Surface segregation of La₂O₃ molecules in Mo-La₂O₃ cathode materials

来源期刊：中国有色金属学报(英文版)2000年第6期

论文作者：王金淑 周美玲 聂祚仁 张久兴 左铁镛 王亦曼

文章页码：745 - 748

Key words：segregation; lanthanum; oxygen; cathode; kinetics; Mo- La₂O₃

Abstract:

The surface segregation of La₂O₃ in Mo- La₂O₃ cathode was carried out by Auger electron spectroscopy. Lanthanum and oxygen ions (La³⁺and O^2-) diffuse from the grain boundaries to the surface respectively, and these ions recombine into La₂O₃ molecules on the surface. The results were analyzed by kinetics of grain boundary diffusion. In the temperature range of 1123~1423K, the diffusion coefficients of La³⁺ and O^2- ions were found to fit with the following equations: D_La=3.670 3×10^-16 exp(-1.01639×10⁵ /RT)

D_O=1.512 2×10^-16 exp(-8.13066×10⁴ /RT).