Preparation of High-Performance Field Emission Cathodes by Deposition of Low WorkFunction Films

摘要

The results of the rather preliminary HfC film experiments on a Mo FEA do notsuggest better performance than ZrC on Mo FEAs. However, we believe there is substantial hope for optimism. The study of ZrC and HfC films deposited onto macroscopic Mo substrates shows approximately the same work function for both systems, approximately 3.0 eV. Our earlier work with single crystal free-standing emitters of ZrC and HfC suggested an even lower ultimate work function for HfC than for ZrC, and an apparently better emission stability. We believe that further studies of deposited films of HfC onto field emitters would allow this lower work function to be realized there as well.