Chemical stability of
La2O3 in La2O3-Mo cathode materials
La2O3 in La2O3-Mo cathode materials
(Key Laboratory of Advanced Functional Materials,
Ministry of Education, P.R.China;
School of Materials Science and Engineering,
Beijing Polytechnic University, Beijing 100022, P.R.China)
Ministry of Education, P.R.China;
School of Materials Science and Engineering,
Beijing Polytechnic University, Beijing 100022, P.R.China)
Abstract: Chemical stability of La2O3 in carbonized and uncarbonized La2O3-Mo cathodes was studied by in-situ XPS analysis. Experimental results show that chemical stability of La2O3 is not good enough. In vacuum and at high temperature, oxygen can be dissociated from the lattice of La2O3 in the uncarbonized La2O3-Mo cathode. Binding energy shifts of La3d5/2 and La3d3/2 core peaks, and obvious decrease of satellite peak intensity in -La3d doublet with increasing temperature show that metallic La appears at carbonized La2O3-Mo cathode surface at high temperature.
Key words: lanthanum; chemical state; La2O3-Mo; cathode; XPS