| 摘要 |
<p>PURPOSE:To shorten the aging time by allowing a layer of oxidated alkali earth metal to contain previously prepared powder of barium scandate in uniformly dispersed condition. CONSTITUTION:5wt.% barium scandate is added to three-element carbonate powder of barium, calcium, and strontium, and thereto nitrocellulose lacker plus butyl acetate are added, followed by rolling, to prepare a suspension. This suspension is coated over the base metal by spray method, and heat is applied by a heater at the vacuum exhaust process to make pyrolysis from carbonate to oxides. This is heated to 900-1100 deg.C and subjected to activating process so as to obtain a cathode with stable electron emitting characteristic. Less than 0.1wt.% addition of barium scandate does not present favorable effect for practical application, while over 20wt.% addition gives a deteriorated initial characteristic that is not favorable in practical application.</p> |
