Retarding Field Technique for Measuring Sublimation from Dispenser and Oxide Cathodes

Publisher Website
Google Scholar
Abstract
A retarding field technique for measuring the instantaneous evaporation rate of barium and barium oxide from dispenser and oxide cathodes is described. The method is based upon measuring the time rate of change of the anode work function caused by the deposition of sublimate from the cathode surface. A simple planar diode, employing a molybdenum anode, is used. In contrast to the typical curve for barium films on molybdenum, showing a minimum work function at approximately a monolayer coverage, the results for barium oxide films indicate a similar decrease in work function up to a monolayer coverage; further deposition leads to a still lower work function.