| 摘要 |
<p>PURPOSE:To prevent any consumption of a reducing agent, and obtain a cathode structure provided with a mechanically stable suppressor layer by providing a base metal with both a second Ni alloy layer having a diffusion suppressing effect, and a selective oxide layer of the compositional element of an Ni alloy, which traps the said reducing agent diffused in the Ni alloy after a long time. CONSTITUTION:A base metal consists of a first Ni alloy layer 7 coated with an electron discharging matter 6, and a second Ni alloy layer 8 uncoated with the matter 6. A selective oxide layer 9 is formed over the external surface of the second layer 8. The first Ni alloy layer 7 contains 0.01-1.0wt% of Mg used as a reducing agent, while the second Ni alloy layer 8 contains 0.1-10wt% of Nb. Owing to the above constitution, the evaporation of the reducing agent from the surface of the base metal is highly suppressed. Besides, a cathode structure provided with a mechanically stable suppressor layer can be obtained.</p> |
