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Work function measurement of lanthanum-boron compoundsThe relationship between emission properties and sample composition is studied for lanthanum-boron compounds. Specifically, the La-B system is considered between 1400 and 2100 K and between LaB(4.24) and LaB(29.2) to determine the phase relationship, chemical activity of the compounds, vapor composition, and vaporization rate. The results indicate that: (1) a blue-colored phase near LaB(9) exists between a purple-colored LaB(6) and elemental boron, (2) vaporization is sufficiently more rapid than diffusion so that great compositional differences exist between the surface and the interior, (3) an activation energy lowers the boron vaporization rate from LaB(6), and (4) a steady-state surface composition between LaB(6.04) and LaB(6.07) exists for freely vaporizing materials as a function of interior composition, purity, and temperature. It is noted that the ultimate life of a thermionic diode is governed by electrode vaporization rate whereas efficiency is governed by the electrode work function.
Document ID
19780053050
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Jacobson, D. L.
(Arizona State University Tempe, Ariz., United States)
Storms, E. K.
(California, University Los Alamos Scientific Laboratory, Los Alamos, N. Mex., United States)
Date Acquired
August 9, 2013
Publication Date
June 1, 1978
Publication Information
Publication: IEEE Transactions on Plasma Science
Volume: PS-6
Subject Category
Solid-State Physics
Accession Number
78A36959
Funding Number(s)
CONTRACT_GRANT: NSG-7019
Distribution Limits
Public
Copyright
Other

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