微波放大管用贵金属冷阴极材料

Cold Cathode Materials of Noble Metal in Microwave Amplifier

介绍了微波放大管中利用贵金属材料制作冷阴极(二次电子发射体)的研究及使用情况。在纯金属中贵金属的δ值较高,如Pt的δmax=1.8,但还不能满足微波放大管的要求,多数使用的是其合金或复合材料。主要包括采用熔炼法在Pt,Pd,Rh,Au中添加Ba组成的二元合金,δmax可达到3。采用粉末冶金法制备复合材料,主要有MgO/Au金属陶瓷薄膜材料、Pt、Pd/氧化物复合材料等,δmax可达4.7。

The secondary-emission properties of the noble metals are better than the other pure metals. Pt has the secondary-electron emission coefficient δ_(max)=1.8, but often fails to meet the requirements of CFA. The precious alloys and its compound materials are used usually for the cold cathodes. The alloys based on Pt, Pd, Rh, Au with additions of Ba are researched and applied, its δ_(max)=3. The promising composites based on Au, Pt, Pd with additions of the oxides, have good secondary-emission properties, its ...