Measurement of oxygen transport in La0.8Sr0.2MnO3 perovskite grains

被引:23
作者
Fearn, S. [1 ]
Rossiny, J. C. H. [1 ]
Kilner, J. A. [1 ]
Evans, J. R. G. [2 ]
机构
[1] Univ London Imperial Coll Sci Technol & Med, Dept Mat, London SW7 2AZ, England
[2] UCL, Dept Chem, London WC1, England
基金
英国工程与自然科学研究理事会;
关键词
Oxygen diffusion; Surface exchange; Focussed ion beam; SIMS; LaSrMnO3; Perovskite oxide; SURFACE EXCHANGE COEFFICIENTS; TRACER DIFFUSION; SIMS; OXIDES; DIFFUSIVITIES;
D O I
10.1016/j.ssi.2012.01.029
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
In this work values for the diffusion coefficient. D*, and surface exchange coefficient, le, have been obtained from individual La0.8Sr0.2MnO3 perovskite grains. Oxygen tracer diffusion profiles were created via the well established isotope exchange techniques. The tracer diffusion profiles were then measured using a FIB-SIMS workstation. Several measurements were taken over randomly selected grains including un-faceted and faceted grains. The values for D* and k* obtained compared very well with previous measurements made on bulk La0.8Sr0.2MnO3 samples i.e. over many grains. The results therefore indicate that D* and k* are independent of orientation. Furthermore the diffusion profiles indicated that only one single grain had been SIMS depth profiled and did not cross a grain boundary. Also by analysing in the centre of large grains, and not analysing up to the edge of the grains, no grain boundary diffusion was observed. Finally, the work also confirms that previous measurements of k* on this material have been correctly measured and not under estimated due to experimental errors. (C) 2012 Elsevier B.V. All rights reserved.
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页码:51 / 57
页数:7
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