Preparing a scandate cathode by impregnating a porous tungsten billet with Ba.sub.3 Al.sub.2 O.sub.6, coating the top surface with a mixture of Sc.sub.6 WO.sub.12, Sc.sub.2 (WO.sub.4).sub.3, and W in a 1:3:2 mole ratio, and heating in a vacuum

摘要

An improved scandate cathode having an increased emission density is prepared from a porous tungsten billet that has been impregnated with Ba. sub.3 Al.sub.2 O.sub.6 by coating the top surface of the impregnated billet with a mixture of Sc.sub.6 WO.sub.12,Sc(WO.sub.4). sub.3, and W in the mole ratio of 1:3:2, heating the billet to about 1000 C. in a vacuum to cause BaWO.sub.4 and Sc to form in the billet in a molar ratio of 1:1, removing the billet and cleaning in a jewelers lathe, and preparing the billet for a cathode environment.