Nanoscale yttrium distribution in yttrium-doped ceria powder
The microstructure and geometry of yttrium-doped ceria particles, synthesized by spray pyrolysis (SP), were characterized by transmission electron microscopy, and the distribution of yttrium was investigated by energy-dispersive X-ray spectroscopy (EDX). The yttrium distribution was investigated by considering an electron interaction volume and geometry of the particle in an EDX profile analysis. Two models, linear and non-linear, for the yttrium concentration gradient were tested against the experimental EDX data for hollow particles. The results showed that the linear concentration distribution of yttrium fits the EDX profiles appreciably better than the non-linear concentration gradient model. This suggests that yttrium distribution is mainly controlled by the different diffusion rates of the precursors from the centre to the surface of the particle, which could be related to their different solubilities, during the heating process in SP.
KeywordsSolid oxide fuel cells Spray pyrolysis TEM EDX Yttrium-doped ceria Synthesis Nanopowder
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