Oxygen tracer diffusion and surface exchange kinetics in La0.6Sr0.4CoO3−δ

Oxygen tracer diffusion and surface exchange kinetics in Ba0.5Sr0.5Co0.8Fe0.2O3−δ

“…At the same time a low 18 O fraction close to the sample surface was observed. Similarly, low values of the 18 O fraction close to the surface have 7 been reported during oxygen diffusion depth profiling in polycrystalline La0.6Sr0.4CoO3 [19] and in epitaxial La2NiO4+δ thin films [20]. The reason for the observed depletion is currently unclear, but may be related to the reformation of the carbonate layer, segregation of constituent ions after high temperature pre-anneal and/or back exchange of 18 O when exposed to the ambient atmosphere after the tracer exchange process.…”

Nanoscaled La0.6Sr0.4CoO3−δ as intermediate temperature solid oxide fuel cell cathode: Microstructure and electrochemical performance

“…Peters et al [8] determined their La 0.5 Sr 0.5 CoO 3−ı thin film cathodes to be surface exchange controlled as well, with an activation energy of E a = 1.07 eV. In good agreement with the trend, that the activation energy of the oxygen surface exchange coefficient decreases with increasing Sr-content [25], a lower activation energy was observed.…”

Effect of the synthesis conditions on the properties of La0.15Sm0.35Sr0.08Ba0.42FeO3−δ cathode material for SOFCs

“…The reason why high temperatures are nevertheless required is the general sluggishness of the kinetics of the elementary processes involved, most of which are thermally activated. A prominent example is the oxygen reduction reaction at the cathode, which is often the main limiting factor to the performance of the whole SOFC system [1]. One important goal in SOFC research is therefore the search for cathode materials which offer a sufficient electrochemical performance at intermediate temperatures (500-750ºC).…”