La2O3-Gd2O3-Mo secondary
emission material
emission material
(Key Laboratory of Advanced Functional Materials, Ministry of Education,
School of Materials Science and Engineering,
Beijing Polytechnic University,Beijing 100022, China)
School of Materials Science and Engineering,
Beijing Polytechnic University,Beijing 100022, China)
Abstract: A new kind of materials La2O3-Gd2O3-Mo has been produced by powder metallurgy method. The composition and microstructure of the material were studied by XRD and SEM. It shows that no chemical reaction takes place among La2O3, Gd2O3, Mo and the rare earth oxides exist along molybdenum grain boundaries and in the pores. The emission property measurement results of this material show that adding rare earth oxide into molybdenum can improve the secondary emission coefficient of the emitter, and the emission property depends on the activating temperature. After La2O3-Gd2O3-Mo was activated at 1360℃, the maximum secondary emission coefficient can be high to 2.62, which has exceeded that for practical uses(2.0).
Key words: La2O3-Gd2O3-Mo; secondary emission; cathode