DETERMINATION OF KINETIC AND TRANSPORT PARAMETERS FOR OXYGEN IN MIXED CONDUCTORS BY AN AC METHOD

被引：11

作者：

LADE, K

JACOBSEN, T

机构：

[1] Department of Physical Chemistry, The Technical University of Denmark

来源：

SOLID STATE IONICS | 1994年 / 72卷 / pt 2期

关键词：

Diffusion in solids - Electric impedance measurement - Lanthanum compounds - Oxides - Oxygen - Reaction kinetics - Surface properties - Thermodynamics - Transport properties;

D O I：

10.1016/0167-2738(94)90150-3

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：

A method for determining the chemical diffusion coefficient and the surface reaction resistance for oxygen in mixed conducting oxides has been developed. The method is based on impedance analysis of a zirconia oxygen pumping cell containing a sample of the oxide. For La0.85Sr0.15MnO3 the reaction resistance at 1000 degrees C in air is measured as 200 Omega cm(2), which corresponds to a surface exchange coefficient of 5x10(-6) cm/s. The value of the chemical diffusion coefficient under the same conditions is 2x10(-9) cm(2)/s, and the thermodynamic enhancement factor is calculated as 200. The corresponding self-diffusion coefficient obtained by this method is then 1x10(-11) cm(2)/s compared with the values of 3x10(-13) cm(2)/s, 4x10(-14) cm(2)/s obtained by O-18/O-16 exchange experiments on La0.65Sr0.35MnO3 at 900 degrees C.

引用

页码：218 / 223

页数：6

共 9 条

[1] MEASUREMENT OF THE CHEMICAL DIFFUSION-COEFFICIENT OF OXYGEN IN MIXED CONDUCTORS BY A SOLID-STATE ELECTROCHEMICAL METHOD [J].