A computational study of oxide ion migration and water incorporation in the cuspidine system, La4(Ti2O8)O2
Kendrick, Emma, Russ, Mike and Slater, Peter (2008) A computational study of oxide ion migration and water incorporation in the cuspidine system, La4(Ti2O8)O2 Solid State Ionics, 179 (2008).
The cuspidine system, La4(Ti2-xGaxO8-x/2)O2 has recently been shown to display significant oxide ion conductivity at elevated temperatures, with evidence for proton conduction at low temperatures in wet atmospheres. In this paper we present a computer modelling study of the La4(Ti2O8)O2 (x=0) end-member. In agreement with experimental studies, the most favourable oxide ion vacancy defect is found at the bridging oxygen position (O3). Oxide ion migration is shown to proceed via a cooperative vacancy migration process with a calculated activation energy of 1.51 eV, in very good agreement with experiment. The computational results for water incorporation suggest that oxygen vacancies are required for water incorporation to occur, which also agrees with experiment, and the most favourable position for the proton is the bridging oxygen (O3).
|Divisions :||Faculty of Engineering and Physical Sciences > Chemistry|
|Date :||15 September 2008|
|Uncontrolled Keywords :||Oxide ion conduction, proton conduction, cuspidine, solid oxide fuel cell, computer modelling|
|Additional Information :||E. Kendrick, M.Russ, P.R. Slater; Solid State Ionics 179 (2008) 819|
|Depositing User :||Mr Adam Field|
|Date Deposited :||27 May 2010 14:43|
|Last Modified :||23 Sep 2013 18:34|
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