A SIMS study of oxygen tracer diffusion and surface exchange in La0.8Sr0.2MnO3+δ

被引：175

作者：

De Souza, RA

Kilner, JA

Walker, JF

机构：

[1] Univ London Imperial Coll Sci Technol & Med, Dept Mat, London SW7 2BP, England

[2] FEI UK, Brookfield Business Ctr, Cambridge CB4 4PS, England

来源：

MATERIALS LETTERS | 2000年 / 43卷 / 1-2期

基金：

英国工程与自然科学研究理事会;

关键词：

oxygen diffusion; surface exchange; perovskite oxide; LaMnO3;

D O I：

10.1016/S0167-577X(99)00228-1

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

The O-18/O-16 isotope exchange/depth profile (IEDP) method has been employed to investigate oxygen tracer diffusion and surface exchange behaviour in the perovskite oxide La0.8Sr0.2MnO3+delta at temperatures between 700 degrees C and 1000 degrees C. The activation enthalpy for oxygen tracer diffusion in the bulk (D-b*) was found to be 270 +/- 13 kT mol(-1), while that for oxygen tracer surface exchange (k(s)*) was 128 +/- 21 W mol(-1). Evidence of short circuit diffusion was observed in all O-18 penetration profiles, and this was ascribed to fast diffusion down grain boundaries. D-6* and k(s)* were also determined as a function of oxygen partial pressure at 1000 degrees C: D-b* was found to vary according to P-O2(-0.41). the P-O2 dependence of k(s)* was unclear, as the O-18 penetration profiles at 1000 degrees C were diffusion-limited. (C) 2000 Elsevier Science B.V. All rights reserved.

引用

页码：43 / 52

页数：10

共 31 条

[1] OXYGEN CHEMICAL DIFFUSION IN STRONTIUM DOPED LANTHANUM MANGANITES [J].