Publication Date:
2011-06-25
Description:
Three-dimensional electron backscatter diffraction was used to measure the crystallographic distribution of the electrochemically relevant triple phase boundary lines and surfaces near them in SOFC cathodes made up of a porous mixture of yttria-stabilized zirconia and lanthanum strontium manganese oxide, both before and after mild electrochemical loading. All distributions were observed to be nearly isotropic, but non-random textures above the detection threshold were observed. The distributions differ between the two cells, as do the phase fractions and the electrochemical history. The different distributions are interpreted as evidence that steady-state distributions vary locally with phase fractions or that they evolve during the initial operation of the fuel cell. The rates at which triple lines, pore surfaces, and interface boundaries in the porous mixture approach a steady-state value appear to decrease with the average amount of mass transport required to reorient that specific feature. This work provides initial insights into the crystallography of interfaces in a multiphase ceramic material.
Print ISSN:
0002-7820
Electronic ISSN:
1551-2916
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
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