کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1448320 | 988670 | 2009 | 10 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Surface and bulk oxygen non-stoichiometry and bulk chemical expansion in gadolinium-doped cerium oxide Surface and bulk oxygen non-stoichiometry and bulk chemical expansion in gadolinium-doped cerium oxide](/preview/png/1448320.png)
Doped and undoped cerium(IV) oxides are ceramics commonly used as catalysts and as solid oxide fuel cell materials. In low oxygen partial pressure, ceria-based materials become non-stoichiometric and can form defect complexes that hinder ionic conductivity. In addition, oxygen non-stoichiometry induces strain (chemical expansion) that can result in stresses for composite or constrained applications. In this paper the non-stoichiometry and chemical expansion behavior has been measured in the temperature range 600–900 °C and in a wide oxygen partial pressure range. Surface oxygen non-stoichiometry has also been measured by comparing low surface area to high surface area samples. The bulk non-stoichiometry and chemical expansion behavior have been successfully modeled using a mass action formalism with defect complex formation to account for defect interactions. It has been found that surface defect concentration, previously ignored in the literature, can result in erroneous non-stoichiometry measurements.
Journal: Acta Materialia - Volume 57, Issue 12, July 2009, Pages 3596–3605