|About this Abstract
||Materials Science & Technology 2012
||International Symposium on Defects, Transport and Related Phenomena
||Microstructural Effects on Oxygen Surface Exchange of La0.6Sr0.4Co0.2Fe0.8O3 Thin Films
||Miaolei Yan, Pei-Hsuan Lee, Lu Yan, Paul Salvador
|On-Site Speaker (Planned)
One of the largest contributors to loss in industrial SOFCs is the sluggish oxygen reduction reaction. The two primary industrial cathode materials are (La,Sr)MnO3 (LSM) and (La,Sr,)(Co,Fe)O3 (LSCF). We have shown that the surface exchange coefficient (kchem) varies by orders of magnitude for thin films of LSM, depending on the strain state, surface orientation, and extended defect population. One interesting observation is that tensile strain produces a surface exchange rate that is an order of magnitude higher than for compressive strain. Here, we continue such work by focusing on anion deficient La0.6Sr0.4Co0.2Fe0.8O3 thin films. The kchem values are compared across a range of microstructural states, including strained and relaxed (100)-epitaxial films on perovskite substrates, as well as (100)- and (110)-textured LSCF films on MgO and YSZ. These results will be compared with previous work on LSM and discussed relative to how microstructural features affect surface chemistry in modified cathodes.