Determination of chemical expansion coefficient and elastic properties of non-stoichiometric GDC using molecular dynamic simulations

Narasimhan Swaminathan, Jianmin Qu

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

Abstract

Gadolinium doped ceria (GDC) which is used as an electrolyte in solid oxide fuel cells, shows significant expansion when exposed to low partial pressures of oxygen. Such a chemical expansion has been attributed to the creation of charge compensating vacancies and the change in the oxidation state of cerium. The chemically induced mechanical stresses also affect diffusion characteristics. Two material properties govern this interaction between stresses and diffusion in ionic solids. These are the chemical coefficient of expansion and the change in elastic properties like Young's modulus with composition. The aim of this research is to determine and study these properties using Molecular Dynamics (MD) simulation for 10 and 20GDC using existing interatomic potential parameters. Results show that chemical expansion is purely volumetric with negligible or no change in MD simulation cell shape. Further it was concluded that there is a linear relation between chemical strains and non-stoichiometry in GDC for the studied range of non-stoichiometry. There was also a drastic reduction in the Young's modulus for higher vacancy concentrations in 10 and 20GDC.

Original languageEnglish
Title of host publicationAdvances in Solid Oxide Fuel Cells III - A Collection of Papers Presented at the 31st International Conference on Advanced Ceramics and Composites
Pages403-411
Number of pages9
Edition4
StatePublished - 2008
Event31st International Conference on Advanced Ceramics and Composites - Daytona Beach, FL, United States
Duration: 21 Jan 200726 Jan 2007

Publication series

NameCeramic Engineering and Science Proceedings
Number4
Volume28
ISSN (Print)0196-6219

Conference

Conference31st International Conference on Advanced Ceramics and Composites
Country/TerritoryUnited States
CityDaytona Beach, FL
Period21/01/0726/01/07

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