Record number :
1000802
Title of article :
The study of the effect of Ba coverage through the accelerations lifetime of activated BaO/SrO cathodes
Author/Authors :
A.A. Hashima، نويسنده , , *، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2005
Pages :
8
From page :
421
To page :
428
Abstract :
A novel type of BaO/SrO oxide cathode with 5% addition of Ni powder by weight on a Ni cap containing an activating impurity was studied. The conductivity and the electron activation energy were studied as a function of temperature in the range of 300–1200 K after conversion and activation of the cathode at 1200 K for 1 h. The experimental results yield three values for the activation energy of 1.49, 2.23 and 3.3 eV, which are close to BaO band structure parameters with a small shift due to the effect of other oxide components and metallic fraction additions. The experiments furthermore confirm that the current density of the cathode was enhanced at high temperature range with the long operation. The conduction mechanisms observed a metallic conduction at low temperature after operation for several 100 h due to improvements in the Ba coverage layer on the grains of oxide layer. Additionally, there appears a qualified conduction stability of the current density J = 10–45 mA cm 2 at the acceleration temperature range of 1100–1150 K under the duty of low voltage. The low voltage duty V = 30 mVis focused on the conduction electrons faraway from the emission electrons
Keywords :
Oxide cathode , Ba and Sr oxides , Electron emission , electrical properties
Journal title :
Applied Surface Science
Journal title :
Applied Surface Science
Serial Year :
2005
Link To Document :
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