Preparation and performance analysis of barium dispenser cathodes

The intercorrelation of aluminate properties, such as structure, component and metal Os film coating with electron emission capability and longevity of Ba dispenser cathodes, has been investigated. It is shown that reactants react completely and the percentage of tribarium aluminates is larger in the normal environment, and that at 1723 K the pulse of cathode impregnated in the above aluminates is larger. Aluminates sintered under the normal environment constitute the multiphase formation, but aluminates sintered under the special environment with Ar gas injection compose the single-phase formation by means of X-ray diffraction (XRD). Both the surface and the fracture surface of cathode are full of aluminates evenly distributed by using Sirion 200 superhigh resolving power field emission scanning electron microscope (SEM). The emission current density of cathode-impregnated aluminates sintered in the special environment with Ar gas injection is larger than that in the common environment by the analysis of diode experiments. The emission capability of Os-coated cathode prepared by laser ablation deposition (LAD), which has good characteristics of low temperature is higher, than that without metal film coating cathodes.