metallic molybdenum segregate, explaining the high electronic conductivity.

Dates et versions

hal-00386323 , version 1 (20-05-2009)

Identifiants

Citer

Samuel Georges, Mathieu Salaün. Redox cycling and metastability of La2Mo2O9-based ceramics. Solid State Ionics, 2008, 178 (37-38), pp. 1898-1906. ⟨10.1016/j.ssi.2007.12.089⟩. ⟨hal-00386323⟩
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