Oxygen migration in A2B2O7 pyrochlores

被引：238

作者：

Pirzada, M

Grimes, RW ^{[1
]}

Minervini, L

Maguire, JF

Sickafus, KE

机构：

[1] Imperial Coll, Dept Mat, London SW7 2BP, England

[2] Los Alamos Natl Lab, Los Alamos, NM 87545 USA

[3] USAF, Res Lab, MLMR, AFRL, Wright Patterson AFB, OH 45433 USA

来源：

SOLID STATE IONICS | 2001年 / 140卷 / 3-4期

基金：

英国工程与自然科学研究理事会;

关键词：

pyrochlore; oxygen transport; defect energies; atomistic simulation; activation energies;

D O I：

10.1016/S0167-2738(00)00836-5

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：

Atomic scale computer simulation has been used to predict activation energies for oxygen migration. In total, 54 compounds with the A(2)B(2)O(7) pyrochlore structure were simulated. In each case, oxygen migration was assumed to proceed via an oxygen vacancy mechanism with oxygen ions hopping between 48f sites. For some compounds the unoccupied 8a interstitial position played an important role in the migration mechanism. The results were analyzed using a contour map of activation energy versus A cation radius along the ordinate and B cation radius along the abscissa. This identified areas of similar cation radii, which exhibit lower activation energy. Results compare favourably with available experimental data. (C) 2001 Elsevier Science B.V, All rights reserved.

引用

页码：201 / 208

页数：8

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