By Topic

Emission of Oxide Cathodes Supported on a Ceramic

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

Formats Non-Member Member
$31 $31
Learn how you can qualify for the best price for this item!
Become an IEEE Member or Subscribe to
IEEE Xplore for exclusive pricing!
close button

puzzle piece

IEEE membership options for an individual and IEEE Xplore subscriptions for an organization offer the most affordable access to essential journal articles, conference papers, standards, eBooks, and eLearning courses.

Learn more about:

IEEE membership

IEEE Xplore subscriptions

2 Author(s)
Moore, G.E. ; Bell‐Telephone Laboratories, Incorporated, Murray Hill, New Jersey ; Allison, H.W.

Your organization might have access to this article on the publisher's site. To check, click on this link:http://dx.doi.org/+10.1063/1.1722257 

To reduce the physical and chemical complexity of the oxide coated cathode, the support metal and interface were eliminated by applying the (BaSr)O layer to a MgO ceramic which is electrically and chemically inert to (BaSr)O. The three interacting chemical phases of the usual oxide coated cathode are thereby reduced to a single phase—the oxide coat alone. At 1000°K, thermionic emission, measured by a pulse technique, is about 1 order of magnitude less than from modern commercial cathodes but considerably greater than from any other cathode system. The emission capability is unaffected by treatment in either atomic hydrogen or methane, which reduce BaO to Ba metal and thereby increase the Ba content of the oxide. The experiments were an attempt to test the usual assumption that emission in conventional oxide coated cathodes is determined by the composition of the (BaSr)O phase. The results suggest strongly that much of the complexity of practical cathodes is in the oxide layer itself and that factors other than the content of excess Ba are decisive for thermionic emission.

Published in:

Journal of Applied Physics  (Volume:27 ,  Issue: 11 )