The surface of complex oxides; ion beam based analysis of energy materials

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS

卷:480

Article

Niania, M.¹  Sharpe, M.³  Webb, R.³  Kilner, J. A.^1,2 

[1] Imperial Coll, Fac Engn, Dept Mat, London SW7 2AZ, England

[2] Int Inst Carbon Neutral Energy Res I2CNER, Nishi Ku, 744 Motooka, Fukuoka 8190395, Japan

[3] Univ Surrey, Ion Beam Ctr, Guildford GU2 7XH, Surrey, England

关键词: SOFC cathodes;    LEIS;    Preferential sputtering;    TRIDYN modelling;    Ar depth profiling;   

DOI  :  10.1016/j.nimb.2020.07.022

来源: Elsevier

【 摘 要 】

LEIS depth profiles, obtained by low energy (0.5 keV) Ar+ sputtering, have been analysed for the mixed conducting oxide material La0.6Sr0.4CO0.2Fe0.8O3-delta. Samples have been examined after differing thermal treatments to examine the sub-surface reorganisation of the cation species. The profiles have shown considerable changes, but these are not strongly correlated with the thermal treatments. The similarity between the profiles suggests that preferential sputtering effects can dominate the sub-surface region (similar to 1-3 nm) where sputtering has not reached equilibrium. Preferential sputtering of oxygen in oxide materials is well known, but here we provide evidence of the preferential sputtering of the cationic species in a complex multicomponent oxide. Of note is strong enrichment (similar to 30%) of the sputtered surface with the heaviest of the elements, La. Simulations using the code TRIDYN have confirmed the observations, in particular, La surface enrichment and the fluence needed to achieve steady state sputtering of > 3 x 10(16) cm(-2).

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