中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 10 No. 6 December 2000 |
Surface segregation of La2O3molecules in Mo-La2O3cathode materials①
（School of Materials Science and Engineering, Beijing Polytechnic University, Beijing 100022, P.R.China）
Abstract:The surface segregation of La2O3 in Mo- La2O3 cathode was carried out by Auger electron spectroscopy. Lanthanum and oxygen ions (La3+and O2-) 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 O2-ions were found to fit with the following equations:
DLa=3.670 3×10-16exp(-1.016 39×105/RT)
DO=1.512 2×10-16exp(-8.130 66×104/RT).
Key words: segregation; lanthanum; oxygen; cathode; kinetics; Mo- La2O3
