Accelerated ceria–zirconia solubilization by cationic diffusion inversion at low oxygen activity

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Fast elemental diffusion at the Gd-doped ceria/Y-stabilized zirconia interface occurs under reducing conditions at low oxygen activity (pO2 < 10−12 atm) and high temperature (1400 °C). This effect leads to formation of thick ceria–zirconia solid solution reaction layers in the micro-range vs. thin layers of few tens of nanometers under oxidative conditions (i.e. in synthetic air at pO2 = 0.21 atm). The fast dissolution occurs by an inversion of the dominating limiting mechanism from the expected Zr4+ diffusion into the CGO lattice at high pO2 to an unexpected Ce3+ diffusion into the YSZ component under reducing conditions. The diffusion coefficient of 8-fold coordinated Ce3+ in YSZ at 1400 °C and pO2 = 10−13 atm is estimated to be around 10−11 cm2 s−1. This value is around 3 orders of magnitude higher than Zr4+ interdiffusion in CGO under oxidative conditions and about 8 orders of magnitude higher than Ce4+ self-diffusion in CGO in air at the same temperature.

Original languageEnglish
JournalJournal of Materials Chemistry A
Volume4
Issue number43
Pages (from-to)16871-16878
Number of pages8
ISSN2050-7488
DOIs
Publication statusPublished - 2016

Bibliographical note

This article is part of themed collection: 2016 Journal of Materials Chemistry A HOT Papers

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