亚微米电子发射材料的合成及发射性能

Preparation and emission properties of a sub-micrometer carbonate emission material

介绍一种气-液相合成技术合成多元碳酸盐及其制备阴极的发射性能.实验表明:采用该方法合成碳酸盐结晶小,形貌呈细丝状,丝径小于1μm,这种亚微米丝状碳酸盐能明显提高氧化物阴极的发射性能.通过对阴极激活后阴极表面的SEM分析,初步讨论了亚微米碳酸盐的发射机理.

Oxide cathodes have widely been used as electron emission source in vacuum electronic devices. Emission of an oxide cathode is dependent upon the ratio of the different ingredients of three kinds of alkaline earth carbonates on the cathode surface and its microcopic shape. The synthesizing method plays a key role on the shape and ingredient of the carbonates. A new synthesis method,gas-liquid method,has been used to prepare the carbonates in this paper. The grains of the carbonates have filamental shape with sub-micrometer diameter. The testing results show that the cathode prepared with this sub-micrometer carbonate has large emission current density and long lifetime. The surface state and structure of the cathode are also analyzed with SEM in order to understand the mechanism of the enhanced emission current.